Issue #7176 - Crash in expire_register

(We need to find out what's causing peer to be undefined, so this
 is just a bandaid, not a real fix)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@27927 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 7fbbd7d9362935c405dbaf06e60b2eea0170b8ab..6eb47c0c66b19a7e4a6c7928ff46821530c1f0b3 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -525,7 +525,7 @@ struct sip_auth {
 #define SIP_REALTIME           (1 << 11)       /*!< Flag for realtime users */
 #define SIP_USECLIENTCODE      (1 << 12)       /*!< Trust X-ClientCode info message */
 #define SIP_OUTGOING           (1 << 13)       /*!< Is this an outgoing call? */
-#define SIP_SELFDESTRUCT       (1 << 14)       
+#define SIP_SELFDESTRUCT       (1 << 14)       /*!< This is an autocreated peer */
 #define SIP_DYNAMIC            (1 << 15)       /*!< Is this a dynamic peer? */
 /* --- Choices for DTMF support in SIP channel */
 #define SIP_DTMF               (3 << 16)       /*!< three settings, uses two bits */
@@ -5639,17 +5639,24 @@ 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);
        
        manager_event(EVENT_FLAG_SYSTEM, "PeerStatus", "Peer: SIP/%s\r\nPeerStatus: Unregistered\r\nCause: Expired\r\n", peer->name);
-       register_peer_exten(peer, 0);
+       register_peer_exten(peer, 0);   /* 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, SIP_SELFDESTRUCT) || ast_test_flag((&peer->flags_page2), SIP_PAGE2_RTAUTOCLEAR)) {
-               peer = ASTOBJ_CONTAINER_UNLINK(&peerl, peer);
+               peer = ASTOBJ_CONTAINER_UNLINK(&peerl, peer);   /* Remove from peer list */
                ASTOBJ_UNREF(peer, sip_destroy_peer);
        }