Commit Graph

280 Commits

Author SHA1 Message Date
Eric Blake
6e07f72ee5 rpc: avoid memory leak on error
Detected by Coverity.  The leak is on an error path, but I'm not
sure whether that path is likely to be triggered in practice.

* src/rpc/virnetserverservice.c (virNetServerServiceAccept): Plug leak.
2011-07-04 10:22:50 +08:00
Eric Blake
2aa83b43d3 rpc: fix logic bug
Spotted by Coverity.  If we don't update tmp each time through
the loop, then if the filter being removed was not the head of
the list, we accidentally lose all filters prior to the one we
wanted to remove.

* src/rpc/virnetserverclient.c (virNetServerClientRemoveFilter):
    Don't lose unrelated filters.
2011-07-04 09:45:21 +08:00
Eric Blake
0ac385bd6c build: remove dead variables
Detected by Coverity.  No real harm in leaving these, but fixing
them cuts down on the noise for future analysis.

* src/rpc/virnetserver.c (virNetServerAddService): Delete unused
entry.
* src/util/sysinfo.c (virSysinfoRead): Delete dead assignment to
base.
2011-07-01 06:48:33 -06:00
Eric Blake
0a8a79af53 rpc: avoid freeing uninitialized variable
Detected by Coverity.  Both are instances of bad things happening
if pipe2 fails; the virNetClientNew failure could free garbage,
and virNetSocketNewConnectCommand could close random fds.

Note: POSIX doesn't guarantee the contents of fd[0] and fd[1]
after pipe failure: http://austingroupbugs.net/view.php?id=467
We may need to introduce a virPipe2 wrapper that guarantees
that on pipe failure, the fds are explicitly set to -1, rather
than our current state of assuming the fds are unchanged from
their value prior to the failed pipe call.

* src/rpc/virnetclient.c (virNetClientNew): Initialize variable.
* src/rpc/virnetsocket.c (virNetSocketNewConnectCommand):
Likewise.
2011-06-30 11:36:52 -06:00
Daniel P. Berrange
cfd4370ad0 Send back an error if we get unexpected stream control message
We ignore any stream data packets which come in for streams which
are not registered, since these packets are async and do not have
a reply. If we get a stream control packet though we must send back
an actual error, otherwise a (broken) client may hang forever
making it hard to diagnose the client bug.

* src/rpc/virnetserverprogram.c: Send back error for unexpected
  stream control messages
2011-06-30 18:04:02 +01:00
Daniel P. Berrange
c69ba67032 Fix release of virNetMessagePtr instances in streams processing
If a message packet for a invalid stream is received it is just
free'd. This is not good because it doesn't let the client RPC
request counter decrement. If a stream is shutdown with pending
packets the message also isn't released properly because of an
incorrect header type

* daemon/stream.c: Fix message header type
* src/rpc/virnetserverprogram.c: Send dummy reply instead of
  free'ing ignored stream message
2011-06-30 18:04:02 +01:00
Daniel P. Berrange
f1c2c0e2dc Add missing include of signal.h in virnetsocket.c
virNetSocketFree uses kill(SIGTERM) so we must include
signal.h for the definitions

* src/rpc/virnetsocket.c: Include signal.h
2011-06-30 18:04:02 +01:00
Daniel P. Berrange
92fa2e58fd Fix leak of mdnsGroupName in virNetServer object
* src/rpc/virnetserver.c: Free mdnsGroupName
2011-06-30 18:04:01 +01:00
Daniel P. Berrange
d840fe93b0 Ensure RPC message is cleared before being reused
To save on memory reallocation, virNetMessage instances that
have been transmitted, may be reused for a subsequent incoming
message. We forgot to clear out the old data of the message
fully, which caused later confusion upon read.

* src/rpc/virnetserverclient.c: memset entire message before
  reusing it
2011-06-30 18:04:01 +01:00
Daniel P. Berrange
27111b350f Fix hardcoded limit on client requests in RPC code
The virNetServerClient object had a hardcoded limit of 10 requests
per client. Extend constructor to allow it to be passed in as a
configurable variable. Wire this up to the 'max_client_requests'
config parameter in libvirtd

* daemon/libvirtd.c: Pass max_client_requests into services
* src/rpc/virnetserverservice.c, src/rpc/virnetserverservice.h: Pass
  nrequests_client_max to clients
* src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h: Allow
  configurable request limit
2011-06-30 18:04:01 +01:00
Daniel P. Berrange
516235c037 Ensure that EOF is dispatched to the stream callback
When the remote client receives end of file on the stream
it never invokes the stream callback. Applications relying
on async event driven I/O will thus never see the EOF
condition on the stream

* src/rpc/virnetclient.c, src/rpc/virnetclientstream.c:
  Ensure EOF is dispatched
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
8a4e28743e Fix locking wrt virNetClientStreamPtr object
The client stream object can be used independently of the
virNetClientPtr object, so must have full locking of its
own and not rely on any caller.

* src/remote/remote_driver.c: Remove locking around stream
  callback
* src/rpc/virnetclientstream.c: Add locking to all APIs
  and callbacks
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
7a779ef6a2 Avoid referencing NULL pointer when copying stream error
* src/rpc/virnetclientstream.c: Avoid referencing NULL
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
c9ede1cfba Avoid free'ing a filtered RPC message in the server
When a filter steals an RPC message, that message must
not be freed, except by the filter code itself

* src/rpc/virnetserverclient.c: Don't free stolen RPC
  messages
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
b7337d03ec Improve two log messages in virNetMessage
Improve log messages issued when encountering a bogus
message length to include the actual length and the
limit violated

* src/rpc/virnetmessage.c: Improve log messages
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
59b877b609 Ensure empty payload is written upon stream completion
On stream completion it is neccessary to send back a
message with an empty payload. The message header was
not being filled out correctly, since we were not writing
any payload. Add a method for encoding an empty payload
which updates the message headers correctly.

* src/rpc/virnetmessage.c, src/rpc/virnetmessage.h: Add
  a virNetMessageEncodePayloadEmpty method
* src/rpc/virnetserverprogram.c: Write empty payload on
  stream completion
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
d550277ca7 Lower logging level when failing to register socket watch
The RPC client treats failure to register a socket watch
as non-fatal, since we do not mandate that a libvirt client
application provide an event loop implementation. It is
thus inappropriate to a log a message at VIR_LOG_WARN

* src/rpc/virnetsocket.c: Lower logging level
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
16c6e2b41e Fix propagation of RPC errors from streams
If a streams error is raised, virNetClientIOEventLoop
returns 0, but an error is set. Check for this and
propagate it if present

* src/rpc/virnetclient.c: Propagate streams error
2011-06-29 11:08:59 +01:00
Daniel P. Berrange
df0b57a95a Convert libvirtd over to the new RPC handling APIs
This guts the libvirtd daemon, removing all its networking and
RPC handling code. Instead it calls out to the new virServerPtr
APIs for all its RPC & networking work

As a fallout all libvirtd daemon error reporting now takes place
via the normal internal error reporting APIs. There is no need
to call separate error reporting APIs in RPC code, nor should
code use VIR_WARN/VIR_ERROR for reporting fatal problems anymore.

* daemon/qemu_dispatch_*.h, daemon/remote_dispatch_*.h: Remove
  old generated dispatcher code
* daemon/qemu_dispatch.h, daemon/remote_dispatch.h: New dispatch
  code
* daemon/dispatch.c, daemon/dispatch.h: Remove obsoleted code
* daemon/remote.c, daemon/remote.h: Rewrite for new dispatch
  APIs
* daemon/libvirtd.c, daemon/libvirtd.h: Remove all networking
  code
* daemon/stream.c, daemon/stream.h: Update for new APIs
* daemon/Makefile.am: Link to libvirt-net-rpc-server.la
2011-06-28 17:33:19 +01:00
Daniel P. Berrange
c1b2264477 Convert the remote driver to new RPC client APIs
This guts the current remote driver, removing all its networking
handling code. Instead it calls out to the new virClientPtr and
virClientProgramPtr APIs for all RPC & networking work.

* src/Makefile.am: Link remote driver with generic RPC code
* src/remote/remote_driver.c: Gut code, replacing with RPC
  API calls
* src/rpc/gendispatch.pl: Update for changes in the way
  streams are handled
2011-06-28 17:33:12 +01:00
Daniel P. Berrange
b17b4afafd Move the RPC generator scripts into src/rpc
Move the daemon/remote_generator.pl to src/rpc/gendispatch.pl
and move the src/remote/rpcgen_fix.pl to src/rpc/genprotocol.pl

* daemon/Makefile.am: Update for new name/location of generator
* src/Makefile.am: Update for new name/location of generator
2011-06-24 11:48:49 +01:00
Daniel P. Berrange
434de30da5 Introduce generic RPC client objects
To facilitate creation of new clients using XDR RPC services,
pull alot of the remote driver code into a set of reusable
objects.

 - virNetClient: Encapsulates a socket connection to a
   remote RPC server. Handles all the network I/O for
   reading/writing RPC messages. Delegates RPC encoding
   and decoding to the registered programs

 - virNetClientProgram: Handles processing and dispatch
   of RPC messages for a single RPC (program,version).
   A program can register to receive async events
   from a client

 - virNetClientStream: Handles generic I/O stream
   integration to RPC layer

Each new client program now merely needs to define the list of
RPC procedures & events it wants and their handlers. It does
not need to deal with any of the network I/O functionality at
all.
2011-06-24 11:48:45 +01:00
Daniel P. Berrange
e23ec81db6 Introduce generic RPC module for advertising via MDNS
Allow RPC servers to advertise themselves using MDNS,
via Avahi

* src/rpc/virnetserver.c, src/rpc/virnetserver.h: Allow
  registration of MDNS services via avahi
* src/rpc/virnetserverservice.c, src/rpc/virnetserverservice.h: Add
  API to fetch the listen port number
* src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: Add API to
  fetch the local port number
* src/rpc/virnetservermdns.c, src/rpc/virnetservermdns.h: Represent
  an MDNS advertisement
2011-06-24 11:48:41 +01:00
Daniel P. Berrange
4e00b1da8a Introduce generic RPC server objects
To facilitate creation of new daemons providing XDR RPC services,
pull a lot of the libvirtd daemon code into a set of reusable
objects.

 * virNetServer: A server contains one or more services which
   accept incoming clients. It maintains the list of active
   clients. It has a list of RPC programs which can be used
   by clients. When clients produce a complete RPC message,
   the server passes this onto the corresponding program for
   handling, and queues any response back with the client.

 * virNetServerClient: Encapsulates a single client connection.
   All I/O for the client is handled, reading & writing RPC
   messages.

 * virNetServerProgram: Handles processing and dispatch of
   RPC method calls for a single RPC (program,version).
   Multiple programs can be registered with the server.

 * virNetServerService: Encapsulates socket(s) listening for
   new connections. Each service listens on a single host/port,
   but may have multiple sockets if on a dual IPv4/6 host.

Each new daemon now merely has to define the list of RPC procedures
& their handlers. It does not need to deal with any network related
functionality at all.
2011-06-24 11:48:37 +01:00
Daniel P. Berrange
f5fa167e8d Integrate TLS/SASL directly into the socket APIs
This extends the basic virNetSocket APIs to allow them to have
a handle to the TLS/SASL session objects, once established.
This ensures that any data reads/writes are automagically
passed through the TLS/SASL encryption layers if required.

* src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: Wire up
  SASL/TLS encryption
2011-06-24 11:48:30 +01:00
Daniel P. Berrange
bb1c9296f5 Generic module for handling SASL authentication & encryption
This provides two modules for handling SASL

 * virNetSASLContext provides the process-wide state, currently
   just a whitelist of usernames on the server and a one time
   library init call

 * virNetTLSSession provides the per-connection state, ie the
   SASL session itself. This also include APIs for providing
   data encryption/decryption once the session is established

* src/Makefile.am: Add to libvirt-net-rpc.la
* src/rpc/virnetsaslcontext.c, src/rpc/virnetsaslcontext.h: Generic
  SASL handling code
2011-06-24 11:48:25 +01:00
Daniel P. Berrange
30fd0bbbfc Generic module for handling TLS encryption and x509 certs
This provides two modules for handling TLS

 * virNetTLSContext provides the process-wide state, in particular
   all the x509 credentials, DH params and x509 whitelists
 * virNetTLSSession provides the per-connection state, ie the
   TLS session itself.

The virNetTLSContext provides APIs for validating a TLS session's
x509 credentials. The virNetTLSSession includes APIs for performing
the initial TLS handshake and sending/recving encrypted data

* src/Makefile.am: Add to libvirt-net-rpc.la
* src/rpc/virnettlscontext.c, src/rpc/virnettlscontext.h: Generic
  TLS handling code
2011-06-24 11:48:22 +01:00
Daniel P. Berrange
58b5b14e5e Introduce a generic object for using network sockets
Introduces a simple wrapper around the raw POSIX sockets APIs
and name resolution APIs. Allows for easy creation of client
and server sockets with correct usage of name resolution APIs
for protocol agnostic socket setup.

It can listen for UNIX and TCP stream sockets.

It can connect to UNIX, TCP streams directly, or indirectly
to UNIX sockets via an SSH tunnel or external command

* src/Makefile.am: Add to libvirt-net-rpc.la
* src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: Generic
  sockets APIs
* tests/Makefile.am: Add socket test
* tests/virnetsockettest.c: New test case
* tests/testutils.c: Avoid overriding LIBVIRT_DEBUG settings
* tests/ssh.c: Dumb helper program for SSH tunnelling tests
2011-06-24 11:48:18 +01:00
Daniel P. Berrange
ceacc1dd4f Provide a simple object for encoding/decoding RPC messages
This provides a new struct that contains a buffer for the RPC
message header+payload, as well as a decoded copy of the message
header. There is an API for applying a XDR encoding & decoding
of the message headers and payloads. There are also APIs for
maintaining a simple FIFO queue of message instances.

Expected usage scenarios are:

To send a message

   msg = virNetMessageNew()

   ...fill in msg->header fields..
   virNetMessageEncodeHeader(msg)
   ...loook at msg->header fields to determine payload filter
   virNetMessageEncodePayload(msg, xdrfilter, data)
   ...send msg->bufferLength worth of data from buffer

To receive a message

   msg = virNetMessageNew()
   ...read VIR_NET_MESSAGE_LEN_MAX of data into buffer
   virNetMessageDecodeLength(msg)
   ...read msg->bufferLength-msg->bufferOffset of data into buffer
   virNetMessageDecodeHeader(msg)
   ...look at msg->header fields to determine payload filter
   virNetMessageDecodePayload(msg, xdrfilter, data)
   ...run payload processor

* src/Makefile.am: Add to libvirt-net-rpc.la
* src/rpc/virnetmessage.c, src/rpc/virnetmessage.h: Internal
  message handling API.
* testutils.c, testutils.h: Helper for printing binary differences
* virnetmessagetest.c: Validate all XDR encoding/decoding
2011-06-24 11:48:14 +01:00
Daniel P. Berrange
980a132a24 Defines the basics of a generic RPC protocol in XDR
This patch defines the basics of a generic RPC protocol in XDR.
This is wire ABI compatible with the original remote_protocol.x.
It takes everything except for the RPC calls / events from that
protocol

 - The basic header virNetMessageHeader (aka remote_message_header)
 - The error object virNetMessageError  (aka remote_error)
 - Two dummy objects virNetMessageDomain & virNetMessageNetwork
   sadly needed to keep virNetMessageError ABI compatible with
   the old remote_error

The RPC protocol supports method calls, async events and
bidirectional data streams as before

* src/Makefile.am: Add rules for generating RPC code from
  protocol & define a new libvirt-net-rpc.la helper library
* src/rpc/virnetprotocol.x: New generic RPC protocol
2011-06-24 11:48:10 +01:00