Const-ify the world (or at least a good part of it)

This patch adds 'const' tags to a number of Asterisk APIs where they are appropriate (where the API already demanded that the function argument not be modified, but the compiler was not informed of that fact). The list includes:

- CLI command handlers
- CLI command handler arguments
- AGI command handlers
- AGI command handler arguments
- Dialplan application handler arguments
- Speech engine API function arguments

In addition, various file-scope and function-scope constant arrays got 'const' and/or 'static' qualifiers where they were missing.

Review: https://reviewboard.asterisk.org/r/251/



git-svn-id: http://svn.digium.com/svn/asterisk/trunk@196072 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 74 insertions, 72 deletions

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 1f3f1554b..4679265e9 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -2348,7 +2348,7 @@ static void free_old_route(struct sip_route *route);
 static void list_route(struct sip_route *route);
 static void build_route(struct sip_pvt *p, struct sip_request *req, int backwards);
 static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr_in *sin,
-					      struct sip_request *req, char *uri);
+					      struct sip_request *req, const char *uri);
 static struct sip_pvt *get_sip_pvt_byid_locked(const char *callid, const char *totag, const char *fromtag);
 static void check_pendings(struct sip_pvt *p);
 static void *sip_park_thread(void *stuff);
@@ -2376,11 +2376,11 @@ static int reply_digest(struct sip_pvt *p, struct sip_request *req, char *header
 static int build_reply_digest(struct sip_pvt *p, int method, char *digest, int digest_len);
 static enum check_auth_result check_auth(struct sip_pvt *p, struct sip_request *req, const char *username,
 					 const char *secret, const char *md5secret, int sipmethod,
-					 char *uri, enum xmittype reliable, int ignore);
+					 const char *uri, enum xmittype reliable, int ignore);
 static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_request *req,
-					      int sipmethod, char *uri, enum xmittype reliable,
+					      int sipmethod, const char *uri, enum xmittype reliable,
 					      struct sockaddr_in *sin, struct sip_peer **authpeer);
-static int check_user(struct sip_pvt *p, struct sip_request *req, int sipmethod, char *uri, enum xmittype reliable, struct sockaddr_in *sin);
+static int check_user(struct sip_pvt *p, struct sip_request *req, int sipmethod, const char *uri, enum xmittype reliable, struct sockaddr_in *sin);
 
 /*--- Domain handling */
 static int check_sip_domain(const char *domain, char *context, size_t len); /* Check if domain is one of our local domains */
@@ -2485,13 +2485,13 @@ static char *complete_sipnotify(const char *line, const char *word, int pos, int
 static char *sip_show_channel(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 static char *sip_show_channelstats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 static char *sip_show_history(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
-static char *sip_do_debug_ip(int fd, char *arg);
-static char *sip_do_debug_peer(int fd, char *arg);
+static char *sip_do_debug_ip(int fd, const char *arg);
+static char *sip_do_debug_peer(int fd, const char *arg);
 static char *sip_do_debug(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 static char *sip_cli_notify(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 static char *sip_set_history(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
-static int sip_dtmfmode(struct ast_channel *chan, void *data);
-static int sip_addheader(struct ast_channel *chan, void *data);
+static int sip_dtmfmode(struct ast_channel *chan, const char *data);
+static int sip_addheader(struct ast_channel *chan, const char *data);
 static int sip_do_reload(enum channelreloadreason reason);
 static char *sip_reload(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 static int acf_channel_read(struct ast_channel *chan, const char *funcname, char *preparse, char *buf, size_t buflen);
@@ -2619,26 +2619,26 @@ static void build_contact(struct sip_pvt *p);
 /*------Request handling functions */
 static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int *recount, int *nounlock);
 static int handle_request_update(struct sip_pvt *p, struct sip_request *req);
-static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, struct sockaddr_in *sin, int *recount, char *e, int *nounlock);
+static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, struct sockaddr_in *sin, int *recount, const char *e, int *nounlock);
 static int handle_request_refer(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, int *nounlock);
 static int handle_request_bye(struct sip_pvt *p, struct sip_request *req);
-static int handle_request_register(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, char *e);
+static int handle_request_register(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, const char *e);
 static int handle_request_cancel(struct sip_pvt *p, struct sip_request *req);
 static int handle_request_message(struct sip_pvt *p, struct sip_request *req);
-static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, char *e);
+static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, const char *e);
 static void handle_request_info(struct sip_pvt *p, struct sip_request *req);
 static int handle_request_options(struct sip_pvt *p, struct sip_request *req);
 static int handle_invite_replaces(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, struct sockaddr_in *sin);
-static int handle_request_notify(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, char *e);
+static int handle_request_notify(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, const char *e);
 static int local_attended_transfer(struct sip_pvt *transferer, struct sip_dual *current, struct sip_request *req, int seqno);
 
 /*------Response handling functions */
-static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
-static void handle_response_notify(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
-static void handle_response_refer(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
-static void handle_response_subscribe(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
-static int handle_response_register(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
-static void handle_response(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno);
+static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
+static void handle_response_notify(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
+static void handle_response_refer(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
+static void handle_response_subscribe(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
+static int handle_response_register(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
+static void handle_response(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno);
 
 /*------ T38 Support --------- */
 static int transmit_response_with_t38_sdp(struct sip_pvt *p, char *msg, struct sip_request *req, int retrans);
@@ -6598,9 +6598,9 @@ static const char *__get_header(const struct sip_request *req, const char *name,
 	for (pass = 0; name && pass < 2;pass++) {
 		int x, len = strlen(name);
 		for (x = *start; x < req->headers; x++) {
-			char *header = REQ_OFFSET_TO_STR(req, header[x]);
+			const char *header = REQ_OFFSET_TO_STR(req, header[x]);
 			if (!strncasecmp(header, name, len)) {
-				char *r = header + len;	/* skip name */
+				const char *r = header + len;	/* skip name */
 				if (sip_cfg.pedanticsipchecking)
 					r = ast_skip_blanks(r);
 
@@ -7545,7 +7545,7 @@ static int find_sdp(struct sip_request *req)
 	   sdp part and the end boundry if it exists */
 
 	for (x = 0; x < (req->lines); x++) {
-		char *line = REQ_OFFSET_TO_STR(req, line[x]);
+		const char *line = REQ_OFFSET_TO_STR(req, line[x]);
 		if (!strncasecmp(line, boundary, strlen(boundary))){
 			if (found_application_sdp && found_end_of_headers) {
 				req->sdp_end = x-1;
@@ -10859,7 +10859,7 @@ static int manager_sipnotify(struct mansession *s, const struct message *m)
 	return 0;
 }
 
-static char mandescr_sipnotify[] =
+static const char mandescr_sipnotify[] =
 "Description: Sends a SIP Notify event\n"
 "All parameters for this event must be specified in the body of this request\n"
 "via multiple Variable: name=value sequences.\n"
@@ -12039,7 +12039,7 @@ AST_THREADSTORAGE(check_auth_buf);
 */
 static enum check_auth_result check_auth(struct sip_pvt *p, struct sip_request *req, const char *username,
 					 const char *secret, const char *md5secret, int sipmethod,
-					 char *uri, enum xmittype reliable, int ignore)
+					 const char *uri, enum xmittype reliable, int ignore)
 {
 	const char *response;
 	char *reqheader, *respheader;
@@ -12404,15 +12404,16 @@ static char *terminate_uri(char *uri)
 	- Registration requests are only matched with peers that are marked as "dynamic"
  */
 static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr_in *sin,
-					      struct sip_request *req, char *uri)
+					      struct sip_request *req, const char *uri)
 {
 	enum check_auth_result res = AUTH_NOT_FOUND;
 	struct sip_peer *peer;
 	char tmp[256];
 	char *name, *c;
 	char *domain;
+	char *uri2 = ast_strdupa(uri);
 
-	terminate_uri(uri);	/* warning, overwrite the string */
+	terminate_uri(uri2);
 
 	ast_copy_string(tmp, get_header(req, "To"), sizeof(tmp));
 	if (sip_cfg.pedanticsipchecking)
@@ -12472,7 +12473,7 @@ static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr
 			ast_copy_flags(&p->flags[0], &peer->flags[0], SIP_NAT);
 			if (ast_test_flag(&p->flags[1], SIP_PAGE2_REGISTERTRYING))
 				transmit_response(p, "100 Trying", req);
-			if (!(res = check_auth(p, req, peer->name, peer->secret, peer->md5secret, SIP_REGISTER, uri, XMIT_UNRELIABLE, req->ignore))) {
+			if (!(res = check_auth(p, req, peer->name, peer->secret, peer->md5secret, SIP_REGISTER, uri2, XMIT_UNRELIABLE, req->ignore))) {
 				if (sip_cancel_destroy(p))
 					ast_log(LOG_WARNING, "Unable to cancel SIP destruction.  Expect bad things.\n");
 
@@ -13695,7 +13696,7 @@ static enum check_auth_result check_peer_ok(struct sip_pvt *p, char *of,
     \return 0 on success, non-zero on failure
 */
 static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_request *req,
-					      int sipmethod, char *uri, enum xmittype reliable,
+					      int sipmethod, const char *uri, enum xmittype reliable,
 					      struct sockaddr_in *sin, struct sip_peer **authpeer)
 {
 	char from[256];
@@ -13813,7 +13814,7 @@ static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_requ
 /*! \brief  Find user 
 	If we get a match, this will add a reference pointer to the user object in ASTOBJ, that needs to be unreferenced
 */
-static int check_user(struct sip_pvt *p, struct sip_request *req, int sipmethod, char *uri, enum xmittype reliable, struct sockaddr_in *sin)
+static int check_user(struct sip_pvt *p, struct sip_request *req, int sipmethod, const char *uri, enum xmittype reliable, struct sockaddr_in *sin)
 {
 	return check_user_full(p, req, sipmethod, uri, reliable, sin, NULL);
 }
@@ -13830,7 +13831,7 @@ static int get_msg_text(char *buf, int len, struct sip_request *req, int addnewl
 	if (y < 0)
 		y = 0;
 	for (x = 0; x < req->lines; x++) {
-		char *line = REQ_OFFSET_TO_STR(req, line[x]);
+		const char *line = REQ_OFFSET_TO_STR(req, line[x]);
 		strncat(buf, line, y); /* safe */
 		y -= strlen(line) + 1;
 		if (y < 0)
@@ -13949,7 +13950,7 @@ static char *transfermode2str(enum transfermodes mode)
 	return "strict";
 }
 
-static struct _map_x_s natmodes[] = {
+static const struct _map_x_s natmodes[] = {
 	{ SIP_NAT_NEVER,        "No"},
 	{ SIP_NAT_ROUTE,        "Route"},
 	{ SIP_NAT_ALWAYS,       "Always"},
@@ -13968,7 +13969,7 @@ static const char *nat2str(int nat)
    delete it. Keeping it enabled generates compiler warnings.
  */
 
-static struct _map_x_s natcfgmodes[] = {
+static const struct _map_x_s natcfgmodes[] = {
 	{ SIP_NAT_NEVER,        "never"},
 	{ SIP_NAT_ROUTE,        "route"},
 	{ SIP_NAT_ALWAYS,       "yes"},
@@ -13989,7 +13990,7 @@ static const char *nat2strconfig(int nat)
 
 
 /* Session-Timer Modes */
-static struct _map_x_s stmodes[] = {
+static const struct _map_x_s stmodes[] = {
         { SESSION_TIMER_MODE_ACCEPT,    "Accept"},
         { SESSION_TIMER_MODE_ORIGINATE, "Originate"},
         { SESSION_TIMER_MODE_REFUSE,    "Refuse"},
@@ -14007,7 +14008,7 @@ static enum st_mode str2stmode(const char *s)
 }
 
 /* Session-Timer Refreshers */
-static struct _map_x_s strefreshers[] = {
+static const struct _map_x_s strefreshers[] = {
         { SESSION_TIMER_REFRESHER_AUTO,     "auto"},
         { SESSION_TIMER_REFRESHER_UAC,      "uac"},
         { SESSION_TIMER_REFRESHER_UAS,      "uas"},
@@ -14166,7 +14167,7 @@ static char *sip_show_users(struct ast_cli_entry *e, int cmd, struct ast_cli_arg
 }
 
 /*! \brief Manager Action SIPShowRegistry description */
-static char mandescr_show_registry[] =
+static const char mandescr_show_registry[] =
 "Description: Lists all registration requests and status\n"
 "Registrations will follow as separate events. followed by a final event called\n"
 "RegistrationsComplete.\n"
@@ -14211,7 +14212,7 @@ static int manager_show_registry(struct mansession *s, const struct message *m)
 	return 0;
 }
 
-static char mandescr_show_peers[] = 
+static const char mandescr_show_peers[] = 
 "Description: Lists SIP peers in text format with details on current status.\n"
 "Peerlist will follow as separate events, followed by a final event called\n"
 "PeerlistComplete.\n"
@@ -14447,10 +14448,10 @@ static int peer_dump_func(void *userobj, void *arg, int flags)
 {
 	struct sip_peer *peer = userobj;
 	int refc = ao2_t_ref(userobj, 0, "");
-	int *fd = arg;
+	struct ast_cli_args *a = (struct ast_cli_args *) arg;
 	
-	ast_cli(*fd, "name: %s\ntype: peer\nobjflags: %d\nrefcount: %d\n\n", 
-			 peer->name, 0, refc);
+	ast_cli(a->fd, "name: %s\ntype: peer\nobjflags: %d\nrefcount: %d\n\n", 
+		peer->name, 0, refc);
 	return 0;
 }
 
@@ -14458,10 +14459,10 @@ static int dialog_dump_func(void *userobj, void *arg, int flags)
 {
 	struct sip_pvt *pvt = userobj;
 	int refc = ao2_t_ref(userobj, 0, "");
-	int *fd = arg;
+	struct ast_cli_args *a = (struct ast_cli_args *) arg;
 	
-	ast_cli(*fd, "name: %s\ntype: dialog\nobjflags: %d\nrefcount: %d\n\n", 
-			 pvt->callid, 0, refc);
+	ast_cli(a->fd, "name: %s\ntype: dialog\nobjflags: %d\nrefcount: %d\n\n", 
+		pvt->callid, 0, refc);
 	return 0;
 }
 
@@ -14485,22 +14486,22 @@ static char *sip_show_objects(struct ast_cli_entry *e, int cmd, struct ast_cli_a
 	if (a->argc != 3)
 		return CLI_SHOWUSAGE;
 	ast_cli(a->fd, "-= Peer objects: %d static, %d realtime, %d autocreate =-\n\n", speerobjs, rpeerobjs, apeerobjs);
-	ao2_t_callback(peers, OBJ_NODATA, peer_dump_func, &a->fd, "initiate ao2_callback to dump peers");
+	ao2_t_callback(peers, OBJ_NODATA, peer_dump_func, a, "initiate ao2_callback to dump peers");
 	ast_cli(a->fd, "-= Registry objects: %d =-\n\n", regobjs);
 	ASTOBJ_CONTAINER_DUMP(a->fd, tmp, sizeof(tmp), &regl);
 	ast_cli(a->fd, "-= Dialog objects:\n\n");
-	ao2_t_callback(dialogs, OBJ_NODATA, dialog_dump_func, &a->fd, "initiate ao2_callback to dump dialogs");
+	ao2_t_callback(dialogs, OBJ_NODATA, dialog_dump_func, a, "initiate ao2_callback to dump dialogs");
 	return CLI_SUCCESS;
 }
 /*! \brief Print call group and pickup group */
-static void  print_group(int fd, ast_group_t group, int crlf)
+static void print_group(int fd, ast_group_t group, int crlf)
 {
 	char buf[256];
 	ast_cli(fd, crlf ? "%s\r\n" : "%s\n", ast_print_group(buf, sizeof(buf), group) );
 }
 
 /*! \brief mapping between dtmf flags and strings */
-static struct _map_x_s dtmfstr[] = {
+static const struct _map_x_s dtmfstr[] = {
 	{ SIP_DTMF_RFC2833,     "rfc2833" },
 	{ SIP_DTMF_INFO,        "info" },
 	{ SIP_DTMF_SHORTINFO,   "shortinfo" },
@@ -14521,7 +14522,7 @@ static int str2dtmfmode(const char *str)
 	return map_s_x(dtmfstr, str, -1);
 }
 
-static struct _map_x_s insecurestr[] = {
+static const struct _map_x_s insecurestr[] = {
 	{ SIP_INSECURE_PORT,    "port" },
 	{ SIP_INSECURE_INVITE,  "invite" },
 	{ SIP_INSECURE_PORT | SIP_INSECURE_INVITE, "port,invite" },
@@ -14644,10 +14645,10 @@ static char *sip_prune_realtime(struct ast_cli_entry *e, int cmd, struct ast_cli
 	struct sip_peer *peer, *pi;
 	int prunepeer = FALSE;
 	int multi = FALSE;
-	char *name = NULL;
+	const char *name = NULL;
 	regex_t regexbuf;
 	struct ao2_iterator i;
-	static char *choices[] = { "all", "like", NULL };
+	static const char * const choices[] = { "all", "like", NULL };
 	char *cmplt;
 	
 	if (cmd == CLI_INIT) {
@@ -14836,7 +14837,7 @@ static char *sip_show_domains(struct ast_cli_entry *e, int cmd, struct ast_cli_a
 }
 #undef FORMAT
 
-static char mandescr_show_peer[] = 
+static const char mandescr_show_peer[] = 
 "Description: Show one SIP peer with details on current status.\n"
 "Variables: \n"
 "  Peer: <name>           The peer name you want to check.\n"
@@ -16393,14 +16394,14 @@ static void handle_request_info(struct sip_pvt *p, struct sip_request *req)
 }
 
 /*! \brief Enable SIP Debugging for a single IP */
-static char *sip_do_debug_ip(int fd, char *arg)
+static char *sip_do_debug_ip(int fd, const char *arg)
 {
 	struct hostent *hp;
 	struct ast_hostent ahp;
 	int port = 0;
 	char *p;
 
-	p = arg;
+	p = ast_strdupa(arg);
 	strsep(&p, ":");
 	if (p)
 		port = atoi(p);
@@ -16422,7 +16423,7 @@ static char *sip_do_debug_ip(int fd, char *arg)
 }
 
 /*! \brief  Turn on SIP debugging for a given peer */
-static char *sip_do_debug_peer(int fd, char *arg)
+static char *sip_do_debug_peer(int fd, const char *arg)
 {
 	struct sip_peer *peer = find_peer(arg, NULL, TRUE, FINDPEERS, FALSE);
 	if (!peer)
@@ -16446,7 +16447,7 @@ static char *sip_do_debug_peer(int fd, char *arg)
 static char *sip_do_debug(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
 	int oldsipdebug = sipdebug & sip_debug_console;
-	char *what;
+	const char *what;
 
 	if (cmd == CLI_INIT) {
 		e->command = "sip set debug {on|off|ip|peer}";
@@ -17310,7 +17311,7 @@ static int sip_reinvite_retry(const void *data)
  *
  * This function is only called upon the receipt of a 401/407 response to an UPDATE.
  */
-static void handle_response_update(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response_update(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	if (p->options) {
 		p->options->auth_type = (resp == 401 ? WWW_AUTH : PROXY_AUTH);
@@ -17321,7 +17322,7 @@ static void handle_response_update(struct sip_pvt *p, int resp, char *rest, stru
 }
 
 /*! \brief Handle SIP response to INVITE dialogue */
-static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	int outgoing = ast_test_flag(&p->flags[0], SIP_OUTGOING);
 	int res = 0;
@@ -17689,7 +17690,7 @@ static void handle_response_invite(struct sip_pvt *p, int resp, char *rest, stru
 /* \brief Handle SIP response in NOTIFY transaction
        We've sent a NOTIFY, now handle responses to it
   */
-static void handle_response_notify(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response_notify(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	switch (resp) {
 	case 200:   /* Notify accepted */
@@ -17732,7 +17733,7 @@ static void handle_response_notify(struct sip_pvt *p, int resp, char *rest, stru
 }
 
 /* \brief Handle SIP response in SUBSCRIBE transaction */
-static void handle_response_subscribe(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response_subscribe(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	struct sip_peer *peer;
 	if (!p->mwi) {
@@ -17803,7 +17804,7 @@ static void handle_response_subscribe(struct sip_pvt *p, int resp, char *rest, s
 /* \brief Handle SIP response in REFER transaction
 	We've sent a REFER, now handle responses to it 
   */
-static void handle_response_refer(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response_refer(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	enum ast_control_transfer message = AST_TRANSFER_FAILED;
 
@@ -17874,7 +17875,7 @@ static void handle_response_refer(struct sip_pvt *p, int resp, char *rest, struc
 }
 
 /*! \brief Handle responses on REGISTER to services */
-static int handle_response_register(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static int handle_response_register(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	int expires, expires_ms;
 	struct sip_registry *r;
@@ -18100,7 +18101,7 @@ static void stop_media_flows(struct sip_pvt *p)
 
 /*! \brief Handle SIP response in dialogue
 	\note only called by handle_incoming */
-static void handle_response(struct sip_pvt *p, int resp, char *rest, struct sip_request *req, int seqno)
+static void handle_response(struct sip_pvt *p, int resp, const char *rest, struct sip_request *req, int seqno)
 {
 	struct ast_channel *owner;
 	int sipmethod;
@@ -18810,7 +18811,7 @@ static const char *gettag(const struct sip_request *req, const char *header, cha
 }
 
 /*! \brief Handle incoming notifications */
-static int handle_request_notify(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, char *e)
+static int handle_request_notify(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, const char *e)
 {
 	/* This is mostly a skeleton for future improvements */
 	/* Mostly created to return proper answers on notifications on outbound REFER's */
@@ -19517,7 +19518,7 @@ static int handle_request_update(struct sip_pvt *p, struct sip_request *req)
  *	plan but try to find the active call and masquerade
  *	into it 
  */
-static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, struct sockaddr_in *sin, int *recount, char *e, int *nounlock)
+static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, struct sockaddr_in *sin, int *recount, const char *e, int *nounlock)
 {
 	int res = 1;
 	int gotdest;
@@ -19580,8 +19581,8 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 		/* If pedantic is on, we need to check the tags. If they're different, this is
 	   	in fact a forked call through a SIP proxy somewhere. */
 		int different;
-		char *initial_rlPart2 = REQ_OFFSET_TO_STR(&p->initreq, rlPart2);
-		char *this_rlPart2 = REQ_OFFSET_TO_STR(req, rlPart2);
+		const char *initial_rlPart2 = REQ_OFFSET_TO_STR(&p->initreq, rlPart2);
+		const char *this_rlPart2 = REQ_OFFSET_TO_STR(req, rlPart2);
 		if (sip_cfg.pedanticsipchecking)
 			different = sip_uri_cmp(initial_rlPart2, this_rlPart2);
 		else
@@ -21013,7 +21014,7 @@ static void add_peer_mwi_subs(struct sip_peer *peer)
 }
 
 /*! \brief  Handle incoming SUBSCRIBE request */
-static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, char *e)
+static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, int seqno, const char *e)
 {
 	int gotdest = 0;
 	int res = 0;
@@ -21333,7 +21334,7 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
 }
 
 /*! \brief Handle incoming REGISTER request */
-static int handle_request_register(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, char *e)
+static int handle_request_register(struct sip_pvt *p, struct sip_request *req, struct sockaddr_in *sin, const char *e)
 {
 	enum check_auth_result res;
 
@@ -21401,7 +21402,7 @@ static int handle_incoming(struct sip_pvt *p, struct sip_request *req, struct so
 	int respid;
 	int res = 0;
 	int debug = sip_debug_test_pvt(p);
-	char *e;
+	const char *e;
 	int error = 0;
 
 	/* Get Method and Cseq */
@@ -25058,10 +25059,10 @@ static char *app_sipaddheader = "SIPAddHeader";
 static char *app_sipremoveheader = "SIPRemoveHeader";
 
 /*! \brief Set the DTMFmode for an outbound SIP call (application) */
-static int sip_dtmfmode(struct ast_channel *chan, void *data)
+static int sip_dtmfmode(struct ast_channel *chan, const char *data)
 {
 	struct sip_pvt *p;
-	char *mode = data;
+	const char *mode = data;
 
 	if (!data) {
 		ast_log(LOG_WARNING, "This application requires the argument: info, inband, rfc2833\n");
@@ -25116,12 +25117,13 @@ static int sip_dtmfmode(struct ast_channel *chan, void *data)
 }
 
 /*! \brief Add a SIP header to an outbound INVITE */
-static int sip_addheader(struct ast_channel *chan, void *data)
+static int sip_addheader(struct ast_channel *chan, const char *data)
 {
 	int no = 0;
 	int ok = FALSE;
 	char varbuf[30];
-	char *inbuf = data, *subbuf;
+	const char *inbuf = data;
+	char *subbuf;
 	
 	if (ast_strlen_zero(inbuf)) {
 		ast_log(LOG_WARNING, "This application requires the argument: Header\n");
@@ -25155,7 +25157,7 @@ static int sip_addheader(struct ast_channel *chan, void *data)
 }
 
 /*! \brief Remove SIP headers added previously with SipAddHeader application */
-static int sip_removeheader(struct ast_channel *chan, void *data)
+static int sip_removeheader(struct ast_channel *chan, const char *data)
 {
 	struct ast_var_t *newvariable;
 	struct varshead *headp;