From Yaniv Kaul: constify parameters

   https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=4422

 From me: Fix a number of instances where the function prototype or
  the function definition wasn't changed so there was a mismatch 
  thus causing Windows (but not gcc) compilation errors.

svn path=/trunk/; revision=32365

31 files changed, 733 insertions, 733 deletions

diff --git a/epan/addr_resolv.c b/epan/addr_resolv.c
index ed833010a1..fb308a1597 100644
--- a/epan/addr_resolv.c
+++ b/epan/addr_resolv.c
@@ -265,7 +265,7 @@ static int      service_resolution_initialized = 0;
 static gboolean new_resolved_objects = FALSE;
 
 static hashether_t *add_eth_name(const guint8 *addr, const gchar *name);
-static void add_serv_port_cb(guint32 port);
+static void add_serv_port_cb(const guint32 port);
 
 /*
  * Flag controlling what names to resolve.
@@ -422,10 +422,10 @@ static int fgetline(char **buf, int *size, FILE *fp)
  *  Local function definitions
  */
 static subnet_entry_t subnet_lookup(const guint32 addr);
-static void subnet_entry_set(guint32 subnet_addr, guint32 mask_length, const gchar* name);
+static void subnet_entry_set(guint32 subnet_addr, const guint32 mask_length, const gchar* name);
 
 
-static void add_service_name(hashport_t **proto_table, guint port, const char *service_name)
+static void add_service_name(hashport_t **proto_table, const guint port, const char *service_name)
 {
   int hash_idx;
   hashport_t *tp;
@@ -525,7 +525,7 @@ static void parse_service_line (char *line)
 
 
 static void
-add_serv_port_cb(guint32 port)
+add_serv_port_cb(const guint32 port)
 {
     if ( port ) {
       add_service_name(cb_port_table, port, cb_service);
@@ -574,7 +574,7 @@ static void initialize_services(void)
 
 
 
-static gchar *serv_name_lookup(guint port, port_type proto)
+static gchar *serv_name_lookup(const guint port, const port_type proto)
 {
   int hash_idx;
   hashport_t *tp;
@@ -650,7 +650,7 @@ static gchar *serv_name_lookup(guint port, port_type proto)
 /* Fill in an IP4 structure with info from subnets file or just with the
  * string form of the address.
  */
-static void fill_dummy_ip4(guint addr, hashipv4_t* volatile tp)
+static void fill_dummy_ip4(const guint addr, hashipv4_t* volatile tp)
 {
   subnet_entry_t subnet_entry;
 
@@ -728,7 +728,7 @@ c_ares_ghba_cb(void *arg, int status, int timeouts _U_, struct hostent *he) {
 #endif /* HAVE_C_ARES */
 
 /* --------------- */
-static hashipv4_t *new_ipv4(guint addr)
+static hashipv4_t *new_ipv4(const guint addr)
 {
     hashipv4_t *tp = g_malloc(sizeof(hashipv4_t));
     tp->addr = addr;
@@ -739,7 +739,7 @@ static hashipv4_t *new_ipv4(guint addr)
     return tp;
 }
 
-static hashipv4_t *host_lookup(guint addr, gboolean resolve, gboolean *found)
+static hashipv4_t *host_lookup(const guint addr, const gboolean resolve, gboolean *found)
 {
   int hash_idx;
   hashipv4_t * volatile tp;
@@ -817,7 +817,7 @@ static hashipv4_t *host_lookup(guint addr, gboolean resolve, gboolean *found)
 
 } /* host_name_lookup */
 
-static gchar *host_name_lookup(guint addr, gboolean *found)
+static gchar *host_name_lookup(const guint addr, gboolean *found)
 {
   hashipv4_t *tp;
   tp = host_lookup(addr, TRUE, found);
@@ -838,7 +838,7 @@ static hashipv6_t *new_ipv6(const struct e_in6_addr *addr)
 }
 
 /* ------------------------------------ */
-static hashipv6_t *host_lookup6(const struct e_in6_addr *addr, gboolean resolve, gboolean *found)
+static hashipv6_t *host_lookup6(const struct e_in6_addr *addr, const gboolean resolve, gboolean *found)
 {
   int hash_idx;
   hashipv6_t * volatile tp;
@@ -1016,7 +1016,7 @@ static const gchar *se_solve_address_to_name(const address *addr)
  */
 static gboolean
 parse_ether_address(const char *cp, ether_t *eth, unsigned int *mask,
-                    gboolean manuf_file)
+                    const gboolean manuf_file)
 {
   int i;
   unsigned long num;
@@ -1112,7 +1112,7 @@ parse_ether_address(const char *cp, ether_t *eth, unsigned int *mask,
 }
 
 static int parse_ether_line(char *line, ether_t *eth, unsigned int *mask,
-                gboolean manuf_file)
+                const gboolean manuf_file)
 {
   /*
    *  See the ethers(4) or ethers(5) man page for ethers file format
@@ -1159,7 +1159,7 @@ static void end_ethent(void)
   }
 }
 
-static ether_t *get_ethent(unsigned int *mask, gboolean manuf_file)
+static ether_t *get_ethent(unsigned int *mask, const gboolean manuf_file)
 {
 
   static ether_t eth;
@@ -1267,7 +1267,7 @@ static int hash_eth_wka(const guint8 *addr, unsigned int mask)
             (HASHETHSIZE - 1);
 }
 
-static void add_manuf_name(guint8 *addr, unsigned int mask, gchar *name)
+static void add_manuf_name(const guint8 *addr, unsigned int mask, gchar *name)
 {
   int hash_idx;
   hashmanuf_t *tp;
@@ -1377,7 +1377,7 @@ static hashmanuf_t *manuf_name_lookup(const guint8 *addr)
 
 } /* manuf_name_lookup */
 
-static hashether_t *wka_name_lookup(const guint8 *addr, unsigned int mask)
+static hashether_t *wka_name_lookup(const guint8 *addr, const unsigned int mask)
 {
   int hash_idx;
   hashether_t *(*wka_tp)[HASHETHSIZE];
@@ -1501,7 +1501,7 @@ static hashether_t *add_eth_name(const guint8 *addr, const gchar *name)
 } /* add_eth_name */
 
 /* XXXX */
-static hashether_t *eth_name_lookup(const guint8 *addr, gboolean resolve)
+static hashether_t *eth_name_lookup(const guint8 *addr, const gboolean resolve)
 {
   int hash_idx;
   hashmanuf_t *manufp;
@@ -2130,7 +2130,7 @@ static subnet_entry_t subnet_lookup(const guint32 addr)
  * The definition is taken by masking the address passed in with the mask of the
  * given length.
  */
-static void subnet_entry_set(guint32 subnet_addr, guint32 mask_length, const gchar* name)
+static void subnet_entry_set(guint32 subnet_addr, const guint32 mask_length, const gchar* name)
 {
     subnet_length_entry_t* entry;
     hashipv4_t * tp;
@@ -2167,7 +2167,7 @@ static void subnet_entry_set(guint32 subnet_addr, guint32 mask_length, const gch
     have_subnet_entry = TRUE;
 }
 
-static guint32 get_subnet_mask(guint32 mask_length) {
+static guint32 get_subnet_mask(const guint32 mask_length) {
 
     static guint32 masks[SUBNETLENGTHSIZE];
     static gboolean initialised = FALSE;
@@ -2509,7 +2509,7 @@ host_name_lookup_cleanup(void) {
 
 #endif /* HAVE_C_ARES */
 
-extern const gchar *get_hostname(guint addr)
+extern const gchar *get_hostname(const guint addr)
 {
   gboolean found;
   gboolean resolve = g_resolv_flags & RESOLV_NETWORK;
@@ -2523,7 +2523,7 @@ extern const gchar *get_hostname(guint addr)
 
 /* -------------------------- */
 
-extern const gchar *get_hostname6(struct e_in6_addr *addr)
+extern const gchar *get_hostname6(const struct e_in6_addr *addr)
 {
   gboolean found;
   gboolean resolve = g_resolv_flags & RESOLV_NETWORK;
@@ -2535,7 +2535,7 @@ extern const gchar *get_hostname6(struct e_in6_addr *addr)
 }
 
 /* -------------------------- */
-extern void add_ipv4_name(guint addr, const gchar *name)
+extern void add_ipv4_name(const guint addr, const gchar *name)
 {
   int hash_idx;
   hashipv4_t *tp;
@@ -2571,7 +2571,7 @@ extern void add_ipv4_name(guint addr, const gchar *name)
 } /* add_ipv4_name */
 
 /* -------------------------- */
-extern void add_ipv6_name(struct e_in6_addr *addrp, const gchar *name)
+extern void add_ipv6_name(const struct e_in6_addr *addrp, const gchar *name)
 {
   int hash_idx;
   hashipv6_t *tp;
@@ -2706,7 +2706,7 @@ const gchar *se_get_addr_name(const address *addr)
   return se_address_to_str(addr);
 }
 
-void get_addr_name_buf(address *addr, gchar *buf, gsize size)
+void get_addr_name_buf(const address *addr, gchar *buf, gsize size)
 {
   const gchar *result = get_addr_name(addr);
 
@@ -2805,7 +2805,7 @@ extern guint8 *get_ether_addr(const gchar *name)
 
 } /* get_ether_addr */
 
-extern void add_ether_byip(guint ip, const guint8 *eth)
+extern void add_ether_byip(const guint ip, const guint8 *eth)
 {
 
   gchar *host;
diff --git a/epan/addr_resolv.h b/epan/addr_resolv.h
index 67871614ef..1031ee8bc1 100644
--- a/epan/addr_resolv.h
+++ b/epan/addr_resolv.h
@@ -114,7 +114,7 @@ const gchar *se_get_addr_name(const address *addr);
 /* the result which is always NUL ('\0') terminated. The buffer should be large enough to */
 /* contain size characters including the terminator */
 
-void get_addr_name_buf(address *addr, gchar *buf, gsize size);
+void get_addr_name_buf(const address *addr, gchar *buf, gsize size);
 
 
 /*
@@ -138,11 +138,11 @@ extern gboolean host_name_lookup_process(gpointer data);
 extern void host_name_lookup_cleanup(void);
 
 /* get_hostname returns the host name or "%d.%d.%d.%d" if not found */
-extern const gchar *get_hostname(guint addr);
+extern const gchar *get_hostname(const guint addr);
 
 /* get_hostname6 returns the host name, or numeric addr if not found */
 struct e_in6_addr;
-extern const gchar* get_hostname6(struct e_in6_addr *ad);
+extern const gchar* get_hostname6(const struct e_in6_addr *ad);
 
 /* get_ether_name returns the logical name if found in ethers files else
    "<vendor>_%02x:%02x:%02x" if the vendor code is known else
@@ -171,13 +171,13 @@ extern guint8 *get_ether_addr(const gchar *name);
 guint32 get_ipxnet_addr(const gchar *name, gboolean *known);
 
 /* adds a hostname/IPv4 in the hash table */
-extern void add_ipv4_name(guint addr, const gchar *name);
+extern void add_ipv4_name(const guint addr, const gchar *name);
 
 /* adds a hostname/IPv6 in the hash table */
-extern void add_ipv6_name(struct e_in6_addr *addr, const gchar *name);
+extern void add_ipv6_name(const struct e_in6_addr *addr, const gchar *name);
 
 /* add ethernet address / name corresponding to IP address  */
-extern void add_ether_byip(guint ip, const guint8 *eth);
+extern void add_ether_byip(const guint ip, const guint8 *eth);
 
 /** Translates a string representing a hostname or dotted-decimal IPv4 address
  *  into a numeric IPv4 address value in network byte order. If compiled with
diff --git a/epan/address_to_str.c b/epan/address_to_str.c
index 0df45c7b8d..a09a4ae11c 100644
--- a/epan/address_to_str.c
+++ b/epan/address_to_str.c
@@ -127,7 +127,7 @@ ip6_to_str_buf(const struct e_in6_addr *ad, gchar *buf)
 }
 
 gchar*
-ipx_addr_to_str(guint32 net, const guint8 *ad)
+ipx_addr_to_str(const guint32 net, const guint8 *ad)
 {
 	gchar	*buf;
 	char	*name;
@@ -152,7 +152,7 @@ ipxnet_to_string(const guint8 *ad)
 }
 
 gchar *
-ipxnet_to_str_punct(const guint32 ad, char punct)
+ipxnet_to_str_punct(const guint32 ad, const char punct)
 {
   gchar *buf = ep_alloc(12);
 
diff --git a/epan/column-utils.c b/epan/column-utils.c
index 6bc3f107f1..cbefe2c4d2 100644
--- a/epan/column-utils.c
+++ b/epan/column-utils.c
@@ -48,7 +48,7 @@
 /* Allocate all the data structures for constructing column data, given
    the number of columns. */
 void
-col_setup(column_info *cinfo, gint num_cols)
+col_setup(column_info *cinfo, const gint num_cols)
 {
   int i;
 
@@ -101,7 +101,7 @@ col_get_writable(column_info *cinfo)
 }
 
 void
-col_set_writable(column_info *cinfo, gboolean writable)
+col_set_writable(column_info *cinfo, const gboolean writable)
 {
     if (cinfo)
         cinfo->writable = writable;
@@ -115,14 +115,14 @@ col_set_writable(column_info *cinfo, gboolean writable)
     ((cinfo)->col_first[el] >= 0))
 
 gint
-check_col(column_info *cinfo, gint el)
+check_col(column_info *cinfo, const gint el)
 {
   return CHECK_COL(cinfo, el);
 }
 
 /* Sets the fence for a column to be at the end of the column. */
 void
-col_set_fence(column_info *cinfo, gint el)
+col_set_fence(column_info *cinfo, const gint el)
 {
   int i;
 
@@ -143,7 +143,7 @@ col_set_fence(column_info *cinfo, gint el)
    later append to it, as the later append will cause a string
    copy to be done. */
 void
-col_clear(column_info *cinfo, gint el)
+col_clear(column_info *cinfo, const gint el)
 {
   int    i;
   int    fence;
@@ -254,7 +254,7 @@ col_custom_prime_edt(epan_dissect_t *edt, column_info *cinfo)
 }
 
 static void
-col_do_append_sep_va_fstr(column_info *cinfo, gint el, const gchar *separator,
+col_do_append_sep_va_fstr(column_info *cinfo, const gint el, const gchar *separator,
               const gchar *format, va_list ap)
 {
   int  i;
@@ -294,7 +294,7 @@ col_do_append_sep_va_fstr(column_info *cinfo, gint el, const gchar *separator,
 
 /* Appends a vararg list to a packet info string. */
 void
-col_append_fstr(column_info *cinfo, gint el, const gchar *format, ...)
+col_append_fstr(column_info *cinfo, const gint el, const gchar *format, ...)
 {
   va_list ap;
 
@@ -309,7 +309,7 @@ col_append_fstr(column_info *cinfo, gint el, const gchar *format, ...)
 /* Appends a vararg list to a packet info string.
  * Prefixes it with the given separator if the column is not empty. */
 void
-col_append_sep_fstr(column_info *cinfo, gint el, const gchar *separator,
+col_append_sep_fstr(column_info *cinfo, const gint el, const gchar *separator,
         const gchar *format, ...)
 {
   va_list ap;
@@ -330,7 +330,7 @@ col_append_sep_fstr(column_info *cinfo, gint el, const gchar *separator,
 #define COL_BUF_MAX_LEN (((COL_MAX_INFO_LEN) > (COL_MAX_LEN)) ? \
     (COL_MAX_INFO_LEN) : (COL_MAX_LEN))
 void
-col_prepend_fstr(column_info *cinfo, gint el, const gchar *format, ...)
+col_prepend_fstr(column_info *cinfo, const gint el, const gchar *format, ...)
 {
   va_list     ap;
   int         i;
@@ -371,7 +371,7 @@ col_prepend_fstr(column_info *cinfo, gint el, const gchar *format, ...)
   va_end(ap);
 }
 void
-col_prepend_fence_fstr(column_info *cinfo, gint el, const gchar *format, ...)
+col_prepend_fence_fstr(column_info *cinfo, const gint el, const gchar *format, ...)
 {
   va_list     ap;
   int         i;
@@ -418,7 +418,7 @@ col_prepend_fence_fstr(column_info *cinfo, gint el, const gchar *format, ...)
 /* Use this if "str" points to something that won't stay around (and
    must thus be copied). */
 void
-col_add_str(column_info *cinfo, gint el, const gchar* str)
+col_add_str(column_info *cinfo, const gint el, const gchar* str)
 {
   int    i;
   int    fence;
@@ -455,7 +455,7 @@ col_add_str(column_info *cinfo, gint el, const gchar* str)
 /* Use this if "str" points to something that will stay around (and thus
    needn't be copied). */
 void
-col_set_str(column_info *cinfo, gint el, const gchar* str)
+col_set_str(column_info *cinfo, const gint el, const gchar* str)
 {
   int i;
   int fence;
@@ -499,7 +499,7 @@ col_set_str(column_info *cinfo, gint el, const gchar* str)
 
 /* Adds a vararg list to a packet info string. */
 void
-col_add_fstr(column_info *cinfo, gint el, const gchar *format, ...) {
+col_add_fstr(column_info *cinfo, const gint el, const gchar *format, ...) {
   va_list ap;
   int     i;
   int     fence;
@@ -536,7 +536,7 @@ col_add_fstr(column_info *cinfo, gint el, const gchar *format, ...) {
 }
 
 static void
-col_do_append_str(column_info *cinfo, gint el, const gchar* separator,
+col_do_append_str(column_info *cinfo, const gint el, const gchar* separator,
     const gchar* str)
 {
   int    i;
@@ -570,7 +570,7 @@ col_do_append_str(column_info *cinfo, gint el, const gchar* separator,
 }
 
 void
-col_append_str(column_info *cinfo, gint el, const gchar* str)
+col_append_str(column_info *cinfo, const gint el, const gchar* str)
 {
   if (!CHECK_COL(cinfo, el))
     return;
@@ -579,7 +579,7 @@ col_append_str(column_info *cinfo, gint el, const gchar* str)
 }
 
 void
-col_append_sep_str(column_info *cinfo, gint el, const gchar* separator,
+col_append_sep_str(column_info *cinfo, const gint el, const gchar* separator,
     const gchar* str)
 {
   if (!CHECK_COL(cinfo, el))
@@ -593,7 +593,7 @@ col_append_sep_str(column_info *cinfo, gint el, const gchar* separator,
 
 /* --------------------------------- */
 gboolean
-col_has_time_fmt(column_info *cinfo, gint col)
+col_has_time_fmt(column_info *cinfo, const gint col)
 {
   return ((cinfo->fmt_matx[col][COL_CLS_TIME]) ||
           (cinfo->fmt_matx[col][COL_ABS_TIME]) ||
@@ -604,7 +604,7 @@ col_has_time_fmt(column_info *cinfo, gint col)
 }
 
 static gint
-set_abs_date_time(frame_data *fd, gchar *buf)
+set_abs_date_time(const frame_data *fd, gchar *buf)
 {
   struct tm *tmp;
   time_t then;
@@ -688,7 +688,7 @@ set_abs_date_time(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_abs_date_time(frame_data *fd, column_info *cinfo, int col)
+col_set_abs_date_time(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_abs_date_time(fd, cinfo->col_buf[col])) {
       cinfo->col_expr.col_expr[col] = "frame.time";
@@ -698,7 +698,7 @@ col_set_abs_date_time(frame_data *fd, column_info *cinfo, int col)
 }
 
 static gint
-set_rel_time(frame_data *fd, gchar *buf)
+set_rel_time(const frame_data *fd, gchar *buf)
 {
   switch(timestamp_get_precision()) {
       case(TS_PREC_FIXED_SEC):
@@ -738,7 +738,7 @@ set_rel_time(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_rel_time(frame_data *fd, column_info *cinfo, int col)
+col_set_rel_time(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_rel_time(fd, cinfo->col_buf[col])) {
       cinfo->col_expr.col_expr[col] = "frame.time_relative";
@@ -748,7 +748,7 @@ col_set_rel_time(frame_data *fd, column_info *cinfo, int col)
 }
 
 static gint
-set_delta_time(frame_data *fd, gchar *buf)
+set_delta_time(const frame_data *fd, gchar *buf)
 {
   switch(timestamp_get_precision()) {
       case(TS_PREC_FIXED_SEC):
@@ -788,7 +788,7 @@ set_delta_time(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_delta_time(frame_data *fd, column_info *cinfo, int col)
+col_set_delta_time(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_delta_time(fd, cinfo->col_buf[col])) {
       cinfo->col_expr.col_expr[col] = "frame.time_delta";
@@ -798,7 +798,7 @@ col_set_delta_time(frame_data *fd, column_info *cinfo, int col)
 }
 
 static gint
-set_delta_time_dis(frame_data *fd, gchar *buf)
+set_delta_time_dis(const frame_data *fd, gchar *buf)
 {
   switch(timestamp_get_precision()) {
       case(TS_PREC_FIXED_SEC):
@@ -838,7 +838,7 @@ set_delta_time_dis(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_delta_time_dis(frame_data *fd, column_info *cinfo, int col)
+col_set_delta_time_dis(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_delta_time_dis(fd, cinfo->col_buf[col])) {
     cinfo->col_expr.col_expr[col] = "frame.time_delta_displayed";
@@ -848,7 +848,7 @@ col_set_delta_time_dis(frame_data *fd, column_info *cinfo, int col)
 }
 
 static gint
-set_abs_time(frame_data *fd, gchar *buf)
+set_abs_time(const frame_data *fd, gchar *buf)
 {
   struct tm *tmp;
   time_t then;
@@ -915,7 +915,7 @@ set_abs_time(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_abs_time(frame_data *fd, column_info *cinfo, int col)
+col_set_abs_time(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_abs_time(fd, cinfo->col_buf[col])) {
       cinfo->col_expr.col_expr[col] = "frame.time";
@@ -925,7 +925,7 @@ col_set_abs_time(frame_data *fd, column_info *cinfo, int col)
 }
 
 static gint
-set_epoch_time(frame_data *fd, gchar *buf)
+set_epoch_time(const frame_data *fd, gchar *buf)
 {
   switch(timestamp_get_precision()) {
       case(TS_PREC_FIXED_SEC):
@@ -965,7 +965,7 @@ set_epoch_time(frame_data *fd, gchar *buf)
 }
 
 static void
-col_set_epoch_time(frame_data *fd, column_info *cinfo, int col)
+col_set_epoch_time(const frame_data *fd, column_info *cinfo, const int col)
 {
   if (set_epoch_time(fd, cinfo->col_buf[col])) {
     cinfo->col_expr.col_expr[col] = "frame.time_delta";
@@ -1021,7 +1021,7 @@ set_cls_time(frame_data *fd, gchar *buf)
 #endif
 
 static void
-col_set_cls_time(frame_data *fd, column_info *cinfo, gint col)
+col_set_cls_time(const frame_data *fd, column_info *cinfo, const gint col)
 {
   switch (timestamp_get_type()) {
     case TS_ABSOLUTE:
@@ -1063,7 +1063,7 @@ col_set_cls_time(frame_data *fd, column_info *cinfo, gint col)
    requiring us to stuff the text into the widget from outside, we
    might be able to clean this up. */
 void
-col_set_fmt_time(frame_data *fd, column_info *cinfo, gint fmt, gint col)
+col_set_fmt_time(const frame_data *fd, column_info *cinfo, const gint fmt, const gint col)
 {
   COL_CHECK_REF_TIME(fd, cinfo->col_buf[col]);
 
@@ -1100,7 +1100,7 @@ col_set_fmt_time(frame_data *fd, column_info *cinfo, gint fmt, gint col)
 
 /* --------------------------- */
 void
-col_set_time(column_info *cinfo, gint el, nstime_t *ts, char *fieldname)
+col_set_time(column_info *cinfo, const gint el, const nstime_t *ts, char *fieldname)
 {
   int col;
 
@@ -1155,7 +1155,7 @@ col_set_time(column_info *cinfo, gint el, nstime_t *ts, char *fieldname)
 }
 
 static void
-col_set_addr(packet_info *pinfo, int col, address *addr, gboolean is_src, gboolean fill_col_exprs)
+col_set_addr(packet_info *pinfo, const int col, const address *addr, const gboolean is_src, const gboolean fill_col_exprs)
 {
   if (addr->type == AT_NONE) {
     pinfo->cinfo->col_data[col] = "";
@@ -1230,7 +1230,7 @@ col_set_addr(packet_info *pinfo, int col, address *addr, gboolean is_src, gboole
 
 /* ------------------------ */
 static void
-col_set_port(packet_info *pinfo, int col, gboolean is_res, gboolean is_src, gboolean fill_col_exprs _U_)
+col_set_port(packet_info *pinfo, const int col, const gboolean is_res, const gboolean is_src, const gboolean fill_col_exprs _U_)
 {
   guint32 port;
 
@@ -1319,7 +1319,7 @@ col_set_port(packet_info *pinfo, int col, gboolean is_res, gboolean is_src, gboo
 }
 
 gboolean
-col_based_on_frame_data(column_info *cinfo, gint col)
+col_based_on_frame_data(column_info *cinfo, const gint col)
 {
     g_assert(cinfo);
     g_assert(col < cinfo->num_cols);
@@ -1343,7 +1343,7 @@ col_based_on_frame_data(column_info *cinfo, gint col)
 }
 
 void
-col_fill_in_frame_data(frame_data *fd, column_info *cinfo, gint col, gboolean fill_col_exprs)
+col_fill_in_frame_data(const frame_data *fd, column_info *cinfo, const gint col, const gboolean fill_col_exprs)
 {
     switch (cinfo->col_fmt[col]) {
 
@@ -1409,7 +1409,7 @@ col_fill_in_frame_data(frame_data *fd, column_info *cinfo, gint col, gboolean fi
 }
 
 void
-col_fill_in(packet_info *pinfo, gboolean fill_col_exprs, gboolean fill_fd_colums)
+col_fill_in(packet_info *pinfo, const gboolean fill_col_exprs, const gboolean fill_fd_colums)
 {
   int i;
 
diff --git a/epan/column-utils.h b/epan/column-utils.h
index 438374b6b8..a9f76ece35 100644
--- a/epan/column-utils.h
+++ b/epan/column-utils.h
@@ -51,7 +51,7 @@ extern "C" {
  *
  * Internal, don't use this in dissectors!
  */
-extern void	col_setup(column_info *cinfo, gint num_cols);
+extern void	col_setup(column_info *cinfo, const gint num_cols);
 
 /** Initialize the data structures for constructing column data.
  *
@@ -63,19 +63,19 @@ extern void	col_init(column_info *cinfo);
  *
  * Internal, don't use this in dissectors!
  */
-extern void	col_set_fmt_time(frame_data *fd, column_info *cinfo, gint fmt, gint col);
+extern void	col_set_fmt_time(const frame_data *fd, column_info *cinfo, const gint fmt, const gint col);
 
 /** Fill in all columns of the given packet which are based on values from frame_data.
  *
  * Internal, don't use this in dissectors!
  */
-extern void col_fill_in_frame_data(frame_data *fd, column_info *cinfo, gint col, gboolean fill_col_exprs);
+extern void col_fill_in_frame_data(const frame_data *fd, column_info *cinfo, const gint col, gboolean const fill_col_exprs);
 
 /** Fill in all columns of the given packet.
  *
  * Internal, don't use this in dissectors!
  */
-extern void	col_fill_in(packet_info *pinfo, gboolean fill_col_exprs, gboolean fill_fd_colums);
+extern void	col_fill_in(packet_info *pinfo, const gboolean fill_col_exprs, const gboolean fill_fd_colums);
 
 /* Utility routines used by packet*.c */
 
@@ -91,14 +91,14 @@ extern gboolean	col_get_writable(column_info *cinfo);
  * @param cinfo the current packet row
  * @param writable TRUE if it's writable, FALSE if not
  */
-extern void	col_set_writable(column_info *cinfo, gboolean writable);
+extern void	col_set_writable(column_info *cinfo, const gboolean writable);
 
 /** Check if the given column be filled with data.
  *
  * @param cinfo the current packet row
  * @param col the column to use, e.g. COL_INFO
  */
-extern gint	check_col(column_info *cinfo, gint col);
+extern gint	check_col(column_info *cinfo, const gint col);
 
 /** Sets a fence for the current column content,
  * so this content won't be affected by further col_... function calls.
@@ -109,14 +109,14 @@ extern gint	check_col(column_info *cinfo, gint col);
  * @param cinfo the current packet row
  * @param col the column to use, e.g. COL_INFO
  */
-extern void	col_set_fence(column_info *cinfo, gint col);
+extern void	col_set_fence(column_info *cinfo, const gint col);
 
 /** Clears the text of a column element.
  *
  * @param cinfo the current packet row
  * @param col the column to use, e.g. COL_INFO
  */
-extern void	col_clear(column_info *cinfo, gint col);
+extern void	col_clear(column_info *cinfo, const gint col);
 
 /** Set (replace) the text of a column element, the text won't be copied.
  *
@@ -126,7 +126,7 @@ extern void	col_clear(column_info *cinfo, gint col);
  * @param col the column to use, e.g. COL_INFO
  * @param str the string to set
  */
-extern void	col_set_str(column_info *cinfo, gint col, const gchar * str);
+extern void	col_set_str(column_info *cinfo, const gint col, const gchar * str);
 
 /** Add (replace) the text of a column element, the text will be copied.
  *
@@ -134,7 +134,7 @@ extern void	col_set_str(column_info *cinfo, gint col, const gchar * str);
  * @param col the column to use, e.g. COL_INFO
  * @param str the string to add
  */
-extern void	col_add_str(column_info *cinfo, gint col, const gchar *str);
+extern void	col_add_str(column_info *cinfo, const gint col, const gchar *str);
 
 /** Add (replace) the text of a column element, the text will be formatted and copied.
  *
@@ -145,7 +145,7 @@ extern void	col_add_str(column_info *cinfo, gint col, const gchar *str);
  * @param format the format string
  * @param ... the variable number of parameters
  */
-extern void	col_add_fstr(column_info *cinfo, gint col, const gchar *format, ...)
+extern void	col_add_fstr(column_info *cinfo, const gint col, const gchar *format, ...)
     G_GNUC_PRINTF(3, 4);
 
 /* For internal Wireshark use only.  Not to be called from dissectors. */
@@ -156,8 +156,8 @@ void col_custom_prime_edt(epan_dissect_t *edt, column_info *cinfo);
 
 /* For internal Wireshark use only.  Not to be called from dissectors. */
 gboolean have_custom_cols(column_info *cinfo);
-gboolean col_has_time_fmt(column_info *cinfo, gint col);
-gboolean col_based_on_frame_data(column_info *cinfo, gint col);
+gboolean col_has_time_fmt(column_info *cinfo, const gint col);
+gboolean col_based_on_frame_data(column_info *cinfo, const gint col);
 
 /** Append the given text to a column element, the text will be copied.
  *
@@ -165,7 +165,7 @@ gboolean col_based_on_frame_data(column_info *cinfo, gint col);
  * @param col the column to use, e.g. COL_INFO
  * @param str the string to append
  */
-extern void	col_append_str(column_info *cinfo, gint col, const gchar *str);
+extern void	col_append_str(column_info *cinfo, const gint col, const gchar *str);
 
 /** Append the given text to a column element, the text will be formatted and copied.
  *
@@ -176,7 +176,7 @@ extern void	col_append_str(column_info *cinfo, gint col, const gchar *str);
  * @param format the format string
  * @param ... the variable number of parameters
  */
-extern void	col_append_fstr(column_info *cinfo, gint col, const gchar *format, ...)
+extern void	col_append_fstr(column_info *cinfo, const gint col, const gchar *format, ...)
     G_GNUC_PRINTF(3, 4);
 
 /** Prepend the given text to a column element, the text will be formatted and copied.
@@ -186,7 +186,7 @@ extern void	col_append_fstr(column_info *cinfo, gint col, const gchar *format, .
  * @param format the format string
  * @param ... the variable number of parameters
  */
-extern void	col_prepend_fstr(column_info *cinfo, gint col, const gchar *format, ...)
+extern void	col_prepend_fstr(column_info *cinfo, const gint col, const gchar *format, ...)
     G_GNUC_PRINTF(3, 4);
 
 /**Prepend the given text to a column element, the text will be formatted and copied.
@@ -197,7 +197,7 @@ extern void	col_prepend_fstr(column_info *cinfo, gint col, const gchar *format,
  * there is already a fence created. This function will create a fence in case
  * it does not yet exist.
  */
-extern void	col_prepend_fence_fstr(column_info *cinfo, gint col, const gchar *format, ...)
+extern void	col_prepend_fence_fstr(column_info *cinfo, const gint col, const gchar *format, ...)
     G_GNUC_PRINTF(3, 4);
 
 /** Append the given text (prepended by a separator) to a column element.
@@ -209,7 +209,7 @@ extern void	col_prepend_fence_fstr(column_info *cinfo, gint col, const gchar *fo
  * @param sep the separator string or NULL for default: ", "
  * @param str the string to append
  */
-extern void	col_append_sep_str(column_info *cinfo, gint col, const gchar *sep,
+extern void	col_append_sep_str(column_info *cinfo, const gint col, const gchar *sep,
 		const gchar *str);
 
 /** Append the given text (prepended by a separator) to a column element.
@@ -222,7 +222,7 @@ extern void	col_append_sep_str(column_info *cinfo, gint col, const gchar *sep,
  * @param format the format string
  * @param ... the variable number of parameters
  */
-extern void	col_append_sep_fstr(column_info *cinfo, gint col, const gchar *sep,
+extern void	col_append_sep_fstr(column_info *cinfo, const gint col, const gchar *sep,
 		const gchar *format, ...)
     G_GNUC_PRINTF(4, 5);
 
@@ -237,8 +237,8 @@ extern void	col_append_sep_fstr(column_info *cinfo, gint col, const gchar *sep,
  * @param fieldname	the fieldname to use for creating a filter (when
  *			  applying/preparing/copying as filter)
  */
-extern void 	col_set_time(column_info *cinfo, int col,
-			nstime_t *ts, char *fieldname);
+extern void 	col_set_time(column_info *cinfo, const int col,
+			const nstime_t *ts, char *fieldname);
 
 #ifdef __cplusplus
 }
diff --git a/epan/column.c b/epan/column.c
index 17dbcb461e..03ed22d673 100644
--- a/epan/column.c
+++ b/epan/column.c
@@ -45,7 +45,7 @@
 /* Given a format number (as defined in column_info.h), returns its equivalent
    string */
 const gchar *
-col_format_to_string(gint fmt) {
+col_format_to_string(const gint fmt) {
   const gchar *slist[] = {
     "%q",                                       /* 0) COL_8021Q_VLAN_ID */
     "%Yt",                                      /* 1) COL_ABS_DATE_TIME */
@@ -179,7 +179,7 @@ static const gchar *dlist[NUM_COL_FMTS] = {
 };
 
 const gchar *
-col_format_desc(gint fmt) {
+col_format_desc(const gint fmt) {
   g_assert((fmt >= 0) && (fmt < NUM_COL_FMTS));
   return(dlist[fmt]);
 }
@@ -187,7 +187,7 @@ col_format_desc(gint fmt) {
 /* Marks each array element true if it can be substituted for the given
    column format */
 void
-get_column_format_matches(gboolean *fmt_list, gint format) {
+get_column_format_matches(gboolean *fmt_list, const gint format) {
 
   /* Get the obvious: the format itself */
   if ((format >= 0) && (format < NUM_COL_FMTS))
@@ -311,7 +311,7 @@ get_column_format_matches(gboolean *fmt_list, gint format) {
 /* Returns a string representing the longest possible value for
    a timestamp column type. */
 static const char *
-get_timestamp_column_longest_string(gint type, gint precision)
+get_timestamp_column_longest_string(const gint type, const gint precision)
 {
 
     switch(type) {
@@ -452,7 +452,7 @@ get_timestamp_column_longest_string(gint type, gint precision)
 /* Returns the longer string of the column title or the hard-coded width of
  * its contents for building the packet list layout. */
 const gchar *
-get_column_width_string(gint format, gint col)
+get_column_width_string(const gint format, const gint col)
 {
     if(strlen(get_column_longest_string(format)) >
        strlen(get_column_title(col)))
@@ -474,7 +474,7 @@ get_column_width_string(gint format, gint col)
    is somewhat arbitrary in any case.  We should probably clean
    that up eventually, though. */
 const char *
-get_column_longest_string(gint format)
+get_column_longest_string(const gint format)
 {
   switch (format) {
     case COL_NUMBER:
@@ -610,13 +610,13 @@ get_column_longest_string(gint format)
 /* Returns the longest possible width, in characters, for a particular
    column type. */
 gint
-get_column_char_width(gint format)
+get_column_char_width(const gint format)
 {
   return (gint)strlen(get_column_longest_string(format));
 }
 
 gint
-get_column_format(gint col)
+get_column_format(const gint col)
 {
   GList    *clp = g_list_nth(prefs.col_list, col);
   fmt_data *cfmt;
@@ -630,7 +630,7 @@ get_column_format(gint col)
 }
 
 gint
-get_column_format_from_str(gchar *str)
+get_column_format_from_str(const gchar *str)
 {
   gint i;
 
@@ -642,7 +642,7 @@ get_column_format_from_str(gchar *str)
 }
 
 gchar *
-get_column_title(gint col)
+get_column_title(const gint col)
 {
   GList    *clp = g_list_nth(prefs.col_list, col);
   fmt_data *cfmt;
@@ -656,7 +656,7 @@ get_column_title(gint col)
 }
 
 const gchar *
-get_column_custom_field(gint col)
+get_column_custom_field(const gint col)
 {
   GList    *clp = g_list_nth(prefs.col_list, col);
   fmt_data *cfmt;
@@ -670,7 +670,7 @@ get_column_custom_field(gint col)
 }
 
 void
-build_column_format_array(column_info *cinfo, gint num_cols, gboolean reset_fences)
+build_column_format_array(column_info *cinfo, const gint num_cols, const gboolean reset_fences)
 {
   int i;
 
diff --git a/epan/column.h b/epan/column.h
index d8cf558bac..89c0bec4a9 100644
--- a/epan/column.h
+++ b/epan/column.h
@@ -35,19 +35,19 @@ typedef struct _fmt_data {
   gchar *custom_field;
 } fmt_data;
 
-const gchar         *col_format_to_string(gint);
-const gchar         *col_format_desc(gint);
-gint                 get_column_format(gint);
-void                 get_column_format_matches(gboolean *, gint);
-gint                 get_column_format_from_str(gchar *);
-gchar               *get_column_title(gint);
-const gchar         *get_column_custom_field(gint);
-const gchar         *get_column_width_string(gint, gint);
-const char          *get_column_longest_string(gint);
-gint                 get_column_char_width(gint format);
+const gchar         *col_format_to_string(const gint);
+const gchar         *col_format_desc(const gint);
+gint                 get_column_format(const gint);
+void                 get_column_format_matches(gboolean *, const gint);
+gint                 get_column_format_from_str(const gchar *);
+gchar               *get_column_title(const gint);
+const gchar         *get_column_custom_field(const gint);
+const gchar         *get_column_width_string(const gint, const gint);
+const char          *get_column_longest_string(const gint);
+gint                 get_column_char_width(const gint format);
 
 void
-build_column_format_array(column_info *cinfo, gint num_cols, gboolean reset_fences);
+build_column_format_array(column_info *cinfo, const gint num_cols, const gboolean reset_fences);
 
 #ifdef __cplusplus
 }
diff --git a/epan/conversation.c b/epan/conversation.c
index 76dd0ef3fa..5a2e435277 100644
--- a/epan/conversation.c
+++ b/epan/conversation.c
@@ -97,7 +97,7 @@ typedef struct _conv_proto_data {
  * options bits are set (NO_ADDR2 and NO_PORT2).
  */
 static conversation_t *
-conversation_create_from_template(conversation_t *conversation, address *addr2, guint32 port2)
+conversation_create_from_template(conversation_t *conversation, const address *addr2, const guint32 port2)
 {
    /*
     * Add a new conversation and keep the conversation template only if the
@@ -474,8 +474,8 @@ conversation_init(void)
  * when searching for this conversation.
  */
 conversation_t *
-conversation_new(guint32 setup_frame, address *addr1, address *addr2, port_type ptype,
-    guint32 port1, guint32 port2, guint options)
+conversation_new(const guint32 setup_frame, const address *addr1, const address *addr2, const port_type ptype,
+    const guint32 port1, const guint32 port2, const guint options)
 {
 /*
 	DISSECTOR_ASSERT(!(options | CONVERSATION_TEMPLATE) || ((options | (NO_ADDR2 | NO_PORT2 | NO_PORT2_FORCE))) &&
@@ -555,7 +555,7 @@ conversation_new(guint32 setup_frame, address *addr1, address *addr2, port_type
  * update the options and port values, insert the updated key.
  */
 void
-conversation_set_port2(conversation_t *conv, guint32 port)
+conversation_set_port2(conversation_t *conv, const guint32 port)
 {
    DISSECTOR_ASSERT(!(conv->options & CONVERSATION_TEMPLATE) &&
             "Use the conversation_create_from_template function when the CONVERSATION_TEMPLATE bit is set in the options mask");
@@ -589,7 +589,7 @@ conversation_set_port2(conversation_t *conv, guint32 port)
  * table, update the options and port values, insert the updated key.
  */
 void
-conversation_set_addr2(conversation_t *conv, address *addr)
+conversation_set_addr2(conversation_t *conv, const address *addr)
 {
    DISSECTOR_ASSERT(!(conv->options & CONVERSATION_TEMPLATE) &&
             "Use the conversation_create_from_template function when the CONVERSATION_TEMPLATE bit is set in the options mask");
@@ -623,8 +623,8 @@ conversation_set_addr2(conversation_t *conv, address *addr)
  * {addr1, port1, addr2, port2} and set up before frame_num.
  */
 static conversation_t *
-conversation_lookup_hashtable(GHashTable *hashtable, guint32 frame_num, address *addr1, address *addr2,
-    port_type ptype, guint32 port1, guint32 port2)
+conversation_lookup_hashtable(GHashTable *hashtable, const guint32 frame_num, const address *addr1, const address *addr2,
+    const port_type ptype, const guint32 port1, const guint32 port2)
 {
 	conversation_t* conversation;
 	conversation_t* match;
@@ -693,8 +693,8 @@ conversation_lookup_hashtable(GHashTable *hashtable, guint32 frame_num, address
  *	otherwise, we found no matching conversation, and return NULL.
  */
 conversation_t *
-find_conversation(guint32 frame_num, address *addr_a, address *addr_b, port_type ptype,
-    guint32 port_a, guint32 port_b, guint options)
+find_conversation(const guint32 frame_num, const address *addr_a, const address *addr_b, const port_type ptype,
+    const guint32 port_a, const guint32 port_b, const guint options)
 {
    conversation_t *conversation;
 
@@ -1014,7 +1014,7 @@ p_compare(gconstpointer a, gconstpointer b)
 }
 
 void
-conversation_add_proto_data(conversation_t *conv, int proto, void *proto_data)
+conversation_add_proto_data(conversation_t *conv, const int proto, void *proto_data)
 {
 	conv_proto_data *p1 = se_alloc(sizeof(conv_proto_data));
 
@@ -1028,7 +1028,7 @@ conversation_add_proto_data(conversation_t *conv, int proto, void *proto_data)
 }
 
 void *
-conversation_get_proto_data(conversation_t *conv, int proto)
+conversation_get_proto_data(const conversation_t *conv, const int proto)
 {
 	conv_proto_data temp, *p1;
 	GSList *item;
@@ -1048,7 +1048,7 @@ conversation_get_proto_data(conversation_t *conv, int proto)
 }
 
 void
-conversation_delete_proto_data(conversation_t *conv, int proto)
+conversation_delete_proto_data(conversation_t *conv, const int proto)
 {
 	conv_proto_data temp;
 	GSList *item;
@@ -1066,7 +1066,7 @@ conversation_delete_proto_data(conversation_t *conv, int proto)
 }
 
 void
-conversation_set_dissector(conversation_t *conversation, dissector_handle_t handle)
+conversation_set_dissector(conversation_t *conversation, const dissector_handle_t handle)
 {
 	conversation->dissector_handle = handle;
 }
@@ -1082,8 +1082,8 @@ conversation_set_dissector(conversation_t *conversation, dissector_handle_t hand
  * this function returns FALSE.
  */
 gboolean
-try_conversation_dissector(address *addr_a, address *addr_b, port_type ptype,
-    guint32 port_a, guint32 port_b, tvbuff_t *tvb, packet_info *pinfo,
+try_conversation_dissector(const address *addr_a, const address *addr_b, const port_type ptype,
+    const guint32 port_a, const guint32 port_b, tvbuff_t *tvb, packet_info *pinfo,
     proto_tree *tree)
 {
 	conversation_t *conversation;
diff --git a/epan/conversation.h b/epan/conversation.h
index 7c4418c68c..d19065a1e2 100644
--- a/epan/conversation.h
+++ b/epan/conversation.h
@@ -80,28 +80,28 @@ typedef struct conversation {
 extern void conversation_cleanup(void);
 extern void conversation_init(void);
 
-extern conversation_t *conversation_new(guint32 setup_frame, address *addr1, address *addr2,
-    port_type ptype, guint32 port1, guint32 port2, guint options);
+extern conversation_t *conversation_new(const guint32 setup_frame, const address *addr1, const address *addr2,
+    const port_type ptype, const guint32 port1, const guint32 port2, const guint options);
 
-extern conversation_t *find_conversation(guint32 frame_num, address *addr_a, address *addr_b,
-    port_type ptype, guint32 port_a, guint32 port_b, guint options);
+extern conversation_t *find_conversation(const guint32 frame_num, const address *addr_a, const address *addr_b,
+    const port_type ptype, const guint32 port_a, const guint32 port_b, const guint options);
 
-extern void conversation_add_proto_data(conversation_t *conv, int proto,
+extern void conversation_add_proto_data(conversation_t *conv, const int proto,
     void *proto_data);
-extern void *conversation_get_proto_data(conversation_t *conv, int proto);
-extern void conversation_delete_proto_data(conversation_t *conv, int proto);
+extern void *conversation_get_proto_data(const conversation_t *conv, const int proto);
+extern void conversation_delete_proto_data(conversation_t *conv, const int proto);
 
 extern void conversation_set_dissector(conversation_t *conversation,
-    dissector_handle_t handle);
+    const dissector_handle_t handle);
 extern gboolean
-try_conversation_dissector(address *addr_a, address *addr_b, port_type ptype,
-    guint32 port_a, guint32 port_b, tvbuff_t *tvb, packet_info *pinfo,
+try_conversation_dissector(const address *addr_a, const address *addr_b, const port_type ptype,
+    const guint32 port_a, const guint32 port_b, tvbuff_t *tvb, packet_info *pinfo,
     proto_tree *tree);
 
 /* These routines are used to set undefined values for a conversation */
 
-extern void conversation_set_port2(conversation_t *conv, guint32 port);
-extern void conversation_set_addr2(conversation_t *conv, address *addr);
+extern void conversation_set_port2(conversation_t *conv, const guint32 port);
+extern void conversation_set_addr2(conversation_t *conv, const address *addr);
 
 #ifdef __cplusplus
 }
diff --git a/epan/dissectors/packet-dcerpc.c b/epan/dissectors/packet-dcerpc.c
index 44187ddf46..a328727e23 100644
--- a/epan/dissectors/packet-dcerpc.c
+++ b/epan/dissectors/packet-dcerpc.c
@@ -3163,7 +3163,7 @@ dissect_dcerpc_cn_stub (tvbuff_t *tvb, int offset, packet_info *pinfo,
        then exit
     */
     if(pinfo->fd->flags.visited){
-	fd_head=fragment_get_reassembled(pinfo, frame, dcerpc_co_reassemble_table);
+	fd_head=fragment_get_reassembled(frame, dcerpc_co_reassemble_table);
 	goto end_cn_stub;
     }
 
diff --git a/epan/dissectors/packet-x11.c b/epan/dissectors/packet-x11.c
index da3d6af80b..33f70ab443 100644
--- a/epan/dissectors/packet-x11.c
+++ b/epan/dissectors/packet-x11.c
@@ -2621,7 +2621,7 @@ static int rounded4(int n)
 
 /* We assume the order to be consistent, until proven wrong. */
 
-static gboolean consistentWithOrder(int length, tvbuff_t *tvb, int offset, guint16 (*v16)(tvbuff_t *, gint))
+static gboolean consistentWithOrder(int length, tvbuff_t *tvb, int offset, guint16 (*v16)(tvbuff_t *, const gint))
 {
       switch(tvb_get_guint8(tvb, offset)) {
 	  case X_CreateWindow:
@@ -2837,7 +2837,7 @@ static gboolean consistentWithOrder(int length, tvbuff_t *tvb, int offset, guint
 
 /* -1 means doesn't match, +1 means match, 0 means don't know */
 
-static int x_endian_match(tvbuff_t *tvb, guint16 (*v16)(tvbuff_t *, gint))
+static int x_endian_match(tvbuff_t *tvb, guint16 (*v16)(tvbuff_t *, const gint))
 {
       int offset, nextoffset;
       int atLeastOne = 0;
diff --git a/epan/epan.c b/epan/epan.c
index 176e83ecc5..7b045c650c 100644
--- a/epan/epan.c
+++ b/epan/epan.c
@@ -150,7 +150,7 @@ epan_circuit_cleanup(void)
 }
 
 epan_dissect_t*
-epan_dissect_init(epan_dissect_t	*edt, gboolean create_proto_tree, gboolean proto_tree_visible)
+epan_dissect_init(epan_dissect_t	*edt, const gboolean create_proto_tree, const gboolean proto_tree_visible)
 {
 	g_assert(edt);
 
@@ -166,7 +166,7 @@ epan_dissect_init(epan_dissect_t	*edt, gboolean create_proto_tree, gboolean prot
 }
 
 epan_dissect_t*
-epan_dissect_new(gboolean create_proto_tree, gboolean proto_tree_visible)
+epan_dissect_new(const gboolean create_proto_tree, const gboolean proto_tree_visible)
 {
 	epan_dissect_t	*edt;
 
@@ -176,7 +176,7 @@ epan_dissect_new(gboolean create_proto_tree, gboolean proto_tree_visible)
 }
 
 void
-epan_dissect_fake_protocols(epan_dissect_t *edt, gboolean fake_protocols)
+epan_dissect_fake_protocols(epan_dissect_t *edt, const gboolean fake_protocols)
 {
 	if (edt)
 		proto_tree_set_fake_protocols(edt->tree, fake_protocols);
@@ -227,13 +227,13 @@ epan_dissect_prime_dfilter(epan_dissect_t *edt, const dfilter_t* dfcode)
 const gchar *
 epan_custom_set(epan_dissect_t *edt, int field_id,
                              gchar *result,
-                             gchar *expr, int size )
+                             gchar *expr, const int size )
 {
     return proto_custom_set(edt->tree, field_id, result, expr, size);
 }
 
 void
-epan_dissect_fill_in_columns(epan_dissect_t *edt, gboolean fill_col_exprs, gboolean fill_fd_colums)
+epan_dissect_fill_in_columns(epan_dissect_t *edt, const gboolean fill_col_exprs, const gboolean fill_fd_colums)
 {
     col_custom_set_edt(edt, edt->pi.cinfo);
     col_fill_in(&edt->pi, fill_col_exprs, fill_fd_colums);
diff --git a/epan/epan.h b/epan/epan.h
index d7c9742ad3..bfad1c8d5c 100644
--- a/epan/epan.h
+++ b/epan/epan.h
@@ -89,16 +89,16 @@ epan_get_version(void);
 
 /* initialize an existing single packet dissection */
 epan_dissect_t*
-epan_dissect_init(epan_dissect_t	*edt, gboolean create_proto_tree, gboolean proto_tree_visible);
+epan_dissect_init(epan_dissect_t	*edt, const gboolean create_proto_tree, const gboolean proto_tree_visible);
 
 /* get a new single packet dissection */
 /* should be freed using epan_dissect_free() after packet dissection completed */
 epan_dissect_t*
-epan_dissect_new(gboolean create_proto_tree, gboolean proto_tree_visible);
+epan_dissect_new(const gboolean create_proto_tree, const gboolean proto_tree_visible);
 
 /* Indicate whether we should fake protocols or not */
 void
-epan_dissect_fake_protocols(epan_dissect_t *edt, gboolean fake_protocols);
+epan_dissect_fake_protocols(epan_dissect_t *edt, const gboolean fake_protocols);
 
 /* run a single packet dissection */
 void
@@ -111,7 +111,7 @@ epan_dissect_prime_dfilter(epan_dissect_t *edt, const dfilter_t *dfcode);
 
 /* fill the dissect run output into the packet list columns */
 void
-epan_dissect_fill_in_columns(epan_dissect_t *edt, gboolean fill_col_exprs, gboolean fill_fd_colums);
+epan_dissect_fill_in_columns(epan_dissect_t *edt, const gboolean fill_col_exprs, const gboolean fill_fd_colums);
 
 /* releases resources attached to the packet dissection. DOES NOT free the actual pointer */
 void
@@ -124,6 +124,6 @@ epan_dissect_free(epan_dissect_t* edt);
 /* Sets custom column */
 const gchar *
 epan_custom_set(epan_dissect_t *edt, int id,
-				gchar *result, gchar *expr, int size );
+				gchar *result, gchar *expr, const int size );
 
 #endif /* EPAN_H */
diff --git a/epan/ipproto.c b/epan/ipproto.c
index 289530f088..c48b44972d 100644
--- a/epan/ipproto.c
+++ b/epan/ipproto.c
@@ -187,7 +187,7 @@ const value_string ipproto_val[] = {
     { 0,		NULL },
 };
 
-const char *ipprotostr(int proto) {
+const char *ipprotostr(const int proto) {
     const char *s;
 
     if ((s = match_strval(proto, ipproto_val)) != NULL)
diff --git a/epan/ipproto.h b/epan/ipproto.h
index f0b7b925a9..ac1eb83878 100644
--- a/epan/ipproto.h
+++ b/epan/ipproto.h
@@ -191,6 +191,6 @@
 #define IP_PROTO_NCS_HEARTBEAT  224             /* Novell NCS Heartbeat - http://support.novell.com/cgi-bin/search/searchtid.cgi?/10071158.htm */
 
 extern const value_string ipproto_val[];
-extern const char *ipprotostr(int proto);
+extern const char *ipprotostr(const int proto);
 
 #endif /* ipproto.h */
diff --git a/epan/ipv4.c b/epan/ipv4.c
index 0472a5be3d..26ff676d30 100644
--- a/epan/ipv4.c
+++ b/epan/ipv4.c
@@ -53,19 +53,19 @@ ipv4_addr_free(ipv4_addr *ipv4)
 }
 
 void
-ipv4_addr_set_host_order_addr(ipv4_addr *ipv4, guint32 new_addr)
+ipv4_addr_set_host_order_addr(ipv4_addr *ipv4, const guint32 new_addr)
 {
 	ipv4->addr = new_addr;
 }
 
 void
-ipv4_addr_set_net_order_addr(ipv4_addr *ipv4, guint32 new_addr)
+ipv4_addr_set_net_order_addr(ipv4_addr *ipv4, const guint32 new_addr)
 {
 	ipv4->addr = g_ntohl(new_addr);
 }
 
 void
-ipv4_addr_set_netmask_bits(ipv4_addr *ipv4, guint new_nmask_bits)
+ipv4_addr_set_netmask_bits(ipv4_addr *ipv4, const guint new_nmask_bits)
 {
 	static guint32 bitmasks[33] = {
 		0x00000000,
diff --git a/epan/ipv4.h b/epan/ipv4.h
index 39ff3de00d..2c05a9e048 100644
--- a/epan/ipv4.h
+++ b/epan/ipv4.h
@@ -42,9 +42,9 @@ ipv4_addr* ipv4_addr_new(void);
 /* Frees an ipv4 struct */
 void ipv4_addr_free(ipv4_addr *ipv4);
 
-void ipv4_addr_set_host_order_addr(ipv4_addr *ipv4, guint32 new_addr);
-void ipv4_addr_set_net_order_addr(ipv4_addr *ipv4, guint32 new_addr);
-void ipv4_addr_set_netmask_bits(ipv4_addr *ipv4, guint new_nmask_bits);
+void ipv4_addr_set_host_order_addr(ipv4_addr *ipv4, const guint32 new_addr);
+void ipv4_addr_set_net_order_addr(ipv4_addr *ipv4, const guint32 new_addr);
+void ipv4_addr_set_netmask_bits(ipv4_addr *ipv4, const guint new_nmask_bits);
 
 guint32 ipv4_get_net_order_addr(ipv4_addr *ipv4);
 guint32 ipv4_get_host_order_addr(ipv4_addr *ipv4);
diff --git a/epan/packet.c b/epan/packet.c
index 7c43e70e96..ef7de2986d 100644
--- a/epan/packet.c
+++ b/epan/packet.c
@@ -81,7 +81,7 @@ packet_cleanup(void)
  * of the tvbuff to reflect the specified length.
  */
 void
-set_actual_length(tvbuff_t *tvb, guint specified_len)
+set_actual_length(tvbuff_t *tvb, const guint specified_len)
 {
 	if (specified_len < tvb_reported_length(tvb)) {
 		/* Adjust the length of this tvbuff to include only the specified
@@ -361,7 +361,7 @@ dissect_packet(epan_dissect_t *edt, union wtap_pseudo_header *pseudo_header,
 /*********************** code added for sub-dissector lookup *********************/
 
 /*
- * An dissector handle.
+ * A dissector handle.
  */
 struct dissector_handle {
 	const char	*name;		/* dissector name */
@@ -668,7 +668,7 @@ find_dissector_table(const char *name)
 
 /* Find an entry in a uint dissector table. */
 static dtbl_entry_t *
-find_uint_dtbl_entry(dissector_table_t sub_dissectors, guint32 pattern)
+find_uint_dtbl_entry(dissector_table_t sub_dissectors, const guint32 pattern)
 {
 	switch (sub_dissectors->type) {
 
@@ -718,7 +718,7 @@ dissector_add_sanity_check(const char *name, guint32 pattern, dissector_handle_t
 
 /* Add an entry to a uint dissector table. */
 void
-dissector_add(const char *name, guint32 pattern, dissector_handle_t handle)
+dissector_add(const char *name, const guint32 pattern, dissector_handle_t handle)
 {
 	dissector_table_t sub_dissectors;
 	dtbl_entry_t *dtbl_entry;
@@ -774,7 +774,7 @@ dissector_add(const char *name, guint32 pattern, dissector_handle_t handle)
 /*	If temporary dissectors are deleted, then the original dissector must */
 /*	be available. */
 void
-dissector_delete(const char *name, guint32 pattern,
+dissector_delete(const char *name, const guint32 pattern,
 	dissector_handle_t handle _U_)
 {
 	dissector_table_t sub_dissectors = find_dissector_table( name);
@@ -805,7 +805,7 @@ dissector_delete(const char *name, guint32 pattern,
 /* Change the entry for a dissector in a uint dissector table
    with a particular pattern to use a new dissector handle. */
 void
-dissector_change(const char *name, guint32 pattern, dissector_handle_t handle)
+dissector_change(const char *name, const guint32 pattern, dissector_handle_t handle)
 {
 	dissector_table_t sub_dissectors = find_dissector_table( name);
 	dtbl_entry_t *dtbl_entry;
@@ -841,7 +841,7 @@ dissector_change(const char *name, guint32 pattern, dissector_handle_t handle)
 
 /* Reset an entry in a uint dissector table to its initial value. */
 void
-dissector_reset(const char *name, guint32 pattern)
+dissector_reset(const char *name, const guint32 pattern)
 {
 	dissector_table_t sub_dissectors = find_dissector_table( name);
 	dtbl_entry_t *dtbl_entry;
@@ -874,8 +874,8 @@ dissector_reset(const char *name, guint32 pattern)
    otherwise return FALSE. */
 
 gboolean
-dissector_try_port_new(dissector_table_t sub_dissectors, guint32 port,
-		       tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean add_proto_name)
+dissector_try_port_new(dissector_table_t sub_dissectors, const guint32 port,
+		       tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, const gboolean add_proto_name)
 {
 	dtbl_entry_t *dtbl_entry;
 	struct dissector_handle *handle;
@@ -926,7 +926,7 @@ dissector_try_port_new(dissector_table_t sub_dissectors, guint32 port,
 }
 
 gboolean
-dissector_try_port(dissector_table_t sub_dissectors, guint32 port,
+dissector_try_port(dissector_table_t sub_dissectors, const guint32 port,
 		   tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
 
@@ -935,7 +935,7 @@ dissector_try_port(dissector_table_t sub_dissectors, guint32 port,
 /* Look for a given value in a given uint dissector table and, if found,
    return the dissector handle for that value. */
 dissector_handle_t
-dissector_get_port_handle(dissector_table_t sub_dissectors, guint32 port)
+dissector_get_port_handle(dissector_table_t const sub_dissectors, const guint32 port)
 {
 	dtbl_entry_t *dtbl_entry;
 
@@ -948,7 +948,7 @@ dissector_get_port_handle(dissector_table_t sub_dissectors, guint32 port)
 
 /* Find an entry in a string dissector table. */
 static dtbl_entry_t *
-find_string_dtbl_entry(dissector_table_t sub_dissectors, const gchar *pattern)
+find_string_dtbl_entry(dissector_table_t const sub_dissectors, const gchar *pattern)
 {
 	switch (sub_dissectors->type) {
 
@@ -1414,7 +1414,7 @@ typedef struct dissector_foreach_table_info {
  * Called for each entry in the table of all dissector tables.
  */
 static void
-dissector_all_tables_foreach_table_func (gpointer key, gpointer value, gpointer user_data)
+dissector_all_tables_foreach_table_func (gpointer key, const gpointer value, const gpointer user_data)
 {
 	dissector_table_t table;
 	dissector_foreach_table_info_t *info;
@@ -1440,8 +1440,8 @@ dissector_all_tables_foreach_table (DATFunc_table func,
 }
 
 dissector_table_t
-register_dissector_table(const char *name, const char *ui_name, ftenum_t type,
-			 int base)
+register_dissector_table(const char *name, const char *ui_name, const ftenum_t type,
+			 const int base)
 {
 	dissector_table_t	sub_dissectors;
 
@@ -1530,7 +1530,7 @@ find_heur_dissector_list(const char *name)
 }
 
 void
-heur_dissector_add(const char *name, heur_dissector_t dissector, int proto)
+heur_dissector_add(const char *name, heur_dissector_t dissector, const int proto)
 {
 	heur_dissector_list_t *sub_dissectors = find_heur_dissector_list(name);
 	heur_dtbl_entry_t *dtbl_entry;
@@ -1555,7 +1555,7 @@ static int find_matching_heur_dissector( gconstpointer a, gconstpointer b) {
 		(dtbl_entry_a->protocol == dtbl_entry_b->protocol) ? 0 : 1;
 }
 
-void heur_dissector_delete(const char *name, heur_dissector_t dissector, int proto) {
+void heur_dissector_delete(const char *name, heur_dissector_t dissector, const int proto) {
 	heur_dissector_list_t *sub_dissectors = find_heur_dissector_list(name);
 	heur_dtbl_entry_t dtbl_entry;
 	GSList* found_entry;
@@ -1693,7 +1693,7 @@ static GHashTable *registered_dissectors = NULL;
 /* Get the short name of the protocol for a dissector handle, if it has
    a protocol. */
 const char *
-dissector_handle_get_short_name(dissector_handle_t handle)
+dissector_handle_get_short_name(const dissector_handle_t handle)
 {
 	if (handle->protocol == NULL) {
 		/*
@@ -1710,7 +1710,7 @@ dissector_handle_get_short_name(dissector_handle_t handle)
 /* Get the index of the protocol for a dissector handle, if it has
    a protocol. */
 int
-dissector_handle_get_protocol_index(dissector_handle_t handle)
+dissector_handle_get_protocol_index(const dissector_handle_t handle)
 {
 	if (handle->protocol == NULL) {
 		/*
@@ -1734,7 +1734,7 @@ find_dissector(const char *name)
 
 /* Create an anonymous handle for a dissector. */
 dissector_handle_t
-create_dissector_handle(dissector_t dissector, int proto)
+create_dissector_handle(dissector_t dissector, const int proto)
 {
 	struct dissector_handle *handle;
 
@@ -1748,7 +1748,7 @@ create_dissector_handle(dissector_t dissector, int proto)
 }
 
 dissector_handle_t
-new_create_dissector_handle(new_dissector_t dissector, int proto)
+new_create_dissector_handle(new_dissector_t dissector, const int proto)
 {
 	struct dissector_handle *handle;
 
@@ -1763,7 +1763,7 @@ new_create_dissector_handle(new_dissector_t dissector, int proto)
 
 /* Register a dissector by name. */
 void
-register_dissector(const char *name, dissector_t dissector, int proto)
+register_dissector(const char *name, dissector_t dissector, const int proto)
 {
 	struct dissector_handle *handle;
 
@@ -1787,7 +1787,7 @@ register_dissector(const char *name, dissector_t dissector, int proto)
 }
 
 void
-new_register_dissector(const char *name, new_dissector_t dissector, int proto)
+new_register_dissector(const char *name, new_dissector_t dissector, const int proto)
 {
 	struct dissector_handle *handle;
 
@@ -1861,7 +1861,7 @@ call_dissector(dissector_handle_t handle, tvbuff_t *tvb,
 
 static void
 dissector_dump_decodes_display(const gchar *table_name,
-			       ftenum_t selector_type _U_, gpointer key, gpointer value,
+			       ftenum_t selector_type _U_, const gpointer key, const gpointer value,
 			       gpointer user_data _U_)
 {
 	guint32 selector = (guint32)(unsigned long) key;
diff --git a/epan/packet.h b/epan/packet.h
index 853d114f0b..5aa87dee59 100644
--- a/epan/packet.h
+++ b/epan/packet.h
@@ -150,7 +150,7 @@ extern void dissector_all_tables_foreach_table (DATFunc_table func,
 
 /* a protocol uses the function to register a sub-dissector table */
 extern dissector_table_t register_dissector_table(const char *name,
-    const char *ui_name, ftenum_t type, int base);
+    const char *ui_name, const ftenum_t type, const int base);
 
 /* Find a dissector table by table name. */
 extern dissector_table_t find_dissector_table(const char *name);
@@ -167,38 +167,38 @@ extern ftenum_t get_dissector_table_selector_type(const char *name);
 extern int get_dissector_table_base(const char *name);
 
 /* Add an entry to a uint dissector table. */
-extern void dissector_add(const char *abbrev, guint32 pattern,
+extern void dissector_add(const char *abbrev, const guint32 pattern,
     dissector_handle_t handle);
 
 /* Delete the entry for a dissector in a uint dissector table
    with a particular pattern. */
-extern void dissector_delete(const char *name, guint32 pattern,
+extern void dissector_delete(const char *name, const guint32 pattern,
     dissector_handle_t handle);
 
 /* Change the entry for a dissector in a uint dissector table
    with a particular pattern to use a new dissector handle. */
-extern void dissector_change(const char *abbrev, guint32 pattern,
+extern void dissector_change(const char *abbrev, const guint32 pattern,
     dissector_handle_t handle);
 
 /* Reset an entry in a uint dissector table to its initial value. */
-extern void dissector_reset(const char *name, guint32 pattern);
+extern void dissector_reset(const char *name, const guint32 pattern);
 
 /* Look for a given value in a given uint dissector table and, if found,
    call the dissector with the arguments supplied, and return TRUE,
    otherwise return FALSE. */
 extern gboolean dissector_try_port(dissector_table_t sub_dissectors,
-    guint32 port, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
+    const guint32 port, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
 
 /* Look for a given value in a given uint dissector table and, if found,
    call the dissector with the arguments supplied, and return TRUE,
    otherwise return FALSE. */
 extern gboolean dissector_try_port_new(dissector_table_t sub_dissectors, 
-	guint32 port, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean add_proto_name);
+	const guint32 port, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, const gboolean add_proto_name);
 
 /* Look for a given value in a given uint dissector table and, if found,
    return the dissector handle for that value. */
 extern dissector_handle_t dissector_get_port_handle(
-    dissector_table_t sub_dissectors, guint32 port);
+    dissector_table_t const sub_dissectors, const guint32 port);
 
 /* Add an entry to a string dissector table. */
 extern void dissector_add_string(const char *name, const gchar *pattern,
@@ -268,7 +268,7 @@ extern gboolean dissector_try_heuristic(heur_dissector_list_t sub_dissectors,
  * @param proto the protocol id of the sub-dissector
  */
 extern void heur_dissector_add(const char *name, heur_dissector_t dissector,
-    int proto);
+    const int proto);
 
 /** Remove a sub-dissector from a heuristic dissector list.
  *  Call this in the prefs_reinit function of the sub-dissector.
@@ -277,28 +277,28 @@ extern void heur_dissector_add(const char *name, heur_dissector_t dissector,
  * @param dissector the sub-dissector to be unregistered
  * @param proto the protocol id of the sub-dissector
  */
-extern void heur_dissector_delete(const char *name, heur_dissector_t dissector, int proto);
+extern void heur_dissector_delete(const char *name, heur_dissector_t dissector, const int proto);
 
 /* Register a dissector. */
 extern void register_dissector(const char *name, dissector_t dissector,
-    int proto);
+    const int proto);
 extern void new_register_dissector(const char *name, new_dissector_t dissector,
-    int proto);
+    const int proto);
 
 /* Get the short name of the protocol for a dissector handle. */
-extern const char *dissector_handle_get_short_name(dissector_handle_t handle);
+extern const char *dissector_handle_get_short_name(const dissector_handle_t handle);
 
 /* Get the index of the protocol for a dissector handle. */
-extern int dissector_handle_get_protocol_index(dissector_handle_t handle);
+extern int dissector_handle_get_protocol_index(const dissector_handle_t handle);
 
 /* Find a dissector by name. */
 extern dissector_handle_t find_dissector(const char *name);
 
 /* Create an anonymous handle for a dissector. */
 extern dissector_handle_t create_dissector_handle(dissector_t dissector,
-    int proto);
+    const int proto);
 extern dissector_handle_t new_create_dissector_handle(new_dissector_t dissector,
-    int proto);
+    const int proto);
 
 /* Call a dissector through a handle and if no dissector was found
  * pass if over to the "data" dissector instead.
@@ -339,7 +339,7 @@ extern void dissect_cleanup(void);
  * Given a tvbuff, and a length from a packet header, adjust the length
  * of the tvbuff to reflect the specified length.
  */
-extern void set_actual_length(tvbuff_t *tvb, guint specified_len);
+extern void set_actual_length(tvbuff_t *tvb, const guint specified_len);
 
 /* Allow protocols to register "init" routines, which are called before
    we make a pass through a capture file and dissect all its packets
diff --git a/epan/proto.c b/epan/proto.c
index a58b83195e..287bf73835 100644
--- a/epan/proto.c
+++ b/epan/proto.c
@@ -74,7 +74,7 @@ struct ptvcursor {
 
 /* Candidates for assembler */
 static int
-wrs_count_bitshift(guint32 bitmask)
+wrs_count_bitshift(const guint32 bitmask)
 {
 	int bitshift = 0;
 
@@ -144,29 +144,29 @@ static void fill_label_bitfield(field_info *fi, gchar *label_str);
 static void fill_label_int(field_info *fi, gchar *label_str);
 static void fill_label_int64(field_info *fi, gchar *label_str);
 
-static const char* hfinfo_uint_vals_format(header_field_info *hfinfo);
-static const char* hfinfo_uint_format(header_field_info *hfinfo);
-static const char* hfinfo_uint_value_format(header_field_info *hfinfo);
-static const char* hfinfo_uint64_format(header_field_info *hfinfo);
-static const char* hfinfo_int_vals_format(header_field_info *hfinfo);
-static const char* hfinfo_int_format(header_field_info *hfinfo);
-static const char* hfinfo_int_value_format(header_field_info *hfinfo);
-static const char* hfinfo_int64_format(header_field_info *hfinfo);
+static const char* hfinfo_uint_vals_format(const header_field_info *hfinfo);
+static const char* hfinfo_uint_format(const header_field_info *hfinfo);
+static const char* hfinfo_uint_value_format(const header_field_info *hfinfo);
+static const char* hfinfo_uint64_format(const header_field_info *hfinfo);
+static const char* hfinfo_int_vals_format(const header_field_info *hfinfo);
+static const char* hfinfo_int_format(const header_field_info *hfinfo);
+static const char* hfinfo_int_value_format(const header_field_info *hfinfo);
+static const char* hfinfo_int64_format(const header_field_info *hfinfo);
 
 static proto_item*
 proto_tree_add_node(proto_tree *tree, field_info *fi);
 
 static header_field_info *
-get_hfi_and_length(int hfindex, tvbuff_t *tvb, gint start, gint *length,
+get_hfi_and_length(int hfindex, tvbuff_t *tvb, const gint start, gint *length,
 	gint *item_length);
 
 static field_info *
 new_field_info(proto_tree *tree, header_field_info *hfinfo, tvbuff_t *tvb,
-	gint start, gint item_length);
+	const gint start, const gint item_length);
 
 static field_info *
 alloc_field_info(proto_tree *tree, int hfindex, tvbuff_t *tvb,
-		gint start, gint *length);
+		const gint start, gint *length);
 
 static proto_item *
 proto_tree_add_pi(proto_tree *tree, int hfindex, tvbuff_t *tvb,
@@ -226,10 +226,10 @@ proto_tree_set_uint64(field_info *fi, guint64 value);
 static void
 proto_tree_set_uint64_tvb(field_info *fi, tvbuff_t *tvb, gint start, guint length, gboolean little_endian);
 static gboolean
-proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, int offset, int len, gint ett,
-	const gint **fields, gboolean little_endian, int flags, gboolean first);
+proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, const int offset, const int len, const gint ett,
+	const gint **fields, const gboolean little_endian, const int flags, gboolean first);
 
-static int proto_register_field_init(header_field_info *hfinfo, int parent);
+static int proto_register_field_init(header_field_info *hfinfo, const int parent);
 
 /* special-case header field used within proto.c */
 int hf_text_only = -1;
@@ -1471,8 +1471,8 @@ ptvcursor_add(ptvcursor_t *ptvc, int hfindex, gint length,
 /* Add an item to a proto_tree, using the text label registered to that item;
    the item is extracted from the tvbuff handed to it. */
 proto_item *
-proto_tree_add_item(proto_tree *tree, int hfindex, tvbuff_t *tvb,
-	gint start, gint length, gboolean little_endian)
+proto_tree_add_item(proto_tree *tree, const int hfindex, tvbuff_t *tvb,
+	const gint start, gint length, const gboolean little_endian)
 {
 	field_info	*new_fi;
 	header_field_info	*hfinfo;
@@ -1490,7 +1490,7 @@ proto_tree_add_item(proto_tree *tree, int hfindex, tvbuff_t *tvb,
 
 /* Add a FT_NONE to a proto_tree */
 proto_item *
-proto_tree_add_none_format(proto_tree *tree, int hfindex, tvbuff_t *tvb, gint start,
+proto_tree_add_none_format(proto_tree *tree, const int hfindex, tvbuff_t *tvb, const gint start,
 		gint length, const char *format, ...)
 {
 	proto_item		*pi;
@@ -3015,7 +3015,7 @@ proto_tree_add_pi(proto_tree *tree, int hfindex, tvbuff_t *tvb, gint start,
 
 
 static header_field_info *
-get_hfi_and_length(int hfindex, tvbuff_t *tvb, gint start, gint *length,
+get_hfi_and_length(int hfindex, tvbuff_t *tvb, const gint start, gint *length,
 	gint *item_length)
 {
 	header_field_info	*hfinfo;
@@ -3150,7 +3150,7 @@ get_hfi_and_length(int hfindex, tvbuff_t *tvb, gint start, gint *length,
 
 static field_info *
 new_field_info(proto_tree *tree, header_field_info *hfinfo, tvbuff_t *tvb,
-	gint start, gint item_length)
+	const gint start, const gint item_length)
 {
 	field_info		*fi;
 
@@ -3177,7 +3177,7 @@ new_field_info(proto_tree *tree, header_field_info *hfinfo, tvbuff_t *tvb,
 }
 
 static field_info *
-alloc_field_info(proto_tree *tree, int hfindex, tvbuff_t *tvb, gint start,
+alloc_field_info(proto_tree *tree, int hfindex, tvbuff_t *tvb, const gint start,
 	gint *length)
 {
 	header_field_info	*hfinfo;
@@ -3282,9 +3282,9 @@ proto_tree_set_representation(proto_item *pi, const char *format, va_list ap)
 
 /* -------------------------- */
 const gchar *
-proto_custom_set(proto_tree* tree, int field_id,
+proto_custom_set(proto_tree* tree, const int field_id,
 							 gchar *result,
-							 gchar *expr, int size )
+							 gchar *expr, const int size )
 {
 	guint32		u_integer;
 	gint32		integer;
@@ -3526,7 +3526,7 @@ proto_item_append_text(proto_item *pi, const char *format, ...)
 }
 
 void
-proto_item_set_len(proto_item *pi, gint length)
+proto_item_set_len(proto_item *pi, const gint length)
 {
 	field_info *fi;
 
@@ -3569,7 +3569,7 @@ proto_item_set_end(proto_item *pi, tvbuff_t *tvb, gint end)
 }
 
 int
-proto_item_get_len(proto_item *pi)
+proto_item_get_len(const proto_item *pi)
 {
 	field_info *fi = PITEM_FINFO(pi);
 	return fi ? fi->length : -1;
@@ -3583,7 +3583,7 @@ proto_item_get_len(proto_item *pi)
 }
 
 gboolean
-proto_item_set_expert_flags(proto_item *pi, int group, guint severity)
+proto_item_set_expert_flags(proto_item *pi, const int group, const guint severity)
 {
 	if(pi == NULL || PITEM_FINFO(pi) == NULL)
 		return FALSE;
@@ -3632,7 +3632,7 @@ proto_tree_create_root(void)
 /* "prime" a proto_tree with a single hfid that a dfilter
  * is interested in. */
 void
-proto_tree_prime_hfid(proto_tree *tree _U_, gint hfid)
+proto_tree_prime_hfid(proto_tree *tree _U_, const gint hfid)
 {
 	header_field_info *hfinfo;
 
@@ -3658,7 +3658,7 @@ proto_tree_prime_hfid(proto_tree *tree _U_, gint hfid)
 }
 
 proto_tree*
-proto_item_add_subtree(proto_item *pi,	gint idx) {
+proto_item_add_subtree(proto_item *pi,	const gint idx) {
 	field_info *fi;
 
 	if (!pi)
@@ -3676,7 +3676,7 @@ proto_item_add_subtree(proto_item *pi,	gint idx) {
 }
 
 proto_tree*
-proto_item_get_subtree(proto_item *pi) {
+proto_item_get_subtree(const proto_item *pi) {
 	field_info *fi;
 
 	if (!pi)
@@ -3688,7 +3688,7 @@ proto_item_get_subtree(proto_item *pi) {
 }
 
 proto_item*
-proto_item_get_parent(proto_item *ti) {
+proto_item_get_parent(const proto_item *ti) {
 	if (!ti)
 		return (NULL);
 	return ti->parent;
@@ -3708,7 +3708,7 @@ proto_item_get_parent_nth(proto_item *ti, int gen) {
 
 
 proto_item*
-proto_tree_get_parent(proto_tree *tree) {
+proto_tree_get_parent(const proto_tree *tree) {
 	if (!tree)
 		return (NULL);
 	return (proto_item*) tree;
@@ -3771,7 +3771,7 @@ proto_tree_move_item(proto_tree *tree, proto_item *fixed_item, proto_item *item_
 }
 
 void
-proto_tree_set_appendix(proto_tree *tree, tvbuff_t *tvb, gint start, gint length)
+proto_tree_set_appendix(proto_tree *tree, tvbuff_t *tvb, gint start, const gint length)
 {
 	field_info *fi;
 
@@ -3890,7 +3890,7 @@ proto_register_protocol(const char *name, const char *short_name, const char *fi
 }
 
 void
-proto_mark_private(int proto_id)
+proto_mark_private(const int proto_id)
 {
 	protocol_t *protocol = find_protocol_by_id(proto_id);
 	if (protocol)
@@ -3898,7 +3898,7 @@ proto_mark_private(int proto_id)
 }
 
 gboolean
-proto_is_private(int proto_id)
+proto_is_private(const int proto_id)
 {
 	protocol_t *protocol = find_protocol_by_id(proto_id);
 	if (protocol)
@@ -3941,7 +3941,7 @@ proto_get_next_protocol(void **cookie)
 }
 
 header_field_info *
-proto_get_first_protocol_field(int proto_id, void **cookie)
+proto_get_first_protocol_field(const int proto_id, void **cookie)
 {
 	protocol_t *protocol = find_protocol_by_id(proto_id);
 	hf_register_info *ptr;
@@ -3970,7 +3970,7 @@ proto_get_next_protocol_field(void **cookie)
 }
 
 protocol_t *
-find_protocol_by_id(int proto_id)
+find_protocol_by_id(const int proto_id)
 {
 	header_field_info *hfinfo;
 
@@ -3992,7 +3992,7 @@ static gint compare_filter_name(gconstpointer proto_arg,
 }
 
 int
-proto_get_id(protocol_t *protocol)
+proto_get_id(const protocol_t *protocol)
 {
 	return protocol->proto_id;
 }
@@ -4012,7 +4012,7 @@ int proto_get_id_by_filter_name(const gchar* filter_name)
 }
 
 const char *
-proto_get_protocol_name(int proto_id)
+proto_get_protocol_name(const int proto_id)
 {
 	protocol_t *protocol;
 
@@ -4021,7 +4021,7 @@ proto_get_protocol_name(int proto_id)
 }
 
 const char *
-proto_get_protocol_short_name(protocol_t *protocol)
+proto_get_protocol_short_name(const protocol_t *protocol)
 {
 	if (protocol == NULL)
 		return "(none)";
@@ -4029,7 +4029,7 @@ proto_get_protocol_short_name(protocol_t *protocol)
 }
 
 const char *
-proto_get_protocol_long_name(protocol_t *protocol)
+proto_get_protocol_long_name(const protocol_t *protocol)
 {
 	if (protocol == NULL)
 		return "(none)";
@@ -4037,7 +4037,7 @@ proto_get_protocol_long_name(protocol_t *protocol)
 }
 
 const char *
-proto_get_protocol_filter_name(int proto_id)
+proto_get_protocol_filter_name(const int proto_id)
 {
 	protocol_t *protocol;
 
@@ -4048,13 +4048,13 @@ proto_get_protocol_filter_name(int proto_id)
 }
 
 gboolean
-proto_is_protocol_enabled(protocol_t *protocol)
+proto_is_protocol_enabled(const protocol_t *protocol)
 {
 	return protocol->is_enabled;
 }
 
 gboolean
-proto_can_toggle_protocol(int proto_id)
+proto_can_toggle_protocol(const int proto_id)
 {
 	protocol_t *protocol;
 
@@ -4063,7 +4063,7 @@ proto_can_toggle_protocol(int proto_id)
 }
 
 void
-proto_set_decoding(int proto_id, gboolean enabled)
+proto_set_decoding(const int proto_id, const gboolean enabled)
 {
 	protocol_t *protocol;
 
@@ -4090,7 +4090,7 @@ proto_enable_all(void)
 }
 
 void
-proto_set_cant_toggle(int proto_id)
+proto_set_cant_toggle(const int proto_id)
 {
 	protocol_t *protocol;
 
@@ -4101,7 +4101,7 @@ proto_set_cant_toggle(int proto_id)
 /* for use with static arrays only, since we don't allocate our own copies
 of the header_field_info struct contained within the hf_register_info struct */
 void
-proto_register_field_array(int parent, hf_register_info *hf, int num_records)
+proto_register_field_array(const int parent, hf_register_info *hf, const int num_records)
 {
 	int			field_id, i;
 	hf_register_info	*ptr = hf;
@@ -4244,7 +4244,7 @@ static void tmp_fld_check_assert(header_field_info *hfinfo) {
 }
 
 static int
-proto_register_field_init(header_field_info *hfinfo, int parent)
+proto_register_field_init(header_field_info *hfinfo, const int parent)
 {
 
 	tmp_fld_check_assert(hfinfo);
@@ -4324,7 +4324,7 @@ proto_register_field_init(header_field_info *hfinfo, int parent)
 }
 
 void
-proto_register_subtree_array(gint *const *indices, int num_indices)
+proto_register_subtree_array(gint *const *indices, const int num_indices)
 {
 	int	i;
 	gint	*const *ptr = indices;
@@ -4786,7 +4786,7 @@ fill_label_int64(field_info *fi, gchar *label_str)
 }
 
 int
-hfinfo_bitwidth(header_field_info *hfinfo)
+hfinfo_bitwidth(const header_field_info *hfinfo)
 {
 	int bitwidth = 0;
 
@@ -4822,7 +4822,7 @@ hfinfo_bitwidth(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_uint_vals_format(header_field_info *hfinfo)
+hfinfo_uint_vals_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -4866,7 +4866,7 @@ hfinfo_uint_vals_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_uint_format(header_field_info *hfinfo)
+hfinfo_uint_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -4950,7 +4950,7 @@ hfinfo_uint_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_uint_value_format(header_field_info *hfinfo)
+hfinfo_uint_value_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5034,7 +5034,7 @@ hfinfo_uint_value_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_int_vals_format(header_field_info *hfinfo)
+hfinfo_int_vals_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5078,7 +5078,7 @@ hfinfo_int_vals_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_uint64_format(header_field_info *hfinfo)
+hfinfo_uint64_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5107,7 +5107,7 @@ hfinfo_uint64_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_int_format(header_field_info *hfinfo)
+hfinfo_int_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5184,7 +5184,7 @@ hfinfo_int_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_int_value_format(header_field_info *hfinfo)
+hfinfo_int_value_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5261,7 +5261,7 @@ hfinfo_int_value_format(header_field_info *hfinfo)
 }
 
 static const char*
-hfinfo_int64_format(header_field_info *hfinfo)
+hfinfo_int64_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -5296,7 +5296,7 @@ proto_registrar_n(void)
 }
 
 const char*
-proto_registrar_get_name(int n)
+proto_registrar_get_name(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5305,7 +5305,7 @@ proto_registrar_get_name(int n)
 }
 
 const char*
-proto_registrar_get_abbrev(int n)
+proto_registrar_get_abbrev(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5314,7 +5314,7 @@ proto_registrar_get_abbrev(int n)
 }
 
 int
-proto_registrar_get_ftype(int n)
+proto_registrar_get_ftype(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5323,7 +5323,7 @@ proto_registrar_get_ftype(int n)
 }
 
 int
-proto_registrar_get_parent(int n)
+proto_registrar_get_parent(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5332,7 +5332,7 @@ proto_registrar_get_parent(int n)
 }
 
 gboolean
-proto_registrar_is_protocol(int n)
+proto_registrar_is_protocol(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5345,7 +5345,7 @@ proto_registrar_is_protocol(int n)
  * 0 means undeterminable at time of registration
  * -1 means the field is not registered. */
 gint
-proto_registrar_get_length(int n)
+proto_registrar_get_length(const int n)
 {
 	header_field_info *hfinfo;
 
@@ -5356,7 +5356,7 @@ proto_registrar_get_length(int n)
 /* Looks for a protocol or a field in a proto_tree. Returns TRUE if
  * it exists anywhere, or FALSE if it exists nowhere. */
 gboolean
-proto_check_for_protocol_or_field(proto_tree* tree, int id)
+proto_check_for_protocol_or_field(const proto_tree* tree, const int id)
 {
 	GPtrArray *ptrs = proto_get_finfo_ptr_array(tree, id);
 
@@ -5377,7 +5377,7 @@ proto_check_for_protocol_or_field(proto_tree* tree, int id)
  * The caller should *not* free the GPtrArray*; proto_tree_free_node()
  * handles that. */
 GPtrArray*
-proto_get_finfo_ptr_array(proto_tree *tree, int id)
+proto_get_finfo_ptr_array(const proto_tree *tree, const int id)
 {
 	if (!tree)
 		return NULL;
@@ -5390,7 +5390,7 @@ proto_get_finfo_ptr_array(proto_tree *tree, int id)
 }
 
 gboolean
-proto_tracking_interesting_fields(proto_tree *tree)
+proto_tracking_interesting_fields(const proto_tree *tree)
 {
 	if (!tree)
 		return FALSE;
@@ -5426,7 +5426,7 @@ find_finfo(proto_node *node, gpointer data)
 * g_ptr_array_free(<array>, TRUE).
 */
 GPtrArray*
-proto_find_finfo(proto_tree *tree, int id)
+proto_find_finfo(proto_tree *tree, const int id)
 {
 	ffdata_t	ffdata;
 
@@ -5473,7 +5473,7 @@ typedef struct {
 } offset_search_t;
 
 static gboolean
-check_for_offset(proto_node *node, gpointer data)
+check_for_offset(proto_node *node, const gpointer data)
 {
 	field_info			*fi = PNODE_FINFO(node);
 	offset_search_t		*offsearch = data;
@@ -5728,7 +5728,7 @@ proto_registrar_dump_values(void)
  * Field 8 = bitmask: format: hex: 0x....
  */
 void
-proto_registrar_dump_fields(int format)
+proto_registrar_dump_fields(const int format)
 {
 	header_field_info	*hfinfo, *parent_hfinfo;
 	int			i, len;
@@ -5848,7 +5848,7 @@ proto_registrar_dump_fields(int format)
 }
 
 static const char*
-hfinfo_numeric_format(header_field_info *hfinfo)
+hfinfo_numeric_format(const header_field_info *hfinfo)
 {
 	const char *format = NULL;
 
@@ -6188,8 +6188,8 @@ proto_construct_match_selected_string(field_info *finfo, epan_dissect_t *edt)
  *	proto_tree_add_bitmask_text() functions.
  */
 static gboolean
-proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, int offset, int len, gint ett,
-	const int **fields, gboolean little_endian, int flags, gboolean first)
+proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, const int offset, const int len, const gint ett,
+	const int **fields, const gboolean little_endian, const int flags, gboolean first)
 {
 	guint32 value = 0, tmpval;
 	proto_tree *tree = NULL;
@@ -6324,8 +6324,8 @@ proto_item_add_bitmask_tree(proto_item *item, tvbuff_t *tvb, int offset, int len
  * matched string displayed on the expansion line.
  */
 proto_item *
-proto_tree_add_bitmask(proto_tree *parent_tree, tvbuff_t *tvb, guint offset, int hf_hdr,
-		gint ett, const int **fields, gboolean little_endian)
+proto_tree_add_bitmask(proto_tree *parent_tree, tvbuff_t *tvb, const guint offset, const int hf_hdr,
+		const gint ett, const int **fields, const gboolean little_endian)
 {
 	proto_item *item = NULL;
 	header_field_info *hf;
@@ -6346,9 +6346,9 @@ proto_tree_add_bitmask(proto_tree *parent_tree, tvbuff_t *tvb, guint offset, int
 
 /* The same as proto_tree_add_bitmask(), but using an arbitrary text as a top-level item */
 proto_item *
-proto_tree_add_bitmask_text(proto_tree *parent_tree, tvbuff_t *tvb, guint offset, guint len,
+proto_tree_add_bitmask_text(proto_tree *parent_tree, tvbuff_t *tvb, const guint offset, const guint len,
 		const char *name, const char *fallback,
-		gint ett, const int **fields, gboolean little_endian, int flags)
+		const gint ett, const int **fields, const gboolean little_endian, const int flags)
 {
 	proto_item *item = NULL;
 
@@ -6365,7 +6365,7 @@ proto_tree_add_bitmask_text(proto_tree *parent_tree, tvbuff_t *tvb, guint offset
 }
 
 proto_item *
-proto_tree_add_bits_item(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian)
+proto_tree_add_bits_item(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, const gboolean little_endian)
 {
 	header_field_info	*hfinfo;
 
@@ -6381,7 +6381,7 @@ proto_tree_add_bits_item(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit
  */
 
 proto_item *
-proto_tree_add_bits_ret_val(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits, guint64 *return_value, gboolean little_endian)
+proto_tree_add_bits_ret_val(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, guint64 *return_value, const gboolean little_endian)
 {
 	const char *format = NULL;
 	gint	offset;
@@ -6497,7 +6497,7 @@ proto_tree_add_bits_ret_val(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint
 }
 
 proto_item *
-proto_tree_add_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits, void *value_ptr, gchar *value_str)
+proto_tree_add_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, void *value_ptr, gchar *value_str)
 {
 	gint	offset;
 	guint	length;
@@ -6599,7 +6599,7 @@ proto_tree_add_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb,
 	va_end(ap);
 
 proto_item *
-proto_tree_add_uint_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_uint_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	guint32 value, const char *format, ...)
 {
 	va_list ap;
@@ -6627,7 +6627,7 @@ proto_tree_add_uint_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *
 }
 
 proto_item *
-proto_tree_add_float_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_float_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	float value, const char *format, ...)
 {
 	va_list ap;
@@ -6644,7 +6644,7 @@ proto_tree_add_float_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t
 }
 
 proto_item *
-proto_tree_add_int_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_int_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	gint32 value, const char *format, ...)
 {
 	va_list ap;
@@ -6672,7 +6672,7 @@ proto_tree_add_int_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *t
 }
 
 proto_item *
-proto_tree_add_boolean_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_boolean_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	guint32 value, const char *format, ...)
 {
 	va_list ap;
diff --git a/epan/proto.h b/epan/proto.h
index 3677ebe492..304494bc5a 100644
--- a/epan/proto.h
+++ b/epan/proto.h
@@ -413,17 +413,17 @@ extern gboolean proto_field_is_referenced(proto_tree *tree, int proto_id);
  @param ti the parent item of the new subtree
  @param idx one of the ett_ array elements registered with proto_register_subtree_array()
  @return the new subtree */
-extern proto_tree* proto_item_add_subtree(proto_item *ti, gint idx);
+extern proto_tree* proto_item_add_subtree(proto_item *ti, const gint idx);
 
 /** Get an existing subtree under an item.
  @param ti the parent item of the subtree
  @return the subtree or NULL */
-extern proto_tree* proto_item_get_subtree(proto_item *ti);
+extern proto_tree* proto_item_get_subtree(const proto_item *ti);
 
 /** Get the parent of a subtree item.
  @param ti the child item in the subtree
  @return parent item or NULL */
-extern proto_item* proto_item_get_parent(proto_item *ti);
+extern proto_item* proto_item_get_parent(const proto_item *ti);
 
 /** Get Nth generation parent item.
  @param ti the child item in the subtree
@@ -448,7 +448,7 @@ extern void proto_item_append_text(proto_item *ti, const char *format, ...)
 /** Set proto_item's length inside tvb, after it has already been created.
  @param ti the item to set the length
  @param length the new length ot the item */
-extern void proto_item_set_len(proto_item *ti, gint length);
+extern void proto_item_set_len(proto_item *ti, const gint length);
 
 /**
  * Sets the length of the item based on its start and on the specified
@@ -466,7 +466,7 @@ extern void proto_item_set_end(proto_item *ti, tvbuff_t *tvb, gint end);
  * to add a variable-length field (e.g., FT_NSTRING_UINT8).
  @param ti the item to get the length from
  @return the current length */
-extern int proto_item_get_len(proto_item *ti);
+extern int proto_item_get_len(const proto_item *ti);
 
 /**
  * Sets an expert info to the proto_item.
@@ -475,7 +475,7 @@ extern int proto_item_get_len(proto_item *ti);
  @param severity of this info (e.g. PI_ERROR)
  @return TRUE if value was written
  */
-extern gboolean proto_item_set_expert_flags(proto_item *ti, int group, guint severity);
+extern gboolean proto_item_set_expert_flags(proto_item *ti, const int group, const guint severity);
 
 
 
@@ -509,12 +509,12 @@ proto_tree_set_fake_protocols(proto_tree *tree, gboolean fake_protocols);
  @param hfid the interesting field id
  @todo what *does* interesting mean? */
 extern void
-proto_tree_prime_hfid(proto_tree *tree, int hfid);
+proto_tree_prime_hfid(proto_tree *tree, const int hfid);
 
 /** Get a parent item of a subtree.
  @param tree the tree to get the parent from
  @return parent item */
-extern proto_item* proto_tree_get_parent(proto_tree *tree);
+extern proto_item* proto_tree_get_parent(const proto_tree *tree);
 
 /** Get the root tree from any subtree.
  @param tree the tree to get the root from
@@ -533,7 +533,7 @@ extern void proto_tree_move_item(proto_tree *tree, proto_item *fixed_item, proto
   @param tvb the tv buffer of the current data
   @param start the start offset of the appendix
   @param length the length of the appendix */
-extern void proto_tree_set_appendix(proto_tree *tree, tvbuff_t *tvb, gint start, gint length);
+extern void proto_tree_set_appendix(proto_tree *tree, tvbuff_t *tvb, gint start, const gint length);
 
 
 /** Add an item to a proto_tree, using the text label registered to that item.
@@ -546,8 +546,8 @@ extern void proto_tree_set_appendix(proto_tree *tree, tvbuff_t *tvb, gint start,
  @param little_endian big or little endian byte representation
  @return the newly created item */
 extern proto_item *
-proto_tree_add_item(proto_tree *tree, int hfindex, tvbuff_t *tvb,
-    gint start, gint length, gboolean little_endian);
+proto_tree_add_item(proto_tree *tree, const int hfindex, tvbuff_t *tvb,
+    const gint start, gint length, const gboolean little_endian);
 
 /** Add a text-only node to a proto_tree.
  @param tree the tree to append this item to
@@ -584,7 +584,7 @@ proto_tree_add_text_valist(proto_tree *tree, tvbuff_t *tvb, gint start,
  @param ... printf like parameters
  @return the newly created item */
 extern proto_item *
-proto_tree_add_none_format(proto_tree *tree, int hfindex, tvbuff_t *tvb, gint start,
+proto_tree_add_none_format(proto_tree *tree, const int hfindex, tvbuff_t *tvb, const gint start,
 	gint length, const char *format, ...) G_GNUC_PRINTF(6,7);
 
 /** Add a FT_PROTOCOL to a proto_tree.
@@ -1360,13 +1360,13 @@ proto_register_protocol(const char *name, const char *short_name, const char *fi
 /** Mark protocol as private
  @param proto_id the handle of the protocol */
 extern void
-proto_mark_private(int proto_id);
+proto_mark_private(const int proto_id);
 
 /** Return if protocol is private
  @param proto_id the handle of the protocol
  @return TRUE if it is a private protocol, FALSE is not. */
 extern gboolean
-proto_is_private(int proto_id);
+proto_is_private(const int proto_id);
 
 /** This is the type of function can be registered to get called whenever
     a given field was not found but a its prefix is matched
@@ -1388,13 +1388,13 @@ extern void proto_initialize_all_prefixes(void);
  @param hf the hf_register_info array
  @param num_records the number of records in hf */
 extern void
-proto_register_field_array(int parent, hf_register_info *hf, int num_records);
+proto_register_field_array(const int parent, hf_register_info *hf, const int num_records);
 
 /** Register a protocol subtree (ett) array.
  @param indices array of ett indices
  @param num_indices the number of records in indices */
 extern void
-proto_register_subtree_array(gint *const *indices, int num_indices);
+proto_register_subtree_array(gint *const *indices, const int num_indices);
 
 /** Returns number of items (protocols or header fields) registered.
  @return the number of items */
@@ -1403,12 +1403,12 @@ extern int proto_registrar_n(void);
 /** Get name of registered header_field number n.
  @param n item # n (0-indexed)
  @return the name of this registered item */
-extern const char* proto_registrar_get_name(int n);
+extern const char* proto_registrar_get_name(const int n);
 
 /** Get abbreviation of registered header_field number n.
  @param n item # n (0-indexed)
  @return the abbreviation of this registered item */
-extern const char* proto_registrar_get_abbrev(int n);
+extern const char* proto_registrar_get_abbrev(const int n);
 
 /** Get the header_field information based upon a field or protocol id.
  @param hfindex item # n (0-indexed)
@@ -1423,22 +1423,22 @@ extern header_field_info* proto_registrar_get_byname(const char *field_name);
 /** Get enum ftenum FT_ of registered header_field number n.
  @param n item # n (0-indexed)
  @return the registered item */
-extern int proto_registrar_get_ftype(int n);
+extern int proto_registrar_get_ftype(const int n);
 
 /** Get parent protocol of registered header_field number n.
  @param n item # n (0-indexed)
  @return -1 if item _is_ a protocol */
-extern int proto_registrar_get_parent(int n);
+extern int proto_registrar_get_parent(const int n);
 
 /** Is item # n a protocol?
  @param n item # n (0-indexed)
  @return TRUE if it's a protocol, FALSE if it's not */
-extern gboolean proto_registrar_is_protocol(int n);
+extern gboolean proto_registrar_is_protocol(const int n);
 
 /** Get length of registered field according to field type.
  @param n item # n (0-indexed)
  @return 0 means undeterminable at registration time, -1 means unknown field */
-extern gint proto_registrar_get_length(int n);
+extern gint proto_registrar_get_length(const int n);
 
 
 /** Routines to use to iterate over the protocols and their fields;
@@ -1446,7 +1446,7 @@ extern gint proto_registrar_get_length(int n);
  * appropriate hfinfo pointer, and keep state in "*cookie". */
 extern int proto_get_first_protocol(void **cookie);
 extern int proto_get_next_protocol(void **cookie);
-extern header_field_info *proto_get_first_protocol_field(int proto_id, void **cookle);
+extern header_field_info *proto_get_first_protocol_field(const int proto_id, void **cookle);
 extern header_field_info *proto_get_next_protocol_field(void **cookle);
 
 /** Given a protocol's filter_name.
@@ -1457,70 +1457,70 @@ extern int proto_get_id_by_filter_name(const gchar* filter_name);
 /** Can item # n decoding be disabled?
  @param proto_id protocol id (0-indexed)
  @return TRUE if it's a protocol, FALSE if it's not */
-extern gboolean proto_can_toggle_protocol(int proto_id);
+extern gboolean proto_can_toggle_protocol(const int proto_id);
 
 /** Get the "protocol_t" structure for the given protocol's item number.
  @param proto_id protocol id (0-indexed) */
-extern protocol_t *find_protocol_by_id(int proto_id);
+extern protocol_t *find_protocol_by_id(const int proto_id);
 
 /** Get the protocol's name for the given protocol's item number.
  @param proto_id protocol id (0-indexed)
  @return its name */
-extern const char *proto_get_protocol_name(int proto_id);
+extern const char *proto_get_protocol_name(const int proto_id);
 
 /** Get the protocol's item number, for the given protocol's "protocol_t".
  @return its proto_id */
-extern int proto_get_id(protocol_t *protocol);
+extern int proto_get_id(const protocol_t *protocol);
 
 /** Get the protocol's short name, for the given protocol's "protocol_t".
  @return its short name. */
-extern const char *proto_get_protocol_short_name(protocol_t *protocol);
+extern const char *proto_get_protocol_short_name(const protocol_t *protocol);
 
 /** Get the protocol's long name, for the given protocol's "protocol_t".
  @return its long name. */
-extern const char *proto_get_protocol_long_name(protocol_t *protocol);
+extern const char *proto_get_protocol_long_name(const protocol_t *protocol);
 
 /** Is protocol's decoding enabled ?
  @param protocol
  @return TRUE if decoding is enabled, FALSE if not */
-extern gboolean proto_is_protocol_enabled(protocol_t *protocol);
+extern gboolean proto_is_protocol_enabled(const protocol_t *protocol);
 
 /** Get a protocol's filter name by it's item number.
  @param proto_id protocol id (0-indexed)
  @return its filter name. */
-extern const char *proto_get_protocol_filter_name(int proto_id);
+extern const char *proto_get_protocol_filter_name(const int proto_id);
 
 /** Enable / Disable protocol of the given item number.
  @param proto_id protocol id (0-indexed)
  @param enabled enable / disable the protocol */
-extern void proto_set_decoding(int proto_id, gboolean enabled);
+extern void proto_set_decoding(const int proto_id, const gboolean enabled);
 
 /** Enable all protocols */
 extern void proto_enable_all(void);
 
 /** Disable disabling/enabling of protocol of the given item number.
  @param proto_id protocol id (0-indexed) */
-extern void proto_set_cant_toggle(int proto_id);
+extern void proto_set_cant_toggle(const int proto_id);
 
 /** Checks for existence any protocol or field within a tree.
  @param tree "Protocols" are assumed to be a child of the [empty] root node.
  @param id hfindex of protocol or field
  @return TRUE = found, FALSE = not found
  @todo add explanation of id parameter */
-extern gboolean proto_check_for_protocol_or_field(proto_tree* tree, int id);
+extern gboolean proto_check_for_protocol_or_field(const proto_tree* tree, const int id);
 
 /** Return GPtrArray* of field_info pointers for all hfindex that appear in
     tree. Only works with primed trees, and is fast.
  @param tree tree of interest
  @param hfindex primed hfindex
  @return GPtrArry pointer */
-extern GPtrArray* proto_get_finfo_ptr_array(proto_tree *tree, int hfindex);
+extern GPtrArray* proto_get_finfo_ptr_array(const proto_tree *tree, const int hfindex);
 
 /** Return whether we're tracking any interesting fields.
     Only works with primed trees, and is fast.
  @param tree tree of interest
  @return TRUE if we're tracking interesting fields */
-extern gboolean proto_tracking_interesting_fields(proto_tree *tree);
+extern gboolean proto_tracking_interesting_fields(const proto_tree *tree);
 
 /** Return GPtrArray* of field_info pointers for all hfindex that appear in
     tree. Works with any tree, primed or unprimed, and is slower than
@@ -1528,7 +1528,7 @@ extern gboolean proto_tracking_interesting_fields(proto_tree *tree);
  @param tree tree of interest
  @param hfidex index of field info of interest
  @return GPtrArry pointer */
-extern GPtrArray* proto_find_finfo(proto_tree *tree, int hfindex);
+extern GPtrArray* proto_find_finfo(proto_tree *tree, const int hfindex);
 
 /** Return GPtrArray* of field_info pointers containg all hfindexes that appear
     in tree.
@@ -1545,7 +1545,7 @@ extern void proto_registrar_dump_values(void);
 /** Dumps a glossary of the protocol and field registrations to STDOUT.
  * Format 1 is the original format. Format 2 includes the base (for integers)
  * and the blurb. */
-extern void proto_registrar_dump_fields(int format);
+extern void proto_registrar_dump_fields(const int format);
 
 
 
@@ -1568,7 +1568,7 @@ WS_VAR_IMPORT int           num_tree_types;
  @param hfinfo header_field
  @return the bitwidth */
 extern int
-hfinfo_bitwidth(header_field_info *hfinfo);
+hfinfo_bitwidth(const header_field_info *hfinfo);
 
 
 
@@ -1616,8 +1616,8 @@ proto_find_field_from_offset(proto_tree *tree, guint offset, tvbuff_t *tvb);
  @param little_endian big or little endian byte representation
  @return the newly created item */
 extern proto_item *
-proto_tree_add_bitmask(proto_tree *tree, tvbuff_t *tvb, guint offset,
-		int hf_hdr, gint ett, const int **fields, gboolean little_endian);
+proto_tree_add_bitmask(proto_tree *tree, tvbuff_t *tvb, const guint offset,
+		const int hf_hdr, const gint ett, const int **fields, const gboolean little_endian);
 
 /** Add a text with a subtree of bitfields.
  @param tree the tree to append this item to
@@ -1630,9 +1630,9 @@ proto_tree_add_bitmask(proto_tree *tree, tvbuff_t *tvb, guint offset,
  @param little_endian big or little endian byte representation
  @return the newly created item */
 extern proto_item *
-proto_tree_add_bitmask_text(proto_tree *tree, tvbuff_t *tvb, guint offset, guint len,
+proto_tree_add_bitmask_text(proto_tree *tree, tvbuff_t *tvb, const guint offset, const guint len,
 		const char *name, const char *fallback,
-		gint ett, const int **fields, gboolean little_endian, int flags);
+		const gint ett, const int **fields, const gboolean little_endian, const int flags);
 
 #define BMT_NO_APPEND	0x01	/**< Don't change the title at all */
 #define BMT_NO_INT	0x02	/**< Don't add integral (non-boolean) fields to title */
@@ -1649,7 +1649,7 @@ proto_tree_add_bitmask_text(proto_tree *tree, tvbuff_t *tvb, guint offset, guint
  @param little_endian big or little endian byte representation
  @return the newly created item */
 extern proto_item *
-proto_tree_add_bits_item(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian);
+proto_tree_add_bits_item(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, const gboolean little_endian);
 
 /** Add bits to a proto_tree, using the text label registered to that item.
    The item is extracted from the tvbuff handed to it.
@@ -1662,7 +1662,7 @@ proto_tree_add_bits_item(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit
  @param little_endian big or little endian byte representation
  @return the newly created item */
 extern proto_item *
-proto_tree_add_bits_ret_val(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits, guint64 *return_value, gboolean little_endian);
+proto_tree_add_bits_ret_val(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, guint64 *return_value, const gboolean little_endian);
 
 /** Add bits for a FT_UINT8, FT_UINT16, FT_UINT24 or FT_UINT32
     header field to a proto_tree, with the format generating the
@@ -1677,7 +1677,7 @@ proto_tree_add_bits_ret_val(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint
  @param ... printf like parameters
  @return the newly created item */
 extern proto_item *
-proto_tree_add_uint_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_uint_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	guint32 value, const char *format, ...) G_GNUC_PRINTF(7,8);
 
 /** Add bits for a FT_BOOLEAN header field to a proto_tree, with
@@ -1693,7 +1693,7 @@ proto_tree_add_uint_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *
  @param ... printf like parameters
  @return the newly created item */
 extern proto_item *
-proto_tree_add_boolean_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_boolean_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	guint32 value, const char *format, ...) G_GNUC_PRINTF(7,8);
 
 /** Add bits for a FT_INT8, FT_INT16, FT_INT24 or FT_INT32
@@ -1709,7 +1709,7 @@ proto_tree_add_boolean_bits_format_value(proto_tree *tree, int hf_index, tvbuff_
  @param ... printf like parameters
  @return the newly created item */
 extern proto_item *
-proto_tree_add_int_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_int_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	gint32 value, const char *format, ...) G_GNUC_PRINTF(7,8);
 
 /** Add bits for a FT_FLOAT header field to a proto_tree, with
@@ -1725,7 +1725,7 @@ proto_tree_add_int_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *t
  @param ... printf like parameters
  @return the newly created item */
 extern proto_item *
-proto_tree_add_float_bits_format_value(proto_tree *tree, int hf_index, tvbuff_t *tvb, gint bit_offset, gint no_of_bits,
+proto_tree_add_float_bits_format_value(proto_tree *tree, const int hf_index, tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits,
 	float value, const char *format, ...) G_GNUC_PRINTF(7,8);
 
 /** Check if given string is a valid field name
@@ -1741,9 +1741,9 @@ proto_check_field_name(const gchar *field_name);
  @param expr the filter expression
  @param aize the size of the string buffer */
 const gchar *
-proto_custom_set(proto_tree* tree, int field_id,
+proto_custom_set(proto_tree* tree, const int field_id,
                              gchar *result,
-                             gchar *expr, int size );
+                             gchar *expr, const int size );
 
 #ifdef __cplusplus
 }
diff --git a/epan/reassemble.c b/epan/reassemble.c
index 851c5c7572..d4aba9df24 100644
--- a/epan/reassemble.c
+++ b/epan/reassemble.c
@@ -246,7 +246,7 @@ free_all_fragments(gpointer key_arg, gpointer value, gpointer user_data _U_)
 }
 
 /* ------------------------- */
-static fragment_data *new_head(guint32 flags)
+static fragment_data *new_head(const guint32 flags)
 {
 	fragment_data *fd_head;
 	/* If head/first structure in list only holds no other data than
@@ -413,7 +413,7 @@ reassemble_init(void)
  * g_free() that buffer.
  */
 unsigned char *
-fragment_delete(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
+fragment_delete(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table)
 {
 	fragment_data *fd_head, *fd;
 	fragment_key key;
@@ -460,7 +460,7 @@ fragment_delete(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
  * matching this packet. I.e. Is there reassembly going on or not for this packet?
  */
 fragment_data *
-fragment_get(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
+fragment_get(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table)
 {
 	fragment_data *fd_head;
 	fragment_key key;
@@ -477,7 +477,7 @@ fragment_get(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
 
 /* id *must* be the frame number for this to work! */
 fragment_data *
-fragment_get_reassembled(packet_info *pinfo _U_, guint32 id, GHashTable *reassembled_table)
+fragment_get_reassembled(const guint32 id, GHashTable *reassembled_table)
 {
 	fragment_data *fd_head;
 	reassembled_key key;
@@ -491,7 +491,7 @@ fragment_get_reassembled(packet_info *pinfo _U_, guint32 id, GHashTable *reassem
 }
 
 fragment_data *
-fragment_get_reassembled_id(packet_info *pinfo, guint32 id, GHashTable *reassembled_table)
+fragment_get_reassembled_id(const packet_info *pinfo, const guint32 id, GHashTable *reassembled_table)
 {
 	fragment_data *fd_head;
 	reassembled_key key;
@@ -519,8 +519,8 @@ fragment_get_reassembled_id(packet_info *pinfo, guint32 id, GHashTable *reassemb
  * actually means we want to defragment 3 blocks, block 0, 1 and 2.
  */
 void
-fragment_set_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-			 guint32 tot_len)
+fragment_set_tot_len(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+			 const guint32 tot_len)
 {
 	fragment_data *fd_head;
 	fragment_key key;
@@ -541,7 +541,7 @@ fragment_set_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
 }
 
 guint32
-fragment_get_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
+fragment_get_tot_len(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table)
 {
 	fragment_data *fd_head;
 	fragment_key key;
@@ -570,7 +570,7 @@ fragment_get_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
 */
 
 void
-fragment_set_partial_reassembly(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
+fragment_set_partial_reassembly(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table)
 {
 	fragment_data *fd_head;
 	fragment_key key;
@@ -634,8 +634,8 @@ fragment_unhash(GHashTable *fragment_table, fragment_key *key)
  * frame number.
  */
 static void
-fragment_reassembled(fragment_data *fd_head, packet_info *pinfo,
-		 GHashTable *reassembled_table, guint32 id)
+fragment_reassembled(fragment_data *fd_head, const packet_info *pinfo,
+		 GHashTable *reassembled_table, const guint32 id)
 {
 	reassembled_key *new_key;
 	fragment_data *fd;
@@ -687,9 +687,9 @@ fragment_reassembled(fragment_data *fd_head, packet_info *pinfo,
  * are lowered when a new extension process is started.
  */
 static gboolean
-fragment_add_work(fragment_data *fd_head, tvbuff_t *tvb, int offset,
-		 packet_info *pinfo, guint32 frag_offset,
-		 guint32 frag_data_len, gboolean more_frags)
+fragment_add_work(fragment_data *fd_head, tvbuff_t *tvb, const int offset,
+		 const packet_info *pinfo, const guint32 frag_offset,
+		 const guint32 frag_data_len, const gboolean more_frags)
 {
 	fragment_data *fd;
 	fragment_data *fd_i;
@@ -914,10 +914,10 @@ fragment_add_work(fragment_data *fd_head, tvbuff_t *tvb, int offset,
 }
 
 static fragment_data *
-fragment_add_common(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
-		 GHashTable *fragment_table, guint32 frag_offset,
-		 guint32 frag_data_len, gboolean more_frags,
-		 gboolean check_already_added)
+fragment_add_common(tvbuff_t *tvb, const int offset, const packet_info *pinfo, const guint32 id,
+		 GHashTable *fragment_table, const guint32 frag_offset,
+		 const guint32 frag_data_len, const gboolean more_frags,
+		 const gboolean check_already_added)
 {
 	fragment_key key, *new_key;
 	fragment_data *fd_head;
@@ -1028,9 +1028,9 @@ fragment_add_common(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
 }
 
 fragment_data *
-fragment_add(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
-		 GHashTable *fragment_table, guint32 frag_offset,
-		 guint32 frag_data_len, gboolean more_frags)
+fragment_add(tvbuff_t *tvb, const int offset, const packet_info *pinfo, const guint32 id,
+		 GHashTable *fragment_table, const guint32 frag_offset,
+		 const guint32 frag_data_len, const gboolean more_frags)
 {
 	return fragment_add_common(tvb, offset, pinfo, id, fragment_table,
 		frag_offset, frag_data_len, more_frags, TRUE);
@@ -1041,20 +1041,20 @@ fragment_add(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
  * to the same reassembled PDU, e.g. with ONC RPC-over-TCP.
  */
 fragment_data *
-fragment_add_multiple_ok(tvbuff_t *tvb, int offset, packet_info *pinfo,
-			 guint32 id, GHashTable *fragment_table,
-			 guint32 frag_offset, guint32 frag_data_len,
-			 gboolean more_frags)
+fragment_add_multiple_ok(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+			 const guint32 id, GHashTable *fragment_table,
+			 const guint32 frag_offset, const guint32 frag_data_len,
+			 const gboolean more_frags)
 {
 	return fragment_add_common(tvb, offset, pinfo, id, fragment_table,
 		frag_offset, frag_data_len, more_frags, FALSE);
 }
 
 fragment_data *
-fragment_add_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
-		 guint32 id, GHashTable *fragment_table,
-		 GHashTable *reassembled_table, guint32 frag_offset,
-		 guint32 frag_data_len, gboolean more_frags)
+fragment_add_check(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+		 const guint32 id, GHashTable *fragment_table,
+		 GHashTable *reassembled_table, const guint32 frag_offset,
+		 const guint32 frag_data_len, const gboolean more_frags)
 {
 	reassembled_key reass_key;
 	fragment_key key, *new_key, *old_key;
@@ -1145,7 +1145,7 @@ fragment_add_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
 
 static void
 fragment_defragment_and_free (fragment_data *fd_head, fragment_data *fd,
-				  packet_info *pinfo)
+				  const packet_info *pinfo)
 {
 	fragment_data *fd_i = NULL;
 	fragment_data *last_fd = NULL;
@@ -1216,10 +1216,10 @@ fragment_defragment_and_free (fragment_data *fd_head, fragment_data *fd,
  * The bsn for the first block is 0.
  */
 static gboolean
-fragment_add_seq_work(fragment_data *fd_head, tvbuff_t *tvb, int offset,
-		 packet_info *pinfo, guint32 frag_number,
-		 guint32 frag_data_len, gboolean more_frags,
-		 guint32 flags _U_)
+fragment_add_seq_work(fragment_data *fd_head, tvbuff_t *tvb, const int offset,
+		 const packet_info *pinfo, const guint32 frag_number,
+		 const guint32 frag_data_len, const gboolean more_frags,
+		 const guint32 flags _U_)
 {
 	fragment_data *fd;
 	fragment_data *fd_i;
@@ -1451,9 +1451,9 @@ fragment_add_seq_work(fragment_data *fd_head, tvbuff_t *tvb, int offset,
  * The bsn for the first block is 0.
  */
 fragment_data *
-fragment_add_seq(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
-		 GHashTable *fragment_table, guint32 frag_number,
-		 guint32 frag_data_len, gboolean more_frags)
+fragment_add_seq(tvbuff_t *tvb, const int offset, const packet_info *pinfo, const guint32 id,
+		 GHashTable *fragment_table, const guint32 frag_number,
+		 const guint32 frag_data_len, const gboolean more_frags)
 {
 	fragment_key key;
 
@@ -1470,10 +1470,10 @@ fragment_add_seq(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
 
 
 fragment_data *
-fragment_add_dcerpc_dg(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
+fragment_add_dcerpc_dg(tvbuff_t *tvb, const int offset, const packet_info *pinfo, const guint32 id,
 					void *v_act_id,
-					GHashTable *fragment_table, guint32 frag_number,
-					guint32 frag_data_len, gboolean more_frags)
+					GHashTable *fragment_table, const guint32 frag_number,
+					const guint32 frag_data_len, const gboolean more_frags)
 {
 	e_uuid_t *act_id = (e_uuid_t *)v_act_id;
 	dcerpc_fragment_key key;
@@ -1491,11 +1491,11 @@ fragment_add_dcerpc_dg(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id
 }
 
 fragment_data *
-fragment_add_seq_key(tvbuff_t *tvb, int offset, packet_info *pinfo,
+fragment_add_seq_key(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
 					 void *key, fragment_key_copier key_copier,
 					GHashTable *fragment_table, guint32 frag_number,
-					guint32 frag_data_len, gboolean more_frags,
-					guint32 flags)
+					const guint32 frag_data_len, const gboolean more_frags,
+					const guint32 flags)
 {
 	fragment_data *fd_head;
 	fd_head = g_hash_table_lookup(fragment_table, key);
@@ -1645,11 +1645,11 @@ fragment_add_seq_key(tvbuff_t *tvb, int offset, packet_info *pinfo,
  * XXX - Should we simply return NULL for zero-length fragments?
  */
 static fragment_data *
-fragment_add_seq_check_work(tvbuff_t *tvb, int offset, packet_info *pinfo,
-		 guint32 id, GHashTable *fragment_table,
-		 GHashTable *reassembled_table, guint32 frag_number,
-		 guint32 frag_data_len, gboolean more_frags,
-		 guint32 flags)
+fragment_add_seq_check_work(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+		 const guint32 id, GHashTable *fragment_table,
+		 GHashTable *reassembled_table, const guint32 frag_number,
+		 const guint32 frag_data_len, const gboolean more_frags,
+		 const guint32 flags)
 {
 	reassembled_key reass_key;
 	fragment_key key;
@@ -1713,10 +1713,10 @@ fragment_add_seq_check_work(tvbuff_t *tvb, int offset, packet_info *pinfo,
 }
 
 fragment_data *
-fragment_add_seq_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
-		 guint32 id, GHashTable *fragment_table,
-		 GHashTable *reassembled_table, guint32 frag_number,
-		 guint32 frag_data_len, gboolean more_frags)
+fragment_add_seq_check(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+		 const guint32 id, GHashTable *fragment_table,
+		 GHashTable *reassembled_table, const guint32 frag_number,
+		 const guint32 frag_data_len, const gboolean more_frags)
 {
 	return fragment_add_seq_check_work(tvb, offset, pinfo, id,
 		fragment_table, reassembled_table, frag_number, frag_data_len,
@@ -1746,8 +1746,8 @@ fragment_add_seq_next(tvbuff_t *tvb, int offset, packet_info *pinfo,
 }
 
 void
-fragment_start_seq_check(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-			 guint32 tot_len)
+fragment_start_seq_check(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+			 const guint32 tot_len)
 {
 	fragment_key key, *new_key;
 	fragment_data *fd_head;
@@ -1790,7 +1790,7 @@ fragment_start_seq_check(packet_info *pinfo, guint32 id, GHashTable *fragment_ta
 }
 
 fragment_data *
-fragment_end_seq_next(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
+fragment_end_seq_next(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
 			  GHashTable *reassembled_table)
 {
 	reassembled_key reass_key;
@@ -1869,7 +1869,7 @@ fragment_end_seq_next(packet_info *pinfo, guint32 id, GHashTable *fragment_table
  * just put a "reassembled in" item into the protocol tree.
  */
 tvbuff_t *
-process_reassembled_data(tvbuff_t *tvb, int offset, packet_info *pinfo,
+process_reassembled_data(tvbuff_t *tvb, const int offset, packet_info *pinfo,
 	const char *name, fragment_data *fd_head, const fragment_items *fit,
 	gboolean *update_col_infop, proto_tree *tree)
 {
@@ -1953,8 +1953,8 @@ process_reassembled_data(tvbuff_t *tvb, int offset, packet_info *pinfo,
  * it in the top-level item for that subtree.
  */
 static void
-show_fragment(fragment_data *fd, int offset, const fragment_items *fit,
-	proto_tree *ft, proto_item *fi, gboolean first_frag, tvbuff_t *tvb)
+show_fragment(fragment_data *fd, const int offset, const fragment_items *fit,
+	proto_tree *ft, proto_item *fi, const gboolean first_frag, tvbuff_t *tvb)
 {
 	proto_item *fei=NULL;
 	int hf;
diff --git a/epan/reassemble.h b/epan/reassemble.h
index 60232c4b88..b67a86b294 100644
--- a/epan/reassemble.h
+++ b/epan/reassemble.h
@@ -132,12 +132,12 @@ void reassemble_init(void);
  * Returns a pointer to the head of the fragment data list if we have all the
  * fragments, NULL otherwise.
  */
-extern fragment_data *fragment_add(tvbuff_t *tvb, int offset, packet_info *pinfo,
-    guint32 id, GHashTable *fragment_table, guint32 frag_offset,
-    guint32 frag_data_len, gboolean more_frags);
-extern fragment_data *fragment_add_multiple_ok(tvbuff_t *tvb, int offset,
-    packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-    guint32 frag_offset, guint32 frag_data_len, gboolean more_frags);
+extern fragment_data *fragment_add(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+    const guint32 id, GHashTable *fragment_table, const guint32 frag_offset,
+    guint32 const frag_data_len, const gboolean more_frags);
+extern fragment_data *fragment_add_multiple_ok(tvbuff_t *tvb, const int offset,
+    const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+    const guint32 frag_offset, const guint32 frag_data_len, const gboolean more_frags);
 
 /*
  * This routine extends fragment_add to use a "reassembled_table".
@@ -147,10 +147,10 @@ extern fragment_data *fragment_add_multiple_ok(tvbuff_t *tvb, int offset,
  * to the table of reassembled fragments, and return a pointer to the
  * head of the fragment list.
  */
-extern fragment_data *fragment_add_check(tvbuff_t *tvb, int offset,
-    packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-    GHashTable *reassembled_table, guint32 frag_offset,
-    guint32 frag_data_len, gboolean more_frags);
+extern fragment_data *fragment_add_check(tvbuff_t *tvb, const int offset,
+    const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+    GHashTable *reassembled_table, const guint32 frag_offset,
+    const guint32 frag_data_len, const gboolean more_frags);
 
 /* same as fragment_add() but this one assumes frag_number is a block
    sequence number. note that frag_number is 0 for the first fragment. */
@@ -186,24 +186,24 @@ extern fragment_data *fragment_add_check(tvbuff_t *tvb, int offset,
  * inserting a new entry to the hash.
  */
 extern fragment_data *
-fragment_add_seq_key(tvbuff_t *tvb, int offset, packet_info *pinfo,
+fragment_add_seq_key(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
                      void *key, fragment_key_copier key_copier,
                      GHashTable *fragment_table, guint32 frag_number,
-                     guint32 frag_data_len, gboolean more_frags,
-                     guint32 flags);
+                     const guint32 frag_data_len, const gboolean more_frags,
+                     const guint32 flags);
 
 /* a wrapper for fragment_add_seq_key - uses a key of source, dest and id */
-extern fragment_data *fragment_add_seq(tvbuff_t *tvb, int offset, packet_info *pinfo,
-    guint32 id, GHashTable *fragment_table, guint32 frag_number,
-    guint32 frag_data_len, gboolean more_frags);
+extern fragment_data *fragment_add_seq(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+    const guint32 id, GHashTable *fragment_table, const guint32 frag_number,
+    const guint32 frag_data_len, const gboolean more_frags);
 
 /* another wrapper for fragment_add_seq_key - uses a key of source, dest, id
  * and act_id */
 extern fragment_data *
-fragment_add_dcerpc_dg(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
+fragment_add_dcerpc_dg(tvbuff_t *tvb, const int offset, const packet_info *pinfo, const guint32 id,
 	void *act_id,
-	GHashTable *fragment_table, guint32 frag_number,
-	guint32 frag_data_len, gboolean more_frags);
+	GHashTable *fragment_table, const guint32 frag_number,
+	const guint32 frag_data_len, const gboolean more_frags);
 
 /*
  * These routines extend fragment_add_seq_key to use a "reassembled_table".
@@ -214,10 +214,10 @@ fragment_add_dcerpc_dg(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id
  * head of the fragment list.
  */
 extern fragment_data *
-fragment_add_seq_check(tvbuff_t *tvb, int offset, packet_info *pinfo,
-	     guint32 id, GHashTable *fragment_table,
-	     GHashTable *reassembled_table, guint32 frag_number,
-	     guint32 frag_data_len, gboolean more_frags);
+fragment_add_seq_check(tvbuff_t *tvb, const int offset, const packet_info *pinfo,
+	     const guint32 id, GHashTable *fragment_table,
+	     GHashTable *reassembled_table, const guint32 frag_number,
+	     const guint32 frag_data_len, const gboolean more_frags);
 
 extern fragment_data *
 fragment_add_seq_802_11(tvbuff_t *tvb, int offset, packet_info *pinfo,
@@ -231,11 +231,11 @@ fragment_add_seq_next(tvbuff_t *tvb, int offset, packet_info *pinfo, guint32 id,
 	     guint32 frag_data_len, gboolean more_frags);
 
 extern void
-fragment_start_seq_check(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-			 guint32 tot_len);
+fragment_start_seq_check(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+			 const guint32 tot_len);
 
 extern fragment_data *
-fragment_end_seq_next(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
+fragment_end_seq_next(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
 		      GHashTable *reassembled_table);
 /* to specify how much to reassemble, for fragmentation where last fragment can not be
  * identified by flags or such.
@@ -245,12 +245,12 @@ fragment_end_seq_next(packet_info *pinfo, guint32 id, GHashTable *fragment_table
  *
  */
 extern void
-fragment_set_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table,
-		     guint32 tot_len);
+fragment_set_tot_len(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table,
+		     const guint32 tot_len);
 
 /* to resad whatever totlen previously set */
 extern guint32
-fragment_get_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
+fragment_get_tot_len(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table);
 
 /*
  * This function will set the partial reassembly flag(FD_PARTIAL_REASSEMBLY) for a fh.
@@ -261,21 +261,21 @@ fragment_get_tot_len(packet_info *pinfo, guint32 id, GHashTable *fragment_table)
  * and if FD_DEFRAGMENTED is set, the reassembly process will be continued.
  */
 extern void
-fragment_set_partial_reassembly(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
+fragment_set_partial_reassembly(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table);
 
 /* This function is used to check if there is partial or completed reassembly state
  * matching this packet. I.e. Are there reassembly going on or not for this packet?
  */
 extern fragment_data *
-fragment_get(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
+fragment_get(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table);
 
 /* The same for the reassemble table */
 /* id *must* be the frame number for this to work! */
 extern fragment_data *
-fragment_get_reassembled(packet_info *pinfo, guint32 id, GHashTable *reassembled_table);
+fragment_get_reassembled(const guint32 id, GHashTable *reassembled_table);
 
 extern fragment_data *
-fragment_get_reassembled_id(packet_info *pinfo, guint32 id, GHashTable *reassembled_table);
+fragment_get_reassembled_id(const packet_info *pinfo, const guint32 id, GHashTable *reassembled_table);
 
 /* This will free up all resources and delete reassembly state for this PDU.
  * Except if the PDU is completely reassembled, then it would NOT deallocate the
@@ -286,7 +286,7 @@ fragment_get_reassembled_id(packet_info *pinfo, guint32 id, GHashTable *reassemb
  * g_free() that buffer.
  */
 extern unsigned char *
-fragment_delete(packet_info *pinfo, guint32 id, GHashTable *fragment_table);
+fragment_delete(const packet_info *pinfo, const guint32 id, GHashTable *fragment_table);
 
 /* hf_fragment, hf_fragment_error, and hf_reassembled_in should be
    FT_FRAMENUM, the others should be FT_BOOLEAN
@@ -309,7 +309,7 @@ typedef struct _fragment_items {
 } fragment_items;
 
 extern tvbuff_t *
-process_reassembled_data(tvbuff_t *tvb, int offset, packet_info *pinfo,
+process_reassembled_data(tvbuff_t *tvb, const int offset, packet_info *pinfo,
     const char *name, fragment_data *fd_head, const fragment_items *fit,
     gboolean *update_col_infop, proto_tree *tree);
 
diff --git a/epan/to_str.c b/epan/to_str.c
index ee1930be0b..f25ff992ad 100644
--- a/epan/to_str.c
+++ b/epan/to_str.c
@@ -118,7 +118,7 @@ bytes_to_hexstr_punct(char *out, const guint8 *ad, guint32 len, char punct) {
  * the resulting string is (len-1) bytes shorter)
  */
 gchar *
-bytestring_to_str(const guint8 *ad, guint32 len, char punct) {
+bytestring_to_str(const guint8 *ad, const guint32 len, const char punct) {
   gchar *buf;
   size_t       buflen;
 
@@ -203,7 +203,7 @@ bytes_to_str_punct(const guint8 *bd, int bd_len, gchar punct) {
 }
 
 static int
-guint32_to_str_buf_len(guint32 u) {
+guint32_to_str_buf_len(const guint32 u) {
     if (u >= 1000000000)return 10;
     if (u >= 100000000) return 9;
     if (u >= 10000000)	return 8;
@@ -280,7 +280,7 @@ guint32_to_str_buf(guint32 u, gchar *buf, int buf_len) {
 }
 
 gchar *
-guint32_to_str(guint32 u) {
+guint32_to_str(const guint32 u) {
   int str_len = 16; /* guint32_to_str_buf_len(u)+1; */
 
   gchar *bp = ep_alloc(str_len);
@@ -309,7 +309,7 @@ guint32_to_str(guint32 u) {
  * If time is negative, add a '-' to all non-null components.
  */
 static void
-time_secs_to_str_buf(gint32 time_val, guint32 frac, gboolean is_nsecs,
+time_secs_to_str_buf(gint32 time_val, const guint32 frac, const gboolean is_nsecs,
 			   emem_strbuf_t *buf)
 {
   int hours, mins, secs;
@@ -360,7 +360,7 @@ time_secs_to_str_buf(gint32 time_val, guint32 frac, gboolean is_nsecs,
 }
 
 gchar *
-time_secs_to_str(gint32 time_val)
+time_secs_to_str(const gint32 time_val)
 {
   emem_strbuf_t *buf;
 
@@ -376,7 +376,7 @@ time_secs_to_str(gint32 time_val)
 }
 
 static void
-time_secs_to_str_buf_unsigned(guint32 time_val, guint32 frac, gboolean is_nsecs,
+time_secs_to_str_buf_unsigned(guint32 time_val, const guint32 frac, const gboolean is_nsecs,
 			 emem_strbuf_t *buf)
 {
   int hours, mins, secs;
@@ -413,7 +413,7 @@ time_secs_to_str_buf_unsigned(guint32 time_val, guint32 frac, gboolean is_nsecs,
 }
 
 gchar *
-time_secs_to_str_unsigned(guint32 time_val)
+time_secs_to_str_unsigned(const guint32 time_val)
 {
   emem_strbuf_t *buf;
 
@@ -473,7 +473,7 @@ static const char *mon_names[12] = {
 };
 
 gchar *
-abs_time_to_str(nstime_t *abs_time, absolute_time_display_e fmt)
+abs_time_to_str(const nstime_t *abs_time, const absolute_time_display_e fmt)
 {
         struct tm *tmp = NULL;
         const char *zonename = "???";
@@ -543,7 +543,7 @@ abs_time_to_str(nstime_t *abs_time, absolute_time_display_e fmt)
 }
 
 gchar *
-abs_time_secs_to_str(time_t abs_time, absolute_time_display_e fmt)
+abs_time_secs_to_str(const time_t abs_time, const absolute_time_display_e fmt)
 {
         struct tm *tmp = NULL;
         const char *zonename = "???";
@@ -611,8 +611,8 @@ abs_time_secs_to_str(time_t abs_time, absolute_time_display_e fmt)
 }
 
 void
-display_signed_time(gchar *buf, int buflen, gint32 sec, gint32 frac,
-    to_str_time_res_t units)
+display_signed_time(gchar *buf, int buflen, const gint32 sec, gint32 frac,
+    const to_str_time_res_t units)
 {
 	/* If the fractional part of the time stamp is negative,
 	   print its absolute value and, if the seconds part isn't
@@ -659,8 +659,8 @@ display_signed_time(gchar *buf, int buflen, gint32 sec, gint32 frac,
 
 
 void
-display_epoch_time(gchar *buf, int buflen, time_t sec, gint32 frac,
-    to_str_time_res_t units)
+display_epoch_time(gchar *buf, int buflen, const time_t sec, gint32 frac,
+    const to_str_time_res_t units)
 {
 	double elapsed_secs;
 
@@ -715,7 +715,7 @@ display_epoch_time(gchar *buf, int buflen, time_t sec, gint32 frac,
  * Display a relative time as days/hours/minutes/seconds.
  */
 gchar *
-rel_time_to_str(nstime_t *rel_time)
+rel_time_to_str(const nstime_t *rel_time)
 {
 	emem_strbuf_t *buf;
 	const char *sign;
@@ -757,7 +757,7 @@ rel_time_to_str(nstime_t *rel_time)
  * Display a relative time as seconds.
  */
 gchar *
-rel_time_to_secs_str(nstime_t *rel_time)
+rel_time_to_secs_str(const nstime_t *rel_time)
 {
         gchar *buf;
 
@@ -775,7 +775,7 @@ rel_time_to_secs_str(nstime_t *rel_time)
  */
 
 char *
-decode_bits_in_field(gint bit_offset, gint no_of_bits, guint64 value)
+decode_bits_in_field(const gint bit_offset, const gint no_of_bits, const guint64 value)
 {
 	guint64 mask = 0,tmp;
 	char *str;
@@ -826,7 +826,7 @@ decode_bits_in_field(gint bit_offset, gint no_of_bits, guint64 value)
    Return a pointer to the character after that string. */
 /*XXX this needs a buf_len check */
 char *
-other_decode_bitfield_value(char *buf, guint32 val, guint32 mask, int width)
+other_decode_bitfield_value(char *buf, const guint32 val, const guint32 mask, const int width)
 {
   int i;
   guint32 bit;
@@ -858,7 +858,7 @@ other_decode_bitfield_value(char *buf, guint32 val, guint32 mask, int width)
 }
 
 char *
-decode_bitfield_value(char *buf, guint32 val, guint32 mask, int width)
+decode_bitfield_value(char *buf, const guint32 val, const guint32 mask, const int width)
 {
   char *p;
 
@@ -871,7 +871,7 @@ decode_bitfield_value(char *buf, guint32 val, guint32 mask, int width)
 /* Generate a string describing a Boolean bitfield (a one-bit field that
    says something is either true of false). */
 const char *
-decode_boolean_bitfield(guint32 val, guint32 mask, int width,
+decode_boolean_bitfield(const guint32 val, const guint32 mask, const int width,
     const char *truedesc, const char *falsedesc)
 {
   char *buf;
@@ -889,7 +889,7 @@ decode_boolean_bitfield(guint32 val, guint32 mask, int width,
 /* Generate a string describing a numeric bitfield (an N-bit field whose
    value is just a number). */
 const char *
-decode_numeric_bitfield(guint32 val, guint32 mask, int width,
+decode_numeric_bitfield(const guint32 val, const guint32 mask, const int width,
     const char *fmt)
 {
   char *buf;
@@ -912,7 +912,7 @@ decode_numeric_bitfield(guint32 val, guint32 mask, int width,
  XXX update the ep_address_to_str stuff to use this function.
 */
 void
-ip_to_str_buf(const guint8 *ad, gchar *buf, int buf_len)
+ip_to_str_buf(const guint8 *ad, gchar *buf, const int buf_len)
 {
 	register gchar const *p;
 	register gchar *b=buf;
diff --git a/epan/to_str.h b/epan/to_str.h
index 7f139f46c1..ab42c03ade 100644
--- a/epan/to_str.h
+++ b/epan/to_str.h
@@ -47,43 +47,43 @@ struct     e_in6_addr;
 extern gchar*	ep_address_to_str(const address *);
 extern gchar*	se_address_to_str(const address *);
 extern void     address_to_str_buf(const address *addr, gchar *buf, int buf_len);
-extern gchar*   bytestring_to_str(const guint8 *, guint32, char);
+extern gchar*   bytestring_to_str(const guint8 *, const guint32, const char);
 extern gchar*	ether_to_str(const guint8 *);
 extern const gchar*	ip_to_str(const guint8 *);
-extern void	ip_to_str_buf(const guint8 *ad, gchar *buf, int buf_len);
+extern void	ip_to_str_buf(const guint8 *ad, gchar *buf, const int buf_len);
 extern gchar*	fc_to_str(const guint8 *);
 extern gchar*	fcwwn_to_str (const guint8 *);
 extern gchar*	ip6_to_str(const struct e_in6_addr *);
 extern void	ip6_to_str_buf(const struct e_in6_addr *, gchar *);
-extern gchar*	ipx_addr_to_str(guint32, const guint8 *);
+extern gchar*	ipx_addr_to_str(const guint32, const guint8 *);
 extern gchar*	ipxnet_to_string(const guint8 *ad);
-extern gchar*	ipxnet_to_str_punct(const guint32 ad, char punct);
+extern gchar*	ipxnet_to_str_punct(const guint32 ad, const char punct);
 extern gchar*	vines_addr_to_str(const guint8 *addrp);
-extern gchar*	time_secs_to_str(gint32);
-extern gchar*	time_secs_to_str_unsigned(guint32);
-extern gchar*	time_msecs_to_str(gint32);
-extern gchar*	abs_time_to_str(nstime_t*, absolute_time_display_e fmt);
-extern gchar*	abs_time_secs_to_str(time_t, absolute_time_display_e fmt);
-extern void	display_signed_time(gchar *, int, gint32, gint32, to_str_time_res_t);
-extern void	display_epoch_time(gchar *, int, time_t,  gint32, to_str_time_res_t);
+extern gchar*	time_secs_to_str(const gint32 time_val);
+extern gchar*	time_secs_to_str_unsigned(const guint32);
+extern gchar*	time_msecs_to_str(gint32 time_val);
+extern gchar*	abs_time_to_str(const nstime_t*, const absolute_time_display_e fmt);
+extern gchar*	abs_time_secs_to_str(const time_t, const absolute_time_display_e fmt);
+extern void	display_signed_time(gchar *, int, const gint32, gint32, const to_str_time_res_t);
+extern void	display_epoch_time(gchar *, int, const time_t,  gint32, const to_str_time_res_t);
 
-extern gchar*	guint32_to_str(guint32 u);
+extern gchar*	guint32_to_str(const guint32 u);
 extern void	guint32_to_str_buf(guint32 u, gchar *buf, int buf_len);
 
-extern gchar*	rel_time_to_str(nstime_t*);
-extern gchar*	rel_time_to_secs_str(nstime_t*);
+extern gchar*	rel_time_to_str(const nstime_t*);
+extern gchar*	rel_time_to_secs_str(const nstime_t*);
 extern gchar*	guid_to_str(const e_guid_t*);
 extern gchar*	guid_to_str_buf(const e_guid_t*, gchar*, int);
 
-extern char *decode_bits_in_field(gint bit_offset, gint no_of_bits, guint64 value);
+extern char *decode_bits_in_field(const gint bit_offset, const gint no_of_bits, const guint64 value);
 
-extern char	*other_decode_bitfield_value(char *buf, guint32 val, guint32 mask,
-    int width);
-extern char	*decode_bitfield_value(char *buf, guint32 val, guint32 mask,
-    int width);
-extern const char *decode_boolean_bitfield(guint32 val, guint32 mask, int width,
+extern char	*other_decode_bitfield_value(char *buf, const guint32 val, const guint32 mask,
+    const int width);
+extern char	*decode_bitfield_value(char *buf, const guint32 val, const guint32 mask,
+    const int width);
+extern const char *decode_boolean_bitfield(const guint32 val, const guint32 mask, const int width,
   const char *truedesc, const char *falsedesc);
-extern const char *decode_numeric_bitfield(guint32 val, guint32 mask, int width,
+extern const char *decode_numeric_bitfield(const guint32 val, const guint32 mask, const int width,
   const char *fmt);
 
 #endif /* __TO_STR_H__  */
diff --git a/epan/tvbparse.c b/epan/tvbparse.c
index 34d78298e2..4525b0e814 100644
--- a/epan/tvbparse.c
+++ b/epan/tvbparse.c
@@ -104,7 +104,7 @@ static tvbparse_elem_t* new_tok(tvbparse_t* tt,
 	return tok;
 }
 
-static int ignore_fcn(tvbparse_t* tt,int offset) {
+static int ignore_fcn(tvbparse_t* tt, int offset) {
     int len = 0;
     int consumed;
     tvbparse_elem_t* ignored = NULL;
@@ -132,7 +132,7 @@ static int ignore_fcn(tvbparse_t* tt,int offset) {
 }
 
 
-static int cond_char (tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_char (tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     gchar c,t;
     guint i;
 
@@ -158,7 +158,7 @@ static int cond_char (tvbparse_t* tt, int offset, const tvbparse_wanted_t * want
     return -1;
 }
 
-tvbparse_wanted_t* tvbparse_char(int id,
+tvbparse_wanted_t* tvbparse_char(const int id,
                                  const gchar* chr,
                                  const void* data,
                                  tvbparse_action_t before_cb,
@@ -217,9 +217,9 @@ next_char:
     }
 }
 
-tvbparse_wanted_t* tvbparse_chars(int id,
-								  guint min_len,
-								  guint max_len,
+tvbparse_wanted_t* tvbparse_chars(const int id,
+								  const guint min_len,
+								  const guint max_len,
 								  const gchar* chr,
 								  const void* data,
 								  tvbparse_action_t before_cb,
@@ -239,7 +239,7 @@ tvbparse_wanted_t* tvbparse_chars(int id,
 }
 
 
-static int cond_not_char(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_not_char(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     gchar c, t;
     guint i;
     gboolean not_matched = FALSE;
@@ -271,7 +271,7 @@ static int cond_not_char(tvbparse_t* tt, int offset, const tvbparse_wanted_t * w
     }
 }
 
-tvbparse_wanted_t* tvbparse_not_char(int id,
+tvbparse_wanted_t* tvbparse_not_char(const int id,
                                      const gchar* chr,
                                      const void* data,
                                      tvbparse_action_t before_cb,
@@ -331,9 +331,9 @@ end_not_chars:
     }
 }
 
-tvbparse_wanted_t* tvbparse_not_chars(int id,
-									  guint min_len,
-									  guint max_len,
+tvbparse_wanted_t* tvbparse_not_chars(const int id,
+									  const guint min_len,
+									  const guint max_len,
 									  const gchar* chr,
 									  const void* data,
 									  tvbparse_action_t before_cb,
@@ -354,7 +354,7 @@ tvbparse_wanted_t* tvbparse_not_chars(int id,
 }
 
 
-static int cond_string(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_string(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     int len = wanted->len;
 #ifdef TVBPARSE_DEBUG
     if (TVBPARSE_DEBUG & TVBPARSE_DEBUG_STRING) g_warning("cond_string: control='%s'",wanted->control.str);
@@ -374,7 +374,7 @@ static int cond_string(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wan
     }
 }
 
-tvbparse_wanted_t* tvbparse_string(int id,
+tvbparse_wanted_t* tvbparse_string(const int id,
 								   const gchar* str,
 								   const void* data,
 								   tvbparse_action_t before_cb,
@@ -392,7 +392,7 @@ tvbparse_wanted_t* tvbparse_string(int id,
 	return w;
 }
 
-static int cond_casestring(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_casestring(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     int len = wanted->len;
 #ifdef TVBPARSE_DEBUG
     if (TVBPARSE_DEBUG & TVBPARSE_DEBUG_CASESTRING) g_warning("cond_casestring: control='%s'",wanted->control.str);
@@ -413,7 +413,7 @@ static int cond_casestring(tvbparse_t* tt, int offset, const tvbparse_wanted_t *
     }
 }
 
-tvbparse_wanted_t* tvbparse_casestring(int id,
+tvbparse_wanted_t* tvbparse_casestring(const int id,
                                        const gchar* str,
                                        const void* data,
                                        tvbparse_action_t before_cb,
@@ -431,7 +431,7 @@ tvbparse_wanted_t* tvbparse_casestring(int id,
 	return w;
 }
 
-static int cond_one_of(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_one_of(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     guint i;
 #ifdef TVBPARSE_DEBUG
     if (TVBPARSE_DEBUG & TVBPARSE_DEBUG_ONEOF) g_warning("cond_one_of: START");
@@ -463,7 +463,7 @@ static int cond_one_of(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wan
     return -1;
 }
 
-tvbparse_wanted_t* tvbparse_set_oneof(int id,
+tvbparse_wanted_t* tvbparse_set_oneof(const int id,
                                       const void* data, 
                                       tvbparse_action_t before_cb,
                                       tvbparse_action_t after_cb,
@@ -490,7 +490,7 @@ tvbparse_wanted_t* tvbparse_set_oneof(int id,
 	return w;
 }
 
-static int cond_hash(tvbparse_t* tt, int offset, const tvbparse_wanted_t* wanted, tvbparse_elem_t** tok) {
+static int cond_hash(tvbparse_t* tt, const int offset, const tvbparse_wanted_t* wanted, tvbparse_elem_t** tok) {
     int key_len;
     gchar* key = NULL;
     tvbparse_elem_t* key_elem = NULL;
@@ -541,7 +541,7 @@ static int cond_hash(tvbparse_t* tt, int offset, const tvbparse_wanted_t* wanted
     return tot_len;
 }
 
-tvbparse_wanted_t* tvbparse_hashed(int id,
+tvbparse_wanted_t* tvbparse_hashed(const int id,
                                    const void* data, 
                                    tvbparse_action_t before_cb,
                                    tvbparse_action_t after_cb,
@@ -639,7 +639,7 @@ static int cond_seq(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted
 }
 
 
-tvbparse_wanted_t* tvbparse_set_seq(int id,
+tvbparse_wanted_t* tvbparse_set_seq(const int id,
                                     const void* data,
                                     tvbparse_action_t before_cb,
                                     tvbparse_action_t after_cb,
@@ -726,9 +726,9 @@ static int cond_some(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wante
     return offset - start;
 }
 
-tvbparse_wanted_t* tvbparse_some(int id,
-								 guint from,
-								 guint to,
+tvbparse_wanted_t* tvbparse_some(const int id,
+								 const guint from,
+								 const guint to,
 								 const void* data,
 								 tvbparse_action_t before_cb,
 								 tvbparse_action_t after_cb,
@@ -751,7 +751,7 @@ tvbparse_wanted_t* tvbparse_some(int id,
 }
 
 
-static int cond_until(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_until(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     tvbparse_elem_t* new = NULL;
     int len = 0;
     int target_offset = offset;
@@ -805,7 +805,7 @@ static int cond_until(tvbparse_t* tt, int offset, const tvbparse_wanted_t * want
     }
 }
 
-tvbparse_wanted_t* tvbparse_until(int id,
+tvbparse_wanted_t* tvbparse_until(const int id,
                                   const void* data,
                                   tvbparse_action_t before_cb,
                                   tvbparse_action_t after_cb,
@@ -824,7 +824,7 @@ tvbparse_wanted_t* tvbparse_until(int id,
 	return w;
 }
 
-static int cond_handle(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
+static int cond_handle(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted, tvbparse_elem_t** tok) {
     tvbparse_wanted_t* w = *(wanted->control.handle);
     int len = w->condition(tt, offset, w,  tok);
 
@@ -844,7 +844,7 @@ tvbparse_wanted_t* tvbparse_handle(tvbparse_wanted_t** handle) {
 	return w;
 }
 
-static int cond_end(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted _U_, tvbparse_elem_t** tok) {
+static int cond_end(tvbparse_t* tt, const int offset, const tvbparse_wanted_t * wanted _U_, tvbparse_elem_t** tok) {
     if (offset == tt->end_offset) {
         *tok = new_tok(tt,wanted->id,offset,0,wanted);
         return 0;
@@ -853,7 +853,7 @@ static int cond_end(tvbparse_t* tt, int offset, const tvbparse_wanted_t * wanted
     }
 }
 
-tvbparse_wanted_t* tvbparse_end_of_buffer(int id,
+tvbparse_wanted_t* tvbparse_end_of_buffer(const int id,
                                const void* data,
                                tvbparse_action_t before_cb,
                                tvbparse_action_t after_cb) {
@@ -1156,12 +1156,12 @@ tvbparse_wanted_t* tvbparse_ft_numcmp(int id,
 #endif
 
 
-tvbparse_wanted_t* tvbparse_quoted(int id,
+tvbparse_wanted_t* tvbparse_quoted(const int id,
 								   const void* data,
 								   tvbparse_action_t before_cb,
 								   tvbparse_action_t after_cb,
-								   char quote,
-								   char esc) {
+								   const char quote,
+								   const char esc) {
 	
 	gchar* esc_quot = g_strdup_printf("%c%c",esc,quote);
 	gchar* quot = g_strdup_printf("%c",quote);
@@ -1193,7 +1193,7 @@ void tvbparse_shrink_token_cb(void* tvbparse_data _U_,
 }
 
 tvbparse_t* tvbparse_init(tvbuff_t* tvb,
-						  int offset,
+						  const int offset,
 						  int len,
 						  void* data,
 						  const tvbparse_wanted_t* ignore) {
@@ -1214,7 +1214,7 @@ tvbparse_t* tvbparse_init(tvbuff_t* tvb,
 }
 
 gboolean tvbparse_reset(tvbparse_t* tt,
-						int offset,
+						const int offset,
 						int len) {
 	
 #ifdef TVBPARSE_DEBUG
diff --git a/epan/tvbparse.h b/epan/tvbparse.h
index 2a971fa946..911367484f 100644
--- a/epan/tvbparse.h
+++ b/epan/tvbparse.h
@@ -89,7 +89,7 @@ typedef struct _tvbparse_t tvbparse_t;
 typedef void (*tvbparse_action_t)(void* tvbparse_data, const void* wanted_data, struct _tvbparse_elem_t* elem);
 
 typedef int (*tvbparse_condition_t)
-(tvbparse_t*, int,
+(tvbparse_t*, const int,
  const tvbparse_wanted_t*, 
  tvbparse_elem_t**);
 
@@ -192,7 +192,7 @@ struct _tvbparse_elem_t {
  * When looked for it returns a simple element one character long if the char
  * at the current offset matches one of the the needles.
  */
-tvbparse_wanted_t* tvbparse_char(int id,
+tvbparse_wanted_t* tvbparse_char(const int id,
 								 const gchar* needles,
 								 const void* private_data,
 								 tvbparse_action_t before_cb,
@@ -204,7 +204,7 @@ tvbparse_wanted_t* tvbparse_char(int id,
  * When looked for it returns a simple element one character long if the char
  * at the current offset does not match one of the the needles.
  */
-tvbparse_wanted_t* tvbparse_not_char(int id,
+tvbparse_wanted_t* tvbparse_not_char(const int id,
 									 const gchar* needle,
 									 const void* private_data,
 									 tvbparse_action_t before_cb,
@@ -218,9 +218,9 @@ tvbparse_wanted_t* tvbparse_not_char(int id,
  * An element will be returned if at least min_len chars are given (1 if it's 0) 
  * It will get at most max_len chars or as much as it can if max_len is 0.
  */
-tvbparse_wanted_t* tvbparse_chars(int id,
-								  guint min_len,
-								  guint max_len,
+tvbparse_wanted_t* tvbparse_chars(const int id,
+								  const guint min_len,
+								  const guint max_len,
 								  const gchar* needles,
 								  const void* private_data,
 								  tvbparse_action_t before_cb,
@@ -235,9 +235,9 @@ tvbparse_wanted_t* tvbparse_chars(int id,
  * An element will be returned if at least min_len chars are given (1 if it's 0) 
  * It will get at most max_len chars or as much as it can if max_len is 0.
  */
-tvbparse_wanted_t* tvbparse_not_chars(int id,
-									  guint min_len,
-									  guint max_len,
+tvbparse_wanted_t* tvbparse_not_chars(const int id,
+									  const guint min_len,
+									  const guint max_len,
 									  const gchar* needles,
 									  const void* private_data,
 									  tvbparse_action_t before_cb,
@@ -249,7 +249,7 @@ tvbparse_wanted_t* tvbparse_not_chars(int id,
  * When looked for it returns a simple element if we have the given string at
  * the current offset 
  */
-tvbparse_wanted_t* tvbparse_string(int id,
+tvbparse_wanted_t* tvbparse_string(const int id,
 								   const gchar* string,
 								   const void* private_data,
 								   tvbparse_action_t before_cb,
@@ -261,7 +261,7 @@ tvbparse_wanted_t* tvbparse_string(int id,
  * When looked for it returns a simple element if we have a matching string at
  * the current offset 
  */
-tvbparse_wanted_t* tvbparse_casestring(int id,
+tvbparse_wanted_t* tvbparse_casestring(const int id,
 									   const gchar* str,
 									   const void* data,
 									   tvbparse_action_t before_cb,
@@ -283,7 +283,7 @@ tvbparse_wanted_t* tvbparse_casestring(int id,
  * op_mode values determine how the terminating element and the current offset
  * of the parser are handled 
  */
-tvbparse_wanted_t* tvbparse_until(int id,
+tvbparse_wanted_t* tvbparse_until(const int id,
 								  const void* private_data,
 								  tvbparse_action_t before_cb,
 								  tvbparse_action_t after_cb,
@@ -299,7 +299,7 @@ tvbparse_wanted_t* tvbparse_until(int id,
  * The list of candidates is terminated with a NULL
  *
  */
-tvbparse_wanted_t* tvbparse_set_oneof(int id,
+tvbparse_wanted_t* tvbparse_set_oneof(const int id,
 									  const void* private_data,
 									  tvbparse_action_t before_cb,
 									  tvbparse_action_t after_cb,
@@ -309,7 +309,7 @@ tvbparse_wanted_t* tvbparse_set_oneof(int id,
  * hashed
  */
 
-tvbparse_wanted_t* tvbparse_hashed(int id,
+tvbparse_wanted_t* tvbparse_hashed(const int id,
                                    const void* data, 
                                    tvbparse_action_t before_cb,
                                    tvbparse_action_t after_cb,
@@ -329,7 +329,7 @@ void tvbparse_hashed_add(tvbparse_wanted_t* w, ...);
  * The list of candidates is terminated with a NULL.
  *
  */
-tvbparse_wanted_t* tvbparse_set_seq(int id,
+tvbparse_wanted_t* tvbparse_set_seq(const int id,
 									const void* private_data,
 									tvbparse_action_t before_cb,
 									tvbparse_action_t after_cb,
@@ -342,9 +342,9 @@ tvbparse_wanted_t* tvbparse_set_seq(int id,
  * a composed element is returned.
  *
  */
-tvbparse_wanted_t* tvbparse_some(int id,
-								 guint min,
-								 guint max,
+tvbparse_wanted_t* tvbparse_some(const int id,
+								 const guint min,
+								 const guint max,
 								 const void* private_data,
 								 tvbparse_action_t before_cb,
 								 tvbparse_action_t after_cb,
@@ -403,12 +403,12 @@ tvbparse_wanted_t* tvbparse_ft_numcmp(int id,
  *
  *  C strings are matched with tvbparse_quoted(-1,NULL,NULL,NULL,"\"","\\")
  */
-tvbparse_wanted_t* tvbparse_quoted(int id,
+tvbparse_wanted_t* tvbparse_quoted(const int id,
 								   const void* data,
 								   tvbparse_action_t before_cb,
 								   tvbparse_action_t after_cb,
-								   char quote,
-								   char escape);
+								   const char quote,
+								   const char escape);
 
 /*
  * a helper callback for quoted strings that will shrink the token to contain
@@ -429,13 +429,13 @@ void tvbparse_shrink_token_cb(void* tvbparse_data,
 * ignore: a wanted token type to be ignored (the associated cb WILL be called when it matches)
 */
 tvbparse_t* tvbparse_init(tvbuff_t* tvb,
-						  int offset,
+						  const int offset,
 						  int len,
 						  void* private_data,
 						  const tvbparse_wanted_t* ignore);
 
 /* reset the parser */
-gboolean tvbparse_reset(tvbparse_t* tt, int offset, int len);
+gboolean tvbparse_reset(tvbparse_t* tt, const int offset, int len);
 
 guint tvbparse_curr_offset(tvbparse_t* tt);
 guint tvbparse_len_left(tvbparse_t* tt);
diff --git a/epan/tvbuff.c b/epan/tvbuff.c
index 4a12b8efa7..8ecc1b9865 100644
--- a/epan/tvbuff.c
+++ b/epan/tvbuff.c
@@ -52,11 +52,11 @@
 #include "proto.h"	/* XXX - only used for DISSECTOR_ASSERT, probably a new header file? */
 
 static const guint8*
-ensure_contiguous_no_exception(tvbuff_t *tvb, gint offset, gint length,
+ensure_contiguous_no_exception(tvbuff_t *tvb, const gint offset, const gint length,
 		int *exception);
 
 static const guint8*
-ensure_contiguous(tvbuff_t *tvb, gint offset, gint length);
+ensure_contiguous(tvbuff_t *tvb, const gint offset, const gint length);
 
 #if GLIB_CHECK_VERSION(2,10,0)
 #else
@@ -87,7 +87,7 @@ tvbuff_cleanup(void)
 }
 
 static void
-tvb_init(tvbuff_t *tvb, tvbuff_type type)
+tvb_init(tvbuff_t *tvb, const tvbuff_type type)
 {
 	tvb_backing_t	*backing;
 	tvb_comp_t	*composite;
@@ -130,7 +130,7 @@ tvb_init(tvbuff_t *tvb, tvbuff_type type)
 
 
 tvbuff_t*
-tvb_new(tvbuff_type type)
+tvb_new(const tvbuff_type type)
 {
 	tvbuff_t	*tvb;
 
@@ -146,7 +146,7 @@ tvb_new(tvbuff_type type)
 }
 
 static tvbuff_t*
-tvb_new_with_subset(guint subset_tvb_offset, guint subset_tvb_length)
+tvb_new_with_subset(const guint subset_tvb_offset, const guint subset_tvb_length)
 {
 	tvbuff_t *tvb = tvb_new(TVBUFF_SUBSET);
 	tvb->tvbuffs.subset.offset = subset_tvb_offset;
@@ -217,7 +217,7 @@ tvb_free(tvbuff_t* tvb)
 }
 
 guint
-tvb_increment_usage_count(tvbuff_t* tvb, guint count)
+tvb_increment_usage_count(tvbuff_t* tvb, const guint count)
 {
 	tvb->usage_count += count;
 
@@ -225,7 +225,7 @@ tvb_increment_usage_count(tvbuff_t* tvb, guint count)
 }
 
 guint
-tvb_decrement_usage_count(tvbuff_t* tvb, guint count)
+tvb_decrement_usage_count(tvbuff_t* tvb, const guint count)
 {
 	if (tvb->usage_count <= count) {
 		tvb->usage_count = 1;
@@ -256,7 +256,7 @@ tvb_free_chain(tvbuff_t* tvb)
 
 
 void
-tvb_set_free_cb(tvbuff_t* tvb, tvbuff_free_cb_t func)
+tvb_set_free_cb(tvbuff_t* tvb, const tvbuff_free_cb_t func)
 {
 	DISSECTOR_ASSERT(tvb);
 	DISSECTOR_ASSERT(tvb->type == TVBUFF_REAL_DATA);
@@ -281,7 +281,7 @@ tvb_set_child_real_data_tvbuff(tvbuff_t* parent, tvbuff_t* child)
 }
 
 static void
-tvb_set_real_data_no_exceptions(tvbuff_t* tvb, const guint8* data, guint length, gint reported_length)
+tvb_set_real_data_no_exceptions(tvbuff_t* tvb, const guint8* data, const guint length, const gint reported_length)
 {
 	tvb->real_data = data;
 	tvb->length = length;
@@ -290,7 +290,7 @@ tvb_set_real_data_no_exceptions(tvbuff_t* tvb, const guint8* data, guint length,
 }
 
 void
-tvb_set_real_data(tvbuff_t* tvb, const guint8* data, guint length, gint reported_length)
+tvb_set_real_data(tvbuff_t* tvb, const guint8* data, const guint length, const gint reported_length)
 {
 	DISSECTOR_ASSERT(tvb);
 	DISSECTOR_ASSERT(tvb->type == TVBUFF_REAL_DATA);
@@ -302,7 +302,7 @@ tvb_set_real_data(tvbuff_t* tvb, const guint8* data, guint length, gint reported
 }
 
 tvbuff_t*
-tvb_new_real_data(const guint8* data, guint length, gint reported_length)
+tvb_new_real_data(const guint8* data, const guint length, const gint reported_length)
 {
 	tvbuff_t	*tvb;
 
@@ -322,7 +322,7 @@ tvb_new_real_data(const guint8* data, guint length, gint reported_length)
 }
 
 tvbuff_t*
-tvb_new_child_real_data(tvbuff_t *parent, const guint8* data, guint length, gint reported_length)
+tvb_new_child_real_data(tvbuff_t *parent, const guint8* data, const guint length, const gint reported_length)
 {
 	tvbuff_t *tvb = tvb_new_real_data(data, length, reported_length);
 	if (tvb) {
@@ -346,7 +346,7 @@ tvb_new_child_real_data(tvbuff_t *parent, const guint8* data, guint length, gint
  * that gets an exception, so the error is reported as an error in that
  * protocol rather than the containing protocol.  */
 static gboolean
-compute_offset_length(guint tvb_length_val, guint tvb_reported_length_val, gint offset, gint length_val,
+compute_offset_length(const guint tvb_length_val, const guint tvb_reported_length_val, const gint offset, const gint length_val,
 		guint *offset_ptr, guint *length_ptr, int *exception)
 {
 	DISSECTOR_ASSERT(offset_ptr);
@@ -410,7 +410,7 @@ compute_offset_length(guint tvb_length_val, guint tvb_reported_length_val, gint
 
 
 static gboolean
-check_offset_length_no_exception(guint tvb_length_val, guint tvb_reported_length_val, gint offset, gint length_val,
+check_offset_length_no_exception(const guint tvb_length_val, const guint tvb_reported_length_val, const gint offset, gint const length_val,
 		guint *offset_ptr, guint *length_ptr, int *exception)
 {
 	guint	end_offset;
@@ -460,7 +460,7 @@ check_offset_length_no_exception(guint tvb_length_val, guint tvb_reported_length
  * either is out of bounds. Sets integer ptrs to the new offset
  * and length. */
 static void
-check_offset_length(guint tvb_length_val, guint tvb_reported_length_val, gint offset, gint length_val,
+check_offset_length(const guint tvb_length_val, const guint tvb_reported_length_val, const gint offset, gint const length_val,
 		guint *offset_ptr, guint *length_ptr)
 {
 	int exception = 0;
@@ -472,7 +472,7 @@ check_offset_length(guint tvb_length_val, guint tvb_reported_length_val, gint of
 }
 
 static void
-tvb_set_subset_no_exceptions(tvbuff_t *tvb, tvbuff_t *backing, gint reported_length)
+tvb_set_subset_no_exceptions(tvbuff_t *tvb, tvbuff_t *backing, const gint reported_length)
 {
 	tvb->tvbuffs.subset.tvb		= backing;
 	tvb->length			= tvb->tvbuffs.subset.length;
@@ -495,7 +495,7 @@ tvb_set_subset_no_exceptions(tvbuff_t *tvb, tvbuff_t *backing, gint reported_len
 
 void
 tvb_set_subset(tvbuff_t *tvb, tvbuff_t *backing,
-		gint backing_offset, gint backing_length, gint reported_length)
+		const gint backing_offset, const gint backing_length, const gint reported_length)
 {
 	DISSECTOR_ASSERT(tvb);
 	DISSECTOR_ASSERT(tvb->type == TVBUFF_SUBSET);
@@ -511,7 +511,7 @@ tvb_set_subset(tvbuff_t *tvb, tvbuff_t *backing,
 }
 
 tvbuff_t*
-tvb_new_subset(tvbuff_t *backing, gint backing_offset, gint backing_length, gint reported_length)
+tvb_new_subset(tvbuff_t *backing, const gint backing_offset, const gint backing_length, const gint reported_length)
 {
 	tvbuff_t	*tvb;
 	guint		subset_tvb_offset;
@@ -539,7 +539,7 @@ tvb_new_subset(tvbuff_t *backing, gint backing_offset, gint backing_length, gint
 }
 
 tvbuff_t*
-tvb_new_subset_remaining(tvbuff_t *backing, gint backing_offset)
+tvb_new_subset_remaining(tvbuff_t *backing, const gint backing_offset)
 {
 	tvbuff_t	*tvb;
 	guint		subset_tvb_offset;
@@ -626,7 +626,7 @@ tvb_composite_finalize(tvbuff_t* tvb)
 
 
 guint
-tvb_length(tvbuff_t* tvb)
+tvb_length(const tvbuff_t* tvb)
 {
 	DISSECTOR_ASSERT(tvb && tvb->initialized);
 
@@ -634,7 +634,7 @@ tvb_length(tvbuff_t* tvb)
 }
 
 gint
-tvb_length_remaining(tvbuff_t *tvb, gint offset)
+tvb_length_remaining(const tvbuff_t *tvb, const gint offset)
 {
 	guint	abs_offset, abs_length;
 
@@ -649,7 +649,7 @@ tvb_length_remaining(tvbuff_t *tvb, gint offset)
 }
 
 guint
-tvb_ensure_length_remaining(tvbuff_t *tvb, gint offset)
+tvb_ensure_length_remaining(const tvbuff_t *tvb, const gint offset)
 {
 	guint	abs_offset, abs_length;
 	int	exception;
@@ -679,7 +679,7 @@ tvb_ensure_length_remaining(tvbuff_t *tvb, gint offset)
 /* Validates that 'length' bytes are available starting from
  * offset (pos/neg). Does not throw an exception. */
 gboolean
-tvb_bytes_exist(tvbuff_t *tvb, gint offset, gint length)
+tvb_bytes_exist(const tvbuff_t *tvb, const gint offset, const gint length)
 {
 	guint		abs_offset, abs_length;
 
@@ -699,7 +699,7 @@ tvb_bytes_exist(tvbuff_t *tvb, gint offset, gint length)
 /* Validates that 'length' bytes are available starting from
  * offset (pos/neg). Throws an exception if they aren't. */
 void
-tvb_ensure_bytes_exist(tvbuff_t *tvb, gint offset, gint length)
+tvb_ensure_bytes_exist(const tvbuff_t *tvb, const gint offset, const gint length)
 {
 	guint		abs_offset, abs_length;
 
@@ -722,7 +722,7 @@ tvb_ensure_bytes_exist(tvbuff_t *tvb, gint offset, gint length)
 }
 
 gboolean
-tvb_offset_exists(tvbuff_t *tvb, gint offset)
+tvb_offset_exists(const tvbuff_t *tvb, const gint offset)
 {
 	guint		abs_offset, abs_length;
 
@@ -739,7 +739,7 @@ tvb_offset_exists(tvbuff_t *tvb, gint offset)
 }
 
 guint
-tvb_reported_length(tvbuff_t* tvb)
+tvb_reported_length(const tvbuff_t* tvb)
 {
 	DISSECTOR_ASSERT(tvb && tvb->initialized);
 
@@ -747,7 +747,7 @@ tvb_reported_length(tvbuff_t* tvb)
 }
 
 gint
-tvb_reported_length_remaining(tvbuff_t *tvb, gint offset)
+tvb_reported_length_remaining(const tvbuff_t *tvb, const gint offset)
 {
 	guint	abs_offset, abs_length;
 
@@ -771,7 +771,7 @@ tvb_reported_length_remaining(tvbuff_t *tvb, gint offset)
 
    Also adjusts the data length. */
 void
-tvb_set_reported_length(tvbuff_t* tvb, guint reported_length)
+tvb_set_reported_length(tvbuff_t* tvb, const guint reported_length)
 {
 	DISSECTOR_ASSERT(tvb && tvb->initialized);
 
@@ -807,7 +807,7 @@ first_real_data_ptr(tvbuff_t *tvb)
 #endif
 
 static guint
-offset_from_real_beginning(tvbuff_t *tvb, guint counter)
+offset_from_real_beginning(const tvbuff_t *tvb, const guint counter)
 {
 	tvbuff_t	*member;
 
@@ -827,14 +827,14 @@ offset_from_real_beginning(tvbuff_t *tvb, guint counter)
 }
 
 guint
-tvb_offset_from_real_beginning(tvbuff_t *tvb)
+tvb_offset_from_real_beginning(const tvbuff_t *tvb)
 {
 	return offset_from_real_beginning(tvb, 0);
 }
 
 static const guint8*
-composite_ensure_contiguous_no_exception(tvbuff_t *tvb, guint abs_offset,
-		guint abs_length)
+composite_ensure_contiguous_no_exception(tvbuff_t *tvb, const guint abs_offset,
+		const guint abs_length)
 {
 	guint		i, num_members;
 	tvb_comp_t	*composite;
@@ -877,7 +877,7 @@ composite_ensure_contiguous_no_exception(tvbuff_t *tvb, guint abs_offset,
 }
 
 static const guint8*
-ensure_contiguous_no_exception(tvbuff_t *tvb, gint offset, gint length,
+ensure_contiguous_no_exception(tvbuff_t *tvb, const gint offset, const gint length,
 		int *exception)
 {
 	guint	abs_offset, abs_length;
@@ -912,7 +912,7 @@ ensure_contiguous_no_exception(tvbuff_t *tvb, gint offset, gint length,
 }
 
 static const guint8*
-ensure_contiguous(tvbuff_t *tvb, gint offset, gint length)
+ensure_contiguous(tvbuff_t *tvb, const gint offset, const gint length)
 {
 	int exception;
 	const guint8 *p;
@@ -926,7 +926,7 @@ ensure_contiguous(tvbuff_t *tvb, gint offset, gint length)
 }
 
 static const guint8*
-fast_ensure_contiguous(tvbuff_t *tvb, gint offset, guint length)
+fast_ensure_contiguous(tvbuff_t *tvb, const gint offset, const guint length)
 {
 	guint	end_offset;
 	guint	u_offset;
@@ -955,7 +955,7 @@ fast_ensure_contiguous(tvbuff_t *tvb, gint offset, guint length)
 }
 
 static const guint8*
-guint8_find(const guint8* haystack, size_t haystacklen, guint8 needle)
+guint8_find(const guint8* haystack, const size_t haystacklen, const guint8 needle)
 {
 	const guint8	*b;
 	int		i;
@@ -1056,7 +1056,7 @@ composite_memcpy(tvbuff_t *tvb, guint8* target, guint abs_offset, size_t abs_len
 }
 
 void*
-tvb_memcpy(tvbuff_t *tvb, void* target, gint offset, size_t length)
+tvb_memcpy(tvbuff_t *tvb, void* target, const gint offset, size_t length)
 {
 	guint	abs_offset, abs_length;
 
@@ -1109,7 +1109,7 @@ tvb_memcpy(tvbuff_t *tvb, void* target, gint offset, size_t length)
  * meaning "to the end of the buffer"?
  */
 void*
-tvb_memdup(tvbuff_t *tvb, gint offset, size_t length)
+tvb_memdup(tvbuff_t *tvb, const gint offset, size_t length)
 {
 	guint	abs_offset, abs_length;
 	void	*duped;
@@ -1139,7 +1139,7 @@ tvb_memdup(tvbuff_t *tvb, gint offset, size_t length)
  * after the current packet has been dissected.
  */
 void*
-ep_tvb_memdup(tvbuff_t *tvb, gint offset, size_t length)
+ep_tvb_memdup(tvbuff_t *tvb, const gint offset, size_t length)
 {
 	guint	abs_offset, abs_length;
 	void	*duped;
@@ -1155,14 +1155,14 @@ ep_tvb_memdup(tvbuff_t *tvb, gint offset, size_t length)
 
 
 const guint8*
-tvb_get_ptr(tvbuff_t *tvb, gint offset, gint length)
+tvb_get_ptr(tvbuff_t *tvb, const gint offset, const gint length)
 {
 	return ensure_contiguous(tvb, offset, length);
 }
 
 /* ---------------- */
 guint8
-tvb_get_guint8(tvbuff_t *tvb, gint offset)
+tvb_get_guint8(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1171,7 +1171,7 @@ tvb_get_guint8(tvbuff_t *tvb, gint offset)
 }
 
 guint16
-tvb_get_ntohs(tvbuff_t *tvb, gint offset)
+tvb_get_ntohs(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1180,7 +1180,7 @@ tvb_get_ntohs(tvbuff_t *tvb, gint offset)
 }
 
 guint32
-tvb_get_ntoh24(tvbuff_t *tvb, gint offset)
+tvb_get_ntoh24(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1189,7 +1189,7 @@ tvb_get_ntoh24(tvbuff_t *tvb, gint offset)
 }
 
 guint32
-tvb_get_ntohl(tvbuff_t *tvb, gint offset)
+tvb_get_ntohl(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1198,7 +1198,7 @@ tvb_get_ntohl(tvbuff_t *tvb, gint offset)
 }
 
 guint64
-tvb_get_ntoh64(tvbuff_t *tvb, gint offset)
+tvb_get_ntoh64(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1248,13 +1248,13 @@ tvb_get_ntoh64(tvbuff_t *tvb, gint offset)
 #define IEEE_SP_BIAS ((1 << (IEEE_SP_EXP_WIDTH - 1)) - 1)
 
 static int
-ieee_float_is_zero(guint32 w)
+ieee_float_is_zero(const guint32 w)
 {
 	return ((w & ~IEEE_SP_SIGN_MASK) == 0);
 }
 
 static gfloat
-get_ieee_float(guint32 w)
+get_ieee_float(const guint32 w)
 {
 	long sign;
 	long exponent;
@@ -1309,13 +1309,13 @@ get_ieee_float(guint32 w)
 #define IEEE_DP_BIAS ((1 << (IEEE_DP_EXP_WIDTH - 1)) - 1)
 
 static int
-ieee_double_is_zero(guint64 w)
+ieee_double_is_zero(const guint64 w)
 {
 	return ((w & ~IEEE_SP_SIGN_MASK) == 0);
 }
 
 static gdouble
-get_ieee_double(guint64 w)
+get_ieee_double(const guint64 w)
 {
 	gint64 sign;
 	gint64 exponent;
@@ -1361,7 +1361,7 @@ get_ieee_double(guint64 w)
  * "float" format?
  */
 gfloat
-tvb_get_ntohieee_float(tvbuff_t *tvb, int offset)
+tvb_get_ntohieee_float(tvbuff_t *tvb, const int offset)
 {
 #if defined(vax)
 	return get_ieee_float(tvb_get_ntohl(tvb, offset));
@@ -1381,7 +1381,7 @@ tvb_get_ntohieee_float(tvbuff_t *tvb, int offset)
  * big-endian form, and returns a "double".
  */
 gdouble
-tvb_get_ntohieee_double(tvbuff_t *tvb, int offset)
+tvb_get_ntohieee_double(tvbuff_t *tvb, const int offset)
 {
 #if defined(vax)
 	union {
@@ -1410,7 +1410,7 @@ tvb_get_ntohieee_double(tvbuff_t *tvb, int offset)
 }
 
 guint16
-tvb_get_letohs(tvbuff_t *tvb, gint offset)
+tvb_get_letohs(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1419,7 +1419,7 @@ tvb_get_letohs(tvbuff_t *tvb, gint offset)
 }
 
 guint32
-tvb_get_letoh24(tvbuff_t *tvb, gint offset)
+tvb_get_letoh24(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1428,7 +1428,7 @@ tvb_get_letoh24(tvbuff_t *tvb, gint offset)
 }
 
 guint32
-tvb_get_letohl(tvbuff_t *tvb, gint offset)
+tvb_get_letohl(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1437,7 +1437,7 @@ tvb_get_letohl(tvbuff_t *tvb, gint offset)
 }
 
 guint64
-tvb_get_letoh64(tvbuff_t *tvb, gint offset)
+tvb_get_letoh64(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 
@@ -1454,7 +1454,7 @@ tvb_get_letoh64(tvbuff_t *tvb, gint offset)
  * "float" format?
  */
 gfloat
-tvb_get_letohieee_float(tvbuff_t *tvb, int offset)
+tvb_get_letohieee_float(tvbuff_t *tvb, const int offset)
 {
 #if defined(vax)
 	return get_ieee_float(tvb_get_letohl(tvb, offset));
@@ -1474,7 +1474,7 @@ tvb_get_letohieee_float(tvbuff_t *tvb, int offset)
  * little-endian form, and returns a "double".
  */
 gdouble
-tvb_get_letohieee_double(tvbuff_t *tvb, int offset)
+tvb_get_letohieee_double(tvbuff_t *tvb, const int offset)
 {
 #if defined(vax)
 	union {
@@ -1506,7 +1506,7 @@ tvb_get_letohieee_double(tvbuff_t *tvb, int offset)
  * We do *not* convert them to host byte order; we leave them in
  * network byte order. */
 guint32
-tvb_get_ipv4(tvbuff_t *tvb, gint offset)
+tvb_get_ipv4(tvbuff_t *tvb, const gint offset)
 {
 	const guint8* ptr;
 	guint32 addr;
@@ -1518,7 +1518,7 @@ tvb_get_ipv4(tvbuff_t *tvb, gint offset)
 
 /* Fetch an IPv6 address. */
 void
-tvb_get_ipv6(tvbuff_t *tvb, gint offset, struct e_in6_addr *addr)
+tvb_get_ipv6(tvbuff_t *tvb, const gint offset, struct e_in6_addr *addr)
 {
 	const guint8* ptr;
 
@@ -1528,7 +1528,7 @@ tvb_get_ipv6(tvbuff_t *tvb, gint offset, struct e_in6_addr *addr)
 
 /* Fetch a GUID. */
 void
-tvb_get_ntohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid)
+tvb_get_ntohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid)
 {
 	ensure_contiguous(tvb, offset, sizeof(*guid));
 	guid->data1 = tvb_get_ntohl(tvb, offset);
@@ -1538,7 +1538,7 @@ tvb_get_ntohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid)
 }
 
 void
-tvb_get_letohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid)
+tvb_get_letohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid)
 {
 	ensure_contiguous(tvb, offset, sizeof(*guid));
 	guid->data1 = tvb_get_letohl(tvb, offset);
@@ -1548,7 +1548,7 @@ tvb_get_letohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid)
 }
 
 void
-tvb_get_guid(tvbuff_t *tvb, gint offset, e_guid_t *guid, gboolean little_endian)
+tvb_get_guid(tvbuff_t *tvb, const gint offset, e_guid_t *guid, const gboolean little_endian)
 {
 	if (little_endian) {
 		tvb_get_letohguid(tvb, offset, guid);
@@ -1582,7 +1582,7 @@ static const guint16 bit_mask16[] = {
 
 /* Get 1 - 8 bits */
 guint8
-tvb_get_bits8(tvbuff_t *tvb, gint bit_offset, gint no_of_bits)
+tvb_get_bits8(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits)
 {
 	gint	offset;
 	guint16	value = 0;
@@ -1627,7 +1627,7 @@ static const guint32 bit_mask32[] = {
 };
 
 guint16
-tvb_get_bits16(tvbuff_t *tvb, gint bit_offset, gint no_of_bits,gboolean little_endian)
+tvb_get_bits16(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits,const gboolean little_endian)
 {
 	gint	offset;
 	guint16	value = 0;
@@ -1681,7 +1681,7 @@ static const guint64 bit_mask64[] = {
 };
 
 guint32
-tvb_get_bits32(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian)
+tvb_get_bits32(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits, const gboolean little_endian)
 {
 	gint	offset;
 	guint32	value = 0;
@@ -1723,7 +1723,7 @@ tvb_get_bits32(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_
 }
 
 guint64
-tvb_get_bits64(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian)
+tvb_get_bits64(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits, const gboolean little_endian)
 {
 	gint	offset;
 	guint64	value = 0;
@@ -1765,7 +1765,7 @@ tvb_get_bits64(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_
 }
 
 guint32
-tvb_get_bits(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian)
+tvb_get_bits(tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, const gboolean little_endian)
 {
 	/* This function can handle only up to 32 requested bits */
 	if (no_of_bits > 32)
@@ -1794,7 +1794,7 @@ tvb_get_bits(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_en
  * in that case, -1 will be returned if the boundary is reached before
  * finding needle. */
 gint
-tvb_find_guint8(tvbuff_t *tvb, gint offset, gint maxlength, guint8 needle)
+tvb_find_guint8(tvbuff_t *tvb, const gint offset, const gint maxlength, const guint8 needle)
 {
 	const guint8	*result;
 	guint		abs_offset, junk_length;
@@ -1859,7 +1859,7 @@ tvb_find_guint8(tvbuff_t *tvb, gint offset, gint maxlength, guint8 needle)
  * in that case, -1 will be returned if the boundary is reached before
  * finding needle. */
 gint
-tvb_pbrk_guint8(tvbuff_t *tvb, gint offset, gint maxlength, const guint8 *needles, guchar *found_needle)
+tvb_pbrk_guint8(tvbuff_t *tvb, const gint offset, const gint maxlength, const guint8 *needles, guchar *found_needle)
 {
 	const guint8	*result;
 	guint		abs_offset, junk_length;
@@ -1922,7 +1922,7 @@ tvb_pbrk_guint8(tvbuff_t *tvb, gint offset, gint maxlength, const guint8 *needle
  * If the NUL isn't found, it throws the appropriate exception.
  */
 guint
-tvb_strsize(tvbuff_t *tvb, gint offset)
+tvb_strsize(tvbuff_t *tvb, const gint offset)
 {
 	guint	abs_offset, junk_length;
 	gint	nul_offset;
@@ -1956,7 +1956,7 @@ tvb_strsize(tvbuff_t *tvb, gint offset)
  * of tvbuff.
  * Returns -1 if 'maxlength' reached before finding EOS. */
 gint
-tvb_strnlen(tvbuff_t *tvb, gint offset, guint maxlength)
+tvb_strnlen(tvbuff_t *tvb, const gint offset, const guint maxlength)
 {
 	gint	result_offset;
 	guint	abs_offset, junk_length;
@@ -1984,7 +1984,7 @@ tvb_strnlen(tvbuff_t *tvb, gint offset, guint maxlength)
  * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
 gint
-tvb_strneql(tvbuff_t *tvb, gint offset, const gchar *str, gint size)
+tvb_strneql(tvbuff_t *tvb, const gint offset, const gchar *str, const gint size)
 {
 	const guint8 *ptr;
 
@@ -2011,7 +2011,7 @@ tvb_strneql(tvbuff_t *tvb, gint offset, const gchar *str, gint size)
  * 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
 gint
-tvb_strncaseeql(tvbuff_t *tvb, gint offset, const gchar *str, gint size)
+tvb_strncaseeql(tvbuff_t *tvb, const gint offset, const gchar *str, const gint size)
 {
 	const guint8 *ptr;
 
@@ -2038,7 +2038,7 @@ tvb_strncaseeql(tvbuff_t *tvb, gint offset, const gchar *str, gint size)
  * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
 gint
-tvb_memeql(tvbuff_t *tvb, gint offset, const guint8 *str, size_t size)
+tvb_memeql(tvbuff_t *tvb, const gint offset, const guint8 *str, size_t size)
 {
 	const guint8 *ptr;
 
@@ -2065,7 +2065,7 @@ tvb_memeql(tvbuff_t *tvb, gint offset, const guint8 *str, size_t size)
  * free the result returned.  The len parameter is the number of guint16's
  * to convert from Unicode. */
 char *
-tvb_fake_unicode(tvbuff_t *tvb, int offset, int len, gboolean little_endian)
+tvb_fake_unicode(tvbuff_t *tvb, int offset, const int len, const gboolean little_endian)
 {
 	char *buffer;
 	int i;
@@ -2100,7 +2100,7 @@ tvb_fake_unicode(tvbuff_t *tvb, int offset, int len, gboolean little_endian)
  * when wireshark starts decoding the next packet.
  */
 char *
-tvb_get_ephemeral_faked_unicode(tvbuff_t *tvb, int offset, int len, gboolean little_endian)
+tvb_get_ephemeral_faked_unicode(tvbuff_t *tvb, int offset, const int len, const gboolean little_endian)
 {
 	char *buffer;
 	int i;
@@ -2131,7 +2131,7 @@ tvb_get_ephemeral_faked_unicode(tvbuff_t *tvb, int offset, int len, gboolean lit
  */
 
 gchar *
-tvb_format_text(tvbuff_t *tvb, gint offset, gint size)
+tvb_format_text(tvbuff_t *tvb, const gint offset, const gint size)
 {
   const guint8 *ptr;
   gint len = size;
@@ -2149,7 +2149,7 @@ tvb_format_text(tvbuff_t *tvb, gint offset, gint size)
  */
 
 gchar *
-tvb_format_text_wsp(tvbuff_t *tvb, gint offset, gint size)
+tvb_format_text_wsp(tvbuff_t *tvb, const gint offset, const gint size)
 {
   const guint8 *ptr;
   gint len = size;
@@ -2170,7 +2170,7 @@ tvb_format_text_wsp(tvbuff_t *tvb, gint offset, gint size)
  * the null padding characters as "\000".
  */
 gchar *
-tvb_format_stringzpad(tvbuff_t *tvb, gint offset, gint size)
+tvb_format_stringzpad(tvbuff_t *tvb, const gint offset, const gint size)
 {
   const guint8 *ptr, *p;
   gint len = size;
@@ -2194,7 +2194,7 @@ tvb_format_stringzpad(tvbuff_t *tvb, gint offset, gint size)
  * the null padding characters as "\000".
  */
 gchar *
-tvb_format_stringzpad_wsp(tvbuff_t *tvb, gint offset, gint size)
+tvb_format_stringzpad_wsp(tvbuff_t *tvb, const gint offset, const gint size)
 {
   const guint8 *ptr, *p;
   gint len = size;
@@ -2222,7 +2222,7 @@ tvb_format_stringzpad_wsp(tvbuff_t *tvb, gint offset, gint size)
  * Throws an exception if the tvbuff ends before the string does.
  */
 guint8 *
-tvb_get_string(tvbuff_t *tvb, gint offset, gint length)
+tvb_get_string(tvbuff_t *tvb, const gint offset, const gint length)
 {
 	const guint8 *ptr;
 	guint8 *strbuf = NULL;
@@ -2252,7 +2252,7 @@ tvb_get_string(tvbuff_t *tvb, gint offset, gint length)
  * after the current packet has been dissected.
  */
 guint8 *
-tvb_get_ephemeral_string(tvbuff_t *tvb, gint offset, gint length)
+tvb_get_ephemeral_string(tvbuff_t *tvb, const gint offset, const gint length)
 {
 	const guint8 *ptr;
 	guint8 *strbuf = NULL;
@@ -2281,7 +2281,7 @@ tvb_get_ephemeral_string(tvbuff_t *tvb, gint offset, gint length)
  * when wireshark starts or opens a new capture.
  */
 guint8 *
-tvb_get_seasonal_string(tvbuff_t *tvb, gint offset, gint length)
+tvb_get_seasonal_string(tvbuff_t *tvb, const gint offset, const gint length)
 {
 	const guint8 *ptr;
 	guint8 *strbuf = NULL;
@@ -2306,7 +2306,7 @@ tvb_get_seasonal_string(tvbuff_t *tvb, gint offset, gint length)
  * string (including the terminating null) through a pointer.
  */
 guint8 *
-tvb_get_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
+tvb_get_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp)
 {
 	guint size;
 	guint8 *strptr;
@@ -2333,7 +2333,7 @@ tvb_get_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
  * after the current packet has been dissected.
  */
 guint8 *
-tvb_get_ephemeral_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
+tvb_get_ephemeral_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp)
 {
 	guint size;
 	guint8 *strptr;
@@ -2359,7 +2359,7 @@ tvb_get_ephemeral_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
  * when wireshark starts or opens a new capture.
  */
 guint8 *
-tvb_get_seasonal_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
+tvb_get_seasonal_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp)
 {
 	guint size;
 	guint8 *strptr;
@@ -2391,7 +2391,7 @@ tvb_get_seasonal_stringz(tvbuff_t *tvb, gint offset, gint *lengthp)
  * including the terminating-NUL.
  */
 static gint
-_tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer,
+_tvb_get_nstringz(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8* buffer,
 		gint *bytes_copied)
 {
 	gint	stringlen;
@@ -2475,7 +2475,7 @@ _tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer,
  * at the correct spot, terminating the string.
  */
 gint
-tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer)
+tvb_get_nstringz(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8* buffer)
 {
 	gint bytes_copied;
 
@@ -2489,7 +2489,7 @@ tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer)
  * a NUL is placed at the end of buffer to terminate it.
  */
 gint
-tvb_get_nstringz0(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer)
+tvb_get_nstringz0(tvbuff_t *tvb, const gint offset, const guint bufsize, guint8* buffer)
 {
 	gint	len, bytes_copied;
 
@@ -2526,8 +2526,8 @@ tvb_get_nstringz0(tvbuff_t *tvb, gint offset, guint bufsize, guint8* buffer)
  * terminator.	(It's not set if we return -1.)
  */
 gint
-tvb_find_line_end(tvbuff_t *tvb, gint offset, int len, gint *next_offset,
-	gboolean desegment)
+tvb_find_line_end(tvbuff_t *tvb, const gint offset, int len, gint *next_offset,
+	const gboolean desegment)
 {
 	gint eob_offset;
 	gint eol_offset;
@@ -2642,7 +2642,7 @@ tvb_find_line_end(tvbuff_t *tvb, gint offset, int len, gint *next_offset,
  * terminator.
  */
 gint
-tvb_find_line_end_unquoted(tvbuff_t *tvb, gint offset, int len,
+tvb_find_line_end_unquoted(tvbuff_t *tvb, const gint offset, int len,
 	gint *next_offset)
 {
 	gint cur_offset, char_offset;
@@ -2783,7 +2783,7 @@ tvb_find_line_end_unquoted(tvbuff_t *tvb, gint offset, int len,
  *			character following offset or offset + maxlength -1 whichever
  *			is smaller.
  */
-gint tvb_skip_wsp(tvbuff_t* tvb, gint offset, gint maxlength)
+gint tvb_skip_wsp(tvbuff_t* tvb, const gint offset, const gint maxlength)
 {
 	gint counter = offset;
 	gint end = offset + maxlength,tvb_len;
@@ -2807,7 +2807,7 @@ gint tvb_skip_wsp(tvbuff_t* tvb, gint offset, gint maxlength)
 	return (counter);
 }
 
-gint tvb_skip_wsp_return(tvbuff_t* tvb, gint offset){
+gint tvb_skip_wsp_return(tvbuff_t* tvb, const gint offset){
 	gint counter = offset;
 	gint end;
 	guint8 tempchar;
@@ -2827,7 +2827,7 @@ gint tvb_skip_wsp_return(tvbuff_t* tvb, gint offset){
  * separator.
  */
 gchar *
-tvb_bytes_to_str_punct(tvbuff_t *tvb, gint offset, gint len, gchar punct)
+tvb_bytes_to_str_punct(tvbuff_t *tvb, const gint offset, const gint len, const gchar punct)
 {
 	return bytes_to_str_punct(tvb_get_ptr(tvb, offset, len), len, punct);
 }
@@ -2837,14 +2837,14 @@ tvb_bytes_to_str_punct(tvbuff_t *tvb, gint offset, gint len, gchar punct)
  * to the string with the formatted data.
  */
 gchar *
-tvb_bytes_to_str(tvbuff_t *tvb, gint offset, gint len)
+tvb_bytes_to_str(tvbuff_t *tvb, const gint offset, const gint len)
 {
 	return bytes_to_str(tvb_get_ptr(tvb, offset, len), len);
 }
 
 /* Find a needle tvbuff within a haystack tvbuff. */
 gint
-tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb, gint haystack_offset)
+tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb, const gint haystack_offset)
 {
 	guint		haystack_abs_offset, haystack_abs_length;
 	const guint8	*haystack_data;
@@ -2887,7 +2887,7 @@ tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb, gint haystack_offset)
 #undef TVB_Z_DEBUG
 
 tvbuff_t *
-tvb_uncompress(tvbuff_t *tvb, int offset, int comprlen)
+tvb_uncompress(tvbuff_t *tvb, const int offset, int comprlen)
 {
 	gint err = Z_OK;
 	guint bytes_out = 0;
@@ -3139,13 +3139,13 @@ tvb_uncompress(tvbuff_t *tvb, int offset, int comprlen)
 }
 #else
 tvbuff_t *
-tvb_uncompress(tvbuff_t *tvb _U_, int offset _U_, int comprlen _U_)
+tvb_uncompress(tvbuff_t *tvb _U_, const int offset _U_, int comprlen _U_)
 {
 	return NULL;
 }
 #endif
 
-tvbuff_t* tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb, int offset, int comprlen)
+tvbuff_t* tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
 {
 	tvbuff_t *new_tvb = tvb_uncompress(tvb, offset, comprlen);
 	if (new_tvb)
diff --git a/epan/tvbuff.h b/epan/tvbuff.h
index dce30af923..0278ce2fd3 100644
--- a/epan/tvbuff.h
+++ b/epan/tvbuff.h
@@ -181,20 +181,20 @@ extern void tvb_free(tvbuff_t*);
 extern void tvb_free_chain(tvbuff_t*);
 
 /** Both return the new usage count, after the increment or decrement */
-extern guint tvb_increment_usage_count(tvbuff_t*, guint count);
+extern guint tvb_increment_usage_count(tvbuff_t*, const guint count);
 
 /** If a decrement causes the usage count to drop to 0, a the tvbuff
  * is immediately freed. Be sure you know exactly what you're doing
  * if you decide to use this function, as another tvbuff could
  * still have a pointer to the just-freed tvbuff, causing corrupted data
  * or a segfault in the future */
-extern guint tvb_decrement_usage_count(tvbuff_t*, guint count);
+extern guint tvb_decrement_usage_count(tvbuff_t*, const guint count);
 
 /** Set a callback function to call when a tvbuff is actually freed
  * (once the usage count drops to 0). One argument is passed to
  * that callback --- a void* that points to the real data.
  * Obviously, this only applies to a TVBUFF_REAL_DATA tvbuff. */
-extern void tvb_set_free_cb(tvbuff_t*, tvbuff_free_cb_t);
+extern void tvb_set_free_cb(tvbuff_t*, const tvbuff_free_cb_t);
 
 
 /** Attach a TVBUFF_REAL_DATA tvbuff to a parent tvbuff. This connection
@@ -208,16 +208,16 @@ extern void tvb_set_free_cb(tvbuff_t*, tvbuff_free_cb_t);
  * the tvbuff routines knowledgable of this fact. */
 extern void tvb_set_child_real_data_tvbuff(tvbuff_t* parent, tvbuff_t* child);
 
-extern tvbuff_t* tvb_new_child_real_data(tvbuff_t* parent, const guint8* data, guint length,
-    gint reported_length);
+extern tvbuff_t* tvb_new_child_real_data(tvbuff_t* parent, const guint8* data, const guint length,
+    const gint reported_length);
 
 /**Sets parameters for TVBUFF_REAL_DATA. Can throw ReportedBoundsError. */
-extern void tvb_set_real_data(tvbuff_t*, const guint8* data, guint length,
-    gint reported_length);
+extern void tvb_set_real_data(tvbuff_t*, const guint8* data, const guint length,
+    const gint reported_length);
 
 /** Combination of tvb_new() and tvb_set_real_data(). Can throw ReportedBoundsError. */
-extern tvbuff_t* tvb_new_real_data(const guint8* data, guint length,
-    gint reported_length);
+extern tvbuff_t* tvb_new_real_data(const guint8* data, const guint length,
+    const gint reported_length);
 
 
 /** Define the subset of the backing buffer to use.
@@ -234,17 +234,17 @@ extern tvbuff_t* tvb_new_real_data(const guint8* data, guint length,
  * is beyond the bounds of the backing tvbuff.
  * Can throw ReportedBoundsError. */
 extern void tvb_set_subset(tvbuff_t* tvb, tvbuff_t* backing,
-		gint backing_offset, gint backing_length, gint reported_length);
+		const gint backing_offset, const gint backing_length, const gint reported_length);
 
 /** Combination of tvb_new() and tvb_set_subset()
  * Can throw ReportedBoundsError. */
 extern tvbuff_t* tvb_new_subset(tvbuff_t* backing,
-		gint backing_offset, gint backing_length, gint reported_length);
+		const gint backing_offset, const gint backing_length, const gint reported_length);
 
 /** Similar to tvb_new_subset() but with backing_length and reported_length set to -1.
  * Can throw ReportedBoundsError. */
 extern tvbuff_t* tvb_new_subset_remaining(tvbuff_t* backing,
-		gint backing_offset);
+		const gint backing_offset);
 
 /** Both tvb_composite_append and tvb_composite_prepend can throw
  * BoundsError if member_offset/member_length goes beyond bounds of
@@ -266,35 +266,35 @@ extern void tvb_composite_finalize(tvbuff_t* tvb);
 
 
 /* Get total length of buffer */
-extern guint tvb_length(tvbuff_t*);
+extern guint tvb_length(const tvbuff_t*);
 
 /** Computes bytes to end of buffer, from offset (which can be negative,
  * to indicate bytes from end of buffer). Function returns -1 to
  * indicate that offset is out of bounds. No exception is thrown. */
-extern gint tvb_length_remaining(tvbuff_t*, gint offset);
+extern gint tvb_length_remaining(const tvbuff_t*, const gint offset);
 
 /** Same as above, but throws an exception if the offset is out of bounds. */
-extern guint tvb_ensure_length_remaining(tvbuff_t*, gint offset);
+extern guint tvb_ensure_length_remaining(const tvbuff_t*, const gint offset);
 
 /* Checks (w/o throwing exception) that the bytes referred to by
  * 'offset'/'length' actually exist in the buffer */
-extern gboolean tvb_bytes_exist(tvbuff_t*, gint offset, gint length);
+extern gboolean tvb_bytes_exist(const tvbuff_t*, const gint offset, const gint length);
 
 /** Checks that the bytes referred to by 'offset'/'length' actually exist
  * in the buffer, and throws an exception if they aren't. */
-extern void tvb_ensure_bytes_exist(tvbuff_t *tvb, gint offset, gint length);
+extern void tvb_ensure_bytes_exist(const tvbuff_t *tvb, const gint offset, const gint length);
 
 /* Checks (w/o throwing exception) that offset exists in buffer */
-extern gboolean tvb_offset_exists(tvbuff_t*, gint offset);
+extern gboolean tvb_offset_exists(const tvbuff_t*, const gint offset);
 
 /* Get reported length of buffer */
-extern guint tvb_reported_length(tvbuff_t*);
+extern guint tvb_reported_length(const tvbuff_t*);
 
 /** Computes bytes of reported packet data to end of buffer, from offset
  * (which can be negative, to indicate bytes from end of buffer). Function
  * returns -1 to indicate that offset is out of bounds. No exception is
  * thrown. */
-extern gint tvb_reported_length_remaining(tvbuff_t *tvb, gint offset);
+extern gint tvb_reported_length_remaining(const tvbuff_t *tvb, const gint offset);
 
 /** Set the reported length of a tvbuff to a given value; used for protocols
    whose headers contain an explicit length and where the calling
@@ -302,9 +302,9 @@ extern gint tvb_reported_length_remaining(tvbuff_t *tvb, gint offset);
    this protocol.
 
    Also adjusts the data length. */
-extern void tvb_set_reported_length(tvbuff_t*, guint);
+extern void tvb_set_reported_length(tvbuff_t*, const guint);
 
-extern guint tvb_offset_from_real_beginning(tvbuff_t *tvb);
+extern guint tvb_offset_from_real_beginning(const tvbuff_t *tvb);
 
 /* Returns the offset from the first byte of real data. */
 #define TVB_RAW_OFFSET(tvb)			\
@@ -313,48 +313,48 @@ extern guint tvb_offset_from_real_beginning(tvbuff_t *tvb);
 /************** START OF ACCESSORS ****************/
 /* All accessors will throw an exception if appropriate */
 
-extern guint8  tvb_get_guint8(tvbuff_t*, gint offset);
+extern guint8  tvb_get_guint8(tvbuff_t*, const gint offset);
 
-extern guint16 tvb_get_ntohs(tvbuff_t*, gint offset);
-extern guint32 tvb_get_ntoh24(tvbuff_t*, gint offset);
-extern guint32 tvb_get_ntohl(tvbuff_t*, gint offset);
-extern guint64 tvb_get_ntoh64(tvbuff_t*, gint offset);
-extern gfloat tvb_get_ntohieee_float(tvbuff_t*, gint offset);
-extern gdouble tvb_get_ntohieee_double(tvbuff_t*, gint offset);
+extern guint16 tvb_get_ntohs(tvbuff_t*, const gint offset);
+extern guint32 tvb_get_ntoh24(tvbuff_t*, const gint offset);
+extern guint32 tvb_get_ntohl(tvbuff_t*, const gint offset);
+extern guint64 tvb_get_ntoh64(tvbuff_t*, const gint offset);
+extern gfloat tvb_get_ntohieee_float(tvbuff_t*, const gint offset);
+extern gdouble tvb_get_ntohieee_double(tvbuff_t*, const gint offset);
 
-extern guint16 tvb_get_letohs(tvbuff_t*, gint offset);
-extern guint32 tvb_get_letoh24(tvbuff_t*, gint offset);
-extern guint32 tvb_get_letohl(tvbuff_t*, gint offset);
-extern guint64 tvb_get_letoh64(tvbuff_t*, gint offset);
-extern gfloat tvb_get_letohieee_float(tvbuff_t*, gint offset);
-extern gdouble tvb_get_letohieee_double(tvbuff_t*, gint offset);
+extern guint16 tvb_get_letohs(tvbuff_t*, const gint offset);
+extern guint32 tvb_get_letoh24(tvbuff_t*, const gint offset);
+extern guint32 tvb_get_letohl(tvbuff_t*, const gint offset);
+extern guint64 tvb_get_letoh64(tvbuff_t*, const gint offset);
+extern gfloat tvb_get_letohieee_float(tvbuff_t*, const gint offset);
+extern gdouble tvb_get_letohieee_double(tvbuff_t*, const gint offset);
 
 /**
  * Fetch an IPv4 address, in network byte order.
  * We do *not* convert it to host byte order; we leave it in
  * network byte order, as that's what its callers expect. */
-extern guint32 tvb_get_ipv4(tvbuff_t*, gint offset);
+extern guint32 tvb_get_ipv4(tvbuff_t*, const gint offset);
 
 /* Fetch an IPv6 address. */
-extern void tvb_get_ipv6(tvbuff_t*, gint offset, struct e_in6_addr *addr);
+extern void tvb_get_ipv6(tvbuff_t*, const gint offset, struct e_in6_addr *addr);
 
 /* Fetch a GUID. */
-extern void tvb_get_ntohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid);
-extern void tvb_get_letohguid(tvbuff_t *tvb, gint offset, e_guid_t *guid);
-extern void tvb_get_guid(tvbuff_t *tvb, gint offset, e_guid_t *guid, gboolean little_endian);
+extern void tvb_get_ntohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid);
+extern void tvb_get_letohguid(tvbuff_t *tvb, const gint offset, e_guid_t *guid);
+extern void tvb_get_guid(tvbuff_t *tvb, const gint offset, e_guid_t *guid, const gboolean little_endian);
 
 /* Fetch a specified number of bits from bit offset in a tvb */
-extern guint8 tvb_get_bits8(tvbuff_t *tvb, gint bit_offset, gint no_of_bits);
-extern guint16 tvb_get_bits16(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian);
-extern guint32 tvb_get_bits32(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian);
-extern guint64 tvb_get_bits64(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian);
+extern guint8 tvb_get_bits8(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits);
+extern guint16 tvb_get_bits16(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits, const gboolean little_endian);
+extern guint32 tvb_get_bits32(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits, const gboolean little_endian);
+extern guint64 tvb_get_bits64(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits, const gboolean little_endian);
 
 /* Fetch a specified number of bits from bit offset in a tvb, but allow number
  * of bits to range between 1 and 32. If the requested number of bits is known
  * beforehand, or its range can be handled by a single function of the group
  * above, use one of them instead.
  */
-extern guint32 tvb_get_bits(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gboolean little_endian);
+extern guint32 tvb_get_bits(tvbuff_t *tvb, const gint bit_offset, const gint no_of_bits, const gboolean little_endian);
 
 /** Returns target for convenience. Does not suffer from possible
  * expense of tvb_get_ptr(), since this routine is smart enough
@@ -362,17 +362,17 @@ extern guint32 tvb_get_bits(tvbuff_t *tvb, gint bit_offset, gint no_of_bits, gbo
  * different TVBUFF_REAL_DATA tvbuffs. This function assumes that the
  * target memory is already allocated; it does not allocate or free the
  * target memory. */
-extern void* tvb_memcpy(tvbuff_t*, void* target, gint offset, size_t length);
+extern void* tvb_memcpy(tvbuff_t*, void* target, const gint offset, size_t length);
 
 /** It is the user's responsibility to g_free() the memory allocated by
  * tvb_memdup(). Calls tvb_memcpy() */
-extern void* tvb_memdup(tvbuff_t*, gint offset, size_t length);
+extern void* tvb_memdup(tvbuff_t*, const gint offset, size_t length);
 
 /* Same as above but the buffer returned from this function does not have to
 * be freed. It will be automatically freed after the packet is dissected.
 * Buffers allocated by this function are NOT persistent.
 */
-extern void* ep_tvb_memdup(tvbuff_t *tvb, gint offset, size_t length);
+extern void* ep_tvb_memdup(tvbuff_t *tvb, const gint offset, size_t length);
 
 /** WARNING! This function is possibly expensive, temporarily allocating
  * another copy of the packet data. Furthermore, it's dangerous because once
@@ -399,7 +399,7 @@ extern void* ep_tvb_memdup(tvbuff_t *tvb, gint offset, size_t length);
  * and the pointer to the newly-contiguous data is returned. This dynamically-
  * allocated memory will be freed when the tvbuff is freed, after the
  * tvbuff_free_cb_t() is called, if any. */
-extern const guint8* tvb_get_ptr(tvbuff_t*, gint offset, gint length);
+extern const guint8* tvb_get_ptr(tvbuff_t*, const gint offset, const gint length);
 
 /** Find first occurence of any of the needles in tvbuff, starting at offset.
  * Searches at most maxlength number of bytes; if maxlength is -1, searches
@@ -408,8 +408,8 @@ extern const guint8* tvb_get_ptr(tvbuff_t*, gint offset, gint length);
  * Will not throw an exception, even if maxlength exceeds boundary of tvbuff;
  * in that case, -1 will be returned if the boundary is reached before
  * finding needle. */
-extern gint tvb_find_guint8(tvbuff_t*, gint offset, gint maxlength,
-    guint8 needle);
+extern gint tvb_find_guint8(tvbuff_t*, const gint offset, const gint maxlength,
+    const guint8 needle);
 
 /** Find first occurence of any of the needles in tvbuff, starting at offset.
  * Searches at most maxlength number of bytes. Returns the offset of the
@@ -417,7 +417,7 @@ extern gint tvb_find_guint8(tvbuff_t*, gint offset, gint maxlength,
  * Will not throw an exception, even if
  * maxlength exceeds boundary of tvbuff; in that case, -1 will be returned if
  * the boundary is reached before finding needle. */
-extern gint tvb_pbrk_guint8(tvbuff_t *, gint offset, gint maxlength,
+extern gint tvb_pbrk_guint8(tvbuff_t *, const gint offset, const gint maxlength,
     const guint8 *needles, guchar *found_needle);
 
 /** Find size of stringz (NUL-terminated string) by looking for terminating
@@ -425,13 +425,13 @@ extern gint tvb_pbrk_guint8(tvbuff_t *, gint offset, gint maxlength,
  *
  * If the NUL isn't found, it throws the appropriate exception.
  */
-extern guint tvb_strsize(tvbuff_t *tvb, gint offset);
+extern guint tvb_strsize(tvbuff_t *tvb, const gint offset);
 
 /** Find length of string by looking for end of zero terminated string, up to
  * 'maxlength' characters'; if 'maxlength' is -1, searches to end
  * of tvbuff.
  * Returns -1 if 'maxlength' reached before finding EOS. */
-extern gint tvb_strnlen(tvbuff_t*, gint offset, guint maxlength);
+extern gint tvb_strnlen(tvbuff_t*, const gint offset, const guint maxlength);
 
 /** Convert a string from Unicode to ASCII.  At the moment we fake it by
  * assuming all characters are ASCII  )-:  The len parameter is the number
@@ -444,33 +444,33 @@ extern gint tvb_strnlen(tvbuff_t*, gint offset, guint maxlength);
  *                    automatically freed when wireshark starts dissecting
  *                    the next packet.
  */
-extern char *tvb_fake_unicode(tvbuff_t *tvb, int offset, int len,
-                              gboolean little_endian);
-extern char *tvb_get_ephemeral_faked_unicode(tvbuff_t *tvb, int offset, int len,
-                              gboolean little_endian);
+extern char *tvb_fake_unicode(tvbuff_t *tvb, int offset, const int len,
+                              const gboolean little_endian);
+extern char *tvb_get_ephemeral_faked_unicode(tvbuff_t *tvb, int offset, const int len,
+                              const gboolean little_endian);
 
 /**
  * Format the data in the tvb from offset for size ...
  */
-extern gchar * tvb_format_text(tvbuff_t *tvb, gint offset, gint size);
+extern gchar * tvb_format_text(tvbuff_t *tvb, const gint offset, const gint size);
 
 /**
  * Like "tvb_format_text()", but for 'wsp'; don't show
  * the characters as C-style escapes.
  */
-extern gchar * tvb_format_text_wsp(tvbuff_t *tvb, gint offset, gint size);
+extern gchar * tvb_format_text_wsp(tvbuff_t *tvb, const gint offset, const gint size);
 
 /**
  * Like "tvb_format_text()", but for null-padded strings; don't show
  * the null padding characters as "\000".
  */
-extern gchar *tvb_format_stringzpad(tvbuff_t *tvb, gint offset, gint size);
+extern gchar *tvb_format_stringzpad(tvbuff_t *tvb, const gint offset, const gint size);
 
 /**
  * Like "tvb_format_text_wsp()", but for null-padded strings; don't show
  * the null padding characters as "\000".
  */
-extern gchar *tvb_format_stringzpad_wsp(tvbuff_t *tvb, gint offset, gint size);
+extern gchar *tvb_format_stringzpad_wsp(tvbuff_t *tvb, const gint offset, const gint size);
 
 
 /**
@@ -493,9 +493,9 @@ extern gchar *tvb_format_stringzpad_wsp(tvbuff_t *tvb, gint offset, gint size);
  *                   instead it will automatically be freed when a new capture
  *                   or file is opened.
  */
-extern guint8 *tvb_get_string(tvbuff_t *tvb, gint offset, gint length);
-extern guint8 *tvb_get_ephemeral_string(tvbuff_t *tvb, gint offset, gint length);
-extern guint8 *tvb_get_seasonal_string(tvbuff_t *tvb, gint offset, gint length);
+extern guint8 *tvb_get_string(tvbuff_t *tvb, const gint offset, const gint length);
+extern guint8 *tvb_get_ephemeral_string(tvbuff_t *tvb, const gint offset, const gint length);
+extern guint8 *tvb_get_seasonal_string(tvbuff_t *tvb, const gint offset, const gint length);
 
 
 /**
@@ -518,9 +518,9 @@ extern guint8 *tvb_get_seasonal_string(tvbuff_t *tvb, gint offset, gint length);
  *                   instead it will automatically be freed when a new capture
  *                   or file is opened.
  */
-extern guint8 *tvb_get_stringz(tvbuff_t *tvb, gint offset, gint *lengthp);
-extern guint8 *tvb_get_ephemeral_stringz(tvbuff_t *tvb, gint offset, gint *lengthp);
-extern guint8 *tvb_get_seasonal_stringz(tvbuff_t *tvb, gint offset, gint *lengthp);
+extern guint8 *tvb_get_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp);
+extern guint8 *tvb_get_ephemeral_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp);
+extern guint8 *tvb_get_seasonal_stringz(tvbuff_t *tvb, const gint offset, gint *lengthp);
 
 /** Looks for a stringz (NUL-terminated string) in tvbuff and copies
  * no more than bufsize number of bytes, including terminating NUL, to buffer.
@@ -535,7 +535,7 @@ extern guint8 *tvb_get_seasonal_stringz(tvbuff_t *tvb, gint offset, gint *length
  * is truncated with a NUL, albeit not at buffer[bufsize - 1], but
  * at the correct spot, terminating the string.
  */
-extern gint tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize,
+extern gint tvb_get_nstringz(tvbuff_t *tvb, const gint offset, const guint bufsize,
     guint8* buffer);
 
 /** Like tvb_get_nstringz(), but never returns -1. The string is guaranteed to
@@ -544,7 +544,7 @@ extern gint tvb_get_nstringz(tvbuff_t *tvb, gint offset, guint bufsize,
  *
  * bufsize MUST be greater than 0.
  */
-extern gint tvb_get_nstringz0(tvbuff_t *tvb, gint offset, guint bufsize,
+extern gint tvb_get_nstringz0(tvbuff_t *tvb, const gint offset, const guint bufsize,
     guint8* buffer);
 
 /**
@@ -566,8 +566,8 @@ extern gint tvb_get_nstringz0(tvbuff_t *tvb, gint offset, guint bufsize,
  * terminator, or past the end of the buffer if we don't find a line
  * terminator.  (It's not set if we return -1.)
  */
-extern gint tvb_find_line_end(tvbuff_t *tvb, gint offset, int len,
-    gint *next_offset, gboolean desegment);
+extern gint tvb_find_line_end(tvbuff_t *tvb, const gint offset, int len,
+    gint *next_offset, const gboolean desegment);
 
 /**
  * Given a tvbuff, an offset into the tvbuff, and a length that starts
@@ -587,7 +587,7 @@ extern gint tvb_find_line_end(tvbuff_t *tvb, gint offset, int len,
  * terminator, or past the end of the buffer if we don't find a line
  * terminator.
  */
-extern gint tvb_find_line_end_unquoted(tvbuff_t *tvb, gint offset, int len,
+extern gint tvb_find_line_end_unquoted(tvbuff_t *tvb, const gint offset, int len,
     gint *next_offset);
 
 /**
@@ -607,29 +607,29 @@ extern gint tvb_find_line_end_unquoted(tvbuff_t *tvb, gint offset, int len,
  *          is smaller.
  */
 
-extern gint tvb_skip_wsp(tvbuff_t* tvb, gint offset, gint maxlength);
+extern gint tvb_skip_wsp(tvbuff_t* tvb, const gint offset, const gint maxlength);
 
-extern gint tvb_skip_wsp_return(tvbuff_t* tvb, gint offset);
+extern gint tvb_skip_wsp_return(tvbuff_t* tvb, const gint offset);
 
 /**
  * Call strncmp after checking if enough chars left, returning 0 if
  * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
-extern gint tvb_strneql(tvbuff_t *tvb, gint offset, const gchar *str,
-    gint size);
+extern gint tvb_strneql(tvbuff_t *tvb, const gint offset, const gchar *str,
+    const gint size);
 
 /**
  * Call g_ascii_strncasecmp after checking if enough chars left, returning
  * 0 if it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
-extern gint tvb_strncaseeql(tvbuff_t *tvb, gint offset, const gchar *str,
-    gint size);
+extern gint tvb_strncaseeql(tvbuff_t *tvb, const gint offset, const gchar *str,
+    const gint size);
 
 /**
  * Call memcmp after checking if enough chars left, returning 0 if
  * it returns 0 (meaning "equal") and -1 otherwise, otherwise return -1.
  */
-extern gint tvb_memeql(tvbuff_t *tvb, gint offset, const guint8 *str,
+extern gint tvb_memeql(tvbuff_t *tvb, const gint offset, const guint8 *str,
     size_t size);
 
 /**
@@ -637,14 +637,14 @@ extern gint tvb_memeql(tvbuff_t *tvb, gint offset, const guint8 *str,
  * to the string with the formatted data, with "punct" as a byte
  * separator.
  */
-extern gchar *tvb_bytes_to_str_punct(tvbuff_t *tvb, gint offset, gint len,
-    gchar punct);
+extern gchar *tvb_bytes_to_str_punct(tvbuff_t *tvb, const gint offset, const gint len,
+    const gchar punct);
 
 /*
  * Format a bunch of data from a tvbuff as bytes, returning a pointer
  * to the string with the formatted data.
  */
-extern gchar *tvb_bytes_to_str(tvbuff_t *tvb, gint offset, gint len);
+extern gchar *tvb_bytes_to_str(tvbuff_t *tvb, const gint offset, const gint len);
 
 #define TVB_GET_DS_TVB(tvb)		\
 	(tvb->ds_tvb)
@@ -654,21 +654,21 @@ extern gchar *tvb_bytes_to_str(tvbuff_t *tvb, gint offset, gint len);
  * 'haystack', or -1 if 'needle' is not found. The index is relative
  * to the start of 'haystack', not 'haystack_offset'. */
 extern gint tvb_find_tvb(tvbuff_t *haystack_tvb, tvbuff_t *needle_tvb,
-	gint haystack_offset);
+	const gint haystack_offset);
 
 /**
  * Uncompresses a zlib compressed packet inside a tvbuff at offset with
  * length comprlen.  Returns an uncompressed tvbuffer if uncompression
  * succeeded or NULL if uncompression failed.
  */
-extern tvbuff_t* tvb_uncompress(tvbuff_t *tvb, int offset, int comprlen);
+extern tvbuff_t* tvb_uncompress(tvbuff_t *tvb, const int offset,  int comprlen);
 
 /**
  * Uncompresses a zlib compressed packet inside a tvbuff at offset with
  * length comprlen.  Returns an uncompressed tvbuffer attached to tvb if uncompression
  * succeeded or NULL if uncompression failed.
  */
-extern tvbuff_t* tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb, int offset, int comprlen);
+extern tvbuff_t* tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen);
 
 /************** END OF ACCESSORS ****************/
 
diff --git a/epan/value_string.c b/epan/value_string.c
index d75def715b..0e43750c71 100644
--- a/epan/value_string.c
+++ b/epan/value_string.c
@@ -37,7 +37,7 @@
    Returns the associated string ptr on a match.
    Formats val with fmt, and returns the resulting string, on failure. */
 const gchar*
-val_to_str(guint32 val, const value_string *vs, const char *fmt) {
+val_to_str(const guint32 val, const value_string *vs, const char *fmt) {
   const gchar *ret;
 
   g_assert(fmt != NULL);
@@ -53,7 +53,7 @@ val_to_str(guint32 val, const value_string *vs, const char *fmt) {
    Returns the associated string ptr on a match.
    Returns 'unknown_str', on failure. */
 const gchar*
-val_to_str_const(guint32 val, const value_string *vs, const char *unknown_str) {
+val_to_str_const(const guint32 val, const value_string *vs, const char *unknown_str) {
   const gchar *ret;
 
   g_assert(unknown_str != NULL);
@@ -70,7 +70,7 @@ val_to_str_const(guint32 val, const value_string *vs, const char *unknown_str) {
    that table, on a match, and returns NULL, and sets "*idx" to -1,
    on failure. */
 const gchar*
-match_strval_idx(guint32 val, const value_string *vs, gint *idx) {
+match_strval_idx(const guint32 val, const value_string *vs, gint *idx) {
   gint i = 0;
 
   if(vs) {
@@ -89,7 +89,7 @@ match_strval_idx(guint32 val, const value_string *vs, gint *idx) {
 
 /* Like match_strval_idx(), but doesn't return the index. */
 const gchar*
-match_strval(guint32 val, const value_string *vs) {
+match_strval(const guint32 val, const value_string *vs) {
     gint ignore_me;
     return match_strval_idx(val, vs, &ignore_me);
 }
@@ -142,7 +142,7 @@ match_strstr(const gchar *val, const string_string *vs) {
 /* Generate a string describing an enumerated bitfield (an N-bit field
    with various specific values having particular names). */
 const char *
-decode_enumerated_bitfield(guint32 val, guint32 mask, int width,
+decode_enumerated_bitfield(const guint32 val, const guint32 mask, const int width,
     const value_string *tab, const char *fmt)
 {
   static char buf[1025];
@@ -157,7 +157,7 @@ decode_enumerated_bitfield(guint32 val, guint32 mask, int width,
 /* Generate a string describing an enumerated bitfield (an N-bit field
    with various specific values having particular names). */
 const char *
-decode_enumerated_bitfield_shifted(guint32 val, guint32 mask, int width,
+decode_enumerated_bitfield_shifted(const guint32 val, const guint32 mask, const int width,
     const value_string *tab, const char *fmt)
 {
   static char buf[1025];
@@ -180,7 +180,7 @@ decode_enumerated_bitfield_shifted(guint32 val, guint32 mask, int width,
 /* Tries to match val against each range in the range_string array rs.
    Returns the associated string ptr on a match.
    Formats val with fmt, and returns the resulting string, on failure. */
-const gchar *rval_to_str(guint32 val, const range_string *rs, const char *fmt) 
+const gchar *rval_to_str(const guint32 val, const range_string *rs, const char *fmt) 
 {
   const gchar *ret = NULL;
 
@@ -197,7 +197,7 @@ const gchar *rval_to_str(guint32 val, const range_string *rs, const char *fmt)
    Returns the associated string ptr, and sets "*idx" to the index in
    that table, on a match, and returns NULL, and sets "*idx" to -1,
    on failure. */
-const gchar *match_strrval_idx(guint32 val, const range_string *rs, gint *idx)
+const gchar *match_strrval_idx(const guint32 val, const range_string *rs, gint *idx)
 {
   gint i = 0;
 
@@ -216,7 +216,7 @@ const gchar *match_strrval_idx(guint32 val, const range_string *rs, gint *idx)
 }
 
 /* Like match_strrval_idx(), but doesn't return the index. */
-const gchar *match_strrval(guint32 val, const range_string *rs)
+const gchar *match_strrval(const guint32 val, const range_string *rs)
 {
     gint ignore_me = 0;
     return match_strrval_idx(val, rs, &ignore_me);
diff --git a/epan/value_string.h b/epan/value_string.h
index a4ae024ef9..7fcbb30500 100644
--- a/epan/value_string.h
+++ b/epan/value_string.h
@@ -55,20 +55,20 @@ typedef struct _range_string {
    Returns the associated string ptr, and sets "*idx" to the index in
    that table, on a match, and returns NULL, and sets "*idx" to -1,
    on failure. */
-extern const gchar* match_strval_idx(guint32 val, const value_string *vs, gint *idx);
+extern const gchar* match_strval_idx(const guint32 val, const value_string *vs, gint *idx);
 
 /* Like match_strval_idx(), but doesn't return the index. */
-extern const gchar* match_strval(guint32 val, const value_string *vs);
+extern const gchar* match_strval(const guint32 val, const value_string *vs);
 
 /* Tries to match val against each element in the value_string array vs.
    Returns the associated string ptr on a match.
    Formats val with fmt, and returns the resulting string, on failure. */
-extern const gchar* val_to_str(guint32 val, const value_string *vs, const char *fmt);
+extern const gchar* val_to_str(const guint32 val, const value_string *vs, const char *fmt);
 
 /* Tries to match val against each element in the value_string array vs.
    Returns the associated string ptr on a match.
    Returns 'unknown_str', on failure. */
-extern const gchar* val_to_str_const(guint32 val, const value_string *vs, const char *unknown_str);
+extern const gchar* val_to_str_const(const guint32 val, const value_string *vs, const char *unknown_str);
 
 /* Tries to match val against each element in the value_string array vs.
    Returns the associated string ptr, and sets "*idx" to the index in
@@ -86,13 +86,13 @@ extern const gchar* str_to_str(const gchar *val, const string_string *vs, const
 
 /* Generate a string describing an enumerated bitfield (an N-bit field
    with various specific values having particular names). */
-extern const char *decode_enumerated_bitfield(guint32 val, guint32 mask,
-  int width, const value_string *tab, const char *fmt);
+extern const char *decode_enumerated_bitfield(const guint32 val, const guint32 mask,
+  const int width, const value_string *tab, const char *fmt);
 
 /* Generate a string describing an enumerated bitfield (an N-bit field
    with various specific values having particular names). */
-extern const char *decode_enumerated_bitfield_shifted(guint32 val, guint32 mask,
-  int width, const value_string *tab, const char *fmt);
+extern const char *decode_enumerated_bitfield_shifted(const guint32 val, const guint32 mask,
+  const int width, const value_string *tab, const char *fmt);
 
 
 /* ranges aware versions */
@@ -100,15 +100,15 @@ extern const char *decode_enumerated_bitfield_shifted(guint32 val, guint32 mask,
 /* Tries to match val against each range in the range_string array rs.
    Returns the associated string ptr on a match.
    Formats val with fmt, and returns the resulting string, on failure. */
-extern const gchar* rval_to_str(guint32 val, const range_string *rs, const char *fmt);
+extern const gchar* rval_to_str(const guint32 val, const range_string *rs, const char *fmt);
 
 /* Tries to match val against each range in the range_string array rs.
    Returns the associated string ptr, and sets "*idx" to the index in
    that table, on a match, and returns NULL, and sets "*idx" to -1,
    on failure. */
-extern const gchar *match_strrval_idx(guint32 val, const range_string *rs, gint *idx);
+extern const gchar *match_strrval_idx(const guint32 val, const range_string *rs, gint *idx);
 
 /* Like match_strrval_idx(), but doesn't return the index. */
-extern const gchar *match_strrval(guint32 val, const range_string *rs);
+extern const gchar *match_strrval(const guint32 val, const range_string *rs);
 
 #endif /* __VALUE_STRING_H__ */