transmission/libtransmission/peer-io.c

874 lines
20 KiB
C

/*
* This file Copyright (C) 2007-2008 Charles Kerr <charles@rebelbase.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <limits.h> /* INT_MAX */
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#ifdef WIN32
#include <winsock2.h>
#else
#include <netinet/in.h> /* struct in_addr */
#include <arpa/inet.h> /* inet_ntoa */
#endif
#include <event.h>
#include "transmission.h"
#include "crypto.h"
#include "net.h"
#include "peer-io.h"
#include "ratecontrol.h"
#include "trevent.h"
#include "utils.h"
#define IO_TIMEOUT_SECS 8
/**
***
**/
#define dbgmsg( io, fmt... ) \
tr_deepLog( __FILE__, __LINE__, tr_peerIoGetAddrStr( io ), ## fmt )
struct tr_bandwidth
{
unsigned int isUnlimited : 1;
size_t bytesUsed;
size_t bytesLeft;
};
struct tr_peerIo
{
unsigned int isEncrypted : 1;
unsigned int isIncoming : 1;
unsigned int peerIdIsSet : 1;
unsigned int extendedProtocolSupported : 1;
unsigned int fastPeersSupported : 1;
uint8_t encryptionMode;
uint8_t timeout;
uint16_t port;
int socket;
uint8_t peerId[20];
time_t timeCreated;
tr_session * session;
struct in_addr in_addr;
struct bufferevent * bufev;
struct evbuffer * output;
tr_can_read_cb canRead;
tr_did_write_cb didWrite;
tr_net_error_cb gotError;
void * userData;
size_t bufferSize[2];
struct tr_bandwidth bandwidth[2];
tr_ratecontrol * speedometer[2];
tr_crypto * crypto;
};
/**
***
**/
static void
adjustOutputBuffer( tr_peerIo * io )
{
struct evbuffer * live = EVBUFFER_OUTPUT( io->bufev );
if( io->bandwidth[TR_UP].isUnlimited )
{
bufferevent_write_buffer( io->bufev, io->output );
}
else if( io->bandwidth[TR_UP].bytesLeft > EVBUFFER_LENGTH( live ) )
{
/* there's free space in bufev's output buffer;
try to fill it up */
const size_t desiredLength = io->bandwidth[TR_UP].bytesLeft;
const size_t under = desiredLength - EVBUFFER_LENGTH( live );
const size_t n = MIN( under, EVBUFFER_LENGTH( io->output ) );
bufferevent_write( io->bufev, EVBUFFER_DATA( io->output ), n );
evbuffer_drain( io->output, n );
}
else if( io->bandwidth[TR_UP].bytesLeft < EVBUFFER_LENGTH( live ) )
{
/* bufev's output buffer exceeds our bandwidth allocation;
move the excess out of bufev so it can't be sent yet */
const size_t desiredLength = io->bandwidth[TR_UP].bytesLeft;
const size_t over = EVBUFFER_LENGTH( live ) - desiredLength;
struct evbuffer * buf = evbuffer_new( );
evbuffer_add( buf, EVBUFFER_DATA( live ) + desiredLength, over );
evbuffer_add_buffer( buf, io->output );
evbuffer_free( io->output );
io->output = buf;
EVBUFFER_LENGTH( live ) = desiredLength;
}
else if( EVBUFFER_LENGTH( live ) )
{
bufferevent_enable( io->bufev, EV_WRITE );
}
io->bufferSize[TR_UP] = EVBUFFER_LENGTH( live );
dbgmsg( io, "after adjusting the output buffer, its size is now %zu",
io->bufferSize[TR_UP] );
}
static void
adjustInputBuffer( tr_peerIo * io )
{
if( io->bandwidth[TR_DOWN].isUnlimited )
{
dbgmsg( io, "unlimited reading..." );
bufferevent_setwatermark( io->bufev, EV_READ, 0, 0 );
bufferevent_enable( io->bufev, EV_READ );
}
else
{
const size_t n = io->bandwidth[TR_DOWN].bytesLeft;
if( n == 0 )
{
dbgmsg( io, "disabling reads because we've hit our limit" );
bufferevent_disable( io->bufev, EV_READ );
}
else
{
dbgmsg( io, "enabling reading of %zu more bytes", n );
bufferevent_setwatermark( io->bufev, EV_READ, 0, n );
bufferevent_enable( io->bufev, EV_READ );
}
}
}
/***
****
***/
static void
didWriteWrapper( struct bufferevent * e,
void * vio )
{
tr_peerIo * io = vio;
const size_t len = EVBUFFER_LENGTH( EVBUFFER_OUTPUT( e ) );
dbgmsg( io, "didWrite... io->outputBufferSize was %zu, is now %zu",
io->bufferSize[TR_UP], len );
if( len < io->bufferSize[TR_UP] )
{
const size_t n = io->bufferSize[TR_UP] - len;
struct tr_bandwidth * b = &io->bandwidth[TR_UP];
b->bytesLeft -= MIN( b->bytesLeft, (size_t)n );
b->bytesUsed += n;
tr_rcTransferred( io->speedometer[TR_UP], n );
dbgmsg( io,
"wrote %zu bytes to peer... upload bytesLeft is now %zu",
n,
b->bytesLeft );
}
adjustOutputBuffer( io );
if( io->didWrite )
io->didWrite( e, io->userData );
}
static void
canReadWrapper( struct bufferevent * e,
void * vio )
{
int done = 0;
int err = 0;
tr_peerIo * io = vio;
tr_session * session = io->session;
const size_t len = EVBUFFER_LENGTH( EVBUFFER_INPUT( e ) );
dbgmsg( io, "canRead" );
/* if the input buffer has grown, record the bytes that were read */
if( len > io->bufferSize[TR_DOWN] )
{
const size_t n = len - io->bufferSize[TR_DOWN];
struct tr_bandwidth * b = io->bandwidth + TR_DOWN;
b->bytesLeft -= MIN( b->bytesLeft, (size_t)n );
b->bytesUsed += n;
tr_rcTransferred( io->speedometer[TR_DOWN], n );
dbgmsg( io,
"%zu new input bytes. bytesUsed is %zu, bytesLeft is %zu",
n, b->bytesUsed,
b->bytesLeft );
adjustInputBuffer( io );
}
/* try to consume the input buffer */
if( io->canRead )
{
tr_globalLock( session );
while( !done && !err )
{
const int ret = io->canRead( e, io->userData );
switch( ret )
{
case READ_NOW:
if( EVBUFFER_LENGTH( e->input ) )
continue;
done = 1;
break;
case READ_LATER:
done = 1;
break;
case READ_ERR:
err = 1;
break;
}
}
tr_globalUnlock( session );
}
if( !err )
io->bufferSize[TR_DOWN] = EVBUFFER_LENGTH( EVBUFFER_INPUT( e ) );
}
static void
gotErrorWrapper( struct bufferevent * e,
short what,
void * userData )
{
tr_peerIo * c = userData;
if( c->gotError )
c->gotError( e, what, c->userData );
}
/**
***
**/
static void
bufevNew( tr_peerIo * io )
{
io->bufev = bufferevent_new( io->socket,
canReadWrapper,
didWriteWrapper,
gotErrorWrapper,
io );
/* tell libevent to call didWriteWrapper after every write,
* not just when the write buffer is empty */
bufferevent_setwatermark( io->bufev, EV_WRITE, INT_MAX, 0 );
bufferevent_settimeout( io->bufev, io->timeout, io->timeout );
bufferevent_enable( io->bufev, EV_READ | EV_WRITE );
}
static tr_peerIo*
tr_peerIoNew( tr_session * session,
const struct in_addr * in_addr,
uint16_t port,
const uint8_t * torrentHash,
int isIncoming,
int socket )
{
tr_peerIo * io;
if( socket >= 0 )
tr_netSetTOS( socket, session->peerSocketTOS );
io = tr_new0( tr_peerIo, 1 );
io->crypto = tr_cryptoNew( torrentHash, isIncoming );
io->session = session;
io->in_addr = *in_addr;
io->port = port;
io->socket = socket;
io->isIncoming = isIncoming != 0;
io->timeout = IO_TIMEOUT_SECS;
io->timeCreated = time( NULL );
io->output = evbuffer_new( );
io->bandwidth[TR_UP].isUnlimited = 1;
io->bandwidth[TR_DOWN].isUnlimited = 1;
io->speedometer[TR_UP] = tr_rcInit( );
io->speedometer[TR_DOWN] = tr_rcInit( );
bufevNew( io );
return io;
}
tr_peerIo*
tr_peerIoNewIncoming( tr_session * session,
const struct in_addr * in_addr,
uint16_t port,
int socket )
{
assert( session );
assert( in_addr );
assert( socket >= 0 );
return tr_peerIoNew( session, in_addr, port,
NULL, 1,
socket );
}
tr_peerIo*
tr_peerIoNewOutgoing( tr_session * session,
const struct in_addr * in_addr,
int port,
const uint8_t * torrentHash )
{
int socket;
assert( session );
assert( in_addr );
assert( port >= 0 );
assert( torrentHash );
socket = tr_netOpenTCP( in_addr, port, 0 );
return socket < 0
? NULL
: tr_peerIoNew( session, in_addr, port, torrentHash, 0, socket );
}
static void
io_dtor( void * vio )
{
tr_peerIo * io = vio;
tr_rcClose( io->speedometer[TR_DOWN] );
tr_rcClose( io->speedometer[TR_UP] );
evbuffer_free( io->output );
bufferevent_free( io->bufev );
tr_netClose( io->socket );
tr_cryptoFree( io->crypto );
tr_free( io );
}
void
tr_peerIoFree( tr_peerIo * io )
{
if( io )
{
io->canRead = NULL;
io->didWrite = NULL;
io->gotError = NULL;
tr_runInEventThread( io->session, io_dtor, io );
}
}
tr_session*
tr_peerIoGetSession( tr_peerIo * io )
{
assert( io );
assert( io->session );
return io->session;
}
const struct in_addr*
tr_peerIoGetAddress( const tr_peerIo * io,
uint16_t * port )
{
assert( io );
if( port )
*port = io->port;
return &io->in_addr;
}
const char*
tr_peerIoAddrStr( const struct in_addr * addr,
uint16_t port )
{
static char buf[512];
tr_snprintf( buf, sizeof( buf ), "%s:%u", inet_ntoa( *addr ),
ntohs( port ) );
return buf;
}
const char*
tr_peerIoGetAddrStr( const tr_peerIo * io )
{
return tr_peerIoAddrStr( &io->in_addr, io->port );
}
static void
tr_peerIoTryRead( tr_peerIo * io )
{
if( EVBUFFER_LENGTH( io->bufev->input ) )
canReadWrapper( io->bufev, io );
}
void
tr_peerIoSetIOFuncs( tr_peerIo * io,
tr_can_read_cb readcb,
tr_did_write_cb writecb,
tr_net_error_cb errcb,
void * userData )
{
io->canRead = readcb;
io->didWrite = writecb;
io->gotError = errcb;
io->userData = userData;
tr_peerIoTryRead( io );
}
int
tr_peerIoIsIncoming( const tr_peerIo * c )
{
return c->isIncoming ? 1 : 0;
}
int
tr_peerIoReconnect( tr_peerIo * io )
{
assert( !tr_peerIoIsIncoming( io ) );
if( io->socket >= 0 )
tr_netClose( io->socket );
io->socket = tr_netOpenTCP( &io->in_addr, io->port, 0 );
if( io->socket >= 0 )
{
tr_netSetTOS( io->socket, io->session->peerSocketTOS );
bufferevent_free( io->bufev );
bufevNew( io );
return 0;
}
return -1;
}
void
tr_peerIoSetTimeoutSecs( tr_peerIo * io,
int secs )
{
io->timeout = secs;
bufferevent_settimeout( io->bufev, io->timeout, io->timeout );
bufferevent_enable( io->bufev, EV_READ | EV_WRITE );
}
/**
***
**/
void
tr_peerIoSetTorrentHash( tr_peerIo * io,
const uint8_t * hash )
{
assert( io );
tr_cryptoSetTorrentHash( io->crypto, hash );
}
const uint8_t*
tr_peerIoGetTorrentHash( tr_peerIo * io )
{
assert( io );
assert( io->crypto );
return tr_cryptoGetTorrentHash( io->crypto );
}
int
tr_peerIoHasTorrentHash( const tr_peerIo * io )
{
assert( io );
assert( io->crypto );
return tr_cryptoHasTorrentHash( io->crypto );
}
/**
***
**/
void
tr_peerIoSetPeersId( tr_peerIo * io,
const uint8_t * peer_id )
{
assert( io );
if( ( io->peerIdIsSet = peer_id != NULL ) )
memcpy( io->peerId, peer_id, 20 );
else
memset( io->peerId, 0, 20 );
}
const uint8_t*
tr_peerIoGetPeersId( const tr_peerIo * io )
{
assert( io );
assert( io->peerIdIsSet );
return io->peerId;
}
/**
***
**/
void
tr_peerIoEnableLTEP( tr_peerIo * io,
int flag )
{
assert( io );
assert( flag == 0 || flag == 1 );
io->extendedProtocolSupported = flag;
}
void
tr_peerIoEnableFEXT( tr_peerIo * io,
int flag )
{
assert( io );
assert( flag == 0 || flag == 1 );
io->fastPeersSupported = flag;
}
int
tr_peerIoSupportsLTEP( const tr_peerIo * io )
{
assert( io );
return io->extendedProtocolSupported;
}
int
tr_peerIoSupportsFEXT( const tr_peerIo * io )
{
assert( io );
return io->fastPeersSupported;
}
/**
***
**/
size_t
tr_peerIoGetBandwidthUsed( const tr_peerIo * io,
tr_direction direction )
{
assert( io );
assert( direction == TR_UP || direction == TR_DOWN );
return io->bandwidth[direction].bytesUsed;
}
size_t
tr_peerIoGetBandwidthLeft( const tr_peerIo * io,
tr_direction direction )
{
assert( io );
assert( direction == TR_UP || direction == TR_DOWN );
return io->bandwidth[direction].bytesLeft;
}
size_t
tr_peerIoGetWriteBufferSpace( const tr_peerIo * io )
{
const size_t desiredBufferLen = 4096;
const size_t currentLiveLen =
EVBUFFER_LENGTH( EVBUFFER_OUTPUT( io->bufev ) );
const size_t desiredLiveLen = tr_peerIoGetBandwidthLeft( io, TR_UP );
const size_t currentLbufLen = EVBUFFER_LENGTH( io->output );
const size_t desiredLen = desiredBufferLen + desiredLiveLen;
const size_t currentLen = currentLiveLen + currentLbufLen;
size_t freeSpace = 0;
if( desiredLen > currentLen )
freeSpace = desiredLen - currentLen;
else
freeSpace = 0;
return freeSpace;
}
void
tr_peerIoSetBandwidth( tr_peerIo * io,
tr_direction direction,
size_t bytesLeft )
{
struct tr_bandwidth * b;
assert( io );
assert( direction == TR_UP || direction == TR_DOWN );
b = io->bandwidth + direction;
b->isUnlimited = 0;
b->bytesUsed = 0;
b->bytesLeft = bytesLeft;
adjustOutputBuffer( io );
adjustInputBuffer( io );
}
void
tr_peerIoSetBandwidthUnlimited( tr_peerIo * io,
tr_direction direction )
{
struct tr_bandwidth * b;
assert( io );
assert( direction == TR_UP || direction == TR_DOWN );
b = io->bandwidth + direction;
b->isUnlimited = 1;
b->bytesUsed = 0;
b->bytesLeft = 0;
adjustInputBuffer( io );
adjustOutputBuffer( io );
}
double
tr_peerIoGetRateToClient( const tr_peerIo * io )
{
return tr_rcRate( io->speedometer[TR_DOWN] );
}
double
tr_peerIoGetRateToPeer( const tr_peerIo * io )
{
return tr_rcRate( io->speedometer[TR_UP] );
}
/**
***
**/
tr_crypto*
tr_peerIoGetCrypto( tr_peerIo * c )
{
return c->crypto;
}
void
tr_peerIoSetEncryption( tr_peerIo * io,
int encryptionMode )
{
assert( io );
assert( encryptionMode == PEER_ENCRYPTION_NONE
|| encryptionMode == PEER_ENCRYPTION_RC4 );
io->encryptionMode = encryptionMode;
}
int
tr_peerIoIsEncrypted( const tr_peerIo * io )
{
return io != NULL && io->encryptionMode == PEER_ENCRYPTION_RC4;
}
/**
***
**/
int
tr_peerIoWantsBandwidth( const tr_peerIo * io,
tr_direction direction )
{
assert( direction == TR_UP || direction == TR_DOWN );
if( direction == TR_DOWN )
{
return TRUE; /* FIXME -- is there a good way to test for this? */
}
else
{
return EVBUFFER_LENGTH( EVBUFFER_OUTPUT( io->bufev ) )
|| EVBUFFER_LENGTH( io->output );
}
}
void
tr_peerIoWrite( tr_peerIo * io,
const void * writeme,
size_t writemeLen )
{
assert( tr_amInEventThread( io->session ) );
dbgmsg( io, "adding %zu bytes into io->output", writemeLen );
if( io->bandwidth[TR_UP].isUnlimited )
bufferevent_write( io->bufev, writeme, writemeLen );
else
evbuffer_add( io->output, writeme, writemeLen );
adjustOutputBuffer( io );
}
void
tr_peerIoWriteBuf( tr_peerIo * io,
struct evbuffer * buf )
{
const size_t n = EVBUFFER_LENGTH( buf );
tr_peerIoWrite( io, EVBUFFER_DATA( buf ), n );
evbuffer_drain( buf, n );
}
/**
***
**/
void
tr_peerIoWriteBytes( tr_peerIo * io,
struct evbuffer * outbuf,
const void * bytes,
size_t byteCount )
{
uint8_t * tmp;
switch( io->encryptionMode )
{
case PEER_ENCRYPTION_NONE:
evbuffer_add( outbuf, bytes, byteCount );
break;
case PEER_ENCRYPTION_RC4:
tmp = tr_new( uint8_t, byteCount );
tr_cryptoEncrypt( io->crypto, byteCount, bytes, tmp );
evbuffer_add( outbuf, tmp, byteCount );
tr_free( tmp );
break;
default:
assert( 0 );
}
}
void
tr_peerIoWriteUint8( tr_peerIo * io,
struct evbuffer * outbuf,
uint8_t writeme )
{
tr_peerIoWriteBytes( io, outbuf, &writeme, sizeof( uint8_t ) );
}
void
tr_peerIoWriteUint16( tr_peerIo * io,
struct evbuffer * outbuf,
uint16_t writeme )
{
uint16_t tmp = htons( writeme );
tr_peerIoWriteBytes( io, outbuf, &tmp, sizeof( uint16_t ) );
}
void
tr_peerIoWriteUint32( tr_peerIo * io,
struct evbuffer * outbuf,
uint32_t writeme )
{
uint32_t tmp = htonl( writeme );
tr_peerIoWriteBytes( io, outbuf, &tmp, sizeof( uint32_t ) );
}
/***
****
***/
void
tr_peerIoReadBytes( tr_peerIo * io,
struct evbuffer * inbuf,
void * bytes,
size_t byteCount )
{
assert( EVBUFFER_LENGTH( inbuf ) >= byteCount );
switch( io->encryptionMode )
{
case PEER_ENCRYPTION_NONE:
evbuffer_remove( inbuf, bytes, byteCount );
break;
case PEER_ENCRYPTION_RC4:
evbuffer_remove( inbuf, bytes, byteCount );
tr_cryptoDecrypt( io->crypto, byteCount, bytes, bytes );
break;
default:
assert( 0 );
}
}
void
tr_peerIoReadUint8( tr_peerIo * io,
struct evbuffer * inbuf,
uint8_t * setme )
{
tr_peerIoReadBytes( io, inbuf, setme, sizeof( uint8_t ) );
}
void
tr_peerIoReadUint16( tr_peerIo * io,
struct evbuffer * inbuf,
uint16_t * setme )
{
uint16_t tmp;
tr_peerIoReadBytes( io, inbuf, &tmp, sizeof( uint16_t ) );
*setme = ntohs( tmp );
}
void
tr_peerIoReadUint32( tr_peerIo * io,
struct evbuffer * inbuf,
uint32_t * setme )
{
uint32_t tmp;
tr_peerIoReadBytes( io, inbuf, &tmp, sizeof( uint32_t ) );
*setme = ntohl( tmp );
}
void
tr_peerIoDrain( tr_peerIo * io,
struct evbuffer * inbuf,
size_t byteCount )
{
uint8_t * tmp = tr_new( uint8_t, byteCount );
tr_peerIoReadBytes( io, inbuf, tmp, byteCount );
tr_free( tmp );
}
int
tr_peerIoGetAge( const tr_peerIo * io )
{
return time( NULL ) - io->timeCreated;
}