LXR qemu/hw/9pfs/9p-util.h

   1/*
   2 * 9p utilities
   3 *
   4 * Copyright IBM, Corp. 2017
   5 *
   6 * Authors:
   7 *  Greg Kurz <groug@kaod.org>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10 * See the COPYING file in the top-level directory.
  11 */
  12
  13#ifndef QEMU_9P_UTIL_H
  14#define QEMU_9P_UTIL_H
  15
  16#ifdef O_PATH
  17#define O_PATH_9P_UTIL O_PATH
  18#else
  19#define O_PATH_9P_UTIL 0
  20#endif
  21
  22static inline void close_preserve_errno(int fd)
  23{
  24    int serrno = errno;
  25    close(fd);
  26    errno = serrno;
  27}
  28
  29static inline int openat_dir(int dirfd, const char *name)
  30{
  31    return openat(dirfd, name,
  32                  O_DIRECTORY | O_RDONLY | O_NOFOLLOW | O_PATH_9P_UTIL);
  33}
  34
  35static inline int openat_file(int dirfd, const char *name, int flags,
  36                              mode_t mode)
  37{
  38    int fd, serrno, ret;
  39
  40    fd = openat(dirfd, name, flags | O_NOFOLLOW | O_NOCTTY | O_NONBLOCK,
  41                mode);
  42    if (fd == -1) {
  43        return -1;
  44    }
  45
  46    serrno = errno;
  47    /* O_NONBLOCK was only needed to open the file. Let's drop it. We don't
  48     * do that with O_PATH since fcntl(F_SETFL) isn't supported, and openat()
  49     * ignored it anyway.
  50     */
  51    if (!(flags & O_PATH_9P_UTIL)) {
  52        ret = fcntl(fd, F_SETFL, flags);
  53        assert(!ret);
  54    }
  55    errno = serrno;
  56    return fd;
  57}
  58
  59ssize_t fgetxattrat_nofollow(int dirfd, const char *path, const char *name,
  60                             void *value, size_t size);
  61int fsetxattrat_nofollow(int dirfd, const char *path, const char *name,
  62                         void *value, size_t size, int flags);
  63ssize_t flistxattrat_nofollow(int dirfd, const char *filename,
  64                              char *list, size_t size);
  65ssize_t fremovexattrat_nofollow(int dirfd, const char *filename,
  66                                const char *name);
  67
  68#endif
  69