[asterisk-commits] dvossel: branch 10 r331868 - in /branches/10: ./ channels/chan_sip.c
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Mon Aug 15 10:14:17 CDT 2011
Author: dvossel
Date: Mon Aug 15 10:14:13 2011
New Revision: 331868
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=331868
Log:
Merged revisions 331867 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.8
........
r331867 | dvossel | 2011-08-15 10:12:16 -0500 (Mon, 15 Aug 2011) | 6 lines
Fixes locking inversion issues present in the handling of the sip REFER method.
(closes issue ASTERISK-18082)
Reported by: James Van Vleet
........
Modified:
branches/10/ (props changed)
branches/10/channels/chan_sip.c
Propchange: branches/10/
------------------------------------------------------------------------------
Binary property 'branch-1.8-merged' - no diff available.
Modified: branches/10/channels/chan_sip.c
URL: http://svnview.digium.com/svn/asterisk/branches/10/channels/chan_sip.c?view=diff&rev=331868&r1=331867&r2=331868
==============================================================================
--- branches/10/channels/chan_sip.c (original)
+++ branches/10/channels/chan_sip.c Mon Aug 15 10:14:13 2011
@@ -23257,15 +23257,26 @@
*/
static int handle_request_refer(struct sip_pvt *p, struct sip_request *req, int debug, int seqno, int *nounlock)
{
- struct sip_dual current; /* Chan1: Call between asterisk and transferer */
- /* Chan2: Call between asterisk and transferee */
-
+ /*!
+ * Chan1: Call between asterisk and transferer
+ * Chan2: Call between asterisk and transferee
+ */
+ struct sip_dual current = { 0, };
+ struct ast_channel *chans[2] = { 0, };
+ char *refer_to = NULL;
+ char *refer_to_domain = NULL;
+ char *refer_to_context = NULL;
+ char *referred_by = NULL;
+ char *callid = NULL;
+ int localtransfer = 0;
+ int attendedtransfer = 0;
int res = 0;
- struct ast_channel *chans[2];
- current.req.data = NULL;
-
- if (req->debug)
- ast_verbose("Call %s got a SIP call transfer from %s: (REFER)!\n", p->callid, ast_test_flag(&p->flags[0], SIP_OUTGOING) ? "callee" : "caller");
+
+ if (req->debug) {
+ ast_verbose("Call %s got a SIP call transfer from %s: (REFER)!\n",
+ p->callid,
+ ast_test_flag(&p->flags[0], SIP_OUTGOING) ? "callee" : "caller");
+ }
if (!p->owner) {
/* This is a REFER outside of an existing SIP dialog */
@@ -23277,9 +23288,9 @@
sip_alreadygone(p);
pvt_set_needdestroy(p, "outside of dialog");
}
- return 0;
- }
-
+ res = 0;
+ goto handle_refer_cleanup;
+ }
/* Check if transfer is allowed from this device */
if (p->allowtransfer == TRANSFER_CLOSED ) {
@@ -23287,21 +23298,24 @@
transmit_response(p, "603 Declined (policy)", req);
append_history(p, "Xfer", "Refer failed. Allowtransfer == closed.");
/* Do not destroy SIP session */
- return 0;
+ res = 0;
+ goto handle_refer_cleanup;
}
if (!req->ignore && ast_test_flag(&p->flags[0], SIP_GOTREFER)) {
/* Already have a pending REFER */
transmit_response(p, "491 Request pending", req);
append_history(p, "Xfer", "Refer failed. Request pending.");
- return 0;
+ res = 0;
+ goto handle_refer_cleanup;
}
/* Allocate memory for call transfer data */
if (!p->refer && !sip_refer_allocate(p)) {
transmit_response(p, "500 Internal Server Error", req);
append_history(p, "Xfer", "Refer failed. Memory allocation error.");
- return -3;
+ res = -3;
+ goto handle_refer_cleanup;
}
res = get_refer_info(p, req); /* Extract headers */
@@ -23313,14 +23327,16 @@
case -2: /* Syntax error */
transmit_response(p, "400 Bad Request (Refer-to missing)", req);
append_history(p, "Xfer", "Refer failed. Refer-to missing.");
- if (req->debug)
+ if (req->debug) {
ast_debug(1, "SIP transfer to black hole can't be handled (no refer-to: )\n");
+ }
break;
case -3:
transmit_response(p, "603 Declined (Non sip: uri)", req);
append_history(p, "Xfer", "Refer failed. Non SIP uri");
- if (req->debug)
+ if (req->debug) {
ast_debug(1, "SIP transfer to non-SIP uri denied\n");
+ }
break;
default:
/* Refer-to extension not found, fake a failed transfer */
@@ -23328,30 +23344,36 @@
append_history(p, "Xfer", "Refer failed. Bad extension.");
transmit_notify_with_sipfrag(p, seqno, "404 Not found", TRUE);
ast_clear_flag(&p->flags[0], SIP_GOTREFER);
- if (req->debug)
+ if (req->debug) {
ast_debug(1, "SIP transfer to bad extension: %s\n", p->refer->refer_to);
+ }
break;
}
- return 0;
- }
- if (ast_strlen_zero(p->context))
+ res = 0;
+ goto handle_refer_cleanup;
+ }
+ if (ast_strlen_zero(p->context)) {
ast_string_field_set(p, context, sip_cfg.default_context);
+ }
/* If we do not support SIP domains, all transfers are local */
if (sip_cfg.allow_external_domains && check_sip_domain(p->refer->refer_to_domain, NULL, 0)) {
p->refer->localtransfer = 1;
- if (sipdebug)
+ if (sipdebug) {
ast_debug(3, "This SIP transfer is local : %s\n", p->refer->refer_to_domain);
+ }
} else if (AST_LIST_EMPTY(&domain_list) || check_sip_domain(p->refer->refer_to_domain, NULL, 0)) {
/* This PBX doesn't bother with SIP domains or domain is local, so this transfer is local */
p->refer->localtransfer = 1;
- } else if (sipdebug)
- ast_debug(3, "This SIP transfer is to a remote SIP extension (remote domain %s)\n", p->refer->refer_to_domain);
+ } else if (sipdebug) {
+ ast_debug(3, "This SIP transfer is to a remote SIP extension (remote domain %s)\n", p->refer->refer_to_domain);
+ }
/* Is this a repeat of a current request? Ignore it */
/* Don't know what else to do right now. */
- if (req->ignore)
- return res;
+ if (req->ignore) {
+ goto handle_refer_cleanup;
+ }
/* If this is a blind transfer, we have the following
channels to work with:
@@ -23377,32 +23399,42 @@
header in the INVITE.
*/
-
/* Get the transferer's channel */
chans[0] = current.chan1 = p->owner;
/* Find the other part of the bridge (2) - transferee */
chans[1] = current.chan2 = ast_bridged_channel(current.chan1);
- if (sipdebug)
- ast_debug(3, "SIP %s transfer: Transferer channel %s, transferee channel %s\n", p->refer->attendedtransfer ? "attended" : "blind", current.chan1->name, current.chan2 ? current.chan2->name : "<none>");
+ ast_channel_ref(current.chan1);
+ if (current.chan2) {
+ ast_channel_ref(current.chan2);
+ }
+
+ if (sipdebug) {
+ ast_debug(3, "SIP %s transfer: Transferer channel %s, transferee channel %s\n",
+ p->refer->attendedtransfer ? "attended" : "blind",
+ current.chan1->name,
+ current.chan2 ? current.chan2->name : "<none>");
+ }
if (!current.chan2 && !p->refer->attendedtransfer) {
/* No bridged channel, propably IVR or echo or similar... */
/* Guess we should masquerade or something here */
/* Until we figure it out, refuse transfer of such calls */
- if (sipdebug)
+ if (sipdebug) {
ast_debug(3, "Refused SIP transfer on non-bridged channel.\n");
+ }
p->refer->status = REFER_FAILED;
append_history(p, "Xfer", "Refer failed. Non-bridged channel.");
transmit_response(p, "603 Declined", req);
- return -1;
+ res = -1;
+ goto handle_refer_cleanup;
}
if (current.chan2) {
- if (sipdebug)
+ if (sipdebug) {
ast_debug(4, "Got SIP transfer, applying to bridged peer '%s'\n", current.chan2->name);
-
+ }
ast_queue_control(current.chan1, AST_CONTROL_UNHOLD);
}
@@ -23413,32 +23445,42 @@
/* Attended transfer: Find all call legs and bridge transferee with target*/
if (p->refer->attendedtransfer) {
- if ((res = local_attended_transfer(p, ¤t, req, seqno, nounlock)))
- return res; /* We're done with the transfer */
+ /* both p and p->owner _MUST_ be locked while calling local_attended_transfer */
+ if ((res = local_attended_transfer(p, ¤t, req, seqno, nounlock))) {
+ goto handle_refer_cleanup; /* We're done with the transfer */
+ }
/* Fall through for remote transfers that we did not find locally */
- if (sipdebug)
+ if (sipdebug) {
ast_debug(4, "SIP attended transfer: Still not our call - generating INVITE with replaces\n");
+ }
/* Fallthrough if we can't find the call leg internally */
}
- /* Must release lock now, because it will not longer
- be accessible after the transfer! */
- *nounlock = 1;
- /*
- * Increase ref count so that we can delay channel destruction until after
- * we get a chance to fire off some events.
- */
- ast_channel_ref(current.chan1);
+ /* Copy data we can not safely access after letting the pvt lock go. */
+ refer_to = ast_strdupa(p->refer->refer_to);
+ refer_to_domain = ast_strdupa(p->refer->refer_to_domain);
+ refer_to_context = ast_strdupa(p->refer->refer_to_context);
+ referred_by = ast_strdupa(p->refer->referred_by);
+ callid = ast_strdupa(p->callid);
+ localtransfer = p->refer->localtransfer;
+ attendedtransfer = p->refer->attendedtransfer;
+ if (!*nounlock) {
+ ast_channel_unlock(p->owner);
+ *nounlock = 1;
+ }
sip_pvt_unlock(p);
- ast_channel_unlock(current.chan1);
-
- /* Parking a call */
- if (p->refer->localtransfer && ast_parking_ext_valid(p->refer->refer_to, p->owner, p->owner->context)) {
+
+ /* Parking a call. DO NOT hold any locks while calling ast_parking_ext_valid() */
+ if (localtransfer && ast_parking_ext_valid(refer_to, current.chan1, current.chan1->context)) {
+
+ copy_request(¤t.req, req);
+
sip_pvt_lock(p);
- copy_request(¤t.req, req);
ast_clear_flag(&p->flags[0], SIP_GOTREFER);
p->refer->status = REFER_200OK;
append_history(p, "Xfer", "REFER to call parking.");
+ sip_pvt_unlock(p);
+
ast_manager_event_multichan(EVENT_FLAG_CALL, "Transfer", 2, chans,
"TransferMethod: SIP\r\n"
"TransferType: Blind\r\n"
@@ -23451,54 +23493,68 @@
"Transfer2Parking: Yes\r\n",
current.chan1->name,
current.chan1->uniqueid,
- p->callid,
+ callid,
current.chan2->name,
current.chan2->uniqueid,
- p->refer->refer_to);
- if (sipdebug)
+ refer_to);
+
+ if (sipdebug) {
ast_debug(4, "SIP transfer to parking: trying to park %s. Parked by %s\n", current.chan2->name, current.chan1->name);
- if (sip_park(current.chan2, current.chan1, req, seqno, p->refer->refer_to)) {
+ }
+
+ /* DO NOT hold any locks while calling sip_park */
+ if (sip_park(current.chan2, current.chan1, req, seqno, refer_to)) {
+ sip_pvt_lock(p);
transmit_notify_with_sipfrag(p, seqno, "500 Internal Server Error", TRUE);
- }
- ast_channel_unref(current.chan1);
- return res;
- }
-
- /* Blind transfers and remote attended xfers */
+ } else {
+ sip_pvt_lock(p);
+ }
+ goto handle_refer_cleanup;
+ }
+
+ /* Blind transfers and remote attended xfers.
+ * Locks should not be held while calling pbx_builtin_setvar_helper. This function
+ * locks the channel being passed into it.*/
if (current.chan1 && current.chan2) {
ast_debug(3, "chan1->name: %s\n", current.chan1->name);
pbx_builtin_setvar_helper(current.chan1, "BLINDTRANSFER", current.chan2->name);
}
- sip_pvt_lock(p);
-
if (current.chan2) {
pbx_builtin_setvar_helper(current.chan2, "BLINDTRANSFER", current.chan1->name);
- pbx_builtin_setvar_helper(current.chan2, "SIPDOMAIN", p->refer->refer_to_domain);
+ pbx_builtin_setvar_helper(current.chan2, "SIPDOMAIN", refer_to_domain);
pbx_builtin_setvar_helper(current.chan2, "SIPTRANSFER", "yes");
/* One for the new channel */
pbx_builtin_setvar_helper(current.chan2, "_SIPTRANSFER", "yes");
/* Attended transfer to remote host, prepare headers for the INVITE */
- if (p->refer->referred_by)
- pbx_builtin_setvar_helper(current.chan2, "_SIPTRANSFER_REFERER", p->refer->referred_by);
- }
+ if (!ast_strlen_zero(referred_by)) {
+ pbx_builtin_setvar_helper(current.chan2, "_SIPTRANSFER_REFERER", referred_by);
+ }
+ }
+
+ sip_pvt_lock(p);
/* Generate a Replaces string to be used in the INVITE during attended transfer */
if (!ast_strlen_zero(p->refer->replaces_callid)) {
char tempheader[SIPBUFSIZE];
snprintf(tempheader, sizeof(tempheader), "%s%s%s%s%s", p->refer->replaces_callid,
- p->refer->replaces_callid_totag ? ";to-tag=" : "",
- p->refer->replaces_callid_totag,
- p->refer->replaces_callid_fromtag ? ";from-tag=" : "",
- p->refer->replaces_callid_fromtag);
- if (current.chan2)
+ p->refer->replaces_callid_totag ? ";to-tag=" : "",
+ p->refer->replaces_callid_totag,
+ p->refer->replaces_callid_fromtag ? ";from-tag=" : "",
+ p->refer->replaces_callid_fromtag);
+
+ if (current.chan2) {
+ sip_pvt_unlock(p);
pbx_builtin_setvar_helper(current.chan2, "_SIPTRANSFER_REPLACES", tempheader);
+ sip_pvt_lock(p);
+ }
}
/* Connect the call */
/* FAKE ringing if not attended transfer */
- if (!p->refer->attendedtransfer)
+ if (!p->refer->attendedtransfer) {
transmit_notify_with_sipfrag(p, seqno, "183 Ringing", FALSE);
+ }
/* For blind transfer, this will lead to a new call */
/* For attended transfer to remote host, this will lead to
@@ -23516,26 +23572,20 @@
transmit_notify_with_sipfrag(p, seqno, "503 Service Unavailable (can't handle one-legged xfers)", TRUE);
ast_clear_flag(&p->flags[0], SIP_GOTREFER);
append_history(p, "Xfer", "Refer failed (only bridged calls).");
- ast_channel_unref(current.chan1);
- return -1;
+ res = -1;
+ goto handle_refer_cleanup;
}
ast_set_flag(&p->flags[0], SIP_DEFER_BYE_ON_TRANSFER); /* Delay hangup */
- {
- char *refer_to_context = ast_strdupa(p->refer->refer_to_context);
- char *refer_to = ast_strdupa(p->refer->refer_to);
-
- /* Do not hold the pvt lock during the indicate and async_goto. Those functions
- * lock channels which will invalidate locking order if the pvt lock is held.*/
- ao2_unlock(p);
- /* For blind transfers, move the call to the new extensions. For attended transfers on multiple
- * servers - generate an INVITE with Replaces. Either way, let the dial plan decided */
- /* indicate before masquerade so the indication actually makes it to the real channel
- *when using local channels with MOH passthru */
- ast_indicate(current.chan2, AST_CONTROL_UNHOLD);
- res = ast_async_goto(current.chan2, refer_to_context, refer_to, 1);
- ao2_lock(p);
- }
+ /* Do not hold the pvt lock during the indicate and async_goto. Those functions
+ * lock channels which will invalidate locking order if the pvt lock is held.*/
+ /* For blind transfers, move the call to the new extensions. For attended transfers on multiple
+ * servers - generate an INVITE with Replaces. Either way, let the dial plan decided
+ * indicate before masquerade so the indication actually makes it to the real channel
+ * when using local channels with MOH passthru */
+ sip_pvt_unlock(p);
+ ast_indicate(current.chan2, AST_CONTROL_UNHOLD);
+ res = ast_async_goto(current.chan2, refer_to_context, refer_to, 1);
if (!res) {
ast_manager_event_multichan(EVENT_FLAG_CALL, "Transfer", 2, chans,
@@ -23550,34 +23600,34 @@
"TransferContext: %s\r\n",
current.chan1->name,
current.chan1->uniqueid,
- p->callid,
+ callid,
current.chan2->name,
current.chan2->uniqueid,
- p->refer->refer_to, p->refer->refer_to_context);
+ refer_to,
+ refer_to_context);
/* Success - we have a new channel */
- ast_debug(3, "%s transfer succeeded. Telling transferer.\n", p->refer->attendedtransfer? "Attended" : "Blind");
-
- while (ast_channel_trylock(current.chan1)) {
- sip_pvt_unlock(p);
- sched_yield();
- sip_pvt_lock(p);
- }
+ ast_debug(3, "%s transfer succeeded. Telling transferer.\n", attendedtransfer? "Attended" : "Blind");
/* XXX - what to we put in CEL 'extra' for attended transfers to external systems? NULL for now */
+ ast_channel_lock(current.chan1);
ast_cel_report_event(current.chan1, p->refer->attendedtransfer? AST_CEL_ATTENDEDTRANSFER : AST_CEL_BLINDTRANSFER, NULL, p->refer->attendedtransfer ? NULL : p->refer->refer_to, current.chan2);
ast_channel_unlock(current.chan1);
+ sip_pvt_lock(p);
transmit_notify_with_sipfrag(p, seqno, "200 Ok", TRUE);
- if (p->refer->localtransfer)
+ if (p->refer->localtransfer) {
p->refer->status = REFER_200OK;
- if (p->owner)
+ }
+ if (p->owner) {
p->owner->hangupcause = AST_CAUSE_NORMAL_CLEARING;
+ }
append_history(p, "Xfer", "Refer succeeded.");
ast_clear_flag(&p->flags[0], SIP_GOTREFER);
/* Do not hangup call, the other side do that when we say 200 OK */
/* We could possibly implement a timer here, auto congestion */
res = 0;
} else {
+ sip_pvt_lock(p);
ast_clear_flag(&p->flags[0], SIP_DEFER_BYE_ON_TRANSFER); /* Don't delay hangup */
ast_debug(3, "%s transfer failed. Resuming original call.\n", p->refer->attendedtransfer? "Attended" : "Blind");
append_history(p, "Xfer", "Refer failed.");
@@ -23588,8 +23638,15 @@
res = -1;
}
- ast_channel_unref(current.chan1);
-
+handle_refer_cleanup:
+ if (current.chan1) {
+ ast_channel_unref(current.chan1);
+ }
+ if (current.chan2) {
+ ast_channel_unref(current.chan2);
+ }
+
+ /* Make sure we exit with the pvt locked */
return res;
}
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