FFmpeg/libavformat/http.c
Baptiste Coudurier 08c8e66a99 restore old buffer content when seek failed in http protocol, fix issue #1631
Originally committed as revision 21208 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-01-13 23:27:52 +00:00

444 lines
12 KiB
C

/*
* HTTP protocol for ffmpeg client
* Copyright (c) 2000, 2001 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
*/
#include "libavutil/base64.h"
#include "libavutil/avstring.h"
#include "avformat.h"
#include <unistd.h>
#include <strings.h>
#include "network.h"
#include "os_support.h"
/* XXX: POST protocol is not completely implemented because ffmpeg uses
only a subset of it. */
/* used for protocol handling */
#define BUFFER_SIZE 1024
#define URL_SIZE 4096
#define MAX_REDIRECTS 8
typedef struct {
URLContext *hd;
unsigned char buffer[BUFFER_SIZE], *buf_ptr, *buf_end;
int line_count;
int http_code;
int64_t chunksize; /**< Used if "Transfer-Encoding: chunked" otherwise -1. */
int64_t off, filesize;
char location[URL_SIZE];
} HTTPContext;
static int http_connect(URLContext *h, const char *path, const char *hoststr,
const char *auth, int *new_location);
static int http_write(URLContext *h, uint8_t *buf, int size);
/* return non zero if error */
static int http_open_cnx(URLContext *h)
{
const char *path, *proxy_path;
char hostname[1024], hoststr[1024];
char auth[1024];
char path1[1024];
char buf[1024];
int port, use_proxy, err, location_changed = 0, redirects = 0;
HTTPContext *s = h->priv_data;
URLContext *hd = NULL;
proxy_path = getenv("http_proxy");
use_proxy = (proxy_path != NULL) && !getenv("no_proxy") &&
av_strstart(proxy_path, "http://", NULL);
/* fill the dest addr */
redo:
/* needed in any case to build the host string */
url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
path1, sizeof(path1), s->location);
if (port > 0) {
snprintf(hoststr, sizeof(hoststr), "%s:%d", hostname, port);
} else {
av_strlcpy(hoststr, hostname, sizeof(hoststr));
}
if (use_proxy) {
url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
NULL, 0, proxy_path);
path = s->location;
} else {
if (path1[0] == '\0')
path = "/";
else
path = path1;
}
if (port < 0)
port = 80;
snprintf(buf, sizeof(buf), "tcp://%s:%d", hostname, port);
err = url_open(&hd, buf, URL_RDWR);
if (err < 0)
goto fail;
s->hd = hd;
if (http_connect(h, path, hoststr, auth, &location_changed) < 0)
goto fail;
if ((s->http_code == 302 || s->http_code == 303) && location_changed == 1) {
/* url moved, get next */
url_close(hd);
if (redirects++ >= MAX_REDIRECTS)
return AVERROR(EIO);
location_changed = 0;
goto redo;
}
return 0;
fail:
if (hd)
url_close(hd);
return AVERROR(EIO);
}
static int http_open(URLContext *h, const char *uri, int flags)
{
HTTPContext *s;
int ret;
h->is_streamed = 1;
s = av_malloc(sizeof(HTTPContext));
if (!s) {
return AVERROR(ENOMEM);
}
h->priv_data = s;
s->filesize = -1;
s->chunksize = -1;
s->off = 0;
av_strlcpy(s->location, uri, URL_SIZE);
ret = http_open_cnx(h);
if (ret != 0)
av_free (s);
return ret;
}
static int http_getc(HTTPContext *s)
{
int len;
if (s->buf_ptr >= s->buf_end) {
len = url_read(s->hd, s->buffer, BUFFER_SIZE);
if (len < 0) {
return AVERROR(EIO);
} else if (len == 0) {
return -1;
} else {
s->buf_ptr = s->buffer;
s->buf_end = s->buffer + len;
}
}
return *s->buf_ptr++;
}
static int http_get_line(HTTPContext *s, char *line, int line_size)
{
int ch;
char *q;
q = line;
for(;;) {
ch = http_getc(s);
if (ch < 0)
return AVERROR(EIO);
if (ch == '\n') {
/* process line */
if (q > line && q[-1] == '\r')
q--;
*q = '\0';
return 0;
} else {
if ((q - line) < line_size - 1)
*q++ = ch;
}
}
}
static int process_line(URLContext *h, char *line, int line_count,
int *new_location)
{
HTTPContext *s = h->priv_data;
char *tag, *p;
/* end of header */
if (line[0] == '\0')
return 0;
p = line;
if (line_count == 0) {
while (!isspace(*p) && *p != '\0')
p++;
while (isspace(*p))
p++;
s->http_code = strtol(p, NULL, 10);
dprintf(NULL, "http_code=%d\n", s->http_code);
/* error codes are 4xx and 5xx */
if (s->http_code >= 400 && s->http_code < 600)
return -1;
} else {
while (*p != '\0' && *p != ':')
p++;
if (*p != ':')
return 1;
*p = '\0';
tag = line;
p++;
while (isspace(*p))
p++;
if (!strcmp(tag, "Location")) {
strcpy(s->location, p);
*new_location = 1;
} else if (!strcmp (tag, "Content-Length") && s->filesize == -1) {
s->filesize = atoll(p);
} else if (!strcmp (tag, "Content-Range")) {
/* "bytes $from-$to/$document_size" */
const char *slash;
if (!strncmp (p, "bytes ", 6)) {
p += 6;
s->off = atoll(p);
if ((slash = strchr(p, '/')) && strlen(slash) > 0)
s->filesize = atoll(slash+1);
}
h->is_streamed = 0; /* we _can_ in fact seek */
} else if (!strcmp (tag, "Transfer-Encoding") && !strncasecmp(p, "chunked", 7)) {
s->filesize = -1;
s->chunksize = 0;
}
}
return 1;
}
static int http_connect(URLContext *h, const char *path, const char *hoststr,
const char *auth, int *new_location)
{
HTTPContext *s = h->priv_data;
int post, err;
char line[1024];
char *auth_b64;
int auth_b64_len = (strlen(auth) + 2) / 3 * 4 + 1;
int64_t off = s->off;
/* send http header */
post = h->flags & URL_WRONLY;
auth_b64 = av_malloc(auth_b64_len);
av_base64_encode(auth_b64, auth_b64_len, auth, strlen(auth));
snprintf(s->buffer, sizeof(s->buffer),
"%s %s HTTP/1.1\r\n"
"User-Agent: %s\r\n"
"Accept: */*\r\n"
"Range: bytes=%"PRId64"-\r\n"
"Host: %s\r\n"
"Authorization: Basic %s\r\n"
"Connection: close\r\n"
"%s"
"\r\n",
post ? "POST" : "GET",
path,
LIBAVFORMAT_IDENT,
s->off,
hoststr,
auth_b64,
post ? "Transfer-Encoding: chunked\r\n" : "");
av_freep(&auth_b64);
if (http_write(h, s->buffer, strlen(s->buffer)) < 0)
return AVERROR(EIO);
/* init input buffer */
s->buf_ptr = s->buffer;
s->buf_end = s->buffer;
s->line_count = 0;
s->off = 0;
s->filesize = -1;
if (post) {
/* always use chunked encoding for upload data */
s->chunksize = 0;
return 0;
}
/* wait for header */
for(;;) {
if (http_get_line(s, line, sizeof(line)) < 0)
return AVERROR(EIO);
dprintf(NULL, "header='%s'\n", line);
err = process_line(h, line, s->line_count, new_location);
if (err < 0)
return err;
if (err == 0)
break;
s->line_count++;
}
return (off == s->off) ? 0 : -1;
}
static int http_read(URLContext *h, uint8_t *buf, int size)
{
HTTPContext *s = h->priv_data;
int len;
if (s->chunksize >= 0) {
if (!s->chunksize) {
char line[32];
for(;;) {
do {
if (http_get_line(s, line, sizeof(line)) < 0)
return AVERROR(EIO);
} while (!*line); /* skip CR LF from last chunk */
s->chunksize = strtoll(line, NULL, 16);
dprintf(NULL, "Chunked encoding data size: %"PRId64"'\n", s->chunksize);
if (!s->chunksize)
return 0;
break;
}
}
size = FFMIN(size, s->chunksize);
}
/* read bytes from input buffer first */
len = s->buf_end - s->buf_ptr;
if (len > 0) {
if (len > size)
len = size;
memcpy(buf, s->buf_ptr, len);
s->buf_ptr += len;
} else {
len = url_read(s->hd, buf, size);
}
if (len > 0) {
s->off += len;
if (s->chunksize > 0)
s->chunksize -= len;
}
return len;
}
/* used only when posting data */
static int http_write(URLContext *h, uint8_t *buf, int size)
{
char temp[11]; /* 32-bit hex + CRLF + nul */
int ret;
char crlf[] = "\r\n";
HTTPContext *s = h->priv_data;
if (s->chunksize == -1) {
/* headers are sent without any special encoding */
return url_write(s->hd, buf, size);
}
/* silently ignore zero-size data since chunk encoding that would
* signal EOF */
if (size > 0) {
/* upload data using chunked encoding */
snprintf(temp, sizeof(temp), "%x\r\n", size);
if ((ret = url_write(s->hd, temp, strlen(temp))) < 0 ||
(ret = url_write(s->hd, buf, size)) < 0 ||
(ret = url_write(s->hd, crlf, sizeof(crlf) - 1)) < 0)
return ret;
}
return size;
}
static int http_close(URLContext *h)
{
int ret = 0;
char footer[] = "0\r\n\r\n";
HTTPContext *s = h->priv_data;
/* signal end of chunked encoding if used */
if ((h->flags & URL_WRONLY) && s->chunksize != -1) {
ret = url_write(s->hd, footer, sizeof(footer) - 1);
ret = ret > 0 ? 0 : ret;
}
url_close(s->hd);
av_free(s);
return ret;
}
static int64_t http_seek(URLContext *h, int64_t off, int whence)
{
HTTPContext *s = h->priv_data;
URLContext *old_hd = s->hd;
int64_t old_off = s->off;
uint8_t old_buf[BUFFER_SIZE];
int old_buf_size;
if (whence == AVSEEK_SIZE)
return s->filesize;
else if ((s->filesize == -1 && whence == SEEK_END) || h->is_streamed)
return -1;
/* we save the old context in case the seek fails */
old_buf_size = s->buf_end - s->buf_ptr;
memcpy(old_buf, s->buf_ptr, old_buf_size);
s->hd = NULL;
if (whence == SEEK_CUR)
off += s->off;
else if (whence == SEEK_END)
off += s->filesize;
s->off = off;
/* if it fails, continue on old connection */
if (http_open_cnx(h) < 0) {
memcpy(s->buffer, old_buf, old_buf_size);
s->buf_ptr = s->buffer;
s->buf_end = s->buffer + old_buf_size;
s->hd = old_hd;
s->off = old_off;
return -1;
}
url_close(old_hd);
return off;
}
static int
http_get_file_handle(URLContext *h)
{
HTTPContext *s = h->priv_data;
return url_get_file_handle(s->hd);
}
URLProtocol http_protocol = {
"http",
http_open,
http_read,
http_write,
http_seek,
http_close,
.url_get_file_handle = http_get_file_handle,
};