yading@11: /*
yading@11:  * MMS protocol common definitions.
yading@11:  * Copyright (c) 2006,2007 Ryan Martell
yading@11:  * Copyright (c) 2007 Björn Axelsson
yading@11:  * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: #include "mms.h"
yading@11: #include "asf.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: 
yading@11: #define MMS_MAX_STREAMS 256    /**< arbitrary sanity check value */
yading@11: 
yading@11: int ff_mms_read_header(MMSContext *mms, uint8_t *buf, const int size)
yading@11: {
yading@11:     char *pos;
yading@11:     int size_to_copy;
yading@11:     int remaining_size = mms->asf_header_size - mms->asf_header_read_size;
yading@11:     size_to_copy = FFMIN(size, remaining_size);
yading@11:     pos = mms->asf_header + mms->asf_header_read_size;
yading@11:     memcpy(buf, pos, size_to_copy);
yading@11:     if (mms->asf_header_read_size == mms->asf_header_size) {
yading@11:         av_freep(&mms->asf_header); // which contains asf header
yading@11:     }
yading@11:     mms->asf_header_read_size += size_to_copy;
yading@11:     return size_to_copy;
yading@11: }
yading@11: 
yading@11: int ff_mms_read_data(MMSContext *mms, uint8_t *buf, const int size)
yading@11: {
yading@11:     int read_size;
yading@11:     read_size = FFMIN(size, mms->remaining_in_len);
yading@11:     memcpy(buf, mms->read_in_ptr, read_size);
yading@11:     mms->remaining_in_len -= read_size;
yading@11:     mms->read_in_ptr      += read_size;
yading@11:     return read_size;
yading@11: }
yading@11: 
yading@11: int ff_mms_asf_header_parser(MMSContext *mms)
yading@11: {
yading@11:     uint8_t *p = mms->asf_header;
yading@11:     uint8_t *end;
yading@11:     int flags, stream_id;
yading@11:     mms->stream_num = 0;
yading@11: 
yading@11:     if (mms->asf_header_size < sizeof(ff_asf_guid) * 2 + 22 ||
yading@11:         memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
yading@11:         av_log(NULL, AV_LOG_ERROR,
yading@11:                "Corrupt stream (invalid ASF header, size=%d)\n",
yading@11:                mms->asf_header_size);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     end = mms->asf_header + mms->asf_header_size;
yading@11: 
yading@11:     p += sizeof(ff_asf_guid) + 14;
yading@11:     while(end - p >= sizeof(ff_asf_guid) + 8) {
yading@11:         uint64_t chunksize;
yading@11:         if (!memcmp(p, ff_asf_data_header, sizeof(ff_asf_guid))) {
yading@11:             chunksize = 50; // see Reference [2] section 5.1
yading@11:         } else {
yading@11:             chunksize = AV_RL64(p + sizeof(ff_asf_guid));
yading@11:         }
yading@11:         if (!chunksize || chunksize > end - p) {
yading@11:             av_log(NULL, AV_LOG_ERROR,
yading@11:                    "Corrupt stream (header chunksize %"PRId64" is invalid)\n",
yading@11:                    chunksize);
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         if (!memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
yading@11:             /* read packet size */
yading@11:             if (end - p > sizeof(ff_asf_guid) * 2 + 68) {
yading@11:                 mms->asf_packet_len = AV_RL32(p + sizeof(ff_asf_guid) * 2 + 64);
yading@11:                 if (mms->asf_packet_len <= 0 || mms->asf_packet_len > sizeof(mms->in_buffer)) {
yading@11:                     av_log(NULL, AV_LOG_ERROR,
yading@11:                            "Corrupt stream (too large pkt_len %d)\n",
yading@11:                            mms->asf_packet_len);
yading@11:                     return AVERROR_INVALIDDATA;
yading@11:                 }
yading@11:             }
yading@11:         } else if (!memcmp(p, ff_asf_stream_header, sizeof(ff_asf_guid))) {
yading@11:             flags     = AV_RL16(p + sizeof(ff_asf_guid)*3 + 24);
yading@11:             stream_id = flags & 0x7F;
yading@11:             //The second condition is for checking CS_PKT_STREAM_ID_REQUEST packet size,
yading@11:             //we can calcuate the packet size by stream_num.
yading@11:             //Please see function send_stream_selection_request().
yading@11:             if (mms->stream_num < MMS_MAX_STREAMS &&
yading@11:                     46 + mms->stream_num * 6 < sizeof(mms->out_buffer)) {
yading@11:                 mms->streams = av_fast_realloc(mms->streams,
yading@11:                                    &mms->nb_streams_allocated,
yading@11:                                    (mms->stream_num + 1) * sizeof(MMSStream));
yading@11:                 mms->streams[mms->stream_num].id = stream_id;
yading@11:                 mms->stream_num++;
yading@11:             } else {
yading@11:                 av_log(NULL, AV_LOG_ERROR,
yading@11:                        "Corrupt stream (too many A/V streams)\n");
yading@11:                 return AVERROR_INVALIDDATA;
yading@11:             }
yading@11:         } else if (!memcmp(p, ff_asf_ext_stream_header, sizeof(ff_asf_guid))) {
yading@11:             if (end - p >= 88) {
yading@11:                 int stream_count = AV_RL16(p + 84), ext_len_count = AV_RL16(p + 86);
yading@11:                 uint64_t skip_bytes = 88;
yading@11:                 while (stream_count--) {
yading@11:                     if (end - p < skip_bytes + 4) {
yading@11:                         av_log(NULL, AV_LOG_ERROR,
yading@11:                                "Corrupt stream (next stream name length is not in the buffer)\n");
yading@11:                         return AVERROR_INVALIDDATA;
yading@11:                     }
yading@11:                     skip_bytes += 4 + AV_RL16(p + skip_bytes + 2);
yading@11:                 }
yading@11:                 while (ext_len_count--) {
yading@11:                     if (end - p < skip_bytes + 22) {
yading@11:                         av_log(NULL, AV_LOG_ERROR,
yading@11:                                "Corrupt stream (next extension system info length is not in the buffer)\n");
yading@11:                         return AVERROR_INVALIDDATA;
yading@11:                     }
yading@11:                     skip_bytes += 22 + AV_RL32(p + skip_bytes + 18);
yading@11:                 }
yading@11:                 if (end - p < skip_bytes) {
yading@11:                     av_log(NULL, AV_LOG_ERROR,
yading@11:                            "Corrupt stream (the last extension system info length is invalid)\n");
yading@11:                     return AVERROR_INVALIDDATA;
yading@11:                 }
yading@11:                 if (chunksize - skip_bytes > 24)
yading@11:                     chunksize = skip_bytes;
yading@11:             }
yading@11:         } else if (!memcmp(p, ff_asf_head1_guid, sizeof(ff_asf_guid))) {
yading@11:             chunksize = 46; // see references [2] section 3.4. This should be set 46.
yading@11:         }
yading@11:         p += chunksize;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }