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-rw-r--r--src/libmgcp/mgcp_network.c579
1 files changed, 579 insertions, 0 deletions
diff --git a/src/libmgcp/mgcp_network.c b/src/libmgcp/mgcp_network.c
new file mode 100644
index 00000000..51c08d15
--- /dev/null
+++ b/src/libmgcp/mgcp_network.c
@@ -0,0 +1,579 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+/* The protocol implementation */
+
+/*
+ * (C) 2009-2011 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2009-2011 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <sys/socket.h>
+#include <arpa/inet.h>
+
+#include <osmocore/msgb.h>
+#include <osmocore/select.h>
+
+#include <openbsc/debug.h>
+#include <openbsc/mgcp.h>
+#include <openbsc/mgcp_internal.h>
+
+#warning "Make use of the rtp proxy code"
+
+/* attempt to determine byte order */
+#include <sys/types.h>
+#include <sys/param.h>
+#include <limits.h>
+
+#ifndef __BYTE_ORDER
+#error "__BYTE_ORDER should be defined by someone"
+#endif
+
+/* according to rtp_proxy.c RFC 3550 */
+struct rtp_hdr {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ uint8_t csrc_count:4,
+ extension:1,
+ padding:1,
+ version:2;
+ uint8_t payload_type:7,
+ marker:1;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+ uint8_t version:2,
+ padding:1,
+ extension:1,
+ csrc_count:4;
+ uint8_t marker:1,
+ payload_type:7;
+#endif
+ uint16_t sequence;
+ uint32_t timestamp;
+ uint32_t ssrc;
+} __attribute__((packed));
+
+
+enum {
+ DEST_NETWORK = 0,
+ DEST_BTS = 1,
+};
+
+enum {
+ PROTO_RTP,
+ PROTO_RTCP,
+};
+
+#define DUMMY_LOAD 0x23
+
+
+static int udp_send(int fd, struct in_addr *addr, int port, char *buf, int len)
+{
+ struct sockaddr_in out;
+ out.sin_family = AF_INET;
+ out.sin_port = port;
+ memcpy(&out.sin_addr, addr, sizeof(*addr));
+
+ return sendto(fd, buf, len, 0, (struct sockaddr *)&out, sizeof(out));
+}
+
+int mgcp_send_dummy(struct mgcp_endpoint *endp)
+{
+ static char buf[] = { DUMMY_LOAD };
+
+ return udp_send(endp->net_end.rtp.fd, &endp->net_end.addr,
+ endp->net_end.rtp_port, buf, 1);
+}
+
+static void patch_and_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *state,
+ int payload, struct sockaddr_in *addr, char *data, int len)
+{
+ uint16_t seq;
+ uint32_t timestamp;
+ struct rtp_hdr *rtp_hdr;
+
+ if (len < sizeof(*rtp_hdr))
+ return;
+
+ rtp_hdr = (struct rtp_hdr *) data;
+ seq = ntohs(rtp_hdr->sequence);
+ timestamp = ntohl(rtp_hdr->timestamp);
+
+ if (!state->initialized) {
+ state->seq_no = seq - 1;
+ state->ssrc = state->orig_ssrc = rtp_hdr->ssrc;
+ state->initialized = 1;
+ state->last_timestamp = timestamp;
+ } else if (state->ssrc != rtp_hdr->ssrc) {
+ state->ssrc = rtp_hdr->ssrc;
+ state->seq_offset = (state->seq_no + 1) - seq;
+ state->timestamp_offset = state->last_timestamp - timestamp;
+ state->patch = endp->allow_patch;
+ LOGP(DMGCP, LOGL_NOTICE,
+ "The SSRC changed on 0x%x SSRC: %u offset: %d from %s:%d in %d\n",
+ ENDPOINT_NUMBER(endp), state->ssrc, state->seq_offset,
+ inet_ntoa(addr->sin_addr), ntohs(addr->sin_port), endp->conn_mode);
+ }
+
+ /* apply the offset and store it back to the packet */
+ if (state->patch) {
+ seq += state->seq_offset;
+ rtp_hdr->sequence = htons(seq);
+ rtp_hdr->ssrc = state->orig_ssrc;
+
+ timestamp += state->timestamp_offset;
+ rtp_hdr->timestamp = htonl(timestamp);
+ }
+
+ /* seq changed, now compare if we have lost something */
+ if (state->seq_no + 1u != seq)
+ state->lost_no = abs(seq - (state->seq_no + 1));
+ state->seq_no = seq;
+
+ state->last_timestamp = timestamp;
+
+ if (payload < 0)
+ return;
+
+ rtp_hdr->payload_type = payload;
+}
+
+/*
+ * The below code is for dispatching. We have a dedicated port for
+ * the data coming from the net and one to discover the BTS.
+ */
+static int forward_data(int fd, struct mgcp_rtp_tap *tap, const char *buf, int len)
+{
+ if (!tap->enabled)
+ return 0;
+
+ return sendto(fd, buf, len, 0,
+ (struct sockaddr *)&tap->forward, sizeof(tap->forward));
+}
+
+static int send_transcoder(struct mgcp_rtp_end *end, struct mgcp_config *cfg,
+ int is_rtp, const char *buf, int len)
+{
+ int rc;
+ int port;
+ struct sockaddr_in addr;
+
+ port = is_rtp ? end->rtp_port : end->rtcp_port;
+
+ addr.sin_family = AF_INET;
+ addr.sin_addr = cfg->transcoder_in;
+ addr.sin_port = port;
+
+ rc = sendto(is_rtp ?
+ end->rtp.fd :
+ end->rtcp.fd, buf, len, 0,
+ (struct sockaddr *) &addr, sizeof(addr));
+
+ if (rc != len)
+ LOGP(DMGCP, LOGL_ERROR,
+ "Failed to send data to the transcoder: %s\n",
+ strerror(errno));
+
+ return rc;
+}
+
+static int send_to(struct mgcp_endpoint *endp, int dest, int is_rtp,
+ struct sockaddr_in *addr, char *buf, int rc)
+{
+ struct mgcp_trunk_config *tcfg = endp->tcfg;
+ /* For loop toggle the destination and then dispatch. */
+ if (tcfg->audio_loop)
+ dest = !dest;
+
+ /* Loop based on the conn_mode, maybe undoing the above */
+ if (endp->conn_mode == MGCP_CONN_LOOPBACK)
+ dest = !dest;
+
+ if (dest == DEST_NETWORK) {
+ if (is_rtp) {
+ patch_and_count(endp, &endp->bts_state,
+ endp->net_end.payload_type,
+ addr, buf, rc);
+ forward_data(endp->net_end.rtp.fd,
+ &endp->taps[MGCP_TAP_NET_OUT], buf, rc);
+ return udp_send(endp->net_end.rtp.fd, &endp->net_end.addr,
+ endp->net_end.rtp_port, buf, rc);
+ } else {
+ return udp_send(endp->net_end.rtcp.fd, &endp->net_end.addr,
+ endp->net_end.rtcp_port, buf, rc);
+ }
+ } else {
+ if (is_rtp) {
+ patch_and_count(endp, &endp->net_state,
+ endp->bts_end.payload_type,
+ addr, buf, rc);
+ forward_data(endp->bts_end.rtp.fd,
+ &endp->taps[MGCP_TAP_BTS_OUT], buf, rc);
+ return udp_send(endp->bts_end.rtp.fd, &endp->bts_end.addr,
+ endp->bts_end.rtp_port, buf, rc);
+ } else {
+ return udp_send(endp->bts_end.rtcp.fd, &endp->bts_end.addr,
+ endp->bts_end.rtcp_port, buf, rc);
+ }
+ }
+}
+
+static int recevice_from(struct mgcp_endpoint *endp, int fd, struct sockaddr_in *addr,
+ char *buf, int bufsize)
+{
+ int rc;
+ socklen_t slen = sizeof(*addr);
+
+ rc = recvfrom(fd, buf, bufsize, 0,
+ (struct sockaddr *) addr, &slen);
+ if (rc < 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to receive message on: 0x%x errno: %d/%s\n",
+ ENDPOINT_NUMBER(endp), errno, strerror(errno));
+ return -1;
+ }
+
+ /* do not forward aynthing... maybe there is a packet from the bts */
+ if (!endp->allocated)
+ return -1;
+
+ #warning "Slight spec violation. With connection mode recvonly we should attempt to forward."
+
+ return rc;
+}
+
+static int rtp_data_net(struct bsc_fd *fd, unsigned int what)
+{
+ char buf[4096];
+ struct sockaddr_in addr;
+ struct mgcp_endpoint *endp;
+ int rc, proto;
+
+ endp = (struct mgcp_endpoint *) fd->data;
+
+ rc = recevice_from(endp, fd->fd, &addr, buf, sizeof(buf));
+ if (rc <= 0)
+ return -1;
+
+ if (memcmp(&addr.sin_addr, &endp->net_end.addr, sizeof(addr.sin_addr)) != 0) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data from wrong address %s on 0x%x\n",
+ inet_ntoa(addr.sin_addr), ENDPOINT_NUMBER(endp));
+ return -1;
+ }
+
+ if (endp->net_end.rtp_port != addr.sin_port &&
+ endp->net_end.rtcp_port != addr.sin_port) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data from wrong source port %d on 0x%x\n",
+ ntohs(addr.sin_port), ENDPOINT_NUMBER(endp));
+ return -1;
+ }
+
+ /* throw away the dummy message */
+ if (rc == 1 && buf[0] == DUMMY_LOAD) {
+ LOGP(DMGCP, LOGL_NOTICE, "Filtered dummy from network on 0x%x\n",
+ ENDPOINT_NUMBER(endp));
+ return 0;
+ }
+
+ proto = fd == &endp->net_end.rtp ? PROTO_RTP : PROTO_RTCP;
+ endp->net_end.packets += 1;
+
+ forward_data(fd->fd, &endp->taps[MGCP_TAP_NET_IN], buf, rc);
+ if (endp->is_transcoded)
+ return send_transcoder(&endp->trans_net, endp->cfg, proto == PROTO_RTP, &buf[0], rc);
+ else
+ return send_to(endp, DEST_BTS, proto == PROTO_RTP, &addr, &buf[0], rc);
+}
+
+static void discover_bts(struct mgcp_endpoint *endp, int proto, struct sockaddr_in *addr)
+{
+ struct mgcp_config *cfg = endp->cfg;
+
+ if (proto == PROTO_RTP && endp->bts_end.rtp_port == 0) {
+ if (!cfg->bts_ip ||
+ memcmp(&addr->sin_addr,
+ &cfg->bts_in, sizeof(cfg->bts_in)) == 0 ||
+ memcmp(&addr->sin_addr,
+ &endp->bts_end.addr, sizeof(endp->bts_end.addr)) == 0) {
+
+ endp->bts_end.rtp_port = addr->sin_port;
+ endp->bts_end.addr = addr->sin_addr;
+
+ LOGP(DMGCP, LOGL_NOTICE,
+ "Found BTS for endpoint: 0x%x on port: %d/%d of %s\n",
+ ENDPOINT_NUMBER(endp), ntohs(endp->bts_end.rtp_port),
+ ntohs(endp->bts_end.rtcp_port), inet_ntoa(addr->sin_addr));
+ }
+ } else if (proto == PROTO_RTCP && endp->bts_end.rtcp_port == 0) {
+ if (memcmp(&endp->bts_end.addr, &addr->sin_addr,
+ sizeof(endp->bts_end.addr)) == 0) {
+ endp->bts_end.rtcp_port = addr->sin_port;
+ }
+ }
+}
+
+static int rtp_data_bts(struct bsc_fd *fd, unsigned int what)
+{
+ char buf[4096];
+ struct sockaddr_in addr;
+ struct mgcp_endpoint *endp;
+ struct mgcp_config *cfg;
+ int rc, proto;
+
+ endp = (struct mgcp_endpoint *) fd->data;
+ cfg = endp->cfg;
+
+ rc = recevice_from(endp, fd->fd, &addr, buf, sizeof(buf));
+ if (rc <= 0)
+ return -1;
+
+ proto = fd == &endp->bts_end.rtp ? PROTO_RTP : PROTO_RTCP;
+
+ /* We have no idea who called us, maybe it is the BTS. */
+ /* it was the BTS... */
+ discover_bts(endp, proto, &addr);
+
+ if (memcmp(&endp->bts_end.addr, &addr.sin_addr, sizeof(addr.sin_addr)) != 0) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data from wrong bts %s on 0x%x\n",
+ inet_ntoa(addr.sin_addr), ENDPOINT_NUMBER(endp));
+ return -1;
+ }
+
+ if (endp->bts_end.rtp_port != addr.sin_port &&
+ endp->bts_end.rtcp_port != addr.sin_port) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data from wrong bts source port %d on 0x%x\n",
+ ntohs(addr.sin_port), ENDPOINT_NUMBER(endp));
+ return -1;
+ }
+
+ /* throw away the dummy message */
+ if (rc == 1 && buf[0] == DUMMY_LOAD) {
+ LOGP(DMGCP, LOGL_NOTICE, "Filtered dummy from bts on 0x%x\n",
+ ENDPOINT_NUMBER(endp));
+ return 0;
+ }
+
+ /* do this before the loop handling */
+ endp->bts_end.packets += 1;
+
+ forward_data(fd->fd, &endp->taps[MGCP_TAP_BTS_IN], buf, rc);
+ if (endp->is_transcoded)
+ return send_transcoder(&endp->trans_bts, endp->cfg, proto == PROTO_RTP, &buf[0], rc);
+ else
+ return send_to(endp, DEST_NETWORK, proto == PROTO_RTP, &addr, &buf[0], rc);
+}
+
+static int rtp_data_transcoder(struct mgcp_rtp_end *end, struct mgcp_endpoint *_endp,
+ int dest, struct bsc_fd *fd)
+{
+ char buf[4096];
+ struct sockaddr_in addr;
+ struct mgcp_config *cfg;
+ int rc, proto;
+
+ cfg = _endp->cfg;
+ rc = recevice_from(_endp, fd->fd, &addr, buf, sizeof(buf));
+ if (rc <= 0)
+ return -1;
+
+ proto = fd == &end->rtp ? PROTO_RTP : PROTO_RTCP;
+
+ if (memcmp(&addr.sin_addr, &cfg->transcoder_in, sizeof(addr.sin_addr)) != 0) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data not coming from transcoder dest: %d %s on 0x%x\n",
+ dest, inet_ntoa(addr.sin_addr), ENDPOINT_NUMBER(_endp));
+ return -1;
+ }
+
+ if (end->rtp_port != addr.sin_port &&
+ end->rtcp_port != addr.sin_port) {
+ LOGP(DMGCP, LOGL_ERROR,
+ "Data from wrong transcoder dest %d source port %d on 0x%x\n",
+ dest, ntohs(addr.sin_port), ENDPOINT_NUMBER(_endp));
+ return -1;
+ }
+
+ /* throw away the dummy message */
+ if (rc == 1 && buf[0] == DUMMY_LOAD) {
+ LOGP(DMGCP, LOGL_NOTICE, "Filtered dummy from transcoder dest %d on 0x%x\n",
+ dest, ENDPOINT_NUMBER(_endp));
+ return 0;
+ }
+
+ end->packets += 1;
+ return send_to(_endp, dest, proto == PROTO_RTP, &addr, &buf[0], rc);
+}
+
+static int rtp_data_trans_net(struct bsc_fd *fd, unsigned int what)
+{
+ struct mgcp_endpoint *endp;
+ endp = (struct mgcp_endpoint *) fd->data;
+
+ return rtp_data_transcoder(&endp->trans_net, endp, DEST_NETWORK, fd);
+}
+
+static int rtp_data_trans_bts(struct bsc_fd *fd, unsigned int what)
+{
+ struct mgcp_endpoint *endp;
+ endp = (struct mgcp_endpoint *) fd->data;
+
+ return rtp_data_transcoder(&endp->trans_bts, endp, DEST_BTS, fd);
+}
+
+static int create_bind(const char *source_addr, struct bsc_fd *fd, int port)
+{
+ struct sockaddr_in addr;
+ int on = 1;
+
+ fd->fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd->fd < 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to create UDP port.\n");
+ return -1;
+ }
+
+ setsockopt(fd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(port);
+ inet_aton(source_addr, &addr.sin_addr);
+
+ if (bind(fd->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+ close(fd->fd);
+ fd->fd = -1;
+ return -1;
+ }
+
+ return 0;
+}
+
+static int set_ip_tos(int fd, int tos)
+{
+ int ret;
+ ret = setsockopt(fd, IPPROTO_IP, IP_TOS,
+ &tos, sizeof(tos));
+ return ret != 0;
+}
+
+static int bind_rtp(struct mgcp_config *cfg, struct mgcp_rtp_end *rtp_end, int endpno)
+{
+ if (create_bind(cfg->source_addr, &rtp_end->rtp, rtp_end->local_port) != 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to create RTP port: %s:%d on 0x%x\n",
+ cfg->source_addr, rtp_end->local_port, endpno);
+ goto cleanup0;
+ }
+
+ if (create_bind(cfg->source_addr, &rtp_end->rtcp, rtp_end->local_port + 1) != 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to create RTCP port: %s:%d on 0x%x\n",
+ cfg->source_addr, rtp_end->local_port + 1, endpno);
+ goto cleanup1;
+ }
+
+ set_ip_tos(rtp_end->rtp.fd, cfg->endp_dscp);
+ set_ip_tos(rtp_end->rtcp.fd, cfg->endp_dscp);
+
+ rtp_end->rtp.when = BSC_FD_READ;
+ if (bsc_register_fd(&rtp_end->rtp) != 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to register RTP port %d on 0x%x\n",
+ rtp_end->local_port, endpno);
+ goto cleanup2;
+ }
+
+ rtp_end->rtcp.when = BSC_FD_READ;
+ if (bsc_register_fd(&rtp_end->rtcp) != 0) {
+ LOGP(DMGCP, LOGL_ERROR, "Failed to register RTCP port %d on 0x%x\n",
+ rtp_end->local_port + 1, endpno);
+ goto cleanup3;
+ }
+
+ return 0;
+
+cleanup3:
+ bsc_unregister_fd(&rtp_end->rtp);
+cleanup2:
+ close(rtp_end->rtcp.fd);
+ rtp_end->rtcp.fd = -1;
+cleanup1:
+ close(rtp_end->rtp.fd);
+ rtp_end->rtp.fd = -1;
+cleanup0:
+ return -1;
+}
+
+static int int_bind(const char *port,
+ struct mgcp_rtp_end *end, int (*cb)(struct bsc_fd *, unsigned),
+ struct mgcp_endpoint *_endp, int rtp_port)
+{
+ if (end->rtp.fd != -1 || end->rtcp.fd != -1) {
+ LOGP(DMGCP, LOGL_ERROR, "Previous %s was still bound on %d\n",
+ port, ENDPOINT_NUMBER(_endp));
+ mgcp_free_rtp_port(end);
+ }
+
+ end->local_port = rtp_port;
+ end->rtp.cb = cb;
+ end->rtp.data = _endp;
+ end->rtcp.data = _endp;
+ end->rtcp.cb = cb;
+ return bind_rtp(_endp->cfg, end, ENDPOINT_NUMBER(_endp));
+}
+
+
+int mgcp_bind_bts_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
+{
+ return int_bind("bts-port", &endp->bts_end,
+ rtp_data_bts, endp, rtp_port);
+}
+
+int mgcp_bind_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
+{
+ return int_bind("net-port", &endp->net_end,
+ rtp_data_net, endp, rtp_port);
+}
+
+int mgcp_bind_trans_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
+{
+ return int_bind("trans-net", &endp->trans_net,
+ rtp_data_trans_net, endp, rtp_port);
+}
+
+int mgcp_bind_trans_bts_rtp_port(struct mgcp_endpoint *endp, int rtp_port)
+{
+ return int_bind("trans-bts", &endp->trans_bts,
+ rtp_data_trans_bts, endp, rtp_port);
+}
+
+int mgcp_free_rtp_port(struct mgcp_rtp_end *end)
+{
+ if (end->rtp.fd != -1) {
+ close(end->rtp.fd);
+ end->rtp.fd = -1;
+ bsc_unregister_fd(&end->rtp);
+ }
+
+ if (end->rtcp.fd != -1) {
+ close(end->rtcp.fd);
+ end->rtcp.fd = -1;
+ bsc_unregister_fd(&end->rtcp);
+ }
+
+ return 0;
+}