transmission/libtransmission/peer.c

436 lines
12 KiB
C

/******************************************************************************
* Copyright (c) 2005 Eric Petit
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include "transmission.h"
#define MAX_REQUEST_COUNT 32
#define OUR_REQUEST_COUNT 8 /* TODO: we should detect if we are on a
high-speed network and adapt */
typedef struct tr_request_s
{
int index;
int begin;
int length;
} tr_request_t;
struct tr_peer_s
{
struct in_addr addr;
in_port_t port;
#define PEER_STATUS_IDLE 1 /* Need to connect */
#define PEER_STATUS_CONNECTING 2 /* Trying to send handshake */
#define PEER_STATUS_HANDSHAKE 4 /* Waiting for peer's handshake */
#define PEER_STATUS_CONNECTED 8 /* Got peer's handshake */
int status;
int socket;
uint64_t date;
uint64_t keepAlive;
char amChoking;
char amInterested;
char peerChoking;
char peerInterested;
uint8_t id[20];
uint8_t * bitfield;
uint8_t * buf;
int size;
int pos;
uint8_t * outMessages;
int outMessagesSize;
int outMessagesPos;
uint8_t outBlock[13+16384];
int outBlockSize;
int outBlockLoaded;
int outBlockSending;
int inRequestCount;
tr_request_t inRequests[OUR_REQUEST_COUNT];
int inIndex;
int inBegin;
int inLength;
uint64_t inTotal;
int outRequestCount;
tr_request_t outRequests[MAX_REQUEST_COUNT];
uint64_t outTotal;
uint64_t outDate;
int outSlow;
};
#define peer_dbg( a... ) __peer_dbg( peer, ## a )
static void __peer_dbg( tr_peer_t * peer, char * msg, ... )
{
char string[256];
va_list args;
va_start( args, msg );
sprintf( string, "%08x:%04x ",
(uint32_t) peer->addr.s_addr, peer->port );
vsnprintf( &string[14], sizeof( string ) - 14, msg, args );
va_end( args );
tr_dbg( "%s", string );
}
#include "peermessages.h"
#include "peerutils.h"
#include "peerparse.h"
/***********************************************************************
* tr_peerAddOld
***********************************************************************
* Tries to add a peer given its IP and port (received from a tracker
* which doesn't support the "compact" extension).
**********************************************************************/
void tr_peerAddOld( tr_torrent_t * tor, char * ip, int port )
{
struct in_addr addr;
if( tr_netResolve( ip, &addr ) )
{
return;
}
addWithAddr( tor, addr, htons( port ) );
}
/***********************************************************************
* tr_peerAddCompact
***********************************************************************
* Tries to add a peer. If 's' is a negative value, will use 'addr' and
* 'port' to connect to the peer. Otherwise, use the already connected
* socket 's'.
**********************************************************************/
void tr_peerAddCompact( tr_torrent_t * tor, struct in_addr addr,
in_port_t port, int s )
{
tr_peer_t * peer;
if( s < 0 )
{
addWithAddr( tor, addr, port );
return;
}
if( !( peer = peerInit( tor ) ) )
{
tr_netClose( s );
tr_fdSocketClosed( tor->fdlimit, 0 );
return;
}
peer->socket = s;
peer->addr = addr;
peer->port = port;
peer->status = PEER_STATUS_CONNECTING;
}
/***********************************************************************
* tr_peerRem
***********************************************************************
* Frees and closes everything related to the peer at index 'i', and
* removes it from the peers list.
**********************************************************************/
void tr_peerRem( tr_torrent_t * tor, int i )
{
tr_peer_t * peer = tor->peers[i];
int j;
for( j = 0; j < peer->inRequestCount; j++ )
{
tr_request_t * r;
int block;
r = &peer->inRequests[j];
block = tr_block( r->index,r->begin );
tr_cpDownloaderRem( tor->completion, block );
}
if( !peer->amChoking )
{
tr_uploadChoked( tor->upload );
}
if( peer->bitfield )
{
free( peer->bitfield );
}
if( peer->buf )
{
free( peer->buf );
}
if( peer->outMessages )
{
free( peer->outMessages );
}
if( peer->status > PEER_STATUS_IDLE )
{
tr_netClose( peer->socket );
tr_fdSocketClosed( tor->fdlimit, 0 );
}
free( peer );
tor->peerCount--;
memmove( &tor->peers[i], &tor->peers[i+1],
( tor->peerCount - i ) * sizeof( tr_peer_t * ) );
}
/***********************************************************************
* tr_peerPulse
***********************************************************************
*
**********************************************************************/
void tr_peerPulse( tr_torrent_t * tor )
{
int i, ret, size;
uint8_t * p;
tr_peer_t * peer;
tor->dates[9] = tr_date();
if( tor->dates[9] > tor->dates[8] + 1000 )
{
memmove( &tor->downloaded[0], &tor->downloaded[1],
9 * sizeof( uint64_t ) );
memmove( &tor->uploaded[0], &tor->uploaded[1],
9 * sizeof( uint64_t ) );
memmove( &tor->dates[0], &tor->dates[1],
9 * sizeof( uint64_t ) );
for( i = 0; i < tor->peerCount; )
{
if( checkPeer( tor, i ) )
{
tr_peerRem( tor, i );
continue;
}
i++;
}
}
if( tor->status & TR_STATUS_STOPPING )
{
return;
}
/* Check for incoming connections */
if( tor->bindSocket > -1 &&
tor->peerCount < TR_MAX_PEER_COUNT &&
!tr_fdSocketWillCreate( tor->fdlimit, 0 ) )
{
int s;
struct in_addr addr;
in_port_t port;
s = tr_netAccept( tor->bindSocket, &addr, &port );
if( s > -1 )
{
tr_peerAddCompact( tor, addr, port, s );
}
else
{
tr_fdSocketClosed( tor->fdlimit, 0 );
}
}
/* Shuffle peers */
if( tor->peerCount > 1 )
{
peer = tor->peers[0];
memmove( &tor->peers[0], &tor->peers[1],
( tor->peerCount - 1 ) * sizeof( void * ) );
tor->peers[tor->peerCount - 1] = peer;
}
/* Handle peers */
for( i = 0; i < tor->peerCount; )
{
peer = tor->peers[i];
if( peer->status < PEER_STATUS_HANDSHAKE )
{
i++;
continue;
}
/* Try to read */
for( ;; )
{
if( peer->size < 1 )
{
peer->size = 1024;
peer->buf = malloc( peer->size );
}
else if( peer->pos >= peer->size )
{
peer->size *= 2;
peer->buf = realloc( peer->buf, peer->size );
}
ret = tr_netRecv( peer->socket, &peer->buf[peer->pos],
peer->size - peer->pos );
if( ret & TR_NET_CLOSE )
{
peer_dbg( "connection closed" );
goto dropPeer;
}
else if( ret & TR_NET_BLOCK )
{
break;
}
peer->date = tr_date();
peer->pos += ret;
if( parseBuf( tor, peer, ret ) )
{
goto dropPeer;
}
}
if( peer->status < PEER_STATUS_CONNECTED )
{
i++;
continue;
}
/* Try to write */
writeBegin:
/* Send all smaller messages regardless of the upload cap */
while( ( p = messagesPending( peer, &size ) ) )
{
ret = tr_netSend( peer->socket, p, size );
if( ret & TR_NET_CLOSE )
{
goto dropPeer;
}
else if( ret & TR_NET_BLOCK )
{
goto writeEnd;
}
messagesSent( peer, ret );
}
/* Send pieces if we can */
while( ( p = blockPending( tor, peer, &size ) ) )
{
if( !tr_uploadCanUpload( tor->upload ) )
{
break;
}
ret = tr_netSend( peer->socket, p, size );
if( ret & TR_NET_CLOSE )
{
goto dropPeer;
}
else if( ret & TR_NET_BLOCK )
{
break;
}
blockSent( peer, ret );
tr_uploadUploaded( tor->upload, ret );
tor->uploaded[9] += ret;
peer->outTotal += ret;
peer->outDate = tr_date();
/* In case this block is done, you may have messages
pending. Send them before we start the next block */
goto writeBegin;
}
writeEnd:
/* Ask for a block whenever possible */
if( !tr_cpIsSeeding( tor->completion ) &&
!peer->amInterested && tor->peerCount > TR_MAX_PEER_COUNT - 2 )
{
/* This peer is no use to us, and it seems there are
more */
peer_dbg( "not interesting" );
tr_peerRem( tor, i );
continue;
}
if( peer->amInterested && !peer->peerChoking )
{
int block;
while( peer->inRequestCount < OUR_REQUEST_COUNT )
{
block = chooseBlock( tor, peer );
if( block < 0 )
{
break;
}
sendRequest( tor, peer, block );
}
}
i++;
continue;
dropPeer:
tr_peerRem( tor, i );
}
}
/***********************************************************************
* tr_peerIsConnected
***********************************************************************
*
**********************************************************************/
int tr_peerIsConnected( tr_peer_t * peer )
{
return peer->status & PEER_STATUS_CONNECTED;
}
/***********************************************************************
* tr_peerIsUploading
***********************************************************************
*
**********************************************************************/
int tr_peerIsUploading( tr_peer_t * peer )
{
return ( peer->inRequestCount > 0 );
}
/***********************************************************************
* tr_peerIsDownloading
***********************************************************************
*
**********************************************************************/
int tr_peerIsDownloading( tr_peer_t * peer )
{
return peer->outBlockSending;
}
/***********************************************************************
* tr_peerBitfield
***********************************************************************
*
**********************************************************************/
uint8_t * tr_peerBitfield( tr_peer_t * peer )
{
return peer->bitfield;
}