That sets a new flag, but that flag does mean the child will get
LISTEN_FDS and LISTEN_PID environment variables properly set and
passed FDs reordered so that it corresponds with LISTEN_FDS (they must
start right after STDERR_FILENO).
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Recent changes in the module seemed to have caused Coverity to reanalyze
certain parts of the code. Previously the code was modified via commit
id '11a11812' to resolve a different error (perhaps DEADCODE). Up through
commit id '7b3f1f8c' there were no issues.
The new error indicats the 'outbuf' was checked for NULL and then complains
because of the dereference. Adding checks for non-NULL prior to the deref
resulted in a DEADCODE message.
So, resolve using an sa_assert() to keep Coverity quiet especially since
it doesn't understand that outbuf will change as a result of a successful
virCommandRun() call.
Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='. One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Commit 631923e used a few macros from sys/wait.h without including
it. On Linux, they were also defined in stdlib.h, but on FreeBSD
the build failed:
../../tests/commandtest.c: In function 'test1':
warning: implicit declaration of function 'WIFEXITED'
warning: nested extern declaration of 'WIFEXITED' [-Wnested-externs]
The old semantics of virFork() violates the priciple of good
usability: it requires the caller to check the pid argument
after use, *even when virFork returned -1*, in order to properly
abort a child process that failed setup done immediately after
fork() - that is, the caller must call _exit() in the child.
While uses in virfile.c did this correctly, uses in 'virsh
lxc-enter-namespace' and 'virt-login-shell' would happily return
from the calling function in both the child and the parent,
leading to very confusing results. [Thankfully, I found the
problem by inspection, and can't actually trigger the double
return on error without an LD_PRELOAD library.]
It is much better if the semantics of virFork are impossible
to abuse. Looking at virFork(), the parent could only ever
return -1 with a non-negative pid if it misused pthread_sigmask,
but this never happens. Up until this patch series, the child
could return -1 with non-negative pid if it fails to set up
signals correctly, but we recently fixed that to make the child
call _exit() at that point instead of forcing the caller to do
it. Thus, the return value and contents of the pid argument are
now redundant (a -1 return now happens only for failure to fork,
a child 0 return only happens for a successful 0 pid, and a
parent 0 return only happens for a successful non-zero pid),
so we might as well return the pid directly rather than an
integer of whether it succeeded or failed; this is also good
from the interface design perspective as users are already
familiar with fork() semantics.
One last change in this patch: before returning the pid directly,
I found cases where using virProcessWait unconditionally on a
cleanup path of a virFork's -1 pid return would be nicer if there
were a way to avoid it overwriting an earlier message. While
such paths are a bit harder to come by with my change to a direct
pid return, I decided to keep the virProcessWait change in this
patch.
* src/util/vircommand.h (virFork): Change signature.
* src/util/vircommand.c (virFork): Guarantee that child will only
return on success, to simplify callers. Return pid rather than
status, now that the situations are always the same.
(virExec): Adjust caller, also avoid open-coding process death.
* src/util/virprocess.c (virProcessWait): Tweak semantics when pid
is -1.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations. Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit. Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big. And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.
So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.
* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself. But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status. This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.
* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Thanks to namespaces, we have a couple of places in the code
base that want to reflect a child exit status, including the
ability to detect death by a signal, back to a grandparent.
Best to make it a reusable function.
* src/util/virprocess.h (virProcessExitWithStatus): New prototype.
* src/libvirt_private.syms (util/virprocess.h): Export it.
* src/util/virprocess.c (virProcessExitWithStatus): New function.
* tests/commandtest.c (test23): Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
When a child fails without exec'ing, we want a well-known status;
best is to match what env(1), nice(1), su(1), and other wrapper
programs do. This patch adds enum values that later patches will
use, and sets up virFork as the first client of EXIT_CANCELED
for errors detected prior to even attempting exec, as well as
virExec to distinguish between a missing executable vs. a binary
that cannot be executed.
This is a slight semantic change in the unlikely case of a child
process failing to restore its signal mask - we now kill the
child with a known status instead of relying on the caller to
notice and do an appropriate _exit(). A subsequent patch will
make further cleanups based on an audit of all callers.
* src/internal.h (EXIT_CANCELED, EXIT_CANNOT_INVOKE)
(EXIT_ENOENT): New enum.
* src/util/vircommand.c (virFork): Document specific exit value if
child aborts early.
(virExec): Distinguish between various exec failures.
* tests/commandtest.c (test1): Enhance test.
(test22): New test.
Signed-off-by: Eric Blake <eblake@redhat.com>
For a "newfd1" the coverity tools thinks that the fd is closed in
a "virCommandPassFD", but with "flags == 0" it cannot be closed.
The code itself is ok, but coverity tool thinks that there is
"double_close" of the "newfd1" and to prevent showing this error
we simply add a comment before the proper close.
This has been found by coverity.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
When running setuid, we must be careful about what env vars
we allow commands to inherit from us. Replace the
virCommandAddEnvPass function with two new ones which do
filtering
virCommandAddEnvPassAllowSUID
virCommandAddEnvPassBlockSUID
And make virCommandAddEnvPassCommon use the appropriate
ones
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The test case average timing code has not been used by any test
case ever. Delete it to remove complexity.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Merge the virCommandPreserveFD / virCommandTransferFD methods
into a single virCommandPasFD method, and use a new
VIR_COMMAND_PASS_FD_CLOSE_PARENT to indicate their difference
in behaviour
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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.
Commit 39c77fe triggered random failures, depending on the platform
and what other fds leak into the testsuite (for me, it passed on
RHEL 6 but failed on Fedora 18). The reason was that we were
expecting an fd that fell outside of our reserved range. By reserving
a larger range, the test once again passes on all platforms.
* tests/commandtest.c (mymain): Reserve enough fds.
This is just a basic test, so we don't break virCommand in the
future. A "Hello world\n" string is written to commanhelper,
which copies input to stdout and stderr where we read it from.
Then the read strings are compared with expected values.
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>
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/
Without this patch, logged command executions can be ambiguous if
the command contained any shell metacharacters. This has caused
more than one person to attempt to patch clients to add unnecessary
quoting, without realizing that the command itself was run with
correct args, and only the logged output was ambiguous.
* src/util/command.c (virCommandToString): Add shell escapes.
* tests/commandtest.c (test16): Test new behavior.
* tests/commanddata/test16.log: Update expected output.
* tests/qemuxml2argvdata/qemuxml2argv-*.args: Likewise.
* tests/networkxml2argvdata/*.argv: Likewise.
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
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.
More bug extermination in the category of:
Error: CHECKED_RETURN:
/libvirt/src/conf/network_conf.c:595:
check_return: Calling function "virAsprintf" without checking return value (as is done elsewhere 515 out of 543 times).
/libvirt/src/qemu/qemu_process.c:2780:
unchecked_value: No check of the return value of "virAsprintf(&msg, "was paused (%s)", virDomainPausedReasonTypeToString(reason))".
/libvirt/tests/commandtest.c:809:
check_return: Calling function "setsid" without checking return value (as is done elsewhere 4 out of 5 times).
/libvirt/tests/commandtest.c:830:
unchecked_value: No check of the return value of "virTestGetDebug()".
/libvirt/tests/commandtest.c:831:
check_return: Calling function "virTestGetVerbose" without checking return value (as is done elsewhere 41 out of 42 times).
/libvirt/tests/commandtest.c:833:
check_return: Calling function "virInitialize" without checking return value (as is done elsewhere 18 out of 21 times).
One note about the error in commandtest line 809: setsid() seems to fail when running the test -- could be removed ?
Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:
List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$'
Found files were modified with this command:
sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Then checked for nonsense.
The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Sometimes, its easier to run children with 2>&1 in shell notation,
and just deal with stdout and stderr interleaved. This was already
possible for fd handling; extend it to also work when doing string
capture of a child process.
* docs/internals/command.html.in: Document this.
* src/util/command.c (virCommandSetErrorBuffer): Likewise.
(virCommandRun, virExecWithHook): Implement it.
* tests/commandtest.c (test14): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Use new command
feature.
I hit a VERY weird testsuite failure on rawhide, which included
_binary_ output to stderr, followed by a hang waiting for me
to type something! (Here, using ^@ for NUL):
$ ./commandtest
TEST: commandtest
WARNING: gnome-keyring:: couldn't send data: Bad file descriptor
.WARNING: gnome-keyring:: couldn't send data: Bad file descriptor
.WARNING: gnome-keyring:: couldn't send data: Bad file descriptor
WARNING: gnome-keyring:: couldn't send data: Bad file descriptor
.8^@^@^@8^@^@^@^A^@^@^@^Bay^A^@^@^@)PRIVATE-GNOME-KEYRING-PKCS11-PROTOCOL-V-1
I finally traced it to the fact that gnome-keyring, called via
gnutls_global_init which is turn called by virNetTLSInit, opens
an internal fd that it expects to communicate to via a
pthread_atfork handler (never mind that it violates POSIX by
using non-async-signal-safe functions in that handler:
https://bugzilla.redhat.com/show_bug.cgi?id=772320).
Our problem stems from the fact that we pulled the rug out from
under the library's expectations by closing an fd that it had
just opened. While we aren't responsible for fixing the bugs
in that pthread_atfork handler, we can at least avoid the bugs
by not closing the fd in the first place.
* tests/commandtest.c (mymain): Avoid closing fds that were opened
by virInitialize.
virBufferContentAndReset (intentionally) returns NULL for a buffer
with no content, but it is feasible to invoke a command with an
explicit empty string.
* src/util/command.c (virCommandAddEnvBuffer): Reject empty string.
(virCommandAddArgBuffer): Allow explicit empty argument.
* tests/commandtest.c (test9): Test it.
* tests/commanddata/test9.log: Adjust.
The VIR_TEST_DEBUG and VIR_TEST_VERBOSE env vars did not work
because we replaced 'environ' with 'newenv'. Simply calling
virTestGetDebug/Verbose() before replacing the 'environ' ensures
we have processed the env variables.
The gnutls initialization code opens /dev/urandom and keeps that
FD around for later use. We have code which kills off FDs 3-5
to avoid interfereing with our test case. Move the virInitialize
call before this point, so it kills off the gnutls /dev/urandom
FD which is irrelevant for testing purposes
* tests/commandtest.c: Fix test debugging & make it robust against
opened FDs
With gcc 4.5.1:
util/virpidfile.c: In function 'virPidFileAcquirePath':
util/virpidfile.c:308:66: error: nested extern declaration of '_gl_verify_function2' [-Wnested-externs]
Then in tests/commandtest.c, the new virPidFile APIs need to be used.
* src/util/virpidfile.c (virPidFileAcquirePath): Move verify to
top level.
* tests/commandtest.c: Use new pid APIs.
Although most functions in libvirt return 0 on success and < 0 on
failure, there are a few functions lingering around that return errno
(a positive value) on failure, and sometimes code calling those
functions incorrectly assumes the <0 standard. I noticed one of these
the other day when auditing networkStartDhcpDaemon after Guido Gunther
found a place where success was improperly returned on failure (that
patch has been acked and is pending a push). The problem was that it
expected the return value from virFileReadPid to be < 0 on failure,
but it was actually positive (it was also neglected to set the return
code in this case, similar to the bug found by Guido).
This all led to the fact that *all* of the virFile*Pid functions in
util.c are returning errno on failure. This patch remedies that
problem by changing them all to return -errno on failure, and makes
any necessary changes to callers of the functions. (In the meantime, I
also properly set the return code on failure of virFileReadPid in
networkStartDhcpDaemon).
Running ./autobuild.sh failed when gcov is installed, because
commandtest ended up crashing during gcov's getenv() call after
exit() had already started. I traced this nasty bug back to
a scoping issue present since the test introduction.
* tests/commandtest.c (mymain): Move newenv...
(newenv): ...to a scope that is still useful during exit().
