/* * This file Copyright (C) 2007-2010 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 #include /* error codes ERANGE, ... */ #include /* INT_MAX */ #include /* memcpy, memcmp, strstr */ #include /* qsort */ #include #include "transmission.h" #include "announcer.h" #include "bandwidth.h" #include "bencode.h" #include "blocklist.h" #include "cache.h" #include "clients.h" #include "completion.h" #include "crypto.h" #include "handshake.h" #include "inout.h" /* tr_ioTestPiece */ #include "net.h" #include "peer-io.h" #include "peer-mgr.h" #include "peer-msgs.h" #include "ptrarray.h" #include "session.h" #include "stats.h" /* tr_statsAddUploaded, tr_statsAddDownloaded */ #include "torrent.h" #include "utils.h" #include "webseed.h" enum { /* how frequently to cull old atoms */ ATOM_PERIOD_MSEC = ( 60 * 1000 ), /* how frequently to change which peers are choked */ RECHOKE_PERIOD_MSEC = ( 10 * 1000 ), /* how frequently to reallocate bandwidth */ BANDWIDTH_PERIOD_MSEC = 500, /* how frequently to age out old piece request lists */ REFILL_UPKEEP_PERIOD_MSEC = ( 10 * 1000 ), /* how frequently to decide which peers live and die */ RECONNECT_PERIOD_MSEC = 500, /* when many peers are available, keep idle ones this long */ MIN_UPLOAD_IDLE_SECS = ( 60 ), /* when few peers are available, keep idle ones this long */ MAX_UPLOAD_IDLE_SECS = ( 60 * 5 ), /* max number of peers to ask for per second overall. * this throttle is to avoid overloading the router */ MAX_CONNECTIONS_PER_SECOND = 12, MAX_CONNECTIONS_PER_PULSE = (int)(MAX_CONNECTIONS_PER_SECOND * (RECONNECT_PERIOD_MSEC/1000.0)), /* number of bad pieces a peer is allowed to send before we ban them */ MAX_BAD_PIECES_PER_PEER = 5, /* amount of time to keep a list of request pieces lying around before it's considered too old and needs to be rebuilt */ PIECE_LIST_SHELF_LIFE_SECS = 60, /* use for bitwise operations w/peer_atom.myflags */ MYFLAG_BANNED = 1, /* use for bitwise operations w/peer_atom.myflags */ /* unreachable for now... but not banned. * if they try to connect to us it's okay */ MYFLAG_UNREACHABLE = 2, /* the minimum we'll wait before attempting to reconnect to a peer */ MINIMUM_RECONNECT_INTERVAL_SECS = 5, /** how long we'll let requests we've made linger before we cancel them */ REQUEST_TTL_SECS = 120, CANCEL_HISTORY_SEC = 120 }; /** *** **/ enum { UPLOAD_ONLY_UKNOWN, UPLOAD_ONLY_YES, UPLOAD_ONLY_NO }; /** * Peer information that should be kept even before we've connected and * after we've disconnected. These are kept in a pool of peer_atoms to decide * which ones would make good candidates for connecting to, and to watch out * for banned peers. * * @see tr_peer * @see tr_peermsgs */ 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 */ uint8_t uploadOnly; /* UPLOAD_ONLY_ */ int8_t seedProbability; /* how likely is this to be a seed... [0..100] or -1 for unknown */ int8_t blocklisted; /* -1 for unknown, TRUE for blocklisted, FALSE for not blocklisted */ tr_port port; uint16_t numFails; time_t time; /* when the peer's connection status last changed */ time_t piece_data_time; time_t lastConnectionAttemptAt; time_t lastConnectionAt; /* similar to a TTL field, but less rigid -- * if the swarm is small, the atom will be kept past this date. */ time_t shelf_date; tr_peer * peer; /* will be NULL if not connected */ tr_address addr; }; #ifdef NDEBUG #define tr_isAtom(a) (TRUE) #else static tr_bool tr_isAtom( const struct peer_atom * atom ) { return ( atom != NULL ) && ( atom->from < TR_PEER_FROM__MAX ) && ( tr_isAddress( &atom->addr ) ); } #endif static const char* tr_atomAddrStr( const struct peer_atom * atom ) { return tr_peerIoAddrStr( &atom->addr, atom->port ); } struct block_request { tr_block_index_t block; tr_peer * peer; time_t sentAt; }; struct weighted_piece { tr_piece_index_t index; int16_t salt; int16_t requestCount; }; /** @brief Opaque, per-torrent data structure for peer connection information */ typedef struct tr_torrent_peers { tr_ptrArray outgoingHandshakes; /* tr_handshake */ tr_ptrArray pool; /* struct peer_atom */ tr_ptrArray peers; /* tr_peer */ tr_ptrArray webseeds; /* tr_webseed */ tr_torrent * tor; tr_peer * optimistic; /* the optimistic peer, or NULL if none */ struct tr_peerMgr * manager; tr_bool isRunning; tr_bool needsCompletenessCheck; struct block_request * requests; int requestCount; int requestAlloc; struct weighted_piece * pieces; int pieceCount; int interestedCount; /* An arbitrary metric of how congested the downloads are. * Based on how many of requests are cancelled and how many are completed. * Lower values indicate less congestion. */ double cancelRate; } Torrent; struct tr_peerMgr { tr_session * session; tr_ptrArray incomingHandshakes; /* tr_handshake */ struct event * bandwidthTimer; struct event * rechokeTimer; struct event * refillUpkeepTimer; struct event * atomTimer; }; #define tordbg( t, ... ) \ do { \ if( tr_deepLoggingIsActive( ) ) \ tr_deepLog( __FILE__, __LINE__, tr_torrentName( t->tor ), __VA_ARGS__ ); \ } while( 0 ) #define dbgmsg( ... ) \ do { \ if( tr_deepLoggingIsActive( ) ) \ tr_deepLog( __FILE__, __LINE__, NULL, __VA_ARGS__ ); \ } while( 0 ) /** *** **/ static inline void managerLock( const struct tr_peerMgr * manager ) { tr_sessionLock( manager->session ); } static inline void managerUnlock( const struct tr_peerMgr * manager ) { tr_sessionUnlock( manager->session ); } static inline void torrentLock( Torrent * torrent ) { managerLock( torrent->manager ); } static inline void torrentUnlock( Torrent * torrent ) { managerUnlock( torrent->manager ); } static inline int torrentIsLocked( const Torrent * t ) { return tr_sessionIsLocked( t->manager->session ); } /** *** **/ static int handshakeCompareToAddr( const void * va, const void * vb ) { const tr_handshake * a = va; return tr_compareAddresses( tr_handshakeGetAddr( a, NULL ), vb ); } static int handshakeCompare( const void * a, const void * b ) { return handshakeCompareToAddr( a, tr_handshakeGetAddr( b, NULL ) ); } static inline tr_handshake* getExistingHandshake( tr_ptrArray * handshakes, const tr_address * addr ) { if( tr_ptrArrayEmpty( handshakes ) ) return NULL; return tr_ptrArrayFindSorted( handshakes, addr, handshakeCompareToAddr ); } static int comparePeerAtomToAddress( const void * va, const void * vb ) { const struct peer_atom * a = va; return tr_compareAddresses( &a->addr, vb ); } static int compareAtomsByAddress( const void * va, const void * vb ) { const struct peer_atom * b = vb; assert( tr_isAtom( b ) ); return comparePeerAtomToAddress( va, &b->addr ); } /** *** **/ const tr_address * tr_peerAddress( const tr_peer * peer ) { return &peer->atom->addr; } static Torrent* getExistingTorrent( tr_peerMgr * manager, const uint8_t * hash ) { tr_torrent * tor = tr_torrentFindFromHash( manager->session, hash ); return tor == NULL ? NULL : tor->torrentPeers; } static int peerCompare( const void * a, const void * b ) { return tr_compareAddresses( tr_peerAddress( a ), tr_peerAddress( b ) ); } static struct peer_atom* getExistingAtom( const Torrent * t, const tr_address * addr ) { Torrent * tt = (Torrent*)t; assert( torrentIsLocked( t ) ); return tr_ptrArrayFindSorted( &tt->pool, addr, comparePeerAtomToAddress ); } static tr_bool peerIsInUse( const Torrent * ct, const struct peer_atom * atom ) { Torrent * t = (Torrent*) ct; assert( torrentIsLocked ( t ) ); return ( atom->peer != NULL ) || getExistingHandshake( &t->outgoingHandshakes, &atom->addr ) || getExistingHandshake( &t->manager->incomingHandshakes, &atom->addr ); } static tr_peer* peerConstructor( struct peer_atom * atom ) { tr_peer * peer = tr_new0( tr_peer, 1 ); tr_bitsetConstructor( &peer->have, 0 ); peer->atom = atom; atom->peer = peer; peer->blocksSentToClient = tr_historyNew( CANCEL_HISTORY_SEC, 1 ); peer->blocksSentToPeer = tr_historyNew( CANCEL_HISTORY_SEC, 1 ); peer->cancelsSentToClient = tr_historyNew( CANCEL_HISTORY_SEC, 1 ); peer->cancelsSentToPeer = tr_historyNew( CANCEL_HISTORY_SEC, 1 ); return peer; } static tr_peer* getPeer( Torrent * torrent, struct peer_atom * atom ) { tr_peer * peer; assert( torrentIsLocked( torrent ) ); peer = atom->peer; if( peer == NULL ) { peer = peerConstructor( atom ); tr_ptrArrayInsertSorted( &torrent->peers, peer, peerCompare ); } return peer; } static void peerDeclinedAllRequests( Torrent *, const tr_peer * ); static void peerDestructor( Torrent * t, tr_peer * peer ) { assert( peer != NULL ); peerDeclinedAllRequests( t, peer ); if( peer->msgs != NULL ) tr_peerMsgsFree( peer->msgs ); tr_peerIoClear( peer->io ); tr_peerIoUnref( peer->io ); /* balanced by the ref in handshakeDoneCB() */ tr_historyFree( peer->blocksSentToClient ); tr_historyFree( peer->blocksSentToPeer ); tr_historyFree( peer->cancelsSentToClient ); tr_historyFree( peer->cancelsSentToPeer ); tr_bitsetDestructor( &peer->have ); tr_bitfieldFree( peer->blame ); tr_free( peer->client ); peer->atom->peer = NULL; tr_free( peer ); } static void removePeer( Torrent * t, tr_peer * peer ) { tr_peer * removed; struct peer_atom * atom = peer->atom; assert( torrentIsLocked( t ) ); assert( atom ); atom->time = tr_time( ); removed = tr_ptrArrayRemoveSorted( &t->peers, peer, peerCompare ); assert( removed == peer ); peerDestructor( t, removed ); } static void removeAllPeers( Torrent * t ) { while( !tr_ptrArrayEmpty( &t->peers ) ) removePeer( t, tr_ptrArrayNth( &t->peers, 0 ) ); } static void torrentDestructor( void * vt ) { Torrent * t = vt; assert( t ); assert( !t->isRunning ); assert( torrentIsLocked( t ) ); assert( tr_ptrArrayEmpty( &t->outgoingHandshakes ) ); assert( tr_ptrArrayEmpty( &t->peers ) ); tr_ptrArrayDestruct( &t->webseeds, (PtrArrayForeachFunc)tr_webseedFree ); tr_ptrArrayDestruct( &t->pool, (PtrArrayForeachFunc)tr_free ); tr_ptrArrayDestruct( &t->outgoingHandshakes, NULL ); tr_ptrArrayDestruct( &t->peers, NULL ); tr_free( t->requests ); tr_free( t->pieces ); tr_free( t ); } static void peerCallbackFunc( tr_peer *, const tr_peer_event *, void * ); static Torrent* torrentConstructor( tr_peerMgr * manager, tr_torrent * tor ) { int i; Torrent * t; t = tr_new0( Torrent, 1 ); t->manager = manager; t->tor = tor; t->pool = TR_PTR_ARRAY_INIT; t->peers = TR_PTR_ARRAY_INIT; t->webseeds = TR_PTR_ARRAY_INIT; t->outgoingHandshakes = TR_PTR_ARRAY_INIT; for( i = 0; i < tor->info.webseedCount; ++i ) { tr_webseed * w = tr_webseedNew( tor, tor->info.webseeds[i], peerCallbackFunc, t ); tr_ptrArrayAppend( &t->webseeds, w ); } return t; } tr_peerMgr* tr_peerMgrNew( tr_session * session ) { tr_peerMgr * m = tr_new0( tr_peerMgr, 1 ); m->session = session; m->incomingHandshakes = TR_PTR_ARRAY_INIT; return m; } static void deleteTimer( struct event ** t ) { if( *t != NULL ) { evtimer_del( *t ); tr_free( *t ); *t = NULL; } } static void deleteTimers( struct tr_peerMgr * m ) { deleteTimer( &m->atomTimer ); deleteTimer( &m->bandwidthTimer ); deleteTimer( &m->rechokeTimer ); deleteTimer( &m->refillUpkeepTimer ); } void tr_peerMgrFree( tr_peerMgr * manager ) { managerLock( manager ); deleteTimers( 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_ptrArrayDestruct( &manager->incomingHandshakes, NULL ); managerUnlock( manager ); tr_free( manager ); } static int clientIsDownloadingFrom( const tr_torrent * tor, const tr_peer * peer ) { if( !tr_torrentHasMetadata( tor ) ) return TRUE; return peer->clientIsInterested && !peer->clientIsChoked; } static int clientIsUploadingTo( const tr_peer * peer ) { return peer->peerIsInterested && !peer->peerIsChoked; } /*** **** ***/ void tr_peerMgrOnBlocklistChanged( tr_peerMgr * mgr ) { tr_torrent * tor = NULL; tr_session * session = mgr->session; /* we cache whether or not a peer is blocklisted... since the blocklist has changed, erase that cached value */ while(( tor = tr_torrentNext( session, tor ))) { int i; Torrent * t = tor->torrentPeers; const int n = tr_ptrArraySize( &t->pool ); for( i=0; ipool, i ); atom->blocklisted = -1; } } } static tr_bool isAtomBlocklisted( tr_session * session, struct peer_atom * atom ) { if( atom->blocklisted < 0 ) atom->blocklisted = tr_sessionIsAddressBlocked( session, &atom->addr ); assert( tr_isBool( atom->blocklisted ) ); return atom->blocklisted; } /*** **** ***/ static void atomSetSeedProbability( struct peer_atom * atom, int seedProbability ) { assert( atom != NULL ); assert( -1<=seedProbability && seedProbability<=100 ); atom->seedProbability = seedProbability; if( seedProbability == 100 ) atom->flags |= ADDED_F_SEED_FLAG; else if( seedProbability != -1 ) atom->flags &= ~ADDED_F_SEED_FLAG; } static void atomSetSeed( struct peer_atom * atom ) { atomSetSeedProbability( atom, 100 ); } static inline tr_bool atomIsSeed( const struct peer_atom * atom ) { return atom->seedProbability == 100; } tr_bool tr_peerMgrPeerIsSeed( const tr_torrent * tor, const tr_address * addr ) { tr_bool isSeed = FALSE; const Torrent * t = tor->torrentPeers; const struct peer_atom * atom = getExistingAtom( t, addr ); if( atom ) isSeed = atomIsSeed( atom ); return isSeed; } /** *** REQUESTS *** *** There are two data structures associated with managing block requests: *** *** 1. Torrent::requests, an array of "struct block_request" which keeps *** track of which blocks have been requested, and when, and by which peers. *** This is list is used for (a) cancelling requests that have been pending *** for too long and (b) avoiding duplicate requests before endgame. *** *** 2. Torrent::pieces, an array of "struct weighted_piece" which lists the *** pieces that we want to request. It's used to decide which blocks to *** return next when tr_peerMgrGetBlockRequests() is called. **/ /** *** struct block_request **/ static int compareReqByBlock( const void * va, const void * vb ) { const struct block_request * a = va; const struct block_request * b = vb; /* primary key: block */ if( a->block < b->block ) return -1; if( a->block > b->block ) return 1; /* secondary key: peer */ if( a->peer < b->peer ) return -1; if( a->peer > b->peer ) return 1; return 0; } static void requestListAdd( Torrent * t, tr_block_index_t block, tr_peer * peer ) { struct block_request key; /* ensure enough room is available... */ if( t->requestCount + 1 >= t->requestAlloc ) { const int CHUNK_SIZE = 128; t->requestAlloc += CHUNK_SIZE; t->requests = tr_renew( struct block_request, t->requests, t->requestAlloc ); } /* populate the record we're inserting */ key.block = block; key.peer = peer; key.sentAt = tr_time( ); /* insert the request to our array... */ { tr_bool exact; const int pos = tr_lowerBound( &key, t->requests, t->requestCount, sizeof( struct block_request ), compareReqByBlock, &exact ); assert( !exact ); memmove( t->requests + pos + 1, t->requests + pos, sizeof( struct block_request ) * ( t->requestCount++ - pos ) ); t->requests[pos] = key; } if( peer != NULL ) { ++peer->pendingReqsToPeer; assert( peer->pendingReqsToPeer >= 0 ); } /*fprintf( stderr, "added request of block %lu from peer %s... " "there are now %d block\n", (unsigned long)block, tr_atomAddrStr( peer->atom ), t->requestCount );*/ } static struct block_request * requestListLookup( Torrent * t, tr_block_index_t block, const tr_peer * peer ) { struct block_request key; key.block = block; key.peer = (tr_peer*) peer; return bsearch( &key, t->requests, t->requestCount, sizeof( struct block_request ), compareReqByBlock ); } /* how many peers are we currently requesting this block from... */ static int countBlockRequests( Torrent * t, tr_block_index_t block ) { tr_bool exact; int i, n, pos; struct block_request key; key.block = block; key.peer = NULL; pos = tr_lowerBound( &key, t->requests, t->requestCount, sizeof( struct block_request ), compareReqByBlock, &exact ); assert( !exact ); /* shouldn't have a request with .peer == NULL */ n = 0; for( i=pos; irequestCount; ++i ) { if( t->requests[i].block == block ) ++n; else break; } return n; } static void decrementPendingReqCount( const struct block_request * b ) { if( b->peer != NULL ) if( b->peer->pendingReqsToPeer > 0 ) --b->peer->pendingReqsToPeer; } static void requestListRemove( Torrent * t, tr_block_index_t block, const tr_peer * peer ) { const struct block_request * b = requestListLookup( t, block, peer ); if( b != NULL ) { const int pos = b - t->requests; assert( pos < t->requestCount ); decrementPendingReqCount( b ); tr_removeElementFromArray( t->requests, pos, sizeof( struct block_request ), t->requestCount-- ); /*fprintf( stderr, "removing request of block %lu from peer %s... " "there are now %d block requests left\n", (unsigned long)block, tr_atomAddrStr( peer->atom ), t->requestCount );*/ } } /** *** struct weighted_piece **/ enum { PIECES_UNSORTED, PIECES_SORTED_BY_INDEX, PIECES_SORTED_BY_WEIGHT }; const tr_torrent * weightTorrent; /* we try to create a "weight" s.t. high-priority pieces come before others, * and that partially-complete pieces come before empty ones. */ static int comparePieceByWeight( const void * va, const void * vb ) { const struct weighted_piece * a = va; const struct weighted_piece * b = vb; int ia, ib, missing, pending; const tr_torrent * tor = weightTorrent; /* primary key: weight */ missing = tr_cpMissingBlocksInPiece( &tor->completion, a->index ); pending = a->requestCount; ia = missing > pending ? missing - pending : (int)(tor->blockCountInPiece + pending); missing = tr_cpMissingBlocksInPiece( &tor->completion, b->index ); pending = b->requestCount; ib = missing > pending ? missing - pending : (int)(tor->blockCountInPiece + pending); if( ia < ib ) return -1; if( ia > ib ) return 1; /* secondary key: higher priorities go first */ ia = tor->info.pieces[a->index].priority; ib = tor->info.pieces[b->index].priority; if( ia > ib ) return -1; if( ia < ib ) return 1; /* tertiary key: random */ if( a->salt < b->salt ) return -1; if( a->salt > b->salt ) return 1; /* okay, they're equal */ return 0; } static int comparePieceByIndex( const void * va, const void * vb ) { const struct weighted_piece * a = va; const struct weighted_piece * b = vb; if( a->index < b->index ) return -1; if( a->index > b->index ) return 1; return 0; } static void pieceListSort( Torrent * t, int mode ) { int(*compar)(const void *, const void *); assert( mode==PIECES_SORTED_BY_INDEX || mode==PIECES_SORTED_BY_WEIGHT ); switch( mode ) { case PIECES_SORTED_BY_WEIGHT: compar = comparePieceByWeight; break; case PIECES_SORTED_BY_INDEX: compar = comparePieceByIndex; break; default: assert( 0 && "unhandled" ); break; } weightTorrent = t->tor; qsort( t->pieces, t->pieceCount, sizeof( struct weighted_piece ), compar ); } static tr_bool isInEndgame( Torrent * t ) { tr_bool endgame = FALSE; if( ( t->pieces != NULL ) && ( t->pieceCount > 0 ) ) { const struct weighted_piece * p = t->pieces; const int pending = p->requestCount; const int missing = tr_cpMissingBlocksInPiece( &t->tor->completion, p->index ); endgame = pending >= missing; } /*if( endgame ) fprintf( stderr, "ENDGAME reached\n" );*/ return endgame; } /** * This function is useful for sanity checking, * but is too expensive even for nightly builds... * let's leave it disabled but add an easy hook to compile it back in */ #if 0 static void assertWeightedPiecesAreSorted( Torrent * t ) { if( !isInEndgame( t ) ) { int i; weightTorrent = t->tor; for( i=0; ipieceCount-1; ++i ) assert( comparePieceByWeight( &t->pieces[i], &t->pieces[i+1] ) <= 0 ); } } #else #define assertWeightedPiecesAreSorted(t) #endif static struct weighted_piece * pieceListLookup( Torrent * t, tr_piece_index_t index ) { int i; for( i=0; ipieceCount; ++i ) if( t->pieces[i].index == index ) return &t->pieces[i]; return NULL; } static void pieceListRebuild( Torrent * t ) { assertWeightedPiecesAreSorted( t ); if( !tr_torrentIsSeed( t->tor ) ) { tr_piece_index_t i; tr_piece_index_t * pool; tr_piece_index_t poolCount = 0; const tr_torrent * tor = t->tor; const tr_info * inf = tr_torrentInfo( tor ); struct weighted_piece * pieces; int pieceCount; /* build the new list */ pool = tr_new( tr_piece_index_t, inf->pieceCount ); for( i=0; ipieceCount; ++i ) if( !inf->pieces[i].dnd ) if( !tr_cpPieceIsComplete( &tor->completion, i ) ) pool[poolCount++] = i; pieceCount = poolCount; pieces = tr_new0( struct weighted_piece, pieceCount ); for( i=0; iindex = pool[i]; piece->requestCount = 0; piece->salt = tr_cryptoWeakRandInt( 4096 ); } /* if we already had a list of pieces, merge it into * the new list so we don't lose its requestCounts */ if( t->pieces != NULL ) { struct weighted_piece * o = t->pieces; struct weighted_piece * oend = o + t->pieceCount; struct weighted_piece * n = pieces; struct weighted_piece * nend = n + pieceCount; pieceListSort( t, PIECES_SORTED_BY_INDEX ); while( o!=oend && n!=nend ) { if( o->index < n->index ) ++o; else if( o->index > n->index ) ++n; else *n++ = *o++; } tr_free( t->pieces ); } t->pieces = pieces; t->pieceCount = pieceCount; pieceListSort( t, PIECES_SORTED_BY_WEIGHT ); /* cleanup */ tr_free( pool ); } } static void pieceListRemovePiece( Torrent * t, tr_piece_index_t piece ) { struct weighted_piece * p; assertWeightedPiecesAreSorted( t ); if(( p = pieceListLookup( t, piece ))) { const int pos = p - t->pieces; tr_removeElementFromArray( t->pieces, pos, sizeof( struct weighted_piece ), t->pieceCount-- ); if( t->pieceCount == 0 ) { tr_free( t->pieces ); t->pieces = NULL; } } assertWeightedPiecesAreSorted( t ); } static void pieceListResortPiece( Torrent * t, struct weighted_piece * p ) { int pos; tr_bool isSorted = TRUE; if( p == NULL ) return; /* is the torrent already sorted? */ pos = p - t->pieces; weightTorrent = t->tor; if( isSorted && ( pos > 0 ) && ( comparePieceByWeight( p-1, p ) > 0 ) ) isSorted = FALSE; if( isSorted && ( pos < t->pieceCount - 1 ) && ( comparePieceByWeight( p, p+1 ) > 0 ) ) isSorted = FALSE; /* if it's not sorted, move it around */ if( !isSorted ) { tr_bool exact; const struct weighted_piece tmp = *p; tr_removeElementFromArray( t->pieces, pos, sizeof( struct weighted_piece ), t->pieceCount-- ); pos = tr_lowerBound( &tmp, t->pieces, t->pieceCount, sizeof( struct weighted_piece ), comparePieceByWeight, &exact ); memmove( &t->pieces[pos + 1], &t->pieces[pos], sizeof( struct weighted_piece ) * ( t->pieceCount++ - pos ) ); t->pieces[pos] = tmp; } assertWeightedPiecesAreSorted( t ); } static void pieceListRemoveRequest( Torrent * t, tr_block_index_t block ) { struct weighted_piece * p; const tr_piece_index_t index = tr_torBlockPiece( t->tor, block ); assertWeightedPiecesAreSorted( t ); if( ((p = pieceListLookup( t, index ))) && ( p->requestCount > 0 ) ) { --p->requestCount; pieceListResortPiece( t, p ); } assertWeightedPiecesAreSorted( t ); } /** *** **/ void tr_peerMgrRebuildRequests( tr_torrent * tor ) { assert( tr_isTorrent( tor ) ); pieceListRebuild( tor->torrentPeers ); } void tr_peerMgrGetNextRequests( tr_torrent * tor, tr_peer * peer, int numwant, tr_block_index_t * setme, int * numgot ) { int i; int got; Torrent * t; tr_bool endgame; struct weighted_piece * pieces; const tr_bitset * have = &peer->have; /* sanity clause */ assert( tr_isTorrent( tor ) ); assert( peer->clientIsInterested ); assert( !peer->clientIsChoked ); assert( numwant > 0 ); /* walk through the pieces and find blocks that should be requested */ got = 0; t = tor->torrentPeers; assertWeightedPiecesAreSorted( t ); /* prep the pieces list */ if( t->pieces == NULL ) pieceListRebuild( t ); endgame = isInEndgame( t ); pieces = t->pieces; for( i=0; ipieceCount && gotcompletion, p->index ); const int maxDuplicatesPerBlock = endgame ? 3 : 1; if( p->requestCount > ( missing * maxDuplicatesPerBlock ) ) continue; /* if the peer has this piece that we want... */ if( tr_bitsetHasFast( have, p->index ) ) { tr_block_index_t b = tr_torPieceFirstBlock( tor, p->index ); const tr_block_index_t e = b + tr_torPieceCountBlocks( tor, p->index ); for( ; b!=e && gotcompletion, b ) ) continue; /* don't send the same request to the same peer twice */ if( tr_peerMgrDidPeerRequest( tor, peer, b ) ) continue; /* don't send the same request to any peer too many times */ if( countBlockRequests( t, b ) >= maxDuplicatesPerBlock ) continue; /* update the caller's table */ setme[got++] = b; /* update our own tables */ requestListAdd( t, b, peer ); ++p->requestCount; } } } /* In most cases we've just changed the weights of a small number of pieces. * So rather than qsort()ing the entire array, it's faster to apply an * adaptive insertion sort algorithm. */ if( got > 0 ) { /* not enough requests || last piece modified */ if ( i == t->pieceCount ) --i; weightTorrent = t->tor; while( --i >= 0 ) { tr_bool exact; /* relative position! */ const int newpos = tr_lowerBound( &t->pieces[i], &t->pieces[i + 1], t->pieceCount - (i + 1), sizeof( struct weighted_piece ), comparePieceByWeight, &exact ); if( newpos > 0 ) { const struct weighted_piece piece = t->pieces[i]; memmove( &t->pieces[i], &t->pieces[i + 1], sizeof( struct weighted_piece ) * ( newpos ) ); t->pieces[i + newpos] = piece; } } } assertWeightedPiecesAreSorted( t ); *numgot = got; } tr_bool tr_peerMgrDidPeerRequest( const tr_torrent * tor, const tr_peer * peer, tr_block_index_t block ) { const Torrent * t = tor->torrentPeers; return requestListLookup( (Torrent*)t, block, peer ) != NULL; } /* cancel requests that are too old */ static void refillUpkeep( int foo UNUSED, short bar UNUSED, void * vmgr ) { time_t now; uint64_t now_msec; time_t too_old; tr_torrent * tor; tr_peerMgr * mgr = vmgr; managerLock( mgr ); now = tr_time( ); now_msec = tr_date( ); too_old = now - REQUEST_TTL_SECS; tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) { Torrent * t = tor->torrentPeers; const int n = t->requestCount; if( n > 0 ) { int keepCount = 0; int cancelCount = 0; struct block_request * cancel = tr_new( struct block_request, n ); const struct block_request * it; const struct block_request * end; for( it=t->requests, end=it+n; it!=end; ++it ) { if( ( it->sentAt <= too_old ) && !tr_peerMsgsIsReadingBlock( it->peer->msgs, it->block ) ) cancel[cancelCount++] = *it; else { if( it != &t->requests[keepCount] ) t->requests[keepCount] = *it; keepCount++; } } /* prune out the ones we aren't keeping */ t->requestCount = keepCount; /* send cancel messages for all the "cancel" ones */ for( it=cancel, end=it+cancelCount; it!=end; ++it ) { if( ( it->peer != NULL ) && ( it->peer->msgs != NULL ) ) { tr_historyAdd( it->peer->cancelsSentToPeer, now_msec, 1 ); tr_peerMsgsCancel( it->peer->msgs, it->block ); decrementPendingReqCount( it ); } } /* decrement the pending request counts for the timed-out blocks */ for( it=cancel, end=it+cancelCount; it!=end; ++it ) pieceListRemoveRequest( t, it->block ); /* cleanup loop */ tr_free( cancel ); } } tr_timerAddMsec( mgr->refillUpkeepTimer, REFILL_UPKEEP_PERIOD_MSEC ); managerUnlock( mgr ); } static void addStrike( Torrent * t, tr_peer * peer ) { tordbg( t, "increasing peer %s strike count to %d", tr_atomAddrStr( peer->atom ), peer->strikes + 1 ); if( ++peer->strikes >= MAX_BAD_PIECES_PER_PEER ) { struct peer_atom * atom = peer->atom; atom->myflags |= MYFLAG_BANNED; peer->doPurge = 1; tordbg( t, "banning peer %s", tr_atomAddrStr( atom ) ); } } static void gotBadPiece( Torrent * t, tr_piece_index_t pieceIndex ) { tr_torrent * tor = t->tor; const uint32_t byteCount = tr_torPieceCountBytes( tor, pieceIndex ); tor->corruptCur += byteCount; tor->downloadedCur -= MIN( tor->downloadedCur, byteCount ); tr_announcerAddBytes( tor, TR_ANN_CORRUPT, byteCount ); } static void peerSuggestedPiece( Torrent * t UNUSED, tr_peer * peer UNUSED, tr_piece_index_t pieceIndex UNUSED, int isFastAllowed UNUSED ) { #if 0 assert( t ); assert( peer ); assert( peer->msgs ); /* is this a valid piece? */ if( pieceIndex >= t->tor->info.pieceCount ) return; /* don't ask for it if we've already got it */ if( tr_cpPieceIsComplete( t->tor->completion, pieceIndex ) ) return; /* don't ask for it if they don't have it */ if( !tr_bitfieldHas( peer->have, pieceIndex ) ) return; /* don't ask for it if we're choked and it's not fast */ if( !isFastAllowed && peer->clientIsChoked ) return; /* request the blocks that we don't have in this piece */ { tr_block_index_t block; const tr_torrent * tor = t->tor; const tr_block_index_t start = tr_torPieceFirstBlock( tor, pieceIndex ); const tr_block_index_t end = start + tr_torPieceCountBlocks( tor, pieceIndex ); for( block=start; blockcompletion, block ) ) { const uint32_t offset = getBlockOffsetInPiece( tor, block ); const uint32_t length = tr_torBlockCountBytes( tor, block ); tr_peerMsgsAddRequest( peer->msgs, pieceIndex, offset, length ); incrementPieceRequests( t, pieceIndex ); } } } #endif } static void removeRequestFromTables( Torrent * t, tr_block_index_t block, const tr_peer * peer ) { requestListRemove( t, block, peer ); pieceListRemoveRequest( t, block ); } /* peer choked us, or maybe it disconnected. either way we need to remove all its requests */ static void peerDeclinedAllRequests( Torrent * t, const tr_peer * peer ) { int i, n; tr_block_index_t * blocks = tr_new( tr_block_index_t, t->requestCount ); for( i=n=0; irequestCount; ++i ) if( peer == t->requests[i].peer ) blocks[n++] = t->requests[i].block; for( i=0; ieventType ) { case TR_PEER_PEER_GOT_DATA: { const time_t now = tr_time( ); tr_torrent * tor = t->tor; tr_torrentSetActivityDate( tor, now ); if( e->wasPieceData ) { tor->uploadedCur += e->length; tr_announcerAddBytes( tor, TR_ANN_UP, e->length ); tr_torrentSetDirty( tor ); } /* update the stats */ if( e->wasPieceData ) tr_statsAddUploaded( tor->session, e->length ); /* update our atom */ if( peer && e->wasPieceData ) peer->atom->piece_data_time = now; break; } case TR_PEER_CLIENT_GOT_REJ: removeRequestFromTables( t, _tr_block( t->tor, e->pieceIndex, e->offset ), peer ); break; case TR_PEER_CLIENT_GOT_CHOKE: peerDeclinedAllRequests( t, peer ); break; case TR_PEER_CLIENT_GOT_PORT: if( peer ) peer->atom->port = e->port; break; case TR_PEER_CLIENT_GOT_SUGGEST: if( peer ) peerSuggestedPiece( t, peer, e->pieceIndex, FALSE ); break; case TR_PEER_CLIENT_GOT_ALLOWED_FAST: if( peer ) peerSuggestedPiece( t, peer, e->pieceIndex, TRUE ); break; case TR_PEER_CLIENT_GOT_DATA: { const time_t now = tr_time( ); tr_torrent * tor = t->tor; tr_torrentSetActivityDate( tor, now ); if( e->wasPieceData ) { tor->downloadedCur += e->length; tr_torrentSetDirty( tor ); } /* update the stats */ if( e->wasPieceData ) tr_statsAddDownloaded( tor->session, e->length ); /* update our atom */ if( peer && e->wasPieceData ) peer->atom->piece_data_time = now; break; } case TR_PEER_PEER_PROGRESS: { if( peer ) { struct peer_atom * atom = peer->atom; if( e->progress >= 1.0 ) { tordbg( t, "marking peer %s as a seed", tr_atomAddrStr( atom ) ); atomSetSeed( atom ); } } break; } case TR_PEER_CLIENT_GOT_BLOCK: { tr_torrent * tor = t->tor; tr_block_index_t block = _tr_block( tor, e->pieceIndex, e->offset ); requestListRemove( t, block, peer ); pieceListRemoveRequest( t, block ); if( peer != NULL ) tr_historyAdd( peer->blocksSentToClient, tr_date( ), 1 ); if( tr_cpBlockIsComplete( &tor->completion, block ) ) { /* we already have this block... */ const uint32_t n = tr_torBlockCountBytes( tor, block ); tor->downloadedCur -= MIN( tor->downloadedCur, n ); tordbg( t, "we have this block already..." ); } else { tr_cpBlockAdd( &tor->completion, block ); pieceListResortPiece( t, pieceListLookup( t, e->pieceIndex ) ); tr_torrentSetDirty( tor ); if( tr_cpPieceIsComplete( &tor->completion, e->pieceIndex ) ) { const tr_piece_index_t p = e->pieceIndex; const tr_bool ok = tr_ioTestPiece( tor, p ); if( !ok ) { tr_torerr( tor, _( "Piece %lu, which was just downloaded, failed its checksum test" ), (unsigned long)p ); } tr_torrentSetHasPiece( tor, p, ok ); tr_torrentSetPieceChecked( tor, p, TRUE ); tr_peerMgrSetBlame( tor, p, ok ); if( !ok ) { gotBadPiece( t, p ); } else { int i; int peerCount; tr_peer ** peers; tr_file_index_t fileIndex; /* only add this to downloadedCur if we got it from a peer -- * webseeds shouldn't count against our ratio. As one tracker * admin put it, "Those pieces are downloaded directly from the * content distributor, not the peers, it is the tracker's job * to manage the swarms, not the web server and does not fit * into the jurisdiction of the tracker." */ if( peer != NULL ) { const uint32_t n = tr_torPieceCountBytes( tor, p ); tr_announcerAddBytes( tor, TR_ANN_DOWN, n ); } peerCount = tr_ptrArraySize( &t->peers ); peers = (tr_peer**) tr_ptrArrayBase( &t->peers ); for( i=0; imsgs, p ); for( fileIndex=0; fileIndexinfo.fileCount; ++fileIndex ) { const tr_file * file = &tor->info.files[fileIndex]; if( ( file->firstPiece <= p ) && ( p <= file->lastPiece ) ) { if( tr_cpFileIsComplete( &tor->completion, fileIndex ) ) { fprintf( stderr, "flushing complete file %d (%s)\n", fileIndex, tor->info.files[fileIndex].name ); tr_cacheFlushFile( tor->session->cache, tor, fileIndex ); tr_torrentFileCompleted( tor, fileIndex ); } } } pieceListRemovePiece( t, p ); } } t->needsCompletenessCheck = TRUE; } break; } case TR_PEER_ERROR: if( ( e->err == ERANGE ) || ( e->err == EMSGSIZE ) || ( e->err == ENOTCONN ) ) { /* some protocol error from the peer */ peer->doPurge = 1; tordbg( t, "setting %s doPurge flag because we got an ERANGE, EMSGSIZE, or ENOTCONN error", tr_atomAddrStr( peer->atom ) ); } else { tordbg( t, "unhandled error: %s", tr_strerror( e->err ) ); } break; default: assert( 0 ); } torrentUnlock( t ); } static int getDefaultShelfLife( uint8_t from ) { /* in general, peers obtained from firsthand contact * are better than those from secondhand, etc etc */ switch( from ) { case TR_PEER_FROM_INCOMING : return 60 * 60 * 6; case TR_PEER_FROM_LTEP : return 60 * 60 * 6; case TR_PEER_FROM_TRACKER : return 60 * 60 * 3; case TR_PEER_FROM_DHT : return 60 * 60 * 3; case TR_PEER_FROM_PEX : return 60 * 60 * 2; case TR_PEER_FROM_RESUME : return 60 * 60; case TR_PEER_FROM_LPD : return 10 * 60; default : return 60 * 60; } } static void ensureAtomExists( Torrent * t, const tr_address * addr, const tr_port port, const uint8_t flags, const int8_t seedProbability, const uint8_t from ) { struct peer_atom * a; assert( tr_isAddress( addr ) ); assert( from < TR_PEER_FROM__MAX ); a = getExistingAtom( t, addr ); if( a == NULL ) { const int jitter = tr_cryptoWeakRandInt( 60*10 ); a = tr_new0( struct peer_atom, 1 ); a->addr = *addr; a->port = port; a->flags = flags; a->from = from; a->shelf_date = tr_time( ) + getDefaultShelfLife( from ) + jitter; a->blocklisted = -1; atomSetSeedProbability( a, seedProbability ); tr_ptrArrayInsertSorted( &t->pool, a, compareAtomsByAddress ); tordbg( t, "got a new atom: %s", tr_atomAddrStr( a ) ); } else if( a->seedProbability == -1 ) { atomSetSeedProbability( a, seedProbability ); } } static int getMaxPeerCount( const tr_torrent * tor ) { return tor->maxConnectedPeers; } static int getPeerCount( const Torrent * t ) { return tr_ptrArraySize( &t->peers );/* + tr_ptrArraySize( &t->outgoingHandshakes ); */ } /* FIXME: this is kind of a mess. */ static tr_bool myHandshakeDoneCB( tr_handshake * handshake, tr_peerIo * io, tr_bool readAnythingFromPeer, tr_bool isConnected, const uint8_t * peer_id, void * vmanager ) { tr_bool ok = isConnected; tr_bool success = FALSE; tr_port port; const tr_address * addr; tr_peerMgr * manager = vmanager; Torrent * t; tr_handshake * ours; assert( io ); assert( tr_isBool( ok ) ); t = tr_peerIoHasTorrentHash( io ) ? getExistingTorrent( manager, tr_peerIoGetTorrentHash( io ) ) : NULL; if( tr_peerIoIsIncoming ( io ) ) ours = tr_ptrArrayRemoveSorted( &manager->incomingHandshakes, handshake, handshakeCompare ); else if( t ) ours = tr_ptrArrayRemoveSorted( &t->outgoingHandshakes, handshake, handshakeCompare ); else ours = handshake; assert( ours ); assert( ours == handshake ); if( t ) 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; if( !readAnythingFromPeer ) { tordbg( t, "marking peer %s as unreachable... numFails is %d", tr_atomAddrStr( atom ), (int)atom->numFails ); atom->myflags |= MYFLAG_UNREACHABLE; } } } } else /* looking good */ { struct peer_atom * atom; ensureAtomExists( t, addr, port, 0, -1, TR_PEER_FROM_INCOMING ); atom = getExistingAtom( t, addr ); atom->time = tr_time( ); atom->piece_data_time = 0; atom->lastConnectionAt = tr_time( ); atom->myflags &= ~MYFLAG_UNREACHABLE; if( atom->myflags & MYFLAG_BANNED ) { tordbg( t, "banned peer %s tried to reconnect", tr_atomAddrStr( atom ) ); } else if( tr_peerIoIsIncoming( io ) && ( getPeerCount( t ) >= getMaxPeerCount( t->tor ) ) ) { } else { tr_peer * peer = atom->peer; if( peer ) /* we already have this peer */ { } else { peer = getPeer( t, atom ); tr_free( peer->client ); if( !peer_id ) peer->client = NULL; else { char client[128]; tr_clientForId( client, sizeof( client ), peer_id ); peer->client = tr_strdup( client ); } peer->io = tr_handshakeStealIO( handshake ); /* this steals its refcount too, which is balanced by our unref in peerDestructor() */ tr_peerIoSetParent( peer->io, t->tor->bandwidth ); tr_peerMsgsNew( t->tor, peer, peerCallbackFunc, t ); success = TRUE; } } } if( t ) torrentUnlock( t ); return success; } void tr_peerMgrAddIncoming( tr_peerMgr * manager, tr_address * addr, tr_port port, int socket ) { tr_session * session; managerLock( manager ); assert( tr_isSession( manager->session ) ); session = manager->session; if( tr_sessionIsAddressBlocked( session, addr ) ) { tr_dbg( "Banned IP address \"%s\" tried to connect to us", tr_ntop_non_ts( addr ) ); tr_netClose( session, socket ); } else if( getExistingHandshake( &manager->incomingHandshakes, addr ) ) { tr_netClose( session, socket ); } else /* we don't have a connection to them yet... */ { tr_peerIo * io; tr_handshake * handshake; io = tr_peerIoNewIncoming( session, session->bandwidth, addr, port, socket ); handshake = tr_handshakeNew( io, session->encryptionMode, myHandshakeDoneCB, manager ); tr_peerIoUnref( io ); /* balanced by the implicit ref in tr_peerIoNewIncoming() */ tr_ptrArrayInsertSorted( &manager->incomingHandshakes, handshake, handshakeCompare ); } managerUnlock( manager ); } static tr_bool tr_isPex( const tr_pex * pex ) { return pex && tr_isAddress( &pex->addr ); } void tr_peerMgrAddPex( tr_torrent * tor, uint8_t from, const tr_pex * pex, int8_t seedProbability ) { if( tr_isPex( pex ) ) /* safeguard against corrupt data */ { Torrent * t = tor->torrentPeers; managerLock( t->manager ); if( !tr_sessionIsAddressBlocked( t->manager->session, &pex->addr ) ) if( tr_isValidPeerAddress( &pex->addr, pex->port ) ) ensureAtomExists( t, &pex->addr, pex->port, pex->flags, seedProbability, from ); managerUnlock( t->manager ); } } void tr_peerMgrMarkAllAsSeeds( tr_torrent * tor ) { Torrent * t = tor->torrentPeers; const int n = tr_ptrArraySize( &t->pool ); struct peer_atom ** it = (struct peer_atom**) tr_ptrArrayBase( &t->pool ); struct peer_atom ** end = it + n; while( it != end ) atomSetSeed( *it++ ); } tr_pex * tr_peerMgrCompactToPex( const void * compact, size_t compactLen, const uint8_t * added_f, size_t added_f_len, size_t * pexCount ) { size_t i; size_t n = compactLen / 6; const uint8_t * walk = compact; tr_pex * pex = tr_new0( tr_pex, n ); for( i = 0; i < n; ++i ) { pex[i].addr.type = TR_AF_INET; memcpy( &pex[i].addr.addr, walk, 4 ); walk += 4; memcpy( &pex[i].port, walk, 2 ); walk += 2; if( added_f && ( n == added_f_len ) ) pex[i].flags = added_f[i]; } *pexCount = n; return pex; } tr_pex * tr_peerMgrCompact6ToPex( const void * compact, size_t compactLen, const uint8_t * added_f, size_t added_f_len, size_t * pexCount ) { size_t i; size_t n = compactLen / 18; const uint8_t * walk = compact; tr_pex * pex = tr_new0( tr_pex, n ); for( i = 0; i < n; ++i ) { pex[i].addr.type = TR_AF_INET6; memcpy( &pex[i].addr.addr.addr6.s6_addr, walk, 16 ); walk += 16; memcpy( &pex[i].port, walk, 2 ); walk += 2; if( added_f && ( n == added_f_len ) ) pex[i].flags = added_f[i]; } *pexCount = n; return pex; } tr_pex * tr_peerMgrArrayToPex( const void * array, size_t arrayLen, size_t * pexCount ) { size_t i; size_t n = arrayLen / ( sizeof( tr_address ) + 2 ); /*size_t n = arrayLen / sizeof( tr_peerArrayElement );*/ const uint8_t * walk = array; tr_pex * pex = tr_new0( tr_pex, n ); for( i = 0 ; i < n ; i++ ) { memcpy( &pex[i].addr, walk, sizeof( tr_address ) ); memcpy( &pex[i].port, walk + sizeof( tr_address ), 2 ); pex[i].flags = 0x00; walk += sizeof( tr_address ) + 2; } *pexCount = n; return pex; } /** *** **/ void tr_peerMgrSetBlame( tr_torrent * tor, tr_piece_index_t pieceIndex, int success ) { if( !success ) { int peerCount, i; Torrent * t = tor->torrentPeers; tr_peer ** peers; assert( torrentIsLocked( t ) ); peers = (tr_peer **) tr_ptrArrayPeek( &t->peers, &peerCount ); for( i = 0; i < peerCount; ++i ) { tr_peer * peer = peers[i]; if( tr_bitfieldHas( peer->blame, pieceIndex ) ) { tordbg( t, "peer %s contributed to corrupt piece (%d); now has %d strikes", tr_atomAddrStr( peer->atom ), pieceIndex, (int)peer->strikes + 1 ); addStrike( t, peer ); } } } } int tr_pexCompare( const void * va, const void * vb ) { const tr_pex * a = va; const tr_pex * b = vb; int i; assert( tr_isPex( a ) ); assert( tr_isPex( b ) ); if(( i = tr_compareAddresses( &a->addr, &b->addr ))) return i; if( a->port != b->port ) return a->port < b->port ? -1 : 1; return 0; } #if 0 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 ); } #endif /* better goes first */ static int compareAtomsByUsefulness( const void * va, const void *vb ) { const struct peer_atom * a = * (const struct peer_atom**) va; const struct peer_atom * b = * (const struct peer_atom**) vb; assert( tr_isAtom( a ) ); assert( tr_isAtom( b ) ); if( a->piece_data_time != b->piece_data_time ) return a->piece_data_time > b->piece_data_time ? -1 : 1; if( a->from != b->from ) return a->from < b->from ? -1 : 1; if( a->numFails != b->numFails ) return a->numFails < b->numFails ? -1 : 1; return 0; } int tr_peerMgrGetPeers( tr_torrent * tor, tr_pex ** setme_pex, uint8_t af, uint8_t list_mode, int maxCount ) { int i; int n; int count = 0; int atomCount = 0; const Torrent * t = tor->torrentPeers; struct peer_atom ** atoms = NULL; tr_pex * pex; tr_pex * walk; assert( tr_isTorrent( tor ) ); assert( setme_pex != NULL ); assert( af==TR_AF_INET || af==TR_AF_INET6 ); assert( list_mode==TR_PEERS_CONNECTED || list_mode==TR_PEERS_ALL ); managerLock( t->manager ); /** *** build a list of atoms **/ if( list_mode == TR_PEERS_CONNECTED ) /* connected peers only */ { int i; const tr_peer ** peers = (const tr_peer **) tr_ptrArrayBase( &t->peers ); atomCount = tr_ptrArraySize( &t->peers ); atoms = tr_new( struct peer_atom *, atomCount ); for( i=0; iatom; } else /* TR_PEERS_ALL */ { const struct peer_atom ** atomsBase = (const struct peer_atom**) tr_ptrArrayBase( &t->pool ); atomCount = tr_ptrArraySize( &t->pool ); atoms = tr_memdup( atomsBase, atomCount * sizeof( struct peer_atom * ) ); } qsort( atoms, atomCount, sizeof( struct peer_atom * ), compareAtomsByUsefulness ); /** *** add the first N of them into our return list **/ n = MIN( atomCount, maxCount ); pex = walk = tr_new0( tr_pex, n ); for( i=0; iaddr.type == af ) { assert( tr_isAddress( &atom->addr ) ); walk->addr = atom->addr; walk->port = atom->port; walk->flags = atom->flags; ++count; ++walk; } } qsort( pex, count, sizeof( tr_pex ), tr_pexCompare ); assert( ( walk - pex ) == count ); *setme_pex = pex; /* cleanup */ tr_free( atoms ); managerUnlock( t->manager ); return count; } static void atomPulse ( int, short, void * ); static void bandwidthPulse ( int, short, void * ); static void rechokePulse ( int, short, void * ); static void reconnectPulse ( int, short, void * ); static struct event * createTimer( int msec, void (*callback)(int, short, void *), void * cbdata ) { struct event * timer = tr_new0( struct event, 1 ); evtimer_set( timer, callback, cbdata ); tr_timerAddMsec( timer, msec ); return timer; } static void ensureMgrTimersExist( struct tr_peerMgr * m ) { if( m->atomTimer == NULL ) m->atomTimer = createTimer( ATOM_PERIOD_MSEC, atomPulse, m ); if( m->bandwidthTimer == NULL ) m->bandwidthTimer = createTimer( BANDWIDTH_PERIOD_MSEC, bandwidthPulse, m ); if( m->rechokeTimer == NULL ) m->rechokeTimer = createTimer( RECHOKE_PERIOD_MSEC, rechokePulse, m ); if( m->refillUpkeepTimer == NULL ) m->refillUpkeepTimer = createTimer( REFILL_UPKEEP_PERIOD_MSEC, refillUpkeep, m ); } void tr_peerMgrStartTorrent( tr_torrent * tor ) { Torrent * t = tor->torrentPeers; assert( t != NULL ); managerLock( t->manager ); ensureMgrTimersExist( t->manager ); t->isRunning = TRUE; rechokePulse( 0, 0, t->manager ); managerUnlock( t->manager ); } static void stopTorrent( Torrent * t ) { int i, n; assert( torrentIsLocked( t ) ); t->isRunning = FALSE; /* disconnect the peers. */ for( i=0, n=tr_ptrArraySize( &t->peers ); ipeers, i ) ); 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_torrent * tor ) { Torrent * t = tor->torrentPeers; managerLock( t->manager ); stopTorrent( t ); managerUnlock( t->manager ); } void tr_peerMgrAddTorrent( tr_peerMgr * manager, tr_torrent * tor ) { managerLock( manager ); assert( tor ); assert( tor->torrentPeers == NULL ); tor->torrentPeers = torrentConstructor( manager, tor ); managerUnlock( manager ); } void tr_peerMgrRemoveTorrent( tr_torrent * tor ) { tr_torrentLock( tor ); stopTorrent( tor->torrentPeers ); torrentDestructor( tor->torrentPeers ); tr_torrentUnlock( tor ); } void tr_peerMgrTorrentAvailability( const tr_torrent * tor, int8_t * tab, unsigned int tabCount ) { tr_piece_index_t i; const Torrent * t; float interval; tr_bool isSeed; int peerCount; const tr_peer ** peers; tr_torrentLock( tor ); t = tor->torrentPeers; tor = t->tor; interval = tor->info.pieceCount / (float)tabCount; isSeed = tor && ( tr_cpGetStatus ( &tor->completion ) == TR_SEED ); peers = (const tr_peer **) tr_ptrArrayBase( &t->peers ); peerCount = tr_ptrArraySize( &t->peers ); memset( tab, 0, tabCount ); for( i = 0; tor && i < tabCount; ++i ) { const int piece = i * interval; if( isSeed || tr_cpPieceIsComplete( &tor->completion, piece ) ) tab[i] = -1; else if( peerCount ) { int j; for( j = 0; j < peerCount; ++j ) if( tr_bitsetHas( &peers[j]->have, i ) ) ++tab[i]; } } tr_torrentUnlock( tor ); } /* Returns the pieces that are available from peers */ tr_bitfield* tr_peerMgrGetAvailable( const tr_torrent * tor ) { int i; int peerCount; Torrent * t = tor->torrentPeers; const tr_peer ** peers; tr_bitfield * pieces; managerLock( t->manager ); pieces = tr_bitfieldNew( t->tor->info.pieceCount ); peerCount = tr_ptrArraySize( &t->peers ); peers = (const tr_peer**) tr_ptrArrayBase( &t->peers ); for( i=0; ihave ); managerUnlock( t->manager ); return pieces; } void tr_peerMgrTorrentStats( tr_torrent * tor, int * setmePeersKnown, int * setmePeersConnected, int * setmeSeedsConnected, int * setmeWebseedsSendingToUs, int * setmePeersSendingToUs, int * setmePeersGettingFromUs, int * setmePeersFrom ) { int i, size; const Torrent * t = tor->torrentPeers; const tr_peer ** peers; const tr_webseed ** webseeds; managerLock( t->manager ); peers = (const tr_peer **) tr_ptrArrayBase( &t->peers ); size = tr_ptrArraySize( &t->peers ); *setmePeersKnown = tr_ptrArraySize( &t->pool ); *setmePeersConnected = 0; *setmeSeedsConnected = 0; *setmePeersGettingFromUs = 0; *setmePeersSendingToUs = 0; *setmeWebseedsSendingToUs = 0; for( i=0; iatom; if( peer->io == NULL ) /* not connected */ continue; ++*setmePeersConnected; ++setmePeersFrom[atom->from]; if( clientIsDownloadingFrom( tor, peer ) ) ++*setmePeersSendingToUs; if( clientIsUploadingTo( peer ) ) ++*setmePeersGettingFromUs; if( atomIsSeed( atom ) ) ++*setmeSeedsConnected; } webseeds = (const tr_webseed**) tr_ptrArrayBase( &t->webseeds ); size = tr_ptrArraySize( &t->webseeds ); for( i=0; imanager ); } float tr_peerMgrGetWebseedSpeed( const tr_torrent * tor, uint64_t now ) { int i; float tmp; float ret = 0; const Torrent * t = tor->torrentPeers; const int n = tr_ptrArraySize( &t->webseeds ); const tr_webseed ** webseeds = (const tr_webseed**) tr_ptrArrayBase( &t->webseeds ); for( i=0; itorrentPeers; const tr_webseed ** webseeds; int i; int webseedCount; float * ret; uint64_t now; assert( t->manager ); managerLock( t->manager ); webseeds = (const tr_webseed**) tr_ptrArrayBase( &t->webseeds ); webseedCount = tr_ptrArraySize( &t->webseeds ); assert( webseedCount == tor->info.webseedCount ); ret = tr_new0( float, webseedCount ); now = tr_date( ); for( i=0; imanager ); return ret; } double tr_peerGetPieceSpeed( const tr_peer * peer, uint64_t now, tr_direction direction ) { return peer->io ? tr_peerIoGetPieceSpeed( peer->io, now, direction ) : 0.0; } struct tr_peer_stat * tr_peerMgrPeerStats( const tr_torrent * tor, int * setmeCount ) { int i, size; const Torrent * t = tor->torrentPeers; const tr_peer ** peers; tr_peer_stat * ret; uint64_t now; static const int CANCEL_HISTORY_MSEC = CANCEL_HISTORY_SEC * 1000; assert( t->manager ); managerLock( t->manager ); size = tr_ptrArraySize( &t->peers ); peers = (const tr_peer**) tr_ptrArrayBase( &t->peers ); ret = tr_new0( tr_peer_stat, size ); now = tr_date( ); for( i=0; iatom; tr_peer_stat * stat = ret + i; tr_ntop( &atom->addr, stat->addr, sizeof( stat->addr ) ); tr_strlcpy( stat->client, ( peer->client ? peer->client : "" ), sizeof( stat->client ) ); stat->port = ntohs( peer->atom->port ); stat->from = atom->from; stat->progress = peer->progress; stat->isEncrypted = tr_peerIoIsEncrypted( peer->io ) ? 1 : 0; stat->rateToPeer = tr_peerGetPieceSpeed( peer, now, TR_CLIENT_TO_PEER ); stat->rateToClient = tr_peerGetPieceSpeed( peer, now, TR_PEER_TO_CLIENT ); stat->peerIsChoked = peer->peerIsChoked; stat->peerIsInterested = peer->peerIsInterested; stat->clientIsChoked = peer->clientIsChoked; stat->clientIsInterested = peer->clientIsInterested; stat->isIncoming = tr_peerIoIsIncoming( peer->io ); stat->isDownloadingFrom = clientIsDownloadingFrom( tor, peer ); stat->isUploadingTo = clientIsUploadingTo( peer ); stat->isSeed = ( atom->uploadOnly == UPLOAD_ONLY_YES ) || ( peer->progress >= 1.0 ); stat->blocksToPeer = tr_historyGet( peer->blocksSentToPeer, now, CANCEL_HISTORY_MSEC ); stat->blocksToClient = tr_historyGet( peer->blocksSentToClient, now, CANCEL_HISTORY_MSEC ); stat->cancelsToPeer = tr_historyGet( peer->cancelsSentToPeer, now, CANCEL_HISTORY_MSEC ); stat->cancelsToClient = tr_historyGet( peer->cancelsSentToClient, now, CANCEL_HISTORY_MSEC ); stat->pendingReqsToPeer = peer->pendingReqsToPeer; stat->pendingReqsToClient = peer->pendingReqsToClient; pch = stat->flagStr; if( t->optimistic == peer ) *pch++ = 'O'; if( stat->isDownloadingFrom ) *pch++ = 'D'; else if( stat->clientIsInterested ) *pch++ = 'd'; if( stat->isUploadingTo ) *pch++ = 'U'; else if( stat->peerIsInterested ) *pch++ = 'u'; if( !stat->clientIsChoked && !stat->clientIsInterested ) *pch++ = 'K'; if( !stat->peerIsChoked && !stat->peerIsInterested ) *pch++ = '?'; if( stat->isEncrypted ) *pch++ = 'E'; if( stat->from == TR_PEER_FROM_DHT ) *pch++ = 'H'; if( stat->from == TR_PEER_FROM_PEX ) *pch++ = 'X'; if( stat->isIncoming ) *pch++ = 'I'; *pch = '\0'; } *setmeCount = size; managerUnlock( t->manager ); return ret; } /** *** **/ /* do we still want this piece and does the peer have it? */ static tr_bool isPieceInteresting( const tr_torrent * tor, const tr_peer * peer, tr_piece_index_t index ) { return ( !tor->info.pieces[index].dnd ) /* we want it */ && ( !tr_cpPieceIsComplete( &tor->completion, index ) ) /* we don't have it */ && ( tr_bitsetHas( &peer->have, index ) ); /* peer has it */ } /* does this peer have any pieces that we want? */ static tr_bool isPeerInteresting( const tr_torrent * tor, const tr_peer * peer ) { tr_piece_index_t i, n; if ( tr_torrentIsSeed( tor ) ) return FALSE; if( !tr_torrentIsPieceTransferAllowed( tor, TR_PEER_TO_CLIENT ) ) return FALSE; for( i=0, n=tor->info.pieceCount; ipeers ); int maxPeers; int badCount = 0; int goodCount = 0; int untestedCount = 0; tr_peer ** bad = tr_new( tr_peer*, peerCount ); tr_peer ** good = tr_new( tr_peer*, peerCount ); tr_peer ** untested = tr_new( tr_peer*, peerCount ); /* decide how many peers to be interested in */ { int blocks = 0; int cancels = 0; /* Count up how many blocks & cancels each peer has. * * There are two situations where we send out cancels -- * * 1. We've got unresponsive peers, which is handled by deciding * -which- peers to be interested in. * * 2. We've hit our bandwidth cap, which is handled by deciding * -how many- peers to be interested in. * * We're working on 2. here, so we need to ignore unresponsive * peers in our calculations lest they confuse Transmission into * thinking it's hit its bandwidth cap. */ for( i=0; ipeers, i ); const int b = tr_historyGet( peer->blocksSentToClient, now, msec ); const int c = tr_historyGet( peer->cancelsSentToPeer, now, msec ); if( b == 0 ) /* ignore unresponsive peers, as described above */ continue; blocks += b; cancels += c; } if( !t->interestedCount ) { /* this is the torrent's first time to call this function... * start off optimistically by allowing interest in many peers */ maxPeers = t->tor->maxConnectedPeers; } else if( !blocks ) { /* we've gotten cancels but zero blocks... * something is seriously wrong. throttle back sharply */ maxPeers = t->interestedCount * 0.5; } else { const double cancelRate = cancels / (double)(cancels + blocks); if( cancelRate >= 0.20 ) maxPeers = t->interestedCount * 0.7; else if( cancelRate >= 0.10 ) maxPeers = t->interestedCount * 0.8; else if( cancelRate >= 0.05 ) maxPeers = t->interestedCount * 0.9; else if( cancelRate >= 0.01 ) maxPeers = t->interestedCount; else maxPeers = t->interestedCount + 1; /* if things are getting worse, don't add more peers */ if( ( t->cancelRate > 0.01 ) && ( cancelRate > t->cancelRate ) ) maxPeers = MIN( maxPeers, t->interestedCount ); t->cancelRate = cancelRate; tordbg( t, "cancel rate is %.3f -- changing the " "number of peers we're interested in from %d to %d", cancelRate, t->interestedCount, maxPeers ); } } /* don't let the previous paragraph's number tweaking go too far... */ if( maxPeers < MIN_INTERESTING_PEERS ) maxPeers = MIN_INTERESTING_PEERS; if( maxPeers > t->tor->maxConnectedPeers ) maxPeers = t->tor->maxConnectedPeers; /* separate the peers into "good" (ones with a low cancel-to-block ratio), * untested peers, and "bad" (ones with a high cancel-to-block ratio). * That's the order in which we'll choose who to show interest in */ { /* Randomize the peer array so the peers in the three groups will be unsorted... */ int n = peerCount; tr_peer ** peers = tr_memdup( tr_ptrArrayBase( &t->peers ), n * sizeof( tr_peer * ) ); while( n > 0 ) { const int i = tr_cryptoWeakRandInt( n ); tr_peer * peer = tr_ptrArrayNth( &t->peers, i ); if( !isPeerInteresting( t->tor, peer ) ) { tr_peerMsgsSetInterested( peer->msgs, FALSE ); } else { const int blocks = tr_historyGet( peer->blocksSentToClient, now, msec ); const int cancels = tr_historyGet( peer->cancelsSentToPeer, now, msec ); if( !blocks && !cancels ) untested[untestedCount++] = peer; else if( !cancels ) good[goodCount++] = peer; else if( !blocks ) bad[badCount++] = peer; else if( ( cancels * 10 ) < blocks ) good[goodCount++] = peer; else bad[badCount++] = peer; } tr_removeElementFromArray( peers, i, sizeof(tr_peer*), n-- ); } tr_free( peers ); } t->interestedCount = 0; /* We've decided (1) how many peers to be interested in, * and (2) which peers are the best candidates, * Now it's time to update our `interest' flags. */ for( i=0; iinterestedCount < maxPeers; tr_peerMsgsSetInterested( good[i]->msgs, b ); if( b ) ++t->interestedCount; } for( i=0; iinterestedCount < maxPeers; tr_peerMsgsSetInterested( untested[i]->msgs, b ); if( b ) ++t->interestedCount; } for( i=0; iinterestedCount < maxPeers; tr_peerMsgsSetInterested( bad[i]->msgs, b ); if( b ) ++t->interestedCount; } /*fprintf( stderr, "num interested: %d\n", t->interestedCount );*/ /* cleanup */ tr_free( untested ); tr_free( good ); tr_free( bad ); } /** *** **/ struct ChokeData { tr_bool doUnchoke; tr_bool isInterested; tr_bool isChoked; int rate; int salt; tr_peer * peer; }; static int compareChoke( const void * va, const void * vb ) { const struct ChokeData * a = va; const struct ChokeData * b = vb; if( a->rate != b->rate ) /* prefer higher overall speeds */ return a->rate > b->rate ? -1 : 1; if( a->isChoked != b->isChoked ) /* prefer unchoked */ return a->isChoked ? 1 : -1; if( a->salt != b->salt ) /* random order */ return a->salt - b->salt; return 0; } /* is this a new connection? */ static int isNew( const tr_peer * peer ) { return peer && peer->io && tr_peerIoGetAge( peer->io ) < 45; } /* get a rate for deciding which peers to choke and unchoke. */ static int getRate( const tr_torrent * tor, struct peer_atom * atom, uint64_t now ) { double KiB_s; if( tr_torrentIsSeed( tor ) ) KiB_s = tr_peerGetPieceSpeed( atom->peer, now, TR_CLIENT_TO_PEER ); /* downloading a private torrent... take upload speed into account * because there may only be a small window of opportunity to share */ else if( tr_torrentIsPrivate( tor ) ) KiB_s = tr_peerGetPieceSpeed( atom->peer, now, TR_PEER_TO_CLIENT ) + tr_peerGetPieceSpeed( atom->peer, now, TR_CLIENT_TO_PEER ); /* downloading a public torrent */ else KiB_s = tr_peerGetPieceSpeed( atom->peer, now, TR_PEER_TO_CLIENT ); /* convert it to bytes per second */ return (int)( KiB_s * 1024 ); } static void rechokeUploads( Torrent * t, const uint64_t now ) { int i, size, unchokedInterested; const int peerCount = tr_ptrArraySize( &t->peers ); tr_peer ** peers = (tr_peer**) tr_ptrArrayBase( &t->peers ); struct ChokeData * choke = tr_new0( struct ChokeData, peerCount ); const tr_session * session = t->manager->session; const int chokeAll = !tr_torrentIsPieceTransferAllowed( t->tor, TR_CLIENT_TO_PEER ); assert( torrentIsLocked( t ) ); /* sort the peers by preference and rate */ for( i = 0, size = 0; i < peerCount; ++i ) { tr_peer * peer = peers[i]; struct peer_atom * atom = peer->atom; if( peer->progress >= 1.0 ) /* choke all seeds */ { tr_peerMsgsSetChoke( peer->msgs, TRUE ); } else if( atom->uploadOnly == UPLOAD_ONLY_YES ) /* choke partial seeds */ { tr_peerMsgsSetChoke( peer->msgs, TRUE ); } else if( chokeAll ) /* choke everyone if we're not uploading */ { tr_peerMsgsSetChoke( peer->msgs, TRUE ); } else { struct ChokeData * n = &choke[size++]; n->peer = peer; n->isInterested = peer->peerIsInterested; n->isChoked = peer->peerIsChoked; n->rate = getRate( t->tor, atom, now ); n->salt = tr_cryptoWeakRandInt( INT_MAX ); } } qsort( choke, size, sizeof( struct ChokeData ), compareChoke ); /** * Reciprocation and number of uploads capping is managed by unchoking * the N peers which have the best upload rate and are interested. * This maximizes the client's download rate. These N peers are * referred to as downloaders, because they are interested in downloading * from the client. * * Peers which have a better upload rate (as compared to the downloaders) * but aren't interested get unchoked. If they become interested, the * downloader with the worst upload rate gets choked. If a client has * a complete file, it uses its upload rate rather than its download * rate to decide which peers to unchoke. */ unchokedInterested = 0; for( i=0; iuploadSlotsPerTorrent; ++i ) { choke[i].doUnchoke = 1; if( choke[i].isInterested ) ++unchokedInterested; } /* optimistic unchoke */ if( i < size ) { int n; struct ChokeData * c; tr_ptrArray randPool = TR_PTR_ARRAY_INIT; for( ; idoUnchoke = 1; t->optimistic = c->peer; } tr_ptrArrayDestruct( &randPool, NULL ); } for( i=0; imsgs, !choke[i].doUnchoke ); /* cleanup */ tr_free( choke ); } static void rechokePulse( int foo UNUSED, short bar UNUSED, void * vmgr ) { uint64_t now; tr_torrent * tor = NULL; tr_peerMgr * mgr = vmgr; managerLock( mgr ); now = tr_date( ); while(( tor = tr_torrentNext( mgr->session, tor ))) { if( tor->isRunning ) { rechokeUploads( tor->torrentPeers, now ); if( !tr_torrentIsSeed( tor ) ) rechokeDownloads( tor->torrentPeers ); } } tr_timerAddMsec( mgr->rechokeTimer, RECHOKE_PERIOD_MSEC ); managerUnlock( mgr ); } /*** **** **** Life and Death **** ***/ typedef enum { TR_CAN_KEEP, TR_CAN_CLOSE, TR_MUST_CLOSE, } tr_close_type_t; static tr_close_type_t shouldPeerBeClosed( const Torrent * t, const tr_peer * peer, int peerCount, const time_t now ) { const tr_torrent * tor = t->tor; const struct peer_atom * atom = peer->atom; /* if it's marked for purging, close it */ if( peer->doPurge ) { tordbg( t, "purging peer %s because its doPurge flag is set", tr_atomAddrStr( atom ) ); return TR_MUST_CLOSE; } /* if we're seeding and the peer has everything we have, * and enough time has passed for a pex exchange, then disconnect */ if( tr_torrentIsSeed( tor ) ) { tr_bool peerHasEverything; if( atom->seedProbability != -1 ) { peerHasEverything = atomIsSeed( atom ); } else { tr_bitfield * tmp = tr_bitfieldDup( tr_cpPieceBitfield( &tor->completion ) ); tr_bitsetDifference( tmp, &peer->have ); peerHasEverything = tr_bitfieldCountTrueBits( tmp ) == 0; tr_bitfieldFree( tmp ); } if( peerHasEverything && ( !tr_torrentAllowsPex(tor) || (now-atom->time>=30 ))) { tordbg( t, "purging peer %s because we're both seeds", tr_atomAddrStr( atom ) ); return TR_MUST_CLOSE; } } /* 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... */ { const int relaxStrictnessIfFewerThanN = (int)( ( getMaxPeerCount( tor ) * 0.9 ) + 0.5 ); /* if we have >= relaxIfFewerThan, strictness is 100%. * if we have zero connections, strictness is 0% */ const float strictness = peerCount >= relaxStrictnessIfFewerThanN ? 1.0 : peerCount / (float)relaxStrictnessIfFewerThanN; const int lo = MIN_UPLOAD_IDLE_SECS; const int hi = MAX_UPLOAD_IDLE_SECS; const int limit = hi - ( ( hi - lo ) * strictness ); const int idleTime = now - MAX( atom->time, atom->piece_data_time ); /*fprintf( stderr, "strictness is %.3f, limit is %d seconds... time since connect is %d, time since piece is %d ... idleTime is %d, doPurge is %d\n", (double)strictness, limit, (int)(now - atom->time), (int)(now - atom->piece_data_time), idleTime, idleTime > limit );*/ if( idleTime > limit ) { tordbg( t, "purging peer %s because it's been %d secs since we shared anything", tr_atomAddrStr( atom ), idleTime ); return TR_CAN_CLOSE; } } return TR_CAN_KEEP; } static void sortPeersByLivelinessReverse( tr_peer ** peers, void ** clientData, int n, uint64_t now ); static tr_peer ** getPeersToClose( Torrent * t, tr_close_type_t closeType, const time_t now, 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; i < peerCount; ++i ) if( shouldPeerBeClosed( t, peers[i], peerCount, now ) == closeType ) ret[outsize++] = peers[i]; sortPeersByLivelinessReverse ( ret, NULL, outsize, tr_date( ) ); *setmeSize = outsize; return ret; } static int getReconnectIntervalSecs( const struct peer_atom * atom, const time_t now ) { int sec; /* if we were recently connected to this peer and transferring piece * data, try to reconnect to them sooner rather that later -- we don't * want network troubles to get in the way of a good peer. */ if( ( now - atom->piece_data_time ) <= ( MINIMUM_RECONNECT_INTERVAL_SECS * 2 ) ) sec = MINIMUM_RECONNECT_INTERVAL_SECS; /* don't allow reconnects more often than our minimum */ else if( ( now - atom->time ) < MINIMUM_RECONNECT_INTERVAL_SECS ) sec = MINIMUM_RECONNECT_INTERVAL_SECS; /* otherwise, the interval depends on how many times we've tried * and failed to connect to the peer */ else switch( atom->numFails ) { case 0: sec = 0; break; case 1: sec = 5; break; case 2: sec = 2 * 60; break; case 3: sec = 15 * 60; break; case 4: sec = 30 * 60; break; case 5: sec = 60 * 60; break; default: sec = 120 * 60; break; } /* penalize peers that were unreachable the last time we tried */ if( atom->myflags & MYFLAG_UNREACHABLE ) sec += sec; dbgmsg( "reconnect interval for %s is %d seconds", tr_atomAddrStr( atom ), sec ); return sec; } static void closePeer( Torrent * t, tr_peer * peer ) { struct peer_atom * atom; assert( t != NULL ); assert( peer != NULL ); atom = peer->atom; /* if we 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 */ if( atom->piece_data_time ) { tordbg( t, "resetting atom %s numFails to 0", tr_atomAddrStr(atom) ); atom->numFails = 0; } else { ++atom->numFails; tordbg( t, "incremented atom %s numFails to %d", tr_atomAddrStr(atom), (int)atom->numFails ); } tordbg( t, "removing bad peer %s", tr_peerIoGetAddrStr( peer->io ) ); removePeer( t, peer ); } static void closeBadPeers( Torrent * t ) { const time_t now = tr_time( ); if( !t->isRunning ) { removeAllPeers( t ); } else { int i; int mustCloseCount; struct tr_peer ** mustClose; /* disconnect the really bad peers */ mustClose = getPeersToClose( t, TR_MUST_CLOSE, now, &mustCloseCount ); for( i=0; idoPurge != b->doPurge ) return a->doPurge ? 1 : -1; if( a->speed != b->speed ) /* faster goes first */ return a->speed > b->speed ? -1 : 1; /* the one to give us data more recently goes first */ if( a->pieceDataTime != b->pieceDataTime ) return a->pieceDataTime > b->pieceDataTime ? -1 : 1; /* the one we connected to most recently goes first */ if( a->time != b->time ) return a->time > b->time ? -1 : 1; return 0; } static int comparePeerLivelinessReverse( const void * va, const void * vb ) { return -comparePeerLiveliness (va, vb); } static void sortPeersByLivelinessImpl( tr_peer ** peers, void ** clientData, int n, uint64_t now, int (*compare) ( const void *va, const void *vb ) ) { int i; struct peer_liveliness *lives, *l; /* build a sortable array of peer + extra info */ lives = l = tr_new0( struct peer_liveliness, n ); for( i=0; ipeer = p; l->doPurge = p->doPurge; l->pieceDataTime = p->atom->piece_data_time; l->time = p->atom->time; l->speed = 1024.0 * ( tr_peerGetPieceSpeed( p, now, TR_UP ) + tr_peerGetPieceSpeed( p, now, TR_DOWN ) ); if( clientData ) l->clientData = clientData[i]; } /* sort 'em */ assert( n == ( l - lives ) ); qsort( lives, n, sizeof( struct peer_liveliness ), compare ); /* build the peer array */ for( i=0, l=lives; ipeer; if( clientData ) clientData[i] = l->clientData; } assert( n == ( l - lives ) ); /* cleanup */ tr_free( lives ); } static void sortPeersByLiveliness( tr_peer ** peers, void ** clientData, int n, uint64_t now ) { sortPeersByLivelinessImpl( peers, clientData, n, now, comparePeerLiveliness ); } static void sortPeersByLivelinessReverse( tr_peer ** peers, void ** clientData, int n, uint64_t now ) { sortPeersByLivelinessImpl( peers, clientData, n, now, comparePeerLivelinessReverse ); } static void enforceTorrentPeerLimit( Torrent * t, uint64_t now ) { int n = tr_ptrArraySize( &t->peers ); const int max = tr_torrentGetPeerLimit( t->tor ); if( n > max ) { void * base = tr_ptrArrayBase( &t->peers ); tr_peer ** peers = tr_memdup( base, n*sizeof( tr_peer* ) ); sortPeersByLiveliness( peers, NULL, n, now ); while( n > max ) closePeer( t, peers[--n] ); tr_free( peers ); } } static void enforceSessionPeerLimit( tr_session * session, uint64_t now ) { int n = 0; tr_torrent * tor = NULL; const int max = tr_sessionGetPeerLimit( session ); /* count the total number of peers */ while(( tor = tr_torrentNext( session, tor ))) n += tr_ptrArraySize( &tor->torrentPeers->peers ); /* if there are too many, prune out the worst */ if( n > max ) { tr_peer ** peers = tr_new( tr_peer*, n ); Torrent ** torrents = tr_new( Torrent*, n ); /* populate the peer array */ n = 0; tor = NULL; while(( tor = tr_torrentNext( session, tor ))) { int i; Torrent * t = tor->torrentPeers; const int tn = tr_ptrArraySize( &t->peers ); for( i=0; ipeers, i ); torrents[n] = t; } } /* sort 'em */ sortPeersByLiveliness( peers, (void**)torrents, n, now ); /* cull out the crappiest */ while( n-- > max ) closePeer( torrents[n], peers[n] ); /* cleanup */ tr_free( torrents ); tr_free( peers ); } } static void makeNewPeerConnections( tr_peerMgr * mgr, const int max ); static void reconnectPulse( int foo UNUSED, short bar UNUSED, void * vmgr ) { tr_torrent * tor; tr_peerMgr * mgr = vmgr; const uint64_t now = tr_date( ); /** *** enforce the per-session and per-torrent peer limits **/ /* if we're over the per-torrent peer limits, cull some peers */ tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) if( tor->isRunning ) enforceTorrentPeerLimit( tor->torrentPeers, now ); /* if we're over the per-session peer limits, cull some peers */ enforceSessionPeerLimit( mgr->session, now ); /* remove crappy peers */ tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) closeBadPeers( tor->torrentPeers ); /* try to make new peer connections */ makeNewPeerConnections( mgr, MAX_CONNECTIONS_PER_PULSE ); } /**** ***** ***** BANDWIDTH ALLOCATION ***** ****/ static void pumpAllPeers( tr_peerMgr * mgr ) { tr_torrent * tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) { int j; Torrent * t = tor->torrentPeers; for( j=0; jpeers ); ++j ) { tr_peer * peer = tr_ptrArrayNth( &t->peers, j ); tr_peerMsgsPulse( peer->msgs ); } } } static void bandwidthPulse( int foo UNUSED, short bar UNUSED, void * vmgr ) { tr_torrent * tor; tr_peerMgr * mgr = vmgr; managerLock( mgr ); /* FIXME: this next line probably isn't necessary... */ pumpAllPeers( mgr ); /* allocate bandwidth to the peers */ tr_bandwidthAllocate( mgr->session->bandwidth, TR_UP, BANDWIDTH_PERIOD_MSEC ); tr_bandwidthAllocate( mgr->session->bandwidth, TR_DOWN, BANDWIDTH_PERIOD_MSEC ); /* possibly stop torrents that have seeded enough */ tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) tr_torrentCheckSeedRatio( tor ); /* run the completeness check for any torrents that need it */ tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) { if( tor->torrentPeers->needsCompletenessCheck ) { tor->torrentPeers->needsCompletenessCheck = FALSE; tr_torrentRecheckCompleteness( tor ); } } /* stop torrents that are ready to stop, but couldn't be stopped earlier * during the peer-io callback call chain */ tor = NULL; while(( tor = tr_torrentNext( mgr->session, tor ))) if( tor->isStopping ) tr_torrentStop( tor ); reconnectPulse( 0, 0, mgr ); tr_timerAddMsec( mgr->bandwidthTimer, BANDWIDTH_PERIOD_MSEC ); managerUnlock( mgr ); } /*** **** ***/ static int compareAtomPtrsByAddress( const void * va, const void *vb ) { const struct peer_atom * a = * (const struct peer_atom**) va; const struct peer_atom * b = * (const struct peer_atom**) vb; assert( tr_isAtom( a ) ); assert( tr_isAtom( b ) ); return tr_compareAddresses( &a->addr, &b->addr ); } /* best come first, worst go last */ static int compareAtomPtrsByShelfDate( const void * va, const void *vb ) { time_t atime; time_t btime; const struct peer_atom * a = * (const struct peer_atom**) va; const struct peer_atom * b = * (const struct peer_atom**) vb; const int data_time_cutoff_secs = 60 * 60; const time_t tr_now = tr_time( ); assert( tr_isAtom( a ) ); assert( tr_isAtom( b ) ); /* primary key: the last piece data time *if* it was within the last hour */ atime = a->piece_data_time; if( atime + data_time_cutoff_secs < tr_now ) atime = 0; btime = b->piece_data_time; if( btime + data_time_cutoff_secs < tr_now ) btime = 0; if( atime != btime ) return atime > btime ? -1 : 1; /* secondary key: shelf date. */ if( a->shelf_date != b->shelf_date ) return a->shelf_date > b->shelf_date ? -1 : 1; return 0; } static int getMaxAtomCount( const tr_torrent * tor ) { /* FIXME: this curve should be smoother... */ const int n = tor->maxConnectedPeers; if( n >= 200 ) return n * 1.5; if( n >= 100 ) return n * 2; if( n >= 50 ) return n * 3; if( n >= 20 ) return n * 5; return n * 10; } static void atomPulse( int foo UNUSED, short bar UNUSED, void * vmgr ) { tr_torrent * tor = NULL; tr_peerMgr * mgr = vmgr; managerLock( mgr ); while(( tor = tr_torrentNext( mgr->session, tor ))) { int atomCount; Torrent * t = tor->torrentPeers; const int maxAtomCount = getMaxAtomCount( tor ); struct peer_atom ** atoms = (struct peer_atom**) tr_ptrArrayPeek( &t->pool, &atomCount ); if( atomCount > maxAtomCount ) /* we've got too many atoms... time to prune */ { int i; int keepCount = 0; int testCount = 0; struct peer_atom ** keep = tr_new( struct peer_atom*, atomCount ); struct peer_atom ** test = tr_new( struct peer_atom*, atomCount ); /* keep the ones that are in use */ for( i=0; ipool, NULL ); t->pool = TR_PTR_ARRAY_INIT; qsort( keep, keepCount, sizeof( struct peer_atom * ), compareAtomPtrsByAddress ); for( i=0; ipool, keep[i] ); tordbg( t, "max atom count is %d... pruned from %d to %d\n", maxAtomCount, atomCount, keepCount ); /* cleanup */ tr_free( test ); tr_free( keep ); } } tr_timerAddMsec( mgr->atomTimer, ATOM_PERIOD_MSEC ); managerUnlock( mgr ); } /*** **** **** **** ***/ static inline tr_bool isBandwidthMaxedOut( const tr_bandwidth * b, const uint64_t now_msec, tr_direction dir ) { if( !tr_bandwidthIsLimited( b, dir ) ) return FALSE; else { const double got = tr_bandwidthGetPieceSpeed( b, now_msec, dir ); const double want = tr_bandwidthGetDesiredSpeed( b, dir ); return got >= want; } } /* is this atom someone that we'd want to initiate a connection to? */ static tr_bool isPeerCandidate( const tr_torrent * tor, struct peer_atom * atom, const time_t now ) { /* not if they're banned... */ if( atom->myflags & MYFLAG_BANNED ) return FALSE; /* not if we're both seeds */ if( tr_torrentIsSeed( tor ) ) if( atomIsSeed( atom ) || ( atom->uploadOnly == UPLOAD_ONLY_YES ) ) return FALSE; /* not if we just tried them already */ if( ( now - atom->time ) < getReconnectIntervalSecs( atom, now ) ) return FALSE; /* not if they're blocklisted */ if( isAtomBlocklisted( tor->session, atom ) ) return FALSE; /* not if we've already got a connection to them... */ if( peerIsInUse( tor->torrentPeers, atom ) ) return FALSE; return TRUE; } struct peer_candidate { uint64_t score; tr_torrent * tor; struct peer_atom * atom; }; static tr_bool torrentWasRecentlyStarted( const tr_torrent * tor ) { return difftime( tr_time( ), tor->startDate ) < 120; } static inline uint64_t addValToKey( uint64_t value, int width, uint64_t addme ) { value = (value << (uint64_t)width); value |= addme; return value; } /* smaller value is better */ static uint64_t getPeerCandidateScore( const tr_torrent * tor, const struct peer_atom * atom, uint8_t salt ) { uint64_t i; uint64_t score = 0; const tr_bool failed = atom->lastConnectionAt < atom->lastConnectionAttemptAt; /* prefer peers we've connected to, or never tried, over peers we failed to connect to. */ i = failed ? 1 : 0; score = addValToKey( score, 1, i ); /* prefer the one we attempted least recently (to cycle through all peers) */ i = atom->lastConnectionAttemptAt; score = addValToKey( score, 32, i ); /* prefer peers belonging to a torrent of a higher priority */ switch( tr_torrentGetPriority( tor ) ) { case TR_PRI_HIGH: i = 0; break; case TR_PRI_NORMAL: i = 1; break; case TR_PRI_LOW: i = 2; break; } score = addValToKey( score, 4, i ); /* prefer recently-started torrents */ i = torrentWasRecentlyStarted( tor ) ? 0 : 1; score = addValToKey( score, 1, i ); /* prefer torrents we're downloading with */ i = tr_torrentIsSeed( tor ) ? 1 : 0; score = addValToKey( score, 1, i ); /* prefer peers that we might have a chance of uploading to... so lower seed probability is better */ if( atom->seedProbability == 100 ) i = 101; else if( atom->seedProbability == -1 ) i = 100; else i = atom->seedProbability; score = addValToKey( score, 8, i ); /* Prefer peers that we got from more trusted sources. * lower `from' values indicate more trusted sources */ score = addValToKey( score, 4, atom->from ); /* salt */ score = addValToKey( score, 8, salt ); return score; } /* sort an array of peer candidates */ static int comparePeerCandidates( const void * va, const void * vb ) { const struct peer_candidate * a = va; const struct peer_candidate * b = vb; if( a->score < b->score ) return -1; if( a->score > b->score ) return 1; return 0; } /** @return an array of all the atoms we might want to connect to */ static struct peer_candidate* getPeerCandidates( tr_session * session, int * candidateCount ) { int n; tr_torrent * tor; struct peer_candidate * candidates; struct peer_candidate * walk; const time_t now = tr_time( ); const uint64_t now_msec = tr_date( ); /* leave 5% of connection slots for incoming connections -- ticket #2609 */ const int maxCandidates = tr_sessionGetPeerLimit( session ) * 0.95; /* don't start any new handshakes if we're full up */ n = 0; tor= NULL; while(( tor = tr_torrentNext( session, tor ))) n += tr_ptrArraySize( &tor->torrentPeers->peers ); if( maxCandidates <= n ) { *candidateCount = 0; return NULL; } /* allocate an array of candidates */ n = 0; tor= NULL; while(( tor = tr_torrentNext( session, tor ))) n += tr_ptrArraySize( &tor->torrentPeers->pool ); walk = candidates = tr_new( struct peer_candidate, n ); /* populate the candidate array */ tor = NULL; while(( tor = tr_torrentNext( session, tor ))) { int i, nAtoms; struct peer_atom ** atoms; if( !tor->torrentPeers->isRunning ) continue; /* if we've already got enough peers in this torrent... */ if( tr_torrentGetPeerLimit( tor ) <= tr_ptrArraySize( &tor->torrentPeers->peers ) ) continue; /* if we've already got enough speed in this torrent... */ if( tr_torrentIsSeed( tor ) && isBandwidthMaxedOut( tor->bandwidth, now_msec, TR_UP ) ) continue; atoms = (struct peer_atom**) tr_ptrArrayPeek( &tor->torrentPeers->pool, &nAtoms ); for( i=0; itor = tor; walk->atom = atom; walk->score = getPeerCandidateScore( tor, atom, salt ); ++walk; } } } *candidateCount = walk - candidates; if( *candidateCount > 1 ) qsort( candidates, *candidateCount, sizeof( struct peer_candidate ), comparePeerCandidates ); return candidates; } static void initiateConnection( tr_peerMgr * mgr, Torrent * t, struct peer_atom * atom ) { tr_peerIo * io; const time_t now = tr_time( ); tordbg( t, "Starting an OUTGOING connection with %s", tr_atomAddrStr( atom ) ); io = tr_peerIoNewOutgoing( mgr->session, mgr->session->bandwidth, &atom->addr, atom->port, t->tor->info.hash, t->tor->completeness == TR_SEED ); if( io == NULL ) { tordbg( t, "peerIo not created; marking peer %s as unreachable", tr_atomAddrStr( atom ) ); atom->myflags |= MYFLAG_UNREACHABLE; atom->numFails++; } else { tr_handshake * handshake = tr_handshakeNew( io, mgr->session->encryptionMode, myHandshakeDoneCB, mgr ); assert( tr_peerIoGetTorrentHash( io ) ); tr_peerIoUnref( io ); /* balanced by the initial ref in tr_peerIoNewOutgoing() */ tr_ptrArrayInsertSorted( &t->outgoingHandshakes, handshake, handshakeCompare ); } atom->lastConnectionAttemptAt = now; atom->time = now; } static void initiateCandidateConnection( tr_peerMgr * mgr, struct peer_candidate * c ) { #if 0 fprintf( stderr, "Starting an OUTGOING connection with %s - [%s] seedProbability==%d; %s, %s\n", tr_atomAddrStr( c->atom ), tr_torrentName( c->tor ), (int)c->atom->seedProbability, tr_torrentIsPrivate( c->tor ) ? "private" : "public", tr_torrentIsSeed( c->tor ) ? "seed" : "downloader" ); #endif initiateConnection( mgr, c->tor->torrentPeers, c->atom ); } static void makeNewPeerConnections( struct tr_peerMgr * mgr, const int max ) { int i, n; struct peer_candidate * candidates; candidates = getPeerCandidates( mgr->session, &n ); for( i=0; i