ARI/PJSIP: Add the ability to redirect (transfer) a channel in a Stasis app
authorMatthew Jordan <mjordan@digium.com>
Thu, 12 Feb 2015 20:34:37 +0000 (20:34 +0000)
committerMatthew Jordan <mjordan@digium.com>
Thu, 12 Feb 2015 20:34:37 +0000 (20:34 +0000)
This patch adds a new feature to ARI to redirect a channel to another server,
and fixes a few bugs in PJSIP's handling of the Transfer dialplan
application/ARI redirect capability.

*New Feature*
A new operation has been added to the ARI channels resource, redirect. With
this, a channel in a Stasis application can be redirected to another endpoint
of the same underlying channel technology.

*Bug fixes*
In the process of writing this new feature, two bugs were fixed in the PJSIP
stack:
(1) The existing .transfer channel callback had the limitation that it could
    only transfer channels to a SIP URI, i.e., you had to pass
    'PJSIP/sip:foo@my_provider.com' to the dialplan application. While this is
    still supported, it is somewhat unintuitive - particularly in a world full
    of endpoints. As such, we now also support specifying the PJSIP endpoint to
    transfer to.
(2) res_pjsip_multihomed was, unfortunately, trying to 'help' a 302 redirect by
    updating its Contact header. Alas, that resulted in the forwarding
    destination set by the dialplan application/ARI resource/whatever being
    rewritten with very incorrect information. Hence, we now don't bother
    updating an outgoing response if it is a 302. Since this took a looong time
    to find, some additional debug statements have been added to those modules
    that update the Contact headers.

Review: https://reviewboard.asterisk.org/r/4316/

ASTERISK-24015 #close
Reported by: Private Name

ASTERISK-24703 #close
Reported by: Matt Jordan
........

Merged revisions 431717 from http://svn.asterisk.org/svn/asterisk/branches/13

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@431718 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES
channels/chan_pjsip.c
include/asterisk/stasis_app.h
res/ari/resource_channels.c
res/ari/resource_channels.h
res/res_ari_channels.c
res/res_pjsip_multihomed.c
res/res_pjsip_nat.c
res/res_pjsip_transport_websocket.c
res/stasis/control.c
rest-api/api-docs/channels.json

diff --git a/CHANGES b/CHANGES
index 84958a2..5f08d5a 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -101,6 +101,24 @@ res_musiconhold
    application (e.g. Queue or Dial) specified music.
 
 ------------------------------------------------------------------------------
+--- Functionality changes from Asterisk 13.2.0 to Asterisk 13.3.0 ------------
+------------------------------------------------------------------------------
+
+chan_pjsip/app_transfer
+------------------
+ * The Transfer application, when used with chan_pjsip, now supports using
+   a PJSIP endpoint as the transfer destination. This is in addition to
+   explicitly specifying a SIP URI to transfer to.
+
+res_ari_channels
+------------------
+ * The ARI /channels resource now supports a new operation, 'redirect'. The
+   redirect operation will perform a technology and state specific redirection
+   on the channel to a specified endpoint or destination. In the case of SIP
+   technologies, this is either a 302 Redirect response to an on-going INVITE
+   dialog or a SIP REFER request.
+
+------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 13.1.0 to Asterisk 13.2.0 ------------
 ------------------------------------------------------------------------------
 
index 3e2e9e2..eaeb9bc 100644 (file)
@@ -1378,6 +1378,8 @@ static void transfer_redirect(struct ast_sip_session *session, const char *targe
        pj_str_t tmp;
 
        if (pjsip_inv_end_session(session->inv_session, 302, NULL, &packet) != PJ_SUCCESS) {
+               ast_log(LOG_WARNING, "Failed to redirect PJSIP session for channel %s\n",
+                       ast_channel_name(session->channel));
                message = AST_TRANSFER_FAILED;
                ast_queue_control_data(session->channel, AST_CONTROL_TRANSFER, &message, sizeof(message));
 
@@ -1390,6 +1392,8 @@ static void transfer_redirect(struct ast_sip_session *session, const char *targe
 
        pj_strdup2_with_null(packet->pool, &tmp, target);
        if (!(contact->uri = pjsip_parse_uri(packet->pool, tmp.ptr, tmp.slen, PJSIP_PARSE_URI_AS_NAMEADDR))) {
+               ast_log(LOG_WARNING, "Failed to parse destination URI '%s' for channel %s\n",
+                       target, ast_channel_name(session->channel));
                message = AST_TRANSFER_FAILED;
                ast_queue_control_data(session->channel, AST_CONTROL_TRANSFER, &message, sizeof(message));
                pjsip_tx_data_dec_ref(packet);
@@ -1431,14 +1435,28 @@ static void transfer_refer(struct ast_sip_session *session, const char *target)
 static int transfer(void *data)
 {
        struct transfer_data *trnf_data = data;
+       struct ast_sip_endpoint *endpoint = NULL;
+       struct ast_sip_contact *contact = NULL;
+       const char *target = trnf_data->target;
+
+       /* See if we have an endpoint; if so, use its contact */
+       endpoint = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", target);
+       if (endpoint) {
+               contact = ast_sip_location_retrieve_contact_from_aor_list(endpoint->aors);
+               if (contact && !ast_strlen_zero(contact->uri)) {
+                       target = contact->uri;
+               }
+       }
 
        if (ast_channel_state(trnf_data->session->channel) == AST_STATE_RING) {
-               transfer_redirect(trnf_data->session, trnf_data->target);
+               transfer_redirect(trnf_data->session, target);
        } else {
-               transfer_refer(trnf_data->session, trnf_data->target);
+               transfer_refer(trnf_data->session, target);
        }
 
        ao2_ref(trnf_data, -1);
+       ao2_cleanup(endpoint);
+       ao2_cleanup(contact);
        return 0;
 }
 
index 0d04caa..567670b 100644 (file)
@@ -486,6 +486,17 @@ void stasis_app_control_clear_roles(struct stasis_app_control *control);
 int stasis_app_control_continue(struct stasis_app_control *control, const char *context, const char *extension, int priority);
 
 /*!
+ * \brief Redirect a channel in \c res_stasis to a particular endpoint
+ *
+ * \param control Control for \c res_stasis
+ * \param endpoint The endpoint transfer string where the channel should be sent to
+ *
+ * \return 0 for success
+ * \return -1 for error
+ */
+int stasis_app_control_redirect(struct stasis_app_control *control, const char *endpoint);
+
+/*!
  * \brief Indicate ringing to the channel associated with this control.
  *
  * \param control Control for \c res_stasis.
index 24aabe5..67498af 100644 (file)
@@ -156,6 +156,64 @@ void ast_ari_channels_continue_in_dialplan(
        ast_ari_response_no_content(response);
 }
 
+void ast_ari_channels_redirect(struct ast_variable *headers,
+       struct ast_ari_channels_redirect_args *args,
+       struct ast_ari_response *response)
+{
+       RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
+       RAII_VAR(struct ast_channel_snapshot *, chan_snapshot, NULL, ao2_cleanup);
+       char *tech;
+       char *resource;
+       int tech_len;
+
+       control = find_control(response, args->channel_id);
+       if (!control) {
+               return;
+       }
+
+       if (ast_strlen_zero(args->endpoint)) {
+               ast_ari_response_error(response, 400, "Not Found",
+                       "Required parameter 'endpoint' not provided.");
+               return;
+       }
+
+       tech = ast_strdupa(args->endpoint);
+       if (!(resource = strchr(tech, '/')) || !(tech_len = resource - tech)) {
+               ast_ari_response_error(response, 422, "Unprocessable Entity",
+                       "Endpoint parameter '%s' does not contain tech/resource", args->endpoint);
+               return;
+       }
+
+       *resource++ = '\0';
+       if (ast_strlen_zero(resource)) {
+               ast_ari_response_error(response, 422, "Unprocessable Entity",
+                       "No resource provided in endpoint parameter '%s'", args->endpoint);
+               return;
+       }
+
+       chan_snapshot = ast_channel_snapshot_get_latest(args->channel_id);
+       if (!chan_snapshot) {
+               ast_ari_response_error(response, 500, "Internal Server Error",
+                       "Unable to find channel snapshot for '%s'", args->channel_id);
+               return;
+       }
+
+       if (strncasecmp(chan_snapshot->type, tech, tech_len)) {
+               ast_ari_response_error(response, 422, "Unprocessable Entity",
+                       "Endpoint technology '%s' does not match channel technology '%s'",
+                       tech, chan_snapshot->type);
+               return;
+       }
+
+       if (stasis_app_control_redirect(control, resource)) {
+               ast_ari_response_error(response, 500, "Internal Server Error",
+                       "Failed to redirect channel");
+               return;
+       }
+
+       ast_ari_response_no_content(response);
+}
+
 void ast_ari_channels_answer(struct ast_variable *headers,
        struct ast_ari_channels_answer_args *args,
        struct ast_ari_response *response)
index bd3b620..4d3ad5f 100644 (file)
@@ -221,6 +221,32 @@ int ast_ari_channels_continue_in_dialplan_parse_body(
  * \param[out] response HTTP response
  */
 void ast_ari_channels_continue_in_dialplan(struct ast_variable *headers, struct ast_ari_channels_continue_in_dialplan_args *args, struct ast_ari_response *response);
+/*! Argument struct for ast_ari_channels_redirect() */
+struct ast_ari_channels_redirect_args {
+       /*! Channel's id */
+       const char *channel_id;
+       /*! The endpoint to redirect the channel to */
+       const char *endpoint;
+};
+/*!
+ * \brief Body parsing function for /channels/{channelId}/redirect.
+ * \param body The JSON body from which to parse parameters.
+ * \param[out] args The args structure to parse into.
+ * \retval zero on success
+ * \retval non-zero on failure
+ */
+int ast_ari_channels_redirect_parse_body(
+       struct ast_json *body,
+       struct ast_ari_channels_redirect_args *args);
+
+/*!
+ * \brief Redirect the channel to a different location.
+ *
+ * \param headers HTTP headers
+ * \param args Swagger parameters
+ * \param[out] response HTTP response
+ */
+void ast_ari_channels_redirect(struct ast_variable *headers, struct ast_ari_channels_redirect_args *args, struct ast_ari_response *response);
 /*! Argument struct for ast_ari_channels_answer() */
 struct ast_ari_channels_answer_args {
        /*! Channel's id */
index 20128ae..a088705 100644 (file)
@@ -707,6 +707,106 @@ static void ast_ari_channels_continue_in_dialplan_cb(
 fin: __attribute__((unused))
        return;
 }
+int ast_ari_channels_redirect_parse_body(
+       struct ast_json *body,
+       struct ast_ari_channels_redirect_args *args)
+{
+       struct ast_json *field;
+       /* Parse query parameters out of it */
+       field = ast_json_object_get(body, "endpoint");
+       if (field) {
+               args->endpoint = ast_json_string_get(field);
+       }
+       return 0;
+}
+
+/*!
+ * \brief Parameter parsing callback for /channels/{channelId}/redirect.
+ * \param get_params GET parameters in the HTTP request.
+ * \param path_vars Path variables extracted from the request.
+ * \param headers HTTP headers.
+ * \param[out] response Response to the HTTP request.
+ */
+static void ast_ari_channels_redirect_cb(
+       struct ast_tcptls_session_instance *ser,
+       struct ast_variable *get_params, struct ast_variable *path_vars,
+       struct ast_variable *headers, struct ast_ari_response *response)
+{
+       struct ast_ari_channels_redirect_args args = {};
+       struct ast_variable *i;
+       RAII_VAR(struct ast_json *, body, NULL, ast_json_unref);
+#if defined(AST_DEVMODE)
+       int is_valid;
+       int code;
+#endif /* AST_DEVMODE */
+
+       for (i = get_params; i; i = i->next) {
+               if (strcmp(i->name, "endpoint") == 0) {
+                       args.endpoint = (i->value);
+               } else
+               {}
+       }
+       for (i = path_vars; i; i = i->next) {
+               if (strcmp(i->name, "channelId") == 0) {
+                       args.channel_id = (i->value);
+               } else
+               {}
+       }
+       /* Look for a JSON request entity */
+       body = ast_http_get_json(ser, headers);
+       if (!body) {
+               switch (errno) {
+               case EFBIG:
+                       ast_ari_response_error(response, 413, "Request Entity Too Large", "Request body too large");
+                       goto fin;
+               case ENOMEM:
+                       ast_ari_response_error(response, 500, "Internal Server Error", "Error processing request");
+                       goto fin;
+               case EIO:
+                       ast_ari_response_error(response, 400, "Bad Request", "Error parsing request body");
+                       goto fin;
+               }
+       }
+       if (ast_ari_channels_redirect_parse_body(body, &args)) {
+               ast_ari_response_alloc_failed(response);
+               goto fin;
+       }
+       ast_ari_channels_redirect(headers, &args, response);
+#if defined(AST_DEVMODE)
+       code = response->response_code;
+
+       switch (code) {
+       case 0: /* Implementation is still a stub, or the code wasn't set */
+               is_valid = response->message == NULL;
+               break;
+       case 500: /* Internal Server Error */
+       case 501: /* Not Implemented */
+       case 400: /* Endpoint parameter not provided */
+       case 404: /* Channel or endpoint not found */
+       case 409: /* Channel not in a Stasis application */
+       case 422: /* Endpoint is not the same type as the channel */
+               is_valid = 1;
+               break;
+       default:
+               if (200 <= code && code <= 299) {
+                       is_valid = ast_ari_validate_void(
+                               response->message);
+               } else {
+                       ast_log(LOG_ERROR, "Invalid error response %d for /channels/{channelId}/redirect\n", code);
+                       is_valid = 0;
+               }
+       }
+
+       if (!is_valid) {
+               ast_log(LOG_ERROR, "Response validation failed for /channels/{channelId}/redirect\n");
+               ast_ari_response_error(response, 500,
+                       "Internal Server Error", "Response validation failed");
+       }
+#endif /* AST_DEVMODE */
+
+fin: __attribute__((unused))
+       return;
+}
 /*!
  * \brief Parameter parsing callback for /channels/{channelId}/answer.
  * \param get_params GET parameters in the HTTP request.
@@ -2462,6 +2562,15 @@ static struct stasis_rest_handlers channels_channelId_continue = {
        .children = {  }
 };
 /*! \brief REST handler for /api-docs/channels.{format} */
+static struct stasis_rest_handlers channels_channelId_redirect = {
+       .path_segment = "redirect",
+       .callbacks = {
+               [AST_HTTP_POST] = ast_ari_channels_redirect_cb,
+       },
+       .num_children = 0,
+       .children = {  }
+};
+/*! \brief REST handler for /api-docs/channels.{format} */
 static struct stasis_rest_handlers channels_channelId_answer = {
        .path_segment = "answer",
        .callbacks = {
@@ -2595,8 +2704,8 @@ static struct stasis_rest_handlers channels_channelId = {
                [AST_HTTP_POST] = ast_ari_channels_originate_with_id_cb,
                [AST_HTTP_DELETE] = ast_ari_channels_hangup_cb,
        },
-       .num_children = 12,
-       .children = { &channels_channelId_continue,&channels_channelId_answer,&channels_channelId_ring,&channels_channelId_dtmf,&channels_channelId_mute,&channels_channelId_hold,&channels_channelId_moh,&channels_channelId_silence,&channels_channelId_play,&channels_channelId_record,&channels_channelId_variable,&channels_channelId_snoop, }
+       .num_children = 13,
+       .children = { &channels_channelId_continue,&channels_channelId_redirect,&channels_channelId_answer,&channels_channelId_ring,&channels_channelId_dtmf,&channels_channelId_mute,&channels_channelId_hold,&channels_channelId_moh,&channels_channelId_silence,&channels_channelId_play,&channels_channelId_record,&channels_channelId_variable,&channels_channelId_snoop, }
 };
 /*! \brief REST handler for /api-docs/channels.{format} */
 static struct stasis_rest_handlers channels = {
index ca56b7c..e1abff3 100644 (file)
@@ -146,12 +146,15 @@ static pj_status_t multihomed_on_tx_message(pjsip_tx_data *tdata)
        if (tdata->msg->type == PJSIP_REQUEST_MSG || !(cseq = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ, NULL)) ||
                pj_strcmp2(&cseq->method.name, "REGISTER")) {
                pjsip_contact_hdr *contact = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CONTACT, NULL);
-               if (contact && (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
+               if (contact && (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))
+                       && !(tdata->msg->type == PJSIP_RESPONSE_MSG && tdata->msg->line.status.code / 100 == 3)) {
                        pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
 
                        /* prm.ret_addr is allocated from the tdata pool OR the transport so it is perfectly fine to just do an assignment like this */
                        pj_strassign(&uri->host, &prm.ret_addr);
                        uri->port = prm.ret_port;
+                       ast_debug(4, "Re-wrote Contact URI host/port to %.*s:%d\n",
+                               (int)pj_strlen(&uri->host), pj_strbuf(&uri->host), uri->port);
 
                        pjsip_tx_data_invalidate_msg(tdata);
                }
index 5887343..b71a84b 100644 (file)
@@ -52,6 +52,8 @@ static pj_bool_t handle_rx_message(struct ast_sip_endpoint *endpoint, pjsip_rx_d
                        uri->transport_param.slen = 0;
                }
                uri->port = rdata->pkt_info.src_port;
+               ast_debug(4, "Re-wrote Contact URI host/port to %.*s:%d\n",
+                       (int)pj_strlen(&uri->host), pj_strbuf(&uri->host), uri->port);
 
                /* rewrite the session target since it may have already been pulled from the contact header */
                if (dlg && (!dlg->remote.contact
@@ -205,6 +207,7 @@ static pj_status_t nat_on_tx_message(pjsip_tx_data *tdata)
                pj_strdup2(tdata->pool, &uri->host, ast_sockaddr_stringify_host(&transport->external_address));
                if (transport->external_signaling_port) {
                        uri->port = transport->external_signaling_port;
+                       ast_debug(4, "Re-wrote Contact URI port to %d\n", uri->port);
                }
        }
 
index 5616715..94902d6 100644 (file)
@@ -329,6 +329,8 @@ static pj_bool_t websocket_on_rx_msg(pjsip_rx_data *rdata)
 
                pj_cstr(&uri->host, rdata->pkt_info.src_name);
                uri->port = rdata->pkt_info.src_port;
+               ast_debug(4, "Re-wrote Contact URI host/port to %.*s:%d\n",
+                       (int)pj_strlen(&uri->host), pj_strbuf(&uri->host), uri->port);
                pj_strdup(rdata->tp_info.pool, &uri->transport_param, (type == (long)transport_type_ws) ? &STR_WS : &STR_WSS);
        }
 
index 7dc1220..e239de2 100644 (file)
@@ -428,6 +428,38 @@ int stasis_app_control_continue(struct stasis_app_control *control, const char *
        return 0;
 }
 
+static int app_control_redirect(struct stasis_app_control *control,
+       struct ast_channel *chan, void *data)
+{
+       char *endpoint = data;
+       int res;
+
+       ast_assert(control->channel != NULL);
+       ast_assert(endpoint != NULL);
+
+       res = ast_transfer(control->channel, endpoint);
+       if (!res) {
+               ast_log(LOG_NOTICE, "Unsupported transfer requested on channel '%s'\n",
+                       ast_channel_name(control->channel));
+               return 0;
+       }
+
+       return 0;
+}
+
+int stasis_app_control_redirect(struct stasis_app_control *control, const char *endpoint)
+{
+       char *endpoint_data = ast_strdup(endpoint);
+
+       if (!endpoint_data) {
+               return -1;
+       }
+
+       stasis_app_send_command_async(control, app_control_redirect, endpoint_data, ast_free_ptr);
+
+       return 0;
+}
+
 struct stasis_app_control_dtmf_data {
        int before;
        int between;
index 6baebe3..9a0a4f3 100644 (file)
                        ]
                },
                {
+                       "path": "/channels/{channelId}/redirect",
+                       "description": "Inform the channel that it should redirect itself to a different location. Note that this will almost certainly cause the channel to exit the application.",
+                       "operations": [
+                               {
+                                       "httpMethod": "POST",
+                                       "summary": "Redirect the channel to a different location.",
+                                       "nickname": "redirect",
+                                       "responseClass": "void",
+                                       "parameters": [
+                                               {
+                                                       "name": "channelId",
+                                                       "description": "Channel's id",
+                                                       "paramType": "path",
+                                                       "required": true,
+                                                       "allowMultiple": false,
+                                                       "dataType": "string"
+                                               },
+                                               {
+                                                       "name": "endpoint",
+                                                       "description": "The endpoint to redirect the channel to",
+                                                       "paramType": "query",
+                                                       "required": true,
+                                                       "allowMultiple": false,
+                                                       "dataType": "string"
+                                               }
+                                       ],
+                                       "errorResponses": [
+                                               {
+                                                       "code": 400,
+                                                       "reason": "Endpoint parameter not provided"
+                                               },
+                                               {
+                                                       "code": 404,
+                                                       "reason": "Channel or endpoint not found"
+                                               },
+                                               {
+                                                       "code": 409,
+                                                       "reason": "Channel not in a Stasis application"
+                                               },
+                                               {
+                                                       "code": 422,
+                                                       "reason": "Endpoint is not the same type as the channel"
+                                               }
+                                       ]
+                               }
+                       ]
+               },
+               {
                        "path": "/channels/{channelId}/answer",
                        "description": "Answer a channel",
                        "operations": [