res_pjsip_outbound_registration: Add virtual line support.

Virtual line support establishes a relationship between messages
related to an outbound registration and a local endpoint. This is
accomplished by attaching a parameter to the Contact of the outbound
registration and looking for it on any received requests. If the
parameter exists and can be matched to an outbound registration
the configured endpoint is associated with the request.

Review: https://reviewboard.asterisk.org/r/2964/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@427165 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 97 insertions, 4 deletions

diff --git a/res/res_pjsip_outbound_registration.c b/res/res_pjsip_outbound_registration.c
index af4a3694d..46c0c1f25 100644
--- a/res/res_pjsip_outbound_registration.c
+++ b/res/res_pjsip_outbound_registration.c
@@ -114,6 +114,22 @@
 						<literal>pjsip.conf</literal>. As with other <literal>res_pjsip</literal> modules, this will use the first available transport of the appropriate type if unconfigured.</para></note>
 					</description>
 				</configOption>
+				<configOption name="line">
+					<synopsis>Whether to add a 'line' parameter to the Contact for inbound call matching</synopsis>
+					<description><para>
+						When enabled this option will cause a 'line' parameter to be added to the Contact
+						header placed into the outgoing registration request. If the remote server sends a call
+						this line parameter will be used to establish a relationship to the outbound registration,
+						ultimately causing the configured endpoint to be used.
+					</para></description>
+				</configOption>
+				<configOption name="endpoint">
+					<synopsis>Endpoint to use for incoming related calls</synopsis>
+					<description><para>
+						When line support is enabled this configured endpoint name is used for incoming calls
+						that are related to the outbound registration.
+					</para></description>
+				</configOption>
 				<configOption name="type">
 					<synopsis>Must be of type 'registration'.</synopsis>
 				</configOption>
@@ -166,6 +182,9 @@
 /*! \brief Amount of buffer time (in seconds) before expiration that we re-register at */
 #define REREGISTER_BUFFER_TIME 10
 
+/*! \brief Size of the buffer for creating a unique string for the line */
+#define LINE_PARAMETER_SIZE 8
+
 /*! \brief Various states that an outbound registration may be in */
 enum sip_outbound_registration_status {
 	/*! \brief Currently unregistered */
@@ -196,6 +215,8 @@ struct sip_outbound_registration_client_state {
 	pjsip_regc *client;
 	/*! \brief Timer entry for retrying on temporal responses */
 	pj_timer_entry timer;
+	/*! \brief Optional line parameter placed into Contact */
+	char line[LINE_PARAMETER_SIZE];
 	/*! \brief Current number of retries */
 	unsigned int retries;
 	/*! \brief Maximum number of retries permitted */
@@ -238,6 +259,8 @@ struct sip_outbound_registration {
 		AST_STRING_FIELD(transport);
 		/*! \brief Outbound proxy to use */
 		AST_STRING_FIELD(outbound_proxy);
+		/*! \brief Endpoint to use for related incoming calls */
+		AST_STRING_FIELD(endpoint);
 	);
 	/*! \brief Requested expiration time */
 	unsigned int expiration;
@@ -249,6 +272,8 @@ struct sip_outbound_registration {
 	unsigned int auth_rejection_permanent;
 	/*! \brief Maximum number of retries permitted */
 	unsigned int max_retries;
+	/*! \brief Whether to add a line parameter to the outbound Contact or not */
+	unsigned int line;
 	/*! \brief Outbound registration state */
 	struct sip_outbound_registration_state *state;
 	/*! \brief Configured authentication credentials */
@@ -257,6 +282,54 @@ struct sip_outbound_registration {
 	unsigned int support_path;
 };
 
+/*! \brief Callback function for matching an outbound registration based on line */
+static int line_identify_relationship(void *obj, void *arg, int flags)
+{
+	struct sip_outbound_registration *registration = obj;
+	pjsip_param *line = arg;
+
+	return !pj_strcmp2(&line->value, registration->state->client_state->line) ? CMP_MATCH | CMP_STOP : 0;
+}
+
+/*! \brief Endpoint identifier which uses the 'line' parameter to establish a relationship to an outgoing registration */
+static struct ast_sip_endpoint *line_identify(pjsip_rx_data *rdata)
+{
+	pjsip_sip_uri *uri;
+	static const pj_str_t LINE_STR = { "line", 4 };
+	pjsip_param *line;
+	RAII_VAR(struct ao2_container *, registrations, NULL, ao2_cleanup);
+	RAII_VAR(struct sip_outbound_registration *, registration, NULL, ao2_cleanup);
+
+	if (!PJSIP_URI_SCHEME_IS_SIP(rdata->msg_info.to->uri) && !PJSIP_URI_SCHEME_IS_SIPS(rdata->msg_info.to->uri)) {
+		return NULL;
+	}
+	uri = pjsip_uri_get_uri(rdata->msg_info.to->uri);
+
+	line = pjsip_param_find(&uri->other_param, &LINE_STR);
+	if (!line) {
+		return NULL;
+	}
+
+	registrations = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "registration", AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
+	if (!registrations) {
+		return NULL;
+	}
+
+	registration = ao2_callback(registrations, 0, line_identify_relationship, line);
+	if (!registration || ast_strlen_zero(registration->endpoint)) {
+		return NULL;
+	}
+
+	ast_debug(3, "Determined relationship to outbound registration '%s' based on line '%s', using configured endpoint '%s'\n",
+		ast_sorcery_object_get_id(registration), registration->state->client_state->line, registration->endpoint);
+
+	return ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "endpoint", registration->endpoint);
+}
+
+static struct ast_sip_endpoint_identifier line_identifier = {
+	.identify_endpoint = line_identify,
+};
+
 /*! \brief Helper function which cancels the timer on a client */
 static void cancel_registration(struct sip_outbound_registration_client_state *client_state)
 {
@@ -626,7 +699,8 @@ static void *sip_outbound_registration_alloc(const char *name)
 }
 
 /*! \brief Helper function which populates a pj_str_t with a contact header */
-static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const char *user, const pj_str_t *target, pjsip_tpselector *selector)
+static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const char *user, const pj_str_t *target, pjsip_tpselector *selector,
+	const char *line)
 {
 	pj_str_t tmp, local_addr;
 	pjsip_uri *uri;
@@ -670,7 +744,7 @@ static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const c
 
 	contact->ptr = pj_pool_alloc(pool, PJSIP_MAX_URL_SIZE);
 	contact->slen = pj_ansi_snprintf(contact->ptr, PJSIP_MAX_URL_SIZE,
-				      "<%s:%s@%s%.*s%s:%d%s%s>",
+				      "<%s:%s@%s%.*s%s:%d%s%s%s%s>",
 				      (pjsip_transport_get_flag_from_type(type) & PJSIP_TRANSPORT_SECURE) ? "sips" : "sip",
 				      user,
 				      (type & PJSIP_TRANSPORT_IPV6) ? "[" : "",
@@ -679,7 +753,9 @@ static int sip_dialog_create_contact(pj_pool_t *pool, pj_str_t *contact, const c
 				      (type & PJSIP_TRANSPORT_IPV6) ? "]" : "",
 				      local_port,
 				      (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? ";transport=" : "",
-				      (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? pjsip_transport_get_type_name(type) : "");
+				      (type != PJSIP_TRANSPORT_UDP && type != PJSIP_TRANSPORT_UDP6) ? pjsip_transport_get_type_name(type) : "",
+				      !ast_strlen_zero(line) ? ";line=" : "",
+				      S_OR(line, ""));
 
 	return 0;
 }
@@ -796,9 +872,14 @@ static int sip_outbound_registration_regc_alloc(void *data)
 		pjsip_regc_set_route_set(registration->state->client_state->client, &route_set);
 	}
 
+	if (registration->line) {
+		ast_generate_random_string(registration->state->client_state->line, sizeof(registration->state->client_state->line));
+	}
+
 	pj_cstr(&server_uri, registration->server_uri);
 
-	if (sip_dialog_create_contact(pjsip_regc_get_pool(registration->state->client_state->client), &contact_uri, S_OR(registration->contact_user, "s"), &server_uri, &selector)) {
+	if (sip_dialog_create_contact(pjsip_regc_get_pool(registration->state->client_state->client), &contact_uri, S_OR(registration->contact_user, "s"), &server_uri, &selector,
+		registration->state->client_state->line)) {
 		return -1;
 	}
 
@@ -825,6 +906,14 @@ static int sip_outbound_registration_apply(const struct ast_sorcery *sorcery, vo
 		ast_log(LOG_ERROR, "No client URI specified on outbound registration '%s'\n",
 			ast_sorcery_object_get_id(applied));
 		return -1;
+	} else if (applied->line && ast_strlen_zero(applied->endpoint)) {
+		ast_log(LOG_ERROR, "Line support has been enabled on outbound registration '%s' without providing an endpoint\n",
+			ast_sorcery_object_get_id(applied));
+		return -1;
+	} else if (!ast_strlen_zero(applied->endpoint) && !applied->line) {
+		ast_log(LOG_ERROR, "An endpoint has been specified on outbound registration '%s' without enabling line support\n",
+			ast_sorcery_object_get_id(applied));
+		return -1;
 	}
 
 	if (!existing) {
@@ -1276,6 +1365,9 @@ static int load_module(void)
 	ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "auth_rejection_permanent", "yes", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, auth_rejection_permanent));
 	ast_sorcery_object_field_register_custom(ast_sip_get_sorcery(), "registration", "outbound_auth", "", outbound_auth_handler, outbound_auths_to_str, outbound_auths_to_var_list, 0, 0);
 	ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "support_path", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, support_path));
+	ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "line", "no", OPT_BOOL_T, 1, FLDSET(struct sip_outbound_registration, line));
+	ast_sorcery_object_field_register(ast_sip_get_sorcery(), "registration", "endpoint", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct sip_outbound_registration, endpoint));
+	ast_sip_register_endpoint_identifier(&line_identifier);
 	ast_sorcery_reload_object(ast_sip_get_sorcery(), "registration");
 	sip_outbound_registration_perform_all();
 
@@ -1310,6 +1402,7 @@ static int reload_module(void)
 
 static int unload_module(void)
 {
+	ast_sip_unregister_endpoint_identifier(&line_identifier);
 	ast_cli_unregister_multiple(cli_outbound_registration, ARRAY_LEN(cli_outbound_registration));
 	ast_sip_unregister_cli_formatter(cli_formatter);
 	ast_manager_unregister("PJSIPShowRegistrationsOutbound");