/* This software was written by Dirk Engling It is considered beerware. Prost. Skol. Cheers or whatever. $id$ */ /* System */ #include #include #include #include #include #include #include /* Libowfat */ #include "byte.h" #include "io.h" #include "iob.h" #include "ip6.h" #include "array.h" /* Opentracker */ #include "trackerlogic.h" #include "ot_vector.h" #include "ot_mutex.h" #include "ot_stats.h" #include "ot_clean.h" #include "ot_http.h" #include "ot_accesslist.h" #include "ot_fullscrape.h" #include "ot_livesync.h" /* Forward declaration */ size_t return_peers_for_torrent( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto ); void free_peerlist( ot_peerlist *peer_list ) { if( peer_list->peers.data ) { if( OT_PEERLIST_HASBUCKETS( peer_list ) ) vector_clean_list( (ot_vector*)peer_list->peers.data, peer_list->peers.size ); else free( peer_list->peers.data ); } free( peer_list ); } void add_torrent_from_saved_state( ot_hash const hash, ot_time base, size_t down_count ) { int exactmatch; ot_torrent *torrent; ot_vector *torrents_list = mutex_bucket_lock_by_hash( hash ); if( !accesslist_hashisvalid( hash ) ) return mutex_bucket_unlock_by_hash( hash, 0 ); torrent = vector_find_or_insert( torrents_list, (void*)hash, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch ); if( !torrent || exactmatch ) return mutex_bucket_unlock_by_hash( hash, 0 ); /* Create a new torrent entry, then */ byte_zero( torrent, sizeof( ot_torrent ) ); memcpy( torrent->hash, hash, sizeof(ot_hash) ); if( !( torrent->peer_list6 = malloc( sizeof (ot_peerlist) ) ) || !( torrent->peer_list4 = malloc( sizeof (ot_peerlist) ) ) ) { vector_remove_torrent( torrents_list, torrent ); return mutex_bucket_unlock_by_hash( hash, 0 ); } byte_zero( torrent->peer_list6, sizeof( ot_peerlist ) ); byte_zero( torrent->peer_list4, sizeof( ot_peerlist ) ); torrent->peer_list6->base = base; torrent->peer_list4->base = base; torrent->peer_list6->down_count = down_count; torrent->peer_list4->down_count = down_count; return mutex_bucket_unlock_by_hash( hash, 1 ); } size_t add_peer_to_torrent_and_return_peers( PROTO_FLAG proto, struct ot_workstruct *ws, size_t amount ) { int exactmatch, delta_torrentcount = 0; ot_torrent *torrent; ot_peer *peer_dest; ot_vector *torrents_list = mutex_bucket_lock_by_hash( *ws->hash ); ot_peerlist *peer_list; size_t peer_size; /* initialized in next line */ ot_peer const *peer_src = peer_from_peer6(&ws->peer, &peer_size); if( !accesslist_hashisvalid( *ws->hash ) ) { mutex_bucket_unlock_by_hash( *ws->hash, 0 ); if( proto == FLAG_TCP ) { const char invalid_hash[] = "d14:failure reason63:Requested download is not authorized for use with this tracker.e"; memcpy( ws->reply, invalid_hash, strlen( invalid_hash ) ); return strlen( invalid_hash ); } return 0; } torrent = vector_find_or_insert( torrents_list, (void*)ws->hash, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch ); if( !torrent ) { mutex_bucket_unlock_by_hash( *ws->hash, 0 ); return 0; } if( !exactmatch ) { /* Create a new torrent entry, then */ byte_zero( torrent, sizeof(ot_torrent)); memcpy( torrent->hash, *ws->hash, sizeof(ot_hash) ); if( !( torrent->peer_list6 = malloc( sizeof (ot_peerlist) ) ) || !( torrent->peer_list4 = malloc( sizeof (ot_peerlist) ) ) ) { vector_remove_torrent( torrents_list, torrent ); mutex_bucket_unlock_by_hash( *ws->hash, 0 ); return 0; } byte_zero( torrent->peer_list6, sizeof( ot_peerlist ) ); byte_zero( torrent->peer_list4, sizeof( ot_peerlist ) ); delta_torrentcount = 1; } else clean_single_torrent( torrent ); torrent->peer_list6->base = g_now_minutes; torrent->peer_list4->base = g_now_minutes; peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4; /* Check for peer in torrent */ peer_dest = vector_find_or_insert_peer( &(peer_list->peers), peer_src, peer_size, &exactmatch ); if( !peer_dest ) { mutex_bucket_unlock_by_hash( *ws->hash, delta_torrentcount ); return 0; } /* Tell peer that it's fresh */ OT_PEERTIME( ws->peer, OT_PEER_SIZE6 ) = 0; /* Sanitize flags: Whoever claims to have completed download, must be a seeder */ if( ( OT_PEERFLAG( ws->peer ) & ( PEER_FLAG_COMPLETED | PEER_FLAG_SEEDING ) ) == PEER_FLAG_COMPLETED ) OT_PEERFLAG( ws->peer ) ^= PEER_FLAG_COMPLETED; /* If we hadn't had a match create peer there */ if( !exactmatch ) { #ifdef WANT_SYNC_LIVE if( proto == FLAG_MCA ) OT_PEERFLAG( ws->peer ) |= PEER_FLAG_FROM_SYNC; else livesync_tell( ws ); #endif peer_list->peer_count++; if( OT_PEERFLAG( ws->peer ) & PEER_FLAG_COMPLETED ) { peer_list->down_count++; stats_issue_event( EVENT_COMPLETED, 0, (uintptr_t)ws ); } if( OT_PEERFLAG(ws->peer) & PEER_FLAG_SEEDING ) peer_list->seed_count++; } else { stats_issue_event( EVENT_RENEW, 0, OT_PEERTIME( peer_dest, peer_size ) ); #ifdef WANT_SPOT_WOODPECKER if( ( OT_PEERTIME(peer_dest, peer_size) > 0 ) && ( OT_PEERTIME(peer_dest, peer_size) < 20 ) ) stats_issue_event( EVENT_WOODPECKER, 0, (uintptr_t)&ws->peer ); #endif #ifdef WANT_SYNC_LIVE /* Won't live sync peers that come back too fast. Only exception: fresh "completed" reports */ if( proto != FLAG_MCA ) { if( OT_PEERTIME( peer_dest, peer_size ) > OT_CLIENT_SYNC_RENEW_BOUNDARY || ( !(OT_PEERFLAG_D(peer_dest, peer_size) & PEER_FLAG_COMPLETED ) && (OT_PEERFLAG(ws->peer) & PEER_FLAG_COMPLETED ) ) ) livesync_tell( ws ); } #endif if( (OT_PEERFLAG_D(peer_dest, peer_size) & PEER_FLAG_SEEDING ) && !(OT_PEERFLAG(ws->peer) & PEER_FLAG_SEEDING ) ) peer_list->seed_count--; if( !(OT_PEERFLAG_D(peer_dest, peer_size) & PEER_FLAG_SEEDING ) && (OT_PEERFLAG(ws->peer) & PEER_FLAG_SEEDING ) ) peer_list->seed_count++; if( !(OT_PEERFLAG_D(peer_dest, peer_size) & PEER_FLAG_COMPLETED ) && (OT_PEERFLAG(ws->peer) & PEER_FLAG_COMPLETED ) ) { peer_list->down_count++; stats_issue_event( EVENT_COMPLETED, 0, (uintptr_t)ws ); } if( OT_PEERFLAG_D(peer_dest, peer_size) & PEER_FLAG_COMPLETED ) OT_PEERFLAG( ws->peer ) |= PEER_FLAG_COMPLETED; } memcpy( peer_dest, peer_src, peer_size ); #ifdef WANT_SYNC if( proto == FLAG_MCA ) { mutex_bucket_unlock_by_hash( *ws->hash, delta_torrentcount ); return 0; } #endif ws->reply_size = return_peers_for_torrent( ws, torrent, amount, ws->reply, proto ); mutex_bucket_unlock_by_hash( *ws->hash, delta_torrentcount ); return ws->reply_size; } static size_t return_peers_all( ot_peerlist *peer_list, size_t peer_size, char *reply ) { unsigned int bucket, num_buckets = 1; ot_vector * bucket_list = &peer_list->peers; size_t compare_size = OT_PEER_COMPARE_SIZE_FROM_PEER_SIZE(peer_size); size_t result = compare_size * peer_list->peer_count; char * r_end = reply + result; if( OT_PEERLIST_HASBUCKETS(peer_list) ) { num_buckets = bucket_list->size; bucket_list = (ot_vector *)bucket_list->data; } for( bucket = 0; bucketpeers; unsigned int shifted_pc = peer_list->peer_count; unsigned int shifted_step = 0; unsigned int shift = 0; size_t compare_size = OT_PEER_COMPARE_SIZE_FROM_PEER_SIZE(peer_size); size_t result = compare_size * amount; char * r_end = reply + result; if( OT_PEERLIST_HASBUCKETS(peer_list) ) { num_buckets = bucket_list->size; bucket_list = (ot_vector *)bucket_list->data; } /* Make fixpoint arithmetic as exact as possible */ #define MAXPRECBIT (1<<(8*sizeof(int)-3)) while( !(shifted_pc & MAXPRECBIT ) ) { shifted_pc <<= 1; shift++; } shifted_step = shifted_pc/amount; #undef MAXPRECBIT /* Initialize somewhere in the middle of peers so that fixpoint's aliasing doesn't alway miss the same peers */ bucket_offset = nrand48(ws->rand48_state) % peer_list->peer_count; while( amount-- ) { ot_peer *peer; /* This is the aliased, non shifted range, next value may fall into */ unsigned int diff = ( ( ( amount + 1 ) * shifted_step ) >> shift ) - ( ( amount * shifted_step ) >> shift ); bucket_offset += 1 + nrand48(ws->rand48_state) % diff; while( bucket_offset >= bucket_list[bucket_index].size ) { bucket_offset -= bucket_list[bucket_index].size; bucket_index = ( bucket_index + 1 ) % num_buckets; } peer = bucket_list[bucket_index].data + peer_size * bucket_offset; if( OT_PEERFLAG_D(peer, peer_size) & PEER_FLAG_SEEDING ) { r_end -= compare_size; memcpy(r_end, peer, compare_size); } else { memcpy(reply, peer, compare_size); reply += compare_size; } } return result; } static size_t return_peers_for_torrent_udp( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply ) { char *r = reply; size_t peer_size = peer_size_from_peer6(&ws->peer); ot_peerlist *peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4; size_t peer_count = torrent->peer_list6->peer_count + torrent->peer_list4->peer_count; size_t seed_count = torrent->peer_list6->seed_count + torrent->peer_list4->seed_count; if( amount > peer_list->peer_count ) amount = peer_list->peer_count; *(uint32_t*)(r+0) = htonl( OT_CLIENT_REQUEST_INTERVAL_RANDOM ); *(uint32_t*)(r+4) = htonl( peer_count - seed_count ); *(uint32_t*)(r+8) = htonl( seed_count ); r += 12; if( amount ) { if( amount == peer_list->peer_count ) r += return_peers_all( peer_list, peer_size, r ); else r += return_peers_selection( ws, peer_list, peer_size, amount, r ); } return r - reply; } static size_t return_peers_for_torrent_tcp( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply ) { char *r = reply; int erval = OT_CLIENT_REQUEST_INTERVAL_RANDOM; size_t seed_count = torrent->peer_list6->seed_count + torrent->peer_list4->seed_count; size_t down_count = torrent->peer_list6->down_count + torrent->peer_list4->down_count; size_t peer_count = torrent->peer_list6->peer_count + torrent->peer_list4->peer_count - seed_count; /* Simple case: amount of peers in both lists is less than requested, here we return all results */ size_t amount_v4 = torrent->peer_list4->peer_count; size_t amount_v6 = torrent->peer_list6->peer_count; /* Complex case: both lists have more than enough entries and we need to split between v4 and v6 clients */ if( amount_v4 + amount_v6 > amount ) { size_t amount_left, percent_v6 = 0, percent_v4 = 0, left_v6, left_v4; const size_t SCALE = 1024; /* If possible, fill at least a quarter of peer from each family */ if( amount / 4 <= amount_v4 ) amount_v4 = amount / 4; if( amount / 4 <= amount_v6 ) amount_v6 = amount / 4; /* Fill the rest according to which family's pool provides more peers */ amount_left = amount - (amount_v4 + amount_v6); left_v4 = torrent->peer_list4->peer_count - amount_v4; left_v6 = torrent->peer_list6->peer_count - amount_v6; if( left_v4 + left_v6 ) { percent_v4 = (SCALE * left_v4) / (left_v4 + left_v6); percent_v6 = (SCALE * left_v6) / (left_v4 + left_v6); } amount_v4 += (amount_left * percent_v4) / SCALE; amount_v6 += (amount_left * percent_v6) / SCALE; /* Integer division rounding can leave out a peer */ if( amount_v4 + amount_v6 < amount && amount_v6 < torrent->peer_list6->peer_count ) ++amount_v6; if( amount_v4 + amount_v6 < amount && amount_v4 < torrent->peer_list4->peer_count ) ++amount_v4; } r += sprintf( r, "d8:completei%zde10:downloadedi%zde10:incompletei%zde8:intervali%ie12:min intervali%ie", seed_count, down_count, peer_count, erval, erval/2 ); if( amount_v4 ) { r += sprintf( r, PEERS_BENCODED4 "%zd:", OT_PEER_COMPARE_SIZE4 * amount_v4); if( amount_v4 == torrent->peer_list4->peer_count ) r += return_peers_all( torrent->peer_list4, OT_PEER_SIZE4, r ); else r += return_peers_selection( ws, torrent->peer_list4, OT_PEER_SIZE4, amount_v4, r ); } if( amount_v6 ) { r += sprintf( r, PEERS_BENCODED6 "%zd:", OT_PEER_COMPARE_SIZE6 * amount_v6); if( amount_v6 == torrent->peer_list6->peer_count ) r += return_peers_all( torrent->peer_list6, OT_PEER_SIZE6, r ); else r += return_peers_selection( ws, torrent->peer_list6, OT_PEER_SIZE6, amount_v6, r ); } *r++ = 'e'; return r - reply; } /* Compiles a list of random peers for a torrent * Reply must have enough space to hold: * 92 + 6 * amount bytes for TCP/IPv4 * 92 + 18 * amount bytes for TCP/IPv6 * 12 + 6 * amount bytes for UDP/IPv4 * 12 + 18 * amount bytes for UDP/IPv6 * Does not yet check not to return self */ size_t return_peers_for_torrent( struct ot_workstruct * ws, ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto ) { return proto == FLAG_TCP ? return_peers_for_torrent_tcp(ws, torrent, amount, reply) : return_peers_for_torrent_udp(ws, torrent, amount, reply); } /* Fetches scrape info for a specific torrent */ size_t return_udp_scrape_for_torrent( ot_hash const hash, char *reply ) { int exactmatch, delta_torrentcount = 0; ot_vector *torrents_list = mutex_bucket_lock_by_hash( hash ); ot_torrent *torrent = binary_search( hash, torrents_list->data, torrents_list->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch ); if( !exactmatch ) { memset( reply, 0, 12); } else { uint32_t *r = (uint32_t*) reply; if( clean_single_torrent( torrent ) ) { vector_remove_torrent( torrents_list, torrent ); memset( reply, 0, 12); delta_torrentcount = -1; } else { r[0] = htonl( torrent->peer_list6->seed_count + torrent->peer_list4->seed_count ); r[1] = htonl( torrent->peer_list6->down_count + torrent->peer_list4->down_count ); r[2] = htonl( torrent->peer_list6->peer_count + torrent->peer_list4->peer_count - torrent->peer_list6->seed_count - torrent->peer_list4->seed_count); } } mutex_bucket_unlock_by_hash( hash, delta_torrentcount ); return 12; } /* Fetches scrape info for a specific torrent */ size_t return_tcp_scrape_for_torrent( ot_hash const *hash_list, int amount, char *reply ) { char *r = reply; int exactmatch, i; r += sprintf( r, "d5:filesd" ); for( i=0; idata, torrents_list->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch ); if( exactmatch ) { if( clean_single_torrent( torrent ) ) { vector_remove_torrent( torrents_list, torrent ); delta_torrentcount = -1; } else { *r++='2';*r++='0';*r++=':'; memcpy( r, hash, sizeof(ot_hash) ); r+=sizeof(ot_hash); r += sprintf( r, "d8:completei%zde10:downloadedi%zde10:incompletei%zdee", torrent->peer_list6->seed_count + torrent->peer_list4->seed_count, torrent->peer_list6->down_count + torrent->peer_list4->down_count, torrent->peer_list6->peer_count + torrent->peer_list4->peer_count - torrent->peer_list6->seed_count - torrent->peer_list4->seed_count); } } mutex_bucket_unlock_by_hash( *hash, delta_torrentcount ); } *r++ = 'e'; *r++ = 'e'; return r - reply; } static ot_peerlist dummy_list; size_t remove_peer_from_torrent( PROTO_FLAG proto, struct ot_workstruct *ws ) { int exactmatch; ot_vector *torrents_list = mutex_bucket_lock_by_hash( *ws->hash ); ot_torrent *torrent = binary_search( ws->hash, torrents_list->data, torrents_list->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch ); ot_peerlist *peer_list = &dummy_list; size_t peer_size; /* initialized in next line */ ot_peer const *peer_src = peer_from_peer6(&ws->peer, &peer_size); size_t peer_count = 0, seed_count = 0; #ifdef WANT_SYNC_LIVE if( proto != FLAG_MCA ) { OT_PEERFLAG( ws->peer ) |= PEER_FLAG_STOPPED; livesync_tell( ws ); } #endif if( exactmatch ) { peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4; switch( vector_remove_peer( &peer_list->peers, peer_src, peer_size ) ) { case 2: peer_list->seed_count--; /* Intentional fallthrough */ case 1: peer_list->peer_count--; /* Intentional fallthrough */ default: break; } peer_count = torrent->peer_list6->peer_count + torrent->peer_list4->peer_count; seed_count = torrent->peer_list6->seed_count + torrent->peer_list4->seed_count; } if( proto == FLAG_TCP ) { int erval = OT_CLIENT_REQUEST_INTERVAL_RANDOM; ws->reply_size = sprintf( ws->reply, "d8:completei%zde10:incompletei%zde8:intervali%ie12:min intervali%ie%s0:e", seed_count, peer_count - seed_count, erval, erval / 2, peer_size == OT_PEER_SIZE6 ? PEERS_BENCODED6 : PEERS_BENCODED4 ); } /* Handle UDP reply */ if( proto == FLAG_UDP ) { ((uint32_t*)ws->reply)[2] = htonl( OT_CLIENT_REQUEST_INTERVAL_RANDOM ); ((uint32_t*)ws->reply)[3] = htonl( peer_count - seed_count ); ((uint32_t*)ws->reply)[4] = htonl( seed_count); ws->reply_size = 20; } mutex_bucket_unlock_by_hash( *ws->hash, 0 ); return ws->reply_size; } void iterate_all_torrents( int (*for_each)( ot_torrent* torrent, uintptr_t data ), uintptr_t data ) { int bucket; size_t j; for( bucket=0; bucketdata); for( j=0; jsize; ++j ) if( for_each( torrents + j, data ) ) break; mutex_bucket_unlock( bucket, 0 ); if( !g_opentracker_running ) return; } } ot_peer *peer_from_peer6( ot_peer6 *peer, size_t *peer_size ) { ot_ip6 *ip = (ot_ip6*)peer; if( !ip6_isv4mapped(ip) ) { *peer_size = OT_PEER_SIZE6; return (ot_peer*)peer; } *peer_size = OT_PEER_SIZE4; return (ot_peer*)(((uint8_t*)peer) + 12); } size_t peer_size_from_peer6(ot_peer6 *peer) { ot_ip6 *ip = (ot_ip6*)peer; if( !ip6_isv4mapped(ip)) return OT_PEER_SIZE6; return OT_PEER_SIZE4; } #ifdef _DEBUG_RANDOMTORRENTS void trackerlogic_add_random_torrents(size_t amount) { struct ot_workstruct ws; memset( &ws, 0, sizeof(ws) ); ws.inbuf=malloc(G_INBUF_SIZE); ws.outbuf=malloc(G_OUTBUF_SIZE); ws.reply=ws.outbuf; ws.hash=ws.inbuf; while( amount-- ) { arc4random_buf(ws.hash, sizeof(ot_hash)); arc4random_buf(&ws.peer, sizeof(ws.peer)); OT_PEERFLAG(ws.peer) &= PEER_FLAG_SEEDING | PEER_FLAG_COMPLETED | PEER_FLAG_STOPPED; add_peer_to_torrent_and_return_peers( FLAG_TCP, &ws, 1 ); } free(ws.inbuf); free(ws.outbuf); } #endif void exerr( char * message ) { fprintf( stderr, "%s\n", message ); exit( 111 ); } void trackerlogic_init( ) { g_tracker_id = random(); if( !g_stats_path ) g_stats_path = "stats"; g_stats_path_len = strlen( g_stats_path ); /* Initialise background worker threads */ mutex_init( ); clean_init( ); fullscrape_init( ); accesslist_init( ); livesync_init( ); stats_init( ); } void trackerlogic_deinit( void ) { int bucket, delta_torrentcount = 0; size_t j; /* Free all torrents... */ for(bucket=0; bucketsize ) { for( j=0; jsize; ++j ) { ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + j; free_peerlist( torrent->peer_list6 ); free_peerlist( torrent->peer_list4 ); delta_torrentcount -= 1; } free( torrents_list->data ); } mutex_bucket_unlock( bucket, delta_torrentcount ); } /* Deinitialise background worker threads */ stats_deinit( ); livesync_deinit( ); accesslist_deinit( ); fullscrape_deinit( ); clean_deinit( ); /* Release mutexes */ mutex_deinit( ); } const char *g_version_trackerlogic_c = "$Source$: $Revision$\n";