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