Continue preparation for extracting platform-specific
parts from bridge_driver: s/Iptables/Firewall/ for
firewall related function names.

Commit 834c9c94 introduced virDBusMessageEncode and
virDBusMessageDecode functions, however corresponding stubs
were not added to !WITH_DBUS section, therefore 'make check'
started to fail when compiled w/out dbus support like that:

Expected symbol virDBusMessageDecode is not in ELF library

The translation must be done before both of cgroup and security
setting, otherwise since the disk source is not translated yet,
it might be skipped on cgroup and security setting.

virDomainDiskDefForeachPath is not only used by the security
setting helpers, also used by cgroup setting helpers, so this
is to ignore the volume type disk with mode="direct" for cgroup
setting.

The difference with already supported pool types (dir, fs, block)
is: there are two modes for iscsi pool (or network pools in future),
one can specify it either to use the volume target path (the path
showed up on host) with mode='host', or to use the remote URI qemu
supports (e.g. file=iscsi://example.org:6000/iqn.1992-01.com.example/1)
with mode='direct'.

For 'host' mode, it copies the volume target path into disk->src. For
'direct' mode, the corresponding info in the *one* pool source host def
is copied to disk->hosts[0].

Introduce a new helper to check if the disk source is of block type

There are two ways to use a iSCSI LUN as disk source for qemu.

 * The LUN's path as it shows up on host, e.g.
   /dev/disk/by-path/ip-$ip:3260-iscsi-$iqn-fc18:iscsi.iscsi0-lun-1

 * The libiscsi URI from the storage pool source element host attribute, e.g.
   iscsi://demo.org:6000/iqn.1992-01.com.example/1

For a "volume" type disk, if the specified "pool" is of iscsi
type, we should support to use the LUN in either of above 2 ways.
That's why to introduce a new XML tag "mode" for the disk source
(libvirt should support iscsi pool with libiscsi, but it's another
new feature, which should be done later).

The "mode" can be either of "host" or "direct". Use "host" to indicate
use of the LUN with the path as it shows up on host. Use "direct" to
indicate to use it with the source pool host URI (future patches may support
to use network type libvirt storage too, e.g. Ceph)

Make sure default iSCSI target is 3260.

The description seems to be copied from virNodeGetCpuState.
Change wrong 'cpu' to 'memory'.
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

This is another cleanup before extracting platform-specific
parts from bridge_driver.

Rename struct network_driver to _virNetworkDriverState and
add appropriate typedefs: virNetworkDriverState and
virNetworkDriverStatePtr.

This will help us to avoid potential problems when moving
this struct to the .h file.

Convert the remaining methods in vircgroup.c to report errors
instead of returning errno values.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of returning errno values, change the virCgroupKill*
APIs to fully report errors.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of returning raw errno values, report full libvirt
errors in virCgroupNew* functions.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add virErrorSetErrnoFromLastError and virLastErrorIsSystemErrno
to simplify code which wants to handle system errors in a more
graceful fashion.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To register virtual machines and containers with systemd-machined,
and thus have cgroups auto-created, we need to talk over DBus.
This is somewhat tedious code, so introduce a dedicated function
to isolate the DBus call in one place.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Doing DBus method calls using libdbus.so is tedious in the
extreme. systemd developers came up with a nice high level
API for DBus method calls (sd_bus_call_method). While
systemd doesn't use libdbus.so, their API design can easily
be ported to libdbus.so.

This patch thus introduces methods virDBusCallMethod &
virDBusMessageRead, which are based on the code used for
sd_bus_call_method and sd_bus_message_read. This code in
systemd is under the LGPLv2+, so we're license compatible.

This code is probably pretty unintelligible unless you are
familiar with the DBus type system. So I added some API
docs trying to explain how to use them, as well as test
cases to validate that I didn't screw up the adaptation
from the original systemd code.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Until now CPU features inherited from a specified CPU model could only
be overridden with 'disable' policy. With this patch, any explicitly
specified feature always overrides the same feature inherited from a CPU
model regardless on the specified policy.

The CPU in x86-exact-force-Haswell.xml would previously be incompatible
with x86-host-SandyBridge.xml CPU even though x86-host-SandyBridge.xml
provides all features required by x86-exact-force-Haswell.xml.

If no explicit driver is set for an image backed filesystem,
set it to use the loop driver (if raw) or nbd driver (if
non-raw)
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

A couple of places in LXC setup for filesystems did not do
a "goto cleanup" after reporting errors. While fixing this,
also add in many more debug statements to aid troubleshooting
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The alias for hostdevs of type SCSI can be too long for QEMU if
larger LUNs are encountered. Here's a real life example:

    <hostdev mode='subsystem' type='scsi' managed='no'>
      <source>
        <adapter name='scsi_host0'/>
        <address bus='0' target='19' unit='1088634913'/>
      </source>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </hostdev>

this results in a too long drive id, resulting in QEMU yelling

Property 'scsi-generic.drive' can't find value 'drive-hostdev-scsi_host0-0-19-1088634913'

This commit changes the alias back to the default hostdev$(index)
scheme.
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

In case libvirtd is asked to unplug a device but the device is actually
unplugged later when libvirtd is not running, we need to detect that and
remove such device when libvirtd starts again and reconnects to running
domains.

This API provides a NULL-terminated list of devices which are currently
attached to a QEMU domain.

Make virStringArrayHasString return false when called on a non-existent
string array.

Attempts to start a domain with both SELinux and DAC security
modules loaded will deadlock; latent problem introduced in commit
fdb3bde3 and exposed in commit 29fe5d74.  Basically, when recursing
into the security manager for other driver's prefork, we have to
undo the asymmetric lock taken at the manager level.

Reported by Jiri Denemark, with diagnosis help from Dan Berrange.

* src/security/security_stack.c (virSecurityStackPreFork): Undo
extra lock grabbed during recursion.
Signed-off-by: NEric Blake <eblake@redhat.com>

Makefiles are another easy file to enforce line limits.

Mostly straightforward; interesting tricks worth noting:
src/Makefile.am: $(confdir) was already defined, use it in more places
tests/Makefile.am: path_add and VG required some interesting compression

* cfg.mk (sc_prohibit_long_lines): Add another test.
* Makefile.am: Fix offenders.
* daemon/Makefile.am: Likewise.
* docs/Makefile.am: Likewise.
* python/Makefile.am: Likewise.
* src/Makefile.am: Likewise.
* tests/Makefile.am: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit 75c12564 states that virGetGroupList must not be called
between fork and exec, then commit ee777e99 promptly violated
that for lxc's use of virSecurityManagerSetProcessLabel.  Hoist
the supplemental group detection to the time that the security
manager needs to fork.  Qemu is safe, as it uses
virSecurityManagerSetChildProcessLabel which in turn uses
virCommand to determine supplemental groups.

This does not fix the fact that virSecurityManagerSetProcessLabel
calls virSecurityDACParseIds calls parseIds which eventually
calls getpwnam_r, which also violates fork/exec async-signal-safe
safety rules, but so far no one has complained of hitting
deadlock in that case.

* src/security/security_dac.c (_virSecurityDACData): Track groups
in private data.
(virSecurityDACPreFork): New function, to set them.
(virSecurityDACClose): Clean up new fields.
(virSecurityDACGetIds): Alter signature.
(virSecurityDACSetSecurityHostdevLabelHelper)
(virSecurityDACSetChardevLabel, virSecurityDACSetProcessLabel)
(virSecurityDACSetChildProcessLabel): Update callers.
Signed-off-by: NEric Blake <eblake@redhat.com>

A future patch wants the DAC security manager to be able to safely
get the supplemental group list for a given uid, but at the time
of a fork rather than during initialization so as to pick up on
live changes to the system's group database.  This patch adds the
framework, including the possibility of a pre-fork callback
failing.

For now, any driver that implements a prefork callback must be
robust against the possibility of being part of a security stack
where a later element in the chain fails prefork.  This means
that drivers cannot do any action that requires a call to postfork
for proper cleanup (no grabbing a mutex, for example).  If this
is too prohibitive in the future, we would have to switch to a
transactioning sequence, where each driver has (up to) 3 callbacks:
PreForkPrepare, PreForkCommit, and PreForkAbort, to either clean
up or commit changes made during prepare.

* src/security/security_driver.h (virSecurityDriverPreFork): New
callback.
* src/security/security_manager.h (virSecurityManagerPreFork):
Change signature.
* src/security/security_manager.c (virSecurityManagerPreFork):
Optionally call into driver, and allow returning failure.
* src/security/security_stack.c (virSecurityDriverStack):
Wrap the handler for the stack driver.
* src/qemu/qemu_process.c (qemuProcessStart): Adjust caller.
Signed-off-by: NEric Blake <eblake@redhat.com>