From b8dba87a4c1af520c92f5183b7b516f006964861 Mon Sep 17 00:00:00 2001
From: Matthew Jordan <mjordan@digium.com>
Date: Tue, 6 Dec 2011 17:34:35 +0000
Subject: [PATCH] Fixed crash from orphaned MWI subscriptions in chan_sip
This patch resolves the issue where MWI subscriptions are orphaned
by subsequent SIP SUBSCRIBE messages. When a peer is removed, either
by pruning realtime SIP peers or by unloading / loading chan_sip, the
MWI subscriptions that were orphaned would still be on the event engine
list of valid subscriptions but have a pointer to a peer that no longer
was valid. When an MWI event would occur, this would cause a seg fault.
(closes issue ASTERISK-18663)
Reported by: Ross Beer
Tested by: Ross Beer, Matt Jordan
Patches:
blf_mwi_diff_12_06_11.txt uploaded by Matt Jordan (license 6283)
Review: https://reviewboard.asterisk.org/r/1610/
........
Merged revisions 347058 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........
Merged revisions 347068 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@347069 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
channels/chan_sip.c | 94 ++++++++++++++++++++++++++++++---------------
1 file changed, 62 insertions(+), 32 deletions(-)
diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index a10106dc7a..ab25f1c46b 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -24940,11 +24940,21 @@ static int handle_request_publish(struct sip_pvt *p, struct sip_request *req, st
return handler_result;
}
+/*! \internal \brief Subscribe to MWI events for the specified peer
+ * \note The peer cannot be locked during this method. sip_send_mwi_peer will
+ * attempt to lock the peer after the event subscription lock is held; if the peer is locked during
+ * this method then we will attempt to lock the event subscription lock but after the peer, creating
+ * a locking inversion.
+ */
static void add_peer_mwi_subs(struct sip_peer *peer)
{
struct sip_mailbox *mailbox;
AST_LIST_TRAVERSE(&peer->mailboxes, mailbox, entry) {
+ if (mailbox->event_sub) {
+ ast_event_unsubscribe(mailbox->event_sub);
+ }
+
mailbox->event_sub = ast_event_subscribe(AST_EVENT_MWI, mwi_event_cb, "SIP mbox event", peer,
AST_EVENT_IE_MAILBOX, AST_EVENT_IE_PLTYPE_STR, mailbox->mailbox,
AST_EVENT_IE_CONTEXT, AST_EVENT_IE_PLTYPE_STR, S_OR(mailbox->context, "default"),
@@ -25098,7 +25108,7 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
/* if an authentication response was sent, we are done here */
if (res == AUTH_CHALLENGE_SENT) /* authpeer = NULL here */
return 0;
- if (res < 0) {
+ if (res != AUTH_SUCCESSFUL) {
if (res == AUTH_FAKE_AUTH) {
ast_log(LOG_NOTICE, "Sending fake auth rejection for device %s\n", sip_get_header(req, "From"));
transmit_fake_auth_response(p, SIP_SUBSCRIBE, req, XMIT_UNRELIABLE);
@@ -25112,17 +25122,17 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
}
}
- /* At this point, authpeer cannot be NULL. Remember we hold a reference,
- * so we must release it when done.
- * XXX must remove all the checks for authpeer == NULL.
+ /* At this point, we hold a reference to authpeer (if not NULL). It
+ * must be released when done.
*/
/* Check if this device is allowed to subscribe at all */
if (!ast_test_flag(&p->flags[1], SIP_PAGE2_ALLOWSUBSCRIBE)) {
transmit_response(p, "403 Forbidden (policy)", req);
pvt_set_needdestroy(p, "subscription not allowed");
- if (authpeer)
+ if (authpeer) {
sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 1)");
+ }
return 0;
}
@@ -25142,8 +25152,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
transmit_response(p, "404 Not Found", req);
}
pvt_set_needdestroy(p, "subscription target not found");
- if (authpeer)
+ if (authpeer) {
sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 2)");
+ }
return 0;
}
@@ -25158,9 +25169,6 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
enum subscriptiontype subscribed = NONE;
const char *unknown_acceptheader = NULL;
- if (authpeer) /* We do not need the authpeer any more */
- authpeer = sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 2)");
-
/* Header from Xten Eye-beam Accept: multipart/related, application/rlmi+xml, application/pidf+xml, application/xpidf+xml */
accept = __get_header(req, "Accept", &start);
while ((subscribed == NONE) && !ast_strlen_zero(accept)) {
@@ -25198,6 +25206,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
p->subscribecontext,
p->subscribeuri);
pvt_set_needdestroy(p, "no Accept header");
+ if (authpeer) {
+ sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 2)");
+ }
return 0;
}
/* if p->subscribed is non-zero, then accept is not obligatory; according to rfc 3265 section 3.1.3, at least.
@@ -25222,6 +25233,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
p->subscribecontext,
p->subscribeuri);
pvt_set_needdestroy(p, "unrecognized format");
+ if (authpeer) {
+ sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 2)");
+ }
return 0;
} else {
p->subscribed = subscribed;
@@ -25244,8 +25258,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
transmit_response(p, "406 Not Acceptable", req);
ast_debug(2, "Received SIP mailbox subscription for unknown format: %s\n", acceptheader);
pvt_set_needdestroy(p, "unknown format");
- if (authpeer)
+ if (authpeer) {
sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 3)");
+ }
return 0;
}
/* Looks like they actually want a mailbox status
@@ -25254,11 +25269,17 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
In most devices, this is configurable to the voicemailmain extension you use
*/
if (!authpeer || AST_LIST_EMPTY(&authpeer->mailboxes)) {
- transmit_response(p, "404 Not found (no mailbox)", req);
+ if (!authpeer) {
+ transmit_response(p, "404 Not found", req);
+ } else {
+ transmit_response(p, "404 Not found (no mailbox)", req);
+ ast_log(LOG_NOTICE, "Received SIP subscribe for peer without mailbox: %s\n", S_OR(authpeer->name, ""));
+ }
pvt_set_needdestroy(p, "received 404 response");
- ast_log(LOG_NOTICE, "Received SIP subscribe for peer without mailbox: %s\n", S_OR(authpeer->name, ""));
- if (authpeer)
- sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 4)");
+
+ if (authpeer) {
+ sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 3)");
+ }
return 0;
}
@@ -25268,18 +25289,21 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
add_peer_mwi_subs(authpeer);
ao2_lock(p);
}
- if (authpeer->mwipvt && authpeer->mwipvt != p) { /* Destroy old PVT if this is a new one */
+ if (authpeer->mwipvt != p) { /* Destroy old PVT if this is a new one */
/* We only allow one subscription per peer */
- dialog_unlink_all(authpeer->mwipvt);
- authpeer->mwipvt = dialog_unref(authpeer->mwipvt, "unref dialog authpeer->mwipvt");
- /* sip_destroy(authpeer->mwipvt); */
- }
- if (authpeer->mwipvt)
- dialog_unref(authpeer->mwipvt, "Unref previously stored mwipvt dialog pointer");
- authpeer->mwipvt = dialog_ref(p, "setting peers' mwipvt to p"); /* Link from peer to pvt UH- should this be dialog_ref()? */
- if (p->relatedpeer)
- sip_unref_peer(p->relatedpeer, "Unref previously stored relatedpeer ptr");
- p->relatedpeer = sip_ref_peer(authpeer, "setting dialog's relatedpeer pointer"); /* already refcounted...Link from pvt to peer UH- should this be dialog_ref()? */
+ if (authpeer->mwipvt) {
+ dialog_unlink_all(authpeer->mwipvt);
+ authpeer->mwipvt = dialog_unref(authpeer->mwipvt, "unref dialog authpeer->mwipvt");
+ }
+ authpeer->mwipvt = dialog_ref(p, "setting peers' mwipvt to p");
+ }
+
+ if (p->relatedpeer != authpeer) {
+ if (p->relatedpeer) {
+ sip_unref_peer(p->relatedpeer, "Unref previously stored relatedpeer ptr");
+ }
+ p->relatedpeer = sip_ref_peer(authpeer, "setting dialog's relatedpeer pointer");
+ }
/* Do not release authpeer here */
} else if (!strcmp(event, "call-completion")) {
handle_cc_subscribe(p, req);
@@ -25287,16 +25311,12 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
transmit_response(p, "489 Bad Event", req);
ast_debug(2, "Received SIP subscribe for unknown event package: %s\n", event);
pvt_set_needdestroy(p, "unknown event package");
- if (authpeer)
+ if (authpeer) {
sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 5)");
+ }
return 0;
}
- /* At this point, if we have an authpeer we should unref it. */
- if (authpeer) {
- authpeer = sip_unref_peer(authpeer, "unref pointer into (*authpeer)");
- }
-
/* Add subscription for extension state from the PBX core */
if (p->subscribed != MWI_NOTIFICATION && p->subscribed != CALL_COMPLETION && !resubscribe) {
if (p->stateid > -1) {
@@ -25321,6 +25341,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
"with Expire header less that 'minexpire' limit. Received \"Expire: %d\" min is %d\n",
p->exten, p->context, p->expiry, min_expiry);
pvt_set_needdestroy(p, "Expires is less that the min expires allowed.");
+ if (authpeer) {
+ sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 6)");
+ }
return 0;
}
@@ -25356,6 +25379,9 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
ast_log(LOG_NOTICE, "Got SUBSCRIBE for extension %s@%s from %s, but there is no hint for that extension.\n", p->exten, p->context, ast_sockaddr_stringify(&p->sa));
transmit_response(p, "404 Not found", req);
pvt_set_needdestroy(p, "no extension for SUBSCRIBE");
+ if (authpeer) {
+ sip_unref_peer(authpeer, "sip_unref_peer, from handle_request_subscribe (authpeer 6)");
+ }
return 0;
}
ast_set_flag(&p->flags[1], SIP_PAGE2_DIALOG_ESTABLISHED);
@@ -25371,6 +25397,10 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
pvt_set_needdestroy(p, "forcing expiration");
}
}
+
+ if (authpeer) {
+ sip_unref_peer(authpeer, "unref pointer into (*authpeer)");
+ }
return 1;
}
@@ -26088,7 +26118,7 @@ static int get_cached_mwi(struct sip_peer *peer, int *new, int *old)
*/
static int sip_send_mwi_to_peer(struct sip_peer *peer, int cache_only)
{
- /* Called with peerl lock, but releases it */
+ /* Called with peer lock, but releases it */
struct sip_pvt *p;
int newmsgs = 0, oldmsgs = 0;
const char *vmexten = NULL;
--
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