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transmission/libtransmission/peer-msgs.c

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/*
* This file Copyright (C) 2007-2008 Charles Kerr <charles@transmissionbt.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 <errno.h>
#include <limits.h> /* INT_MAX */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <event.h>
#include "transmission.h"
#include "session.h"
#include "bencode.h"
#include "completion.h"
#include "crypto.h"
#include "inout.h"
#ifdef WIN32
#include "net.h" /* for ECONN */
#endif
#include "peer-io.h"
#include "peer-mgr.h"
#include "peer-mgr-private.h"
#include "peer-msgs.h"
#include "platform.h" /* MAX_STACK_ARRAY_SIZE */
#include "ratecontrol.h"
#include "request-list.h"
#include "stats.h"
#include "torrent.h"
#include "trevent.h"
#include "utils.h"
/**
***
**/
enum
{
BT_CHOKE = 0,
BT_UNCHOKE = 1,
BT_INTERESTED = 2,
BT_NOT_INTERESTED = 3,
BT_HAVE = 4,
BT_BITFIELD = 5,
BT_REQUEST = 6,
BT_PIECE = 7,
BT_CANCEL = 8,
BT_PORT = 9,
BT_FEXT_SUGGEST = 13,
BT_FEXT_HAVE_ALL = 14,
BT_FEXT_HAVE_NONE = 15,
BT_FEXT_REJECT = 16,
BT_FEXT_ALLOWED_FAST = 17,
BT_LTEP = 20,
LTEP_HANDSHAKE = 0,
TR_LTEP_PEX = 1,
MIN_CHOKE_PERIOD_SEC = ( 10 ),
/* idle seconds before we send a keepalive */
KEEPALIVE_INTERVAL_SECS = 100,
PEX_INTERVAL = ( 90 * 1000 ), /* msec between sendPex() calls */
MAX_BLOCK_SIZE = ( 1024 * 16 ),
/* how long an unsent request can stay queued before it's returned
back to the peer-mgr's pool of requests */
QUEUED_REQUEST_TTL_SECS = 20,
/* how long a sent request can stay queued before it's returned
back to the peer-mgr's pool of requests */
SENT_REQUEST_TTL_SECS = 240,
/* used in lowering the outMessages queue period */
IMMEDIATE_PRIORITY_INTERVAL_SECS = 0,
HIGH_PRIORITY_INTERVAL_SECS = 2,
LOW_PRIORITY_INTERVAL_SECS = 20,
/* number of pieces to remove from the bitfield when
* lazy bitfields are turned on */
LAZY_PIECE_COUNT = 26,
/* number of pieces we'll allow in our fast set */
MAX_FAST_SET_SIZE = 3
};
enum
{
AWAITING_BT_LENGTH,
AWAITING_BT_ID,
AWAITING_BT_MESSAGE,
AWAITING_BT_PIECE
};
/**
***
**/
/* this is raw, unchanged data from the peer regarding
* the current message that it's sending us. */
struct tr_incoming
{
uint8_t id;
uint32_t length; /* includes the +1 for id length */
struct peer_request blockReq; /* metadata for incoming blocks */
struct evbuffer * block; /* piece data for incoming blocks */
};
/**
* Low-level communication state information about a connected peer.
*
* This structure remembers the low-level protocol states that we're
* in with this peer, such as active requests, pex messages, and so on.
* Its fields are all private to peer-msgs.c.
*
* Data not directly involved with sending & receiving messages is
* stored in tr_peer, where it can be accessed by both peermsgs and
* the peer manager.
*
* @see struct peer_atom
* @see tr_peer
*/
struct tr_peermsgs
{
tr_bool peerSupportsPex;
tr_bool clientSentLtepHandshake;
tr_bool peerSentLtepHandshake;
tr_bool haveFastSet;
uint8_t state;
uint8_t ut_pex_id;
uint16_t pexCount;
uint16_t pexCount6;
uint16_t maxActiveRequests;
size_t fastsetSize;
tr_piece_index_t fastset[MAX_FAST_SET_SIZE];
/* how long the outMessages batch should be allowed to grow before
* it's flushed -- some messages (like requests >:) should be sent
* very quickly; others aren't as urgent. */
int outMessagesBatchPeriod;
tr_peer * peer;
tr_session * session;
tr_torrent * torrent;
tr_publisher publisher;
struct evbuffer * outMessages; /* all the non-piece messages */
struct request_list peerAskedFor;
struct request_list clientAskedFor;
struct request_list clientWillAskFor;
tr_timer * pexTimer;
tr_pex * pex;
tr_pex * pex6;
time_t clientSentPexAt;
time_t clientSentAnythingAt;
/* when we started batching the outMessages */
time_t outMessagesBatchedAt;
struct tr_incoming incoming;
/* if the peer supports the Extension Protocol in BEP 10 and
supplied a reqq argument, it's stored here. otherwise the
value is zero and should be ignored. */
int64_t reqq;
};
/**
***
**/
static void
myDebug( const char * file, int line,
const struct tr_peermsgs * msgs,
const char * fmt, ... )
{
FILE * fp = tr_getLog( );
if( fp )
{
va_list args;
char timestr[64];
struct evbuffer * buf = tr_getBuffer( );
char * base = tr_basename( file );
evbuffer_add_printf( buf, "[%s] %s - %s [%s]: ",
tr_getLogTimeStr( timestr, sizeof( timestr ) ),
msgs->torrent->info.name,
tr_peerIoGetAddrStr( msgs->peer->io ),
msgs->peer->client );
va_start( args, fmt );
evbuffer_add_vprintf( buf, fmt, args );
va_end( args );
evbuffer_add_printf( buf, " (%s:%d)\n", base, line );
fwrite( EVBUFFER_DATA( buf ), 1, EVBUFFER_LENGTH( buf ), fp );
tr_free( base );
tr_releaseBuffer( buf );
}
}
#define dbgmsg( msgs, ... ) \
do { \
if( tr_deepLoggingIsActive( ) ) \
myDebug( __FILE__, __LINE__, msgs, __VA_ARGS__ ); \
} while( 0 )
/**
***
**/
static void
pokeBatchPeriod( tr_peermsgs * msgs,
int interval )
{
if( msgs->outMessagesBatchPeriod > interval )
{
msgs->outMessagesBatchPeriod = interval;
dbgmsg( msgs, "lowering batch interval to %d seconds", interval );
}
}
static inline void
dbgOutMessageLen( tr_peermsgs * msgs )
{
dbgmsg( msgs, "outMessage size is now %zu", EVBUFFER_LENGTH( msgs->outMessages ) );
}
static void
protocolSendReject( tr_peermsgs * msgs, const struct peer_request * req )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
assert( tr_peerIoSupportsFEXT( msgs->peer->io ) );
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) + 3 * sizeof( uint32_t ) );
tr_peerIoWriteUint8 ( io, out, BT_FEXT_REJECT );
tr_peerIoWriteUint32( io, out, req->index );
tr_peerIoWriteUint32( io, out, req->offset );
tr_peerIoWriteUint32( io, out, req->length );
dbgmsg( msgs, "rejecting %u:%u->%u...", req->index, req->offset, req->length );
dbgOutMessageLen( msgs );
}
static void
protocolSendRequest( tr_peermsgs * msgs,
const struct peer_request * req )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) + 3 * sizeof( uint32_t ) );
tr_peerIoWriteUint8 ( io, out, BT_REQUEST );
tr_peerIoWriteUint32( io, out, req->index );
tr_peerIoWriteUint32( io, out, req->offset );
tr_peerIoWriteUint32( io, out, req->length );
dbgmsg( msgs, "requesting %u:%u->%u...", req->index, req->offset, req->length );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
static void
protocolSendCancel( tr_peermsgs * msgs,
const struct peer_request * req )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) + 3 * sizeof( uint32_t ) );
tr_peerIoWriteUint8 ( io, out, BT_CANCEL );
tr_peerIoWriteUint32( io, out, req->index );
tr_peerIoWriteUint32( io, out, req->offset );
tr_peerIoWriteUint32( io, out, req->length );
dbgmsg( msgs, "cancelling %u:%u->%u...", req->index, req->offset, req->length );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
static void
protocolSendHave( tr_peermsgs * msgs,
uint32_t index )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
tr_peerIoWriteUint32( io, out, sizeof(uint8_t) + sizeof(uint32_t) );
tr_peerIoWriteUint8 ( io, out, BT_HAVE );
tr_peerIoWriteUint32( io, out, index );
dbgmsg( msgs, "sending Have %u", index );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, LOW_PRIORITY_INTERVAL_SECS );
}
#if 0
static void
protocolSendAllowedFast( tr_peermsgs * msgs, uint32_t pieceIndex )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
assert( tr_peerIoSupportsFEXT( msgs->peer->io ) );
tr_peerIoWriteUint32( io, out, sizeof(uint8_t) + sizeof(uint32_t) );
tr_peerIoWriteUint8 ( io, out, BT_FEXT_ALLOWED_FAST );
tr_peerIoWriteUint32( io, out, pieceIndex );
dbgmsg( msgs, "sending Allowed Fast %u...", pieceIndex );
dbgOutMessageLen( msgs );
}
#endif
static void
protocolSendChoke( tr_peermsgs * msgs,
int choke )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) );
tr_peerIoWriteUint8 ( io, out, choke ? BT_CHOKE : BT_UNCHOKE );
dbgmsg( msgs, "sending %s...", choke ? "Choke" : "Unchoke" );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
static void
protocolSendHaveAll( tr_peermsgs * msgs )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
assert( tr_peerIoSupportsFEXT( msgs->peer->io ) );
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) );
tr_peerIoWriteUint8 ( io, out, BT_FEXT_HAVE_ALL );
dbgmsg( msgs, "sending HAVE_ALL..." );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
static void
protocolSendHaveNone( tr_peermsgs * msgs )
{
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = msgs->outMessages;
assert( tr_peerIoSupportsFEXT( msgs->peer->io ) );
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) );
tr_peerIoWriteUint8 ( io, out, BT_FEXT_HAVE_NONE );
dbgmsg( msgs, "sending HAVE_NONE..." );
dbgOutMessageLen( msgs );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
/**
*** EVENTS
**/
static const tr_peer_event blankEvent = { 0, 0, 0, 0, 0.0f, 0, 0, 0 };
static void
publish( tr_peermsgs * msgs, tr_peer_event * e )
{
assert( msgs->peer );
assert( msgs->peer->msgs == msgs );
tr_publisherPublish( &msgs->publisher, msgs->peer, e );
}
static void
fireError( tr_peermsgs * msgs, int err )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_ERROR;
e.err = err;
publish( msgs, &e );
}
static void
fireUploadOnly( tr_peermsgs * msgs, tr_bool uploadOnly )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_UPLOAD_ONLY;
e.uploadOnly = uploadOnly;
publish( msgs, &e );
}
static void
fireNeedReq( tr_peermsgs * msgs )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_NEED_REQ;
publish( msgs, &e );
}
static void
firePeerProgress( tr_peermsgs * msgs )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_PEER_PROGRESS;
e.progress = msgs->peer->progress;
publish( msgs, &e );
}
static void
fireGotBlock( tr_peermsgs * msgs, const struct peer_request * req )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_CLIENT_GOT_BLOCK;
e.pieceIndex = req->index;
e.offset = req->offset;
e.length = req->length;
publish( msgs, &e );
}
static void
fireClientGotData( tr_peermsgs * msgs,
uint32_t length,
int wasPieceData )
{
tr_peer_event e = blankEvent;
e.length = length;
e.eventType = TR_PEER_CLIENT_GOT_DATA;
e.wasPieceData = wasPieceData;
publish( msgs, &e );
}
static void
fireClientGotSuggest( tr_peermsgs * msgs, uint32_t pieceIndex )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_CLIENT_GOT_SUGGEST;
e.pieceIndex = pieceIndex;
publish( msgs, &e );
}
static void
fireClientGotAllowedFast( tr_peermsgs * msgs, uint32_t pieceIndex )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_CLIENT_GOT_ALLOWED_FAST;
e.pieceIndex = pieceIndex;
publish( msgs, &e );
}
static void
firePeerGotData( tr_peermsgs * msgs,
uint32_t length,
int wasPieceData )
{
tr_peer_event e = blankEvent;
e.length = length;
e.eventType = TR_PEER_PEER_GOT_DATA;
e.wasPieceData = wasPieceData;
publish( msgs, &e );
}
static void
fireCancelledReq( tr_peermsgs * msgs, const struct peer_request * req )
{
tr_peer_event e = blankEvent;
e.eventType = TR_PEER_CANCEL;
e.pieceIndex = req->index;
e.offset = req->offset;
e.length = req->length;
publish( msgs, &e );
}
/**
*** ALLOWED FAST SET
*** For explanation, see http://www.bittorrent.org/beps/bep_0006.html
**/
size_t
tr_generateAllowedSet( tr_piece_index_t * setmePieces,
size_t desiredSetSize,
size_t pieceCount,
const uint8_t * infohash,
const tr_address * addr )
{
size_t setSize = 0;
assert( setmePieces );
assert( desiredSetSize <= pieceCount );
assert( desiredSetSize );
assert( pieceCount );
assert( infohash );
assert( addr );
if( addr->type == TR_AF_INET )
{
uint8_t w[SHA_DIGEST_LENGTH + 4];
uint8_t x[SHA_DIGEST_LENGTH];
*(uint32_t*)w = ntohl( htonl( addr->addr.addr4.s_addr ) & 0xffffff00 ); /* (1) */
memcpy( w + 4, infohash, SHA_DIGEST_LENGTH ); /* (2) */
tr_sha1( x, w, sizeof( w ), NULL ); /* (3) */
while( setSize<desiredSetSize )
{
int i;
for( i=0; i<5 && setSize<desiredSetSize; ++i ) /* (4) */
{
size_t k;
uint32_t j = i * 4; /* (5) */
uint32_t y = ntohl( *( uint32_t* )( x + j ) ); /* (6) */
uint32_t index = y % pieceCount; /* (7) */
for( k=0; k<setSize; ++k ) /* (8) */
if( setmePieces[k] == index )
break;
if( k == setSize )
setmePieces[setSize++] = index; /* (9) */
}
tr_sha1( x, x, sizeof( x ), NULL ); /* (3) */
}
}
return setSize;
}
static void
updateFastSet( tr_peermsgs * msgs UNUSED )
{
#if 0
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
const int peerIsNeedy = msgs->peer->progress < 0.10;
if( fext && peerIsNeedy && !msgs->haveFastSet )
{
size_t i;
const struct tr_address * addr = tr_peerIoGetAddress( msgs->peer->io, NULL );
const tr_info * inf = &msgs->torrent->info;
const size_t numwant = MIN( MAX_FAST_SET_SIZE, inf->pieceCount );
/* build the fast set */
msgs->fastsetSize = tr_generateAllowedSet( msgs->fastset, numwant, inf->pieceCount, inf->hash, addr );
msgs->haveFastSet = 1;
/* send it to the peer */
for( i=0; i<msgs->fastsetSize; ++i )
protocolSendAllowedFast( msgs, msgs->fastset[i] );
}
#endif
}
/**
*** INTEREST
**/
static int
isPieceInteresting( const tr_peermsgs * msgs,
tr_piece_index_t piece )
{
const tr_torrent * torrent = msgs->torrent;
return ( !torrent->info.pieces[piece].dnd ) /* we want it */
&& ( !tr_cpPieceIsComplete( &torrent->completion, piece ) ) /* !have */
&& ( tr_bitfieldHas( msgs->peer->have, piece ) ); /* peer has it */
}
/* "interested" means we'll ask for piece data if they unchoke us */
static int
isPeerInteresting( const tr_peermsgs * msgs )
{
tr_piece_index_t i;
const tr_torrent * torrent;
const tr_bitfield * bitfield;
const int clientIsSeed = tr_torrentIsSeed( msgs->torrent );
if( clientIsSeed )
return FALSE;
if( !tr_torrentIsPieceTransferAllowed( msgs->torrent, TR_PEER_TO_CLIENT ) )
return FALSE;
torrent = msgs->torrent;
bitfield = tr_cpPieceBitfield( &torrent->completion );
if( !msgs->peer->have )
return TRUE;
assert( bitfield->byteCount == msgs->peer->have->byteCount );
for( i = 0; i < torrent->info.pieceCount; ++i )
if( isPieceInteresting( msgs, i ) )
return TRUE;
return FALSE;
}
static void
sendInterest( tr_peermsgs * msgs,
int weAreInterested )
{
struct evbuffer * out = msgs->outMessages;
assert( msgs );
assert( weAreInterested == 0 || weAreInterested == 1 );
msgs->peer->clientIsInterested = weAreInterested;
dbgmsg( msgs, "Sending %s", weAreInterested ? "Interested" : "Not Interested" );
tr_peerIoWriteUint32( msgs->peer->io, out, sizeof( uint8_t ) );
tr_peerIoWriteUint8 ( msgs->peer->io, out, weAreInterested ? BT_INTERESTED : BT_NOT_INTERESTED );
pokeBatchPeriod( msgs, HIGH_PRIORITY_INTERVAL_SECS );
dbgOutMessageLen( msgs );
}
static void
updateInterest( tr_peermsgs * msgs )
{
const int i = isPeerInteresting( msgs );
if( i != msgs->peer->clientIsInterested )
sendInterest( msgs, i );
if( i )
fireNeedReq( msgs );
}
static int
popNextRequest( tr_peermsgs * msgs,
struct peer_request * setme )
{
return reqListPop( &msgs->peerAskedFor, setme );
}
static void
cancelAllRequestsToClient( tr_peermsgs * msgs )
{
struct peer_request req;
const int mustSendCancel = tr_peerIoSupportsFEXT( msgs->peer->io );
while( popNextRequest( msgs, &req ) )
if( mustSendCancel )
protocolSendReject( msgs, &req );
}
void
tr_peerMsgsSetChoke( tr_peermsgs * msgs,
int choke )
{
const time_t now = time( NULL );
const time_t fibrillationTime = now - MIN_CHOKE_PERIOD_SEC;
assert( msgs );
assert( msgs->peer );
assert( choke == 0 || choke == 1 );
if( msgs->peer->chokeChangedAt > fibrillationTime )
{
dbgmsg( msgs, "Not changing choke to %d to avoid fibrillation", choke );
}
else if( msgs->peer->peerIsChoked != choke )
{
msgs->peer->peerIsChoked = choke;
if( choke )
cancelAllRequestsToClient( msgs );
protocolSendChoke( msgs, choke );
msgs->peer->chokeChangedAt = now;
}
}
/**
***
**/
void
tr_peerMsgsHave( tr_peermsgs * msgs,
uint32_t index )
{
protocolSendHave( msgs, index );
/* since we have more pieces now, we might not be interested in this peer */
updateInterest( msgs );
}
/**
***
**/
static int
reqIsValid( const tr_peermsgs * peer,
uint32_t index,
uint32_t offset,
uint32_t length )
{
return tr_torrentReqIsValid( peer->torrent, index, offset, length );
}
static int
requestIsValid( const tr_peermsgs * msgs, const struct peer_request * req )
{
return reqIsValid( msgs, req->index, req->offset, req->length );
}
static void
expireFromList( tr_peermsgs * msgs,
struct request_list * list,
const time_t oldestAllowed )
{
size_t i;
struct request_list tmp = REQUEST_LIST_INIT;
/* since the fifo list is sorted by time, the oldest will be first */
if( !list->len || ( list->fifo[0].time_requested >= oldestAllowed ) )
return;
/* if we found one too old, start pruning them */
reqListCopy( &tmp, list );
for( i=0; i<tmp.len; ++i ) {
const struct peer_request * req = &tmp.fifo[i];
if( req->time_requested >= oldestAllowed )
break;
tr_peerMsgsCancel( msgs, req->index, req->offset, req->length );
}
reqListClear( &tmp );
}
static void
expireOldRequests( tr_peermsgs * msgs, const time_t now )
{
time_t oldestAllowed;
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
dbgmsg( msgs, "entering `expire old requests' block" );
/* cancel requests that have been queued for too long */
oldestAllowed = now - QUEUED_REQUEST_TTL_SECS;
expireFromList( msgs, &msgs->clientWillAskFor, oldestAllowed );
/* if the peer doesn't support "Reject Request",
* cancel requests that were sent too long ago. */
if( !fext ) {
oldestAllowed = now - SENT_REQUEST_TTL_SECS;
expireFromList( msgs, &msgs->clientAskedFor, oldestAllowed );
}
dbgmsg( msgs, "leaving `expire old requests' block" );
}
static void
pumpRequestQueue( tr_peermsgs * msgs, const time_t now )
{
const int max = msgs->maxActiveRequests;
int sent = 0;
int len = msgs->clientAskedFor.len;
struct peer_request req;
if( msgs->peer->clientIsChoked )
return;
if( !tr_torrentIsPieceTransferAllowed( msgs->torrent, TR_PEER_TO_CLIENT ) )
return;
while( ( len < max ) && reqListPop( &msgs->clientWillAskFor, &req ) )
{
const tr_block_index_t block = _tr_block( msgs->torrent, req.index, req.offset );
assert( requestIsValid( msgs, &req ) );
assert( tr_bitfieldHas( msgs->peer->have, req.index ) );
/* don't ask for it if we've already got it... this block may have
* come in from a different peer after we cancelled a request for it */
if( !tr_cpBlockIsComplete( &msgs->torrent->completion, block ) )
{
protocolSendRequest( msgs, &req );
req.time_requested = now;
reqListAppend( &msgs->clientAskedFor, &req );
++len;
++sent;
}
}
if( sent )
dbgmsg( msgs, "pump sent %d requests, now have %d active and %d queued",
sent, msgs->clientAskedFor.len, msgs->clientWillAskFor.len );
if( len < max )
fireNeedReq( msgs );
}
static inline int
requestQueueIsFull( const tr_peermsgs * msgs )
{
const int req_max = msgs->maxActiveRequests;
return msgs->clientWillAskFor.len >= (size_t)req_max;
}
tr_addreq_t
tr_peerMsgsAddRequest( tr_peermsgs * msgs,
uint32_t index,
uint32_t offset,
uint32_t length )
{
struct peer_request req;
assert( msgs );
assert( msgs->torrent );
assert( reqIsValid( msgs, index, offset, length ) );
/**
*** Reasons to decline the request
**/
/* don't send requests to choked clients */
if( msgs->peer->clientIsChoked ) {
dbgmsg( msgs, "declining request because they're choking us" );
return TR_ADDREQ_CLIENT_CHOKED;
}
/* peer doesn't have this piece */
if( !tr_bitfieldHas( msgs->peer->have, index ) )
return TR_ADDREQ_MISSING;
/* peer's queue is full */
if( requestQueueIsFull( msgs ) ) {
dbgmsg( msgs, "declining request because we're full" );
return TR_ADDREQ_FULL;
}
/* have we already asked for this piece? */
req.index = index;
req.offset = offset;
req.length = length;
if( reqListHas( &msgs->clientAskedFor, &req ) ) {
dbgmsg( msgs, "declining because it's a duplicate" );
return TR_ADDREQ_DUPLICATE;
}
if( reqListHas( &msgs->clientWillAskFor, &req ) ) {
dbgmsg( msgs, "declining because it's a duplicate" );
return TR_ADDREQ_DUPLICATE;
}
/**
*** Accept this request
**/
dbgmsg( msgs, "adding req for %"PRIu32":%"PRIu32"->%"PRIu32" to our `will request' list",
index, offset, length );
req.time_requested = time( NULL );
reqListAppend( &msgs->clientWillAskFor, &req );
return TR_ADDREQ_OK;
}
static void
cancelAllRequestsToPeer( tr_peermsgs * msgs, tr_bool sendCancel )
{
size_t i;
struct request_list a = msgs->clientWillAskFor;
struct request_list b = msgs->clientAskedFor;
dbgmsg( msgs, "cancelling all requests to peer" );
msgs->clientAskedFor = REQUEST_LIST_INIT;
msgs->clientWillAskFor = REQUEST_LIST_INIT;
for( i=0; i<a.len; ++i )
fireCancelledReq( msgs, &a.fifo[i] );
for( i = 0; i < b.len; ++i ) {
fireCancelledReq( msgs, &b.fifo[i] );
if( sendCancel )
protocolSendCancel( msgs, &b.fifo[i] );
}
reqListClear( &a );
reqListClear( &b );
}
void
tr_peerMsgsCancel( tr_peermsgs * msgs,
uint32_t pieceIndex,
uint32_t offset,
uint32_t length )
{
struct peer_request req;
assert( msgs != NULL );
assert( length > 0 );
/* have we asked the peer for this piece? */
req.index = pieceIndex;
req.offset = offset;
req.length = length;
/* if it's only in the queue and hasn't been sent yet, free it */
if( reqListRemove( &msgs->clientWillAskFor, &req ) ) {
dbgmsg( msgs, "cancelling %"PRIu32":%"PRIu32"->%"PRIu32, pieceIndex, offset, length );
fireCancelledReq( msgs, &req );
}
/* if it's already been sent, send a cancel message too */
if( reqListRemove( &msgs->clientAskedFor, &req ) ) {
dbgmsg( msgs, "cancelling %"PRIu32":%"PRIu32"->%"PRIu32, pieceIndex, offset, length );
protocolSendCancel( msgs, &req );
fireCancelledReq( msgs, &req );
}
}
/**
***
**/
static void
sendLtepHandshake( tr_peermsgs * msgs )
{
tr_benc val, *m;
char * buf;
int len;
int pex;
struct evbuffer * out = msgs->outMessages;
if( msgs->clientSentLtepHandshake )
return;
dbgmsg( msgs, "sending an ltep handshake" );
msgs->clientSentLtepHandshake = 1;
/* decide if we want to advertise pex support */
if( !tr_torrentAllowsPex( msgs->torrent ) )
pex = 0;
else if( msgs->peerSentLtepHandshake )
pex = msgs->peerSupportsPex ? 1 : 0;
else
pex = 1;
tr_bencInitDict( &val, 5 );
tr_bencDictAddInt( &val, "e", msgs->session->encryptionMode != TR_CLEAR_PREFERRED );
tr_bencDictAddInt( &val, "p", tr_sessionGetPeerPort( msgs->session ) );
tr_bencDictAddInt( &val, "upload_only", tr_torrentIsSeed( msgs->torrent ) );
tr_bencDictAddStr( &val, "v", TR_NAME " " USERAGENT_PREFIX );
m = tr_bencDictAddDict( &val, "m", 1 );
if( pex )
tr_bencDictAddInt( m, "ut_pex", TR_LTEP_PEX );
buf = tr_bencSave( &val, &len );
tr_peerIoWriteUint32( msgs->peer->io, out, 2 * sizeof( uint8_t ) + len );
tr_peerIoWriteUint8 ( msgs->peer->io, out, BT_LTEP );
tr_peerIoWriteUint8 ( msgs->peer->io, out, LTEP_HANDSHAKE );
tr_peerIoWriteBytes ( msgs->peer->io, out, buf, len );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
dbgOutMessageLen( msgs );
/* cleanup */
tr_bencFree( &val );
tr_free( buf );
}
static void
parseLtepHandshake( tr_peermsgs * msgs,
int len,
struct evbuffer * inbuf )
{
int64_t i;
tr_benc val, * sub;
uint8_t * tmp = tr_new( uint8_t, len );
tr_peerIoReadBytes( msgs->peer->io, inbuf, tmp, len );
msgs->peerSentLtepHandshake = 1;
if( tr_bencLoad( tmp, len, &val, NULL ) || !tr_bencIsDict( &val ) )
{
dbgmsg( msgs, "GET extended-handshake, couldn't get dictionary" );
tr_free( tmp );
return;
}
dbgmsg( msgs, "here is the handshake: [%*.*s]", len, len, tmp );
/* does the peer prefer encrypted connections? */
if( tr_bencDictFindInt( &val, "e", &i ) )
msgs->peer->encryption_preference = i ? ENCRYPTION_PREFERENCE_YES
: ENCRYPTION_PREFERENCE_NO;
/* check supported messages for utorrent pex */
msgs->peerSupportsPex = 0;
if( tr_bencDictFindDict( &val, "m", &sub ) ) {
if( tr_bencDictFindInt( sub, "ut_pex", &i ) ) {
msgs->ut_pex_id = (uint8_t) i;
msgs->peerSupportsPex = msgs->ut_pex_id == 0 ? 0 : 1;
dbgmsg( msgs, "msgs->ut_pex is %d", (int)msgs->ut_pex_id );
}
}
/* look for upload_only (BEP 21) */
if( tr_bencDictFindInt( &val, "upload_only", &i ) )
fireUploadOnly( msgs, i!=0 );
/* get peer's listening port */
if( tr_bencDictFindInt( &val, "p", &i ) ) {
msgs->peer->port = htons( (uint16_t)i );
dbgmsg( msgs, "msgs->port is now %hu", msgs->peer->port );
}
/* get peer's maximum request queue size */
if( tr_bencDictFindInt( &val, "reqq", &i ) )
msgs->reqq = i;
tr_bencFree( &val );
tr_free( tmp );
}
static void
parseUtPex( tr_peermsgs * msgs, int msglen, struct evbuffer * inbuf )
{
int loaded = 0;
uint8_t * tmp = tr_new( uint8_t, msglen );
tr_benc val;
const tr_torrent * tor = msgs->torrent;
const uint8_t * added;
size_t added_len;
tr_peerIoReadBytes( msgs->peer->io, inbuf, tmp, msglen );
if( tr_torrentAllowsPex( tor )
&& ( ( loaded = !tr_bencLoad( tmp, msglen, &val, NULL ) ) ) )
{
if( tr_bencDictFindRaw( &val, "added", &added, &added_len ) )
{
const uint8_t * added_f = NULL;
tr_pex * pex;
size_t i, n;
size_t added_f_len = 0;
tr_bencDictFindRaw( &val, "added.f", &added_f, &added_f_len );
pex =
tr_peerMgrCompactToPex( added, added_len, added_f, added_f_len,
&n );
for( i = 0; i < n; ++i )
tr_peerMgrAddPex( msgs->session->peerMgr, tor->info.hash,
TR_PEER_FROM_PEX, pex + i );
tr_free( pex );
}
if( tr_bencDictFindRaw( &val, "added6", &added, &added_len ) )
{
const uint8_t * added_f = NULL;
tr_pex * pex;
size_t i, n;
size_t added_f_len = 0;
tr_bencDictFindRaw( &val, "added6.f", &added_f, &added_f_len );
pex =
tr_peerMgrCompact6ToPex( added, added_len, added_f, added_f_len,
&n );
for( i = 0; i < n; ++i )
tr_peerMgrAddPex( msgs->session->peerMgr, tor->info.hash,
TR_PEER_FROM_PEX, pex + i );
tr_free( pex );
}
}
if( loaded )
tr_bencFree( &val );
tr_free( tmp );
}
static void sendPex( tr_peermsgs * msgs );
static void
parseLtep( tr_peermsgs * msgs,
int msglen,
struct evbuffer * inbuf )
{
uint8_t ltep_msgid;
tr_peerIoReadUint8( msgs->peer->io, inbuf, &ltep_msgid );
msglen--;
if( ltep_msgid == LTEP_HANDSHAKE )
{
dbgmsg( msgs, "got ltep handshake" );
parseLtepHandshake( msgs, msglen, inbuf );
if( tr_peerIoSupportsLTEP( msgs->peer->io ) )
{
sendLtepHandshake( msgs );
sendPex( msgs );
}
}
else if( ltep_msgid == TR_LTEP_PEX )
{
dbgmsg( msgs, "got ut pex" );
msgs->peerSupportsPex = 1;
parseUtPex( msgs, msglen, inbuf );
}
else
{
dbgmsg( msgs, "skipping unknown ltep message (%d)", (int)ltep_msgid );
evbuffer_drain( inbuf, msglen );
}
}
static int
readBtLength( tr_peermsgs * msgs,
struct evbuffer * inbuf,
size_t inlen )
{
uint32_t len;
if( inlen < sizeof( len ) )
return READ_LATER;
tr_peerIoReadUint32( msgs->peer->io, inbuf, &len );
if( len == 0 ) /* peer sent us a keepalive message */
dbgmsg( msgs, "got KeepAlive" );
else
{
msgs->incoming.length = len;
msgs->state = AWAITING_BT_ID;
}
return READ_NOW;
}
static int readBtMessage( tr_peermsgs * msgs,
struct evbuffer * inbuf,
size_t inlen );
static int
readBtId( tr_peermsgs * msgs,
struct evbuffer * inbuf,
size_t inlen )
{
uint8_t id;
if( inlen < sizeof( uint8_t ) )
return READ_LATER;
tr_peerIoReadUint8( msgs->peer->io, inbuf, &id );
msgs->incoming.id = id;
if( id == BT_PIECE )
{
msgs->state = AWAITING_BT_PIECE;
return READ_NOW;
}
else if( msgs->incoming.length != 1 )
{
msgs->state = AWAITING_BT_MESSAGE;
return READ_NOW;
}
else return readBtMessage( msgs, inbuf, inlen - 1 );
}
static void
updatePeerProgress( tr_peermsgs * msgs )
{
msgs->peer->progress = tr_bitfieldCountTrueBits( msgs->peer->have ) / (float)msgs->torrent->info.pieceCount;
dbgmsg( msgs, "peer progress is %f", msgs->peer->progress );
updateFastSet( msgs );
updateInterest( msgs );
firePeerProgress( msgs );
}
static void
peerMadeRequest( tr_peermsgs * msgs,
const struct peer_request * req )
{
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
const int reqIsValid = requestIsValid( msgs, req );
const int clientHasPiece = reqIsValid && tr_cpPieceIsComplete( &msgs->torrent->completion, req->index );
const int peerIsChoked = msgs->peer->peerIsChoked;
int allow = FALSE;
if( !reqIsValid )
dbgmsg( msgs, "rejecting an invalid request." );
else if( !clientHasPiece )
dbgmsg( msgs, "rejecting request for a piece we don't have." );
else if( peerIsChoked )
dbgmsg( msgs, "rejecting request from choked peer" );
else
allow = TRUE;
if( allow )
reqListAppend( &msgs->peerAskedFor, req );
else if( fext )
protocolSendReject( msgs, req );
}
static int
messageLengthIsCorrect( const tr_peermsgs * msg, uint8_t id, uint32_t len )
{
switch( id )
{
case BT_CHOKE:
case BT_UNCHOKE:
case BT_INTERESTED:
case BT_NOT_INTERESTED:
case BT_FEXT_HAVE_ALL:
case BT_FEXT_HAVE_NONE:
return len == 1;
case BT_HAVE:
case BT_FEXT_SUGGEST:
case BT_FEXT_ALLOWED_FAST:
return len == 5;
case BT_BITFIELD:
return len == ( msg->torrent->info.pieceCount + 7u ) / 8u + 1u;
case BT_REQUEST:
case BT_CANCEL:
case BT_FEXT_REJECT:
return len == 13;
case BT_PIECE:
return len > 9 && len <= 16393;
case BT_PORT:
return len == 3;
case BT_LTEP:
return len >= 2;
default:
return FALSE;
}
}
static int clientGotBlock( tr_peermsgs * msgs,
const uint8_t * block,
const struct peer_request * req );
static int
readBtPiece( tr_peermsgs * msgs,
struct evbuffer * inbuf,
size_t inlen,
size_t * setme_piece_bytes_read )
{
struct peer_request * req = &msgs->incoming.blockReq;
assert( EVBUFFER_LENGTH( inbuf ) >= inlen );
dbgmsg( msgs, "In readBtPiece" );
if( !req->length )
{
if( inlen < 8 )
return READ_LATER;
tr_peerIoReadUint32( msgs->peer->io, inbuf, &req->index );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &req->offset );
req->length = msgs->incoming.length - 9;
dbgmsg( msgs, "got incoming block header %u:%u->%u", req->index, req->offset, req->length );
return READ_NOW;
}
else
{
int err;
/* read in another chunk of data */
const size_t nLeft = req->length - EVBUFFER_LENGTH( msgs->incoming.block );
size_t n = MIN( nLeft, inlen );
size_t i = n;
while( i > 0 )
{
uint8_t buf[MAX_STACK_ARRAY_SIZE];
const size_t thisPass = MIN( i, sizeof( buf ) );
tr_peerIoReadBytes( msgs->peer->io, inbuf, buf, thisPass );
evbuffer_add( msgs->incoming.block, buf, thisPass );
i -= thisPass;
}
fireClientGotData( msgs, n, TRUE );
*setme_piece_bytes_read += n;
dbgmsg( msgs, "got %zu bytes for block %u:%u->%u ... %d remain",
n, req->index, req->offset, req->length,
(int)( req->length - EVBUFFER_LENGTH( msgs->incoming.block ) ) );
if( EVBUFFER_LENGTH( msgs->incoming.block ) < req->length )
return READ_LATER;
/* we've got the whole block ... process it */
err = clientGotBlock( msgs, EVBUFFER_DATA( msgs->incoming.block ), req );
/* cleanup */
evbuffer_drain( msgs->incoming.block, EVBUFFER_LENGTH( msgs->incoming.block ) );
req->length = 0;
msgs->state = AWAITING_BT_LENGTH;
if( !err )
return READ_NOW;
else {
fireError( msgs, err );
return READ_ERR;
}
}
}
static int
readBtMessage( tr_peermsgs * msgs, struct evbuffer * inbuf, size_t inlen )
{
uint32_t ui32;
uint32_t msglen = msgs->incoming.length;
const uint8_t id = msgs->incoming.id;
const size_t startBufLen = EVBUFFER_LENGTH( inbuf );
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
--msglen; /* id length */
if( inlen < msglen )
return READ_LATER;
dbgmsg( msgs, "got BT id %d, len %d, buffer size is %zu", (int)id, (int)msglen, inlen );
if( !messageLengthIsCorrect( msgs, id, msglen + 1 ) )
{
dbgmsg( msgs, "bad packet - BT message #%d with a length of %d", (int)id, (int)msglen );
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
switch( id )
{
case BT_CHOKE:
dbgmsg( msgs, "got Choke" );
msgs->peer->clientIsChoked = 1;
if( !fext )
cancelAllRequestsToPeer( msgs, FALSE );
break;
case BT_UNCHOKE:
dbgmsg( msgs, "got Unchoke" );
msgs->peer->clientIsChoked = 0;
fireNeedReq( msgs );
break;
case BT_INTERESTED:
dbgmsg( msgs, "got Interested" );
msgs->peer->peerIsInterested = 1;
break;
case BT_NOT_INTERESTED:
dbgmsg( msgs, "got Not Interested" );
msgs->peer->peerIsInterested = 0;
break;
case BT_HAVE:
tr_peerIoReadUint32( msgs->peer->io, inbuf, &ui32 );
dbgmsg( msgs, "got Have: %u", ui32 );
if( tr_bitfieldAdd( msgs->peer->have, ui32 ) ) {
fireError( msgs, ERANGE );
return READ_ERR;
}
updatePeerProgress( msgs );
tr_rcTransferred( &msgs->torrent->swarmSpeed,
msgs->torrent->info.pieceSize );
break;
case BT_BITFIELD:
{
dbgmsg( msgs, "got a bitfield" );
tr_peerIoReadBytes( msgs->peer->io, inbuf, msgs->peer->have->bits, msglen );
updatePeerProgress( msgs );
fireNeedReq( msgs );
break;
}
case BT_REQUEST:
{
struct peer_request r;
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.index );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.offset );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.length );
dbgmsg( msgs, "got Request: %u:%u->%u", r.index, r.offset, r.length );
peerMadeRequest( msgs, &r );
break;
}
case BT_CANCEL:
{
struct peer_request r;
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.index );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.offset );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.length );
dbgmsg( msgs, "got a Cancel %u:%u->%u", r.index, r.offset, r.length );
if( reqListRemove( &msgs->peerAskedFor, &r ) && fext )
protocolSendReject( msgs, &r );
break;
}
case BT_PIECE:
assert( 0 ); /* handled elsewhere! */
break;
case BT_PORT:
dbgmsg( msgs, "Got a BT_PORT" );
tr_peerIoReadUint16( msgs->peer->io, inbuf, &msgs->peer->port );
break;
case BT_FEXT_SUGGEST:
dbgmsg( msgs, "Got a BT_FEXT_SUGGEST" );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &ui32 );
if( fext )
fireClientGotSuggest( msgs, ui32 );
else {
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
break;
case BT_FEXT_ALLOWED_FAST:
dbgmsg( msgs, "Got a BT_FEXT_ALLOWED_FAST" );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &ui32 );
if( fext )
fireClientGotAllowedFast( msgs, ui32 );
else {
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
break;
case BT_FEXT_HAVE_ALL:
dbgmsg( msgs, "Got a BT_FEXT_HAVE_ALL" );
if( fext ) {
tr_bitfieldAddRange( msgs->peer->have, 0, msgs->torrent->info.pieceCount );
updatePeerProgress( msgs );
} else {
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
break;
case BT_FEXT_HAVE_NONE:
dbgmsg( msgs, "Got a BT_FEXT_HAVE_NONE" );
if( fext ) {
tr_bitfieldClear( msgs->peer->have );
updatePeerProgress( msgs );
} else {
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
break;
case BT_FEXT_REJECT:
{
struct peer_request r;
dbgmsg( msgs, "Got a BT_FEXT_REJECT" );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.index );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.offset );
tr_peerIoReadUint32( msgs->peer->io, inbuf, &r.length );
if( fext )
reqListRemove( &msgs->clientAskedFor, &r );
else {
fireError( msgs, EMSGSIZE );
return READ_ERR;
}
break;
}
case BT_LTEP:
dbgmsg( msgs, "Got a BT_LTEP" );
parseLtep( msgs, msglen, inbuf );
break;
default:
dbgmsg( msgs, "peer sent us an UNKNOWN: %d", (int)id );
tr_peerIoDrain( msgs->peer->io, inbuf, msglen );
break;
}
assert( msglen + 1 == msgs->incoming.length );
assert( EVBUFFER_LENGTH( inbuf ) == startBufLen - msglen );
msgs->state = AWAITING_BT_LENGTH;
return READ_NOW;
}
static inline void
decrementDownloadedCount( tr_peermsgs * msgs, uint32_t byteCount )
{
tr_torrent * tor = msgs->torrent;
tor->downloadedCur -= MIN( tor->downloadedCur, byteCount );
}
static inline void
clientGotUnwantedBlock( tr_peermsgs * msgs, const struct peer_request * req )
{
decrementDownloadedCount( msgs, req->length );
}
static void
addPeerToBlamefield( tr_peermsgs * msgs, uint32_t index )
{
if( !msgs->peer->blame )
msgs->peer->blame = tr_bitfieldNew( msgs->torrent->info.pieceCount );
tr_bitfieldAdd( msgs->peer->blame, index );
}
/* returns 0 on success, or an errno on failure */
static int
clientGotBlock( tr_peermsgs * msgs,
const uint8_t * data,
const struct peer_request * req )
{
int err;
tr_torrent * tor = msgs->torrent;
const tr_block_index_t block = _tr_block( tor, req->index, req->offset );
assert( msgs );
assert( req );
if( req->length != tr_torBlockCountBytes( msgs->torrent, block ) ) {
dbgmsg( msgs, "wrong block size -- expected %u, got %d",
tr_torBlockCountBytes( msgs->torrent, block ), req->length );
return EMSGSIZE;
}
/* save the block */
dbgmsg( msgs, "got block %u:%u->%u", req->index, req->offset, req->length );
/**
*** Remove the block from our `we asked for this' list
**/
if( !reqListRemove( &msgs->clientAskedFor, req ) ) {
clientGotUnwantedBlock( msgs, req );
dbgmsg( msgs, "we didn't ask for this message..." );
return 0;
}
dbgmsg( msgs, "peer has %d more blocks we've asked for",
msgs->clientAskedFor.len );
/**
*** Error checks
**/
if( tr_cpBlockIsComplete( &tor->completion, block ) ) {
dbgmsg( msgs, "we have this block already..." );
clientGotUnwantedBlock( msgs, req );
return 0;
}
/**
*** Save the block
**/
if(( err = tr_ioWrite( tor, req->index, req->offset, req->length, data )))
return err;
addPeerToBlamefield( msgs, req->index );
fireGotBlock( msgs, req );
return 0;
}
static int peerPulse( void * vmsgs );
static void
didWrite( tr_peerIo * io UNUSED, size_t bytesWritten, int wasPieceData, void * vmsgs )
{
tr_peermsgs * msgs = vmsgs;
firePeerGotData( msgs, bytesWritten, wasPieceData );
peerPulse( msgs );
}
static ReadState
canRead( tr_peerIo * io, void * vmsgs, size_t * piece )
{
ReadState ret;
tr_peermsgs * msgs = vmsgs;
struct evbuffer * in = tr_peerIoGetReadBuffer( io );
const size_t inlen = EVBUFFER_LENGTH( in );
if( !inlen )
{
ret = READ_LATER;
}
else if( msgs->state == AWAITING_BT_PIECE )
{
ret = inlen ? readBtPiece( msgs, in, inlen, piece ) : READ_LATER;
}
else switch( msgs->state )
{
case AWAITING_BT_LENGTH:
ret = readBtLength ( msgs, in, inlen ); break;
case AWAITING_BT_ID:
ret = readBtId ( msgs, in, inlen ); break;
case AWAITING_BT_MESSAGE:
ret = readBtMessage( msgs, in, inlen ); break;
default:
assert( 0 );
}
/* log the raw data that was read */
if( ( ret != READ_ERR ) && ( EVBUFFER_LENGTH( in ) != inlen ) )
fireClientGotData( msgs, inlen - EVBUFFER_LENGTH( in ), FALSE );
return ret;
}
/**
***
**/
static int
ratePulse( tr_peermsgs * msgs, uint64_t now )
{
const double rateToClient = tr_peerGetPieceSpeed( msgs->peer, now, TR_PEER_TO_CLIENT );
const int seconds = 10;
const int floor = 8;
const int estimatedBlocksInPeriod = ( rateToClient * seconds * 1024 ) / msgs->torrent->blockSize;
msgs->maxActiveRequests = floor + estimatedBlocksInPeriod;
if( msgs->reqq > 0 )
msgs->maxActiveRequests = MIN( msgs->maxActiveRequests, msgs->reqq );
return TRUE;
}
static size_t
fillOutputBuffer( tr_peermsgs * msgs, time_t now )
{
size_t bytesWritten = 0;
struct peer_request req;
const tr_bool haveMessages = EVBUFFER_LENGTH( msgs->outMessages ) != 0;
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
/**
*** Protocol messages
**/
if( haveMessages && !msgs->outMessagesBatchedAt ) /* fresh batch */
{
dbgmsg( msgs, "started an outMessages batch (length is %zu)", EVBUFFER_LENGTH( msgs->outMessages ) );
msgs->outMessagesBatchedAt = now;
}
else if( haveMessages && ( ( now - msgs->outMessagesBatchedAt ) >= msgs->outMessagesBatchPeriod ) )
{
const size_t len = EVBUFFER_LENGTH( msgs->outMessages );
/* flush the protocol messages */
dbgmsg( msgs, "flushing outMessages... to %p (length is %zu)", msgs->peer->io, len );
tr_peerIoWriteBuf( msgs->peer->io, msgs->outMessages, FALSE );
msgs->clientSentAnythingAt = now;
msgs->outMessagesBatchedAt = 0;
msgs->outMessagesBatchPeriod = LOW_PRIORITY_INTERVAL_SECS;
bytesWritten += len;
}
/**
*** Blocks
**/
if( ( tr_peerIoGetWriteBufferSpace( msgs->peer->io, now ) >= msgs->torrent->blockSize )
&& popNextRequest( msgs, &req ) )
{
if( requestIsValid( msgs, &req )
&& tr_cpPieceIsComplete( &msgs->torrent->completion, req.index ) )
{
int err;
static uint8_t buf[MAX_BLOCK_SIZE];
/* send a block */
if(( err = tr_ioRead( msgs->torrent, req.index, req.offset, req.length, buf ))) {
fireError( msgs, err );
bytesWritten = 0;
msgs = NULL;
} else {
tr_peerIo * io = msgs->peer->io;
struct evbuffer * out = tr_getBuffer( );
dbgmsg( msgs, "sending block %u:%u->%u", req.index, req.offset, req.length );
tr_peerIoWriteUint32( io, out, sizeof( uint8_t ) + 2 * sizeof( uint32_t ) + req.length );
tr_peerIoWriteUint8 ( io, out, BT_PIECE );
tr_peerIoWriteUint32( io, out, req.index );
tr_peerIoWriteUint32( io, out, req.offset );
tr_peerIoWriteBytes ( io, out, buf, req.length );
tr_peerIoWriteBuf( io, out, TRUE );
bytesWritten += EVBUFFER_LENGTH( out );
msgs->clientSentAnythingAt = now;
tr_releaseBuffer( out );
}
}
else if( fext ) /* peer needs a reject message */
{
protocolSendReject( msgs, &req );
}
}
/**
*** Keepalive
**/
if( ( msgs != NULL )
&& ( msgs->clientSentAnythingAt != 0 )
&& ( ( now - msgs->clientSentAnythingAt ) > KEEPALIVE_INTERVAL_SECS ) )
{
dbgmsg( msgs, "sending a keepalive message" );
tr_peerIoWriteUint32( msgs->peer->io, msgs->outMessages, 0 );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
}
return bytesWritten;
}
static int
peerPulse( void * vmsgs )
{
tr_peermsgs * msgs = vmsgs;
const time_t now = time( NULL );
ratePulse( msgs, now );
pumpRequestQueue( msgs, now );
expireOldRequests( msgs, now );
for( ;; )
if( fillOutputBuffer( msgs, now ) < 1 )
break;
return TRUE; /* loop forever */
}
void
tr_peerMsgsPulse( tr_peermsgs * msgs )
{
if( msgs != NULL )
peerPulse( msgs );
}
static void
gotError( tr_peerIo * io UNUSED,
short what,
void * vmsgs )
{
if( what & EVBUFFER_TIMEOUT )
dbgmsg( vmsgs, "libevent got a timeout, what=%hd", what );
if( what & ( EVBUFFER_EOF | EVBUFFER_ERROR ) )
dbgmsg( vmsgs, "libevent got an error! what=%hd, errno=%d (%s)",
what, errno, tr_strerror( errno ) );
fireError( vmsgs, ENOTCONN );
}
static void
sendBitfield( tr_peermsgs * msgs )
{
struct evbuffer * out = msgs->outMessages;
tr_bitfield * field;
tr_piece_index_t lazyPieces[LAZY_PIECE_COUNT];
size_t i;
size_t lazyCount = 0;
field = tr_bitfieldDup( tr_cpPieceBitfield( &msgs->torrent->completion ) );
if( tr_sessionIsLazyBitfieldEnabled( msgs->session ) )
{
/** Lazy bitfields aren't a high priority or secure, so I'm opting for
speed over a truly random sample -- let's limit the pool size to
the first 1000 pieces so large torrents don't bog things down */
size_t poolSize;
const size_t maxPoolSize = MIN( msgs->torrent->info.pieceCount, 1000 );
tr_piece_index_t * pool = tr_new( tr_piece_index_t, maxPoolSize );
/* build the pool */
for( i=poolSize=0; i<maxPoolSize; ++i )
if( tr_bitfieldHas( field, i ) )
pool[poolSize++] = i;
/* pull random piece indices from the pool */
while( ( poolSize > 0 ) && ( lazyCount < LAZY_PIECE_COUNT ) )
{
const int pos = tr_cryptoWeakRandInt( poolSize );
const tr_piece_index_t piece = pool[pos];
tr_bitfieldRem( field, piece );
lazyPieces[lazyCount++] = piece;
pool[pos] = pool[--poolSize];
}
/* cleanup */
tr_free( pool );
}
tr_peerIoWriteUint32( msgs->peer->io, out,
sizeof( uint8_t ) + field->byteCount );
tr_peerIoWriteUint8 ( msgs->peer->io, out, BT_BITFIELD );
tr_peerIoWriteBytes ( msgs->peer->io, out, field->bits, field->byteCount );
dbgmsg( msgs, "sending bitfield... outMessage size is now %zu",
EVBUFFER_LENGTH( out ) );
pokeBatchPeriod( msgs, IMMEDIATE_PRIORITY_INTERVAL_SECS );
for( i = 0; i < lazyCount; ++i )
protocolSendHave( msgs, lazyPieces[i] );
tr_bitfieldFree( field );
}
static void
tellPeerWhatWeHave( tr_peermsgs * msgs )
{
const tr_bool fext = tr_peerIoSupportsFEXT( msgs->peer->io );
if( fext && ( tr_cpGetStatus( &msgs->torrent->completion ) == TR_SEED ) )
{
protocolSendHaveAll( msgs );
}
else if( fext && ( tr_cpHaveValid( &msgs->torrent->completion ) == 0 ) )
{
protocolSendHaveNone( msgs );
}
else
{
sendBitfield( msgs );
}
}
/**
***
**/
/* some peers give us error messages if we send
more than this many peers in a single pex message
http://wiki.theory.org/BitTorrentPeerExchangeConventions */
#define MAX_PEX_ADDED 50
#define MAX_PEX_DROPPED 50
typedef struct
{
tr_pex * added;
tr_pex * dropped;
tr_pex * elements;
int addedCount;
int droppedCount;
int elementCount;
}
PexDiffs;
static void
pexAddedCb( void * vpex,
void * userData )
{
PexDiffs * diffs = userData;
tr_pex * pex = vpex;
if( diffs->addedCount < MAX_PEX_ADDED )
{
diffs->added[diffs->addedCount++] = *pex;
diffs->elements[diffs->elementCount++] = *pex;
}
}
static inline void
pexDroppedCb( void * vpex,
void * userData )
{
PexDiffs * diffs = userData;
tr_pex * pex = vpex;
if( diffs->droppedCount < MAX_PEX_DROPPED )
{
diffs->dropped[diffs->droppedCount++] = *pex;
}
}
static inline void
pexElementCb( void * vpex,
void * userData )
{
PexDiffs * diffs = userData;
tr_pex * pex = vpex;
diffs->elements[diffs->elementCount++] = *pex;
}
static void
sendPex( tr_peermsgs * msgs )
{
if( msgs->peerSupportsPex && tr_torrentAllowsPex( msgs->torrent ) )
{
PexDiffs diffs;
PexDiffs diffs6;
tr_pex * newPex = NULL;
tr_pex * newPex6 = NULL;
const int newCount = tr_peerMgrGetPeers( msgs->session->peerMgr,
msgs->torrent->info.hash,
&newPex, TR_AF_INET );
const int newCount6 = tr_peerMgrGetPeers( msgs->session->peerMgr,
msgs->torrent->info.hash,
&newPex6, TR_AF_INET6 );
/* build the diffs */
diffs.added = tr_new( tr_pex, newCount );
diffs.addedCount = 0;
diffs.dropped = tr_new( tr_pex, msgs->pexCount );
diffs.droppedCount = 0;
diffs.elements = tr_new( tr_pex, newCount + msgs->pexCount );
diffs.elementCount = 0;
tr_set_compare( msgs->pex, msgs->pexCount,
newPex, newCount,
tr_pexCompare, sizeof( tr_pex ),
pexDroppedCb, pexAddedCb, pexElementCb, &diffs );
diffs6.added = tr_new( tr_pex, newCount6 );
diffs6.addedCount = 0;
diffs6.dropped = tr_new( tr_pex, msgs->pexCount6 );
diffs6.droppedCount = 0;
diffs6.elements = tr_new( tr_pex, newCount6 + msgs->pexCount6 );
diffs6.elementCount = 0;
tr_set_compare( msgs->pex6, msgs->pexCount6,
newPex6, newCount6,
tr_pexCompare, sizeof( tr_pex ),
pexDroppedCb, pexAddedCb, pexElementCb, &diffs6 );
dbgmsg(
msgs,
"pex: old peer count %d, new peer count %d, added %d, removed %d",
msgs->pexCount, newCount + newCount6,
diffs.addedCount + diffs6.addedCount,
diffs.droppedCount + diffs6.droppedCount );
if( !diffs.addedCount && !diffs.droppedCount && !diffs6.addedCount &&
!diffs6.droppedCount )
{
tr_free( diffs.elements );
tr_free( diffs6.elements );
}
else
{
int i;
tr_benc val;
char * benc;
int bencLen;
uint8_t * tmp, *walk;
struct evbuffer * out = msgs->outMessages;
/* update peer */
tr_free( msgs->pex );
msgs->pex = diffs.elements;
msgs->pexCount = diffs.elementCount;
tr_free( msgs->pex6 );
msgs->pex6 = diffs6.elements;
msgs->pexCount6 = diffs6.elementCount;
/* build the pex payload */
tr_bencInitDict( &val, 3 ); /* ipv6 support: left as 3:
* speed vs. likelihood? */
/* "added" */
tmp = walk = tr_new( uint8_t, diffs.addedCount * 6 );
for( i = 0; i < diffs.addedCount; ++i )
{
tr_suspectAddress( &diffs.added[i].addr, "pex" );
memcpy( walk, &diffs.added[i].addr.addr, 4 ); walk += 4;
memcpy( walk, &diffs.added[i].port, 2 ); walk += 2;
}
assert( ( walk - tmp ) == diffs.addedCount * 6 );
tr_bencDictAddRaw( &val, "added", tmp, walk - tmp );
tr_free( tmp );
/* "added.f" */
tmp = walk = tr_new( uint8_t, diffs.addedCount );
for( i = 0; i < diffs.addedCount; ++i )
*walk++ = diffs.added[i].flags;
assert( ( walk - tmp ) == diffs.addedCount );
tr_bencDictAddRaw( &val, "added.f", tmp, walk - tmp );
tr_free( tmp );
/* "dropped" */
tmp = walk = tr_new( uint8_t, diffs.droppedCount * 6 );
for( i = 0; i < diffs.droppedCount; ++i )
{
memcpy( walk, &diffs.dropped[i].addr.addr, 4 ); walk += 4;
memcpy( walk, &diffs.dropped[i].port, 2 ); walk += 2;
}
assert( ( walk - tmp ) == diffs.droppedCount * 6 );
tr_bencDictAddRaw( &val, "dropped", tmp, walk - tmp );
tr_free( tmp );
/* "added6" */
tmp = walk = tr_new( uint8_t, diffs6.addedCount * 18 );
for( i = 0; i < diffs6.addedCount; ++i )
{
tr_suspectAddress( &diffs6.added[i].addr, "pex6" );
memcpy( walk, &diffs6.added[i].addr.addr.addr6.s6_addr, 16 );
walk += 16;
memcpy( walk, &diffs6.added[i].port, 2 );
walk += 2;
}
assert( ( walk - tmp ) == diffs6.addedCount * 18 );
tr_bencDictAddRaw( &val, "added6", tmp, walk - tmp );
tr_free( tmp );
/* "added6.f" */
tmp = walk = tr_new( uint8_t, diffs6.addedCount );
for( i = 0; i < diffs6.addedCount; ++i )
*walk++ = diffs6.added[i].flags;
assert( ( walk - tmp ) == diffs6.addedCount );
tr_bencDictAddRaw( &val, "added6.f", tmp, walk - tmp );
tr_free( tmp );
/* "dropped6" */
tmp = walk = tr_new( uint8_t, diffs6.droppedCount * 18 );
for( i = 0; i < diffs6.droppedCount; ++i )
{
memcpy( walk, &diffs6.dropped[i].addr.addr.addr6.s6_addr, 16 );
walk += 16;
memcpy( walk, &diffs6.dropped[i].port, 2 );
walk += 2;
}
assert( ( walk - tmp ) == diffs6.droppedCount * 18);
tr_bencDictAddRaw( &val, "dropped6", tmp, walk - tmp );
tr_free( tmp );
/* write the pex message */
benc = tr_bencSave( &val, &bencLen );
tr_peerIoWriteUint32( msgs->peer->io, out, 2 * sizeof( uint8_t ) + bencLen );
tr_peerIoWriteUint8 ( msgs->peer->io, out, BT_LTEP );
tr_peerIoWriteUint8 ( msgs->peer->io, out, msgs->ut_pex_id );
tr_peerIoWriteBytes ( msgs->peer->io, out, benc, bencLen );
pokeBatchPeriod( msgs, HIGH_PRIORITY_INTERVAL_SECS );
dbgmsg( msgs, "sending a pex message; outMessage size is now %zu", EVBUFFER_LENGTH( out ) );
tr_free( benc );
tr_bencFree( &val );
}
/* cleanup */
tr_free( diffs.added );
tr_free( diffs.dropped );
tr_free( newPex );
tr_free( diffs6.added );
tr_free( diffs6.dropped );
tr_free( newPex6 );
msgs->clientSentPexAt = time( NULL );
}
}
static inline int
pexPulse( void * vpeer )
{
sendPex( vpeer );
return TRUE;
}
/**
***
**/
tr_peermsgs*
tr_peerMsgsNew( struct tr_torrent * torrent,
struct tr_peer * peer,
tr_delivery_func func,
void * userData,
tr_publisher_tag * setme )
{
tr_peermsgs * m;
assert( peer );
assert( peer->io );
m = tr_new0( tr_peermsgs, 1 );
m->publisher = TR_PUBLISHER_INIT;
m->peer = peer;
m->session = torrent->session;
m->torrent = torrent;
m->peer->clientIsChoked = 1;
m->peer->peerIsChoked = 1;
m->peer->clientIsInterested = 0;
m->peer->peerIsInterested = 0;
m->peer->have = tr_bitfieldNew( torrent->info.pieceCount );
m->state = AWAITING_BT_LENGTH;
m->pexTimer = tr_timerNew( m->session, pexPulse, m, PEX_INTERVAL );
m->outMessages = evbuffer_new( );
m->outMessagesBatchedAt = 0;
m->outMessagesBatchPeriod = LOW_PRIORITY_INTERVAL_SECS;
m->incoming.block = evbuffer_new( );
m->peerAskedFor = REQUEST_LIST_INIT;
m->clientAskedFor = REQUEST_LIST_INIT;
m->clientWillAskFor = REQUEST_LIST_INIT;
peer->msgs = m;
*setme = tr_publisherSubscribe( &m->publisher, func, userData );
if( tr_peerIoSupportsLTEP( peer->io ) )
sendLtepHandshake( m );
tellPeerWhatWeHave( m );
tr_peerIoSetIOFuncs( m->peer->io, canRead, didWrite, gotError, m );
ratePulse( m, tr_date() );
return m;
}
void
tr_peerMsgsFree( tr_peermsgs* msgs )
{
if( msgs )
{
tr_timerFree( &msgs->pexTimer );
tr_publisherDestruct( &msgs->publisher );
reqListClear( &msgs->clientWillAskFor );
reqListClear( &msgs->clientAskedFor );
reqListClear( &msgs->peerAskedFor );
evbuffer_free( msgs->incoming.block );
evbuffer_free( msgs->outMessages );
tr_free( msgs->pex6 );
tr_free( msgs->pex );
memset( msgs, ~0, sizeof( tr_peermsgs ) );
tr_free( msgs );
}
}
void
tr_peerMsgsUnsubscribe( tr_peermsgs * peer,
tr_publisher_tag tag )
{
tr_publisherUnsubscribe( &peer->publisher, tag );
}
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