From: Jonathan Rose <jrose@digium.com>
Date: Wed, 11 Sep 2013 19:46:39 +0000 (+0000)
Subject: chan_sip: Reject calls without prior SDP on 200 OK
X-Git-Tag: 11.6.0-rc1~3^2~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0860ba2a1be17e2c611a5230291b9f6fcf3ec481;p=thirdparty%2Fasterisk.git

chan_sip: Reject calls without prior SDP on 200 OK

If we receive a 200 OK without SDP, we will now check to see if
the remote address has been established for that channel's RTP
session and if the to tag for that channel has changed from
the most recent to tag in a response less than 200.
If either a change has been made since the last to-tag was
received or the remote address is unset, then we will drop
the call.

(closes issue ASTERISK-22424)
Reported by: Jonathan Rose
Review: https://reviewboard.asterisk.org/r/2827/diff/#index_header
........

Merged revisions 398835 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@398836 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index db48ca1d83..ee8c9c38ff 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -22788,6 +22788,15 @@ static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest
 					ast_set_flag(&p->flags[0], SIP_PENDINGBYE);
 				}
 			ast_rtp_instance_activate(p->rtp);
+		} else if (!reinvite) {
+			struct ast_sockaddr remote_address = {{0,}};
+
+			ast_rtp_instance_get_remote_address(p->rtp, &remote_address);
+			if (ast_sockaddr_isnull(&remote_address) || (!ast_strlen_zero(p->theirprovtag) && strcmp(p->theirtag, p->theirprovtag))) {
+				ast_log(LOG_WARNING, "Received response: \"200 OK\" from '%s' without SDP\n", p->relatedpeer->name);
+				ast_set_flag(&p->flags[0], SIP_PENDINGBYE);
+				ast_rtp_instance_activate(p->rtp);
+			}
 		}
 
 		if (!req->ignore && p->owner) {
@@ -23710,7 +23719,11 @@ static void handle_response(struct sip_pvt *p, int resp, const char *rest, struc
 
 		gettag(req, "To", tag, sizeof(tag));
 		ast_string_field_set(p, theirtag, tag);
+	} else {
+		/* Store theirtag to track for changes when 200 responses to invites are received without SDP */
+		ast_string_field_set(p, theirprovtag, p->theirtag);
 	}
+
 	/* This needs to be configurable on a channel/peer level,
 	   not mandatory for all communication. Sadly enough, NAT implementations
 	   are not so stable so we can always rely on these headers.
diff --git a/channels/sip/include/sip.h b/channels/sip/include/sip.h
index 073f5f4d6a..d8bee122ed 100644
--- a/channels/sip/include/sip.h
+++ b/channels/sip/include/sip.h
@@ -1038,6 +1038,7 @@ struct sip_pvt {
 		AST_STRING_FIELD(rdnis);        /*!< Referring DNIS */
 		AST_STRING_FIELD(redircause);   /*!< Referring cause */
 		AST_STRING_FIELD(theirtag);     /*!< Their tag */
+		AST_STRING_FIELD(theirprovtag); /*!< Provisional their tag, used when evaluating responses to invites */
 		AST_STRING_FIELD(tag);          /*!< Our tag for this session */
 		AST_STRING_FIELD(username);     /*!< [user] name */
 		AST_STRING_FIELD(peername);     /*!< [peer] name, not set if [user] */