Index: channels/chan_sip.c
===================================================================
RCS file: /usr/cvsroot/asterisk/channels/chan_sip.c,v
retrieving revision 1.839
diff -u -r1.839 chan_sip.c
--- channels/chan_sip.c	7 Sep 2005 04:23:15 -0000	1.839
+++ channels/chan_sip.c	7 Sep 2005 17:11:23 -0000
@@ -433,6 +433,7 @@
 	char *line[SIP_MAX_LINES];
 	char data[SIP_MAX_PACKET];
 	int debug;		/* Debug flag for this packet */
+	unsigned int flags;	/* SIP_PKT Flags for this packet */
 };
 
 struct sip_pkt;
@@ -515,7 +516,8 @@
 #define SIP_OSPAUTH_EXCLUSIVE	(2 << 26)
 /* Call states */
 #define SIP_CALL_ONHOLD		(1 << 28)	 
-#define SIP_CALL_LIMIT		(1 << 29)
+#define SIP_CALL_LIMIT		(1 << 29)	/* Call limit enforced on this session */
+
 
 /* a new page of flags for peer */
 #define SIP_PAGE2_RTCACHEFRIENDS 	(1 << 0)
@@ -523,6 +525,11 @@
 #define SIP_PAGE2_RTAUTOCLEAR 		(1 << 2)
 #define SIP_PAGE2_RTIGNOREREGEXPIRE       (1 << 3)
 
+/* SIP packet flags */
+#define SIP_PKT_WITH_TOTAG	(1 << 0)	/* This packet has a to-tag */
+#define SIP_PKT_WITH_FROMTAG	(1 << 1)	/* This packet has a from-tag */
+#define SIP_PKT_DEBUG		(1 << 2)	/* Debug this packet */
+
 static int global_rtautoclear = 120;
 
 /* sip_pvt: PVT structures are used for each SIP conversation, ie. a call  */
@@ -642,7 +649,7 @@
 	int retrans;				/* Retransmission number */
 	int method;				/* SIP method for this packet */
 	int seqno;				/* Sequence number */
-	unsigned int flags;			/* non-zero if this is a response packet (e.g. 200 OK) */
+	unsigned int flags;			/* Flags */
 	struct sip_pvt *owner;			/* Owner call */
 	int retransid;				/* Retransmission ID */
 	int timer_a;				/* SIP timer A, retransmission timer */
@@ -2992,13 +2999,16 @@
 }
 
 /*--- find_call: Connect incoming SIP message to current dialog or create new dialog structure */
-/*               Called by handle_request ,sipsock_read */
+/*               Called by handle_request, sipsock_read */
 static struct sip_pvt *find_call(struct sip_request *req, struct sockaddr_in *sin, const int intended_method)
 {
 	struct sip_pvt *p;
 	char *callid;
-	char tmp[256] = "";
 	char *tag = "", *c;
+	int badsyntax = 0;
+	char toheader[128] = "";
+	char fromheader[128] = "";
+	char *fromtag = "", *totag = "";
 
 	callid = get_header(req, "Call-ID");
 
@@ -3006,32 +3016,98 @@
 		/* In principle Call-ID's uniquely identify a call, but with a forking SIP proxy
 		   we need more to identify a branch - so we have to check branch, from
 		   and to tags to identify a call leg.
-		     For Asterisk to behave correctly, you need to turn on pedanticsipchecking
+		   For Asterisk to behave correctly, you need to turn on pedanticsipchecking
 		   in sip.conf
 		   */
+		totag = get_header(req, "To");
+		c = strcasestr(totag, ";tag=");
+		if (c) {
+			ast_copy_string(toheader, c+5 , sizeof(toheader));
+			totag = toheader;
+			ast_set_flag(req, SIP_PKT_WITH_TOTAG);
+		} else
+			totag = NULL;
+		if (totag) {
+			if ((c = strchr(totag, ';')))
+				*c = '\0';
+		}
+		fromtag = get_header(req, "From");
+		c = strcasestr(fromtag, ";tag=");
+		if (c) {
+			ast_copy_string(fromheader, c+5, sizeof(fromheader));
+			fromtag = fromheader;
+			ast_set_flag(req, SIP_PKT_WITH_FROMTAG);
+		} else
+			fromtag = NULL;
+
+		if (fromtag) {
+			if ((c = strchr(fromtag, ';')))
+				*c = '\0';
+		}
 		if (req->method == SIP_RESPONSE)
-			ast_copy_string(tmp, get_header(req, "To"), sizeof(tmp));
+			tag = totag;
 		else
-			ast_copy_string(tmp, get_header(req, "From"), sizeof(tmp));
-		tag = strcasestr(tmp, "tag=");
-		if (tag) {
-			tag += 4;
-			c = strchr(tag, ';');
-			if (c)
-				*c = '\0';
+			tag = fromtag;
+		if (option_debug > 3) {
+			if (req->method != SIP_RESPONSE) { 		/* Request */
+				if (totag && fromtag)
+					ast_log(LOG_DEBUG, "...Request within an existing dialog\n");
+				else if (totag && !fromtag)
+					ast_log(LOG_DEBUG, "...Request with no fromtag? Bad request.\n");
+				else if (!totag && !fromtag)
+					ast_log(LOG_DEBUG, "...Request with no tags? Bad request.\n");
+				else if (option_debug > 3)	/* From tag, no to tag */
+					ast_log(LOG_DEBUG, "New SIP request coming in:  Call ID: %s (Checking %s) --From tag %s --To-tag %s  \n", callid, req->method==SIP_RESPONSE ? "To" : "From", fromtag, totag);
+			} else {					/* Response */
+				if (totag && fromtag)
+					ast_log(LOG_DEBUG, "SIP response coming in:  Call ID: %s (Checking %s) --From tag %s --To-tag %s  \n", callid, req->method==SIP_RESPONSE ? "To" : "From", fromtag, totag);
+				else if (totag && !fromtag)
+					ast_log(LOG_DEBUG, "...Response with no fromtag? Bad response on bad request.\n");
+				else if (!totag && !fromtag)
+					ast_log(LOG_DEBUG, "...Response with no tags at all? Bad response.\n");
+					
+			}
+		}
+		if (!fromtag) {					/* Always need from tags */
+			badsyntax = 1;
+			ast_log(LOG_WARNING, "Bad SIP %s in dialog %s. \n", req->method==SIP_RESPONSE ? "Response" : "Request", callid);
 		}
 			
 	}
+
+	if (!badsyntax && option_debug > 3)
+		ast_log(LOG_DEBUG, "= Looking for  Call ID: %s (Checking %s) --From tag %s --To-tag %s  \n", callid, req->method==SIP_RESPONSE ? "To" : "From", fromtag, totag);
 		
 	ast_mutex_lock(&iflock);
 	p = iflist;
-	while(p) {
+	while(p && !badsyntax) {	/* In pedantic, we do not want packets with bad syntax to be connected to a PVT */
 		int found = 0;
 		if (req->method == SIP_REGISTER)
 			found = (!strcmp(p->callid, callid));
 		else 
 			found = (!strcmp(p->callid, callid) && 
 			(!pedanticsipchecking || !tag || ast_strlen_zero(p->theirtag) || !strcmp(p->theirtag, tag))) ;
+
+		if (option_debug > 3)
+			ast_log(LOG_DEBUG, "= %s Their Call ID: %s Their Tag %s Our tag: as%08x\n", found ? "Found" : "No match", p->callid, p->theirtag, p->tag);
+
+		/* If we get a new request within an existing to-tag - check the to tag as well */
+		if (pedanticsipchecking && found  && req->method != SIP_RESPONSE) {	/* SIP Request */
+			if (p->tag == 0 && totag) {
+				/* We have no to tag, and they have. Wrong dialog */
+				found = 0;
+			} else if (totag) {			/* Both have tags, compare them */
+				char ourtag[12];
+				sprintf(ourtag, "as%08x", p->tag);
+				if (strcmp(totag, ourtag)) {
+					found = 0;		/* This is not our packet */
+				}
+			}
+			if (!found && option_debug > 3)
+				ast_log(LOG_DEBUG, "= Being pedantic: This is not our match on request: Call ID: %s Ourtag <null> Totag %s Method %s\n", p->callid, totag, sip_methods[req->method].text);
+		}
+
+
 		if (found) {
 			/* Found the call */
 			ast_mutex_lock(&p->lock);
@@ -3042,8 +3118,6 @@
 	}
 	ast_mutex_unlock(&iflock);
 	p = sip_alloc(callid, sin, 1, intended_method);
-	if (p)
-		ast_mutex_lock(&p->lock);
 	return p;
 }
 
@@ -9079,13 +9153,13 @@
 		msg = "";
 	else
 		msg++;
-	sipmethod = find_sip_method(msg);
+	sipmethod = find_sip_method(msg);	/* Find method of packet we're getting response to */
 
 	owner = p->owner;
 	if (owner) 
 		owner->hangupcause = hangup_sip2cause(resp);
 
-	/* Acknowledge whatever it is destined for */
+	/* Stop retransmission of packet this is a reply to */
 	if ((resp >= 100) && (resp <= 199))
 		__sip_semi_ack(p, seqno, 0, sipmethod);
 	else
@@ -9102,7 +9176,8 @@
 			if (to)
 				*to = '\0';
 		}
-	}
+	} 
+
 	if (p->peerpoke) {
 		/* We don't really care what the response is, just that it replied back. 
 		   Well, as long as it's not a 100 response...  since we might
@@ -10212,12 +10287,15 @@
 	/* New SIP request coming in 
 	   (could be new request in existing SIP dialog as well...) 
 	 */			
+	
 	p->method = req->method;	/* Find out which SIP method they are using */
 	if (option_debug > 2)
 		ast_log(LOG_DEBUG, "**** Received %s (%d) - Command in SIP %s\n", sip_methods[p->method].text, sip_methods[p->method].id, cmd); 
 
 	if (p->icseq && (p->icseq > seqno)) {
 		ast_log(LOG_DEBUG, "Ignoring too old SIP packet packet %d (expecting >= %d)\n", seqno, p->icseq);
+		/* No from tag on request? Don't bother with it */
+		transmit_response(p, "503 Server error", req);	/* We must respond according to RFC 3261 sec 12.2 */
 		return -1;
 	} else if (p->icseq && (p->icseq == seqno) && req->method != SIP_ACK &&(p->method != SIP_CANCEL|| ast_test_flag(p, SIP_ALREADYGONE))) {
 		/* ignore means "don't do anything with it" but still have to 
@@ -10237,9 +10315,9 @@
 	/* Find their tag if we haven't got it */
 	if (ast_strlen_zero(p->theirtag)) {
 		from = get_header(req, "From");
-		from = strcasestr(from, "tag=");
+		from = strcasestr(from, ";tag=");
 		if (from) {
-			from += 4;
+			from += 5;
 			ast_copy_string(p->theirtag, from, sizeof(p->theirtag));
 			from = strchr(p->theirtag, ';');
 			if (from)
@@ -10248,6 +10326,35 @@
 	}
 	snprintf(p->lastmsg, sizeof(p->lastmsg), "Rx: %s", cmd);
 
+	if (pedanticsipchecking) {
+		/* If this is a request packet without a from tag, it's not
+			correct according to RFC 3261  */
+		if (!ast_test_flag(req, SIP_PKT_WITH_FROMTAG)) {	/* Only happens in pedantic */
+			/* No from tag on request? Don't bother with it */
+			if (!ignore && req->method == SIP_INVITE) {
+				transmit_response_reliable(p, "400 Bad Request", req, 1);
+				/* Will cease to exist after ACK */
+			} else {
+				transmit_response(p, "400 Bad Request", req);
+				ast_set_flag(p, SIP_NEEDDESTROY);
+			}
+		}
+
+		/* Check if this a new request in a new dialog with a totag already attached to it,
+			if it is, and it is not matched to a current call, forget it. 
+			RFC 3261 - section 12.2 - and we don't want to mess with recovery  */
+		if (!p->initreq.headers && ast_test_flag(req, SIP_PKT_WITH_TOTAG)) {
+			/* If this is a first request and it got a to-tag, it is not for us */
+			if (!ignore && req->method == SIP_INVITE) {
+				transmit_response_reliable(p, "481 Call/Transaction Does Not Exist", req, 1);
+				/* Will cease to exist after ACK */
+			} else {
+				transmit_response(p, "481 Call/Transaction Does Not Exist", req);
+				ast_set_flag(p, SIP_NEEDDESTROY);
+			}
+		}
+	}
+
 	/* Handle various incoming SIP methods in requests */
 	switch (p->method) {
 	case SIP_OPTIONS:
@@ -10344,14 +10451,16 @@
 	}
 	req.data[res] = '\0';
 	req.len = res;
-	req.debug = sip_debug_test_addr(&sin);
+	if(sip_debug_test_addr(&sin))
+		ast_set_flag(&req, SIP_PKT_DEBUG);
 	if (pedanticsipchecking)
 		req.len = lws2sws(req.data, req.len);	/* Fix multiline headers */
-	if (req.debug)
+	if (ast_test_flag(&req, SIP_PKT_DEBUG)) {
 		ast_verbose("\n<-- SIP read from %s:%d: \n%s\n", ast_inet_ntoa(iabuf, sizeof(iabuf), sin.sin_addr), ntohs(sin.sin_port), req.data);
+	}
 	parse_request(&req);
 	req.method = find_sip_method(req.rlPart1);
-	if (req.debug) {
+	if (ast_test_flag(&req, SIP_PKT_DEBUG)) {
 		ast_verbose("--- (%d headers %d lines)", req.headers, req.lines);
 		if (req.headers + req.lines == 0) 
 			ast_verbose(" Nat keepalive ");