/* * MMS protocol common definitions. * Copyright (c) 2006,2007 Ryan Martell * Copyright (c) 2007 Bj�rn Axelsson * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "mms.h" #include "asf.h" #include "libavutil/intreadwrite.h" #define MMS_MAX_STREAMS 256 /**< arbitrary sanity check value */ int ff_mms_read_header(MMSContext *mms, uint8_t *buf, const int size) { char *pos; int size_to_copy; int remaining_size = mms->asf_header_size - mms->asf_header_read_size; size_to_copy = FFMIN(size, remaining_size); pos = mms->asf_header + mms->asf_header_read_size; memcpy(buf, pos, size_to_copy); if (mms->asf_header_read_size == mms->asf_header_size) { av_freep(&mms->asf_header); // which contains asf header } mms->asf_header_read_size += size_to_copy; return size_to_copy; } int ff_mms_read_data(MMSContext *mms, uint8_t *buf, const int size) { int read_size; read_size = FFMIN(size, mms->remaining_in_len); memcpy(buf, mms->read_in_ptr, read_size); mms->remaining_in_len -= read_size; mms->read_in_ptr += read_size; return read_size; } int ff_mms_asf_header_parser(MMSContext *mms) { uint8_t *p = mms->asf_header; uint8_t *end; int flags, stream_id; mms->stream_num = 0; if (mms->asf_header_size < sizeof(ff_asf_guid) * 2 + 22 || memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (invalid ASF header, size=%d)\n", mms->asf_header_size); return AVERROR_INVALIDDATA; } end = mms->asf_header + mms->asf_header_size; p += sizeof(ff_asf_guid) + 14; while(end - p >= sizeof(ff_asf_guid) + 8) { uint64_t chunksize; if (!memcmp(p, ff_asf_data_header, sizeof(ff_asf_guid))) { chunksize = 50; // see Reference [2] section 5.1 } else { chunksize = AV_RL64(p + sizeof(ff_asf_guid)); } if (!chunksize || chunksize > end - p) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (header chunksize %"PRId64" is invalid)\n", chunksize); return AVERROR_INVALIDDATA; } if (!memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) { /* read packet size */ if (end - p > sizeof(ff_asf_guid) * 2 + 68) { mms->asf_packet_len = AV_RL32(p + sizeof(ff_asf_guid) * 2 + 64); if (mms->asf_packet_len <= 0 || mms->asf_packet_len > sizeof(mms->in_buffer)) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (too large pkt_len %d)\n", mms->asf_packet_len); return AVERROR_INVALIDDATA; } } } else if (!memcmp(p, ff_asf_stream_header, sizeof(ff_asf_guid))) { flags = AV_RL16(p + sizeof(ff_asf_guid)*3 + 24); stream_id = flags & 0x7F; //The second condition is for checking CS_PKT_STREAM_ID_REQUEST packet size, //we can calcuate the packet size by stream_num. //Please see function send_stream_selection_request(). if (mms->stream_num < MMS_MAX_STREAMS && 46 + mms->stream_num * 6 < sizeof(mms->out_buffer)) { mms->streams = av_fast_realloc(mms->streams, &mms->nb_streams_allocated, (mms->stream_num + 1) * sizeof(MMSStream)); mms->streams[mms->stream_num].id = stream_id; mms->stream_num++; } else { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (too many A/V streams)\n"); return AVERROR_INVALIDDATA; } } else if (!memcmp(p, ff_asf_ext_stream_header, sizeof(ff_asf_guid))) { if (end - p >= 88) { int stream_count = AV_RL16(p + 84), ext_len_count = AV_RL16(p + 86); uint64_t skip_bytes = 88; while (stream_count--) { if (end - p < skip_bytes + 4) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (next stream name length is not in the buffer)\n"); return AVERROR_INVALIDDATA; } skip_bytes += 4 + AV_RL16(p + skip_bytes + 2); } while (ext_len_count--) { if (end - p < skip_bytes + 22) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (next extension system info length is not in the buffer)\n"); return AVERROR_INVALIDDATA; } skip_bytes += 22 + AV_RL32(p + skip_bytes + 18); } if (end - p < skip_bytes) { av_log(NULL, AV_LOG_ERROR, "Corrupt stream (the last extension system info length is invalid)\n"); return AVERROR_INVALIDDATA; } if (chunksize - skip_bytes > 24) chunksize = skip_bytes; } } else if (!memcmp(p, ff_asf_head1_guid, sizeof(ff_asf_guid))) { chunksize = 46; // see references [2] section 3.4. This should be set 46. } p += chunksize; } return 0; }