FFmpeg
tcp.c
Go to the documentation of this file.
1 /*
2  * TCP protocol
3  * Copyright (c) 2002 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 #include "avformat.h"
22 #include "libavutil/avassert.h"
23 #include "libavutil/parseutils.h"
24 #include "libavutil/opt.h"
25 #include "libavutil/time.h"
26 
27 #include "internal.h"
28 #include "network.h"
29 #include "os_support.h"
30 #include "url.h"
31 #if HAVE_POLL_H
32 #include <poll.h>
33 #endif
34 
35 typedef struct TCPContext {
36  const AVClass *class;
37  int fd;
38  int listen;
45 #if !HAVE_WINSOCK2_H
46  int tcp_mss;
47 #endif /* !HAVE_WINSOCK2_H */
48 } TCPContext;
49 
50 #define OFFSET(x) offsetof(TCPContext, x)
51 #define D AV_OPT_FLAG_DECODING_PARAM
52 #define E AV_OPT_FLAG_ENCODING_PARAM
53 static const AVOption options[] = {
54  { "listen", "Listen for incoming connections", OFFSET(listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, .flags = D|E },
55  { "timeout", "set timeout (in microseconds) of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
56  { "listen_timeout", "Connection awaiting timeout (in milliseconds)", OFFSET(listen_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
57  { "send_buffer_size", "Socket send buffer size (in bytes)", OFFSET(send_buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
58  { "recv_buffer_size", "Socket receive buffer size (in bytes)", OFFSET(recv_buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
59  { "tcp_nodelay", "Use TCP_NODELAY to disable nagle's algorithm", OFFSET(tcp_nodelay), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, .flags = D|E },
60 #if !HAVE_WINSOCK2_H
61  { "tcp_mss", "Maximum segment size for outgoing TCP packets", OFFSET(tcp_mss), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
62 #endif /* !HAVE_WINSOCK2_H */
63  { NULL }
64 };
65 
66 static const AVClass tcp_class = {
67  .class_name = "tcp",
68  .item_name = av_default_item_name,
69  .option = options,
70  .version = LIBAVUTIL_VERSION_INT,
71 };
72 
73 static void customize_fd(void *ctx, int fd)
74 {
75  TCPContext *s = ctx;
76  /* Set the socket's send or receive buffer sizes, if specified.
77  If unspecified or setting fails, system default is used. */
78  if (s->recv_buffer_size > 0) {
79  if (setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &s->recv_buffer_size, sizeof (s->recv_buffer_size))) {
80  ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(SO_RCVBUF)");
81  }
82  }
83  if (s->send_buffer_size > 0) {
84  if (setsockopt (fd, SOL_SOCKET, SO_SNDBUF, &s->send_buffer_size, sizeof (s->send_buffer_size))) {
85  ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(SO_SNDBUF)");
86  }
87  }
88  if (s->tcp_nodelay > 0) {
89  if (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, &s->tcp_nodelay, sizeof (s->tcp_nodelay))) {
90  ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(TCP_NODELAY)");
91  }
92  }
93 #if !HAVE_WINSOCK2_H
94  if (s->tcp_mss > 0) {
95  if (setsockopt (fd, IPPROTO_TCP, TCP_MAXSEG, &s->tcp_mss, sizeof (s->tcp_mss))) {
96  ff_log_net_error(ctx, AV_LOG_WARNING, "setsockopt(TCP_MAXSEG)");
97  }
98  }
99 #endif /* !HAVE_WINSOCK2_H */
100 }
101 
102 /* return non zero if error */
103 static int tcp_open(URLContext *h, const char *uri, int flags)
104 {
105  struct addrinfo hints = { 0 }, *ai, *cur_ai;
106  int port, fd = -1;
107  TCPContext *s = h->priv_data;
108  const char *p;
109  char buf[256];
110  int ret;
111  char hostname[1024],proto[1024],path[1024];
112  char portstr[10];
113  s->open_timeout = 5000000;
114 
115  av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
116  &port, path, sizeof(path), uri);
117  if (strcmp(proto, "tcp"))
118  return AVERROR(EINVAL);
119  if (port <= 0 || port >= 65536) {
120  av_log(h, AV_LOG_ERROR, "Port missing in uri\n");
121  return AVERROR(EINVAL);
122  }
123  p = strchr(uri, '?');
124  if (p) {
125  if (av_find_info_tag(buf, sizeof(buf), "listen", p)) {
126  char *endptr = NULL;
127  s->listen = strtol(buf, &endptr, 10);
128  /* assume if no digits were found it is a request to enable it */
129  if (buf == endptr)
130  s->listen = 1;
131  }
132  if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
133  s->rw_timeout = strtol(buf, NULL, 10);
134  }
135  if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
136  s->listen_timeout = strtol(buf, NULL, 10);
137  }
138  if (av_find_info_tag(buf, sizeof(buf), "tcp_nodelay", p)) {
139  s->tcp_nodelay = strtol(buf, NULL, 10);
140  }
141  }
142  if (s->rw_timeout >= 0) {
143  s->open_timeout =
144  h->rw_timeout = s->rw_timeout;
145  }
146  hints.ai_family = AF_UNSPEC;
147  hints.ai_socktype = SOCK_STREAM;
148  snprintf(portstr, sizeof(portstr), "%d", port);
149  if (s->listen)
150  hints.ai_flags |= AI_PASSIVE;
151  if (!hostname[0])
152  ret = getaddrinfo(NULL, portstr, &hints, &ai);
153  else
154  ret = getaddrinfo(hostname, portstr, &hints, &ai);
155  if (ret) {
157  "Failed to resolve hostname %s: %s\n",
158  hostname, gai_strerror(ret));
159  return AVERROR(EIO);
160  }
161 
162  cur_ai = ai;
163 
164 #if HAVE_STRUCT_SOCKADDR_IN6
165  // workaround for IOS9 getaddrinfo in IPv6 only network use hardcode IPv4 address can not resolve port number.
166  if (cur_ai->ai_family == AF_INET6){
167  struct sockaddr_in6 * sockaddr_v6 = (struct sockaddr_in6 *)cur_ai->ai_addr;
168  if (!sockaddr_v6->sin6_port){
169  sockaddr_v6->sin6_port = htons(port);
170  }
171  }
172 #endif
173 
174  if (s->listen > 0) {
175  while (cur_ai && fd < 0) {
176  fd = ff_socket(cur_ai->ai_family,
177  cur_ai->ai_socktype,
178  cur_ai->ai_protocol);
179  if (fd < 0) {
180  ret = ff_neterrno();
181  cur_ai = cur_ai->ai_next;
182  }
183  }
184  if (fd < 0)
185  goto fail1;
186  customize_fd(s, fd);
187  }
188 
189  if (s->listen == 2) {
190  // multi-client
191  if ((ret = ff_listen(fd, cur_ai->ai_addr, cur_ai->ai_addrlen)) < 0)
192  goto fail1;
193  } else if (s->listen == 1) {
194  // single client
195  if ((ret = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
196  s->listen_timeout, h)) < 0)
197  goto fail1;
198  // Socket descriptor already closed here. Safe to overwrite to client one.
199  fd = ret;
200  } else {
201  ret = ff_connect_parallel(ai, s->open_timeout / 1000, 3, h, &fd, customize_fd, s);
202  if (ret < 0)
203  goto fail1;
204  }
205 
206  h->is_streamed = 1;
207  s->fd = fd;
208 
209  freeaddrinfo(ai);
210  return 0;
211 
212  fail1:
213  if (fd >= 0)
214  closesocket(fd);
215  freeaddrinfo(ai);
216  return ret;
217 }
218 
220 {
221  TCPContext *sc = s->priv_data;
222  TCPContext *cc;
223  int ret;
224  av_assert0(sc->listen);
225  if ((ret = ffurl_alloc(c, s->filename, s->flags, &s->interrupt_callback)) < 0)
226  return ret;
227  cc = (*c)->priv_data;
228  ret = ff_accept(sc->fd, sc->listen_timeout, s);
229  if (ret < 0) {
230  ffurl_closep(c);
231  return ret;
232  }
233  cc->fd = ret;
234  return 0;
235 }
236 
237 static int tcp_read(URLContext *h, uint8_t *buf, int size)
238 {
239  TCPContext *s = h->priv_data;
240  int ret;
241 
242  if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
243  ret = ff_network_wait_fd_timeout(s->fd, 0, h->rw_timeout, &h->interrupt_callback);
244  if (ret)
245  return ret;
246  }
247  ret = recv(s->fd, buf, size, 0);
248  if (ret == 0)
249  return AVERROR_EOF;
250  return ret < 0 ? ff_neterrno() : ret;
251 }
252 
253 static int tcp_write(URLContext *h, const uint8_t *buf, int size)
254 {
255  TCPContext *s = h->priv_data;
256  int ret;
257 
258  if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
259  ret = ff_network_wait_fd_timeout(s->fd, 1, h->rw_timeout, &h->interrupt_callback);
260  if (ret)
261  return ret;
262  }
263  ret = send(s->fd, buf, size, MSG_NOSIGNAL);
264  return ret < 0 ? ff_neterrno() : ret;
265 }
266 
267 static int tcp_shutdown(URLContext *h, int flags)
268 {
269  TCPContext *s = h->priv_data;
270  int how;
271 
273  how = SHUT_RDWR;
274  } else if (flags & AVIO_FLAG_WRITE) {
275  how = SHUT_WR;
276  } else {
277  how = SHUT_RD;
278  }
279 
280  return shutdown(s->fd, how);
281 }
282 
283 static int tcp_close(URLContext *h)
284 {
285  TCPContext *s = h->priv_data;
286  closesocket(s->fd);
287  return 0;
288 }
289 
291 {
292  TCPContext *s = h->priv_data;
293  return s->fd;
294 }
295 
297 {
298  TCPContext *s = h->priv_data;
299  int avail;
300  socklen_t avail_len = sizeof(avail);
301 
302 #if HAVE_WINSOCK2_H
303  /* SO_RCVBUF with winsock only reports the actual TCP window size when
304  auto-tuning has been disabled via setting SO_RCVBUF */
305  if (s->recv_buffer_size < 0) {
306  return AVERROR(ENOSYS);
307  }
308 #endif
309 
310  if (getsockopt(s->fd, SOL_SOCKET, SO_RCVBUF, &avail, &avail_len)) {
311  return ff_neterrno();
312  }
313  return avail;
314 }
315 
317  .name = "tcp",
318  .url_open = tcp_open,
319  .url_accept = tcp_accept,
320  .url_read = tcp_read,
321  .url_write = tcp_write,
322  .url_close = tcp_close,
323  .url_get_file_handle = tcp_get_file_handle,
324  .url_get_short_seek = tcp_get_window_size,
325  .url_shutdown = tcp_shutdown,
326  .priv_data_size = sizeof(TCPContext),
328  .priv_data_class = &tcp_class,
329 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
av_find_info_tag
int av_find_info_tag(char *arg, int arg_size, const char *tag1, const char *info)
Attempt to find a specific tag in a URL.
Definition: parseutils.c:751
E
#define E
Definition: tcp.c:52
tcp_accept
static int tcp_accept(URLContext *s, URLContext **c)
Definition: tcp.c:219
URL_PROTOCOL_FLAG_NETWORK
#define URL_PROTOCOL_FLAG_NETWORK
Definition: url.h:34
TCPContext::tcp_mss
int tcp_mss
Definition: tcp.c:46
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
OFFSET
#define OFFSET(x)
Definition: tcp.c:50
tcp_write
static int tcp_write(URLContext *h, const uint8_t *buf, int size)
Definition: tcp.c:253
AVOption
AVOption.
Definition: opt.h:247
ff_log_net_error
void ff_log_net_error(void *ctx, int level, const char *prefix)
Definition: network.c:581
ff_socket
int ff_socket(int af, int type, int proto)
Definition: network.c:183
URLProtocol
Definition: url.h:54
os_support.h
freeaddrinfo
#define freeaddrinfo
Definition: network.h:218
ff_listen_bind
int ff_listen_bind(int fd, const struct sockaddr *addr, socklen_t addrlen, int timeout, URLContext *h)
Bind to a file descriptor and poll for a connection.
Definition: network.c:246
avassert.h
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
TCPContext::rw_timeout
int rw_timeout
Definition: tcp.c:40
ff_listen
int ff_listen(int fd, const struct sockaddr *addr, socklen_t addrlen)
Bind to a file descriptor to an address without accepting connections.
Definition: network.c:210
TCPContext::fd
int fd
Definition: tcp.c:37
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
AVIO_FLAG_WRITE
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:656
tcp_open
static int tcp_open(URLContext *h, const char *uri, int flags)
Definition: tcp.c:103
ctx
AVFormatContext * ctx
Definition: movenc.c:48
TCPContext::listen
int listen
Definition: tcp.c:38
if
if(ret)
Definition: filter_design.txt:179
tcp_read
static int tcp_read(URLContext *h, uint8_t *buf, int size)
Definition: tcp.c:237
internal.h
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
TCPContext::send_buffer_size
int send_buffer_size
Definition: tcp.c:43
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
parseutils.h
ff_network_wait_fd_timeout
int ff_network_wait_fd_timeout(int fd, int write, int64_t timeout, AVIOInterruptCB *int_cb)
This works similarly to ff_network_wait_fd, but waits up to 'timeout' microseconds Uses ff_network_wa...
Definition: network.c:78
time.h
ff_neterrno
#define ff_neterrno()
Definition: network.h:68
options
static const AVOption options[]
Definition: tcp.c:53
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
tcp_close
static int tcp_close(URLContext *h)
Definition: tcp.c:283
ff_tcp_protocol
const URLProtocol ff_tcp_protocol
Definition: tcp.c:316
addrinfo::ai_family
int ai_family
Definition: network.h:139
TCPContext
Definition: tcp.c:35
ff_accept
int ff_accept(int fd, int timeout, URLContext *h)
Poll for a single connection on the passed file descriptor.
Definition: network.c:228
size
int size
Definition: twinvq_data.h:10344
URLProtocol::name
const char * name
Definition: url.h:55
tcp_get_file_handle
static int tcp_get_file_handle(URLContext *h)
Definition: tcp.c:290
tcp_get_window_size
static int tcp_get_window_size(URLContext *h)
Definition: tcp.c:296
gai_strerror
#define gai_strerror
Definition: network.h:225
TCPContext::tcp_nodelay
int tcp_nodelay
Definition: tcp.c:44
ffurl_alloc
int ffurl_alloc(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb)
Create a URLContext for accessing to the resource indicated by url, but do not initiate the connectio...
Definition: avio.c:293
getaddrinfo
#define getaddrinfo
Definition: network.h:217
TCPContext::recv_buffer_size
int recv_buffer_size
Definition: tcp.c:42
TCPContext::listen_timeout
int listen_timeout
Definition: tcp.c:41
URLContext
Definition: url.h:38
ff_connect_parallel
int ff_connect_parallel(struct addrinfo *addrs, int timeout_ms_per_address, int parallel, URLContext *h, int *fd, void(*customize_fd)(void *, int), void *customize_ctx)
Connect to any of the given addrinfo addresses, with multiple attempts running in parallel.
Definition: network.c:403
TCPContext::open_timeout
int open_timeout
Definition: tcp.c:39
av_url_split
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:4653
url.h
D
#define D
Definition: tcp.c:51
tcp_shutdown
static int tcp_shutdown(URLContext *h, int flags)
Definition: tcp.c:267
ffurl_closep
int ffurl_closep(URLContext **hh)
Close the resource accessed by the URLContext h, and free the memory used by it.
Definition: avio.c:438
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
addrinfo::ai_socktype
int ai_socktype
Definition: network.h:140
avformat.h
network.h
tcp_class
static const AVClass tcp_class
Definition: tcp.c:66
addrinfo::ai_flags
int ai_flags
Definition: network.h:138
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
AVIO_FLAG_READ
#define AVIO_FLAG_READ
read-only
Definition: avio.h:655
MSG_NOSIGNAL
#define MSG_NOSIGNAL
Definition: network.h:133
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:241
AVIO_FLAG_NONBLOCK
#define AVIO_FLAG_NONBLOCK
Use non-blocking mode.
Definition: avio.h:674
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
customize_fd
static void customize_fd(void *ctx, int fd)
Definition: tcp.c:73
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
h
h
Definition: vp9dsp_template.c:2038
addrinfo
Definition: network.h:137
snprintf
#define snprintf
Definition: snprintf.h:34
AI_PASSIVE
#define AI_PASSIVE
Definition: network.h:179