Merge the pimp_my_sip branch into trunk.

The pimp_my_sip branch is being merged at this point because
it offers basic functionality, and from an API standpoint, things
are complete.

SIP work is *not* feature-complete; however, with the completion
of the SUBSCRIBE/NOTIFY API, all APIs (except a PUBLISH API) have
been created, and thus it is possible for developers to attempt
to create new SIP work.

API documentation can be found in the doxygen in the code, but
usability documentation is still lacking.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@386540 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 235 insertions, 0 deletions

diff --git a/res/res_sip_nat.c b/res/res_sip_nat.c
new file mode 100644
index 000000000..6c924af68
--- /dev/null
+++ b/res/res_sip_nat.c
@@ -0,0 +1,235 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include <pjsip.h>
+#include <pjsip_ua.h>
+
+#include "asterisk/res_sip.h"
+#include "asterisk/module.h"
+#include "asterisk/acl.h"
+
+static pj_bool_t nat_on_rx_request(pjsip_rx_data *rdata)
+{
+	RAII_VAR(struct ast_sip_endpoint *, endpoint, ast_pjsip_rdata_get_endpoint(rdata), ao2_cleanup);
+	pjsip_contact_hdr *contact;
+
+	if (!endpoint) {
+		return PJ_FALSE;
+	}
+
+	if (endpoint->rewrite_contact && (contact = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_CONTACT, NULL)) &&
+		(PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
+		pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
+
+		pj_cstr(&uri->host, rdata->pkt_info.src_name);
+		uri->port = rdata->pkt_info.src_port;
+	}
+
+	if (endpoint->force_rport) {
+		rdata->msg_info.via->rport_param = 0;
+	}
+
+	return PJ_FALSE;
+}
+
+/*! \brief Structure which contains information about a transport */
+struct request_transport_details {
+	/*! \brief Type of transport */
+	enum ast_sip_transport_type type;
+	/*! \brief Potential pointer to the transport itself, if UDP */
+	pjsip_transport *transport;
+	/*! \brief Potential pointer to the transport factory itself, if TCP/TLS */
+	pjsip_tpfactory *factory;
+	/*! \brief Local address for transport */
+	pj_str_t local_address;
+	/*! \brief Local port for transport */
+	int local_port;
+};
+
+/*! \brief Callback function for finding the transport the request is going out on */
+static int find_transport_in_use(void *obj, void *arg, int flags)
+{
+	struct ast_sip_transport *transport = obj;
+	struct request_transport_details *details = arg;
+
+	/* If an explicit transport or factory matches then this is what is in use, if we are unavailable
+	 * to compare based on that we make sure that the type is the same and the source IP address/port are the same
+	 */
+	if ((details->transport && details->transport == transport->state->transport) ||
+		(details->factory && details->factory == transport->state->factory) ||
+		((details->type == transport->type) && (transport->state->factory) &&
+			!pj_strcmp(&transport->state->factory->addr_name.host, &details->local_address) &&
+			transport->state->factory->addr_name.port == details->local_port)) {
+		return CMP_MATCH | CMP_STOP;
+	}
+
+	return 0;
+}
+
+/*! \brief Helper function which returns the SIP URI of a Contact header */
+static pjsip_sip_uri *nat_get_contact_sip_uri(pjsip_tx_data *tdata)
+{
+	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))) {
+		return NULL;
+	}
+
+	return pjsip_uri_get_uri(contact->uri);
+}
+
+/*! \brief Structure which contains hook details */
+struct nat_hook_details {
+	/*! \brief Outgoing message itself */
+	pjsip_tx_data *tdata;
+	/*! \brief Chosen transport */
+	struct ast_sip_transport *transport;
+};
+
+/*! \brief Callback function for invoking hooks */
+static int nat_invoke_hook(void *obj, void *arg, int flags)
+{
+	struct ast_sip_nat_hook *hook = obj;
+	struct nat_hook_details *details = arg;
+
+	if (hook->outgoing_external_message) {
+		hook->outgoing_external_message(details->tdata, details->transport);
+	}
+
+	return 0;
+}
+
+static pj_status_t nat_on_tx_message(pjsip_tx_data *tdata)
+{
+	RAII_VAR(struct ao2_container *, transports, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_sip_transport *, transport, NULL, ao2_cleanup);
+	struct request_transport_details details = { 0, };
+	pjsip_via_hdr *via = NULL;
+	struct ast_sockaddr addr = { { 0, } };
+	pjsip_sip_uri *uri = NULL;
+	RAII_VAR(struct ao2_container *, hooks, NULL, ao2_cleanup);
+
+	/* If a transport selector is in use we know the transport or factory, so explicitly find it */
+	if (tdata->tp_sel.type == PJSIP_TPSELECTOR_TRANSPORT) {
+		details.transport = tdata->tp_sel.u.transport;
+	} else if (tdata->tp_sel.type == PJSIP_TPSELECTOR_LISTENER) {
+		details.factory = tdata->tp_sel.u.listener;
+	} else if (tdata->tp_info.transport->key.type == PJSIP_TRANSPORT_UDP || tdata->tp_info.transport->key.type == PJSIP_TRANSPORT_UDP6) {
+		/* Connectionless uses the same transport for all requests */
+		details.type = AST_SIP_TRANSPORT_UDP;
+		details.transport = tdata->tp_info.transport;
+	} else {
+		if (tdata->tp_info.transport->key.type == PJSIP_TRANSPORT_TCP) {
+			details.type = AST_SIP_TRANSPORT_TCP;
+		} else if (tdata->tp_info.transport->key.type == PJSIP_TRANSPORT_TLS) {
+			details.type = AST_SIP_TRANSPORT_TLS;
+		} else {
+			/* Unknown transport type, we can't map and thus can't apply NAT changes */
+			return PJ_SUCCESS;
+		}
+
+		if ((uri = nat_get_contact_sip_uri(tdata))) {
+			details.local_address = uri->host;
+			details.local_port = uri->port;
+		} else if ((tdata->msg->type == PJSIP_REQUEST_MSG) &&
+			(via = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_VIA, NULL))) {
+			details.local_address = via->sent_by.host;
+			details.local_port = via->sent_by.port;
+		} else {
+			return PJ_SUCCESS;
+		}
+
+		if (!details.local_port) {
+			details.local_port = (details.type == AST_SIP_TRANSPORT_TLS) ? 5061 : 5060;
+		}
+	}
+
+	if (!(transports = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "transport", AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL)) ||
+		!(transport = ao2_callback(transports, 0, find_transport_in_use, &details)) || !transport->localnet ||
+		ast_sockaddr_isnull(&transport->external_address)) {
+		return PJ_SUCCESS;
+	}
+
+	ast_sockaddr_parse(&addr, tdata->tp_info.dst_name, PARSE_PORT_FORBID);
+	ast_sockaddr_set_port(&addr, tdata->tp_info.dst_port);
+
+	/* See if where we are sending this request is local or not, and if not that we can get a Contact URI to modify */
+	if (ast_apply_ha(transport->localnet, &addr) != AST_SENSE_ALLOW) {
+		return PJ_SUCCESS;
+	}
+
+	/* Update the contact header with the external address */
+	if (uri || (uri = nat_get_contact_sip_uri(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;
+		}
+	}
+
+	/* Update the via header if relevant */
+	if ((tdata->msg->type == PJSIP_REQUEST_MSG) && (via || (via = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_VIA, NULL)))) {
+		pj_strdup2(tdata->pool, &via->sent_by.host, ast_sockaddr_stringify_host(&transport->external_address));
+		if (transport->external_signaling_port) {
+			via->sent_by.port = transport->external_signaling_port;
+		}
+	}
+
+	/* Invoke any additional hooks that may be registered */
+	if ((hooks = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "nat_hook", AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL))) {
+		struct nat_hook_details hook_details = {
+			.tdata = tdata,
+			.transport = transport,
+		};
+		ao2_callback(hooks, 0, nat_invoke_hook, &hook_details);
+	}
+
+	return PJ_SUCCESS;
+}
+
+static pjsip_module nat_module = {
+	.name = { "NAT", 3 },
+	.id = -1,
+	.priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 2,
+	.on_rx_request = nat_on_rx_request,
+	.on_tx_request = nat_on_tx_message,
+	.on_tx_response = nat_on_tx_message,
+};
+
+static int load_module(void)
+{
+	ast_sip_register_service(&nat_module);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+	ast_sip_unregister_service(&nat_module);
+	return 0;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "SIP NAT Support",
+		.load = load_module,
+		.unload = unload_module,
+		.load_pri = AST_MODPRI_APP_DEPEND,
+	       );