An open and free bittorrent tracker https://erdgeist.org/gitweb/opentracker
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/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$id$ */
/* System */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
/* Libowfat */
#include "byte.h"
#include "io.h"
/* Opentracker */
#include "trackerlogic.h"
#include "ot_mutex.h"
#include "ot_stats.h"
#include "ot_clean.h"
#include "ot_accesslist.h"
#include "ot_fullscrape.h"
#include "ot_livesync.h"
/* Forward declaration */
size_t return_peers_for_torrent( 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 ) ) {
ot_vector *bucket_list = (ot_vector*)(peer_list->peers.data);
while( peer_list->peers.size-- )
free( bucket_list++->data );
}
free( peer_list->peers.data );
}
free( peer_list );
}
size_t add_peer_to_torrent_and_return_peers( ot_hash hash, ot_peer *peer, PROTO_FLAG proto, size_t amount, char * reply ) {
int exactmatch, delta_torrentcount = 0;
size_t reply_size;
ot_torrent *torrent;
ot_peer *peer_dest;
ot_vector *torrents_list = mutex_bucket_lock_by_hash( hash );
if( !accesslist_hashisvalid( hash ) ) {
mutex_bucket_unlock_by_hash( hash, 0 );
return 0;
}
torrent = vector_find_or_insert( torrents_list, (void*)hash, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch );
if( !torrent ) {
mutex_bucket_unlock_by_hash( hash, 0 );
return 0;
}
if( !exactmatch ) {
/* Create a new torrent entry, then */
memcpy( torrent->hash, hash, sizeof(ot_hash) );
if( !( torrent->peer_list = malloc( sizeof (ot_peerlist) ) ) ) {
vector_remove_torrent( torrents_list, torrent );
mutex_bucket_unlock_by_hash( hash, 0 );
return 0;
}
byte_zero( torrent->peer_list, sizeof( ot_peerlist ) );
delta_torrentcount = 1;
} else
clean_single_torrent( torrent );
torrent->peer_list->base = g_now_minutes;
/* Check for peer in torrent */
peer_dest = vector_find_or_insert_peer( &(torrent->peer_list->peers), peer, &exactmatch );
if( !peer_dest ) {
mutex_bucket_unlock_by_hash( hash, delta_torrentcount );
return 0;
}
/* Tell peer that it's fresh */
OT_PEERTIME( peer ) = 0;
/* Sanitize flags: Whoever claims to have completed download, must be a seeder */
if( ( OT_PEERFLAG( peer ) & ( PEER_FLAG_COMPLETED | PEER_FLAG_SEEDING ) ) == PEER_FLAG_COMPLETED )
OT_PEERFLAG( 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( peer ) |= PEER_FLAG_FROM_SYNC;
else
livesync_tell( hash, peer );
#endif
torrent->peer_list->peer_count++;
if( OT_PEERFLAG(peer) & PEER_FLAG_COMPLETED )
torrent->peer_list->down_count++;
if( OT_PEERFLAG(peer) & PEER_FLAG_SEEDING )
torrent->peer_list->seed_count++;
} else {
stats_issue_event( EVENT_RENEW, 0, OT_PEERTIME( peer_dest ) );
#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 ) > OT_CLIENT_SYNC_RENEW_BOUNDARY ||
( !(OT_PEERFLAG(peer_dest) & PEER_FLAG_COMPLETED ) && (OT_PEERFLAG(peer) & PEER_FLAG_COMPLETED ) ) )
livesync_tell( hash, peer );
}
#endif
if( (OT_PEERFLAG(peer_dest) & PEER_FLAG_SEEDING ) && !(OT_PEERFLAG(peer) & PEER_FLAG_SEEDING ) )
torrent->peer_list->seed_count--;
if( !(OT_PEERFLAG(peer_dest) & PEER_FLAG_SEEDING ) && (OT_PEERFLAG(peer) & PEER_FLAG_SEEDING ) )
torrent->peer_list->seed_count++;
if( !(OT_PEERFLAG(peer_dest) & PEER_FLAG_COMPLETED ) && (OT_PEERFLAG(peer) & PEER_FLAG_COMPLETED ) )
torrent->peer_list->down_count++;
if( OT_PEERFLAG(peer_dest) & PEER_FLAG_COMPLETED )
OT_PEERFLAG( peer ) |= PEER_FLAG_COMPLETED;
}
memcpy( peer_dest, peer, sizeof(ot_peer) );
#ifdef WANT_SYNC
if( proto == FLAG_MCA ) {
mutex_bucket_unlock_by_hash( hash, delta_torrentcount );
return 0;
}
#endif
reply_size = return_peers_for_torrent( torrent, amount, reply, proto );
mutex_bucket_unlock_by_hash( torrent->hash, delta_torrentcount );
return reply_size;
}
static size_t return_peers_all( ot_peerlist *peer_list, char *reply ) {
unsigned int bucket, num_buckets = 1;
ot_vector * bucket_list = &peer_list->peers;
char * r = reply;
if( OT_PEERLIST_HASBUCKETS(peer_list) ) {
num_buckets = bucket_list->size;
bucket_list = (ot_vector *)bucket_list->data;
}
for( bucket = 0; bucket<num_buckets; ++bucket ) {
ot_peer * peers = (ot_peer*)bucket_list[bucket].data;
size_t peer_count = bucket_list[bucket].size;
while( peer_count-- ) {
memcpy(r,peers++,OT_PEER_COMPARE_SIZE);
r+=OT_PEER_COMPARE_SIZE;
}
}
return r - reply;
}
static size_t return_peers_selection( ot_peerlist *peer_list, size_t amount, char *reply ) {
unsigned int bucket_offset, bucket_index = 0, num_buckets = 1;
ot_vector * bucket_list = &peer_list->peers;
unsigned int shifted_pc = peer_list->peer_count;
unsigned int shifted_step = 0;
unsigned int shift = 0;
char * r = reply;
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 = random() % 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 + random() % diff;
while( bucket_offset >= bucket_list[bucket_index].size ) {
bucket_offset -= bucket_list[bucket_index].size;
bucket_index = ( bucket_index + 1 ) % num_buckets;
}
peer = ((ot_peer*)bucket_list[bucket_index].data) + bucket_offset;
memcpy(r,peer,OT_PEER_COMPARE_SIZE);
r+=OT_PEER_COMPARE_SIZE;
}
return r - reply;
}
/* Compiles a list of random peers for a torrent
* reply must have enough space to hold 92+6*amount bytes
* does not yet check not to return self
*/
size_t return_peers_for_torrent( ot_torrent *torrent, size_t amount, char *reply, PROTO_FLAG proto ) {
ot_peerlist *peer_list = torrent->peer_list;
char *r = reply;
if( amount > peer_list->peer_count )
amount = peer_list->peer_count;
if( proto == FLAG_TCP ) {
int erval = OT_CLIENT_REQUEST_INTERVAL_RANDOM;
r += sprintf( r, "d8:completei%zde10:downloadedi%zde10:incompletei%zde8:intervali%ie12:min intervali%ie" PEERS_BENCODED "%zd:", peer_list->seed_count, peer_list->down_count, peer_list->peer_count-peer_list->seed_count, erval, erval/2, OT_PEER_COMPARE_SIZE*amount );
} else {
*(uint32_t*)(r+0) = htonl( OT_CLIENT_REQUEST_INTERVAL_RANDOM );
*(uint32_t*)(r+4) = htonl( peer_list->peer_count );
*(uint32_t*)(r+8) = htonl( peer_list->seed_count );
r += 12;
}
if( amount ) {
if( amount == peer_list->peer_count )
r += return_peers_all( peer_list, r );
else
r += return_peers_selection( peer_list, amount, r );
}
if( proto == FLAG_TCP )
*r++ = 'e';
return r - reply;
}
/* Fetches scrape info for a specific torrent */
size_t return_udp_scrape_for_torrent( ot_hash 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_list->seed_count );
r[1] = htonl( torrent->peer_list->down_count );
r[2] = htonl( torrent->peer_list->peer_count-torrent->peer_list->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 *hash_list, int amount, char *reply ) {
char *r = reply;
int exactmatch, i;
int delta_torrentcount = 0;
r += sprintf( r, "d5:filesd" );
for( i=0; i<amount; ++i ) {
ot_hash *hash = hash_list + i;
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 ) {
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_list->seed_count, torrent->peer_list->down_count, torrent->peer_list->peer_count-torrent->peer_list->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( ot_hash hash, ot_peer *peer, char *reply, PROTO_FLAG proto ) {
int exactmatch;
size_t reply_size = 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 );
ot_peerlist *peer_list = &dummy_list;
#ifdef WANT_SYNC_LIVE
if( proto != FLAG_MCA ) {
OT_PEERFLAG( peer ) |= PEER_FLAG_STOPPED;
livesync_tell( hash, peer );
}
#endif
if( exactmatch ) {
peer_list = torrent->peer_list;
switch( vector_remove_peer( &peer_list->peers, peer ) ) {
case 2: peer_list->seed_count--; /* Fall throughs intended */
case 1: peer_list->peer_count--; /* Fall throughs intended */
default: break;
}
}
if( proto == FLAG_TCP ) {
int erval = OT_CLIENT_REQUEST_INTERVAL_RANDOM;
reply_size = sprintf( reply, "d8:completei%zde10:incompletei%zde8:intervali%ie12:min intervali%ie" PEERS_BENCODED "0:e", peer_list->seed_count, peer_list->peer_count - peer_list->seed_count, erval, erval / 2 );
}
/* Handle UDP reply */
if( proto == FLAG_UDP ) {
((uint32_t*)reply)[2] = htonl( OT_CLIENT_REQUEST_INTERVAL_RANDOM );
((uint32_t*)reply)[3] = htonl( peer_list->peer_count - peer_list->seed_count );
((uint32_t*)reply)[4] = htonl( peer_list->seed_count);
reply_size = 20;
}
mutex_bucket_unlock_by_hash( hash, 0 );
return reply_size;
}
void exerr( char * message ) {
fprintf( stderr, "%s\n", message );
exit( 111 );
}
void trackerlogic_init( ) {
srandom( time(NULL) );
g_tracker_id = random();
/* 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; bucket<OT_BUCKET_COUNT; ++bucket ) {
ot_vector *torrents_list = mutex_bucket_lock( bucket );
if( torrents_list->size ) {
for( j=0; j<torrents_list->size; ++j ) {
ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + j;
free_peerlist( torrent->peer_list );
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: /home/cvsroot/opentracker/trackerlogic.c,v $: $Revision: 1.125 $\n";