Switch around internal fromtag/totag/endpoint representation

monologue_offer_answer() had A-side and B-side reversed, resulting in
incomplete dialogue association when more than 2 parties are involved.

It also fixes #21 by catching errors returned by
monologue_offer_answer() (e.g. when running out of ports)

daemon/call.c

@@ -1957,23 +1957,26 @@ static void __tos_change(struct call *call, const struct sdp_ng_flags *flags) {
 }
 
 /* called with call->master_lock held in W */
-int monologue_offer_answer(struct call_monologue *monologue, GQueue *streams,
+int monologue_offer_answer(struct call_monologue *other_ml, GQueue *streams,
 		const struct sdp_ng_flags *flags)
 {
 	struct stream_params *sp;
 	GList *media_iter, *ml_media, *other_ml_media;
 	struct call_media *media, *other_media;
 	unsigned int num_ports;
-	struct call_monologue *other_ml = monologue->active_dialogue;
+	struct call_monologue *monologue = other_ml->active_dialogue;
 	struct endpoint_map *em;
 
 	monologue->call->last_signal = poller_now;
 	monologue->call->deleted = 0;
 
-	/* we must have a complete dialogue, even though the to-tag (other_ml->tag)
+	/* we must have a complete dialogue, even though the to-tag (monologue->tag)
 	 * may not be known yet */
-	if (!other_ml)
+	if (!other_ml) {
+		ilog(LOG_ERROR, "Incomplete dialogue association");
 		return -1;
+	}
+	__C_DBG("this="STR_FORMAT" other="STR_FORMAT, STR_FMT(&monologue->tag), STR_FMT(&other_ml->tag));
 
 	__tos_change(monologue->call, flags);
 
@@ -1987,9 +1990,12 @@ int monologue_offer_answer(struct call_monologue *monologue, GQueue *streams,
 		 * the dialogue */
 		media = __get_media(monologue, &ml_media, sp);
 		other_media = __get_media(other_ml, &other_ml_media, sp);
-		/* THIS side corresponds to what's being sent to the recipient of the
+		/* OTHER is the side which has sent the message. SDP parameters in
-		 * offer/answer. The OTHER side corresponds to what WILL BE sent to the
+		 * "sp" are as advertised by OTHER side. The message will be sent to
-		 * offerer or WAS sent to the answerer. */
+		 * THIS side. Parameters sent to THIS side may be overridden by
+		 * what's in "flags". If this is an answer, or if we have talked to
+		 * THIS side (recipient) before, then the structs will be populated with
+		 * details already. */
 
 		/* deduct protocol from stream parameters received */
 		if (other_media->protocol != sp->protocol) {
@@ -2014,11 +2020,13 @@ int monologue_offer_answer(struct call_monologue *monologue, GQueue *streams,
 		if (other_media->sdes_in.params.crypto_suite)
 			MEDIA_SET(other_media, SDES);
 
+		/* send and recv are from our POV */
 		bf_copy_same(&media->media_flags, &sp->sp_flags,
 				SP_FLAG_SEND | SP_FLAG_RECV);
 		bf_copy(&other_media->media_flags, MEDIA_FLAG_RECV, &sp->sp_flags, SP_FLAG_SEND);
 		bf_copy(&other_media->media_flags, MEDIA_FLAG_SEND, &sp->sp_flags, SP_FLAG_RECV);
 
+		/* active and passive are also from our POV */
 		bf_copy(&other_media->media_flags, MEDIA_FLAG_SETUP_PASSIVE,
 				&sp->sp_flags, SP_FLAG_SETUP_ACTIVE);
 		bf_copy(&other_media->media_flags, MEDIA_FLAG_SETUP_ACTIVE,

daemon/call_interfaces.c

@@ -126,6 +126,7 @@ static str *call_update_lookup_udp(char **out, struct callmaster *m, enum call_o
 	GQueue q = G_QUEUE_INIT;
 	struct stream_params sp;
 	str *ret, callid, viabranch, fromtag, totag = STR_NULL;
+	int i;
 
 	str_init(&callid, out[RE_UDP_UL_CALLID]);
 	str_init(&viabranch, out[RE_UDP_UL_VIABRANCH]);
@@ -147,11 +148,14 @@ static str *call_update_lookup_udp(char **out, struct callmaster *m, enum call_o
 		goto addr_fail;
 
 	g_queue_push_tail(&q, &sp);
-	/* XXX return value */
+	i = monologue_offer_answer(monologue, &q, NULL);
-	monologue_offer_answer(monologue, &q, NULL);
 	g_queue_clear(&q);
 
-	ret = streams_print(&monologue->medias, sp.index, sp.index, out[RE_UDP_COOKIE], SAF_UDP);
+	if (i)
+		goto unlock_fail;
+
+	ret = streams_print(&monologue->active_dialogue->medias,
+			sp.index, sp.index, out[RE_UDP_COOKIE], SAF_UDP);
 	rwlock_unlock_w(&c->master_lock);
 
 	redis_update(c, m->conf.redis);
@@ -160,16 +164,16 @@ static str *call_update_lookup_udp(char **out, struct callmaster *m, enum call_o
 	goto out;
 
 ml_fail:
-	rwlock_unlock_w(&c->master_lock);
+	ilog(LOG_ERR, "Invalid dialogue association");
-	ilog(LOG_WARNING, "Invalid dialogue association");
+	goto unlock_fail;
-	goto fail_out;
 
 addr_fail:
-	rwlock_unlock_w(&c->master_lock);
+	ilog(LOG_ERR, "Failed to parse a media stream: %s/%s:%s",
-	ilog(LOG_WARNING, "Failed to parse a media stream: %s/%s:%s", out[RE_UDP_UL_ADDR4], out[RE_UDP_UL_ADDR6], out[RE_UDP_UL_PORT]);
+			out[RE_UDP_UL_ADDR4], out[RE_UDP_UL_ADDR6], out[RE_UDP_UL_PORT]);
-	goto fail_out;
+	goto unlock_fail;
 
-fail_out:
+unlock_fail:
+	rwlock_unlock_w(&c->master_lock);
 	ret = str_sprintf("%s E8\n", out[RE_UDP_COOKIE]);
 out:
 	obj_put(c);
@@ -283,10 +287,10 @@ static str *call_request_lookup_tcp(char **out, struct callmaster *m, enum call_
 		ilog(LOG_WARNING, "Invalid dialogue association");
 		goto out2;
 	}
-	/* XXX return value */
+	if (monologue_offer_answer(monologue, &s, NULL))
-	monologue_offer_answer(monologue, &s, NULL);
+		goto out2;
 
-	ret = streams_print(&monologue->medias, 1, s.length, NULL, SAF_TCP);
+	ret = streams_print(&monologue->active_dialogue->medias, 1, s.length, NULL, SAF_TCP);
 
 out2:
 	rwlock_unlock_w(&c->master_lock);
@@ -598,9 +602,9 @@ static const char *call_offer_answer_ng(bencode_item_t *input, struct callmaster
 
 	chopper = sdp_chopper_new(&sdp);
 	bencode_buffer_destroy_add(output->buffer, (free_func_t) sdp_chopper_destroy, chopper);
-	/* XXX return value */
+	ret = monologue_offer_answer(monologue, &streams, &flags);
-	monologue_offer_answer(monologue, &streams, &flags);
+	if (!ret)
-	ret = sdp_replace(chopper, &parsed, monologue, &flags);
+		ret = sdp_replace(chopper, &parsed, monologue->active_dialogue, &flags);
 
 	rwlock_unlock_w(&call->master_lock);
 	redis_update(call, m->conf.redis);