| /* mgcp_utils - common functions to setup an MGCP connection |
| */ |
| /* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| * 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 <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <osmocom/core/select.h> |
| #include <osmocom/core/write_queue.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/logging.h> |
| |
| #include <openbsc/mgcpgw_client.h> |
| #include <openbsc/mgcp.h> |
| #include <openbsc/mgcp_internal.h> |
| #include <openbsc/debug.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| |
| #include <errno.h> |
| #include <unistd.h> |
| #include <string.h> |
| |
| struct mgcpgw_client { |
| struct mgcpgw_client_conf actual; |
| uint32_t remote_addr; |
| struct osmo_wqueue wq; |
| mgcp_trans_id_t next_trans_id; |
| uint16_t next_endpoint; |
| struct llist_head responses_pending; |
| }; |
| |
| void mgcpgw_client_conf_init(struct mgcpgw_client_conf *conf) |
| { |
| /* NULL and -1 default to MGCPGW_CLIENT_*_DEFAULT values */ |
| *conf = (struct mgcpgw_client_conf){ |
| .local_addr = NULL, |
| .local_port = -1, |
| .remote_addr = NULL, |
| .remote_port = -1, |
| }; |
| } |
| |
| unsigned int mgcpgw_client_next_endpoint(struct mgcpgw_client *client) |
| { |
| return client->next_endpoint ++; |
| } |
| |
| static void mgcpgw_client_handle_response(struct mgcpgw_client *mgcp, |
| struct mgcp_response_pending *pending, |
| struct mgcp_response *response) |
| { |
| if (!pending) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot handle NULL response\n"); |
| return; |
| } |
| if (pending->response_cb) |
| pending->response_cb(response, pending->priv); |
| else |
| LOGP(DMGCP, LOGL_INFO, "MGCP response ignored (NULL cb)\n"); |
| talloc_free(pending); |
| } |
| |
| static int mgcp_response_parse_head(struct mgcp_response *r, struct msgb *msg) |
| { |
| int comment_pos; |
| char *end; |
| |
| if (mgcp_msg_terminate_nul(msg)) |
| goto response_parse_failure; |
| |
| r->body = (char *)msg->data; |
| |
| if (sscanf(r->body, "%3d %u %n", |
| &r->head.response_code, &r->head.trans_id, |
| &comment_pos) != 2) |
| goto response_parse_failure; |
| |
| r->head.comment = r->body + comment_pos; |
| end = strchr(r->head.comment, '\r'); |
| if (!end) |
| goto response_parse_failure; |
| /* Mark the end of the comment */ |
| *end = '\0'; |
| r->body = end + 1; |
| if (r->body[0] == '\n') |
| r->body ++; |
| return 0; |
| |
| response_parse_failure: |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response header\n"); |
| return -EINVAL; |
| } |
| |
| /* TODO undup against mgcp_protocol.c:mgcp_check_param() */ |
| static bool mgcp_line_is_valid(const char *line) |
| { |
| const size_t line_len = strlen(line); |
| if (line[0] == '\0') |
| return true; |
| |
| if (line_len < 2 |
| || line[1] != '=') { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Wrong MGCP option format: '%s'\n", |
| line); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /* Parse a line like "m=audio 16002 RTP/AVP 98" */ |
| static int mgcp_parse_audio(struct mgcp_response *r, const char *line) |
| { |
| if (sscanf(line, "m=audio %hu", |
| &r->audio_port) != 1) |
| goto response_parse_failure; |
| |
| return 0; |
| |
| response_parse_failure: |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response header\n"); |
| return -EINVAL; |
| } |
| |
| int mgcp_response_parse_params(struct mgcp_response *r) |
| { |
| char *line; |
| int rc; |
| OSMO_ASSERT(r->body); |
| char *data = strstr(r->body, "\n\n"); |
| |
| if (!data) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "MGCP response: cannot find start of parameters\n"); |
| return -EINVAL; |
| } |
| |
| /* Advance to after the \n\n, replace the second \n with \0. That's |
| * where the parameters start. */ |
| data ++; |
| *data = '\0'; |
| data ++; |
| |
| for_each_line(line, data) { |
| if (!mgcp_line_is_valid(line)) |
| return -EINVAL; |
| |
| switch (line[0]) { |
| case 'm': |
| rc = mgcp_parse_audio(r, line); |
| if (rc) |
| return rc; |
| break; |
| default: |
| /* skip unhandled parameters */ |
| break; |
| } |
| } |
| return 0; |
| } |
| |
| static struct mgcp_response_pending *mgcpgw_client_response_pending_get( |
| struct mgcpgw_client *mgcp, |
| struct mgcp_response *r) |
| { |
| struct mgcp_response_pending *pending; |
| if (!r) |
| return NULL; |
| llist_for_each_entry(pending, &mgcp->responses_pending, entry) { |
| if (pending->trans_id == r->head.trans_id) { |
| llist_del(&pending->entry); |
| return pending; |
| } |
| } |
| return NULL; |
| } |
| |
| /* Feed an MGCP message into the receive processing. |
| * Parse the head and call any callback registered for the transaction id found |
| * in the MGCP message. This is normally called directly from the internal |
| * mgcp_do_read that reads from the socket connected to the MGCP gateway. This |
| * function is published mainly to be able to feed data from the test suite. |
| */ |
| int mgcpgw_client_rx(struct mgcpgw_client *mgcp, struct msgb *msg) |
| { |
| struct mgcp_response r = { 0 }; |
| struct mgcp_response_pending *pending; |
| int rc; |
| |
| rc = mgcp_response_parse_head(&r, msg); |
| if (rc) { |
| LOGP(DMGCP, LOGL_ERROR, "Cannot parse MGCP response\n"); |
| return -1; |
| } |
| |
| pending = mgcpgw_client_response_pending_get(mgcp, &r); |
| if (!pending) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot find matching MGCP transaction for trans_id %d\n", |
| r.head.trans_id); |
| return -1; |
| } |
| |
| mgcpgw_client_handle_response(mgcp, pending, &r); |
| return 0; |
| } |
| |
| static int mgcp_do_read(struct osmo_fd *fd) |
| { |
| struct mgcpgw_client *mgcp = fd->data; |
| struct msgb *msg; |
| int ret; |
| |
| msg = msgb_alloc_headroom(4096, 128, "mgcp_from_gw"); |
| if (!msg) { |
| LOGP(DMGCP, LOGL_ERROR, "Failed to allocate MGCP message.\n"); |
| return -1; |
| } |
| |
| ret = read(fd->fd, msg->data, 4096 - 128); |
| if (ret <= 0) { |
| LOGP(DMGCP, LOGL_ERROR, "Failed to read: %d/%s\n", errno, strerror(errno)); |
| msgb_free(msg); |
| return -1; |
| } else if (ret > 4096 - 128) { |
| LOGP(DMGCP, LOGL_ERROR, "Too much data: %d\n", ret); |
| msgb_free(msg); |
| return -1; |
| } |
| |
| msg->l2h = msgb_put(msg, ret); |
| ret = mgcpgw_client_rx(mgcp, msg); |
| talloc_free(msg); |
| return ret; |
| } |
| |
| static int mgcp_do_write(struct osmo_fd *fd, struct msgb *msg) |
| { |
| int ret; |
| static char strbuf[4096]; |
| unsigned int l = msg->len < sizeof(strbuf)-1 ? msg->len : sizeof(strbuf)-1; |
| strncpy(strbuf, (const char*)msg->data, l); |
| strbuf[l] = '\0'; |
| DEBUGP(DMGCP, "Tx MGCP msg to MGCP GW: '%s'\n", strbuf); |
| |
| LOGP(DMGCP, LOGL_DEBUG, "Sending msg to MGCP GW size: %u\n", msg->len); |
| |
| ret = write(fd->fd, msg->data, msg->len); |
| if (ret != msg->len) |
| LOGP(DMGCP, LOGL_ERROR, "Failed to forward message to MGCP" |
| " GW: %s\n", strerror(errno)); |
| |
| return ret; |
| } |
| |
| struct mgcpgw_client *mgcpgw_client_init(void *ctx, |
| struct mgcpgw_client_conf *conf) |
| { |
| struct mgcpgw_client *mgcp; |
| |
| mgcp = talloc_zero(ctx, struct mgcpgw_client); |
| |
| INIT_LLIST_HEAD(&mgcp->responses_pending); |
| |
| mgcp->next_trans_id = 1; |
| mgcp->next_endpoint = 1; |
| |
| mgcp->actual.local_addr = conf->local_addr ? conf->local_addr : |
| MGCPGW_CLIENT_LOCAL_ADDR_DEFAULT; |
| mgcp->actual.local_port = conf->local_port >= 0 ? (uint16_t)conf->local_port : |
| MGCPGW_CLIENT_LOCAL_PORT_DEFAULT; |
| |
| mgcp->actual.remote_addr = conf->remote_addr ? conf->remote_addr : |
| MGCPGW_CLIENT_REMOTE_ADDR_DEFAULT; |
| mgcp->actual.remote_port = conf->remote_port >= 0 ? (uint16_t)conf->remote_port : |
| MGCPGW_CLIENT_REMOTE_PORT_DEFAULT; |
| |
| return mgcp; |
| } |
| |
| int mgcpgw_client_connect(struct mgcpgw_client *mgcp) |
| { |
| int on; |
| struct sockaddr_in addr; |
| struct osmo_wqueue *wq; |
| int rc; |
| |
| if (!mgcp) { |
| LOGP(DMGCP, LOGL_FATAL, "MGCPGW client not initialized properly\n"); |
| return -EINVAL; |
| } |
| |
| wq = &mgcp->wq; |
| |
| wq->bfd.fd = socket(AF_INET, SOCK_DGRAM, 0); |
| if (wq->bfd.fd < 0) { |
| LOGP(DMGCP, LOGL_FATAL, "Failed to create UDP socket errno: %d\n", errno); |
| return -errno; |
| } |
| |
| on = 1; |
| if (setsockopt(wq->bfd.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) { |
| LOGP(DMGCP, LOGL_FATAL, |
| "Failed to initialize socket for MGCP GW: %s\n", |
| strerror(errno)); |
| rc = -errno; |
| goto error_close_fd; |
| } |
| |
| /* bind socket */ |
| memset(&addr, 0, sizeof(addr)); |
| addr.sin_family = AF_INET; |
| inet_aton(mgcp->actual.local_addr, &addr.sin_addr); |
| addr.sin_port = htons(mgcp->actual.local_port); |
| if (bind(wq->bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| LOGP(DMGCP, LOGL_FATAL, |
| "Failed to bind for MGCP GW to %s %u\n", |
| mgcp->actual.local_addr, mgcp->actual.local_port); |
| rc = -errno; |
| goto error_close_fd; |
| } |
| |
| /* connect to the remote */ |
| inet_aton(mgcp->actual.remote_addr, &addr.sin_addr); |
| addr.sin_port = htons(mgcp->actual.remote_port); |
| if (connect(wq->bfd.fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { |
| LOGP(DMGCP, LOGL_FATAL, |
| "Failed to connect to MGCP GW at %s %u: %s\n", |
| mgcp->actual.remote_addr, mgcp->actual.remote_port, |
| strerror(errno)); |
| rc = -errno; |
| goto error_close_fd; |
| } |
| |
| mgcp->remote_addr = htonl(addr.sin_addr.s_addr); |
| |
| osmo_wqueue_init(wq, 10); |
| wq->bfd.when = BSC_FD_READ; |
| wq->bfd.data = mgcp; |
| wq->read_cb = mgcp_do_read; |
| wq->write_cb = mgcp_do_write; |
| |
| if (osmo_fd_register(&wq->bfd) != 0) { |
| LOGP(DMGCP, LOGL_FATAL, "Failed to register BFD\n"); |
| rc = -EIO; |
| goto error_close_fd; |
| } |
| LOGP(DMGCP, LOGL_INFO, "MGCP GW connection: %s:%u -> %s:%u\n", |
| mgcp->actual.local_addr, mgcp->actual.local_port, |
| mgcp->actual.remote_addr, mgcp->actual.remote_port); |
| |
| return 0; |
| error_close_fd: |
| close(wq->bfd.fd); |
| wq->bfd.fd = -1; |
| return rc; |
| } |
| |
| const char *mgcpgw_client_remote_addr_str(struct mgcpgw_client *mgcp) |
| { |
| return mgcp->actual.remote_addr; |
| } |
| |
| uint16_t mgcpgw_client_remote_port(struct mgcpgw_client *mgcp) |
| { |
| return mgcp->actual.remote_port; |
| } |
| |
| /* Return the MGCP GW binary IPv4 address in network byte order. */ |
| uint32_t mgcpgw_client_remote_addr_n(struct mgcpgw_client *mgcp) |
| { |
| return mgcp->remote_addr; |
| } |
| |
| struct mgcp_response_pending * mgcpgw_client_pending_add( |
| struct mgcpgw_client *mgcp, |
| mgcp_trans_id_t trans_id, |
| mgcp_response_cb_t response_cb, |
| void *priv) |
| { |
| struct mgcp_response_pending *pending; |
| |
| pending = talloc_zero(mgcp, struct mgcp_response_pending); |
| pending->trans_id = trans_id; |
| pending->response_cb = response_cb; |
| pending->priv = priv; |
| llist_add_tail(&pending->entry, &mgcp->responses_pending); |
| |
| return pending; |
| } |
| |
| /* Send the MGCP message in msg to the MGCP GW and handle a response with |
| * response_cb. NOTE: the response_cb still needs to call |
| * mgcp_response_parse_params(response) to get the parsed parameters -- to |
| * potentially save some CPU cycles, only the head line has been parsed when |
| * the response_cb is invoked. */ |
| int mgcpgw_client_tx(struct mgcpgw_client *mgcp, struct msgb *msg, |
| mgcp_response_cb_t response_cb, void *priv) |
| { |
| struct mgcp_response_pending *pending; |
| mgcp_trans_id_t trans_id; |
| int rc; |
| |
| trans_id = msg->cb[MSGB_CB_MGCP_TRANS_ID]; |
| if (!trans_id) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Unset transaction id in mgcp send request\n"); |
| talloc_free(msg); |
| return -EINVAL; |
| } |
| |
| pending = mgcpgw_client_pending_add(mgcp, trans_id, response_cb, priv); |
| |
| if (msgb_l2len(msg) > 4096) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Cannot send, MGCP message too large: %u\n", |
| msgb_l2len(msg)); |
| msgb_free(msg); |
| rc = -EINVAL; |
| goto mgcp_tx_error; |
| } |
| |
| rc = osmo_wqueue_enqueue(&mgcp->wq, msg); |
| if (rc) { |
| LOGP(DMGCP, LOGL_FATAL, "Could not queue message to MGCP GW\n"); |
| msgb_free(msg); |
| goto mgcp_tx_error; |
| } else |
| LOGP(DMGCP, LOGL_INFO, "Queued %u bytes for MGCP GW\n", |
| msgb_l2len(msg)); |
| return 0; |
| |
| mgcp_tx_error: |
| /* Pass NULL to response cb to indicate an error */ |
| mgcpgw_client_handle_response(mgcp, pending, NULL); |
| return -1; |
| } |
| |
| static struct msgb *mgcp_msg_from_buf(mgcp_trans_id_t trans_id, |
| const char *buf, int len) |
| { |
| struct msgb *msg; |
| |
| if (len > (4096 - 128)) { |
| LOGP(DMGCP, LOGL_ERROR, "Cannot send to MGCP GW:" |
| " message too large: %d\n", len); |
| return NULL; |
| } |
| |
| msg = msgb_alloc_headroom(4096, 128, "MGCP tx"); |
| OSMO_ASSERT(msg); |
| |
| char *dst = (char*)msgb_put(msg, len); |
| memcpy(dst, buf, len); |
| msg->l2h = msg->data; |
| msg->cb[MSGB_CB_MGCP_TRANS_ID] = trans_id; |
| |
| return msg; |
| } |
| |
| static struct msgb *mgcp_msg_from_str(mgcp_trans_id_t trans_id, |
| const char *fmt, ...) |
| { |
| static char compose[4096 - 128]; |
| va_list ap; |
| int len; |
| OSMO_ASSERT(fmt); |
| |
| va_start(ap, fmt); |
| len = vsnprintf(compose, sizeof(compose), fmt, ap); |
| va_end(ap); |
| if (len >= sizeof(compose)) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Message too large: trans_id=%u len=%d\n", |
| trans_id, len); |
| return NULL; |
| } |
| if (len < 1) { |
| LOGP(DMGCP, LOGL_ERROR, |
| "Failed to compose message: trans_id=%u len=%d\n", |
| trans_id, len); |
| return NULL; |
| } |
| return mgcp_msg_from_buf(trans_id, compose, len); |
| } |
| |
| static mgcp_trans_id_t mgcpgw_client_next_trans_id(struct mgcpgw_client *mgcp) |
| { |
| /* avoid zero trans_id to distinguish from unset trans_id */ |
| if (!mgcp->next_trans_id) |
| mgcp->next_trans_id ++; |
| return mgcp->next_trans_id ++; |
| } |
| |
| struct msgb *mgcp_msg_crcx(struct mgcpgw_client *mgcp, |
| uint16_t rtp_endpoint, unsigned int call_id, |
| enum mgcp_connection_mode mode) |
| { |
| mgcp_trans_id_t trans_id = mgcpgw_client_next_trans_id(mgcp); |
| return mgcp_msg_from_str(trans_id, |
| "CRCX %u %x@mgw MGCP 1.0\r\n" |
| "C: %x\r\n" |
| "L: p:20, a:AMR, nt:IN\r\n" |
| "M: %s\r\n" |
| , |
| trans_id, |
| rtp_endpoint, |
| call_id, |
| mgcp_cmode_name(mode)); |
| } |
| |
| struct msgb *mgcp_msg_mdcx(struct mgcpgw_client *mgcp, |
| uint16_t rtp_endpoint, const char *rtp_conn_addr, |
| uint16_t rtp_port, enum mgcp_connection_mode mode) |
| |
| { |
| mgcp_trans_id_t trans_id = mgcpgw_client_next_trans_id(mgcp); |
| return mgcp_msg_from_str(trans_id, |
| "MDCX %u %x@mgw MGCP 1.0\r\n" |
| "M: %s\r\n" |
| "\r\n" |
| "c=IN IP4 %s\r\n" |
| "m=audio %u RTP/AVP 255\r\n" |
| , |
| trans_id, |
| rtp_endpoint, |
| mgcp_cmode_name(mode), |
| rtp_conn_addr, |
| rtp_port); |
| } |