/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */ /* The protocol implementation */ /* * (C) 2009-2012 by Holger Hans Peter Freyther * (C) 2009-2012 by On-Waves * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct mgcp_request { char *name; struct msgb *(*handle_request) (struct mgcp_parse_data * data); char *debug_name; }; #define MGCP_REQUEST(NAME, REQ, DEBUG_NAME) \ { .name = NAME, .handle_request = REQ, .debug_name = DEBUG_NAME }, static struct msgb *handle_audit_endpoint(struct mgcp_parse_data *data); static struct msgb *handle_create_con(struct mgcp_parse_data *data); static struct msgb *handle_delete_con(struct mgcp_parse_data *data); static struct msgb *handle_modify_con(struct mgcp_parse_data *data); static struct msgb *handle_rsip(struct mgcp_parse_data *data); static struct msgb *handle_noti_req(struct mgcp_parse_data *data); /* Initalize transcoder */ static int setup_rtp_processing(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn) { struct mgcp_config *cfg = endp->cfg; struct mgcp_conn_rtp *conn_src = NULL; struct mgcp_conn_rtp *conn_dst = conn; struct mgcp_conn *_conn; if (conn->type != MGCP_RTP_DEFAULT) { LOGP(DLMGCP, LOGL_NOTICE, "endpoint:%x RTP-setup: Endpoint is not configured as RTP default, stopping here!\n", ENDPOINT_NUMBER(endp)); return 0; } if (conn->conn->mode == MGCP_CONN_LOOPBACK) { LOGP(DLMGCP, LOGL_NOTICE, "endpoint:%x RTP-setup: Endpoint is in loopback mode, stopping here!\n", ENDPOINT_NUMBER(endp)); return 0; } /* Find the "sister" connection */ llist_for_each_entry(_conn, &endp->conns, entry) { if (_conn->id != conn->conn->id) { conn_src = &_conn->u.rtp; break; } } return cfg->setup_rtp_processing_cb(endp, conn_dst, conn_src); } /* array of function pointers for handling various * messages. In the future this might be binary sorted * for performance reasons. */ static const struct mgcp_request mgcp_requests[] = { MGCP_REQUEST("AUEP", handle_audit_endpoint, "AuditEndpoint") MGCP_REQUEST("CRCX", handle_create_con, "CreateConnection") MGCP_REQUEST("DLCX", handle_delete_con, "DeleteConnection") MGCP_REQUEST("MDCX", handle_modify_con, "ModifiyConnection") MGCP_REQUEST("RQNT", handle_noti_req, "NotificationRequest") /* SPEC extension */ MGCP_REQUEST("RSIP", handle_rsip, "ReSetInProgress") }; /* Helper function to allocate some memory for responses and retransmissions */ static struct msgb *mgcp_msgb_alloc(void) { struct msgb *msg; msg = msgb_alloc_headroom(4096, 128, "MGCP msg"); if (!msg) LOGP(DLMGCP, LOGL_ERROR, "Failed to msgb for MGCP data.\n"); return msg; } /* Helper function for do_retransmission() and create_resp() */ static struct msgb *do_retransmission(const struct mgcp_endpoint *endp) { struct msgb *msg = mgcp_msgb_alloc(); if (!msg) return NULL; msg->l2h = msgb_put(msg, strlen(endp->last_response)); memcpy(msg->l2h, endp->last_response, msgb_l2len(msg)); mgcp_disp_msg(msg->l2h, msgb_l2len(msg), "Retransmitted response"); return msg; } static struct msgb *create_resp(struct mgcp_endpoint *endp, int code, const char *txt, const char *msg, const char *trans, const char *param, const char *sdp) { int len; struct msgb *res; res = mgcp_msgb_alloc(); if (!res) return NULL; len = snprintf((char *)res->data, 2048, "%d %s%s%s\r\n%s", code, trans, txt, param ? param : "", sdp ? sdp : ""); if (len < 0) { LOGP(DLMGCP, LOGL_ERROR, "Failed to sprintf MGCP response.\n"); msgb_free(res); return NULL; } res->l2h = msgb_put(res, len); LOGP(DLMGCP, LOGL_DEBUG, "Generated response: code=%d\n", code); mgcp_disp_msg(res->l2h, msgb_l2len(res), "Generated response"); /* * Remember the last transmission per endpoint. */ if (endp) { struct mgcp_trunk_config *tcfg = endp->tcfg; talloc_free(endp->last_response); talloc_free(endp->last_trans); endp->last_trans = talloc_strdup(tcfg->endpoints, trans); endp->last_response = talloc_strndup(tcfg->endpoints, (const char *)res->l2h, msgb_l2len(res)); } return res; } static struct msgb *create_ok_resp_with_param(struct mgcp_endpoint *endp, int code, const char *msg, const char *trans, const char *param) { return create_resp(endp, code, " OK", msg, trans, param, NULL); } static struct msgb *create_ok_response(struct mgcp_endpoint *endp, int code, const char *msg, const char *trans) { return create_ok_resp_with_param(endp, code, msg, trans, NULL); } static struct msgb *create_err_response(struct mgcp_endpoint *endp, int code, const char *msg, const char *trans) { return create_resp(endp, code, " FAIL", msg, trans, NULL, NULL); } /* Add MGCP parameters to a message buffer */ static int add_params(struct msgb *msg, const struct mgcp_endpoint *endp, const struct mgcp_conn_rtp *conn) { int rc; /* NOTE: Only in the virtual trunk we allow dynamic endpoint names */ if (endp->wildcarded_req && endp->tcfg->trunk_type == MGCP_TRUNK_VIRTUAL) { rc = msgb_printf(msg, "Z: %s%x@%s\r\n", MGCP_ENDPOINT_PREFIX_VIRTUAL_TRUNK, ENDPOINT_NUMBER(endp), endp->cfg->domain); if (rc < 0) return -EINVAL; } rc = msgb_printf(msg, "I: %s\r\n", conn->conn->id); if (rc < 0) return -EINVAL; return 0; } /* Format MGCP response string (with SDP attached) */ static struct msgb *create_response_with_sdp(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn, const char *msg, const char *trans_id, bool add_conn_params) { const char *addr = endp->cfg->local_ip; struct msgb *sdp; int rc; struct msgb *result; char osmux_extension[strlen("X-Osmux: 255") + 1]; char local_ip_addr[INET_ADDRSTRLEN]; sdp = msgb_alloc_headroom(4096, 128, "sdp record"); if (!sdp) return NULL; if (!addr) { mgcp_get_local_addr(local_ip_addr, conn); addr = local_ip_addr; } if (conn->osmux.state == OSMUX_STATE_NEGOTIATING) { sprintf(osmux_extension, "X-Osmux: %u", conn->osmux.cid); conn->osmux.state = OSMUX_STATE_ACTIVATING; } else { osmux_extension[0] = '\0'; } /* Attach optional connection parameters */ if (add_conn_params) { rc = add_params(sdp, endp, conn); if (rc < 0) goto error; } /* Attach optional OSMUX parameters */ if (conn->osmux.state == OSMUX_STATE_NEGOTIATING) { rc = msgb_printf(sdp, "%s\r\n", osmux_extension); if (rc < 0) goto error; } /* Attach line break to separate the parameters from the SDP block */ rc = msgb_printf(sdp, "\r\n"); rc = mgcp_write_response_sdp(endp, conn, sdp, addr); if (rc < 0) goto error; result = create_resp(endp, 200, " OK", msg, trans_id, NULL, (char*) sdp->data); msgb_free(sdp); return result; error: msgb_free(sdp); return NULL; } /* Send out dummy packet to keep the connection open, if the connection is an * osmux connection, send the dummy packet via OSMUX */ static void send_dummy(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn) { if (conn->osmux.state != OSMUX_STATE_DISABLED) osmux_send_dummy(endp, conn); else mgcp_send_dummy(endp, conn); } /* handle incoming messages: * - this can be a command (four letters, space, transaction id) * - or a response (three numbers, space, transaction id) */ struct msgb *mgcp_handle_message(struct mgcp_config *cfg, struct msgb *msg) { struct mgcp_parse_data pdata; int rc, i, code, handled = 0; struct msgb *resp = NULL; char *data; if (msgb_l2len(msg) < 4) { LOGP(DLMGCP, LOGL_ERROR, "msg too short: %d\n", msg->len); return NULL; } if (mgcp_msg_terminate_nul(msg)) return NULL; mgcp_disp_msg(msg->l2h, msgb_l2len(msg), "Received message"); /* attempt to treat it as a response */ if (sscanf((const char *)&msg->l2h[0], "%3d %*s", &code) == 1) { LOGP(DLMGCP, LOGL_DEBUG, "Response: Code: %d\n", code); return NULL; } msg->l3h = &msg->l2h[4]; /* * Check for a duplicate message and respond. */ memset(&pdata, 0, sizeof(pdata)); pdata.cfg = cfg; data = mgcp_strline((char *)msg->l3h, &pdata.save); rc = mgcp_parse_header(&pdata, data); if (pdata.endp && pdata.trans && pdata.endp->last_trans && strcmp(pdata.endp->last_trans, pdata.trans) == 0) { return do_retransmission(pdata.endp); } /* check for general parser failure */ if (rc < 0) { LOGP(DLMGCP, LOGL_NOTICE, "%s: failed to find the endpoint\n", msg->l2h); return create_err_response(NULL, -rc, (const char *) msg->l2h, pdata.trans); } for (i = 0; i < ARRAY_SIZE(mgcp_requests); ++i) { if (strncmp (mgcp_requests[i].name, (const char *)&msg->l2h[0], 4) == 0) { handled = 1; resp = mgcp_requests[i].handle_request(&pdata); break; } } if (!handled) LOGP(DLMGCP, LOGL_NOTICE, "MSG with type: '%.4s' not handled\n", &msg->l2h[0]); return resp; } /* AUEP command handler, processes the received command */ static struct msgb *handle_audit_endpoint(struct mgcp_parse_data *p) { LOGP(DLMGCP, LOGL_NOTICE, "AUEP: auditing endpoint ...\n"); return create_ok_response(p->endp, 200, "AUEP", p->trans); } /* Try to find a free port by attempting to bind on it. Also handle the * counter that points on the next free port. Since we have a pointer * to the next free port, binding should in work on the first attempt in * general. In case of failure the next port is tryed until the whole port * range is tryed once. */ static int allocate_port(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn) { int i; struct mgcp_rtp_end *end; struct mgcp_port_range *range; unsigned int tries; OSMO_ASSERT(conn); end = &conn->end; OSMO_ASSERT(end); range = &endp->cfg->net_ports; /* attempt to find a port */ tries = (range->range_end - range->range_start) / 2; for (i = 0; i < tries; ++i) { int rc; if (range->last_port >= range->range_end) range->last_port = range->range_start; rc = mgcp_bind_net_rtp_port(endp, range->last_port, conn); range->last_port += 2; if (rc == 0) { return 0; } } LOGP(DLMGCP, LOGL_ERROR, "Allocating a RTP/RTCP port failed %u times 0x%x.\n", tries, ENDPOINT_NUMBER(endp)); return -1; } /*! Helper function for check_local_cx_options() to get a pointer of the next * lco option identifier * \param[in] lco string * \returns pointer to the beginning of the LCO identifier, NULL on failure */ char *get_lco_identifier(const char *options) { char *ptr; unsigned int count = 0; /* Jump to the end of the lco identifier */ ptr = strstr(options, ":"); if (!ptr) return NULL; /* Walk backwards until the pointer points to the beginning of the * lco identifier. We know that we stand at the beginning when we * are either at the beginning of the memory or see a space or * comma. (this is tolerant, it will accept a:10, b:11 as well as * a:10,b:11) */ while (1) { /* Endless loop protection */ if (count > 10000) return NULL; else if (ptr < options || *ptr == ' ' || *ptr == ',') { ptr++; break; } ptr--; count++; } /* Check if we got any result */ if (*ptr == ':') return NULL; return ptr; } /*! Check the LCO option. This function checks for multiple appearence of LCO * options, which is illegal * \param[in] ctx talloc context * \param[in] lco string * \returns 0 on success, -1 on failure */ int check_local_cx_options(void *ctx, const char *options) { int i; char *options_copy; char *lco_identifier; char *lco_identifier_end; char *next_lco_identifier; char **lco_seen; unsigned int lco_seen_n = 0; if (!options) return -1; lco_seen = (char **)talloc_zero_size(ctx, strlen(options) * sizeof(char *)); options_copy = talloc_strdup(ctx, options); lco_identifier = options_copy; do { /* Move the lco_identifier pointer to the beginning of the * current lco option identifier */ lco_identifier = get_lco_identifier(lco_identifier); if (!lco_identifier) goto error; /* Look ahead to the next LCO option early, since we * will parse destructively */ next_lco_identifier = strstr(lco_identifier + 1, ","); /* Pinch off the end of the lco field identifier name * and see if we still got something, also check if * there is some value after the colon. */ lco_identifier_end = strstr(lco_identifier, ":"); if (!lco_identifier_end) goto error; if (*(lco_identifier_end + 1) == ' ' || *(lco_identifier_end + 1) == ',' || *(lco_identifier_end + 1) == '\0') goto error; *lco_identifier_end = '\0'; if (strlen(lco_identifier) == 0) goto error; /* Check if we have already seen the current field identifier * before. If yes, we must bail, an LCO must only appear once * in the LCO string */ for (i = 0; i < lco_seen_n; i++) { if (strcmp(lco_seen[i], lco_identifier) == 0) goto error; } lco_seen[lco_seen_n] = lco_identifier; lco_seen_n++; /* The first identifier must always be found at the beginnning * of the LCO string */ if (lco_seen[0] != options_copy) goto error; /* Go to the next lco option */ lco_identifier = next_lco_identifier; } while (lco_identifier); talloc_free(lco_seen); talloc_free(options_copy); return 0; error: talloc_free(lco_seen); talloc_free(options_copy); return -1; } /* Set the LCO from a string (see RFC 3435). * The string is stored in the 'string' field. A NULL string is handled exactly * like an empty string, the 'string' field is never NULL after this function * has been called. */ static int set_local_cx_options(void *ctx, struct mgcp_lco *lco, const char *options) { char *p_opt, *a_opt; char codec[9]; if (!options) return 0; if (strlen(options) == 0) return 0; /* Make sure the encoding of the LCO is consistant before we proceed */ if (check_local_cx_options(ctx, options) != 0) { LOGP(DLMGCP, LOGL_ERROR, "local CX options: Internal inconsistency in Local Connection Options!\n"); return 524; } talloc_free(lco->string); lco->string = talloc_strdup(ctx, options); p_opt = strstr(lco->string, "p:"); if (p_opt && sscanf(p_opt, "p:%d-%d", &lco->pkt_period_min, &lco->pkt_period_max) == 1) lco->pkt_period_max = lco->pkt_period_min; /* FIXME: LCO also supports the negotiation of more then one codec. * (e.g. a:PCMU;G726-32) But this implementation only supports a single * codec only. */ a_opt = strstr(lco->string, "a:"); if (a_opt && sscanf(a_opt, "a:%8[^,]", codec) == 1) { talloc_free(lco->codec); lco->codec = talloc_strdup(ctx, codec); } LOGP(DLMGCP, LOGL_DEBUG, "local CX options: lco->pkt_period_max: %i, lco->codec: %s\n", lco->pkt_period_max, lco->codec); /* Check if the packetization fits the 20ms raster */ if (lco->pkt_period_min % 20 && lco->pkt_period_max % 20) { LOGP(DLMGCP, LOGL_ERROR, "local CX options: packetization interval is not a multiple of 20ms!\n"); return 535; } return 0; } void mgcp_rtp_end_config(struct mgcp_endpoint *endp, int expect_ssrc_change, struct mgcp_rtp_end *rtp) { struct mgcp_trunk_config *tcfg = endp->tcfg; int patch_ssrc = expect_ssrc_change && tcfg->force_constant_ssrc; rtp->force_aligned_timing = tcfg->force_aligned_timing; rtp->force_constant_ssrc = patch_ssrc ? 1 : 0; LOGP(DLMGCP, LOGL_DEBUG, "Configuring RTP endpoint: local port %d%s%s\n", ntohs(rtp->rtp_port), rtp->force_aligned_timing ? ", force constant timing" : "", rtp->force_constant_ssrc ? ", force constant ssrc" : ""); } uint32_t mgcp_rtp_packet_duration(struct mgcp_endpoint *endp, struct mgcp_rtp_end *rtp) { int f = 0; /* Get the number of frames per channel and packet */ if (rtp->frames_per_packet) f = rtp->frames_per_packet; else if (rtp->packet_duration_ms && rtp->codec->frame_duration_num) { int den = 1000 * rtp->codec->frame_duration_num; f = (rtp->packet_duration_ms * rtp->codec->frame_duration_den + den / 2) / den; } return rtp->codec->rate * f * rtp->codec->frame_duration_num / rtp->codec->frame_duration_den; } static int mgcp_osmux_setup(struct mgcp_endpoint *endp, const char *line) { if (!endp->cfg->osmux_init) { if (osmux_init(OSMUX_ROLE_BSC, endp->cfg) < 0) { LOGP(DLMGCP, LOGL_ERROR, "Cannot init OSMUX\n"); return -1; } LOGP(DLMGCP, LOGL_NOTICE, "OSMUX socket has been set up\n"); } return mgcp_parse_osmux_cid(line); } /* Process codec information contained in CRCX/MDCX */ static int handle_codec_info(struct mgcp_conn_rtp *conn, struct mgcp_parse_data *p, int have_sdp, bool crcx) { struct mgcp_endpoint *endp = p->endp; int rc; char *cmd; if (crcx) cmd = "CRCX"; else cmd = "MDCX"; /* Collect codec information */ if (have_sdp) { /* If we have SDP, we ignore the local connection options and * use only the SDP information. */ mgcp_codec_reset_all(conn); rc = mgcp_parse_sdp_data(endp, conn, p); if (rc != 0) { LOGP(DLMGCP, LOGL_ERROR, "%s: endpoint:%x sdp not parseable\n", cmd, ENDPOINT_NUMBER(endp)); /* See also RFC 3661: Protocol error */ return 510; } } else if (endp->local_options.codec) { /* When no SDP is available, we use the codec information from * the local connection options (if present) */ mgcp_codec_reset_all(conn); rc = mgcp_codec_add(conn, PTYPE_UNDEFINED, endp->local_options.codec); if (rc != 0) goto error; } /* Make sure we always set a sane default codec */ if (conn->end.codecs_assigned == 0) { /* When SDP and/or LCO did not supply any codec information, * than it makes sense to pick a sane default: (payload-type 0, * PCMU), see also: OS#2658 */ mgcp_codec_reset_all(conn); rc = mgcp_codec_add(conn, 0, NULL); if (rc != 0) goto error; } /* Make codec decision */ if (mgcp_codec_decide(conn) != 0) goto error; return 0; error: LOGP(DLMGCP, LOGL_ERROR, "%s: endpoint:0x%x codec negotiation failure\n", cmd, ENDPOINT_NUMBER(endp)); /* See also RFC 3661: Codec negotiation failure */ return 534; } /* CRCX command handler, processes the received command */ static struct msgb *handle_create_con(struct mgcp_parse_data *p) { struct mgcp_trunk_config *tcfg; struct mgcp_endpoint *endp = p->endp; int error_code = 400; const char *local_options = NULL; const char *callid = NULL; const char *mode = NULL; char *line; int have_sdp = 0, osmux_cid = -1; struct mgcp_conn_rtp *conn = NULL; struct mgcp_conn *_conn = NULL; char conn_name[512]; int rc; LOGP(DLMGCP, LOGL_NOTICE, "CRCX: creating new connection ...\n"); /* parse CallID C: and LocalParameters L: */ for_each_line(line, p->save) { if (!mgcp_check_param(endp, line)) continue; switch (line[0]) { case 'L': local_options = (const char *)line + 3; break; case 'C': callid = (const char *)line + 3; break; case 'I': /* It is illegal to send a connection identifier * together with a CRCX, the MGW will assign the * connection identifier by itself on CRCX */ return create_err_response(NULL, 523, "CRCX", p->trans); break; case 'M': mode = (const char *)line + 3; break; case 'X': /* If osmoux is disabled, just skip setting it up */ if (!p->endp->cfg->osmux) break; if (strncmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) osmux_cid = mgcp_osmux_setup(endp, line); break; case '\0': have_sdp = 1; goto mgcp_header_done; default: LOGP(DLMGCP, LOGL_NOTICE, "CRCX: endpoint:%x unhandled option: '%c'/%d\n", ENDPOINT_NUMBER(endp), *line, *line); return create_err_response(NULL, 539, "CRCX", p->trans); break; } } mgcp_header_done: tcfg = p->endp->tcfg; /* Check parameters */ if (!callid) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:%x insufficient parameters, missing callid\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 516, "CRCX", p->trans); } if (!mode) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:%x insufficient parameters, missing mode\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 517, "CRCX", p->trans); } /* Check if we are able to accept the creation of another connection */ if (llist_count(&endp->conns) >= endp->type->max_conns) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:%x endpoint full, max. %i connections allowed!\n", endp->type->max_conns, ENDPOINT_NUMBER(endp)); if (tcfg->force_realloc) { /* There is no more room for a connection, make some * room by blindly tossing the oldest of the two two * connections */ mgcp_conn_free_oldest(endp); } else { /* There is no more room for a connection, leave * everything as it is and return with an error */ return create_err_response(endp, 540, "CRCX", p->trans); } } /* Check if this endpoint already serves a call, if so, check if the * callids match up so that we are sure that this is our call */ if (endp->callid && mgcp_verify_call_id(endp, callid)) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:0x%x allready seized by other call (%s)\n", ENDPOINT_NUMBER(endp), endp->callid); if (tcfg->force_realloc) /* This is not our call, toss everything by releasing * the entire endpoint. (rude!) */ mgcp_endp_release(endp); else { /* This is not our call, leave everything as it is and * return with an error. */ return create_err_response(endp, 400, "CRCX", p->trans); } } /* Set the callid, creation of another connection will only be possible * when the callid matches up. (Connections are distinguished by their * connection ids) */ endp->callid = talloc_strdup(tcfg->endpoints, callid); snprintf(conn_name, sizeof(conn_name), "%s", callid); _conn = mgcp_conn_alloc(NULL, endp, MGCP_CONN_TYPE_RTP, conn_name); if (!_conn) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:0x%x unable to allocate RTP connection\n", ENDPOINT_NUMBER(endp)); goto error2; } conn = mgcp_conn_get_rtp(endp, _conn->id); OSMO_ASSERT(conn); if (mgcp_parse_conn_mode(mode, endp, conn->conn) != 0) { error_code = 517; goto error2; } /* Annotate Osmux circuit ID and set it to negotiating state until this * is fully set up from the dummy load. */ conn->osmux.state = OSMUX_STATE_DISABLED; if (osmux_cid >= 0) { conn->osmux.cid = osmux_cid; conn->osmux.state = OSMUX_STATE_NEGOTIATING; } else if (endp->cfg->osmux == OSMUX_USAGE_ONLY) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:0x%x osmux only and no osmux offered\n", ENDPOINT_NUMBER(endp)); goto error2; } /* Set local connection options, if present */ if (local_options) { rc = set_local_cx_options(endp->tcfg->endpoints, &endp->local_options, local_options); if (rc != 0) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:%x inavlid local connection options!\n", ENDPOINT_NUMBER(endp)); error_code = rc; goto error2; } } /* Handle codec information and decide for a suitable codec */ rc = handle_codec_info(conn, p, have_sdp, true); mgcp_codec_summary(conn); if (rc) { error_code = rc; goto error2; } conn->end.fmtp_extra = talloc_strdup(tcfg->endpoints, tcfg->audio_fmtp_extra); if (p->cfg->force_ptime) { conn->end.packet_duration_ms = p->cfg->force_ptime; conn->end.force_output_ptime = 1; } mgcp_rtp_end_config(endp, 0, &conn->end); /* check connection mode setting */ if (conn->conn->mode != MGCP_CONN_LOOPBACK && conn->conn->mode != MGCP_CONN_RECV_ONLY && conn->end.rtp_port == 0) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:%x selected connection mode type requires an opposite end!\n", ENDPOINT_NUMBER(endp)); error_code = 527; goto error2; } if (allocate_port(endp, conn) != 0) { goto error2; } if (setup_rtp_processing(endp, conn) != 0) { LOGP(DLMGCP, LOGL_ERROR, "CRCX: endpoint:0x%x could not start RTP processing!\n", ENDPOINT_NUMBER(endp)); goto error2; } /* policy CB */ if (p->cfg->policy_cb) { int rc; rc = p->cfg->policy_cb(tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_CRCX, p->trans); switch (rc) { case MGCP_POLICY_REJECT: LOGP(DLMGCP, LOGL_NOTICE, "CRCX: endpoint:0x%x CRCX rejected by policy\n", ENDPOINT_NUMBER(endp)); mgcp_endp_release(endp); return create_err_response(endp, 400, "CRCX", p->trans); break; case MGCP_POLICY_DEFER: /* stop processing */ return NULL; break; case MGCP_POLICY_CONT: /* just continue */ break; } } LOGP(DLMGCP, LOGL_DEBUG, "CRCX: endpoint:0x%x Creating connection: CI: %s port: %u\n", ENDPOINT_NUMBER(endp), conn->conn->id, conn->end.local_port); if (p->cfg->change_cb) p->cfg->change_cb(tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_CRCX); /* Send dummy packet, see also comments in mgcp_keepalive_timer_cb() */ OSMO_ASSERT(tcfg->keepalive_interval >= MGCP_KEEPALIVE_ONCE); if (conn->conn->mode & MGCP_CONN_RECV_ONLY && tcfg->keepalive_interval != MGCP_KEEPALIVE_NEVER) send_dummy(endp, conn); LOGP(DLMGCP, LOGL_NOTICE, "CRCX: endpoint:0x%x connection successfully created\n", ENDPOINT_NUMBER(endp)); return create_response_with_sdp(endp, conn, "CRCX", p->trans, true); error2: mgcp_endp_release(endp); LOGP(DLMGCP, LOGL_NOTICE, "CRCX: endpoint:0x%x unable to create connection\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, error_code, "CRCX", p->trans); } /* MDCX command handler, processes the received command */ static struct msgb *handle_modify_con(struct mgcp_parse_data *p) { struct mgcp_endpoint *endp = p->endp; int error_code = 500; int silent = 0; int have_sdp = 0; char *line; const char *local_options = NULL; const char *mode = NULL; struct mgcp_conn_rtp *conn = NULL; const char *conn_id = NULL; int rc; LOGP(DLMGCP, LOGL_NOTICE, "MDCX: modifying existing connection ...\n"); /* Prohibit wildcarded requests */ if (endp->wildcarded_req) { LOGP(DLMGCP, LOGL_ERROR, "MDCX: endpoint:0x%x wildcarded endpoint names not supported.\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 507, "MDCX", p->trans); } if (llist_count(&endp->conns) <= 0) { LOGP(DLMGCP, LOGL_ERROR, "MDCX: endpoint:0x%x endpoint is not holding a connection.\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 400, "MDCX", p->trans); } for_each_line(line, p->save) { if (!mgcp_check_param(endp, line)) continue; switch (line[0]) { case 'C': if (mgcp_verify_call_id(endp, line + 3) != 0) { error_code = 516; goto error3; } break; case 'I': conn_id = (const char *)line + 3; if (mgcp_verify_ci(endp, conn_id) != 0) { error_code = 515; goto error3; } break; case 'L': local_options = (const char *)line + 3; break; case 'M': mode = (const char *)line + 3; break; case 'Z': silent = strcmp("noanswer", line + 3) == 0; break; case '\0': have_sdp = 1; goto mgcp_header_done; break; default: LOGP(DLMGCP, LOGL_NOTICE, "MDCX: endpoint:0x%x Unhandled MGCP option: '%c'/%d\n", ENDPOINT_NUMBER(endp), line[0], line[0]); return create_err_response(NULL, 539, "MDCX", p->trans); break; } } mgcp_header_done: if (!conn_id) { LOGP(DLMGCP, LOGL_ERROR, "MDCX: endpoint:0x%x insufficient parameters, missing ci (connectionIdentifier)\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 515, "MDCX", p->trans); } conn = mgcp_conn_get_rtp(endp, conn_id); if (!conn) return create_err_response(endp, 400, "MDCX", p->trans); if (mode) { if (mgcp_parse_conn_mode(mode, endp, conn->conn) != 0) { error_code = 517; goto error3; } } else conn->conn->mode = conn->conn->mode_orig; /* Set local connection options, if present */ if (local_options) { rc = set_local_cx_options(endp->tcfg->endpoints, &endp->local_options, local_options); if (rc != 0) { LOGP(DLMGCP, LOGL_ERROR, "MDCX: endpoint:%x inavlid local connection options!\n", ENDPOINT_NUMBER(endp)); error_code = rc; goto error3; } } /* Handle codec information and decide for a suitable codec */ rc = handle_codec_info(conn, p, have_sdp, false); mgcp_codec_summary(conn); if (rc) { error_code = rc; goto error3; } /* check connection mode setting */ if (conn->conn->mode != MGCP_CONN_LOOPBACK && conn->conn->mode != MGCP_CONN_RECV_ONLY && conn->end.rtp_port == 0) { LOGP(DLMGCP, LOGL_ERROR, "MDCX: endpoint:%x selected connection mode type requires an opposite end!\n", ENDPOINT_NUMBER(endp)); error_code = 527; goto error3; } if (setup_rtp_processing(endp, conn) != 0) goto error3; /* policy CB */ if (p->cfg->policy_cb) { int rc; rc = p->cfg->policy_cb(endp->tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_MDCX, p->trans); switch (rc) { case MGCP_POLICY_REJECT: LOGP(DLMGCP, LOGL_NOTICE, "MDCX: endpoint:0x%x rejected by policy\n", ENDPOINT_NUMBER(endp)); if (silent) goto out_silent; return create_err_response(endp, 400, "MDCX", p->trans); break; case MGCP_POLICY_DEFER: /* stop processing */ LOGP(DLMGCP, LOGL_DEBUG, "MDCX: endpoint:0x%x defered by policy\n", ENDPOINT_NUMBER(endp)); return NULL; break; case MGCP_POLICY_CONT: /* just continue */ break; } } mgcp_rtp_end_config(endp, 1, &conn->end); /* modify */ LOGP(DLMGCP, LOGL_DEBUG, "MDCX: endpoint:0x%x modified conn:%s\n", ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn->conn)); if (p->cfg->change_cb) p->cfg->change_cb(endp->tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_MDCX); /* Send dummy packet, see also comments in mgcp_keepalive_timer_cb() */ OSMO_ASSERT(endp->tcfg->keepalive_interval >= MGCP_KEEPALIVE_ONCE); if (conn->conn->mode & MGCP_CONN_RECV_ONLY && endp->tcfg->keepalive_interval != MGCP_KEEPALIVE_NEVER) send_dummy(endp, conn); if (silent) goto out_silent; LOGP(DLMGCP, LOGL_NOTICE, "MDCX: endpoint:0x%x connection successfully modified\n", ENDPOINT_NUMBER(endp)); return create_response_with_sdp(endp, conn, "MDCX", p->trans, false); error3: return create_err_response(endp, error_code, "MDCX", p->trans); out_silent: LOGP(DLMGCP, LOGL_DEBUG, "MDCX: endpoint:0x%x silent exit\n", ENDPOINT_NUMBER(endp)); return NULL; } /* DLCX command handler, processes the received command */ static struct msgb *handle_delete_con(struct mgcp_parse_data *p) { struct mgcp_endpoint *endp = p->endp; int error_code = 400; int silent = 0; char *line; char stats[1048]; const char *conn_id = NULL; struct mgcp_conn_rtp *conn = NULL; LOGP(DLMGCP, LOGL_NOTICE, "DLCX: endpoint:0x%x deleting connection ...\n", ENDPOINT_NUMBER(endp)); /* Prohibit wildcarded requests */ if (endp->wildcarded_req) { LOGP(DLMGCP, LOGL_ERROR, "DLCX: endpoint:0x%x wildcarded endpoint names not supported.\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 507, "DLCX", p->trans); } if (llist_count(&endp->conns) <= 0) { LOGP(DLMGCP, LOGL_ERROR, "DLCX: endpoint:0x%x endpoint is not holding a connection.\n", ENDPOINT_NUMBER(endp)); return create_err_response(endp, 515, "DLCX", p->trans); } for_each_line(line, p->save) { if (!mgcp_check_param(endp, line)) continue; switch (line[0]) { case 'C': if (mgcp_verify_call_id(endp, line + 3) != 0) { error_code = 516; goto error3; } break; case 'I': conn_id = (const char *)line + 3; if (mgcp_verify_ci(endp, conn_id) != 0) { error_code = 515; goto error3; } break; case 'Z': silent = strcmp("noanswer", line + 3) == 0; break; default: LOGP(DLMGCP, LOGL_NOTICE, "DLCX: endpoint:0x%x Unhandled MGCP option: '%c'/%d\n", ENDPOINT_NUMBER(endp), line[0], line[0]); return create_err_response(NULL, 539, "DLCX", p->trans); break; } } /* policy CB */ if (p->cfg->policy_cb) { int rc; rc = p->cfg->policy_cb(endp->tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_DLCX, p->trans); switch (rc) { case MGCP_POLICY_REJECT: LOGP(DLMGCP, LOGL_NOTICE, "DLCX: endpoint:0x%x rejected by policy\n", ENDPOINT_NUMBER(endp)); if (silent) goto out_silent; return create_err_response(endp, 400, "DLCX", p->trans); break; case MGCP_POLICY_DEFER: /* stop processing */ return NULL; break; case MGCP_POLICY_CONT: /* just continue */ break; } } /* When no connection id is supplied, we will interpret this as a * wildcarded DLCX and drop all connections at once. (See also * RFC3435 Section F.7) */ if (!conn_id) { LOGP(DLMGCP, LOGL_NOTICE, "DLCX: endpoint:0x%x missing ci (connectionIdentifier), will remove all connections at once\n", ENDPOINT_NUMBER(endp)); mgcp_endp_release(endp); /* Note: In this case we do not return any statistics, * as we assume that the client is not interested in * this case. */ return create_ok_response(endp, 200, "DLCX", p->trans); } /* Find the connection */ conn = mgcp_conn_get_rtp(endp, conn_id); if (!conn) goto error3; /* save the statistics of the current connection */ mgcp_format_stats(stats, sizeof(stats), conn->conn); /* delete connection */ LOGP(DLMGCP, LOGL_DEBUG, "DLCX: endpoint:0x%x deleting conn:%s\n", ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn->conn)); mgcp_conn_free(endp, conn_id); LOGP(DLMGCP, LOGL_NOTICE, "DLCX: endpoint:0x%x connection successfully deleted\n", ENDPOINT_NUMBER(endp)); /* When all connections are closed, the endpoint will be released * in order to be ready to be used by another call. */ if (llist_count(&endp->conns) <= 0) { mgcp_endp_release(endp); LOGP(DLMGCP, LOGL_DEBUG, "DLCX: endpoint:0x%x endpoint released\n", ENDPOINT_NUMBER(endp)); } if (p->cfg->change_cb) p->cfg->change_cb(endp->tcfg, ENDPOINT_NUMBER(endp), MGCP_ENDP_DLCX); if (silent) goto out_silent; return create_ok_resp_with_param(endp, 250, "DLCX", p->trans, stats); error3: return create_err_response(endp, error_code, "DLCX", p->trans); out_silent: LOGP(DLMGCP, LOGL_DEBUG, "DLCX: endpoint:0x%x silent exit\n", ENDPOINT_NUMBER(endp)); return NULL; } /* RSIP command handler, processes the received command */ static struct msgb *handle_rsip(struct mgcp_parse_data *p) { /* TODO: Also implement the resetting of a specific endpoint * to make mgcp_send_reset_ep() work. Currently this will call * mgcp_rsip_cb() in mgw_main.c, which sets reset_endpoints=1 * to make read_call_agent() reset all endpoints when called * next time. In order to selectively reset endpoints some * mechanism to distinguish which endpoint shall be resetted * is needed */ LOGP(DLMGCP, LOGL_NOTICE, "RSIP: resetting all endpoints ...\n"); if (p->cfg->reset_cb) p->cfg->reset_cb(p->endp->tcfg); return NULL; } static char extract_tone(const char *line) { const char *str = strstr(line, "D/"); if (!str) return CHAR_MAX; return str[2]; } /* This can request like DTMF detection and forward, fax detection... it * can also request when the notification should be send and such. We don't * do this right now. */ static struct msgb *handle_noti_req(struct mgcp_parse_data *p) { int res = 0; char *line; char tone = CHAR_MAX; LOGP(DLMGCP, LOGL_NOTICE, "RQNT: processing request for notification ...\n"); for_each_line(line, p->save) { switch (line[0]) { case 'S': tone = extract_tone(line); break; } } /* we didn't see a signal request with a tone */ if (tone == CHAR_MAX) return create_ok_response(p->endp, 200, "RQNT", p->trans); if (p->cfg->rqnt_cb) res = p->cfg->rqnt_cb(p->endp, tone); return res == 0 ? create_ok_response(p->endp, 200, "RQNT", p->trans) : create_err_response(p->endp, res, "RQNT", p->trans); } /* Connection keepalive timer, will take care that dummy packets are send * regularly, so that NAT connections stay open */ static void mgcp_keepalive_timer_cb(void *_tcfg) { struct mgcp_trunk_config *tcfg = _tcfg; struct mgcp_conn *conn; int i; LOGP(DLMGCP, LOGL_DEBUG, "triggered trunk %d keepalive timer\n", tcfg->trunk_nr); /* Do not accept invalid configuration values * valid is MGCP_KEEPALIVE_NEVER, MGCP_KEEPALIVE_ONCE and * values greater 0 */ OSMO_ASSERT(tcfg->keepalive_interval >= MGCP_KEEPALIVE_ONCE); /* The dummy packet functionality has been disabled, we will exit * immediately, no further timer is scheduled, which means we will no * longer send dummy packets even when we did before */ if (tcfg->keepalive_interval == MGCP_KEEPALIVE_NEVER) return; /* In cases where only one dummy packet is sent, we do not need * the timer since the functions that handle the CRCX and MDCX are * triggering the sending of the dummy packet. So we behave like in * the MGCP_KEEPALIVE_NEVER case */ if (tcfg->keepalive_interval == MGCP_KEEPALIVE_ONCE) return; /* Send walk over all endpoints and send out dummy packets through * every connection present on each endpoint */ for (i = 1; i < tcfg->number_endpoints; ++i) { struct mgcp_endpoint *endp = &tcfg->endpoints[i]; llist_for_each_entry(conn, &endp->conns, entry) { if (conn->mode == MGCP_CONN_RECV_ONLY) send_dummy(endp, &conn->u.rtp); } } /* Schedule the keepalive timer for the next round */ LOGP(DLMGCP, LOGL_DEBUG, "rescheduling trunk %d keepalive timer\n", tcfg->trunk_nr); osmo_timer_schedule(&tcfg->keepalive_timer, tcfg->keepalive_interval, 0); } void mgcp_trunk_set_keepalive(struct mgcp_trunk_config *tcfg, int interval) { tcfg->keepalive_interval = interval; osmo_timer_setup(&tcfg->keepalive_timer, mgcp_keepalive_timer_cb, tcfg); if (interval <= 0) osmo_timer_del(&tcfg->keepalive_timer); else osmo_timer_schedule(&tcfg->keepalive_timer, tcfg->keepalive_interval, 0); } /*! allocate configuration with default values. * (called once at startup by main function) */ struct mgcp_config *mgcp_config_alloc(void) { struct mgcp_config *cfg; cfg = talloc_zero(NULL, struct mgcp_config); if (!cfg) { LOGP(DLMGCP, LOGL_FATAL, "Failed to allocate config.\n"); return NULL; } osmo_strlcpy(cfg->domain, "mgw", sizeof(cfg->domain)); cfg->net_ports.range_start = RTP_PORT_DEFAULT_RANGE_START; cfg->net_ports.range_end = RTP_PORT_DEFAULT_RANGE_END; cfg->net_ports.last_port = cfg->net_ports.range_start; cfg->source_port = 2427; cfg->source_addr = talloc_strdup(cfg, "0.0.0.0"); cfg->osmux_addr = talloc_strdup(cfg, "0.0.0.0"); cfg->rtp_processing_cb = &mgcp_rtp_processing_default; cfg->setup_rtp_processing_cb = &mgcp_setup_rtp_processing_default; cfg->get_net_downlink_format_cb = &mgcp_get_net_downlink_format_default; /* default trunk handling */ cfg->trunk.cfg = cfg; cfg->trunk.trunk_nr = 0; cfg->trunk.trunk_type = MGCP_TRUNK_VIRTUAL; cfg->trunk.audio_name = talloc_strdup(cfg, "AMR/8000"); cfg->trunk.audio_payload = 126; cfg->trunk.audio_send_ptime = 1; cfg->trunk.audio_send_name = 1; cfg->trunk.omit_rtcp = 0; mgcp_trunk_set_keepalive(&cfg->trunk, MGCP_KEEPALIVE_ONCE); INIT_LLIST_HEAD(&cfg->trunks); return cfg; } /*! allocate configuration with default values. * (called once at startup by VTY) * \param[in] cfg mgcp configuration * \param[in] nr trunk number * \returns pointer to allocated trunk configuration */ struct mgcp_trunk_config *mgcp_trunk_alloc(struct mgcp_config *cfg, int nr) { struct mgcp_trunk_config *trunk; trunk = talloc_zero(cfg, struct mgcp_trunk_config); if (!trunk) { LOGP(DLMGCP, LOGL_ERROR, "Failed to allocate.\n"); return NULL; } trunk->cfg = cfg; trunk->trunk_type = MGCP_TRUNK_E1; trunk->trunk_nr = nr; trunk->audio_name = talloc_strdup(cfg, "AMR/8000"); trunk->audio_payload = 126; trunk->audio_send_ptime = 1; trunk->audio_send_name = 1; trunk->vty_number_endpoints = 33; trunk->omit_rtcp = 0; mgcp_trunk_set_keepalive(trunk, MGCP_KEEPALIVE_ONCE); llist_add_tail(&trunk->entry, &cfg->trunks); return trunk; } /*! get trunk configuration by trunk number (index). * \param[in] cfg mgcp configuration * \param[in] index trunk number * \returns pointer to trunk configuration, NULL on error */ struct mgcp_trunk_config *mgcp_trunk_num(struct mgcp_config *cfg, int index) { struct mgcp_trunk_config *trunk; llist_for_each_entry(trunk, &cfg->trunks, entry) if (trunk->trunk_nr == index) return trunk; return NULL; } /*! allocate endpoints and set default values. * (called once at startup by VTY) * \param[in] tcfg trunk configuration * \returns 0 on success, -1 on failure */ int mgcp_endpoints_allocate(struct mgcp_trunk_config *tcfg) { int i; tcfg->endpoints = _talloc_zero_array(tcfg->cfg, sizeof(struct mgcp_endpoint), tcfg->vty_number_endpoints, "endpoints"); if (!tcfg->endpoints) return -1; for (i = 0; i < tcfg->vty_number_endpoints; ++i) { INIT_LLIST_HEAD(&tcfg->endpoints[i].conns); tcfg->endpoints[i].cfg = tcfg->cfg; tcfg->endpoints[i].tcfg = tcfg; /* NOTE: Currently all endpoints are of type RTP, this will * change when new variations are implemented */ tcfg->endpoints[i].type = &ep_typeset.rtp; } tcfg->number_endpoints = tcfg->vty_number_endpoints; return 0; } static int send_agent(struct mgcp_config *cfg, const char *buf, int len) { return write(cfg->gw_fd.bfd.fd, buf, len); } /*! Reset all endpoints by sending RSIP message to self. * (called by VTY) * \param[in] endp trunk endpoint * \param[in] endpoint number * \returns 0 on success, -1 on error */ int mgcp_send_reset_all(struct mgcp_config *cfg) { char buf[MGCP_ENDPOINT_MAXLEN + 128]; int len; int rc; len = snprintf(buf, sizeof(buf), "RSIP 1 *@%s MGCP 1.0\r\n", cfg->domain); if (len < 0) return -1; rc = send_agent(cfg, buf, len); if (rc <= 0) return -1; return 0; } /*! Reset a single endpoint by sending RSIP message to self. * (called by VTY) * \param[in] endp trunk endpoint * \param[in] endpoint number * \returns 0 on success, -1 on error */ int mgcp_send_reset_ep(struct mgcp_endpoint *endp, int endpoint) { char buf[MGCP_ENDPOINT_MAXLEN + 128]; int len; int rc; len = snprintf(buf, sizeof(buf), "RSIP 39 %x@%s MGCP 1.0\r\n", endpoint, endp->cfg->domain); if (len < 0) return -1; rc = send_agent(endp->cfg, buf, len); if (rc <= 0) return -1; return 0; }