Normally dnsmasq will send a default route (the address of the host in
the network definition) to any client requesting an address via
DHCP. On an isolated network this makes no sense, as we have iptables
to prevent any traffic going out via that interface, so anything sent
that way would be dropped anyway.
This extra/unusable default route becomes problematic if you have
setup a guest with multiple network interfaces, with one connected to
an isolated network and another that provides connectivity to the
outside (example - one interface directly connecting to a physical
interface via macvtap, with a second connected to an isolated network
so that the host and guest can communicate (macvtap doesn't support
guest<->host communication without an external switch that supports
vepa, or reflecting all traffic back)). In this case, if the guest
chooses the default route of the isolated network, the guest will not
be able to get network traffic beyond the host.
To prevent dnsmasq from sending a default route, you can tell it to
send 0 bytes of data for the default route option (option number 3)
with --dhcp-option=3 (normally the data to send for the option would
follow the option number; no extra data means "don't send this option").
I have checked on RHEL5 (a good representative of the oldest supported
libvirt platforms) and its version of dnsmasq (2.45) does support
--dhcp-option, so this shouldn't create any compatibility problems.
As pointed on CVE-2011-1146, some API forgot to check the read-only
status of the connection for entry point which modify the state
of the system or may lead to a remote execution using user data.
The entry points concerned are:
- virConnectDomainXMLToNative
- virNodeDeviceDettach
- virNodeDeviceReAttach
- virNodeDeviceReset
- virDomainRevertToSnapshot
- virDomainSnapshotDelete
* src/libvirt.c: fix the above set of entry points to error on read-only
connections
By default, all dnsmasq processes share the same leases file. libvirt
also uses the --dhcp-lease-max option to control the maximum number of
leases allowed. The problem is that libvirt puts in a number equal to
the number of addresses in the range for the one network handled by a
single instance of dnsmasq, but dnsmasq checks the total number of
leases in the file (which could potentially contain many more).
The solution is to tell each instance of dnsmasq to create and use its
own leases file. (/var/lib/libvirt/network/<net-name>.leases).
This file is created by dnsmasq when it starts, but not deleted when
it exists. This is fine when the network is just being stopped, but if
the leases file was left around when a network was undefined, we could
end up with an ever-increasing number of dead files - instead, we
explicitly unlink the leases file when a network is undefined.
Note that Ubuntu carries a patch against an older version of libvirt for this:
hhttps://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/713071
ttp://bazaar.launchpad.net/~serge-hallyn/ubuntu/maverick/libvirt/bugall/revision/109
I was certain I'd also seen discussion of this on libvir-list or
libvirt-users, but couldn't find it.
This fixes a regression introduced in commit ad48df, and reported on
the libvirt-users list:
https://www.redhat.com/archives/libvirt-users/2011-March/msg00018.html
The problem in that commit was that we began searching a list of ip
address definitions (rather than just having one) to look for a dhcp
range or static host; when we didn't find any, our pointer (ipdef) was
left at NULL, and when ipdef was NULL, we returned without starting up
dnsmasq.
Previously dnsmasq was started even without any dhcp ranges or static
entries, because it's still useful for DNS services.
Another problem I noticed while investigating was that, if there are
IPv6 addresses, but no IPv4 addresses of any kind, we would jump out
at an ever higher level in the call chain.
This patch does the following:
1) networkBuildDnsmasqArgv() = all uses of ipdef are protected from
NULL dereference. (this patch doesn't change indentation, to make
review easier. The next patch will change just the
indentation). ipdef is intended to point to the first IPv4 address
with DHCP info (or the first IPv4 address if none of them have any
dhcp info).
2) networkStartDhcpDaemon() = if the loop looking for an ipdef with
DHCP info comes up empty, we then grab the first IPv4 def from the
list. Also, instead of returning if there are no IPv4 defs, we just
return if there are no IP defs at all (either v4 or v6). This way a
network that is IPv6-only will still get dnsmasq listening for DNS
queries.
3) in networkStartNetworkDaemon() - we will startup dhcp not just if there
are any IPv4 addresses, but also if there are any IPv6 addresses.
Currently a single storage volume with a broken backing file will disable the
whole storage pool. This can happen when the backing file is on some
unavailable network storage or if the backing volume is deleted, while the
storage volumes using it remain.
Since the storage pool can not be re-activated, re-creating the missing
or deleting the now useless volumes using libvirt only is not possible.
Fixing this is a little bit tricky:
1. virStorageBackendProbeTarget() only detects the missing backing file,
if the backing file format is not explicitly specified. If the
backing file is created using
kvm-img create -f qcow2 -o backing_fmt=qcow2,backing_file=... ...
no error is detected at this stage.
The new return code -3 signals that the backing file could not be
opened.
2. The backingStore.format must be >= 0, since values < 0 would break
virStorageVolTargetDefFormat() when dumping the XML data such as
<format type='...'/>
Because of this the format is faked as VIR_STORAGE_FILE_RAW.
3. virStorageBackendUpdateVolTargetInfo() always opens the backing file
and thus always detects a missing backing file.
Since it "only" updates the capacity, allocation, owner, group, mode
and SELinux label, just ignore errors at this stage, print an error
message and continue.
4. Using vol-dump on a broken volume still doesn't work, but at least
vol-destroy and pool-refresh do work now.
To reproduce:
dir=$(mktemp -d)
virsh pool-create-as tmp dir '' '' '' '' "$dir"
virsh vol-create-as --format qcow2 tmp back 1G
virsh vol-create-as --format qcow2 --backing-vol-format qcow2 --backing-vol back tmp cow 1G
virsh vol-delete --pool tmp back
virsh pool-refresh tmp
After the last step, the pool will be gone (because it was not persistent). As
long as the now broken image stays in the directory, you will not be able to
re-create or re-start the pool.
Signed-off-by: Philipp Hahn <hahn@univention.de>
This patch introduces a new libvirt API (virDomainSetMemoryFlags) and
a flag (virDomainMemoryModFlags).
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Opening raw network devices with the intent of passing those fds to
qemu is worth an audit point. This makes a multi-part audit: first,
we audit the device(s) that libvirt opens on behalf of the MAC address
of a to-be-created interface (which can independently succeed or
fail), then we audit whether qemu actually started the network device
with the same MAC (so searching backwards for successful audits with
the same MAC will show which fd(s) qemu is actually using). Note that
it is possible for the fd to be successfully opened but no attempt
made to pass the fd to qemu (for example, because intermediate
nwfilter operations failed) - no interface start audit will occur in
that case; so the audit for a successful opened fd does not imply
rights given to qemu unless there is a followup audit about the
attempt to start a new interface.
Likewise, when a network device is hot-unplugged, there is only one
audit message about the MAC being discontinued; again, searching back
to the earlier device open audits will show which fds that qemu quits
using (and yes, I checked via /proc/<qemu-pid>/fd that qemu _does_
close out the fds associated with an interface on hot-unplug). The
code would require much more refactoring to be able to definitively
state which device(s) were discontinued at that point, since we
currently don't record anywhere in the XML whether /dev/vhost-net was
opened for a given interface.
* src/qemu/qemu_audit.h (qemuAuditNetDevice): New prototype.
* src/qemu/qemu_audit.c (qemuAuditNetDevice): New function.
* src/qemu/qemu_command.h (qemuNetworkIfaceConnect)
(qemuPhysIfaceConnect, qemuOpenVhostNet): Adjust prototype.
* src/qemu/qemu_command.c (qemuNetworkIfaceConnect)
(qemuPhysIfaceConnect, qemuOpenVhostNet): Add audit points and
adjust parameters.
(qemuBuildCommandLine): Adjust caller.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
Since libvirt always passes /dev/net/tun to qemu via fd, we should
never trigger the cases where qemu tries to directly open the
device. Therefore, it is safer to deny the cgroup device ACL.
* src/qemu/qemu_cgroup.c (defaultDeviceACL): Remove /dev/net/tun.
* src/qemu/qemu.conf (cgroup_device_acl): Reflect this change.
qemu driver in libvirt gained support for creating domain snapshots
almost a year ago in libvirt 0.8.0. Since then we enabled QMP support
for qemu >= 0.13.0 but QMP equivalents of {save,load,del}vm commands are
not implemented in current qemu (0.14.0) so the domain snapshot support
is not very useful.
This patch detects when the appropriate QMP command is not implemented
and tries to use human-monitor-command (aka HMP passthrough) to run
it's HMP equivalent.
JSON monitor command implementation can now just directly call text
monitor implementation and it will be automatically encapsulated into
QMP's human-monitor-command.
Some qemu monitor event handlers were issuing inadequate warning when
virDomainSaveStatus() failed. They copied the message from I/O error
handler without customizing it to provide better information on why
virDomainSaveStatus() was called.
For newer qemu-img, the help string for "backing file format" is
"[-F backing_fmt]".
Fix the wrong logic error by commit e997c268.
* src/storage/storage_backend.c
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.
Although the cgroup device ACL controller path can be worked out
by researching the code, it is more efficient to include that
information directly in the audit message.
* src/util/cgroup.h (virCgroupPathOfController): New prototype.
* src/util/cgroup.c (virCgroupPathOfController): Export.
* src/libvirt_private.syms: Likewise.
* src/qemu/qemu_audit.c (qemuAuditCgroup): Use it.
Device names can be manipulated, so it is better to also log
the major/minor device number corresponding to the cgroup ACL
changes that libvirt made. This required some refactoring
of the relatively new qemu cgroup audit code.
Also, qemuSetupChardevCgroup was only auditing on failure, not success.
* src/qemu/qemu_audit.h (qemuDomainCgroupAudit): Delete.
(qemuAuditCgroup, qemuAuditCgroupMajor, qemuAuditCgroupPath): New
prototypes.
* src/qemu/qemu_audit.c (qemuDomainCgroupAudit): Rename...
(qemuAuditCgroup): ...and drop a parameter.
(qemuAuditCgroupMajor, qemuAuditCgroupPath): New functions, to
allow listing device major/minor in audit.
(qemuAuditGetRdev): New helper function.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Adjust callers.
* src/qemu/qemu_cgroup.c (qemuSetupDiskPathAllow)
(qemuSetupHostUsbDeviceCgroup, qemuSetupCgroup)
(qemuTeardownDiskPathDeny): Likewise.
(qemuSetupChardevCgroup): Likewise, fixing missing audit.
* src/qemu/qemu_audit.c (qemuDomainHostdevAudit): Avoid use of
"type", which has a pre-defined meaning.
(qemuDomainCgroupAudit): Likewise, as well as "item".
I noticed these while testing 'make dist'.
Parsing ./../src/util/event.c
Function comment for virEventRegisterDefaultImpl lacks description of return value
Function comment for virEventRunDefaultImpl lacks description of return value
Parsing ./../src/util/virterror.c
Missing comment for function virSetErrorLogPriorityFunc
* src/util/event.c (virEventRegisterDefaultImpl)
(virEventRunDefaultImpl): Document return types.
* src/util/virterror.c (virSetErrorLogPriorityFunc): Provide docs.
virRun gives pretty useful error output, let's not overwrite it unless there
is a good reason. Some places were providing more information about what
the commands were _attempting_ to do, however that's usually less useful from
a debugging POV than what actually happened.
as described at
http://wiki.debian.org/ToolChain/DSOLinkinghttps://fedoraproject.org/wiki/UnderstandingDSOLinkChange
otherwise the build fails on current Debian unstable with:
CCLD libvirtd
/usr/bin/ld: ../src/.libs/libvirt_driver_lxc.a(libvirt_driver_lxc_la-lxc_container.o): undefined reference to symbol 'capng_apply'
/usr/bin/ld: note: 'capng_apply' is defined in DSO //usr/lib/libcap-ng.so.0 so try adding it to the linker command line
CCLD libvirtd
/usr/bin/ld: ../src/.libs/libvirt_driver_storage.a(libvirt_driver_storage_la-storage_backend.o): undefined reference to symbol 'fgetfilecon'
/usr/bin/ld: note: 'fgetfilecon' is defined in DSO //lib/libselinux.so.1 so try adding it to the linker command line
//lib/libselinux.so.1: could not read symbols: Invalid operation
and similar errors.
On cygwin:
CC libvirt_driver_security_la-security_dac.lo
security/security_dac.c: In function 'virSecurityDACSetProcessLabel':
security/security_dac.c:618: warning: format '%d' expects type 'int', but argument 7 has type 'uid_t' [-Wformat]
We've done this before (see src/util/util.c).
* src/security/security_dac.c (virSecurityDACSetProcessLabel): On
cygwin, uid_t is a 32-bit long.
On cygwin:
CC libvirt_util_la-cgroup.lo
util/cgroup.c: In function 'virCgroupKillRecursiveInternal':
util/cgroup.c:1458: warning: implicit declaration of function 'virCgroupNew' [-Wimplicit-function-declaration]
* src/util/cgroup.c (virCgroupKill): Don't build on platforms
where virCgroupNew is unsupported.
Apparently some signals found on Unix are not exposed, this led
to a compilation failure
* src/util/logging.c: make code related to each signal dependant
upon the definition of that signal
The way to detach a USB disk is the same as that to detach a SCSI
disk. Rename this function and we can use it to detach a USB disk.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
When I use newest libvirt to save a domain, libvirtd will be deadlock.
Here is the output of gdb:
(gdb) thread 3
[Switching to thread 3 (Thread 0x7f972a1fc710 (LWP 30265))]#0 0x000000351fe0e034 in __lll_lock_wait () from /lib64/libpthread.so.0
(gdb) bt
at qemu/qemu_driver.c:2074
ret=0x7f972a1fbbe0) at remote.c:2273
(gdb) thread 7
[Switching to thread 7 (Thread 0x7f9730bcd710 (LWP 30261))]#0 0x000000351fe0e034 in __lll_lock_wait () from /lib64/libpthread.so.0
(gdb) bt
(gdb) p *(virMutexPtr)0x6fdd60
$2 = {lock = {__data = {__lock = 2, __count = 0, __owner = 30261, __nusers = 1, __kind = 0, __spins = 0, __list = {__prev = 0x0, __next = 0x0}},
__size = "\002\000\000\000\000\000\000\000\065v\000\000\001", '\000' <repeats 26 times>, __align = 2}}
(gdb) p *(virMutexPtr)0x1a63ac0
$3 = {lock = {__data = {__lock = 2, __count = 0, __owner = 30265, __nusers = 1, __kind = 0, __spins = 0, __list = {__prev = 0x0, __next = 0x0}},
__size = "\002\000\000\000\000\000\000\000\071v\000\000\001", '\000' <repeats 26 times>, __align = 2}}
(gdb) info threads
7 Thread 0x7f9730bcd710 (LWP 30261) 0x000000351fe0e034 in __lll_lock_wait () from /lib64/libpthread.so.0
6 Thread 0x7f972bfff710 (LWP 30262) 0x000000351fe0b43c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
5 Thread 0x7f972b5fe710 (LWP 30263) 0x000000351fe0b43c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
4 Thread 0x7f972abfd710 (LWP 30264) 0x000000351fe0b43c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
* 3 Thread 0x7f972a1fc710 (LWP 30265) 0x000000351fe0e034 in __lll_lock_wait () from /lib64/libpthread.so.0
2 Thread 0x7f97297fb710 (LWP 30266) 0x000000351fe0b43c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
1 Thread 0x7f9737aac800 (LWP 30260) 0x000000351fe0803d in pthread_join () from /lib64/libpthread.so.0
The reason is that we will try to lock some object in callback function, and we may call event API with locking the same object.
In the function virEventDispatchHandles(), we unlock eventLoop before calling callback function. I think we should
do the same thing in the function virEventCleanupTimeouts() and virEventCleanupHandles().
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Not all applications have an existing event loop they need
to integrate with. Forcing them to implement the libvirt
event loop integration APIs is an undue burden. This just
exposes our simple poll() based implementation for apps
to use. So instead of calling
virEventRegister(....callbacks...)
The app would call
virEventRegisterDefaultImpl()
And then have a thread somewhere calling
static bool quit = false;
....
while (!quit)
virEventRunDefaultImpl()
* daemon/libvirtd.c, tools/console.c,
tools/virsh.c: Convert to public event loop APIs
* include/libvirt/libvirt.h.in, src/libvirt_private.syms: Add
virEventRegisterDefaultImpl and virEventRunDefaultImpl
* src/util/event.c: Implement virEventRegisterDefaultImpl
and virEventRunDefaultImpl using poll() event loop
* src/util/event_poll.c: Add full error reporting
* src/util/virterror.c, include/libvirt/virterror.h: Add
VIR_FROM_EVENTS
The event loop implementation is used by more than just the
daemon, so move it into the shared area.
* daemon/event.c, src/util/event_poll.c: Renamed
* daemon/event.h, src/util/event_poll.h: Renamed
* tools/Makefile.am, tools/console.c, tools/virsh.c: Update
to use new virEventPoll APIs
* daemon/mdns.c, daemon/mdns.c, daemon/Makefile.am: Update
to use new virEventPoll APIs
* src/util/logging.c: fix virLogDumpAllFD() to avoid snprintf, simplify
the code and provide more useful signal descriptions. Also remove an
unused variable.
For qemu names the primary vga as "qxl-vga":
1) if vram is specified for 2nd qxl device:
-vga qxl -global qxl-vga.vram_size=$SIZE \
-device qxl,id=video1,vram_size=$SIZE,...
2) if vram is not specified for 2nd qxl device, (use the default
set by global):
-vga qxl -global qxl-vga.vram_size=$SIZE \
-device qxl,id=video1,...
For qemu names all qxl devices as "qxl":
1) if vram is specified for 2nd qxl device:
-vga qxl -global qxl.vram_size=$SIZE \
-device qxl,id=video1,vram_size=$SIZE ...
2) if vram is not specified for 2nd qxl device:
-vga qxl -global qxl-vga.vram_size=$SIZE \
-device qxl,id=video1,...
"-global" is the only way to define vram_size for the primary qxl
device, regardless of how qemu names it, (It's not good a good
way, as original idea of "-global" is to set a global default for
a driver property, but to specify vram for first qxl device, we
have to use it).
For other qxl devices, as they are represented by "-device", could
specify it directly and seperately for each, and it overrides the
default set by "-global" if specified.
v1 - v2:
* modify "virDomainVideoDefaultRAM" so that it returns 16M as the
default vram_size for qxl device.
* vram_size * 1024 (qemu accepts bytes for vram_size).
* apply default vram_size for qxl device for which vram_size is
not specified.
* modify "graphics-spice" tests (more sensiable vram_size)
* Add an argument of virDomainDefPtr type for qemuBuildVideoDevStr,
to use virDomainVideoDefaultRAM in qemuBuildVideoDevStr).
v2 - v3:
* Modify default video memory size for qxl device from 16M to 24M
* Update codes to be consistent with changes on qemu_capabilities.*
virLogEmergencyDumpAll() allows to dump the content of the
debug buffer from within a signal handler. It saves to all
log file or stderr if none is found
* src/util/logging.h src/util/logging.c: add the new API
and cleanup the old virLogDump code
* src/libvirt_private.syms: exports it as a private symbol
