res_rtp_asterisk: Fix checklist creating problems in ICE sessions

Prior to this patch, local candidate lists including SRFLX would fail to start
properly when building ICE candidate check lists. This patch fixes that problem
by making sure that each SRFLX candidate is associated with the proper
base address so that the check list can create matches properly.
This patch was written by jcolp. The issue will be left open to await testing
by the issue participants.

(issue ASTERISK-23213)
Reported by: Andrea Suisani
Review: https://reviewboard.asterisk.org/r/3256/




git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@409129 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_rtp_asterisk.c

@@ -678,7 +678,7 @@ static void ast_rtp_ice_add_cand(struct ast_rtp *rtp, unsigned comp_id, unsigned
 		return;
 	}
 
-	if (pj_ice_sess_add_cand(rtp->ice, comp_id, transport_id, type, local_pref, &foundation, addr, addr, rel_addr, addr_len, NULL) != PJ_SUCCESS) {
+	if (pj_ice_sess_add_cand(rtp->ice, comp_id, transport_id, type, local_pref, &foundation, addr, base_addr, rel_addr, addr_len, NULL) != PJ_SUCCESS) {
 		ao2_ref(candidate, -1);
 		return;
 	}
@@ -1683,15 +1683,20 @@ static void rtp_add_candidates_to_ice(struct ast_rtp_instance *instance, struct
 	}
 
 	/* If configured to use a STUN server to get our external mapped address do so */
-	if (stunaddr.sin_addr.s_addr && ast_sockaddr_is_ipv4(addr)) {
+	if (stunaddr.sin_addr.s_addr && ast_sockaddr_is_ipv4(addr) && count) {
 		struct sockaddr_in answer;
 
-		if (!ast_stun_request(rtp->s, &stunaddr, NULL, &answer)) {
+		if (!ast_stun_request(component == AST_RTP_ICE_COMPONENT_RTCP ? rtp->rtcp->s : rtp->s, &stunaddr, NULL, &answer)) {
+			pj_sockaddr base;
+
+			/* Use the first local host candidate as the base */
+			pj_sockaddr_cp(&base, &address[0]);
+
 			pj_str_t mapped = pj_str(ast_strdupa(ast_inet_ntoa(answer.sin_addr)));
 
 			pj_sockaddr_init(pj_AF_INET(), &address[0], &mapped, ntohs(answer.sin_port));
 
-			ast_rtp_ice_add_cand(rtp, component, transport, PJ_ICE_CAND_TYPE_SRFLX, 65535, &address[0], &address[0],
+			ast_rtp_ice_add_cand(rtp, component, transport, PJ_ICE_CAND_TYPE_SRFLX, 65535, &address[0], &base,
 					     NULL, pj_sockaddr_get_len(&address[0]));
 		}
 	}