The lxc contoller eventually makes use of virRandomBits(), which was
segfaulting since virRandomInitialize() is never invoked.
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff554d560 in random_r () from /lib64/libc.so.6
(gdb) bt
0 0x00007ffff554d560 in random_r () from /lib64/libc.so.6
1 0x0000000000469eaa in virRandomBits (nbits=32) at util/virrandom.c:80
2 0x000000000045bf69 in virHashCreateFull (size=256,
dataFree=0x4aa2a2 <hashDataFree>, keyCode=0x45bd40 <virHashStrCode>,
keyEqual=0x45bdad <virHashStrEqual>, keyCopy=0x45bdfa <virHashStrCopy>,
keyFree=0x45be37 <virHashStrFree>) at util/virhash.c:134
3 0x000000000045c069 in virHashCreate (size=0, dataFree=0x4aa2a2 <hashDataFree>)
at util/virhash.c:164
4 0x00000000004aa562 in virNWFilterHashTableCreate (n=0)
at conf/nwfilter_params.c:686
5 0x00000000004aa95b in virNWFilterParseParamAttributes (cur=0x711d30)
at conf/nwfilter_params.c:793
6 0x0000000000481a7f in virDomainNetDefParseXML (caps=0x702c90, node=0x7116b0,
ctxt=0x7101b0, bootMap=0x0, flags=0) at conf/domain_conf.c:4589
7 0x000000000048cc36 in virDomainDefParseXML (caps=0x702c90, xml=0x710040,
root=0x7103b0, ctxt=0x7101b0, expectedVirtTypes=16, flags=0)
at conf/domain_conf.c:8658
8 0x000000000048f011 in virDomainDefParseNode (caps=0x702c90, xml=0x710040,
root=0x7103b0, expectedVirtTypes=16, flags=0) at conf/domain_conf.c:9360
9 0x000000000048ee30 in virDomainDefParse (xmlStr=0x0,
filename=0x702ae0 "/var/run/libvirt/lxc/x.xml", caps=0x702c90,
expectedVirtTypes=16, flags=0) at conf/domain_conf.c:9310
10 0x000000000048ef00 in virDomainDefParseFile (caps=0x702c90,
filename=0x702ae0 "/var/run/libvirt/lxc/x.xml", expectedVirtTypes=16, flags=0)
at conf/domain_conf.c:9332
11 0x0000000000425053 in main (argc=5, argv=0x7fffffffe2b8)
at lxc/lxc_controller.c:1773
Instead of hardcoding use of SELinux contexts in the LXC driver,
switch over to using the official security driver API.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To allow the security drivers to apply different configuration
information per hypervisor, pass the virtualization driver name
into the security manager constructor.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virLogSetFromEnv call was done too late in startup to
catch many log messages (eg from security driver initialization).
To assist debugging also explicitly log the security details
at startup
Currently the libvirt_lxc process uses VIR_DOMAIN_XML_INACTIVE
when loading the XML for the container. This means it loses
any dynamic data such as the, just allocated, SELinux label.
Further there is an inconsistency in the libvirt LXC driver
whereby it saves the live config XML and then later overwrites
the file with the live status XML instead. Add a comment about
this for future reference.
* src/lxc/lxc_controller.c: Remove VIR_DOMAIN_XML_INACTIVE
when loading XML
* src/lxc/lxc_driver.c: Add comment about inconsistent
config file formats
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Error: UNINIT:
/libvirt/src/lxc/lxc_driver.c:1412:
var_decl: Declaring variable "fd" without initializer.
/libvirt/src/lxc/lxc_driver.c:1460:
uninit_use_in_call: Using uninitialized value "fd" when calling "virFileClose".
/libvirt/src/util/virfile.c:50:
read_parm: Reading a parameter value.
Error: DEADCODE:
/libvirt/src/lxc/lxc_controller.c:960:
dead_error_condition: On this path, the condition "ret == 4" cannot be true.
/libvirt/src/lxc/lxc_controller.c:959:
at_most: After this line, the value of "ret" is at most -1.
/libvirt/src/lxc/lxc_controller.c:959:
new_values: Noticing condition "ret < 0".
/libvirt/src/lxc/lxc_controller.c:961:
dead_error_line: Execution cannot reach this statement "continue;".
Error: UNINIT:
/libvirt/src/lxc/lxc_controller.c:1104:
var_decl: Declaring variable "consoles" without initializer.
/libvirt/src/lxc/lxc_controller.c:1237:
uninit_use: Using uninitialized value "consoles".
This patch fixes the access of variable "con" in two files where the
variable was declared only on SELinux builds and thus the build failed
without SELinux. It's a rather nasty fix but helps fix the build
quickly and without any major changes to the code.
To allow the container to access /dev and /dev/pts when under
sVirt, set an explicit mount option. Also set a max size on
the /dev mount to prevent DOS on memory usage
* src/lxc/lxc_container.c: Set /dev mount context
* src/lxc/lxc_controller.c: Set /dev/pts mount context
For the sake of backwards compat, LXC guests are *not*
confined by default. This is because it is not practical
to dynamically relabel containers using large filesystem
trees. Applications can create confined containers though,
by giving suitable XML configs
* src/Makefile.am: Link libvirt_lxc to security drivers
* src/lxc/libvirtd_lxc.aug, src/lxc/lxc_conf.h,
src/lxc/lxc_conf.c, src/lxc/lxc.conf,
src/lxc/test_libvirtd_lxc.aug: Config file handling for
security driver
* src/lxc/lxc_driver.c: Wire up security driver functions
* src/lxc/lxc_controller.c: Add a '--security' flag to
specify which security driver to activate
* src/lxc/lxc_container.c, src/lxc/lxc_container.h: Set
the process label just before exec'ing init.
Currently the LXC controller attempts to deal with EOF on a
tty by spawning a thread to do an edge triggered epoll_wait().
This avoids the normal event loop spinning on POLLHUP. There
is a subtle mistake though - even after seeing POLLHUP on a
master PTY, it is still perfectly possible & valid to write
data to the PTY. There is a buffer that can be filled with
data, even when no client is present.
The second mistake is that the epoll_wait() thread was not
looking for the EPOLLOUT condition, so when a new client
connects to the LXC console, it had to explicitly send a
character before any queued output would appear.
Finally, there was in fact no need to spawn a new thread to
deal with epoll_wait(). The epoll file descriptor itself
can be poll()'d on normally.
This patch attempts to deal with all these problems.
- The blocking epoll_wait() thread is replaced by a poll
on the epoll file descriptor which then does a non-blocking
epoll_wait() to handle events
- Even if POLLHUP is seen, we continue trying to write
any pending output until getting EAGAIN from write.
- Once write returns EAGAIN, we modify the epoll event
mask to also look for EPOLLOUT
* src/lxc/lxc_controller.c: Avoid stalled I/O upon
connected to an LXC console
To make lxcSetContainerResources smaller, pull the mem tune
and device ACL setup code out into separate methods
* src/lxc/lxc_controller.c: Introduce lxcSetContainerMemTune
and lxcSetContainerDeviceACL
While LXC does not have the concept of VCPUS, so we can't do
per-VCPU pCPU placement, we can support the VM level CPU
placement. Todo this simply set the CPU affinity of the LXC
controller at startup. All child processes will inherit this
affinity.
* src/lxc/lxc_controller.c: Set process affinity
Move the virNetDevSetName and virNetDevSetNamespace APIs out
of LXC's veth.c and into virnetdev.c.
Move the remaining content of the file to src/util/virnetdevveth.c
* src/lxc/veth.c: Rename to src/util/virnetdevveth.c
* src/lxc/veth.h: Rename to src/util/virnetdevveth.h
* src/util/virnetdev.c, src/util/virnetdev.h: Add
virNetDevSetName and virNetDevSetNamespace
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
src/lxc/lxc_driver.c: Update include paths
The src/lxc/veth.c file contains APIs for managing veth devices,
but some of the APIs duplicate stuff from src/util/virnetdev.h.
Delete thed duplicate APIs and rename the remaining ones to
follow virNetDevVethXXXX
* src/lxc/veth.c, src/lxc/veth.h: Rename APIs & delete duplicates
* src/lxc/lxc_container.c, src/lxc/lxc_controller.c,
src/lxc/lxc_driver.c: Update for API renaming
Based on a Coverity report - the return value of waitpid() should
always be checked, to avoid problems with leaking resources.
* src/lxc/lxc_controller.c (lxcControllerRun): Use simpler virPidAbort.
Currently the LXC controller only supports setup of a single
text console. This is wired up to the container init's stdio,
as well as /dev/console and /dev/tty1. Extending support for
multiple consoles, means wiring up additional PTYs to /dev/tty2,
/dev/tty3, etc, etc. The LXC controller is passed multiple open
file handles, one for each console requested.
* src/lxc/lxc_container.c, src/lxc/lxc_container.h: Wire up
all the /dev/ttyN links required to symlink to /dev/pts/NN
* src/lxc/lxc_container.h: Open more container side /dev/pts/NN
devices, and adapt event loop to handle I/O from all consoles
* src/lxc/lxc_driver.c: Setup multiple host side PTYs
The current I/O code for LXC uses a hand crafted event loop
to forward I/O between the container & host app, based on
epoll to handle EOF on PTYs. This event loop is not easily
extensible to add more consoles, or monitor other types of
file descriptors.
Remove the custom event loop and replace it with a normal
libvirt event loop. When detecting EOF on a PTY, disable
the event watch on that FD, and fork off a background thread
that does a edge-triggered epoll() on the FD. When the FD
finally shows new incoming data, the thread re-enables the
watch on the FD and exits.
When getting EOF from a read() on the PTY, the existing code
would do waitpid(WNOHANG) to see if the container had exited.
Unfortunately there is a race condition, because even though
the process has closed its stdio handles, it might still
exist.
To deal with this the new event loop uses a SIG_CHILD handler
to perform the waitpid only when the container is known to
have actually exited.
* src/lxc/lxc_controller.c: Rewrite the event loop to use
the standard APIs.
Previous commit clears number of items alocated in lxcSetupLoopDevices
if VIR_REALLOC_N fails. In that case, the pointer is not NULL, and
causes leaking FDs that have been allocated.
* src/lxc/lxc_controller.c: revert zeroing array size
If the function lxcSetupLoopDevices(def, &nloopDevs, &loopDevs) failed,
the variable loopDevs will keep a initial NULL value, however, the
function VIR_FORCE_CLOSE(loopDevs[i]) will directly deref it.
This patch also fixes returning a bogous number of devices from
lxcSetupLoopDevices on an error path.
* rc/lxc/lxc_controller.c: fixed a null pointer dereference.
Signed-off-by: Alex Jia <ajia@redhat.com>
The glibc ones (intentionally) cannot handle ptys opened in a
devpts not mounted at /dev/pts.
Drop the (un-exported, unused) virFileOpenTtyAt.
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Detected by Coverity. We want to increment the size_t counter,
not the pointer to the counter. Bug present since 5f5c6fde (0.9.5).
* src/lxc/lxc_controller.c (lxcSetupLoopDevices): Use correct
precedence.
The functions for manipulating pidfiles are in util/util.{c,h}.
We will shortly be adding some further pidfile related functions.
To avoid further growing util.c, this moves the pidfile related
functions into a dedicated virpidfile.{c,h}. The functions are
also all renamed to have 'virPidFile' as their name prefix
* util/util.h, util/util.c: Remove all pidfile code
* util/virpidfile.c, util/virpidfile.h: Add new APIs for pidfile
handling.
* lxc/lxc_controller.c, lxc/lxc_driver.c, network/bridge_driver.c,
qemu/qemu_process.c: Add virpidfile.h include and adapt for API
renames
A previous commit gave the LXC driver the ability to mount
block devices for the container filesystem. Through use of
the loopback device functionality, we can build on this to
support use of plain file images for LXC filesytems.
By setting the LO_FLAGS_AUTOCLEAR flag we can ensure that
the loop device automatically disappears when the container
dies / shuts down
* src/lxc/lxc_container.c: Raise error if we see a file
based filesystem, since it should have been turned into
a loopback device already
* src/lxc/lxc_controller.c: Rewrite any filesystems of
type=file, into type=block, by binding the file image
to a free loop device
Currently the LXC driver can only populate filesystems from
host filesystems, using bind mounts. This patch allows host
block devices to be mounted. It autodetects the filesystem
format at mount time, and adds the block device to the cgroups
ACL. Example usage is
<filesystem type='block' accessmode='passthrough'>
<source dev='/dev/sda1'/>
<target dir='/home'/>
</filesystem>
* src/lxc/lxc_container.c: Mount block device filesystems
* src/lxc/lxc_controller.c: Add block device filesystems
to cgroups ACL
Although most functions in libvirt return 0 on success and < 0 on
failure, there are a few functions lingering around that return errno
(a positive value) on failure, and sometimes code calling those
functions incorrectly assumes the <0 standard. I noticed one of these
the other day when auditing networkStartDhcpDaemon after Guido Gunther
found a place where success was improperly returned on failure (that
patch has been acked and is pending a push). The problem was that it
expected the return value from virFileReadPid to be < 0 on failure,
but it was actually positive (it was also neglected to set the return
code in this case, similar to the bug found by Guido).
This all led to the fact that *all* of the virFile*Pid functions in
util.c are returning errno on failure. This patch remedies that
problem by changing them all to return -errno on failure, and makes
any necessary changes to callers of the functions. (In the meantime, I
also properly set the return code on failure of virFileReadPid in
networkStartDhcpDaemon).
The drivers were accepting domain configs without checking if those
were actually meant for them. For example the LXC driver happily
accepts configs with type QEMU.
Add a check for the expected domain types to the virDomainDefParse*
functions.
Some callers expected virFileMakePath to set errno, some expected
it to return an errno value. Unify this to return 0 on success and
-1 on error. Set errno to report detailed error information.
Also optimize virFileMakePath if stat fails with an errno different
from ENOENT.
Add a simple handshake with the lxc_controller process so we can detect
process startup failures. We do this by adding a new --handshake cli arg
to lxc_controller for passing a file descriptor. If the process fails to
launch, we scrape all output from the logfile and report it to the user.
These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
* Correct the documentation for cgroup: the swap_hard_limit indicates
mem+swap_hard_limit.
* Change cgroup private apis to: virCgroupGet/SetMemSwapHardLimit
Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
The current LXC I/O controller looks for HUP to detect
when a guest has quit. This isn't reliable as during
initial bootup it is possible that 'init' will close
the console and let mingetty re-open it. The shutdown
of containers was also flakey because it only killed
the libvirt I/O controller and expected container
processes to gracefully follow.
Change the I/O controller such that when it see HUP
or an I/O error, it uses kill($PID, 0) to see if the
process has really quit.
Change the container shutdown sequence to use the
virCgroupKillPainfully function to ensure every
really goes away
This change makes the use of the 'cpu', 'devices'
and 'memory' cgroups controllers compulsory with
LXC
* docs/drvlxc.html.in: Document that certain cgroups
controllers are now mandatory
* src/lxc/lxc_controller.c: Check if PID is still
alive before quitting on I/O error/HUP
* src/lxc/lxc_driver.c: Use virCgroupKillPainfully
Adding audit points showed that we were granting too much privilege
to qemu; it should not need any mknod rights to recreate any
devices. On the other hand, lxc should have all device privileges.
The solution is adding a flag parameter.
This also lets us restrict write access to read-only disks.
* src/util/cgroup.h (virCgroup*Device*): Adjust prototypes.
* src/util/cgroup.c (virCgroupAllowDevice)
(virCgroupAllowDeviceMajor, virCgroupAllowDevicePath)
(virCgroupDenyDevice, virCgroupDenyDeviceMajor)
(virCgroupDenyDevicePath): Add parameter.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Update clients.
* src/lxc/lxc_controller.c (lxcSetContainerResources): Likewise.
* src/qemu/qemu_cgroup.c: Likewise.
(qemuSetupDiskPathAllow): Also, honor read-only disks.
Using the 'personality(2)' system call, we can make a container
on an x86_64 host appear to be i686. Likewise for most other
Linux 64bit arches.
* src/lxc/lxc_conf.c: Fill in 32bit capabilities for x86_64 hosts
* src/lxc/lxc_container.h, src/lxc/lxc_container.c: Add API to
check if an arch has a 32bit alternative
* src/lxc/lxc_controller.c: Set the process personality when
starting guest
Normal practice for /dev/pts is to have it mode=620,gid=5
but LXC was leaving mode=000,gid=0 preventing unprivilegd
users in the guest use of PTYs
* src/lxc/lxc_controller.c: Fix /dev/pts setup
Done mechanically with:
$ git grep -l '\bDEBUG0\? *(' | xargs -L1 sed -i 's/\bDEBUG0\? *(/VIR_&/'
followed by manual deletion of qemudDebug in daemon/libvirtd.c, along
with a single 'make syntax-check' fallout in the same file, and the
actual deletion in src/util/logging.h.
* src/util/logging.h (DEBUG, DEBUG0): Delete.
* daemon/libvirtd.h (qemudDebug): Likewise.
* global: Change remaining clients over to VIR_DEBUG counterpart.
Per the gettext developer:
http://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00019.htmlhttp://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00021.html
gettext() doesn't work correctly on all platforms unless you have
called setlocale(). Furthermore, gnulib's gettext.h has provisions
for setting up a default locale, which is the preferred method for
libraries to use gettext without having to call textdomain() and
override the main program's default domain (virInitialize already
calls bindtextdomain(), but this is insufficient without the
setlocale() added in this patch; and a redundant bindtextdomain()
in this patch doesn't hurt, but serves as a good example for other
packages that need to bind a second translation domain).
This patch is needed to silence a new gnulib 'make syntax-check'
rule in the next patch.
* daemon/libvirtd.c (main): Setup locale and gettext.
* src/lxc/lxc_controller.c (main): Likewise.
* src/security/virt-aa-helper.c (main): Likewise.
* src/storage/parthelper.c (main): Likewise.
* tools/virsh.c (main): Fix exit status.
* src/internal.h (DEFAULT_TEXT_DOMAIN): Define, for gettext.h.
(_): Simplify definition accordingly.
* po/POTFILES.in: Add src/storage/parthelper.c.
