chan_iax2: Prevent deadlock due to duplicate autoservice.
If a switch is invoked using chan_iax2, deadlock can result because the PBX core is autoservicing the channel while chan_iax2 also then attempts to service it while waiting for the result of the switch. This removes servicing of the channel to prevent any conflicts. ASTERISK-30064 #close Change-Id: Ie92f206d32f9a36924af734ddde652b21106af22
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@ -14214,9 +14214,7 @@ static struct iax2_dpcache *find_cache(struct ast_channel *chan, const char *dat
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{
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struct iax2_dpcache *dp = NULL;
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struct timeval now = ast_tvnow();
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int x, com[2], timeout, old = 0, outfd, doabort, callno;
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struct ast_channel *c = NULL;
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struct ast_frame *f = NULL;
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int x, com[2], timeout, doabort, callno;
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AST_LIST_TRAVERSE_SAFE_BEGIN(&dpcache, dp, cache_list) {
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if (ast_tvcmp(now, dp->expiry) > 0) {
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@ -14263,8 +14261,8 @@ static struct iax2_dpcache *find_cache(struct ast_channel *chan, const char *dat
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/* By here we must have a dp */
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if (dp->flags & CACHE_FLAG_PENDING) {
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struct timeval start;
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int ms;
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int res;
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struct pollfd pfd;
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/* Okay, here it starts to get nasty. We need a pipe now to wait
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for a reply to come back so long as it's pending */
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for (x = 0; x < ARRAY_LEN(dp->waiters); x++) {
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@ -14285,35 +14283,31 @@ static struct iax2_dpcache *find_cache(struct ast_channel *chan, const char *dat
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timeout = iaxdefaulttimeout * 1000;
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/* Temporarily unlock */
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AST_LIST_UNLOCK(&dpcache);
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/* Defer any dtmf */
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if (chan)
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old = ast_channel_defer_dtmf(chan);
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doabort = 0;
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start = ast_tvnow();
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while ((ms = ast_remaining_ms(start, timeout))) {
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c = ast_waitfor_nandfds(&chan, chan ? 1 : 0, &com[0], 1, NULL, &outfd, &ms);
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if (outfd > -1)
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break;
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if (!c)
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continue;
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if (!(f = ast_read(c))) {
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doabort = 1;
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break;
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}
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ast_frfree(f);
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}
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if (!ms) {
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/* chan is in autoservice here, so do NOT service it here! */
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pfd.fd = com[0];
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pfd.events = POLLIN;
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pfd.revents = 0;
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/* Wait for pipe activity... if the channel hangs up, we'll catch it on the way out. */
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res = ast_poll(&pfd, 1, timeout);
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if (res < 0) {
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ast_log(LOG_WARNING, "poll returned < 0: %s\n", strerror(errno));
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return NULL;
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} else if (!pfd.revents) {
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ast_log(LOG_WARNING, "Timeout waiting for %s exten %s\n", data, exten);
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}
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if (ast_check_hangup(chan)) {
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doabort = 1;
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}
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AST_LIST_LOCK(&dpcache);
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dp->waiters[x] = -1;
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close(com[1]);
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close(com[0]);
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if (doabort) {
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/* Don't interpret anything, just abort. Not sure what th epoint
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of undeferring dtmf on a hung up channel is but hey whatever */
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if (!old && chan)
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ast_channel_undefer_dtmf(chan);
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/* Don't interpret anything, just abort. */
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return NULL;
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}
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if (!(dp->flags & CACHE_FLAG_TIMEOUT)) {
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@ -14336,8 +14330,6 @@ static struct iax2_dpcache *find_cache(struct ast_channel *chan, const char *dat
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}
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}
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/* Our caller will obtain the rest */
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if (!old && chan)
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ast_channel_undefer_dtmf(chan);
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}
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return dp;
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}
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