transmission/libtransmission/bencode.c

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C
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2006-07-16 19:39:23 +00:00
/******************************************************************************
* $Id$
*
* Copyright (c) 2005-2006 Transmission authors and contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include "transmission.h"
#define LIST_SIZE 20
#define OUTBUF_SIZE 100
static int tr_bencSprintf( char ** buf, size_t * used, size_t * max,
char * format, ... )
#ifdef __GNUC__
__attribute__ ((format (printf, 4, 5)))
#endif
;
int _tr_bencLoad( char * buf, size_t len, benc_val_t * val, char ** end )
{
char * p, * e, * foo;
if( 1 >= len )
{
return 1;
}
if( !end )
{
/* So we only have to check once */
end = &foo;
}
val->begin = buf;
if( buf[0] == 'i' )
{
e = memchr( &buf[1], 'e', len - 1 );
if( NULL == e )
{
return 1;
}
/* Integer: i1242e */
val->type = TYPE_INT;
*e = '\0';
val->val.i = strtoll( &buf[1], &p, 10 );
*e = 'e';
if( p != e )
{
return 1;
}
val->end = p + 1;
}
else if( buf[0] == 'l' || buf[0] == 'd' )
{
/* List: l<item1><item2>e
Dict: d<string1><item1><string2><item2>e
A dictionary is just a special kind of list with an even
count of items, and where even items are strings. */
char * cur;
char is_dict;
char str_expected;
is_dict = ( buf[0] == 'd' );
val->type = is_dict ? TYPE_DICT : TYPE_LIST;
val->val.l.alloc = LIST_SIZE;
val->val.l.count = 0;
val->val.l.vals = malloc( LIST_SIZE * sizeof( benc_val_t ) );
cur = &buf[1];
str_expected = 1;
while( (size_t)(cur - buf) < len && cur[0] != 'e' )
{
if( val->val.l.count == val->val.l.alloc )
{
/* We need a bigger boat */
val->val.l.alloc += LIST_SIZE;
val->val.l.vals = realloc( val->val.l.vals,
val->val.l.alloc * sizeof( benc_val_t ) );
}
if( tr_bencLoad( cur, len - (cur - buf),
&val->val.l.vals[val->val.l.count], &p ) )
{
tr_bencFree( val );
return 1;
}
val->val.l.count++;
if( is_dict && str_expected &&
val->val.l.vals[val->val.l.count - 1].type != TYPE_STR )
{
tr_bencFree( val );
return 1;
}
str_expected = !str_expected;
cur = p;
}
if( is_dict && ( val->val.l.count & 1 ) )
{
tr_bencFree( val );
return 1;
}
val->end = cur + 1;
}
else
{
e = memchr( buf, ':', len );
if( NULL == e )
{
return 1;
}
/* String: 12:whateverword */
val->type = TYPE_STR;
e[0] = '\0';
val->val.s.i = strtol( buf, &p, 10 );
e[0] = ':';
if( p != e || 0 > val->val.s.i ||
(size_t)(val->val.s.i) > len - ((p + 1) - buf) )
{
return 1;
}
val->val.s.s = malloc( val->val.s.i + 1 );
val->val.s.s[val->val.s.i] = 0;
memcpy( val->val.s.s, p + 1, val->val.s.i );
val->end = p + 1 + val->val.s.i;
}
*end = val->end;
return 0;
}
static void __bencPrint( benc_val_t * val, int space )
{
int i;
for( i = 0; i < space; i++ )
{
fprintf( stderr, " " );
}
switch( val->type )
{
case TYPE_INT:
fprintf( stderr, "int: %"PRIu64"\n", val->val.i );
break;
case TYPE_STR:
fprintf( stderr, "%s\n", val->val.s.s );
break;
case TYPE_LIST:
fprintf( stderr, "list\n" );
for( i = 0; i < val->val.l.count; i++ )
__bencPrint( &val->val.l.vals[i], space + 1 );
break;
case TYPE_DICT:
fprintf( stderr, "dict\n" );
for( i = 0; i < val->val.l.count; i++ )
__bencPrint( &val->val.l.vals[i], space + 1 );
break;
}
}
void tr_bencPrint( benc_val_t * val )
{
__bencPrint( val, 0 );
}
void tr_bencFree( benc_val_t * val )
{
int i;
switch( val->type )
{
case TYPE_INT:
break;
case TYPE_STR:
if( val->val.s.s )
{
free( val->val.s.s );
}
break;
case TYPE_LIST:
case TYPE_DICT:
for( i = 0; i < val->val.l.count; i++ )
{
tr_bencFree( &val->val.l.vals[i] );
}
free( val->val.l.vals );
break;
}
}
benc_val_t * tr_bencDictFind( benc_val_t * val, char * key )
{
int i;
if( val->type != TYPE_DICT )
{
return NULL;
}
for( i = 0; i < val->val.l.count; i += 2 )
{
if( !strcmp( val->val.l.vals[i].val.s.s, key ) )
{
return &val->val.l.vals[i+1];
}
}
return NULL;
}
char * tr_bencSaveMalloc( benc_val_t * val, size_t * len )
{
char * buf = NULL;
size_t alloc = 0;
*len = 0;
if( tr_bencSave( val, &buf, len, &alloc ) )
{
if( NULL != buf )
{
free(buf);
}
*len = 0;
return NULL;
}
return buf;
}
int tr_bencSave( benc_val_t * val, char ** buf, size_t * used, size_t * max )
{
int ii;
switch( val->type )
{
case TYPE_INT:
if( tr_bencSprintf( buf, used, max, "i%"PRIu64"e", val->val.i ) )
{
return 1;
}
break;
case TYPE_STR:
if( (int)strlen(val->val.s.s) != val->val.s.i )
{
return 1;
}
if( tr_bencSprintf( buf, used, max, "%i:%s",
val->val.s.i, val->val.s.s ) )
{
return 1;
}
break;
case TYPE_LIST:
case TYPE_DICT:
if( tr_bencSprintf( buf, used, max,
(TYPE_LIST == val->type ? "l" : "d") ) )
{
return 1;
}
for( ii = 0; val->val.l.count > ii; ii++ )
{
if( tr_bencSave( val->val.l.vals + ii, buf, used, max ) )
{
return 1;
}
}
if( tr_bencSprintf( buf, used, max, "e" ) )
{
return 1;
}
break;
}
return 0;
}
static int tr_bencSprintf( char ** buf, size_t * used, size_t * max,
char * format, ... )
{
va_list ap;
int want;
char * newbuf;
va_start( ap, format );
want = vsnprintf( NULL, 0, format, ap );
va_end(ap);
while( *used + want + 1 > *max )
{
*max += OUTBUF_SIZE;
newbuf = realloc( *buf, *max );
if( NULL == newbuf )
{
return 1;
}
*buf = newbuf;
}
va_start( ap, format );
*used += vsnprintf( *buf + *used, *max - *used, format, ap );
va_end( ap );
return 0;
}