libavformat/http.c

   1 /*
   2  * HTTP protocol for ffmpeg client
   3  * Copyright (c) 2000, 2001 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
  22 #include "libavutil/base64.h"
  23 #include "libavutil/avstring.h"
  24 #include "avformat.h"
  25 #include <unistd.h>
  26 #include <strings.h>
  27 #include "network.h"
  28 #include "os_support.h"
  29
  30 /* XXX: POST protocol is not completely implemented because ffmpeg uses
  31    only a subset of it. */
  32
  33 /* used for protocol handling */
  34 #define BUFFER_SIZE 1024
  35 #define URL_SIZE    4096
  36 #define MAX_REDIRECTS 8
  37
  38 typedef struct {
  39     URLContext *hd;
  40     unsigned char buffer[BUFFER_SIZE], *buf_ptr, *buf_end;
  41     int line_count;
  42     int http_code;
  43     int64_t chunksize;      /**< Used if "Transfer-Encoding: chunked" otherwise -1. */
  44     int64_t off, filesize;
  45     char location[URL_SIZE];
  46 } HTTPContext;
  47
  48 static int http_connect(URLContext *h, const char *path, const char *hoststr,
  49                         const char *auth, int *new_location);
  50 static int http_write(URLContext *h, uint8_t *buf, int size);
  51
  52
  53 /* return non zero if error */
  54 static int http_open_cnx(URLContext *h)
  55 {
  56     const char *path, *proxy_path;
  57     char hostname[1024], hoststr[1024];
  58     char auth[1024];
  59     char path1[1024];
  60     char buf[1024];
  61     int port, use_proxy, err, location_changed = 0, redirects = 0;
  62     HTTPContext *s = h->priv_data;
  63     URLContext *hd = NULL;
  64
  65     proxy_path = getenv("http_proxy");
  66     use_proxy = (proxy_path != NULL) && !getenv("no_proxy") &&
  67         av_strstart(proxy_path, "http://", NULL);
  68
  69     /* fill the dest addr */
  70  redo:
  71     /* needed in any case to build the host string */
  72     url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
  73               path1, sizeof(path1), s->location);
  74     if (port > 0) {
  75         snprintf(hoststr, sizeof(hoststr), "%s:%d", hostname, port);
  76     } else {
  77         av_strlcpy(hoststr, hostname, sizeof(hoststr));
  78     }
  79
  80     if (use_proxy) {
  81         url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
  82                   NULL, 0, proxy_path);
  83         path = s->location;
  84     } else {
  85         if (path1[0] == '\0')
  86             path = "/";
  87         else
  88             path = path1;
  89     }
  90     if (port < 0)
  91         port = 80;
  92
  93     snprintf(buf, sizeof(buf), "tcp://%s:%d", hostname, port);
  94     err = url_open(&hd, buf, URL_RDWR);
  95     if (err < 0)
  96         goto fail;
  97
  98     s->hd = hd;
  99     if (http_connect(h, path, hoststr, auth, &location_changed) < 0)
 100         goto fail;
 101     if ((s->http_code == 302 || s->http_code == 303) && location_changed == 1) {
 102         /* url moved, get next */
 103         url_close(hd);
 104         if (redirects++ >= MAX_REDIRECTS)
 105             return AVERROR(EIO);
 106         location_changed = 0;
 107         goto redo;
 108     }
 109     return 0;
 110  fail:
 111     if (hd)
 112         url_close(hd);
 113     return AVERROR(EIO);
 114 }
 115
 116 static int http_open(URLContext *h, const char *uri, int flags)
 117 {
 118     HTTPContext *s;
 119     int ret;
 120
 121     h->is_streamed = 1;
 122
 123     s = av_malloc(sizeof(HTTPContext));
 124     if (!s) {
 125         return AVERROR(ENOMEM);
 126     }
 127     h->priv_data = s;
 128     s->filesize = -1;
 129     s->chunksize = -1;
 130     s->off = 0;
 131     av_strlcpy(s->location, uri, URL_SIZE);
 132
 133     ret = http_open_cnx(h);
 134     if (ret != 0)
 135         av_free (s);
 136     return ret;
 137 }
 138 static int http_getc(HTTPContext *s)
 139 {
 140     int len;
 141     if (s->buf_ptr >= s->buf_end) {
 142         len = url_read(s->hd, s->buffer, BUFFER_SIZE);
 143         if (len < 0) {
 144             return AVERROR(EIO);
 145         } else if (len == 0) {
 146             return -1;
 147         } else {
 148             s->buf_ptr = s->buffer;
 149             s->buf_end = s->buffer + len;
 150         }
 151     }
 152     return *s->buf_ptr++;
 153 }
 154
 155 static int http_get_line(HTTPContext *s, char *line, int line_size)
 156 {
 157     int ch;
 158     char *q;
 159
 160     q = line;
 161     for(;;) {
 162         ch = http_getc(s);
 163         if (ch < 0)
 164             return AVERROR(EIO);
 165         if (ch == '\n') {
 166             /* process line */
 167             if (q > line && q[-1] == '\r')
 168                 q--;
 169             *q = '\0';
 170
 171             return 0;
 172         } else {
 173             if ((q - line) < line_size - 1)
 174                 *q++ = ch;
 175         }
 176     }
 177 }
 178
 179 static int process_line(URLContext *h, char *line, int line_count,
 180                         int *new_location)
 181 {
 182     HTTPContext *s = h->priv_data;
 183     char *tag, *p;
 184
 185     /* end of header */
 186     if (line[0] == '\0')
 187         return 0;
 188
 189     p = line;
 190     if (line_count == 0) {
 191         while (!isspace(*p) && *p != '\0')
 192             p++;
 193         while (isspace(*p))
 194             p++;
 195         s->http_code = strtol(p, NULL, 10);
 196
 197         dprintf(NULL, "http_code=%d\n", s->http_code);
 198
 199         /* error codes are 4xx and 5xx */
 200         if (s->http_code >= 400 && s->http_code < 600)
 201             return -1;
 202     } else {
 203         while (*p != '\0' && *p != ':')
 204             p++;
 205         if (*p != ':')
 206             return 1;
 207
 208         *p = '\0';
 209         tag = line;
 210         p++;
 211         while (isspace(*p))
 212             p++;
 213         if (!strcmp(tag, "Location")) {
 214             strcpy(s->location, p);
 215             *new_location = 1;
 216         } else if (!strcmp (tag, "Content-Length") && s->filesize == -1) {
 217             s->filesize = atoll(p);
 218         } else if (!strcmp (tag, "Content-Range")) {
 219             /* "bytes $from-$to/$document_size" */
 220             const char *slash;
 221             if (!strncmp (p, "bytes ", 6)) {
 222                 p += 6;
 223                 s->off = atoll(p);
 224                 if ((slash = strchr(p, '/')) && strlen(slash) > 0)
 225                     s->filesize = atoll(slash+1);
 226             }
 227             h->is_streamed = 0; /* we _can_ in fact seek */
 228         } else if (!strcmp (tag, "Transfer-Encoding") && !strncasecmp(p, "chunked", 7)) {
 229             s->filesize = -1;
 230             s->chunksize = 0;
 231         }
 232     }
 233     return 1;
 234 }
 235
 236 static int http_connect(URLContext *h, const char *path, const char *hoststr,
 237                         const char *auth, int *new_location)
 238 {
 239     HTTPContext *s = h->priv_data;
 240     int post, err;
 241     char line[1024];
 242     char *auth_b64;
 243     int auth_b64_len = (strlen(auth) + 2) / 3 * 4 + 1;
 244     int64_t off = s->off;
 245
 246
 247     /* send http header */
 248     post = h->flags & URL_WRONLY;
 249     auth_b64 = av_malloc(auth_b64_len);
 250     av_base64_encode(auth_b64, auth_b64_len, auth, strlen(auth));
 251     snprintf(s->buffer, sizeof(s->buffer),
 252              "%s %s HTTP/1.1\r\n"
 253              "User-Agent: %s\r\n"
 254              "Accept: */*\r\n"
 255              "Range: bytes=%"PRId64"-\r\n"
 256              "Host: %s\r\n"
 257              "Authorization: Basic %s\r\n"
 258              "Connection: close\r\n"
 259              "\r\n",
 260              post ? "POST" : "GET",
 261              path,
 262              LIBAVFORMAT_IDENT,
 263              s->off,
 264              hoststr,
 265              auth_b64);
 266
 267     av_freep(&auth_b64);
 268     if (http_write(h, s->buffer, strlen(s->buffer)) < 0)
 269         return AVERROR(EIO);
 270
 271     /* init input buffer */
 272     s->buf_ptr = s->buffer;
 273     s->buf_end = s->buffer;
 274     s->line_count = 0;
 275     s->off = 0;
 276     s->filesize = -1;
 277     if (post) {
 278         return 0;
 279     }
 280
 281     /* wait for header */
 282     for(;;) {
 283         if (http_get_line(s, line, sizeof(line)) < 0)
 284             return AVERROR(EIO);
 285
 286         dprintf(NULL, "header='%s'\n", line);
 287
 288         err = process_line(h, line, s->line_count, new_location);
 289         if (err < 0)
 290             return err;
 291         if (err == 0)
 292             break;
 293         s->line_count++;
 294     }
 295
 296     return (off == s->off) ? 0 : -1;
 297 }
 298
 299
 300 static int http_read(URLContext *h, uint8_t *buf, int size)
 301 {
 302     HTTPContext *s = h->priv_data;
 303     int len;
 304
 305     if (s->chunksize >= 0) {
 306         if (!s->chunksize) {
 307             char line[32];
 308
 309             for(;;) {
 310                 do {
 311                     if (http_get_line(s, line, sizeof(line)) < 0)
 312                         return AVERROR(EIO);
 313                 } while (!*line);    /* skip CR LF from last chunk */
 314
 315                 s->chunksize = strtoll(line, NULL, 16);
 316
 317                 dprintf(NULL, "Chunked encoding data size: %"PRId64"'\n", s->chunksize);
 318
 319                 if (!s->chunksize)
 320                     return 0;
 321                 break;
 322             }
 323         }
 324         size = FFMIN(size, s->chunksize);
 325     }
 326     /* read bytes from input buffer first */
 327     len = s->buf_end - s->buf_ptr;
 328     if (len > 0) {
 329         if (len > size)
 330             len = size;
 331         memcpy(buf, s->buf_ptr, len);
 332         s->buf_ptr += len;
 333     } else {
 334         len = url_read(s->hd, buf, size);
 335     }
 336     if (len > 0) {
 337         s->off += len;
 338         if (s->chunksize > 0)
 339             s->chunksize -= len;
 340     }
 341     return len;
 342 }
 343
 344 /* used only when posting data */
 345 static int http_write(URLContext *h, uint8_t *buf, int size)
 346 {
 347     HTTPContext *s = h->priv_data;
 348     return url_write(s->hd, buf, size);
 349 }
 350
 351 static int http_close(URLContext *h)
 352 {
 353     HTTPContext *s = h->priv_data;
 354     url_close(s->hd);
 355     av_free(s);
 356     return 0;
 357 }
 358
 359 static int64_t http_seek(URLContext *h, int64_t off, int whence)
 360 {
 361     HTTPContext *s = h->priv_data;
 362     URLContext *old_hd = s->hd;
 363     int64_t old_off = s->off;
 364
 365     if (whence == AVSEEK_SIZE)
 366         return s->filesize;
 367     else if ((s->filesize == -1 && whence == SEEK_END) || h->is_streamed)
 368         return -1;
 369
 370     /* we save the old context in case the seek fails */
 371     s->hd = NULL;
 372     if (whence == SEEK_CUR)
 373         off += s->off;
 374     else if (whence == SEEK_END)
 375         off += s->filesize;
 376     s->off = off;
 377
 378     /* if it fails, continue on old connection */
 379     if (http_open_cnx(h) < 0) {
 380         s->hd = old_hd;
 381         s->off = old_off;
 382         return -1;
 383     }
 384     url_close(old_hd);
 385     return off;
 386 }
 387
 388 static int
 389 http_get_file_handle(URLContext *h)
 390 {
 391     HTTPContext *s = h->priv_data;
 392     return url_get_file_handle(s->hd);
 393 }
 394
 395 URLProtocol http_protocol = {
 396     "http",
 397     http_open,
 398     http_read,
 399     http_write,
 400     http_seek,
 401     http_close,
 402     .url_get_file_handle = http_get_file_handle,
 403 };