Miroirs/xwords
1
0
Fork 0
mirror of git://xwords.git.sourceforge.net/gitroot/xwords/xwords synced 2025-01-30 08:34:16 +01:00
Code Issues Projects Releases Packages Wiki Activity

use stream_getSize to detect corrupt (truncated) messages.

Browse source
This commit is contained in:
ehouse 2006-08-29 13:18:12 +00:00
parent 9d541a7d91
commit af7767389c
1 changed files with 66 additions and 53 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

119
common/comms.c
View file

@ -813,7 +813,7 @@ comms_checkIncomingStream( CommsCtxt* comms, XWStreamCtxt* stream,
XP_U32 connID;
MsgID msgID;
MsgID lastMsgRcd;
XP_Bool validMessage = XP_TRUE;
XP_Bool validMessage = XP_FALSE;
AddressRecord* recs = (AddressRecord*)NULL;
XWHostID senderID;
XP_Bool usingRelay = XP_FALSE;
@ -830,72 +830,85 @@ comms_checkIncomingStream( CommsCtxt* comms, XWStreamCtxt* stream,
usingRelay = comms->addr.conType == COMMS_CONN_RELAY;
#endif
connID = stream_getU32( stream );
XP_STATUSF( "read connID of %lx", connID );
if ( stream_getSize( stream ) >= sizeof(connID) ) {
connID = stream_getU32( stream );
XP_STATUSF( "read connID of %lx", connID );
if ( comms->connID == connID || comms->connID == CONN_ID_NONE ) {
if ( comms->connID == connID || comms->connID == CONN_ID_NONE ) {
if ( stream_getSize( stream )
>= sizeof(channelNo) + sizeof(msgID) + sizeof(lastMsgRcd) ) {
channelNo = stream_getU16( stream );
msgID = stream_getU32( stream );
lastMsgRcd = stream_getU32( stream );
validMessage = XP_TRUE;
XP_DEBUGF( "rcd: msg " XP_LD " on chnl %d", msgID, channelNo );
channelNo = stream_getU16( stream );
msgID = stream_getU32( stream );
lastMsgRcd = stream_getU32( stream );
removeFromQueue( comms, channelNo, lastMsgRcd );
XP_DEBUGF( "rcd: msg " XP_LD " on chnl %d", msgID, channelNo );
/* Problem: need to detect duplicate messages even before the server's
had a chance to assign channels. Solution, which is a hack: since
hostID does the same thing, use it in the relay case. But in the
relay-less case, which still needs to work, do assign channels.
The dup message problem is far less common there. */
removeFromQueue( comms, channelNo, lastMsgRcd );
if ( channelNo == 0 ) {
XP_ASSERT( comms->isServer );
if ( usingRelay ) {
XP_ASSERT( senderID != 0 );
channelNo = senderID;
} else {
XP_ASSERT( msgID == 0 );
channelNo = ++comms->nextChannelNo;
channelWas0 = XP_TRUE;
}
XP_STATUSF( "assigning channelNo=%d", channelNo );
}
if ( usingRelay || !channelWas0 ) {
recs = getRecordFor( comms, channelNo );
/* messageID for an incomming message should be one greater than
* the id most recently used for that channel. */
if ( !!recs && (msgID != recs->lastMsgReceived + 1) ) {
XP_DEBUGF( "on channel %d, old msgID " XP_LD
" (next should be " XP_LD ")", channelNo,
msgID, recs->lastMsgReceived+1 );
validMessage = XP_FALSE;
}
/* Problem: need to detect duplicate messages even before the
server's had a chance to assign channels. Solution, which
is a hack: since hostID does the same thing, use it in the
relay case. But in the relay-less case, which still needs
to work, do assign channels. The dup message problem is
far less common there. */
if ( channelNo == 0 ) {
XP_ASSERT( comms->isServer );
if ( usingRelay ) {
XP_ASSERT( senderID != 0 );
channelNo = senderID;
} else {
XP_ASSERT( msgID == 0 );
channelNo = ++comms->nextChannelNo;
channelWas0 = XP_TRUE;
}
XP_STATUSF( "assigning channelNo=%d", channelNo );
}
if ( usingRelay || !channelWas0 ) {
recs = getRecordFor( comms, channelNo );
/* messageID for an incomming message should be one
* greater than the id most recently used for that
* channel. */
if ( !!recs && (msgID != recs->lastMsgReceived + 1) ) {
XP_DEBUGF( "on channel %d, old msgID " XP_LD
" (next should be " XP_LD ")", channelNo,
msgID, recs->lastMsgReceived+1 );
validMessage = XP_FALSE;
}
#ifdef DEBUG
if ( !!recs ) {
XP_ASSERT( lastMsgRcd < 0x0000FFFF );
recs->lastACK = (XP_U16)lastMsgRcd;
}
if ( !!recs ) {
XP_ASSERT( lastMsgRcd < 0x0000FFFF );
recs->lastACK = (XP_U16)lastMsgRcd;
}
#endif
}
}
if ( validMessage ) {
XP_LOGF( "remembering senderID %x for channel %d",
senderID, channelNo );
if ( validMessage ) {
XP_LOGF( "remembering senderID %x for channel %d",
senderID, channelNo );
recs = rememberChannelAddress( comms, channelNo, senderID, addr );
stream_setAddress( stream, channelNo );
recs = rememberChannelAddress( comms, channelNo, senderID,
addr );
stream_setAddress( stream, channelNo );
if ( !!recs ) {
recs->lastMsgReceived = msgID;
if ( !!recs ) {
recs->lastMsgReceived = msgID;
}
XP_STATUSF( "set channel %d's lastMsgReceived to " XP_LD,
channelNo, msgID );
}
} else {
XP_LOGF( "%s: message too small", __FUNCTION__ );
}
XP_STATUSF( "set channel %d's lastMsgReceived to " XP_LD,
channelNo, msgID );
} else {
XP_STATUSF( "refusing non-matching connID; got %lx, wanted %lx",
connID, comms->connID );
}
} else {
validMessage = XP_FALSE;
XP_STATUSF( "refusing non-matching connID; got %lx, wanted %lx",
connID, comms->connID );
XP_LOGF( "%s: message too small", __FUNCTION__ );
}
return validMessage;
} /* comms_checkIncomingStream */