ice: fix issue in nomination of triggered checks

There is an issue with the nomination of triggered checks in ICE
that causes ICE negotiation to conclude on sub-optimal pairs.
The issue was reported, and acknolegded by PJSIP maintainers.
This patch will fix the issue.

Gitlab: #622

Change-Id: I4bed7191692051d6215fbde8ee2ca9f94b76e0f9

contrib/src/pjproject/0020-avoid-immediate-nominating-triggered-check.patch

+diff --git a/pjnath/src/pjnath/ice_session.c b/pjnath/src/pjnath/ice_session.c
+index ef88807a1..5feb32b21 100644
+--- a/pjnath/src/pjnath/ice_session.c
++++ b/pjnath/src/pjnath/ice_session.c
+@@ -3382,14 +3382,22 @@ static void handle_incoming_check(pj_ice_sess *ice,
+ 	if (c->state == PJ_ICE_SESS_CHECK_STATE_FROZEN ||
+ 	    c->state == PJ_ICE_SESS_CHECK_STATE_WAITING)
+ 	{
+-	    /* See if we shall nominate this check */
+-	    pj_bool_t nominate = (c->nominated || ice->is_nominating);
+-
+-	    LOG5((ice->obj_name, "Performing triggered check for check %d",i));
+-	    pj_log_push_indent();
+-	    perform_check(ice, &ice->clist, i, nominate);
+-	    pj_log_pop_indent();
++	    /* If we are nominating in regular nomination, don't nominate this
++	     * triggered check immediately, just wait for its scheduled check.
++	     */
++	    if (ice->is_nominating && !ice->opt.aggressive) {
++		LOG5((ice->obj_name, "Triggered check for check %d not "
++		      "performed because nomination is in progress", i));
++	    } else {
++		/* See if we shall nominate this check */
++		pj_bool_t nominate = (c->nominated || ice->is_nominating);
+ 
++		LOG5((ice->obj_name, "Performing triggered check for "
++		      "check %d",i));
++		pj_log_push_indent();
++		perform_check(ice, &ice->clist, i, nominate);
++		pj_log_pop_indent();
++	    }
+ 	} else if (c->state == PJ_ICE_SESS_CHECK_STATE_IN_PROGRESS) {
+ 	    /* Should retransmit immediately
+ 	     */
+@@ -3449,7 +3457,7 @@ static void handle_incoming_check(pj_ice_sess *ice,
+     else if (ice->clist.count < PJ_ICE_MAX_CHECKS) {
+ 
+ 	pj_ice_sess_check *c = &ice->clist.checks[ice->clist.count];
+-	pj_bool_t nominate;
++	unsigned check_id = ice->clist.count;
+ 
+ 	c->lcand = lcand;
+ 	c->rcand = rcand;
+@@ -3457,19 +3465,38 @@ static void handle_incoming_check(pj_ice_sess *ice,
+ 	c->state = PJ_ICE_SESS_CHECK_STATE_WAITING;
+ 	c->nominated = rcheck->use_candidate;
+ 	c->err_code = PJ_SUCCESS;
++	++ice->clist.count;
+ 
+-	nominate = (c->nominated || ice->is_nominating);
++	LOG4((ice->obj_name, "New triggered check added: %d", check_id));
+ 
+-	LOG4((ice->obj_name, "New triggered check added: %d", 
+-	     ice->clist.count));
+-	pj_log_push_indent();
++	/* If we are nominating in regular nomination, don't nominate this
++	 * newly found pair.
++	 */
++	if (ice->is_nominating && !ice->opt.aggressive) {
++	    LOG5((ice->obj_name, "Triggered check for check %d not "
++		  "performed because nomination is in progress", check_id));
++
++	    /* Just in case the periodic check has been stopped (due to no more
++	     * pair to check), let's restart it for this pair.
++	     */
++	    if (!pj_timer_entry_running(&ice->clist.timer)) {
++		pj_time_val delay = {0, 0};
++		pj_timer_heap_schedule_w_grp_lock(ice->stun_cfg.timer_heap,
++						  &ice->clist.timer, &delay,
++						  PJ_TRUE, ice->grp_lock);
++	    }
++	} else {
++	    pj_bool_t nominate;
++	    nominate = (c->nominated || ice->is_nominating);
++
++	    pj_log_push_indent();
++	    perform_check(ice, &ice->clist, check_id, nominate);
++	    pj_log_pop_indent();
++	}
+ 
+-	perform_check(ice, &ice->clist, ice->clist.count++, nominate);
+     	/* Re-sort the list because of the newly added pair. */
+     	sort_checklist(ice, &ice->clist);
+ 
+-	pj_log_pop_indent();
+-
+     } else {
+ 	LOG4((ice->obj_name, "Error: unable to perform triggered check: "
+ 	     "TOO MANY CHECKS IN CHECKLIST!"));

contrib/src/pjproject/package.json

@@ -23,6 +23,7 @@
         "0017-auto-register-thread.patch",
         "0018-fix-ioqueue-lock-acquire.patch",
         "0019-resort-check-list-after-adding-prflx.patch",
+        "0020-avoid-immediate-nominating-triggered-check.patch",
         "0001-win-config.patch",
         "0002-win-vs-gnutls.patch",
         "0003-win-vs2017-props.patch"

contrib/src/pjproject/rules.mak

@@ -64,7 +64,8 @@ pjproject: pjproject-$(PJPROJECT_VERSION).tar.gz .sum-pjproject
 	$(APPLY) $(SRC)/pjproject/0016-use-larger-Ta-interval.patch
 	$(APPLY) $(SRC)/pjproject/0017-auto-register-thread.patch
 	$(APPLY) $(SRC)/pjproject/0018-fix-ioqueue-lock-acquire.patch
-	$(APPLY) $(SRC)/pjproject/0019-resort-check-list-after-adding-prflx.patch
+	$(APPLY) $(SRC)/pjproject/0019-resort-check-list-after-adding-prflx.patch # TODO remove with 2.12 (https://github.com/pjsip/pjproject/pull/2806)
+	$(APPLY) $(SRC)/pjproject/0020-avoid-immediate-nominating-triggered-check.patch # TODO remove with 2.12 (https://github.com/pjsip/pjproject/issues/2812)
 ifdef HAVE_ANDROID
 	$(APPLY) $(SRC)/pjproject/0001-android.patch
 endif