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Diffstat (limited to 'res/res_pjsip_multihomed.c')
| -rw-r--r-- | res/res_pjsip_multihomed.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/res/res_pjsip_multihomed.c b/res/res_pjsip_multihomed.c new file mode 100644 index 000000000..c959fa777 --- /dev/null +++ b/res/res_pjsip_multihomed.c @@ -0,0 +1,187 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2014, 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 + <depend>pjproject</depend> + <depend>res_pjsip</depend> + <support_level>core</support_level> + ***/ + +#include "asterisk.h" + +#include <pjsip.h> +#include <pjsip_ua.h> + +#include "asterisk/res_pjsip.h" +#include "asterisk/module.h" + +/*! \brief Local host address for IPv4 */ +static char host_ipv4[PJ_INET_ADDRSTRLEN + 2]; + +/*! \brief Local host address for IPv6 */ +static char host_ipv6[PJ_INET6_ADDRSTRLEN + 2]; + +/*! \brief Helper function which returns a UDP transport bound to the given address and port */ +static pjsip_transport *multihomed_get_udp_transport(pj_str_t *address, int port) +{ + struct ao2_container *transports = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "transport", + AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL); + struct ast_sip_transport *transport; + struct ao2_iterator iter; + pjsip_transport *sip_transport = NULL; + + if (!transports) { + return NULL; + } + + for (iter = ao2_iterator_init(transports, 0); (transport = ao2_iterator_next(&iter)); ao2_ref(transport, -1)) { + if ((transport->type != AST_TRANSPORT_UDP) || + (pj_strcmp(&transport->state->transport->local_name.host, address)) || + (transport->state->transport->local_name.port != port)) { + continue; + } + + sip_transport = transport->state->transport; + ao2_ref(transport, -1); + break; + } + ao2_iterator_destroy(&iter); + + ao2_ref(transports, -1); + + return sip_transport; +} + +/*! \brief Helper function which determines if the address within SDP should be rewritten */ +static int multihomed_rewrite_sdp(struct pjmedia_sdp_session *sdp) +{ + if (!sdp->conn) { + return 0; + } + + /* If the host address is used in the SDP replace it with the address of what this is going out on */ + if ((!pj_strcmp2(&sdp->conn->addr_type, "IP4") && !pj_strcmp2(&sdp->conn->addr, host_ipv4)) || + (!pj_strcmp2(&sdp->conn->addr_type, "IP6") && !pj_strcmp2(&sdp->conn->addr, host_ipv6))) { + return 1; + } + + return 0; +} + +static pj_status_t multihomed_on_tx_message(pjsip_tx_data *tdata) +{ + pjsip_tpmgr_fla2_param prm; + pjsip_transport *transport; + pjsip_contact_hdr *contact; + pjsip_via_hdr *via; + + /* Use the destination information to determine what local interface this message will go out on */ + pjsip_tpmgr_fla2_param_default(&prm); + prm.tp_type = tdata->tp_info.transport->key.type; + pj_strset2(&prm.dst_host, tdata->tp_info.dst_name); + prm.local_if = PJ_TRUE; + + /* If we can't get the local address use best effort and let it pass */ + if (pjsip_tpmgr_find_local_addr2(pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint()), tdata->pool, &prm) != PJ_SUCCESS) { + return PJ_SUCCESS; + } + + /* If the transport it is going out on is different reflect it in the message */ + transport = multihomed_get_udp_transport(&prm.ret_addr, prm.ret_port); + if (transport && (tdata->tp_info.transport != transport)) { + tdata->tp_info.transport = transport; + } + + /* If the message needs to be updated with new address do so */ + 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))) { + pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri); + + /* prm.ret_addr is allocated from the tdata pool so it is perfectly fine to just do an assignment like this */ + pj_strassign(&uri->host, &prm.ret_addr); + uri->port = prm.ret_port; + + pjsip_tx_data_invalidate_msg(tdata); + } + + if (tdata->msg->type == PJSIP_REQUEST_MSG && (via = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_VIA, NULL))) { + pj_strassign(&via->sent_by.host, &prm.ret_addr); + via->sent_by.port = prm.ret_port; + + pjsip_tx_data_invalidate_msg(tdata); + } + + /* Update the SDP if it is present */ + if (tdata->msg->body && ast_sip_is_content_type(&tdata->msg->body->content_type, "application", "sdp") && + multihomed_rewrite_sdp(tdata->msg->body->data)) { + struct pjmedia_sdp_session *sdp = tdata->msg->body->data; + int stream; + + pj_strassign(&sdp->conn->addr, &prm.ret_addr); + + for (stream = 0; stream < sdp->media_count; ++stream) { + if (sdp->media[stream]->conn) { + pj_strassign(&sdp->media[stream]->conn->addr, &prm.ret_addr); + } + } + + pjsip_tx_data_invalidate_msg(tdata); + } + + return PJ_SUCCESS; +} + +static pjsip_module multihomed_module = { + .name = { "Multihomed Routing", 18 }, + .id = -1, + .priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 1, + .on_tx_request = multihomed_on_tx_message, + .on_tx_response = multihomed_on_tx_message, +}; + +static int unload_module(void) +{ + ast_sip_unregister_service(&multihomed_module); + return 0; +} + +static int load_module(void) +{ + pj_sockaddr addr; + + if (!pj_gethostip(pj_AF_INET(), &addr)) { + pj_sockaddr_print(&addr, host_ipv4, sizeof(host_ipv4), 2); + } + + if (!pj_gethostip(pj_AF_INET6(), &addr)) { + pj_sockaddr_print(&addr, host_ipv6, sizeof(host_ipv6), 2); + } + + if (ast_sip_register_service(&multihomed_module)) { + ast_log(LOG_ERROR, "Could not register multihomed module for incoming and outgoing requests\n"); + return AST_MODULE_LOAD_FAILURE; + } + + return AST_MODULE_LOAD_SUCCESS; +} + +AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Multihomed Routing Support", + .load = load_module, + .unload = unload_module, + .load_pri = AST_MODPRI_APP_DEPEND, + ); |