virFileOperation previously returned 0 on success, or the value of
errno on failure. Although there are other functions in libvirt that
use this convention, the preferred (and more common) convention is to
return 0 on success and -errno (or simply -1 in some cases) on
failure. This way the check for failure is always (ret < 0).
* src/util/util.c - change virFileOperation and virFileOperationNoFork to
return -errno on failure.
* src/storage/storage_backend.c, src/qemu/qemu_driver.c
- change the hook functions passed to virFileOperation to return
-errno on failure.
Any error message raised after the process has forked needs
to be followed by virDispatchError, otherwise we have no chance of
ever seeing it. This was selectively done for hook functions in the past,
but really applies to all post-fork errors.
We've been running into a lot of situations where
virGetHostname() is returning "localhost", where a plain
gethostname() would have returned the correct thing. This
is because virGetHostname() is *always* trying to canonicalize
the name returned from gethostname(), even when it doesn't
have to.
This patch changes virGetHostname so that if the value returned
from gethostname() is already FQDN or localhost, it returns
that string directly. If the value returned from gethostname()
is a shortened hostname, then we try to canonicalize it. If
that succeeds, we returned the canonicalized hostname. If
that fails, and/or returns "localhost", then we just return
the original string we got from gethostname() and hope for
the best.
Note that after this patch it is up to clients to check whether
"localhost" is an allowed return value. The only place
where it's currently not is in qemu migration.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Spurious / in a pool target path makes life difficult for apps using the
GetVolByPath, and doing other path based comparisons with pools. This
has caused a few issues for virt-manager users:
https://bugzilla.redhat.com/show_bug.cgi?id=494005https://bugzilla.redhat.com/show_bug.cgi?id=593565
Add a new util API which removes spurious /, virFileSanitizePath. Sanitize
target paths when parsing pool XML, and for paths passed to GetVolByPath.
v2: Leading // must be preserved, properly sanitize path=/, sanitize
away /./ -> /
v3: Properly handle starting ./ and ending /.
v4: Drop all '.' handling, just sanitize / for now.
virFileResolveLink was returning a positive value on error,
thus confusing callers that assumed failure was < 0. The
confusion is further evidenced by callers that would have
ended up calling virReportSystemError with a negative value
instead of a valid errno.
Fixes Red Hat BZ #591363.
* src/util/util.c (virFileResolveLink): Live up to documentation.
* src/qemu/qemu_security_dac.c
(qemuSecurityDACRestoreSecurityFileLabel): Adjust callers.
* src/security/security_selinux.c
(SELinuxRestoreSecurityFileLabel): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskDeleteVol): Likewise.
Gnulib can guarantee that pthread.h exists, but for now, it is a dummy
header with no support for most pthread_* functions. Modify our
use of pthread to use function checks, rather than header checks,
to determine how much pthread support is present.
* bootstrap.conf (gnulib_modules): Add pthread.
* configure.ac: Drop all pthread.h checks. Optimize function
checks. Add check for pthread functions.
* src/Makefile.am (libvirt_lxc_LDADD): Ensure proper link.
* src/remote/remote_driver.c (remoteIOEventLoop): Depend on
pthread_sigmask, now that gnulib guarantees pthread.h.
* src/util/util.c (virFork): Likewise.
* src/util/threads.c (threads-pthread.c): Depend on
pthread_mutexattr_init, as a witness of full pthread support.
* src/util/threads.h (threads-pthread.h): Likewise.
Detected by clang. POSIX requires that the second argument to
va_start be the name of the last variable; and in some implementations,
passing *path instead of path would dereference bogus memory instead
of pulling arguments off the stack.
* src/util/util.c (virBuildPathInternal): Use correct argument to
va_start.
Add an empty body for virCondWaitUntil and move virPipeReadUntilEOF
out of the '#ifndef WIN32' block, because it compiles fine with MinGW
in combination with gnulib.
Necessary on cygwin, where uid_t and gid_t are 4-byte long rather
than int, causing gcc -Wformat warnings.
* src/util/util.c (virFileOperationNoFork, virDirCreateNoFork)
(virFileOperation, virDirCreate, virGetUserEnt): Cast uid_t and
gid_t before passing to printf.
* .gitignore: Ignore Windows executables.
virParseVersionString uses virStrToLong_ui instead of sscanf.
This also fixes a bug in the UML driver, that always returned 0
as version number.
Introduce STRSKIP to check if a string has a certain prefix and
to skip this prefix.
used to read the data from virExec stdout/err file descriptors
* src/util/util.c src/util/util.h: not static anymore and export it
* src/libvirt_private.syms: allow access internally
Even if gnulib can provide stubs, it won't help that much. So just
replace affected util functions (virFileOperation and virDirCreate)
with stubs on Windows. Both functions aren't used on libvirt's
client side, so this is fine for MinGW builds.
to saferead_lim, which interprets it as a size_t.
* src/util/util.c (virFileReadLimFD): Do not malfunction when
maxlen < -1. Return -1,EINVAL in that case. Handle maxlen==0
in the same manner.
Various safezero() implementations used either -1, errno or -errno
return values. This patch fixes them all to return -1 and set errno
appropriately.
There was also a bug in size parameter passed to safewrite() which could
result in an attempt to write gigabytes out of a megabyte buffer.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
It turns out it is also useful to be able to perform other operations
on a file created while running as a different uid (eg, write things
to that file), and possibly to do this to a file that already
exists. This patch adds an optional hook function to the renamed (for
more accuracy of purpose) virFileOperation; the hook will be called
after the file has been opened (possibly created) and gid/mode
checked/set, before closing it.
As with the other operations on the file, if the VIR_FILE_OP_AS_UID
flag is set, this hook function will be called in the context of a
child process forked from the process that called virFileOperation.
The implication here is that, while all data in memory is available to
this hook function, any modification to that data will not be seen by
the caller - the only indication in memory of what happened in the
hook will be the return value (which the hook should set to 0 on
success, or one of the standard errno values on failure).
Another piece of making the function more flexible was to add an
"openflags" argument. This arg should contain exactly the flags to be
passed to open(2), eg O_RDWR | O_EXCL, etc.
In the process of adding the hook to virFileOperation, I also realized
that the bits to fix up file owner/group/mode settings after creation
were being done in the parent process, which could fail, so I moved
them to the child process where they should be.
* src/util/util.[ch]: rename and rework virFileCreate-->virFileOperation,
and redo flags in virDirCreate
* storage/storage_backend.c, storage/storage_backend_fs.c: update the
calls to virFileOperation/virDirCreate to reflect changes in the API,
but don't yet take advantage of the hook.
If the hostname as returned by "gethostname" resolves
to "localhost" (as it does with the broken Fedora-12
installer), then live migration will fail because the
source will try to migrate to itself. Detect this
situation up-front and abort the live migration before
we do any real work.
* src/util/util.h src/util/util.c: add a new virGetHostnameLocalhost
with an optional localhost check, and rewire virGetHostname() to use
it
* src/libvirt_private.syms: expose the new function
* src/qemu/qemu_driver.c: use it in qemudDomainMigratePrepare2()
For __virExec() this is a semantic NOP except for when fork()
fails. __virExec() would previously forget to restore the signal mask
in this case; virFork() corrects this behavior.
virFileCreate() and virDirCreate() gain the code to reset the logging
and properly deal with the signal handling race condition.
This also removes a log message that had a typo ("cannot fork o create
file '%s'") - this error is now logged in a more generic manner in
virFork() (more generic, but really just as informative, since the
fact that it's forking to create a file is immaterial to the fact that
it simply can't fork)
* src/util/util.c: use the generic virFork() in the 3 functions
virFork() contains bookkeeping that must be done any time a process
forks. Currently this includes:
1) Call virLogLock() prior to fork() and virLogUnlock() just after,
to avoid a deadlock if some other thread happens to hold that lock
during the fork.
2) Reset the logging hooks and send all child process log messages to
stderr.
3) Block all signals prior to fork(), then either a) reset the signal
mask for the parent process, or b) clear the signal mask for the
child process.
Note that the signal mask handling in __virExec erroneously fails to
restore the signal mask when fork() fails. virFork() fixes this
problem.
Other than this, it attempts to behave as closely to fork() as
possible (including preserving errno for the caller), with a couple
exceptions:
1) The return value is 0 (success) or -1 (failure), while the pid is
returned via the pid_t* argument. Like fork(), if pid < 0 there is
no child process, otherwise both the child and the parent will
return to the caller, and both should look at the return value,
which will indicate if some of the extra processing outlined above
encountered an error.
2) If virFork() returns with pid < 0 or with a return value < 0
indicating an error condition, the error has already been
reported. You can log an additional message if you like, but it
isn't necessary, and may be awkwardly extraneous.
Note that virFork()'s child process will *never* call _exit() - if a
child process is created, it will return to the caller.
* util.c util.h: add virFork() function, based on what is currently
done in __virExec().
Similar fix as previous one but for fork() usage when creating
a file or directory
* src/util/util.c: virLogLock() and virLogUnlock() around fork()
in virFileCreate() and virDirCreateSimple()
Ad pointed out by Dan Berrange:
So if some thread in libvirtd is currently executing a logging call,
while another thread calls virExec(), that other thread no longer
exists in the child, but its lock is never released. So when the
child then does virLogReset() it deadlocks.
The only way I see to address this, is for the parent process to call
virLogLock(), immediately before fork(), and then virLogUnlock()
afterwards in both parent & child. This will ensure that no other
thread
can be holding the lock across fork().
* src/util/logging.[ch] src/libvirt_private.syms: export virLogLock() and
virLogUnlock()
* src/util/util.c: lock just before forking and unlock just after - in
both parent and child.
* src/util/util.c (virGetUserID, virGetGroupID): In the unlikely event
that sysconf(_SC_GETPW_R_SIZE_MAX) fails, don't use -1 as the size in
the subsequent allocation.
On RHEL-5 the qemu-kvm binary is located in /usr/libexec.
To reduce confusion for people trying to run upstream libvirt
on RHEL-5 machines, make the qemu driver look in /usr/libexec
for the qemu-kvm binary.
To make this work, I modified virFindFileInPath to handle an
absolute path correctly. I also ran into an issue where
NULL was sometimes being passed for the file parameter
to virFindFileInPath; it didn't crash prior to this patch
since it was building paths like /usr/bin/(null). This
is non-standard behavior, though, so I added a NULL
check at the beginning.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
* src/util/util.c (virGetUserEnt): In the unlikely event that
sysconf(_SC_GETPW_R_SIZE_MAX) fails, don't use -1 as the size in
the subsequent allocation.
virFileMakePath is a recursive function that was creates a buffer
PATH_MAX bytes long for each recursion (one recursion for each element
in the path). This changes it to have no buffers on the stack, and to
allocate just one buffer total, no matter how many elements are in the
path. Because the modified algorithm requires a char* to be passed in
rather than const char *, it is now 2 functions - a toplevel API
function that remains identical in function, and a 2nd helper function
called for the recursions, which 1) doesn't allocate anything, and 2)
takes a char* arg, so it can modify the contents.
* src/util/util.c: rewrite virFileMakePath
These functions create a new file or directory with the given
uid/gid. If the flag VIR_FILE_CREATE_AS_UID is given, they do this by
forking a new process, calling setuid/setgid in the new process, and
then creating the file. This is better than simply calling open then
fchown, because in the latter case, a root-squashing nfs server would
create the new file as user nobody, then refuse to allow fchown.
If VIR_FILE_CREATE_AS_UID is not specified, the simpler tactic of
creating the file/dir, then chowning is is used. This gives better
results in cases where the parent directory isn't on a root-squashing
NFS server, but doesn't give permission for the specified uid/gid to
create files. (Note that if the fork/setuid method fails to create the
file due to access privileges, the parent process will make a second
attempt using this simpler method.)
If the bit VIR_FILE_CREATE_ALLOW_EXIST is set in the flags, an
existing file/directory will not cause an error; in this case, the
function will simply set the permissions of the file/directory to
those requested. If VIR_FILE_CREATE_ALLOW_EXIST is not specified, an
existing file/directory is considered (and reported as) an error.
Return from both of these functions is 0 on success, or the value of
errno if there was a failure.
* src/util/util.[ch]: add the 2 new util functions
Until recently, some gnulib-generated replacement headers
included *other* headers that were not strictly necessary,
thus masking the need in this file for an explicit <stdlib.h>.
* src/util/util.c: Include <stdlib.h> for declarations of e.g.,
strtol, random_r, getenv, etc.
With the introduction virDispatchError, hook function errors are
never sent through the error callback, so users will never see
these messages.
Fix this by calling virDispatchError after hook failure.
This allows debug statements and raised errors in hook functions to
actually be logged somewhere (stderr). Users can enable debugging in the
daemon and now see more info in /var/log/libvirt/...
The virFileResolveLink utility function relied on the POSIX guarantee
that stat.st_size of a symlink is the length of the value. However,
on some types of file systems, it is invalid, so do not rely on it.
Use gnulib's areadlink module instead.
* bootstrap (modules): Add areadlink.
* src/util/util.c: Include "areadlink.h".
Let areadlink perform the readlink and malloc.
* configure.in (AC_CHECK_FUNCS): Remove readlink. No need,
since it's presence is guaranteed by gnulib.
Replace free(virBufferContentAndReset()) with virBufferFreeAndReset().
Update documentation and replace all remaining calls to free() with
calls to VIR_FREE(). Also add missing calls to virBufferFreeAndReset()
and virReportOOMError() in OOM error cases.
esxVMX_IndexToDiskName handles indices up to 701. This limit comes
from a mapping gap in virDiskNameToIndex:
sdzy -> 700
sdzz -> 701
sdaaa -> 728
sdaab -> 729
This line in virDiskNameToIndex causes this gap:
idx = (idx + i) * 26;
Fixing it by altering this line to:
idx = (idx + (i < 1 ? 0 : 1)) * 26;
Also add a new version of virIndexToDiskName that handles the inverse
mapping for arbitrary indices.
* src/esx/esx_vmx.[ch]: remove esxVMX_IndexToDiskName
* src/util/util.[ch]: add virIndexToDiskName and fix mapping gap
* tests/esxutilstest.c: update test to verify that the gap is fixed
* configure.in: add new --with-udev, disabled by default, and requiring
libudev > 145
* src/node_device/node_device_udev.c src/node_device/node_device_udev.h:
the new node device backend
* src/node_device/node_device_linux_sysfs.c: moved node_device_hal_linux.c
to a better file name
* src/conf/node_device_conf.c src/conf/node_device_conf.h: add a couple
of fields in node device definitions, and an API to look them up,
remove a couple of unused fields from previous patch.
* src/node_device/node_device_driver.c src/node_device/node_device_driver.h:
plug the new driver
* po/POTFILES.in src/Makefile.am src/libvirt_private.syms: add the new
files and symbols
* src/util/util.h src/util/util.c: add a new convenience macro
virBuildPath and virBuildPathInternal() function
All drivers have copy + pasted inadequate error reporting which wraps
util.c:virGetHostname. Move all error reporting to this function, and improve
what we report.
Changes from v1:
Drop the driver wrappers around virGetHostname. This means we still need
to keep the new conn argument to virGetHostname, but I think it's worth
it.
Nearly all of the methods in src/util/util.h have error codes that
must be checked by the caller to correct detect & report failure.
Add ATTRIBUTE_RETURN_CHECK to ensure compile time validation of
this
* daemon/libvirtd.c: Add explicit check on return value of virAsprintf
* src/conf/domain_conf.c: Add missing check on virParseMacAddr return
value status & report error
* src/network/bridge_driver.c: Add missing OOM check on virAsprintf
and report error
* src/qemu/qemu_conf.c: Add missing check on virParseMacAddr return
value status & report error
* src/security/security_selinux.c: Remove call to virRandomInitialize
that's done in libvirt.c already
* src/storage/storage_backend_logical.c: Add check & log on virRun
return status
* src/util/util.c: Add missing checks on virAsprintf/Run status
* src/util/util.h: Annotate all methods with ATTRIBUTE_RETURN_CHECK
if they return an error status code
* src/vbox/vbox_tmpl.c: Add missing check on virParseMacAddr
* src/xen/xm_internal.c: Add missing checks on virAsprintf
* tests/qemuargv2xmltest.c: Remove bogus call to virRandomInitialize()
The fread_file_lim() function uses fread() but never handles
EINTR results, causing unexpected failures when reading QEMU
help arg info. It was unneccessarily using FILE * instead
of plain UNIX file handles, which prevented use of saferead()
* src/util/util.c: Switch fread_file_lim over to use saferead
instead of fread, remove FILE * use, and rename
* src/util/util.[ch]: Add virFileAbsPath() function to ensure an
absolute path for a potentially realtive path.
* src/libvirt_private.syms: add it in libvirt private symbols
Add the virStrncpy function, which takes a dst string, source string,
the number of bytes to copy and the number of bytes available in the
dest string. If the source string is too large to fit into the
destination string, including the \0 byte, then no data is copied and
the function returns NULL. Otherwise, this function copies n bytes
from source into dst, including the \0, and returns a pointer to the
dst string. This function is intended to replace all unsafe uses
of strncpy in the code base, since strncpy does *not* guarantee that
the buffer terminates with a \0.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
