transmission/libtransmission/tracker.c

624 lines
15 KiB
C

/******************************************************************************
* $Id$
*
* Copyright (c) 2005-2006 Transmission authors and contributors
*
* 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_ATTEMPT_NOREACH 1
#define TC_ATTEMPT_ERROR 2
#define TC_ATTEMPT_OK 4
char lastAttempt;
tr_http_t * http;
int bindPort;
int newPort;
};
static tr_http_t * getQuery ( tr_tracker_t * tc );
static void readAnswer ( tr_tracker_t * tc, const char *, int );
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->interval = 300;
tc->seeders = -1;
tc->leechers = -1;
tc->lastAttempt = TC_ATTEMPT_NOREACH;
tc->bindPort = *(tor->bindPort);
tc->newPort = -1;
return tc;
}
static int shouldConnect( tr_tracker_t * tc )
{
uint64_t now = tr_date();
/* Unreachable tracker, try 10 seconds before trying again */
if( tc->lastAttempt == TC_ATTEMPT_NOREACH &&
now < tc->dateTry + 10000 )
{
return 0;
}
/* The tracker rejected us (like 4XX code, unauthorized IP...),
don't hammer it - we'll probably get the same answer next time
anyway */
if( tc->lastAttempt == TC_ATTEMPT_ERROR &&
now < tc->dateTry + 1000 * tc->interval )
{
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;
const char * data;
int len;
if( ( NULL == tc->http ) && shouldConnect( tc ) )
{
if( tr_fdSocketWillCreate( tor->fdlimit, 1 ) )
{
return 0;
}
tc->dateTry = tr_date();
tc->http = getQuery( tc );
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" ) ) ) );
}
if( NULL != tc->http )
{
switch( tr_httpPulse( tc->http, &data, &len ) )
{
case TR_WAIT:
return 0;
case TR_ERROR:
tr_httpClose( tc->http );
tr_fdSocketClosed( tor->fdlimit, 1 );
tc->http = NULL;
tc->dateTry = tr_date();
return 0;
case TR_OK:
readAnswer( tc, data, len );
tr_httpClose( tc->http );
tc->http = NULL;
tr_fdSocketClosed( tor->fdlimit, 1 );
break;
}
}
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( NULL != tc->http )
{
/* If we are already sendy a query at the moment, we need to
reconnect */
tr_httpClose( tc->http );
tc->http = NULL;
tr_fdSocketClosed( tor->fdlimit, 1 );
}
tc->started = 0;
tc->completed = 0;
tc->stopped = 1;
/* Even if we have connected recently, reconnect right now */
tc->dateTry = 0;
}
void tr_trackerClose( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
if( NULL != tc->http )
{
tr_httpClose( tc->http );
tr_fdSocketClosed( tor->fdlimit, 1 );
}
free( tc );
}
static tr_http_t * getQuery( tr_tracker_t * tc )
{
tr_torrent_t * tor = tc->tor;
tr_info_t * inf = &tor->info;
char * event;
uint64_t left;
uint64_t down;
uint64_t up;
char * start;
int numwant = 50;
down = tor->downloadedCur;
up = tor->uploadedCur;
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";
numwant = 0;
}
else
{
event = "";
}
if( NULL == strchr( inf->trackerAnnounce, '?' ) )
{
start = "?";
}
else
{
start = "&";
}
left = tr_cpLeftBytes( tor->completion );
return tr_httpClient( TR_HTTP_GET, inf->trackerAddress,
inf->trackerPort,
"%s%s"
"info_hash=%s&"
"peer_id=%s&"
"port=%d&"
"uploaded=%"PRIu64"&"
"downloaded=%"PRIu64"&"
"left=%"PRIu64"&"
"compact=1&"
"numwant=%d&"
"key=%s"
"%s",
inf->trackerAnnounce, start, tor->hashString, tc->id,
tc->bindPort, up, down, left, numwant, tor->key, event );
}
static void readAnswer( tr_tracker_t * tc, const char * data, int len )
{
tr_torrent_t * tor = tc->tor;
int i;
int code;
benc_val_t beAll;
benc_val_t * bePeers, * beFoo;
const uint8_t * body;
int bodylen;
int shouldfree;
tc->dateTry = tr_date();
code = tr_httpResponseCode( data, len );
if( 0 > code )
{
/* We don't have a valid HTTP status line */
tr_inf( "Tracker: invalid HTTP status line" );
tc->lastAttempt = TC_ATTEMPT_NOREACH;
return;
}
if( !TR_HTTP_STATUS_OK( code ) )
{
/* we didn't get a 2xx status code */
tr_err( "Tracker: invalid HTTP status code: %i", code );
tc->lastAttempt = TC_ATTEMPT_ERROR;
return;
}
/* find the end of the http headers */
body = (uint8_t *) tr_httpParse( data, len, NULL );
if( NULL == body )
{
tr_err( "Tracker: could not find end of HTTP headers" );
tc->lastAttempt = TC_ATTEMPT_NOREACH;
return;
}
bodylen = len - (body - (const uint8_t*)data);
/* Find and load the dictionary */
shouldfree = 0;
for( i = 0; i < bodylen; i++ )
{
if( !tr_bencLoad( &body[i], bodylen - i, &beAll, NULL ) )
{
shouldfree = 1;
break;
}
}
if( i >= bodylen )
{
if( tc->stopped || 0 < tc->newPort )
{
tc->lastAttempt = TC_ATTEMPT_OK;
goto nodict;
}
tr_err( "Tracker: no valid dictionary found in answer" );
tc->lastAttempt = TC_ATTEMPT_ERROR;
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 );
tc->lastAttempt = TC_ATTEMPT_ERROR;
goto cleanup;
}
tor->error &= ~TR_ETRACKER;
tc->lastAttempt = TC_ATTEMPT_OK;
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" ) ) )
{
if( tc->stopped || 0 < tc->newPort )
{
goto nodict;
}
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;
}
}
nodict:
/* 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:
if( shouldfree )
{
tr_bencFree( &beAll );
}
}
int tr_trackerScrape( tr_torrent_t * tor, int * seeders, int * leechers )
{
tr_info_t * inf = &tor->info;
tr_http_t * http;
const char * data, * body;
int datalen, bodylen;
int code, ii;
benc_val_t scrape, * val1, * val2;
if( !tor->scrape[0] )
{
/* scrape not supported */
return 1;
}
http = tr_httpClient( TR_HTTP_GET, inf->trackerAddress, inf->trackerPort,
"%s?info_hash=%s", tor->scrape, tor->hashString );
data = NULL;
while( NULL == data )
{
switch( tr_httpPulse( http, &data, &datalen ) )
{
case TR_WAIT:
break;
case TR_ERROR:
tr_httpClose( http );
return 1;
case TR_OK:
if( NULL == data || 0 >= datalen )
{
tr_httpClose( http );
return 1;
}
break;
}
tr_wait( 10 );
}
code = tr_httpResponseCode( data, datalen );
if( !TR_HTTP_STATUS_OK( code ) )
{
tr_httpClose( http );
return 1;
}
body = tr_httpParse( data, datalen , NULL );
if( NULL == body )
{
tr_httpClose( http );
return 1;
}
bodylen = datalen - ( body - data );
for( ii = 0; ii < bodylen - 8; ii++ )
{
if( !memcmp( body + ii, "d5:files", 8 ) )
{
break;
}
}
if( ii >= bodylen - 8 )
{
tr_httpClose( http );
return 1;
}
if( tr_bencLoad( body + ii, bodylen - ii, &scrape, NULL ) )
{
tr_httpClose( http );
return 1;
}
val1 = tr_bencDictFind( &scrape, "files" );
if( !val1 )
{
tr_bencFree( &scrape );
tr_httpClose( http );
return 1;
}
val1 = &val1->val.l.vals[1];
if( !val1 )
{
tr_bencFree( &scrape );
tr_httpClose( http );
return 1;
}
val2 = tr_bencDictFind( val1, "complete" );
if( !val2 )
{
tr_bencFree( &scrape );
tr_httpClose( http );
return 1;
}
*seeders = val2->val.i;
val2 = tr_bencDictFind( val1, "incomplete" );
if( !val2 )
{
tr_bencFree( &scrape );
tr_httpClose( http );
return 1;
}
*leechers = val2->val.i;
tr_bencFree( &scrape );
tr_httpClose( http );
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;
}