/* * This file Copyright (C) 2007 Charles Kerr * * 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 #include /* memcpy, memcmp, strstr */ #include /* qsort */ #include /* printf */ #include /* INT_MAX */ #include /* basename */ #include /* inet_ntoa */ #include #include "transmission.h" #include "clients.h" #include "completion.h" #include "crypto.h" #include "handshake.h" #include "net.h" #include "peer-io.h" #include "peer-mgr.h" #include "peer-mgr-private.h" #include "peer-msgs.h" #include "platform.h" #include "ptrarray.h" #include "ratecontrol.h" #include "shared.h" #include "trcompat.h" /* strlcpy */ #include "trevent.h" #include "utils.h" /** *** The "SWIFT" system is described by Karthik Tamilmani, *** Vinay Pai, and Alexander Mohr of Stony Brook University *** in their paper "SWIFT: A System With Incentives For Trading" *** http://citeseer.ist.psu.edu/tamilmani04swift.html *** *** More SWIFT constants are defined in peer-mgr-private.h **/ /** * Allow new peers to download this many bytes from * us when getting started. This can prevent gridlock * with other peers using tit-for-tat algorithms */ static const int SWIFT_INITIAL_CREDIT = 64 * 1024; /* 64 KiB */ /** * We expend a fraction of our torrent's total upload speed * on largesse by uniformly distributing free credit to * all of our peers. This too helps prevent gridlock. */ static const double SWIFT_LARGESSE = 0.15; /* 15% of our UL */ /** * How frequently to extend largesse-based credit */ static const int SWIFT_PERIOD_MSEC = 5000; enum { /* how frequently to change which peers are choked */ RECHOKE_PERIOD_MSEC = (1000), /* how frequently to decide which peers live and die */ RECONNECT_PERIOD_MSEC = (2 * 1000), /* how frequently to refill peers' request lists */ REFILL_PERIOD_MSEC = 666, /* don't change a peer's choke status more often than this */ MIN_CHOKE_PERIOD_SEC = 10, /* following the BT spec, we consider ourselves `snubbed' if * we're we don't get piece data from a peer in this long */ SNUBBED_SEC = 60, /* arbitrary */ MAX_CONNECTED_PEERS_PER_TORRENT = 50, /* when many peers are available, keep idle ones this long */ MIN_UPLOAD_IDLE_SECS = (60 * 3), /* when few peers are available, keep idle ones this long */ MAX_UPLOAD_IDLE_SECS = (60 * 10), /* how many peers to unchoke per-torrent. */ /* FIXME: make this user-configurable? */ NUM_UNCHOKED_PEERS_PER_TORRENT = 16, /* arbitrary */ /* set this too high and there will be a lot of churn. * set it too low and you'll get peers too slowly */ MAX_RECONNECTIONS_PER_PULSE = 2, /* corresponds to ut_pex's added.f flags */ ADDED_F_ENCRYPTION_FLAG = 1, /* corresponds to ut_pex's added.f flags */ ADDED_F_SEED_FLAG = 2, /* number of bad pieces a peer is allowed to send before we ban them */ MAX_BAD_PIECES_PER_PEER = 3, /* use for bitwise operations w/peer_atom.myflags */ MYFLAG_BANNED = 1 }; /** *** **/ /* We keep one of these for every peer we know about, whether * it's connected or not, so the struct must be small. * When our current connections underperform, we dip back * into this list for new ones. */ struct peer_atom { uint8_t from; uint8_t flags; /* these match the added_f flags */ uint8_t myflags; /* flags that aren't defined in added_f */ uint16_t port; uint16_t numFails; struct in_addr addr; time_t time; }; typedef struct { uint8_t hash[SHA_DIGEST_LENGTH]; tr_ptrArray * outgoingHandshakes; /* tr_handshake */ tr_ptrArray * pool; /* struct peer_atom */ tr_ptrArray * peers; /* tr_peer */ tr_timer * reconnectTimer; tr_timer * rechokeTimer; tr_timer * refillTimer; tr_timer * swiftTimer; tr_torrent * tor; tr_bitfield * requested; unsigned int isRunning : 1; struct tr_peerMgr * manager; } Torrent; struct tr_peerMgr { tr_handle * handle; tr_ptrArray * torrents; /* Torrent */ tr_ptrArray * incomingHandshakes; /* tr_handshake */ }; /** *** **/ static void myDebug( const char * file, int line, const Torrent * t, const char * fmt, ... ) { FILE * fp = tr_getLog( ); if( fp != NULL ) { va_list args; char timestr[64]; struct evbuffer * buf = evbuffer_new( ); char * myfile = tr_strdup( file ); evbuffer_add_printf( buf, "[%s] ", tr_getLogTimeStr( timestr, sizeof(timestr) ) ); if( t != NULL ) evbuffer_add_printf( buf, "%s ", t->tor->info.name ); va_start( args, fmt ); evbuffer_add_vprintf( buf, fmt, args ); va_end( args ); evbuffer_add_printf( buf, " (%s:%d)\n", basename(myfile), line ); fwrite( EVBUFFER_DATA(buf), 1, EVBUFFER_LENGTH(buf), fp ); tr_free( myfile ); evbuffer_free( buf ); } } #define tordbg(t, fmt...) myDebug(__FILE__, __LINE__, t, ##fmt ) /** *** **/ static void managerLock( struct tr_peerMgr * manager ) { tr_globalLock( manager->handle ); } static void managerUnlock( struct tr_peerMgr * manager ) { tr_globalUnlock( manager->handle ); } static void torrentLock( Torrent * torrent ) { managerLock( torrent->manager ); } static void torrentUnlock( Torrent * torrent ) { managerUnlock( torrent->manager ); } static int torrentIsLocked( const Torrent * t ) { return tr_globalIsLocked( t->manager->handle ); } /** *** **/ static int compareAddresses( const struct in_addr * a, const struct in_addr * b ) { return tr_compareUint32( a->s_addr, b->s_addr ); } static int handshakeCompareToAddr( const void * va, const void * vb ) { const tr_handshake * a = va; return compareAddresses( tr_handshakeGetAddr( a, NULL ), vb ); } static int handshakeCompare( const void * a, const void * b ) { return handshakeCompareToAddr( a, tr_handshakeGetAddr( b, NULL ) ); } static tr_handshake* getExistingHandshake( tr_ptrArray * handshakes, const struct in_addr * in_addr ) { return tr_ptrArrayFindSorted( handshakes, in_addr, handshakeCompareToAddr ); } static int comparePeerAtomToAddress( const void * va, const void * vb ) { const struct peer_atom * a = va; return compareAddresses( &a->addr, vb ); } static int comparePeerAtoms( const void * va, const void * vb ) { const struct peer_atom * b = vb; return comparePeerAtomToAddress( va, &b->addr ); } /** *** **/ static int torrentCompare( const void * va, const void * vb ) { const Torrent * a = va; const Torrent * b = vb; return memcmp( a->hash, b->hash, SHA_DIGEST_LENGTH ); } static int torrentCompareToHash( const void * va, const void * vb ) { const Torrent * a = va; const uint8_t * b_hash = vb; return memcmp( a->hash, b_hash, SHA_DIGEST_LENGTH ); } static Torrent* getExistingTorrent( tr_peerMgr * manager, const uint8_t * hash ) { return (Torrent*) tr_ptrArrayFindSorted( manager->torrents, hash, torrentCompareToHash ); } static int peerCompare( const void * va, const void * vb ) { const tr_peer * a = va; const tr_peer * b = vb; return compareAddresses( &a->in_addr, &b->in_addr ); } static int peerCompareToAddr( const void * va, const void * vb ) { const tr_peer * a = va; return compareAddresses( &a->in_addr, vb ); } static tr_peer* getExistingPeer( Torrent * torrent, const struct in_addr * in_addr ) { assert( torrentIsLocked( torrent ) ); assert( in_addr != NULL ); return (tr_peer*) tr_ptrArrayFindSorted( torrent->peers, in_addr, peerCompareToAddr ); } static struct peer_atom* getExistingAtom( const Torrent * t, const struct in_addr * addr ) { assert( torrentIsLocked( t ) ); return tr_ptrArrayFindSorted( t->pool, addr, comparePeerAtomToAddress ); } static int peerIsInUse( const Torrent * ct, const struct in_addr * addr ) { Torrent * t = (Torrent*) ct; assert( torrentIsLocked ( t ) ); return getExistingPeer( t, addr ) || getExistingHandshake( t->outgoingHandshakes, addr ) || getExistingHandshake( t->manager->incomingHandshakes, addr ); } static tr_peer* peerConstructor( const struct in_addr * in_addr ) { tr_peer * p; p = tr_new0( tr_peer, 1 ); p->credit = SWIFT_INITIAL_CREDIT; p->rcToClient = tr_rcInit( ); p->rcToPeer = tr_rcInit( ); memcpy( &p->in_addr, in_addr, sizeof(struct in_addr) ); return p; } static tr_peer* getPeer( Torrent * torrent, const struct in_addr * in_addr ) { tr_peer * peer; assert( torrentIsLocked( torrent ) ); peer = getExistingPeer( torrent, in_addr ); if( peer == NULL ) { peer = peerConstructor( in_addr ); tr_ptrArrayInsertSorted( torrent->peers, peer, peerCompare ); } return peer; } static void peerDestructor( tr_peer * peer ) { assert( peer != NULL ); assert( peer->msgs != NULL ); tr_peerMsgsUnsubscribe( peer->msgs, peer->msgsTag ); tr_peerMsgsFree( peer->msgs ); tr_peerIoFree( peer->io ); tr_bitfieldFree( peer->have ); tr_bitfieldFree( peer->blame ); tr_rcClose( peer->rcToClient ); tr_rcClose( peer->rcToPeer ); tr_free( peer->client ); tr_free( peer ); } static void removePeer( Torrent * t, tr_peer * peer ) { tr_peer * removed; struct peer_atom * atom; assert( torrentIsLocked( t ) ); atom = getExistingAtom( t, &peer->in_addr ); assert( atom != NULL ); atom->time = time( NULL ); removed = tr_ptrArrayRemoveSorted ( t->peers, peer, peerCompare ); assert( removed == peer ); peerDestructor( removed ); } static void removeAllPeers( Torrent * t ) { while( !tr_ptrArrayEmpty( t->peers ) ) removePeer( t, tr_ptrArrayNth( t->peers, 0 ) ); } static void torrentDestructor( Torrent * t ) { uint8_t hash[SHA_DIGEST_LENGTH]; assert( t != NULL ); assert( !t->isRunning ); assert( t->peers != NULL ); assert( torrentIsLocked( t ) ); assert( tr_ptrArrayEmpty( t->outgoingHandshakes ) ); assert( tr_ptrArrayEmpty( t->peers ) ); memcpy( hash, t->hash, SHA_DIGEST_LENGTH ); tr_timerFree( &t->reconnectTimer ); tr_timerFree( &t->rechokeTimer ); tr_timerFree( &t->refillTimer ); tr_timerFree( &t->swiftTimer ); tr_bitfieldFree( t->requested ); tr_ptrArrayFree( t->pool, (PtrArrayForeachFunc)tr_free ); tr_ptrArrayFree( t->outgoingHandshakes, NULL ); tr_ptrArrayFree( t->peers, NULL ); tr_free( t ); } static Torrent* torrentConstructor( tr_peerMgr * manager, tr_torrent * tor ) { Torrent * t; t = tr_new0( Torrent, 1 ); t->manager = manager; t->tor = tor; t->pool = tr_ptrArrayNew( ); t->peers = tr_ptrArrayNew( ); t->outgoingHandshakes = tr_ptrArrayNew( ); t->requested = tr_bitfieldNew( tor->blockCount ); memcpy( t->hash, tor->info.hash, SHA_DIGEST_LENGTH ); return t; } /** *** **/ struct tr_bitfield * tr_peerMgrGenerateAllowedSet( const uint32_t setCount, const uint32_t pieceCount, const uint8_t infohash[20], const struct in_addr * ip ) { /* This has been checked against the spec example implementation. Feeding it with : setCount = 9, pieceCount = 1313, infohash = Oxaa,0xaa,...0xaa, ip = 80.4.4.200 generate : 1059, 431, 808, 1217, 287, 376, 1188, 353, 508 but since we're storing in a bitfield, it won't be in this order... */ /* TODO : We should translate link-local IPv4 adresses to external IP, * so that being on same local network gives us the same allowed pieces */ uint8_t *seed; char buf[4]; uint32_t allowedPieceCount = 0; tr_bitfield_t * ret; #if 0 printf( "%d piece allowed fast set for torrent with %d pieces and hex infohash\n", setCount, pieceCount ); printf( "%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x for node with IP %s:\n", infohash[0], infohash[1], infohash[2], infohash[3], infohash[4], infohash[5], infohash[6], infohash[7], infohash[8], infohash[9], infohash[10], infohash[11], infohash[12], infohash[13], infohash[14], infohash[15], infohash[16], infohash[7], infohash[18], infohash[19], inet_ntoa( *ip ) ); #endif seed = malloc(4 + SHA_DIGEST_LENGTH); ret = tr_bitfieldNew( pieceCount ); /* We need a seed based on most significant bytes of peer address concatenated with torrent's infohash */ *(uint32_t*)buf = ntohl( htonl(ip->s_addr) & 0xffffff00 ); memcpy( seed, &buf, 4 ); memcpy( seed + 4, infohash, SHA_DIGEST_LENGTH ); tr_sha1( seed, seed, 4 + SHA_DIGEST_LENGTH, NULL ); while ( allowedPieceCount < setCount ) { int i; for ( i = 0 ; i < 5 && allowedPieceCount < setCount ; i++ ) { /* We generate indices from 4-byte chunks of the seed */ uint32_t j = i * 4; uint32_t y = ntohl( *(uint32_t*)(seed + j) ); uint32_t index = y % pieceCount; if ( !tr_bitfieldHas( ret, index ) ) { tr_bitfieldAdd( ret, index ); allowedPieceCount++; } } /* We randomize the seed, in case we need to iterate more */ tr_sha1( seed, seed, SHA_DIGEST_LENGTH, NULL ); } tr_free( seed ); return ret; } tr_peerMgr* tr_peerMgrNew( tr_handle * handle ) { tr_peerMgr * m = tr_new0( tr_peerMgr, 1 ); m->handle = handle; m->torrents = tr_ptrArrayNew( ); m->incomingHandshakes = tr_ptrArrayNew( ); return m; } void tr_peerMgrFree( tr_peerMgr * manager ) { managerLock( manager ); /* free the handshakes. Abort invokes handshakeDoneCB(), which removes * the item from manager->handshakes, so this is a little roundabout... */ while( !tr_ptrArrayEmpty( manager->incomingHandshakes ) ) tr_handshakeAbort( tr_ptrArrayNth( manager->incomingHandshakes, 0 ) ); tr_ptrArrayFree( manager->incomingHandshakes, NULL ); /* free the torrents. */ tr_ptrArrayFree( manager->torrents, (PtrArrayForeachFunc)torrentDestructor ); managerUnlock( manager ); tr_free( manager ); } static tr_peer** getConnectedPeers( Torrent * t, int * setmeCount ) { int i, peerCount, connectionCount; tr_peer **peers; tr_peer **ret; assert( torrentIsLocked( t ) ); peers = (tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount ); ret = tr_new( tr_peer*, peerCount ); for( i=connectionCount=0; imsgs != NULL ) ret[connectionCount++] = peers[i]; *setmeCount = connectionCount; return ret; } /*** **** Refill ***/ struct tr_refill_piece { tr_priority_t priority; int percentDone; uint16_t random; uint32_t piece; uint32_t peerCount; uint32_t fastAllowed; uint32_t suggested; }; static int compareRefillPiece (const void * aIn, const void * bIn) { const struct tr_refill_piece * a = aIn; const struct tr_refill_piece * b = bIn; /* if one *might be* fastallowed to us, get it first... * I'm putting it on top so we prioritize those pieces at * startup, then we'll have them, and we'll be denied access * to them */ if (a->fastAllowed != b->fastAllowed) return a->fastAllowed < b->fastAllowed ? -1 : 1; /* if one piece has a higher priority, it goes first */ if (a->priority != b->priority) return a->priority > b->priority ? -1 : 1; /* otherwise if one was suggested to us, get it */ if (a->suggested != b->suggested) return a->suggested < b->suggested ? -1 : 1; /* try to fill partial pieces */ if( a->percentDone != b->percentDone ) return a->percentDone > b->percentDone ? -1 : 1; /* otherwise if one has fewer peers, it goes first */ if (a->peerCount != b->peerCount) return a->peerCount < b->peerCount ? -1 : 1; /* otherwise go with our random seed */ return tr_compareUint16( a->random, b->random ); } static int isPieceInteresting( const tr_torrent * tor, int piece ) { if( tor->info.pieces[piece].dnd ) /* we don't want it */ return 0; if( tr_cpPieceIsComplete( tor->completion, piece ) ) /* we have it */ return 0; return 1; } static uint32_t* getPreferredPieces( Torrent * t, uint32_t * pieceCount ) { const tr_torrent * tor = t->tor; const tr_info * inf = &tor->info; int i; uint32_t poolSize = 0; uint32_t * pool = tr_new( uint32_t, inf->pieceCount ); int peerCount; tr_peer** peers; assert( torrentIsLocked( t ) ); peers = getConnectedPeers( t, &peerCount ); for( i=0; ipieceCount; ++i ) if( isPieceInteresting( tor, i ) ) pool[poolSize++] = i; /* sort the pool from most interesting to least... */ if( poolSize > 1 ) { uint32_t j; struct tr_refill_piece * p = tr_new( struct tr_refill_piece, poolSize ); for( j=0; jpiece = piece; setme->priority = inf->pieces[piece].priority; setme->peerCount = 0; setme->fastAllowed = 0; setme->random = tr_rand( UINT16_MAX ); setme->percentDone = (int)( 100.0 * tr_cpPercentBlocksInPiece( tor->completion, piece ) ); for( k=0; kpeerIsInterested && !peer->clientIsChoked && tr_bitfieldHas( peer->have, piece ) ) ++setme->peerCount; /* The fast peer extension doesn't force a peer to actually HAVE a fast-allowed piece, but we're guaranteed to get the same pieces from different peers, so we'll build a list and pray one actually have this one */ setme->fastAllowed = tr_peerMsgsIsPieceFastAllowed( peer->msgs, i ); /* Also, if someone SUGGESTed a piece to us, prioritize it over non-suggested others */ setme->suggested = tr_peerMsgsIsPieceSuggested( peer->msgs, i ); } } qsort( p, poolSize, sizeof(struct tr_refill_piece), compareRefillPiece ); for( j=0; jtor; assert( torrentIsLocked( t ) ); pieces = getPreferredPieces( t, &pieceCount ); req = tr_new( uint64_t, pieceCount * tor->blockCountInPiece ); reqCount = 0; unreq = tr_new( uint64_t, pieceCount * tor->blockCountInPiece ); unreqCount = 0; for( i=0; icompletion, block ) ) continue; else if( tr_bitfieldHas( t->requested, block ) ) req[reqCount++] = block; else unreq[unreqCount++] = block; } ret = walk = tr_new( uint64_t, unreqCount + reqCount ); memcpy( walk, unreq, sizeof(uint64_t) * unreqCount ); walk += unreqCount; memcpy( walk, req, sizeof(uint64_t) * reqCount ); walk += reqCount; assert( ( walk - ret ) == ( unreqCount + reqCount ) ); *setmeCount = walk - ret; tr_free( req ); tr_free( unreq ); tr_free( pieces ); return ret; } static int refillPulse( void * vtorrent ) { Torrent * t = vtorrent; tr_torrent * tor = t->tor; uint32_t i; int peerCount; tr_peer ** peers; uint64_t blockCount; uint64_t * blocks; if( !t->isRunning ) return TRUE; if( tr_torrentIsSeed( t->tor ) ) return TRUE; torrentLock( t ); tordbg( t, "Refilling Request Buffers..." ); blocks = getPreferredBlocks( t, &blockCount ); peers = getConnectedPeers( t, &peerCount ); for( i=0; peerCount && iblockSize) - (index * tor->info.pieceSize); const uint32_t length = tr_torBlockCountBytes( tor, (int)block ); int j; assert( _tr_block( tor, index, begin ) == (int)block ); assert( begin < (uint32_t)tr_torPieceCountBytes( tor, (int)index ) ); assert( (begin + length) <= (uint32_t)tr_torPieceCountBytes( tor, (int)index ) ); /* find a peer who can ask for this block */ for( j=0; jmsgs, index, begin, length ); switch( val ) { case TR_ADDREQ_FULL: case TR_ADDREQ_CLIENT_CHOKED: memmove( peers+j, peers+j+1, sizeof(tr_peer*)*(--peerCount-j) ); break; case TR_ADDREQ_MISSING: case TR_ADDREQ_DUPLICATE: ++j; break; case TR_ADDREQ_OK: tr_bitfieldAdd( t->requested, block ); j = peerCount; break; default: assert( 0 && "unhandled value" ); break; } } } /* cleanup */ tr_free( peers ); tr_free( blocks ); t->refillTimer = NULL; torrentUnlock( t ); return FALSE; } static void broadcastClientHave( Torrent * t, uint32_t index ) { int i, size; tr_peer ** peers; assert( torrentIsLocked( t ) ); peers = getConnectedPeers( t, &size ); for( i=0; imsgs, index ); tr_free( peers ); } static void broadcastGotBlock( Torrent * t, uint32_t index, uint32_t offset, uint32_t length ) { int i, size; tr_peer ** peers; assert( torrentIsLocked( t ) ); peers = getConnectedPeers( t, &size ); for( i=0; imsgs, index, offset, length ); tr_free( peers ); } static void addStrike( Torrent * t, tr_peer * peer ) { tordbg( t, "increasing peer %s strike count to %d", tr_peerIoAddrStr(&peer->in_addr,peer->port), peer->strikes+1 ); if( ++peer->strikes >= MAX_BAD_PIECES_PER_PEER ) { struct peer_atom * atom = getExistingAtom( t, &peer->in_addr ); atom->myflags |= MYFLAG_BANNED; peer->doPurge = 1; tordbg( t, "banning peer %s", tr_peerIoAddrStr(&atom->addr,atom->port) ); } } static void msgsCallbackFunc( void * vpeer, void * vevent, void * vt ) { tr_peer * peer = vpeer; Torrent * t = (Torrent *) vt; const tr_peermsgs_event * e = (const tr_peermsgs_event *) vevent; torrentLock( t ); switch( e->eventType ) { case TR_PEERMSG_NEED_REQ: if( t->refillTimer == NULL ) t->refillTimer = tr_timerNew( t->manager->handle, refillPulse, t, REFILL_PERIOD_MSEC ); break; case TR_PEERMSG_CANCEL: tr_bitfieldRem( t->requested, _tr_block( t->tor, e->pieceIndex, e->offset ) ); break; case TR_PEERMSG_CLIENT_HAVE: broadcastClientHave( t, e->pieceIndex ); tr_torrentRecheckCompleteness( t->tor ); break; case TR_PEERMSG_PEER_PROGRESS: { struct peer_atom * atom = getExistingAtom( t, &peer->in_addr ); const int peerIsSeed = e->progress >= 1.0; if( peerIsSeed ) { tordbg( t, "marking peer %s as a seed", tr_peerIoAddrStr(&atom->addr,atom->port) ); atom->flags |= ADDED_F_SEED_FLAG; } else { tordbg( t, "marking peer %s as a non-seed", tr_peerIoAddrStr(&atom->addr,atom->port) ); atom->flags &= ~ADDED_F_SEED_FLAG; } break; } case TR_PEERMSG_CLIENT_BLOCK: broadcastGotBlock( t, e->pieceIndex, e->offset, e->length ); break; case TR_PEERMSG_GOT_ASSERT_ERROR: addStrike( t, peer ); peer->doPurge = 1; break; case TR_PEERMSG_GOT_ERROR: peer->doPurge = 1; break; default: assert(0); } torrentUnlock( t ); } static void ensureAtomExists( Torrent * t, const struct in_addr * addr, uint16_t port, uint8_t flags, uint8_t from ) { if( getExistingAtom( t, addr ) == NULL ) { struct peer_atom * a; a = tr_new0( struct peer_atom, 1 ); a->addr = *addr; a->port = port; a->flags = flags; a->from = from; tordbg( t, "got a new atom: %s", tr_peerIoAddrStr(&a->addr,a->port) ); tr_ptrArrayInsertSorted( t->pool, a, comparePeerAtoms ); } } /* FIXME: this is kind of a mess. */ static void myHandshakeDoneCB( tr_handshake * handshake, tr_peerIo * io, int isConnected, const uint8_t * peer_id, void * vmanager ) { int ok = isConnected; uint16_t port; const struct in_addr * addr; tr_peerMgr * manager = (tr_peerMgr*) vmanager; Torrent * t; tr_handshake * ours; assert( io != NULL ); assert( isConnected==0 || isConnected==1 ); t = tr_peerIoHasTorrentHash( io ) ? getExistingTorrent( manager, tr_peerIoGetTorrentHash( io ) ) : NULL; if( tr_peerIoIsIncoming ( io ) ) ours = tr_ptrArrayRemoveSorted( manager->incomingHandshakes, handshake, handshakeCompare ); else if( t != NULL ) ours = tr_ptrArrayRemoveSorted( t->outgoingHandshakes, handshake, handshakeCompare ); else ours = handshake; assert( ours != NULL ); assert( ours == handshake ); if( t != NULL ) torrentLock( t ); addr = tr_peerIoGetAddress( io, &port ); if( !ok || !t || !t->isRunning ) { if( t ) { struct peer_atom * atom = getExistingAtom( t, addr ); if( atom ) ++atom->numFails; } tr_peerIoFree( io ); } else /* looking good */ { struct peer_atom * atom; ensureAtomExists( t, addr, port, 0, TR_PEER_FROM_INCOMING ); atom = getExistingAtom( t, addr ); if( atom->myflags & MYFLAG_BANNED ) { tordbg( t, "banned peer %s tried to reconnect", tr_peerIoAddrStr(&atom->addr,atom->port) ); tr_peerIoFree( io ); } else if( tr_ptrArraySize( t->peers ) >= MAX_CONNECTED_PEERS_PER_TORRENT ) { tr_peerIoFree( io ); } else { tr_peer * peer = getExistingPeer( t, addr ); if( peer != NULL ) /* we already have this peer */ { tr_peerIoFree( io ); } else { peer = getPeer( t, addr ); tr_free( peer->client ); peer->client = peer_id ? tr_clientForId( peer_id ) : NULL; peer->port = port; peer->io = io; peer->msgs = tr_peerMsgsNew( t->tor, peer, msgsCallbackFunc, t, &peer->msgsTag ); atom->time = time( NULL ); } } } if( t != NULL ) torrentUnlock( t ); } void tr_peerMgrAddIncoming( tr_peerMgr * manager, struct in_addr * addr, uint16_t port, int socket ) { managerLock( manager ); if( getExistingHandshake( manager->incomingHandshakes, addr ) ) { tr_netClose( socket ); } else /* we don't have a connetion to them yet... */ { tr_peerIo * io; tr_handshake * handshake; tordbg( NULL, "Got an INCOMING connection with %s", tr_peerIoAddrStr( addr, port ) ); io = tr_peerIoNewIncoming( manager->handle, addr, port, socket ); handshake = tr_handshakeNew( io, manager->handle->encryptionMode, myHandshakeDoneCB, manager ); tr_ptrArrayInsertSorted( manager->incomingHandshakes, handshake, handshakeCompare ); } managerUnlock( manager ); } void tr_peerMgrAddPex( tr_peerMgr * manager, const uint8_t * torrentHash, uint8_t from, const tr_pex * pex, int pexCount ) { Torrent * t; const tr_pex * end; managerLock( manager ); t = getExistingTorrent( manager, torrentHash ); for( end=pex+pexCount; pex!=end; ++pex ) ensureAtomExists( t, &pex->in_addr, pex->port, pex->flags, from ); managerUnlock( manager ); } void tr_peerMgrAddPeers( tr_peerMgr * manager, const uint8_t * torrentHash, uint8_t from, const uint8_t * peerCompact, int peerCount ) { int i; const uint8_t * walk = peerCompact; Torrent * t; managerLock( manager ); t = getExistingTorrent( manager, torrentHash ); for( i=0; t!=NULL && ipeers, &peerCount ); for( i=0; iblame, pieceIndex ) ) { tordbg( t, "peer %s contributed to corrupt piece (%d); now has %d strikes", tr_peerIoAddrStr(&peer->in_addr,peer->port), pieceIndex, (int)peer->strikes+1 ); addStrike( t, peer ); } } } } int tr_pexCompare( const void * va, const void * vb ) { const tr_pex * a = (const tr_pex *) va; const tr_pex * b = (const tr_pex *) vb; int i = memcmp( &a->in_addr, &b->in_addr, sizeof(struct in_addr) ); if( i ) return i; if( a->port < b->port ) return -1; if( a->port > b->port ) return 1; return 0; } int tr_pexCompare( const void * a, const void * b ); static int peerPrefersCrypto( const tr_peer * peer ) { if( peer->encryption_preference == ENCRYPTION_PREFERENCE_YES ) return TRUE; if( peer->encryption_preference == ENCRYPTION_PREFERENCE_NO ) return FALSE; return tr_peerIoIsEncrypted( peer->io ); }; int tr_peerMgrGetPeers( tr_peerMgr * manager, const uint8_t * torrentHash, tr_pex ** setme_pex ) { const Torrent * t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); int i, peerCount; const tr_peer ** peers; tr_pex * pex; tr_pex * walk; torrentLock( (Torrent*)t ); peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount ); pex = walk = tr_new( tr_pex, peerCount ); for( i=0; iin_addr = peer->in_addr; walk->port = peer->port; walk->flags = 0; if( peerPrefersCrypto(peer) ) walk->flags |= ADDED_F_ENCRYPTION_FLAG; if( peer->progress >= 1.0 ) walk->flags |= ADDED_F_SEED_FLAG; } assert( ( walk - pex ) == peerCount ); qsort( pex, peerCount, sizeof(tr_pex), tr_pexCompare ); *setme_pex = pex; torrentUnlock( (Torrent*)t ); return peerCount; } static int reconnectPulse( void * vtorrent ); static int rechokePulse( void * vtorrent ); static int swiftPulse( void * vtorrent ); void tr_peerMgrStartTorrent( tr_peerMgr * manager, const uint8_t * torrentHash ) { Torrent * t; managerLock( manager ); t = getExistingTorrent( manager, torrentHash ); assert( t != NULL ); assert( ( t->isRunning != 0 ) == ( t->reconnectTimer != NULL ) ); assert( ( t->isRunning != 0 ) == ( t->rechokeTimer != NULL ) ); assert( ( t->isRunning != 0 ) == ( t->swiftTimer != NULL ) ); if( !t->isRunning ) { t->isRunning = 1; t->reconnectTimer = tr_timerNew( t->manager->handle, reconnectPulse, t, RECONNECT_PERIOD_MSEC ); t->rechokeTimer = tr_timerNew( t->manager->handle, rechokePulse, t, RECHOKE_PERIOD_MSEC ); t->swiftTimer = tr_timerNew( t->manager->handle, swiftPulse, t, SWIFT_PERIOD_MSEC ); reconnectPulse( t ); rechokePulse( t ); swiftPulse( t ); } managerUnlock( manager ); } static void stopTorrent( Torrent * t ) { assert( torrentIsLocked( t ) ); t->isRunning = 0; tr_timerFree( &t->rechokeTimer ); tr_timerFree( &t->reconnectTimer ); tr_timerFree( &t->swiftTimer ); /* disconnect the peers. */ tr_ptrArrayForeach( t->peers, (PtrArrayForeachFunc)peerDestructor ); tr_ptrArrayClear( t->peers ); /* disconnect the handshakes. handshakeAbort calls handshakeDoneCB(), * which removes the handshake from t->outgoingHandshakes... */ while( !tr_ptrArrayEmpty( t->outgoingHandshakes ) ) tr_handshakeAbort( tr_ptrArrayNth( t->outgoingHandshakes, 0 ) ); } void tr_peerMgrStopTorrent( tr_peerMgr * manager, const uint8_t * torrentHash) { managerLock( manager ); stopTorrent( getExistingTorrent( manager, torrentHash ) ); managerUnlock( manager ); } void tr_peerMgrAddTorrent( tr_peerMgr * manager, tr_torrent * tor ) { Torrent * t; managerLock( manager ); assert( tor != NULL ); assert( getExistingTorrent( manager, tor->info.hash ) == NULL ); t = torrentConstructor( manager, tor ); tr_ptrArrayInsertSorted( manager->torrents, t, torrentCompare ); managerUnlock( manager ); } void tr_peerMgrRemoveTorrent( tr_peerMgr * manager, const uint8_t * torrentHash ) { Torrent * t; managerLock( manager ); t = getExistingTorrent( manager, torrentHash ); assert( t != NULL ); stopTorrent( t ); tr_ptrArrayRemoveSorted( manager->torrents, t, torrentCompare ); torrentDestructor( t ); managerUnlock( manager ); } void tr_peerMgrTorrentAvailability( const tr_peerMgr * manager, const uint8_t * torrentHash, int8_t * tab, int tabCount ) { int i; const Torrent * t; const tr_torrent * tor; float interval; managerLock( (tr_peerMgr*)manager ); t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); tor = t->tor; interval = tor->info.pieceCount / (float)tabCount; memset( tab, 0, tabCount ); for( i=0; icompletion, piece ) ) tab[i] = -1; else { int j, peerCount; const tr_peer ** peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount ); for( j=0; jhave, i ) ) ++tab[i]; } } managerUnlock( (tr_peerMgr*)manager ); } /* Returns the pieces that we and/or a connected peer has */ tr_bitfield* tr_peerMgrGetAvailable( const tr_peerMgr * manager, const uint8_t * torrentHash ) { int i, size; const Torrent * t; const tr_peer ** peers; tr_bitfield * pieces; managerLock( (tr_peerMgr*)manager ); t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &size ); pieces = tr_bitfieldDup( tr_cpPieceBitfield( t->tor->completion ) ); for( i=0; iio != NULL ) tr_bitfieldOr( pieces, peers[i]->have ); managerUnlock( (tr_peerMgr*)manager ); return pieces; } int tr_peerMgrHasConnections( const tr_peerMgr * manager, const uint8_t * torrentHash ) { int ret; const Torrent * t; managerLock( (tr_peerMgr*)manager ); t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); ret = t && tr_ptrArraySize( t->peers ); managerUnlock( (tr_peerMgr*)manager ); return ret; } void tr_peerMgrTorrentStats( const tr_peerMgr * manager, const uint8_t * torrentHash, int * setmePeersKnown, int * setmePeersConnected, int * setmePeersSendingToUs, int * setmePeersGettingFromUs, int * setmePeersFrom ) { int i, size; const Torrent * t; const tr_peer ** peers; managerLock( (tr_peerMgr*)manager ); t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &size ); *setmePeersKnown = tr_ptrArraySize( t->pool ); *setmePeersConnected = 0; *setmePeersSendingToUs = 0; *setmePeersGettingFromUs = 0; for( i=0; iin_addr ); if( peer->io == NULL ) /* not connected */ continue; ++*setmePeersConnected; ++setmePeersFrom[atom->from]; if( peer->rateToPeer > 0.01 ) ++*setmePeersGettingFromUs; if( peer->rateToClient > 0.01 ) ++*setmePeersSendingToUs; } managerUnlock( (tr_peerMgr*)manager ); } struct tr_peer_stat * tr_peerMgrPeerStats( const tr_peerMgr * manager, const uint8_t * torrentHash, int * setmeCount UNUSED ) { int i, size; const Torrent * t; tr_peer ** peers; tr_peer_stat * ret; assert( manager != NULL ); managerLock( (tr_peerMgr*)manager ); t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash ); peers = getConnectedPeers( (Torrent*)t, &size ); ret = tr_new0( tr_peer_stat, size ); for( i=0; iin_addr ); tr_peer_stat * stat = ret + i; tr_netNtop( &peer->in_addr, stat->addr, sizeof(stat->addr) ); strlcpy( stat->client, (peer->client ? peer->client : ""), sizeof(stat->client) ); stat->port = peer->port; stat->from = atom->from; stat->progress = peer->progress; stat->isEncrypted = tr_peerIoIsEncrypted( peer->io ) ? 1 : 0; stat->uploadToRate = peer->rateToPeer; stat->downloadFromRate = peer->rateToClient; stat->isDownloading = stat->uploadToRate > 0.01; stat->isUploading = stat->downloadFromRate > 0.01; stat->status = peer->status; } *setmeCount = size; tr_free( peers ); managerUnlock( (tr_peerMgr*)manager ); return ret; } /** *** **/ struct ChokeData { tr_peer * peer; int rate; uint8_t preferred; uint8_t preferred_t; uint8_t doUnchoke; }; static int compareChoke( const void * va, const void * vb ) { const struct ChokeData * a = va; const struct ChokeData * b = vb; if( a->rate > b->rate ) return -1; if( a->rate < b->rate ) return 1; if( a->preferred_t != b->preferred_t ) return a->preferred_t ? -1 : 1; if( a->preferred != b->preferred ) return a->preferred ? -1 : 1; return 0; } static int clientIsSnubbedBy( const tr_peer * peer, int clientIsSeed ) { assert( peer != NULL ); return !clientIsSeed && ( peer->peerSentPieceDataAt < (time(NULL) - SNUBBED_SEC ) ); } /** *** **/ static double getWeightedThroughput( const tr_peer * peer, int clientIsSeed ) { return (int)( 10.0 * ( clientIsSeed ? peer->rateToPeer : peer->rateToClient ) ); } static void rechoke( Torrent * t ) { int i, peerCount, size=0, unchoked=0; const time_t fibrillationTime = time(NULL) - MIN_CHOKE_PERIOD_SEC; tr_peer ** peers = getConnectedPeers( t, &peerCount ); struct ChokeData * choke = tr_new0( struct ChokeData, peerCount ); const int clientIsSeed = tr_torrentIsSeed( t->tor ); assert( torrentIsLocked( t ) ); /* sort the peers by preference and rate */ for( i=0; ichokeChangedAt > fibrillationTime ) { if( !peer->peerIsChoked ) ++unchoked; continue; } node = &choke[size++]; node->peer = peer; node->preferred = peer->peerIsInterested && !clientIsSnubbedBy( peer, clientIsSeed ); node->preferred_t = node->preferred && peer->client && strstr( peer->client, "Transmission" ); node->rate = getWeightedThroughput( peer, clientIsSeed ); } qsort( choke, size, sizeof(struct ChokeData), compareChoke ); for( i=0; ipeerIsInterested ) break; } for( i=0; imsgs, !choke[i].doUnchoke ); /* cleanup */ tr_free( choke ); tr_free( peers ); } static int rechokePulse( void * vtorrent ) { Torrent * t = vtorrent; torrentLock( t ); rechoke( t ); torrentUnlock( t ); return TRUE; } /*** **** ***/ static int swiftPulse( void * vtorrent ) { Torrent * t = vtorrent; torrentLock( t ); if( !tr_torrentIsSeed( t->tor ) ) { int i; int peerCount = 0; int deadbeatCount = 0; tr_peer ** peers = getConnectedPeers( t, &peerCount ); tr_peer ** deadbeats = tr_new( tr_peer*, peerCount ); const double ul_KiBsec = tr_rcRate( t->tor->upload ); const double ul_KiB = ul_KiBsec * (SWIFT_PERIOD_MSEC/1000.0); const double ul_bytes = ul_KiB * 1024; const double freeCreditTotal = ul_bytes * SWIFT_LARGESSE; int freeCreditPerPeer; for( i=0; icredit <= 0 ) deadbeats[deadbeatCount++] = peer; } freeCreditPerPeer = (int)( freeCreditTotal / deadbeatCount ); for( i=0; icredit = freeCreditPerPeer; tordbg( t, "%d deadbeats, " "who are each being granted %d bytes' credit " "for a total of %.1f KiB, " "%d%% of the torrent's ul speed %.1f\n", deadbeatCount, freeCreditPerPeer, ul_KiBsec*SWIFT_LARGESSE, (int)(SWIFT_LARGESSE*100), ul_KiBsec ); tr_free( deadbeats ); tr_free( peers ); } torrentUnlock( t ); return TRUE; } /*** **** **** Life and Death **** ***/ static int shouldPeerBeClosed( const Torrent * t, const tr_peer * peer, int peerCount ) { const tr_torrent * tor = t->tor; const time_t now = time( NULL ); const struct peer_atom * atom = getExistingAtom( t, &peer->in_addr ); /* if it's marked for purging, close it */ if( peer->doPurge ) { tordbg( t, "purging peer %s because its doPurge flag is set", tr_peerIoAddrStr(&atom->addr,atom->port) ); return TRUE; } /* if we're both seeds and it's been long enough for a pex exchange, close it */ if( 1 ) { const int clientIsSeed = tr_torrentIsSeed( tor ); const int peerIsSeed = atom->flags & ADDED_F_SEED_FLAG; if( peerIsSeed && clientIsSeed && ( !tr_torrentIsPexEnabled(tor) || (now-atom->time>=30) ) ) { tordbg( t, "purging peer %s because we're both seeds", tr_peerIoAddrStr(&atom->addr,atom->port) ); return TRUE; } } /* disconnect if it's been too long since piece data has been transferred. * this is on a sliding scale based on number of available peers... */ if( 1 ) { const int relaxStrictnessIfFewerThanN = (int)((MAX_CONNECTED_PEERS_PER_TORRENT * 0.9) + 0.5); /* if we have >= relaxIfFewerThan, strictness is 100%. * if we have zero connections, strictness is 0% */ const double strictness = peerCount >= relaxStrictnessIfFewerThanN ? 1.0 : peerCount / (double)relaxStrictnessIfFewerThanN; const int lo = MIN_UPLOAD_IDLE_SECS; const int hi = MAX_UPLOAD_IDLE_SECS; const int limit = lo + ((hi-lo) * strictness); const time_t then = peer->pieceDataActivityDate; const int idleTime = then ? (now-then) : 0; if( idleTime > limit ) { tordbg( t, "purging peer %s because it's been %d secs since we shared anything", tr_peerIoAddrStr(&atom->addr,atom->port), idleTime ); return TRUE; } } return FALSE; } static tr_peer ** getPeersToClose( Torrent * t, int * setmeSize ) { int i, peerCount, outsize; tr_peer ** peers = (tr_peer**) tr_ptrArrayPeek( t->peers, &peerCount ); struct tr_peer ** ret = tr_new( tr_peer*, peerCount ); assert( torrentIsLocked( t ) ); for( i=outsize=0; inumFails, b->numFails ))) return i; if( a->time != b->time ) return a->time < b->time ? -1 : 1; return 0; } static struct peer_atom ** getPeerCandidates( Torrent * t, int * setmeSize ) { int i, atomCount, retCount; struct peer_atom ** atoms; struct peer_atom ** ret; const time_t now = time( NULL ); const int seed = tr_torrentIsSeed( t->tor ); assert( torrentIsLocked( t ) ); atoms = (struct peer_atom**) tr_ptrArrayPeek( t->pool, &atomCount ); ret = tr_new( struct peer_atom*, atomCount ); for( i=retCount=0; imyflags & MYFLAG_BANNED ) { #if 0 tordbg( t, "RECONNECT peer %d (%s) is banned...", i, tr_peerIoAddrStr(&atom->addr,atom->port) ); #endif continue; } /* we don't need two connections to the same peer... */ if( peerIsInUse( t, &atom->addr ) ) { #if 0 tordbg( t, "RECONNECT peer %d (%s) is in use..", i, tr_peerIoAddrStr(&atom->addr,atom->port) ); #endif continue; } /* no need to connect if we're both seeds... */ if( seed && (atom->flags & ADDED_F_SEED_FLAG) ) { #if 0 tordbg( t, "RECONNECT peer %d (%s) is a seed and so are we..", i, tr_peerIoAddrStr(&atom->addr,atom->port) ); #endif continue; } /* we're wasting our time trying to connect to this bozo. */ if( atom->numFails > 10 ) { #if 0 tordbg( t, "RECONNECT peer %d (%s) gives us nothing but failure.", i, tr_peerIoAddrStr(&atom->addr,atom->port) ); #endif continue; } /* if we used this peer recently, give someone else a turn */ minWait = 60; maxWait = (60 * 20); /* twenty minutes */ wait = atom->numFails * 30; /* add 30 secs to the wait interval for each consecutive failure*/ if( wait < minWait ) wait = minWait; if( wait > maxWait ) wait = maxWait; if( ( now - atom->time ) < wait ) { tordbg( t, "RECONNECT peer %d (%s) is in its grace period of %d seconds..", i, tr_peerIoAddrStr(&atom->addr,atom->port), wait ); continue; } ret[retCount++] = atom; } qsort( ret, retCount, sizeof(struct peer_atom*), compareCandidates ); *setmeSize = retCount; return ret; } static int reconnectPulse( void * vtorrent ) { Torrent * t = vtorrent; torrentLock( t ); if( !t->isRunning ) { removeAllPeers( t ); } else { int i, nCandidates, nBad; struct peer_atom ** candidates = getPeerCandidates( t, &nCandidates ); struct tr_peer ** connections = getPeersToClose( t, &nBad ); if( nBad || nCandidates ) tordbg( t, "reconnect pulse for [%s]: %d bad connections, " "%d connection candidates, %d atoms, max per pulse is %d", t->tor->info.name, nBad, nCandidates, tr_ptrArraySize(t->pool), (int)MAX_RECONNECTIONS_PER_PULSE ); /* disconnect some peers. if we got transferred piece data, then they might be good peers, so reset their `numFails' weight to zero. otherwise we connected to them fruitlessly, so mark it as another fail */ for( i=0; iin_addr ); if( peer->pieceDataActivityDate ) atom->numFails = 0; else ++atom->numFails; removePeer( t, peer ); } /* add some new ones */ for( i=0; imanager; struct peer_atom * atom = candidates[i]; tr_peerIo * io; tr_handshake * handshake; tordbg( t, "Starting an OUTGOING connection with %s", tr_peerIoAddrStr( &atom->addr, atom->port ) ); io = tr_peerIoNewOutgoing( mgr->handle, &atom->addr, atom->port, t->hash ); handshake = tr_handshakeNew( io, mgr->handle->encryptionMode, myHandshakeDoneCB, mgr ); assert( tr_peerIoGetTorrentHash( io ) != NULL ); tr_ptrArrayInsertSorted( t->outgoingHandshakes, handshake, handshakeCompare ); atom->time = time( NULL ); } /* cleanup */ tr_free( connections ); tr_free( candidates ); } torrentUnlock( t ); return TRUE; }