Currently there is a hook function that is invoked when a
new client connection comes in, which allows an app to
setup private data. This setup will make it difficult to
serialize client state during process re-exec(). Change to
a model where the app registers a callback when creating
the virNetServerPtr instance, which is used to allocate
the client private data immediately during virNetClientPtr
construction.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
All callers used the same initialization seed (well, the new
viratomictest forgot to look at getpid()); so we might as well
make this value automatic. And while it may feel like we are
giving up functionality, I documented how to get it back in the
unlikely case that you actually need to debug with a fixed
pseudo-random sequence. I left that crippled by default, so
that a stray environment variable doesn't cause a lack of
randomness to become a security issue.
* src/util/virrandom.c (virRandomInitialize): Rename...
(virRandomOnceInit): ...and make static, with one-shot call.
Document how to do fixed-seed debugging.
* src/util/virrandom.h (virRandomInitialize): Drop prototype.
* src/libvirt_private.syms (virrandom.h): Don't export it.
* src/libvirt.c (virInitialize): Adjust caller.
* src/lxc/lxc_controller.c (main): Likewise.
* src/security/virt-aa-helper.c (main): Likewise.
* src/util/iohelper.c (main): Likewise.
* tests/seclabeltest.c (main): Likewise.
* tests/testutils.c (virtTestMain): Likewise.
* tests/viratomictest.c (mymain): Likewise.
The reboot() syscall is allowed by new kernels for LXC containers.
The LXC controller can detect whether a reboot was requested
(instead of a normal shutdown) by looking at the "init" process
exit status. If a reboot was triggered, the exit status will
record SIGHUP as the kill reason.
The LXC controller has cleared all its capabilities, and the
veth network devices will no longer exist at this time. Thus
it cannot restart the container init process itself. Instead
it emits an event which is picked up by the LXC driver in
libvirtd. This will then re-create the container, using the
same configuration as it was previously running with (ie it
will not activate 'newDef').
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This defines a new RPC protocol to be used between the LXC
controller and the libvirtd LXC driver. There is only a
single RPC message defined thus far, an asynchronous "EXIT"
event that is emitted just before the LXC controller process
exits. This provides the LXC driver with details about how
the container shutdown - normally, or abnormally (crashed),
thus allowing the driver to emit better libvirt events.
Emitting the event in the LXC controller requires a few
little tricks with the RPC service. Simply calling the
virNetServiceClientSendMessage does not work, since this
merely queues the message for asynchronous processing.
In addition the main event loop is no longer running at
the point the event is emitted, so no I/O is processed.
Thus after invoking virNetServiceClientSendMessage it is
necessary to mark the client as being in "delayed close"
mode. Then the event loop is run again, until the client
completes its close - this happens only after the queued
message has been fully transmitted. The final complexity
is that it is not safe to run virNetServerQuit() from the
client close callback, since that is invoked from a
context where the server is locked. Thus a zero-second
timer is used to trigger shutdown of the event loop,
causing the controller to finally exit.
* src/Makefile.am: Add rules for generating RPC protocol
files and dispatch methods
* src/lxc/lxc_controller.c: Emit an RPC event immediately
before exiting
* src/lxc/lxc_domain.h: Record the shutdown reason
given by the controller
* src/lxc/lxc_monitor.c, src/lxc/lxc_monitor.h: Register
RPC program and event handler. Add callback to let
driver receive EXIT event.
* src/lxc/lxc_process.c: Use monitor exit event to decide
what kind of domain event to emit
* src/lxc/lxc_protocol.x: Define wire protocol for LXC
controller monitor.
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
Move the cgroup setup code out of the lxc_controller.c file
and into lxc_cgroup.{c,h}. This reduces the size of the
lxc_controller.c file and paves the way to invoke cgroup
setup from lxc_driver.c instead of lxc_controller.c in the
future
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since we are not yet using the virNetServerPtr object for running
the event loop, we can't use virNetServerQuit(). Instead set the
global 'quit' flag in libvirt_lxc
In preparation for introducing a full RPC protocol for
libvirt_lxc, switch over to using the virNetServer APIs
for the monitor connection
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
While it is not currently used elsewhere in libvirt, the code
for finding a free loop device & associating a file with it
is not LXC specific. Move it into the viffile.{c,h} file where
potentially shared code is more commonly kept.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the cgroup object into virLXCControllerPtr and rename
all the setup methods to include 'Cgroup' in their name
if appropriate
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the monitor FDs into the virLXCControllerPtr object
removing the need for the 'struct lxcMonitor' object
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virLXCControllerRun method is getting a little too large,
and about 50% of its code is related to setting up a /dev/pts
mount. Move the latter out into a dedicated method
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the security manager object into the virLXCControllerPtr
object. Also simplify the code creating it in the first place
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Move the list of loop device FDs into the virLXCControllerPtr
object and make sure that virLXCControllerStopInit will
close them all
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Turn 'struct lxc_console' into virLXCControllerConsolePtr and make it
a part of virLXCControllerPtr
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Keep a record of the init PID in the virLXCController object
and create a virLXCControllerStopInit method for killing this
process
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>
The LXC controller code is having to pass around an ever increasing
number of parameters between methods. To make the code more managable
introduce a virLXCControllerPtr to hold all this state, starting with
the container name and virDomainDefPtr object
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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
