Our virCommand module allows us to set a pidfile for commands we
want to spawn. The caller constructs the string of pidfile path
and then uses virCommandSetPidFile() to tell the module to write
the pidfile once the command is ran. This usually works, but has
two flaws:
1) the child process does not hold the pidfile open & locked.
Therefore, the caller (or anybody else) can't use our fancy
virPidFileForceCleanupPath() function to kill the command
afterwards. Also, for everybody else on the system it's
needlessly harder to check if the pid from the pidfile is still
alive or not.
2) if the caller ever makes a mistake and passes the same pidfile
path for two different commands, the start of the second command
will overwrite the pidfile even though the first command might
still be running.
NOTE that this temporarily renders some command spawning
unusable, specifically those code patterns where both
virCommandSetPidFile() is used together with instructing spawned
command to acquire pidfile itself. Fortunately, there is only one
occurrence of such pattern and it is in
qemuProcessStartManagedPRDaemon(). This is fixed in next commit.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Historically threads are given a name based on the C function,
and this name is just used inside libvirt. With OS level thread
naming this name is now visible to debuggers, but also has to
fit in 15 characters on Linux, so function names are too long
in some cases.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
On FreeBSD 12 the default ulimit settings allow for 100,000
open file descriptors. As a result spawning processes in
libvirt is abominably slow. Fortunately FreeBSD has long
since provided a good solution in the form of closefrom(),
which closes all FDs equal to or larger than the specified
parameter.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This addreses portability to Windows and standardizes
error reporting. This fixes a number of places which
failed to set O_CLOEXEC or failed to report errors.
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
A large part of the virCommand code is still built on
WIN32, despite the fact that the core fork() & execve()
functions are not available. So despite succesfully
building most of the code, at runtime the APIs are
none the less unusuable. With the elimination of GNULIB
many of the APIs being used in this code no longer have
portability wrappers/shims for Windows.
Rather than try to add portability wrappers, or do tests
for each individual function, it is clearer to conditionalize
nearly all of the code using #ifdef WIN32.
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
This saves us from allocating vars upfront, since GLib deals with
that for us.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Libvirtd has set SIGPIPE to ignored, and virFork resets all signal
handlers to the defaults. But child process may write logs to
stderr/stdout, that may generate SIGPIPE if journald has stopped.
So set SIGPIPE to a dummy no-op handler before unmask signals in
virFork(), and the handler will get reset to SIG_DFL when execve()
runs. Now we can delete sigaction() call entirely in virExec().
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Wang Yechao <wang.yechao255@zte.com.cn>
The function now does not return an error so we can drop it fully.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The function now does not return an error so we can drop it fully.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Replace all occurrences of
if (VIR_STRDUP(a, b) < 0)
/* effectively dead code */
with:
a = g_strdup(b);
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Since commit 44e7f02915
util: rewrite auto cleanup macros to use glib's equivalent
VIR_AUTOPTR aliases to g_autoptr. Replace all of its use by the GLib
macro version.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Since commit 44e7f02915
util: rewrite auto cleanup macros to use glib's equivalent
VIR_AUTOFREE is just an alias for g_autofree. Use the GLib macros
directly instead of our custom aliases.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Use G_GNUC_UNUSED from GLib instead of ATTRIBUTE_UNUSED.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Now that 100% of libvirt code is forbidden in a SUID environment,
we no longer need to worry about whether env variables are
trustworthy or not. The virt-login-shell setuid program, which
does not link to any libvirt code, will purge all environment
variables, except $TERM, before invoking the virt-login-shell-helper
program which uses libvirt.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Now that 100% of libvirt code is forbidden in a SUID environment,
we no longer need to worry about whether env variables are
trustworthy or not. The virt-login-shell setuid program, which
does not link to any libvirt code, will purge all environment
variables, except $TERM, before invoking the virt-login-shell-helper
program which uses libvirt.
Thus we only need one API for env passthrough in virCommand.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Remove the ATTRIBUTE_NONNULL(1) from virCommandSetSendBuffer()
prototype since we are checking for '!cmd' and move the initialization
if 'i' after the test for '!cmd'.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Message-Id: <20190726205633.2041912-4-stefanb@linux.vnet.ibm.com>
Extend virCommandProcessIO to include the send buffers in the poll
loop.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Mark a virCommand's inpipe (write-end of pipe) as non-blocking so that it
will never block when we were to try to write too many bytes to it while
it doesn't have the capacity to hold them.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Convert the struct pollfd *fds to be allocated rather than residing
on the stack. This prepares it for the next patch where the size of
the array of fds becomes dynamic.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Implement virCommandSetSendBuffer() that allows the caller to pass a
file descriptor and buffer to virCommand. virCommand will write the
buffer into the file descriptor. That file descriptor could be the
write end of a pipe or one of the file descriptors of a socketpair.
The other file descriptor should be passed to the launched process to
read the data from.
Only implement the function to allocate memory for send buffers
and to free them later on.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Avoid the chance that sysconf(_SC_OPEN_MAX) returns -1 and thus
would cause virBitmapNew would attempt to allocate a very large
bitmap.
Found by Coverity
Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by: Peter Krempa <pkrempa@redhat.com>
When spawning a child process, between fork() and exec() we close
all file descriptors and keep only those the caller wants us to
pass onto the child. The problem is how we do that. Currently, we
get the limit of opened files and then iterate through each one
of them and either close() it or make it survive exec(). This
approach is suboptimal (although, not that much in default
configurations where the limit is pretty low - 1024). We have
/proc where we can learn what FDs we hold open and thus we can
selectively close only those.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
I will optimize this code a bit in the next commit. But for that
it is better if the code lives in a separate function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The only use of this code was removed by:
commit be78814ae0
Author: Michal Privoznik <mprivozn@redhat.com>
Date: Thu Apr 2 14:41:17 2015 +0200
virNetSocketNewConnectUNIX: Use flocks when spawning a daemon
less than a year after it was first introduced in
commit 1b807f92db
Author: Martin Kletzander <mkletzan@redhat.com>
Date: Wed Jul 16 08:00:19 2014 +0200
rpc: pass listen FD to the daemon being started
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The idea of virCommand* APIs is that a possible error that
occurred while constructing cmd line is kept in virCommand
struct. If that's the case all subsequent calls to virCommand*()
are NO-OPs or they return an error. Well,
virCommandPassFDGetFDIndex() is not honoring that.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
'viralloc.h' does not provide any type or macro which would be necessary
in headers. Prevent leakage of the inclusion.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Some modules/libraries within QEMU could make use of the XDG_ vars when
writing their data to the disk. Define the most common XDG variables
and point them to the specific driver's libDir, i.e.
XDG_CACHE_HOME -> /var/lib/libvirt/<driver>/.cache
XDG_DATA_HOME -> /var/lib/libvirt/<driver>/.local/share
XDG_CONFIG_HOME -> /var/lib/libvirt/<driver>/.config
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Use of VIR_AUTOPTR and virString is confusing as it's a list and not a
single pointer. Replace it by VIR_AUTOSTRINGLIST as string lists are
basically the only sane NULL-terminated list we can have.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
The memory allocated by VIR_REALLOC_N() is uninitialized,
which means it's not possible to figure out whether any
output was produced at all after the fact.
Since we don't care about the previous contents of buffers,
if any, use VIR_FREE() followed by VIR_ALLOC_N() instead.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The QEMU command line arguments are very long and currently all written
on a single line to /var/log/libvirt/qemu/$GUEST.log. This introduces
logic to add line breaks after every env variable and "-" optional
argument, and every positional argument. This will create a clearer log
file, which will in turn present better in bug reports when people cut +
paste from the log into a bug comment.
An example log file entry now looks like this:
2018-12-14 12:57:03.677+0000: starting up libvirt version: 5.0.0, qemu version: 3.0.0qemu-3.0.0-1.fc29, kernel: 4.19.5-300.fc29.x86_64, hostname: localhost.localdomain
LC_ALL=C \
PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin \
HOME=/home/berrange \
USER=berrange \
LOGNAME=berrange \
QEMU_AUDIO_DRV=none \
/usr/bin/qemu-system-ppc64 \
-name guest=guest,debug-threads=on \
-S \
-object secret,id=masterKey0,format=raw,file=/home/berrange/.config/libvirt/qemu/lib/domain-33-guest/master-key.aes \
-machine pseries-2.10,accel=tcg,usb=off,dump-guest-core=off \
-m 1024 \
-realtime mlock=off \
-smp 1,sockets=1,cores=1,threads=1 \
-uuid c8a74977-ab18-41d0-ae3b-4041c7fffbcd \
-display none \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=23,server,nowait \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=utc \
-no-shutdown \
-boot strict=on \
-device qemu-xhci,id=usb,bus=pci.0,addr=0x1 \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
-msg timestamp=on
2018-12-14 12:57:03.730+0000: shutting down, reason=failed
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The virCommand APIs do not expect to be given a NULL value for an arg
name or value. Such a mistake can lead to execution of the wrong
command, as the NULL may prematurely terminate the list of args.
Detect this and report suitable error messages.
This identified a flaw in the storage test which was passing a NULL
instead of the volume path. This flaw was then validated by an incorrect
set of qemu-img args as expected data.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Require that all headers are guarded by a symbol named
LIBVIRT_$FILENAME
where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.
Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
All of the ones being removed are pulled in by internal.h. The only
exception is sanlock which expects the application to include <stdint.h>
before sanlock's headers, because sanlock prototypes use fixed width
int, but they don't include stdint.h themselves, so we have to leave
that one in place.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
The documentation to virCommandWait() function states that if
@exitstatus is NULL and command finished with error -1 is
returned. In other words, if @dryRunCallback is set and returns
an error (by setting its @status argument to a nonzero value) we
must propagate this error properly honouring the documentation
(and also regular run).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
By making use of GNU C's cleanup attribute handled by the
VIR_AUTOPTR macro for declaring aggregate pointer variables,
majority of the calls to *Free functions can be dropped, which
in turn leads to getting rid of most of our cleanup sections.
Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
By making use of GNU C's cleanup attribute handled by the
VIR_AUTOFREE macro for declaring scalar variables, majority
of the VIR_FREE calls can be dropped, which in turn leads to
getting rid of most of our cleanup sections.
Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Using the new VIR_DEFINE_AUTOPTR_FUNC macro defined in
src/util/viralloc.h, define a new wrapper around an existing
cleanup function which will be called when a variable declared
with VIR_AUTOPTR macro goes out of scope. Also, drop the redundant
viralloc.h include, since that has moved from the source module into the
header.
When a variable of type virCommandPtr is declared using VIR_AUTOPTR,
the function virCommandFree will be run automatically on it when it
goes out of scope.
Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
The set of arguments was changed a long time ago (040d996342
which dates back to July 2013) but the corresponding
documentation was not updated.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
The flags passed to virCommandPassFD() are unnamed and
documentation to this function doesn't list them either.
Give them name and mention it in documentation to functions
using them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Laine Stump <laine@laine.org>
Right-aligning backslashes when defining macros or using complex
commands in Makefiles looks cute, but as soon as any changes is
required to the code you end up with either distractingly broken
alignment or unnecessarily big diffs where most of the changes
are just pushing all backslashes a few characters to one side.
Generated using
$ git grep -El '[[:blank:]][[:blank:]]\\$' | \
grep -E '*\.([chx]|am|mk)$$' | \
while read f; do \
sed -Ei 's/[[:blank:]]*[[:blank:]]\\$/ \\/g' "$f"; \
done
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
This commit fixes the deadlock introduced by commit
0980764dee. The call getgrouplist() of
the glibc library isn't safe to be called in between fork and
exec (see commit 75c125641a).
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Fixes: 0980764dee ("util: share code between virExec and virCommandExec")
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
These functions are used by an upcoming commit.
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
