We read from the agent until seeing a \r\n pair to indicate a completed
reply or event. To avoid memory denial-of-service though, we must have a
size limit on amount of data we buffer. 10 MB is large enough that it
ought to cope with normal agent replies, and small enough that we're not
consuming unreasonable mem.
This is identical to the flaw we had reading from the QEMU monitor
as CVE-2018-5748, so rather embarrassing that we forgot to fix
the agent code at the same time.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
We forgot to free alloced mem when failed to
dup ifname or macaddr.
Also use VIR_STEAL_PTR to simplify codes.
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
qemuAgentNotifyEvent accesses monitor structure and is called on qemu
reset/shutdown/suspend events under domain lock. Other monitor
functions on the other hand take monitor lock and don't hold domain lock.
Thus it is possible to have risky simultaneous access to the structure
from 2 threads. Let's take monitor lock here to make access exclusive.
In case of 0 filesystems *info is not set while according
to virDomainGetFSInfo contract user should call free on it even
in case of 0 filesystems. Thus we need to properly set
it. NULL will be enough as free eats NULLs ok.
We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:
virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix
We can do better:
virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We can receive NULL as sync reply in two situations. First
is garbage sync reply and this situation is handled by
resending sync message. Second is different cases
of rebooting guest, destroing domain etc and we can
give more meaningful error message. Actually we have
this error message in qemuAgentCommand already which checks
for the same sitatuion. AFAIK case with mon->running
is just to be safe on adding some future(?) cases of
returning NULL reply.
We can easily handle receiving garbage on sync. We don't
have to make client deal with this situation. We just
need to resend sync command but this time garbage is
not be possible.
When we wait for sync reply we can receive delayed
reply to syncs or commands that were sent erlier. We can
safely skip them until we receive sync reply with correct id.
There is no much sense report this situation to client.
Actually with a bit of "luck" if we involve client into
this the play can go on forever: send sync 0, receive
sync reply -1, send sync 1, receive reply 0 ...
After sync is sent we can receive garbare and this is not error.
Consider next regular case:
1. libvirtd sends sync
2. qga sends partial sync reply and die
3. libvirtd sends sync
4. qga sends sync reply
5. libvirtd receives garbage
(half of first reply and second reply together)
We should handle this situation as it is recoverable.
Next sync can succeed. Let's report reply is NULL,
it will be converted to the VIR_ERR_AGENT_UNSYNCED
which signals client to retry.
Errors in qemuAgentIOProcessLine stop agent IO processing just
like any regular IO error, however some of current errors
that this functions spawns are false positives. Consider
next case for example:
1. send sync (unsynced state)
2. receive sync reply (sync established)
3. command send, but timeout occured (unsynced state)
4. receive command reply
Last IO triggers error because current code ignores
only delayed syncs when unsynced
We should not treat any delayed reply as error in unsynced
state. Until client and qga are not in sync delayed reply to any
command is possible. msg == NULL is the exact criterion
that we are not in sync.
Both qemu monitor and agent print the same
log on HUANGUP event, which would be confusing
when reading libvirtd log.
This patch will give a different log message to them.
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Documentation for the "guest-set-vcpus" command describes a proper
algorithm how to set vcpus. This patch makes the following changes:
- state of cpus that has not changed is not updated
- if the command was partially successful the command is re-tried with
the rest of the arguments to get a proper error message
- code is more robust against malicious guest agent
- fix testsuite to the new semantics
We had both and the only difference was that the latter also included
information about multifunction setting. The problem with that was that
we couldn't use functions made for only one of the structs (e.g.
parsing). To consolidate those two structs, use the one in virpci.h,
include that in domain_conf.h and add the multifunction member in it.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
In a few places in libvirt we busy-wait for events, for example qemu
creating a monitor socket. This is problematic because:
- We need to choose a sufficiently small polling period so that
libvirt doesn't add unnecessary delays.
- We need to choose a sufficiently large polling period so that
the effect of busy-waiting doesn't affect the system.
The solution to this conflict is to use an exponential backoff.
This patch adds two functions to hide the details, and modifies a few
places where we currently busy-wait.
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Replace the nonsensical debug statement by adding the expected event
code into the existing debug statement.
Since the monitor code always notifies the agent on guest
reboot/shutdown even if that was not initiated by the agent the warning
emitted later is bogus and pollutes the logs in such cases. Delete it
and keep just the original debug message where this info can be
inferred.
We have this function qemuAgentNotifyEvent() which is supposed to
be called from thread pool responsible for processing qemu
monitor events. The function then should wake up other thread
that is waiting for a guest to shutdown or reboot. However, if we
have received a different error a warning is printed out. This
warning lacks info on which event is expected.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
While this is no functional change, whole channel definition is
going to be needed very soon. Moreover, while touching this obey
const correctness rule in qemuAgentOpen() - so far it was passed
regular pointer to channel config even though the function is
expected to not change pointee at all. Pass const pointer
instead.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The internal representation of a JSON array counts the items in
size_t. However, for some reason, when asking for the count it's
reported as int. Firstly, we need the function to return a signed
type as it's returning -1 on an error. But, not every system has
integer the same size as size_t. Therefore, lets return ssize_t.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
While CPU0 was made unpluggable in Linux a while ago it's not desirable
to unplug it since some parts of the kernel (suspend-to-ram) still
depend on it.
This patch fixes the vCPU selection code in libvirt so that it will not
be disabled.
Most virDomainDiskIndexByName callers do not care about the index; what
they really want is a disk def pointer.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=890648
So, imagine you've issued an API that involves guest agent. For
instance, you want to query guest's IP addresses. So the API acquires
QUERY_JOB, locks the guest agent and issues the agent command.
However, for some reason, guest agent replies to initial ping
correctly, but then crashes tragically while executing real command
(in this case guest-network-get-interfaces). Since initial ping went
well, libvirt thinks guest agent is accessible and awaits reply to the
real command. But it will never come. What will is a monitor event.
Our handler (processSerialChangedEvent) will try to acquire
MODIFY_JOB, which will fail obviously because the other thread that's
executing the API already holds a job. So the event handler exits
early, and the QUERY_JOB is never released nor ended.
The way how to solve this is to put flag somewhere in the monitor
internals. The flag is called @running and agent commands are issued
iff the flag is set. The flag itself is set when we connect to the
agent socket. And unset whenever we see DISCONNECT event from the
agent. Moreover, we must wake up all the threads waiting for the
agent. This is done by signalizing the condition they're waiting on.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When we shutdown/reboot a guest using agent-mode, if the guest itself blocks infinitely,
libvirt would block in qemuAgentShutdown() forever.
Thus, we set a timeout for shutdown/reboot, from our experience, 60 seconds would be fine.
Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com>
Signed-off-by: Wang Yufei <james.wangyufei@huawei.com>
Now that we allow HW address to be not present on our RPC layer,
don't error out if qemu-ga hasn't provided any.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
By querying the qemu guest agent with the QMP command
"guest-network-get-interfaces" and converting the received JSON
output to structured objects.
Although "ifconfig" is deprecated, IP aliases created by "ifconfig"
are supported by this API. The legacy syntax of an IP alias is:
"<ifname>:<alias-name>". Since we want all aliases to be clubbed
under parent interface, simply stripping ":<alias-name>" suffices.
Note that IP aliases formed by "ip" aren't visible to "ifconfig",
and aliases created by "ip" do not have any specific name. But
we are lucky, as qemu guest agent detects aliases created by both.
src/qemu/qemu_agent.h:
* Define qemuAgentGetInterfaces
src/qemu/qemu_agent.c:
* Implement qemuAgentGetInterface
src/qemu/qemu_driver.c:
* New function qemuGetDHCPInterfaces
* New function qemuDomainInterfaceAddresses
src/remote_protocol-sructs:
* Define new structs
tests/qemuagenttest.c:
* Add new test: testQemuAgentGetInterfaces
Test cases for IP aliases, 0 or multiple ipv4/ipv6 address(es)
Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>
Get mounted filesystems list, which contains hardware info of disks and its
controllers, from QEMU guest agent 2.2+. Then, convert the hardware info
to corresponding device aliases for the disks.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Not every error message from qemu-ga has to have the 'class' field
filled out. For instance, I've seen this error message lately:
qemuAgentCheckError:1047 : unable to execute QEMU agent command \
{"execute":"guest-set-time"}: \
{"error":{"desc":"Invalid parameter type, expected: integer"}}
However, this got translated into rather generic error message:
internal error: unable to execute QEMU agent command
'guest-set-time': unknown QEMU command error
So we've dropped better error message in favor of a generic one.
This is due to our code which expects 'class' which is not
present here.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Coverity found that on error paths, the 'arg' value wasn't be cleaned
up. Followed the example in qemuAgentSetVCPUs() where upon successful call
to qemuAgentCommand() the 'cpus' is set to NULL; otherwise, when cleanup
occurs the free the memory for 'arg'
A command to freeze a part of mounted file systems is implemented in
upstream QEMU-guest-agent with a name of 'guest-fsfreeze-freeze-list'.
This fixes the name of the command used to partial fsfreeze in qemu driver
when 'mountpoints' option is specified to virDomainFSFreeze API.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Old gcc complains about shadowing 'sync' variable:
../../src/qemu/qemu_agent.c: In function 'qemuAgentSetTime':
../../src/qemu/qemu_agent.c:1737: warning: declaration of 'sync'
shadows a global declaration [-Wshadow]
/usr/include/unistd.h:464: warning: shadowed declaration is here
[-Wshadow]
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
One caveat though, qemu-ga is expecting time and returning time
in nanoseconds. With all the buffering and propagation delay, the
time is already wrong once it gets to the qemu-ga, but there's
nothing we can do about it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
With this patch, virDomainFSFreeze will pass the mountpoints argument
to qemu guest agent. For example,
virDomainFSFreeze(dom, {"/mnt/vol1", "/mnt/vol2"}, 2, 0)
will issue qemu guest agent command:
{"execute":"guest-fsfreeze-freeze",
"arguments":{"mountpoints":["/mnt/vol1","/mnt/vol2"]}}
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
Commit 5b3492fa aimed to fix this and caught one error but exposed
another one. When agent command is being executed and the thread
waiting for the reply is woken up by an event (e.g. EOF in case of
shutdown), the command finishes with no data (rxObject == NULL), but
no error is reported, since this might be desired by the caller
(e.g. suspend through agent). However, in other situations, when the
data are required (e.g. getting vCPUs), we proceed to getting desired
data out of the reply, but none of the virJSON*() functions works well
with NULLs. I chose the way of a new parameter for qemuAgentCommand()
function that specifies whether reply is required and behaves
according to that.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1058149
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
On all the places where qemuAgentComand() was called, we did a check
for errors in the reply. Unfortunately, some of the places called
qemuAgentCheckError() without checking for non-null reply which might
have resulted in a crash.
So this patch makes the error-checking part of qemuAgentCommand()
itself, which:
a) makes it look better,
b) makes the check mandatory and, most importantly,
c) checks for the errors if and only if it is appropriate.
This actually fixes a potential crashers when qemuAgentComand()
returned 0, but reply was NULL. Having said that, it *should* fix the
following bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1058149
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When an error occurred in qemuAgentIO, it will be saved in mon->lastError,
but it will not be freed at the end. Present since commit c160ce33;
and compare to commit 9cc8a5af fixing the same problem in qemu_monitor.c.
==22219== 54 bytes in 1 blocks are definitely lost in loss record 982 of 1,379
==22219== at 0x4C26B9B: malloc (vg_replace_malloc.c:263)
==22219== by 0x8520521: strdup (in /lib64/libc-2.11.3.so)
==22219== by 0x52E99CB: virStrdup (virstring.c:554)
==22219== by 0x52B44C4: virCopyError (virerror.c:195)
==22219== by 0x52B5123: virCopyLastError (virerror.c:312)
==22219== by 0x10905877: qemuAgentIO (qemu_agent.c:660)
==22219== by 0x52B6122: virEventPollDispatchHandles (vireventpoll.c:501)
==22219== by 0x52B7AEA: virEventPollRunOnce (vireventpoll.c:647)
==22219== by 0x52B5C1B: virEventRunDefaultImpl (virevent.c:274)
==22219== by 0x54181FD: virNetServerRun (virnetserver.c:1112)
==22219== by 0x11EF4D: main (libvirtd.c:1513)
Signed-off-by: Zhou Yimin <zhouyimin@huawei.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Although this isn't apparently needed for the guest agent itself, the
test I will be adding later depends on the newline as a separator of
messages to process.
A part of the returned monitor response was freed twice and caused
crashes of the daemon when using guest agent cpu count retrieval.
# virsh vcpucount dom --guest
Introduced in v1.0.6-48-gc6afcb0
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>
The qemu guest agent allows to online and offline CPUs from the
perspective of the guest. This patch adds helpers that call
'guest-get-vcpus' and 'guest-set-vcpus' guest agent functions and
convert the data for internal libvirt usage.
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.
I built without yajl support, and noticed a strange failure message
in qemumonitorjsontest:
2013-02-22 16:12:37.503+0000: 19812: error : virJSONValueToString:1119 : internal error No JSON parser implementation is available
2013-02-22 16:12:37.503+0000: 19812: error : qemuMonitorJSONCommandWithFd:253 : out of memory
While a later patch will fix the test to skip when json is not present,
this patch avoids overriding the more useful error message from
virJSONValueToString returning NULL.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCommandWithFd):
Don't override message.
(qemuMonitorJSONCheckError): Don't print NULL.
* src/qemu/qemu_agent.c (qemuAgentCommand): Don't override message.
(qemuAgentCheckError): Don't print NULL.
(qemuAgentArbitraryCommand): Properly fail on OOM.
The virDomainObj, qemuAgent, qemuMonitor, lxcMonitor classes
all require a mutex, so can be switched to use virObjectLockable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently all classes must directly inherit from virObject.
This allows for arbitrarily deep hierarchy. There's not much
to this aside from chaining up the 'dispose' handlers from
each class & providing APIs to check types.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Error messages produced while dispatching guest agent commands didn't
have an apparent reference to the fact that they are dealing with guest
agent commands. This patch fixes up some of the messages to contain that
reference.
using qemu guest agent. As said in previous patch,
@mountPoint must be NULL and @flags zero because
qemu guest agent doesn't support these arguments
yet. If qemu learns them, we can start supporting
them as well.
There are a number of process related functions spread
across multiple files. Start to consolidate them by
creating a virprocess.{c,h} file
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/
When reboot using qemu guest agent was requested, qemu driver kept
waiting for SHUTDOWN event from qemu. However, such event is never
emitted during guest reboot and qemu driver would keep waiting forever.
Before commit 05447e3af4, qemuAgentCommand
blocked until it got a reply or appropriate event. When new parameter
was added to qemuAgentCommand in the above commit, all existing callers
of it were updated in a wrong way changing them from blocking to
5-seconds timeout.
Currently, when guest agent is configured but not responsive
(e.g. due to appropriate service not running in the guest)
we return VIR_ERR_INTERNAL_ERROR. Both are wrong. Therefore
we need to introduce new error code to reflect this case.
Add @seconds variable to qemuAgentSend().
When @timemout is true, @seconds controls how long to wait for a
response (if @seconds is VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT,
default to QEMU_AGENT_WAIT_TIME).
In addition, @seconds must be >= 0 or VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT.
If @timeout is false, @seconds is ignored.
Signed-off-by: MATSUDA Daiki <matsudadik@intellilink.co.jp>
While the QEMU monitor/agent do not want JSON strings pretty
printed, other parts of libvirt might. Instead of hardcoding
QEMU's desired behaviour in virJSONValueToString(), add a
boolean flag to control pretty printing
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
With latest changes to qemu-ga success on some commands is not reported
anymore, e.g. guest-shutdown or guest-suspend-*. However, errors are
still being reported. Therefore, we need to find different source of
indication if operation was successful. Events.
Currently, qemu GA is not providing 'desc' field for errors like
we are used to from qemu monitor. Therefore, we fall back to this
general 'unknown error' string. However, GA is reporting 'class' which
is not perfect, but much more helpful than generic error string.
Thus we should fall back to class firstly and if even no class
is presented, then we can fall back to that generic string.
Before this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': unknown QEMU command error
After this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': The command has not been found
If we issue guest command and GA is not running, the issuing thread
will block endlessly. We can check for GA presence by issuing
guest-sync with unique ID (timestamp). We don't want to issue real
command as even if GA is not running, once it is started, it process
all commands written to GA socket.
The code is splattered with a mix of
sizeof foo
sizeof (foo)
sizeof(foo)
Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There is now a standard QEMU guest agent that can be installed
and given a virtio serial channel
<channel type='unix'>
<source mode='bind' path='/var/lib/libvirt/qemu/f16x86_64.agent'/>
<target type='virtio' name='org.qemu.guest_agent.0'/>
</channel>
The protocol that runs over the guest agent is JSON based and
very similar to the JSON monitor. We can't use exactly the same
code because there are some odd differences in the way messages
and errors are structured. The qemu_agent.c file is based on
a combination and simplification of qemu_monitor.c and
qemu_monitor_json.c
* src/qemu/qemu_agent.c, src/qemu/qemu_agent.h: Support for
talking to the agent for shutdown
* src/qemu/qemu_domain.c, src/qemu/qemu_domain.h: Add thread
helpers for talking to the agent
* src/qemu/qemu_process.c: Connect to agent whenever starting
a guest
* src/qemu/qemu_monitor_json.c: Make variable static
