Changeset 2362 for pjproject/trunk/pjsip/src/pjsip-ua/sip_inv.c

Timestamp:

Oct 31, 2008 6:01:48 PM (15 years ago)

Author:

bennylp

Message:

Ticket #657: (Partial early media forking support) renegotiate SDP upon receiving forked 2xx response after 183 is received

File:

• pjproject/trunk/pjsip/src/pjsip-ua/sip_inv.c (modified) (9 diffs)

pjproject/trunk/pjsip/src/pjsip-ua/sip_inv.c

@@ -143 +143 @@
 struct tsx_inv_data
 {
-    pjsip_inv_session   *inv;
-    pj_bool_t            sdp_done;
+    pjsip_inv_session   *inv;       /* The invite session                   */
+    pj_bool_t            sdp_done;  /* SDP negotiation done for this tsx?   */
+    pj_str_t             done_tag;  /* To tag in RX response with answer    */
+    pj_bool_t            done_early;/* Negotiation was done for early med?  */
 };
 
@@ -1408 +1410 @@
     pj_status_t status;
     pjsip_msg *msg;
-    pjmedia_sdp_session *sdp;
+    pjmedia_sdp_session *rem_sdp;
+
+    /* Check if SDP is present in the message. */
+
+    msg = rdata->msg_info.msg;
+    if (msg->body == NULL) {
+        /* Message doesn't have body. */
+        return PJ_SUCCESS;
+    }
+
+    if (pj_stricmp(&msg->body->content_type.type, &str_application) ||
+        pj_stricmp(&msg->body->content_type.subtype, &str_sdp))
+    {
+        /* Message body is not "application/sdp" */
+        return PJMEDIA_SDP_EINSDP;
+    }
 
     /* Get/attach invite session's transaction data */
@@ -1418 +1435 @@
     }
 
-    /* MUST NOT do multiple SDP offer/answer in a single transaction. 
+    /* MUST NOT do multiple SDP offer/answer in a single transaction,
+     * EXCEPT if:
+     *  - this is an initial UAC INVITE transaction (i.e. not re-INVITE), and
+     *  - the previous negotiation was done on an early media (18x) and
+     *    this response is a final/2xx response, and
+     *  - the 2xx response has different To tag than the 18x response
+     *    (i.e. the request has forked).
+     *
+     * The exception above is to add a rudimentary support for early media
+     * forking (sample case: custom ringback). See this ticket for more
+     * info: http://trac.pjsip.org/repos/ticket/657
      */
-
     if (tsx_inv_data->sdp_done) {
-        if (rdata->msg_info.msg->body) {
-            PJ_LOG(4,(inv->obj_name, "SDP negotiation done, message "
-                      "body is ignored"));
-        }
-        return PJ_SUCCESS;
-    }
-
-    /* Check if SDP is present in the message. */
-
-    msg = rdata->msg_info.msg;
-    if (msg->body == NULL) {
-        /* Message doesn't have body. */
-        return PJ_SUCCESS;
-    }
-
-    if (pj_stricmp(&msg->body->content_type.type, &str_application) ||
-        pj_stricmp(&msg->body->content_type.subtype, &str_sdp))
-    {
-        /* Message body is not "application/sdp" */
-        return PJMEDIA_SDP_EINSDP;
+        pj_str_t res_tag;
+
+        res_tag = rdata->msg_info.to->tag;
+
+        /* Allow final response after SDP has been negotiated in early
+         * media, IF this response is a final response with different
+         * tag.
+         */
+        if (tsx->role == PJSIP_ROLE_UAC &&
+            rdata->msg_info.msg->line.status.code/100 == 2 &&
+            tsx_inv_data->done_early &&
+            pj_strcmp(&tsx_inv_data->done_tag, &res_tag))
+        {
+            const pjmedia_sdp_session *reoffer_sdp = NULL;
+
+            PJ_LOG(4,(inv->obj_name, "Received forked final response "
+                      "after SDP negotiation has been done in early "
+                      "media. Renegotiating SDP.."));
+
+            /* Retrieve original SDP offer from INVITE request */
+            reoffer_sdp = (const pjmedia_sdp_session*) 
+                          tsx->last_tx->msg->body->data;
+
+            /* Feed the original offer to negotiator */
+            status = pjmedia_sdp_neg_modify_local_offer(inv->pool, inv->neg,
+                                                        reoffer_sdp);
+            if (status != PJ_SUCCESS) {
+                PJ_LOG(1,(inv->obj_name, "Error updating local offer for "
+                          "forked 2xx response (err=%d)", status));
+                return status;
+            }
+
+        } else {
+
+            if (rdata->msg_info.msg->body) {
+                PJ_LOG(4,(inv->obj_name, "SDP negotiation done, message "
+                          "body is ignored"));
+            }
+            return PJ_SUCCESS;
+        }
     }
 
@@ -1448 +1494 @@
     status = pjmedia_sdp_parse(rdata->tp_info.pool, 
                                (char*)msg->body->data,
-                               msg->body->len, &sdp);
+                               msg->body->len, &rem_sdp);
     if (status == PJ_SUCCESS)
-        status = pjmedia_sdp_validate(sdp);
+        status = pjmedia_sdp_validate(rem_sdp);
 
     if (status != PJ_SUCCESS) {
@@ -1473 +1519 @@
         if (inv->neg == NULL) {
             status=pjmedia_sdp_neg_create_w_remote_offer(inv->pool, NULL, 
-                                                         sdp, &inv->neg);
+                                                         rem_sdp, &inv->neg);
         } else {
-            status=pjmedia_sdp_neg_set_remote_offer(inv->pool, inv->neg, sdp);
+            status=pjmedia_sdp_neg_set_remote_offer(inv->pool, inv->neg, 
+                                                    rem_sdp);
         }
 
@@ -1490 +1537 @@
         if (mod_inv.cb.on_rx_offer && inv->notify) {
 
-            (*mod_inv.cb.on_rx_offer)(inv, sdp);
+            (*mod_inv.cb.on_rx_offer)(inv, rem_sdp);
 
         }
@@ -1497 +1544 @@
                 PJMEDIA_SDP_NEG_STATE_LOCAL_OFFER) 
     {
+        int status_code;
 
         /* This is an answer. 
@@ -1505 +1553 @@
                   pjsip_rx_data_get_info(rdata)));
 
-        status = pjmedia_sdp_neg_set_remote_answer(inv->pool, inv->neg, sdp);
+        status = pjmedia_sdp_neg_set_remote_answer(inv->pool, inv->neg, 
+                                                   rem_sdp);
 
         if (status != PJ_SUCCESS) {
@@ -1519 +1568 @@
         inv_negotiate_sdp(inv);
 
-        /* Mark this transaction has having SDP offer/answer done. */
+        /* Mark this transaction has having SDP offer/answer done, and
+         * save the reference to the To tag
+         */
 
         tsx_inv_data->sdp_done = 1;
+        status_code = rdata->msg_info.msg->line.status.code;
+        tsx_inv_data->done_early = (status_code/100==1);
+        pj_strdup(tsx->pool, &tsx_inv_data->done_tag, 
+                  &rdata->msg_info.to->tag);
 
     } else {