/* * This file Copyright (C) 2007-2014 Mnemosyne LLC * * It may be used under the GNU Public License v2 or v3 licenses, * or any future license endorsed by Mnemosyne LLC. * * $Id$ */ #include #include /* error codes ERANGE, ... */ #include /* INT_MAX */ #include /* memcpy, memcmp, strstr */ #include /* qsort */ #include #include #include "transmission.h" #include "announcer.h" #include "bandwidth.h" #include "blocklist.h" #include "cache.h" #include "clients.h" #include "completion.h" #include "crypto.h" #include "handshake.h" #include "log.h" #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 "tr-utp.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), /* an optimistically unchoked peer is immune from rechoking for this many calls to rechokeUploads (). */ OPTIMISTIC_UNCHOKE_MULTIPLIER = 4, /* 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.flags2 */ MYFLAG_BANNED = 1, /* use for bitwise operations w/peer_atom.flags2 */ /* 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 = 90, NO_BLOCKS_CANCEL_HISTORY = 120, CANCEL_HISTORY_SEC = 60 }; const tr_peer_event TR_PEER_EVENT_INIT = { 0, 0, NULL, 0, 0, 0, 0 }; const tr_swarm_stats TR_SWARM_STATS_INIT = { { 0, 0 }, 0, 0, { 0, 0, 0, 0, 0, 0, 0 } }; /** *** **/ /** * 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 fromFirst; /* where the peer was first found */ uint8_t fromBest; /* the "best" value of where the peer has been found */ uint8_t flags; /* these match the added_f flags */ uint8_t flags2; /* flags that aren't defined in added_f */ 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; bool utp_failed; /* We recently failed to connect over uTP */ 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 bool tr_isAtom (const struct peer_atom * atom) { return (atom != NULL) && (atom->fromFirst < TR_PEER_FROM__MAX) && (atom->fromBest < TR_PEER_FROM__MAX) && (tr_address_is_valid (&atom->addr)); } #endif static const char* tr_atomAddrStr (const struct peer_atom * atom) { return atom ? tr_peerIoAddrStr (&atom->addr, atom->port) : "[no atom]"; } 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; }; enum piece_sort_state { PIECES_UNSORTED, PIECES_SORTED_BY_INDEX, PIECES_SORTED_BY_WEIGHT }; /** @brief Opaque, per-torrent data structure for peer connection information */ typedef struct tr_swarm { tr_swarm_stats stats; tr_ptrArray outgoingHandshakes; /* tr_handshake */ tr_ptrArray pool; /* struct peer_atom */ tr_ptrArray peers; /* tr_peerMsgs */ tr_ptrArray webseeds; /* tr_webseed */ tr_torrent * tor; struct tr_peerMgr * manager; tr_peerMsgs * optimistic; /* the optimistic peer, or NULL if none */ int optimisticUnchokeTimeScaler; bool isRunning; bool needsCompletenessCheck; struct block_request * requests; int requestCount; int requestAlloc; struct weighted_piece * pieces; int pieceCount; enum piece_sort_state pieceSortState; /* An array of pieceCount items stating how many peers have each piece. This is used to help us for downloading pieces "rarest first." This may be NULL if we don't have metainfo yet, or if we're not downloading and don't care about rarity */ uint16_t * pieceReplication; size_t pieceReplicationSize; int interestedCount; int maxPeers; time_t lastCancel; /* Before the endgame this should be 0. In endgame, is contains the average * number of pending requests per peer. Only peers which have more pending * requests are considered 'fast' are allowed to request a block that's * already been requested from another (slower?) peer. */ int endgame; } tr_swarm; 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_logGetDeepEnabled ()) \ tr_logAddDeep (__FILE__, __LINE__, tr_torrentName (t->tor), __VA_ARGS__); \ } \ while (0) #define dbgmsg(...) \ do \ { \ if (tr_logGetDeepEnabled ()) \ tr_logAddDeep (__FILE__, __LINE__, NULL, __VA_ARGS__); \ } \ while (0) /** *** tr_peer virtual functions **/ static bool tr_peerIsTransferringPieces (const tr_peer * peer, uint64_t now, tr_direction direction, unsigned int * Bps) { assert (peer != NULL); assert (peer->funcs != NULL); return (*peer->funcs->is_transferring_pieces)(peer, now, direction, Bps); } unsigned int tr_peerGetPieceSpeed_Bps (const tr_peer * peer, uint64_t now, tr_direction direction) { unsigned int Bps = 0; tr_peerIsTransferringPieces (peer, now, direction, &Bps); return Bps; } static void tr_peerFree (tr_peer * peer) { assert (peer != NULL); assert (peer->funcs != NULL); (*peer->funcs->destruct)(peer); tr_free (peer); } void tr_peerConstruct (tr_peer * peer, const tr_torrent * tor) { assert (peer != NULL); assert (tr_isTorrent (tor)); memset (peer, 0, sizeof (tr_peer)); peer->client = TR_KEY_NONE; peer->swarm = tor->swarm; tr_bitfieldConstruct (&peer->have, tor->info.pieceCount); tr_bitfieldConstruct (&peer->blame, tor->blockCount); } static void peerDeclinedAllRequests (tr_swarm *, const tr_peer *); void tr_peerDestruct (tr_peer * peer) { assert (peer != NULL); if (peer->swarm != NULL) peerDeclinedAllRequests (peer->swarm, peer); tr_bitfieldDestruct (&peer->have); tr_bitfieldDestruct (&peer->blame); if (peer->atom) peer->atom->peer = NULL; } /** *** **/ 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 swarmLock (tr_swarm * swarm) { managerLock (swarm->manager); } static inline void swarmUnlock (tr_swarm * swarm) { managerUnlock (swarm->manager); } static inline int swarmIsLocked (const tr_swarm * swarm) { return tr_sessionIsLocked (swarm->manager->session); } /** *** **/ static int handshakeCompareToAddr (const void * va, const void * vb) { const tr_handshake * a = va; return tr_address_compare (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_address_compare (&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 tr_swarm * getExistingSwarm (tr_peerMgr * manager, const uint8_t * hash) { tr_torrent * tor = tr_torrentFindFromHash (manager->session, hash); return tor == NULL ? NULL : tor->swarm; } static int peerCompare (const void * a, const void * b) { return tr_address_compare (tr_peerAddress (a), tr_peerAddress (b)); } static struct peer_atom* getExistingAtom (const tr_swarm * cswarm, const tr_address * addr) { tr_swarm * swarm = (tr_swarm*) cswarm; return tr_ptrArrayFindSorted (&swarm->pool, addr, comparePeerAtomToAddress); } static bool peerIsInUse (const tr_swarm * cs, const struct peer_atom * atom) { tr_swarm * s = (tr_swarm*) cs; assert (swarmIsLocked (s)); return (atom->peer != NULL) || getExistingHandshake (&s->outgoingHandshakes, &atom->addr) || getExistingHandshake (&s->manager->incomingHandshakes, &atom->addr); } static inline bool replicationExists (const tr_swarm * s) { return s->pieceReplication != NULL; } static void replicationFree (tr_swarm * s) { tr_free (s->pieceReplication); s->pieceReplication = NULL; s->pieceReplicationSize = 0; } static void replicationNew (tr_swarm * s) { tr_piece_index_t piece_i; const tr_piece_index_t piece_count = s->tor->info.pieceCount; const int n = tr_ptrArraySize (&s->peers); assert (!replicationExists (s)); s->pieceReplicationSize = piece_count; s->pieceReplication = tr_new0 (uint16_t, piece_count); for (piece_i=0; piece_ipeers, peer_i); if (tr_bitfieldHas (&peer->have, piece_i)) ++r; } s->pieceReplication[piece_i] = r; } } static void swarmFree (void * vs) { tr_swarm * s = vs; assert (s); assert (!s->isRunning); assert (swarmIsLocked (s)); assert (tr_ptrArrayEmpty (&s->outgoingHandshakes)); assert (tr_ptrArrayEmpty (&s->peers)); tr_ptrArrayDestruct (&s->webseeds, (PtrArrayForeachFunc)tr_peerFree); tr_ptrArrayDestruct (&s->pool, (PtrArrayForeachFunc)tr_free); tr_ptrArrayDestruct (&s->outgoingHandshakes, NULL); tr_ptrArrayDestruct (&s->peers, NULL); s->stats = TR_SWARM_STATS_INIT; replicationFree (s); tr_free (s->requests); tr_free (s->pieces); tr_free (s); } static void peerCallbackFunc (tr_peer *, const tr_peer_event *, void *); static void rebuildWebseedArray (tr_swarm * s, tr_torrent * tor) { unsigned int i; const tr_info * inf = &tor->info; /* clear the array */ tr_ptrArrayDestruct (&s->webseeds, (PtrArrayForeachFunc)tr_peerFree); s->webseeds = TR_PTR_ARRAY_INIT; s->stats.activeWebseedCount = 0; /* repopulate it */ for (i=0; iwebseedCount; ++i) { tr_webseed * w = tr_webseedNew (tor, inf->webseeds[i], peerCallbackFunc, s); tr_ptrArrayAppend (&s->webseeds, w); } } static tr_swarm * swarmNew (tr_peerMgr * manager, tr_torrent * tor) { tr_swarm * s; s = tr_new0 (tr_swarm, 1); s->manager = manager; s->tor = tor; s->pool = TR_PTR_ARRAY_INIT; s->peers = TR_PTR_ARRAY_INIT; s->webseeds = TR_PTR_ARRAY_INIT; s->outgoingHandshakes = TR_PTR_ARRAY_INIT; rebuildWebseedArray (s, tor); return s; } static void ensureMgrTimersExist (struct tr_peerMgr * m); tr_peerMgr* tr_peerMgrNew (tr_session * session) { tr_peerMgr * m = tr_new0 (tr_peerMgr, 1); m->session = session; m->incomingHandshakes = TR_PTR_ARRAY_INIT; ensureMgrTimersExist (m); return m; } static void deleteTimer (struct event ** t) { if (*t != NULL) { event_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); } /*** **** ***/ 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; tr_swarm * s = tor->swarm; const int n = tr_ptrArraySize (&s->pool); for (i=0; ipool, i); atom->blocklisted = -1; } } } static 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 inline bool atomIsSeed (const struct peer_atom * atom) { return atom->seedProbability == 100; } static void atomSetSeed (const tr_swarm * s, struct peer_atom * atom) { if (!atomIsSeed (atom)) { tordbg (s, "marking peer %s as a seed", tr_atomAddrStr (atom)); atomSetSeedProbability (atom, 100); } } bool tr_peerMgrPeerIsSeed (const tr_torrent * tor, const tr_address * addr) { bool isSeed = false; const tr_swarm * s = tor->swarm; const struct peer_atom * atom = getExistingAtom (s, addr); if (atom) isSeed = atomIsSeed (atom); return isSeed; } void tr_peerMgrSetUtpSupported (tr_torrent * tor, const tr_address * addr) { struct peer_atom * atom = getExistingAtom (tor->swarm, addr); if (atom) atom->flags |= ADDED_F_UTP_FLAGS; } void tr_peerMgrSetUtpFailed (tr_torrent *tor, const tr_address *addr, bool failed) { struct peer_atom * atom = getExistingAtom (tor->swarm, addr); if (atom) atom->utp_failed = failed; } /** *** REQUESTS *** *** There are two data structures associated with managing block requests: *** *** 1. tr_swarm::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. tr_swarm::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 (tr_swarm * s, tr_block_index_t block, tr_peer * peer) { struct block_request key; /* ensure enough room is available... */ if (s->requestCount + 1 >= s->requestAlloc) { const int CHUNK_SIZE = 128; s->requestAlloc += CHUNK_SIZE; s->requests = tr_renew (struct block_request, s->requests, s->requestAlloc); } /* populate the record we're inserting */ key.block = block; key.peer = peer; key.sentAt = tr_time (); /* insert the request to our array... */ { bool exact; const int pos = tr_lowerBound (&key, s->requests, s->requestCount, sizeof (struct block_request), compareReqByBlock, &exact); assert (!exact); memmove (s->requests + pos + 1, s->requests + pos, sizeof (struct block_request) * (s->requestCount++ - pos)); s->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), s->requestCount);*/ } static struct block_request * requestListLookup (tr_swarm * s, tr_block_index_t block, const tr_peer * peer) { struct block_request key; key.block = block; key.peer = (tr_peer*) peer; return bsearch (&key, s->requests, s->requestCount, sizeof (struct block_request), compareReqByBlock); } /** * Find the peers are we currently requesting the block * with index @a block from and append them to @a peerArr. */ static void getBlockRequestPeers (tr_swarm * s, tr_block_index_t block, tr_ptrArray * peerArr) { bool exact; int i, pos; struct block_request key; key.block = block; key.peer = NULL; pos = tr_lowerBound (&key, s->requests, s->requestCount, sizeof (struct block_request), compareReqByBlock, &exact); assert (!exact); /* shouldn't have a request with .peer == NULL */ for (i=pos; irequestCount; ++i) { if (s->requests[i].block != block) break; tr_ptrArrayAppend (peerArr, s->requests[i].peer); } } static void decrementPendingReqCount (const struct block_request * b) { if (b->peer != NULL) if (b->peer->pendingReqsToPeer > 0) --b->peer->pendingReqsToPeer; } static void requestListRemove (tr_swarm * s, tr_block_index_t block, const tr_peer * peer) { const struct block_request * b = requestListLookup (s, block, peer); if (b != NULL) { const int pos = b - s->requests; assert (pos < s->requestCount); decrementPendingReqCount (b); tr_removeElementFromArray (s->requests, pos, sizeof (struct block_request), s->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);*/ } } static int countActiveWebseeds (tr_swarm * s) { int activeCount = 0; if (s->tor->isRunning && !tr_torrentIsSeed (s->tor)) { int i; const int n = tr_ptrArraySize (&s->webseeds); const uint64_t now = tr_time_msec (); for (i=0; iwebseeds,i), now, TR_DOWN, NULL)) ++activeCount; } return activeCount; } static bool testForEndgame (const tr_swarm * s) { /* we consider ourselves to be in endgame if the number of bytes we've got requested is >= the number of bytes left to download */ return (s->requestCount * s->tor->blockSize) >= tr_torrentGetLeftUntilDone (s->tor); } static void updateEndgame (tr_swarm * s) { assert (s->requestCount >= 0); if (!testForEndgame (s)) { /* not in endgame */ s->endgame = 0; } else if (!s->endgame) /* only recalculate when endgame first begins */ { int i; int numDownloading = 0; const int n = tr_ptrArraySize (&s->peers); /* add the active bittorrent peers... */ for (i=0; ipeers, i); if (p->pendingReqsToPeer > 0) ++numDownloading; } /* add the active webseeds... */ numDownloading += countActiveWebseeds (s); /* average number of pending requests per downloading peer */ s->endgame = s->requestCount / MAX (numDownloading, 1); } } /**** ***** ***** Piece List Manipulation / Accessors ***** ****/ static inline void invalidatePieceSorting (tr_swarm * s) { s->pieceSortState = PIECES_UNSORTED; } static const tr_torrent * weightTorrent; static const uint16_t * weightReplication; static void setComparePieceByWeightTorrent (tr_swarm * s) { if (!replicationExists (s)) replicationNew (s); weightTorrent = s->tor; weightReplication = s->pieceReplication; } /* 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; const uint16_t * rep = weightReplication; /* primary key: weight */ missing = tr_torrentMissingBlocksInPiece (tor, a->index); pending = a->requestCount; ia = missing > pending ? missing - pending : (tor->blockCountInPiece + pending); missing = tr_torrentMissingBlocksInPiece (tor, b->index); pending = b->requestCount; ib = missing > pending ? missing - pending : (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: rarest first. */ ia = rep[a->index]; ib = rep[b->index]; if (ia < ib) return -1; if (ia > ib) return 1; /* quaternary 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 (tr_swarm * s, enum piece_sort_state state) { assert (state==PIECES_SORTED_BY_INDEX || state==PIECES_SORTED_BY_WEIGHT); if (state == PIECES_SORTED_BY_WEIGHT) { setComparePieceByWeightTorrent (s); qsort (s->pieces, s->pieceCount, sizeof (struct weighted_piece), comparePieceByWeight); } else { qsort (s->pieces, s->pieceCount, sizeof (struct weighted_piece), comparePieceByIndex); } s->pieceSortState = state; } /** * These functions are useful for testing, but too expensive for nightly builds. * let's leave it disabled but add an easy hook to compile it back in */ #if 1 #define assertWeightedPiecesAreSorted(t) #define assertReplicationCountIsExact(t) #else static void assertWeightedPiecesAreSorted (Torrent * t) { if (!t->endgame) { int i; setComparePieceByWeightTorrent (t); for (i=0; ipieceCount-1; ++i) assert (comparePieceByWeight (&t->pieces[i], &t->pieces[i+1]) <= 0); } } static void assertReplicationCountIsExact (Torrent * t) { /* This assert might fail due to errors of implementations in other * clients. It happens when receiving duplicate bitfields/HaveAll/HaveNone * from a client. If a such a behavior is noticed, * a bug report should be filled to the faulty client. */ size_t piece_i; const uint16_t * rep = t->pieceReplication; const size_t piece_count = t->pieceReplicationSize; const tr_peer ** peers = (const tr_peer**) tr_ptrArrayBase (&t->peers); const int peer_count = tr_ptrArraySize (&t->peers); assert (piece_count == t->tor->info.pieceCount); for (piece_i=0; piece_ihave, piece_i)) ++r; assert (rep[piece_i] == r); } } #endif static struct weighted_piece * pieceListLookup (tr_swarm * s, tr_piece_index_t index) { int i; for (i=0; ipieceCount; ++i) if (s->pieces[i].index == index) return &s->pieces[i]; return NULL; } static void pieceListRebuild (tr_swarm * s) { if (!tr_torrentIsSeed (s->tor)) { tr_piece_index_t i; tr_piece_index_t * pool; tr_piece_index_t poolCount = 0; const tr_torrent * tor = s->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_torrentPieceIsComplete (tor, 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 (s->pieces != NULL) { struct weighted_piece * o = s->pieces; struct weighted_piece * oend = o + s->pieceCount; struct weighted_piece * n = pieces; struct weighted_piece * nend = n + pieceCount; pieceListSort (s, 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 (s->pieces); } s->pieces = pieces; s->pieceCount = pieceCount; pieceListSort (s, PIECES_SORTED_BY_WEIGHT); /* cleanup */ tr_free (pool); } } static void pieceListRemovePiece (tr_swarm * s, tr_piece_index_t piece) { struct weighted_piece * p; if ((p = pieceListLookup (s, piece))) { const int pos = p - s->pieces; tr_removeElementFromArray (s->pieces, pos, sizeof (struct weighted_piece), s->pieceCount--); if (s->pieceCount == 0) { tr_free (s->pieces); s->pieces = NULL; } } } static void pieceListResortPiece (tr_swarm * s, struct weighted_piece * p) { int pos; bool isSorted = true; if (p == NULL) return; /* is the torrent already sorted? */ pos = p - s->pieces; setComparePieceByWeightTorrent (s); if (isSorted && (pos > 0) && (comparePieceByWeight (p-1, p) > 0)) isSorted = false; if (isSorted && (pos < s->pieceCount - 1) && (comparePieceByWeight (p, p+1) > 0)) isSorted = false; if (s->pieceSortState != PIECES_SORTED_BY_WEIGHT) { pieceListSort (s, PIECES_SORTED_BY_WEIGHT); isSorted = true; } /* if it's not sorted, move it around */ if (!isSorted) { bool exact; const struct weighted_piece tmp = *p; tr_removeElementFromArray (s->pieces, pos, sizeof (struct weighted_piece), s->pieceCount--); pos = tr_lowerBound (&tmp, s->pieces, s->pieceCount, sizeof (struct weighted_piece), comparePieceByWeight, &exact); memmove (&s->pieces[pos + 1], &s->pieces[pos], sizeof (struct weighted_piece) * (s->pieceCount++ - pos)); s->pieces[pos] = tmp; } assertWeightedPiecesAreSorted (s); } static void pieceListRemoveRequest (tr_swarm * s, tr_block_index_t block) { struct weighted_piece * p; const tr_piece_index_t index = tr_torBlockPiece (s->tor, block); if (((p = pieceListLookup (s, index))) && (p->requestCount > 0)) { --p->requestCount; pieceListResortPiece (s, p); } } /**** ***** ***** Replication count (for rarest first policy) ***** ****/ /** * Increase the replication count of this piece and sort it if the * piece list is already sorted */ static void tr_incrReplicationOfPiece (tr_swarm * s, const size_t index) { assert (replicationExists (s)); assert (s->pieceReplicationSize == s->tor->info.pieceCount); /* One more replication of this piece is present in the swarm */ ++s->pieceReplication[index]; /* we only resort the piece if the list is already sorted */ if (s->pieceSortState == PIECES_SORTED_BY_WEIGHT) pieceListResortPiece (s, pieceListLookup (s, index)); } /** * Increases the replication count of pieces present in the bitfield */ static void tr_incrReplicationFromBitfield (tr_swarm * s, const tr_bitfield * b) { size_t i; uint16_t * rep = s->pieceReplication; const size_t n = s->tor->info.pieceCount; assert (replicationExists (s)); for (i=0; ipieceSortState == PIECES_SORTED_BY_WEIGHT) invalidatePieceSorting (s); } /** * Increase the replication count of every piece */ static void tr_incrReplication (tr_swarm * s) { int i; const int n = s->pieceReplicationSize; assert (replicationExists (s)); assert (s->pieceReplicationSize == s->tor->info.pieceCount); for (i=0; ipieceReplication[i]; } /** * Decrease the replication count of pieces present in the bitset. */ static void tr_decrReplicationFromBitfield (tr_swarm * s, const tr_bitfield * b) { int i; const int n = s->pieceReplicationSize; assert (replicationExists (s)); assert (s->pieceReplicationSize == s->tor->info.pieceCount); if (tr_bitfieldHasAll (b)) { for (i=0; ipieceReplication[i]; } else if (!tr_bitfieldHasNone (b)) { for (i=0; ipieceReplication[i]; if (s->pieceSortState == PIECES_SORTED_BY_WEIGHT) invalidatePieceSorting (s); } } /** *** **/ void tr_peerMgrRebuildRequests (tr_torrent * tor) { assert (tr_isTorrent (tor)); pieceListRebuild (tor->swarm); } void tr_peerMgrGetNextRequests (tr_torrent * tor, tr_peer * peer, int numwant, tr_block_index_t * setme, int * numgot, bool get_intervals) { int i; int got; tr_swarm * s; struct weighted_piece * pieces; const tr_bitfield * const have = &peer->have; /* sanity clause */ assert (tr_isTorrent (tor)); assert (numwant > 0); /* walk through the pieces and find blocks that should be requested */ got = 0; s = tor->swarm; /* prep the pieces list */ if (s->pieces == NULL) pieceListRebuild (s); if (s->pieceSortState != PIECES_SORTED_BY_WEIGHT) pieceListSort (s, PIECES_SORTED_BY_WEIGHT); assertReplicationCountIsExact (s); assertWeightedPiecesAreSorted (s); updateEndgame (s); pieces = s->pieces; for (i=0; ipieceCount && gotindex)) { tr_block_index_t b; tr_block_index_t first; tr_block_index_t last; tr_ptrArray peerArr = TR_PTR_ARRAY_INIT; tr_torGetPieceBlockRange (tor, p->index, &first, &last); for (b=first; b<=last && (gotendgame) continue; /* don't have more than two peers requesting this block */ if (peerCount > 1) continue; /* don't send the same request to the same peer twice */ if (peer == peers[0]) continue; /* in the endgame allow an additional peer to download a block but only if the peer seems to be handling requests relatively fast */ if (peer->pendingReqsToPeer + numwant - got < s->endgame) continue; } /* update the caller's table */ if (!get_intervals) { setme[got++] = b; } /* if intervals are requested two array entries are necessarry: one for the interval's starting block and one for its end block */ else if (got && setme[2 * got - 1] == b - 1 && b != first) { /* expand the last interval */ ++setme[2 * got - 1]; } else { /* begin a new interval */ setme[2 * got] = setme[2 * got + 1] = b; ++got; } /* update our own tables */ requestListAdd (s, b, peer); ++p->requestCount; } tr_ptrArrayDestruct (&peerArr, NULL); } } /* 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 == s->pieceCount) --i; setComparePieceByWeightTorrent (s); while (--i >= 0) { bool exact; /* relative position! */ const int newpos = tr_lowerBound (&s->pieces[i], &s->pieces[i + 1], s->pieceCount - (i + 1), sizeof (struct weighted_piece), comparePieceByWeight, &exact); if (newpos > 0) { const struct weighted_piece piece = s->pieces[i]; memmove (&s->pieces[i], &s->pieces[i + 1], sizeof (struct weighted_piece) * (newpos)); s->pieces[i + newpos] = piece; } } } assertWeightedPiecesAreSorted (t); *numgot = got; } bool tr_peerMgrDidPeerRequest (const tr_torrent * tor, const tr_peer * peer, tr_block_index_t block) { return requestListLookup ((tr_swarm*)tor->swarm, block, peer) != NULL; } /* cancel requests that are too old */ static void refillUpkeep (evutil_socket_t foo UNUSED, short bar UNUSED, void * vmgr) { time_t now; time_t too_old; tr_torrent * tor; int cancel_buflen = 0; struct block_request * cancel = NULL; tr_peerMgr * mgr = vmgr; managerLock (mgr); now = tr_time (); too_old = now - REQUEST_TTL_SECS; /* alloc the temporary "cancel" buffer */ tor = NULL; while ((tor = tr_torrentNext (mgr->session, tor))) cancel_buflen = MAX (cancel_buflen, tor->swarm->requestCount); if (cancel_buflen > 0) cancel = tr_new (struct block_request, cancel_buflen); /* prune requests that are too old */ tor = NULL; while ((tor = tr_torrentNext (mgr->session, tor))) { tr_swarm * s = tor->swarm; const int n = s->requestCount; if (n > 0) { int keepCount = 0; int cancelCount = 0; const struct block_request * it; const struct block_request * end; for (it=s->requests, end=it+n; it!=end; ++it) { tr_peerMsgs * msgs = PEER_MSGS(it->peer); if ((msgs !=NULL) && (it->sentAt <= too_old) && !tr_peerMsgsIsReadingBlock (msgs, it->block)) cancel[cancelCount++] = *it; else { if (it != &s->requests[keepCount]) s->requests[keepCount] = *it; keepCount++; } } /* prune out the ones we aren't keeping */ s->requestCount = keepCount; /* send cancel messages for all the "cancel" ones */ for (it=cancel, end=it+cancelCount; it!=end; ++it) { tr_peerMsgs * msgs = PEER_MSGS(it->peer); if (msgs != NULL) { tr_historyAdd (&it->peer->cancelsSentToPeer, now, 1); tr_peerMsgsCancel (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 (s, it->block); } } tr_free (cancel); tr_timerAddMsec (mgr->refillUpkeepTimer, REFILL_UPKEEP_PERIOD_MSEC); managerUnlock (mgr); } static void addStrike (tr_swarm * s, tr_peer * peer) { tordbg (s, "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->flags2 |= MYFLAG_BANNED; peer->doPurge = 1; tordbg (s, "banning peer %s", tr_atomAddrStr (atom)); } } static void peerSuggestedPiece (tr_swarm * s 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_torrentPieceIsComplete (t->tor, 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 b; tr_block_index_t first; tr_block_index_t last; const tr_torrent * tor = t->tor; tr_torGetPieceBlockRange (t->tor, pieceIndex, &first, &last); for (b=first; b<=last; ++b) { if (tr_torrentBlockIsComplete (tor, b)) { const uint32_t offset = getBlockOffsetInPiece (tor, b); const uint32_t length = tr_torBlockCountBytes (tor, b); tr_peerMsgsAddRequest (peer->msgs, pieceIndex, offset, length); incrementPieceRequests (t, pieceIndex); } } } #endif } static void removeRequestFromTables (tr_swarm * s, tr_block_index_t block, const tr_peer * peer) { requestListRemove (s, block, peer); pieceListRemoveRequest (s, block); } /* peer choked us, or maybe it disconnected. either way we need to remove all its requests */ static void peerDeclinedAllRequests (tr_swarm * s, const tr_peer * peer) { int i, n; tr_block_index_t * blocks = tr_new (tr_block_index_t, s->requestCount); for (i=n=0; irequestCount; ++i) if (peer == s->requests[i].peer) blocks[n++] = s->requests[i].block; for (i=0; icancelsSentToPeer, tr_time (), 1); tr_peerMsgsCancel (PEER_MSGS(p), block); } removeRequestFromTables (s, block, p); } tr_ptrArrayDestruct (&peerArr, NULL); } void tr_peerMgrPieceCompleted (tr_torrent * tor, tr_piece_index_t p) { int i; bool pieceCameFromPeers = false; tr_swarm * const s = tor->swarm; const int n = tr_ptrArraySize (&s->peers); /* walk through our peers */ for (i=0; ipeers, i); /* notify the peer that we now have this piece */ tr_peerMsgsHave (PEER_MSGS(peer), p); if (!pieceCameFromPeers) pieceCameFromPeers = tr_bitfieldHas (&peer->blame, p); } if (pieceCameFromPeers) /* webseed downloads don't belong in announce totals */ tr_announcerAddBytes (tor, TR_ANN_DOWN, tr_torPieceCountBytes (tor, p)); /* bookkeeping */ pieceListRemovePiece (s, p); s->needsCompletenessCheck = true; } static void peerCallbackFunc (tr_peer * peer, const tr_peer_event * e, void * vs) { tr_swarm * s = vs; swarmLock (s); assert (peer != NULL); switch (e->eventType) { case TR_PEER_PEER_GOT_PIECE_DATA: { const time_t now = tr_time (); tr_torrent * tor = s->tor; tor->uploadedCur += e->length; tr_announcerAddBytes (tor, TR_ANN_UP, e->length); tr_torrentSetActivityDate (tor, now); tr_torrentSetDirty (tor); tr_statsAddUploaded (tor->session, e->length); if (peer->atom != NULL) peer->atom->piece_data_time = now; break; } case TR_PEER_CLIENT_GOT_PIECE_DATA: { const time_t now = tr_time (); tr_torrent * tor = s->tor; tor->downloadedCur += e->length; tr_torrentSetActivityDate (tor, now); tr_torrentSetDirty (tor); tr_statsAddDownloaded (tor->session, e->length); if (peer->atom != NULL) peer->atom->piece_data_time = now; break; } case TR_PEER_CLIENT_GOT_HAVE: if (replicationExists (s)) { tr_incrReplicationOfPiece (s, e->pieceIndex); assertReplicationCountIsExact (s); } break; case TR_PEER_CLIENT_GOT_HAVE_ALL: if (replicationExists (s)) { tr_incrReplication (s); assertReplicationCountIsExact (s); } break; case TR_PEER_CLIENT_GOT_HAVE_NONE: /* noop */ break; case TR_PEER_CLIENT_GOT_BITFIELD: assert (e->bitfield != NULL); if (replicationExists (s)) { tr_incrReplicationFromBitfield (s, e->bitfield); assertReplicationCountIsExact (s); } break; case TR_PEER_CLIENT_GOT_REJ: { tr_block_index_t b = _tr_block (s->tor, e->pieceIndex, e->offset); if (b < s->tor->blockCount) removeRequestFromTables (s, b, peer); else tordbg (s, "Peer %s sent an out-of-range reject message", tr_atomAddrStr (peer->atom)); break; } case TR_PEER_CLIENT_GOT_CHOKE: peerDeclinedAllRequests (s, peer); break; case TR_PEER_CLIENT_GOT_PORT: if (peer->atom) peer->atom->port = e->port; break; case TR_PEER_CLIENT_GOT_SUGGEST: peerSuggestedPiece (s, peer, e->pieceIndex, false); break; case TR_PEER_CLIENT_GOT_ALLOWED_FAST: peerSuggestedPiece (s, peer, e->pieceIndex, true); break; case TR_PEER_CLIENT_GOT_BLOCK: { tr_torrent * tor = s->tor; const tr_piece_index_t p = e->pieceIndex; const tr_block_index_t block = _tr_block (tor, p, e->offset); cancelAllRequestsForBlock (s, block, peer); tr_historyAdd (&peer->blocksSentToClient, tr_time(), 1); pieceListResortPiece (s, pieceListLookup (s, p)); tr_torrentGotBlock (tor, block); 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 (s, "setting %s doPurge flag because we got an ERANGE, EMSGSIZE, or ENOTCONN error", tr_atomAddrStr (peer->atom)); } else { tordbg (s, "unhandled error: %s", tr_strerror (e->err)); } break; default: assert (0); } swarmUnlock (s); } 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 (tr_swarm * s, 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_address_is_valid (addr)); assert (from < TR_PEER_FROM__MAX); a = getExistingAtom (s, 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->fromFirst = from; a->fromBest = from; a->shelf_date = tr_time () + getDefaultShelfLife (from) + jitter; a->blocklisted = -1; atomSetSeedProbability (a, seedProbability); tr_ptrArrayInsertSorted (&s->pool, a, compareAtomsByAddress); tordbg (s, "got a new atom: %s", tr_atomAddrStr (a)); } else { if (from < a->fromBest) a->fromBest = from; if (a->seedProbability == -1) atomSetSeedProbability (a, seedProbability); a->flags |= flags; } } static int getMaxPeerCount (const tr_torrent * tor) { return tor->maxConnectedPeers; } static int getPeerCount (const tr_swarm * s) { return tr_ptrArraySize (&s->peers);/* + tr_ptrArraySize (&t->outgoingHandshakes); */ } static void createBitTorrentPeer (tr_torrent * tor, struct tr_peerIo * io, struct peer_atom * atom, tr_quark client) { tr_peer * peer; tr_peerMsgs * msgs; tr_swarm * swarm; assert (atom != NULL); assert (tr_isTorrent (tor)); assert (tor->swarm != NULL); swarm = tor->swarm; peer = (tr_peer*) tr_peerMsgsNew (tor, io, peerCallbackFunc, swarm); peer->atom = atom; peer->client = client; atom->peer = peer; tr_ptrArrayInsertSorted (&swarm->peers, peer, peerCompare); ++swarm->stats.peerCount; ++swarm->stats.peerFromCount[atom->fromFirst]; assert (swarm->stats.peerCount == tr_ptrArraySize (&swarm->peers)); assert (swarm->stats.peerFromCount[atom->fromFirst] <= swarm->stats.peerCount); msgs = PEER_MSGS (peer); tr_peerMsgsUpdateActive (msgs, TR_UP); tr_peerMsgsUpdateActive (msgs, TR_DOWN); } /* FIXME: this is kind of a mess. */ static bool myHandshakeDoneCB (tr_handshake * handshake, tr_peerIo * io, bool readAnythingFromPeer, bool isConnected, const uint8_t * peer_id, void * vmanager) { bool ok = isConnected; bool success = false; tr_port port; const tr_address * addr; tr_peerMgr * manager = vmanager; tr_swarm * s; assert (io); assert (tr_isBool (ok)); s = tr_peerIoHasTorrentHash (io) ? getExistingSwarm (manager, tr_peerIoGetTorrentHash (io)) : NULL; if (tr_peerIoIsIncoming (io)) tr_ptrArrayRemoveSortedPointer (&manager->incomingHandshakes, handshake, handshakeCompare); else if (s) tr_ptrArrayRemoveSortedPointer (&s->outgoingHandshakes, handshake, handshakeCompare); if (s) swarmLock (s); addr = tr_peerIoGetAddress (io, &port); if (!ok || !s || !s->isRunning) { if (s) { struct peer_atom * atom = getExistingAtom (s, addr); if (atom) { ++atom->numFails; if (!readAnythingFromPeer) { tordbg (s, "marking peer %s as unreachable... numFails is %d", tr_atomAddrStr (atom), (int)atom->numFails); atom->flags2 |= MYFLAG_UNREACHABLE; } } } } else /* looking good */ { struct peer_atom * atom; ensureAtomExists (s, addr, port, 0, -1, TR_PEER_FROM_INCOMING); atom = getExistingAtom (s, addr); atom->time = tr_time (); atom->piece_data_time = 0; atom->lastConnectionAt = tr_time (); if (!tr_peerIoIsIncoming (io)) { atom->flags |= ADDED_F_CONNECTABLE; atom->flags2 &= ~MYFLAG_UNREACHABLE; } /* In principle, this flag specifies whether the peer groks uTP, not whether it's currently connected over uTP. */ if (io->utp_socket) atom->flags |= ADDED_F_UTP_FLAGS; if (atom->flags2 & MYFLAG_BANNED) { tordbg (s, "banned peer %s tried to reconnect", tr_atomAddrStr (atom)); } else if (tr_peerIoIsIncoming (io) && (getPeerCount (s) >= getMaxPeerCount (s->tor))) { } else { tr_peer * peer = atom->peer; if (peer) /* we already have this peer */ { } else { tr_quark client; tr_peerIo * io; char buf[128]; if (peer_id != NULL) client = tr_quark_new (tr_clientForId (buf, sizeof (buf), peer_id), -1); else client = TR_KEY_NONE; io = tr_handshakeStealIO (handshake); /* this steals its refcount too, which is balanced by our unref in peerDelete () */ tr_peerIoSetParent (io, &s->tor->bandwidth); createBitTorrentPeer (s->tor, io, atom, client); success = true; } } } if (s != NULL) swarmUnlock (s); return success; } void tr_peerMgrAddIncoming (tr_peerMgr * manager, tr_address * addr, tr_port port, int socket, struct UTPSocket * utp_socket) { tr_session * session; managerLock (manager); assert (tr_isSession (manager->session)); session = manager->session; if (tr_sessionIsAddressBlocked (session, addr)) { tr_logAddDebug ("Banned IP address \"%s\" tried to connect to us", tr_address_to_string (addr)); if (socket >= 0) tr_netClose (session, socket); else UTP_Close (utp_socket); } else if (getExistingHandshake (&manager->incomingHandshakes, addr)) { if (socket >= 0) tr_netClose (session, socket); else UTP_Close (utp_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, utp_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); } void tr_peerMgrAddPex (tr_torrent * tor, uint8_t from, const tr_pex * pex, int8_t seedProbability) { if (tr_isPex (pex)) /* safeguard against corrupt data */ { tr_swarm * s = tor->swarm; managerLock (s->manager); if (!tr_sessionIsAddressBlocked (s->manager->session, &pex->addr)) if (tr_address_is_valid_for_peers (&pex->addr, pex->port)) ensureAtomExists (s, &pex->addr, pex->port, pex->flags, seedProbability, from); managerUnlock (s->manager); } } void tr_peerMgrMarkAllAsSeeds (tr_torrent * tor) { tr_swarm * s = tor->swarm; const int n = tr_ptrArraySize (&s->pool); struct peer_atom ** it = (struct peer_atom**) tr_ptrArrayBase (&s->pool); struct peer_atom ** end = it + n; while (it != end) atomSetSeed (s, *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; iswarm; const uint32_t byteCount = tr_torPieceCountBytes (tor, pieceIndex); for (i=0, n=tr_ptrArraySize(&s->peers); i!=n; ++i) { tr_peer * peer = tr_ptrArrayNth (&s->peers, i); if (tr_bitfieldHas (&peer->blame, pieceIndex)) { tordbg (s, "peer %s contributed to corrupt piece (%d); now has %d strikes", tr_atomAddrStr(peer->atom), pieceIndex, (int)peer->strikes + 1); addStrike (s, peer); } } tr_announcerAddBytes (tor, TR_ANN_CORRUPT, byteCount); } int tr_pexCompare (const void * va, const void * vb) { int i; const tr_pex * a = va; const tr_pex * b = vb; assert (tr_isPex (a)); assert (tr_isPex (b)); if ((i = tr_address_compare (&a->addr, &b->addr))) return i; if (a->port != b->port) return a->port < b->port ? -1 : 1; return 0; } /* 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->fromBest != b->fromBest) return a->fromBest < b->fromBest ? -1 : 1; if (a->numFails != b->numFails) return a->numFails < b->numFails ? -1 : 1; return 0; } static bool isAtomInteresting (const tr_torrent * tor, struct peer_atom * atom) { if (tr_torrentIsSeed (tor) && atomIsSeed (atom)) return false; if (peerIsInUse (tor->swarm, atom)) return true; if (isAtomBlocklisted (tor->session, atom)) return false; if (atom->flags2 & MYFLAG_BANNED) return false; return true; } 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 tr_swarm * s = tor->swarm; 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_INTERESTING); managerLock (s->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 (&s->peers); atomCount = tr_ptrArraySize (&s->peers); atoms = tr_new (struct peer_atom *, atomCount); for (i=0; iatom; } else /* TR_PEERS_INTERESTING */ { int i; struct peer_atom ** atomBase = (struct peer_atom**) tr_ptrArrayBase (&s->pool); n = tr_ptrArraySize (&s->pool); atoms = tr_new (struct peer_atom *, n); for (i=0; iaddr.type == af) { assert (tr_address_is_valid (&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 (s->manager); return count; } static void atomPulse (evutil_socket_t, short, void *); static void bandwidthPulse (evutil_socket_t, short, void *); static void rechokePulse (evutil_socket_t, short, void *); static void reconnectPulse (evutil_socket_t, short, void *); static struct event * createTimer (tr_session * session, int msec, event_callback_fn callback, void * cbdata) { struct event * timer = evtimer_new (session->event_base, callback, cbdata); tr_timerAddMsec (timer, msec); return timer; } static void ensureMgrTimersExist (struct tr_peerMgr * m) { if (m->atomTimer == NULL) m->atomTimer = createTimer (m->session, ATOM_PERIOD_MSEC, atomPulse, m); if (m->bandwidthTimer == NULL) m->bandwidthTimer = createTimer (m->session, BANDWIDTH_PERIOD_MSEC, bandwidthPulse, m); if (m->rechokeTimer == NULL) m->rechokeTimer = createTimer (m->session, RECHOKE_PERIOD_MSEC, rechokePulse, m); if (m->refillUpkeepTimer == NULL) m->refillUpkeepTimer = createTimer (m->session, REFILL_UPKEEP_PERIOD_MSEC, refillUpkeep, m); } void tr_peerMgrStartTorrent (tr_torrent * tor) { tr_swarm * s; assert (tr_isTorrent (tor)); assert (tr_torrentIsLocked (tor)); s = tor->swarm; ensureMgrTimersExist (s->manager); s->isRunning = true; s->maxPeers = tor->maxConnectedPeers; s->pieceSortState = PIECES_UNSORTED; rechokePulse (0, 0, s->manager); } static void removeAllPeers (tr_swarm *); static void stopSwarm (tr_swarm * swarm) { swarm->isRunning = false; replicationFree (swarm); invalidatePieceSorting (swarm); removeAllPeers (swarm); /* disconnect the handshakes. handshakeAbort calls handshakeDoneCB (), * which removes the handshake from t->outgoingHandshakes... */ while (!tr_ptrArrayEmpty (&swarm->outgoingHandshakes)) tr_handshakeAbort (tr_ptrArrayNth (&swarm->outgoingHandshakes, 0)); } void tr_peerMgrStopTorrent (tr_torrent * tor) { assert (tr_isTorrent (tor)); assert (tr_torrentIsLocked (tor)); stopSwarm (tor->swarm); } void tr_peerMgrAddTorrent (tr_peerMgr * manager, tr_torrent * tor) { assert (tr_isTorrent (tor)); assert (tr_torrentIsLocked (tor)); assert (tor->swarm == NULL); tor->swarm = swarmNew (manager, tor); } void tr_peerMgrRemoveTorrent (tr_torrent * tor) { assert (tr_isTorrent (tor)); assert (tr_torrentIsLocked (tor)); stopSwarm (tor->swarm); swarmFree (tor->swarm); } void tr_peerUpdateProgress (tr_torrent * tor, tr_peer * peer) { const tr_bitfield * have = &peer->have; if (tr_bitfieldHasAll (have)) { peer->progress = 1.0; } else if (tr_bitfieldHasNone (have)) { peer->progress = 0.0; } else { const float true_count = tr_bitfieldCountTrueBits (have); if (tr_torrentHasMetadata (tor)) { peer->progress = true_count / tor->info.pieceCount; } else /* without pieceCount, this result is only a best guess... */ { peer->progress = true_count / (have->bit_count + 1); } } /* clamp the progress range */ if (peer->progress < 0.0) peer->progress = 0.0; if (peer->progress > 1.0) peer->progress = 1.0; if (peer->atom && (peer->progress >= 1.0)) atomSetSeed (tor->swarm, peer->atom); } void tr_peerMgrOnTorrentGotMetainfo (tr_torrent * tor) { int i; int peerCount; tr_peer ** peers; /* the webseed list may have changed... */ rebuildWebseedArray (tor->swarm, tor); /* some peer_msgs' progress fields may not be accurate if we didn't have the metadata before now... so refresh them all... */ peerCount = tr_ptrArraySize (&tor->swarm->peers); peers = (tr_peer**) tr_ptrArrayBase (&tor->swarm->peers); for (i=0; i 0); memset (tab, 0, tabCount); if (tr_torrentHasMetadata (tor)) { tr_piece_index_t i; const int peerCount = tr_ptrArraySize (&tor->swarm->peers); const tr_peer ** peers = (const tr_peer**) tr_ptrArrayBase (&tor->swarm->peers); const float interval = tor->info.pieceCount / (float)tabCount; const bool isSeed = tr_torrentGetCompleteness (tor) == TR_SEED; for (i=0; ihave, piece)) ++tab[i]; } } } } void tr_swarmGetStats (const tr_swarm * swarm, tr_swarm_stats * setme) { assert (swarm != NULL); assert (setme != NULL); *setme = swarm->stats; } void tr_swarmIncrementActivePeers (tr_swarm * swarm, tr_direction direction, bool is_active) { int n = swarm->stats.activePeerCount[direction]; if (is_active) ++n; else --n; assert (0 <= n); assert (n <= swarm->stats.peerCount); swarm->stats.activePeerCount[direction] = n; } bool tr_peerIsSeed (const tr_peer * peer) { if (peer->progress >= 1.0) return true; if (peer->atom && atomIsSeed (peer->atom)) return true; return false; } /* count how many bytes we want that connected peers have */ uint64_t tr_peerMgrGetDesiredAvailable (const tr_torrent * tor) { size_t i; size_t n; uint64_t desiredAvailable; const tr_swarm * s; assert (tr_isTorrent (tor)); /* common shortcuts... */ if (tr_torrentIsSeed (tor)) return 0; if (!tr_torrentHasMetadata (tor)) return 0; s = tor->swarm; if (s == NULL) return 0; n = tr_ptrArraySize (&s->peers); if (n == 0) { return 0; } else { const tr_peer ** peers = (const tr_peer**) tr_ptrArrayBase (&s->peers); for (i=0; iatom && atomIsSeed (peers[i]->atom)) return tr_torrentGetLeftUntilDone (tor); } if (!s->pieceReplication || !s->pieceReplicationSize) return 0; /* do it the hard way */ desiredAvailable = 0; for (i=0, n=MIN (tor->info.pieceCount, s->pieceReplicationSize); iinfo.pieces[i].dnd && (s->pieceReplication[i] > 0)) desiredAvailable += tr_torrentMissingBytesInPiece (tor, i); assert (desiredAvailable <= tor->info.totalSize); return desiredAvailable; } double* tr_peerMgrWebSpeeds_KBps (const tr_torrent * tor) { unsigned int i; tr_swarm * s; unsigned int n; double * ret = NULL; const uint64_t now = tr_time_msec (); assert (tr_isTorrent (tor)); s = tor->swarm; n = tr_ptrArraySize (&s->webseeds); ret = tr_new0 (double, n); assert (s->manager != NULL); assert (n == tor->info.webseedCount); for (i=0; iwebseeds,i), now, TR_DOWN, &Bps)) ret[i] = Bps / (double)tr_speed_K; else ret[i] = -1.0; } return ret; } struct tr_peer_stat * tr_peerMgrPeerStats (const tr_torrent * tor, int * setmeCount) { int i; int size = 0; tr_peer_stat * ret; const tr_swarm * s; tr_peer ** peers; const time_t now = tr_time (); const uint64_t now_msec = tr_time_msec (); assert (tr_isTorrent (tor)); assert (tor->swarm->manager != NULL); s = tor->swarm; peers = (tr_peer**) tr_ptrArrayBase (&s->peers); size = tr_ptrArraySize (&s->peers); ret = tr_new0 (tr_peer_stat, size); for (i=0; iatom; tr_peer_stat * stat = ret + i; tr_address_to_string_with_buf (&atom->addr, stat->addr, sizeof (stat->addr)); tr_strlcpy (stat->client, tr_quark_get_string(peer->client,NULL), sizeof (stat->client)); stat->port = ntohs (peer->atom->port); stat->from = atom->fromFirst; stat->progress = peer->progress; stat->isUTP = tr_peerMsgsIsUtpConnection (msgs); stat->isEncrypted = tr_peerMsgsIsEncrypted (msgs); stat->rateToPeer_KBps = toSpeedKBps (tr_peerGetPieceSpeed_Bps (peer, now_msec, TR_CLIENT_TO_PEER)); stat->rateToClient_KBps = toSpeedKBps (tr_peerGetPieceSpeed_Bps (peer, now_msec, TR_PEER_TO_CLIENT)); stat->peerIsChoked = tr_peerMsgsIsPeerChoked (msgs); stat->peerIsInterested = tr_peerMsgsIsPeerInterested (msgs); stat->clientIsChoked = tr_peerMsgsIsClientChoked (msgs); stat->clientIsInterested = tr_peerMsgsIsClientInterested (msgs); stat->isIncoming = tr_peerMsgsIsIncomingConnection (msgs); stat->isDownloadingFrom = tr_peerMsgsIsActive (msgs, TR_PEER_TO_CLIENT); stat->isUploadingTo = tr_peerMsgsIsActive (msgs, TR_CLIENT_TO_PEER); stat->isSeed = tr_peerIsSeed (peer); stat->blocksToPeer = tr_historyGet (&peer->blocksSentToPeer, now, CANCEL_HISTORY_SEC); stat->blocksToClient = tr_historyGet (&peer->blocksSentToClient, now, CANCEL_HISTORY_SEC); stat->cancelsToPeer = tr_historyGet (&peer->cancelsSentToPeer, now, CANCEL_HISTORY_SEC); stat->cancelsToClient = tr_historyGet (&peer->cancelsSentToClient, now, CANCEL_HISTORY_SEC); stat->pendingReqsToPeer = peer->pendingReqsToPeer; stat->pendingReqsToClient = peer->pendingReqsToClient; pch = stat->flagStr; if (stat->isUTP) *pch++ = 'T'; if (s->optimistic == msgs) *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'; else if (stat->from == TR_PEER_FROM_PEX) *pch++ = 'X'; if (stat->isIncoming) *pch++ = 'I'; *pch = '\0'; } *setmeCount = size; return ret; } /*** **** **** ***/ void tr_peerMgrClearInterest (tr_torrent * tor) { int i; tr_swarm * s = tor->swarm; const int peerCount = tr_ptrArraySize (&s->peers); assert (tr_isTorrent (tor)); assert (tr_torrentIsLocked (tor)); for (i=0; ipeers, i), false); } /* does this peer have any pieces that we want? */ static bool isPeerInteresting (tr_torrent * const tor, const bool * const piece_is_interesting, const tr_peer * const peer) { tr_piece_index_t i, n; /* these cases should have already been handled by the calling code... */ assert (!tr_torrentIsSeed (tor)); assert (tr_torrentIsPieceTransferAllowed (tor, TR_PEER_TO_CLIENT)); if (tr_peerIsSeed (peer)) return true; for (i=0, n=tor->info.pieceCount; ihave, i)) return true; return false; } typedef enum { RECHOKE_STATE_GOOD, RECHOKE_STATE_UNTESTED, RECHOKE_STATE_BAD } tr_rechoke_state; struct tr_rechoke_info { tr_peer * peer; int salt; int rechoke_state; }; static int compare_rechoke_info (const void * va, const void * vb) { const struct tr_rechoke_info * a = va; const struct tr_rechoke_info * b = vb; if (a->rechoke_state != b->rechoke_state) return a->rechoke_state - b->rechoke_state; return a->salt - b->salt; } /* determines who we send "interested" messages to */ static void rechokeDownloads (tr_swarm * s) { int i; int maxPeers = 0; int rechoke_count = 0; struct tr_rechoke_info * rechoke = NULL; const int MIN_INTERESTING_PEERS = 5; const int peerCount = tr_ptrArraySize (&s->peers); const time_t now = tr_time (); /* some cases where this function isn't necessary */ if (tr_torrentIsSeed (s->tor)) return; if (!tr_torrentIsPieceTransferAllowed (s->tor, TR_PEER_TO_CLIENT)) return; /* decide HOW MANY peers to be interested in */ { int blocks = 0; int cancels = 0; time_t timeSinceCancel; /* 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, CANCEL_HISTORY_SEC); const int c = tr_historyGet (&peer->cancelsSentToPeer, now, CANCEL_HISTORY_SEC); if (b == 0) /* ignore unresponsive peers, as described above */ continue; blocks += b; cancels += c; } if (cancels > 0) { /* cancelRate: of the block requests we've recently made, the percentage we cancelled. * higher values indicate more congestion. */ const double cancelRate = cancels / (double)(cancels + blocks); const double mult = 1 - MIN (cancelRate, 0.5); maxPeers = s->interestedCount * mult; tordbg (s, "cancel rate is %.3f -- reducing the " "number of peers we're interested in by %.0f percent", cancelRate, mult * 100); s->lastCancel = now; } timeSinceCancel = now - s->lastCancel; if (timeSinceCancel) { const int maxIncrease = 15; const time_t maxHistory = 2 * CANCEL_HISTORY_SEC; const double mult = MIN (timeSinceCancel, maxHistory) / (double) maxHistory; const int inc = maxIncrease * mult; maxPeers = s->maxPeers + inc; tordbg (s, "time since last cancel is %li -- increasing the " "number of peers we're interested in by %d", timeSinceCancel, inc); } } /* don't let the previous section's number tweaking go too far... */ if (maxPeers < MIN_INTERESTING_PEERS) maxPeers = MIN_INTERESTING_PEERS; if (maxPeers > s->tor->maxConnectedPeers) maxPeers = s->tor->maxConnectedPeers; s->maxPeers = maxPeers; if (peerCount > 0) { bool * piece_is_interesting; const tr_torrent * const tor = s->tor; const int n = tor->info.pieceCount; /* build a bitfield of interesting pieces... */ piece_is_interesting = tr_new (bool, n); for (i=0; iinfo.pieces[i].dnd && !tr_torrentPieceIsComplete (tor, i); /* decide WHICH peers to be interested in (based on their cancel-to-block ratio) */ for (i=0; ipeers, i); if (!isPeerInteresting (s->tor, piece_is_interesting, peer)) { tr_peerMsgsSetInterested (PEER_MSGS(peer), false); } else { tr_rechoke_state rechoke_state; const int blocks = tr_historyGet (&peer->blocksSentToClient, now, CANCEL_HISTORY_SEC); const int cancels = tr_historyGet (&peer->cancelsSentToPeer, now, CANCEL_HISTORY_SEC); if (!blocks && !cancels) rechoke_state = RECHOKE_STATE_UNTESTED; else if (!cancels) rechoke_state = RECHOKE_STATE_GOOD; else if (!blocks) rechoke_state = RECHOKE_STATE_BAD; else if ((cancels * 10) < blocks) rechoke_state = RECHOKE_STATE_GOOD; else rechoke_state = RECHOKE_STATE_BAD; if (rechoke == NULL) rechoke = tr_new (struct tr_rechoke_info, peerCount); rechoke[rechoke_count].peer = peer; rechoke[rechoke_count].rechoke_state = rechoke_state; rechoke[rechoke_count].salt = tr_cryptoWeakRandInt (INT_MAX); rechoke_count++; } } tr_free (piece_is_interesting); } /* now that we know which & how many peers to be interested in... update the peer interest */ qsort (rechoke, rechoke_count, sizeof (struct tr_rechoke_info), compare_rechoke_info); s->interestedCount = MIN (maxPeers, rechoke_count); for (i=0; iinterestedCount); /* cleanup */ tr_free (rechoke); } /** *** **/ struct ChokeData { bool isInterested; bool wasChoked; bool isChoked; int rate; int salt; tr_peerMsgs * msgs; }; 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->wasChoked != b->wasChoked) /* prefer unchoked */ return a->wasChoked ? 1 : -1; if (a->salt != b->salt) /* random order */ return a->salt - b->salt; return 0; } /* is this a new connection? */ static bool isNew (const tr_peerMsgs * msgs) { return (msgs != NULL) && (tr_peerMsgsGetConnectionAge (msgs) < 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) { unsigned int Bps; if (tr_torrentIsSeed (tor)) Bps = tr_peerGetPieceSpeed_Bps (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)) Bps = tr_peerGetPieceSpeed_Bps (atom->peer, now, TR_PEER_TO_CLIENT) + tr_peerGetPieceSpeed_Bps (atom->peer, now, TR_CLIENT_TO_PEER); /* downloading a public torrent */ else Bps = tr_peerGetPieceSpeed_Bps (atom->peer, now, TR_PEER_TO_CLIENT); /* convert it to bytes per second */ return Bps; } static inline bool isBandwidthMaxedOut (const tr_bandwidth * b, const uint64_t now_msec, tr_direction dir) { if (!tr_bandwidthIsLimited (b, dir)) { return false; } else { const unsigned int got = tr_bandwidthGetPieceSpeed_Bps (b, now_msec, dir); const unsigned int want = tr_bandwidthGetDesiredSpeed_Bps (b, dir); return got >= want; } } static void rechokeUploads (tr_swarm * s, const uint64_t now) { int i, size, unchokedInterested; const int peerCount = tr_ptrArraySize (&s->peers); tr_peer ** peers = (tr_peer**) tr_ptrArrayBase (&s->peers); struct ChokeData * choke = tr_new0 (struct ChokeData, peerCount); const tr_session * session = s->manager->session; const int chokeAll = !tr_torrentIsPieceTransferAllowed (s->tor, TR_CLIENT_TO_PEER); const bool isMaxedOut = isBandwidthMaxedOut (&s->tor->bandwidth, now, TR_UP); assert (swarmIsLocked (s)); /* an optimistic unchoke peer's "optimistic" * state lasts for N calls to rechokeUploads (). */ if (s->optimisticUnchokeTimeScaler > 0) s->optimisticUnchokeTimeScaler--; else s->optimistic = NULL; /* sort the peers by preference and rate */ for (i=0, size=0; iatom; if (tr_peerIsSeed (peer)) /* choke seeds and partial seeds */ { tr_peerMsgsSetChoke (PEER_MSGS(peer), true); } else if (chokeAll) /* choke everyone if we're not uploading */ { tr_peerMsgsSetChoke (PEER_MSGS(peer), true); } else if (msgs != s->optimistic) { struct ChokeData * n = &choke[size++]; n->msgs = msgs; n->isInterested = tr_peerMsgsIsPeerInterested (msgs); n->wasChoked = tr_peerMsgsIsPeerChoked (msgs); n->rate = getRate (s->tor, atom, now); n->salt = tr_cryptoWeakRandInt (INT_MAX); n->isChoked = true; } } 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. * * If our bandwidth is maxed out, don't unchoke any more peers. */ unchokedInterested = 0; for (i=0; iuploadSlotsPerTorrent; ++i) { choke[i].isChoked = isMaxedOut ? choke[i].wasChoked : false; if (choke[i].isInterested) ++unchokedInterested; } /* optimistic unchoke */ if (!s->optimistic && !isMaxedOut && (iisChoked = false; s->optimistic = c->msgs; s->optimisticUnchokeTimeScaler = OPTIMISTIC_UNCHOKE_MULTIPLIER; } tr_ptrArrayDestruct (&randPool, NULL); } for (i=0; isession, tor))) { if (tor->isRunning) { tr_swarm * s = tor->swarm; if (s->stats.peerCount > 0) { rechokeUploads (s, now); rechokeDownloads (s); } } } tr_timerAddMsec (mgr->rechokeTimer, RECHOKE_PERIOD_MSEC); managerUnlock (mgr); } /*** **** **** Life and Death **** ***/ static bool shouldPeerBeClosed (const tr_swarm * s, const tr_peer * peer, int peerCount, const time_t now) { const tr_torrent * tor = s->tor; const struct peer_atom * atom = peer->atom; /* if it's marked for purging, close it */ if (peer->doPurge) { tordbg (s, "purging peer %s because its doPurge flag is set", tr_atomAddrStr (atom)); return true; } /* disconnect if we're both seeds and enough time has passed for PEX */ if (tr_torrentIsSeed (tor) && tr_peerIsSeed (peer)) return !tr_torrentAllowsPex (tor) || (now-atom->time>=30); /* 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 (s, "purging peer %s because it's been %d secs since we shared anything", tr_atomAddrStr (atom), idleTime); return true; } } return false; } static tr_peer ** getPeersToClose (tr_swarm * s, const time_t now_sec, int * setmeSize) { int i, peerCount, outsize; struct tr_peer ** ret = NULL; tr_peer ** peers = (tr_peer**) tr_ptrArrayPeek (&s->peers, &peerCount); assert (swarmIsLocked (s)); for (i=outsize=0; iflags2 & MYFLAG_UNREACHABLE) != 0; /* 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 (!unreachable && ((now - atom->piece_data_time) <= (MINIMUM_RECONNECT_INTERVAL_SECS * 2))) sec = MINIMUM_RECONNECT_INTERVAL_SECS; /* otherwise, the interval depends on how many times we've tried * and failed to connect to the peer */ else { int step = atom->numFails; /* penalize peers that were unreachable the last time we tried */ if (unreachable) step += 2; switch (step) { case 0: sec = 0; break; case 1: sec = 10; break; case 2: sec = 60 * 2; break; case 3: sec = 60 * 15; break; case 4: sec = 60 * 30; break; case 5: sec = 60 * 60; break; default: sec = 60 * 120; break; } } dbgmsg ("reconnect interval for %s is %d seconds", tr_atomAddrStr (atom), sec); return sec; } static void removePeer (tr_swarm * s, tr_peer * peer) { struct peer_atom * atom = peer->atom; assert (swarmIsLocked (s)); assert (atom); atom->time = tr_time (); tr_ptrArrayRemoveSortedPointer (&s->peers, peer, peerCompare); --s->stats.peerCount; --s->stats.peerFromCount[atom->fromFirst]; if (replicationExists (s)) tr_decrReplicationFromBitfield (s, &peer->have); assert (s->stats.peerCount == tr_ptrArraySize (&s->peers)); assert (s->stats.peerFromCount[atom->fromFirst] >= 0); tr_peerFree (peer); } static void closePeer (tr_swarm * s, tr_peer * peer) { struct peer_atom * atom; assert (s != 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 (s, "resetting atom %s numFails to 0", tr_atomAddrStr (atom)); atom->numFails = 0; } else { ++atom->numFails; tordbg (s, "incremented atom %s numFails to %d", tr_atomAddrStr (atom), (int)atom->numFails); } tordbg (s, "removing bad peer %s", tr_atomAddrStr (peer->atom)); removePeer (s, peer); } static void removeAllPeers (tr_swarm * s) { while (!tr_ptrArrayEmpty (&s->peers)) removePeer (s, tr_ptrArrayNth (&s->peers, 0)); assert (!s->stats.peerCount); } static void closeBadPeers (tr_swarm * s, const time_t now_sec) { if (!tr_ptrArrayEmpty (&s->peers)) { int i; int peerCount; struct tr_peer ** peers; peers = getPeersToClose (s, now_sec, &peerCount); 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 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 = tr_peerGetPieceSpeed_Bps (p, now, TR_UP) + tr_peerGetPieceSpeed_Bps (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 enforceTorrentPeerLimit (tr_swarm * s, uint64_t now) { int n = tr_ptrArraySize (&s->peers); const int max = tr_torrentGetPeerLimit (s->tor); if (n > max) { void * base = tr_ptrArrayBase (&s->peers); tr_peer ** peers = tr_memdup (base, n*sizeof (tr_peer*)); sortPeersByLiveliness (peers, NULL, n, now); while (n > max) closePeer (s, 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->swarm->peers); /* if there are too many, prune out the worst */ if (n > max) { tr_peer ** peers = tr_new (tr_peer*, n); tr_swarm ** swarms = tr_new (tr_swarm*, n); /* populate the peer array */ n = 0; tor = NULL; while ((tor = tr_torrentNext (session, tor))) { int i; tr_swarm * s = tor->swarm; const int tn = tr_ptrArraySize (&s->peers); for (i=0; ipeers, i); swarms[n] = s; } } /* sort 'em */ sortPeersByLiveliness (peers, (void**)swarms, n, now); /* cull out the crappiest */ while (n-- > max) closePeer (swarms[n], peers[n]); /* cleanup */ tr_free (swarms); tr_free (peers); } } static void makeNewPeerConnections (tr_peerMgr * mgr, const int max); static void reconnectPulse (evutil_socket_t foo UNUSED, short bar UNUSED, void * vmgr) { tr_torrent * tor; tr_peerMgr * mgr = vmgr; const time_t now_sec = tr_time (); const uint64_t now_msec = tr_time_msec (); /** *** 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->swarm, now_msec); /* if we're over the per-session peer limits, cull some peers */ enforceSessionPeerLimit (mgr->session, now_msec); /* remove crappy peers */ tor = NULL; while ((tor = tr_torrentNext (mgr->session, tor))) if (!tor->swarm->isRunning) removeAllPeers (tor->swarm); else closeBadPeers (tor->swarm, now_sec); /* 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; tr_swarm * s = tor->swarm; for (j=0; jpeers); ++j) tr_peerMsgsPulse (tr_ptrArrayNth (&s->peers, j)); } } static void queuePulseForeach (void * vtor) { tr_torrent * tor = vtor; tr_torrentStartNow (tor); if (tor->queue_started_callback != NULL) (*tor->queue_started_callback)(tor, tor->queue_started_user_data); } static void queuePulse (tr_session * session, tr_direction dir) { assert (tr_isSession (session)); assert (tr_isDirection (dir)); if (tr_sessionGetQueueEnabled (session, dir)) { tr_ptrArray torrents = TR_PTR_ARRAY_INIT; tr_sessionGetNextQueuedTorrents (session, dir, tr_sessionCountQueueFreeSlots (session, dir), &torrents); tr_ptrArrayForeach (&torrents, queuePulseForeach); tr_ptrArrayDestruct (&torrents, NULL); } } static void bandwidthPulse (evutil_socket_t foo UNUSED, short bar UNUSED, void * vmgr) { tr_torrent * tor; tr_peerMgr * mgr = vmgr; tr_session * session = mgr->session; managerLock (mgr); /* FIXME: this next line probably isn't necessary... */ pumpAllPeers (mgr); /* allocate bandwidth to the peers */ tr_bandwidthAllocate (&session->bandwidth, TR_UP, BANDWIDTH_PERIOD_MSEC); tr_bandwidthAllocate (&session->bandwidth, TR_DOWN, BANDWIDTH_PERIOD_MSEC); /* torrent upkeep */ tor = NULL; while ((tor = tr_torrentNext (session, tor))) { /* possibly stop torrents that have seeded enough */ tr_torrentCheckSeedLimit (tor); /* run the completeness check for any torrents that need it */ if (tor->swarm->needsCompletenessCheck) { tor->swarm->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 */ if (tor->isStopping) tr_torrentStop (tor); /* update the torrent's stats */ tor->swarm->stats.activeWebseedCount = countActiveWebseeds (tor->swarm); } /* pump the queues */ queuePulse (session, TR_UP); queuePulse (session, TR_DOWN); 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_address_compare (&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) { return MIN (50, tor->maxConnectedPeers * 3); } static void atomPulse (evutil_socket_t 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; tr_swarm * s = tor->swarm; const int maxAtomCount = getMaxAtomCount (tor); struct peer_atom ** atoms = (struct peer_atom**) tr_ptrArrayPeek (&s->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); s->pool = TR_PTR_ARRAY_INIT; qsort (keep, keepCount, sizeof (struct peer_atom *), compareAtomPtrsByAddress); for (i=0; ipool, keep[i]); tordbg (s, "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); } /*** **** **** **** ***/ /* is this atom someone that we'd want to initiate a connection to? */ static bool isPeerCandidate (const tr_torrent * tor, struct peer_atom * atom, const time_t now) { /* not if we're both seeds */ if (tr_torrentIsSeed (tor) && atomIsSeed (atom)) return false; /* not if we've already got a connection to them... */ if (peerIsInUse (tor->swarm, atom)) 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 they're banned... */ if (atom->flags2 & MYFLAG_BANNED) return false; return true; } struct peer_candidate { uint64_t score; tr_torrent * tor; struct peer_atom * atom; }; static 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 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 are known to be connectible */ i = (atom->flags & ADDED_F_CONNECTABLE) ? 0 : 1; 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 `fromBest' values indicate more trusted sources */ score = addValToKey (score, 4, atom->fromBest); /* salt */ score = addValToKey (score, 8, salt); return score; } static int comparePeerCandidates (const void * va, const void * vb) { int ret; const struct peer_candidate * a = va; const struct peer_candidate * b = vb; if (a->score < b->score) ret = -1; else if (a->score > b->score) ret = 1; else ret = 0; return ret; } /* Partial sorting -- selecting the k best candidates Adapted from http://en.wikipedia.org/wiki/Selection_algorithm */ static void selectPeerCandidates (struct peer_candidate * candidates, int candidate_count, int select_count) { tr_quickfindFirstK (candidates, candidate_count, sizeof(struct peer_candidate), comparePeerCandidates, select_count); } #ifndef NDEBUG static bool checkBestScoresComeFirst (const struct peer_candidate * candidates, int n, int k) { int i; uint64_t worstFirstScore = 0; const int x = MIN (n, k) - 1; for (i=0; i= worstFirstScore); return true; } #endif /* NDEBUG */ /** @return an array of all the atoms we might want to connect to */ static struct peer_candidate* getPeerCandidates (tr_session * session, int * candidateCount, int max) { int atomCount; int peerCount; tr_torrent * tor; struct peer_candidate * candidates; struct peer_candidate * walk; const time_t now = tr_time (); const uint64_t now_msec = tr_time_msec (); /* leave 5% of connection slots for incoming connections -- ticket #2609 */ const int maxCandidates = tr_sessionGetPeerLimit (session) * 0.95; /* count how many peers and atoms we've got */ tor= NULL; atomCount = 0; peerCount = 0; while ((tor = tr_torrentNext (session, tor))) { atomCount += tr_ptrArraySize (&tor->swarm->pool); peerCount += tr_ptrArraySize (&tor->swarm->peers); } /* don't start any new handshakes if we're full up */ if (maxCandidates <= peerCount) { *candidateCount = 0; return NULL; } /* allocate an array of candidates */ walk = candidates = tr_new (struct peer_candidate, atomCount); /* populate the candidate array */ tor = NULL; while ((tor = tr_torrentNext (session, tor))) { int i, nAtoms; struct peer_atom ** atoms; if (!tor->swarm->isRunning) continue; /* if we've already got enough peers in this torrent... */ if (tr_torrentGetPeerLimit (tor) <= tr_ptrArraySize (&tor->swarm->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->swarm->pool, &nAtoms); for (i=0; itor = tor; walk->atom = atom; walk->score = getPeerCandidateScore (tor, atom, salt); ++walk; } } } *candidateCount = walk - candidates; if (walk != candidates) selectPeerCandidates (candidates, walk-candidates, max); assert (checkBestScoresComeFirst (candidates, *candidateCount, max)); return candidates; } static void initiateConnection (tr_peerMgr * mgr, tr_swarm * s, struct peer_atom * atom) { tr_peerIo * io; const time_t now = tr_time (); bool utp = tr_sessionIsUTPEnabled (mgr->session) && !atom->utp_failed; if (atom->fromFirst == TR_PEER_FROM_PEX) /* PEX has explicit signalling for uTP support. If an atom originally came from PEX and doesn't have the uTP flag, skip the uTP connection attempt. Are we being optimistic here? */ utp = utp && (atom->flags & ADDED_F_UTP_FLAGS); tordbg (s, "Starting an OUTGOING%s connection with %s", utp ? " µTP" : "", tr_atomAddrStr (atom)); io = tr_peerIoNewOutgoing (mgr->session, &mgr->session->bandwidth, &atom->addr, atom->port, s->tor->info.hash, s->tor->completeness == TR_SEED, utp); if (io == NULL) { tordbg (s, "peerIo not created; marking peer %s as unreachable", tr_atomAddrStr (atom)); atom->flags2 |= 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 (&s->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->swarm, c->atom); } static void makeNewPeerConnections (struct tr_peerMgr * mgr, const int max) { int i, n; struct peer_candidate * candidates; candidates = getPeerCandidates (mgr->session, &n, max); for (i=0; i