PJSIP: Add Path header support

This adds Path support to chan_pjsip in res_pjsip_path.c with minimal
additions in res_pjsip_registrar.c to store the path and additions in
res_pjsip_outbound_registration.c to enable advertisement of path
support to registrars and intervening proxies.

Path information is stored on contacts and is enabled via Address of
Record (AoRs) and Registration configuration sections.

While adding path support, it became necessary to be able to add SIP
supplements that handled messages outside of sessions, so a framework
for handling these types of hooks was added in parallel to the
already-existing session supplements and several senders of
out-of-dialog requests were refactored as a result.

(closes issue ASTERISK-21084)
Review: https://reviewboard.asterisk.org/r/3050/
........

Merged revisions 405565 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@405566 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 97 insertions, 16 deletions

diff --git a/res/res_pjsip_registrar.c b/res/res_pjsip_registrar.c
index 89e8cd141..7624472fc 100644
--- a/res/res_pjsip_registrar.c
+++ b/res/res_pjsip_registrar.c
@@ -347,6 +347,64 @@ static struct rx_task_data *rx_task_data_create(pjsip_rx_data *rdata,
 	return task_data;
 }
 
+static const pj_str_t path_hdr_name = { "Path", 4 };
+
+static int build_path_data(struct rx_task_data *task_data, struct ast_str **path_str)
+{
+	pjsip_generic_string_hdr *path_hdr = pjsip_msg_find_hdr_by_name(task_data->rdata->msg_info.msg, &path_hdr_name, NULL);
+
+	if (!path_hdr) {
+		return 0;
+	}
+
+	*path_str = ast_str_create(64);
+	if (!path_str) {
+		return -1;
+	}
+
+	ast_str_set(path_str, 0, "%.*s", (int)path_hdr->hvalue.slen, path_hdr->hvalue.ptr);
+
+	while ((path_hdr = (pjsip_generic_string_hdr *) pjsip_msg_find_hdr_by_name(task_data->rdata->msg_info.msg, &path_hdr_name, path_hdr->next))) {
+		ast_str_append(path_str, 0, ",%.*s", (int)path_hdr->hvalue.slen, path_hdr->hvalue.ptr);
+	}
+
+	return 0;
+}
+
+static int registrar_validate_path(struct rx_task_data *task_data, struct ast_str **path_str)
+{
+	const pj_str_t path_supported_name = { "path", 4 };
+	pjsip_supported_hdr *supported_hdr;
+	int i;
+
+	if (!task_data->aor->support_path) {
+		return 0;
+	}
+
+	if (build_path_data(task_data, path_str)) {
+		return -1;
+	}
+
+	if (!*path_str) {
+		return 0;
+	}
+
+	supported_hdr = pjsip_msg_find_hdr(task_data->rdata->msg_info.msg, PJSIP_H_SUPPORTED, NULL);
+	if (!supported_hdr) {
+		return -1;
+	}
+
+	/* Find advertised path support */
+	for (i = 0; i < supported_hdr->count; i++) {
+		if (!pj_stricmp(&supported_hdr->values[i], &path_supported_name)) {
+			return 0;
+		}
+	}
+
+	/* Path header present, but support not advertised */
+	return -1;
+}
+
 static int rx_task(void *data)
 {
 	RAII_VAR(struct rx_task_data *, task_data, data, ao2_cleanup);
@@ -358,6 +416,8 @@ static int rx_task(void *data)
 	pjsip_tx_data *tdata;
 	pjsip_response_addr addr;
 	const char *aor_name = ast_sorcery_object_get_id(task_data->aor);
+	RAII_VAR(struct ast_str *, path_str, NULL, ast_free);
+	struct ast_sip_contact *response_contact;
 
 	/* Retrieve the current contacts, we'll need to know whether to update or not */
 	contacts = ast_sip_location_retrieve_aor_contacts(task_data->aor);
@@ -374,6 +434,14 @@ static int rx_task(void *data)
 		return PJ_TRUE;
 	}
 
+	if (registrar_validate_path(task_data, &path_str)) {
+		/* Ensure that intervening proxies did not make invalid modifications to the request */
+		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), task_data->rdata, 420, NULL, NULL, NULL);
+		ast_log(LOG_WARNING, "Invalid modifications made to REGISTER request from '%s' by intervening proxy\n",
+				ast_sorcery_object_get_id(task_data->endpoint));
+		return PJ_TRUE;
+	}
+
 	if ((MAX(added - deleted, 0) + (!task_data->aor->remove_existing ? ao2_container_count(contacts) : 0)) > task_data->aor->max_contacts) {
 		/* Enforce the maximum number of contacts */
 		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), task_data->rdata, 403, NULL, NULL, NULL);
@@ -417,7 +485,8 @@ static int rx_task(void *data)
 				continue;
 			}
 
-			ast_sip_location_add_contact(task_data->aor, contact_uri, ast_tvadd(ast_tvnow(), ast_samp2tv(expiration, 1)));
+			ast_sip_location_add_contact(task_data->aor, contact_uri, ast_tvadd(ast_tvnow(),
+				ast_samp2tv(expiration, 1)), path_str ? ast_str_buffer(path_str) : NULL);
 			ast_verb(3, "Added contact '%s' to AOR '%s' with expiration of %d seconds\n",
 				contact_uri, aor_name, expiration);
 			ast_test_suite_event_notify("AOR_CONTACT_ADDED",
@@ -432,6 +501,9 @@ static int rx_task(void *data)
 			updated->expiration_time = ast_tvadd(ast_tvnow(), ast_samp2tv(expiration, 1));
 			updated->qualify_frequency = task_data->aor->qualify_frequency;
 			updated->authenticate_qualify = task_data->aor->authenticate_qualify;
+			if (path_str) {
+				ast_string_field_set(updated, path, ast_str_buffer(path_str));
+			}
 
 			ast_sip_location_update_contact(updated);
 			ast_debug(3, "Refreshed contact '%s' on AOR '%s' with new expiration of %d seconds\n",
@@ -465,12 +537,16 @@ static int rx_task(void *data)
 
 	/* Update the contacts as things will probably have changed */
 	ao2_cleanup(contacts);
+
 	contacts = ast_sip_location_retrieve_aor_contacts(task_data->aor);
+	response_contact = ao2_callback(contacts, 0, NULL, NULL);
 
 	/* Send a response containing all of the contacts (including static) that are present on this AOR */
-	if (pjsip_endpt_create_response(ast_sip_get_pjsip_endpoint(), task_data->rdata, 200, NULL, &tdata) != PJ_SUCCESS) {
+	if (ast_sip_create_response(task_data->rdata, 200, response_contact, &tdata) != PJ_SUCCESS) {
+		ao2_cleanup(response_contact);
 		return PJ_TRUE;
 	}
+	ao2_cleanup(response_contact);
 
 	/* Add the date header to the response, some UAs use this to set their date and time */
 	registrar_add_date_header(tdata);
@@ -478,7 +554,7 @@ static int rx_task(void *data)
 	ao2_callback(contacts, 0, registrar_add_contact, tdata);
 
 	if (pjsip_get_response_addr(tdata->pool, task_data->rdata, &addr) == PJ_SUCCESS) {
-		pjsip_endpt_send_response(ast_sip_get_pjsip_endpoint(), &addr, tdata, NULL, NULL);
+		ast_sip_send_response(&addr, tdata, task_data->endpoint);
 	} else {
 		pjsip_tx_data_dec_ref(tdata);
 	}
@@ -495,8 +571,9 @@ static pj_bool_t registrar_on_rx_request(struct pjsip_rx_data *rdata)
 		 ast_pjsip_rdata_get_endpoint(rdata), ao2_cleanup);
 	RAII_VAR(struct ast_sip_aor *, aor, NULL, ao2_cleanup);
 	pjsip_sip_uri *uri;
-	char user_name[64], domain_name[64];
+	char *domain_name;
 	char *configured_aors, *aor_name;
+	RAII_VAR(struct ast_str *, id, NULL, ast_free);
 
 	if (pjsip_method_cmp(&rdata->msg_info.msg->line.req.method, &pjsip_register_method) || !endpoint) {
 		return PJ_FALSE;
@@ -518,29 +595,33 @@ static pj_bool_t registrar_on_rx_request(struct pjsip_rx_data *rdata)
 	}
 
 	uri = pjsip_uri_get_uri(rdata->msg_info.to->uri);
-	ast_copy_pj_str(user_name, &uri->user, sizeof(user_name));
-	ast_copy_pj_str(domain_name, &uri->host, sizeof(domain_name));
+	domain_name = ast_alloca(uri->host.slen + 1);
+	ast_copy_pj_str(domain_name, &uri->host, uri->host.slen + 1);
 
 	configured_aors = ast_strdupa(endpoint->aors);
 
 	/* Iterate the configured AORs to see if the user or the user+domain match */
 	while ((aor_name = strsep(&configured_aors, ","))) {
-		char id[AST_UUID_STR_LEN];
-		RAII_VAR(struct ast_sip_domain_alias *, alias, NULL, ao2_cleanup);
+		struct ast_sip_domain_alias *alias = NULL;
 
-		snprintf(id, sizeof(id), "%s@%s", user_name, domain_name);
-		if (!strcmp(aor_name, id)) {
+		if (!pj_strcmp2(&uri->user, aor_name)) {
 			break;
 		}
 
+		if (!id && !(id = ast_str_create(uri->user.slen + uri->host.slen + 2))) {
+			return PJ_TRUE;
+		}
+
+		ast_str_set(&id, 0, "%.*s@", (int)uri->user.slen, uri->user.ptr);
 		if ((alias = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "domain_alias", domain_name))) {
-			snprintf(id, sizeof(id), "%s@%s", user_name, alias->domain);
-			if (!strcmp(aor_name, id)) {
-				break;
-			}
+			ast_str_append(&id, 0, "%s", alias->domain);
+			ao2_cleanup(alias);
+		} else {
+			ast_str_append(&id, 0, "%s", domain_name);
 		}
 
-		if (!strcmp(aor_name, user_name)) {
+		if (!strcmp(aor_name, ast_str_buffer(id))) {
+			ast_free(id);
 			break;
 		}
 	}
@@ -549,7 +630,7 @@ static pj_bool_t registrar_on_rx_request(struct pjsip_rx_data *rdata)
 		/* The provided AOR name was not found (be it within the configuration or sorcery itself) */
 		pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 404, NULL, NULL, NULL);
 		ast_sip_report_req_no_support(endpoint, rdata, "registrar_requested_aor_not_found");
-		ast_log(LOG_WARNING, "AOR '%s' not found for endpoint '%s'\n", user_name, ast_sorcery_object_get_id(endpoint));
+		ast_log(LOG_WARNING, "AOR '%.*s' not found for endpoint '%s'\n", (int)uri->user.slen, uri->user.ptr, ast_sorcery_object_get_id(endpoint));
 		return PJ_TRUE;
 	}