add RTP support
This patch adds the initial RTP support for libosmo-netif, it's based on Harald's RTP support available in openBSC. I have also added a couple of example to show how our new channel infrastructure interacts with the RTP layer. Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
This commit is contained in:
Pablo Neira Ayuso
Pablo Neira Ayuso
parent
2b5d3ce7c6
commit
72cd95b352
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@ -31,6 +31,8 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([char foo;])],
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CFLAGS="$saved_CFLAGS"
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AC_SUBST(SYMBOL_VISIBILITY)
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AC_CHECK_HEADER([endian.h], [], [AC_MSG_ERROR([endian.h not found!]) ])
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dnl Generate the output
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AM_CONFIG_HEADER(config.h)
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@ -9,7 +9,9 @@ noinst_PROGRAMS = ipa-stream-client \
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lapd-over-datagram-user \
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lapd-over-datagram-network \
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stream-client \
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stream-server
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stream-server \
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rtp-udp-test-client \
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rtp-udp-test-server
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ipa_stream_client_SOURCES = ipa-stream-client.c
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ipa_stream_client_LDADD = $(top_builddir)/src/libosmonetif.la \
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@ -36,3 +38,11 @@ stream_client_LDADD = $(top_builddir)/src/libosmonetif.la \
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stream_server_SOURCES = stream-server.c
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stream_server_LDADD = $(top_builddir)/src/libosmonetif.la \
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$(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS)
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rtp_udp_test_client_SOURCES = rtp-udp-test-client.c
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rtp_udp_test_client_LDADD = $(top_builddir)/src/libosmonetif.la \
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$(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS)
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rtp_udp_test_server_SOURCES = rtp-udp-test-server.c
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rtp_udp_test_server_LDADD = $(top_builddir)/src/libosmonetif.la \
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$(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS)
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@ -0,0 +1,143 @@
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <signal.h>
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#include <unistd.h>
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#include <arpa/inet.h>
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#include <time.h>
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#include <osmocom/core/linuxlist.h>
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#include <osmocom/core/talloc.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/application.h>
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#include <osmocom/core/select.h>
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#include <osmocom/netif/rtp.h>
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#include <osmocom/netif/datagram.h>
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#define DRTP_TEST 0
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struct log_info_cat rtp_test_cat[] = {
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[DRTP_TEST] = {
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.name = "DRTP_TEST",
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.description = "RTP client test",
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.color = "\033[1;35m",
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.enabled = 1, .loglevel = LOGL_DEBUG,
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},
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};
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const struct log_info rtp_test_log_info = {
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.filter_fn = NULL,
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.cat = rtp_test_cat,
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.num_cat = ARRAY_SIZE(rtp_test_cat),
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};
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static struct osmo_dgram_conn *conn;
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static struct osmo_rtp_handle *rtp;
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static int read_cb(struct osmo_dgram_conn *conn)
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{
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struct msgb *msg;
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int payload_type;
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LOGP(DLINP, LOGL_DEBUG, "received message\n");
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msg = msgb_alloc(RTP_MSGB_SIZE, "RTP/test");
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if (msg == NULL) {
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot allocate message\n");
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return -1;
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}
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if (osmo_dgram_conn_recv(conn, msg) < 0) {
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msgb_free(msg);
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot receive message\n");
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return -1;
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}
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payload_type = osmo_rtp_parse(rtp, msg);
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if (payload_type < 0) {
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msgb_free(msg);
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot parse RTP message\n");
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return -1;
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}
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LOGP(DLINP, LOGL_DEBUG, "received message with RTP payload type: %d\n",
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payload_type);
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msgb_free(msg);
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return 0;
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}
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void sighandler(int foo)
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{
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LOGP(DLINP, LOGL_NOTICE, "closing RTP.\n");
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osmo_dgram_conn_close(conn);
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osmo_dgram_conn_destroy(conn);
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osmo_rtp_handle_free(rtp);
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exit(EXIT_SUCCESS);
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}
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static void *tall_test;
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int main(int argc, char *argv[])
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{
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int i;
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char dummy_data[RTP_PT_GSM_FULL_PAYLOAD_LEN] = {};
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signal(SIGINT, sighandler);
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tall_test = talloc_named_const(NULL, 1, "rtp_test");
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osmo_init_logging(&rtp_test_log_info);
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log_set_log_level(osmo_stderr_target, LOGL_DEBUG);
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/*
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* initialize RTP stuff.
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*/
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rtp = osmo_rtp_handle_create(tall_test);
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if (rtp == NULL) {
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LOGP(DLINP, LOGL_ERROR, "creating RTP handler\n");
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exit(EXIT_FAILURE);
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}
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osmo_rtp_handle_tx_set_sequence(rtp, random());
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osmo_rtp_handle_tx_set_ssrc(rtp, random());
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osmo_rtp_handle_tx_set_timestamp(rtp, time(NULL));
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/*
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* initialize datagram socket.
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*/
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conn = osmo_dgram_conn_create(tall_test);
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if (conn == NULL) {
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fprintf(stderr, "cannot create client\n");
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exit(EXIT_FAILURE);
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}
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osmo_dgram_conn_set_local_addr(conn, "127.0.0.1");
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osmo_dgram_conn_set_local_port(conn, 20001);
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osmo_dgram_conn_set_remote_addr(conn, "127.0.0.1");
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osmo_dgram_conn_set_remote_port(conn, 20000);
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osmo_dgram_conn_set_read_cb(conn, read_cb);
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if (osmo_dgram_conn_open(conn) < 0) {
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fprintf(stderr, "cannot open client\n");
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exit(EXIT_FAILURE);
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}
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for(i=0; i<10; i++) {
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struct msgb *msg;
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msg = osmo_rtp_build(rtp, RTP_PT_GSM_FULL,
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RTP_PT_GSM_FULL_PAYLOAD_LEN,
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dummy_data, RTP_PT_GSM_FULL_DURATION);
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if (msg == NULL) {
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LOGP(DLINP, LOGL_ERROR, "OOM\n");
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continue;
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}
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osmo_dgram_conn_send(conn, msg);
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}
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LOGP(DLINP, LOGL_NOTICE, "Entering main loop\n");
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while(1) {
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osmo_select_main(0);
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}
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}
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@ -0,0 +1,145 @@
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <signal.h>
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#include <unistd.h>
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#include <osmocom/core/talloc.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/application.h>
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#include <osmocom/core/select.h>
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#include <osmocom/netif/rtp.h>
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#include <osmocom/netif/datagram.h>
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#define DRTP_TEST 0
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struct log_info_cat rtp_test_cat[] = {
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[DRTP_TEST] = {
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.name = "DRTP_TEST",
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.description = "RPT-server test",
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.color = "\033[1;35m",
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.enabled = 1, .loglevel = LOGL_DEBUG,
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},
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};
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const struct log_info rtp_test_log_info = {
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.filter_fn = NULL,
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.cat = rtp_test_cat,
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.num_cat = ARRAY_SIZE(rtp_test_cat),
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};
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static struct osmo_dgram_conn *conn;
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static struct osmo_rtp_handle *rtp;
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int read_cb(struct osmo_dgram_conn *conn)
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{
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struct msgb *msg;
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char dummy_data[RTP_PT_GSM_FULL_PAYLOAD_LEN] = {};
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int payload_type;
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LOGP(DRTP_TEST, LOGL_DEBUG, "received message from datagram\n");
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msg = msgb_alloc(RTP_MSGB_SIZE, "RTP/test");
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if (msg == NULL) {
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot allocate message\n");
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return -1;
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}
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if (osmo_dgram_conn_recv(conn, msg) < 0) {
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot receive message\n");
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return -1;
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}
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payload_type = osmo_rtp_parse(rtp, msg);
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if (payload_type < 0) {
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msgb_free(msg);
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot parse RTP message\n");
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return -1;
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}
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LOGP(DLINP, LOGL_DEBUG, "received message with payload type: %d\n",
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payload_type);
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/*
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* ... now build gsm_data_frame, set callref and msg_type based
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* on the rtp payload type (map RTP_PT_GSM_FULL to GSM_THCF_FRAME).
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* Then, pass it to the RSL layer.
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*/
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msg = msgb_alloc(1200, "RTP/test");
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if (msg == NULL) {
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot allocate message\n");
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return -1;
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}
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/* build reply. */
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msg = osmo_rtp_build(rtp, RTP_PT_GSM_FULL,
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RTP_PT_GSM_FULL_PAYLOAD_LEN,
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dummy_data, RTP_PT_GSM_FULL_DURATION);
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if (msg == NULL) {
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LOGP(DLINP, LOGL_ERROR, "OOM\n");
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return -1;
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}
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osmo_dgram_conn_send(conn, msg);
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return 0;
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}
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void sighandler(int foo)
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{
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LOGP(DLINP, LOGL_NOTICE, "closing RTP.\n");
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osmo_dgram_conn_close(conn);
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osmo_dgram_conn_destroy(conn);
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osmo_rtp_handle_free(rtp);
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exit(EXIT_SUCCESS);
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}
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static void *tall_test;
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int main(int argc, char *argv[])
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{
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signal(SIGINT, sighandler);
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tall_test = talloc_named_const(NULL, 1, "udp_rtp_test");
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osmo_init_logging(&rtp_test_log_info);
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log_set_log_level(osmo_stderr_target, LOGL_DEBUG);
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/*
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* initialize RTP handler.
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*/
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rtp = osmo_rtp_handle_create(tall_test);
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if (rtp == NULL) {
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LOGP(DRTP_TEST, LOGL_ERROR, "Error init RTP handler\n");
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exit(EXIT_FAILURE);
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}
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osmo_rtp_handle_tx_set_sequence(rtp, random());
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osmo_rtp_handle_tx_set_ssrc(rtp, random());
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osmo_rtp_handle_tx_set_timestamp(rtp, time(NULL));
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/*
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* initialize datagram server.
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*/
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conn = osmo_dgram_conn_create(tall_test);
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if (conn == NULL) {
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LOGP(DRTP_TEST, LOGL_ERROR, "cannot create UDP socket\n");
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exit(EXIT_FAILURE);
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}
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osmo_dgram_conn_set_local_addr(conn, "127.0.0.1");
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osmo_dgram_conn_set_local_port(conn, 20000);
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osmo_dgram_conn_set_remote_addr(conn, "127.0.0.1");
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osmo_dgram_conn_set_remote_port(conn, 20001);
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osmo_dgram_conn_set_read_cb(conn, read_cb);
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if (osmo_dgram_conn_open(conn) < 0) {
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fprintf(stderr, "cannot open client\n");
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exit(EXIT_FAILURE);
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}
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LOGP(DRTP_TEST, LOGL_NOTICE, "Entering main loop\n");
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while(1) {
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osmo_select_main(0);
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}
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}
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@ -3,6 +3,7 @@ SUBDIRS = channel
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osmonetif_HEADERS = channel.h \
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datagram.h \
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ipa.h \
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rtp.h \
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stream.h
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osmonetifdir = $(includedir)/osmocom/netif
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@ -0,0 +1,27 @@
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#ifndef _OSMO_RTP_H_
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#define _OSMO_RTP_H_
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/* XXX: RFC specifies that MTU should used, add generic function to obtain
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existing MTU. */
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#define RTP_MSGB_SIZE 1500
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struct osmo_rtp_handle *osmo_rtp_handle_create(void *ctx);
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void osmo_rtp_handle_free(struct osmo_rtp_handle *h);
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int osmo_rtp_handle_tx_set_sequence(struct osmo_rtp_handle *h, uint16_t seq);
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int osmo_rtp_handle_tx_set_ssrc(struct osmo_rtp_handle *h, uint32_t ssrc);
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int osmo_rtp_handle_tx_set_timestamp(struct osmo_rtp_handle *h, uint32_t timestamp);
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int osmo_rtp_parse(struct osmo_rtp_handle *h, struct msgb *msg);
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struct msgb *osmo_rtp_build(struct osmo_rtp_handle *h, uint8_t payload_type, uint32_t payload_len, const void *data, uint32_t duration);
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/* supported RTP payload types. */
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#define RTP_PT_GSM_FULL 3
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#define RTP_PT_GSM_FULL_PAYLOAD_LEN 33
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#define RTP_PT_GSM_FULL_DURATION 160 /* in samples. */
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#define RTP_PT_GSM_EFR 97
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#define RTP_PT_GSM_EFR_PAYLOAD_LEN 31
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#define RTP_PT_GSM_EFR_DURATION 160 /* in samples. */
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#endif
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@ -15,4 +15,5 @@ libosmonetif_la_LIBADD = channel/libosmonetif-channel.la
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libosmonetif_la_SOURCES = channel.c \
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datagram.c \
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ipa.c \
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rtp.c \
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stream.c
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@ -0,0 +1,231 @@
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#include <stdint.h>
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#include <sys/time.h>
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#include <endian.h>
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#include <errno.h>
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#include <string.h> /* for memcpy. */
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#include <arpa/inet.h> /* for ntohs. */
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#include <osmocom/core/talloc.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/netif/rtp.h>
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/*
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* Definitions in RFC 3550.
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*/
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/* RTP header. */
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struct rtp_hdr {
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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uint8_t csrc_count:4,
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extension:1,
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padding:1,
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version:2;
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uint8_t payload_type:7,
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marker:1;
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#elif __BYTE_ORDER == __BIG_ENDIAN
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uint8_t version:2,
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padding:1,
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extension:1,
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csrc_count:4;
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uint8_t marker:1,
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payload_type:7;
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#endif
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uint16_t sequence;
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uint32_t timestamp;
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uint32_t ssrc;
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} __attribute__((packed));
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#define RTP_VERSION 2
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/* 5.3.1 RTP Header Extension
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*
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* If the X bit in the RTP header is one, a variable-length header
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* extension MUST be appended to the RTP header, following the CSRC list
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* if present. The header extension contains a 16-bit length field that
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* counts the number of 32-bit words in the extension, excluding the
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* four-octet extension header (therefore zero is a valid length). Only
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* a single extension can be appended to the RTP data header.
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*/
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struct rtp_x_hdr {
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uint16_t by_profile;
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uint16_t length;
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} __attribute__((packed));
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/* RTPC header. */
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struct rtcp_hdr {
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uint8_t byte0;
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uint8_t type;
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uint16_t length;
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} __attribute__((packed));
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/*
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* Internal definitions for this implementation.
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*/
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struct osmo_rtp_handle {
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struct {
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uint16_t sequence;
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uint32_t timestamp;
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uint32_t ssrc;
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struct timeval last_tv;
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} tx;
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};
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struct osmo_rtp_handle *osmo_rtp_handle_create(void *ctx)
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{
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struct osmo_rtp_handle *h;
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|
||||
h = talloc_zero(ctx, struct osmo_rtp_handle);
|
||||
if (h == NULL) {
|
||||
LOGP(DLMUX, LOGL_ERROR, "OOM\n");
|
||||
return NULL;
|
||||
}
|
||||
return h;
|
||||
}
|
||||
|
||||
void osmo_rtp_handle_free(struct osmo_rtp_handle *h)
|
||||
{
|
||||
DEBUGP(DLMUX, "%s (h=%p)\n", __FUNCTION__, h);
|
||||
|
||||
talloc_free(h);
|
||||
}
|
||||
|
||||
int osmo_rtp_handle_tx_set_sequence(struct osmo_rtp_handle *h, uint16_t seq)
|
||||
{
|
||||
DEBUGP(DLMUX, "%s (handle=%p, seq=%hu)\n", __FUNCTION__, h, seq);
|
||||
|
||||
h->tx.sequence = seq;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int osmo_rtp_handle_tx_set_ssrc(struct osmo_rtp_handle *h, uint32_t ssrc)
|
||||
{
|
||||
DEBUGP(DLMUX, "%s (handle=%p, seq=%hu)\n", __FUNCTION__, h, ssrc);
|
||||
|
||||
h->tx.ssrc = ssrc;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int osmo_rtp_handle_tx_set_timestamp(struct osmo_rtp_handle *h, uint32_t timestamp)
|
||||
{
|
||||
DEBUGP(DLMUX, "%s (handle=%p, ts=%hu)\n", __FUNCTION__, h, timestamp);
|
||||
|
||||
h->tx.timestamp = timestamp;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* decode and pull RTP header out and return payload_type. The msg->data
|
||||
points to data payload after this is called. This function returns the
|
||||
RTP payload type on success. */
|
||||
int osmo_rtp_parse(struct osmo_rtp_handle *h, struct msgb *msg)
|
||||
{
|
||||
struct rtp_hdr *rtph = (struct rtp_hdr *)msg->data;
|
||||
struct rtp_x_hdr *rtpxh;
|
||||
uint8_t *payload;
|
||||
int payload_len;
|
||||
int x_len;
|
||||
int csrc_len;
|
||||
|
||||
if (msg->len < sizeof(struct rtp_hdr)) {
|
||||
DEBUGPC(DLMUX, "received RTP frame too short (len = %d)\n",
|
||||
msg->len);
|
||||
return -EINVAL;
|
||||
}
|
||||
if (rtph->version != RTP_VERSION) {
|
||||
DEBUGPC(DLMUX, "received RTP version %d not supported.\n",
|
||||
rtph->version);
|
||||
return -EINVAL;
|
||||
}
|
||||
csrc_len = rtph->csrc_count << 2;
|
||||
payload = msg->data + sizeof(struct rtp_hdr) + csrc_len;
|
||||
payload_len = msg->len - sizeof(struct rtp_hdr) - csrc_len;
|
||||
if (payload_len < 0) {
|
||||
DEBUGPC(DLMUX, "received RTP frame too short (len = %d, "
|
||||
"csrc count = %d)\n", msg->len, rtph->csrc_count);
|
||||
return -EINVAL;
|
||||
}
|
||||
if (rtph->extension) {
|
||||
if (payload_len < sizeof(struct rtp_x_hdr)) {
|
||||
DEBUGPC(DLMUX, "received RTP frame too short for "
|
||||
"extension header\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
rtpxh = (struct rtp_x_hdr *)payload;
|
||||
x_len = ntohs(rtpxh->length) * 4 + sizeof(struct rtp_x_hdr);
|
||||
payload += x_len;
|
||||
payload_len -= x_len;
|
||||
if (payload_len < 0) {
|
||||
DEBUGPC(DLMUX, "received RTP frame too short, "
|
||||
"extension header exceeds frame length\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
if (rtph->padding) {
|
||||
if (payload_len < 0) {
|
||||
DEBUGPC(DLMUX, "received RTP frame too short for "
|
||||
"padding length\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
payload_len -= payload[payload_len - 1];
|
||||
if (payload_len < 0) {
|
||||
DEBUGPC(DLMUX, "received RTP frame with padding "
|
||||
"greater than payload\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
msgb_pull(msg, msg->len - payload_len);
|
||||
|
||||
return rtph->payload_type;
|
||||
}
|
||||
|
||||
struct msgb *
|
||||
osmo_rtp_build(struct osmo_rtp_handle *h, uint8_t payload_type,
|
||||
uint32_t payload_len, const void *data, uint32_t duration)
|
||||
{
|
||||
struct msgb *msg;
|
||||
struct rtp_hdr *rtph;
|
||||
struct timeval tv, tv_diff = {};
|
||||
long int usec_diff, frame_diff;
|
||||
|
||||
gettimeofday(&tv, NULL);
|
||||
timersub(&tv_diff, &h->tx.last_tv, &tv);
|
||||
h->tx.last_tv = tv;
|
||||
|
||||
usec_diff = tv_diff.tv_sec * 1000000 + tv_diff.tv_usec;
|
||||
frame_diff = (usec_diff / 20000);
|
||||
|
||||
if (abs(frame_diff) > 1) {
|
||||
long int frame_diff_excess = frame_diff - 1;
|
||||
|
||||
LOGP(DLMUX, LOGL_NOTICE,
|
||||
"Correcting frame difference of %ld frames\n",
|
||||
frame_diff_excess);
|
||||
h->tx.sequence += frame_diff_excess;
|
||||
h->tx.timestamp += frame_diff_excess * duration;
|
||||
}
|
||||
|
||||
msg = msgb_alloc(sizeof(struct rtp_hdr) + payload_len, "RTP");
|
||||
if (!msg) {
|
||||
LOGP(DLMUX, LOGL_ERROR, "OOM\n");
|
||||
return NULL;
|
||||
}
|
||||
rtph = (struct rtp_hdr *)msg->data;
|
||||
rtph->version = RTP_VERSION;
|
||||
rtph->padding = 0;
|
||||
rtph->extension = 0;
|
||||
rtph->csrc_count = 0;
|
||||
rtph->marker = 0;
|
||||
rtph->payload_type = payload_type;
|
||||
rtph->sequence = htons(h->tx.sequence++);
|
||||
rtph->timestamp = htonl(h->tx.timestamp);
|
||||
h->tx.timestamp += duration;
|
||||
rtph->ssrc = htonl(h->tx.ssrc);
|
||||
memcpy(msg->data + sizeof(struct rtp_hdr), data, payload_len);
|
||||
msgb_put(msg, sizeof(struct rtp_hdr) + payload_len);
|
||||
|
||||
return msg;
|
||||
}
|
||||
Loading…
Reference in New Issue