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 <sys/types.h>
#include <sys/uio.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
/* Libowfat */
#include "socket.h"
#include "ndelay.h"
#include "byte.h"
#include "ip6.h"
/* Opentracker */
#include "trackerlogic.h"
#include "ot_livesync.h"
#include "ot_accesslist.h"
#include "ot_stats.h"
#include "ot_mutex.h"
#ifdef WANT_SYNC_LIVE
char groupip_1[4] = { 224,0,23,5 };
#define LIVESYNC_INCOMING_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 */
enum { OT_SYNC_PEER };
/* Forward declaration */
static void * livesync_worker( void * args );
/* For outgoing packets */
static int64 g_socket_in = -1;
/* For incoming packets */
static int64 g_socket_out = -1;
static pthread_mutex_t g_outbuf_mutex = PTHREAD_MUTEX_INITIALIZER;
char g_outbuf[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
static size_t g_outbuf_data;
static ot_time g_next_packet_time;
static pthread_t thread_id;
void livesync_init( ) {
if( g_socket_in == -1 )
exerr( "No socket address for live sync specified." );
/* Prepare outgoing peers buffer */
memcpy( g_outbuf, &g_tracker_id, sizeof( g_tracker_id ) );
uint32_pack_big( g_outbuf + sizeof( g_tracker_id ), OT_SYNC_PEER);
g_outbuf_data = sizeof( g_tracker_id ) + sizeof( uint32_t );
g_next_packet_time = g_now_seconds + LIVESYNC_MAXDELAY;
pthread_create( &thread_id, NULL, livesync_worker, NULL );
}
void livesync_deinit() {
if( g_socket_in != -1 )
close( g_socket_in );
if( g_socket_out != -1 )
close( g_socket_out );
pthread_cancel( thread_id );
}
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, 0);
}
/* Caller MUST hold g_outbuf_mutex. Returns with g_outbuf_mutex unlocked */
static void livesync_issue_peersync( ) {
char mycopy[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
size_t data = g_outbuf_data;
memcpy( mycopy, g_outbuf, data );
g_outbuf_data = sizeof( g_tracker_id ) + sizeof( uint32_t );
g_next_packet_time = g_now_seconds + LIVESYNC_MAXDELAY;
/* From now this thread has a local copy of the buffer and
has modified the protected element */
pthread_mutex_unlock(&g_outbuf_mutex);
socket_send4(g_socket_out, mycopy, data, groupip_1, LIVESYNC_PORT);
}
static void livesync_handle_peersync( struct ot_workstruct *ws ) {
int off = sizeof( g_tracker_id ) + sizeof( uint32_t );
/* Now basic sanity checks have been done on the live sync packet
We might add more testing and logging. */
while( off + (ssize_t)sizeof( ot_hash ) + (ssize_t)sizeof( ot_peer ) <= ws->request_size ) {
memcpy( &ws->peer, ws->request + off + sizeof(ot_hash), sizeof( ot_peer ) );
ws->hash = (ot_hash*)(ws->request + off);
if( !g_opentracker_running ) return;
if( OT_PEERFLAG(&ws->peer) & PEER_FLAG_STOPPED )
remove_peer_from_torrent( FLAG_MCA, ws );
else
add_peer_to_torrent_and_return_peers( FLAG_MCA, ws, /* amount = */ 0 );
off += sizeof( ot_hash ) + sizeof( ot_peer );
}
stats_issue_event(EVENT_SYNC, 0,
(ws->request_size - sizeof( g_tracker_id ) - sizeof( uint32_t ) ) /
((ssize_t)sizeof( ot_hash ) + (ssize_t)sizeof( ot_peer )));
}
/* Tickle the live sync module from time to time, so no events get
stuck when there's not enough traffic to fill udp packets fast
enough */
void livesync_ticker( ) {
/* livesync_issue_peersync sets g_next_packet_time */
pthread_mutex_lock(&g_outbuf_mutex);
if( g_now_seconds > g_next_packet_time &&
g_outbuf_data > sizeof( g_tracker_id ) + sizeof( uint32_t ) )
livesync_issue_peersync();
else
pthread_mutex_unlock(&g_outbuf_mutex);
}
/* Inform live sync about whats going on. */
void livesync_tell( struct ot_workstruct *ws ) {
pthread_mutex_lock(&g_outbuf_mutex);
memcpy( g_outbuf + g_outbuf_data, ws->hash, sizeof(ot_hash) );
memcpy( g_outbuf + g_outbuf_data + sizeof(ot_hash), &ws->peer, sizeof(ot_peer) );
g_outbuf_data += sizeof(ot_hash) + sizeof(ot_peer);
if( g_outbuf_data >= LIVESYNC_OUTGOING_BUFFSIZE_PEERS - LIVESYNC_OUTGOING_WATERMARK_PEERS )
livesync_issue_peersync();
else
pthread_mutex_unlock(&g_outbuf_mutex);
}
static void * livesync_worker( void * args ) {
struct ot_workstruct ws;
ot_ip6 in_ip; uint16_t in_port;
(void)args;
/* Initialize our "thread local storage" */
ws.inbuf = ws.request = malloc( LIVESYNC_INCOMING_BUFFSIZE );
ws.outbuf = ws.reply = 0;
memcpy( in_ip, V4mappedprefix, sizeof( V4mappedprefix ) );
while( 1 ) {
ws.request_size = socket_recv4(g_socket_in, (char*)ws.inbuf, LIVESYNC_INCOMING_BUFFSIZE, 12+(char*)in_ip, &in_port);
/* Expect at least tracker id and packet type */
if( ws.request_size <= (ssize_t)(sizeof( g_tracker_id ) + sizeof( uint32_t )) )
continue;
if( !accesslist_isblessed(in_ip, OT_PERMISSION_MAY_LIVESYNC))
continue;
if( !memcmp( ws.inbuf, &g_tracker_id, sizeof( g_tracker_id ) ) ) {
/* TODO: log packet coming from ourselves */
continue;
}
switch( uint32_read_big( sizeof( g_tracker_id ) + (char *)ws.inbuf ) ) {
case OT_SYNC_PEER:
livesync_handle_peersync( &ws );
break;
default:
break;
}
}
/* Never returns. */
return NULL;
}
#endif
const char *g_version_livesync_c = "$Source: /home/cvsroot/opentracker/ot_livesync.c,v $: $Revision: 1.20 $\n";