static int
readPeerId( tr_handshake * handshake,
struct evbuffer * inbuf )
{
tr_bool peerIsGood;
char client[128];
tr_torrent * tor;
const uint8_t * tor_peer_id;
uint8_t peer_id[PEER_ID_LEN];
if( evbuffer_get_length( inbuf ) < PEER_ID_LEN )
return READ_LATER;
/* peer id */
tr_peerIoReadBytes( handshake->io, inbuf, peer_id, PEER_ID_LEN );
tr_peerIoSetPeersId( handshake->io, peer_id );
handshake->havePeerID = TRUE;
tr_clientForId( client, sizeof( client ), peer_id );
dbgmsg( handshake, "peer-id is [%s] ... isIncoming is %d", client,
tr_peerIoIsIncoming( handshake->io ) );
/* if we've somehow connected to ourselves, don't keep the connection */
tor = tr_torrentFindFromHash( handshake->session, tr_peerIoGetTorrentHash( handshake->io ) );
tor_peer_id = tor && tor->peer_id ? tor->peer_id : tr_getPeerId( );
peerIsGood = memcmp( peer_id, tor_peer_id, PEER_ID_LEN ) != 0;
dbgmsg( handshake, "isPeerGood == %d", (int)peerIsGood );
return tr_handshakeDone( handshake, peerIsGood );
}
static int
readPeerId (tr_handshake * handshake,
struct evbuffer * inbuf)
{
bool connected_to_self;
char client[128];
uint8_t peer_id[PEER_ID_LEN];
tr_torrent * tor;
if (evbuffer_get_length (inbuf) < PEER_ID_LEN)
return READ_LATER;
/* peer id */
tr_peerIoReadBytes (handshake->io, inbuf, peer_id, PEER_ID_LEN);
tr_peerIoSetPeersId (handshake->io, peer_id);
handshake->havePeerID = true;
tr_clientForId (client, sizeof (client), peer_id);
dbgmsg (handshake, "peer-id is [%s] ... isIncoming is %d", client,
tr_peerIoIsIncoming (handshake->io));
/* if we've somehow connected to ourselves, don't keep the connection */
tor = tr_torrentFindFromHash (handshake->session, tr_peerIoGetTorrentHash (handshake->io));
connected_to_self = (tor != NULL) && !memcmp (peer_id, tr_torrentGetPeerId(tor), PEER_ID_LEN);
return tr_handshakeDone (handshake, !connected_to_self);
}
int
tr_peerIoReconnect( tr_peerIo * io )
{
short int pendingEvents;
tr_session * session;
assert( tr_isPeerIo( io ) );
assert( !tr_peerIoIsIncoming( io ) );
session = tr_peerIoGetSession( io );
pendingEvents = io->pendingEvents;
event_disable( io, EV_READ | EV_WRITE );
if( io->socket >= 0 )
tr_netClose( session, io->socket );
io->socket = tr_netOpenPeerSocket( session, &io->addr, io->port, io->isSeed );
event_set( &io->event_read, io->socket, EV_READ, event_read_cb, io );
event_set( &io->event_write, io->socket, EV_WRITE, event_write_cb, io );
if( io->socket >= 0 )
{
event_enable( io, pendingEvents );
tr_netSetTOS( io->socket, session->peerSocketTOS );
maybeSetCongestionAlgorithm( io->socket, session->peer_congestion_algorithm );
return 0;
}
return -1;
}
tr_handshake*
tr_handshakeNew (tr_peerIo * io,
tr_encryption_mode encryptionMode,
handshakeDoneCB doneCB,
void * doneUserData)
{
tr_handshake * handshake;
tr_session * session = tr_peerIoGetSession (io);
handshake = tr_new0 (tr_handshake, 1);
handshake->io = io;
handshake->crypto = tr_peerIoGetCrypto (io);
handshake->encryptionMode = encryptionMode;
handshake->doneCB = doneCB;
handshake->doneUserData = doneUserData;
handshake->session = session;
handshake->timeout_timer = evtimer_new (session->event_base, handshakeTimeout, handshake);
tr_timerAdd (handshake->timeout_timer, HANDSHAKE_TIMEOUT_SEC, 0);
tr_peerIoRef (io); /* balanced by the unref in tr_handshakeFree */
tr_peerIoSetIOFuncs (handshake->io, canRead, NULL, gotError, handshake);
tr_peerIoSetEncryption (io, PEER_ENCRYPTION_NONE);
if (tr_peerIoIsIncoming (handshake->io))
{
setReadState (handshake, AWAITING_HANDSHAKE);
}
else if (encryptionMode != TR_CLEAR_PREFERRED)
{
sendYa (handshake);
}
else
{
uint8_t msg[HANDSHAKE_SIZE];
buildHandshakeMessage (handshake, msg);
handshake->haveSentBitTorrentHandshake = 1;
setReadState (handshake, AWAITING_HANDSHAKE);
tr_peerIoWriteBytes (handshake->io, msg, sizeof (msg), false);
}
return handshake;
}
static int
readHandshake( tr_handshake * handshake,
struct evbuffer * inbuf )
{
uint8_t pstrlen;
uint8_t * pstr;
uint8_t reserved[HANDSHAKE_FLAGS_LEN];
uint8_t hash[SHA_DIGEST_LENGTH];
dbgmsg( handshake, "payload: need %d, got %zu",
INCOMING_HANDSHAKE_LEN, evbuffer_get_length( inbuf ) );
if( evbuffer_get_length( inbuf ) < INCOMING_HANDSHAKE_LEN )
return READ_LATER;
handshake->haveReadAnythingFromPeer = TRUE;
pstrlen = evbuffer_pullup( inbuf, 1 )[0]; /* peek, don't read. We may be
handing inbuf to AWAITING_YA */
if( pstrlen == 19 ) /* unencrypted */
{
tr_peerIoSetEncryption( handshake->io, PEER_ENCRYPTION_NONE );
if( handshake->encryptionMode == TR_ENCRYPTION_REQUIRED )
{
dbgmsg( handshake,
"peer is unencrypted, and we're disallowing that" );
return tr_handshakeDone( handshake, FALSE );
}
}
else /* encrypted or corrupt */
{
tr_peerIoSetEncryption( handshake->io, PEER_ENCRYPTION_RC4 );
if( tr_peerIoIsIncoming( handshake->io ) )
{
dbgmsg( handshake,
"I think peer is sending us an encrypted handshake..." );
setState( handshake, AWAITING_YA );
return READ_NOW;
}
tr_cryptoDecrypt( handshake->crypto, 1, &pstrlen, &pstrlen );
if( pstrlen != 19 )
{
dbgmsg( handshake,
"I think peer has sent us a corrupt handshake..." );
return tr_handshakeDone( handshake, FALSE );
}
}
evbuffer_drain( inbuf, 1 );
/* pstr (BitTorrent) */
pstr = tr_new( uint8_t, pstrlen + 1 );
tr_peerIoReadBytes( handshake->io, inbuf, pstr, pstrlen );
pstr[pstrlen] = '\0';
if( strcmp( (char*)pstr, "BitTorrent protocol" ) )
{
tr_free( pstr );
return tr_handshakeDone( handshake, FALSE );
}
tr_free( pstr );
/* reserved bytes */
tr_peerIoReadBytes( handshake->io, inbuf, reserved, sizeof( reserved ) );
/**
*** Extensions
**/
tr_peerIoEnableLTEP( handshake->io, HANDSHAKE_HAS_LTEP( reserved ) );
tr_peerIoEnableFEXT( handshake->io, HANDSHAKE_HAS_FASTEXT( reserved ) );
tr_peerIoEnableDHT( handshake->io, HANDSHAKE_HAS_DHT( reserved ) );
/* torrent hash */
tr_peerIoReadBytes( handshake->io, inbuf, hash, sizeof( hash ) );
if( tr_peerIoIsIncoming( handshake->io ) )
{
if( !tr_torrentExists( handshake->session, hash ) )
{
dbgmsg( handshake, "peer is trying to connect to us for a torrent we don't have." );
return tr_handshakeDone( handshake, FALSE );
}
else
{
assert( !tr_peerIoHasTorrentHash( handshake->io ) );
tr_peerIoSetTorrentHash( handshake->io, hash );
}
}
else /* outgoing */
{
assert( tr_peerIoHasTorrentHash( handshake->io ) );
if( memcmp( hash, tr_peerIoGetTorrentHash( handshake->io ),
SHA_DIGEST_LENGTH ) )
{
dbgmsg( handshake, "peer returned the wrong hash. wtf?" );
return tr_handshakeDone( handshake, FALSE );
}
}
/**
*** If it's an incoming message, we need to send a response handshake
**/
if( !handshake->haveSentBitTorrentHandshake )
{
uint8_t msg[HANDSHAKE_SIZE];
buildHandshakeMessage( handshake, msg );
tr_peerIoWriteBytes( handshake->io, msg, sizeof( msg ), FALSE );
handshake->haveSentBitTorrentHandshake = 1;
}
setReadState( handshake, AWAITING_PEER_ID );
return READ_NOW;
}
