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tcp.c
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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/parseutils.h"
23 #include "libavutil/opt.h"
24 #include "libavutil/time.h"
25 #include "internal.h"
26 #include "network.h"
27 #include "os_support.h"
28 #include "url.h"
29 #if HAVE_POLL_H
30 #include <poll.h>
31 #endif
32 
33 typedef struct TCPContext {
34  const AVClass *class;
35  int fd;
36  int listen;
40 } TCPContext;
41 
42 #define OFFSET(x) offsetof(TCPContext, x)
43 #define D AV_OPT_FLAG_DECODING_PARAM
44 #define E AV_OPT_FLAG_ENCODING_PARAM
45 static const AVOption options[] = {
46 {"listen", "listen on port instead of connecting", OFFSET(listen), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, D|E },
47 {"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
48 {"listen_timeout", "set connection awaiting timeout", OFFSET(listen_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
49 {NULL}
50 };
51 
52 static const AVClass tcp_context_class = {
53  .class_name = "tcp",
54  .item_name = av_default_item_name,
55  .option = options,
56  .version = LIBAVUTIL_VERSION_INT,
57 };
58 
59 /* return non zero if error */
60 static int tcp_open(URLContext *h, const char *uri, int flags)
61 {
62  struct addrinfo hints = { 0 }, *ai, *cur_ai;
63  int port, fd = -1;
64  TCPContext *s = h->priv_data;
65  const char *p;
66  char buf[256];
67  int ret;
68  char hostname[1024],proto[1024],path[1024];
69  char portstr[10];
70  s->open_timeout = 5000000;
71 
72  av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
73  &port, path, sizeof(path), uri);
74  if (strcmp(proto, "tcp"))
75  return AVERROR(EINVAL);
76  if (port <= 0 || port >= 65536) {
77  av_log(h, AV_LOG_ERROR, "Port missing in uri\n");
78  return AVERROR(EINVAL);
79  }
80  p = strchr(uri, '?');
81  if (p) {
82  if (av_find_info_tag(buf, sizeof(buf), "listen", p)) {
83  char *endptr = NULL;
84  s->listen = strtol(buf, &endptr, 10);
85  /* assume if no digits were found it is a request to enable it */
86  if (buf == endptr)
87  s->listen = 1;
88  }
89  if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
90  s->rw_timeout = strtol(buf, NULL, 10);
91  }
92  if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
93  s->listen_timeout = strtol(buf, NULL, 10);
94  }
95  }
96  if (s->rw_timeout >= 0) {
97  s->open_timeout =
98  h->rw_timeout = s->rw_timeout;
99  }
100  hints.ai_family = AF_UNSPEC;
101  hints.ai_socktype = SOCK_STREAM;
102  snprintf(portstr, sizeof(portstr), "%d", port);
103  if (s->listen)
104  hints.ai_flags |= AI_PASSIVE;
105  if (!hostname[0])
106  ret = getaddrinfo(NULL, portstr, &hints, &ai);
107  else
108  ret = getaddrinfo(hostname, portstr, &hints, &ai);
109  if (ret) {
110  av_log(h, AV_LOG_ERROR,
111  "Failed to resolve hostname %s: %s\n",
112  hostname, gai_strerror(ret));
113  return AVERROR(EIO);
114  }
115 
116  cur_ai = ai;
117 
118  restart:
119  fd = ff_socket(cur_ai->ai_family,
120  cur_ai->ai_socktype,
121  cur_ai->ai_protocol);
122  if (fd < 0) {
123  ret = ff_neterrno();
124  goto fail;
125  }
126 
127  if (s->listen) {
128  if ((fd = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
129  s->listen_timeout, h)) < 0) {
130  ret = fd;
131  goto fail1;
132  }
133  } else {
134  if ((ret = ff_listen_connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
135  s->open_timeout / 1000, h, !!cur_ai->ai_next)) < 0) {
136 
137  if (ret == AVERROR_EXIT)
138  goto fail1;
139  else
140  goto fail;
141  }
142  }
143 
144  h->is_streamed = 1;
145  s->fd = fd;
146  freeaddrinfo(ai);
147  return 0;
148 
149  fail:
150  if (cur_ai->ai_next) {
151  /* Retry with the next sockaddr */
152  cur_ai = cur_ai->ai_next;
153  if (fd >= 0)
154  closesocket(fd);
155  ret = 0;
156  goto restart;
157  }
158  fail1:
159  if (fd >= 0)
160  closesocket(fd);
161  freeaddrinfo(ai);
162  return ret;
163 }
164 
165 static int tcp_read(URLContext *h, uint8_t *buf, int size)
166 {
167  TCPContext *s = h->priv_data;
168  int ret;
169 
170  if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
172  if (ret)
173  return ret;
174  }
175  ret = recv(s->fd, buf, size, 0);
176  return ret < 0 ? ff_neterrno() : ret;
177 }
178 
179 static int tcp_write(URLContext *h, const uint8_t *buf, int size)
180 {
181  TCPContext *s = h->priv_data;
182  int ret;
183 
184  if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
186  if (ret)
187  return ret;
188  }
189  ret = send(s->fd, buf, size, 0);
190  return ret < 0 ? ff_neterrno() : ret;
191 }
192 
193 static int tcp_shutdown(URLContext *h, int flags)
194 {
195  TCPContext *s = h->priv_data;
196  int how;
197 
198  if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
199  how = SHUT_RDWR;
200  } else if (flags & AVIO_FLAG_WRITE) {
201  how = SHUT_WR;
202  } else {
203  how = SHUT_RD;
204  }
205 
206  return shutdown(s->fd, how);
207 }
208 
209 static int tcp_close(URLContext *h)
210 {
211  TCPContext *s = h->priv_data;
212  closesocket(s->fd);
213  return 0;
214 }
215 
217 {
218  TCPContext *s = h->priv_data;
219  return s->fd;
220 }
221 
223  .name = "tcp",
224  .url_open = tcp_open,
225  .url_read = tcp_read,
226  .url_write = tcp_write,
227  .url_close = tcp_close,
228  .url_get_file_handle = tcp_get_file_handle,
229  .url_shutdown = tcp_shutdown,
230  .priv_data_size = sizeof(TCPContext),
231  .priv_data_class = &tcp_context_class,
233 };