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libvirt/src/util/virfile.c
Peter Krempa 92427948b3 maint: Prohibit "devname" by a syntax check rules 
and tweak the code to avoid using it.
2014-10-01 16:39:01 +02:00

3080 lines
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/*
* virfile.c: safer file handling
*
* Copyright (C) 2010-2014 Red Hat, Inc.
* Copyright (C) 2010 IBM Corporation
* Copyright (C) 2010 Stefan Berger
* Copyright (C) 2010 Eric Blake
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*/
#include <config.h>
#include "internal.h"
#include <passfd.h>
#include <fcntl.h>
#include <pty.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <dirent.h>
#include <dirname.h>
#if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R
# include <mntent.h>
#endif
#include <stdlib.h>
#if HAVE_MMAP
# include <sys/mman.h>
#endif
#ifdef __linux__
# if HAVE_LINUX_MAGIC_H
# include <linux/magic.h>
# endif
# include <sys/statfs.h>
#endif
#if defined(__linux__) && HAVE_DECL_LO_FLAGS_AUTOCLEAR
# include <linux/loop.h>
# include <sys/ioctl.h>
#endif
#include "configmake.h"
#include "viralloc.h"
#include "vircommand.h"
#include "virerror.h"
#include "virfile.h"
#include "virlog.h"
#include "virprocess.h"
#include "virstring.h"
#include "virstoragefile.h"
#include "virutil.h"
#include "c-ctype.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("util.file");
int virFileClose(int *fdptr, virFileCloseFlags flags)
{
int saved_errno = 0;
int rc = 0;
if (*fdptr < 0)
return 0;
if (flags & VIR_FILE_CLOSE_PRESERVE_ERRNO)
saved_errno = errno;
rc = close(*fdptr);
if (!(flags & VIR_FILE_CLOSE_DONT_LOG)) {
if (rc < 0) {
if (errno == EBADF) {
if (!(flags & VIR_FILE_CLOSE_IGNORE_EBADF))
VIR_WARN("Tried to close invalid fd %d", *fdptr);
} else {
char ebuf[1024] ATTRIBUTE_UNUSED;
VIR_DEBUG("Failed to close fd %d: %s",
*fdptr, virStrerror(errno, ebuf, sizeof(ebuf)));
}
} else {
VIR_DEBUG("Closed fd %d", *fdptr);
}
}
*fdptr = -1;
if (flags & VIR_FILE_CLOSE_PRESERVE_ERRNO)
errno = saved_errno;
return rc;
}
int virFileFclose(FILE **file, bool preserve_errno)
{
int saved_errno = 0;
int rc = 0;
if (*file) {
if (preserve_errno)
saved_errno = errno;
rc = fclose(*file);
*file = NULL;
if (preserve_errno)
errno = saved_errno;
}
return rc;
}
FILE *virFileFdopen(int *fdptr, const char *mode)
{
FILE *file = NULL;
if (*fdptr >= 0) {
file = fdopen(*fdptr, mode);
if (file)
*fdptr = -1;
} else {
errno = EBADF;
}
return file;
}
/**
* virFileDirectFdFlag:
*
* Returns 0 if the kernel can avoid file system cache pollution
* without any additional flags, O_DIRECT if the original fd must be
* opened in direct mode, or -1 if there is no support for bypassing
* the file system cache.
*/
int
virFileDirectFdFlag(void)
{
/* XXX For now, Linux posix_fadvise is not powerful enough to
* avoid O_DIRECT. */
return O_DIRECT ? O_DIRECT : -1;
}
/* Opaque type for managing a wrapper around a fd. For now,
* read-write is not supported, just a single direction. */
struct _virFileWrapperFd {
virCommandPtr cmd; /* Child iohelper process to do the I/O. */
char *err_msg; /* stderr of @cmd */
};
#ifndef WIN32
/**
* virFileWrapperFdNew:
* @fd: pointer to fd to wrap
* @name: name of fd, for diagnostics
* @flags: bitwise-OR of virFileWrapperFdFlags
*
* Update @fd so that it meets parameters requested by @flags.
*
* If VIR_FILE_WRAPPER_BYPASS_CACHE bit is set in @flags, @fd will be updated
* in a way that all I/O to that file will bypass the system cache. The
* original fd must have been created with virFileDirectFdFlag() among the
* flags to open().
*
* If VIR_FILE_WRAPPER_NON_BLOCKING bit is set in @flags, @fd will be updated
* to ensure it properly supports non-blocking I/O, i.e., it will report
* EAGAIN.
*
* This must be called after open() and optional fchown() or fchmod(), but
* before any seek or I/O, and only on seekable fd. The file must be O_RDONLY
* (to read the entire existing file) or O_WRONLY (to write to an empty file).
* In some cases, @fd is changed to a non-seekable pipe; in this case, the
* caller must not do anything further with the original fd.
*
* On success, the new wrapper object is returned, which must be later
* freed with virFileWrapperFdFree(). On failure, @fd is unchanged, an
* error message is output, and NULL is returned.
*/
virFileWrapperFdPtr
virFileWrapperFdNew(int *fd, const char *name, unsigned int flags)
{
virFileWrapperFdPtr ret = NULL;
bool output = false;
int pipefd[2] = { -1, -1 };
int mode = -1;
char *iohelper_path = NULL;
if (!flags) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("invalid use with no flags"));
return NULL;
}
/* XXX support posix_fadvise rather than O_DIRECT, if the kernel support
* for that is decent enough. In that case, we will also need to
* explicitly support VIR_FILE_WRAPPER_NON_BLOCKING since
* VIR_FILE_WRAPPER_BYPASS_CACHE alone will no longer require spawning
* iohelper.
*/
if ((flags & VIR_FILE_WRAPPER_BYPASS_CACHE) && !O_DIRECT) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("O_DIRECT unsupported on this platform"));
return NULL;
}
if (VIR_ALLOC(ret) < 0)
return NULL;
mode = fcntl(*fd, F_GETFL);
if (mode < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, _("invalid fd %d for %s"),
*fd, name);
goto error;
} else if ((mode & O_ACCMODE) == O_WRONLY) {
output = true;
} else if ((mode & O_ACCMODE) != O_RDONLY) {
virReportError(VIR_ERR_INTERNAL_ERROR, _("unexpected mode %x for %s"),
mode & O_ACCMODE, name);
goto error;
}
if (pipe2(pipefd, O_CLOEXEC) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unable to create pipe for %s"), name);
goto error;
}
if (!(iohelper_path = virFileFindResource("libvirt_iohelper",
"src",
LIBEXECDIR)))
goto error;
ret->cmd = virCommandNewArgList(iohelper_path, name, "0", NULL);
VIR_FREE(iohelper_path);
if (output) {
virCommandSetInputFD(ret->cmd, pipefd[0]);
virCommandSetOutputFD(ret->cmd, fd);
virCommandAddArg(ret->cmd, "1");
} else {
virCommandSetInputFD(ret->cmd, *fd);
virCommandSetOutputFD(ret->cmd, &pipefd[1]);
virCommandAddArg(ret->cmd, "0");
}
/* In order to catch iohelper stderr, we must change
* iohelper's env so virLog functions print to stderr
*/
virCommandAddEnvPair(ret->cmd, "LIBVIRT_LOG_OUTPUTS", "1:stderr");
virCommandSetErrorBuffer(ret->cmd, &ret->err_msg);
virCommandDoAsyncIO(ret->cmd);
if (virCommandRunAsync(ret->cmd, NULL) < 0)
goto error;
if (VIR_CLOSE(pipefd[!output]) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("unable to close pipe"));
goto error;
}
VIR_FORCE_CLOSE(*fd);
*fd = pipefd[output];
return ret;
error:
VIR_FREE(iohelper_path);
VIR_FORCE_CLOSE(pipefd[0]);
VIR_FORCE_CLOSE(pipefd[1]);
virFileWrapperFdFree(ret);
return NULL;
}
#else
virFileWrapperFdPtr
virFileWrapperFdNew(int *fd ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED,
unsigned int fdflags ATTRIBUTE_UNUSED)
{
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("virFileWrapperFd unsupported on this platform"));
return NULL;
}
#endif
/**
* virFileWrapperFdClose:
* @wfd: fd wrapper, or NULL
*
* If @wfd is valid, then ensure that I/O has completed, which may
* include reaping a child process. Return 0 if all data for the
* wrapped fd is complete, or -1 on failure with an error emitted.
* This function intentionally returns 0 when @wfd is NULL, so that
* callers can conditionally create a virFileWrapperFd wrapper but
* unconditionally call the cleanup code. To avoid deadlock, only
* call this after closing the fd resulting from virFileWrapperFdNew().
*/
int
virFileWrapperFdClose(virFileWrapperFdPtr wfd)
{
int ret;
if (!wfd)
return 0;
ret = virCommandWait(wfd->cmd, NULL);
if (wfd->err_msg)
VIR_WARN("iohelper reports: %s", wfd->err_msg);
return ret;
}
/**
* virFileWrapperFdFree:
* @wfd: fd wrapper, or NULL
*
* Free all remaining resources associated with @wfd. If
* virFileWrapperFdClose() was not previously called, then this may
* discard some previous I/O. To avoid deadlock, only call this after
* closing the fd resulting from virFileWrapperFdNew().
*/
void
virFileWrapperFdFree(virFileWrapperFdPtr wfd)
{
if (!wfd)
return;
VIR_FREE(wfd->err_msg);
virCommandFree(wfd->cmd);
VIR_FREE(wfd);
}
#ifndef WIN32
/**
* virFileLock:
* @fd: file descriptor to acquire the lock on
* @shared: type of lock to acquire
* @start: byte offset to start lock
* @len: length of lock (0 to acquire entire remaining file from @start)
* @waitForLock: wait for previously held lock or not
*
* Attempt to acquire a lock on the file @fd. If @shared
* is true, then a shared lock will be acquired,
* otherwise an exclusive lock will be acquired. If
* the lock cannot be acquired, an error will be
* returned. If @waitForLock is true, this will wait
* for the lock if another process has already acquired it.
*
* The lock will be released when @fd is closed. The lock
* will also be released if *any* other open file descriptor
* pointing to the same underlying file is closed. As such
* this function should not be relied on in multi-threaded
* apps where other threads can be opening/closing arbitrary
* files.
*
* Returns 0 on success, or -errno otherwise
*/
int virFileLock(int fd, bool shared, off_t start, off_t len, bool waitForLock)
{
struct flock fl = {
.l_type = shared ? F_RDLCK : F_WRLCK,
.l_whence = SEEK_SET,
.l_start = start,
.l_len = len,
};
int cmd = waitForLock ? F_SETLKW : F_SETLK;
if (fcntl(fd, cmd, &fl) < 0)
return -errno;
return 0;
}
/**
* virFileUnlock:
* @fd: file descriptor to release the lock on
* @start: byte offset to start unlock
* @len: length of lock (0 to release entire remaining file from @start)
*
* Release a lock previously acquired with virFileUnlock().
* NB the lock will also be released if any open file descriptor
* pointing to the same file as @fd is closed
*
* Returns 0 on succcess, or -errno on error
*/
int virFileUnlock(int fd, off_t start, off_t len)
{
struct flock fl = {
.l_type = F_UNLCK,
.l_whence = SEEK_SET,
.l_start = start,
.l_len = len,
};
if (fcntl(fd, F_SETLK, &fl) < 0)
return -errno;
return 0;
}
#else
int virFileLock(int fd ATTRIBUTE_UNUSED,
bool shared ATTRIBUTE_UNUSED,
off_t start ATTRIBUTE_UNUSED,
off_t len ATTRIBUTE_UNUSED,
bool waitForLock ATTRIBUTE_UNUSED)
{
return -ENOSYS;
}
int virFileUnlock(int fd ATTRIBUTE_UNUSED,
off_t start ATTRIBUTE_UNUSED,
off_t len ATTRIBUTE_UNUSED)
{
return -ENOSYS;
}
#endif
int
virFileRewrite(const char *path,
mode_t mode,
virFileRewriteFunc rewrite,
void *opaque)
{
char *newfile = NULL;
int fd = -1;
int ret = -1;
if (virAsprintf(&newfile, "%s.new", path) < 0)
goto cleanup;
if ((fd = open(newfile, O_WRONLY | O_CREAT | O_TRUNC, mode)) < 0) {
virReportSystemError(errno, _("cannot create file '%s'"),
newfile);
goto cleanup;
}
if (rewrite(fd, opaque) < 0) {
virReportSystemError(errno, _("cannot write data to file '%s'"),
newfile);
goto cleanup;
}
if (fsync(fd) < 0) {
virReportSystemError(errno, _("cannot sync file '%s'"),
newfile);
goto cleanup;
}
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno, _("cannot save file '%s'"),
newfile);
goto cleanup;
}
if (rename(newfile, path) < 0) {
virReportSystemError(errno, _("cannot rename file '%s' as '%s'"),
newfile, path);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FORCE_CLOSE(fd);
if (newfile) {
unlink(newfile);
VIR_FREE(newfile);
}
return ret;
}
int virFileTouch(const char *path, mode_t mode)
{
int fd = -1;
if ((fd = open(path, O_WRONLY | O_CREAT, mode)) < 0) {
virReportSystemError(errno, _("cannot create file '%s'"),
path);
return -1;
}
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno, _("cannot save file '%s'"),
path);
VIR_FORCE_CLOSE(fd);
return -1;
}
return 0;
}
#define MODE_BITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
int virFileUpdatePerm(const char *path,
mode_t mode_remove,
mode_t mode_add)
{
struct stat sb;
mode_t mode;
if (mode_remove & ~MODE_BITS || mode_add & ~MODE_BITS) {
virReportError(VIR_ERR_INVALID_ARG, "%s", _("invalid mode"));
return -1;
}
if (stat(path, &sb) < 0) {
virReportSystemError(errno, _("cannot stat '%s'"), path);
return -1;
}
mode = sb.st_mode & MODE_BITS;
if ((mode & mode_remove) == 0 && (mode & mode_add) == mode_add)
return 0;
mode &= MODE_BITS ^ mode_remove;
mode |= mode_add;
if (chmod(path, mode) < 0) {
virReportSystemError(errno, _("cannot change permission of '%s'"),
path);
return -1;
}
return 0;
}
#if defined(__linux__) && HAVE_DECL_LO_FLAGS_AUTOCLEAR && \
!defined(LIBVIRT_SETUID_RPC_CLIENT)
# if HAVE_DECL_LOOP_CTL_GET_FREE
/* virFileLoopDeviceOpenLoopCtl() returns -1 when a real failure has occurred
* while in the process of allocating or opening the loop device. On success
* we return 0 and modify the fd to the appropriate file descriptor.
* If /dev/loop-control does not exist, we return 0 and do not set fd. */
static int virFileLoopDeviceOpenLoopCtl(char **dev_name, int *fd)
{
int devnr;
int ctl_fd;
char *looppath = NULL;
VIR_DEBUG("Opening loop-control device");
if ((ctl_fd = open("/dev/loop-control", O_RDWR)) < 0) {
if (errno == ENOENT)
return 0;
virReportSystemError(errno, "%s",
_("Unable to open /dev/loop-control"));
return -1;
}
if ((devnr = ioctl(ctl_fd, LOOP_CTL_GET_FREE)) < 0) {
virReportSystemError(errno, "%s",
_("Unable to get free loop device via ioctl"));
close(ctl_fd);
return -1;
}
close(ctl_fd);
VIR_DEBUG("Found free loop device number %i", devnr);
if (virAsprintf(&looppath, "/dev/loop%i", devnr) < 0)
return -1;
if ((*fd = open(looppath, O_RDWR)) < 0) {
virReportSystemError(errno,
_("Unable to open %s"), looppath);
VIR_FREE(looppath);
return -1;
}
*dev_name = looppath;
return 0;
}
# endif /* HAVE_DECL_LOOP_CTL_GET_FREE */
static int virFileLoopDeviceOpenSearch(char **dev_name)
{
int fd = -1;
DIR *dh = NULL;
struct dirent *de;
char *looppath = NULL;
struct loop_info64 lo;
int direrr;
VIR_DEBUG("Looking for loop devices in /dev");
if (!(dh = opendir("/dev"))) {
virReportSystemError(errno, "%s",
_("Unable to read /dev"));
goto cleanup;
}
while ((direrr = virDirRead(dh, &de, "/dev")) > 0) {
/* Checking 'loop' prefix is insufficient, since
* new kernels have a dev named 'loop-control'
*/
if (!STRPREFIX(de->d_name, "loop") ||
!c_isdigit(de->d_name[4]))
continue;
if (virAsprintf(&looppath, "/dev/%s", de->d_name) < 0)
goto cleanup;
VIR_DEBUG("Checking up on device %s", looppath);
if ((fd = open(looppath, O_RDWR)) < 0) {
virReportSystemError(errno,
_("Unable to open %s"), looppath);
goto cleanup;
}
if (ioctl(fd, LOOP_GET_STATUS64, &lo) < 0) {
/* Got a free device, return the fd */
if (errno == ENXIO)
goto cleanup;
VIR_FORCE_CLOSE(fd);
virReportSystemError(errno,
_("Unable to get loop status on %s"),
looppath);
goto cleanup;
}
/* Oh well, try the next device */
VIR_FORCE_CLOSE(fd);
VIR_FREE(looppath);
}
if (direrr < 0)
goto cleanup;
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Unable to find a free loop device in /dev"));
cleanup:
if (fd != -1) {
VIR_DEBUG("Got free loop device %s %d", looppath, fd);
*dev_name = looppath;
} else {
VIR_DEBUG("No free loop devices available");
VIR_FREE(looppath);
}
if (dh)
closedir(dh);
return fd;
}
static int virFileLoopDeviceOpen(char **dev_name)
{
int loop_fd = -1;
# if HAVE_DECL_LOOP_CTL_GET_FREE
if (virFileLoopDeviceOpenLoopCtl(dev_name, &loop_fd) < 0)
return -1;
VIR_DEBUG("Return from loop-control got fd %d\n", loop_fd);
if (loop_fd >= 0)
return loop_fd;
# endif /* HAVE_DECL_LOOP_CTL_GET_FREE */
/* Without the loop control device we just use the old technique. */
loop_fd = virFileLoopDeviceOpenSearch(dev_name);
return loop_fd;
}
int virFileLoopDeviceAssociate(const char *file,
char **dev)
{
int lofd = -1;
int fsfd = -1;
struct loop_info64 lo;
char *loname = NULL;
int ret = -1;
if ((lofd = virFileLoopDeviceOpen(&loname)) < 0)
return -1;
memset(&lo, 0, sizeof(lo));
lo.lo_flags = LO_FLAGS_AUTOCLEAR;
if ((fsfd = open(file, O_RDWR)) < 0) {
virReportSystemError(errno,
_("Unable to open %s"), file);
goto cleanup;
}
if (ioctl(lofd, LOOP_SET_FD, fsfd) < 0) {
virReportSystemError(errno,
_("Unable to attach %s to loop device"),
file);
goto cleanup;
}
if (ioctl(lofd, LOOP_SET_STATUS64, &lo) < 0) {
virReportSystemError(errno, "%s",
_("Unable to mark loop device as autoclear"));
if (ioctl(lofd, LOOP_CLR_FD, 0) < 0)
VIR_WARN("Unable to detach %s from loop device", file);
goto cleanup;
}
VIR_DEBUG("Attached loop device %s %d to %s", file, lofd, loname);
*dev = loname;
loname = NULL;
ret = 0;
cleanup:
VIR_FREE(loname);
VIR_FORCE_CLOSE(fsfd);
if (ret == -1)
VIR_FORCE_CLOSE(lofd);
return lofd;
}
# define SYSFS_BLOCK_DIR "/sys/block"
static int
virFileNBDDeviceIsBusy(const char *dev_name)
{
char *path;
int ret = -1;
if (virAsprintf(&path, SYSFS_BLOCK_DIR "/%s/pid",
dev_name) < 0)
return -1;
if (!virFileExists(path)) {
if (errno == ENOENT)
ret = 0;
else
virReportSystemError(errno,
_("Cannot check NBD device %s pid"),
dev_name);
goto cleanup;
}
ret = 1;
cleanup:
VIR_FREE(path);
return ret;
}
static char *
virFileNBDDeviceFindUnused(void)
{
DIR *dh;
char *ret = NULL;
struct dirent *de;
int direrr;
if (!(dh = opendir(SYSFS_BLOCK_DIR))) {
virReportSystemError(errno,
_("Cannot read directory %s"),
SYSFS_BLOCK_DIR);
return NULL;
}
while ((direrr = virDirRead(dh, &de, SYSFS_BLOCK_DIR)) > 0) {
if (STRPREFIX(de->d_name, "nbd")) {
int rv = virFileNBDDeviceIsBusy(de->d_name);
if (rv < 0)
goto cleanup;
if (rv == 0) {
if (virAsprintf(&ret, "/dev/%s", de->d_name) < 0)
goto cleanup;
goto cleanup;
}
}
}
if (direrr < 0)
goto cleanup;
virReportSystemError(EBUSY, "%s",
_("No free NBD devices"));
cleanup:
closedir(dh);
return ret;
}
int virFileNBDDeviceAssociate(const char *file,
virStorageFileFormat fmt,
bool readonly,
char **dev)
{
char *nbddev;
char *qemunbd = NULL;
virCommandPtr cmd = NULL;
int ret = -1;
const char *fmtstr = NULL;
if (!(nbddev = virFileNBDDeviceFindUnused()))
goto cleanup;
if (!(qemunbd = virFindFileInPath("qemu-nbd"))) {
virReportSystemError(ENOENT, "%s",
_("Unable to find 'qemu-nbd' binary in $PATH"));
goto cleanup;
}
if (fmt > 0)
fmtstr = virStorageFileFormatTypeToString(fmt);
cmd = virCommandNew(qemunbd);
/* Explicitly not trying to cope with old qemu-nbd which
* lacked --format. We want to see a fatal error in that
* case since it would be security flaw to continue */
if (fmtstr)
virCommandAddArgList(cmd, "--format", fmtstr, NULL);
if (readonly)
virCommandAddArg(cmd, "-r");
virCommandAddArgList(cmd,
"-n", /* Don't cache in qemu-nbd layer */
"-c", nbddev,
file, NULL);
/* qemu-nbd will daemonize itself */
if (virCommandRun(cmd, NULL) < 0)
goto cleanup;
VIR_DEBUG("Associated NBD device %s with file %s and format %s",
nbddev, file, fmtstr);
*dev = nbddev;
nbddev = NULL;
ret = 0;
cleanup:
VIR_FREE(nbddev);
VIR_FREE(qemunbd);
virCommandFree(cmd);
return ret;
}
#else /* __linux__ */
int virFileLoopDeviceAssociate(const char *file,
char **dev ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS,
_("Unable to associate file %s with loop device"),
file);
*dev = NULL;
return -1;
}
int virFileNBDDeviceAssociate(const char *file,
virStorageFileFormat fmt ATTRIBUTE_UNUSED,
bool readonly ATTRIBUTE_UNUSED,
char **dev ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS,
_("Unable to associate file %s with NBD device"),
file);
return -1;
}
#endif /* __linux__ */
/**
* virFileDeleteTree:
*
* Recursively deletes all files / directories
* starting from the directory @dir. Does not
* follow symlinks
*
* NB the algorithm is not efficient, and is subject to
* race conditions which can be exploited by malicious
* code. It should not be used in any scenarios where
* performance is important, or security is critical.
*/
int virFileDeleteTree(const char *dir)
{
DIR *dh = opendir(dir);
struct dirent *de;
char *filepath = NULL;
int ret = -1;
int direrr;
if (!dh) {
virReportSystemError(errno, _("Cannot open dir '%s'"),
dir);
return -1;
}
while ((direrr = virDirRead(dh, &de, dir)) > 0) {
struct stat sb;
if (STREQ(de->d_name, ".") ||
STREQ(de->d_name, ".."))
continue;
if (virAsprintf(&filepath, "%s/%s",
dir, de->d_name) < 0)
goto cleanup;
if (lstat(filepath, &sb) < 0) {
virReportSystemError(errno, _("Cannot access '%s'"),
filepath);
goto cleanup;
}
if (S_ISDIR(sb.st_mode)) {
if (virFileDeleteTree(filepath) < 0)
goto cleanup;
} else {
if (unlink(filepath) < 0 && errno != ENOENT) {
virReportSystemError(errno,
_("Cannot delete file '%s'"),
filepath);
goto cleanup;
}
}
VIR_FREE(filepath);
}
if (direrr < 0)
goto cleanup;
if (rmdir(dir) < 0 && errno != ENOENT) {
virReportSystemError(errno,
_("Cannot delete directory '%s'"),
dir);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(filepath);
closedir(dh);
return ret;
}
int
virFileStripSuffix(char *str, const char *suffix)
{
int len = strlen(str);
int suffixlen = strlen(suffix);
if (len < suffixlen)
return 0;
if (!STREQ(str + len - suffixlen, suffix))
return 0;
str[len-suffixlen] = '\0';
return 1;
}
/* Like read(), but restarts after EINTR. Doesn't play
* nicely with nonblocking FD and EAGAIN, in which case
* you want to use bare read(). Or even use virSocket()
* if the FD is related to a socket rather than a plain
* file or pipe. */
ssize_t
saferead(int fd, void *buf, size_t count)
{
size_t nread = 0;
while (count > 0) {
ssize_t r = read(fd, buf, count);
if (r < 0 && errno == EINTR)
continue;
if (r < 0)
return r;
if (r == 0)
return nread;
buf = (char *)buf + r;
count -= r;
nread += r;
}
return nread;
}
/* Like write(), but restarts after EINTR. Doesn't play
* nicely with nonblocking FD and EAGAIN, in which case
* you want to use bare write(). Or even use virSocket()
* if the FD is related to a socket rather than a plain
* file or pipe. */
ssize_t
safewrite(int fd, const void *buf, size_t count)
{
size_t nwritten = 0;
while (count > 0) {
ssize_t r = write(fd, buf, count);
if (r < 0 && errno == EINTR)
continue;
if (r < 0)
return r;
if (r == 0)
return nwritten;
buf = (const char *)buf + r;
count -= r;
nwritten += r;
}
return nwritten;
}
#ifdef HAVE_POSIX_FALLOCATE
int
safezero(int fd, off_t offset, off_t len)
{
int ret = posix_fallocate(fd, offset, len);
if (ret == 0)
return 0;
errno = ret;
return -1;
}
#else
int
safezero(int fd, off_t offset, off_t len)
{
int r;
char *buf;
unsigned long long remain, bytes;
# ifdef HAVE_MMAP
static long pagemask = 0;
off_t map_skip;
/* align offset and length, rounding offset down and length up */
if (pagemask == 0)
pagemask = ~(sysconf(_SC_PAGESIZE) - 1);
map_skip = offset - (offset & pagemask);
/* memset wants the mmap'ed file to be present on disk so create a
* sparse file
*/
r = ftruncate(fd, offset + len);
if (r < 0)
return -1;
buf = mmap(NULL, len + map_skip, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, offset - map_skip);
if (buf != MAP_FAILED) {
memset(buf + map_skip, 0, len);
munmap(buf, len + map_skip);
return 0;
}
/* fall back to writing zeroes using safewrite if mmap fails (for
* example because of virtual memory limits) */
# endif /* HAVE_MMAP */
if (lseek(fd, offset, SEEK_SET) < 0)
return -1;
/* Split up the write in small chunks so as not to allocate lots of RAM */
remain = len;
bytes = MIN(1024 * 1024, len);
r = VIR_ALLOC_N(buf, bytes);
if (r < 0) {
errno = ENOMEM;
return -1;
}
while (remain) {
if (bytes > remain)
bytes = remain;
r = safewrite(fd, buf, bytes);
if (r < 0) {
VIR_FREE(buf);
return -1;
}
/* safewrite() guarantees all data will be written */
remain -= bytes;
}
VIR_FREE(buf);
return 0;
}
#endif /* HAVE_POSIX_FALLOCATE */
#if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R
/* search /proc/mounts for mount point of *type; return pointer to
* malloc'ed string of the path if found, otherwise return NULL
* with errno set to an appropriate value.
*/
char *
virFileFindMountPoint(const char *type)
{
FILE *f;
struct mntent mb;
char mntbuf[1024];
char *ret = NULL;
f = setmntent("/proc/mounts", "r");
if (!f)
return NULL;
while (getmntent_r(f, &mb, mntbuf, sizeof(mntbuf))) {
if (STREQ(mb.mnt_type, type)) {
ignore_value(VIR_STRDUP_QUIET(ret, mb.mnt_dir));
goto cleanup;
}
}
if (!ret)
errno = ENOENT;
cleanup:
endmntent(f);
return ret;
}
#else /* defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R */
char *
virFileFindMountPoint(const char *type ATTRIBUTE_UNUSED)
{
errno = ENOSYS;
return NULL;
}
#endif /* defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R */
int
virBuildPathInternal(char **path, ...)
{
char *path_component = NULL;
virBuffer buf = VIR_BUFFER_INITIALIZER;
va_list ap;
int ret = 0;
va_start(ap, path);
path_component = va_arg(ap, char *);
virBufferAdd(&buf, path_component, -1);
while ((path_component = va_arg(ap, char *)) != NULL) {
virBufferAddChar(&buf, '/');
virBufferAdd(&buf, path_component, -1);
}
va_end(ap);
*path = virBufferContentAndReset(&buf);
if (*path == NULL) {
ret = -1;
}
return ret;
}
/* Like gnulib's fread_file, but read no more than the specified maximum
number of bytes. If the length of the input is <= max_len, and
upon error while reading that data, it works just like fread_file. */
static char *
saferead_lim(int fd, size_t max_len, size_t *length)
{
char *buf = NULL;
size_t alloc = 0;
size_t size = 0;
int save_errno;
for (;;) {
int count;
int requested;
if (size + BUFSIZ + 1 > alloc) {
alloc += alloc / 2;
if (alloc < size + BUFSIZ + 1)
alloc = size + BUFSIZ + 1;
if (VIR_REALLOC_N(buf, alloc) < 0) {
save_errno = errno;
break;
}
}
/* Ensure that (size + requested <= max_len); */
requested = MIN(size < max_len ? max_len - size : 0,
alloc - size - 1);
count = saferead(fd, buf + size, requested);
size += count;
if (count != requested || requested == 0) {
save_errno = errno;
if (count < 0)
break;
buf[size] = '\0';
*length = size;
return buf;
}
}
VIR_FREE(buf);
errno = save_errno;
return NULL;
}
/* A wrapper around saferead_lim that merely stops reading at the
* specified maximum size. */
int
virFileReadHeaderFD(int fd, int maxlen, char **buf)
{
size_t len;
char *s;
if (maxlen <= 0) {
errno = EINVAL;
return -1;
}
s = saferead_lim(fd, maxlen, &len);
if (s == NULL)
return -1;
*buf = s;
return len;
}
/* A wrapper around saferead_lim that maps a failure due to
exceeding the maximum size limitation to EOVERFLOW. */
int
virFileReadLimFD(int fd, int maxlen, char **buf)
{
size_t len;
char *s;
if (maxlen <= 0) {
errno = EINVAL;
return -1;
}
s = saferead_lim(fd, maxlen+1, &len);
if (s == NULL)
return -1;
if (len > maxlen || (int)len != len) {
VIR_FREE(s);
/* There was at least one byte more than MAXLEN.
Set errno accordingly. */
errno = EOVERFLOW;
return -1;
}
*buf = s;
return len;
}
int
virFileReadAll(const char *path, int maxlen, char **buf)
{
int fd = open(path, O_RDONLY);
if (fd < 0) {
virReportSystemError(errno, _("Failed to open file '%s'"), path);
return -1;
}
int len = virFileReadLimFD(fd, maxlen, buf);
VIR_FORCE_CLOSE(fd);
if (len < 0) {
virReportSystemError(errno, _("Failed to read file '%s'"), path);
return -1;
}
return len;
}
int
virFileReadAllQuiet(const char *path, int maxlen, char **buf)
{
int fd = open(path, O_RDONLY);
if (fd < 0)
return -errno;
int len = virFileReadLimFD(fd, maxlen, buf);
VIR_FORCE_CLOSE(fd);
if (len < 0)
return -errno;
return len;
}
/* Truncate @path and write @str to it. If @mode is 0, ensure that
@path exists; otherwise, use @mode if @path must be created.
Return 0 for success, nonzero for failure.
Be careful to preserve any errno value upon failure. */
int
virFileWriteStr(const char *path, const char *str, mode_t mode)
{
int fd;
if (mode)
fd = open(path, O_WRONLY|O_TRUNC|O_CREAT, mode);
else
fd = open(path, O_WRONLY|O_TRUNC);
if (fd == -1)
return -1;
if (safewrite(fd, str, strlen(str)) < 0) {
VIR_FORCE_CLOSE(fd);
return -1;
}
/* Use errno from failed close only if there was no write error. */
if (VIR_CLOSE(fd) != 0)
return -1;
return 0;
}
int
virFileMatchesNameSuffix(const char *file,
const char *name,
const char *suffix)
{
int filelen = strlen(file);
int namelen = strlen(name);
int suffixlen = strlen(suffix);
if (filelen == (namelen + suffixlen) &&
STREQLEN(file, name, namelen) &&
STREQLEN(file + namelen, suffix, suffixlen))
return 1;
else
return 0;
}
int
virFileHasSuffix(const char *str,
const char *suffix)
{
int len = strlen(str);
int suffixlen = strlen(suffix);
if (len < suffixlen)
return 0;
return STRCASEEQ(str + len - suffixlen, suffix);
}
#define SAME_INODE(Stat_buf_1, Stat_buf_2) \
((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
&& (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
/* Return nonzero if checkLink and checkDest
* refer to the same file. Otherwise, return 0.
*/
int
virFileLinkPointsTo(const char *checkLink,
const char *checkDest)
{
struct stat src_sb;
struct stat dest_sb;
return (stat(checkLink, &src_sb) == 0
&& stat(checkDest, &dest_sb) == 0
&& SAME_INODE(src_sb, dest_sb));
}
/* Return positive if checkLink (residing within directory if not
* absolute) and checkDest refer to the same file. Otherwise, return
* -1 on allocation failure (error reported), or 0 if not the same
* (silent).
*/
int
virFileRelLinkPointsTo(const char *directory,
const char *checkLink,
const char *checkDest)
{
char *candidate;
int ret;
if (*checkLink == '/')
return virFileLinkPointsTo(checkLink, checkDest);
if (!directory) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("cannot resolve '%s' without starting directory"),
checkLink);
return -1;
}
if (virAsprintf(&candidate, "%s/%s", directory, checkLink) < 0)
return -1;
ret = virFileLinkPointsTo(candidate, checkDest);
VIR_FREE(candidate);
return ret;
}
static int
virFileResolveLinkHelper(const char *linkpath,
bool intermediatePaths,
char **resultpath)
{
struct stat st;
*resultpath = NULL;
/* We don't need the full canonicalization of intermediate
* directories, if linkpath is absolute and the basename is
* already a non-symlink. */
if (IS_ABSOLUTE_FILE_NAME(linkpath) && !intermediatePaths) {
if (lstat(linkpath, &st) < 0)
return -1;
if (!S_ISLNK(st.st_mode))
return VIR_STRDUP_QUIET(*resultpath, linkpath) < 0 ? -1 : 0;
}
*resultpath = canonicalize_file_name(linkpath);
return *resultpath == NULL ? -1 : 0;
}
/*
* Attempt to resolve a symbolic link, returning an
* absolute path where only the last component is guaranteed
* not to be a symlink.
*
* Return 0 if path was not a symbolic, or the link was
* resolved. Return -1 with errno set upon error
*/
int
virFileResolveLink(const char *linkpath, char **resultpath)
{
return virFileResolveLinkHelper(linkpath, false, resultpath);
}
/*
* Attempt to resolve a symbolic link, returning an
* absolute path where every component is guaranteed
* not to be a symlink.
*
* Return 0 if path was not a symbolic, or the link was
* resolved. Return -1 with errno set upon error
*/
int
virFileResolveAllLinks(const char *linkpath, char **resultpath)
{
return virFileResolveLinkHelper(linkpath, true, resultpath);
}
/*
* Check whether the given file is a link.
* Returns 1 in case of the file being a link, 0 in case it is not
* a link and the negative errno in all other cases.
*/
int
virFileIsLink(const char *linkpath)
{
struct stat st;
if (lstat(linkpath, &st) < 0)
return -errno;
return S_ISLNK(st.st_mode) != 0;
}
/*
* Finds a requested executable file in the PATH env. e.g.:
* "kvm-img" will return "/usr/bin/kvm-img"
*
* You must free the result
*/
char *
virFindFileInPath(const char *file)
{
const char *origpath = NULL;
char *path = NULL;
char *pathiter;
char *pathseg;
char *fullpath = NULL;
if (file == NULL)
return NULL;
/* if we are passed an absolute path (starting with /), return a
* copy of that path, after validating that it is executable
*/
if (IS_ABSOLUTE_FILE_NAME(file)) {
char *ret = NULL;
if (virFileIsExecutable(file))
ignore_value(VIR_STRDUP_QUIET(ret, file));
return ret;
}
/* If we are passed an anchored path (containing a /), then there
* is no path search - it must exist in the current directory
*/
if (strchr(file, '/')) {
if (virFileIsExecutable(file))
ignore_value(virFileAbsPath(file, &path));
return path;
}
/* copy PATH env so we can tweak it */
origpath = virGetEnvBlockSUID("PATH");
if (!origpath)
origpath = "/bin:/usr/bin";
if (VIR_STRDUP_QUIET(path, origpath) <= 0)
return NULL;
/* for each path segment, append the file to search for and test for
* it. return it if found.
*/
pathiter = path;
while ((pathseg = strsep(&pathiter, ":")) != NULL) {
if (virAsprintf(&fullpath, "%s/%s", pathseg, file) < 0 ||
virFileIsExecutable(fullpath))
break;
VIR_FREE(fullpath);
}
VIR_FREE(path);
return fullpath;
}
static bool useDirOverride;
/**
* virFileFindResourceFull:
* @filename: libvirt distributed filename without any path
* @prefix: optional string to prepend to filename
* @suffix: optional string to append to filename
* @builddir: location of the binary in the source tree build tree
* @installdir: location of the installed binary
* @envname: environment variable used to override all dirs
*
* A helper which will return a path to @filename within
* the current build tree, if the calling binary is being
* run from the source tree. Otherwise it will return the
* path in the installed location.
*
* If @envname is non-NULL it will override all other
* directory lookup
*
* Only use this with @filename files that are part of
* the libvirt tree, not 3rd party binaries/files.
*
* Returns the resolved path (caller frees) or NULL on error
*/
char *
virFileFindResourceFull(const char *filename,
const char *prefix,
const char *suffix,
const char *builddir,
const char *installdir,
const char *envname)
{
char *ret = NULL;
const char *envval = envname ? virGetEnvBlockSUID(envname) : NULL;
if (!prefix)
prefix = "";
if (!suffix)
suffix = "";
if (envval) {
if (virAsprintf(&ret, "%s/%s%s%s", envval, prefix, filename, suffix) < 0)
return NULL;
} else if (useDirOverride) {
if (virAsprintf(&ret, "%s/%s/%s%s%s", abs_topbuilddir, builddir, prefix, filename, suffix) < 0)
return NULL;
} else {
if (virAsprintf(&ret, "%s/%s%s%s", installdir, prefix, filename, suffix) < 0)
return NULL;
}
VIR_DEBUG("Resolved '%s' to '%s'", filename, ret);
return ret;
}
char *
virFileFindResource(const char *filename,
const char *builddir,
const char *installdir)
{
return virFileFindResourceFull(filename, NULL, NULL, builddir, installdir, NULL);
}
/**
* virFileActivateDirOverride:
* @argv0: argv[0] of the calling program
*
* Look at @argv0 and try to detect if running from
* a build directory, by looking for a 'lt-' prefix
* on the binary name, or '/.libs/' in the path
*/
void
virFileActivateDirOverride(const char *argv0)
{
char *file = strrchr(argv0, '/');
if (!file || file[1] == '\0')
return;
file++;
if (STRPREFIX(file, "lt-") ||
strstr(argv0, "/.libs/")) {
useDirOverride = true;
VIR_DEBUG("Activating build dir override for %s", argv0);
}
}
bool
virFileIsDir(const char *path)
{
struct stat s;
return (stat(path, &s) == 0) && S_ISDIR(s.st_mode);
}
/**
* virFileExists: Check for presence of file
* @path: Path of file to check
*
* Returns if the file exists. Preserves errno in case it does not exist.
*/
bool
virFileExists(const char *path)
{
return access(path, F_OK) == 0;
}
/* Check that a file is regular and has executable bits. If false is
* returned, errno is valid.
*
* Note: In the presence of ACLs, this may return true for a file that
* would actually fail with EACCES for a given user, or false for a
* file that the user could actually execute, but setups with ACLs
* that weird are unusual. */
bool
virFileIsExecutable(const char *file)
{
struct stat sb;
/* We would also want to check faccessat if we cared about ACLs,
* but we don't. */
if (stat(file, &sb) < 0)
return false;
if (S_ISREG(sb.st_mode) && (sb.st_mode & 0111) != 0)
return true;
errno = S_ISDIR(sb.st_mode) ? EISDIR : EACCES;
return false;
}
/*
* Check that a file refers to a mount point. Trick is that for
* a mount point, the st_dev field will differ from the parent
* directory.
*
* Note that this will not detect bind mounts of dirs/files,
* only true filesystem mounts.
*/
int virFileIsMountPoint(const char *file)
{
char *parent = NULL;
int ret = -1;
struct stat sb1, sb2;
if (!(parent = mdir_name(file))) {
virReportOOMError();
goto cleanup;
}
VIR_DEBUG("Comparing '%s' to '%s'", file, parent);
if (stat(file, &sb1) < 0) {
if (errno == ENOENT)
ret = 0;
else
virReportSystemError(errno,
_("Cannot stat '%s'"),
file);
goto cleanup;
}
if (stat(parent, &sb2) < 0) {
virReportSystemError(errno,
_("Cannot stat '%s'"),
parent);
goto cleanup;
}
if (!S_ISDIR(sb1.st_mode)) {
ret = 0;
goto cleanup;
}
ret = sb1.st_dev != sb2.st_dev;
VIR_DEBUG("Is mount %d", ret);
cleanup:
VIR_FREE(parent);
return ret;
}
#if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R
static int
virFileGetMountSubtreeImpl(const char *mtabpath,
const char *prefix,
char ***mountsret,
size_t *nmountsret,
bool reverse)
{
FILE *procmnt;
struct mntent mntent;
char mntbuf[1024];
int ret = -1;
char **mounts = NULL;
size_t nmounts = 0;
VIR_DEBUG("prefix=%s", prefix);
*mountsret = NULL;
*nmountsret = 0;
if (!(procmnt = setmntent(mtabpath, "r"))) {
virReportSystemError(errno,
_("Failed to read %s"), mtabpath);
return -1;
}
while (getmntent_r(procmnt, &mntent, mntbuf, sizeof(mntbuf)) != NULL) {
if (!(STREQ(mntent.mnt_dir, prefix) ||
(STRPREFIX(mntent.mnt_dir, prefix) &&
mntent.mnt_dir[strlen(prefix)] == '/')))
continue;
if (VIR_EXPAND_N(mounts, nmounts, nmounts ? 1 : 2) < 0)
goto cleanup;
if (VIR_STRDUP(mounts[nmounts - 2], mntent.mnt_dir) < 0)
goto cleanup;
}
if (mounts)
qsort(mounts, nmounts - 1, sizeof(mounts[0]),
reverse ? virStringSortRevCompare : virStringSortCompare);
*mountsret = mounts;
*nmountsret = nmounts ? nmounts - 1 : 0;
ret = 0;
cleanup:
if (ret < 0)
virStringFreeList(mounts);
endmntent(procmnt);
return ret;
}
#else /* ! defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R */
static int
virFileGetMountSubtreeImpl(const char *mtabpath ATTRIBUTE_UNUSED,
const char *prefix ATTRIBUTE_UNUSED,
char ***mountsret ATTRIBUTE_UNUSED,
size_t *nmountsret ATTRIBUTE_UNUSED,
bool reverse ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, "%s",
_("Unable to determine mount table on this platform"));
return -1;
}
#endif /* ! defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R */
/**
* virFileGetMountSubtree:
* @mtabpath: mount file to parser (eg /proc/mounts)
* @prefix: mount path prefix to match
* @mountsret: allocated and filled with matching mounts
* @nmountsret: filled with number of matching mounts, not counting NULL terminator
*
* Return the list of mounts from @mtabpath which contain
* the path @prefix, sorted from shortest to longest path.
*
* The @mountsret array will be NULL terminated and should
* be freed with virStringFreeList
*
* Returns 0 on success, -1 on error
*/
int virFileGetMountSubtree(const char *mtabpath,
const char *prefix,
char ***mountsret,
size_t *nmountsret)
{
return virFileGetMountSubtreeImpl(mtabpath, prefix, mountsret, nmountsret, false);
}
/**
* virFileGetMountReverseSubtree:
* @mtabpath: mount file to parser (eg /proc/mounts)
* @prefix: mount path prefix to match
* @mountsret: allocated and filled with matching mounts
* @nmountsret: filled with number of matching mounts, not counting NULL terminator
*
* Return the list of mounts from @mtabpath which contain
* the path @prefix, sorted from longest to shortest path.
* ie opposite order to which they appear in @mtabpath
*
* The @mountsret array will be NULL terminated and should
* be freed with virStringFreeList
*
* Returns 0 on success, -1 on error
*/
int virFileGetMountReverseSubtree(const char *mtabpath,
const char *prefix,
char ***mountsret,
size_t *nmountsret)
{
return virFileGetMountSubtreeImpl(mtabpath, prefix, mountsret, nmountsret, true);
}
#ifndef WIN32
/* Check that a file is accessible under certain
* user & gid.
* @mode can be F_OK, or a bitwise combination of R_OK, W_OK, and X_OK.
* see 'man access' for more details.
* Returns 0 on success, -1 on fail with errno set.
*/
int
virFileAccessibleAs(const char *path, int mode,
uid_t uid, gid_t gid)
{
pid_t pid = 0;
int status, ret = 0;
int forkRet = 0;
gid_t *groups;
int ngroups;
if (uid == geteuid() &&
gid == getegid())
return access(path, mode);
ngroups = virGetGroupList(uid, gid, &groups);
if (ngroups < 0)
return -1;
pid = virFork();
if (pid < 0) {
VIR_FREE(groups);
return -1;
}
if (pid) { /* parent */
VIR_FREE(groups);
if (virProcessWait(pid, &status, false) < 0) {
/* virProcessWait() already reported error */
errno = EINTR;
return -1;
}
if (status) {
errno = status;
return -1;
}
return 0;
}
/* child.
* Return positive value here. Parent
* will change it to negative one. */
if (forkRet < 0) {
ret = errno;
goto childerror;
}
if (virSetUIDGID(uid, gid, groups, ngroups) < 0) {
ret = errno;
goto childerror;
}
if (access(path, mode) < 0)
ret = errno;
childerror:
if ((ret & 0xFF) != ret) {
VIR_WARN("unable to pass desired return value %d", ret);
ret = 0xFF;
}
_exit(ret);
}
/* virFileOpenForceOwnerMode() - an internal utility function called
* only by virFileOpenAs(). Sets the owner and mode of the file
* opened as "fd" if it's not correct AND the flags say it should be
* forced. */
static int
virFileOpenForceOwnerMode(const char *path, int fd, mode_t mode,
uid_t uid, gid_t gid, unsigned int flags)
{
int ret = 0;
struct stat st;
if (!(flags & (VIR_FILE_OPEN_FORCE_OWNER | VIR_FILE_OPEN_FORCE_MODE)))
return 0;
if (fstat(fd, &st) == -1) {
ret = -errno;
virReportSystemError(errno, _("stat of '%s' failed"), path);
return ret;
}
/* NB: uid:gid are never "-1" (default) at this point - the caller
* has always changed -1 to the value of get[gu]id().
*/
if ((flags & VIR_FILE_OPEN_FORCE_OWNER) &&
((st.st_uid != uid) || (st.st_gid != gid)) &&
(fchown(fd, uid, gid) < 0)) {
ret = -errno;
virReportSystemError(errno,
_("cannot chown '%s' to (%u, %u)"),
path, (unsigned int) uid,
(unsigned int) gid);
return ret;
}
if ((flags & VIR_FILE_OPEN_FORCE_MODE) &&
((mode & (S_IRWXU|S_IRWXG|S_IRWXO)) !=
(st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO))) &&
(fchmod(fd, mode) < 0)) {
ret = -errno;
virReportSystemError(errno,
_("cannot set mode of '%s' to %04o"),
path, mode);
return ret;
}
return ret;
}
/* virFileOpenForked() - an internal utility function called only by
* virFileOpenAs(). It forks, then the child does setuid+setgid to
* given uid:gid and attempts to open the file, while the parent just
* calls recvfd to get the open fd back from the child. returns the
* fd, or -errno if there is an error. */
static int
virFileOpenForked(const char *path, int openflags, mode_t mode,
uid_t uid, gid_t gid, unsigned int flags)
{
pid_t pid;
int waitret, status, ret = 0;
int fd = -1;
int pair[2] = { -1, -1 };
gid_t *groups;
int ngroups;
/* parent is running as root, but caller requested that the
* file be opened as some other user and/or group). The
* following dance avoids problems caused by root-squashing
* NFS servers. */
ngroups = virGetGroupList(uid, gid, &groups);
if (ngroups < 0)
return -errno;
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) < 0) {
ret = -errno;
virReportSystemError(errno,
_("failed to create socket needed for '%s'"),
path);
VIR_FREE(groups);
return ret;
}
pid = virFork();
if (pid < 0) {
ret = -errno;
VIR_FREE(groups);
return ret;
}
if (pid == 0) {
/* child */
/* set desired uid/gid, then attempt to create the file */
VIR_FORCE_CLOSE(pair[0]);
if (virSetUIDGID(uid, gid, groups, ngroups) < 0) {
ret = -errno;
goto childerror;
}
if ((fd = open(path, openflags, mode)) < 0) {
ret = -errno;
virReportSystemError(errno,
_("child process failed to create file '%s'"),
path);
goto childerror;
}
/* File is successfully open. Set permissions if requested. */
ret = virFileOpenForceOwnerMode(path, fd, mode, uid, gid, flags);
if (ret < 0)
goto childerror;
do {
ret = sendfd(pair[1], fd);
} while (ret < 0 && errno == EINTR);
if (ret < 0) {
ret = -errno;
virReportSystemError(errno, "%s",
_("child process failed to send fd to parent"));
goto childerror;
}
childerror:
/* ret tracks -errno on failure, but exit value must be positive.
* If the child exits with EACCES, then the parent tries again. */
/* XXX This makes assumptions about errno being < 255, which is
* not true on Hurd. */
VIR_FORCE_CLOSE(pair[1]);
if (ret < 0) {
VIR_FORCE_CLOSE(fd);
}
ret = -ret;
if ((ret & 0xff) != ret) {
VIR_WARN("unable to pass desired return value %d", ret);
ret = 0xff;
}
_exit(ret);
}
/* parent */
VIR_FREE(groups);
VIR_FORCE_CLOSE(pair[1]);
do {
fd = recvfd(pair[0], 0);
} while (fd < 0 && errno == EINTR);
VIR_FORCE_CLOSE(pair[0]); /* NB: this preserves errno */
if (fd < 0 && errno != EACCES) {
ret = -errno;
while (waitpid(pid, NULL, 0) == -1 && errno == EINTR);
return ret;
}
/* wait for child to complete, and retrieve its exit code */
while ((waitret = waitpid(pid, &status, 0)) == -1 && errno == EINTR);
if (waitret == -1) {
ret = -errno;
virReportSystemError(errno,
_("failed to wait for child creating '%s'"),
path);
VIR_FORCE_CLOSE(fd);
return ret;
}
if (!WIFEXITED(status) || (ret = -WEXITSTATUS(status)) == -EACCES ||
fd == -1) {
/* fall back to the simpler method, which works better in
* some cases */
VIR_FORCE_CLOSE(fd);
if (flags & VIR_FILE_OPEN_NOFORK) {
/* If we had already tried opening w/o fork+setuid and
* failed, no sense trying again. Just set return the
* original errno that we got at that time (by
* definition, always either EACCES or EPERM - EACCES
* is close enough).
*/
return -EACCES;
}
if ((fd = open(path, openflags, mode)) < 0)
return -errno;
ret = virFileOpenForceOwnerMode(path, fd, mode, uid, gid, flags);
if (ret < 0) {
VIR_FORCE_CLOSE(fd);
return ret;
}
}
return fd;
}
/**
* virFileOpenAs:
* @path: file to open or create
* @openflags: flags to pass to open
* @mode: mode to use on creation or when forcing permissions
* @uid: uid that should own file on creation
* @gid: gid that should own file
* @flags: bit-wise or of VIR_FILE_OPEN_* flags
*
* Open @path, and return an fd to the open file. @openflags contains
* the flags normally passed to open(2), while those in @flags are
* used internally. If @flags includes VIR_FILE_OPEN_NOFORK, then try
* opening the file while executing with the current uid:gid
* (i.e. don't fork+setuid+setgid before the call to open()). If
* @flags includes VIR_FILE_OPEN_FORK, then try opening the file while
* the effective user id is @uid (by forking a child process); this
* allows one to bypass root-squashing NFS issues; NOFORK is always
* tried before FORK (the absence of both flags is treated identically
* to (VIR_FILE_OPEN_NOFORK | VIR_FILE_OPEN_FORK)). If @flags includes
* VIR_FILE_OPEN_FORCE_OWNER, then ensure that @path is owned by
* uid:gid before returning (even if it already existed with a
* different owner). If @flags includes VIR_FILE_OPEN_FORCE_MODE,
* ensure it has those permissions before returning (again, even if
* the file already existed with different permissions).
*
* The return value (if non-negative) is the file descriptor, left
* open. Returns -errno on failure.
*/
int
virFileOpenAs(const char *path, int openflags, mode_t mode,
uid_t uid, gid_t gid, unsigned int flags)
{
int ret = 0, fd = -1;
/* allow using -1 to mean "current value" */
if (uid == (uid_t) -1)
uid = geteuid();
if (gid == (gid_t) -1)
gid = getegid();
/* treat absence of both flags as presence of both for simpler
* calling. */
if (!(flags & (VIR_FILE_OPEN_NOFORK|VIR_FILE_OPEN_FORK)))
flags |= VIR_FILE_OPEN_NOFORK|VIR_FILE_OPEN_FORK;
if ((flags & VIR_FILE_OPEN_NOFORK)
|| (geteuid() != 0)
|| ((uid == 0) && (gid == 0))) {
if ((fd = open(path, openflags, mode)) < 0) {
ret = -errno;
if (!(flags & VIR_FILE_OPEN_FORK))
goto error;
} else {
ret = virFileOpenForceOwnerMode(path, fd, mode, uid, gid, flags);
if (ret < 0)
goto error;
}
}
/* If we either 1) didn't try opening as current user at all, or
* 2) failed, and errno/virStorageFileIsSharedFS indicate we might
* be successful if we try as a different uid, then try doing
* fork+setuid+setgid before opening.
*/
if ((fd < 0) && (flags & VIR_FILE_OPEN_FORK)) {
if (ret < 0) {
/* An open(2) that failed due to insufficient permissions
* could return one or the other of these depending on OS
* version and circumstances. Any other errno indicates a
* problem that couldn't be remedied by fork+setuid
* anyway. */
if (ret != -EACCES && ret != -EPERM)
goto error;
/* On Linux we can also verify the FS-type of the
* directory. (this is a NOP on other platforms). */
if (virFileIsSharedFS(path) <= 0)
goto error;
}
/* passed all prerequisites - retry the open w/fork+setuid */
if ((fd = virFileOpenForked(path, openflags, mode, uid, gid, flags)) < 0) {
ret = fd;
goto error;
}
}
/* File is successfully opened */
return fd;
error:
if (fd >= 0) {
/* some other failure after the open succeeded */
VIR_FORCE_CLOSE(fd);
}
/* whoever failed the open last has already set ret = -errno */
return ret;
}
/* return -errno on failure, or 0 on success */
static int
virDirCreateNoFork(const char *path,
mode_t mode, uid_t uid, gid_t gid,
unsigned int flags)
{
int ret = 0;
struct stat st;
if ((mkdir(path, mode) < 0)
&& !((errno == EEXIST) && (flags & VIR_DIR_CREATE_ALLOW_EXIST))) {
ret = -errno;
virReportSystemError(errno, _("failed to create directory '%s'"),
path);
goto error;
}
if (stat(path, &st) == -1) {
ret = -errno;
virReportSystemError(errno, _("stat of '%s' failed"), path);
goto error;
}
if (((st.st_uid != uid) || (st.st_gid != gid))
&& (chown(path, uid, gid) < 0)) {
ret = -errno;
virReportSystemError(errno, _("cannot chown '%s' to (%u, %u)"),
path, (unsigned int) uid, (unsigned int) gid);
goto error;
}
if ((flags & VIR_DIR_CREATE_FORCE_PERMS)
&& (chmod(path, mode) < 0)) {
ret = -errno;
virReportSystemError(errno,
_("cannot set mode of '%s' to %04o"),
path, mode);
goto error;
}
error:
return ret;
}
/* return -errno on failure, or 0 on success */
int
virDirCreate(const char *path,
mode_t mode, uid_t uid, gid_t gid,
unsigned int flags)
{
struct stat st;
pid_t pid;
int waitret;
int status, ret = 0;
gid_t *groups;
int ngroups;
/* allow using -1 to mean "current value" */
if (uid == (uid_t) -1)
uid = geteuid();
if (gid == (gid_t) -1)
gid = getegid();
if ((!(flags & VIR_DIR_CREATE_AS_UID))
|| (geteuid() != 0)
|| ((uid == 0) && (gid == 0))
|| ((flags & VIR_DIR_CREATE_ALLOW_EXIST) && (stat(path, &st) >= 0))) {
return virDirCreateNoFork(path, mode, uid, gid, flags);
}
ngroups = virGetGroupList(uid, gid, &groups);
if (ngroups < 0)
return -errno;
pid = virFork();
if (pid < 0) {
ret = -errno;
VIR_FREE(groups);
return ret;
}
if (pid) { /* parent */
/* wait for child to complete, and retrieve its exit code */
VIR_FREE(groups);
while ((waitret = waitpid(pid, &status, 0)) == -1 && errno == EINTR);
if (waitret == -1) {
ret = -errno;
virReportSystemError(errno,
_("failed to wait for child creating '%s'"),
path);
goto parenterror;
}
if (!WIFEXITED(status) || (ret = -WEXITSTATUS(status)) == -EACCES) {
/* fall back to the simpler method, which works better in
* some cases */
return virDirCreateNoFork(path, mode, uid, gid, flags);
}
parenterror:
return ret;
}
/* child */
/* set desired uid/gid, then attempt to create the directory */
if (virSetUIDGID(uid, gid, groups, ngroups) < 0) {
ret = -errno;
goto childerror;
}
if (mkdir(path, mode) < 0) {
ret = -errno;
if (ret != -EACCES) {
/* in case of EACCES, the parent will retry */
virReportSystemError(errno, _("child failed to create directory '%s'"),
path);
}
goto childerror;
}
/* check if group was set properly by creating after
* setgid. If not, try doing it with chown */
if (stat(path, &st) == -1) {
ret = -errno;
virReportSystemError(errno,
_("stat of '%s' failed"), path);
goto childerror;
}
if ((st.st_gid != gid) && (chown(path, (uid_t) -1, gid) < 0)) {
ret = -errno;
virReportSystemError(errno,
_("cannot chown '%s' to group %u"),
path, (unsigned int) gid);
goto childerror;
}
if ((flags & VIR_DIR_CREATE_FORCE_PERMS)
&& chmod(path, mode) < 0) {
virReportSystemError(errno,
_("cannot set mode of '%s' to %04o"),
path, mode);
goto childerror;
}
childerror:
_exit(ret);
}
#else /* WIN32 */
int
virFileAccessibleAs(const char *path,
int mode,
uid_t uid ATTRIBUTE_UNUSED,
gid_t gid ATTRIBUTE_UNUSED)
{
VIR_WARN("Ignoring uid/gid due to WIN32");
return access(path, mode);
}
/* return -errno on failure, or 0 on success */
int
virFileOpenAs(const char *path ATTRIBUTE_UNUSED,
int openflags ATTRIBUTE_UNUSED,
mode_t mode ATTRIBUTE_UNUSED,
uid_t uid ATTRIBUTE_UNUSED,
gid_t gid ATTRIBUTE_UNUSED,
unsigned int flags_unused ATTRIBUTE_UNUSED)
{
virReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virFileOpenAs is not implemented for WIN32"));
return -ENOSYS;
}
int
virDirCreate(const char *path ATTRIBUTE_UNUSED,
mode_t mode ATTRIBUTE_UNUSED,
uid_t uid ATTRIBUTE_UNUSED,
gid_t gid ATTRIBUTE_UNUSED,
unsigned int flags_unused ATTRIBUTE_UNUSED)
{
virReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virDirCreate is not implemented for WIN32"));
return -ENOSYS;
}
#endif /* WIN32 */
/**
* virDirRead:
* @dirp: directory to read
* @end: output one entry
* @name: if non-NULL, the name related to @dirp for use in error reporting
*
* Wrapper around readdir. Typical usage:
* struct dirent ent;
* int value;
* DIR *dir;
* if (!(dir = opendir(name)))
* goto error;
* while ((value = virDirRead(dir, &ent, name)) > 0)
* process ent;
* if (value < 0)
* goto error;
*
* Returns -1 on error, with error already reported if @name was
* supplied. On success, returns 1 for entry read, 0 for end-of-dir.
*/
int virDirRead(DIR *dirp, struct dirent **ent, const char *name)
{
errno = 0;
*ent = readdir(dirp); /* exempt from syntax-check */
if (!*ent && errno) {
if (name)
virReportSystemError(errno, _("Unable to read directory '%s'"),
name);
return -1;
}
return !!*ent;
}
static int
virFileMakePathHelper(char *path, mode_t mode)
{
struct stat st;
char *p;
VIR_DEBUG("path=%s mode=0%o", path, mode);
if (stat(path, &st) >= 0) {
if (S_ISDIR(st.st_mode))
return 0;
errno = ENOTDIR;
return -1;
}
if (errno != ENOENT)
return -1;
if ((p = strrchr(path, '/')) == NULL) {
errno = EINVAL;
return -1;
}
if (p != path) {
*p = '\0';
if (virFileMakePathHelper(path, mode) < 0)
return -1;
*p = '/';
}
if (mkdir(path, mode) < 0 && errno != EEXIST)
return -1;
return 0;
}
/**
* Creates the given directory with mode 0777 if it's not already existing.
*
* Returns 0 on success, or -1 if an error occurred (in which case, errno
* is set appropriately).
*/
int
virFileMakePath(const char *path)
{
return virFileMakePathWithMode(path, 0777);
}
int
virFileMakePathWithMode(const char *path,
mode_t mode)
{
int ret = -1;
char *tmp;
if (VIR_STRDUP(tmp, path) < 0) {
errno = ENOMEM;
goto cleanup;
}
ret = virFileMakePathHelper(tmp, mode);
cleanup:
VIR_FREE(tmp);
return ret;
}
int
virFileMakeParentPath(const char *path)
{
char *p;
char *tmp;
int ret = -1;
VIR_DEBUG("path=%s", path);
if (VIR_STRDUP(tmp, path) < 0) {
errno = ENOMEM;
return -1;
}
if ((p = strrchr(tmp, '/')) == NULL) {
errno = EINVAL;
goto cleanup;
}
*p = '\0';
ret = virFileMakePathHelper(tmp, 0777);
cleanup:
VIR_FREE(tmp);
return ret;
}
/* Build up a fully qualified path for a config file to be
* associated with a persistent guest or network */
char *
virFileBuildPath(const char *dir, const char *name, const char *ext)
{
char *path;
if (ext == NULL) {
ignore_value(virAsprintf(&path, "%s/%s", dir, name));
} else {
ignore_value(virAsprintf(&path, "%s/%s%s", dir, name, ext));
}
return path;
}
/* Open a non-blocking master side of a pty. If ttyName is not NULL,
* then populate it with the name of the slave. If rawmode is set,
* also put the master side into raw mode before returning. */
#ifndef WIN32
int
virFileOpenTty(int *ttymaster, char **ttyName, int rawmode)
{
/* XXX A word of caution - on some platforms (Solaris and HP-UX),
* additional ioctl() calls are needs after opening the slave
* before it will cause isatty() to return true. Should we make
* virFileOpenTty also return the opened slave fd, so the caller
* doesn't have to worry about that mess? */
int ret = -1;
int slave = -1;
char *name = NULL;
/* Unfortunately, we can't use the name argument of openpty, since
* there is no guarantee on how large the buffer has to be.
* Likewise, we can't use the termios argument: we have to use
* read-modify-write since there is no portable way to initialize
* a struct termios without use of tcgetattr. */
if (openpty(ttymaster, &slave, NULL, NULL, NULL) < 0)
return -1;
/* What a shame that openpty cannot atomically set FD_CLOEXEC, but
* that using posix_openpt/grantpt/unlockpt/ptsname is not
* thread-safe, and that ptsname_r is not portable. */
if (virSetNonBlock(*ttymaster) < 0 ||
virSetCloseExec(*ttymaster) < 0)
goto cleanup;
/* While Linux supports tcgetattr on either the master or the
* slave, Solaris requires it to be on the slave. */
if (rawmode) {
struct termios ttyAttr;
if (tcgetattr(slave, &ttyAttr) < 0)
goto cleanup;
cfmakeraw(&ttyAttr);
if (tcsetattr(slave, TCSADRAIN, &ttyAttr) < 0)
goto cleanup;
}
/* ttyname_r on the slave is required by POSIX, while ptsname_r on
* the master is a glibc extension, and the POSIX ptsname is not
* thread-safe. Since openpty gave us both descriptors, guess
* which way we will determine the name? :) */
if (ttyName) {
/* Initial guess of 64 is generally sufficient; rely on ERANGE
* to tell us if we need to grow. */
size_t len = 64;
int rc;
if (VIR_ALLOC_N(name, len) < 0)
goto cleanup;
while ((rc = ttyname_r(slave, name, len)) == ERANGE) {
if (VIR_RESIZE_N(name, len, len, len) < 0)
goto cleanup;
}
if (rc != 0) {
errno = rc;
goto cleanup;
}
*ttyName = name;
name = NULL;
}
ret = 0;
cleanup:
if (ret != 0)
VIR_FORCE_CLOSE(*ttymaster);
VIR_FORCE_CLOSE(slave);
VIR_FREE(name);
return ret;
}
#else /* WIN32 */
int
virFileOpenTty(int *ttymaster ATTRIBUTE_UNUSED,
char **ttyName ATTRIBUTE_UNUSED,
int rawmode ATTRIBUTE_UNUSED)
{
/* mingw completely lacks pseudo-terminals, and the gnulib
* replacements are not (yet) license compatible. */
errno = ENOSYS;
return -1;
}
#endif /* WIN32 */
bool
virFileIsAbsPath(const char *path)
{
if (!path)
return false;
if (VIR_FILE_IS_DIR_SEPARATOR(path[0]))
return true;
#ifdef WIN32
if (c_isalpha(path[0]) &&
path[1] == ':' &&
VIR_FILE_IS_DIR_SEPARATOR(path[2]))
return true;
#endif
return false;
}
const char *
virFileSkipRoot(const char *path)
{
#ifdef WIN32
/* Skip \\server\share or //server/share */
if (VIR_FILE_IS_DIR_SEPARATOR(path[0]) &&
VIR_FILE_IS_DIR_SEPARATOR(path[1]) &&
path[2] &&
!VIR_FILE_IS_DIR_SEPARATOR(path[2]))
{
const char *p = strchr(path + 2, VIR_FILE_DIR_SEPARATOR);
const char *q = strchr(path + 2, '/');
if (p == NULL || (q != NULL && q < p))
p = q;
if (p && p > path + 2 && p[1]) {
path = p + 1;
while (path[0] &&
!VIR_FILE_IS_DIR_SEPARATOR(path[0]))
path++;
/* Possibly skip a backslash after the share name */
if (VIR_FILE_IS_DIR_SEPARATOR(path[0]))
path++;
return path;
}
}
#endif
/* Skip initial slashes */
if (VIR_FILE_IS_DIR_SEPARATOR(path[0])) {
while (VIR_FILE_IS_DIR_SEPARATOR(path[0]))
path++;
return path;
}
#ifdef WIN32
/* Skip X:\ */
if (c_isalpha(path[0]) &&
path[1] == ':' &&
VIR_FILE_IS_DIR_SEPARATOR(path[2]))
return path + 3;
#endif
return path;
}
/*
* Creates an absolute path for a potentially relative path.
* Return 0 if the path was not relative, or on success.
* Return -1 on error.
*
* You must free the result.
*/
int
virFileAbsPath(const char *path, char **abspath)
{
char *buf;
if (path[0] == '/') {
if (VIR_STRDUP(*abspath, path) < 0)
return -1;
} else {
buf = getcwd(NULL, 0);
if (buf == NULL)
return -1;
if (virAsprintf(abspath, "%s/%s", buf, path) < 0) {
VIR_FREE(buf);
return -1;
}
VIR_FREE(buf);
}
return 0;
}
/* Remove spurious / characters from a path. The result must be freed */
char *
virFileSanitizePath(const char *path)
{
const char *cur = path;
char *cleanpath;
int idx = 0;
if (VIR_STRDUP(cleanpath, path) < 0)
return NULL;
/* Need to sanitize:
* // -> //
* /// -> /
* /../foo -> /../foo
* /foo///bar/ -> /foo/bar
*/
/* Starting with // is valid posix, but ///foo == /foo */
if (cur[0] == '/' && cur[1] == '/' && cur[2] != '/') {
idx = 2;
cur += 2;
}
/* Sanitize path in place */
while (*cur != '\0') {
if (*cur != '/') {
cleanpath[idx++] = *cur++;
continue;
}
/* Skip all extra / */
while (*++cur == '/')
continue;
/* Don't add a trailing / */
if (idx != 0 && *cur == '\0')
break;
cleanpath[idx++] = '/';
}
cleanpath[idx] = '\0';
return cleanpath;
}
/**
* virFilePrintf:
*
* A replacement for fprintf() which uses virVasprintf to
* ensure that portable string format placeholders can be
* used, since gnulib's fprintf() replacement is not
* LGPLV2+ compatible
*/
int virFilePrintf(FILE *fp, const char *msg, ...)
{
va_list vargs;
char *str;
int ret;
va_start(vargs, msg);
if ((ret = virVasprintf(&str, msg, vargs)) < 0)
goto cleanup;
if (fwrite(str, 1, ret, fp) != ret) {
virReportSystemError(errno, "%s",
_("Could not write to stream"));
ret = -1;
}
VIR_FREE(str);
cleanup:
va_end(vargs);
return ret;
}
#ifdef __linux__
# ifndef NFS_SUPER_MAGIC
# define NFS_SUPER_MAGIC 0x6969
# endif
# ifndef OCFS2_SUPER_MAGIC
# define OCFS2_SUPER_MAGIC 0x7461636f
# endif
# ifndef GFS2_MAGIC
# define GFS2_MAGIC 0x01161970
# endif
# ifndef AFS_FS_MAGIC
# define AFS_FS_MAGIC 0x6B414653
# endif
# ifndef SMB_SUPER_MAGIC
# define SMB_SUPER_MAGIC 0x517B
# endif
# ifndef CIFS_SUPER_MAGIC
# define CIFS_SUPER_MAGIC 0xFF534D42
# endif
# ifndef HUGETLBFS_MAGIC
# define HUGETLBFS_MAGIC 0x958458f6
# endif
int
virFileIsSharedFSType(const char *path,
int fstypes)
{
char *dirpath, *p;
struct statfs sb;
int statfs_ret;
if (VIR_STRDUP(dirpath, path) < 0)
return -1;
do {
/* Try less and less of the path until we get to a
* directory we can stat. Even if we don't have 'x'
* permission on any directory in the path on the NFS
* server (assuming it's NFS), we will be able to stat the
* mount point, and that will properly tell us if the
* fstype is NFS.
*/
if ((p = strrchr(dirpath, '/')) == NULL) {
virReportSystemError(EINVAL,
_("Invalid relative path '%s'"), path);
VIR_FREE(dirpath);
return -1;
}
if (p == dirpath)
*(p+1) = '\0';
else
*p = '\0';
statfs_ret = statfs(dirpath, &sb);
} while ((statfs_ret < 0) && (p != dirpath));
VIR_FREE(dirpath);
if (statfs_ret < 0) {
virReportSystemError(errno,
_("cannot determine filesystem for '%s'"),
path);
return -1;
}
VIR_DEBUG("Check if path %s with FS magic %lld is shared",
path, (long long int)sb.f_type);
if ((fstypes & VIR_FILE_SHFS_NFS) &&
(sb.f_type == NFS_SUPER_MAGIC))
return 1;
if ((fstypes & VIR_FILE_SHFS_GFS2) &&
(sb.f_type == GFS2_MAGIC))
return 1;
if ((fstypes & VIR_FILE_SHFS_OCFS) &&
(sb.f_type == OCFS2_SUPER_MAGIC))
return 1;
if ((fstypes & VIR_FILE_SHFS_AFS) &&
(sb.f_type == AFS_FS_MAGIC))
return 1;
if ((fstypes & VIR_FILE_SHFS_SMB) &&
(sb.f_type == SMB_SUPER_MAGIC))
return 1;
if ((fstypes & VIR_FILE_SHFS_CIFS) &&
(sb.f_type == CIFS_SUPER_MAGIC))
return 1;
return 0;
}
int
virFileGetHugepageSize(const char *path,
unsigned long long *size)
{
int ret = -1;
struct statfs fs;
if (statfs(path, &fs) < 0) {
virReportSystemError(errno,
_("cannot determine filesystem for '%s'"),
path);
goto cleanup;
}
if (fs.f_type != HUGETLBFS_MAGIC) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("not a hugetlbfs mount: '%s'"),
path);
goto cleanup;
}
*size = fs.f_bsize / 1024; /* we are storing size in KiB */
ret = 0;
cleanup:
return ret;
}
# define PROC_MEMINFO "/proc/meminfo"
# define HUGEPAGESIZE_STR "Hugepagesize:"
static int
virFileGetDefaultHugepageSize(unsigned long long *size)
{
int ret = -1;
char *meminfo, *c, *n, *unit;
if (virFileReadAll(PROC_MEMINFO, 4096, &meminfo) < 0)
goto cleanup;
if (!(c = strstr(meminfo, HUGEPAGESIZE_STR))) {
virReportError(VIR_ERR_NO_SUPPORT,
_("%s not found in %s"),
HUGEPAGESIZE_STR,
PROC_MEMINFO);
goto cleanup;
}
c += strlen(HUGEPAGESIZE_STR);
if ((n = strchr(c, '\n'))) {
/* Cut off the rest of the meminfo file */
*n = '\0';
}
if (virStrToLong_ull(c, &unit, 10, size) < 0 || STRNEQ(unit, " kB")) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unable to parse %s %s"),
HUGEPAGESIZE_STR, c);
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(meminfo);
return ret;
}
# define PROC_MOUNTS "/proc/mounts"
int
virFileFindHugeTLBFS(virHugeTLBFSPtr *ret_fs,
size_t *ret_nfs)
{
int ret = -1;
FILE *f = NULL;
struct mntent mb;
char mntbuf[1024];
virHugeTLBFSPtr fs = NULL;
size_t nfs = 0;
unsigned long long default_hugepagesz = 0;
if (!(f = setmntent(PROC_MOUNTS, "r"))) {
virReportSystemError(errno,
_("Unable to open %s"),
PROC_MOUNTS);
goto cleanup;
}
while (getmntent_r(f, &mb, mntbuf, sizeof(mntbuf))) {
virHugeTLBFSPtr tmp;
if (STRNEQ(mb.mnt_type, "hugetlbfs"))
continue;
if (VIR_EXPAND_N(fs, nfs, 1) < 0)
goto cleanup;
tmp = &fs[nfs - 1];
if (VIR_STRDUP(tmp->mnt_dir, mb.mnt_dir) < 0)
goto cleanup;
if (virFileGetHugepageSize(tmp->mnt_dir, &tmp->size) < 0)
goto cleanup;
if (!default_hugepagesz &&
virFileGetDefaultHugepageSize(&default_hugepagesz) < 0)
goto cleanup;
tmp->deflt = tmp->size == default_hugepagesz;
}
*ret_fs = fs;
*ret_nfs = nfs;
fs = NULL;
nfs = 0;
ret = 0;
cleanup:
endmntent(f);
while (nfs)
VIR_FREE(fs[--nfs].mnt_dir);
VIR_FREE(fs);
return ret;
}
#else /* defined __linux__ */
int virFileIsSharedFSType(const char *path ATTRIBUTE_UNUSED,
int fstypes ATTRIBUTE_UNUSED)
{
/* XXX implement me :-) */
return 0;
}
int
virFileGetHugepageSize(const char *path ATTRIBUTE_UNUSED,
unsigned long long *size ATTRIBUTE_UNUSED)
{
/* XXX implement me :-) */
virReportUnsupportedError();
return -1;
}
int
virFileFindHugeTLBFS(virHugeTLBFSPtr *ret_fs ATTRIBUTE_UNUSED,
size_t *ret_nfs ATTRIBUTE_UNUSED)
{
/* XXX implement me :-) */
virReportUnsupportedError();
return -1;
}
#endif /* defined __linux__ */
int virFileIsSharedFS(const char *path)
{
return virFileIsSharedFSType(path,
VIR_FILE_SHFS_NFS |
VIR_FILE_SHFS_GFS2 |
VIR_FILE_SHFS_OCFS |
VIR_FILE_SHFS_AFS |
VIR_FILE_SHFS_SMB |
VIR_FILE_SHFS_CIFS);
}
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