libavformat/mms.c

   1 /*
   2  * MMS protocol common definitions.
   3  * Copyright (c) 2006,2007 Ryan Martell
   4  * Copyright (c) 2007 Björn Axelsson
   5  * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com>
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23 #include "mms.h"
  24 #include "asf.h"
  25 #include "libavutil/intreadwrite.h"
  26 #include "libavutil/mem.h"
  27
  28 #define MMS_MAX_STREAMS 256    /**< arbitrary sanity check value */
  29
  30 int ff_mms_read_header(MMSContext *mms, uint8_t *buf, const int size)
  31 {
  32     char *pos;
  33     int size_to_copy;
  34     int remaining_size = mms->asf_header_size - mms->asf_header_read_size;
  35     size_to_copy = FFMIN(size, remaining_size);
  36     pos = mms->asf_header + mms->asf_header_read_size;
  37     memcpy(buf, pos, size_to_copy);
  38     if (mms->asf_header_read_size == mms->asf_header_size) {
  39         av_freep(&mms->asf_header); // which contains asf header
  40     }
  41     mms->asf_header_read_size += size_to_copy;
  42     return size_to_copy;
  43 }
  44
  45 int ff_mms_read_data(MMSContext *mms, uint8_t *buf, const int size)
  46 {
  47     int read_size;
  48     read_size = FFMIN(size, mms->remaining_in_len);
  49     memcpy(buf, mms->read_in_ptr, read_size);
  50     mms->remaining_in_len -= read_size;
  51     mms->read_in_ptr      += read_size;
  52     return read_size;
  53 }
  54
  55 int ff_mms_asf_header_parser(MMSContext *mms)
  56 {
  57     uint8_t *p = mms->asf_header;
  58     uint8_t *end;
  59     int flags, stream_id;
  60     mms->stream_num = 0;
  61
  62     if (mms->asf_header_size < sizeof(ff_asf_guid) * 2 + 22 ||
  63         memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
  64         av_log(mms->mms_hd, AV_LOG_ERROR,
  65                "Corrupt stream (invalid ASF header, size=%d)\n",
  66                mms->asf_header_size);
  67         return AVERROR_INVALIDDATA;
  68     }
  69
  70     end = mms->asf_header + mms->asf_header_size;
  71
  72     p += sizeof(ff_asf_guid) + 14;
  73     while(end - p >= sizeof(ff_asf_guid) + 8) {
  74         uint64_t chunksize;
  75         if (!memcmp(p, ff_asf_data_header, sizeof(ff_asf_guid))) {
  76             chunksize = 50; // see Reference [2] section 5.1
  77         } else {
  78             chunksize = AV_RL64(p + sizeof(ff_asf_guid));
  79         }
  80         if (!chunksize || chunksize > end - p) {
  81             av_log(mms->mms_hd, AV_LOG_ERROR,
  82                    "Corrupt stream (header chunksize %"PRId64" is invalid)\n",
  83                    chunksize);
  84             return AVERROR_INVALIDDATA;
  85         }
  86         if (!memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
  87             /* read packet size */
  88             if (end - p > sizeof(ff_asf_guid) * 2 + 68) {
  89                 mms->asf_packet_len = AV_RL32(p + sizeof(ff_asf_guid) * 2 + 64);
  90                 if (mms->asf_packet_len <= 0 || mms->asf_packet_len > sizeof(mms->in_buffer)) {
  91                     av_log(mms->mms_hd, AV_LOG_ERROR,
  92                            "Corrupt stream (too large pkt_len %d)\n",
  93                            mms->asf_packet_len);
  94                     return AVERROR_INVALIDDATA;
  95                 }
  96             }
  97         } else if (!memcmp(p, ff_asf_stream_header, sizeof(ff_asf_guid))) {
  98             if (end - p >= (sizeof(ff_asf_guid) * 3 + 26)) {
  99                 flags     = AV_RL16(p + sizeof(ff_asf_guid)*3 + 24);
 100                 stream_id = flags & 0x7F;
 101                 //The second condition is for checking CS_PKT_STREAM_ID_REQUEST packet size,
 102                 //we can calculate the packet size by stream_num.
 103                 //Please see function send_stream_selection_request().
 104                 if (mms->stream_num < MMS_MAX_STREAMS &&
 105                         46 + mms->stream_num * 6 < sizeof(mms->out_buffer)) {
 106                     mms->streams = av_fast_realloc(mms->streams,
 107                                        &mms->nb_streams_allocated,
 108                                        (mms->stream_num + 1) * sizeof(MMSStream));
 109                     if (!mms->streams)
 110                         return AVERROR(ENOMEM);
 111                     mms->streams[mms->stream_num].id = stream_id;
 112                     mms->stream_num++;
 113                 } else {
 114                     av_log(mms->mms_hd, AV_LOG_ERROR,
 115                            "Corrupt stream (too many A/V streams)\n");
 116                     return AVERROR_INVALIDDATA;
 117                 }
 118             }
 119         } else if (!memcmp(p, ff_asf_ext_stream_header, sizeof(ff_asf_guid))) {
 120             if (end - p >= 88) {
 121                 int stream_count = AV_RL16(p + 84), ext_len_count = AV_RL16(p + 86);
 122                 uint64_t skip_bytes = 88;
 123                 while (stream_count--) {
 124                     if (end - p < skip_bytes + 4) {
 125                         av_log(mms->mms_hd, AV_LOG_ERROR,
 126                                "Corrupt stream (next stream name length is not in the buffer)\n");
 127                         return AVERROR_INVALIDDATA;
 128                     }
 129                     skip_bytes += 4 + AV_RL16(p + skip_bytes + 2);
 130                 }
 131                 while (ext_len_count--) {
 132                     if (end - p < skip_bytes + 22) {
 133                         av_log(mms->mms_hd, AV_LOG_ERROR,
 134                                "Corrupt stream (next extension system info length is not in the buffer)\n");
 135                         return AVERROR_INVALIDDATA;
 136                     }
 137                     skip_bytes += 22 + AV_RL32(p + skip_bytes + 18);
 138                 }
 139                 if (end - p < skip_bytes) {
 140                     av_log(mms->mms_hd, AV_LOG_ERROR,
 141                            "Corrupt stream (the last extension system info length is invalid)\n");
 142                     return AVERROR_INVALIDDATA;
 143                 }
 144                 if (chunksize - skip_bytes > 24)
 145                     chunksize = skip_bytes;
 146             }
 147         } else if (!memcmp(p, ff_asf_head1_guid, sizeof(ff_asf_guid))) {
 148             chunksize = 46; // see references [2] section 3.4. This should be set 46.
 149             if (chunksize > end - p) {
 150                 av_log(mms->mms_hd, AV_LOG_ERROR,
 151                     "Corrupt stream (header chunksize %"PRId64" is invalid)\n",
 152                     chunksize);
 153                 return AVERROR_INVALIDDATA;
 154             }
 155         }
 156         p += chunksize;
 157     }
 158
 159     return 0;
 160 }