mirror of
https://github.com/transmission/transmission
synced 2024-12-26 17:47:37 +00:00
344 lines
10 KiB
C
344 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.
|
|
*****************************************************************************/
|
|
|
|
static void updateInterest( tr_torrent_t * tor, tr_peer_t * peer );
|
|
|
|
/***********************************************************************
|
|
* peerInit
|
|
***********************************************************************
|
|
* Allocates a new tr_peer_t and returns a pointer to it.
|
|
**********************************************************************/
|
|
static tr_peer_t * peerInit()
|
|
{
|
|
tr_peer_t * peer;
|
|
|
|
peer = calloc( sizeof( tr_peer_t ), 1 );
|
|
peertreeInit( &peer->sentPeers );
|
|
peer->amChoking = 1;
|
|
peer->peerChoking = 1;
|
|
peer->date = tr_date();
|
|
peer->keepAlive = peer->date;
|
|
peer->download = tr_rcInit();
|
|
peer->upload = tr_rcInit();
|
|
|
|
return peer;
|
|
}
|
|
|
|
static int peerCmp( tr_peer_t * peer1, tr_peer_t * peer2 )
|
|
{
|
|
/* Wait until we got the peers' ids */
|
|
if( peer1->status <= PEER_STATUS_HANDSHAKE ||
|
|
peer2->status <= PEER_STATUS_HANDSHAKE )
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
return memcmp( peer1->id, peer2->id, 20 );
|
|
}
|
|
|
|
static int checkPeer( tr_peer_t * peer )
|
|
{
|
|
tr_torrent_t * tor = peer->tor;
|
|
uint64_t now;
|
|
int ret;
|
|
|
|
now = tr_date();
|
|
|
|
if( peer->status < PEER_STATUS_CONNECTED &&
|
|
now > peer->date + 8000 )
|
|
{
|
|
/* If it has been too long, don't wait for the socket
|
|
to timeout - forget about it now */
|
|
peer_dbg( "connection timeout" );
|
|
return TR_ERROR;
|
|
}
|
|
|
|
/* Drop peers who haven't even sent a keep-alive within the
|
|
last 3 minutes */
|
|
if( now > peer->date + 180000 )
|
|
{
|
|
peer_dbg( "read timeout" );
|
|
return TR_ERROR;
|
|
}
|
|
|
|
/* Drop peers which are supposed to upload but actually
|
|
haven't sent anything within the last minute */
|
|
if( peer->inRequestCount && now > peer->date + 60000 )
|
|
{
|
|
peer_dbg( "bad uploader" );
|
|
return TR_ERROR;
|
|
}
|
|
|
|
if( PEER_STATUS_CONNECTED == peer->status )
|
|
{
|
|
/* Send keep-alive every 2 minutes */
|
|
if( now > peer->keepAlive + 120000 )
|
|
{
|
|
sendKeepAlive( peer );
|
|
peer->keepAlive = now;
|
|
}
|
|
|
|
/* Resend extended handshake if our public port changed */
|
|
if( EXTENDED_HANDSHAKE == peer->extStatus &&
|
|
tor->publicPort != peer->advertisedPort )
|
|
{
|
|
sendExtended( tor, peer, EXTENDED_HANDSHAKE_ID );
|
|
}
|
|
|
|
/* Send peer list */
|
|
if( !peer->private && 0 < peer->pexStatus )
|
|
{
|
|
if( 0 == peer->lastPex )
|
|
{
|
|
/* randomize time when first pex message is sent */
|
|
peer->lastPex = now - 1000 * tr_rand( PEX_INTERVAL );
|
|
}
|
|
if( now > peer->lastPex + 1000 * PEX_INTERVAL )
|
|
{
|
|
if( EXTENDED_HANDSHAKE == peer->extStatus )
|
|
{
|
|
ret = sendExtended( tor, peer, EXTENDED_PEX_ID );
|
|
}
|
|
else if( peer->azproto )
|
|
{
|
|
ret = sendAZPex( tor, peer );
|
|
}
|
|
else
|
|
{
|
|
assert( 0 );
|
|
ret = TR_ERROR;
|
|
}
|
|
if( ret )
|
|
{
|
|
return ret;
|
|
}
|
|
peer->lastPex = now + 1000 *
|
|
( PEX_INTERVAL + tr_rand( PEX_INTERVAL / 10 ) );
|
|
}
|
|
}
|
|
}
|
|
|
|
return TR_OK;
|
|
}
|
|
|
|
/***********************************************************************
|
|
* isInteresting
|
|
***********************************************************************
|
|
* Returns 1 if 'peer' has at least one piece that we haven't completed,
|
|
* or 0 otherwise.
|
|
**********************************************************************/
|
|
static int isInteresting( tr_torrent_t * tor, tr_peer_t * peer )
|
|
{
|
|
int ii;
|
|
tr_bitfield_t * bitfield = tr_cpPieceBitfield( tor->completion );
|
|
|
|
if( !peer->bitfield )
|
|
{
|
|
/* We don't know what this peer has */
|
|
return 0;
|
|
}
|
|
|
|
assert( bitfield->len == peer->bitfield->len );
|
|
for( ii = 0; ii < bitfield->len; ii++ )
|
|
{
|
|
if( ( peer->bitfield->bits[ii] & ~(bitfield->bits[ii]) ) & 0xFF )
|
|
{
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
static void updateInterest( tr_torrent_t * tor, tr_peer_t * peer )
|
|
{
|
|
int interested = isInteresting( tor, peer );
|
|
|
|
if( interested && !peer->amInterested )
|
|
{
|
|
sendInterest( peer, 1 );
|
|
}
|
|
if( !interested && peer->amInterested )
|
|
{
|
|
sendInterest( peer, 0 );
|
|
}
|
|
}
|
|
|
|
/***********************************************************************
|
|
* chooseBlock
|
|
***********************************************************************
|
|
* At this point, we know the peer has at least one block we have an
|
|
* interest in. If he has more than one, we choose which one we are
|
|
* going to ask first.
|
|
* Our main goal is to complete pieces, so we look the pieces which are
|
|
* missing less blocks.
|
|
**********************************************************************/
|
|
static inline int chooseBlock( tr_torrent_t * tor, tr_peer_t * peer )
|
|
{
|
|
tr_info_t * inf = &tor->info;
|
|
|
|
int i;
|
|
int missingBlocks, minMissing;
|
|
int poolSize, * pool;
|
|
int block, minDownloading;
|
|
|
|
/* Choose a piece */
|
|
pool = malloc( inf->pieceCount * sizeof( int ) );
|
|
poolSize = 0;
|
|
minMissing = tor->blockCount + 1;
|
|
for( i = 0; i < inf->pieceCount; i++ )
|
|
{
|
|
missingBlocks = tr_cpMissingBlocksForPiece( tor->completion, i );
|
|
if( missingBlocks < 1 )
|
|
{
|
|
/* We already have or are downloading all blocks */
|
|
continue;
|
|
}
|
|
if( !tr_bitfieldHas( peer->bitfield, i ) )
|
|
{
|
|
/* The peer doesn't have this piece */
|
|
continue;
|
|
}
|
|
if( peer->banfield && tr_bitfieldHas( peer->banfield, i ) )
|
|
{
|
|
/* The peer is banned for this piece */
|
|
continue;
|
|
}
|
|
|
|
/* We are interested in this piece, remember it */
|
|
if( missingBlocks < minMissing )
|
|
{
|
|
minMissing = missingBlocks;
|
|
poolSize = 0;
|
|
}
|
|
if( missingBlocks <= minMissing )
|
|
{
|
|
pool[poolSize++] = i;
|
|
}
|
|
}
|
|
|
|
if( poolSize )
|
|
{
|
|
/* All pieces in 'pool' have 'minMissing' missing blocks. Find
|
|
the rarest ones. */
|
|
tr_bitfield_t * bitfield;
|
|
int piece;
|
|
int min, foo, j;
|
|
int * pool2;
|
|
int pool2Size;
|
|
|
|
pool2 = malloc( poolSize * sizeof( int ) );
|
|
pool2Size = 0;
|
|
min = TR_MAX_PEER_COUNT + 1;
|
|
for( i = 0; i < poolSize; i++ )
|
|
{
|
|
foo = 0;
|
|
for( j = 0; j < tor->peerCount; j++ )
|
|
{
|
|
bitfield = tor->peers[j]->bitfield;
|
|
if( bitfield && tr_bitfieldHas( bitfield, pool[i] ) )
|
|
{
|
|
foo++;
|
|
}
|
|
}
|
|
if( foo < min )
|
|
{
|
|
min = foo;
|
|
pool2Size = 0;
|
|
}
|
|
if( foo <= min )
|
|
{
|
|
pool2[pool2Size++] = pool[i];
|
|
}
|
|
}
|
|
free( pool );
|
|
|
|
if( pool2Size < 1 )
|
|
{
|
|
/* Shouldn't happen */
|
|
free( pool2 );
|
|
return -1;
|
|
}
|
|
|
|
/* All pieces in pool2 have the same number of missing blocks,
|
|
and are availabme from the same number of peers. Pick a
|
|
random one */
|
|
piece = pool2[tr_rand(pool2Size)];
|
|
free( pool2 );
|
|
|
|
/* Pick a block in this piece */
|
|
block = tr_cpMissingBlockInPiece( tor->completion, piece );
|
|
goto check;
|
|
}
|
|
|
|
free( pool );
|
|
|
|
/* "End game" mode */
|
|
minDownloading = 255;
|
|
block = -1;
|
|
for( i = 0; i < inf->pieceCount; i++ )
|
|
{
|
|
int downloaders, block2;
|
|
if( !tr_bitfieldHas( peer->bitfield, i ) )
|
|
{
|
|
/* The peer doesn't have this piece */
|
|
continue;
|
|
}
|
|
if( peer->banfield && tr_bitfieldHas( peer->banfield, i ) )
|
|
{
|
|
/* The peer is banned for this piece */
|
|
continue;
|
|
}
|
|
if( tr_cpPieceIsComplete( tor->completion, i ) )
|
|
{
|
|
/* We already have it */
|
|
continue;
|
|
}
|
|
block2 = tr_cpMostMissingBlockInPiece( tor->completion, i, &downloaders );
|
|
if( block2 > -1 && downloaders < minDownloading )
|
|
{
|
|
block = block2;
|
|
minDownloading = downloaders;
|
|
}
|
|
}
|
|
|
|
check:
|
|
if( block < 0 )
|
|
{
|
|
/* Shouldn't happen */
|
|
return -1;
|
|
}
|
|
|
|
for( i = 0; i < peer->inRequestCount; i++ )
|
|
{
|
|
tr_request_t * r;
|
|
r = &peer->inRequests[i];
|
|
if( tr_block( r->index, r->begin ) == block )
|
|
{
|
|
/* We are already asking this peer for this block */
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
return block;
|
|
}
|