transmission/libtransmission/bencode.c

477 lines
10 KiB
C

/******************************************************************************
* $Id$
*
* Copyright (c) 2005-2007 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"
/* setting to 1 to help expose bugs with tr_bencListAdd and tr_bencDictAdd */
#define LIST_SIZE 20 /* number of items to increment list/dict buffer by */
static int makeroom( benc_val_t * val, int count )
{
int len;
void * new;
assert( TYPE_LIST == val->type || TYPE_DICT == val->type );
if( val->val.l.count + count <= val->val.l.alloc )
{
return 1;
}
/* We need a bigger boat */
len = val->val.l.alloc + count + ( count % LIST_SIZE ? 0 : LIST_SIZE );
new = realloc( val->val.l.vals, len * sizeof( benc_val_t ) );
if( NULL == new )
{
return 1;
}
val->val.l.alloc = len;
val->val.l.vals = new;
return 0;
}
int _tr_bencLoad( char * buf, int len, benc_val_t * val, char ** end )
{
char * p, * e, * foo;
if( NULL == buf || 1 >= len )
{
return 1;
}
if( !end )
{
/* So we only have to check once */
end = &foo;
}
if( buf[0] == 'i' )
{
int64_t num;
e = memchr( &buf[1], 'e', len - 1 );
if( NULL == e )
{
return 1;
}
/* Integer: i1242e */
*e = '\0';
num = strtoll( &buf[1], &p, 10 );
*e = 'e';
if( p != e )
{
return 1;
}
tr_bencInitInt( val, num );
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' );
cur = &buf[1];
str_expected = 1;
tr_bencInit( val, ( is_dict ? TYPE_DICT : TYPE_LIST ) );
while( cur - buf < len && cur[0] != 'e' )
{
if( makeroom( val, 1 ) ||
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
{
int slen;
char * sbuf;
e = memchr( buf, ':', len );
if( NULL == e )
{
return 1;
}
/* String: 12:whateverword */
e[0] = '\0';
slen = strtol( buf, &p, 10 );
e[0] = ':';
if( p != e || 0 > slen || len - ( ( p + 1 ) - buf ) < slen )
{
return 1;
}
sbuf = malloc( slen + 1 );
if( NULL == sbuf )
{
return 1;
}
memcpy( sbuf, p + 1, slen );
sbuf[slen] = '\0';
tr_bencInitStr( val, sbuf, slen, 0 );
val->end = p + 1 + val->val.s.i;
}
val->begin = buf;
*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:
fwrite( val->val.s.s, 1, val->val.s.i, stderr );
putc( '\n', stderr );
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.nofree )
{
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, const char * key )
{
int len, i;
if( val->type != TYPE_DICT )
{
return NULL;
}
len = strlen( key );
for( i = 0; i < val->val.l.count; i += 2 )
{
if( TYPE_STR != val->val.l.vals[i].type ||
len != val->val.l.vals[i].val.s.i )
{
continue;
}
if( 0 == memcmp(val->val.l.vals[i].val.s.s, key, len ) )
{
return &val->val.l.vals[i+1];
}
}
return NULL;
}
benc_val_t * tr_bencDictFindFirst( benc_val_t * val, ... )
{
const char * key;
benc_val_t * ret;
va_list ap;
va_start( ap, val );
while( ( key = va_arg( ap, const char * ) ) )
{
ret = tr_bencDictFind( val, key );
if( NULL != ret )
{
break;
}
}
va_end( ap );
return ret;
}
benc_val_t * tr_bencListIter( benc_val_t * list, int * pos )
{
assert( TYPE_LIST == list->type );
if( NULL == list->val.l.vals )
{
return NULL;
}
if( 0 > *pos )
{
*pos = 0;
}
if( list->val.l.count <= *pos )
{
return NULL;
}
(*pos)++;
return &list->val.l.vals[ (*pos) - 1 ];
}
char * tr_bencStealStr( benc_val_t * val )
{
assert( TYPE_STR == val->type );
val->val.s.nofree = 1;
return val->val.s.s;
}
void _tr_bencInitStr( benc_val_t * val, char * str, int len, int nofree )
{
tr_bencInit( val, TYPE_STR );
val->val.s.s = str;
val->val.s.nofree = nofree;
if( 0 >= len )
{
len = ( NULL == str ? 0 : strlen( str ) );
}
val->val.s.i = len;
}
int tr_bencInitStrDup( benc_val_t * val, const char * str )
{
char * new = NULL;
if( NULL != str )
{
new = strdup( str );
if( NULL == new )
{
return 1;
}
}
_tr_bencInitStr( val, new, 0, 0 );
return 0;
}
void tr_bencInitInt( benc_val_t * val, int64_t num )
{
tr_bencInit( val, TYPE_INT );
val->val.i = num;
}
int tr_bencListReserve( benc_val_t * val, int count )
{
assert( TYPE_LIST == val->type );
if( makeroom( val, count ) )
{
return 1;
}
return 0;
}
int tr_bencDictReserve( benc_val_t * val, int count )
{
assert( TYPE_DICT == val->type );
if( makeroom( val, count * 2 ) )
{
return 1;
}
return 0;
}
benc_val_t * tr_bencListAdd( benc_val_t * list )
{
benc_val_t * item;
assert( TYPE_LIST == list->type );
assert( list->val.l.count < list->val.l.alloc );
item = &list->val.l.vals[list->val.l.count];
list->val.l.count++;
tr_bencInit( item, TYPE_INT );
return item;
}
benc_val_t * tr_bencDictAdd( benc_val_t * dict, const char * key )
{
benc_val_t * keyval, * itemval;
assert( TYPE_DICT == dict->type );
assert( dict->val.l.count + 2 <= dict->val.l.alloc );
keyval = &dict->val.l.vals[dict->val.l.count];
dict->val.l.count++;
itemval = &dict->val.l.vals[dict->val.l.count];
dict->val.l.count++;
tr_bencInitStr( keyval, key, -1, 1 );
tr_bencInit( itemval, TYPE_INT );
return itemval;
}
char * tr_bencSaveMalloc( benc_val_t * val, int * len )
{
char * buf = NULL;
int 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, int * used, int * max )
{
int ii;
switch( val->type )
{
case TYPE_INT:
if( tr_sprintf( buf, used, max, "i%"PRIu64"e", val->val.i ) )
{
return 1;
}
break;
case TYPE_STR:
if( tr_sprintf( buf, used, max, "%i:", val->val.s.i ) ||
tr_concat( buf, used, max, val->val.s.s, val->val.s.i ) )
{
return 1;
}
break;
case TYPE_LIST:
case TYPE_DICT:
if( tr_sprintf( 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_sprintf( buf, used, max, "e" ) )
{
return 1;
}
break;
}
return 0;
}