/*
* RTP network protocol
* Copyright (c) 2002 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* RTP protocol
*/
#include "libavutil/parseutils.h"
#include "libavutil/avstring.h"
#include "avformat.h"
#include "avio_internal.h"
#include "rtp.h"
#include "rtpproto.h"
#include "url.h"
#include <stdarg.h>
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include <fcntl.h>
#if HAVE_POLL_H
#include <sys/poll.h>
#endif
typedef struct RTPContext {
URLContext *rtp_hd, *rtcp_hd;
int rtp_fd, rtcp_fd, nb_ssm_include_addrs, nb_ssm_exclude_addrs;
struct sockaddr_storage **ssm_include_addrs, **ssm_exclude_addrs;
int write_to_source;
struct sockaddr_storage last_rtp_source, last_rtcp_source;
socklen_t last_rtp_source_len, last_rtcp_source_len;
} RTPContext;
/**
* If no filename is given to av_open_input_file because you want to
* get the local port first, then you must call this function to set
* the remote server address.
*
* @param h media file context
* @param uri of the remote server
* @return zero if no error.
*/
int ff_rtp_set_remote_url(URLContext *h, const char *uri)
{
RTPContext *s = h->priv_data;
char hostname[256];
int port, rtcp_port;
const char *p;
char buf[1024];
char path[1024];
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
path, sizeof(path), uri);
rtcp_port = port + 1;
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
rtcp_port = strtol(buf, NULL, 10);
}
}
ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);
ff_udp_set_remote_url(s->rtp_hd, buf);
ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, rtcp_port, "%s", path);
ff_udp_set_remote_url(s->rtcp_hd, buf);
return 0;
}
static struct addrinfo* rtp_resolve_host(const char *hostname, int port,
int type, int family, int flags)
{
struct addrinfo hints = { 0 }, *res = 0;
int error;
char service[16];
snprintf(service, sizeof(service), "%d", port);
hints.ai_socktype = type;
hints.ai_family = family;
hints.ai_flags = flags;
if ((error = getaddrinfo(hostname, service, &hints, &res))) {
res = NULL;
av_log(NULL, AV_LOG_ERROR, "rtp_resolve_host: %s\n", gai_strerror(error));
}
return res;
}
static int compare_addr(const struct sockaddr_storage *a,
const struct sockaddr_storage *b)
{
if (a->ss_family != b->ss_family)
return 1;
if (a->ss_family == AF_INET) {
return (((const struct sockaddr_in *)a)->sin_addr.s_addr !=
((const struct sockaddr_in *)b)->sin_addr.s_addr);
}
#if HAVE_STRUCT_SOCKADDR_IN6
if (a->ss_family == AF_INET6) {
const uint8_t *s6_addr_a = ((const struct sockaddr_in6 *)a)->sin6_addr.s6_addr;
const uint8_t *s6_addr_b = ((const struct sockaddr_in6 *)b)->sin6_addr.s6_addr;
return memcmp(s6_addr_a, s6_addr_b, 16);
}
#endif
return 1;
}
static int get_port(const struct sockaddr_storage *ss)
{
if (ss->ss_family == AF_INET)
return ntohs(((const struct sockaddr_in *)ss)->sin_port);
#if HAVE_STRUCT_SOCKADDR_IN6
if (ss->ss_family == AF_INET6)
return ntohs(((const struct sockaddr_in6 *)ss)->sin6_port);
#endif
return 0;
}
static void set_port(struct sockaddr_storage *ss, int port)
{
if (ss->ss_family == AF_INET)
((struct sockaddr_in *)ss)->sin_port = htons(port);
#if HAVE_STRUCT_SOCKADDR_IN6
else if (ss->ss_family == AF_INET6)
((struct sockaddr_in6 *)ss)->sin6_port = htons(port);
#endif
}
static int rtp_check_source_lists(RTPContext *s, struct sockaddr_storage *source_addr_ptr)
{
int i;
if (s->nb_ssm_exclude_addrs) {
for (i = 0; i < s->nb_ssm_exclude_addrs; i++) {
if (!compare_addr(source_addr_ptr, s->ssm_exclude_addrs[i]))
return 1;
}
}
if (s->nb_ssm_include_addrs) {
for (i = 0; i < s->nb_ssm_include_addrs; i++) {
if (!compare_addr(source_addr_ptr, s->ssm_include_addrs[i]))
return 0;
}
return 1;
}
return 0;
}
/**
* add option to url of the form:
* "http://host:port/path?option1=val1&option2=val2...
*/
static av_printf_format(3, 4) void url_add_option(char *buf, int buf_size, const char *fmt, ...)
{
char buf1[1024];
va_list ap;
va_start(ap, fmt);
if (strchr(buf, '?'))
av_strlcat(buf, "&", buf_size);
else
av_strlcat(buf, "?", buf_size);
vsnprintf(buf1, sizeof(buf1), fmt, ap);
av_strlcat(buf, buf1, buf_size);
va_end(ap);
}
static void build_udp_url(char *buf, int buf_size,
const char *hostname, int port,
int local_port, int ttl,
int max_packet_size, int connect,
const char *include_sources,
const char *exclude_sources)
{
ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);
if (local_port >= 0)
url_add_option(buf, buf_size, "localport=%d", local_port);
if (ttl >= 0)
url_add_option(buf, buf_size, "ttl=%d", ttl);
if (max_packet_size >=0)
url_add_option(buf, buf_size, "pkt_size=%d", max_packet_size);
if (connect)
url_add_option(buf, buf_size, "connect=1");
url_add_option(buf, buf_size, "fifo_size=0");
if (include_sources && include_sources[0])
url_add_option(buf, buf_size, "sources=%s", include_sources);
if (exclude_sources && exclude_sources[0])
url_add_option(buf, buf_size, "block=%s", exclude_sources);
}
static void rtp_parse_addr_list(URLContext *h, char *buf,
struct sockaddr_storage ***address_list_ptr,
int *address_list_size_ptr)
{
struct addrinfo *ai = NULL;
struct sockaddr_storage *source_addr;
char tmp = '\0', *p = buf, *next;
/* Resolve all of the IPs */
while (p && p[0]) {
next = strchr(p, ',');
if (next) {
tmp = *next;
*next = '\0';
}
ai = rtp_resolve_host(p, 0, SOCK_DGRAM, AF_UNSPEC, 0);
if (ai) {
source_addr = av_mallocz(sizeof(struct sockaddr_storage));
if (!source_addr)
break;
memcpy(source_addr, ai->ai_addr, ai->ai_addrlen);
freeaddrinfo(ai);
dynarray_add(address_list_ptr, address_list_size_ptr, source_addr);
} else {
av_log(h, AV_LOG_WARNING, "Unable to resolve %s\n", p);
}
if (next) {
*next = tmp;
p = next + 1;
} else {
p = NULL;
}
}
}
/**
* url syntax: rtp://host:port[?option=val...]
* option: 'ttl=n' : set the ttl value (for multicast only)
* 'rtcpport=n' : set the remote rtcp port to n
* 'localrtpport=n' : set the local rtp port to n
* 'localrtcpport=n' : set the local rtcp port to n
* 'pkt_size=n' : set max packet size
* 'connect=0/1' : do a connect() on the UDP socket
* 'sources=ip[,ip]' : list allowed source IP addresses
* 'block=ip[,ip]' : list disallowed source IP addresses
* 'write_to_source=0/1' : send packets to the source address of the latest received packet
* deprecated option:
* 'localport=n' : set the local port to n
*
* if rtcpport isn't set the rtcp port will be the rtp port + 1
* if local rtp port isn't set any available port will be used for the local
* rtp and rtcp ports
* if the local rtcp port is not set it will be the local rtp port + 1
*/
static int rtp_open(URLContext *h, const char *uri, int flags)
{
RTPContext *s = h->priv_data;
int rtp_port, rtcp_port,
ttl, connect,
local_rtp_port, local_rtcp_port, max_packet_size;
char hostname[256], include_sources[1024] = "", exclude_sources[1024] = "";
char buf[1024];
char path[1024];
const char *p;
int i, max_retry_count = 3;
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
path, sizeof(path), uri);
/* extract parameters */
ttl = -1;
rtcp_port = rtp_port+1;
local_rtp_port = -1;
local_rtcp_port = -1;
max_packet_size = -1;
connect = 0;
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
ttl = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
rtcp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
local_rtp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localrtpport", p)) {
local_rtp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localrtcpport", p)) {
local_rtcp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
max_packet_size = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
connect = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "write_to_source", p)) {
s->write_to_source = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "sources", p)) {
av_strlcpy(include_sources, buf, sizeof(include_sources));
rtp_parse_addr_list(h, buf, &s->ssm_include_addrs, &s->nb_ssm_include_addrs);
}
if (av_find_info_tag(buf, sizeof(buf), "block", p)) {
av_strlcpy(exclude_sources, buf, sizeof(exclude_sources));
rtp_parse_addr_list(h, buf, &s->ssm_exclude_addrs, &s->nb_ssm_exclude_addrs);
}
}
for (i = 0;i < max_retry_count;i++) {
build_udp_url(buf, sizeof(buf),
hostname, rtp_port, local_rtp_port, ttl, max_packet_size,
connect, include_sources, exclude_sources);
if (ffurl_open(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)
goto fail;
local_rtp_port = ff_udp_get_local_port(s->rtp_hd);
if(local_rtp_port == 65535) {
local_rtp_port = -1;
continue;
}
if (local_rtcp_port<0) {
local_rtcp_port = local_rtp_port + 1;
build_udp_url(buf, sizeof(buf),
hostname, rtcp_port, local_rtcp_port, ttl, max_packet_size,
connect, include_sources, exclude_sources);
if (ffurl_open(&s->rtcp_hd, buf, flags, &h->interrupt_callback, NULL) < 0) {
local_rtp_port = local_rtcp_port = -1;
continue;
}
break;
}
build_udp_url(buf, sizeof(buf),
hostname, rtcp_port, local_rtcp_port, ttl, max_packet_size,
connect, include_sources, exclude_sources);
if (ffurl_open(&s->rtcp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)
goto fail;
break;
}
/* just to ease handle access. XXX: need to suppress direct handle
access */
s->rtp_fd = ffurl_get_file_handle(s->rtp_hd);
s->rtcp_fd = ffurl_get_file_handle(s->rtcp_hd);
h->max_packet_size = s->rtp_hd->max_packet_size;
h->is_streamed = 1;
return 0;
fail:
if (s->rtp_hd)
ffurl_close(s->rtp_hd);
if (s->rtcp_hd)
ffurl_close(s->rtcp_hd);
return AVERROR(EIO);
}
static int rtp_read(URLContext *h, uint8_t *buf, int size)
{
RTPContext *s = h->priv_data;
int len, n, i;
struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};
int poll_delay = h->flags & AVIO_FLAG_NONBLOCK ? 0 : 100;
struct sockaddr_storage *addrs[2] = { &s->last_rtp_source, &s->last_rtcp_source };
socklen_t *addr_lens[2] = { &s->last_rtp_source_len, &s->last_rtcp_source_len };
for(;;) {
if (ff_check_interrupt(&h->interrupt_callback))
return AVERROR_EXIT;
n = poll(p, 2, poll_delay);
if (n > 0) {
/* first try RTCP, then RTP */
for (i = 1; i >= 0; i--) {
if (!(p[i].revents & POLLIN))
continue;
*addr_lens[i] = sizeof(*addrs[i]);
len = recvfrom(p[i].fd, buf, size, 0,
(struct sockaddr *)addrs[i], addr_lens[i]);
if (len < 0) {
if (ff_neterrno() == AVERROR(EAGAIN) ||
ff_neterrno() == AVERROR(EINTR))
continue;
return AVERROR(EIO);
}
if (rtp_check_source_lists(s, addrs[i]))
continue;
return len;
}
} else if (n < 0) {
if (ff_neterrno() == AVERROR(EINTR))
continue;
return AVERROR(EIO);
}
if (h->flags & AVIO_FLAG_NONBLOCK)
return AVERROR(EAGAIN);
}
return len;
}
static int rtp_write(URLContext *h, const uint8_t *buf, int size)
{
RTPContext *s = h->priv_data;
int ret;
URLContext *hd;
if (size < 2)
return AVERROR(EINVAL);
if (s->write_to_source) {
int fd;
struct sockaddr_storage *source, temp_source;
socklen_t *source_len, temp_len;
if (!s->last_rtp_source.ss_family && !s->last_rtcp_source.ss_family) {
av_log(h, AV_LOG_ERROR,
"Unable to send packet to source, no packets received yet\n");
// Intentionally not returning an error here
return size;
}
if (RTP_PT_IS_RTCP(buf[1])) {
fd = s->rtcp_fd;
source = &s->last_rtcp_source;
source_len = &s->last_rtcp_source_len;
} else {
fd = s->rtp_fd;
source = &s->last_rtp_source;
source_len = &s->last_rtp_source_len;
}
if (!source->ss_family) {
source = &temp_source;
source_len = &temp_len;
if (RTP_PT_IS_RTCP(buf[1])) {
temp_source = s->last_rtp_source;
temp_len = s->last_rtp_source_len;
set_port(source, get_port(source) + 1);
av_log(h, AV_LOG_INFO,
"Not received any RTCP packets yet, inferring peer port "
"from the RTP port\n");
} else {
temp_source = s->last_rtcp_source;
temp_len = s->last_rtcp_source_len;
set_port(source, get_port(source) - 1);
av_log(h, AV_LOG_INFO,
"Not received any RTP packets yet, inferring peer port "
"from the RTCP port\n");
}
}
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
ret = ff_network_wait_fd(fd, 1);
if (ret < 0)
return ret;
}
ret = sendto(fd, buf, size, 0, (struct sockaddr *) source,
*source_len);
return ret < 0 ? ff_neterrno() : ret;
}
if (RTP_PT_IS_RTCP(buf[1])) {
/* RTCP payload type */
hd = s->rtcp_hd;
} else {
/* RTP payload type */
hd = s->rtp_hd;
}
ret = ffurl_write(hd, buf, size);
return ret;
}
static int rtp_close(URLContext *h)
{
RTPContext *s = h->priv_data;
int i;
for (i = 0; i < s->nb_ssm_include_addrs; i++)
av_free(s->ssm_include_addrs[i]);
av_freep(&s->ssm_include_addrs);
for (i = 0; i < s->nb_ssm_exclude_addrs; i++)
av_free(s->ssm_exclude_addrs[i]);
av_freep(&s->ssm_exclude_addrs);
ffurl_close(s->rtp_hd);
ffurl_close(s->rtcp_hd);
return 0;
}
/**
* Return the local rtp port used by the RTP connection
* @param h media file context
* @return the local port number
*/
int ff_rtp_get_local_rtp_port(URLContext *h)
{
RTPContext *s = h->priv_data;
return ff_udp_get_local_port(s->rtp_hd);
}
/**
* Return the local rtcp port used by the RTP connection
* @param h media file context
* @return the local port number
*/
int ff_rtp_get_local_rtcp_port(URLContext *h)
{
RTPContext *s = h->priv_data;
return ff_udp_get_local_port(s->rtcp_hd);
}
static int rtp_get_file_handle(URLContext *h)
{
RTPContext *s = h->priv_data;
return s->rtp_fd;
}
static int rtp_get_multi_file_handle(URLContext *h, int **handles,
int *numhandles)
{
RTPContext *s = h->priv_data;
int *hs = *handles = av_malloc(sizeof(**handles) * 2);
if (!hs)
return AVERROR(ENOMEM);
hs[0] = s->rtp_fd;
hs[1] = s->rtcp_fd;
*numhandles = 2;
return 0;
}
URLProtocol ff_rtp_protocol = {
.name = "rtp",
.url_open = rtp_open,
.url_read = rtp_read,
.url_write = rtp_write,
.url_close = rtp_close,
.url_get_file_handle = rtp_get_file_handle,
.url_get_multi_file_handle = rtp_get_multi_file_handle,
.priv_data_size = sizeof(RTPContext),
.flags = URL_PROTOCOL_FLAG_NETWORK,
};