xref: /qemu/hw/9pfs/9p-util.h (revision 6482a961636d66cc10928dde5d4d908206e5f65a)
1*6482a961SGreg Kurz /*
2*6482a961SGreg Kurz  * 9p utilities
3*6482a961SGreg Kurz  *
4*6482a961SGreg Kurz  * Copyright IBM, Corp. 2017
5*6482a961SGreg Kurz  *
6*6482a961SGreg Kurz  * Authors:
7*6482a961SGreg Kurz  *  Greg Kurz <groug@kaod.org>
8*6482a961SGreg Kurz  *
9*6482a961SGreg Kurz  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10*6482a961SGreg Kurz  * See the COPYING file in the top-level directory.
11*6482a961SGreg Kurz  */
12*6482a961SGreg Kurz 
13*6482a961SGreg Kurz #ifndef QEMU_9P_UTIL_H
14*6482a961SGreg Kurz #define QEMU_9P_UTIL_H
15*6482a961SGreg Kurz 
16*6482a961SGreg Kurz static inline void close_preserve_errno(int fd)
17*6482a961SGreg Kurz {
18*6482a961SGreg Kurz     int serrno = errno;
19*6482a961SGreg Kurz     close(fd);
20*6482a961SGreg Kurz     errno = serrno;
21*6482a961SGreg Kurz }
22*6482a961SGreg Kurz 
23*6482a961SGreg Kurz static inline int openat_dir(int dirfd, const char *name)
24*6482a961SGreg Kurz {
25*6482a961SGreg Kurz     return openat(dirfd, name, O_DIRECTORY | O_RDONLY | O_PATH);
26*6482a961SGreg Kurz }
27*6482a961SGreg Kurz 
28*6482a961SGreg Kurz static inline int openat_file(int dirfd, const char *name, int flags,
29*6482a961SGreg Kurz                               mode_t mode)
30*6482a961SGreg Kurz {
31*6482a961SGreg Kurz     int fd, serrno, ret;
32*6482a961SGreg Kurz 
33*6482a961SGreg Kurz     fd = openat(dirfd, name, flags | O_NOFOLLOW | O_NOCTTY | O_NONBLOCK,
34*6482a961SGreg Kurz                 mode);
35*6482a961SGreg Kurz     if (fd == -1) {
36*6482a961SGreg Kurz         return -1;
37*6482a961SGreg Kurz     }
38*6482a961SGreg Kurz 
39*6482a961SGreg Kurz     serrno = errno;
40*6482a961SGreg Kurz     /* O_NONBLOCK was only needed to open the file. Let's drop it. */
41*6482a961SGreg Kurz     ret = fcntl(fd, F_SETFL, flags);
42*6482a961SGreg Kurz     assert(!ret);
43*6482a961SGreg Kurz     errno = serrno;
44*6482a961SGreg Kurz     return fd;
45*6482a961SGreg Kurz }
46*6482a961SGreg Kurz 
47*6482a961SGreg Kurz int relative_openat_nofollow(int dirfd, const char *path, int flags,
48*6482a961SGreg Kurz                              mode_t mode);
49*6482a961SGreg Kurz 
50*6482a961SGreg Kurz #endif
51