Changeset 106 for pjproject/trunk/pjsip/src/pjsip/sip_endpoint.c

Timestamp:

Dec 30, 2005 11:50:15 PM (18 years ago)

Author:

bennylp

Message:

Basic module, transport, and sending messages

File:

• pjproject/trunk/pjsip/src/pjsip/sip_endpoint.c (modified) (17 diffs)

pjproject/trunk/pjsip/src/pjsip/sip_endpoint.c

@@ -57 +57 @@
     pj_str_t             name;
 
-    /** Transaction table. */
-    pj_hash_table_t     *tsx_table;
-
-    /** Mutex for transaction table. */
-    pj_mutex_t          *tsx_table_mutex;
-
     /** Timer heap. */
     pj_timer_heap_t     *timer_heap;
@@ -75 +69 @@
     pjsip_resolver_t    *resolver;
 
-    /** Number of modules registered. */
-    pj_uint32_t          mod_count;
+    /** Modules lock. */
+    pj_rwmutex_t        *mod_mutex;
 
     /** Modules. */
     pjsip_module        *modules[PJSIP_MAX_MODULE];
+
+    /** Module list, sorted by priority. */
+    pjsip_module         module_list;
 
     /** Number of supported methods. */
@@ -128 +125 @@
 
 /*
- * Initialize modules.
- */
-static pj_status_t init_modules( pjsip_endpoint *endpt )
+ * Register new module to the endpoint.
+ * The endpoint will then call the load and start function in the module to 
+ * properly initialize the module, and assign a unique module ID for the 
+ * module.
+ */
+PJ_DEF(pj_status_t) pjsip_endpt_register_module( pjsip_endpoint *endpt,
+                                                 pjsip_module *mod )
+{
+    pj_status_t status = PJ_SUCCESS;
+    pjsip_module *m;
+    int i;
+
+    pj_rwmutex_lock_write(endpt->mod_mutex);
+
+    /* Make sure that this module has not been registered. */
+    PJ_ASSERT_ON_FAIL(  pj_list_find_node(&endpt->module_list, mod) == NULL,
+                        {status = PJ_EEXISTS; goto on_return;});
+
+    /* Find unused ID for this module. */
+    for (i=0; i<PJ_ARRAY_SIZE(endpt->modules); ++i) {
+        if (endpt->modules[i] == NULL)
+            break;
+    }
+    if (i == PJ_ARRAY_SIZE(endpt->modules)) {
+        pj_assert(!"Too many modules registered!");
+        status = PJ_ETOOMANY;
+        goto on_return;
+    }
+
+    /* Assign the ID. */
+    mod->id = i;
+
+    /* Try to load the module. */
+    if (mod->load) {
+        status = (*mod->load)(endpt);
+        if (status != PJ_SUCCESS)
+            goto on_return;
+    }
+
+    /* Try to start the module. */
+    if (mod->start) {
+        status = (*mod->start)();
+        if (status != PJ_SUCCESS)
+            goto on_return;
+    }
+
+    /* Save the module. */
+    endpt->modules[i] = mod;
+
+    /* Put in the module list, sorted by priority. */
+    m = endpt->module_list.next;
+    while (m != &endpt->module_list) {
+        if (m->priority > mod->priority)
+            break;
+        m = m->next;
+    }
+    pj_list_insert_before(m, mod);
+
+    /* Done. */
+    PJ_TODO(BUILD_ALLOW_HEADER_BASED_ON_MODULES_SUPPORTED_METHODS);
+
+on_return:
+    pj_rwmutex_unlock_write(endpt->mod_mutex);
+    return status;
+}
+
+/*
+ * Unregister a module from the endpoint.
+ * The endpoint will then call the stop and unload function in the module to 
+ * properly shutdown the module.
+ */
+PJ_DEF(pj_status_t) pjsip_endpt_unregister_module( pjsip_endpoint *endpt,
+                                                   pjsip_module *mod )
 {
     pj_status_t status;
-    unsigned i;
-    //pj_str_t str_COMMA = { ", ", 2 };
-    extern pjsip_module aux_tsx_module;
-
-    PJ_LOG(5, (THIS_FILE, "init_modules()"));
-
-    /* Load static modules. */
-    endpt->mod_count = PJSIP_MAX_MODULE;
-    status = register_static_modules( &endpt->mod_count, endpt->modules );
-    if (status != 0) {
-        return status;
-    }
-
-    /* Add mini aux module. */
-    endpt->modules[endpt->mod_count++] = &aux_tsx_module;
-
-    /* Load dynamic modules. */
-    // Not supported yet!
-
-    /* Sort modules on the priority. */
-    for (i=endpt->mod_count-1; i>0; --i) {
-        pj_uint32_t max = 0;
-        unsigned j;
-        for (j=1; j<=i; ++j) {
-            if (endpt->modules[j]->priority > endpt->modules[max]->priority)
-                max = j;
-        }
-        if (max != i) {
-            pjsip_module *temp = endpt->modules[max];
-            endpt->modules[max] = endpt->modules[i];
-            endpt->modules[i] = temp;
-        }
-    }
-
-    /* Initialize each module. */
-    for (i=0; i < endpt->mod_count; ++i) {
-        int j;
-
-        pjsip_module *mod = endpt->modules[i];
-        if (mod->init_module) {
-            status = mod->init_module(endpt, mod, i);
-            if (status != 0) {
-                return status;
-            }
-        }
-
-        /* Collect all supported methods from modules. */
-        for (j=0; j<mod->method_cnt; ++j) {
-            unsigned k;
-            for (k=0; k<endpt->method_cnt; ++k) {
-                if (pjsip_method_cmp(mod->methods[j], endpt->methods[k]) == 0)
-                    break;
-            }
-            if (k == endpt->method_cnt) {
-                if (endpt->method_cnt < MAX_METHODS) {
-                    endpt->methods[endpt->method_cnt++] = mod->methods[j];
-                } else {
-                    PJ_LOG(1,(THIS_FILE, "Too many methods"));
-                    return -1;
-                }
-            }
-        }
-    }
-
-    /* Create Allow header. */
-    endpt->allow_hdr = pjsip_allow_hdr_create( endpt->pool );
-    endpt->allow_hdr->count = endpt->method_cnt;
-    for (i=0; i<endpt->method_cnt; ++i) {
-        endpt->allow_hdr->values[i] = endpt->methods[i]->name;
-    }
-
-    /* Start each module. */
-    for (i=0; i < endpt->mod_count; ++i) {
-        pjsip_module *mod = endpt->modules[i];
-        if (mod->start_module) {
-            status = mod->start_module(mod);
-            if (status != 0) {
-                return status;
-            }
-        }
-    }
+
+    pj_rwmutex_lock_write(endpt->mod_mutex);
+
+    /* Make sure the module exists in the list. */
+    PJ_ASSERT_ON_FAIL(  pj_list_find_node(&endpt->module_list, mod) == mod,
+                        {status = PJ_ENOTFOUND;goto on_return;} );
+
+    /* Make sure the module exists in the array. */
+    PJ_ASSERT_ON_FAIL(  mod->id>=0 && mod->id<PJ_ARRAY_SIZE(endpt->modules) &&
+                        endpt->modules[mod->id] == mod,
+                        {status = PJ_ENOTFOUND; goto on_return;});
+
+    /* Try to stop the module. */
+    if (mod->stop) {
+        status = (*mod->stop)();
+        if (status != PJ_SUCCESS) goto on_return;
+    }
+
+    /* Try to unload the module. */
+    if (mod->unload) {
+        status = (*mod->unload)();
+        if (status != PJ_SUCCESS) goto on_return;
+    }
+
+    /* Remove module from array. */
+    endpt->modules[mod->id] = NULL;
+
+    /* Remove module from list. */
+    pj_list_erase(mod);
 
     /* Done. */
-    return 0;
-}
-
-/*
- * Unregister the transaction from the hash table, and destroy the resources
- * from the transaction.
- */
-PJ_DEF(void) pjsip_endpt_destroy_tsx( pjsip_endpoint *endpt,
-                                      pjsip_transaction *tsx)
-{
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_destroy_tsx(%s)", tsx->obj_name));
-
-    pj_assert(tsx->state == PJSIP_TSX_STATE_DESTROYED);
-
-    /* No need to lock transaction. 
-     * This function typically is called from the transaction callback, which
-     * means that transaction mutex is being held.
-     */
-    pj_assert( pj_mutex_is_locked(tsx->mutex) );
-
-    /* Lock endpoint. */
-    pj_mutex_lock( endpt->tsx_table_mutex );
-
-    /* Unregister from the hash table. */
-    pj_hash_set( NULL, endpt->tsx_table, tsx->transaction_key.ptr, 
-                 tsx->transaction_key.slen, NULL);
-
-    /* Unlock endpoint mutex. */
-    pj_mutex_unlock( endpt->tsx_table_mutex );
-
-    /* Destroy transaction mutex. */
-    pj_mutex_destroy( tsx->mutex );
-
-    /* Release the pool for the transaction. */
-    pj_pool_release(tsx->pool);
-
-    PJ_LOG(4, (THIS_FILE, "tsx%p destroyed", tsx));
-}
-
-
-/*
- * Receive transaction events from transactions and dispatch them to the 
- * modules.
- */
-static void endpt_do_event( pjsip_endpoint *endpt, pjsip_event *evt)
-{
-    unsigned i;
-
-    /* Dispatch event to modules. */
-    for (i=0; i<endpt->mod_count; ++i) {
-        pjsip_module *mod = endpt->modules[i];
-        if (mod && mod->tsx_handler) {
-            mod->tsx_handler( mod, evt );
-        }
-    }
-
-    /* Destroy transaction if it is terminated. */
-    if (evt->type == PJSIP_EVENT_TSX_STATE && 
-        evt->body.tsx_state.tsx->state == PJSIP_TSX_STATE_DESTROYED) 
-    {
-        /* No need to lock mutex. Mutex is locked inside the destroy function */
-        pjsip_endpt_destroy_tsx( endpt, evt->body.tsx_state.tsx );
-    }
-}
-
-/*
- * Receive transaction events from transactions and put in the event queue
- * to be processed later.
- */
-void pjsip_endpt_send_tsx_event( pjsip_endpoint *endpt, pjsip_event *evt )
-{
-    // Need to protect this with try/catch?
-    endpt_do_event(endpt, evt);
+    status = PJ_SUCCESS;
+
+    PJ_TODO(REMOVE_METHODS_FROM_ALLOW_HEADER_WHEN_MODULE_IS_UNREGISTERED);
+
+on_return:
+    pj_rwmutex_unlock_write(endpt->mod_mutex);
+    return status;
 }
 
@@ -376 +325 @@
 
     /* Create endpoint. */
-    endpt = pj_pool_calloc(pool, 1, sizeof(*endpt));
+    endpt = pj_pool_zalloc(pool, sizeof(*endpt));
     endpt->pool = pool;
     endpt->pf = pf;
+
+    /* Init modules list. */
+    pj_list_init(&endpt->module_list);
+
+    /* Create R/W mutex for module manipulation. */
+    status = pj_rwmutex_create(endpt->pool, "ept%p", &endpt->mod_mutex);
+    if (status != PJ_SUCCESS)
+        goto on_error;
 
     /* Init parser. */
@@ -400 +357 @@
     }
 
-    /* Create mutex for the transaction table. */
-    status = pj_mutex_create_recursive( endpt->pool, "mtbl%p", 
-                                        &endpt->tsx_table_mutex);
-    if (status != PJ_SUCCESS) {
-        goto on_error;
-    }
-
-    /* Create hash table for transaction. */
-    endpt->tsx_table = pj_hash_create( endpt->pool, PJSIP_MAX_TSX_COUNT );
-    if (!endpt->tsx_table) {
-        status = PJ_ENOMEM;
-        goto on_error;
-    }
-
     /* Create timer heap to manage all timers within this endpoint. */
     status = pj_timer_heap_create( endpt->pool, PJSIP_MAX_TIMER_COUNT, 
@@ -453 +396 @@
     }
 
-    /* Initialize TLS ID for transaction lock. */
-    status = pj_thread_local_alloc(&pjsip_tsx_lock_tls_id);
-    if (status != PJ_SUCCESS) {
-        goto on_error;
-    }
-    pj_thread_local_set(pjsip_tsx_lock_tls_id, NULL);
-
     /* Initialize request headers. */
     pj_list_init(&endpt->req_hdr);
@@ -471 +407 @@
     pj_list_insert_before( &endpt->req_hdr, mf_hdr);
 
-    /* Load and init modules. */
-    status = init_modules(endpt);
-    if (status != PJ_SUCCESS) {
-        PJ_LOG(4, (THIS_FILE, "pjsip_endpt_init(): error in init_modules()"));
-        return status;
-    }
-
     /* Done. */
     *p_endpt = endpt;
@@ -491 +420 @@
         endpt->mutex = NULL;
     }
-    if (endpt->tsx_table_mutex) {
-        pj_mutex_destroy(endpt->tsx_table_mutex);
-        endpt->tsx_table_mutex = NULL;
+    if (endpt->mod_mutex) {
+        pj_rwmutex_destroy(endpt->mod_mutex);
+        endpt->mod_mutex = NULL;
     }
     pj_pool_release( endpt->pool );
@@ -513 +442 @@
     /* Delete endpoint mutex. */
     pj_mutex_destroy(endpt->mutex);
-
-    /* Delete transaction table mutex. */
-    pj_mutex_destroy(endpt->tsx_table_mutex);
 
     /* Finally destroy pool. */
@@ -625 +551 @@
 
 /*
- * Create a new transaction.
- * Endpoint must then initialize the new transaction as either UAS or UAC, and
- * register it to the hash table.
- */
-PJ_DEF(pj_status_t) pjsip_endpt_create_tsx(pjsip_endpoint *endpt,
-                                           pjsip_transaction **p_tsx)
-{
-    pj_pool_t *pool;
-
-    PJ_ASSERT_RETURN(endpt && p_tsx, PJ_EINVAL);
-
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_create_tsx()"));
-
-    /* Request one pool for the transaction. Mutex is locked there. */
-    pool = pjsip_endpt_create_pool(endpt, "ptsx%p", 
-                                      PJSIP_POOL_LEN_TSX, PJSIP_POOL_INC_TSX);
-    if (pool == NULL) {
-        return PJ_ENOMEM;
-    }
-
-    /* Create the transaction. */
-    return pjsip_tsx_create(pool, endpt, p_tsx);
-}
-
-/*
- * Register the transaction to the endpoint.
- * This will put the transaction to the transaction hash table. Before calling
- * this function, the transaction must be INITIALIZED as either UAS or UAC, so
- * that the transaction key is built.
- */
-PJ_DEF(void) pjsip_endpt_register_tsx( pjsip_endpoint *endpt,
-                                       pjsip_transaction *tsx)
-{
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_register_tsx(%s)", tsx->obj_name));
-
-    pj_assert(tsx->transaction_key.slen != 0);
-    //pj_assert(tsx->state != PJSIP_TSX_STATE_NULL);
-
-    /* Lock hash table mutex. */
-    pj_mutex_lock(endpt->tsx_table_mutex);
-
-    /* Register the transaction to the hash table. */
-    pj_hash_set( tsx->pool, endpt->tsx_table, tsx->transaction_key.ptr,
-                 tsx->transaction_key.slen, tsx);
-
-    /* Unlock mutex. */
-    pj_mutex_unlock(endpt->tsx_table_mutex);
-}
-
-/*
- * Find transaction by the key.
- */
-PJ_DEF(pjsip_transaction*) pjsip_endpt_find_tsx( pjsip_endpoint *endpt,
-                                                  const pj_str_t *key )
-{
-    pjsip_transaction *tsx;
-
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_find_tsx()"));
-
-    /* Start lock mutex in the endpoint. */
-    pj_mutex_lock(endpt->tsx_table_mutex);
-
-    /* Find the transaction in the hash table. */
-    tsx = pj_hash_get( endpt->tsx_table, key->ptr, key->slen );
-
-    /* Unlock mutex. */
-    pj_mutex_unlock(endpt->tsx_table_mutex);
-
-    return tsx;
-}
-
-/*
- * Create key.
- */
-static void rdata_create_key( pjsip_rx_data *rdata)
-{
-    pjsip_role_e role;
-    if (rdata->msg_info.msg->type == PJSIP_REQUEST_MSG) {
-        role = PJSIP_ROLE_UAS;
-    } else {
-        role = PJSIP_ROLE_UAC;
-    }
-    pjsip_tsx_create_key(rdata->tp_info.pool, &rdata->endpt_info.key, role,
-                         &rdata->msg_info.cseq->method, rdata);
-}
-
-/*
  * This is the callback that is called by the transport manager when it 
  * receives a message from the network.
@@ -720 +559 @@
 {
     pjsip_msg *msg = rdata->msg_info.msg;
-    pjsip_transaction *tsx;
-    pj_bool_t a_new_transaction_just_been_created = PJ_FALSE;
 
     PJ_LOG(5, (THIS_FILE, "endpt_transport_callback(rdata=%p)", rdata));
 
     if (status != PJ_SUCCESS) {
-        const char *src_addr = rdata->pkt_info.src_name;
-        int port = rdata->pkt_info.src_port;
         PJSIP_ENDPT_LOG_ERROR((endpt, "transport", status,
-                               "Src.addr=%s:%d, packet:--\n"
+                               "Error processing packet from %s:%d, packet:--\n"
                                "%s\n"
-                               "-- end of packet. Error",
-                               src_addr, port, rdata->msg_info.msg_buf));
+                               "-- end of packet.",
+                               rdata->pkt_info.src_name, 
+                               rdata->pkt_info.src_port, 
+                               rdata->msg_info.msg_buf));
         return;
     }
@@ -741 +578 @@
      */
     if (msg->type == PJSIP_RESPONSE_MSG) {
-        const pj_str_t *addr_addr;
+        const pj_str_t *local_addr;
         int port = rdata->msg_info.via->sent_by.port;
         pj_bool_t mismatch = PJ_FALSE;
@@ -749 +586 @@
             port = pjsip_transport_get_default_port_for_type(type);
         }
-        addr_addr = &rdata->tp_info.transport->local_name.host;
-        if (pj_strcmp(&rdata->msg_info.via->sent_by.host, addr_addr) != 0)
+        local_addr = &rdata->tp_info.transport->local_name.host;
+        if (pj_strcmp(&rdata->msg_info.via->sent_by.host, local_addr) != 0)
             mismatch = PJ_TRUE;
         else if (port != rdata->tp_info.transport->local_name.port) {
@@ -760 +597 @@
              * both the port in sent-by and rport. We try to be lenient here!
              */
-            if (rdata->msg_info.via->rport_param != rdata->tp_info.transport->local_name.port)
+            if (rdata->msg_info.via->rport_param != 
+                rdata->tp_info.transport->local_name.port)
                 mismatch = PJ_TRUE;
             else {
-                PJ_LOG(4,(THIS_FILE, "Response %p has mismatch port in sent-by"
-                                    " but the rport parameter is correct",
-                                    rdata));
+                PJ_LOG(4,(THIS_FILE, "Response %p from %s has mismatch port in "
+                                     "sent-by but the rport parameter is "
+                                     "correct",
+                                     rdata, rdata->pkt_info.src_name));
             }
         }
 
         if (mismatch) {
-            pjsip_event e;
-
-            PJSIP_EVENT_INIT_DISCARD_MSG(e, rdata, PJSIP_EINVALIDVIA);
-            endpt_do_event( endpt, &e );
+            PJ_TODO(ENDPT_REPORT_WHEN_DROPPING_MESSAGE);
+            PJ_LOG(4,(THIS_FILE, "Dropping response from %s:%d because sent-by"
+                                 " is mismatch", 
+                                 rdata->pkt_info.src_name, 
+                                 rdata->pkt_info.src_port));
             return;
         }
-    } 
-
-    /* Create key for transaction lookup. */
-    rdata_create_key( rdata);
-
-    /* Find the transaction for the received message. */
-    PJ_LOG(5, (THIS_FILE, "finding tsx with key=%.*s", 
-                         rdata->endpt_info.key.slen, rdata->endpt_info.key.ptr));
-
-    /* Start lock mutex in the endpoint. */
-    pj_mutex_lock(endpt->tsx_table_mutex);
-
-    /* Find the transaction in the hash table. */
-    tsx = pj_hash_get( endpt->tsx_table, rdata->endpt_info.key.ptr, rdata->endpt_info.key.slen );
-
-    /* Unlock mutex. */
-    pj_mutex_unlock(endpt->tsx_table_mutex);
-
-    /* If the transaction is not found... */
-    if (tsx == NULL || tsx->state == PJSIP_TSX_STATE_TERMINATED) {
-
-        /* 
-         * For response message, discard the message, except if the response is
-         * an 2xx class response to INVITE, which in this case it must be
-         * passed to TU to be acked.
-         */
-        if (msg->type == PJSIP_RESPONSE_MSG) {
-
-            /* Inform TU about the 200 message, only if it's INVITE. */
-            if (PJSIP_IS_STATUS_IN_CLASS(msg->line.status.code, 200) &&
-                rdata->msg_info.cseq->method.id == PJSIP_INVITE_METHOD) 
-            {
-                pjsip_event e;
-
-                /* Should not happen for UA. Tsx theoritically lives until
-                 * all responses are absorbed.
-                 */
-                pj_assert(0);
-
-                PJSIP_EVENT_INIT_RX_200_MSG(e, rdata);
-                endpt_do_event( endpt, &e );
-
-            } else {
-                /* Just discard the response, inform TU. */
-                pjsip_event e;
-
-                PJSIP_EVENT_INIT_DISCARD_MSG(e, rdata, 
-                    PJSIP_ERRNO_FROM_SIP_STATUS(PJSIP_SC_CALL_TSX_DOES_NOT_EXIST));
-                endpt_do_event( endpt, &e );
-            }
-
-        /*
-         * For non-ACK request message, create a new transaction.
-         */
-        } else if (rdata->msg_info.msg->line.req.method.id != PJSIP_ACK_METHOD) {
-
-            pj_status_t status;
-
-            /* Create transaction, mutex is locked there. */
-            status = pjsip_endpt_create_tsx(endpt, &tsx);
-            if (status != PJ_SUCCESS) {
-                PJSIP_ENDPT_LOG_ERROR((endpt, THIS_FILE, status,
-                                       "Unable to create transaction"));
-                return;
-            }
-
-            /* Initialize transaction as UAS. */
-            pjsip_tsx_init_uas( tsx, rdata );
-
-            /* Register transaction, mutex is locked there. */
-            pjsip_endpt_register_tsx( endpt, tsx );
-
-            a_new_transaction_just_been_created = PJ_TRUE;
+    }
+
+
+    /* Distribute to modules. */
+    pj_rwmutex_lock_read(endpt->mod_mutex);
+
+    if (msg->type == PJSIP_REQUEST_MSG) {
+        pjsip_module *mod;
+        pj_bool_t handled = PJ_FALSE;
+
+        mod = endpt->module_list.next;
+        while (mod != &endpt->module_list) {
+            if (mod->on_rx_request)
+                handled = (*mod->on_rx_request)(rdata);
+            if (handled)
+                break;
+            mod = mod->next;
         }
-    }
-
-    /* If transaction is found (or newly created), pass the message.
-     * Otherwise if it's an ACK request, pass directly to TU.
-     */
-    if (tsx && tsx->state != PJSIP_TSX_STATE_TERMINATED) {
-        /* Dispatch message to transaction. */
-        pjsip_tsx_on_rx_msg( tsx, rdata );
-
-    } else if (rdata->msg_info.msg->line.req.method.id == PJSIP_ACK_METHOD) {
-        /*
-         * This is an ACK message, but the INVITE transaction could not
-         * be found (possibly because the branch parameter in Via in ACK msg
-         * is different than the branch in original INVITE). This happens with
-         * SER!
-         */
-        pjsip_event event;
-
-        PJSIP_EVENT_INIT_RX_ACK_MSG(event,rdata);
-        endpt_do_event( endpt, &event );
-    }
-
-    /*
-     * If a new request message has just been receieved, but no modules
-     * seem to be able to handle the request message, then terminate the
-     * transaction.
-     *
-     * Ideally for cases like "unsupported method", we should be able to
-     * answer the request statelessly. But we can not do that since the
-     * endpoint shoule be able to be used as both user agent and proxy stack,
-     * and a proxy stack should be able to handle arbitrary methods.
-     */
-    if (a_new_transaction_just_been_created && tsx->status_code < 100) {
-        /* Certainly no modules has sent any response message.
-         * Check that any modules has attached a module data.
-         */
-        int i;
-        for (i=0; i<PJSIP_MAX_MODULE; ++i) {
-            if (tsx->module_data[i] != NULL) {
+
+        /* No module is able to handle the request. */
+        if (!handled) {
+            PJ_TODO(ENDPT_RESPOND_UNHANDLED_REQUEST);
+            PJ_LOG(4,(THIS_FILE, "Request from %s:%d was dropped/unhandled by"
+                                 " any modules"));
+        }
+
+    } else {
+        pjsip_module *mod;
+        pj_bool_t handled = PJ_FALSE;
+
+        mod = endpt->module_list.next;
+        while (mod != &endpt->module_list) {
+            if (mod->on_rx_response)
+                handled = (*mod->on_rx_response)(rdata);
+            if (handled)
                 break;
-            }
+            mod = mod->next;
         }
-        if (i == PJSIP_MAX_MODULE) {
-            /* No modules have attached itself to the transaction. 
-             * Terminate the transaction with 501/Not Implemented.
-             */
-            pjsip_tx_data *tdata;
-            pj_status_t status;
-            
-            if (tsx->method.id == PJSIP_OPTIONS_METHOD) {
-                status = pjsip_endpt_create_response(endpt, rdata, 200, 
-                                                     &tdata);
-            } else {
-                status = pjsip_endpt_create_response(endpt, rdata, 
-                                                     PJSIP_SC_METHOD_NOT_ALLOWED,
-                                                     &tdata);
-            }
-
-            if (status != PJ_SUCCESS) {
-                PJSIP_ENDPT_LOG_ERROR((endpt, THIS_FILE, status,
-                                       "Unable to create response"));
-                return;
-            }
-
-            if (endpt->allow_hdr) {
-                pjsip_msg_add_hdr( tdata->msg, 
-                                   pjsip_hdr_shallow_clone(tdata->pool, endpt->allow_hdr));
-            }
-            pjsip_tsx_on_tx_msg( tsx, tdata );
-
-        } else {
-            /*
-             * If a module has registered itself in the transaction but it
-             * hasn't responded the request, chances are the module wouldn't
-             * respond to the request at all. We terminate the request here
-             * with 500/Internal Server Error, to be safe.
-             */
-            pjsip_tx_data *tdata;
-            pj_status_t status;
-
-            status = pjsip_endpt_create_response(endpt, rdata, 500, &tdata);
-            if (status != PJ_SUCCESS) {
-                PJSIP_ENDPT_LOG_ERROR((endpt, THIS_FILE, status,
-                                       "Unable to create response"));
-                return;
-            }
-
-            pjsip_tsx_on_tx_msg(tsx, tdata);
+
+        if (!handled) {
+            PJ_LOG(4,(THIS_FILE, "Response from %s:%d was dropped/unhandled by"
+                                 " any modules"));
         }
     }
+
+    pj_rwmutex_unlock_read(endpt->mod_mutex);
 }
 
@@ -984 +706 @@
  * Find/create transport.
  */
-PJ_DEF(pj_status_t) pjsip_endpt_alloc_transport( pjsip_endpoint *endpt,
+PJ_DEF(pj_status_t) pjsip_endpt_acquire_transport(pjsip_endpoint *endpt,
                                                   pjsip_transport_type_e type,
-                                                  const pj_sockaddr *remote,
+                                                  const pj_sockaddr_t *remote,
                                                   int addr_len,
-                                                  pjsip_transport **p_transport)
-{
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_alloc_transport()"));
-    return pjsip_tpmgr_alloc_transport( endpt->transport_mgr, type, 
-                                        remote, addr_len, p_transport);
+                                                  pjsip_transport **transport)
+{
+    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_acquire_transport()"));
+    return pjsip_tpmgr_acquire_transport(endpt->transport_mgr, type, 
+                                         remote, addr_len, transport);
 }
 
@@ -1050 +772 @@
 {
 #if PJ_LOG_MAX_LEVEL >= 3
-    unsigned count;
-
     PJ_LOG(5, (THIS_FILE, "pjsip_endpt_dump()"));
 
@@ -1066 +786 @@
                pj_pool_get_capacity(endpt->pool),
                pj_pool_get_used_size(endpt->pool)));
-
-    /* Transaction tables. */
-    count = pj_hash_count(endpt->tsx_table);
-    PJ_LOG(3, (THIS_FILE, " Number of transactions: %u", count));
-
-    if (count && detail) {
-        pj_hash_iterator_t it_val;
-        pj_hash_iterator_t *it;
-        pj_time_val now;
-
-        PJ_LOG(3, (THIS_FILE, " Dumping transaction tables:"));
-
-        pj_gettimeofday(&now);
-        it = pj_hash_first(endpt->tsx_table, &it_val);
-
-        while (it != NULL) {
-            int timeout_diff;
-
-            /* Get the transaction. No need to lock transaction's mutex
-             * since we already hold endpoint mutex, so that no transactions
-             * will be deleted.
-             */
-            pjsip_transaction *tsx = pj_hash_this(endpt->tsx_table, it);
-
-            const char *role = (tsx->role == PJSIP_ROLE_UAS ? "UAS" : "UAC");
-        
-            if (tsx->timeout_timer._timer_id != -1) {
-                if (tsx->timeout_timer._timer_value.sec > now.sec) {
-                    timeout_diff = tsx->timeout_timer._timer_value.sec - now.sec;
-                } else {
-                    timeout_diff = now.sec - tsx->timeout_timer._timer_value.sec;
-                    timeout_diff = 0 - timeout_diff;
-                }
-            } else {
-                timeout_diff = -1;
-            }
-
-            PJ_LOG(3, (THIS_FILE, "  %s %s %10.*s %.9u %s t=%ds", 
-                       tsx->obj_name, role, 
-                       tsx->method.name.slen, tsx->method.name.ptr,
-                       tsx->cseq,
-                       pjsip_tsx_state_str(tsx->state),
-                       timeout_diff));
-
-            it = pj_hash_next(endpt->tsx_table, it);
-        }
-    }
 
     /* Transports.