1 /* Work around unlinkat bugs on Solaris 9 and Hurd.
3 Copyright (C) 2009-2016 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Eric Blake. */
38 /* unlinkat without AT_REMOVEDIR does not honor trailing / on Solaris 9.
39 Hurd has the same issue.
41 unlinkat without AT_REMOVEDIR erroneously ignores ".." on Darwin 14.
43 Solve these in a similar manner to unlink. */
46 rpl_unlinkat (int fd, char const *name, int flag)
50 /* rmdir behavior has no problems with trailing slash. */
51 if (flag & AT_REMOVEDIR)
52 return unlinkat (fd, name, flag);
55 if (len && ISSLASH (name[len - 1]))
57 /* See the lengthy comment in unlink.c why we disobey the POSIX
58 rule of letting unlink("link-to-dir/") attempt to unlink a
61 result = lstatat (fd, name, &st);
64 /* Trailing NUL will overwrite the trailing slash. */
65 char *short_name = malloc (len);
71 memcpy (short_name, name, len);
72 while (len && ISSLASH (short_name[len - 1]))
73 short_name[--len] = '\0';
74 if (len && (lstatat (fd, short_name, &st) || S_ISLNK (st.st_mode)))
85 # if UNLINK_PARENT_BUG
86 if (len >= 2 && name[len - 1] == '.' && name[len - 2] == '.'
87 && (len == 2 || ISSLASH (name[len - 3])))
89 errno = EISDIR; /* could also use EPERM */
93 result = unlinkat (fd, name, flag);
98 #else /* !HAVE_UNLINKAT */
100 /* Replacement for Solaris' function by the same name.
101 <http://www.google.com/search?q=unlinkat+site:docs.sun.com>
102 First, try to simulate it via (unlink|rmdir) ("/proc/self/fd/FD/FILE").
103 Failing that, simulate it via save_cwd/fchdir/(unlink|rmdir)/restore_cwd.
104 If either the save_cwd or the restore_cwd fails (relatively unlikely),
105 then give a diagnostic and exit nonzero.
106 Otherwise, this function works just like Solaris' unlinkat. */
108 # define AT_FUNC_NAME unlinkat
109 # define AT_FUNC_F1 rmdir
110 # define AT_FUNC_F2 unlink
111 # define AT_FUNC_USE_F1_COND AT_REMOVEDIR
112 # define AT_FUNC_POST_FILE_PARAM_DECLS , int flag
113 # define AT_FUNC_POST_FILE_ARGS /* empty */
114 # include "at-func.c"
118 # undef AT_FUNC_USE_F1_COND
119 # undef AT_FUNC_POST_FILE_PARAM_DECLS
120 # undef AT_FUNC_POST_FILE_ARGS
122 #endif /* !HAVE_UNLINKAT */