465 lines
14 KiB
C
465 lines
14 KiB
C
/******************************************************************************
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* Copyright (c) 2005 Eric Petit
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*****************************************************************************/
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#include "transmission.h"
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#define MAX_REQUEST_COUNT 32
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#define OUR_REQUEST_COUNT 8 /* TODO: we should detect if we are on a
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high-speed network and adapt */
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typedef struct tr_request_s
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{
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int index;
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int begin;
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int length;
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} tr_request_t;
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struct tr_peer_s
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{
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struct in_addr addr;
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in_port_t port;
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#define PEER_STATUS_IDLE 1 /* Need to connect */
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#define PEER_STATUS_CONNECTING 2 /* Trying to send handshake */
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#define PEER_STATUS_HANDSHAKE 4 /* Waiting for peer's handshake */
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#define PEER_STATUS_CONNECTED 8 /* Got peer's handshake */
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int status;
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int socket;
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uint64_t date;
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uint64_t keepAlive;
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char amChoking;
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char amInterested;
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char peerChoking;
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char peerInterested;
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uint8_t id[20];
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uint8_t * bitfield;
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uint8_t * buf;
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int size;
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int pos;
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uint8_t * outMessages;
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int outMessagesSize;
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int outMessagesPos;
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uint8_t outBlock[13+16384];
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int outBlockSize;
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int outBlockLoaded;
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int outBlockSending;
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int inRequestCount;
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tr_request_t inRequests[OUR_REQUEST_COUNT];
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int inIndex;
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int inBegin;
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int inLength;
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uint64_t inTotal;
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int outRequestCount;
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tr_request_t outRequests[MAX_REQUEST_COUNT];
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uint64_t outTotal;
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uint64_t outDate;
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int outSlow;
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};
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#define peer_dbg( a... ) __peer_dbg( peer, ## a )
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static void __peer_dbg( tr_peer_t * peer, char * msg, ... )
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{
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char string[256];
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va_list args;
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va_start( args, msg );
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sprintf( string, "%08x:%04x ",
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(uint32_t) peer->addr.s_addr, peer->port );
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vsnprintf( &string[14], sizeof( string ) - 14, msg, args );
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va_end( args );
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tr_dbg( "%s", string );
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}
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#include "peermessages.h"
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#include "peerutils.h"
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/***********************************************************************
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* tr_peerAddOld
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***********************************************************************
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* Tries to add a peer given its IP and port (received from a tracker
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* which doesn't support the "compact" extension).
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**********************************************************************/
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void tr_peerAddOld( tr_torrent_t * tor, char * ip, int port )
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{
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struct in_addr addr;
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if( tr_netResolve( ip, &addr ) )
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{
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return;
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}
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addWithAddr( tor, addr, htons( port ) );
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}
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/***********************************************************************
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* tr_peerAddCompact
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***********************************************************************
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* Tries to add a peer. If 's' is a negative value, will use 'addr' and
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* 'port' to connect to the peer. Otherwise, use the already connected
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* socket 's'.
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**********************************************************************/
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void tr_peerAddCompact( tr_torrent_t * tor, struct in_addr addr,
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in_port_t port, int s )
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{
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tr_peer_t * peer;
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if( s < 0 )
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{
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addWithAddr( tor, addr, port );
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return;
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}
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if( !( peer = peerInit( tor ) ) )
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{
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tr_netClose( s );
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tr_fdSocketClosed( tor->fdlimit, 0 );
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return;
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}
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peer->socket = s;
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peer->addr = addr;
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peer->port = port;
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peer->status = PEER_STATUS_CONNECTING;
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}
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/***********************************************************************
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* tr_peerRem
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***********************************************************************
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* Frees and closes everything related to the peer at index 'i', and
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* removes it from the peers list.
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**********************************************************************/
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void tr_peerRem( tr_torrent_t * tor, int i )
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{
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tr_peer_t * peer = tor->peers[i];
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int j;
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for( j = 0; j < peer->inRequestCount; j++ )
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{
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tr_request_t * r;
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int block;
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r = &peer->inRequests[j];
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block = tr_block( r->index,r->begin );
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if( tor->blockHave[block] > 0 )
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{
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(tor->blockHave[block])--;
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}
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}
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if( !peer->amChoking )
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{
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tr_uploadChoked( tor->upload );
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}
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if( peer->bitfield )
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{
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free( peer->bitfield );
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}
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if( peer->buf )
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{
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free( peer->buf );
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}
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if( peer->outMessages )
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{
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free( peer->outMessages );
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}
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if( peer->status > PEER_STATUS_IDLE )
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{
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tr_netClose( peer->socket );
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tr_fdSocketClosed( tor->fdlimit, 0 );
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}
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free( peer );
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tor->peerCount--;
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memmove( &tor->peers[i], &tor->peers[i+1],
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( tor->peerCount - i ) * sizeof( tr_peer_t * ) );
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}
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/***********************************************************************
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* tr_peerPulse
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***********************************************************************
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*
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**********************************************************************/
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void tr_peerPulse( tr_torrent_t * tor )
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{
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int i, ret, size;
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uint8_t * p;
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tr_peer_t * peer;
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tor->dates[9] = tr_date();
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if( tor->dates[9] > tor->dates[8] + 1000 )
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{
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memmove( &tor->downloaded[0], &tor->downloaded[1],
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9 * sizeof( uint64_t ) );
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memmove( &tor->uploaded[0], &tor->uploaded[1],
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9 * sizeof( uint64_t ) );
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memmove( &tor->dates[0], &tor->dates[1],
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9 * sizeof( uint64_t ) );
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for( i = 0; i < tor->peerCount; )
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{
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if( checkPeer( tor, i ) )
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{
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tr_peerRem( tor, i );
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continue;
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}
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i++;
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}
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}
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/* Check for incoming connections */
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if( tor->bindSocket > -1 &&
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tor->peerCount < TR_MAX_PEER_COUNT &&
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!tr_fdSocketWillCreate( tor->fdlimit, 0 ) )
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{
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int s;
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struct in_addr addr;
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in_port_t port;
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s = tr_netAccept( tor->bindSocket, &addr, &port );
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if( s > -1 )
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{
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tr_peerAddCompact( tor, addr, port, s );
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}
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else
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{
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tr_fdSocketClosed( tor->fdlimit, 0 );
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}
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}
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/* Shuffle peers */
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if( tor->peerCount > 1 )
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{
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peer = tor->peers[0];
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memmove( &tor->peers[0], &tor->peers[1],
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( tor->peerCount - 1 ) * sizeof( void * ) );
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tor->peers[tor->peerCount - 1] = peer;
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}
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/* Handle peers */
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for( i = 0; i < tor->peerCount; )
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{
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peer = tor->peers[i];
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/* Connect */
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if( ( peer->status & PEER_STATUS_IDLE ) &&
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!tr_fdSocketWillCreate( tor->fdlimit, 0 ) )
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{
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peer->socket = tr_netOpen( peer->addr, peer->port );
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if( peer->socket < 0 )
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{
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peer_dbg( "connection failed" );
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goto dropPeer;
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}
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peer->status = PEER_STATUS_CONNECTING;
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}
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/* Try to send handshake */
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if( peer->status & PEER_STATUS_CONNECTING )
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{
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uint8_t buf[68];
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tr_info_t * inf = &tor->info;
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buf[0] = 19;
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memcpy( &buf[1], "BitTorrent protocol", 19 );
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memset( &buf[20], 0, 8 );
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memcpy( &buf[28], inf->hash, 20 );
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memcpy( &buf[48], tor->id, 20 );
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ret = tr_netSend( peer->socket, buf, 68 );
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if( ret & TR_NET_CLOSE )
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{
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peer_dbg( "connection closed" );
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goto dropPeer;
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}
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else if( !( ret & TR_NET_BLOCK ) )
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{
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peer_dbg( "SEND handshake" );
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peer->status = PEER_STATUS_HANDSHAKE;
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}
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}
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/* Try to read */
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if( peer->status >= PEER_STATUS_HANDSHAKE )
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{
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for( ;; )
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{
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if( peer->size < 1 )
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{
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peer->size = 1024;
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peer->buf = malloc( peer->size );
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}
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else if( peer->pos >= peer->size )
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{
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peer->size *= 2;
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peer->buf = realloc( peer->buf, peer->size );
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}
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ret = tr_netRecv( peer->socket, &peer->buf[peer->pos],
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peer->size - peer->pos );
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if( ret & TR_NET_CLOSE )
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{
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peer_dbg( "connection closed" );
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goto dropPeer;
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}
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else if( ret & TR_NET_BLOCK )
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{
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break;
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}
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peer->date = tr_date();
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peer->pos += ret;
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if( parseMessage( tor, peer, ret ) )
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{
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goto dropPeer;
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}
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}
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}
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/* Try to write */
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writeBegin:
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/* Send all smaller messages regardless of the upload cap */
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while( ( p = messagesPending( peer, &size ) ) )
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{
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ret = tr_netSend( peer->socket, p, size );
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if( ret & TR_NET_CLOSE )
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{
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goto dropPeer;
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}
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else if( ret & TR_NET_BLOCK )
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{
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goto writeEnd;
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}
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messagesSent( peer, ret );
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}
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/* Send pieces if we can */
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while( ( p = blockPending( tor, peer, &size ) ) )
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{
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if( !tr_uploadCanUpload( tor->upload ) )
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{
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break;
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}
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ret = tr_netSend( peer->socket, p, size );
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if( ret & TR_NET_CLOSE )
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{
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goto dropPeer;
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}
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else if( ret & TR_NET_BLOCK )
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{
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break;
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}
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blockSent( peer, ret );
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tr_uploadUploaded( tor->upload, ret );
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tor->uploaded[9] += ret;
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peer->outTotal += ret;
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peer->outDate = tr_date();
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/* In case this block is done, you may have messages
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pending. Send them before we start the next block */
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goto writeBegin;
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}
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writeEnd:
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/* Connected peers: ask for a block whenever possible */
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if( peer->status & PEER_STATUS_CONNECTED )
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{
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if( tor->blockHaveCount < tor->blockCount &&
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!peer->amInterested && tor->peerCount > TR_MAX_PEER_COUNT - 2 )
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{
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/* This peer is no use to us, and it seems there are
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more */
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peer_dbg( "not interesting" );
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tr_peerRem( tor, i );
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continue;
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}
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if( peer->amInterested && !peer->peerChoking )
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{
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int block;
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while( peer->inRequestCount < OUR_REQUEST_COUNT )
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{
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block = chooseBlock( tor, peer );
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if( block < 0 )
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{
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break;
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}
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sendRequest( tor, peer, block );
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}
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}
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}
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i++;
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continue;
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dropPeer:
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tr_peerRem( tor, i );
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}
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}
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/***********************************************************************
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* tr_peerIsConnected
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***********************************************************************
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*
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**********************************************************************/
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int tr_peerIsConnected( tr_peer_t * peer )
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{
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return peer->status & PEER_STATUS_CONNECTED;
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}
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/***********************************************************************
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* tr_peerIsUploading
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***********************************************************************
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*
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**********************************************************************/
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int tr_peerIsUploading( tr_peer_t * peer )
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{
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return ( peer->inRequestCount > 0 );
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}
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/***********************************************************************
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* tr_peerIsDownloading
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***********************************************************************
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*
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**********************************************************************/
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int tr_peerIsDownloading( tr_peer_t * peer )
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{
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return peer->outBlockSending;
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}
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/***********************************************************************
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* tr_peerBitfield
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***********************************************************************
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*
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**********************************************************************/
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uint8_t * tr_peerBitfield( tr_peer_t * peer )
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{
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return peer->bitfield;
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}
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