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transmission/libtransmission/peer-msgs.c

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/*
* This file Copyright (C) 2007 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 <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/types.h> /* event.h needs this */
#include <event.h>
#include "transmission.h"
#include "bencode.h"
#include "completion.h"
#include "inout.h"
#include "list.h"
#include "peer-io.h"
#include "peer-mgr.h"
#include "peer-mgr-private.h"
#include "peer-msgs.h"
#include "ratecontrol.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_SUGGEST = 13,
BT_HAVE_ALL = 14,
BT_HAVE_NONE = 15,
BT_REJECT = 16,
BT_ALLOWED_FAST = 17,
BT_LTEP = 20,
LTEP_HANDSHAKE = 0,
OUR_LTEP_PEX = 1,
MAX_REQUEST_BYTE_COUNT = (16 * 1024), /* drop requests who want too much */
KEEPALIVE_INTERVAL_SECS = 90, /* idle seconds before we send a keepalive */
PEX_INTERVAL = (60 * 1000), /* msec between calls to sendPex() */
PEER_PULSE_INTERVAL = (100), /* msec between calls to pulse() */
};
enum
{
AWAITING_BT_LENGTH,
AWAITING_BT_MESSAGE,
READING_BT_PIECE
};
struct peer_request
{
uint32_t index;
uint32_t offset;
uint32_t length;
time_t time_requested;
};
static int
peer_request_compare( const void * va, const void * vb )
{
struct peer_request * a = (struct peer_request*) va;
struct peer_request * b = (struct peer_request*) vb;
if( a->index != b->index ) return a->index - b->index;
if( a->offset != b->offset ) return a->offset - b->offset;
if( a->length != b->length ) return a->length - b->length;
return 0;
}
struct tr_peermsgs
{
tr_peer * info;
tr_handle * handle;
tr_torrent * torrent;
tr_peerIo * io;
tr_publisher_t * publisher;
struct evbuffer * outMessages; /* buffer of all the non-piece messages */
struct evbuffer * outBlock; /* the block we're currently sending */
struct evbuffer * inBlock; /* the block we're currently receiving */
tr_list * peerAskedFor;
tr_list * clientAskedFor;
tr_timer * pulseTimer;
tr_timer * pexTimer;
struct peer_request blockToUs; /* the block currntly being sent to us */
time_t lastReqAddedAt;
time_t clientSentPexAt;
time_t clientSentAnythingAt;
unsigned int notListening : 1;
unsigned int peerSupportsPex : 1;
unsigned int hasSentLtepHandshake : 1;
uint8_t state;
uint8_t ut_pex_id;
uint16_t pexCount;
uint32_t incomingMessageLength;
tr_pex * pex;
};
/**
***
**/
static void
myDebug( const char * file, int line, const struct tr_peermsgs * msgs, const char * fmt, ... )
{
FILE * fp = tr_getLog( );
if( fp != NULL )
{
va_list args;
const char * addr = tr_peerIoGetAddrStr( msgs->io );
struct evbuffer * buf = evbuffer_new( );
evbuffer_add_printf( buf, "[%s:%d] %s (%p) ", file, line, addr, msgs );
va_start( args, fmt );
evbuffer_add_vprintf( buf, fmt, args );
va_end( args );
fprintf( fp, "%s\n", EVBUFFER_DATA(buf) );
evbuffer_free( buf );
}
}
#define dbgmsg(handshake, fmt...) myDebug(__FILE__, __LINE__, handshake, ##fmt )
/**
*** EVENTS
**/
static const tr_peermsgs_event blankEvent = { 0, 0, 0, 0, 0.0f };
static void
publish( tr_peermsgs * msgs, tr_peermsgs_event * e )
{
tr_publisherPublish( msgs->publisher, msgs->info, e );
}
static void
fireGotError( tr_peermsgs * msgs )
{
tr_peermsgs_event e = blankEvent;
e.eventType = TR_PEERMSG_GOT_ERROR;
publish( msgs, &e );
}
static void
fireNeedReq( tr_peermsgs * msgs )
{
tr_peermsgs_event e = blankEvent;
e.eventType = TR_PEERMSG_NEED_REQ;
publish( msgs, &e );
}
static void
firePeerProgress( tr_peermsgs * msgs )
{
tr_peermsgs_event e = blankEvent;
e.eventType = TR_PEERMSG_PEER_PROGRESS;
e.progress = msgs->info->progress;
publish( msgs, &e );
}
static void
fireClientHave( tr_peermsgs * msgs, uint32_t pieceIndex )
{
tr_peermsgs_event e = blankEvent;
e.eventType = TR_PEERMSG_CLIENT_HAVE;
e.pieceIndex = pieceIndex;
publish( msgs, &e );
}
static void
fireGotBlock( tr_peermsgs * msgs, uint32_t pieceIndex, uint32_t offset, uint32_t length )
{
tr_peermsgs_event e = blankEvent;
e.eventType = TR_PEERMSG_CLIENT_BLOCK;
e.pieceIndex = pieceIndex;
e.offset = offset;
e.length = length;
publish( msgs, &e );
}
/**
*** INTEREST
**/
static int
isPieceInteresting( const tr_peermsgs * peer,
int piece )
{
const tr_torrent * torrent = peer->torrent;
if( torrent->info.pieces[piece].dnd ) /* we don't want it */
return FALSE;
if( tr_cpPieceIsComplete( torrent->completion, piece ) ) /* we already have it */
return FALSE;
if( !tr_bitfieldHas( peer->info->have, piece ) ) /* peer doesn't have it */
return FALSE;
if( tr_bitfieldHas( peer->info->banned, piece ) ) /* peer is banned for it */
return FALSE;
return TRUE;
}
static int
isPeerInteresting( const tr_peermsgs * msgs )
{
const int clientIsSeed = tr_cpGetStatus( msgs->torrent->completion ) != TR_CP_INCOMPLETE;
const int peerIsSeed = msgs->info->progress >= 1.0;
if( peerIsSeed )
{
return !clientIsSeed;
}
else if( clientIsSeed )
{
return !peerIsSeed;
}
else /* we're both leeches... */
{
int i;
const tr_torrent * torrent = msgs->torrent;
const tr_bitfield * bitfield = tr_cpPieceBitfield( torrent->completion );
if( !msgs->info->have ) /* We don't know what this peer has... what should this be? */
return TRUE;
assert( bitfield->len == msgs->info->have->len );
for( i=0; i<torrent->info.pieceCount; ++i )
if( isPieceInteresting( msgs, i ) )
return TRUE;
return FALSE;
}
}
static void
sendInterest( tr_peermsgs * msgs, int weAreInterested )
{
assert( msgs != NULL );
assert( weAreInterested==0 || weAreInterested==1 );
msgs->info->clientIsInterested = weAreInterested;
dbgmsg( msgs, ": sending an %s message", (weAreInterested ? "INTERESTED" : "NOT_INTERESTED") );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, weAreInterested ? BT_INTERESTED : BT_NOT_INTERESTED );
}
static void
updateInterest( tr_peermsgs * msgs )
{
const int i = isPeerInteresting( msgs );
if( i != msgs->info->clientIsInterested )
sendInterest( msgs, i );
if( i )
fireNeedReq( msgs );
}
void
tr_peerMsgsSetChoke( tr_peermsgs * msgs, int choke )
{
assert( msgs != NULL );
assert( msgs->info != NULL );
assert( choke==0 || choke==1 );
if( msgs->info->peerIsChoked != choke )
{
msgs->info->peerIsChoked = choke ? 1 : 0;
if( msgs->info )
{
tr_list_foreach( msgs->peerAskedFor, tr_free );
tr_list_free( &msgs->peerAskedFor );
}
dbgmsg( msgs, "sending a %s message", (choke ? "CHOKE" : "UNCHOKE") );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, choke ? BT_CHOKE : BT_UNCHOKE );
}
}
/**
***
**/
void
tr_peerMsgsCancel( tr_peermsgs * msgs,
uint32_t pieceIndex,
uint32_t offset,
uint32_t length )
{
tr_list * node;
struct peer_request tmp;
assert( msgs != NULL );
assert( length > 0 );
tmp.index = pieceIndex;
tmp.offset = offset;
tmp.length = length;
node = tr_list_find( msgs->clientAskedFor, &tmp, peer_request_compare );
if( node != NULL )
{
/* cancel the request */
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) + 3*sizeof(uint32_t) );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, BT_CANCEL );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, pieceIndex );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, offset );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, length );
/* remove it from our "requested" list */
tr_list_remove_data( &msgs->peerAskedFor, node->data );
}
}
/**
***
**/
void
tr_peerMsgsHave( tr_peermsgs * msgs,
uint32_t pieceIndex )
{
dbgmsg( msgs, "w00t telling them we HAVE piece #%d", pieceIndex );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) + sizeof(uint32_t) );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, BT_HAVE );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, pieceIndex );
updateInterest( msgs );
}
/**
***
**/
static int
pulse( void * vmsgs );
static int
reqIsValid( const tr_peermsgs * msgs, uint32_t index, uint32_t offset, uint32_t length )
{
const tr_torrent * tor = msgs->torrent;
if( index >= (uint32_t) tor->info.pieceCount )
return FALSE;
if ( (int)offset >= tr_torPieceCountBytes( tor, (int)index ) )
return FALSE;
if( length > MAX_REQUEST_BYTE_COUNT )
return FALSE;
if( tr_pieceOffset( tor, index, offset, length ) > tor->info.totalSize )
return FALSE;
return TRUE;
}
static int
requestIsValid( const tr_peermsgs * msgs, struct peer_request * req )
{
return reqIsValid( msgs, req->index, req->offset, req->length );
}
int
tr_peerMsgsAddRequest( tr_peermsgs * msgs,
uint32_t index,
uint32_t offset,
uint32_t length )
{
struct peer_request * req;
int maxSize;
assert( msgs != NULL );
assert( msgs->torrent != NULL );
assert( reqIsValid( msgs, index, offset, length ) );
if( msgs->info->clientIsChoked )
return TR_ADDREQ_CLIENT_CHOKED;
if( !tr_bitfieldHas( msgs->info->have, index ) )
return TR_ADDREQ_MISSING;
maxSize = MIN( 2 + (int)(tr_peerIoGetRateToClient(msgs->io)/10), 100 );
//if( ( time(NULL) - msgs->lastReqAddedAt <= 5 ) && ( tr_list_size( msgs->clientAskedFor) >= maxSize ) )
if( tr_list_size( msgs->clientAskedFor) >= maxSize )
return TR_ADDREQ_FULL;
dbgmsg( msgs, "w00t peer has a max request queue size of %d... adding request for piece %d, offset %d", maxSize, (int)index, (int)offset );
/* queue the request */
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) + 3*sizeof(uint32_t) );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, BT_REQUEST );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, index );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, offset );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, length );
/* add it to our `requests sent' list */
req = tr_new( struct peer_request, 1 );
req->index = index;
req->offset = offset;
req->length = length;
req->time_requested = msgs->lastReqAddedAt = time( NULL );
tr_list_append( &msgs->clientAskedFor, req );
pulse( msgs );
return TR_ADDREQ_OK;
}
/**
***
**/
static void
sendLtepHandshake( tr_peermsgs * msgs )
{
benc_val_t val, *m;
char * buf;
int len;
const char * v = TR_NAME " " USERAGENT_PREFIX;
const int port = tr_getPublicPort( msgs->handle );
struct evbuffer * outbuf = evbuffer_new( );
dbgmsg( msgs, "sending an ltep handshake" );
tr_bencInit( &val, TYPE_DICT );
tr_bencDictReserve( &val, 3 );
m = tr_bencDictAdd( &val, "m" );
tr_bencInit( m, TYPE_DICT );
tr_bencDictReserve( m, 1 );
tr_bencInitInt( tr_bencDictAdd( m, "ut_pex" ), OUR_LTEP_PEX );
if( port > 0 )
tr_bencInitInt( tr_bencDictAdd( &val, "p" ), port );
tr_bencInitStr( tr_bencDictAdd( &val, "v" ), v, 0, 1 );
buf = tr_bencSaveMalloc( &val, &len );
tr_peerIoWriteUint32( msgs->io, outbuf, 2*sizeof(uint8_t) + len );
tr_peerIoWriteUint8 ( msgs->io, outbuf, BT_LTEP );
tr_peerIoWriteUint8 ( msgs->io, outbuf, LTEP_HANDSHAKE );
tr_peerIoWriteBytes ( msgs->io, outbuf, buf, len );
tr_peerIoWriteBuf( msgs->io, outbuf );
msgs->hasSentLtepHandshake = 1;
/* cleanup */
tr_bencFree( &val );
tr_free( buf );
evbuffer_free( outbuf );
}
static void
parseLtepHandshake( tr_peermsgs * msgs, int len, struct evbuffer * inbuf )
{
benc_val_t val, * sub;
uint8_t * tmp = tr_new( uint8_t, len );
tr_peerIoReadBytes( msgs->io, inbuf, tmp, len );
if( tr_bencLoad( tmp, len, &val, NULL ) || val.type!=TYPE_DICT ) {
dbgmsg( msgs, "GET extended-handshake, couldn't get dictionary" );
tr_free( tmp );
return;
}
/* check supported messages for utorrent pex */
sub = tr_bencDictFind( &val, "m" );
if( tr_bencIsDict( sub ) ) {
sub = tr_bencDictFind( sub, "ut_pex" );
if( tr_bencIsInt( sub ) ) {
msgs->peerSupportsPex = 1;
msgs->ut_pex_id = (uint8_t) sub->val.i;
dbgmsg( msgs, "msgs->ut_pex is %d", (int)msgs->ut_pex_id );
}
}
#if 0
/* get peer's client name */
sub = tr_bencDictFind( &val, "v" );
if( tr_bencIsStr( sub ) ) {
int i;
tr_free( msgs->info->client );
fprintf( stderr, "dictionary says client is [%s]\n", sub->val.s.s );
msgs->info->client = tr_strndup( sub->val.s.s, sub->val.s.i );
for( i=0; i<sub->val.s.i; ++i ) { fprintf( stderr, "[%c] (%d)\n", sub->val.s.s[i], (int)sub->val.s.s[i] );
if( (int)msgs->info->client[i]==-75 ) msgs->info->client[i]='u'; }
fprintf( stderr, "msgs->client is now [%s]\n", msgs->info->client );
}
#endif
/* get peer's listening port */
sub = tr_bencDictFind( &val, "p" );
if( tr_bencIsInt( sub ) ) {
msgs->info->port = htons( (uint16_t)sub->val.i );
dbgmsg( msgs, "msgs->port is now %hu", msgs->info->port );
}
tr_bencFree( &val );
tr_free( tmp );
}
static void
parseUtPex( tr_peermsgs * msgs, int msglen, struct evbuffer * inbuf )
{
benc_val_t val, * sub;
uint8_t * tmp;
if( msgs->torrent->pexDisabled ) /* no sharing! */
return;
tmp = tr_new( uint8_t, msglen );
tr_peerIoReadBytes( msgs->io, inbuf, tmp, msglen );
if( tr_bencLoad( tmp, msglen, &val, NULL ) || !tr_bencIsDict( &val ) ) {
dbgmsg( msgs, "GET can't read extended-pex dictionary" );
tr_free( tmp );
return;
}
sub = tr_bencDictFind( &val, "added" );
if( tr_bencIsStr(sub) && ((sub->val.s.i % 6) == 0)) {
const int n = sub->val.s.i / 6 ;
dbgmsg( msgs, "got %d peers from uT pex", n );
tr_peerMgrAddPeers( msgs->handle->peerMgr,
msgs->torrent->info.hash,
TR_PEER_FROM_PEX,
(uint8_t*)sub->val.s.s, n );
}
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->io, inbuf, &ltep_msgid );
msglen--;
if( ltep_msgid == LTEP_HANDSHAKE )
{
dbgmsg( msgs, "got ltep handshake" );
parseLtepHandshake( msgs, msglen, inbuf );
if( !msgs->hasSentLtepHandshake )
sendLtepHandshake( msgs );
}
else if( ltep_msgid == msgs->ut_pex_id )
{
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 )
{
uint32_t len;
const size_t needlen = sizeof(uint32_t);
if( EVBUFFER_LENGTH(inbuf) < needlen )
return READ_MORE;
tr_peerIoReadUint32( msgs->io, inbuf, &len );
if( len == 0 ) /* peer sent us a keepalive message */
dbgmsg( msgs, "peer sent us a keepalive message..." );
else {
dbgmsg( msgs, "peer is sending us a message with %"PRIu64" bytes...", (uint64_t)len );
msgs->incomingMessageLength = len;
msgs->state = AWAITING_BT_MESSAGE;
}
return READ_AGAIN;
}
static int
readBtMessage( tr_peermsgs * msgs, struct evbuffer * inbuf )
{
uint8_t id;
uint32_t ui32;
uint32_t msglen = msgs->incomingMessageLength;
if( EVBUFFER_LENGTH(inbuf) < msglen )
return READ_MORE;
tr_peerIoReadUint8( msgs->io, inbuf, &id );
msglen--;
dbgmsg( msgs, "peer sent us a message... "
"bt id number is %d, and remaining len is %d", (int)id, (int)msglen );
switch( id )
{
case BT_CHOKE:
assert( msglen == 0 );
dbgmsg( msgs, "w00t peer sent us a BT_CHOKE" );
msgs->info->clientIsChoked = 1;
tr_list_foreach( msgs->peerAskedFor, tr_free );
tr_list_free( &msgs->peerAskedFor );
tr_list_foreach( msgs->clientAskedFor, tr_free );
tr_list_free( &msgs->clientAskedFor );
break;
case BT_UNCHOKE:
assert( msglen == 0 );
dbgmsg( msgs, "w00t peer sent us a BT_UNCHOKE" );
msgs->info->clientIsChoked = 0;
fireNeedReq( msgs );
break;
case BT_INTERESTED:
assert( msglen == 0 );
dbgmsg( msgs, "w00t peer sent us a BT_INTERESTED" );
msgs->info->peerIsInterested = 1;
break;
case BT_NOT_INTERESTED:
assert( msglen == 0 );
dbgmsg( msgs, "w00t peer sent us a BT_NOT_INTERESTED" );
msgs->info->peerIsInterested = 0;
break;
case BT_HAVE:
assert( msglen == 4 );
dbgmsg( msgs, "w00t peer sent us a BT_HAVE" );
tr_peerIoReadUint32( msgs->io, inbuf, &ui32 );
tr_bitfieldAdd( msgs->info->have, ui32 );
msgs->info->progress = tr_bitfieldCountTrueBits( msgs->info->have ) / (float)msgs->torrent->info.pieceCount;
dbgmsg( msgs, "after the HAVE message, peer progress is %f", msgs->info->progress );
updateInterest( msgs );
firePeerProgress( msgs );
break;
case BT_BITFIELD:
assert( msglen == msgs->info->have->len );
dbgmsg( msgs, "w00t peer sent us a BT_BITFIELD" );
tr_peerIoReadBytes( msgs->io, inbuf, msgs->info->have->bits, msglen );
msgs->info->progress = tr_bitfieldCountTrueBits( msgs->info->have ) / (float)msgs->torrent->info.pieceCount;
dbgmsg( msgs, "after the HAVE message, peer progress is %f", msgs->info->progress );
updateInterest( msgs );
fireNeedReq( msgs );
firePeerProgress( msgs );
break;
case BT_REQUEST: {
struct peer_request * req;
assert( msglen == 12 );
dbgmsg( msgs, "peer sent us a BT_REQUEST" );
req = tr_new( struct peer_request, 1 );
tr_peerIoReadUint32( msgs->io, inbuf, &req->index );
tr_peerIoReadUint32( msgs->io, inbuf, &req->offset );
tr_peerIoReadUint32( msgs->io, inbuf, &req->length );
if( !msgs->info->peerIsChoked && requestIsValid( msgs, req ) )
tr_list_append( &msgs->peerAskedFor, req );
else
tr_free( req );
break;
}
case BT_CANCEL: {
struct peer_request req;
void * data;
assert( msglen == 12 );
dbgmsg( msgs, "peer sent us a BT_CANCEL" );
tr_peerIoReadUint32( msgs->io, inbuf, &req.index );
tr_peerIoReadUint32( msgs->io, inbuf, &req.offset );
tr_peerIoReadUint32( msgs->io, inbuf, &req.length );
data = tr_list_remove( &msgs->peerAskedFor, &req, peer_request_compare );
tr_free( data );
break;
}
case BT_PIECE: {
dbgmsg( msgs, "peer sent us a BT_PIECE" );
assert( msgs->blockToUs.length == 0 );
tr_peerIoReadUint32( msgs->io, inbuf, &msgs->blockToUs.index );
tr_peerIoReadUint32( msgs->io, inbuf, &msgs->blockToUs.offset );
msgs->blockToUs.length = msglen - 8;
assert( EVBUFFER_LENGTH(msgs->inBlock) == 0 );
//evbuffer_drain( msgs->inBlock, ~0 );
msgs->state = msgs->blockToUs.length ? READING_BT_PIECE : AWAITING_BT_LENGTH;
return READ_AGAIN;
break;
}
case BT_PORT: {
assert( msglen == 2 );
dbgmsg( msgs, "peer sent us a BT_PORT" );
tr_peerIoReadUint16( msgs->io, inbuf, &msgs->info->port );
break;
}
case BT_SUGGEST: {
/* tiennou TODO */
break;
}
case BT_HAVE_ALL: {
/* tiennou TODO */
break;
}
case BT_HAVE_NONE: {
/* tiennou TODO */
break;
}
case BT_REJECT: {
/* tiennou TODO */
break;
}
case BT_ALLOWED_FAST: {
/* tiennou TODO */
break;
}
case BT_LTEP:
dbgmsg( msgs, "peer sent us a BT_LTEP" );
parseLtep( msgs, msglen, inbuf );
break;
default:
dbgmsg( msgs, "peer sent us an UNKNOWN: %d", (int)id );
tr_peerIoDrain( msgs->io, inbuf, msglen );
assert( 0 );
}
msgs->incomingMessageLength = -1;
msgs->state = AWAITING_BT_LENGTH;
return READ_AGAIN;
}
static void
clientGotBytes( tr_peermsgs * msgs, uint32_t byteCount )
{
tr_torrent * tor = msgs->torrent;
tor->activityDate = tr_date( );
tor->downloadedCur += byteCount;
tr_rcTransferred( tor->download, byteCount );
tr_rcTransferred( tor->handle->download, byteCount );
}
static void
peerGotBytes( tr_peermsgs * msgs, uint32_t byteCount )
{
tr_torrent * tor = msgs->torrent;
tor->activityDate = tr_date( );
tor->uploadedCur += byteCount;
tr_rcTransferred( tor->upload, byteCount );
tr_rcTransferred( tor->handle->upload, byteCount );
}
static int
canDownload( const tr_peermsgs * msgs )
{
tr_torrent * tor = msgs->torrent;
if( tor->downloadLimitMode == TR_SPEEDLIMIT_GLOBAL )
return !tor->handle->useDownloadLimit || tr_rcCanTransfer( tor->handle->download );
if( tor->downloadLimitMode == TR_SPEEDLIMIT_SINGLE )
return tr_rcCanTransfer( tor->download );
return TRUE;
}
static void
reassignBytesToCorrupt( tr_peermsgs * msgs, uint32_t byteCount )
{
tr_torrent * tor = msgs->torrent;
/* increment the `corrupt' field */
tor->corruptCur += byteCount;
/* decrement the `downloaded' field */
if( tor->downloadedCur >= byteCount )
tor->downloadedCur -= byteCount;
else
tor->downloadedCur = 0;
}
static void
gotBadPiece( tr_peermsgs * msgs, uint32_t pieceIndex )
{
const uint32_t byteCount = tr_torPieceCountBytes( msgs->torrent, (int)pieceIndex );
reassignBytesToCorrupt( msgs, byteCount );
}
static void
gotUnwantedBlock( tr_peermsgs * msgs, uint32_t index UNUSED, uint32_t offset UNUSED, uint32_t length )
{
reassignBytesToCorrupt( msgs, length );
}
static void
addUsToBlamefield( tr_peermsgs * msgs, uint32_t index )
{
if( !msgs->info->blame )
msgs->info->blame = tr_bitfieldNew( msgs->torrent->info.pieceCount );
tr_bitfieldAdd( msgs->info->blame, index );
}
static void
gotBlock( tr_peermsgs * msgs,
struct evbuffer * inbuf,
uint32_t index,
uint32_t offset,
uint32_t length )
{
tr_torrent * tor = msgs->torrent;
const int block = _tr_block( tor, index, offset );
struct peer_request key, *req;
/**
*** Remove the block from our `we asked for this' list
**/
key.index = index;
key.offset = offset;
key.length = length;
req = (struct peer_request*) tr_list_remove( &msgs->clientAskedFor, &key,
peer_request_compare );
if( req == NULL ) {
gotUnwantedBlock( msgs, index, offset, length );
dbgmsg( msgs, "we didn't ask for this message..." );
return;
}
dbgmsg( msgs, "w00t peer sent us a block. turnaround time was %d seconds",
(int)(time(NULL) - req->time_requested) );
tr_free( req );
dbgmsg( msgs, "peer has %d more blocks we've asked for",
tr_list_size(msgs->clientAskedFor));
/**
*** Error checks
**/
if( tr_cpBlockIsComplete( tor->completion, block ) ) {
dbgmsg( msgs, "have this block already..." );
tr_dbg( "have this block already..." );
gotUnwantedBlock( msgs, index, offset, length );
return;
}
if( (int)length != tr_torBlockCountBytes( tor, block ) ) {
dbgmsg( msgs, "block is the wrong length..." );
tr_dbg( "block is the wrong length..." );
gotUnwantedBlock( msgs, index, offset, length );
return;
}
/**
*** Write the block
**/
if( tr_ioWrite( tor, index, offset, length, EVBUFFER_DATA( inbuf ))) {
return;
}
tr_cpBlockAdd( tor->completion, block );
addUsToBlamefield( msgs, index );
fireGotBlock( msgs, index, offset, length );
fireNeedReq( msgs );
/**
*** Handle if this was the last block in the piece
**/
if( tr_cpPieceIsComplete( tor->completion, index ) )
{
if( tr_ioHash( tor, index ) )
{
gotBadPiece( msgs, index );
return;
}
fireClientHave( msgs, index );
}
}
static ReadState
readBtPiece( tr_peermsgs * msgs, struct evbuffer * inbuf )
{
uint32_t inlen;
uint8_t * tmp;
assert( msgs != NULL );
assert( msgs->blockToUs.length > 0 );
assert( inbuf != NULL );
assert( EVBUFFER_LENGTH( inbuf ) > 0 );
/* read from the inbuf into our block buffer */
inlen = MIN( EVBUFFER_LENGTH(inbuf), msgs->blockToUs.length );
tmp = tr_new( uint8_t, inlen );
tr_peerIoReadBytes( msgs->io, inbuf, tmp, inlen );
evbuffer_add( msgs->inBlock, tmp, inlen );
/* update our tables accordingly */
assert( inlen >= msgs->blockToUs.length );
msgs->blockToUs.length -= inlen;
msgs->info->peerSentPieceDataAt = time( NULL );
clientGotBytes( msgs, inlen );
/* if this was the entire block, save it */
if( !msgs->blockToUs.length )
{
dbgmsg( msgs, "w00t -- got block index %u, offset %u", msgs->blockToUs.index, msgs->blockToUs.offset );
assert( (int)EVBUFFER_LENGTH( msgs->inBlock ) == tr_torBlockCountBytes( msgs->torrent, _tr_block(msgs->torrent,msgs->blockToUs.index, msgs->blockToUs.offset) ) );
gotBlock( msgs, msgs->inBlock,
msgs->blockToUs.index,
msgs->blockToUs.offset,
EVBUFFER_LENGTH( msgs->inBlock ) );
evbuffer_drain( msgs->inBlock, ~0 );
msgs->state = AWAITING_BT_LENGTH;
}
/* cleanup */
tr_free( tmp );
return READ_AGAIN;
}
static ReadState
canRead( struct bufferevent * evin, void * vmsgs )
{
ReadState ret;
tr_peermsgs * msgs = (tr_peermsgs *) vmsgs;
struct evbuffer * inbuf = EVBUFFER_INPUT ( evin );
if( !canDownload( msgs ) )
{
msgs->notListening = 1;
tr_peerIoSetIOMode ( msgs->io, 0, EV_READ );
ret = READ_DONE;
}
else switch( msgs->state )
{
case AWAITING_BT_LENGTH: ret = readBtLength ( msgs, inbuf ); break;
case AWAITING_BT_MESSAGE: ret = readBtMessage ( msgs, inbuf ); break;
case READING_BT_PIECE: ret = readBtPiece ( msgs, inbuf ); break;
default: assert( 0 );
}
return ret;
}
static void
sendKeepalive( tr_peermsgs * msgs )
{
dbgmsg( msgs, "sending a keepalive message" );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, 0 );
}
/**
***
**/
static int
canWrite( const tr_peermsgs * msgs )
{
/* don't let our outbuffer get too large */
if( tr_peerIoWriteBytesWaiting( msgs->io ) > 8192 )
return FALSE;
return TRUE;
}
static int
canUpload( const tr_peermsgs * msgs )
{
const tr_torrent * tor = msgs->torrent;
if( !canWrite( msgs ) )
return FALSE;
if( tor->uploadLimitMode == TR_SPEEDLIMIT_GLOBAL )
return !tor->handle->useUploadLimit || tr_rcCanTransfer( tor->handle->upload );
if( tor->uploadLimitMode == TR_SPEEDLIMIT_SINGLE )
return tr_rcCanTransfer( tor->upload );
return TRUE;
}
static int
pulse( void * vmsgs )
{
const time_t now = time( NULL );
tr_peermsgs * msgs = (tr_peermsgs *) vmsgs;
size_t len;
/* if we froze out a downloaded block because of speed limits,
start listening to the peer again */
if( msgs->notListening && canDownload( msgs ) )
{
fprintf( stderr, "msgs %p thawing out...\n", msgs );
msgs->notListening = 0;
tr_peerIoSetIOMode ( msgs->io, EV_READ, 0 );
}
if( !canWrite( msgs ) )
{
}
else if(( len = EVBUFFER_LENGTH( msgs->outBlock ) ))
{
while ( len && canUpload( msgs ) )
{
const size_t outlen = len; //MIN( len, 2048 );
tr_peerIoWrite( msgs->io, EVBUFFER_DATA(msgs->outBlock), outlen );
evbuffer_drain( msgs->outBlock, outlen );
peerGotBytes( msgs, outlen );
len -= outlen;
msgs->info->clientSentPieceDataAt = now;
msgs->clientSentAnythingAt = now;
dbgmsg( msgs, "wrote %d bytes; %d left in block", (int)outlen, (int)len );
}
}
else if(( len = EVBUFFER_LENGTH( msgs->outMessages ) ))
{
tr_peerIoWriteBuf( msgs->io, msgs->outMessages );
msgs->clientSentAnythingAt = now;
}
else if(( msgs->peerAskedFor ))
{
struct peer_request * req = tr_list_pop_front( &msgs->peerAskedFor );
uint8_t * tmp = tr_new( uint8_t, req->length );
const uint32_t msglen = sizeof(uint8_t) + 2*sizeof(uint32_t) + req->length;
tr_ioRead( msgs->torrent, req->index, req->offset, req->length, tmp );
tr_peerIoWriteUint32( msgs->io, msgs->outBlock, msglen );
tr_peerIoWriteUint8 ( msgs->io, msgs->outBlock, BT_PIECE );
tr_peerIoWriteUint32( msgs->io, msgs->outBlock, req->index );
tr_peerIoWriteUint32( msgs->io, msgs->outBlock, req->offset );
tr_peerIoWriteBytes ( msgs->io, msgs->outBlock, tmp, req->length );
tr_free( tmp );
dbgmsg( msgs, "putting req into out queue: index %d, offset %d, length %d ... %d blocks left in our queue", (int)req->index, (int)req->offset, (int)req->length, tr_list_size(msgs->peerAskedFor) );
tr_free( req );
}
else if( ( now - msgs->clientSentAnythingAt ) > KEEPALIVE_INTERVAL_SECS )
{
sendKeepalive( msgs );
}
return TRUE; /* loop forever */
}
static void
didWrite( struct bufferevent * evin UNUSED, void * vpeer )
{
pulse( (tr_peermsgs *) vpeer );
}
static void
gotError( struct bufferevent * evbuf UNUSED, short what UNUSED, void * vpeer )
{
fireGotError( vpeer );
}
static void
sendBitfield( tr_peermsgs * msgs )
{
const tr_bitfield * bitfield = tr_cpPieceBitfield( msgs->torrent->completion );
dbgmsg( msgs, "sending peer a bitfield message" );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, sizeof(uint8_t) + bitfield->len );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, BT_BITFIELD );
tr_peerIoWriteBytes ( msgs->io, msgs->outMessages, bitfield->bits, bitfield->len );
}
/**
***
**/
#define MAX_DIFFS 50
typedef struct
{
tr_pex * added;
tr_pex * dropped;
tr_pex * elements;
int addedCount;
int droppedCount;
int elementCount;
int diffCount;
}
PexDiffs;
static void
pexAddedCb( void * vpex, void * userData )
{
PexDiffs * diffs = (PexDiffs *) userData;
tr_pex * pex = (tr_pex *) vpex;
if( diffs->diffCount < MAX_DIFFS )
{
diffs->diffCount++;
diffs->added[diffs->addedCount++] = *pex;
diffs->elements[diffs->elementCount++] = *pex;
}
}
static void
pexRemovedCb( void * vpex, void * userData )
{
PexDiffs * diffs = (PexDiffs *) userData;
tr_pex * pex = (tr_pex *) vpex;
if( diffs->diffCount < MAX_DIFFS )
{
diffs->diffCount++;
diffs->dropped[diffs->droppedCount++] = *pex;
}
}
static void
pexElementCb( void * vpex, void * userData )
{
PexDiffs * diffs = (PexDiffs *) userData;
tr_pex * pex = (tr_pex *) vpex;
if( diffs->diffCount < MAX_DIFFS )
{
diffs->diffCount++;
diffs->elements[diffs->elementCount++] = *pex;
}
}
static void
sendPex( tr_peermsgs * msgs )
{
if( msgs->peerSupportsPex && !msgs->torrent->pexDisabled )
{
int i;
tr_pex * newPex = NULL;
const int newCount = tr_peerMgrGetPeers( msgs->handle->peerMgr, msgs->torrent->info.hash, &newPex );
PexDiffs diffs;
benc_val_t val, *added, *dropped, *flags;
uint8_t *tmp, *walk;
char * benc;
int bencLen;
/* 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;
diffs.diffCount = 0;
tr_set_compare( msgs->pex, msgs->pexCount,
newPex, newCount,
tr_pexCompare, sizeof(tr_pex),
pexRemovedCb, pexAddedCb, pexElementCb, &diffs );
dbgmsg( msgs, "pex: old peer count %d, new peer count %d, added %d, removed %d", msgs->pexCount, newCount, diffs.addedCount, diffs.droppedCount );
/* update peer */
tr_free( msgs->pex );
msgs->pex = diffs.elements;
msgs->pexCount = diffs.elementCount;
/* build the pex payload */
tr_bencInit( &val, TYPE_DICT );
tr_bencDictReserve( &val, 3 );
/* "added" */
added = tr_bencDictAdd( &val, "added" );
tmp = walk = tr_new( uint8_t, diffs.addedCount * 6 );
for( i=0; i<diffs.addedCount; ++i ) {
memcpy( walk, &diffs.added[i].in_addr, 4 ); walk += 4;
memcpy( walk, &diffs.added[i].port, 2 ); walk += 2;
}
assert( ( walk - tmp ) == diffs.addedCount * 6 );
tr_bencInitStr( added, tmp, walk-tmp, FALSE );
/* "added.f" */
flags = tr_bencDictAdd( &val, "added.f" );
tmp = walk = tr_new( uint8_t, diffs.addedCount );
for( i=0; i<diffs.addedCount; ++i ) {
dbgmsg( msgs, "PEX -->> -->> flag is %d", (int)diffs.added[i].flags );
*walk++ = diffs.added[i].flags;
}
assert( ( walk - tmp ) == diffs.addedCount );
tr_bencInitStr( flags, tmp, walk-tmp, FALSE );
/* "dropped" */
dropped = tr_bencDictAdd( &val, "dropped" );
tmp = walk = tr_new( uint8_t, diffs.droppedCount * 6 );
for( i=0; i<diffs.droppedCount; ++i ) {
memcpy( walk, &diffs.dropped[i].in_addr, 4 ); walk += 4;
memcpy( walk, &diffs.dropped[i].port, 2 ); walk += 2;
}
assert( ( walk - tmp ) == diffs.droppedCount * 6 );
tr_bencInitStr( dropped, tmp, walk-tmp, FALSE );
/* write the pex message */
benc = tr_bencSaveMalloc( &val, &bencLen );
tr_peerIoWriteUint32( msgs->io, msgs->outMessages, 2*sizeof(uint8_t) + bencLen );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, BT_LTEP );
tr_peerIoWriteUint8 ( msgs->io, msgs->outMessages, OUR_LTEP_PEX );
tr_peerIoWriteBytes ( msgs->io, msgs->outMessages, benc, bencLen );
/* cleanup */
tr_free( benc );
tr_bencFree( &val );
tr_free( diffs.added );
tr_free( diffs.dropped );
tr_free( newPex );
msgs->clientSentPexAt = time( NULL );
}
}
static int
pexPulse( void * vpeer )
{
sendPex( vpeer );
return TRUE;
}
/**
***
**/
tr_peermsgs*
tr_peerMsgsNew( struct tr_torrent * torrent, struct tr_peer * info )
{
tr_peermsgs * msgs;
assert( info != NULL );
assert( info->io != NULL );
msgs = tr_new0( tr_peermsgs, 1 );
msgs->publisher = tr_publisherNew( );
msgs->info = info;
msgs->handle = torrent->handle;
msgs->torrent = torrent;
msgs->io = info->io;
msgs->info->clientIsChoked = 1;
msgs->info->peerIsChoked = 1;
msgs->info->clientIsInterested = 0;
msgs->info->peerIsInterested = 0;
msgs->info->have = tr_bitfieldNew( torrent->info.pieceCount );
msgs->pulseTimer = tr_timerNew( msgs->handle, pulse, msgs, PEER_PULSE_INTERVAL );
msgs->pexTimer = tr_timerNew( msgs->handle, pexPulse, msgs, PEX_INTERVAL );
msgs->outMessages = evbuffer_new( );
msgs->outBlock = evbuffer_new( );
msgs->inBlock = evbuffer_new( );
tr_peerIoSetIOFuncs( msgs->io, canRead, didWrite, gotError, msgs );
tr_peerIoSetIOMode( msgs->io, EV_READ|EV_WRITE, 0 );
/**
*** If we initiated this connection,
*** we may need to send LTEP/AZMP handshakes.
*** Otherwise we'll wait for the peer to send theirs first.
**/
if( !tr_peerIoIsIncoming( msgs->io ) )
{
if ( tr_peerIoSupportsLTEP( msgs->io ) ) {
sendLtepHandshake( msgs );
} else if ( tr_peerIoSupportsAZMP( msgs->io ) ) {
dbgmsg( msgs, "FIXME: need to send AZMP handshake" );
} else {
/* no-op */
}
}
sendBitfield( msgs );
return msgs;
}
void
tr_peerMsgsFree( tr_peermsgs* msgs )
{
if( msgs != NULL )
{
tr_timerFree( &msgs->pulseTimer );
tr_timerFree( &msgs->pexTimer );
tr_publisherFree( &msgs->publisher );
tr_list_foreach( msgs->clientAskedFor, tr_free );
tr_list_free( &msgs->clientAskedFor );
tr_list_foreach( msgs->peerAskedFor, tr_free );
tr_list_free( &msgs->peerAskedFor );
evbuffer_free( msgs->outMessages );
evbuffer_free( msgs->outBlock );
evbuffer_free( msgs->inBlock );
tr_free( msgs->pex );
msgs->pexCount = 0;
tr_free( msgs );
}
}
tr_publisher_tag
tr_peerMsgsSubscribe( tr_peermsgs * peer,
tr_delivery_func func,
void * userData )
{
return tr_publisherSubscribe( peer->publisher, func, userData );
}
void
tr_peerMsgsUnsubscribe( tr_peermsgs * peer,
tr_publisher_tag tag )
{
tr_publisherUnsubscribe( peer->publisher, tag );
}
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