freetdm: fix hangup race

diff --git a/libs/freetdm/src/ftdm_io.c b/libs/freetdm/src/ftdm_io.c
index efdf662e2b8e3b3fb7bb384fd726ee0b2ce1775c..75af0c176cb2bdd868edafe37248fcc6d05bc5e9 100644 (file)
--- a/libs/freetdm/src/ftdm_io.c
+++ b/libs/freetdm/src/ftdm_io.c
@@ -1899,15 +1899,27 @@ FT_DECLARE(ftdm_status_t) _ftdm_channel_call_unhold(const char *file, const char
 
 FT_DECLARE(ftdm_status_t) _ftdm_channel_call_answer(const char *file, const char *func, int line, ftdm_channel_t *ftdmchan)
 {
+       ftdm_status_t status = FTDM_SUCCESS;
+
        ftdm_channel_lock(ftdmchan);
 
+       if (ftdmchan->state == FTDM_CHANNEL_STATE_TERMINATING) {
+               ftdm_log_chan_msg(ftdmchan, FTDM_LOG_DEBUG, "Ignoring answer because the call is already terminating\n");
+               goto done;
+       }
+
        ftdm_set_flag(ftdmchan, FTDM_CHANNEL_ANSWERED);
        ftdm_set_flag(ftdmchan, FTDM_CHANNEL_PROGRESS);
        ftdm_set_flag(ftdmchan, FTDM_CHANNEL_MEDIA);
 
        if (ftdm_test_flag(ftdmchan, FTDM_CHANNEL_OUTBOUND)) {
-               ftdm_channel_unlock(ftdmchan);
-               return FTDM_SUCCESS;
+               goto done;
+       }
+
+       if (ftdmchan->state >= FTDM_CHANNEL_STATE_UP) {
+               ftdm_log_chan(ftdmchan, FTDM_LOG_WARNING, "Ignoring answer because the call state is (%d/%s)\n", ftdmchan->state, ftdm_channel_state2str(ftdmchan->state));
+               status = FTDM_FAIL;
+               goto done;
        }
 
        if (ftdmchan->state < FTDM_CHANNEL_STATE_PROGRESS) {
@@ -1920,14 +1932,33 @@ FT_DECLARE(ftdm_status_t) _ftdm_channel_call_answer(const char *file, const char
 
        ftdm_channel_set_state(file, func, line, ftdmchan, FTDM_CHANNEL_STATE_UP, 1);
 
+done:
+
        ftdm_channel_unlock(ftdmchan);
-       return FTDM_SUCCESS;
+       return status;
 }
 
 /* lock must be acquired by the caller! */
 static ftdm_status_t call_hangup(ftdm_channel_t *chan, const char *file, const char *func, int line)
 {
        if (chan->state != FTDM_CHANNEL_STATE_DOWN) {
+               if (chan->state == FTDM_CHANNEL_STATE_HANGUP) {
+                       /* make user's life easier, and just ignore double hangup requests */
+                       return FTDM_SUCCESS;
+               }
+               if (chan->state == FTDM_CHANNEL_STATE_TERMINATING && ftdm_test_flag(chan, FTDM_CHANNEL_STATE_CHANGE)) {
+                       /* the signaling stack is already terminating the call but has not yet notified the user about it 
+                        * with SIGEVENT_STOP, we must flag this channel as hangup and wait for the SIGEVENT_STOP before
+                        * proceeding, at that point we will move the channel to hangup, but the SIGEVENT_STOP will not
+                        * be sent to the user since they already made clear they want to hangup!
+                        * */
+                       ftdm_set_flag(chan, FTDM_CHANNEL_USER_HANGUP);
+                       ftdm_wait_for_flag_cleared(chan, FTDM_CHANNEL_STATE_CHANGE, 5000);
+                       if (ftdm_test_flag(chan, FTDM_CHANNEL_STATE_CHANGE)) {
+                               ftdm_log_chan(chan, FTDM_LOG_CRIT, "Failed to hangup, state change for %d/%s is still pending!\n", chan->state, ftdm_channel_state2str(chan->state));
+                               return FTDM_FAIL;
+                       }
+               }
                ftdm_channel_set_state(file, func, line, chan, FTDM_CHANNEL_STATE_HANGUP, 1);
        } else {
                /* the signaling stack did not touch the state, 
@@ -2163,6 +2194,7 @@ FT_DECLARE(ftdm_status_t) ftdm_channel_done(ftdm_channel_t *ftdmchan)
        ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_PROGRESS);
        ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_MEDIA);
        ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_ANSWERED);
+       ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_USER_HANGUP);
        ftdm_mutex_lock(ftdmchan->pre_buffer_mutex);
        ftdm_buffer_destroy(&ftdmchan->pre_buffer);
        ftdmchan->pre_buffer_size = 0;
@@ -4214,6 +4246,13 @@ FT_DECLARE(ftdm_status_t) ftdm_span_send_signal(ftdm_span_t *span, ftdm_sigmsg_t
                ftdm_clear_flag(sigmsg->channel, FTDM_CHANNEL_HOLD);
                break;
 
+       case FTDM_SIGEVENT_STOP:
+               if (ftdm_test_flag(sigmsg->channel, FTDM_CHANNEL_USER_HANGUP)) {
+                       ftdm_log_chan_msg(sigmsg->channel, FTDM_LOG_DEBUG, "Ignoring SIGEVENT_STOP since user already requested hangup\n");
+                       goto done;
+               }
+               break;
+
        default:
                break;  
 
@@ -4224,6 +4263,7 @@ FT_DECLARE(ftdm_status_t) ftdm_span_send_signal(ftdm_span_t *span, ftdm_sigmsg_t
                status = span->signal_cb(sigmsg);
        }
 
+done:
        if (sigmsg->channel) {
                ftdm_mutex_unlock(sigmsg->channel->mutex);
        }

diff --git a/libs/freetdm/src/include/private/ftdm_types.h b/libs/freetdm/src/include/private/ftdm_types.h
index 1fe0859349e799e8ff3403e0e6a593171efe5157..ae9f7db24a5bcd76a34b4d2309ce9ed5144d7943 100644 (file)
--- a/libs/freetdm/src/include/private/ftdm_types.h
+++ b/libs/freetdm/src/include/private/ftdm_types.h
@@ -250,6 +250,7 @@ typedef enum {
        FTDM_CHANNEL_USE_TX_GAIN = (1 << 26),
        FTDM_CHANNEL_IN_ALARM = (1 << 27),
        FTDM_CHANNEL_SIG_UP = (1 << 28),
+       FTDM_CHANNEL_USER_HANGUP = (1 << 29),
 } ftdm_channel_flag_t;
 #if defined(__cplusplus) && defined(WIN32) 
     // fix C2676