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osmo-mgw/src/libosmo-mgcp/mgcp_network.c

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/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
/* The protocol implementation */
/*
* (C) 2009-2012 by Holger Hans Peter Freyther <zecke@selfish.org>
* (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 <http://www.gnu.org/licenses/>.
*
*/
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <limits.h>
#include <arpa/inet.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/select.h>
#include <osmocom/core/socket.h>
#include <osmocom/netif/rtp.h>
#include <osmocom/mgcp/mgcp.h>
#include <osmocom/mgcp/mgcp_common.h>
#include <osmocom/mgcp/mgcp_internal.h>
#include <osmocom/mgcp/mgcp_stat.h>
#include <osmocom/mgcp/osmux.h>
#include <osmocom/mgcp/mgcp_conn.h>
#include <osmocom/mgcp/mgcp_endp.h>
#include <osmocom/mgcp/debug.h>
#define RTP_SEQ_MOD (1 << 16)
#define RTP_MAX_DROPOUT 3000
#define RTP_MAX_MISORDER 100
#define RTP_BUF_SIZE 4096
enum {
MGCP_PROTO_RTP,
MGCP_PROTO_RTCP,
};
/*! Determine the local rtp bind IP-address.
* \param[out] addr caller provided memory to store the resulting IP-Address
* \param[in] endp mgcp endpoint, that holds a copy of the VTY parameters
*
* The local bind IP-address is automatically selected by probing the
* IP-Address of the interface that is pointing towards the remote IP-Address,
* if no remote IP-Address is known yet, the statically configured
* IP-Addresses are used as fallback. */
void mgcp_get_local_addr(char *addr, struct mgcp_conn_rtp *conn)
{
struct mgcp_endpoint *endp;
int rc;
endp = conn->conn->endp;
/* Try probing the local IP-Address */
if (endp->cfg->net_ports.bind_addr_probe && conn->end.addr.s_addr != 0) {
rc = osmo_sock_local_ip(addr, inet_ntoa(conn->end.addr));
if (rc < 0)
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x CI:%s local interface auto detection failed, using configured addresses...\n",
ENDPOINT_NUMBER(endp), conn->conn->id);
else {
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x CI:%s selected local rtp bind ip %s by probing using remote ip %s\n",
ENDPOINT_NUMBER(endp), conn->conn->id, addr,
inet_ntoa(conn->end.addr));
return;
}
}
/* Select from preconfigured IP-Addresses */
if (endp->cfg->net_ports.bind_addr) {
/* Check there is a bind IP for the RTP traffic configured,
* if so, use that IP-Address */
osmo_strlcpy(addr, endp->cfg->net_ports.bind_addr, INET_ADDRSTRLEN);
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x CI:%s using configured rtp bind ip as local bind ip %s\n",
ENDPOINT_NUMBER(endp), conn->conn->id, addr);
} else {
/* No specific bind IP is configured for the RTP traffic, so
* assume the IP where we listen for incoming MGCP messages
* as bind IP */
osmo_strlcpy(addr, endp->cfg->source_addr, INET_ADDRSTRLEN);
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x CI:%s using mgcp bind ip as local rtp bind ip: %s\n",
ENDPOINT_NUMBER(endp), conn->conn->id, addr);
}
}
/* This does not need to be a precision timestamp and
* is allowed to wrap quite fast. The returned value is
* 1/codec_rate seconds. */
static uint32_t get_current_ts(unsigned codec_rate)
{
struct timespec tp;
uint64_t ret;
if (!codec_rate)
return 0;
memset(&tp, 0, sizeof(tp));
if (clock_gettime(CLOCK_MONOTONIC, &tp) != 0)
LOGP(DRTP, LOGL_NOTICE, "Getting the clock failed.\n");
/* convert it to 1/unit seconds */
ret = tp.tv_sec;
ret *= codec_rate;
ret += (int64_t) tp.tv_nsec * codec_rate / 1000 / 1000 / 1000;
return ret;
}
/*! send udp packet.
* \param[in] fd associated file descriptor
* \param[in] addr destination ip-address
* \param[in] port destination UDP port
* \param[in] buf buffer that holds the data to be send
* \param[in] len length of the data to be sent
* \returns bytes sent, -1 on error */
int mgcp_udp_send(int fd, struct in_addr *addr, int port, char *buf, int len)
{
struct sockaddr_in out;
LOGP(DRTP, LOGL_DEBUG,
"sending %i bytes length packet to %s:%u ...\n",
len, inet_ntoa(*addr), ntohs(port));
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));
}
/*! send RTP dummy packet (to keep NAT connection open).
* \param[in] endp mcgp endpoint that holds the RTP connection
* \param[in] conn associated RTP connection
* \returns bytes sent, -1 on error */
int mgcp_send_dummy(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn)
{
static char buf[] = { MGCP_DUMMY_LOAD };
int rc;
int was_rtcp = 0;
OSMO_ASSERT(endp);
OSMO_ASSERT(conn);
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x sending dummy packet...\n", ENDPOINT_NUMBER(endp));
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x conn:%s\n",
ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn->conn));
rc = mgcp_udp_send(conn->end.rtp.fd, &conn->end.addr,
conn->end.rtp_port, buf, 1);
if (rc == -1)
goto failed;
if (endp->tcfg->omit_rtcp)
return rc;
was_rtcp = 1;
rc = mgcp_udp_send(conn->end.rtcp.fd, &conn->end.addr,
conn->end.rtcp_port, buf, 1);
if (rc >= 0)
return rc;
failed:
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x Failed to send dummy %s packet.\n",
ENDPOINT_NUMBER(endp), was_rtcp ? "RTCP" : "RTP");
return -1;
}
/* Compute timestamp alignment error */
static int32_t ts_alignment_error(struct mgcp_rtp_stream_state *sstate,
int ptime, uint32_t timestamp)
{
int32_t timestamp_delta;
if (ptime == 0)
return 0;
/* Align according to: T - Tlast = k * Tptime */
timestamp_delta = timestamp - sstate->last_timestamp;
return timestamp_delta % ptime;
}
/* Check timestamp and sequence number for plausibility */
static int check_rtp_timestamp(struct mgcp_endpoint *endp,
struct mgcp_rtp_state *state,
struct mgcp_rtp_stream_state *sstate,
struct mgcp_rtp_end *rtp_end,
struct sockaddr_in *addr,
uint16_t seq, uint32_t timestamp,
const char *text, int32_t * tsdelta_out)
{
int32_t tsdelta;
int32_t timestamp_error;
/* Not fully intialized, skip */
if (sstate->last_tsdelta == 0 && timestamp == sstate->last_timestamp)
return 0;
if (seq == sstate->last_seq) {
if (timestamp != sstate->last_timestamp) {
rate_ctr_inc(sstate->err_ts_ctr);
LOGP(DRTP, LOGL_ERROR,
"The %s timestamp delta is != 0 but the sequence "
"number %d is the same, "
"TS offset: %d, SeqNo offset: %d "
"on 0x%x SSRC: %u timestamp: %u "
"from %s:%d\n",
text, seq,
state->patch.timestamp_offset, state->patch.seq_offset,
ENDPOINT_NUMBER(endp), sstate->ssrc, timestamp,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
return 0;
}
tsdelta =
(int32_t)(timestamp - sstate->last_timestamp) /
(int16_t)(seq - sstate->last_seq);
if (tsdelta == 0) {
/* Don't update *tsdelta_out */
LOGP(DRTP, LOGL_NOTICE,
"The %s timestamp delta is %d "
"on 0x%x SSRC: %u timestamp: %u "
"from %s:%d\n",
text, tsdelta,
ENDPOINT_NUMBER(endp), sstate->ssrc, timestamp,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
return 0;
}
if (sstate->last_tsdelta != tsdelta) {
if (sstate->last_tsdelta) {
LOGP(DRTP, LOGL_INFO,
"The %s timestamp delta changes from %d to %d "
"on 0x%x SSRC: %u timestamp: %u from %s:%d\n",
text, sstate->last_tsdelta, tsdelta,
ENDPOINT_NUMBER(endp), sstate->ssrc, timestamp,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
}
if (tsdelta_out)
*tsdelta_out = tsdelta;
timestamp_error =
ts_alignment_error(sstate, state->packet_duration, timestamp);
if (timestamp_error) {
rate_ctr_inc(sstate->err_ts_ctr);
LOGP(DRTP, LOGL_NOTICE,
"The %s timestamp has an alignment error of %d "
"on 0x%x SSRC: %u "
"SeqNo delta: %d, TS delta: %d, dTS/dSeq: %d "
"from %s:%d. ptime: %d\n",
text, timestamp_error,
ENDPOINT_NUMBER(endp), sstate->ssrc,
(int16_t)(seq - sstate->last_seq),
(int32_t)(timestamp - sstate->last_timestamp),
tsdelta,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port),
state->packet_duration);
}
return 1;
}
/* Set the timestamp offset according to the packet duration. */
static int adjust_rtp_timestamp_offset(struct mgcp_endpoint *endp,
struct mgcp_rtp_state *state,
struct mgcp_rtp_end *rtp_end,
struct sockaddr_in *addr,
int16_t delta_seq, uint32_t in_timestamp)
{
int32_t tsdelta = state->packet_duration;
int timestamp_offset;
uint32_t out_timestamp;
if (tsdelta == 0) {
tsdelta = state->out_stream.last_tsdelta;
if (tsdelta != 0) {
LOGP(DRTP, LOGL_NOTICE,
"A fixed packet duration is not available on 0x%x, "
"using last output timestamp delta instead: %d "
"from %s:%d\n",
ENDPOINT_NUMBER(endp), tsdelta,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
} else {
tsdelta = rtp_end->codec->rate * 20 / 1000;
LOGP(DRTP, LOGL_NOTICE,
"Fixed packet duration and last timestamp delta "
"are not available on 0x%x, "
"using fixed 20ms instead: %d "
"from %s:%d\n",
ENDPOINT_NUMBER(endp), tsdelta,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
}
out_timestamp = state->out_stream.last_timestamp + delta_seq * tsdelta;
timestamp_offset = out_timestamp - in_timestamp;
if (state->patch.timestamp_offset != timestamp_offset) {
state->patch.timestamp_offset = timestamp_offset;
LOGP(DRTP, LOGL_NOTICE,
"Timestamp offset change on 0x%x SSRC: %u "
"SeqNo delta: %d, TS offset: %d, "
"from %s:%d\n",
ENDPOINT_NUMBER(endp), state->in_stream.ssrc,
delta_seq, state->patch.timestamp_offset,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
return timestamp_offset;
}
/* Set the timestamp offset according to the packet duration. */
static int align_rtp_timestamp_offset(struct mgcp_endpoint *endp,
struct mgcp_rtp_state *state,
struct mgcp_rtp_end *rtp_end,
struct sockaddr_in *addr,
uint32_t timestamp)
{
int ts_error = 0;
int ts_check = 0;
int ptime = state->packet_duration;
/* Align according to: T + Toffs - Tlast = k * Tptime */
ts_error = ts_alignment_error(&state->out_stream, ptime,
timestamp + state->patch.timestamp_offset);
/* If there is an alignment error, we have to compensate it */
if (ts_error) {
state->patch.timestamp_offset += ptime - ts_error;
LOGP(DRTP, LOGL_NOTICE,
"Corrected timestamp alignment error of %d on 0x%x SSRC: %u "
"new TS offset: %d, "
"from %s:%d\n",
ts_error,
ENDPOINT_NUMBER(endp), state->in_stream.ssrc,
state->patch.timestamp_offset, inet_ntoa(addr->sin_addr),
ntohs(addr->sin_port));
}
/* Check we really managed to compensate the timestamp
* offset. There should not be any remaining error, failing
* here would point to a serous problem with the alignment
* error computation function */
ts_check = ts_alignment_error(&state->out_stream, ptime,
timestamp + state->patch.timestamp_offset);
OSMO_ASSERT(ts_check == 0);
/* Return alignment error before compensation */
return ts_error;
}
/*! dummy callback to disable transcoding (see also cfg->rtp_processing_cb).
* \param[in] associated endpoint
* \param[in] destination RTP end
* \param[in,out] pointer to buffer with voice data
* \param[in] voice data length
* \param[in] maximum size of caller provided voice data buffer
* \returns ignores input parameters, return always 0 */
int mgcp_rtp_processing_default(struct mgcp_endpoint *endp,
struct mgcp_rtp_end *dst_end,
char *data, int *len, int buf_size)
{
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x transcoding disabled\n",
ENDPOINT_NUMBER(endp));
return 0;
}
/*! dummy callback to disable transcoding (see also cfg->setup_rtp_processing_cb).
* \param[in] associated endpoint
* \param[in] destination RTP connnection
* \param[in] source RTP connection
* \returns ignores input parameters, return always 0 */
int mgcp_setup_rtp_processing_default(struct mgcp_endpoint *endp,
struct mgcp_conn_rtp *conn_dst,
struct mgcp_conn_rtp *conn_src)
{
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x transcoding disabled\n",
ENDPOINT_NUMBER(endp));
return 0;
}
void mgcp_get_net_downlink_format_default(struct mgcp_endpoint *endp,
int *payload_type,
const char **audio_name,
const char **fmtp_extra,
struct mgcp_conn_rtp *conn)
{
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x conn:%s using format defaults\n",
ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn->conn));
*payload_type = conn->end.codec->payload_type;
*audio_name = conn->end.codec->audio_name;
*fmtp_extra = conn->end.fmtp_extra;
}
void mgcp_rtp_annex_count(struct mgcp_endpoint *endp,
struct mgcp_rtp_state *state, const uint16_t seq,
const int32_t transit, const uint32_t ssrc)
{
int32_t d;
/* initialize or re-initialize */
if (!state->stats.initialized || state->stats.ssrc != ssrc) {
state->stats.initialized = 1;
state->stats.base_seq = seq;
state->stats.max_seq = seq - 1;
state->stats.ssrc = ssrc;
state->stats.jitter = 0;
state->stats.transit = transit;
state->stats.cycles = 0;
} else {
uint16_t udelta;
/* The below takes the shape of the validation of
* Appendix A. Check if there is something weird with
* the sequence number, otherwise check for a wrap
* around in the sequence number.
* It can't wrap during the initialization so let's
* skip it here. The Appendix A probably doesn't have
* this issue because of the probation. */
udelta = seq - state->stats.max_seq;
if (udelta < RTP_MAX_DROPOUT) {
if (seq < state->stats.max_seq)
state->stats.cycles += RTP_SEQ_MOD;
} else if (udelta <= RTP_SEQ_MOD - RTP_MAX_MISORDER) {
LOGP(DRTP, LOGL_NOTICE,
"RTP seqno made a very large jump on 0x%x delta: %u\n",
ENDPOINT_NUMBER(endp), udelta);
}
}
/* Calculate the jitter between the two packages. The TS should be
* taken closer to the read function. This was taken from the
* Appendix A of RFC 3550. Timestamp and arrival_time have a 1/rate
* resolution. */
d = transit - state->stats.transit;
state->stats.transit = transit;
if (d < 0)
d = -d;
state->stats.jitter += d - ((state->stats.jitter + 8) >> 4);
state->stats.max_seq = seq;
}
/* The RFC 3550 Appendix A assumes there are multiple sources but
* some of the supported endpoints (e.g. the nanoBTS) can only handle
* one source and this code will patch RTP header to appear as if there
* is only one source.
* There is also no probation period for new sources. Every RTP header
* we receive will be seen as a switch in streams. */
void mgcp_patch_and_count(struct mgcp_endpoint *endp,
struct mgcp_rtp_state *state,
struct mgcp_rtp_end *rtp_end,
struct sockaddr_in *addr, char *data, int len)
{
uint32_t arrival_time;
int32_t transit;
uint16_t seq;
uint32_t timestamp, ssrc;
struct rtp_hdr *rtp_hdr;
int payload = rtp_end->codec->payload_type;
if (len < sizeof(*rtp_hdr))
return;
rtp_hdr = (struct rtp_hdr *)data;
seq = ntohs(rtp_hdr->sequence);
timestamp = ntohl(rtp_hdr->timestamp);
arrival_time = get_current_ts(rtp_end->codec->rate);
ssrc = ntohl(rtp_hdr->ssrc);
transit = arrival_time - timestamp;
mgcp_rtp_annex_count(endp, state, seq, transit, ssrc);
if (!state->initialized) {
state->initialized = 1;
state->in_stream.last_seq = seq - 1;
state->in_stream.ssrc = state->patch.orig_ssrc = ssrc;
state->in_stream.last_tsdelta = 0;
state->packet_duration =
mgcp_rtp_packet_duration(endp, rtp_end);
state->out_stream.last_seq = seq - 1;
state->out_stream.ssrc = state->patch.orig_ssrc = ssrc;
state->out_stream.last_tsdelta = 0;
state->out_stream.last_timestamp = timestamp;
state->out_stream.ssrc = ssrc - 1; /* force output SSRC change */
LOGP(DRTP, LOGL_INFO,
"endpoint:0x%x initializing stream, SSRC: %u timestamp: %u "
"pkt-duration: %d, from %s:%d\n",
ENDPOINT_NUMBER(endp), state->in_stream.ssrc,
state->patch.seq_offset, state->packet_duration,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
if (state->packet_duration == 0) {
state->packet_duration =
rtp_end->codec->rate * 20 / 1000;
LOGP(DRTP, LOGL_NOTICE,
"endpoint:0x%x fixed packet duration is not available, "
"using fixed 20ms instead: %d from %s:%d\n",
ENDPOINT_NUMBER(endp), state->packet_duration,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
} else if (state->in_stream.ssrc != ssrc) {
LOGP(DRTP, LOGL_NOTICE,
"endpoint:0x%x SSRC changed: %u -> %u "
"from %s:%d\n",
ENDPOINT_NUMBER(endp),
state->in_stream.ssrc, rtp_hdr->ssrc,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
state->in_stream.ssrc = ssrc;
if (rtp_end->force_constant_ssrc) {
int16_t delta_seq;
/* Always increment seqno by 1 */
state->patch.seq_offset =
(state->out_stream.last_seq + 1) - seq;
/* Estimate number of packets that would have been sent */
delta_seq =
(arrival_time - state->in_stream.last_arrival_time
+ state->packet_duration / 2) /
state->packet_duration;
adjust_rtp_timestamp_offset(endp, state, rtp_end, addr,
delta_seq, timestamp);
state->patch.patch_ssrc = 1;
ssrc = state->patch.orig_ssrc;
if (rtp_end->force_constant_ssrc != -1)
rtp_end->force_constant_ssrc -= 1;
LOGP(DRTP, LOGL_NOTICE,
"endpoint:0x%x SSRC patching enabled, SSRC: %u "
"SeqNo offset: %d, TS offset: %d "
"from %s:%d\n",
ENDPOINT_NUMBER(endp), state->in_stream.ssrc,
state->patch.seq_offset, state->patch.timestamp_offset,
inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
}
state->in_stream.last_tsdelta = 0;
} else {
/* Compute current per-packet timestamp delta */
check_rtp_timestamp(endp, state, &state->in_stream, rtp_end,
addr, seq, timestamp, "input",
&state->in_stream.last_tsdelta);
if (state->patch.patch_ssrc)
ssrc = state->patch.orig_ssrc;
}
/* Save before patching */
state->in_stream.last_timestamp = timestamp;
state->in_stream.last_seq = seq;
state->in_stream.last_arrival_time = arrival_time;
if (rtp_end->force_aligned_timing &&
state->out_stream.ssrc == ssrc && state->packet_duration)
/* Align the timestamp offset */
align_rtp_timestamp_offset(endp, state, rtp_end, addr,
timestamp);
/* Store the updated SSRC back to the packet */
if (state->patch.patch_ssrc)
rtp_hdr->ssrc = htonl(ssrc);
/* Apply the offset and store it back to the packet.
* This won't change anything if the offset is 0, so the conditional is
* omitted. */
seq += state->patch.seq_offset;
rtp_hdr->sequence = htons(seq);
timestamp += state->patch.timestamp_offset;
rtp_hdr->timestamp = htonl(timestamp);
/* Check again, whether the timestamps are still valid */
if (state->out_stream.ssrc == ssrc)
check_rtp_timestamp(endp, state, &state->out_stream, rtp_end,
addr, seq, timestamp, "output",
&state->out_stream.last_tsdelta);
/* Save output values */
state->out_stream.last_seq = seq;
state->out_stream.last_timestamp = timestamp;
state->out_stream.ssrc = ssrc;
if (payload < 0)
return;
#if 0
DEBUGP(DRTP,
"endpoint:0x%x payload hdr payload %u -> endp payload %u\n",
ENDPOINT_NUMBER(endp), rtp_hdr->payload_type, payload);
rtp_hdr->payload_type = payload;
#endif
}
/* Forward data to a debug tap. This is debug function that is intended for
* debugging the voice traffic with tools like gstreamer */
static void forward_data(int fd, struct mgcp_rtp_tap *tap, const char *buf,
int len)
{
int rc;
if (!tap->enabled)
return;
rc = sendto(fd, buf, len, 0, (struct sockaddr *)&tap->forward,
sizeof(tap->forward));
if (rc < 0)
LOGP(DRTP, LOGL_ERROR,
"Forwarding tapped (debug) voice data failed.\n");
}
/*! Send RTP/RTCP data to a specified destination connection.
* \param[in] endp associated endpoint (for configuration, logging)
* \param[in] is_rtp flag to specify if the packet is of type RTP or RTCP
* \param[in] spoofed source address (set to NULL to disable)
* \param[in] buf buffer that contains the RTP/RTCP data
* \param[in] len length of the buffer that contains the RTP/RTCP data
* \param[in] conn_src associated source connection
* \param[in] conn_dst associated destination connection
* \returns 0 on success, -1 on ERROR */
int mgcp_send(struct mgcp_endpoint *endp, int is_rtp, struct sockaddr_in *addr,
char *buf, int len, struct mgcp_conn_rtp *conn_src,
struct mgcp_conn_rtp *conn_dst)
{
/*! When no destination connection is available (e.g. when only one
* connection in loopback mode exists), then the source connection
* shall be specified as destination connection */
struct mgcp_trunk_config *tcfg = endp->tcfg;
struct mgcp_rtp_end *rtp_end;
struct mgcp_rtp_state *rtp_state;
char *dest_name;
OSMO_ASSERT(conn_src);
OSMO_ASSERT(conn_dst);
if (is_rtp) {
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x delivering RTP packet...\n",
ENDPOINT_NUMBER(endp));
} else {
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x delivering RTCP packet...\n",
ENDPOINT_NUMBER(endp));
}
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x loop:%d, mode:%d%s\n",
ENDPOINT_NUMBER(endp), tcfg->audio_loop, conn_src->conn->mode,
conn_src->conn->mode == MGCP_CONN_LOOPBACK ? " (loopback)" : "");
/* Note: In case of loopback configuration, both, the source and the
* destination will point to the same connection. */
rtp_end = &conn_dst->end;
rtp_state = &conn_src->state;
dest_name = conn_dst->conn->name;
if (!rtp_end->output_enabled) {
rate_ctr_inc(&conn_dst->rate_ctr_group->ctr[RTP_DROPPED_PACKETS_CTR]);
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x output disabled, drop to %s %s "
"rtp_port:%u rtcp_port:%u\n",
ENDPOINT_NUMBER(endp),
dest_name,
inet_ntoa(rtp_end->addr),
ntohs(rtp_end->rtp_port), ntohs(rtp_end->rtcp_port)
);
} else if (is_rtp) {
int cont;
int nbytes = 0;
int buflen = len;
do {
/* Run transcoder */
cont = endp->cfg->rtp_processing_cb(endp, rtp_end,
buf, &buflen,
RTP_BUF_SIZE);
if (cont < 0)
break;
if (addr)
mgcp_patch_and_count(endp, rtp_state, rtp_end,
addr, buf, buflen);
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x process/send to %s %s "
"rtp_port:%u rtcp_port:%u\n",
ENDPOINT_NUMBER(endp), dest_name,
inet_ntoa(rtp_end->addr), ntohs(rtp_end->rtp_port),
ntohs(rtp_end->rtcp_port)
);
/* Forward a copy of the RTP data to a debug ip/port */
forward_data(rtp_end->rtp.fd, &conn_src->tap_out,
buf, buflen);
/* FIXME: HACK HACK HACK. See OS#2459.
* The ip.access nano3G needs the first RTP payload's first two bytes to read hex
* 'e400', or it will reject the RAB assignment. It seems to not harm other femto
* cells (as long as we patch only the first RTP payload in each stream).
*/
if (!rtp_state->patched_first_rtp_payload
&& conn_src->conn->mode == MGCP_CONN_LOOPBACK) {
uint8_t *data = (uint8_t *) & buf[12];
if (data[0] == 0xe0) {
data[0] = 0xe4;
data[1] = 0x00;
rtp_state->patched_first_rtp_payload = true;
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x Patching over first two bytes"
" to fake an IuUP Initialization Ack\n",
ENDPOINT_NUMBER(endp));
}
}
len = mgcp_udp_send(rtp_end->rtp.fd,
&rtp_end->addr,
rtp_end->rtp_port, buf, buflen);
if (len <= 0)
return len;
rate_ctr_inc(&conn_dst->rate_ctr_group->ctr[RTP_PACKETS_TX_CTR]);
rate_ctr_add(&conn_dst->rate_ctr_group->ctr[RTP_OCTETS_TX_CTR], len);
nbytes += len;
buflen = cont;
} while (buflen > 0);
return nbytes;
} else if (!tcfg->omit_rtcp) {
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x send to %s %s rtp_port:%u rtcp_port:%u\n",
ENDPOINT_NUMBER(endp),
dest_name,
inet_ntoa(rtp_end->addr),
ntohs(rtp_end->rtp_port), ntohs(rtp_end->rtcp_port)
);
len = mgcp_udp_send(rtp_end->rtcp.fd,
&rtp_end->addr,
rtp_end->rtcp_port, buf, len);
rate_ctr_inc(&conn_dst->rate_ctr_group->ctr[RTP_PACKETS_TX_CTR]);
rate_ctr_add(&conn_dst->rate_ctr_group->ctr[RTP_OCTETS_TX_CTR], len);
return len;
}
return 0;
}
/* Helper function for mgcp_recv(),
Receive one RTP Packet + Originating address from file descriptor */
static int receive_from(struct mgcp_endpoint *endp, int fd,
struct sockaddr_in *addr, char *buf, int bufsize)
{
int rc;
socklen_t slen = sizeof(*addr);
struct sockaddr_in addr_sink;
char buf_sink[RTP_BUF_SIZE];
bool tossed = false;
if (!addr)
addr = &addr_sink;
if (!buf) {
tossed = true;
buf = buf_sink;
bufsize = sizeof(buf_sink);
}
rc = recvfrom(fd, buf, bufsize, 0, (struct sockaddr *)addr, &slen);
LOGP(DRTP, LOGL_DEBUG,
"receiving %u bytes length packet from %s:%u ...\n",
rc, inet_ntoa(addr->sin_addr), ntohs(addr->sin_port));
if (rc < 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x failed to receive packet, errno: %d/%s\n",
ENDPOINT_NUMBER(endp), errno, strerror(errno));
return -1;
}
if (tossed) {
LOGP(DRTP, LOGL_ERROR, "endpoint:0x%x packet tossed\n",
ENDPOINT_NUMBER(endp));
}
return rc;
}
/* Check if the origin (addr) matches the address/port data of the RTP
* connections. */
static int check_rtp_origin(struct mgcp_conn_rtp *conn,
struct sockaddr_in *addr)
{
struct mgcp_endpoint *endp;
endp = conn->conn->endp;
/* Note: Check if the inbound RTP data comes from the same host to
* which we send our outgoing RTP traffic. */
if (memcmp(&addr->sin_addr, &conn->end.addr, sizeof(addr->sin_addr))
!= 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x data from wrong address: %s, ",
ENDPOINT_NUMBER(endp), inet_ntoa(addr->sin_addr));
LOGPC(DRTP, LOGL_ERROR, "expected: %s\n",
inet_ntoa(conn->end.addr));
LOGP(DRTP, LOGL_ERROR, "endpoint:0x%x packet tossed\n",
ENDPOINT_NUMBER(endp));
return -1;
}
/* Note: Usually the remote remote port of the data we receive will be
* the same as the remote port where we transmit outgoing RTP traffic
* to (set by MDCX). We use this to check the origin of the data for
* plausibility. */
if (conn->end.rtp_port != addr->sin_port &&
conn->end.rtcp_port != addr->sin_port) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x data from wrong source port: %d, ",
ENDPOINT_NUMBER(endp), ntohs(addr->sin_port));
LOGPC(DRTP, LOGL_ERROR,
"expected: %d for RTP or %d for RTCP\n",
ntohs(conn->end.rtp_port), ntohs(conn->end.rtcp_port));
LOGP(DRTP, LOGL_ERROR, "endpoint:0x%x packet tossed\n",
ENDPOINT_NUMBER(endp));
return -1;
}
return 0;
}
/* Check the if the destination address configuration of an RTP connection
* makes sense */
static int check_rtp_destin(struct mgcp_conn_rtp *conn)
{
struct mgcp_endpoint *endp;
endp = conn->conn->endp;
/* Note: it is legal to create a connection but never setting a port
* and IP-address for outgoing data. */
if (strcmp(inet_ntoa(conn->end.addr), "0.0.0.0") == 0 && conn->end.rtp_port == 0) {
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x destination IP-address and rtp port is (not yet) known\n",
ENDPOINT_NUMBER(endp));
return -1;
}
if (strcmp(inet_ntoa(conn->end.addr), "0.0.0.0") == 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x destination IP-address is invalid\n",
ENDPOINT_NUMBER(endp));
return -1;
}
if (conn->end.rtp_port == 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x destination rtp port is invalid\n",
ENDPOINT_NUMBER(endp));
return -1;
}
return 0;
}
/* Receive RTP data from a specified source connection and dispatch it to a
* destination connection. */
static int mgcp_recv(int *proto, struct sockaddr_in *addr, char *buf,
unsigned int buf_size, struct osmo_fd *fd)
{
struct mgcp_endpoint *endp;
struct mgcp_conn_rtp *conn;
struct mgcp_trunk_config *tcfg;
int rc;
conn = (struct mgcp_conn_rtp*) fd->data;
endp = conn->conn->endp;
tcfg = endp->tcfg;
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x receiving RTP/RTCP packet...\n",
ENDPOINT_NUMBER(endp));
rc = receive_from(endp, fd->fd, addr, buf, buf_size);
if (rc <= 0)
return -1;
*proto = fd == &conn->end.rtp ? MGCP_PROTO_RTP : MGCP_PROTO_RTCP;
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x ", ENDPOINT_NUMBER(endp));
LOGPC(DRTP, LOGL_DEBUG, "receiving from %s %s %d\n",
conn->conn->name, inet_ntoa(addr->sin_addr),
ntohs(addr->sin_port));
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x conn:%s\n", ENDPOINT_NUMBER(endp),
mgcp_conn_dump(conn->conn));
/* Check if the origin of the RTP packet seems plausible */
if (tcfg->rtp_accept_all == 0) {
if (check_rtp_origin(conn, addr) != 0)
return -1;
}
/* Filter out dummy message */
if (rc == 1 && buf[0] == MGCP_DUMMY_LOAD) {
LOGP(DRTP, LOGL_NOTICE,
"endpoint:0x%x dummy message received\n",
ENDPOINT_NUMBER(endp));
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x packet tossed\n", ENDPOINT_NUMBER(endp));
return 0;
}
/* Increment RX statistics */
rate_ctr_inc(&conn->rate_ctr_group->ctr[RTP_PACKETS_RX_CTR]);
rate_ctr_add(&conn->rate_ctr_group->ctr[RTP_OCTETS_RX_CTR], rc);
/* Forward a copy of the RTP data to a debug ip/port */
forward_data(fd->fd, &conn->tap_in, buf, rc);
return rc;
}
/* Send RTP data. Possible options are standard RTP packet
* transmission or trsmission via an osmux connection */
static int mgcp_send_rtp(int proto, struct sockaddr_in *addr, char *buf,
unsigned int buf_size,
struct mgcp_conn_rtp *conn_src,
struct mgcp_conn_rtp *conn_dst)
{
struct mgcp_endpoint *endp;
endp = conn_src->conn->endp;
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x destin conn:%s\n",
ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn_dst->conn));
/* Before we try to deliver the packet, we check if the destination
* port and IP-Address make sense at all. If not, we will be unable
* to deliver the packet. */
if (check_rtp_destin(conn_dst) != 0)
return -1;
/* Depending on the RTP connection type, deliver the RTP packet to the
* destination connection. */
switch (conn_dst->type) {
case MGCP_RTP_DEFAULT:
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x endpoint type is MGCP_RTP_DEFAULT, "
"using mgcp_send() to forward data directly\n",
ENDPOINT_NUMBER(endp));
return mgcp_send(endp, proto == MGCP_PROTO_RTP,
addr, buf, buf_size, conn_src, conn_dst);
case MGCP_OSMUX_BSC_NAT:
case MGCP_OSMUX_BSC:
LOGP(DRTP, LOGL_DEBUG,
"endpoint:0x%x endpoint type is MGCP_OSMUX_BSC_NAT, "
"using osmux_xfrm_to_osmux() to forward data through OSMUX\n",
ENDPOINT_NUMBER(endp));
return osmux_xfrm_to_osmux(buf, buf_size, conn_dst);
}
/* If the data has not been handled/forwarded until here, it will
* be discarded, this should not happen, normally the MGCP type
* should be properly set */
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x bad MGCP type -- data discarded!\n",
ENDPOINT_NUMBER(endp));
return -1;
}
/*! dispatch incoming RTP packet to opposite RTP connection.
* \param[in] proto protocol (MGCP_CONN_TYPE_RTP or MGCP_CONN_TYPE_RTCP)
* \param[in] addr socket address where the RTP packet has been received from
* \param[in] buf buffer that hold the RTP payload
* \param[in] buf_size size data length of buf
* \param[in] conn originating connection
* \returns 0 on success, -1 on ERROR */
int mgcp_dispatch_rtp_bridge_cb(int proto, struct sockaddr_in *addr, char *buf,
unsigned int buf_size, struct mgcp_conn *conn)
{
struct mgcp_conn *conn_dst;
struct mgcp_endpoint *endp;
endp = conn->endp;
/*! NOTE: This callback function implements the endpoint specific
* dispatch bahviour of an rtp bridge/proxy endpoint. It is assumed
* that the endpoint will hold only two connections. This premise
* is used to determine the opposite connection (it is always the
* connection that is not the originating connection). Once the
* destination connection is known the RTP packet is sent via
* the destination connection. */
/* Find a destination connection. */
/* NOTE: This code path runs every time an RTP packet is received. The
* function mgcp_find_dst_conn() we use to determine the detination
* connection will iterate the connection list inside the endpoint.
* Since list iterations are quite costly, we will figure out the
* destination only once and use the optional private data pointer of
* the connection to cache the destination connection pointer. */
if (!conn->priv) {
conn_dst = mgcp_find_dst_conn(conn);
conn->priv = conn_dst;
} else {
conn_dst = (struct mgcp_conn *)conn->priv;
}
/* There is no destination conn, stop here */
if (!conn_dst) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x unable to find destination conn\n",
ENDPOINT_NUMBER(endp));
return -1;
}
/* The destination conn is not an RTP connection */
if (conn_dst->type != MGCP_CONN_TYPE_RTP) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x unable to find suitable destination conn\n",
ENDPOINT_NUMBER(endp));
return -1;
}
/* Dispatch RTP packet to destination RTP connection */
return mgcp_send_rtp(proto, addr, buf,
buf_size, &conn->u.rtp, &conn_dst->u.rtp);
}
/*! cleanup an endpoint when a connection on an RTP bridge endpoint is removed.
* \param[in] endp Endpoint on which the connection resides.
* \param[in] conn Connection that is about to be removed (ignored).
* \returns 0 on success, -1 on ERROR. */
void mgcp_cleanup_rtp_bridge_cb(struct mgcp_endpoint *endp, struct mgcp_conn *conn)
{
struct mgcp_conn *conn_cleanup;
/* In mgcp_dispatch_rtp_bridge_cb() we use conn->priv to cache the
* pointer to the destination connection, so that we do not have
* to go through the list every time an RTP packet arrives. To prevent
* a use-after-free situation we invalidate this information for all
* connections present when one connection is removed from the
* endpoint. */
llist_for_each_entry(conn_cleanup, &endp->conns, entry) {
conn_cleanup->priv = NULL;
}
}
/* Handle incoming RTP data from NET */
static int rtp_data_net(struct osmo_fd *fd, unsigned int what)
{
/* NOTE: This is a generic implementation. RTP data is received. In
* case of loopback the data is just sent back to its origin. All
* other cases implement endpoint specific behaviour (e.g. how is the
* destination connection determined?). That specific behaviour is
* implemented by the callback function that is called at the end of
* the function */
struct mgcp_conn_rtp *conn_src;
struct mgcp_endpoint *endp;
struct sockaddr_in addr;
char buf[RTP_BUF_SIZE];
int proto;
int len;
conn_src = (struct mgcp_conn_rtp *)fd->data;
OSMO_ASSERT(conn_src);
endp = conn_src->conn->endp;
OSMO_ASSERT(endp);
LOGP(DRTP, LOGL_DEBUG, "endpoint:0x%x source conn:%s\n",
ENDPOINT_NUMBER(endp), mgcp_conn_dump(conn_src->conn));
/* Receive packet */
len = mgcp_recv(&proto, &addr, buf, sizeof(buf), fd);
if (len < 0)
return -1;
/* Check if the connection is in loopback mode, if yes, just send the
* incoming data back to the origin */
if (conn_src->conn->mode == MGCP_CONN_LOOPBACK) {
/* When we are in loopback mode, we loop back all incoming
* packets back to their origin. We will use the originating
* address data from the UDP packet header to patch the
* outgoing address in connection on the fly */
if (conn_src->end.rtp_port == 0) {
conn_src->end.addr = addr.sin_addr;
conn_src->end.rtp_port = addr.sin_port;
}
return mgcp_send_rtp(proto, &addr, buf,
len, conn_src, conn_src);
}
/* Execute endpoint specific implementation that handles the
* dispatching of the RTP data */
return endp->type->dispatch_rtp_cb(proto, &addr, buf, len,
conn_src->conn);
}
/*! set IP Type of Service parameter.
* \param[in] fd associated file descriptor
* \param[in] tos dscp value
* \returns 0 on success, -1 on ERROR */
int mgcp_set_ip_tos(int fd, int tos)
{
int ret;
ret = setsockopt(fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
if (ret < 0)
return -1;
return 0;
}
/*! bind RTP port to osmo_fd.
* \param[in] source_addr source (local) address to bind on
* \param[in] fd associated file descriptor
* \param[in] port to bind on
* \returns 0 on success, -1 on ERROR */
int mgcp_create_bind(const char *source_addr, struct osmo_fd *fd, int port)
{
int rc;
rc = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP, source_addr, port,
NULL, 0, OSMO_SOCK_F_BIND);
if (rc < 0) {
LOGP(DRTP, LOGL_ERROR, "failed to bind UDP port (%s:%i).\n",
source_addr, port);
return -1;
}
fd->fd = rc;
LOGP(DRTP, LOGL_DEBUG, "created socket + bound UDP port (%s:%i).\n", source_addr, port);
return 0;
}
/* Bind RTP and RTCP port (helper function for mgcp_bind_net_rtp_port()) */
static int bind_rtp(struct mgcp_config *cfg, const char *source_addr,
struct mgcp_rtp_end *rtp_end, int endpno)
{
/* NOTE: The port that is used for RTCP is the RTP port incremented by one
* (e.g. RTP-Port = 16000 ==> RTCP-Port = 16001) */
if (mgcp_create_bind(source_addr, &rtp_end->rtp,
rtp_end->local_port) != 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x failed to create RTP port: %s:%d\n", endpno,
source_addr, rtp_end->local_port);
goto cleanup0;
}
if (mgcp_create_bind(source_addr, &rtp_end->rtcp,
rtp_end->local_port + 1) != 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x failed to create RTCP port: %s:%d\n", endpno,
source_addr, rtp_end->local_port + 1);
goto cleanup1;
}
/* Set Type of Service (DSCP-Value) as configured via VTY */
mgcp_set_ip_tos(rtp_end->rtp.fd, cfg->endp_dscp);
mgcp_set_ip_tos(rtp_end->rtcp.fd, cfg->endp_dscp);
rtp_end->rtp.when = BSC_FD_READ;
if (osmo_fd_register(&rtp_end->rtp) != 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x failed to register RTP port %d\n", endpno,
rtp_end->local_port);
goto cleanup2;
}
rtp_end->rtcp.when = BSC_FD_READ;
if (osmo_fd_register(&rtp_end->rtcp) != 0) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x failed to register RTCP port %d\n", endpno,
rtp_end->local_port + 1);
goto cleanup3;
}
return 0;
cleanup3:
osmo_fd_unregister(&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;
}
/*! bind RTP port to endpoint/connection.
* \param[in] endp endpoint that holds the RTP connection
* \param[in] rtp_port port number to bind on
* \param[in] conn associated RTP connection
* \returns 0 on success, -1 on ERROR */
int mgcp_bind_net_rtp_port(struct mgcp_endpoint *endp, int rtp_port,
struct mgcp_conn_rtp *conn)
{
char name[512];
struct mgcp_rtp_end *end;
char local_ip_addr[INET_ADDRSTRLEN];
snprintf(name, sizeof(name), "%s-%s", conn->conn->name, conn->conn->id);
end = &conn->end;
if (end->rtp.fd != -1 || end->rtcp.fd != -1) {
LOGP(DRTP, LOGL_ERROR,
"endpoint:0x%x %u was already bound on conn:%s\n",
ENDPOINT_NUMBER(endp), rtp_port,
mgcp_conn_dump(conn->conn));
/* Double bindings should never occour! Since we always allocate
* connections dynamically and free them when they are not
* needed anymore, there must be no previous binding leftover.
* Should there be a connection bound twice, we have a serious
* problem and must exit immediately! */
OSMO_ASSERT(false);
}
end->local_port = rtp_port;
end->rtp.cb = rtp_data_net;
end->rtp.data = conn;
end->rtcp.data = conn;
end->rtcp.cb = rtp_data_net;
mgcp_get_local_addr(local_ip_addr, conn);
return bind_rtp(endp->cfg, local_ip_addr, end,
ENDPOINT_NUMBER(endp));
}
/*! free allocated RTP and RTCP ports.
* \param[in] end RTP end */
void mgcp_free_rtp_port(struct mgcp_rtp_end *end)
{
if (end->rtp.fd != -1) {
close(end->rtp.fd);
end->rtp.fd = -1;
osmo_fd_unregister(&end->rtp);
}
if (end->rtcp.fd != -1) {
close(end->rtcp.fd);
end->rtcp.fd = -1;
osmo_fd_unregister(&end->rtcp);
}
}
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