Wire up the new virDomainCreate{XML}WithFiles methods in the
LXC driver, so that FDs get passed down to the init process.
The lxc_container code needs to do a little dance in order
to renumber the file descriptors it receives into linear
order, starting from STDERR_FILENO + 1.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit 75c1256 states that virGetGroupList must not be called
between fork and exec, then commit ee777e99 promptly violated
that for lxc.
Patch originally posted by Eric Blake <eblake@redhat.com>.
Otherwise the container will fail to start if we
enable user namespace, since there is no rights to
do mknod in uninit user namespace.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
lxc driver will use this function to change the owner
of hot added devices.
Move virLXCControllerChown to lxc_container.c and Rename
it to lxcContainerChown.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
When failing to start a container due to inaccessible root
filesystem path, we did not log any meaningful error. Add a
few debug statements to assist diagnosis
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=964358
POSIX states that multi-threaded apps should not use functions
that are not async-signal-safe between fork and exec, yet we
were using getpwuid_r and initgroups. Although rare, it is
possible to hit deadlock in the child, when it tries to grab
a mutex that was already held by another thread in the parent.
I actually hit this deadlock when testing multiple domains
being started in parallel with a command hook, with the following
backtrace in the child:
Thread 1 (Thread 0x7fd56bbf2700 (LWP 3212)):
#0 __lll_lock_wait ()
at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:136
#1 0x00007fd5761e7388 in _L_lock_854 () from /lib64/libpthread.so.0
#2 0x00007fd5761e7257 in __pthread_mutex_lock (mutex=0x7fd56be00360)
at pthread_mutex_lock.c:61
#3 0x00007fd56bbf9fc5 in _nss_files_getpwuid_r (uid=0, result=0x7fd56bbf0c70,
buffer=0x7fd55c2a65f0 "", buflen=1024, errnop=0x7fd56bbf25b8)
at nss_files/files-pwd.c:40
#4 0x00007fd575aeff1d in __getpwuid_r (uid=0, resbuf=0x7fd56bbf0c70,
buffer=0x7fd55c2a65f0 "", buflen=1024, result=0x7fd56bbf0cb0)
at ../nss/getXXbyYY_r.c:253
#5 0x00007fd578aebafc in virSetUIDGID (uid=0, gid=0) at util/virutil.c:1031
#6 0x00007fd578aebf43 in virSetUIDGIDWithCaps (uid=0, gid=0, capBits=0,
clearExistingCaps=true) at util/virutil.c:1388
#7 0x00007fd578a9a20b in virExec (cmd=0x7fd55c231f10) at util/vircommand.c:654
#8 0x00007fd578a9dfa2 in virCommandRunAsync (cmd=0x7fd55c231f10, pid=0x0)
at util/vircommand.c:2247
#9 0x00007fd578a9d74e in virCommandRun (cmd=0x7fd55c231f10, exitstatus=0x0)
at util/vircommand.c:2100
#10 0x00007fd56326fde5 in qemuProcessStart (conn=0x7fd53c000df0,
driver=0x7fd55c0dc4f0, vm=0x7fd54800b100, migrateFrom=0x0, stdin_fd=-1,
stdin_path=0x0, snapshot=0x0, vmop=VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
flags=1) at qemu/qemu_process.c:3694
...
The solution is to split the work of getpwuid_r/initgroups into the
unsafe portions (getgrouplist, called pre-fork) and safe portions
(setgroups, called post-fork).
* src/util/virutil.h (virSetUIDGID, virSetUIDGIDWithCaps): Adjust
signature.
* src/util/virutil.c (virSetUIDGID): Add parameters.
(virSetUIDGIDWithCaps): Adjust clients.
* src/util/vircommand.c (virExec): Likewise.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* src/security/security_dac.c (virSecurityDACSetProcessLabel):
Likewise.
* src/lxc/lxc_container.c (lxcContainerSetID): Likewise.
* configure.ac (AC_CHECK_FUNCS_ONCE): Check for setgroups, not
initgroups.
Signed-off-by: Eric Blake <eblake@redhat.com>
Recent changes uncovered a NEGATIVE_RETURNS in the return from sysconf()
when processing a for loop in virtTestCaptureProgramExecChild() in
testutils.c
Code review uncovered 3 other code paths with the same condition that
weren't found by Covirity, so fixed those as well.
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Create parent directroy for hostdev automatically when we
start a lxc domain or attach a hostdev to a lxc domain.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
This helper function is used to create parent directory for
the hostdev which will be added to the container. If the
parent directory of this hostdev doesn't exist, the mknod of
the hostdev will fail. eg with /dev/net/tun
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
User namespaces will deny the ability to mount the SELinux
filesystem. This is harmless for libvirt's LXC needs, so the
error can be ignored.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
user namespace doesn't allow to create devices in
uninit userns. We should create devices on host side.
We first mount tmpfs on dev directroy under state dir
of container. then create devices under this dev dir.
Finally in container, mount the dev directroy created
on host to the /dev/ directroy of container.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
This patch introduces new helper function
virLXCControllerSetupUserns, in this function,
we set the files uid_map and gid_map of the init
task of container.
lxcContainerSetID is used for creating cred for
tasks running in container. Since after setuid/setgid,
we may be a new user. This patch calls lxcContainerSetUserns
at first to make sure the new created files belong to
right user.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
User namespace will be enabled only when the idmap exist
in configuration.
If you want disable user namespace,just remove these
elements from XML.
If kernel doesn't support user namespace and idmap exist
in configuration file, libvirt lxc will start failed and
return "Kernel doesn't support user namespace" message.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Earlier commit f7e8653f dropped support for using LXC with
kernels having single-instance devpts filesystem from the
LXC controller. It forgot to remove the same code from the
LXC container setup.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
After commit c131525bec
"Auto-add a root <filesystem> element to LXC containers on startup"
for libvirt lxc, root must be existent.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Re-add the selinux header to lxc_container.c since other
functions now use it, beyond the patch that was just
reverted.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Before trying to mount the selinux filesystem in a container
use is_selinux_enabled() to check if the machine actually
has selinux support (eg not booted with selinux=0)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
During startup, the LXC driver uses paths such as
/.oldroot/var/run/libvirt/lxc/...
to access directories from the previous root filesystem
after doing a pivot_root(). Unfortunately if /var/run
is an absolute symlink to /run, instead of a relative
symlink to ../run, these paths break.
At least one Linux distro is known to use an absolute
symlink for /var/run, so workaround this, by resolving
all symlinks before doing the pivot_root().
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We do not want to allow contained applications to be able to read fusefs_t.
So we want /proc/meminfo label to match the system default proc_t.
Fix checking of error codes
The lxcContainerMountAllFS method had a 'bool skipRoot'
flag to control whether it mounts the / filesystem. Since
removal of the non-pivot root container setup codepaths,
this flag is obsolete as the only caller always passes
'true'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Many methods accept a string parameter specifying the
old root directory prefix. Since removal of the non-pivot
root container setup codepaths, this parameter is obsolete
in many methods where the callers always pass "/.oldroot".
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The lxcContainerMountBasicFS method had a 'bool pivotRoot'
flag to control whether it mounted a private /dev. Since
removal of the non-pivot root container setup codepaths,
this flag is obsolete as the only caller always passes
'true'.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
The LXC driver currently has code to detect cgroups mounts
and then re-mount them inside the new root filesystem. Replace
this fragile code with a call to virCgroupIsolateMount.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the user requests a mount for /run, this may hide any existing
mounts that are lower down in /run. The result is that the
container still sees the mounts in /proc/mounts, but cannot
access them
sh-4.2# df
df: '/run/user/501/gvfs': No such file or directory
df: '/run/media/berrange/LIVE': No such file or directory
df: '/run/media/berrange/SecureDiskA1': No such file or directory
df: '/run/libvirt/lxc/sandbox': No such file or directory
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vg_t500wlan-lv_root 151476396 135390200 8384900 95% /
tmpfs 1970888 3204 1967684 1% /run
/dev/sda1 194241 155940 28061 85% /boot
devfs 64 0 64 0% /dev
tmpfs 64 0 64 0% /sys/fs/cgroup
tmpfs 1970888 1200 1969688 1% /etc/libvirt-sandbox/scratch
Before mounting any filesystem at a particular location, we
must recursively unmount anything at or below the target mount
point
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Ensure lxcContainerUnmountSubtree is at the top of the
lxc_container.c file so it is easily referenced from
any other method. No functional change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This allows a container-type domain to have exclusive access to one of
the host's NICs.
Wire <hostdev caps=net> with the lxc_controller - when moving the newly
created veth devices into a new namespace, also look for any hostdev
devices that should be moved. Note: once the container domain has been
destroyed, there is no code that moves the interfaces back to the
original namespace. This does happen, though, probably due to default
cleanup on namespace destruction.
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Currently the LXC container code has two codepaths, depending on
whether there is a <filesystem> element with a target path of '/'.
If we automatically add a <filesystem> device with src=/ and dst=/,
for any container which has not specified a root filesystem, then
we only need one codepath for setting up the filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
For a root filesystem with type=file or type=block, the LXC
container was forgetting to actually mount it, before doing
the pivot root step.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently the lxc controller sets up the devpts instance on
$rootfsdef->src, but this only works if $rootfsdef is using
type=mount. To support type=block or type=file for the root
filesystem, we must use /var/lib/libvirt/lxc/$NAME.devpts
for the temporary devpts mount in the controller
Instead of using /var/lib/libvirt/lxc/$NAME for the FUSE
filesystem, use /var/lib/libvirt/lxc/$NAME.fuse. This allows
room for other temporary mounts in the same directory
In the LXC container startup code when switching stdio
streams, we call VIR_FORCE_CLOSE on all FDs. This triggers
a huge number of warnings, but we don't see them because
stdio is closed at this point. strace() however shows them
which can confuse people debugging the code. Switch to
VIR_MASS_CLOSE to avoid this
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
libvirt lxc will fail to start when selinux is disabled.
error: Failed to start domain noroot
error: internal error guest failed to start: PATH=/bin:/sbin TERM=linux container=lxc-libvirt container_uuid=b9873916-3516-c199-8112-1592ff694a9e LIBVIRT_LXC_UUID=b9873916-3516-c199-8112-1592ff694a9e LIBVIRT_LXC_NAME=noroot /bin/sh
2013-01-09 11:04:05.384+0000: 1: info : libvirt version: 1.0.1
2013-01-09 11:04:05.384+0000: 1: error : lxcContainerMountBasicFS:546 : Failed to mkdir /sys/fs/selinux: No such file or directory
2013-01-09 11:04:05.384+0000: 7536: info : libvirt version: 1.0.1
2013-01-09 11:04:05.384+0000: 7536: error : virLXCControllerRun:1466 : error receiving signal from container: Input/output error
2013-01-09 11:04:05.404+0000: 7536: error : virCommandWait:2287 : internal error Child process (ip link del veth1) unexpected exit status 1: Cannot find device "veth1"
fix this problem by checking if selinuxfs is mounted
in host before we try to create dir /sys/fs/selinux.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
when we has no host's src mapped to container.
there is no .oldroot dir,so libvirt lxc will fail
to start when mouting meminfo.
in this case,the parameter srcprefix of function
lxcContainerMountProcFuse should be NULL.and make
this method handle NULL correctly.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Convert the host capabilities and domain config structs to
use the virArch datatype. Update the parsers and all drivers
to take account of datatype change
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This extends support for host device passthrough with LXC to
cover misc devices. In this case all we need todo is a
mknod in the container's /dev and whitelist the device in
cgroups
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This extends support for host device passthrough with LXC to
cover storage devices. In this case all we need todo is a
mknod in the container's /dev and whitelist the device in
cgroups
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This adds support for host device passthrough with the
LXC driver. Since there is only a single kernel image,
it doesn't make sense to pass through PCI devices, but
USB devices are fine. For the latter we merely need to
make the /dev/bus/usb/NNN/MMM character device exist
in the container's /dev
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently LXC guests can be given arbitrary pre-mounted
filesystems, however, for some usecases it is more appropriate
to provide block devices which the container can mount itself.
This first impl only allows for <disk type='block'>, in other
words exposing a host disk device to a container. Since LXC
does not have device namespace virtualization, we are cheating
a little bit. If the XML specifies /dev/sdc4 to be given to
the container as /dev/sda1, when we do the mknod /dev/sda1
in the container's /dev, we actually use the major:minor
number of /dev/sdc4, not /dev/sda1.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
we already have virtualize meminfo for container through fuse filesystem,
add function lxcContainerMountProcFuse to mount this meminfo file to
the container's /proc/meminfo.
So we can isolate container's /proc/meminfo from host now.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Currently the lxcContainerSetupMounts method uses the
virSecurityManagerPtr instance to obtain the mount options
string and then only passes the string down into methods
it calls. As functionality in LXC grows though, those
methods need to have direct access to the virSecurityManagerPtr
instance. So push the code down a level.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The impls of virSecurityManagerGetMountOptions had no way to
return errors, since the code was treating 'NULL' as a success
value. This is somewhat pointless, since the calling code did
not want NULL in the first place and has to translate it into
the empty string "". So change the code so that the impls can
return "" directly, allowing use of NULL for error reporting
once again
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This needs to be done before the container starts. Turning
off the mknod capability is noticed by systemd, which will
no longer attempt to create device nodes.
This eliminates SELinux AVC messages and ugly failure messages in the journal.
Continue consolidation of process functions by moving some
helpers out of command.{c,h} into virprocess.{c,h}
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Some kernel versions (at least RHEL-6 2.6.32) do not let you over-mount
an existing selinuxfs instance with a new one. Thus we must unmount the
existing instance inside our namespace.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
The introduction of /sys/fs/cgroup came in fairly recent kernels.
Prior to that time distros would pick a custom directory like
/cgroup or /dev/cgroup. We need to auto-detect where this is,
rather than hardcoding it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Otherwise, a build may fail with:
lxc/lxc_conatiner.c: In function 'lxcContainerDropCapabilities':
lxc/lxc_container.c:1662:46: error: unused parameter 'keepReboot' [-Werror=unused-parameter]
* src/lxc/lxc_container.c (lxcContainerDropCapabilities): Mark
parameter unused.
Check whether the reboot() system call is virtualized, and if
it is, then allow the container to keep CAP_SYS_REBOOT.
Based on an original patch by Serge Hallyn
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
Basically within a Secure Linux Container (virt-sandbox) we want all content
that the process within the container can write to be labeled the same. We
are labeling the physical disk correctly but when we create "RAM" based file
systems
libvirt is not labeling them, and they are defaulting to tmpfs_t, which will
will not allow the processes to write. This patch labels the RAM based file
systems correctly.
Previous commits added code to unmount the existing /proc,
/sys and /dev hierarchies on the root filesystem of the
container. This should only have been done if the container's
root filesystem was the same as the host's root. ie if
the root source is '/'. As it is, this causes LXC containersr
to fail to start if their root source is not '/'
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the veth device name state into the virLXCControllerPtr
object and stop passing it around. Also use size_t instead
of unsigned int for the array length parameters.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since we are mounting a new /dev in the container, we must
remove any sub-mounts like /dev/shm, /dev/mqueue, etc,
otherwise they'll be recorded in /proc/mounts, but not be
accessible to applications.
Currently libvirt-lxc checks to see if the destination exists and is a
directory. If it is not a directory then the mount fails. Since
libvirt-lxc can bind mount files on an inode, this patch is needed to
allow us to bind mount files on files. Currently we want to bind mount
on top of /etc/machine-id, and /etc/adjtime
If the destination of the mount point does not exists, it checks if the
src is a directory and then attempts to create a directory, otherwise it
creates an empty file for the destination. The code will then bind mount
over the destination.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently you can configure LXC to bind a host directory to
a guest directory, but not to bind a guest directory to a
guest directory. While the guest container init could do
this itself, allowing it in the libvirt XML means a stricter
SELinux policy can be written
Introduce a new syntax for filesystems to allow use of a RAM
filesystem
<filesystem type='ram'>
<source usage='10' units='MiB'/>
<target dir='/mnt'/>
</filesystem>
The usage units default to KiB to limit consumption of host memory.
* docs/formatdomain.html.in: Document new syntax
* docs/schemas/domaincommon.rng: Add new attributes
* src/conf/domain_conf.c: Parsing/formatting of RAM filesystems
* src/lxc/lxc_container.c: Mounting of RAM filesystems
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
when lxcContainerIdentifyCGroups failed, the memory it allocated
has been freed, so we should not free this memory again in
lxcContainerSetupPivortRoot and lxcContainerSetupExtraMounts.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
when libvirt_lxc trigger oom error in lxcContainerGetSubtree
we should free the alloced memory for mounts.
so when lxcContainerGetSubtree failed,we should do some
memory cleanup in lxcContainerUnmountSubtree.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
we alloc the memory for format in lxcContainerMountDetectFilesystem
but without free it in lxcContainerMountFSBlockHelper.
this patch just call VIR_FREE to free it.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
This reverts
commit c16b4c43fc
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Fri May 11 15:09:27 2012 +0100
Avoid LXC pivot root in the root source is still /
This commit broke setup of /dev, because the code which
deals with setting up a private /dev and /dev/pts only
works if you do a pivotroot.
The original intent of avoiding the pivot root was to
try and ensure the new root has a minimumal mount
tree. The better way todo this is to just unmount the
bits we don't want (ie old /proc & /sys subtrees.
So apply the logic from
commit c529b47a75
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Fri May 11 11:35:28 2012 +0100
Trim /proc & /sys subtrees before mounting new instances
to the pivot_root codepath as well
when do remount,the source and target should be the same
values specified in the initial mount() call.
So change fs->dst to src.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Normal practice is for cgroups controllers to be mounted at
/sys/fs/cgroup. When setting up a container, /sys is mounted
with a new sysfs instance, thus we must re-mount all the
cgroups controllers. The complexity is that we must mount
them in the same layout as the host OS. ie if 'cpu' and 'cpuacct'
were mounted at the same location in the host we must preserve
this in the container. Also if any controllers are co-located
we must setup symlinks from the individual controller name to
the co-located mount-point
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Both /proc and /sys may have sub-mounts in them from the host
OS. We must explicitly unmount them all before mounting the
new instance over that location. If we don't then /proc/mounts
will show the sub-mounts as existing, even though nothing will
be able to access them, due to the over-mount.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the LXC config has a filesystem
<filesystem>
<source dir='/'/>
<target dir='/'/>
</filesystem>
then there is no need to go down the pivot root codepath.
We can simply use the existing root as needed.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
