Show SACK information in TCP graphs. Also add a generated field for the

number of SACK ranges found in the SACK option.

This involved extending the IP options framework to include an extra
void* data field, which in the case of TCP is filled in with the tap
struct - other users currently pass NULL.

I first implemented the graph to sort the SACK ranges and show (in red)
the unacknowledged regions between them, but this became confusing where
the number of ranges is limited by TCP padding bytes. i.e. you can't
tell how many SACKs could have been encoded, so some of the gaps between
ranges may already have been received.

svn path=/trunk/; revision=46006

1 files changed, 30 insertions, 19 deletions

diff --git a/epan/dissectors/packet-ip.c b/epan/dissectors/packet-ip.c
index 7146f4bced..d1957d8a35 100644
--- a/epan/dissectors/packet-ip.c
+++ b/epan/dissectors/packet-ip.c
@@ -660,7 +660,7 @@ dissect_ipopt_type(tvbuff_t *tvb, int offset, proto_tree *tree)
 static void
 dissect_ipopt_eool(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
                    guint optlen _U_, packet_info *pinfo _U_,
-                   proto_tree *opt_tree)
+                   proto_tree *opt_tree, void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -732,7 +732,8 @@ static const int *ip_opt_sec_prot_auth_fields_byte_n[] = {
 };
 static void
 dissect_ipopt_security(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                       guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                       guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                       void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -803,7 +804,8 @@ dissect_ipopt_security(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 
 static void
 dissect_ipopt_ext_security(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                           guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                           guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                           void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -842,7 +844,8 @@ dissect_ipopt_ext_security(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
  * http://tools.ietf.org/html/draft-ietf-cipso-ipsecurity-01 */
 static void
 dissect_ipopt_cipso(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                    guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                    guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                    void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1103,7 +1106,8 @@ dissect_option_route(proto_tree *tree, tvbuff_t *tvb, int offset, int hf,
 
 static void
 dissect_ipopt_route(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                    guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                    guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                    void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1187,7 +1191,7 @@ dissect_ipopt_route(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 static void
 dissect_ipopt_record_route(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
                            guint optlen, packet_info *pinfo,
-                           proto_tree *opt_tree)
+                           proto_tree *opt_tree, void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1251,7 +1255,8 @@ dissect_ipopt_record_route(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 /* Stream Identifier */
 static void
 dissect_ipopt_sid(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                  guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                  guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                  void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1270,7 +1275,8 @@ dissect_ipopt_sid(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 /* RFC 1063: MTU Probe and MTU Reply */
 static void
 dissect_ipopt_mtu(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                  guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                  guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                  void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1289,7 +1295,8 @@ dissect_ipopt_mtu(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 /* RFC 1393: Traceroute */
 static void
 dissect_ipopt_tr(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                  guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                  guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                  void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1312,7 +1319,7 @@ dissect_ipopt_tr(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 static void
 dissect_ipopt_timestamp(const ip_tcp_opt *optp, tvbuff_t *tvb,
                         int offset, guint optlen, packet_info *pinfo,
-                        proto_tree *opt_tree)
+                        proto_tree *opt_tree, void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1395,7 +1402,8 @@ static const range_string ra_rvals[] = {
 
 static void
 dissect_ipopt_ra(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                 guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                 guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                 void * data _U_)
 {
   /* Router-Alert, as defined by RFC2113 */
   proto_tree *field_tree;
@@ -1418,7 +1426,8 @@ dissect_ipopt_ra(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
 /* RFC 1770: Selective Directed Broadcast */
 static void
 dissect_ipopt_sdb(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                 guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                 guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                 void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1467,7 +1476,8 @@ value_string_ext qs_rate_vals_ext = VALUE_STRING_EXT_INIT(qs_rate_vals);
 
 static void
 dissect_ipopt_qs(const ip_tcp_opt *optp, tvbuff_t *tvb, int offset,
-                 guint optlen, packet_info *pinfo, proto_tree *opt_tree)
+                 guint optlen, packet_info *pinfo, proto_tree *opt_tree,
+                 void * data _U_)
 {
   proto_tree *field_tree;
   proto_item *tf;
@@ -1587,8 +1597,8 @@ static const ip_tcp_opt ipopts[] = {
 void
 dissect_ip_tcp_options(tvbuff_t *tvb, int offset, guint length,
                        const ip_tcp_opt *opttab, int nopts, int eol,
-                        packet_info *pinfo, proto_tree *opt_tree,
-                        proto_item *opt_item)
+                       packet_info *pinfo, proto_tree *opt_tree,
+                       proto_item *opt_item, void * data)
 {
   guchar            opt;
   const ip_tcp_opt *optp;
@@ -1596,7 +1606,8 @@ dissect_ip_tcp_options(tvbuff_t *tvb, int offset, guint length,
   unsigned int      optlen;
   const char       *name;
   void            (*dissect)(const struct ip_tcp_opt *, tvbuff_t *,
-                             int, guint, packet_info *, proto_tree *);
+                             int, guint, packet_info *, proto_tree *,
+                             void *);
   guint             len, nop_count = 0;
 
   while (length > 0) {
@@ -1679,7 +1690,7 @@ dissect_ip_tcp_options(tvbuff_t *tvb, int offset, guint length,
             /* Option has a dissector. */
             proto_item_append_text(proto_tree_get_parent(opt_tree), ", %s",
                                    optp->name);
-            (*dissect)(optp, tvb, offset, len, pinfo, opt_tree);
+            (*dissect)(optp, tvb, offset, len, pinfo, opt_tree, data);
           } else {
             proto_tree *field_tree;
             proto_item *tf;
@@ -1700,7 +1711,7 @@ dissect_ip_tcp_options(tvbuff_t *tvb, int offset, guint length,
       if (dissect != NULL) {
         proto_item_append_text(proto_tree_get_parent(opt_tree), ", %s",
                                optp->name);
-        (*dissect)(optp, tvb, offset, 1, pinfo, opt_tree);
+        (*dissect)(optp, tvb, offset, 1, pinfo, opt_tree, data);
       } else {
         proto_tree *field_tree;
         proto_item *tf;
@@ -2304,7 +2315,7 @@ dissect_ip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
                              "Options: (%u bytes)", optlen);
     field_tree = proto_item_add_subtree(tf, ett_ip_options);
     dissect_ip_tcp_options(tvb, offset + 20, optlen, ipopts, N_IP_OPTS,
-                           IPOPT_EOOL, pinfo, field_tree, tf);
+                           IPOPT_EOOL, pinfo, field_tree, tf, NULL);
   }
 
   pinfo->ipproto = iph->ip_p;