Commit Graph

68 Commits

Author SHA1 Message Date
Gerd Hoffmann
f31f9c1080 vnc: add magic cookie to VncState
Set magic cookie on initialization.  Clear on cleanup.  Sprinkle a bunch
of assert()s checking the cookie, to verify the pointer is valid.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20180507102254.12107-1-kraxel@redhat.com
2018-05-15 10:36:55 +02:00
Markus Armbruster
9af2398977 Include less of the generated modular QAPI headers
In my "build everything" tree, a change to the types in
qapi-schema.json triggers a recompile of about 4800 out of 5100
objects.

The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h,
qapi-types.h.  Each of these headers still includes all its shards.
Reduce compile time by including just the shards we actually need.

To illustrate the benefits: adding a type to qapi/migration.json now
recompiles some 2300 instead of 4800 objects.  The next commit will
improve it further.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-24-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[eblake: rebase to master]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02 13:45:50 -06:00
Markus Armbruster
522ece32d2 Drop superfluous includes of qapi-types.h and test-qapi-types.h
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-4-armbru@redhat.com>
2018-02-09 05:05:11 +01:00
Daniel P. Berrange
13e1d0e71e ui: convert VNC server to QIONetListener
The VNC server already has the ability to listen on multiple sockets.
Converting it to use the QIONetListener APIs though, will reduce the
amount of code in the VNC server and improve the clarity of what is
left.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20180201164514.10330-1-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-02-02 07:47:39 +01:00
Daniel P. Berrange
4c956bd81e ui: avoid sign extension using client width/height
Pixman returns a signed int for the image width/height, but the VNC
protocol only permits a unsigned int16. Effective framebuffer size
is determined by the guest, limited by the video RAM size, so the
dimensions are unlikely to exceed the range of an unsigned int16,
but this is not currently validated.

With the current use of 'int' for client width/height, the calculation
of offsets in vnc_update_throttle_offset() suffers from integer size
promotion and sign extension, causing coverity warnings

*** CID 1385147:  Integer handling issues  (SIGN_EXTENSION)
/ui/vnc.c: 979 in vnc_update_throttle_offset()
973      * than that the client would already suffering awful audio
974      * glitches, so dropping samples is no worse really).
975      */
976     static void vnc_update_throttle_offset(VncState *vs)
977     {
978         size_t offset =
>>>     CID 1385147:  Integer handling issues  (SIGN_EXTENSION)
>>>     Suspicious implicit sign extension:
    "vs->client_pf.bytes_per_pixel" with type "unsigned char" (8 bits,
    unsigned) is promoted in "vs->client_width * vs->client_height *
    vs->client_pf.bytes_per_pixel" to type "int" (32 bits, signed), then
    sign-extended to type "unsigned long" (64 bits, unsigned).  If
    "vs->client_width * vs->client_height * vs->client_pf.bytes_per_pixel"
    is greater than 0x7FFFFFFF, the upper bits of the result will all be 1.
979             vs->client_width * vs->client_height * vs->client_pf.bytes_per_pixel;

Change client_width / client_height to be a size_t to avoid sign
extension and integer promotion. Then validate that dimensions are in
range wrt the RFB protocol u16 limits.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20180118155254.17053-1-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-25 15:02:00 +01:00
Daniel P. Berrange
30b80fd526 ui: mix misleading comments & return types of VNC I/O helper methods
While the QIOChannel APIs for reading/writing data return ssize_t, with negative
value indicating an error, the VNC code passes this return value through the
vnc_client_io_error() method. This detects the error condition, disconnects the
client and returns 0 to indicate error. Thus all the VNC helper methods should
return size_t (unsigned), and misleading comments which refer to the possibility
of negative return values need fixing.

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: 20171218191228.31018-14-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00
Daniel P. Berrange
ada8d2e436 ui: fix VNC client throttling when forced update is requested
The VNC server must throttle data sent to the client to prevent the 'output'
buffer size growing without bound, if the client stops reading data off the
socket (either maliciously or due to stalled/slow network connection).

The current throttling is very crude because it simply checks whether the
output buffer offset is zero. This check is disabled if the client has requested
a forced update, because we want to send these as soon as possible.

As a result, the VNC client can cause QEMU to allocate arbitrary amounts of RAM.
They can first start something in the guest that triggers lots of framebuffer
updates eg play a youtube video. Then repeatedly send full framebuffer update
requests, but never read data back from the server. This can easily make QEMU's
VNC server send buffer consume 100MB of RAM per second, until the OOM killer
starts reaping processes (hopefully the rogue QEMU process, but it might pick
others...).

To address this we make the throttling more intelligent, so we can throttle
full updates. When we get a forced update request, we keep track of exactly how
much data we put on the output buffer. We will not process a subsequent forced
update request until this data has been fully sent on the wire. We always allow
one forced update request to be in flight, regardless of what data is queued
for incremental updates or audio data. The slight complication is that we do
not initially know how much data an update will send, as this is done in the
background by the VNC job thread. So we must track the fact that the job thread
has an update pending, and not process any further updates until this job is
has been completed & put data on the output buffer.

This unbounded memory growth affects all VNC server configurations supported by
QEMU, with no workaround possible. The mitigating factor is that it can only be
triggered by a client that has authenticated with the VNC server, and who is
able to trigger a large quantity of framebuffer updates or audio samples from
the guest OS. Mostly they'll just succeed in getting the OOM killer to kill
their own QEMU process, but its possible other processes can get taken out as
collateral damage.

This is a more general variant of the similar unbounded memory usage flaw in
the websockets server, that was previously assigned CVE-2017-15268, and fixed
in 2.11 by:

  commit a7b20a8efa
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Mon Oct 9 14:43:42 2017 +0100

    io: monitor encoutput buffer size from websocket GSource

This new general memory usage flaw has been assigned CVE-2017-15124, and is
partially fixed by this patch.

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: 20171218191228.31018-11-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00
Daniel P. Berrange
e2b72cb6e0 ui: fix VNC client throttling when audio capture is active
The VNC server must throttle data sent to the client to prevent the 'output'
buffer size growing without bound, if the client stops reading data off the
socket (either maliciously or due to stalled/slow network connection).

The current throttling is very crude because it simply checks whether the
output buffer offset is zero. This check must be disabled if audio capture is
enabled, because when streaming audio the output buffer offset will rarely be
zero due to queued audio data, and so this would starve framebuffer updates.

As a result, the VNC client can cause QEMU to allocate arbitrary amounts of RAM.
They can first start something in the guest that triggers lots of framebuffer
updates eg play a youtube video. Then enable audio capture, and simply never
read data back from the server. This can easily make QEMU's VNC server send
buffer consume 100MB of RAM per second, until the OOM killer starts reaping
processes (hopefully the rogue QEMU process, but it might pick others...).

To address this we make the throttling more intelligent, so we can throttle
when audio capture is active too. To determine how to throttle incremental
updates or audio data, we calculate a size threshold. Normally the threshold is
the approximate number of bytes associated with a single complete framebuffer
update. ie width * height * bytes per pixel. We'll send incremental updates
until we hit this threshold, at which point we'll stop sending updates until
data has been written to the wire, causing the output buffer offset to fall
back below the threshold.

If audio capture is enabled, we increase the size of the threshold to also
allow for upto 1 seconds worth of audio data samples. ie nchannels * bytes
per sample * frequency. This allows the output buffer to have a mixture of
incremental framebuffer updates and audio data queued, but once the threshold
is exceeded, audio data will be dropped and incremental updates will be
throttled.

This unbounded memory growth affects all VNC server configurations supported by
QEMU, with no workaround possible. The mitigating factor is that it can only be
triggered by a client that has authenticated with the VNC server, and who is
able to trigger a large quantity of framebuffer updates or audio samples from
the guest OS. Mostly they'll just succeed in getting the OOM killer to kill
their own QEMU process, but its possible other processes can get taken out as
collateral damage.

This is a more general variant of the similar unbounded memory usage flaw in
the websockets server, that was previously assigned CVE-2017-15268, and fixed
in 2.11 by:

  commit a7b20a8efa
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Mon Oct 9 14:43:42 2017 +0100

    io: monitor encoutput buffer size from websocket GSource

This new general memory usage flaw has been assigned CVE-2017-15124, and is
partially fixed by this patch.

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: 20171218191228.31018-10-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00
Daniel P. Berrange
fef1bbadfb ui: introduce enum to track VNC client framebuffer update request state
Currently the VNC servers tracks whether a client has requested an incremental
or forced update with two boolean flags. There are only really 3 distinct
states to track, so create an enum to more accurately reflect permitted states.

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: 20171218191228.31018-7-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00
Daniel P. Berrange
4ee74fa708 ui: refactor VncDisplay to allow multiple listening sockets
Currently there is only a single listener for plain VNC and
a single listener for websockets VNC. This means that if
getaddrinfo() returns multiple IP addresses, for a hostname,
the VNC server can only listen on one of them. This is
just bearable if listening on wildcard interface, or if
the host only has a single network interface to listen on,
but if there are multiple NICs and the VNC server needs
to listen on 2 or more specific IP addresses, it can't be
done.

This refactors the VncDisplay state so that it holds an
array of listening sockets, but still only listens on
one socket.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170203120649.15637-4-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2017-02-08 14:59:37 +01:00
Pierre Ossman
a54f0d2ba3 vnc: track LED state separately
Piggy-backing on the modifier state array made it difficult to send
out updates at the proper times.

Signed-off-by: Pierre Ossman <ossman@cendio.se>
Message-id: 5aa28297d665cee24ddab26bbf4633e4252f97b6.1483978442.git.ossman@cendio.se
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2017-01-31 08:14:52 +01:00
Daniel P. Berrange
dbee9897d5 ui: rename vnc_init_state to vnc_start_protocol
Rename the vnc_init_state method to reflect what its actual
purpose is, to discourage future devs from using it for more
general state initialization.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-10-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-13 09:22:31 +02:00
Daniel P. Berrange
90cd03a30e ui: move some initialization out of vnc_init_state
Most of the fields in VncState are initialized in the
vnc_connect() method, but some are done in vnc_init_state()
instead.

The purpose of having vnc_init_state() is to delay starting
of the VNC wire protocol until after the websockets handshake
has completed. As such the vnc_init_state() method only needs
to be used for initialization that is dependant on the wire
protocol running.

This also lets us get rid of the initialized boolean flag
from the VncState struct.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-9-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-13 09:22:30 +02:00
Daniel P. Berrange
eda24e1886 ui: refactor method for setting up VncDisplay auth types
There is a lot of repeated code in the auth type setup method,
particularly around checking TLS credential types. Refactor
it to reduce duplication and instead of having one method
do both plain and websockets at once, call it separately
for each.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-6-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-13 09:22:20 +02:00
Daniel P. Berrange
38e5756a61 ui: remove 'ws_tls' field from VncState
The 'ws_tls' field in VncState is only ever representing
the result of 'tlscreds != NULL' and is thus pointless.
Replace use of 'ws_tls' with a direct check against
'tlscreds'

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-4-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-13 09:21:02 +02:00
Daniel P. Berrange
12b2806761 ui: remove 'enabled' and 'ws_enabled' fields from VncState
The 'ws_enabled' field is never used outside of the
vnc_display_open method, so can be a local variable.

The 'enabled' field is easily replaced by a check
for whether 'lsock' is non-NULL.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475163940-26094-3-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-13 09:21:02 +02:00
Markus Armbruster
2a6a4076e1 Clean up ill-advised or unusual header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Gerd Hoffmann
c5ce833344 vnc: add configurable keyboard delay
Limits the rate kbd events from the vnc server are forwarded to the
guest, so input devices which are typically low-bandwidth can keep
up even on bulky input.

v2: update documentation too.
v3: spell fixes.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Yang Hongyang <hongyang.yang@easystack.cn>
Message-id: 1464762150-25817-1-git-send-email-kraxel@redhat.com
2016-06-03 08:23:26 +02:00
Peter Maydell
30456d5ba3 all: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-02-23 12:43:05 +00:00
Daniel P. Berrange
d5f042232c ui: convert VNC server to use QIOChannelWebsock
Remove custom websock handling code from the VNC server and use
the QIOChannelWebsock class instead.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 15:02:11 +00:00
Daniel P. Berrange
2cc452281e ui: convert VNC server to use QIOChannelTLS
Switch VNC server over to using the QIOChannelTLS object for
the TLS session. This removes all remaining VNC specific code
for dealing with TLS handshakes.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 15:02:11 +00:00
Daniel P. Berrange
04d2529da2 ui: convert VNC server to use QIOChannelSocket
The minimal first step conversion to use QIOChannelSocket
classes instead of directly using POSIX sockets API. This
will later be extended to also cover the TLS, SASL and
websockets code.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 15:02:11 +00:00
Daniel P. Berrange
88c5f205fa util: pull Buffer code out of VNC module
The Buffer code in the VNC server is useful for the IO channel
code, so pull it out into a shared module, QIOBuffer.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-10-20 14:59:09 +01:00
Daniel P. Berrange
3e305e4a47 ui: convert VNC server to use QCryptoTLSSession
Switch VNC server over to using the QCryptoTLSSession object
for the TLS session. This removes the direct use of gnutls
from the VNC server code. It also removes most knowledge
about TLS certificate handling from the VNC server code.
This has the nice effect that all the CONFIG_VNC_TLS
conditionals go away and the user gets an actual error
message when requesting TLS instead of it being silently
ignored.

With this change, the existing configuration options for
enabling TLS with -vnc are deprecated.

Old syntax for anon-DH credentials:

  -vnc hostname:0,tls

New syntax:

  -object tls-creds-anon,id=tls0,endpoint=server \
  -vnc hostname:0,tls-creds=tls0

Old syntax for x509 credentials, no client certs:

  -vnc hostname:0,tls,x509=/path/to/certs

New syntax:

  -object tls-creds-x509,id=tls0,dir=/path/to/certs,endpoint=server,verify-peer=no \
  -vnc hostname:0,tls-creds=tls0

Old syntax for x509 credentials, requiring client certs:

  -vnc hostname:0,tls,x509verify=/path/to/certs

New syntax:

  -object tls-creds-x509,id=tls0,dir=/path/to/certs,endpoint=server,verify-peer=yes \
  -vnc hostname:0,tls-creds=tls0

This aligns VNC with the way TLS credentials are to be
configured in the future for chardev, nbd and migration
backends. It also has the benefit that the same TLS
credentials can be shared across multiple VNC server
instances, if desired.

If someone uses the deprecated syntax, it will internally
result in the creation of a 'tls-creds' object with an ID
based on the VNC server ID. This allows backwards compat
with the CLI syntax, while still deleting all the original
TLS code from the VNC server.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-15 15:20:55 +01:00
Daniel P. Berrange
fdd1ab6ad5 ui: fix return type for VNC I/O functions to be ssize_t
Various VNC server I/O functions return 'long' and then
also pass this to a method accepting 'int'. All these
should be ssize_t to match the signature of read/write
APIs and thus avoid potential for integer truncation /
wraparound.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-09-15 15:07:44 +01:00
Daniel P. Berrange
8e9b0d24fb ui: convert VNC websockets to use crypto APIs
Remove the direct use of gnutls for hash processing in the
websockets code, in favour of using the crypto APIs. This
allows the websockets code to be built unconditionally
removing countless conditional checks from the VNC code.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-9-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-08 13:11:01 +02:00
Daniel P. Berrange
a2bebfd6e0 CVE-2015-1779: incrementally decode websocket frames
The logic for decoding websocket frames wants to fully
decode the frame header and payload, before allowing the
VNC server to see any of the payload data. There is no
size limit on websocket payloads, so this allows a
malicious network client to consume 2^64 bytes in memory
in QEMU. It can trigger this denial of service before
the VNC server even performs any authentication.

The fix is to decode the header, and then incrementally
decode the payload data as it is needed. With this fix
the websocket decoder will allow at most 4k of data to
be buffered before decoding and processing payload.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

[ kraxel: fix frequent spurious disconnects, suggested by Peter Maydell ]

  @@ -361,7 +361,7 @@ int vncws_decode_frame_payload(Buffer *input,
  -        *payload_size = input->offset;
  +        *payload_size = *payload_remain;

[ kraxel: fix 32bit build ]

  @@ -306,7 +306,7 @@ struct VncState
  -    uint64_t ws_payload_remain;
  +    size_t ws_payload_remain;

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-04-01 17:11:34 +02:00
Daniel P. Berrange
7b45a00d05 ui: remove separate gnutls_session for websockets server
The previous change to the auth scheme handling guarantees we
can never have nested TLS sessions in the VNC websockets server.
Thus we can remove the separate gnutls_session instance.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-03-18 09:25:14 +01:00
Daniel P. Berrange
f9148c8ae7 ui: fix setup of VNC websockets auth scheme with TLS
The way the websockets TLS code was integrated into the VNC server
made it essentially useless. The only time that the websockets TLS
support could be used is if the primary VNC server had its existing
TLS support disabled. ie QEMU had to be launched with:

  # qemu -vnc localhost:1,websockets=5902,x509=/path/to/certs

Note the absence of the 'tls' flag. This is already a bug, because
the docs indicate that 'x509' is ignored unless 'tls' is given.

If the primary VNC server had TLS turned on via the 'tls' flag,
then this prevented the websockets TLS support from being used,
because it activates the VeNCrypt auth which would have resulted
in TLS being run over a TLS session. Of course no websockets VNC
client supported VeNCrypt so in practice, since the browser clients
cannot setup a nested TLS session over the main HTTPS connection,
so it would not even get past auth.

This patch causes us to decide our auth scheme separately for the
main VNC server vs the websockets VNC server. We take account of
the fact that if TLS is enabled, then the websockets client will
use https, so setting up VeNCrypt is thus redundant as it would
lead to nested TLS sessions.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-03-18 09:25:13 +01:00
Daniel P. Berrange
d169f04b8b ui: report error if user requests VNC option that is unsupported
If the VNC server is built without tls, sasl or websocket support
and the user requests one of these features, they are just silently
ignored. This is bad because it means the VNC server ends up running
in a configuration that is less secure than the user asked for.
It also leads to an tangled mass of preprocessor conditionals when
configuring the VNC server.

This ensures that the tls, sasl & websocket options are always
processed and an error is reported back to the user if any of
them were disabled at build time.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-03-18 09:25:13 +01:00
Gerd Hoffmann
bf7aa45e7b vnc: drop display+ws_display from VncDisplay
Nobody cares about those strings, they are only used to check whenever
the vnc server / websocket support is enabled or not.  Add bools for
this and drop the strings.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2015-03-12 08:22:07 +01:00
Gerd Hoffmann
e5f34cdd2d vnc: track & limit connections
Also track the number of connections in "connecting" and "shared" state
(in addition to the "exclusive" state).  Apply a configurable limit to
these connections.

The logic to apply the limit to connections in "shared" state is pretty
simple:  When the limit is reached no new connections are allowed.

The logic to apply the limit to connections in "connecting" state (this
is the state you are in *before* successful authentication) is
slightly different:  A new connect kicks out the oldest client which is
still in "connecting" state.  This avoids a easy DoS by unauthenticated
users by simply opening connections until the limit is reached.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-01-22 11:18:47 +01:00
Gerd Hoffmann
d616ccc5dd vnc: remove vnc_display global
Replace with a vnc_displays list, so we can have multiple vnc server
instances.  Add vnc_server_find function to lookup a display by id.
With no id supplied return the first vnc server, for backward
compatibility reasons.

It is not possible (yet) to actually create multiple vnc server
instances.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2015-01-22 11:18:46 +01:00
Gerd Hoffmann
6365828003 vnc update fix
We need to remember has_updates for each vnc client.  Otherwise it might
happen that vnc_update_client(has_dirty=1) takes the first exit due to
output buffers not being flushed yet and subsequent calls with
has_dirty=0 take the second exit, wrongly assuming there is nothing to
do because the work defered in the first call is ignored.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
2014-07-25 09:43:31 +02:00
Peter Lieven
bea60dd767 ui/vnc: fix potential memory corruption issues
this patch makes the VNC server work correctly if the
server surface and the guest surface have different sizes.

Basically the server surface is adjusted to not exceed VNC_MAX_WIDTH
x VNC_MAX_HEIGHT and additionally the width is rounded up to multiple of
VNC_DIRTY_PIXELS_PER_BIT.

If we have a resolution whose width is not dividable by VNC_DIRTY_PIXELS_PER_BIT
we now get a small black bar on the right of the screen.

If the surface is too big to fit the limits only the upper left area is shown.

On top of that this fixes 2 memory corruption issues:

The first was actually discovered during playing
around with a Windows 7 vServer. During resolution
change in Windows 7 it happens sometimes that Windows
changes to an intermediate resolution where
server_stride % cmp_bytes != 0 (in vnc_refresh_server_surface).
This happens only if width % VNC_DIRTY_PIXELS_PER_BIT != 0.

The second is a theoretical issue, but is maybe exploitable
by the guest. If for some reason the guest surface size is bigger
than VNC_MAX_WIDTH x VNC_MAX_HEIGHT we end up in severe corruption since
this limit is nowhere enforced.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-07-01 13:26:40 +02:00
Wenchao Xia
fb6ba0d525 qapi event: convert VNC events
Since VNC_CONNECTED, VNC_DISCONNECTED, VNC_INITIALIZED share some
common functions, convert them in one patch.

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23 11:12:28 -04:00
Peter Lieven
12b316d4c1 ui/vnc: optimize dirty bitmap tracking
vnc_update_client currently scans the dirty bitmap of each client
bitwise which is a very costly operation if only few bits are dirty.
vnc_refresh_server_surface does almost the same.
this patch optimizes both by utilizing the heavily optimized
function find_next_bit to find the offset of the next dirty
bit in the dirty bitmaps.

The following artifical test (just the bitmap operation part) running
vnc_update_client 65536 times on a 2560x2048 surface illustrates the
performance difference:

All bits clean - vnc_update_client_new: 0.07 secs
 vnc_update_client_old: 10.98 secs

All bits dirty - vnc_update_client_new: 11.26 secs
 vnc_update_client_old: 20.19 secs

Few bits dirty - vnc_update_client_new: 0.08 secs
 vnc_update_client_old: 10.98 secs

The case for all bits dirty is still rather slow, this
is due to the implementation of find_and_clear_dirty_height.
This will be addresses in a separate patch.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Peter Lieven
b4c85ddcec ui/vnc: introduce VNC_DIRTY_PIXELS_PER_BIT macro
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Gerd Hoffmann
14768eba46 input: mouse: switch vnc ui to new core
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-05 09:52:02 +01:00
Tim Hardeck
0057a0d590 TLS support for VNC Websockets
Added TLS support to the VNC QEMU Websockets implementation.
VNC-TLS needs to be enabled for this feature to be used.

The required certificates are specified as in case of VNC-TLS
with the VNC parameter "x509=<path>".

If the server certificate isn't signed by a rooth authority it needs to
be manually imported in the browser because at least in case of Firefox
and Chrome there is no user dialog, the connection just gets canceled.

As a side note VEncrypt over Websocket doesn't work atm because TLS can't
be stacked in the current implementation. (It also didn't work before)
Nevertheless to my knowledge there is no HTML 5 VNC client which supports
it and the Websocket connection can be encrypted with regular TLS now so
it should be fine for most use cases.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366727581-5772-1-git-send-email-thardeck@suse.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-03 12:04:57 -05:00
Lei Li
ab99e5c1d9 vnc: Support for LED state extension
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1366867752-11578-3-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-29 08:28:51 -05:00
Gerd Hoffmann
0f7b2864d0 console: gui timer fixes
Make gui update rate adaption code in gui_update() actually work.
Sprinkle in a tracepoint so you can see the code at work.  Remove
the update rate adaption code in vnc and make vnc simply use the
generic bits instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-16 09:03:49 +02:00
Gerd Hoffmann
d39fa6d86d vnc: stop using DisplayState
Rework DisplayStateListener callbacks to not use the DisplayState
any more.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:58 +01:00
Gerd Hoffmann
21ef45d712 console: kill DisplayState->opaque
It's broken by design.  There can be multiple DisplayChangeListener
instances, so they simply can't store state in the (single) DisplayState
struct.  Try 'qemu -display gtk -vnc :0', watch it crash & burn.

With DisplayChangeListenerOps having a more sane interface now we can
simply use the DisplayChangeListener pointer to get access to our
private data instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:58 +01:00
Tim Hardeck
6fd8e79af0 vnc: fix possible uninitialized removals
Some VncState values are not initialized before the Websocket handshake.
If it fails QEMU segfaults during the cleanup. To prevent this behavior
intialization checks are added.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-01-21 13:33:12 -06:00
Tim Hardeck
7536ee4bc3 vnc: added initial websocket protocol support
This patch adds basic Websocket Protocol version 13 - RFC 6455 - support
to QEMU VNC. Binary encoding support on the client side is mandatory.

Because of the GnuTLS requirement the Websockets implementation is
optional (--enable-vnc-ws).

To activate Websocket support the VNC option "websocket"is used, for
example "-vnc :0,websocket".
The listen port for Websocket connections is (5700 + display) so if
QEMU VNC is started with :0 the Websocket port would be 5700.
As an alternative the Websocket port could be manually specified by
using ",websocket=<port>" instead.

Parts of the implementation base on Anthony Liguori's QEMU Websocket
patch from 2010 and on Joel Martin's LibVNC Websocket implementation.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-01-21 13:33:12 -06:00
Tim Hardeck
32ed26808d vnc: added buffer_advance function
Following Anthony Liguori's Websocket implementation I have added the
buffer_advance function to VNC and replaced all related buffer memmove
operations with it.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-01-21 13:33:12 -06:00
Paolo Bonzini
1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini
83c9089e73 monitor: move include files to include/monitor/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00
Paolo Bonzini
28ecbaeecb ui: move files to ui/ and include/ui/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:30 +01:00