Commit f93e275d authored by Sam Hocevar's avatar Sam Hocevar

* modules/codec/spudec: fixed various (innocuous) buffer overflows and

    paved the way for private SPU commands.
parent 6fbe51ed
/*****************************************************************************
* parse.c: SPU parser
*****************************************************************************
* Copyright (C) 2000-2001, 2005 the VideoLAN team
* Copyright (C) 2000-2001, 2005, 2006 the VideoLAN team
* $Id$
*
* Authors: Samuel Hocevar <sam@zoy.org>
* Authors: Sam Hocevar <sam@zoy.org>
* Laurent Aimar <fenrir@via.ecp.fr>
* Gildas Bazin <gbazin@videolan.org>
*
......@@ -149,21 +149,18 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
p_spu->i_start = p_spu->i_stop = 0;
p_spu->b_ephemer = VLC_FALSE;
do
for( i_index = 4 + p_sys->i_rle_size; i_index < p_sys->i_spu_size ; )
{
if( (int)i_index >= p_sys->i_spu_size + 1 )
{
/* sanity
* XXX only on test by loop as p_sys->buffer is bigger than needed
* to avoid checking at each access
*/
break;
}
/* If we just read a command sequence, read the next one;
* otherwise, go on with the commands of the current sequence. */
if( i_command == SPU_CMD_END )
{
if( i_index + 4 > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU command sequence" );
return VLC_EGENERIC;
}
/* Get the control sequence date */
date = (mtime_t)GetWBE( &p_sys->buffer[i_index] ) * 11000;
/* FIXME How to access i_rate
......@@ -174,41 +171,56 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
i_cur_seq = i_index;
i_next_seq = GetWBE( &p_sys->buffer[i_index+2] );
if( i_next_seq > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU next command sequence" );
return VLC_EGENERIC;
}
/* Skip what we just read */
i_index += 4;
}
i_command = p_sys->buffer[i_index++];
i_command = p_sys->buffer[i_index];
switch( i_command )
{
case SPU_CMD_FORCE_DISPLAY: /* 00 (force displaying) */
p_spu->i_start = p_spu_data->i_pts + date;
p_spu->b_ephemer = VLC_TRUE;
i_index += 1;
break;
/* Convert the dates in seconds to PTS values */
case SPU_CMD_START_DISPLAY: /* 01 (start displaying) */
p_spu->i_start = p_spu_data->i_pts + date;
i_index += 1;
break;
case SPU_CMD_STOP_DISPLAY: /* 02 (stop displaying) */
p_spu->i_stop = p_spu_data->i_pts + date;
i_index += 1;
break;
case SPU_CMD_SET_PALETTE:
/* 03xxxx (palette) */
if( i_index + 3 > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU command" );
return VLC_EGENERIC;
}
if( p_dec->fmt_in.subs.spu.palette[0] == 0xBeeF )
{
unsigned int idx[4];
p_spu_data->b_palette = VLC_TRUE;
idx[0] = (p_sys->buffer[i_index+0]>>4)&0x0f;
idx[1] = (p_sys->buffer[i_index+0])&0x0f;
idx[2] = (p_sys->buffer[i_index+1]>>4)&0x0f;
idx[3] = (p_sys->buffer[i_index+1])&0x0f;
idx[0] = (p_sys->buffer[i_index+1]>>4)&0x0f;
idx[1] = (p_sys->buffer[i_index+1])&0x0f;
idx[2] = (p_sys->buffer[i_index+2]>>4)&0x0f;
idx[3] = (p_sys->buffer[i_index+2])&0x0f;
for( i = 0; i < 4 ; i++ )
{
......@@ -220,15 +232,21 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
p_spu_data->pi_yuv[3-i][2] = (i_color>>8) & 0xff;
}
}
i_index += 2;
i_index += 3;
break;
case SPU_CMD_SET_ALPHACHANNEL: /* 04xxxx (alpha channel) */
pi_alpha[3] = (p_sys->buffer[i_index+0]>>4)&0x0f;
pi_alpha[2] = (p_sys->buffer[i_index+0])&0x0f;
pi_alpha[1] = (p_sys->buffer[i_index+1]>>4)&0x0f;
pi_alpha[0] = (p_sys->buffer[i_index+1])&0x0f;
if( i_index + 3 > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU command" );
return VLC_EGENERIC;
}
pi_alpha[3] = (p_sys->buffer[i_index+1]>>4)&0x0f;
pi_alpha[2] = (p_sys->buffer[i_index+1])&0x0f;
pi_alpha[1] = (p_sys->buffer[i_index+2]>>4)&0x0f;
pi_alpha[0] = (p_sys->buffer[i_index+2])&0x0f;
/* Ignore blank alpha palette. Sometimes spurious blank
* alpha palettes are present - dunno why. */
......@@ -244,39 +262,73 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
msg_Warn( p_dec, "ignoring blank alpha palette" );
}
i_index += 2;
i_index += 3;
break;
case SPU_CMD_SET_COORDINATES: /* 05xxxyyyxxxyyy (coordinates) */
p_spu->i_x = (p_sys->buffer[i_index+0]<<4)|
((p_sys->buffer[i_index+1]>>4)&0x0f);
p_spu->i_width = (((p_sys->buffer[i_index+1]&0x0f)<<8)|
p_sys->buffer[i_index+2]) - p_spu->i_x + 1;
if( i_index + 7 > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU command" );
return VLC_EGENERIC;
}
p_spu->i_y = (p_sys->buffer[i_index+3]<<4)|
((p_sys->buffer[i_index+4]>>4)&0x0f);
p_spu->i_height = (((p_sys->buffer[i_index+4]&0x0f)<<8)|
p_sys->buffer[i_index+5]) - p_spu->i_y + 1;
p_spu->i_x = (p_sys->buffer[i_index+1]<<4)|
((p_sys->buffer[i_index+2]>>4)&0x0f);
p_spu->i_width = (((p_sys->buffer[i_index+2]&0x0f)<<8)|
p_sys->buffer[i_index+3]) - p_spu->i_x + 1;
p_spu->i_y = (p_sys->buffer[i_index+4]<<4)|
((p_sys->buffer[i_index+5]>>4)&0x0f);
p_spu->i_height = (((p_sys->buffer[i_index+5]&0x0f)<<8)|
p_sys->buffer[i_index+6]) - p_spu->i_y + 1;
/* Auto crop fullscreen subtitles */
if( p_spu->i_height > 250 )
p_spu_data->b_auto_crop = VLC_TRUE;
i_index += 6;
i_index += 7;
break;
case SPU_CMD_SET_OFFSETS: /* 06xxxxyyyy (byte offsets) */
p_spu_data->pi_offset[0] = GetWBE(&p_sys->buffer[i_index+0]) - 4;
p_spu_data->pi_offset[1] = GetWBE(&p_sys->buffer[i_index+2]) - 4;
i_index += 4;
if( i_index + 5 > p_sys->i_spu_size )
{
msg_Err( p_dec, "overflow in SPU command" );
return VLC_EGENERIC;
}
p_spu_data->pi_offset[0] = GetWBE(&p_sys->buffer[i_index+1]) - 4;
p_spu_data->pi_offset[1] = GetWBE(&p_sys->buffer[i_index+3]) - 4;
i_index += 5;
break;
case SPU_CMD_END: /* ff (end) */
i_index += 1;
break;
default: /* xx (unknown command) */
msg_Warn( p_dec, "unknown command 0x%.2x", i_command );
return VLC_EGENERIC;
msg_Warn( p_dec, "unknown SPU command 0x%.2x", i_command );
if( i_index + 1 < i_next_seq )
{
/* There is at least one other command sequence */
if( p_sys->buffer[i_next_seq - 1] == SPU_CMD_END )
{
/* This is consistent. Skip to that command sequence. */
i_index = i_next_seq;
}
else
{
/* There were other commands. */
msg_Warn( p_dec, "cannot recover, dropping subtitle" );
return VLC_EGENERIC;
}
}
else
{
/* We were in the last command sequence. Stop parsing by
* pretending we met an SPU_CMD_END command. */
i_command = SPU_CMD_END;
i_index++;
}
}
/* We need to check for quit commands here */
......@@ -285,7 +337,11 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
return VLC_EGENERIC;
}
} while( i_command != SPU_CMD_END || i_index == i_next_seq );
if( i_command == SPU_CMD_END && i_index != i_next_seq )
{
break;
}
}
/* Check that the next sequence index matches the current one */
if( i_next_seq != i_cur_seq )
......@@ -295,7 +351,7 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
return VLC_EGENERIC;
}
if( (int)i_index > p_sys->i_spu_size )
if( i_index > p_sys->i_spu_size )
{
msg_Err( p_dec, "uh-oh, we went too far (0x%.4x > 0x%.4x)",
i_index, p_sys->i_spu_size );
......@@ -315,11 +371,11 @@ static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
}
/* Get rid of padding bytes */
if( p_sys->i_spu_size > (int)i_index + 1 )
if( p_sys->i_spu_size > i_index + 1 )
{
/* Zero or one padding byte, are quite usual
/* Zero or one padding byte are quite usual
* More than one padding byte - this is very strange, but
* we can deal with it */
* we can ignore them. */
msg_Warn( p_dec, "%i padding bytes, we usually get 0 or 1 of them",
p_sys->i_spu_size - i_index );
}
......
/*****************************************************************************
* spudec.c : SPU decoder thread
*****************************************************************************
* Copyright (C) 2000-2001 the VideoLAN team
* Copyright (C) 2000-2001, 2006 the VideoLAN team
* $Id$
*
* Authors: Samuel Hocevar <sam@zoy.org>
* Authors: Sam Hocevar <sam@zoy.org>
* Laurent Aimar <fenrir@via.ecp.fr>
*
* This program is free software; you can redistribute it and/or modify
......@@ -119,7 +119,11 @@ static void Close( vlc_object_t *p_this )
decoder_t *p_dec = (decoder_t*)p_this;
decoder_sys_t *p_sys = p_dec->p_sys;
if( p_sys->p_block ) block_ChainRelease( p_sys->p_block );
if( p_sys->p_block )
{
block_ChainRelease( p_sys->p_block );
}
free( p_sys );
}
......@@ -130,28 +134,30 @@ static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
{
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_spu_block;
subpicture_t *p_spu;
if( (p_spu_block = Reassemble( p_dec, pp_block )) )
{
subpicture_t *p_spu;
p_spu_block = Reassemble( p_dec, pp_block );
p_sys->i_spu = block_ChainExtract( p_spu_block, p_sys->buffer, 65536 );
p_sys->i_pts = p_spu_block->i_pts;
block_ChainRelease( p_spu_block );
if( ! p_spu_block )
{
return NULL;
}
/* Parse and decode */
p_spu = E_(ParsePacket)( p_dec );
/* FIXME: what the, we shouldn’t need to allocate 64k of buffer --sam. */
p_sys->i_spu = block_ChainExtract( p_spu_block, p_sys->buffer, 65536 );
p_sys->i_pts = p_spu_block->i_pts;
block_ChainRelease( p_spu_block );
/* reinit context */
p_sys->i_spu_size = 0;
p_sys->i_rle_size = 0;
p_sys->i_spu = 0;
p_sys->p_block = NULL;
/* Parse and decode */
p_spu = E_(ParsePacket)( p_dec );
return p_spu;
}
/* reinit context */
p_sys->i_spu_size = 0;
p_sys->i_rle_size = 0;
p_sys->i_spu = 0;
p_sys->p_block = NULL;
return NULL;
return p_spu;
}
/*****************************************************************************
......@@ -162,21 +168,21 @@ static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_spu = Reassemble( p_dec, pp_block );
if( p_spu )
if( ! p_spu )
{
p_spu->i_dts = p_spu->i_pts;
p_spu->i_length = 0;
return NULL;
}
/* reinit context */
p_sys->i_spu_size = 0;
p_sys->i_rle_size = 0;
p_sys->i_spu = 0;
p_sys->p_block = NULL;
p_spu->i_dts = p_spu->i_pts;
p_spu->i_length = 0;
return block_ChainGather( p_spu );
}
/* reinit context */
p_sys->i_spu_size = 0;
p_sys->i_rle_size = 0;
p_sys->i_spu = 0;
p_sys->p_block = NULL;
return NULL;
return block_ChainGather( p_spu );
}
/*****************************************************************************
......
/*****************************************************************************
* spudec.h : sub picture unit decoder thread interface
*****************************************************************************
* Copyright (C) 1999, 2000 the VideoLAN team
* Copyright (C) 1999, 2000, 2006 the VideoLAN team
* $Id$
*
* Authors: Samuel Hocevar <sam@zoy.org>
* Authors: Sam Hocevar <sam@zoy.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
......@@ -26,14 +26,14 @@ struct decoder_sys_t
int b_packetizer;
mtime_t i_pts;
int i_spu_size;
int i_rle_size;
int i_spu;
unsigned int i_spu_size;
unsigned int i_rle_size;
unsigned int i_spu;
block_t *p_block;
/* We will never overflow more than 11 bytes if I'm right */
uint8_t buffer[65536 + 20 ];
/* We will never overflow */
uint8_t buffer[65536];
};
typedef struct subpicture_data_t
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment