qemu/ui/vnc-auth-sasl.h
Daniel P. Berrange 8f61f1c5a6 ui: track how much decoded data we consumed when doing SASL encoding
When we encode data for writing with SASL, we encode the entire pending output
buffer. The subsequent write, however, may not be able to send the full encoded
data in one go though, particularly with a slow network. So we delay setting the
output buffer offset back to zero until all the SASL encoded data is sent.

Between encoding the data and completing sending of the SASL encoded data,
however, more data might have been placed on the pending output buffer. So it
is not valid to set offset back to zero. Instead we must keep track of how much
data we consumed during encoding and subtract only that amount.

With the current bug we would be throwing away some pending data without having
sent it at all. By sheer luck this did not previously cause any serious problem
because appending data to the send buffer is always an atomic action, so we
only ever throw away complete RFB protocol messages. In the case of frame buffer
updates we'd catch up fairly quickly, so no obvious problem was visible.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20171218191228.31018-6-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00

74 lines
2.3 KiB
C

/*
* QEMU VNC display driver: SASL auth protocol
*
* Copyright (C) 2009 Red Hat, Inc
*
* 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.
*/
#ifndef QEMU_VNC_AUTH_SASL_H
#define QEMU_VNC_AUTH_SASL_H
#include <sasl/sasl.h>
typedef struct VncStateSASL VncStateSASL;
typedef struct VncDisplaySASL VncDisplaySASL;
#include "qemu/acl.h"
#include "qemu/main-loop.h"
struct VncStateSASL {
sasl_conn_t *conn;
/* If we want to negotiate an SSF layer with client */
bool wantSSF;
/* If we are now running the SSF layer */
bool runSSF;
/*
* If this is non-zero, then wait for that many bytes
* to be written plain, before switching to SSF encoding
* This allows the VNC auth result to finish being
* written in plain.
*/
unsigned int waitWriteSSF;
/*
* Buffering encoded data to allow more clear data
* to be stuffed onto the output buffer
*/
const uint8_t *encoded;
unsigned int encodedLength;
unsigned int encodedRawLength;
unsigned int encodedOffset;
char *username;
char *mechlist;
};
struct VncDisplaySASL {
qemu_acl *acl;
};
void vnc_sasl_client_cleanup(VncState *vs);
long vnc_client_read_sasl(VncState *vs);
long vnc_client_write_sasl(VncState *vs);
void start_auth_sasl(VncState *vs);
#endif /* QEMU_VNC_AUTH_SASL_H */