1 /* Create a device inode.
2 Copyright (C) 2009-2021 Free Software Foundation, Inc.
3
4 This file is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 3 of the
7 License, or (at your option) any later version.
8
9 This file is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 /* written by Eric Blake */
18
19 #include <config.h>
20
21 #include <sys/stat.h>
22
23 #include <errno.h>
24 #include <string.h>
25
26 #if !HAVE_MKNOD
27 /* Mingw lacks mknod; always fail with ENOSYS. */
28
29 int
mknod(_GL_UNUSED char const * name,_GL_UNUSED mode_t mode,_GL_UNUSED dev_t dev)30 mknod (_GL_UNUSED char const *name, _GL_UNUSED mode_t mode,
31 _GL_UNUSED dev_t dev)
32 {
33 errno = ENOSYS;
34 return -1;
35 }
36
37 #else /* HAVE_MKNOD */
38
39 # undef mknod
40
41 /* Create a file system node FILE, with access permissions and file
42 type in MODE, and device type in DEV. Usually, non-root
43 applications can only create named fifos (mode includes S_IFIFO),
44 with DEV set to 0. Also work around trailing slash bugs. */
45
46 int
rpl_mknod(char const * name,mode_t mode,dev_t dev)47 rpl_mknod (char const *name, mode_t mode, dev_t dev)
48 {
49 # if MKFIFO_TRAILING_SLASH_BUG
50 /* Trailing slash only makes sense for directories. Of course,
51 using mknod to create a directory is not very portable, so it may
52 still fail later on. */
53 if (!S_ISDIR (mode))
54 {
55 size_t len = strlen (name);
56 if (len && name[len - 1] == '/')
57 {
58 struct stat st;
59 if (stat (name, &st) == 0 || errno == EOVERFLOW)
60 errno = EEXIST;
61 return -1;
62 }
63 }
64 # endif
65 # if MKNOD_FIFO_BUG
66 /* POSIX requires mknod to create fifos for non-privileged
67 processes, but BSD implementations fail with EPERM. */
68 if (S_ISFIFO (mode) && dev == 0)
69 return mkfifo (name, mode & ~S_IFIFO);
70 # endif
71 return mknod (name, mode, dev);
72 }
73
74 #endif /* HAVE_MKNOD */
75