It is possible to deadlock libvirt by having a domain with XML
longer than PIPE_BUF, and by writing a hook script that closes
stdin early. This is because libvirt was keeping a copy of the
child's stdin read fd open, which means the write fd in the
parent will never see EPIPE (remember, libvirt should always be
run with SIGPIPE ignored, so we should never get a SIGPIPE signal).
Since there is no error, libvirt blocks waiting for a write to
complete, even though the only reader is also libvirt. The
solution is to ensure that only the child can act as a reader
before the parent does any writes; and then dealing with the
fallout of dealing with EPIPE.
Thankfully, this is not a security hole - since the only way to
trigger the deadlock is to install a custom hook script, anyone
that already has privileges to install a hook script already has
privileges to do any number of other equally disruptive things
to libvirt; it would only be a security hole if an unprivileged
user could install a hook script to DoS a privileged user.
* src/util/command.c (virCommandRun): Close parent's copy of child
read fd earlier.
(virCommandProcessIO): Don't let EPIPE be fatal; the child may
be done parsing input.
* tests/commandhelper.c (main): Set up a SIGPIPE situation.
* tests/commandtest.c (test20): Trigger it.
* tests/commanddata/test20.log: New file.
Although src/util/viratomic.h has been added to the repo, up until now
it hasn't been used. Stefan Berger is using it in his proposed dhcp
snooping patches, and an rpm build with those patches failed due to
viratomic.h not being packed up with the rest of the sources.
glibc 2.15 (on Fedora 17) coupled with explicit disabling of
optimization during development dies a painful death:
In file included from /usr/include/limits.h:27:0,
from /usr/lib/gcc/x86_64-redhat-linux/4.7.0/include/limits.h:169,
from /usr/lib/gcc/x86_64-redhat-linux/4.7.0/include/syslimits.h:7,
from /usr/lib/gcc/x86_64-redhat-linux/4.7.0/include/limits.h:34,
from util/bitmap.c:26:
/usr/include/features.h:314:4: error: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Werror=cpp]
cc1: all warnings being treated as errors
Work around this by only conditionally defining _FORTIFY_SOURCE,
in the case where glibc can actually use it. The trick is using
AH_VERBATIM instead of AC_DEFINE.
* m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Squelch
_FORTIFY_SOURCE when needed to avoid glibc #warnings.
I noticed this during 'make syntax-check':
prohibit_readlink
grep: Unmatched ( or \(
* cfg.mk (exclude_file_name_regexp--sc_prohibit_readlink): Fix
mismatched '('.
EBADF errors are logged as warnings as they normally indicate a double
close bug. This patch also provides VIR_MASS_CLOSE helper to be user in
the only case of mass close after fork when EBADF should rather be
ignored.
If users *-edit but make a mistake in XML all changes are
permanently lost. However, if virsh is not running within
a script we can ask user if he wants to re-edit the file
and correct the mistakes.
Currently, we either generate some cmd*Edit commands (cmdPoolEdit
and cmdNetworkEdit) via sed script or copy the body of cmdEdit
(e.g. cmdInterfaceEdit, cmdNWFilterEdit, etc.). This fact makes
it harder to implement any new feature to our editing system.
Therefore switch to new implementation - define macros to:
- dump XML (EDIT_GET_XML)
- take an action if XML wasn't changed,
usually just vshPrint() (EDIT_NOT_CHANGED)
- define new object (EDIT_DEFINE) - the edited XML is in @doc_edited
- free object defined by EDIT_DEFINE (EDIT_FREE)
and #include "virsh-edit.c"
With support for multiple IP addresses per interface in place, this patch
now adds support for multiple IP addresses per interface for the DHCP
snooping code.
Testing:
Since the infrastructure I tested this with does not provide multiple IP
addresses per MAC address (anymore), I either had to plug the VM's interface
from the virtual bride connected directly to the infrastructure to virbr0
to get a 2nd IP address from dnsmasq (kill and run dhclient inside the VM)
or changed the lease file (/var/run/libvirt/network/nwfilter.leases) and
restart libvirtd to have a 2nd IP address on an existing interface.
Note that dnsmasq can take a lease timeout parameter as part of the --dhcp-range
command line parameter, so that timeouts can be tested that way
(--dhcp-range 192.168.122.2,192.168.122.254,120). So, terminating and restarting
dnsmasq with that parameter is another choice to watch an IP address disappear
after 120 seconds.
Regards,
Stefan
The goal of this patch is to prepare for support for multiple IP
addresses per interface in the DHCP snooping code.
Move the code for the IP address map that maps interface names to
IP addresses into their own file. Rename the functions on the way
but otherwise leave the code as-is. Initialize this new layer
separately before dependent layers (iplearning, dhcpsnooping)
and shut it down after them.
This patch adds DHCP snooping support to libvirt. The learning method for
IP addresses is specified by setting the "CTRL_IP_LEARNING" variable to one of
"any" [default] (existing IP learning code), "none" (static only addresses)
or "dhcp" (DHCP snooping).
Active leases are saved in a lease file and reloaded on restart or HUP.
The following interface XML activates and uses the DHCP snooping:
<interface type='bridge'>
<source bridge='virbr0'/>
<filterref filter='clean-traffic'>
<parameter name='CTRL_IP_LEARNING' value='dhcp'/>
</filterref>
</interface>
All filters containing the variable 'IP' are automatically adjusted when
the VM receives an IP address via DHCP. However, multiple IP addresses per
interface are silently ignored in this patch, thus only supporting one IP
address per interface. Multiple IP address support is added in a later
patch in this series.
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Currently, monitoring QEMU virtual machines with standard Unix
sysadmin tools is harder than it has to be. The QEMU command line is
often miles long and mostly redundant, it's hard to tell which process
is which.
This patch reorders the QEMU -name argument to be the first, so it's
immediately visible in "ps x", htop and "atop -c" output.
This patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=827519
The problem is that an interface with type='hostdev' will have an
alias of the form "hostdev%d", while the function that looks through
existing netdevs to determine the name to use for a new addition will
fail if there's an existing entry that does not match the form
"net%d".
This is another of the handful of places that need an exception due to
the hybrid nature of <interface type='hostdev'> (which is not exactly
an <interface> or a <hostdev>, but is both at the same time).
If we migrate to fd, spec->fwdType is not MIGRATION_FWD_DIRECT,
we will close spec->dest.fd.local in qemuMigrationRun(). So we
should set spec->dest.fd.local to -1 in qemuMigrationRun().
Bug present since 0.9.5 (commit 326176179).
Wen Congyang reported that we have a double-close bug if we fail
virFDStreamOpenInternal, since childfd duplicated one of the fds[]
array contents. In truth, since we always transfer both members
of fds to other variables, we should close the fds through those
other names, and just use fds[] for pipe().
Bug present since 0.9.0 (commit e886237a).
* src/fdstream.c (virFDStreamOpenFileInternal): Swap scope of
childfd and fds[], to avoid a double close.
KAMEZAWA Hiroyuki reported a nasty double-free bug when virCommand
is used to convert a string into input to a child command. The
problem is that the poll() loop of virCommandProcessIO would close()
the write end of the pipe in order to let the child see EOF, then
the caller virCommandRun() would also close the same fd number, with
the second close possibly nuking an fd opened by some other thread
in the meantime. This in turn can have all sorts of bad effects.
The bug has been present since the introduction of virCommand in
commit f16ad06f.
This is based on his first attempt at a patch, at
https://bugzilla.redhat.com/show_bug.cgi?id=823716
* src/util/command.c (_virCommand): Drop inpipe member.
(virCommandProcessIO): Add argument, to avoid closing caller's fd
without informing caller.
(virCommandRun, virCommandNewArgs): Adjust clients.
Apart from the non-sanlock check build, there is also a little fix for
qemu (EXTRA_DIST had qemu.conf and others inside even if the build was
supposed to be without qemu).
Some of our rules used $(PERL), while others used 'perl'. Always
using the variable allows a developer to point to a different (often
better) perl than the default one found on $PATH.
* daemon/Makefile.am ($(srcdir)/remote_dispatch.h): s/perl/$(PERL).
* src/Makefile.am ($(srcdir)/remote/remote_client_bodies.h)
(PDWTAGS, %protocol.c, %_probes.stp): Likewise.
Without this fix, a VPATH build (such as used by ./autobuild.sh)
fails with messages like:
make[3]: Entering directory `/home/remote/eblake/libvirt-tmp2/build/daemon'
../../build-aux/augeas-gentest.pl libvirtd.conf ../../daemon/test_libvirtd.aug.in test_libvirtd.aug
cannot read libvirtd.conf: No such file or directory at ../../build-aux/augeas-gentest.pl line 38.
Since the test files are not part of the tarball, we can generate
them into the build dir, but rather than create a subdirectory
just for the test file, it is easier to test them directly in
libvirt.git/src.
* daemon/Makefile.am (AUG_GENTEST): Factor out definition.
(test_libvirtd.aug): Look for correct file.
* src/Makefile.am (AUG_GENTEST): Use $(PERL).
(qemu/test_libvirtd_qemu.aug, lxc/test_libvirtd_lxc.aug)
(locking/test_libvirt_sanlock.aug): Rename to avoid subdirectories.
(check-augeas-qemu, check-augeas-lxc, check-augeas-sanlock): Reflect
location of built tests.
* configure.ac (PERL): Substitute perl.
Autoconf 2.60 and later insist on using ${datarootdir}, rather than
the derived ${datadir} (although the latter defaults to the former,
it is possible to set configure arguments so that they differ):
config.status: creating libvirt.pc
config.status: WARNING: 'libvirt.pc.in' seems to ignore the --datarootdir setting
This patch follows the autoconf manual's suggestions for how to
support 2.59 (RHEL 5) and newer simultaneously.
* libvirt.pc.in (datarootdir): Define, so ${datadir} will not ignore
datarootdir when using newer autoconf.
Currently, we are logging only one side of pipes we
create in virCommandRequireHandshake(); This is enough
in cases where pipe2() returns two consecutive FDs. However,
it is not guaranteed and it may return any FDs.
Therefore, it's wise to log the other ends as well.
When getting number of CPUs the host has assigned, there was always
number "1" returned. Even though all lxc domains with no pinning
launched by libvirt run on all pCPUs (by default, no matter what's the
number), we should at least return the same number as the user
specified when creating the domain.
I added libvirt_qemu_probes.h into BUILT_SOURCES. That makes it
generated, but most probably it is not the clearest way how to do
that, but it fixes the build.
A while back I wrote the attached code to demonstrate how to use
events and serial console to create a serial console that stays up
even when the VM is down. It might need some work, as I am not
terribly strong with Python.
* examples/python/consolecallback.py: New file.
* examples/python/Makefile.am (EXTRA_DIST): Ship it.
The previous patch fixed an incremental build, but missed that on
a fresh checkout, we now have nothing left that stops make from
nuking libvirt_qemu_probes.o.
* src/Makefile.am ($(libvirt_driver_qemu_la_SOURCES)): Delete,
since this variable is empty.
(.PRECIOUS): Add %_probes.o, so they don't get nuked as an
intermediate by-product after creating %_probes.lo.
The moment you specify a _DEPENDENCIES, older automake (stupidly)
assumes that you will specify _all_ dependencies for that target.
This stupidity has been fixed in automake 1.12, but we cannot rely on
newer automake everywhere. For libvirt_la_DEPENDENCIES, we took
care of providing the full list, but for libvirt_qemu_la_DEPENDENCIES,
we were missing the dependency on libvirt_qemu_impl.la, which resulted
in a failed build:
make[3]: Entering directory `/home/ajia/Workspace/libvirt/src'
CCLD libvirt_driver_qemu.la
libtool: link: `libvirt_qemu_probes.lo' is not a valid libtool object
* src/Makefile.am (libvirt_driver_qemu_la_DEPENDENCIES): Delete;
automake does a better job if it does the entire job.
strncpy is generally evil - it runs the risk of missing NUL
termination, and more often than not wastes time zeroing way
more bytes than strictly necessary. We've avoided this evil
in our virStrncpy wrapper, except for places where we forgot
to use the wrapper; meanwhile, we have also added an even
higher layer wrapper for setting virTypedParameter values.
* tools/virsh.c (cmdMemtune, cmdBlkdeviotune): Use modern API.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_strncpy): Tighten.
Gnulib finally relaxed the isatty license, needed as first mentioned here:
https://www.redhat.com/archives/libvir-list/2012-February/msg01022.html
Other improvements include better syntax-check rules (we can delete one
of ours now that it is a duplicate) and better compiler warning usage.
* .gnulib: Update to latest, for isatty.
* cfg.mk (sc_prohibit_strncpy): Drop a now-redundant rule.
* bootstrap.conf (gnulib_modules): Add isatty.
* bootstrap: Resync from gnulib.
==3240== 23 bytes in 1 blocks are definitely lost in loss record 242 of 744
==3240== at 0x4C2A4CD: malloc (vg_replace_malloc.c:236)
==3240== by 0x8077537: __vasprintf_chk (vasprintf_chk.c:82)
==3240== by 0x509C677: virVasprintf (stdio2.h:199)
==3240== by 0x509C733: virAsprintf (util.c:1912)
==3240== by 0x1906583A: qemudStartup (qemu_driver.c:679)
==3240== by 0x511991D: virStateInitialize (libvirt.c:809)
==3240== by 0x40CD84: daemonRunStateInit (libvirtd.c:751)
==3240== by 0x5098745: virThreadHelper (threads-pthread.c:161)
==3240== by 0x7953D8F: start_thread (pthread_create.c:309)
==3240== by 0x805FF5C: clone (clone.S:115)
To ensure consistent error reporting of invalid arguments,
provide a number of predefined helper methods & macros.
- An arg which must not be NULL:
virCheckNonNullArgReturn(argname, retvalue)
virCheckNonNullArgGoto(argname, label)
- An arg which must be NULL
virCheckNullArgGoto(argname, label)
- An arg which must be positive (ie 1 or greater)
virCheckPositiveArgGoto(argname, label)
- An arg which must not be 0
virCheckNonZeroArgGoto(argname, label)
- An arg which must be zero
virCheckZeroArgGoto(argname, label)
- An arg which must not be negative (ie 0 or greater)
virCheckNonNegativeArgGoto(argname, label)
* src/libvirt.c, src/libvirt-qemu.c,
src/nodeinfo.c, src/datatypes.c: Update to use
virCheckXXXX macros
* po/POTFILES.in: Add libvirt-qemu.c and virterror_internal.h
* src/internal.h: Define macros for checking invalid args
* src/util/virterror_internal.h: Define macros for reporting
invalid args
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Libtool is picky about linking against a module library (aka a .so);
giving lots of warnings like this in the tests directory:
CCLD networkxml2argvtest
*** Warning: Linking the executable networkxml2argvtest against the loadable module
*** libvirt_driver_network.so is not portable!
Fix that by splitting things into a convenience library which can
be used directly by the tests, and making the real .so just wrap
the convenience library.
Based on a suggestion by Daniel P. Berrange.
* configure.ac (--with-driver-modules): Fix help test.
* src/Makefile.am (libvirt_driver_xen.la, libvirt_driver_libxl.la)
(libvirt_driver_qemu.la, libvirt_driver_lxc.la)
(libvirt_driver_uml.la): Factor into new convenience libraries.
* tests/Makefile.am (xen_LDADDS, qemu_LDADDS, lxc_LDADDS)
(networkxml2argvtest_LDADD): Link to convenience libraries, not
shared libraries.
There was no rule forcing libvirt_qemu_probes.o to be built
before libvirt_qemu_probes.lo was used. Also libvirtd was
still referencing the .o file, rather than the .lo file.
Both the .lo and .o file must be listed as DEPENDENCIES,
otherwise libtool will unhelpfully delete the .o file
once the .lo file is created.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The CoTaskMemFree function requires the ole32 DLL to be
linked against. Currently this is only done for the
VirtualBox driver. Also add it to libvirt_util.la
* configure.ac: Unconditionally add ole32 DLL to Win32
* src/Makefile.am: Link old32 to libvirt_util.la
When adding new config file parameters, the corresponding
additions to the augeas lens' are constantly forgotten.
Also there are augeas test cases, these don't catch the
error, since they too are never updated.
To address this, the augeas test cases need to be auto-generated
from the example config files.
* build-aux/augeas-gentest.pl: Helper to generate an
augeas test file, substituting in elements from the
example config files
* src/Makefile.am, daemon/Makefile.am: Switch to
auto-generated augeas test cases
* daemon/test_libvirtd.aug, daemon/test_libvirtd.aug.in,
src/locking/test_libvirt_sanlock.aug,
src/locking/test_libvirt_sanlock.aug.in,
src/lxc/test_libvirtd_lxc.aug,
src/lxc/test_libvirtd_lxc.aug.in,
src/qemu/test_libvirtd_qemu.aug,
src/qemu/test_libvirtd_qemu.aug.in: Remove example
config file data, replacing with a ::CONFIG:: placeholder
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently all the config options are listed under a 'vnc_entry'
group. Create a bunch of new groups & move options to the
right place
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add nmissing 'host_uuid' entry to libvirtd.conf lens and
rename spice_passwd to spice_password in qemu.conf lens
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Instead of doing
# example_config
use
#example_config
so it is possible to programatically uncomment example config
options, as distinct from their comment/descriptions
Also delete rogue trailing comma not allowed by lens
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add an impl of +virGetUserRuntimeDirectory, virGetUserCacheDirectory
virGetUserConfigDirectory and virGetUserDirectory for Win32 platform.
Also create stubs for non-Win32 platforms which lack getpwuid_r()
In adding these two helpers were added virFileIsAbsPath and
virFileSkipRoot, along with some macros VIR_FILE_DIR_SEPARATOR,
VIR_FILE_DIR_SEPARATOR_S, VIR_FILE_IS_DIR_SEPARATOR,
VIR_FILE_PATH_SEPARATOR, VIR_FILE_PATH_SEPARATOR_S
All this code was adapted from GLib2 under terms of LGPLv2+ license.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
