Merged revisions 335319 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r335319 | oej | 2011-09-12 15:25:30 +0200 (Mån, 12 Sep 2011) | 12 lines

  Lock the peer->mvipvt to avoid crashes with SIP history enabled

  After the launch of 1.6 event-based MWI we have two threads handling the peer->mwipvt,
  which cause issues with SIP history additions in combination with the max limit for
  number of history entries.

  Review: https://reviewboard.asterisk.org/r/1373/

  (closes issue ASTERISK-18288)

  Thanks to irrot for peer review. Work with this bug funded by IPvision AS
........

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@335323 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index a0e53cfa2dd1a239c7f425a5470c0e42c8081c1d..7054efeb28933345ae5645ca907bed0904bce4e8 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -14341,9 +14341,7 @@ static void mwi_event_cb(const struct ast_event *event, void *userdata)
 {
        struct sip_peer *peer = userdata;
 
-       ao2_lock(peer);
        sip_send_mwi_to_peer(peer, 0);
-       ao2_unlock(peer);
 }
 
 static void network_change_event_subscribe(void)
@@ -24909,9 +24907,7 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
                        ast_set_flag(&p->flags[1], SIP_PAGE2_DIALOG_ESTABLISHED);
                        transmit_response(p, "200 OK", req);
                        if (p->relatedpeer) {   /* Send first notification */
-                               ao2_lock(p->relatedpeer); /* was WRLOCK */
                                sip_send_mwi_to_peer(p->relatedpeer, 0);
-                               ao2_unlock(p->relatedpeer);
                        }
                } else if (p->subscribed != CALL_COMPLETION) {
 
@@ -25649,14 +25645,18 @@ static int sip_send_mwi_to_peer(struct sip_peer *peer, int cache_only)
                }
                ast_app_inboxcount(mailbox_str->str, &newmsgs, &oldmsgs);
        }
+       ao2_lock(peer);
 
        if (peer->mwipvt) {
                /* Base message on subscription */
                p = dialog_ref(peer->mwipvt, "sip_send_mwi_to_peer: Setting dialog ptr p from peer->mwipvt-- should this be done?");
        } else {
                /* Build temporary dialog for this message */
-               if (!(p = sip_alloc(NULL, NULL, 0, SIP_NOTIFY, NULL)))
+               if (!(p = sip_alloc(NULL, NULL, 0, SIP_NOTIFY, NULL))) {
+                       ao2_unlock(peer);
                        return -1;
+               }
+
                /* If we don't set the socket type to 0, then create_addr_from_peer will fail immediately if the peer
                 * uses any transport other than UDP. We set the type to 0 here and then let create_addr_from_peer copy
                 * the peer's socket information to the sip_pvt we just allocated
@@ -25684,11 +25684,17 @@ static int sip_send_mwi_to_peer(struct sip_peer *peer, int cache_only)
                sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
        }
 
+       /* We have multiple threads (mwi events and monitor retransmits) working with this PVT and as we modify the sip history if that's turned on,
+          we really need to have a lock on it */
+       sip_pvt_lock(p);
+
        /* Send MWI */
        ast_set_flag(&p->flags[0], SIP_OUTGOING);
        /* the following will decrement the refcount on p as it finishes */
        transmit_notify_with_mwi(p, newmsgs, oldmsgs, peer->vmexten);
+       sip_pvt_unlock(p);
        dialog_unref(p, "unref dialog ptr p just before it goes out of scope at the end of sip_send_mwi_to_peer.");
+       ao2_unlock(peer);
        return 0;
 }