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 "network.h"
  27 #include "os_support.h"
  28
  29 /* XXX: POST protocol is not completely implemented because ffmpeg uses
  30    only a subset of it. */
  31
  32 //#define DEBUG
  33
  34 /* used for protocol handling */
  35 #define BUFFER_SIZE 1024
  36 #define URL_SIZE    4096
  37 #define MAX_REDIRECTS 8
  38
  39 typedef struct {
  40     URLContext *hd;
  41     unsigned char buffer[BUFFER_SIZE], *buf_ptr, *buf_end;
  42     int line_count;
  43     int http_code;
  44     offset_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->off = 0;
 130     av_strlcpy(s->location, uri, URL_SIZE);
 131
 132     ret = http_open_cnx(h);
 133     if (ret != 0)
 134         av_free (s);
 135     return ret;
 136 }
 137 static int http_getc(HTTPContext *s)
 138 {
 139     int len;
 140     if (s->buf_ptr >= s->buf_end) {
 141         len = url_read(s->hd, s->buffer, BUFFER_SIZE);
 142         if (len < 0) {
 143             return AVERROR(EIO);
 144         } else if (len == 0) {
 145             return -1;
 146         } else {
 147             s->buf_ptr = s->buffer;
 148             s->buf_end = s->buffer + len;
 149         }
 150     }
 151     return *s->buf_ptr++;
 152 }
 153
 154 static int process_line(URLContext *h, char *line, int line_count,
 155                         int *new_location)
 156 {
 157     HTTPContext *s = h->priv_data;
 158     char *tag, *p;
 159
 160     /* end of header */
 161     if (line[0] == '\0')
 162         return 0;
 163
 164     p = line;
 165     if (line_count == 0) {
 166         while (!isspace(*p) && *p != '\0')
 167             p++;
 168         while (isspace(*p))
 169             p++;
 170         s->http_code = strtol(p, NULL, 10);
 171 #ifdef DEBUG
 172         printf("http_code=%d\n", s->http_code);
 173 #endif
 174         /* error codes are 4xx and 5xx */
 175         if (s->http_code >= 400 && s->http_code < 600)
 176             return -1;
 177     } else {
 178         while (*p != '\0' && *p != ':')
 179             p++;
 180         if (*p != ':')
 181             return 1;
 182
 183         *p = '\0';
 184         tag = line;
 185         p++;
 186         while (isspace(*p))
 187             p++;
 188         if (!strcmp(tag, "Location")) {
 189             strcpy(s->location, p);
 190             *new_location = 1;
 191         } else if (!strcmp (tag, "Content-Length") && s->filesize == -1) {
 192             s->filesize = atoll(p);
 193         } else if (!strcmp (tag, "Content-Range")) {
 194             /* "bytes $from-$to/$document_size" */
 195             const char *slash;
 196             if (!strncmp (p, "bytes ", 6)) {
 197                 p += 6;
 198                 s->off = atoll(p);
 199                 if ((slash = strchr(p, '/')) && strlen(slash) > 0)
 200                     s->filesize = atoll(slash+1);
 201             }
 202             h->is_streamed = 0; /* we _can_ in fact seek */
 203         }
 204     }
 205     return 1;
 206 }
 207
 208 static int http_connect(URLContext *h, const char *path, const char *hoststr,
 209                         const char *auth, int *new_location)
 210 {
 211     HTTPContext *s = h->priv_data;
 212     int post, err, ch;
 213     char line[1024], *q;
 214     char *auth_b64;
 215     int auth_b64_len = strlen(auth)* 4 / 3 + 12;
 216     offset_t off = s->off;
 217
 218
 219     /* send http header */
 220     post = h->flags & URL_WRONLY;
 221     auth_b64 = av_malloc(auth_b64_len);
 222     av_base64_encode(auth_b64, auth_b64_len, auth, strlen(auth));
 223     snprintf(s->buffer, sizeof(s->buffer),
 224              "%s %s HTTP/1.1\r\n"
 225              "User-Agent: %s\r\n"
 226              "Accept: */*\r\n"
 227              "Range: bytes=%"PRId64"-\r\n"
 228              "Host: %s\r\n"
 229              "Authorization: Basic %s\r\n"
 230              "Connection: close\r\n"
 231              "\r\n",
 232              post ? "POST" : "GET",
 233              path,
 234              LIBAVFORMAT_IDENT,
 235              s->off,
 236              hoststr,
 237              auth_b64);
 238
 239     av_freep(&auth_b64);
 240     if (http_write(h, s->buffer, strlen(s->buffer)) < 0)
 241         return AVERROR(EIO);
 242
 243     /* init input buffer */
 244     s->buf_ptr = s->buffer;
 245     s->buf_end = s->buffer;
 246     s->line_count = 0;
 247     s->off = 0;
 248     s->filesize = -1;
 249     if (post) {
 250         return 0;
 251     }
 252
 253     /* wait for header */
 254     q = line;
 255     for(;;) {
 256         ch = http_getc(s);
 257         if (ch < 0)
 258             return AVERROR(EIO);
 259         if (ch == '\n') {
 260             /* process line */
 261             if (q > line && q[-1] == '\r')
 262                 q--;
 263             *q = '\0';
 264 #ifdef DEBUG
 265             printf("header='%s'\n", line);
 266 #endif
 267             err = process_line(h, line, s->line_count, new_location);
 268             if (err < 0)
 269                 return err;
 270             if (err == 0)
 271                 break;
 272             s->line_count++;
 273             q = line;
 274         } else {
 275             if ((q - line) < sizeof(line) - 1)
 276                 *q++ = ch;
 277         }
 278     }
 279
 280     return (off == s->off) ? 0 : -1;
 281 }
 282
 283
 284 static int http_read(URLContext *h, uint8_t *buf, int size)
 285 {
 286     HTTPContext *s = h->priv_data;
 287     int len;
 288
 289     /* read bytes from input buffer first */
 290     len = s->buf_end - s->buf_ptr;
 291     if (len > 0) {
 292         if (len > size)
 293             len = size;
 294         memcpy(buf, s->buf_ptr, len);
 295         s->buf_ptr += len;
 296     } else {
 297         len = url_read(s->hd, buf, size);
 298     }
 299     if (len > 0)
 300         s->off += len;
 301     return len;
 302 }
 303
 304 /* used only when posting data */
 305 static int http_write(URLContext *h, uint8_t *buf, int size)
 306 {
 307     HTTPContext *s = h->priv_data;
 308     return url_write(s->hd, buf, size);
 309 }
 310
 311 static int http_close(URLContext *h)
 312 {
 313     HTTPContext *s = h->priv_data;
 314     url_close(s->hd);
 315     av_free(s);
 316     return 0;
 317 }
 318
 319 static offset_t http_seek(URLContext *h, offset_t off, int whence)
 320 {
 321     HTTPContext *s = h->priv_data;
 322     URLContext *old_hd = s->hd;
 323     offset_t old_off = s->off;
 324
 325     if (whence == AVSEEK_SIZE)
 326         return s->filesize;
 327     else if ((s->filesize == -1 && whence == SEEK_END) || h->is_streamed)
 328         return -1;
 329
 330     /* we save the old context in case the seek fails */
 331     s->hd = NULL;
 332     if (whence == SEEK_CUR)
 333         off += s->off;
 334     else if (whence == SEEK_END)
 335         off += s->filesize;
 336     s->off = off;
 337
 338     /* if it fails, continue on old connection */
 339     if (http_open_cnx(h) < 0) {
 340         s->hd = old_hd;
 341         s->off = old_off;
 342         return -1;
 343     }
 344     url_close(old_hd);
 345     return off;
 346 }
 347
 348 URLProtocol http_protocol = {
 349     "http",
 350     http_open,
 351     http_read,
 352     http_write,
 353     http_seek,
 354     http_close,
 355 };