PN Support: Complete commit e7cf1d5

The fix in e7cf1d5 was not complete, as we must add both PN, non-PN
branches as well as any pre-existing append_branches() into the
t_wait_for_new_branches() wait count, otherwise the UAC-side transaction
could end prematurely, before the PN-branch gets a chance to deliver and
connect the call.

(cherry picked from commit 6b05893)

Author: liviuchircu

lib/reg/lookup.c

@@ -62,6 +62,8 @@ lookup_rc lookup(struct sip_msg *req, udomain_t *d,
 	int max_latency = 0, ruri_is_pushed = 0;
 	unsigned int flags = 0;
 	int rc, ret = LOOKUP_NO_RESULTS, have_pn_cts = 0, single_branch = 0;
+	int pn_cts_sz;
+	unsigned int dst_branches = 0;
 	str sip_instance = STR_NULL, call_id = STR_NULL;
 	regex_t *ua_re = NULL;
 
@@ -78,6 +80,13 @@ lookup_rc lookup(struct sip_msg *req, udomain_t *d,
 		max_latency = lookup_flags->max_latency;
 	}
 
+	if (!(flags & REG_BRANCH_AOR_LOOKUP_FLAG))
+		dst_branches += get_nr_branches();
+
+	if ((flags & REG_LOOKUP_NO_RURI_FLAG) &&
+	        req->first_line.type == SIP_REQUEST)
+		dst_branches++;
+
 	single_branch = flags & REG_LOOKUP_NOBRANCH_FLAG;
 
 	if (flags & REG_BRANCH_AOR_LOOKUP_FLAG) {
@@ -150,6 +159,8 @@ lookup_rc lookup(struct sip_msg *req, udomain_t *d,
 			goto done;
 		} else if (rc == 2) {
 			*pn_cts++ = *ptr;
+		} else if (rc == 0) {
+			dst_branches++;
 		}
 
 		if (rc == 0 && single_branch)
@@ -160,13 +171,18 @@ lookup_rc lookup(struct sip_msg *req, udomain_t *d,
 	        && (flags & REG_LOOKUP_GLOBAL_FLAG)) {
 		for (ct = r->remote_aors; ct; ct = ct->next) {
 			rc = push_branch(req, ct, &ruri_is_pushed);
-			if (rc == 0 && single_branch)
-				goto done;
+			if (rc == 0) {
+				dst_branches++;
+				if (single_branch)
+					goto done;
+			}
 		}
 	}
 
 	if (pn_cts > cts) {
-		rc = pn_awake_pn_contacts(req, cts, single_branch ? 1 : pn_cts - cts);
+		pn_cts_sz = single_branch ? 1 : pn_cts - cts;
+		rc = pn_awake_pn_contacts(req, cts, pn_cts_sz,
+			dst_branches + pn_cts_sz);
 		if (rc <= 0) {
 			ret = (rc == 0 ? LOOKUP_STOP_SCRIPT : LOOKUP_ERROR);
 			goto done;

lib/reg/pn.c

@@ -595,7 +595,8 @@ static void pn_inject_branch(void)
 }
 
 
-int pn_awake_pn_contacts(struct sip_msg *req, ucontact_t **cts, int sz)
+int pn_awake_pn_contacts(struct sip_msg *req, ucontact_t **cts, int sz,
+	unsigned int wait_branches)
 {
 	ucontact_t **end;
 	struct sip_uri puri;
@@ -625,7 +626,7 @@ int pn_awake_pn_contacts(struct sip_msg *req, ucontact_t **cts, int sz)
 		return -1;
 	}
 
-	if (tmb.t_wait_for_new_branches(req, (unsigned int)sz) != 1)
+	if (tmb.t_wait_for_new_branches(req, wait_branches) != 1)
 		LM_ERR("failed to enable waiting for new branches\n");
 
 	for (end = cts + sz; cts < end; cts++) {

lib/reg/pn.h

@@ -182,12 +182,15 @@ int pn_append_rpl_fcaps(struct sip_msg *msg);
  * @req: the current SIP request
  * @cts: array of PN-enabled contacts
  * @sz: array size
+ * @wait_branches: maximum number of outgoing branches to wait for, including
+ *                 already selected destinations and PN-injected branches
  *
  * Return:
  *	 success: 1 if at least one PN was sent, 2 otherwise
  *	 failure: 0 on retransmission, -1 on internal error
  */
-int pn_awake_pn_contacts(struct sip_msg *req, ucontact_t **cts, int sz);
+int pn_awake_pn_contacts(struct sip_msg *req, ucontact_t **cts, int sz,
+	unsigned int wait_branches);
 
 
 /**

modules/mid_registrar/lookup.c

@@ -53,6 +53,7 @@ int mid_reg_lookup(struct sip_msg *req, udomain_t *d,
 	struct sip_uri puri;
 	unsigned int flags = 0;
 	int ret = LOOKUP_ERROR, pos, ruri_is_pushed = 0;
+	unsigned int dst_branches = 0;
 	uint64_t contact_id;
 	str aor;
 	ucontact_t *ct;
@@ -64,7 +65,13 @@ int mid_reg_lookup(struct sip_msg *req, udomain_t *d,
 	if (lookup_flags)
 		flags = lookup_flags->flags;
 
-	ruri_is_pushed = flags & REG_LOOKUP_NO_RURI_FLAG;
+	dst_branches = get_nr_branches();
+
+	if (flags & REG_LOOKUP_NO_RURI_FLAG) {
+		ruri_is_pushed = 1;
+		if (req->first_line.type == SIP_REQUEST)
+			dst_branches++;
+	}
 
 	if (!uri)
 		uri = GET_RURI(req);
@@ -127,7 +134,7 @@ int mid_reg_lookup(struct sip_msg *req, udomain_t *d,
 		break;
 
 	case 2:
-		switch (pn_awake_pn_contacts(req, &ct, 1)) {
+		switch (pn_awake_pn_contacts(req, &ct, 1, dst_branches + 1)) {
 		case 1:
 			ret = LOOKUP_PN_SENT;
 			break;