When analyzing our debug log, I'm always confused about what each of the
pointers mean. Let's be explicit.

My latest patch for RPC rework (a2c304f6) introduced a memory leak.
virNetMessageEncodeHeader() is calling VIR_ALLOC_N(msg->buffer, ...)
despite fact, that msg->buffer isn't VIR_FREE()'d on all paths calling
the function. Therefore, rather than injecting free statement switch to
VIR_REALLOC_N().

Since we are allocating RPC buffer dynamically, we can increase limits
for max. size of RPC message and RPC string. This is needed to cover
some corner cases where libvirt is run on such huge machines that their
capabilities XML is 4 times bigger than our current limit. This leaves
users with inability to even connect.

Currently, we are allocating buffer for RPC messages statically.
This is not such pain when RPC limits are small. However, if we want
ever to increase those limits, we need to allocate buffer dynamically,
based on RPC message len (= the first 4 bytes). Therefore we will
decrease our mem usage in most cases and still be flexible enough in
corner cases.

The stream lock is unlocked twice instead of being locked and then
unlocked. Probably a typo.

Remove the uid param from virGetUserConfigDirectory,
virGetUserCacheDirectory, virGetUserRuntimeDirectory,
and virGetUserDirectory

These functions were universally called with the
results of getuid() or geteuid(). To make it practical
to port to Win32, remove the uid parameter and hardcode
geteuid()
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When you try to connect to a socket in the abstract namespace,
the error will be ECONNREFUSED for a non-listening daemon. With
the non-abstract namespace though, you instead get ENOENT. Add
a check for this extra errno when auto-spawning the daemon
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This reverts commit b1e374a7, which was
rather bad since I failed to consider all sides of the issue. The main
things I didn't consider properly are:

- a thread which sends a non-blocking call waits for the thread with
  the buck to process the call
- the code doesn't expect non-blocking calls to remain in the queue
  unless they were already partially sent

Thus, the reverted patch actually breaks more than what it fixes and
clients (which may even be libvirtd during p2p migrations) will likely
end up in a deadlock.

Currently, non-blocking calls are either sent immediately or discarded
in case sending would block. This was implemented based on the
assumption that the non-blocking keepalive call is not needed as there
are other calls in the queue which would keep the connection alive.
However, if those calls are no-reply calls (such as those carrying
stream data), the remote party knows the connection is alive but since
we don't get any reply from it, we think the connection is dead.

This is most visible in tunnelled migration. If it happens to be longer
than keepalive timeout (30s by default), it may be unexpectedly aborted
because the connection is considered to be dead.

With this patch, we only discard non-blocking calls when the last call
with a thread is completed and thus there is no thread left to keep
sending the remaining non-blocking calls.

The docs for virConnectSetKeepAlive() advertise that this function
should be able to disable keepalives on negative or zero interval time.

This patch removes the check that prohibited this and adds code to
disable keepalives on negative/zero interval.

* src/libvirt.c: virConnectSetKeepAlive(): - remove check for negative
                                             values
* src/rpc/virnetclient.c
* src/rpc/virnetclient.h: - add virNetClientKeepAliveStop() to disable
                            keepalive messages
* src/remote/remote_driver.c: remoteSetKeepAlive(): -add ability to
                                                     disable keepalives

POSIX says that sa_sigaction is only safe to use if sa_flags
includes SA_SIGINFO; conversely, sa_handler is only safe to
use when flags excludes that bit.  Gnulib doesn't guarantee
an implementation of SA_SIGINFO, but does guarantee that
if SA_SIGINFO is undefined, we can safely define it to 0 as
long as we don't dereference the 2nd or 3rd argument of
any handler otherwise registered via sa_sigaction.

Based on a report by Wen Congyang.

* src/rpc/virnetserver.c (SA_SIGINFO): Stub for mingw.
(virNetServerSignalHandler): Avoid bogus dereference.
(virNetServerFatalSignal, virNetServerNew): Set flags properly.
(virNetServerAddSignalHandler): Drop unneeded #ifdef.

DBus connection. The HAL device code further requires that
the DBus connection is integrated with the event loop and
provides such glue logic itself.

The forthcoming FirewallD integration also requires a
dbus connection with event loop integration. Thus we need
to pull the current event loop glue out of the HAL driver.

Thus we create src/util/virdbus.{c,h} files. This contains
just one method virDBusGetSystemBus() which obtains a handle
to the single shared system bus instance, with event glue
automagically setup.

The code is splattered with a mix of

  sizeof foo
  sizeof (foo)
  sizeof(foo)

Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit 5d4b0c4c tried to fix certain classes of VPATH builds,
but was too limited.  In particular, Guannan Ren reported:

>    For example: The libvirt source code resides in /home/testuser,
>                 I make dist in /tmp/buildvpath, the XDR routine .c file will
>                 include full path of the header file like:
>
>                 #include "/home/testuser/src/rpc/virnetprotocol.h"
>                 #include "internal.h"
>                 #include <arpa/inet.h>
>
>    If we distribute the tarball to another machine to compile,
>    it will report error as follows:
>
>    rpc/virnetprotocol.c:7:59: fatal error:
>    /home/testuser/src/rpc/virnetprotocol.h: No such file or directory

* src/rpc/genprotocol.pl: Fix more include lines.

On 64-bit platforms, unsigned long and unsigned long long are
identical, so we don't have to worry about overflow checks.
On 32-bit platforms, anywhere we narrow unsigned long long back
to unsigned long, we have to worry about overflow; it's easier
to do this in one place by having most of the code use the same
or wider types, and only doing the narrowing at the last minute.
Therefore, the memory set commands remain unsigned long, and
the memory get command now centralizes the overflow check into
libvirt.c, so that drivers don't have to repeat the work.

This also fixes a bug where xen returned the wrong value on
failure (most APIs return -1 on failure, but getMaxMemory
must return 0 on failure).

* src/driver.h (virDrvDomainGetMaxMemory): Use long long.
* src/libvirt.c (virDomainGetMaxMemory): Raise overflow.
* src/test/test_driver.c (testGetMaxMemory): Fix driver.
* src/rpc/gendispatch.pl (name_to_ProcName): Likewise.
* src/xen/xen_hypervisor.c (xenHypervisorGetMaxMemory): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainGetMaxMemory): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xend_internal.h (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xm_internal.c (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xm_internal.h (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.c (xenStoreDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.h (xenStoreDomainGetMaxMemory): Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainGetMaxMemory):
Likewise.
* src/esx/esx_driver.c (esxDomainGetMaxMemory): Likewise.
* src/libxl/libxl_driver.c (libxlDomainGetMaxMemory): Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetMaxMemory): Likewise.
* src/lxc/lxc_driver.c (lxcDomainGetMaxMemory): Likewise.
* src/uml/uml_driver.c (umlDomainGetMaxMemory): Likewise.

A multi-threaded client with event loop may crash if one of its threads
closes a connection while event loop is in the middle of sending
keep-alive message (either request or response). The right place for it
is inside virNetClientIOEventLoop() between poll() and
virNetClientLock(). We should only close a connection directly if no-one
is using it and defer the closing to the last user otherwise. So far we
only did so if the close was initiated by keep-alive timeout.

Nuke the last vestiges of printing pid_t values with the wrong
types, at least in code compiled on mingw64.  There may be other
places, but for now they are only compiled on systems where the
existing %d doesn't trigger gcc warnings.

* src/rpc/virnetsocket.c (virNetSocketNew): Use %lld and casting,
rather than assuming any particular int type for pid_t.
* src/util/command.c (virCommandRunAsync, virPidWait)
(virPidAbort): Likewise.
(verify): Drop a now stale assertion.

compat{a->i}bility
erron{->e}ous
nec{c->}essary.
Either "the" or "a".
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

Our HACKING discourages use of malloc and free, for at least
a couple of years now.  But we weren't enforcing it, until now :)

For now, I've exempted python and tests, and will clean those up
in subsequent patches.  Examples should be permanently exempt,
since anyone copying our examples won't have use of our
internal-only memory.h via libvirt_util.la.

* cfg.mk (sc_prohibit_raw_allocation): New rule.
(exclude_file_name_regexp--sc_prohibit_raw_allocation): and
exemptions.
* src/cpu/cpu.c (cpuDataFree): Avoid false positive.
* src/conf/network_conf.c (virNetworkDNSSrvDefParseXML): Fix
offenders.
* src/libxl/libxl_conf.c (libxlMakeDomBuildInfo, libxlMakeVfb)
(libxlMakeDeviceModelInfo): Likewise.
* src/rpc/virnetmessage.c (virNetMessageSaveError): Likewise.
* tools/virsh.c (_vshMalloc, _vshCalloc): Likewise.

Qemu is adding the ability to do a partial rebase.  That is, given:

base <- intermediate <- current

virDomainBlockPull will produce:

current

but qemu now has the ability to leave base in the chain, to produce:

base <- current

Note that current qemu can only do a forward merge, and only with
the current image as the destination, which is fully described by
this API without flags.  But in the future, it may be possible to
enhance this API for additional scenarios by using flags:

Merging the current image back into a previous image (that is,
undoing a live snapshot), could be done by passing base as the
destination and flags with a bit requesting a backward merge.

Merging any other part of the image chain, whether forwards (the
backing image contents are pulled into the newer file) or backwards
(the deltas recorded in the newer file are merged back into the
backing file), could also be done by passing a new flag that says
that base should be treated as an XML snippet rather than an
absolute path name, where the XML could then supply the additional
instructions of which part of the image chain is being merged into
any other part.

* include/libvirt/libvirt.h.in (virDomainBlockRebase): New
declaration.
* src/libvirt.c (virDomainBlockRebase): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.9.10): Export it.
* src/driver.h (virDrvDomainBlockRebase): New driver callback.
* src/rpc/gendispatch.pl (long_legacy): Add exemption.
* docs/apibuild.py (long_legacy_functions): Likewise.

This API allows a domain to be put into one of S# ACPI states.
Currently, S3 and S4 are supported. These states are shared
with virNodeSuspendForDuration.
However, for now we don't support any duration other than zero.
The same apply for flags.

The RPC generator transforms methods matching certain
patterns like 'id' or 'uuid', etc but does not anchor
its matches to the end of the word. So if a method
contains 'id' in the middle (eg virIdentity) then the
RPC generator munges that.

* src/rpc/gendispatch.pl: Anchor matches

To avoid a namespace clash with forthcoming identity APIs,
rename the virNet*GetLocalIdentity() APIs to have the form
virNet*GetUNIXIdentity()

* daemon/remote.c, src/libvirt_private.syms: Update
  for renamed APIs
* src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h,
  src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: s/LocalIdentity/UNIXIdentity/

* daemon/remote.c, src/rpc/virnetserverclient.c,
  src/rpc/virnetserverclient.h, src/rpc/virnetsocket.c,
  src/rpc/virnetsocket.h: Add gid parameter

If client stream does not have any data to sink and neither received
EOF, a dummy packet is sent to the daemon signalising client is ready to
sink some data. However, after we added event loop to client a race may
occur:

Thread 1 calls virNetClientStreamRecvPacket and since no data are cached
nor stream has EOF, it decides to send dummy packet to server which will
sent some data in turn. However, during this decision and actual message
exchange with server -

Thread 2 receives last stream data from server. Therefore an EOF is set
on stream and if there is a call waiting (which is not yet) it is woken
up. However, Thread 1 haven't sent anything so far, so there is no call
to be woken up. So this thread sent dummy packet to daemon, which
ignores that as no stream is associated with such packet and therefore
no reply will ever come.

This race causes client to hang indefinitely.

The RPC code had several latent memory leaks and an attempt to
free the wrong string, but thankfully nothing triggered them
(blkiotune was the only one returning a string, and always as
the last parameter).  Also, our cleanups for rpcgen ended up
nuking a line of code that renders VIR_TYPED_PARAM_INT broken,
because it was the only use of 'i' in a function, even though
it was a member usage rather than a standalone declaration.

* daemon/remote.c (remoteSerializeTypedParameters): Free the
correct array element.
(remoteDispatchDomainGetSchedulerParameters)
(remoteDispatchDomainGetSchedulerParametersFlags)
(remoteDispatchDomainBlockStatsFlags)
(remoteDispatchDomainGetMemoryParameters): Don't leak strings.
* src/rpc/genprotocol.pl: Don't nuke member-usage of 'buf' or 'i'.

When one thread passes the buck to another thread, it uses
virCondSignal to wake up the target thread. The variable
'haveTheBuck' is not updated in a race-free manner when
this occurs. The current thread sets it to false, and the
woken up thread sets it to true. There is a window where
a 3rd thread can come in and grab the buck.

Even if this didn't lead to crashes & deadlocks, this would
still result in unfairness in the buckpassing algorithm.

A better solution is to *never* set haveTheBuck to false
when we're passing the buck. Only set it to false when there
is no further thread waiting for the buck.

* src/rpc/virnetclient.c: Only set haveTheBuck to false
  if no thread is waiting

Commit fd066925 tried to fix
a race condition in

  commit fa959500
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Fri Nov 11 15:28:41 2011 +0000

    Explicitly track whether the buck is held in remote client

Unfortunately there is a second race condition whereby the
event loop can trigger due to incoming data to read. Revert
this fix, so a complete fix for the problem can be cleanly
applied

* src/rpc/virnetclient.c: Revert fd066925

Currently if you try to connect to a local libvirtd when
libvirtd is not in $PATH, you'll get an error

  error: internal error invalid use of command API

This is because remoteFindDaemonPath() returns NULL, which
causes us to pass NULL into virNetSocketConnectUNIX which
in turn causes us to pass NULL into virCommandNewArgList.

Adding missing error checks improves this to

  error: internal error Unable to locate libvirtd daemon in $PATH

* src/remote/remote_driver.c: Report error if libvirtd
  cannot be found
* src/rpc/virnetsocket.c: Report error if caller requested
  spawning of daemon, but provided no binary path

https://bugzilla.redhat.com/show_bug.cgi?id=648855 mentioned a
misuse of 'an' where 'a' is proper; that has since been fixed,
but a search found other problems (some were a spelling error for
'and', while most were fixed by 'a').

* daemon/stream.c: Fix grammar.
* src/conf/domain_conf.c: Likewise.
* src/conf/domain_event.c: Likewise.
* src/esx/esx_driver.c: Likewise.
* src/esx/esx_vi.c: Likewise.
* src/rpc/virnetclient.c: Likewise.
* src/rpc/virnetserverprogram.c: Likewise.
* src/storage/storage_backend_fs.c: Likewise.
* src/util/conf.c: Likewise.
* src/util/dnsmasq.c: Likewise.
* src/util/iptables.c: Likewise.
* src/xen/xen_hypervisor.c: Likewise.
* src/xen/xend_internal.c: Likewise.
* src/xen/xs_internal.c: Likewise.
* tools/virsh.c: Likewise.

The RPC fixups needed on Linux are also needed on cygwin, and
worked without further tweaking to the list of fixups.  Also,
unlike BSD, Cygwin exports 'struct ifreq', but unlike Linux,
Cygwin lacks the ioctls that we were using 'struct ifreq' to
access.  This patch allows compilation under cygwin.

* src/rpc/genprotocol.pl: Also perform fixups on cygwin.
* src/util/virnetdev.c (HAVE_STRUCT_IFREQ): Also require AF_PACKET
definition.
* src/util/virnetdevbridge.c (virNetDevSetupControlFull): Only
compile if SIOCBRADDBR works.

Originaly, the code checked if another client is the queue and infered
ownership of the buck from that. Commit fa959500
added a separate variable to track the buck. That caused, that a new
call might enter claiming it has the buck, while another thread was
signalled to take the buck. This ends in two threads claiming they hold
the buck and entering poll(). This happens due to a race on waking up
threads on the client lock mutex.

This caused multi-threaded clients to hang, most prominently visible and
reproducible on python based clients, like virt-manager.

This patch causes threads, that have been signalled to take the buck to
re-check if buck is held by another thread.

Detected by Coverity. Leak introduced in commit 673adba5.

Two separate bugs here:
1. call was not freed on all error paths
2. virCondDestroy was called even if virCondInit failed
Signed-off-by: NAlex Jia <ajia@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

When another thread was dispatching while we wanted to send a
non-blocking call, we correctly queued the call and woke up the thread
but the thread just threw the call away since it forgot to recheck if
its socket was writable.

When spawning an ssh connection, the environment variables
DISPLAY, SSH_ASKPASS, ... are passed. However XAUTHORITY,
which is necessary if the .Xauthority is in a non default
place, was not passed.
Signed-off-by: NChristian Franke <nobody@nowhere.ws>