Don't print the pool option name if it's null.

Before:
virsh # vol-name vol
error: failed to get vol 'vol', specifying --(null) might help
error: Storage volume not found: no storage vol with matching path vol

After:

virsh # vol-name vol
error: failed to get vol 'vol'
error: Storage volume not found: no storage vol with matching path vol

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=924571

Use the exclusive parameter checker and touch up some parts to simplify
code.

The check is done on the "--paused" flag but the error message stated
"--saved"

Use the new helpers to determine mutually exclusive options and touch up
some parts to simplify the code.

Simplify error handling and mutually exclusive option checking.

This patch adds three macros to the virsh source tree that help to
easily check for mutually exclusive parameters.

VSH_EXCLUSIVE_OPTIONS_EXPR has four arguments, two expressions to check
and two names of the parameters to print in the message.

VSH_EXCLUSIVE_OPTIONS is more specific and check the command structure
for the parameters using vshCommandOptBool.

VSH_EXCLUSIVE_OPTIONS_VAR is meant to check boolean variables with the
same name as the parameters.

Clarify that net-create deals with a transient virtual
network whereas net-define defines a persistent virtual
network definition and will create the network (xml)
definition file.

Clarify that net-destroy works with both transient and
persistent virtual networks.
Signed-off-by: NGene Czarcinski <gene@czarc.net>

After we switched to C99 initialization, I noticed there were many
places where the specification of .flags parameter differed.  After
going through many options and deciding whether to unify the
initialization to be '.flags = 0' or '.flags = VSH_OFLAG_NONE', I
realized both can be removed and it makes the code easier to go
through.

According to the man page, the memspec parameter should have the
'--memspec' option mandatory and this is as close as we can get to
that.  What this change does is explained below.

man virsh:

snapshot-create-as ... [[--live] [--memspec memspec]]

virsh help snapshot-create-as before this patch:

  SYNOPSIS
    snapshot-create-as ... [<memspec>] ...
...
  OPTIONS
    [--memspec] <string> ...

virsh help snapshot-create-as after this patch:

  SYNOPSIS
    snapshot-create-as ... [--memspec <string>] ...
...
  OPTIONS
    --memspec <string> ...

The vshInit initializes ctl->debug by which vshDebug (which is also
called in vshParseArgv) decides whether to print out the message or
not.

Signed-off-by: NYanbing Du <ydu@redhat.com>

Add a new virDomainLxcEnterSecurityLabel() function as a
counterpart to virDomainLxcEnterNamespaces(), which can
change the current calling process to have a new security
context. This call runs client side, not in libvirtd
so we can't use the security driver infrastructure.

When entering a namespace, the process spawned from virsh
will default to running with the security label of virsh.
The actual desired behaviour is to run with the security
label of the container most of the time. So this changes
virsh lxc-enter-namespace command to invoke the
virDomainLxcEnterSecurityLabel method.

The current behaviour is:

LABEL                             PID TTY          TIME CMD
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 29 ? 00:00:00 dhclient
staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 47 ? 00:00:00 ps

Note the ps command is running as unconfined_t,  After this patch,

The new behaviour is this:

virsh -c lxc:/// lxc-enter-namespace dan -- /bin/ps -eZ
LABEL                             PID TTY          TIME CMD
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 38 ? 00:00:00 ps

The '--noseclabel' flag can be used to skip security labelling.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Properly check the return value of vshCommandOptStringReq for xmlfile:
* error out on incorrect input (--xmlfile '')
* use default XML <domainsnapshot/> with no --xmlfile specified

(Broken by commit b2e85855)

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=919826

The function is marked as unused and breaks compilation on RHEL4. Remove
it from the tree until a new use case can be found.

The commit originally fixed code that isn't being used. Revert
it and remove the unused code as a real fix.

This reverts commit a66b32d9.

RHEL4 vintage libxml2 header files are missing xmlSaveToBuffer
despite the symbol existing in the binary
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Help script creators by not having to parse the names from the table.

This is a command wrapping virDomainMigrateGetCompressionCache and
virDomainMigrateSetCompressionCache.

This flag may be used with migration APIs to request compression of
migration data.

Specifying ':' to suppress the error messages printed by getopt().
Then, distinguish the two types of errors.

Before:
 # virsh -c
   virsh: option requires an argument -- 'c'
   error: unsupported option '-?'. See --help.

After:
 # virsh -c
   error: option '-c' requires an argument

 # virsh -x
   error: unsupported option '-x'. See --help.

It doesn't make sense to print the unit (B) only with Ki, Mi, ...
prefixes. Even those poor bytes under 1 KiB are still bytes :-)

Coverity found that commit '41b5e845' had a possible NULL dereference on
arg->data processing

Only nodedev-destroy and nodedev-dumpxml can benifit from the
new API, other commands like nodedev-detach only works for
PCI devices, WWN makes no sense for them.

Manual for "virsh snapshot-create-as" states that --no-metadata and
--print-xml are incompatible. Honor this detail in the code.