Commit Graph

138 Commits

Author SHA1 Message Date
Daniel P. Berrange
7fc3fcefe2 io: fix mem leak in websock error path
Coverity pointed out the 'date' is not free()d in the error
path

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
0efd6c9ec1 io: add trace points for websocket HTTP protocol headers
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
6d5d23b007 io: cope with websock 'Connection' header having multiple values
The noVNC server sends a header "Connection: keep-alive, Upgrade" which
fails our simple equality test. Split the header on ',', trim whitespace
and then check for 'upgrade' token.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
8dfd5f9651 io: get rid of bounce buffering in websock write path
Currently most outbound I/O on the websock channel gets copied into the
rawoutput buffer, and then immediately copied again into the encoutput
buffer, with a header prepended. Now that qio_channel_websock_encode
accepts a struct iovec, we can trivially remove this bounce buffering
and write directly to encoutput.

In doing so, we also now correctly validate the encoutput size against
the QIO_CHANNEL_WEBSOCK_MAX_BUFFER limit.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
fb74e59039 io: pass a struct iovec into qio_channel_websock_encode
Instead of requiring use of another Buffer, pass a struct iovec
into qio_channel_websock_encode, which gives callers more
flexibility in how they process data.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
bac6c95415 io: get rid of qio_channel_websock_encode helper method
The qio_channel_websock_encode method is only used in one place,
everything else calls qio_channel_websock_encode_buffer directly.
It can also be pushed up a level into the qio_channel_websock_writev
method, since every other caller of qio_channel_websock_write_wire
has already filled encoutput.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
57b0cdf152 io: simplify websocket ping reply handling
We must ensure we don't get flooded with ping replies if the outbound
channel is slow. Currently we do this by keeping the ping reply in a
separate temporary buffer and only writing it if the encoutput buffer
is completely empty. This is overly pessimistic, as it is reasonable
to add a ping reply to the encoutput buffer even if it has previous
data in it, as long as that previous data doesn't include a ping
reply.

To track this better, put the ping reply directly into the encoutput
buffer, and then record the size of encoutput at this time in
pong_remain. As we write encoutput to the underlying channel, we
can decrement the pong_remain counter. Once it hits zero, we can
accept further ping replies for transmission.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
a7b20a8efa io: monitor encoutput buffer size from websocket GSource
The websocket GSource is monitoring the size of the rawoutput
buffer to determine if the channel can accepts more writes.
The rawoutput buffer, however, is merely a temporary staging
buffer before data is copied into the encoutput buffer. Thus
its size will always be zero when the GSource runs.

This flaw causes the encoutput buffer to grow without bound
if the other end of the underlying data channel doesn't
read data being sent. This can be seen with VNC if a client
is on a slow WAN link and the guest OS is sending many screen
updates. A malicious VNC client can act like it is on a slow
link by playing a video in the guest and then reading data
very slowly, causing QEMU host memory to expand arbitrarily.

This issue is assigned CVE-2017-15268, publically reported in

  https://bugs.launchpad.net/qemu/+bug/1718964

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange
59f183bbd5 io: add trace events for websockets frame handling
It is useful to trace websockets frame encoding/decoding when debugging
problems.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
530ca60c16 io: Attempt to send websocket close messages to client
Make a best effort attempt to close websocket connections according to
the RFC. Sends the close message, as room permits in the socket buffer,
and immediately closes the socket.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
268a53f50d io: Reply to ping frames
Add an immediate ping reply (pong) to the outgoing stream when a ping
is received. Unsolicited pongs are ignored.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
01af17fc00 io: Ignore websocket PING and PONG frames
Keep pings and gratuitous pongs generated by web browsers from killing
websocket connections.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
3a29640e2c io: Allow empty websocket payload
Some browsers send pings/pongs with no payload, so allow empty payloads
instead of closing the connection.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
ff1300e626 io: Add support for fragmented websocket binary frames
Allows fragmented binary frames by saving the previous opcode. Handles
the case where an intermediary (i.e., web proxy) fragments frames
originally sent unfragmented by the client.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter
eefa3d8ef6 io: Small updates in preparation for websocket changes
Gets rid of unnecessary bit shifting and performs proper EOF checking to
avoid a large number of repeated calls to recvmsg() when a client
abruptly terminates a connection (bug fix).

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange
33badfd1e3 io: use case insensitive check for Connection & Upgrade websock headers
When checking the value of the Connection and Upgrade HTTP headers
the websock RFC (6455) requires the comparison to be case insensitive.
The Connection value should be an exact match not a substring.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange
3a3f870596 io: include full error message in websocket handshake trace
When the websocket handshake fails it is useful to log the real
error message via the trace points for debugging purposes.

Fixes bug: #1715186

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange
f69a8bde29 io: send proper HTTP response for websocket errors
When any error occurs while processing the websockets handshake,
QEMU just terminates the connection abruptly. This is in violation
of the HTTP specs and does not help the client understand what they
did wrong. This is particularly bad when the client gives the wrong
path, as a "404 Not Found" would be very helpful.

Refactor the handshake code so that it always sends a response to
the client unless there was an I/O error.

Fixes bug: #1715186

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Eric Blake
e8ffaa3110 io: Add new qio_channel_read{, v}_all_eof functions
Some callers want to distinguish between clean EOF (no bytes read)
vs. a short read (at least one byte read, but EOF encountered
before reaching the desired length), as it allows clients the
ability to do a graceful shutdown when a server shuts down at
defined safe points in the protocol, rather than treating all
shutdown scenarios as an error due to EOF.  However, we don't want
to require all callers to have to check for early EOF.  So add
another wrapper function that can be used by the callers that care
about the distinction.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170905191114.5959-3-eblake@redhat.com>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
2017-09-06 10:11:54 -05:00
Eric Blake
9ffb827020 io: Yield rather than wait when already in coroutine
The new qio_channel_{read,write}{,v}_all functions are documented
as yielding until data is available.  When used on a blocking
channel, this yield is done via qio_channel_wait() which spawns
a nested event loop under the hood (so it is that secondary loop
which yields as needed); but if we are already in a coroutine (at
which point QIO_CHANNEL_ERR_BLOCK is only possible if we are a
non-blocking channel), we want to yield the current coroutine
instead of spawning a nested event loop.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170905191114.5959-2-eblake@redhat.com>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
[commit message updated]
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-09-06 10:10:58 -05:00
Daniel P. Berrange
d4622e5588 io: add new qio_channel_{readv, writev, read, write}_all functions
These functions wait until they are able to read / write the full
requested data buffer(s).

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-09-05 13:21:58 +01:00
Cao jin
b258793258 util: remove the obsolete non-blocking connect
The non-blocking connect mechanism is obsolete, and it doesn't
work well in inet connection, because it will call getaddrinfo
first and getaddrinfo will blocks on DNS lookups. Since commit
e65c67e4 & d984464e, the non-blocking connect of migration goes
through QIOChannel in a different manner(using a thread), and
nobody use this old non-blocking connect anymore.

Any newly written code which needs a non-blocking connect should
use the QIOChannel code, so we can drop NonBlockingConnectHandler
as a concept entirely.

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-09-05 13:21:58 +01:00
Peter Xu
8bd9c4e6c5 io: fix qio_channel_socket_accept err handling
When accept failed, we should setup errp with the reason. More
importantly, the caller may assume errp be non-NULL when error happens,
and not setting the errp may crash QEMU.

At the same time, move the trace_qio_channel_socket_accept_fail() after
the if check on EINTR. Two reasons:

1. when EINTR happened, it's not really a fault (we should just try
   again), so we should not log with an "accept failure".

2. trace_*() functions may overwrite errno, then the old errno will be
   missing. We need to either check errno before trace_*() calls, or
   reserve the errno.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1501666880-10159-3-git-send-email-peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-08-02 11:27:44 +01:00
Philippe Mathieu-Daudé
87e0331c5a docs: fix broken paths to docs/devel/tracing.txt
With the move of some docs/ to docs/devel/ on ac06724a71,
no references were updated.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-31 13:12:53 +03:00
Peter Maydell
63cb55783c Merge I/O 2017/07/18 v1
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Merge remote-tracking branch 'remotes/berrange/tags/pull-qio-2017-07-18-1' into staging

Merge I/O 2017/07/18 v1

# gpg: Signature made Tue 18 Jul 2017 11:31:53 BST
# gpg:                using RSA key 0xBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/pull-qio-2017-07-18-1:
  io: simplify qio_channel_attach_aio_context

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-19 09:11:38 +01:00
Daniel P. Berrange
563a3987b9 io: preserve ipv4/ipv6 flags when resolving InetSocketAddress
The original InetSocketAddress struct may have has_ipv4 and
has_ipv6 fields set, which will control both the ai_family
used during DNS resolution, and later use of the V6ONLY
flag.

Currently the standalone DNS resolver code drops the
has_ipv4 & has_ipv6 flags after resolving, which means
the later bind() code won't correctly set V6ONLY.

This fixes the following scenarios

  -vnc :0,ipv4=off
  -vnc :0,ipv6=on
  -vnc :::0,ipv4=off
  -vnc :::0,ipv6=on

which all mistakenly accepted IPv4 clients

Acked-by: Gerd Hoffmann <kraxel@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-07-14 14:28:29 +01:00
Eduardo Habkost
e79ea67a97 websock: Don't try to set *errp directly
Assigning directly to *errp is not valid, as errp may be NULL,
&error_fatal, or &error_abort.  Use error_propagate() instead.

Cc: "Daniel P. Berrange" <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170608133906.12737-4-ehabkost@redhat.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-13 13:45:53 +02:00
Paolo Bonzini
8f7168b343 io: simplify qio_channel_attach_aio_context
If properly preceded by qio_channel_detach_aio_context, this function really
has nothing to do except setting ioc->ctx.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-05-26 10:38:08 +01:00
Markus Armbruster
bd269ebc82 sockets: Limit SocketAddressLegacy to external interfaces
SocketAddressLegacy is a simple union, and simple unions are awkward:
they have their variant members wrapped in a "data" object on the
wire, and require additional indirections in C.  SocketAddress is the
equivalent flat union.  Convert all users of SocketAddressLegacy to
SocketAddress, except for existing external interfaces.

See also commit fce5d53..9445673 and 85a82e8..c5f1ae3.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1493192202-3184-7-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Minor editing accident fixed, commit message and a comment tweaked]

Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:14:40 +02:00
Markus Armbruster
dfd100f242 sockets: Rename SocketAddress to SocketAddressLegacy
The next commit will rename SocketAddressFlat to SocketAddress, and
the commit after that will replace most uses of SocketAddressLegacy by
SocketAddress, replacing most of this commit's renames right back.

Note that checkpatch emits a few "line over 80 characters" warnings.
The long lines are all temporary; the SocketAddressLegacy replacement
will shorten them again.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1493192202-3184-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:14:40 +02:00
Fam Zheng
226799cec5 socket: Make errp the last parameter of socket_connect
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-2-famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24 09:12:59 +02:00
Daniel P. Berrange
b8a68728b6 io: fix FD socket handling in DNS lookup
The qio_dns_resolver_lookup_sync() method is required to be a no-op
for socket kinds that don't require name resolution. Thus the KIND_FD
handling should not return an error.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-04-04 16:17:03 +01:00
Wang guang
0e5d6327f3 io: fix incoming client socket initialization
The channel socket was initialized manually, but forgot to set
QIO_CHANNEL_FEATURE_SHUTDOWN. Thus, the colo_process_incoming_thread
would hang at recvmsg. This patch just call qio_channel_socket_new to
get channel, Which set QIO_CHANNEL_FEATURE_SHUTDOWN already.

Signed-off-by: Wang Guang<wang.guang55@zte.com.cn>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-04-04 16:17:03 +01:00
Markus Armbruster
a6c76285f2 io vnc sockets: Clean up SocketAddressKind switches
We have quite a few switches over SocketAddressKind.  Some have case
labels for all enumeration values, others rely on a default label.
Some abort when the value isn't a valid SocketAddressKind, others
report an error then.

Unify as follows.  Always provide case labels for all enumeration
values, to clarify intent.  Abort when the value isn't a valid
SocketAddressKind, because the program state is messed up then.

Improve a few error messages while there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1490895797-29094-4-git-send-email-armbru@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Daniel P. Berrange
07e95cd529 io: fully parse & validate HTTP headers for websocket protocol handshake
The current websockets protocol handshake code is very relaxed, just
doing crude string searching across the HTTP header data. This causes
it to both reject valid connections and fail to reject invalid
connections. For example, according to the RFC 6455 it:

 - MUST reject any method other than "GET"
 - MUST reject any HTTP version less than "HTTP/1.1"
 - MUST reject Connection header without "Upgrade" listed
 - MUST reject Upgrade header which is not 'websocket'
 - MUST reject missing Host header
 - MUST treat HTTP header names as case insensitive

To do all this validation correctly requires that we fully parse the
HTTP headers, populating a data structure containing the header
fields.

After this change, we also reject any path other than '/'

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-28 11:51:16 +00:00
Daniel P. Berrange
cd892a2efc io: fix decoding when multiple websockets frames arrive at once
The qio_channel_websock_read_wire() method will read upto 4096
bytes off the socket and then decode the websockets header and
payload. The code was only decoding a single websockets frame,
even if the buffered data contained multiple frames. This meant
that decoding of subsequent frames was delayed until further
input arrived on the socket. This backlog of delayed frames
gets worse & worse over time.

Symptom was that when connecting to the VNC server via the
built-in websockets server, mouse/keyboard interaction would
start out fine, but slowly get more & more delayed until it
was unusable.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-28 10:36:31 +00:00
Paolo Bonzini
c4c497d27f io: make qio_channel_yield aware of AioContexts
Support separate coroutines for reading and writing, and place the
read/write handlers on the AioContext that the QIOChannel is registered
with.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:14:07 +00:00
Paolo Bonzini
bf88c1247f io: add methods to set I/O handlers on AioContext
This is in preparation for making qio_channel_yield work on
AioContexts other than the main one.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-6-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:14:07 +00:00
Daniel P. Berrange
80fb34eda0 io: fix possible double free of task error object
If a QIOTask has an error set and the calling code uses
qio_task_propagate_error() to steal the reference to
that Error object, the task would not clear its own
reference. This would lead to a double-free when
qio_task_free runs, if the caller had (correctly) freed
the Error object they now owned.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-26 10:26:18 +00:00
Daniel P. Berrange
c1b412f1d9 io: introduce a DNS resolver API
Currently DNS resolution is done automatically as part
of the creation of a QIOChannelSocket object instance.
This works ok for network clients where you just end
up a single network socket, but for servers, the results
of DNS resolution may require creation of multiple
sockets.

Introducing a DNS resolver API allows DNS resolution
to be separated from the socket object creation. This
will make it practical to create multiple QIOChannelSocket
instances for servers.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:46 +00:00
Daniel P. Berrange
59de517d8d io: remove Error parameter from QIOTask thread worker
Now that task objects have a directly associated error,
there's no need for an an Error **errp parameter to
the QIOTask thread worker function. It already has a
QIOTask object, so can directly set the error on it.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:19 +00:00
Daniel P. Berrange
60e705c51c io: change the QIOTask callback signature
Currently the QIOTaskFunc signature takes an Object * for
the source, and an Error * for any error. We also need to
be able to provide a result pointer. Rather than continue
to add parameters to QIOTaskFunc, remove the existing
ones and simply pass the QIOTask object instead. This
has methods to access all the other data items required
in the callback impl.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:18 +00:00
Daniel P. Berrange
1a447e4f02 io: add ability to associate an error with a task
Currently when a task fails, the error is never explicitly
associated with the task object, it is just passed along
through the completion callback. This adds the ability to
explicitly associate an error with the task.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:18 +00:00
Daniel P. Berrange
52dd99e8a4 io: add ability to associate an opaque "result" with with a task
Currently there is no data associated with a successful
task completion. This adds an opaque pointer to the task
to store an arbitrary result.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:18 +00:00
Daniel P. Berrange
937470bb54 io: stop incrementing reference in qio_task_get_source
Incrementing the reference in qio_task_get_source is
not necessary, since we're not running concurrently
with any other code touching the QIOTask. This
minimizes chances of further memory leaks.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:18 +00:00
Daniel P. Berrange
20f4aa265e io: add ability to set a name for IO channels
The GSource object has ability to have a name, which is useful
when debugging performance problems with the mainloop event
callbacks that take too long. By associating a name with a
QIOChannel object, we can then set the name on any GSource
associated with the channel.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-27 09:13:10 +02:00
Daniel P. Berrange
bf53520827 io: set LISTEN flag explicitly for listen sockets
The SO_ACCEPTCONN ioctl is not portable across OS, with
some BSD versions and OS-X not supporting it. There is
no viable alternative to this, so instead just set the
feature explicitly when creating a listener socket.

The current users of qio_channel_socket_new_fd() won't
ever be given a listening socket, so there's no problem
with no auto-detecting it in this scenario

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-27 09:13:00 +02:00
Felipe Franciosi
d8d3c7cc67 io: Introduce a qio_channel_set_feature() helper
Testing QIOChannel feature support can be done with a helper called
qio_channel_has_feature(). Setting feature support, however, was
done manually with a logical OR. This patch introduces a new helper
called qio_channel_set_feature() and makes use of it where applicable.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-26 18:19:53 +02:00
Felipe Franciosi
e413ae0c04 io: Use qio_channel_has_feature() where applicable
Parts of the code have been testing QIOChannel features directly with a
logical AND. This patch makes it all consistent by using the
qio_channel_has_feature() function to test if a feature is present.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-26 18:19:53 +02:00
Felipe Franciosi
8fbf661212 io: Fix double shift usages on QIOChannel features
When QIOChannels were introduced in 666a3af9, the feature bits were
already defined shifted. However, when using them, the code was shifting
them again. The incorrect use was consistent until 74b6ce43, where
QIO_CHANNEL_FEATURE_LISTEN was defined shifted but tested unshifted.

This patch changes the definition to be unshifted and fixes the
incorrect usage introduced on 74b6ce43.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-26 18:19:53 +02:00
Daniel P. Berrange
2c7c4cf0c4 trace: move util/buffer.c trace points into correct file
The trace points for util/buffer.c were mistakenly put
in the io/trace-events file, instead of util/trace-events
in

  commit 892bd32ea3
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Thu Jun 16 09:39:50 2016 +0100

    trace: split out trace events for io/ directory

    Move all trace-events for files in the io/ directory to

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1473872624-23285-2-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-28 19:17:54 +01:00
Laurent Vivier
e723b87103 trace-events: fix first line comment in trace-events
Documentation is docs/tracing.txt instead of docs/trace-events.txt.

find . -name trace-events -exec \
     sed -i "s?See docs/trace-events.txt for syntax documentation.?See docs/tracing.txt for syntax documentation.?" \
     {} \;

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-id: 1470669081-17860-1-git-send-email-lvivier@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-12 10:36:01 +01:00
Daniel P. Berrange
bc35d51077 io: remove mistaken call to object_ref on QTask
The QTask struct is just a standalone struct, not a QOM Object,
so calling object_ref() on it is not appropriate. This results
in mangling the 'destroy' field in the QTask struct, causing
the later call to qtask_free() to try to call the function
at address 0x1, with predictably segfault happy results.

There is in fact no need for ref counting with QTask, as the
call to qtask_abort() or qtask_complete() will automatically
free associated memory.

This fixes the crash shown in

  https://bugs.launchpad.net/qemu/+bug/1589923

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-08-03 10:28:50 +01:00
Paolo Bonzini
0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c).  So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.

Mostly done with the following semantic patch:

@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));

@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);

except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00
Eric Blake
37f9e0a2b6 sockets: Use new QAPI cloning
Rather than rolling our own clone via an expensive conversion
in and back out of QObject, use the new clone visitor.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-15-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-07-06 10:52:04 +02:00
Marc-André Lureau
74b6ce43e3 socket: unlink unix socket on remove
qemu leaves unix socket files behind when removing a listening chardev
or leaving. qemu could clean that up, even if doing so isn't race-free.

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1347077

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1466105332-10285-4-git-send-email-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29 16:49:41 +02:00
Marc-André Lureau
3fa27a9a1e socket: add listen feature
Add a flag to tell whether the channel socket is listening.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1466105332-10285-3-git-send-email-marcandre.lureau@redhat.com>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-06-29 16:49:41 +02:00
Daniel P. Berrange
892bd32ea3 trace: split out trace events for io/ directory
Move all trace-events for files in the io/ directory to
their own file.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-5-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 17:22:14 +01:00
Daniel P. Berrange
d656ec5ea8 io: avoid double-free when closing QIOChannelBuffer
The QIOChannelBuffer's close implementation will free
the internal data buffer. It failed to reset the pointer
to NULL though, so when the object is later finalized
it will free it a second time with predictable crash.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-3-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:09 +05:30
Paolo Bonzini
58369e22cf qemu-common: stop including qemu/bswap.h from qemu-common.h
Move it to the actual users.  There are still a few includes of
qemu/bswap.h in headers; removing them is left for future work.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:28 +02:00
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Daniel P. Berrange
b16a44e13e osdep: remove use of socket_error() from all code
Now that QEMU wraps the Win32 sockets methods to automatically
set errno upon failure, there is no reason for callers to use
the socket_error() method. They can rely on accessing errno
even on Win32. Remove all use of socket_error() from general
code, leaving it as a static method in oslib-win32.c only.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-10 17:19:34 +00:00
Paolo Bonzini
a589720567 io: implement socket watch for win32 using WSAEventSelect+select
On Win32 we cannot directly poll on socket handles. Instead we
create a Win32 event object and associate the socket handle with
the event. When the event signals readyness we then have to
use select to determine which events are ready. Creating Win32
events is moderately heavyweight, so we don't want todo it
every time we create a GSource, so this associates a single
event with a QIOChannel.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-10 17:19:07 +00:00
Daniel P. Berrange
30fd3e2790 io: remove checking of EWOULDBLOCK
Since we now canonicalize WSAEWOULDBLOCK into EAGAIN there is
no longer any need to explicitly check EWOULDBLOCK for Win32.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-10 17:19:05 +00:00
Daniel P. Berrange
de7971ffb9 io: use qemu_accept to ensure SOCK_CLOEXEC is set
The QIOChannelSocket code mistakenly uses the bare accept()
function which does not set SOCK_CLOEXEC.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-10 17:11:40 +00:00
Paolo Bonzini
b83b68a013 io: introduce qio_channel_create_socket_watch
Sockets are not in the same namespace as file descriptors on Windows.
As an initial step, introduce separate APIs for file descriptor and
socket watches.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-10 17:10:19 +00:00
Paolo Bonzini
e560d141ab io: pass HANDLE to g_source_add_poll on Win32
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-10 17:10:19 +00:00
Daniel P. Berrange
5151d23e65 io: fix copy+paste mistake in socket error message
s/write/read/ in the error message reported after
readmsg() fails

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-03-10 17:10:18 +00:00
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
e8f117f3b3 io: convert QIOChannelBuffer to use uint8_t instead of char
The QIOChannelBuffer struct uses a 'char *' for its data
buffer. It will give simpler type compatibility with the
migration APIs if it uses 'uint8_t *' instead, avoiding
several casts.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-02-15 14:49:18 +00:00
Daniel P. Berrange
c767ae62b9 io: introduce helper for creating channels from file descriptors
Depending on what object a file descriptor refers to a different
type of IO channel will be needed - either a QIOChannelFile or
a QIOChannelSocket. Introduce a qio_channel_new_fd() method
which will return the appropriate channel implementation.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-02-15 14:49:00 +00:00
Paolo Bonzini
150dcd1aed qemu-char, io: fix ordering of arguments for UDP socket creation
Two wrongs make a right, but they should be fixed anyway.

Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1455015557-15106-1-git-send-email-pbonzini@redhat.com>
2016-02-09 17:09:15 +01:00
Peter Maydell
cae9fc567d io: 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>
Message-id: 1454089805-5470-14-git-send-email-peter.maydell@linaro.org
2016-02-04 17:41:30 +00:00
Daniel P. Berrange
ccf1e2dcd6 io: use memset instead of { 0 } for initializing array
Some versions of GCC on OS-X complain about CMSG_SPACE
not being constant size, which prevents use of { 0 }

io/channel-socket.c: In function 'qio_channel_socket_writev':
io/channel-socket.c:497:18: error: variable-sized object may not be initialized
     char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)] = { 0 };

The compiler is at fault here, but it is nicer to avoid
tickling this compiler bug by using memset instead.

Reviewed-By: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-01-20 11:31:01 +00:00
Daniel P. Berrange
e155494cf0 io: some fixes to handling of /dev/null when running commands
The /dev/null file handle was leaked in a couple of places.
There is also the possibility that both readfd and writefd
point to the same /dev/null file handle, so care must be
taken not to close the same file handle twice.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-01-20 11:30:56 +00:00
Daniel P. Berrange
0c0a55b229 io: increment counter when killing off subcommand
When killing the subcommand, it is intended to first send
SIGTERM, then SIGKILL and only report an error if it still
doesn't die after SIGKILL. The 'step' counter was not
being incremented though, so the code never got past the
SIGTERM stage.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-01-19 14:03:27 +00:00
Daniel P. Berrange
cc75a50c68 io: fix sign of errno value passed to error report
When reporting the number of FDs has been exceeded, pass
EINVAL to error_setg_errno, rather than -EINVAL.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-01-19 14:03:27 +00:00
Daniel P. Berrange
7b3c618ad0 io: fix stack allocation when sending of file descriptors
When sending file descriptors over a socket, we have to
allocate a data buffer to hold the FDs in the scmsghdr.
Unfortunately we allocated the buffer on the stack inside
an if () {} block, but called sendmsg() outside the block.
So the stack bytes holding the FDs were liable to be
overwritten with other data. By luck this was not a problem
when sending 1 FD, but if sending 2 or more then it would
fail.

The fix is to simply move the variables outside the nested
'if' block. To keep valgrind quiet we also zero-initialize
the 'control' buffer.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-23 10:53:03 +00:00
Daniel P. Berrange
bead59946a io: fix setting of QIO_CHANNEL_FEATURE_FD_PASS on server connections
The QIO_CHANNEL_FEATURE_FD_PASS feature flag is set in the
qio_channel_socket_set_fd() method, however, this only deals
with client side connections.

To ensure server side connections also have the feature flag
set, we must set it in qio_channel_socket_accept() too. This
also highlighted a typo fix where the code updated the
sockaddr struct in the wrong object instance.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-22 18:19:32 +00:00
Daniel P. Berrange
d98e4eb7de io: add QIOChannelBuffer class
Add a QIOChannel subclass that is capable of performing I/O
to/from a memory buffer. This implementation does not attempt
to support concurrent readers & writers. It is designed for
serialized access where by a single thread at a time may write
data, seek and then read data back out.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
195e14d026 io: add QIOChannelCommand class
Add a QIOChannel subclass that is capable of performing I/O
to/from a separate process, via a pair of pipes. The command
can be used for unidirectional or bi-directional I/O.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
2d1d0e70cf io: add QIOChannelWebsock class
Add a QIOChannel subclass that can run the websocket protocol over
the top of another QIOChannel instance. This initial implementation
is only capable of acting as a websockets server. There is no support
for acting as a websockets client yet.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
ed8ee42c40 io: add QIOChannelTLS class
Add a QIOChannel subclass that can run the TLS protocol over
the top of another QIOChannel instance. The object provides a
simplified API to perform the handshake when starting the TLS
session. The layering of TLS over the underlying channel does
not have to be setup immediately. It is possible to take an
existing QIOChannel that has done some handshake and then swap
in the QIOChannelTLS layer. This allows for use with protocols
which start TLS right away, and those which start plain text
and then negotiate TLS.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
d6e48869a4 io: add QIOChannelFile class
Add a QIOChannel subclass that is capable of operating on things
that are files, such as plain files, pipes, character/block
devices, but notably not sockets.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
559607ea17 io: add QIOChannelSocket class
Implement a QIOChannel subclass that supports sockets I/O.
The implementation is able to manage a single socket file
descriptor, whether a TCP/UNIX listener, TCP/UNIX connection,
or a UDP datagram. It provides APIs which can listen and
connect either asynchronously or synchronously. Since there
is no asynchronous DNS lookup API available, it uses the
QIOTask helper for spawning a background thread to ensure
non-blocking operation.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00
Daniel P. Berrange
b02db2d920 io: add QIOTask class for async operations
A number of I/O operations need to be performed asynchronously
to avoid blocking the main loop. The caller of such APIs need
to provide a callback to be invoked on completion/error and
need access to the error, if any. The small QIOTask provides
a simple framework for dealing with such probes. The API
docs inline provide an outline of how this is to be used.

Some functions don't have the ability to run asynchronously
(eg getaddrinfo always blocks), so to facilitate their use,
the task class provides a mechanism to run a blocking
function in a thread, while triggering the completion
callback in the main event loop thread. This easily allows
any synchronous function to be made asynchronous, albeit
at the cost of spawning a thread.

In this series, the QIOTask class will be used for things like
the TLS handshake, the websockets handshake and TCP connect()
progress.

The concept of QIOTask is inspired by the GAsyncResult
interface / GTask class in the GIO libraries. The min
version requirements on glib don't allow those to be
used from QEMU, so QIOTask provides a facsimilie which
can be easily switched to GTask in the future if the
min version is increased.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:30 +00:00
Daniel P. Berrange
1c809fa01d io: add helper module for creating watches on FDs
A number of the channel implementations will require the
ability to create watches on file descriptors / sockets.
To avoid duplicating this code in each channel, provide a
helper API for dealing with file descriptor watches.

There are two watch implementations provided. The first
is useful for bi-directional file descriptors such as
sockets, regular files, character devices, etc. The
second works with a pair of unidirectional file descriptors
such as pipes.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:05 +00:00
Daniel P. Berrange
666a3af9c8 io: add abstract QIOChannel classes
Start the new generic I/O channel framework by defining a
QIOChannel abstract base class. This is designed to feel
similar to GLib's GIOChannel, but with the addition of
support for using iovecs, qemu error reporting, file
descriptor passing, coroutine integration and use of
the QOM framework for easier sub-classing.

The intention is that anywhere in QEMU that almost
anywhere that deals with sockets will use this new I/O
infrastructure, so that it becomes trivial to then layer
in support for TLS encryption. This will at least include
the VNC server, char device backend and migration code.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:05 +00:00