chan_sip: Prevent extra Session-Expires headers from being added

When chan_sip does a re-INVITE to refresh a session and authentication
is required, the INVITE with the Authorization header containes a
second Session-Expires header without the ";refersher=" parameter.
This is causing some proxies to return a 400.  Also, when Asterisk is
the uas and the refresher, it is including the Session-Expires and
Min-SE headers in OPTIONS messages which is not allowed per RFC4028.

This patch (based on the reporter's) Checks to see if a Session-Expires
header is already in the message before adding another one.  It also
checks that the method is INVITE or UPDATE.

ASTERISK-26030 #close

Change-Id: I58a7b07bab5a3177748d8a7034fb8ad8e11ce1d9

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 0ebfec8b7538637bfbd2fbf27571a51823228d68..dc7218c65e176ac83cbfc3883dfcb1647ce60fa3 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -14172,10 +14172,12 @@ static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init,
                add_header(&req, "Require", "replaces");
        }
 
-       /* Add Session-Timers related headers */
-       if (st_get_mode(p, 0) == SESSION_TIMER_MODE_ORIGINATE
+       /* Add Session-Timers related headers if not already there */
+       if (ast_strlen_zero(sip_get_header(&req, "Session-Expires")) &&
+               (sipmethod == SIP_INVITE || sipmethod == SIP_UPDATE) &&
+               (st_get_mode(p, 0) == SESSION_TIMER_MODE_ORIGINATE
                || (st_get_mode(p, 0) == SESSION_TIMER_MODE_ACCEPT
-                       && st_get_se(p, FALSE) != DEFAULT_MIN_SE)) {
+                       && st_get_se(p, FALSE) != DEFAULT_MIN_SE))) {
                char i2astr[10];
 
                if (!p->stimer->st_interval) {