Issue #7176 - Crash in expire_register (imported from 1.2)

This is a bad fix, since peer should never be 0. Why is it zero
on Royk's system?

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@27928 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index c776517b5d6c9877d2c1a2945058f340a444bd6a..ac1fd58d0f3a38524544d88cf66d322c8d3eb6a0 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -6070,19 +6070,26 @@ static void destroy_association(struct sip_peer *peer)
 static int expire_register(void *data)
 {
        struct sip_peer *peer = data;
+       
+       if (!peer)              /* Hmmm. We have no peer. Weird. */
+               return 0;
 
        memset(&peer->addr, 0, sizeof(peer->addr));
 
-       destroy_association(peer);
+       destroy_association(peer);      /* remove registration data from storage */
        
        manager_event(EVENT_FLAG_SYSTEM, "PeerStatus", "Peer: SIP/%s\r\nPeerStatus: Unregistered\r\nCause: Expired\r\n", peer->name);
-       register_peer_exten(peer, FALSE);
+       register_peer_exten(peer, FALSE);       /* Remove regexten */
        peer->expire = -1;
        ast_device_state_changed("SIP/%s", peer->name);
+
+       /* Do we need to release this peer from memory? 
+               Only for realtime peers and autocreated peers
+       */
        if (ast_test_flag(&peer->flags[1], SIP_PAGE2_SELFDESTRUCT) ||
            ast_test_flag(&peer->flags[1], SIP_PAGE2_RTAUTOCLEAR)) {
-               peer = ASTOBJ_CONTAINER_UNLINK(&peerl, peer);
-               ASTOBJ_UNREF(peer, sip_destroy_peer);
+               peer = ASTOBJ_CONTAINER_UNLINK(&peerl, peer);   /* Remove from peer list */
+               ASTOBJ_UNREF(peer, sip_destroy_peer);           /* Remove from memory */
        }
 
        return 0;