The last Viktor's effort to fix the race and memory corruption unfortunately
wasn't complete in the case the close callback was not registered in an
connection. At that time, the trail of event's that I'll describe later could
still happen and corrupt the memory or cause a crash of the client (including
the daemon in case of a p2p migration).
Consider the following prerequisities and trail of events:
Let's have a remote connection to a hypervisor that doesn't have a close
callback registered and the client is using the event loop. The crash happens in
cooperation of 2 threads. Thread E is the event loop and thread W is the worker
that does some stuff. R denotes the remote client.
1.) W - The client finishes everything and sheds the last reference on the client
2.) W - The virObject stuff invokes virConnectDispose that invokes doRemoteClose
3.) W - the remote close method invokes the REMOTE_PROC_CLOSE RPC method.
4.) W - The thread is preempted at this point.
5.) R - The remote side receives the close and closes the socket.
6.) E - poll() wakes up due to the closed socket and invokes the close callback
7.) E - The event loop is preempted right before remoteClientCloseFunc is called
8.) W - The worker now finishes, and frees the conn object.
9.) E - The remoteClientCloseFunc accesses the now-freed conn object in the
attempt to retrieve pointer for the real close callback.
10.) Kaboom, corrupted memory/segfault.
This patch tries to fix this by introducing a new object that survives the
freeing of the connection object. We can't increase the reference count on the
connection object itself or the connection would never be closed, as the
connection is closed only when the reference count reaches zero.
The new object - virConnectCloseCallbackData - is a lockable object that keeps
the pointers to the real user registered callback and ensures that the
connection callback is either not called if the connection was already freed or
that the connection isn't freed while this is being called.
remoteDeserializeTypedParameters can now be called with either
preallocated params array (size of which is announced by nparams) or it
can allocate params array according to the number of parameters received
from the server.
Like virNodeDeviceCreateXML, virNodeDeviceLookupSCSIHostByWWN
has to be treated specially when generating the RPC codes. Also
new rules are added in fixup_name to keep the name SCSIHostByWWN.
Upon successful return of virNetClientStreamEventAddCallback() the
allocated cbdata field will be freed by virNetClientStreamEventRemoveCallback()
as cbOpaque using the free function remoteStreamCallbackFree().
This patch adds a new API, virDomainOpenChannel, that uses streams to
connect to a virtio channel on a guest. This creates a secure
communication channel between a guest and a libvirt client.
This behaves the same as virDomainOpenConsole, except on channels
instead of console/serial/parallel devices.
https://bugzilla.redhat.com/show_bug.cgi?id=866524
Since the virConnect object is not locked wholely when doing
virConenctDispose, a thread can get the lock and thus might
cause the race.
Detected by valgrind:
==23687== Invalid read of size 4
==23687== at 0x38BAA091EC: pthread_mutex_lock (pthread_mutex_lock.c:61)
==23687== by 0x3FBA919E36: remoteClientCloseFunc (remote_driver.c:337)
==23687== by 0x3FBA936BF2: virNetClientCloseLocked (virnetclient.c:688)
==23687== by 0x3FBA9390D8: virNetClientIncomingEvent (virnetclient.c:1859)
==23687== by 0x3FBA851AAE: virEventPollRunOnce (event_poll.c:485)
==23687== by 0x3FBA850846: virEventRunDefaultImpl (event.c:247)
==23687== by 0x40CD61: vshEventLoop (virsh.c:2128)
==23687== by 0x3FBA8626F8: virThreadHelper (threads-pthread.c:161)
==23687== by 0x38BAA077F0: start_thread (pthread_create.c:301)
==23687== by 0x33F68E570C: clone (clone.S:115)
==23687== Address 0x4ca94e0 is 144 bytes inside a block of size 312 free'd
==23687== at 0x4A0595D: free (vg_replace_malloc.c:366)
==23687== by 0x3FBA8588B8: virFree (memory.c:309)
==23687== by 0x3FBA86AAFC: virObjectUnref (virobject.c:145)
==23687== by 0x3FBA8EA767: virConnectClose (libvirt.c:1458)
==23687== by 0x40C8B8: vshDeinit (virsh.c:2584)
==23687== by 0x41071E: main (virsh.c:3022)
The above race is caused by the eventLoop thread tries to handle
the net client event by calling the callback set by:
virNetClientSetCloseCallback(priv->client,
remoteClientCloseFunc,
conn, NULL);
I.E. remoteClientCloseFunc, which lock/unlock the virConnect object.
This patch is to fix the bug by setting the callback to NULL when
doRemoteClose.
Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virStateInitialize method and several cgroups methods were
using an 'int privileged' parameter or similar for dual-state
values. These are better represented with the bool type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
* src/remote/remote_protocol.x: message definition
* src/remote/remote_driver.c: Register driver function
* src/remote_protocol-structs: Test case
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This will simplify the refactoring of the ESX storage driver to support
a VMFS and an iSCSI backend.
One of the tasks the storage driver needs to do is to decide which backend
driver needs to be invoked for a given request. This approach extends
virStoragePool and virStorageVol to store extra parameters:
1. privateData: stores pointer to respective backend storage driver.
2. privateDataFreeFunc: stores cleanup function pointer.
virGetStoragePool and virGetStorageVol are modfied to accept these extra
parameters as user params. virStoragePoolDispose and virStorageVolDispose
checks for cleanup operation if available.
The private data pointer allows the ESX storage driver to store a pointer
to the used backend with each storage pool and volume. This avoids the need
to detect the correct backend in each storage driver function call.
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>
It turns out that calling virNodeGetCPUMap(conn, NULL, NULL, 0)
is both useful, and with Viktor's patches, common enough to
optimize. Since this interface hasn't been released yet, we
can change the RPC call.
A bit more background on the optimization - learning the cpu count
is a single file read (/sys/devices/system/cpu/possible), but
learning the number of online cpus can possibly trigger a file
read per cpu, depending on the age of the kernel, and all wasted
if the caller passed NULL for both arguments.
* src/nodeinfo.c (nodeGetCPUMap): Avoid bitmap when not needed.
* src/remote/remote_protocol.x (remote_node_get_cpu_map_args):
Supply two separate flags for needed arguments.
* src/remote/remote_driver.c (remoteNodeGetCPUMap): Update
caller.
* daemon/remote.c (remoteDispatchNodeGetCPUMap): Likewise.
* src/remote_protocol-structs: Regenerate.
- Defined the wire protocol format for virNodeGetCPUMap and its
arguments
- Implemented remote method invocation (remoteNodeGetCPUMap)
- Implemented method dispatcher (remoteDispatchNodeGetCPUMap)
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This patch adds support for SUSPEND_DISK event; both lifecycle and
separated. The support is added for QEMU, machines are changed to
PMSUSPENDED, but as QEMU sends SHUTDOWN afterwards, the state changes
to shut-off. This and much more needs to be done in order for libvirt
to work with transient devices, wake-ups etc. This patch is not
aiming for that functionality.
When auto-probing hypervisor drivers, the conn->uri field will
initially be NULL. Care must be taken not to access members
when doing auth lookups in the config 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/
Currently we search along the hard-coded names:
SBINDIR "/libvirtd"
SBINDIR "/libvirtd_dbg"
but if the environment variable $LIBVIRTD_PATH is set to the
name of the libvirtd binary, that is used instead. Fix the
error message so it accurately reflects current behaviour
($PATH is NOT searched).
This is very short, because almost everything is autogenerated. All
that's needed are:
* src/remote/remote_driver.c: add pointer to autogenerated
remoteNetworkUpdate to the function table for the remote
network driver.
* src/remote/remote_protocol.x: add the "args" struct and add one more
item to the remote_procedure enum for this function.
* src/remote_protocol-struct: update to match remote_protocol.x
Relatively straightforward. Our decision to make block job
speed a long keeps haunting us on new API.
* src/remote/remote_protocol.x (remote_domain_block_commit_args):
New struct.
* src/remote/remote_driver.c (remote_driver): Enable it.
* src/remote_protocol-structs: Regenerate.
* src/rpc/gendispatch.pl (long_legacy): Exempt another bandwidth.
* src/rpc/gendispatch.pl: (virNodeSetMemoryParameters is the
the special one which needs a connection object as the first
argument, improve the generator to support it).
* daemon/remote.c: (Implement the server side handler for
virDomainGetMemoryParameters)
* src/remote/remote_driver.c: (Implement the client side handler
for virDomainGetMemoryParameters)
* src/remote/remote_protocol.x: (New RPC procedures for the two
new APIs and structs to represent the args and ret for it)
* src/remote_protocol-structs: Likewise
The RPC generator doesn't support returning list of object yet, this patch
does the work manually.
* daemon/remote.c:
Implement the server side handler remoteDispatchConnectListAllSecrets.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllSecrets.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_SECRETS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The RPC generator doesn't support returning list of object yet, this patch
do the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllNWFilters.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllNWFilters.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_NWFILTERS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The RPC generator doesn't support returning list of object yet, this patch
does the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllNodeDevices.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllNodeDevices.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_INTERFACES and
The RPC generator doesn't support returning list of object yet, this patch
do the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllInterfaces.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllInterfaces.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_INTERFACES and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The remote driver first looks at the libvirt auth config file to
fill in any credentials. It then invokes the auth callback for
any remaining credentials. It was accidentally invoking the
auth callback even if there were not any more credentials
required.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The RPC generator doesn't support returning list of object, this patch
do the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchConnectListAllNetworks.
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllNetworks.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_NETWORKS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The RPC generator doesn't returning support list of object, this
patch do the work manually.
* daemon/remote.c:
Implemente the server side handler remoteDispatchStoragePoolListAllVolumes
* src/remote/remote_driver.c:
Add remote driver handler remoteStoragePoolListAllVolumes
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_STORAGE_POOL_LIST_ALL_VOLUMES and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The RPC generator doesn't support returning list of object, this patch does
the work manually.
* daemon/remote.c:
Implement the server side handler remoteDispatchConnectListAllStoragePools
* src/remote/remote_driver.c:
Add remote driver handler remoteConnectListAllStoragePools.
* src/remote/remote_protocol.x:
New RPC procedure REMOTE_PROC_CONNECT_LIST_ALL_STORAGE_POOLS and
structs to represent the args and ret for it.
* src/remote_protocol-structs: Likewise.
The recent virDomainQemuAgentCommand addition is part of 0.10.0;
also, grouping all libvirt-qemu.so callbacks together makes them
easier to identify.
* src/libvirt_qemu.syms: Fix release symbol.
* src/qemu/qemu_driver.c (qemuDriver): Likewise.
* src/remote/remote_driver.c (remote_driver): Likewise.
* src/driver.h (_virDriver): Group qemu-specific callbacks.
Add qemuDomainAgentCommand() which is generated automatically,
for .qemuDomainArbitraryAgentCommand to remote driver.
Signed-off-by: MATSUDA Daiki <matsudadik@intellilink.co.jp>
Introduce 2 APIs to support emulator threads in remote driver.
1) remoteDomainPinEmulator: call driver api, such as qemudDomainPinEmulator.
2) remoteDomainGetEmulatorPinInfo: call driver api, such as qemudDomainGetEmulatorPinInfo.
They are similar to remoteDomainPinVcpuFlags and remoteDomainGetVcpuPinInfo.
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
This patch adds URI options to support libssh2 transport in the remote
driver.
A new transport sceme is introduced eg. "qemu+libssh2://..." that
utilizes the libssh2 code added in previous patches.
The libssh2 code requires the authentication callback to be able to
perform keyboard-interactive authentication or to ask t passprhases or
add host keys to known hosts database.
Added URI components:
- known_hosts - path to a knownHosts file in OpenSSH format to check
for known ssh host keys
- known_hosts_verify - how to deal with server key verification:
* "normal" (default) - ask to add new keys
* "auto" - automaticaly add new keys
* "ignore" - don't validate host keys
- sshauth - authentication methods to use. Default is
"agent,privkey,keyboard-interactive". It's a comma separated
string of methods to try while authenticating. The order is
preserved. Some of the methods may require additional
parameters.
Locations of the known_hosts file and private keys are set to default
values if they're present. (~/.ssh/known_hosts, ~/.ssh/id_rsa,
~/.ssh/id_dsa)
This patch updates libvirt's API to allow applications to inspect the
full list of security labels of a domain.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
