virPidFileReadPathIfAlive passed in an 'int *' where a 'pid_t *'
was expected, which breaks on Mingw64 targets. Also a few places
were using '%d' for formatting pid_t, change them to '%lld' and
force a cast to the longer type as done elsewhere in the same
file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This patch resolves: https://bugzilla.redhat.com/show_bug.cgi?id=871201
If libvirt is restarted after updating the dnsmasq or radvd packages,
a subsequent "virsh net-destroy" will fail to kill the dnsmasq/radvd
process.
The problem is that when libvirtd restarts, it re-reads the dnsmasq
and radvd pidfiles, then does a sanity check on each pid it finds,
including checking that the symbolic link in /proc/$pid/exe actually
points to the same file as the path used by libvirt to execute the
binary in the first place. If this fails, libvirt assumes that the
process is no longer alive.
But if the original binary has been replaced, the link in /proc is set
to "$binarypath (deleted)" (it literally has the string " (deleted)"
appended to the link text stored in the filesystem), so even if a new
binary exists in the same location, attempts to resolve the link will
fail.
In the end, not only is the old dnsmasq/radvd not terminated when the
network is stopped, but a new dnsmasq can't be started when the
network is later restarted (because the original process is still
listening on the ports that the new process wants).
The solution is, when the initial "use stat to check for identical
inodes" check for identity between /proc/$pid/exe and $binpath fails,
to check /proc/$pid/exe for a link ending with " (deleted)" and if so,
truncate that part of the link and compare what's left with the
original binarypath.
A twist to this problem is that on systems with "merged" /sbin and
/usr/sbin (i.e. /sbin is really just a symlink to /usr/sbin; Fedora
17+ is an example of this), libvirt may have started the process using
one path, but /proc/$pid/exe lists a different path (indeed, on F17
this is the case - libvirtd uses /sbin/dnsmasq, but /proc/$pid/exe
shows "/usr/sbin/dnsmasq"). The further bit of code to resolve this is
to call virFileResolveAllLinks() on both the original binarypath and
on the truncated link we read from /proc/$pid/exe, and compare the
results.
The resulting code still succeeds in all the same cases it did before,
but also succeeds if the binary was deleted or replaced after it was
started.
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/
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
The code is splattered with a mix of
sizeof foo
sizeof (foo)
sizeof(foo)
Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This patch changes behavior of virPidFileRead to enable passing NULL as
path to the binary the pid file should be checked against to skip this
check. This enables using this function for reading files that have same
semantics as pid files, but belong to unknown processes.
Regression introduced in commit b7e5ca4.
Mingw lacks kill(), but we were only using it for a sanity check;
so we can go with one less check.
Also, on OOM error, this function should outright fail rather than
claim that the pid file was successfully read.
* src/util/virpidfile.c (virPidFileReadPathIfAlive): Skip kill
call where unsupported, and report error on OOM.
Get rid of the #if __linux__ check in virPidFileReadPathIfAlive that
was preventing a check of a symbolic link in /proc/<pid>/exe on
non-linux platforms against an expected executable. Replace
this with a run-time check testing whether the /proc/<pid>/exe is a
symbolic link and if so call the function doing the comparison
against the expected file the link is supposed to point to.
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.
In daemons using pidfiles to protect against concurrent
execution there is a possibility that a crash may leave a stale
pidfile on disk, which then prevents later restart of the daemon.
To avoid this problem, introduce a pair of APIs which make
use of virFileLock to ensure crash-safe & race condition-safe
pidfile acquisition & releae
* src/libvirt_private.syms, src/util/virpidfile.c,
src/util/virpidfile.h: Add virPidFileAcquire and virPidFileRelease
In some cases the caller of virPidFileRead might like extra checks
to determine whether the pid just read is really the one they are
expecting. This adds virPidFileReadIfAlive which will check whether
the pid is still alive with kill(0, -1), and (on linux only) will
look at /proc/$PID/path
* libvirt_private.syms, util/virpidfile.c, util/virpidfile.h: Add
virPidFileReadIfValid and virPidFileReadPathIfValid
* network/bridge_driver.c: Use new APIs to check PID validity
The functions for manipulating pidfiles are in util/util.{c,h}.
We will shortly be adding some further pidfile related functions.
To avoid further growing util.c, this moves the pidfile related
functions into a dedicated virpidfile.{c,h}. The functions are
also all renamed to have 'virPidFile' as their name prefix
* util/util.h, util/util.c: Remove all pidfile code
* util/virpidfile.c, util/virpidfile.h: Add new APIs for pidfile
handling.
* lxc/lxc_controller.c, lxc/lxc_driver.c, network/bridge_driver.c,
qemu/qemu_process.c: Add virpidfile.h include and adapt for API
renames
