1
0
Fork 0
mirror of https://github.com/transmission/transmission synced 2024-12-25 17:17:31 +00:00
transmission/libtransmission/torrent-magnet.c
Jordan Lee 879a2afcbd Update the copyright year in the source code comments.
The Berne Convention says that the copyright year is moot, so instead of adding another year to each file as in previous years, I've removed the year altogether from the source code comments in libtransmission, gtk, qt, utils, daemon, and cli.

Juliusz's copyright notice in tr-dht and Johannes' copyright notice in tr-lpd have been left alone; it didn't seem appropriate to modify them.
2011-01-19 13:48:47 +00:00

394 lines
11 KiB
C

/*
* This file Copyright (C) Mnemosyne LLC
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <stdio.h> /* remove() */
#include <event2/buffer.h>
#include "transmission.h"
#include "bencode.h"
#include "crypto.h"
#include "magnet.h"
#include "metainfo.h"
#include "resume.h"
#include "torrent.h"
#include "torrent-magnet.h"
#include "utils.h"
#include "web.h"
#define dbgmsg( tor, ... ) \
do { \
if( tr_deepLoggingIsActive( ) ) \
tr_deepLog( __FILE__, __LINE__, tor->info.name, __VA_ARGS__ ); \
} while( 0 )
/***
****
***/
enum
{
/* don't ask for the same metadata piece more than this often */
MIN_REPEAT_INTERVAL_SECS = 3
};
struct metadata_node
{
time_t requestedAt;
int piece;
};
struct tr_incomplete_metadata
{
uint8_t * metadata;
int metadata_size;
int pieceCount;
/** sorted from least to most recently requested */
struct metadata_node * piecesNeeded;
int piecesNeededCount;
};
static void
incompleteMetadataFree( struct tr_incomplete_metadata * m )
{
tr_free( m->metadata );
tr_free( m->piecesNeeded );
tr_free( m );
}
void
tr_torrentSetMetadataSizeHint( tr_torrent * tor, int size )
{
if( !tr_torrentHasMetadata( tor ) )
{
if( tor->incompleteMetadata == NULL )
{
int i;
struct tr_incomplete_metadata * m;
const int n = ( size + ( METADATA_PIECE_SIZE - 1 ) ) / METADATA_PIECE_SIZE;
dbgmsg( tor, "metadata is %d bytes in %d pieces", size, n );
m = tr_new( struct tr_incomplete_metadata, 1 );
m->pieceCount = n;
m->metadata = tr_new( uint8_t, size );
m->metadata_size = size;
m->piecesNeededCount = n;
m->piecesNeeded = tr_new( struct metadata_node, n );
for( i=0; i<n; ++i ) {
m->piecesNeeded[i].piece = i;
m->piecesNeeded[i].requestedAt = 0;
}
tor->incompleteMetadata = m;
}
}
}
static int
findInfoDictOffset( const tr_torrent * tor )
{
size_t fileLen;
uint8_t * fileContents;
int offset = 0;
/* load the file, and find the info dict's offset inside the file */
if(( fileContents = tr_loadFile( tor->info.torrent, &fileLen )))
{
tr_benc top;
if( !tr_bencParse( fileContents, fileContents + fileLen, &top, NULL ) )
{
tr_benc * infoDict;
if( tr_bencDictFindDict( &top, "info", &infoDict ) )
{
int infoLen;
char * infoContents = tr_bencToStr( infoDict, TR_FMT_BENC, &infoLen );
const uint8_t * i = (const uint8_t*) tr_memmem( (char*)fileContents, fileLen, infoContents, infoLen );
offset = i != NULL ? i - fileContents : 0;
tr_free( infoContents );
}
tr_bencFree( &top );
}
tr_free( fileContents );
}
return offset;
}
static void
ensureInfoDictOffsetIsCached( tr_torrent * tor )
{
assert( tr_torrentHasMetadata( tor ) );
if( !tor->infoDictOffsetIsCached )
{
tor->infoDictOffset = findInfoDictOffset( tor );
tor->infoDictOffsetIsCached = TRUE;
}
}
void*
tr_torrentGetMetadataPiece( tr_torrent * tor, int piece, int * len )
{
char * ret = NULL;
assert( tr_isTorrent( tor ) );
assert( piece >= 0 );
assert( len != NULL );
if( tr_torrentHasMetadata( tor ) )
{
FILE * fp;
ensureInfoDictOffsetIsCached( tor );
assert( tor->infoDictLength > 0 );
assert( tor->infoDictOffset >= 0 );
fp = fopen( tor->info.torrent, "rb" );
if( fp != NULL )
{
const int o = piece * METADATA_PIECE_SIZE;
if( !fseek( fp, tor->infoDictOffset + o, SEEK_SET ) )
{
const int l = o + METADATA_PIECE_SIZE <= tor->infoDictLength
? METADATA_PIECE_SIZE
: tor->infoDictLength - o;
if( 0<l && l<=METADATA_PIECE_SIZE )
{
char * buf = tr_new( char, l );
const int n = fread( buf, 1, l, fp );
if( n == l )
{
*len = l;
ret = buf;
buf = NULL;
}
tr_free( buf );
}
}
fclose( fp );
}
}
return ret;
}
void
tr_torrentSetMetadataPiece( tr_torrent * tor, int piece, const void * data, int len )
{
int i;
struct tr_incomplete_metadata * m;
const int offset = piece * METADATA_PIECE_SIZE;
assert( tr_isTorrent( tor ) );
dbgmsg( tor, "got metadata piece %d", piece );
/* are we set up to download metadata? */
m = tor->incompleteMetadata;
if( m == NULL )
return;
/* does this data pass the smell test? */
if( offset + len > m->metadata_size )
return;
/* do we need this piece? */
for( i=0; i<m->piecesNeededCount; ++i )
if( m->piecesNeeded[i].piece == piece )
break;
if( i==m->piecesNeededCount )
return;
memcpy( m->metadata + offset, data, len );
tr_removeElementFromArray( m->piecesNeeded, i,
sizeof( struct metadata_node ),
m->piecesNeededCount-- );
dbgmsg( tor, "saving metainfo piece %d... %d remain", piece, m->piecesNeededCount );
/* are we done? */
if( m->piecesNeededCount == 0 )
{
tr_bool success = FALSE;
tr_bool checksumPassed = FALSE;
tr_bool metainfoParsed = FALSE;
uint8_t sha1[SHA_DIGEST_LENGTH];
/* we've got a complete set of metainfo... see if it passes the checksum test */
dbgmsg( tor, "metainfo piece %d was the last one", piece );
tr_sha1( sha1, m->metadata, m->metadata_size, NULL );
if(( checksumPassed = !memcmp( sha1, tor->info.hash, SHA_DIGEST_LENGTH )))
{
/* checksum passed; now try to parse it as benc */
tr_benc infoDict;
const int err = tr_bencLoad( m->metadata, m->metadata_size, &infoDict, NULL );
dbgmsg( tor, "err is %d", err );
if(( metainfoParsed = !err ))
{
/* yay we have bencoded metainfo... merge it into our .torrent file */
tr_benc newMetainfo;
char * path = tr_strdup( tor->info.torrent );
if( !tr_bencLoadFile( &newMetainfo, TR_FMT_BENC, path ) )
{
tr_bool hasInfo;
tr_info info;
int infoDictLength;
/* remove any old .torrent and .resume files */
remove( path );
tr_torrentRemoveResume( tor );
dbgmsg( tor, "Saving completed metadata to \"%s\"", path );
tr_bencMergeDicts( tr_bencDictAddDict( &newMetainfo, "info", 0 ), &infoDict );
memset( &info, 0, sizeof( tr_info ) );
success = tr_metainfoParse( tor->session, &newMetainfo, &info, &hasInfo, &infoDictLength );
if( success && !tr_getBlockSize( info.pieceSize ) )
{
tr_torrentSetLocalError( tor, "%s", _( "Magnet torrent's metadata is not usable" ) );
success = FALSE;
}
if( success )
{
/* keep the new info */
tor->info = info;
tor->infoDictLength = infoDictLength;
/* save the new .torrent file */
tr_bencToFile( &newMetainfo, TR_FMT_BENC, tor->info.torrent );
tr_sessionSetTorrentFile( tor->session, tor->info.hashString, tor->info.torrent );
tr_torrentGotNewInfoDict( tor );
tr_torrentSetDirty( tor );
}
tr_bencFree( &newMetainfo );
}
tr_bencFree( &infoDict );
tr_free( path );
}
}
if( success )
{
incompleteMetadataFree( tor->incompleteMetadata );
tor->incompleteMetadata = NULL;
}
else /* drat. */
{
const int n = m->pieceCount;
for( i=0; i<n; ++i )
{
m->piecesNeeded[i].piece = i;
m->piecesNeeded[i].requestedAt = 0;
}
m->piecesNeededCount = n;
dbgmsg( tor, "metadata error; trying again. %d pieces left", n );
tr_err( "magnet status: checksum passed %d, metainfo parsed %d",
(int)checksumPassed, (int)metainfoParsed );
}
}
}
tr_bool
tr_torrentGetNextMetadataRequest( tr_torrent * tor, time_t now, int * setme_piece )
{
tr_bool have_request = FALSE;
struct tr_incomplete_metadata * m;
assert( tr_isTorrent( tor ) );
m = tor->incompleteMetadata;
if( ( m != NULL )
&& ( m->piecesNeededCount > 0 )
&& ( m->piecesNeeded[0].requestedAt + MIN_REPEAT_INTERVAL_SECS < now ) )
{
int i;
const int piece = m->piecesNeeded[0].piece;
tr_removeElementFromArray( m->piecesNeeded, 0,
sizeof( struct metadata_node ),
m->piecesNeededCount-- );
i = m->piecesNeededCount++;
m->piecesNeeded[i].piece = piece;
m->piecesNeeded[i].requestedAt = now;
dbgmsg( tor, "next piece to request: %d", piece );
*setme_piece = piece;
have_request = TRUE;
}
return have_request;
}
double
tr_torrentGetMetadataPercent( const tr_torrent * tor )
{
double ret;
if( tr_torrentHasMetadata( tor ) )
ret = 1.0;
else {
const struct tr_incomplete_metadata * m = tor->incompleteMetadata;
if( !m || !m->pieceCount )
ret = 0.0;
else
ret = (m->pieceCount - m->piecesNeededCount) / (double)m->pieceCount;
}
return ret;
}
char*
tr_torrentGetMagnetLink( const tr_torrent * tor )
{
int i;
const char * name;
struct evbuffer * s;
assert( tr_isTorrent( tor ) );
s = evbuffer_new( );
evbuffer_add_printf( s, "magnet:?xt=urn:btih:%s", tor->info.hashString );
name = tr_torrentName( tor );
if( name && *name )
{
evbuffer_add_printf( s, "%s", "&dn=" );
tr_http_escape( s, tr_torrentName( tor ), -1, TRUE );
}
for( i=0; i<tor->info.trackerCount; ++i )
{
evbuffer_add_printf( s, "%s", "&tr=" );
tr_http_escape( s, tor->info.trackers[i].announce, -1, TRUE );
}
return evbuffer_free_to_str( s );
}