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transmission/libtransmission/peer-mgr.c

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/*
* This file Copyright (C) 2007-2008 Charles Kerr <charles@rebelbase.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <string.h> /* memcpy, memcmp, strstr */
#include <stdlib.h> /* qsort */
#include <stdio.h> /* printf */
#include <limits.h> /* INT_MAX */
#include <event.h>
#include "transmission.h"
#include "blocklist.h"
#include "clients.h"
#include "completion.h"
#include "crypto.h"
#include "handshake.h"
#include "inout.h" /* tr_ioTestPiece */
#include "net.h"
#include "peer-io.h"
#include "peer-mgr.h"
#include "peer-mgr-private.h"
#include "peer-msgs.h"
#include "ptrarray.h"
#include "ratecontrol.h"
#include "stats.h" /* tr_statsAddDownloaded */
#include "torrent.h"
#include "trevent.h"
#include "utils.h"
#include "webseed.h"
enum
{
/* how frequently to change which peers are choked */
RECHOKE_PERIOD_MSEC = (10 * 1000),
/* minimum interval for refilling peers' request lists */
REFILL_PERIOD_MSEC = 333,
/* when many peers are available, keep idle ones this long */
MIN_UPLOAD_IDLE_SECS = (60 * 3),
/* when few peers are available, keep idle ones this long */
MAX_UPLOAD_IDLE_SECS = (60 * 10),
/* how frequently to decide which peers live and die */
RECONNECT_PERIOD_MSEC = (2 * 1000),
/* max # of peers to ask fer per torrent per reconnect pulse */
MAX_RECONNECTIONS_PER_PULSE = 2,
/* max number of peers to ask for per second overall.
* this throttle is to avoid overloading the router */
MAX_CONNECTIONS_PER_SECOND = 4,
/* number of unchoked peers per torrent.
* FIXME: this probably ought to be configurable */
MAX_UNCHOKED_PEERS = 12,
/* number of bad pieces a peer is allowed to send before we ban them */
MAX_BAD_PIECES_PER_PEER = 3,
/* use for bitwise operations w/peer_atom.myflags */
MYFLAG_BANNED = 1,
/* unreachable for now... but not banned. if they try to connect to us it's okay */
MYFLAG_UNREACHABLE = 2
};
/**
***
**/
/* We keep one of these for every peer we know about, whether
* it's connected or not, so the struct must be small.
* When our current connections underperform, we dip back
* into this list for new ones. */
struct peer_atom
{
uint8_t from;
uint8_t flags; /* these match the added_f flags */
uint8_t myflags; /* flags that aren't defined in added_f */
uint16_t port;
uint16_t numFails;
struct in_addr addr;
time_t time;
time_t piece_data_time;
};
typedef struct
{
uint8_t hash[SHA_DIGEST_LENGTH];
tr_ptrArray * outgoingHandshakes; /* tr_handshake */
tr_ptrArray * pool; /* struct peer_atom */
tr_ptrArray * peers; /* tr_peer */
tr_ptrArray * webseeds; /* tr_webseed */
tr_timer * reconnectTimer;
tr_timer * rechokeTimer;
tr_timer * refillTimer;
tr_torrent * tor;
tr_peer * optimistic; /* the optimistic peer, or NULL if none */
tr_bitfield * requestedPieces;
unsigned int isRunning : 1;
struct tr_peerMgr * manager;
}
Torrent;
struct tr_peerMgr
{
tr_handle * handle;
tr_ptrArray * torrents; /* Torrent */
tr_ptrArray * incomingHandshakes; /* tr_handshake */
};
#define tordbg(t, fmt...) tr_deepLog( __FILE__, __LINE__, t->tor->info.name, ##fmt )
/**
***
**/
/* The following is not a very high quality random number generator. It
* is mainly used as a simple stupid random number generator inside some
* functions below. Please don't use it for anything else unless you
* know what you're doing. Use tr_cryptoRandInt() instead.
*/
static int
tr_stupidRandInt( int sup )
{
static int init = 0;
assert( sup > 0 );
if ( !init )
{
srand( tr_date() );
init = 1;
}
return rand() % sup;
}
static void
managerLock( const struct tr_peerMgr * manager )
{
tr_globalLock( manager->handle );
}
static void
managerUnlock( const struct tr_peerMgr * manager )
{
tr_globalUnlock( manager->handle );
}
static void
torrentLock( Torrent * torrent )
{
managerLock( torrent->manager );
}
static void
torrentUnlock( Torrent * torrent )
{
managerUnlock( torrent->manager );
}
static int
torrentIsLocked( const Torrent * t )
{
return tr_globalIsLocked( t->manager->handle );
}
/**
***
**/
static int
compareAddresses( const struct in_addr * a, const struct in_addr * b )
{
return a->s_addr - b->s_addr;
}
static int
handshakeCompareToAddr( const void * va, const void * vb )
{
const tr_handshake * a = va;
return compareAddresses( tr_handshakeGetAddr( a, NULL ), vb );
}
static int
handshakeCompare( const void * a, const void * b )
{
return handshakeCompareToAddr( a, tr_handshakeGetAddr( b, NULL ) );
}
static tr_handshake*
getExistingHandshake( tr_ptrArray * handshakes, const struct in_addr * in_addr )
{
return tr_ptrArrayFindSorted( handshakes,
in_addr,
handshakeCompareToAddr );
}
static int
comparePeerAtomToAddress( const void * va, const void * vb )
{
const struct peer_atom * a = va;
return compareAddresses( &a->addr, vb );
}
static int
comparePeerAtoms( const void * va, const void * vb )
{
const struct peer_atom * b = vb;
return comparePeerAtomToAddress( va, &b->addr );
}
/**
***
**/
static int
torrentCompare( const void * va, const void * vb )
{
const Torrent * a = va;
const Torrent * b = vb;
return memcmp( a->hash, b->hash, SHA_DIGEST_LENGTH );
}
static int
torrentCompareToHash( const void * va, const void * vb )
{
const Torrent * a = va;
const uint8_t * b_hash = vb;
return memcmp( a->hash, b_hash, SHA_DIGEST_LENGTH );
}
static Torrent*
getExistingTorrent( tr_peerMgr * manager, const uint8_t * hash )
{
return (Torrent*) tr_ptrArrayFindSorted( manager->torrents,
hash,
torrentCompareToHash );
}
static int
peerCompare( const void * va, const void * vb )
{
const tr_peer * a = va;
const tr_peer * b = vb;
return compareAddresses( &a->in_addr, &b->in_addr );
}
static int
peerCompareToAddr( const void * va, const void * vb )
{
const tr_peer * a = va;
return compareAddresses( &a->in_addr, vb );
}
static tr_peer*
getExistingPeer( Torrent * torrent, const struct in_addr * in_addr )
{
assert( torrentIsLocked( torrent ) );
assert( in_addr );
return tr_ptrArrayFindSorted( torrent->peers,
in_addr,
peerCompareToAddr );
}
static struct peer_atom*
getExistingAtom( const Torrent * t, const struct in_addr * addr )
{
assert( torrentIsLocked( t ) );
return tr_ptrArrayFindSorted( t->pool, addr, comparePeerAtomToAddress );
}
static int
peerIsInUse( const Torrent * ct, const struct in_addr * addr )
{
Torrent * t = (Torrent*) ct;
assert( torrentIsLocked ( t ) );
return getExistingPeer( t, addr )
|| getExistingHandshake( t->outgoingHandshakes, addr )
|| getExistingHandshake( t->manager->incomingHandshakes, addr );
}
static tr_peer*
peerConstructor( const struct in_addr * in_addr )
{
tr_peer * p;
p = tr_new0( tr_peer, 1 );
p->rcToClient = tr_rcInit( );
p->rcToPeer = tr_rcInit( );
memcpy( &p->in_addr, in_addr, sizeof(struct in_addr) );
return p;
}
static tr_peer*
getPeer( Torrent * torrent, const struct in_addr * in_addr )
{
tr_peer * peer;
assert( torrentIsLocked( torrent ) );
peer = getExistingPeer( torrent, in_addr );
if( peer == NULL ) {
peer = peerConstructor( in_addr );
tr_ptrArrayInsertSorted( torrent->peers, peer, peerCompare );
}
return peer;
}
static void
peerDestructor( tr_peer * peer )
{
assert( peer );
assert( peer->msgs );
tr_peerMsgsUnsubscribe( peer->msgs, peer->msgsTag );
tr_peerMsgsFree( peer->msgs );
tr_peerIoFree( peer->io );
tr_bitfieldFree( peer->have );
tr_bitfieldFree( peer->blame );
tr_rcClose( peer->rcToClient );
tr_rcClose( peer->rcToPeer );
tr_free( peer->client );
tr_free( peer );
}
static void
removePeer( Torrent * t, tr_peer * peer )
{
tr_peer * removed;
struct peer_atom * atom;
assert( torrentIsLocked( t ) );
atom = getExistingAtom( t, &peer->in_addr );
assert( atom );
atom->time = time( NULL );
removed = tr_ptrArrayRemoveSorted( t->peers, peer, peerCompare );
assert( removed == peer );
peerDestructor( removed );
}
static void
removeAllPeers( Torrent * t )
{
while( !tr_ptrArrayEmpty( t->peers ) )
removePeer( t, tr_ptrArrayNth( t->peers, 0 ) );
}
static void
torrentDestructor( Torrent * t )
{
uint8_t hash[SHA_DIGEST_LENGTH];
assert( t );
assert( !t->isRunning );
assert( t->peers );
assert( torrentIsLocked( t ) );
assert( tr_ptrArrayEmpty( t->outgoingHandshakes ) );
assert( tr_ptrArrayEmpty( t->peers ) );
memcpy( hash, t->hash, SHA_DIGEST_LENGTH );
tr_timerFree( &t->reconnectTimer );
tr_timerFree( &t->rechokeTimer );
tr_timerFree( &t->refillTimer );
tr_bitfieldFree( t->requestedPieces );
tr_ptrArrayFree( t->webseeds, (PtrArrayForeachFunc)tr_webseedFree );
tr_ptrArrayFree( t->pool, (PtrArrayForeachFunc)tr_free );
tr_ptrArrayFree( t->outgoingHandshakes, NULL );
tr_ptrArrayFree( t->peers, NULL );
tr_free( t );
}
static void peerCallbackFunc( void * vpeer, void * vevent, void * vt );
static Torrent*
torrentConstructor( tr_peerMgr * manager, tr_torrent * tor )
{
int i;
Torrent * t;
t = tr_new0( Torrent, 1 );
t->manager = manager;
t->tor = tor;
t->pool = tr_ptrArrayNew( );
t->peers = tr_ptrArrayNew( );
t->webseeds = tr_ptrArrayNew( );
t->outgoingHandshakes = tr_ptrArrayNew( );
t->requestedPieces = tr_bitfieldNew( tor->info.pieceCount );
memcpy( t->hash, tor->info.hash, SHA_DIGEST_LENGTH );
for( i=0; i<tor->info.webseedCount; ++i ) {
tr_webseed * w = tr_webseedNew( tor, tor->info.webseeds[i], peerCallbackFunc, t );
tr_ptrArrayAppend( t->webseeds, w );
}
return t;
}
/**
* For explanation, see http://www.bittorrent.org/fast_extensions.html
* Also see the "test-allowed-set" unit test
*/
struct tr_bitfield *
tr_peerMgrGenerateAllowedSet( const uint32_t k, /* number of pieces in set */
const uint32_t sz, /* number of pieces in torrent */
const uint8_t * infohash, /* torrent's SHA1 hash*/
const struct in_addr * ip ) /* peer's address */
{
uint8_t w[SHA_DIGEST_LENGTH + 4];
uint8_t x[SHA_DIGEST_LENGTH];
tr_bitfield_t * a;
uint32_t a_size;
*(uint32_t*)w = ntohl( htonl(ip->s_addr) & 0xffffff00 ); /* (1) */
memcpy( w + 4, infohash, SHA_DIGEST_LENGTH ); /* (2) */
tr_sha1( x, w, sizeof( w ), NULL ); /* (3) */
a = tr_bitfieldNew( sz );
a_size = 0;
while( a_size < k )
{
int i;
for ( i=0; i<5 && a_size<k; ++i ) /* (4) */
{
uint32_t j = i * 4; /* (5) */
uint32_t y = ntohl(*(uint32_t*)(x+j)); /* (6) */
uint32_t index = y % sz; /* (7) */
if ( !tr_bitfieldHas( a, index ) ) { /* (8) */
tr_bitfieldAdd( a, index ); /* (9) */
++a_size;
}
}
tr_sha1( x, x, sizeof( x ), NULL ); /* (3) */
}
return a;
}
tr_peerMgr*
tr_peerMgrNew( tr_handle * handle )
{
tr_peerMgr * m = tr_new0( tr_peerMgr, 1 );
m->handle = handle;
m->torrents = tr_ptrArrayNew( );
m->incomingHandshakes = tr_ptrArrayNew( );
return m;
}
void
tr_peerMgrFree( tr_peerMgr * manager )
{
managerLock( manager );
/* free the handshakes. Abort invokes handshakeDoneCB(), which removes
* the item from manager->handshakes, so this is a little roundabout... */
while( !tr_ptrArrayEmpty( manager->incomingHandshakes ) )
tr_handshakeAbort( tr_ptrArrayNth( manager->incomingHandshakes, 0 ) );
tr_ptrArrayFree( manager->incomingHandshakes, NULL );
/* free the torrents. */
tr_ptrArrayFree( manager->torrents, (PtrArrayForeachFunc)torrentDestructor );
managerUnlock( manager );
tr_free( manager );
}
static tr_peer**
getConnectedPeers( Torrent * t, int * setmeCount )
{
int i, peerCount, connectionCount;
tr_peer **peers;
tr_peer **ret;
assert( torrentIsLocked( t ) );
peers = (tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount );
ret = tr_new( tr_peer*, peerCount );
for( i=connectionCount=0; i<peerCount; ++i )
if( peers[i]->msgs )
ret[connectionCount++] = peers[i];
*setmeCount = connectionCount;
return ret;
}
static int
clientIsDownloadingFrom( const tr_peer * peer )
{
return peer->clientIsInterested && !peer->clientIsChoked;
}
static int
clientIsUploadingTo( const tr_peer * peer )
{
return peer->peerIsInterested && !peer->peerIsChoked;
}
/***
****
***/
int
tr_peerMgrPeerIsSeed( const tr_peerMgr * mgr,
const uint8_t * torrentHash,
const struct in_addr * addr )
{
int isSeed = FALSE;
const Torrent * t = NULL;
const struct peer_atom * atom = NULL;
t = getExistingTorrent( (tr_peerMgr*)mgr, torrentHash );
if( t )
atom = getExistingAtom( t, addr );
if( atom )
isSeed = ( atom->flags & ADDED_F_SEED_FLAG ) != 0;
return isSeed;
}
/***
**** Refill
***/
struct tr_refill_piece
{
tr_priority_t priority;
int missingBlockCount;
int random;
uint32_t piece;
uint32_t peerCount;
};
static int
compareRefillPiece (const void * aIn, const void * bIn)
{
const struct tr_refill_piece * a = aIn;
const struct tr_refill_piece * b = bIn;
/* if one piece has a higher priority, it goes first */
if( a->priority != b->priority )
return a->priority > b->priority ? -1 : 1;
/* otherwise if one has fewer peers, it goes first */
if (a->peerCount != b->peerCount)
return a->peerCount < b->peerCount ? -1 : 1;
/* otherwise go with our random seed */
return a->random - b->random;
}
static int
isPieceInteresting( const tr_torrent * tor,
tr_piece_index_t piece )
{
if( tor->info.pieces[piece].dnd ) /* we don't want it */
return 0;
if( tr_cpPieceIsComplete( tor->completion, piece ) ) /* we have it */
return 0;
return 1;
}
static uint32_t*
getPreferredPieces( Torrent * t,
uint32_t * pieceCount )
{
const tr_torrent * tor = t->tor;
const tr_info * inf = &tor->info;
tr_piece_index_t i;
uint32_t poolSize = 0;
uint32_t * pool = tr_new( uint32_t, inf->pieceCount );
int peerCount;
tr_peer** peers;
assert( torrentIsLocked( t ) );
peers = getConnectedPeers( t, &peerCount );
for( i=0; i<inf->pieceCount; ++i )
if( isPieceInteresting( tor, i ) )
pool[poolSize++] = i;
/* sort the pool from most interesting to least... */
if( poolSize > 1 )
{
uint32_t j;
struct tr_refill_piece * p = tr_new( struct tr_refill_piece, poolSize );
for( j=0; j<poolSize; ++j )
{
int k;
const tr_piece_index_t piece = pool[j];
struct tr_refill_piece * setme = p + j;
setme->piece = piece;
setme->priority = inf->pieces[piece].priority;
setme->peerCount = 0;
setme->random = tr_stupidRandInt( INT_MAX );
setme->missingBlockCount = tr_cpMissingBlocksInPiece( tor->completion, piece );
for( k=0; k<peerCount; ++k ) {
const tr_peer * peer = peers[k];
if( peer->peerIsInterested && !peer->clientIsChoked && tr_bitfieldHas( peer->have, piece ) )
++setme->peerCount;
}
}
qsort( p, poolSize, sizeof(struct tr_refill_piece), compareRefillPiece );
for( j=0; j<poolSize; ++j )
pool[j] = p[j].piece;
tr_free( p );
}
tr_free( peers );
*pieceCount = poolSize;
return pool;
}
static tr_peer**
getPeersUploadingToClient( Torrent * t, int * setmeCount )
{
int i;
int peerCount = 0;
int retCount = 0;
tr_peer ** peers = (tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount );
tr_peer ** ret = tr_new( tr_peer*, peerCount );
/* get a list of peers we're downloading from */
for( i=0; i<peerCount; ++i )
if( clientIsDownloadingFrom( peers[i] ) )
ret[retCount++] = peers[i];
/* pick a different starting point each time so all peers
* get a chance at the first blocks in the queue */
if( retCount ) {
tr_peer ** tmp = tr_new( tr_peer*, retCount );
i = tr_stupidRandInt( retCount );
memcpy( tmp, ret, sizeof(tr_peer*) * retCount );
memcpy( ret, tmp+i, sizeof(tr_peer*) * (retCount-i) );
memcpy( ret+(retCount-i), tmp, sizeof(tr_peer*) * i );
tr_free( tmp );
}
*setmeCount = retCount;
return ret;
}
static int
refillPulse( void * vtorrent )
{
Torrent * t = vtorrent;
tr_torrent * tor = t->tor;
int peerCount;
int webseedCount;
tr_peer ** peers;
tr_webseed ** webseeds;
uint32_t pieceCount;
uint32_t * pieces;
tr_piece_index_t i;
if( !t->isRunning )
return TRUE;
if( tr_torrentIsSeed( t->tor ) )
return TRUE;
torrentLock( t );
tordbg( t, "Refilling Request Buffers..." );
pieces = getPreferredPieces( t, &pieceCount );
peers = getPeersUploadingToClient( t, &peerCount );
webseedCount = tr_ptrArraySize( t->webseeds );
webseeds = tr_memdup( tr_ptrArrayBase(t->webseeds), webseedCount*sizeof(tr_webseed*) );
for( i=0; (webseedCount || peerCount) && i<pieceCount; ++i )
{
int j;
int handled = FALSE;
const tr_piece_index_t piece = pieces[i];
assert( piece < tor->info.pieceCount );
/* find a peer who can ask for this piece */
for( j=0; !handled && j<peerCount; )
{
const int val = tr_peerMsgsAddRequest( peers[j]->msgs, piece );
switch( val )
{
case TR_ADDREQ_FULL:
case TR_ADDREQ_CLIENT_CHOKED:
memmove( peers+j, peers+j+1, sizeof(tr_peer*)*(--peerCount-j) );
break;
case TR_ADDREQ_MISSING:
case TR_ADDREQ_DUPLICATE:
++j;
break;
case TR_ADDREQ_OK:
tr_bitfieldAdd( t->requestedPieces, piece );
handled = TRUE;
break;
default:
assert( 0 && "unhandled value" );
break;
}
}
/* maybe one of the webseeds can do it */
for( j=0; !handled && j<webseedCount; )
{
const int val = tr_webseedAddRequest( webseeds[j], piece );
switch( val )
{
case TR_ADDREQ_FULL:
memmove( webseeds+j, webseeds+j+1, sizeof(tr_webseed*)*(--webseedCount-j) );
break;
case TR_ADDREQ_OK:
tr_bitfieldAdd( t->requestedPieces, piece );
handled = TRUE;
break;
default:
assert( 0 && "unhandled value" );
break;
}
}
}
/* cleanup */
tr_free( webseeds );
tr_free( peers );
tr_free( pieces );
t->refillTimer = NULL;
torrentUnlock( t );
return FALSE;
}
static void
addStrike( Torrent * t, tr_peer * peer )
{
tordbg( t, "increasing peer %s strike count to %d", tr_peerIoAddrStr(&peer->in_addr,peer->port), peer->strikes+1 );
if( ++peer->strikes >= MAX_BAD_PIECES_PER_PEER )
{
struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
atom->myflags |= MYFLAG_BANNED;
peer->doPurge = 1;
tordbg( t, "banning peer %s", tr_peerIoAddrStr(&atom->addr,atom->port) );
}
}
static void
gotBadPiece( Torrent * t, tr_piece_index_t pieceIndex )
{
tr_torrent * tor = t->tor;
const uint32_t byteCount = tr_torPieceCountBytes( tor, pieceIndex );
tor->corruptCur += byteCount;
tor->downloadedCur -= MIN( tor->downloadedCur, byteCount );
}
static void
refillSoon( Torrent * t )
{
if( t->refillTimer == NULL )
t->refillTimer = tr_timerNew( t->manager->handle,
refillPulse, t,
REFILL_PERIOD_MSEC );
}
static void
peerCallbackFunc( void * vpeer, void * vevent, void * vt )
{
tr_peer * peer = vpeer; /* may be NULL if peer is a webseed */
Torrent * t = (Torrent *) vt;
const tr_peer_event * e = vevent;
torrentLock( t );
switch( e->eventType )
{
case TR_PEER_NEED_REQ:
refillSoon( t );
break;
case TR_PEER_CANCEL:
tr_bitfieldRem( t->requestedPieces, e->pieceIndex );
break;
case TR_PEER_PEER_GOT_DATA: {
const time_t now = time( NULL );
tr_torrent * tor = t->tor;
tor->activityDate = now;
tor->uploadedCur += e->length;
tr_rcTransferred( tor->upload, e->length );
tr_rcTransferred( tor->handle->upload, e->length );
tr_statsAddUploaded( tor->handle, e->length );
if( peer ) {
struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
atom->piece_data_time = time( NULL );
}
break;
}
case TR_PEER_CLIENT_GOT_DATA: {
const time_t now = time( NULL );
tr_torrent * tor = t->tor;
tor->activityDate = now;
/* only add this to downloadedCur if we got it from a peer --
* webseeds shouldn't count against our ratio. As one tracker
* admin put it, "Those pieces are downloaded directly from the
* content distributor, not the peers, it is the tracker's job
* to manage the swarms, not the web server and does not fit
* into the jurisdiction of the tracker." */
if( peer )
tor->downloadedCur += e->length;
tr_rcTransferred( tor->download, e->length );
tr_rcTransferred( tor->handle->download, e->length );
tr_statsAddDownloaded( tor->handle, e->length );
if( peer ) {
struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
atom->piece_data_time = time( NULL );
}
break;
}
case TR_PEER_PEER_PROGRESS: {
if( peer ) {
struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
const int peerIsSeed = e->progress >= 1.0;
if( peerIsSeed ) {
tordbg( t, "marking peer %s as a seed", tr_peerIoAddrStr(&atom->addr,atom->port) );
atom->flags |= ADDED_F_SEED_FLAG;
} else {
tordbg( t, "marking peer %s as a non-seed", tr_peerIoAddrStr(&atom->addr,atom->port) );
atom->flags &= ~ADDED_F_SEED_FLAG;
}
}
break;
}
case TR_PEER_CLIENT_GOT_BLOCK:
{
tr_torrent * tor = t->tor;
tr_block_index_t block = _tr_block( tor, e->pieceIndex, e->offset );
tr_cpBlockAdd( tor->completion, block );
if( tr_cpPieceIsComplete( tor->completion, e->pieceIndex ) )
{
const tr_piece_index_t p = e->pieceIndex;
const tr_errno err = tr_ioTestPiece( tor, p );
if( err ) {
tr_torerr( tor, _( "Piece %lu, which was just downloaded, failed its checksum test: %s" ),
(unsigned long)p, tr_errorString( err ) );
}
tr_torrentSetHasPiece( tor, p, !err );
tr_torrentSetPieceChecked( tor, p, TRUE );
tr_peerMgrSetBlame( tor->handle->peerMgr, tor->info.hash, p, !err );
if( err )
gotBadPiece( t, p );
else {
int i, peerCount;
tr_peer ** peers = getConnectedPeers( t, &peerCount );
for( i=0; i<peerCount; ++i )
tr_peerMsgsHave( peers[i]->msgs, p );
tr_free( peers );
}
tr_torrentRecheckCompleteness( tor );
}
break;
}
case TR_PEER_ERROR:
if( TR_ERROR_IS_IO( e->err ) ) {
t->tor->error = e->err;
tr_strlcpy( t->tor->errorString, tr_errorString( e->err ), sizeof(t->tor->errorString) );
tr_torrentStop( t->tor );
} else if( e->err == TR_ERROR_ASSERT ) {
addStrike( t, peer );
}
peer->doPurge = 1;
break;
default:
assert(0);
}
torrentUnlock( t );
}
static void
ensureAtomExists( Torrent * t, const struct in_addr * addr, uint16_t port, uint8_t flags, uint8_t from )
{
if( getExistingAtom( t, addr ) == NULL )
{
struct peer_atom * a;
a = tr_new0( struct peer_atom, 1 );
a->addr = *addr;
a->port = port;
a->flags = flags;
a->from = from;
tordbg( t, "got a new atom: %s", tr_peerIoAddrStr(&a->addr,a->port) );
tr_ptrArrayInsertSorted( t->pool, a, comparePeerAtoms );
}
}
static int
getMaxPeerCount( const tr_torrent * tor UNUSED )
{
return tor->maxConnectedPeers;
}
/* FIXME: this is kind of a mess. */
static void
myHandshakeDoneCB( tr_handshake * handshake,
tr_peerIo * io,
int isConnected,
const uint8_t * peer_id,
void * vmanager )
{
int ok = isConnected;
uint16_t port;
const struct in_addr * addr;
tr_peerMgr * manager = (tr_peerMgr*) vmanager;
Torrent * t;
tr_handshake * ours;
assert( io );
assert( isConnected==0 || isConnected==1 );
t = tr_peerIoHasTorrentHash( io )
? getExistingTorrent( manager, tr_peerIoGetTorrentHash( io ) )
: NULL;
if( tr_peerIoIsIncoming ( io ) )
ours = tr_ptrArrayRemoveSorted( manager->incomingHandshakes,
handshake, handshakeCompare );
else if( t )
ours = tr_ptrArrayRemoveSorted( t->outgoingHandshakes,
handshake, handshakeCompare );
else
ours = handshake;
assert( ours );
assert( ours == handshake );
if( t )
torrentLock( t );
addr = tr_peerIoGetAddress( io, &port );
if( !ok || !t || !t->isRunning )
{
if( t ) {
struct peer_atom * atom = getExistingAtom( t, addr );
if( atom )
++atom->numFails;
}
tr_peerIoFree( io );
}
else /* looking good */
{
struct peer_atom * atom;
ensureAtomExists( t, addr, port, 0, TR_PEER_FROM_INCOMING );
atom = getExistingAtom( t, addr );
if( atom->myflags & MYFLAG_BANNED )
{
tordbg( t, "banned peer %s tried to reconnect", tr_peerIoAddrStr(&atom->addr,atom->port) );
tr_peerIoFree( io );
}
else if( tr_ptrArraySize( t->peers ) >= getMaxPeerCount( t->tor ) )
{
tr_peerIoFree( io );
}
else
{
tr_peer * peer = getExistingPeer( t, addr );
if( peer ) /* we already have this peer */
{
tr_peerIoFree( io );
}
else
{
peer = getPeer( t, addr );
tr_free( peer->client );
if( !peer_id )
peer->client = NULL;
else {
char client[128];
tr_clientForId( client, sizeof( client ), peer_id );
peer->client = tr_strdup( client );
}
peer->port = port;
peer->io = io;
peer->msgs = tr_peerMsgsNew( t->tor, peer, peerCallbackFunc, t, &peer->msgsTag );
atom->time = time( NULL );
}
}
}
if( t )
torrentUnlock( t );
}
void
tr_peerMgrAddIncoming( tr_peerMgr * manager,
struct in_addr * addr,
uint16_t port,
int socket )
{
managerLock( manager );
if( tr_sessionIsAddressBlocked( manager->handle, addr ) )
{
tr_dbg( "Banned IP address \"%s\" tried to connect to us",
inet_ntoa( *addr ) );
tr_netClose( socket );
}
else if( getExistingHandshake( manager->incomingHandshakes, addr ) )
{
tr_netClose( socket );
}
else /* we don't have a connetion to them yet... */
{
tr_peerIo * io;
tr_handshake * handshake;
io = tr_peerIoNewIncoming( manager->handle, addr, port, socket );
handshake = tr_handshakeNew( io,
manager->handle->encryptionMode,
myHandshakeDoneCB,
manager );
tr_ptrArrayInsertSorted( manager->incomingHandshakes, handshake, handshakeCompare );
}
managerUnlock( manager );
}
void
tr_peerMgrAddPex( tr_peerMgr * manager,
const uint8_t * torrentHash,
uint8_t from,
const tr_pex * pex )
{
Torrent * t;
managerLock( manager );
t = getExistingTorrent( manager, torrentHash );
if( !tr_sessionIsAddressBlocked( t->manager->handle, &pex->in_addr ) )
ensureAtomExists( t, &pex->in_addr, pex->port, pex->flags, from );
managerUnlock( manager );
}
tr_pex *
tr_peerMgrCompactToPex( const void * compact,
size_t compactLen,
const uint8_t * added_f,
size_t added_f_len,
size_t * pexCount )
{
size_t i;
size_t n = compactLen / 6;
const uint8_t * walk = compact;
tr_pex * pex = tr_new0( tr_pex, n );
for( i=0; i<n; ++i ) {
memcpy( &pex[i].in_addr, walk, 4 ); walk += 4;
memcpy( &pex[i].port, walk, 2 ); walk += 2;
if( added_f && ( n == added_f_len ) )
pex[i].flags = added_f[i];
}
*pexCount = n;
return pex;
}
/**
***
**/
void
tr_peerMgrSetBlame( tr_peerMgr * manager,
const uint8_t * torrentHash,
tr_piece_index_t pieceIndex,
int success )
{
if( !success )
{
int peerCount, i;
Torrent * t = getExistingTorrent( manager, torrentHash );
tr_peer ** peers;
assert( torrentIsLocked( t ) );
peers = (tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount );
for( i=0; i<peerCount; ++i )
{
tr_peer * peer = peers[i];
if( tr_bitfieldHas( peer->blame, pieceIndex ) )
{
tordbg( t, "peer %s contributed to corrupt piece (%d); now has %d strikes",
tr_peerIoAddrStr(&peer->in_addr,peer->port),
pieceIndex, (int)peer->strikes+1 );
addStrike( t, peer );
}
}
}
}
int
tr_pexCompare( const void * va, const void * vb )
{
const tr_pex * a = va;
const tr_pex * b = vb;
int i = memcmp( &a->in_addr, &b->in_addr, sizeof(struct in_addr) );
if( i ) return i;
if( a->port < b->port ) return -1;
if( a->port > b->port ) return 1;
return 0;
}
int tr_pexCompare( const void * a, const void * b );
static int
peerPrefersCrypto( const tr_peer * peer )
{
if( peer->encryption_preference == ENCRYPTION_PREFERENCE_YES )
return TRUE;
if( peer->encryption_preference == ENCRYPTION_PREFERENCE_NO )
return FALSE;
return tr_peerIoIsEncrypted( peer->io );
};
int
tr_peerMgrGetPeers( tr_peerMgr * manager,
const uint8_t * torrentHash,
tr_pex ** setme_pex )
{
const Torrent * t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
int i, peerCount;
const tr_peer ** peers;
tr_pex * pex;
tr_pex * walk;
managerLock( manager );
peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount );
pex = walk = tr_new( tr_pex, peerCount );
for( i=0; i<peerCount; ++i, ++walk )
{
const tr_peer * peer = peers[i];
walk->in_addr = peer->in_addr;
walk->port = peer->port;
walk->flags = 0;
if( peerPrefersCrypto(peer) ) walk->flags |= ADDED_F_ENCRYPTION_FLAG;
if( peer->progress >= 1.0 ) walk->flags |= ADDED_F_SEED_FLAG;
}
assert( ( walk - pex ) == peerCount );
qsort( pex, peerCount, sizeof(tr_pex), tr_pexCompare );
*setme_pex = pex;
managerUnlock( manager );
return peerCount;
}
static int reconnectPulse( void * vtorrent );
static int rechokePulse( void * vtorrent );
void
tr_peerMgrStartTorrent( tr_peerMgr * manager,
const uint8_t * torrentHash )
{
Torrent * t;
managerLock( manager );
t = getExistingTorrent( manager, torrentHash );
assert( t );
assert( ( t->isRunning != 0 ) == ( t->reconnectTimer != NULL ) );
assert( ( t->isRunning != 0 ) == ( t->rechokeTimer != NULL ) );
if( !t->isRunning )
{
t->isRunning = 1;
t->reconnectTimer = tr_timerNew( t->manager->handle,
reconnectPulse, t,
RECONNECT_PERIOD_MSEC );
t->rechokeTimer = tr_timerNew( t->manager->handle,
rechokePulse, t,
RECHOKE_PERIOD_MSEC );
reconnectPulse( t );
rechokePulse( t );
if( !tr_ptrArrayEmpty( t->webseeds ) )
refillSoon( t );
}
managerUnlock( manager );
}
static void
stopTorrent( Torrent * t )
{
assert( torrentIsLocked( t ) );
t->isRunning = 0;
tr_timerFree( &t->rechokeTimer );
tr_timerFree( &t->reconnectTimer );
/* disconnect the peers. */
tr_ptrArrayForeach( t->peers, (PtrArrayForeachFunc)peerDestructor );
tr_ptrArrayClear( t->peers );
/* disconnect the handshakes. handshakeAbort calls handshakeDoneCB(),
* which removes the handshake from t->outgoingHandshakes... */
while( !tr_ptrArrayEmpty( t->outgoingHandshakes ) )
tr_handshakeAbort( tr_ptrArrayNth( t->outgoingHandshakes, 0 ) );
}
void
tr_peerMgrStopTorrent( tr_peerMgr * manager,
const uint8_t * torrentHash)
{
managerLock( manager );
stopTorrent( getExistingTorrent( manager, torrentHash ) );
managerUnlock( manager );
}
void
tr_peerMgrAddTorrent( tr_peerMgr * manager,
tr_torrent * tor )
{
Torrent * t;
managerLock( manager );
assert( tor );
assert( getExistingTorrent( manager, tor->info.hash ) == NULL );
t = torrentConstructor( manager, tor );
tr_ptrArrayInsertSorted( manager->torrents, t, torrentCompare );
managerUnlock( manager );
}
void
tr_peerMgrRemoveTorrent( tr_peerMgr * manager,
const uint8_t * torrentHash )
{
Torrent * t;
managerLock( manager );
t = getExistingTorrent( manager, torrentHash );
assert( t );
stopTorrent( t );
tr_ptrArrayRemoveSorted( manager->torrents, t, torrentCompare );
torrentDestructor( t );
managerUnlock( manager );
}
void
tr_peerMgrTorrentAvailability( const tr_peerMgr * manager,
const uint8_t * torrentHash,
int8_t * tab,
unsigned int tabCount )
{
tr_piece_index_t i;
const Torrent * t;
const tr_torrent * tor;
float interval;
int isComplete;
int peerCount;
const tr_peer ** peers;
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
tor = t->tor;
interval = tor->info.pieceCount / (float)tabCount;
isComplete = tor && ( tr_cpGetStatus ( tor->completion ) == TR_CP_COMPLETE );
peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &peerCount );
memset( tab, 0, tabCount );
for( i=0; tor && i<tabCount; ++i )
{
const int piece = i * interval;
if( isComplete || tr_cpPieceIsComplete( tor->completion, piece ) )
tab[i] = -1;
else if( peerCount ) {
int j;
for( j=0; j<peerCount; ++j )
if( tr_bitfieldHas( peers[j]->have, i ) )
++tab[i];
}
}
managerUnlock( manager );
}
/* Returns the pieces that are available from peers */
tr_bitfield*
tr_peerMgrGetAvailable( const tr_peerMgr * manager,
const uint8_t * torrentHash )
{
int i, size;
Torrent * t;
tr_peer ** peers;
tr_bitfield * pieces;
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
pieces = tr_bitfieldNew( t->tor->info.pieceCount );
peers = getConnectedPeers( t, &size );
for( i=0; i<size; ++i )
tr_bitfieldOr( pieces, peers[i]->have );
managerUnlock( manager );
tr_free( peers );
return pieces;
}
int
tr_peerMgrHasConnections( const tr_peerMgr * manager,
const uint8_t * torrentHash )
{
int ret;
const Torrent * t;
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
ret = t && ( !tr_ptrArrayEmpty( t->peers ) || !tr_ptrArrayEmpty( t->webseeds ) );
managerUnlock( manager );
return ret;
}
void
tr_peerMgrTorrentStats( const tr_peerMgr * manager,
const uint8_t * torrentHash,
int * setmePeersKnown,
int * setmePeersConnected,
int * setmeSeedsConnected,
int * setmeWebseedsSendingToUs,
int * setmePeersSendingToUs,
int * setmePeersGettingFromUs,
int * setmePeersFrom )
{
int i, size;
const Torrent * t;
const tr_peer ** peers;
const tr_webseed ** webseeds;
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
peers = (const tr_peer **) tr_ptrArrayPeek( t->peers, &size );
*setmePeersKnown = tr_ptrArraySize( t->pool );
*setmePeersConnected = 0;
*setmeSeedsConnected = 0;
*setmePeersGettingFromUs = 0;
*setmePeersSendingToUs = 0;
*setmeWebseedsSendingToUs = 0;
for( i=0; i<TR_PEER_FROM__MAX; ++i )
setmePeersFrom[i] = 0;
for( i=0; i<size; ++i )
{
const tr_peer * peer = peers[i];
const struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
if( peer->io == NULL ) /* not connected */
continue;
++*setmePeersConnected;
++setmePeersFrom[atom->from];
if( clientIsDownloadingFrom( peer ) )
++*setmePeersSendingToUs;
if( clientIsUploadingTo( peer ) )
++*setmePeersGettingFromUs;
if( atom->flags & ADDED_F_SEED_FLAG )
++*setmeSeedsConnected;
}
webseeds = (const tr_webseed **) tr_ptrArrayPeek( t->webseeds, &size );
for( i=0; i<size; ++i )
{
if( tr_webseedIsActive( webseeds[i] ) )
++*setmeWebseedsSendingToUs;
}
managerUnlock( manager );
}
float*
tr_peerMgrWebSpeeds( const tr_peerMgr * manager,
const uint8_t * torrentHash )
{
const Torrent * t;
const tr_webseed ** webseeds;
int i;
int webseedCount;
float * ret;
assert( manager );
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
webseeds = (const tr_webseed**) tr_ptrArrayPeek( t->webseeds, &webseedCount );
assert( webseedCount == t->tor->info.webseedCount );
ret = tr_new0( float, webseedCount );
for( i=0; i<webseedCount; ++i )
if( !tr_webseedGetSpeed( webseeds[i], &ret[i] ) )
ret[i] = -1.0;
managerUnlock( manager );
return ret;
}
struct tr_peer_stat *
tr_peerMgrPeerStats( const tr_peerMgr * manager,
const uint8_t * torrentHash,
int * setmeCount UNUSED )
{
int i, size;
const Torrent * t;
tr_peer ** peers;
tr_peer_stat * ret;
assert( manager );
managerLock( manager );
t = getExistingTorrent( (tr_peerMgr*)manager, torrentHash );
peers = getConnectedPeers( (Torrent*)t, &size );
ret = tr_new0( tr_peer_stat, size );
for( i=0; i<size; ++i )
{
char * pch;
const tr_peer * peer = peers[i];
const struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
tr_peer_stat * stat = ret + i;
tr_netNtop( &peer->in_addr, stat->addr, sizeof(stat->addr) );
tr_strlcpy( stat->client, (peer->client ? peer->client : ""), sizeof(stat->client) );
stat->port = peer->port;
stat->from = atom->from;
stat->progress = peer->progress;
stat->isEncrypted = tr_peerIoIsEncrypted( peer->io ) ? 1 : 0;
stat->uploadToRate = peer->rateToPeer;
stat->downloadFromRate = peer->rateToClient;
stat->peerIsChoked = peer->peerIsChoked;
stat->peerIsInterested = peer->peerIsInterested;
stat->clientIsChoked = peer->clientIsChoked;
stat->clientIsInterested = peer->clientIsInterested;
stat->isIncoming = tr_peerIoIsIncoming( peer->io );
stat->isDownloadingFrom = clientIsDownloadingFrom( peer );
stat->isUploadingTo = clientIsUploadingTo( peer );
pch = stat->flagStr;
if( t->optimistic == peer ) *pch++ = 'O';
if( stat->isDownloadingFrom ) *pch++ = 'D';
else if( stat->clientIsInterested ) *pch++ = 'd';
if( stat->isUploadingTo ) *pch++ = 'U';
else if( stat->peerIsInterested ) *pch++ = 'u';
if( !stat->clientIsChoked && !stat->clientIsInterested ) *pch++ = 'K';
if( !stat->peerIsChoked && !stat->peerIsInterested ) *pch++ = '?';
if( stat->isEncrypted ) *pch++ = 'E';
if( stat->from == TR_PEER_FROM_PEX ) *pch++ = 'X';
if( stat->isIncoming ) *pch++ = 'I';
*pch = '\0';
}
*setmeCount = size;
tr_free( peers );
managerUnlock( manager );
return ret;
}
/**
***
**/
struct ChokeData
{
unsigned int doUnchoke : 1;
unsigned int isInterested : 1;
tr_peer * peer;
};
static int
tr_compareDouble( double a, double b )
{
if( a < b ) return -1;
if( a > b ) return 1;
return 0;
}
static int
compareChoke( const void * va, const void * vb )
{
const struct ChokeData * a = va;
const struct ChokeData * b = vb;
int diff = 0;
if( diff == 0 ) /* prefer higher dl speeds */
diff = -tr_compareDouble( a->peer->rateToClient, b->peer->rateToClient );
if( diff == 0 ) /* prefer higher ul speeds */
diff = -tr_compareDouble( a->peer->rateToPeer, b->peer->rateToPeer );
if( diff == 0 ) /* prefer unchoked */
diff = (int)a->peer->peerIsChoked - (int)b->peer->peerIsChoked;
return diff;
}
static int
isNew( const tr_peer * peer )
{
return peer && peer->io && tr_peerIoGetAge( peer->io ) < 45;
}
static int
isSame( const tr_peer * peer )
{
return peer && peer->client && strstr( peer->client, "Transmission" );
}
/**
***
**/
static void
rechoke( Torrent * t )
{
int i, peerCount, size, unchokedInterested;
tr_peer ** peers = getConnectedPeers( t, &peerCount );
struct ChokeData * choke = tr_new0( struct ChokeData, peerCount );
assert( torrentIsLocked( t ) );
/* sort the peers by preference and rate */
for( i=0, size=0; i<peerCount; ++i )
{
tr_peer * peer = peers[i];
if( peer->progress >= 1.0 ) /* choke all seeds */
tr_peerMsgsSetChoke( peer->msgs, TRUE );
else {
struct ChokeData * node = &choke[size++];
node->peer = peer;
node->isInterested = peer->peerIsInterested;
}
}
qsort( choke, size, sizeof(struct ChokeData), compareChoke );
/**
* Reciprocation and number of uploads capping is managed by unchoking
* the N peers which have the best upload rate and are interested.
* This maximizes the client's download rate. These N peers are
* referred to as downloaders, because they are interested in downloading
* from the client.
*
* Peers which have a better upload rate (as compared to the downloaders)
* but aren't interested get unchoked. If they become interested, the
* downloader with the worst upload rate gets choked. If a client has
* a complete file, it uses its upload rate rather than its download
* rate to decide which peers to unchoke.
*/
unchokedInterested = 0;
for( i=0; i<size && unchokedInterested<MAX_UNCHOKED_PEERS; ++i ) {
choke[i].doUnchoke = 1;
if( choke[i].isInterested )
++unchokedInterested;
}
/* optimistic unchoke */
if( i < size )
{
int n;
struct ChokeData * c;
tr_ptrArray * randPool = tr_ptrArrayNew( );
for( ; i<size; ++i )
{
if( choke[i].isInterested )
{
const tr_peer * peer = choke[i].peer;
int x=1, y;
if( isNew( peer ) ) x *= 3;
if( isSame( peer ) ) x *= 3;
for( y=0; y<x; ++y )
tr_ptrArrayAppend( randPool, &choke[i] );
}
}
if(( n = tr_ptrArraySize( randPool )))
{
c = tr_ptrArrayNth( randPool, tr_stupidRandInt( n ));
c->doUnchoke = 1;
t->optimistic = c->peer;
}
tr_ptrArrayFree( randPool, NULL );
}
for( i=0; i<size; ++i )
tr_peerMsgsSetChoke( choke[i].peer->msgs, !choke[i].doUnchoke );
/* cleanup */
tr_free( choke );
tr_free( peers );
}
static int
rechokePulse( void * vtorrent )
{
Torrent * t = vtorrent;
torrentLock( t );
rechoke( t );
torrentUnlock( t );
return TRUE;
}
/***
****
**** Life and Death
****
***/
static int
shouldPeerBeClosed( const Torrent * t, const tr_peer * peer, int peerCount )
{
const tr_torrent * tor = t->tor;
const time_t now = time( NULL );
const struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
/* if it's marked for purging, close it */
if( peer->doPurge ) {
tordbg( t, "purging peer %s because its doPurge flag is set", tr_peerIoAddrStr(&atom->addr,atom->port) );
return TRUE;
}
/* if we're seeding and the peer has everything we have,
* and enough time has passed for a pex exchange, then disconnect */
if( tr_torrentIsSeed( tor ) ) {
int peerHasEverything;
if( atom->flags & ADDED_F_SEED_FLAG )
peerHasEverything = TRUE;
else if( peer->progress < tr_cpPercentDone( tor->completion ) )
peerHasEverything = FALSE;
else {
tr_bitfield * tmp = tr_bitfieldDup( tr_cpPieceBitfield( tor->completion ) );
tr_bitfieldDifference( tmp, peer->have );
peerHasEverything = tr_bitfieldCountTrueBits( tmp ) == 0;
tr_bitfieldFree( tmp );
}
if( peerHasEverything && ( !tr_torrentAllowsPex(tor) || (now-atom->time>=30) ) ) {
tordbg( t, "purging peer %s because we're both seeds", tr_peerIoAddrStr(&atom->addr,atom->port) );
return TRUE;
}
}
/* disconnect if it's been too long since piece data has been transferred.
* this is on a sliding scale based on number of available peers... */
{
const int relaxStrictnessIfFewerThanN = (int)((getMaxPeerCount(tor) * 0.9) + 0.5);
/* if we have >= relaxIfFewerThan, strictness is 100%.
* if we have zero connections, strictness is 0% */
const float strictness = peerCount >= relaxStrictnessIfFewerThanN
? 1.0
: peerCount / (float)relaxStrictnessIfFewerThanN;
const int lo = MIN_UPLOAD_IDLE_SECS;
const int hi = MAX_UPLOAD_IDLE_SECS;
const int limit = lo + ((hi-lo) * strictness);
const time_t then = peer->pieceDataActivityDate;
const int idleTime = then ? (now-then) : 0;
if( idleTime > limit ) {
tordbg( t, "purging peer %s because it's been %d secs since we shared anything",
tr_peerIoAddrStr(&atom->addr,atom->port), idleTime );
return TRUE;
}
}
return FALSE;
}
static tr_peer **
getPeersToClose( Torrent * t, int * setmeSize )
{
int i, peerCount, outsize;
tr_peer ** peers = (tr_peer**) tr_ptrArrayPeek( t->peers, &peerCount );
struct tr_peer ** ret = tr_new( tr_peer*, peerCount );
assert( torrentIsLocked( t ) );
for( i=outsize=0; i<peerCount; ++i )
if( shouldPeerBeClosed( t, peers[i], peerCount ) )
ret[outsize++] = peers[i];
*setmeSize = outsize;
return ret;
}
static int
compareCandidates( const void * va, const void * vb )
{
const struct peer_atom * a = * (const struct peer_atom**) va;
const struct peer_atom * b = * (const struct peer_atom**) vb;
int i;
if( a->piece_data_time > b->piece_data_time ) return -1;
if( a->piece_data_time < b->piece_data_time ) return 1;
if(( i = a->numFails - b->numFails ))
return i;
if( a->time != b->time )
return a->time < b->time ? -1 : 1;
return 0;
}
static int
getReconnectIntervalSecs( const struct peer_atom * atom )
{
int sec;
switch( atom->numFails )
{
case 0: sec = 0; break;
case 1: sec = 5; break;
case 2: sec = 2*60; break;
case 3: sec = 15*60; break;
case 4: sec = 30*60; break;
case 5: sec = 60*60; break;
default: sec = 120*60; break;
}
return sec;
}
static struct peer_atom **
getPeerCandidates( Torrent * t, int * setmeSize )
{
int i, atomCount, retCount;
struct peer_atom ** atoms;
struct peer_atom ** ret;
const time_t now = time( NULL );
const int seed = tr_torrentIsSeed( t->tor );
assert( torrentIsLocked( t ) );
atoms = (struct peer_atom**) tr_ptrArrayPeek( t->pool, &atomCount );
ret = tr_new( struct peer_atom*, atomCount );
for( i=retCount=0; i<atomCount; ++i )
{
struct peer_atom * atom = atoms[i];
/* peer fed us too much bad data ... we only keep it around
* now to weed it out in case someone sends it to us via pex */
if( atom->myflags & MYFLAG_BANNED )
continue;
/* peer was unconnectable before, so we're not going to keep trying.
* this is needs a separate flag from `banned', since if they try
* to connect to us later, we'll let them in */
if( atom->myflags & MYFLAG_UNREACHABLE )
continue;
/* we don't need two connections to the same peer... */
if( peerIsInUse( t, &atom->addr ) )
continue;
/* no need to connect if we're both seeds... */
if( seed && (atom->flags & ADDED_F_SEED_FLAG) )
continue;
/* If we were connected to this peer recently and transferring
* piece data, try to reconnect -- network troubles may have
* disconnected us. but if we weren't sharing piece data,
* hold off on this peer to give another one a try instead */
if( ( now - atom->piece_data_time ) > 10 )
{
const int wait = getReconnectIntervalSecs( atom );
if( ( now - atom->time ) < wait ) {
tordbg( t, "RECONNECT peer %d (%s) is in its grace period of %d seconds..",
i, tr_peerIoAddrStr(&atom->addr,atom->port), wait );
continue;
}
}
/* Don't connect to peers in our blocklist */
if( tr_sessionIsAddressBlocked( t->manager->handle, &atom->addr ) )
continue;
ret[retCount++] = atom;
}
qsort( ret, retCount, sizeof(struct peer_atom*), compareCandidates );
*setmeSize = retCount;
return ret;
}
static int
reconnectPulse( void * vtorrent )
{
Torrent * t = vtorrent;
static time_t prevTime = 0;
static int newConnectionsThisSecond = 0;
time_t now;
torrentLock( t );
now = time( NULL );
if( prevTime != now )
{
prevTime = now;
newConnectionsThisSecond = 0;
}
if( !t->isRunning )
{
removeAllPeers( t );
}
else
{
int i, nCandidates, nBad;
struct peer_atom ** candidates = getPeerCandidates( t, &nCandidates );
struct tr_peer ** connections = getPeersToClose( t, &nBad );
if( nBad || nCandidates )
tordbg( t, "reconnect pulse for [%s]: %d bad connections, "
"%d connection candidates, %d atoms, max per pulse is %d",
t->tor->info.name, nBad, nCandidates,
tr_ptrArraySize(t->pool),
(int)MAX_RECONNECTIONS_PER_PULSE );
/* disconnect some peers.
if we transferred piece data, then they might be good peers,
so reset their `numFails' weight to zero. otherwise we connected
to them fruitlessly, so mark it as another fail */
for( i=0; i<nBad; ++i ) {
tr_peer * peer = connections[i];
struct peer_atom * atom = getExistingAtom( t, &peer->in_addr );
if( peer->pieceDataActivityDate )
atom->numFails = 0;
else
++atom->numFails;
tordbg( t, "removing bad peer %s", tr_peerIoGetAddrStr( peer->io ) );
removePeer( t, peer );
}
/* add some new ones */
for( i=0; i < nCandidates
&& i < MAX_RECONNECTIONS_PER_PULSE
&& newConnectionsThisSecond < MAX_CONNECTIONS_PER_SECOND; ++i )
{
tr_peerMgr * mgr = t->manager;
struct peer_atom * atom = candidates[i];
tr_peerIo * io;
tordbg( t, "Starting an OUTGOING connection with %s",
tr_peerIoAddrStr( &atom->addr, atom->port ) );
io = tr_peerIoNewOutgoing( mgr->handle, &atom->addr, atom->port, t->hash );
if( io == NULL )
{
atom->myflags |= MYFLAG_UNREACHABLE;
}
else
{
tr_handshake * handshake = tr_handshakeNew( io,
mgr->handle->encryptionMode,
myHandshakeDoneCB,
mgr );
assert( tr_peerIoGetTorrentHash( io ) );
++newConnectionsThisSecond;
tr_ptrArrayInsertSorted( t->outgoingHandshakes, handshake, handshakeCompare );
}
atom->time = time( NULL );
}
/* cleanup */
tr_free( connections );
tr_free( candidates );
}
torrentUnlock( t );
return TRUE;
}
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