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transmission/libtransmission/tracker.c
Eric Petit 7449c80d67 Should fix a race condition
2006-04-07 20:17:40 +00:00

686 lines
16 KiB
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/******************************************************************************
* Copyright (c) 2005 Eric Petit
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include "transmission.h"
struct tr_tracker_s
{
tr_torrent_t * tor;
char * id;
char started;
char completed;
char stopped;
int interval;
int seeders;
int leechers;
int hasManyPeers;
uint64_t dateTry;
uint64_t dateOk;
#define TC_STATUS_IDLE 1
#define TC_STATUS_RESOLVE 2
#define TC_STATUS_CONNECT 4
#define TC_STATUS_RECV 8
char status;
tr_resolve_t * resolve;
int socket;
uint8_t * buf;
int size;
int pos;
int bindPort;
int newPort;
uint64_t download;
uint64_t upload;
};
static void sendQuery ( tr_tracker_t * tc );
static void recvAnswer ( tr_tracker_t * tc );
tr_tracker_t * tr_trackerInit( tr_torrent_t * tor )
{
tr_tracker_t * tc;
tc = calloc( 1, sizeof( tr_tracker_t ) );
tc->tor = tor;
tc->id = tor->id;
tc->started = 1;
tc->seeders = -1;
tc->leechers = -1;
tc->status = TC_STATUS_IDLE;
tc->size = 1024;
tc->buf = malloc( tc->size );
tc->bindPort = *(tor->bindPort);
tc->newPort = -1;
tc->download = tor->downloaded;
tc->upload = tor->uploaded;
return tc;
}
static int shouldConnect( tr_tracker_t * tc )
{
uint64_t now = tr_date();
/* In any case, always wait 5 seconds between two requests */
if( now < tc->dateTry + 5000 )
{
return 0;
}
/* Do we need to send an event? */
if( tc->started || tc->completed || tc->stopped || 0 < tc->newPort )
{
return 1;
}
/* Should we try and get more peers? */
if( now > tc->dateOk + 1000 * tc->interval )
{
return 1;
}
/* If there is quite a lot of people on this torrent, stress
the tracker a bit until we get a decent number of peers */
if( tc->hasManyPeers )
{
if( tc->tor->peerCount < 5 && now > tc->dateOk + 10000 )
{
return 1;
}
if( tc->tor->peerCount < 10 && now > tc->dateOk + 20000 )
{
return 1;
}
if( tc->tor->peerCount < 15 && now > tc->dateOk + 30000 )
{
return 1;
}
}
return 0;
}
void tr_trackerChangePort( tr_tracker_t * tc, int port )
{
tc->newPort = port;
}
int tr_trackerPulse( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
tr_info_t * inf = &tor->info;
uint64_t now = tr_date();
if( ( tc->status & TC_STATUS_IDLE ) && shouldConnect( tc ) )
{
tc->resolve = tr_netResolveInit( inf->trackerAddress );
tr_inf( "Tracker: connecting to %s:%d (%s)",
inf->trackerAddress, inf->trackerPort,
tc->started ? "sending 'started'" :
( tc->completed ? "sending 'completed'" :
( tc->stopped ? "sending 'stopped'" :
( 0 < tc->newPort ? "sending 'stopped' to change port" :
"getting peers" ) ) ) );
tc->status = TC_STATUS_RESOLVE;
tc->dateTry = tr_date();
}
if( tc->status & TC_STATUS_RESOLVE )
{
int ret;
struct in_addr addr;
ret = tr_netResolvePulse( tc->resolve, &addr );
if( ret == TR_RESOLVE_WAIT )
{
return 0;
}
else
{
tr_netResolveClose( tc->resolve );
}
if( ret == TR_RESOLVE_ERROR )
{
tc->status = TC_STATUS_IDLE;
return 0;
}
if( tr_fdSocketWillCreate( tor->fdlimit, 1 ) )
{
return 0;
}
tc->socket = tr_netOpen( addr, htons( inf->trackerPort ) );
if( tc->socket < 0 )
{
tr_fdSocketClosed( tor->fdlimit, 1 );
return 0;
}
tc->status = TC_STATUS_CONNECT;
}
if( tc->status & TC_STATUS_CONNECT )
{
/* We are connecting to the tracker. Try to send the query */
sendQuery( tc );
}
if( tc->status & TC_STATUS_RECV )
{
/* Try to get something */
recvAnswer( tc );
}
if( tc->status > TC_STATUS_IDLE && now > tc->dateTry + 60000 )
{
/* Give up if the request wasn't successful within 60 seconds */
tr_inf( "Tracker: timeout reached (60 s)" );
tr_netClose( tc->socket );
tr_fdSocketClosed( tor->fdlimit, 1 );
tc->status = TC_STATUS_IDLE;
tc->dateTry = tr_date();
}
return 0;
}
void tr_trackerCompleted( tr_tracker_t * tc )
{
tc->started = 0;
tc->completed = 1;
tc->stopped = 0;
}
void tr_trackerStopped( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
if( tc->status > TC_STATUS_CONNECT )
{
/* If we are already sendy a query at the moment, we need to
reconnect */
tr_netClose( tc->socket );
tr_fdSocketClosed( tor->fdlimit, 1 );
tc->status = TC_STATUS_IDLE;
}
tc->started = 0;
tc->completed = 0;
tc->stopped = 1;
/* Even if we have connected recently, reconnect right now */
if( tc->status & TC_STATUS_IDLE )
{
tc->dateTry = 0;
}
}
void tr_trackerClose( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
if( tc->status > TC_STATUS_IDLE )
{
tr_netClose( tc->socket );
tr_fdSocketClosed( tor->fdlimit, 1 );
}
free( tc->buf );
free( tc );
}
static void sendQuery( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
tr_info_t * inf = &tor->info;
char * event;
uint64_t left;
int ret;
uint64_t down;
uint64_t up;
down = tor->downloaded - tc->download;
up = tor->uploaded - tc->upload;
if( tc->started )
{
event = "&event=started";
down = up = 0;
if( 0 < tc->newPort )
{
tc->bindPort = tc->newPort;
tc->newPort = -1;
}
}
else if( tc->completed )
{
event = "&event=completed";
}
else if( tc->stopped || 0 < tc->newPort )
{
event = "&event=stopped";
}
else
{
event = "";
}
left = tr_cpLeftBytes( tor->completion );
ret = snprintf( (char *) tc->buf, tc->size,
"GET %s?"
"info_hash=%s&"
"peer_id=%s&"
"port=%d&"
"uploaded=%lld&"
"downloaded=%lld&"
"left=%lld&"
"compact=1&"
"numwant=50&"
"key=%s"
"%s "
"HTTP/1.1\r\n"
"Host: %s\r\n"
"User-Agent: Transmission/%d.%d\r\n"
"Connection: close\r\n\r\n",
inf->trackerAnnounce, tor->hashString, tc->id,
tc->bindPort, up, down,
left, tor->key, event, inf->trackerAddress,
VERSION_MAJOR, VERSION_MINOR );
ret = tr_netSend( tc->socket, tc->buf, ret );
if( ret & TR_NET_CLOSE )
{
tr_inf( "Tracker: connection failed" );
tr_netClose( tc->socket );
tr_fdSocketClosed( tor->fdlimit, 1 );
tc->status = TC_STATUS_IDLE;
tc->dateTry = tr_date();
}
else if( !( ret & TR_NET_BLOCK ) )
{
// printf( "Tracker: sent %s", tc->buf );
tc->status = TC_STATUS_RECV;
tc->pos = 0;
}
}
static void recvAnswer( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
int ret;
int i;
benc_val_t beAll;
benc_val_t * bePeers, * beFoo;
if( tc->pos == tc->size )
{
tc->size *= 2;
tc->buf = realloc( tc->buf, tc->size );
}
ret = tr_netRecv( tc->socket, &tc->buf[tc->pos],
tc->size - tc->pos );
if( ret & TR_NET_BLOCK )
{
return;
}
if( !( ret & TR_NET_CLOSE ) )
{
// printf( "got %d bytes\n", ret );
tc->pos += ret;
return;
}
tr_netClose( tc->socket );
tr_fdSocketClosed( tor->fdlimit, 1 );
// printf( "connection closed, got total %d bytes\n", tc->pos );
tc->status = TC_STATUS_IDLE;
tc->dateTry = tr_date();
if( tc->pos < 1 )
{
/* We got nothing */
return;
}
/* Find the beginning of the dictionary */
for( i = 0; i < tc->pos - 18; i++ )
{
/* Hem */
if( !memcmp( &tc->buf[i], "d8:interval", 11 ) ||
!memcmp( &tc->buf[i], "d8:complete", 11 ) ||
!memcmp( &tc->buf[i], "d14:failure reason", 18 ) )
{
break;
}
}
if( i >= tc->pos - 18 )
{
tr_err( "Tracker: no dictionary in answer" );
// printf( "%s\n", tc->buf );
return;
}
if( tr_bencLoad( &tc->buf[i], &beAll, NULL ) )
{
tr_err( "Tracker: error parsing bencoded data" );
return;
}
// tr_bencPrint( &beAll );
if( ( bePeers = tr_bencDictFind( &beAll, "failure reason" ) ) )
{
tr_err( "Tracker: %s", bePeers->val.s.s );
tor->error |= TR_ETRACKER;
snprintf( tor->trackerError, sizeof( tor->trackerError ),
"%s", bePeers->val.s.s );
goto cleanup;
}
tor->error &= ~TR_ETRACKER;
if( !tc->interval )
{
/* Get the tracker interval, ignore it if it is not between
10 sec and 5 mins */
if( !( beFoo = tr_bencDictFind( &beAll, "interval" ) ) ||
!( beFoo->type & TYPE_INT ) )
{
tr_err( "Tracker: no 'interval' field" );
goto cleanup;
}
tc->interval = beFoo->val.i;
tc->interval = MIN( tc->interval, 300 );
tc->interval = MAX( 10, tc->interval );
tr_inf( "Tracker: interval = %d seconds", tc->interval );
}
if( ( beFoo = tr_bencDictFind( &beAll, "complete" ) ) &&
( beFoo->type & TYPE_INT ) )
{
tc->seeders = beFoo->val.i;
}
if( ( beFoo = tr_bencDictFind( &beAll, "incomplete" ) ) &&
( beFoo->type & TYPE_INT ) )
{
tc->leechers = beFoo->val.i;
}
if( tc->seeders + tc->leechers >= 50 )
{
tc->hasManyPeers = 1;
}
if( !( bePeers = tr_bencDictFind( &beAll, "peers" ) ) )
{
tr_err( "Tracker: no \"peers\" field" );
goto cleanup;
}
if( bePeers->type & TYPE_LIST )
{
char * ip;
int port;
/* Original protocol */
tr_inf( "Tracker: got %d peers", bePeers->val.l.count );
for( i = 0; i < bePeers->val.l.count; i++ )
{
beFoo = tr_bencDictFind( &bePeers->val.l.vals[i], "ip" );
if( !beFoo )
continue;
ip = beFoo->val.s.s;
beFoo = tr_bencDictFind( &bePeers->val.l.vals[i], "port" );
if( !beFoo )
continue;
port = beFoo->val.i;
tr_peerAddOld( tor, ip, port );
}
if( bePeers->val.l.count >= 50 )
{
tc->hasManyPeers = 1;
}
}
else if( bePeers->type & TYPE_STR )
{
struct in_addr addr;
in_port_t port;
/* "Compact" extension */
if( bePeers->val.s.i % 6 )
{
tr_err( "Tracker: \"peers\" of size %d",
bePeers->val.s.i );
tr_lockUnlock( &tor->lock );
goto cleanup;
}
tr_inf( "Tracker: got %d peers", bePeers->val.s.i / 6 );
for( i = 0; i < bePeers->val.s.i / 6; i++ )
{
memcpy( &addr, &bePeers->val.s.s[6*i], 4 );
memcpy( &port, &bePeers->val.s.s[6*i+4], 2 );
tr_peerAddCompact( tor, addr, port );
}
if( bePeers->val.s.i / 6 >= 50 )
{
tc->hasManyPeers = 1;
}
}
/* Success */
tc->started = 0;
tc->completed = 0;
tc->dateOk = tr_date();
if( tc->stopped )
{
tor->status = TR_STATUS_STOPPED;
tc->stopped = 0;
}
else if( 0 < tc->newPort )
{
tc->started = 1;
}
cleanup:
tr_bencFree( &beAll );
}
int tr_trackerScrape( tr_torrent_t * tor, int * seeders, int * leechers )
{
tr_info_t * inf = &tor->info;
int s, i, ret;
uint8_t buf[1024];
benc_val_t scrape, * val1, * val2;
struct in_addr addr;
uint64_t date;
int pos, len;
if( !tor->scrape[0] )
{
/* scrape not supported */
return 1;
}
if( tr_netResolve( inf->trackerAddress, &addr ) )
{
return 0;
}
s = tr_netOpen( addr, htons( inf->trackerPort ) );
if( s < 0 )
{
return 1;
}
len = snprintf( (char *) buf, sizeof( buf ),
"GET %s?info_hash=%s HTTP/1.1\r\n"
"Host: %s\r\n"
"Connection: close\r\n\r\n",
tor->scrape, tor->hashString,
inf->trackerAddress );
for( date = tr_date();; )
{
ret = tr_netSend( s, buf, len );
if( ret & TR_NET_CLOSE )
{
fprintf( stderr, "Could not connect to tracker\n" );
tr_netClose( s );
return 1;
}
else if( ret & TR_NET_BLOCK )
{
if( tr_date() > date + 10000 )
{
fprintf( stderr, "Could not connect to tracker\n" );
tr_netClose( s );
return 1;
}
}
else
{
break;
}
tr_wait( 10 );
}
pos = 0;
for( date = tr_date();; )
{
ret = tr_netRecv( s, &buf[pos], sizeof( buf ) - pos );
if( ret & TR_NET_CLOSE )
{
break;
}
else if( ret & TR_NET_BLOCK )
{
if( tr_date() > date + 10000 )
{
fprintf( stderr, "Could not read from tracker\n" );
tr_netClose( s );
return 1;
}
}
else
{
pos += ret;
}
tr_wait( 10 );
}
if( pos < 1 )
{
fprintf( stderr, "Could not read from tracker\n" );
tr_netClose( s );
return 1;
}
for( i = 0; i < pos - 8; i++ )
{
if( !memcmp( &buf[i], "d5:files", 8 ) )
{
break;
}
}
if( i >= pos - 8 )
{
return 1;
}
if( tr_bencLoad( &buf[i], &scrape, NULL ) )
{
return 1;
}
val1 = tr_bencDictFind( &scrape, "files" );
if( !val1 )
{
return 1;
}
val1 = &val1->val.l.vals[1];
if( !val1 )
{
return 1;
}
val2 = tr_bencDictFind( val1, "complete" );
if( !val2 )
{
return 1;
}
*seeders = val2->val.i;
val2 = tr_bencDictFind( val1, "incomplete" );
if( !val2 )
{
return 1;
}
*leechers = val2->val.i;
tr_bencFree( &scrape );
return 0;
}
int tr_trackerSeeders( tr_tracker_t * tc )
{
if( !tc )
{
return -1;
}
return tc->seeders;
}
int tr_trackerLeechers( tr_tracker_t * tc )
{
if( !tc )
{
return -1;
}
return tc->leechers;
}
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