Note that 'virsh lxc-enter-namespace' must double-fork, for two
reasons: some namespaces can only be done from a single thread,
while virsh is multithreaded; and because virsh can be run in
batch mode where we must not corrupt the namespace of that
execution upon return from the subsidiary command.

When virt-login-shell was first written, it blindly copied from
'virsh lxc-enter-namespace', including the double-fork.  But
neither of the reasons for double forking apply to
virt-login-shell (we are single-threaded, and we have nothing to
do after the child completes that would require us to preserve a
namespace), so we can simplify life by using a single fork.
In turn, this will make it easier for a future patch to pass the
child's exit status on to the invoking shell.

In flattening to a single fork, note that closing the fds must
be done after fork, because the parent process still needs to
use fds to control the virConnectPtr; meanwhile, chdir can be
done prior to forking (in fact, it's easier to report errors
on anything attempted before forking).

* tools/virt-login-shell.c (main): Single rather than double fork.
(virLoginShellFini): Delete, by inlining actions instead.
Signed-off-by: NEric Blake <eblake@redhat.com>

The old semantics of virFork() violates the priciple of good
usability: it requires the caller to check the pid argument
after use, *even when virFork returned -1*, in order to properly
abort a child process that failed setup done immediately after
fork() - that is, the caller must call _exit() in the child.
While uses in virfile.c did this correctly, uses in 'virsh
lxc-enter-namespace' and 'virt-login-shell' would happily return
from the calling function in both the child and the parent,
leading to very confusing results. [Thankfully, I found the
problem by inspection, and can't actually trigger the double
return on error without an LD_PRELOAD library.]

It is much better if the semantics of virFork are impossible
to abuse.  Looking at virFork(), the parent could only ever
return -1 with a non-negative pid if it misused pthread_sigmask,
but this never happens.  Up until this patch series, the child
could return -1 with non-negative pid if it fails to set up
signals correctly, but we recently fixed that to make the child
call _exit() at that point instead of forcing the caller to do
it.  Thus, the return value and contents of the pid argument are
now redundant (a -1 return now happens only for failure to fork,
a child 0 return only happens for a successful 0 pid, and a
parent 0 return only happens for a successful non-zero pid),
so we might as well return the pid directly rather than an
integer of whether it succeeded or failed; this is also good
from the interface design perspective as users are already
familiar with fork() semantics.

One last change in this patch: before returning the pid directly,
I found cases where using virProcessWait unconditionally on a
cleanup path of a virFork's -1 pid return would be nicer if there
were a way to avoid it overwriting an earlier message.  While
such paths are a bit harder to come by with my change to a direct
pid return, I decided to keep the virProcessWait change in this
patch.

* src/util/vircommand.h (virFork): Change signature.
* src/util/vircommand.c (virFork): Guarantee that child will only
return on success, to simplify callers.  Return pid rather than
status, now that the situations are always the same.
(virExec): Adjust caller, also avoid open-coding process death.
* src/util/virprocess.c (virProcessWait): Tweak semantics when pid
is -1.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations.  Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit.  Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big.  And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.

So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.

* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself.  But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status.  This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.

* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The documentation of namespace callbacks was inconsistent on whether
it preserved positive return values.  Now that we have a dedicated
EXIT_CANCELED to flag all errors before getting to the callback,
it is possible to use positive return values (not that any of the
current callers do, but it is better to match the docs).

Also, while vircommand.c is careful to close fds that a child should
not have, it's still better to be in the practice of setting
FD_CLOEXEC up front.

* src/util/virprocess.c (virProcessRunInMountNamespace): Tweak
return value to pass back non-zero status.  Avoid leaking pipe fds
to other threads.
* src/util/virprocess.h: Fix comment.
Signed-off-by: NEric Blake <eblake@redhat.com>

Thanks to namespaces, we have a couple of places in the code
base that want to reflect a child exit status, including the
ability to detect death by a signal, back to a grandparent.
Best to make it a reusable function.

* src/util/virprocess.h (virProcessExitWithStatus): New prototype.
* src/libvirt_private.syms (util/virprocess.h): Export it.
* src/util/virprocess.c (virProcessExitWithStatus): New function.
* tests/commandtest.c (test23): Test it.
Signed-off-by: NEric Blake <eblake@redhat.com>

When a child fails without exec'ing, we want a well-known status;
best is to match what env(1), nice(1), su(1), and other wrapper
programs do.  This patch adds enum values that later patches will
use, and sets up virFork as the first client of EXIT_CANCELED
for errors detected prior to even attempting exec, as well as
virExec to distinguish between a missing executable vs. a binary
that cannot be executed.

This is a slight semantic change in the unlikely case of a child
process failing to restore its signal mask - we now kill the
child with a known status instead of relying on the caller to
notice and do an appropriate _exit().  A subsequent patch will
make further cleanups based on an audit of all callers.

* src/internal.h (EXIT_CANCELED, EXIT_CANNOT_INVOKE)
(EXIT_ENOENT): New enum.
* src/util/vircommand.c (virFork): Document specific exit value if
child aborts early.
(virExec): Distinguish between various exec failures.
* tests/commandtest.c (test1): Enhance test.
(test22): New test.
Signed-off-by: NEric Blake <eblake@redhat.com>

While auditing all callers of virCommandRun, I noticed that nwfilter
code never paid attention to commands with a non-zero status; they
were merely passing a pointer to avoid spamming the logs with a
message about commands that might indeed fail.  But proving this
required chasing through a lot of code; refactoring things to
localize the decision of whether to ignore non-zero status makes
it easier to prove that later changes to virFork don't negatively
affect this code.

While at it, I also noticed that ebiptablesRemoveRules would
actually report success if the child process failed for a
reason other than non-zero status, such as OOM.

* src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesExecCLI):
Change parameter from pointer to bool.
(ebtablesApplyBasicRules, ebtablesApplyDHCPOnlyRules)
(ebtablesApplyDropAllRules, ebtablesCleanAll)
(ebiptablesApplyNewRules, ebiptablesTearNewRules)
(ebiptablesTearOldRules, ebiptablesAllTeardown)
(ebiptablesDriverInitWithFirewallD)
(ebiptablesDriverTestCLITools, ebiptablesDriverProbeStateMatch):
Adjust all clients.
(ebiptablesRemoveRules): Likewise, and fix return value on failure.
Signed-off-by: NEric Blake <eblake@redhat.com>

Openstack Nova calls virConnectBaselineCPU() during initialization
of the instance to get a full list of CPU features.
This patch adds a stub to arm-specific code to handle
this request (no actual work is done).
Signed-off-by: NOleg Strikov <oleg.strikov@canonical.com>

 * drvuml.html.in: (connected) s/toa PTY/to a PTY/

All the other test_programs in the section use tabs
and virportallocatortest sticks out with tab width
other than 8.

Most of them are already tested in a limited way
by testing virUSBDeviceFind.

Mock the /sys/bus/usb directory and test the finding
(and not finding) of some USB devices.

When probing QEMU capabilities fails for a binary generate a
log message with MESSAGE_ID==8ae2f3fb-2dbe-498e-8fbd-012d40afa361.

This can be directly queried from journald based on the UUID
instead of needing string grep. This lets tools like libguestfs'
bug reporting tool trivially do automated sanity tests on the
host they're running on.

 $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361
 Feb 21 17:11:01 localhost.localdomain lt-libvirtd[9196]:
 Failed to probe capabilities for /bin/qemu-system-alpha:
 internal error: Child process (LC_ALL=C LD_LIBRARY_PATH=
 /home/berrange/src/virt/libvirt/src/.libs PATH=/usr/lib64/
 ccache:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:
 /usr/bin:/root/bin HOME=/root USER=root LOGNAME=root
 /bin/qemu-system-alpha -help) unexpected exit status 127:
 /bin/qemu-system-alpha: error while loading shared libraries:
 libglapi.so.0: cannot open shared object file: No such file
 or directory

 $ journalctl MESSAGE_ID=8ae2f3fb-2dbe-498e-8fbd-012d40afa361 --output=json
 { ...snip...
  "LIBVIRT_SOURCE" : "file",
  "PRIORITY" : "3",
  "CODE_FILE" : "qemu/qemu_capabilities.c",
  "CODE_LINE" : "2770",
  "CODE_FUNC" : "virQEMUCapsLogProbeFailure",
  "MESSAGE_ID" : "8ae2f3fb-2dbe-498e-8fbd-012d40afa361",
  "LIBVIRT_QEMU_BINARY" : "/bin/qemu-system-xtensa",
  "MESSAGE" : "Failed to probe capabilities for /bin/qemu-system-xtensa:
   internal error: Child process (LC_ALL=C LD_LIBRARY_PATH=/home/berrange
   /src/virt/libvirt/src/.libs PATH=/usr/lib64/ccache:/usr/local/sbin:
   /usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin HOME=/root
   USER=root LOGNAME=root /bin/qemu-system-xtensa -help) unexpected
   exit status 127: /bin/qemu-system-xtensa: error while loading shared
   libraries: libglapi.so.0: cannot open shared object file: No such
    file or directory\n" }
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

- docs/news.html.in libvirt.spec.in: update for the release
* po/*.po*: update localization and merge

Similar to our event-test demo program, it's nice to be able to
have a mode where we can sniff all events at once, rather than
having to spawn multiple virsh in parallel with one for each
event type.

(Can I just say our RegisterAny design is lousy?  The fact that
the majority of our callback pointers have a function signature
with the opaque data in a different position, and that we have
to cast the function signature before registering it, makes it
hard to write a generic callback function; we have to write one
for every type of event id.  Life would have been easier if we
had designed the callback as a fixed signature with a void*
and size parameter, and then allowed the caller to downcast
the void* to a particular struct for data specific to their
callback id, where we could have then had a single function
with a switch statement for each event id, and register that
one function for all types of events.  It would also be nicer
if the callback functions knew which callbackID was being used
when invoking that callback, so that I could use a common data
structure among all registrations instead of having to create
an array of one data per callback.  But I really don't want to
go add yet another event API design.)

* tools/virsh-domain.c (cmdEvent): Add --all parameter; convert
all callbacks to support shared counter.
* tools/virsh.pod (event): Document it.
Signed-off-by: NEric Blake <eblake@redhat.com>

Earlier, I added 'virsh event' for lifecycle events, to get the
concept approved; this patch finishes the support for all other
events, although the user still has to register for one event
type at a time.  A future patch may add an --all parameter to
make it possible to register for all events through a single
call.

* tools/virsh-domain.c (vshDomainEventWatchdogToString)
(vshDomainEventIOErrorToString, vshGraphicsPhaseToString)
(vshGraphicsAddressToString, vshDomainBlockJobStatusToString)
(vshDomainEventDiskChangeToString)
(vshDomainEventTrayChangeToString, vshEventGenericPrint)
(vshEventRTCChangePrint, vshEventWatchdogPrint)
(vshEventIOErrorPrint, vshEventGraphicsPrint)
(vshEventIOErrorReasonPrint, vshEventBlockJobPrint)
(vshEventDiskChangePrint, vshEventTrayChangePrint)
(vshEventPMChangePrint, vshEventBalloonChangePrint)
(vshEventDeviceRemovedPrint): New helper routines.
(cmdEvent): Support full array of event callbacks.
Signed-off-by: NEric Blake <eblake@redhat.com>

Implement domainUndefine and required helper functions:
 - domainIsActive
 - domainIsPersistent

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

When a virError is raised, pass the error domain and code
onto the systemd journald using metadata fields.

This allows error messages to be queried by code eg

  $ journalctl LIBVIRT_CODE=43
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Document the various fields that libvirt will emit for
journal log records.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The logging doc had a hand-written table of contents
instead of using the automatic XSL generated one.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The logging docs went straight from <h1> to <h3> header level,
skipping out <h2>.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The systemd journal expects log record PRIORITY values to
be encoded using the syslog compatible numbering scheme,
not libvirt's own native numbering scheme. We must therefore
apply a conversion.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The systemd journal accepts arbitrary user specified log
fields. These can be passed into virLogMessage via the
virLogMetadata structure. Allow up to 5 custom fields to
be reported by libvirt callers.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch allows libvirt user to specify 'host-passthrough'
cpu mode while using qemu/kvm backend on arm (arm32).
It uses 'host' as a CPU model name instead of some other stub
(correct CPU detection is not implemented yet) to allow libvirt
user to specify 'host-model' cpu mode as well.
Signed-off-by: NOleg Strikov <oleg.strikov@canonical.com>

Compare:

  # virsh domblkstat freebsd hdd
  error: Failed to get block stats freebsd hdd
  error: invalid argument: invalid path: hdd

with:

  # virsh domblkstat freebsd hdd
  error: Failed to get block stats for domain 'freebsd' device 'hdd'
  error: invalid argument: invalid path: hdd
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

As of 0bd2ccde an empty disk path for virDomainBlockStats (or the one
with Flags) is allowed meaning "get me overall summarized statistics".
However, running 'virsh domblkstat $dom' throws a misleading error:

  # ./tools/virsh domblkstat dom
  error: Failed to get block stats dom
  error: invalid argument: invalid path:

while after this commit

  # virsh domblkstat dom
  error: Operation not supported: summary statistics are not supported yet
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Running 'make -C tests check TESTS=qemuagenttest' left a directory
/tmp/libvirt_XXXXXX/ behind.  The culprit was failure to cleanup
when short-circuiting an expensive test.

* tests/qemuagenttest.c (testQemuAgentTimeout): Free resources
when skipping expensive test.
Signed-off-by: NEric Blake <eblake@redhat.com>

Libvirt uses a domain name to fill in owner_name in sanlock_options in
virLockManagerSanlockAcquire. Unfortunately, owner_name is limited to
SANLK_NAME_LEN characters (including trailing '\0'), which means domains
with longer names fail to start when sanlock is enabled. However, we can
truncate the name when setting owner_name as explained by sanlock's
author:

Setting sanlk_options or the owner_name is unnecessary, and has very
little to no benefit.  If you do provide something in owner_name, it can
be anything, sanlock doesn't care or use it.

If you run the command "sanlock status", the output will display a list
of clients connected to the sanlock daemon.  This client list is
displayed as "pid owner_name" if the client has provided an owner_name
via sanlk_options. This debugging output is the only usage of
owner_name, so its only benefit is to potentially provide a more human
friendly output for debugging purposes.

Cygwin supports <dlfcn.h> and even has limited LD_PRELOAD
capabilities; but because it does not use ELF binaries it
cannot support RTLD_NEXT lookups.

  CC       libvirportallocatormock_la-virportallocatortest.lo
virportallocatortest.c: In function 'init_syms':
virportallocatortest.c:47:24: error: 'RTLD_NEXT' undeclared (first use in this function)
     realsocket = dlsym(RTLD_NEXT, "socket");

* tests/virportallocatortest.c: Also require RTLD_NEXT.
Signed-off-by: NEric Blake <eblake@redhat.com>

The cygwin compiler automatically creates a '*.exe.manifest'
companion file for any .exe file that contains a substring
that would otherwise cause newer Windows to pester users about
needing admin rights (such as "update", "instal", "setup"...).
This means that compilation on cygwin left behind
tests/networkxml2xmlupdatetest.exe.manifest.

* .gitignore: Ignore manifest files.
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NEric Blake <eblake@redhat.com>

Only tested on v7 but the v8 equivalent seems pretty obvious.

XEN_CAP_REGEX already accepts more than it should (e.g. x86_64p or x86_32be)
but I have stuck with the existing pattern.

With this I can create a guest from:
  <domain type='xen'>
    <name>libvirt-test</name>
    <uuid>6343998e-9eda-11e3-98f6-77252a7d02f3</uuid>
    <memory>393216</memory>
    <currentMemory>393216</currentMemory>
    <vcpu>1</vcpu>
    <os>
      <type arch='armv7l' machine='xenpv'>linux</type>
      <kernel>/boot/vmlinuz-arm-native</kernel>
      <cmdline>console=hvc0 earlyprintk debug root=/dev/xvda1</cmdline>
    </os>
    <clock offset='utc'/>
    <on_poweroff>destroy</on_poweroff>
    <on_reboot>restart</on_reboot>
    <on_crash>destroy</on_crash>
    <devices>
      <disk type='block' device='disk'>
        <source dev='/dev/marilith-n0/debian-disk'/>
        <target dev='xvda1'/>
      </disk>
      <interface type='bridge'>
        <mac address='8e:a7:8e:3c:f4:f6'/>
        <source bridge='xenbr0'/>
      </interface>
    </devices>
  </domain>

Using virsh create and I can destroy it too.

Currently virsh console fails with:
  Connected to domain libvirt-test
  Escape character is ^]
  error: internal error: cannot find character device <null>

I haven't investigated yet.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

In commit 72f7658b I've added a few
macros with bad bracing. Although they work as expected fix them so that
we use uniform syntax.

If user wants to grep some info from domain, e.g. disk paths:

    # virsh -q domblklist win7 | awk '{print $2}'
    Source

    /var/lib/libvirt/images/windows.qcow2
    /home/zippy/work/tmp/en_windows_7_professional_x64_dvd_X15-65805.iso

while with my change:

    # virsh -q domblklist win7 | awk '{print $2}'
    /var/lib/libvirt/images/windows.qcow2
    /home/zippy/work/tmp/en_windows_7_professional_x64_dvd_X15-65805.iso

We don't print table header in other commands, like list.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>