Bother those kernel developers.  In the latest rawhide, kernel
and glibc have now been unified so that <netinet/in.h> and
<linux/in6.h> no longer clash; but <linux/if_bridge.h> is still
not self-contained.  Because of the latest header change, the
build is failing with:

checking for linux/param.h... no
configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support

with details:

In file included from conftest.c:561:0:
/usr/include/linux/in6.h:71:18: error: field 'flr_dst' has incomplete type
  struct in6_addr flr_dst;

We need a workaround to avoid our workaround :)

* configure.ac (NETINET_LINUX_WORKAROUND): New test.
* src/util/virnetdevbridge.c (includes): Use it.
Signed-off-by: NEric Blake <eblake@redhat.com>

The function existed in two identical instances in lxc and qemu. Move it
to vircgroup.c and simplify it. Refactor the callers too.

Semantics of the libvirt helper are more clear. This change also allows
to clean up some pieces of code.

Explicitly state that some parts of the code may require virFileExists
to set or preserve a correct errno so that future modifications don't
break.

Debian systems may run the 'systemd-logind' daemon, which causes the
/sys/fs/cgroup/systemd  mount to be setup, but no other cgroup
controllers are created. While the LXC driver considers cgroups to
be mandatory, the QEMU driver is supposed to accept them as optional.

We detect whether they are present by looking in /proc/mounts for
any mounts of type 'cgroups', but this is not sufficient. We need to
skip any named mounts (as seen by a name=XXX string in the mount
options), so that we only detect actual resource controllers.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721979Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch introduces virDBusIsServiceEnabled, we can use
this method to get if the service is supported.

In one case, if org.freedesktop.machine1 is unavailable on
host, we should skip creating machine through systemd.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Some users in Ubuntu/Debian seem to have a setup where all the
cgroup controllers are mounted on /sys/fs/cgroup rather than
any /sys/fs/cgroup/<controller> name. In the loop which detects
which controllers are present for a mount point we were modifying
'mnt_dir' field in the 'struct mntent' var, but not always restoring
the original value. This caused detection to break in the all-in-one
mount setup.

Fix that logic bug and add test case coverage for this mount
setup.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NOskari Saarenmaa <os@ohmu.fi>
Signed-off-by: NEric Blake <eblake@redhat.com>

ARM v7 can operate in either little or big endian modes. Add
support for the big-endian version known as armv7b from uname.
Signed-off-by: NYogesh Tillu <tillu.yogesh@gmail.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch changes virFileLoopDeviceOpen() to use the new loop-control
device to allocate a new loop device.  If this behavior is unsupported
we fall back to the previous method of searching /dev for a free device.

With this patch you can start as many image based LXC domains as you
like (well almost).

Fixes bug https://bugzilla.redhat.com/show_bug.cgi?id=995543

The VIR_FREE() macro will cast away any const-ness. This masked a
number of places where we passed a 'const char *' string to
VIR_FREE. Fortunately in all of these cases, the variable was not
in fact const data, but a heap allocated string. Fix all the
variable declarations to reflect this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When virGetUserEnt() and virGetGroupEnt() fail due to the uid or gid not
existing on the machine they'll print a message like:

$ virsh -c vbox:///session list
error: failed to connect to the hypervisor
error: Failed to find user record for uid '32655': Success

The success at the end is a bit confusing. This changes it to:

$ virsh -c vbox:///session list
error: failed to connect to the hypervisor
error: Failed to find user record for uid '32655'

The @qemunbd variable can be used uninitialized.

Currently, kernel supports up to 8 queues for a multiqueue tap device.
However, if user tries to enter a huge number (e.g. one million) the tap
allocation fails, as expected. But what is not expected is the log full
of warnings:

    warning : virFileClose:83 : Tried to close invalid fd 0

The problem is, upon error we iterate over an array of FDs (handlers to
queues) and VIR_FORCE_CLOSE() over each item. However, the array is
pre-filled with zeros. Hence, we repeatedly close stdin. Ouch.
But there's more. The queues allocation is done in virNetDevTapCreate()
which cleans up the FDs in case of error. Then, its caller, the
virNetDevTapCreateInBridgePort() iterates over the FD array and tries to
close them too. And so does qemuNetworkIfaceConnect() and
qemuBuildInterfaceCommandLine().

FreeBSD 10 recently changed their definition of RAND_MAX, to try
and cover the fact that their evenly distributed results of rand()
really are a smaller range than a full power of 2.  As a result,
I did some investigation, and learned:

1. POSIX requires random() to be evenly distributed across exactly
31 bits.  glibc also guarantees this for rand(), but the two are
unrelated, and POSIX only associates RAND_MAX with rand().
Avoiding RAND_MAX altogether thus avoids a build failure on
FreeBSD 10.

2. Concatenating random bits from a PRNG will NOT provide uniform
coverage over the larger value UNLESS the period of the original
PRNG is at least as large as the number of bits being concatenated.
Simple example: suppose that RAND_MAX were 1 with a period of 2**1
(which means that the PRNG merely alternates between 0 and 1).
Concatenating two successive rand() calls would then invariably
result in 01 or 10, which is a rather non-uniform distribution
(00 and 11 are impossible) and an even worse period (2**0, since
our second attempt will get the same number as our first attempt).
But a RAND_MAX of 1 with a period of 2**2 (alternating between
0, 1, 1, 0) provides sane coverage of all four values, if properly
tempered.  (Back-to-back calls would still only see half the values
if we don't do some tempering).  We therefore want to guarantee a
period of at least 2**64, preferably larger (as a tempering factor);
POSIX only makes this guarantee for random() with 256 bytes of info.

* src/util/virrandom.c (virRandomBits): Use constants that are
accurate for the PRNG we are using, not an unrelated PRNG.
(randomState): Ensure the period of our PRNG exceeds our usage.
Signed-off-by: NEric Blake <eblake@redhat.com>

Re-arrange the code so that the returned bitmap is always initialized to
NULL even on early failures and return an error message as some callers
are already expecting it. Fix up the rest not to shadow the error.

Provide an implementation of virNetDev(Set|Clear)IPv4Address based on
BSD ifconfig tool in addition to 'ip' from Linux iproute2 package.

On hosts that don't have the DBus service running or installed the new
systemd cgroups code failed with hard error instead of falling back to
"manual" cgroup creation.

Use the new helper to check for the system bus and use the fallback code
in case it isn't available.

Some systems may not use DBus in their system. Add a method to check if
the system bus is available that doesn't print error messages so that
code can later check for this condition and use an alternative approach.

The virBitmapParse function was calling virBitmapIsSet() function that
requires the caller to check the bounds of the bitmap without checking
them. This resulted into crashes when parsing a bitmap string that was
exceeding the bounds used as argument.

This patch refactors the function to use virBitmapSetBit without
checking if the bit is set (this function does the checks internally)
and then counts the bits in the bitmap afterwards (instead of keeping
track while parsing the string).

This patch also changes the "parse_error" label to a more common
"error".

The refactor should also get rid of the need to call sa_assert on the
returned variable as the callpath should allow coverity to infer the
possible return values.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=997367

Thanks to Alex Jia for tracking down the issue. This issue is introduced
by commit 0fc89098.

* src/util/virnetdevvportprofile.c: Fix typo.
* src/conf/domain_conf.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Complete the refactoring by adding missing stubs so it compiles on
platform without cgroup support.
Signed-off-by: NEric Blake <eblake@redhat.com>

Complete moving to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

Continue converting to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

- Convert virCgroupGet* to VIR_CGROUP_SUPPORTED
- Convert virCgroup(Get|Set)FreezerState to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

- Introduce VIR_CGROUP_SUPPORTED conditional
- Convert virCgroupKill* to use it
- Convert virCgroupIsolateMount() to use it
- Convert virCgroupRemoveRecursively to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

Make future patches smaller by matching a sane header listing in
the first place.  No semantic change.

* src/util/vircgroup.h: Move free next to new, and controller
functions next to each other.
* src/util/vircgroup.c (virCgroupFree, virCgroupHasController)
(virCgroupPathOfController, virCgroupRemoveRecursively)
(virCgroupRemove): Sort implementation to be closer to header.
Signed-off-by: NEric Blake <eblake@redhat.com>

Avoid a forward declaration of a static function.

* src/util/vircgroup.c (virCgroupPartitionNeedsEscaping)
(virCgroupParticionEscape): Move up.
Signed-off-by: NEric Blake <eblake@redhat.com>

Format all functions with two blank lines between, and return type
on separate line from function name.  Also break some lines longer
than 80 columns.  This makes the subsequent macro refactoring
less noisy.

* src/util/vircgroup.c: Match prevailing style.
Signed-off-by: NEric Blake <eblake@redhat.com>

Recentish (2011) kernels introduced a new device called /dev/loop-control,
which causes libvirt's detection of loop devices to get confused
since it only checks for a prefix of 'loop'. Also check that the
next character is a digit
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This is a second attempt at fixing the problem first attempted
in commit 2df8d991; basically undoing the fact that it was
reverted in commit 43cee32f, plus fixing two more issues: the
code in configure.ac has to EXACTLY match virnetdevbridge.c
with regards to declaring in6 types before using if_bridge.h,
and the fact that RHEL 5 has even more conflicts:

In file included from util/virnetdevbridge.c:49:
/usr/include/linux/in6.h:47: error: conflicting types for 'in6addr_any'
/usr/include/netinet/in.h:206: error: previous declaration of 'in6addr_any' was here
/usr/include/linux/in6.h:49: error: conflicting types for 'in6addr_loopback'
/usr/include/netinet/in.h:207: error: previous declaration of 'in6addr_loopback' was here

The rest of this commit message borrows from the original try
of 2df8d991:

A fresh checkout on a RHEL 6 machine with these packages:
kernel-headers-2.6.32-405.el6.x86_64
glibc-2.12-1.128.el6.x86_64
failed to configure with this message:
checking for linux/if_bridge.h... no
configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support

Digging in config.log, we see that the problem is identical to
what we fixed earlier in commit d12c2811:

configure:98831: checking for linux/if_bridge.h
configure:98853: gcc -std=gnu99 -c -g -O2  conftest.c >&5
In file included from /usr/include/linux/if_bridge.h:17,
                 from conftest.c:559:
/usr/include/linux/in6.h:31: error: redefinition of 'struct in6_addr'
/usr/include/linux/in6.h:48: error: redefinition of 'struct sockaddr_in6'
/usr/include/linux/in6.h:56: error: redefinition of 'struct ipv6_mreq'
configure:98860: $? = 1

I had not hit it earlier because I was using incremental builds,
where config.cache had shielded me from the kernel-headers breakage.

* configure.ac (if_bridge.h): Avoid conflicting type definitions.
* src/util/virnetdevbridge.c (includes): Also sanitize for RHEL 5.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit 3d0e3c1a reintroduced a problem previously squelched in
commit 7e5aa78d.  Add a syntax check this time around.

util/virutil.c: In function 'virGetGroupList':
util/virutil.c:1015: error: 'for' loop initial declaration used outside C99 mode

* cfg.mk (sc_prohibit_loop_var_decl): New rule.
* src/util/virutil.c (virGetGroupList): Fix offender.
Signed-off-by: NEric Blake <eblake@redhat.com>

The change from initgroups to virGetGroupList/setgroups in
cab36cfe71ba83b71e536ba5c98e596f02b697b0 dropped the primary group from
processes group list iff the passed in group to virGetGroupList differs
from the user's primary group.

So always include the primary group to bring back the old behaviour.

Debian has the kvm group as primary group but uses
libvirt-qemu:libvirt-qemu as user:group to run the kvm process so
without this change the /dev/kvm is inaccessible.

The journald code would crash if a NULL was passed for the
filename / funcname in the logging code. This shouldn't
happen in general, but it is better to be safe, since there
have been bugs triggering this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

*src/util/virstoragefile.c: Add a helper function to get
the first name of missing backing files, if the name is NULL,
it means the diskchain is not broken.
*src/qemu/qemu_domain.c: qemuDiskChainCheckBroken(disk) to
check if its chain is broken

Make the virCgroupNewMachine method try to use systemd-machined
first. If that fails, then fallback to using the traditional
cgroup setup code path.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When systemd is involved in managing processes, it may start
killing off & tearing down croups associated with the process
while we're still doing virCgroupKillPainfully. We must
explicitly check for ENOENT and treat it as if we had finished
killing processes
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Systemd uses a named cgroup mount for tracking processes. Add
it as another type of controller, albeit one which we have to
special case in a number of places. In particular we must
never create/delete directories there, nor add tasks. Essentially
the systemd mount is to be considered read-only for libvirt.

With this change both the virCgroupDetectPlacement and
virCgroupCopyPlacement methods must be invoked. The copy
placement method will copy setup for resource controllers
only. The detect placement method will probe for any
named controllers, or resource controllers not already
setup.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

There are some interesting escaping rules to consider when dealing
with systemd slice/scope names. Thus it is helpful to have APIs
for formatting names
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This function is needed for virt-login-shell.  Also modify virGirUserDirectory
to use the new function, to simplify the code.
Signed-off-by: NEric Blake <eblake@redhat.com>