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opentracker – An open and free bittorrent tracker
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opentracker/proxy.c

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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 <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <pwd.h>
#include <ctype.h>
#include <pthread.h>
/* Libowfat */
#include "socket.h"
#include "io.h"
#include "iob.h"
#include "byte.h"
#include "scan.h"
#include "ip6.h"
#include "ndelay.h"
/* Opentracker */
#include "trackerlogic.h"
#include "ot_vector.h"
#include "ot_mutex.h"
#include "ot_stats.h"
#ifndef WANT_SYNC_LIVE
#define WANT_SYNC_LIVE
#endif
#include "ot_livesync.h"
ot_ip6 g_serverip;
uint16_t g_serverport = 9009;
uint32_t g_tracker_id;
char groupip_1[4] = { 224,0,23,5 };
int g_self_pipe[2];
/* If you have more than 10 peers, don't use this proxy
Use 20 slots for 10 peers to have room for 10 incoming connection slots
*/
#define MAX_PEERS 20
#define LIVESYNC_INCOMING_BUFFSIZE (256*256)
#define STREAMSYNC_OUTGOING_BUFFSIZE (256*256)
#define LIVESYNC_OUTGOING_BUFFSIZE_PEERS 1480
#define LIVESYNC_OUTGOING_WATERMARK_PEERS (sizeof(ot_peer)+sizeof(ot_hash))
#define LIVESYNC_MAXDELAY 15 /* seconds */
/* The amount of time a complete sync cycle should take */
#define OT_SYNC_INTERVAL_MINUTES 2
/* So after each bucket wait 1 / OT_BUCKET_COUNT intervals */
#define OT_SYNC_SLEEP ( ( ( OT_SYNC_INTERVAL_MINUTES ) * 60 * 1000000 ) / ( OT_BUCKET_COUNT ) )
enum { OT_SYNC_PEER4, OT_SYNC_PEER6 };
enum { FLAG_SERVERSOCKET = 1 };
/* For incoming packets */
static int64 g_socket_in = -1;
static uint8_t g_inbuffer[LIVESYNC_INCOMING_BUFFSIZE];
/* For outgoing packets */
static int64 g_socket_out = -1;
static uint8_t g_peerbuffer_start[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
static uint8_t *g_peerbuffer_pos;
static uint8_t *g_peerbuffer_highwater = g_peerbuffer_start + LIVESYNC_OUTGOING_BUFFSIZE_PEERS - LIVESYNC_OUTGOING_WATERMARK_PEERS;
static ot_time g_next_packet_time;
static void * livesync_worker( void * args );
static void * streamsync_worker( void * args );
static void livesync_proxytell( uint8_t prefix, uint8_t *info_hash, uint8_t *peer );
void exerr( char * message ) {
fprintf( stderr, "%s\n", message );
exit( 111 );
}
void stats_issue_event( ot_status_event event, PROTO_FLAG proto, uintptr_t event_data ) {
(void) event;
(void) proto;
(void) event_data;
}
void livesync_bind_mcast( ot_ip6 ip, uint16_t port) {
char tmpip[4] = {0,0,0,0};
char *v4ip;
if( !ip6_isv4mapped(ip))
exerr("v6 mcast support not yet available.");
v4ip = ip+12;
if( g_socket_in != -1 )
exerr("Error: Livesync listen ip specified twice.");
if( ( g_socket_in = socket_udp4( )) < 0)
exerr("Error: Cant create live sync incoming socket." );
ndelay_off(g_socket_in);
if( socket_bind4_reuse( g_socket_in, tmpip, port ) == -1 )
exerr("Error: Cant bind live sync incoming socket." );
if( socket_mcjoin4( g_socket_in, groupip_1, v4ip ) )
exerr("Error: Cant make live sync incoming socket join mcast group.");
if( ( g_socket_out = socket_udp4()) < 0)
exerr("Error: Cant create live sync outgoing socket." );
if( socket_bind4_reuse( g_socket_out, v4ip, port ) == -1 )
exerr("Error: Cant bind live sync outgoing socket." );
socket_mcttl4(g_socket_out, 1);
socket_mcloop4(g_socket_out, 1);
}
size_t add_peer_to_torrent_proxy( ot_hash hash, ot_peer *peer, size_t peer_size ) {
int exactmatch;
ot_torrent *torrent;
ot_peerlist *peer_list;
ot_peer *peer_dest;
ot_vector *torrents_list = mutex_bucket_lock_by_hash( hash );
size_t compare_size = OT_PEER_COMPARE_SIZE_FROM_PEER_SIZE(peer_size);
torrent = vector_find_or_insert( torrents_list, (void*)hash, sizeof( ot_torrent ), compare_size, &exactmatch );
if( !torrent )
return -1;
if( !exactmatch ) {
/* Create a new torrent entry, then */
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 );
mutex_bucket_unlock_by_hash( hash, 0 );
return -1;
}
byte_zero( torrent->peer_list6, sizeof( ot_peerlist ) );
byte_zero( torrent->peer_list4, sizeof( ot_peerlist ) );
}
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, peer_size, &exactmatch );
if( !peer_dest ) {
mutex_bucket_unlock_by_hash( hash, 0 );
return -1;
}
/* Tell peer that it's fresh */
OT_PEERTIME( peer, peer_size ) = 0;
/* If we hadn't had a match create peer there */
if( !exactmatch ) {
peer_list->peer_count++;
if( OT_PEERFLAG_D(peer, peer_size) & PEER_FLAG_SEEDING )
peer_list->seed_count++;
}
memcpy( peer_dest, peer, peer_size );
mutex_bucket_unlock_by_hash( hash, 0 );
return 0;
}
size_t remove_peer_from_torrent_proxy( ot_hash hash, ot_peer *peer, size_t peer_size ) {
int exactmatch;
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 ) {
ot_peerlist *peer_list = peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4;
switch( vector_remove_peer( &peer_list->peers, peer, peer_size ) ) {
case 2: peer_list->seed_count--; /* Intentional fallthrough */
case 1: peer_list->peer_count--; /* Intentional fallthrough */
default: break;
}
}
mutex_bucket_unlock_by_hash( hash, 0 );
return 0;
}
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 );
}
static void livesync_handle_peersync( ssize_t datalen, size_t peer_size ) {
int off = sizeof( g_tracker_id ) + sizeof( uint32_t );
fprintf( stderr, "." );
while( (ssize_t)(off + sizeof( ot_hash ) + peer_size) <= datalen ) {
ot_peer *peer = (ot_peer*)(g_inbuffer + off + sizeof(ot_hash));
ot_hash *hash = (ot_hash*)(g_inbuffer + off);
if( OT_PEERFLAG_D(peer, peer_size) & PEER_FLAG_STOPPED )
remove_peer_from_torrent_proxy( *hash, peer, peer_size );
else
add_peer_to_torrent_proxy( *hash, peer, peer_size );
off += sizeof( ot_hash ) + peer_size;
}
}
int usage( char *self ) {
fprintf( stderr, "Usage: %s -L <livesync_iface_ip> -l <listenip>:<listenport> -c <connectip>:<connectport>\n", self );
return 0;
}
enum {
FLAG_OUTGOING = 0x80,
FLAG_DISCONNECTED = 0x00,
FLAG_CONNECTING = 0x01,
FLAG_WAITTRACKERID = 0x02,
FLAG_CONNECTED = 0x03,
FLAG_MASK = 0x07
};
#define PROXYPEER_NEEDSCONNECT(flag) ((flag)==FLAG_OUTGOING)
#define PROXYPEER_ISCONNECTED(flag) (((flag)&FLAG_MASK)==FLAG_CONNECTED)
#define PROXYPEER_SETDISCONNECTED(flag) (flag)=(((flag)&FLAG_OUTGOING)|FLAG_DISCONNECTED)
#define PROXYPEER_SETCONNECTING(flag) (flag)=(((flag)&FLAG_OUTGOING)|FLAG_CONNECTING)
#define PROXYPEER_SETWAITTRACKERID(flag) (flag)=(((flag)&FLAG_OUTGOING)|FLAG_WAITTRACKERID)
#define PROXYPEER_SETCONNECTED(flag) (flag)=(((flag)&FLAG_OUTGOING)|FLAG_CONNECTED)
typedef struct {
int state; /* Whether we want to connect, how far our handshake is, etc. */
ot_ip6 ip; /* The peer to connect to */
uint16_t port; /* The peers port */
uint8_t indata[8192*16]; /* Any data not processed yet */
size_t indata_length; /* Length of unprocessed data */
uint32_t tracker_id; /* How the other end greeted */
int64 fd; /* A file handle, if connected, <= 0 is disconnected (0 initially, -1 else) */
io_batch outdata; /* The iobatch containing our sync data */
size_t packet_tcount; /* Number of unprocessed torrents in packet we currently receive */
uint8_t packet_tprefix; /* Prefix byte for all torrents in current packet */
uint8_t packet_type; /* Type of current packet */
uint32_t packet_tid; /* Tracker id for current packet */
} proxy_peer;
static void process_indata( proxy_peer * peer );
void reset_info_block( proxy_peer * peer ) {
peer->indata_length = 0;
peer->tracker_id = 0;
peer->fd = -1;
peer->packet_tcount = 0;
iob_reset( &peer->outdata );
PROXYPEER_SETDISCONNECTED( peer->state );
}
/* Number of connections to peers
* If a peer's IP is set, we try to reconnect, when the connection drops
* If we already have a connected tracker_id in our records for an _incoming_ connection, drop it
* Multiple connections to/from the same ip are okay, if tracker_id doesn't match
* Reconnect attempts occur only twice a minute
*/
static int g_connection_count;
static ot_time g_connection_reconn;
static proxy_peer g_connections[MAX_PEERS];
static void handle_reconnects( void ) {
int i;
for( i=0; i<g_connection_count; ++i )
if( PROXYPEER_NEEDSCONNECT( g_connections[i].state ) ) {
int64 newfd = socket_tcp6( );
fprintf( stderr, "(Re)connecting to peer..." );
if( newfd < 0 ) continue; /* No socket for you */
io_fd(newfd);
if( socket_bind6_reuse(newfd,g_serverip,g_serverport,0) ) {
io_close( newfd );
continue;
}
if( socket_connect6(newfd,g_connections[i].ip,g_connections[i].port,0) == -1 &&
errno != EINPROGRESS && errno != EWOULDBLOCK ) {
close(newfd);
continue;
}
io_wantwrite(newfd); /* So we will be informed when it is connected */
io_setcookie(newfd,g_connections+i);
/* Prepare connection info block */
reset_info_block( g_connections+i );
g_connections[i].fd = newfd;
PROXYPEER_SETCONNECTING( g_connections[i].state );
}
g_connection_reconn = time(NULL) + 30;
}
/* Handle incoming connection requests, check against whitelist */
static void handle_accept( int64 serversocket ) {
int64 newfd;
ot_ip6 ip;
uint16 port;
while( ( newfd = socket_accept6( serversocket, ip, &port, NULL ) ) != -1 ) {
/* XXX some access control */
/* Put fd into a non-blocking mode */
io_nonblock( newfd );
if( !io_fd( newfd ) )
io_close( newfd );
else {
/* Find a new home for our incoming connection */
int i;
for( i=0; i<MAX_PEERS; ++i )
if( g_connections[i].state == FLAG_DISCONNECTED )
break;
if( i == MAX_PEERS ) {
fprintf( stderr, "No room for incoming connection." );
close( newfd );
continue;
}
/* Prepare connection info block */
reset_info_block( g_connections+i );
PROXYPEER_SETCONNECTING( g_connections[i].state );
g_connections[i].port = port;
g_connections[i].fd = newfd;
io_setcookie( newfd, g_connections + i );
/* We expect the connecting side to begin with its tracker_id */
io_wantread( newfd );
}
}
return;
}
/* New sync data on the stream */
static void handle_read( int64 peersocket ) {
int i;
int64 datalen;
uint32_t tracker_id;
proxy_peer *peer = io_getcookie( peersocket );
if( !peer ) {
/* Can't happen ;) */
io_close( peersocket );
return;
}
switch( peer->state & FLAG_MASK ) {
case FLAG_DISCONNECTED:
io_close( peersocket );
break; /* Shouldnt happen */
case FLAG_CONNECTING:
case FLAG_WAITTRACKERID:
/* We want at least the first four bytes to come at once, to avoid keeping extra states (for now)
This also catches 0 bytes reads == EOF and negative values, denoting connection errors */
if( io_tryread( peersocket, (void*)&tracker_id, sizeof( tracker_id ) ) != sizeof( tracker_id ) )
goto close_socket;
/* See, if we already have a connection to that peer */
for( i=0; i<MAX_PEERS; ++i )
if( ( g_connections[i].state & FLAG_MASK ) == FLAG_CONNECTED &&
g_connections[i].tracker_id == tracker_id ) {
fprintf( stderr, "Peer already connected. Closing connection.\n" );
goto close_socket;
}
/* Also no need for soliloquy */
if( tracker_id == g_tracker_id )
goto close_socket;
/* The new connection is good, send our tracker_id on incoming connections */
if( peer->state == FLAG_CONNECTING )
if( io_trywrite( peersocket, (void*)&g_tracker_id, sizeof( g_tracker_id ) ) != sizeof( g_tracker_id ) )
goto close_socket;
peer->tracker_id = tracker_id;
PROXYPEER_SETCONNECTED( peer->state );
if( peer->state & FLAG_OUTGOING )
fprintf( stderr, "succeeded.\n" );
else
fprintf( stderr, "Incoming connection successful.\n" );
break;
close_socket:
fprintf( stderr, "Handshake incomplete, closing socket\n" );
io_close( peersocket );
reset_info_block( peer );
break;
case FLAG_CONNECTED:
/* Here we acutally expect data from peer
indata_length should be less than 20+256*7 bytes, for incomplete torrent entries */
datalen = io_tryread( peersocket, (void*)(peer->indata + peer->indata_length), sizeof( peer->indata ) - peer->indata_length );
if( !datalen || datalen < -1 ) {
fprintf( stderr, "Connection closed by remote peer.\n" );
io_close( peersocket );
reset_info_block( peer );
} else if( datalen > 0 ) {
peer->indata_length += datalen;
process_indata( peer );
}
break;
}
}
/* Can write new sync data to the stream */
static void handle_write( int64 peersocket ) {
proxy_peer *peer = io_getcookie( peersocket );
if( !peer ) {
/* Can't happen ;) */
io_close( peersocket );
return;
}
switch( peer->state & FLAG_MASK ) {
case FLAG_DISCONNECTED:
default: /* Should not happen */
io_close( peersocket );
break;
case FLAG_CONNECTING:
/* Ensure that the connection is established and handle connection error */
if( peer->state & FLAG_OUTGOING && !socket_connected( peersocket ) ) {
fprintf( stderr, "failed\n" );
reset_info_block( peer );
io_close( peersocket );
break;
}
if( io_trywrite( peersocket, (void*)&g_tracker_id, sizeof( g_tracker_id ) ) == sizeof( g_tracker_id ) ) {
PROXYPEER_SETWAITTRACKERID( peer->state );
io_dontwantwrite( peersocket );
io_wantread( peersocket );
} else {
fprintf( stderr, "Handshake incomplete, closing socket\n" );
io_close( peersocket );
reset_info_block( peer );
}
break;
case FLAG_CONNECTED:
switch( iob_send( peersocket, &peer->outdata ) ) {
case 0: /* all data sent */
io_dontwantwrite( peersocket );
break;
case -3: /* an error occured */
io_close( peersocket );
reset_info_block( peer );
break;
default: /* Normal operation or eagain */
break;
}
break;
}
return;
}
static void server_mainloop() {
int64 sock;
/* inlined livesync_init() */
memset( g_peerbuffer_start, 0, sizeof( g_peerbuffer_start ) );
g_peerbuffer_pos = g_peerbuffer_start;
memcpy( g_peerbuffer_pos, &g_tracker_id, sizeof( g_tracker_id ) );
uint32_pack_big( (char*)g_peerbuffer_pos + sizeof( g_tracker_id ), OT_SYNC_PEER);
g_peerbuffer_pos += sizeof( g_tracker_id ) + sizeof( uint32_t);
g_next_packet_time = time(NULL) + LIVESYNC_MAXDELAY;
while(1) {
/* See if we need to connect to anyone */
if( time(NULL) > g_connection_reconn )
handle_reconnects( );
/* Wait for io events until next approx reconn check time */
io_waituntil2( 30*1000 );
/* Loop over readable sockets */
while( ( sock = io_canread( ) ) != -1 ) {
const void *cookie = io_getcookie( sock );
if( (uintptr_t)cookie == FLAG_SERVERSOCKET )
handle_accept( sock );
else
handle_read( sock );
}
/* Loop over writable sockets */
while( ( sock = io_canwrite( ) ) != -1 )
handle_write( sock );
livesync_ticker( );
}
}
static void panic( const char *routine ) {
fprintf( stderr, "%s: %s\n", routine, strerror(errno) );
exit( 111 );
}
static int64_t ot_try_bind( ot_ip6 ip, uint16_t port ) {
int64 sock = socket_tcp6( );
if( socket_bind6_reuse( sock, ip, port, 0 ) == -1 )
panic( "socket_bind6_reuse" );
if( socket_listen( sock, SOMAXCONN) == -1 )
panic( "socket_listen" );
if( !io_fd( sock ) )
panic( "io_fd" );
io_setcookie( sock, (void*)FLAG_SERVERSOCKET );
io_wantread( sock );
return sock;
}
static int scan_ip6_port( const char *src, ot_ip6 ip, uint16 *port ) {
const char *s = src;
int off, bracket = 0;
while( isspace(*s) ) ++s;
if( *s == '[' ) ++s, ++bracket; /* for v6 style notation */
if( !(off = scan_ip6( s, ip ) ) )
return 0;
s += off;
if( *s == 0 || isspace(*s)) return s-src;
if( *s == ']' && bracket ) ++s;
if( !ip6_isv4mapped(ip)){
if( ( bracket && *(s) != ':' ) || ( *(s) != '.' ) ) return 0;
s++;
} else {
if( *(s++) != ':' ) return 0;
}
if( !(off = scan_ushort (s, port ) ) )
return 0;
return off+s-src;
}
int main( int argc, char **argv ) {
static pthread_t sync_in_thread_id;
static pthread_t sync_out_thread_id;
ot_ip6 serverip;
uint16_t tmpport;
int scanon = 1, lbound = 0, sbound = 0;
srandom( time(NULL) );
#ifdef WANT_ARC4RANDOM
g_tracker_id = arc4random();
#else
g_tracker_id = random();
#endif
while( scanon ) {
switch( getopt( argc, argv, ":l:c:L:h" ) ) {
case -1: scanon = 0; break;
case 'l':
tmpport = 0;
if( !scan_ip6_port( optarg, serverip, &tmpport ) || !tmpport ) { usage( argv[0] ); exit( 1 ); }
ot_try_bind( serverip, tmpport );
++sbound;
break;
case 'c':
if( g_connection_count > MAX_PEERS / 2 ) exerr( "Connection limit exceeded.\n" );
tmpport = 0;
if( !scan_ip6_port( optarg,
g_connections[g_connection_count].ip,
&g_connections[g_connection_count].port ) ||
!g_connections[g_connection_count].port ) { usage( argv[0] ); exit( 1 ); }
g_connections[g_connection_count++].state = FLAG_OUTGOING;
break;
case 'L':
tmpport = 9696;
if( !scan_ip6_port( optarg, serverip, &tmpport ) || !tmpport ) { usage( argv[0] ); exit( 1 ); }
livesync_bind_mcast( serverip, tmpport); ++lbound; break;
default:
case '?': usage( argv[0] ); exit( 1 );
}
}
if( !lbound ) exerr( "No livesync port bound." );
if( !g_connection_count && !sbound ) exerr( "No streamsync port bound." );
pthread_create( &sync_in_thread_id, NULL, livesync_worker, NULL );
pthread_create( &sync_out_thread_id, NULL, streamsync_worker, NULL );
server_mainloop();
return 0;
}
static void * streamsync_worker( void * args ) {
(void)args;
while( 1 ) {
int bucket;
/* For each bucket... */
for( bucket=0; bucket<OT_BUCKET_COUNT; ++bucket ) {
/* Get exclusive access to that bucket */
ot_vector *torrents_list = mutex_bucket_lock( bucket );
size_t tor_offset, count_def = 0, count_one = 0, count_two = 0, count_peers = 0;
size_t mem, mem_a = 0, mem_b = 0;
uint8_t *ptr = 0, *ptr_a, *ptr_b, *ptr_c;
if( !torrents_list->size ) goto unlock_continue;
/* For each torrent in this bucket.. */
for( tor_offset=0; tor_offset<torrents_list->size; ++tor_offset ) {
/* Address torrents members */
ot_peerlist *peer_list = ( ((ot_torrent*)(torrents_list->data))[tor_offset] ).peer_list;
switch( peer_list->peer_count ) {
case 2: count_two++; break;
case 1: count_one++; break;
case 0: break;
default: count_def++;
count_peers += peer_list->peer_count;
}
}
/* Maximal memory requirement: max 3 blocks, max torrents * 20 + max peers * 7 */
mem = 3 * ( 1 + 1 + 2 ) + ( count_one + count_two ) * ( 19 + 1 ) + count_def * ( 19 + 8 ) +
( count_one + 2 * count_two + count_peers ) * 7;
fprintf( stderr, "Mem: %zd\n", mem );
ptr = ptr_a = ptr_b = ptr_c = malloc( mem );
if( !ptr ) goto unlock_continue;
if( count_one > 4 || !count_def ) {
mem_a = 1 + 1 + 2 + count_one * ( 19 + 7 );
ptr_b += mem_a; ptr_c += mem_a;
ptr_a[0] = 1; /* Offset 0: packet type 1 */
ptr_a[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_a[2] = count_one >> 8;
ptr_a[3] = count_one & 255;
ptr_a += 4;
} else
count_def += count_one;
if( count_two > 4 || !count_def ) {
mem_b = 1 + 1 + 2 + count_two * ( 19 + 14 );
ptr_c += mem_b;
ptr_b[0] = 2; /* Offset 0: packet type 2 */
ptr_b[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_b[2] = count_two >> 8;
ptr_b[3] = count_two & 255;
ptr_b += 4;
} else
count_def += count_two;
if( count_def ) {
ptr_c[0] = 0; /* Offset 0: packet type 0 */
ptr_c[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_c[2] = count_def >> 8;
ptr_c[3] = count_def & 255;
ptr_c += 4;
}
/* For each torrent in this bucket.. */
for( tor_offset=0; tor_offset<torrents_list->size; ++tor_offset ) {
/* Address torrents members */
ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + tor_offset;
ot_peerlist *peer_list = torrent->peer_list;
ot_peer *peers = (ot_peer*)(peer_list->peers.data);
uint8_t **dst;
/* Determine destination slot */
count_peers = peer_list->peer_count;
switch( count_peers ) {
case 0: continue;
case 1: dst = mem_a ? &ptr_a : &ptr_c; break;
case 2: dst = mem_b ? &ptr_b : &ptr_c; break;
default: dst = &ptr_c; break;
}
/* Copy tail of info_hash, advance pointer */
memcpy( *dst, ((uint8_t*)torrent->hash) + 1, sizeof( ot_hash ) - 1);
*dst += sizeof( ot_hash ) - 1;
/* Encode peer count */
if( dst == &ptr_c )
while( count_peers ) {
if( count_peers <= 0x7f )
*(*dst)++ = count_peers;
else
*(*dst)++ = 0x80 | ( count_peers & 0x7f );
count_peers >>= 7;
}
/* Copy peers */
count_peers = peer_list->peer_count;
while( count_peers-- ) {
memcpy( *dst, peers++, OT_IP_SIZE + 3 );
*dst += OT_IP_SIZE + 3;
}
free_peerlist(peer_list);
}
free( torrents_list->data );
memset( torrents_list, 0, sizeof(*torrents_list ) );
unlock_continue:
mutex_bucket_unlock( bucket, 0 );
if( ptr ) {
int i;
if( ptr_b > ptr_c ) ptr_c = ptr_b;
if( ptr_a > ptr_c ) ptr_c = ptr_a;
mem = ptr_c - ptr;
for( i=0; i < MAX_PEERS; ++i ) {
if( PROXYPEER_ISCONNECTED(g_connections[i].state) ) {
void *tmp = malloc( mem );
if( tmp ) {
memcpy( tmp, ptr, mem );
iob_addbuf_free( &g_connections[i].outdata, tmp, mem );
io_wantwrite( g_connections[i].fd );
}
}
}
free( ptr );
}
usleep( OT_SYNC_SLEEP );
}
}
return 0;
}
static void livesync_issue_peersync( ) {
socket_send4(g_socket_out, (char*)g_peerbuffer_start, g_peerbuffer_pos - g_peerbuffer_start,
groupip_1, LIVESYNC_PORT);
g_peerbuffer_pos = g_peerbuffer_start + sizeof( g_tracker_id ) + sizeof( uint32_t );
g_next_packet_time = time(NULL) + LIVESYNC_MAXDELAY;
}
void livesync_ticker( ) {
/* livesync_issue_peersync sets g_next_packet_time */
if( time(NULL) > g_next_packet_time &&
g_peerbuffer_pos > g_peerbuffer_start + sizeof( g_tracker_id ) )
livesync_issue_peersync();
}
static void livesync_proxytell( uint8_t prefix, uint8_t *info_hash, uint8_t *peer ) {
// unsigned int i;
*g_peerbuffer_pos = prefix;
memcpy( g_peerbuffer_pos + 1, info_hash, sizeof(ot_hash) - 1 );
memcpy( g_peerbuffer_pos + sizeof(ot_hash), peer, sizeof(ot_peer) - 1 );
#if 0
/* Dump info_hash */
for( i=0; i<sizeof(ot_hash); ++i )
printf( "%02X", g_peerbuffer_pos[i] );
putchar( ':' );
#endif
g_peerbuffer_pos += sizeof(ot_hash);
#if 0
printf( "%hhu.%hhu.%hhu.%hhu:%hu (%02X %02X)\n", g_peerbuffer_pos[0], g_peerbuffer_pos[1], g_peerbuffer_pos[2], g_peerbuffer_pos[3],
g_peerbuffer_pos[4] | ( g_peerbuffer_pos[5] << 8 ), g_peerbuffer_pos[6], g_peerbuffer_pos[7] );
#endif
g_peerbuffer_pos += sizeof(ot_peer);
if( g_peerbuffer_pos >= g_peerbuffer_highwater )
livesync_issue_peersync();
}
static void process_indata( proxy_peer * peer ) {
size_t consumed, peers;
uint8_t *data = peer->indata, *hash;
uint8_t *dataend = data + peer->indata_length;
while( 1 ) {
/* If we're not inside of a packet, make a new one */
if( !peer->packet_tcount ) {
/* Ensure the header is complete or postpone processing */
if( data + 4 > dataend ) break;
peer->packet_type = data[0];
peer->packet_tprefix = data[1];
peer->packet_tcount = data[2] * 256 + data[3];
data += 4;
printf( "type: %hhu, prefix: %02X, torrentcount: %zd\n", peer->packet_type, peer->packet_tprefix, peer->packet_tcount );
}
/* Ensure size for a minimal torrent block */
if( data + sizeof(ot_hash) + OT_IP_SIZE + 3 > dataend ) break;
/* Advance pointer to peer count or peers */
hash = data;
data += sizeof(ot_hash) - 1;
/* Type 0 has peer count encoded before each peers */
peers = peer->packet_type;
if( !peers ) {
int shift = 0;
do peers |= ( 0x7f & *data ) << ( 7 * shift );
while ( *(data++) & 0x80 && shift++ < 6 );
}
#if 0
printf( "peers: %zd\n", peers );
#endif
/* Ensure enough data being read to hold all peers */
if( data + (OT_IP_SIZE + 3) * peers > dataend ) {
data = hash;
break;
}
while( peers-- ) {
livesync_proxytell( peer->packet_tprefix, hash, data );
data += OT_IP_SIZE + 3;
}
--peer->packet_tcount;
}
consumed = data - peer->indata;
memmove( peer->indata, data, peer->indata_length - consumed );
peer->indata_length -= consumed;
}
static void * livesync_worker( void * args ) {
(void)args;
while( 1 ) {
ot_ip6 in_ip; uint16_t in_port;
size_t datalen = socket_recv4(g_socket_in, (char*)g_inbuffer, LIVESYNC_INCOMING_BUFFSIZE, 12+(char*)in_ip, &in_port);
/* Expect at least tracker id and packet type */
if( datalen <= (ssize_t)(sizeof( g_tracker_id ) + sizeof( uint32_t )) )
continue;
if( !memcmp( g_inbuffer, &g_tracker_id, sizeof( g_tracker_id ) ) ) {
/* drop packet coming from ourselves */
continue;
}
switch( uint32_read_big( (char*)g_inbuffer + sizeof( g_tracker_id ) ) ) {
case OT_SYNC_PEER4:
livesync_handle_peersync( datalen, OT_PEER_SIZE4 );
break;
case OT_SYNC_PEER6:
livesync_handle_peersync( datalen, OT_PEER_SIZE6 );
break;
default:
// fprintf( stderr, "Received an unknown live sync packet type %u.\n", uint32_read_big( sizeof( g_tracker_id ) + (char*)g_inbuffer ) );
break;
}
}
return 0;
}