From 758f820bcc0f68aeebac1717e537ca13a320b909 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:11:47 +0200 Subject: Adding upstream version 9.1. Signed-off-by: Daniel Baumann --- lib/unlinkat.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 lib/unlinkat.c (limited to 'lib/unlinkat.c') diff --git a/lib/unlinkat.c b/lib/unlinkat.c new file mode 100644 index 0000000..c9ff3ab --- /dev/null +++ b/lib/unlinkat.c @@ -0,0 +1,124 @@ +/* Work around unlinkat bugs on Solaris 9 and Hurd. + + Copyright (C) 2009-2022 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +/* Written by Eric Blake. */ + +#include + +#include + +#include +#include +#include +#include + +#include + +#include "filename.h" +#include "openat.h" + +#if HAVE_UNLINKAT + +# undef unlinkat + +/* unlinkat without AT_REMOVEDIR does not honor trailing / on Solaris 9. + Hurd has the same issue. + + unlinkat without AT_REMOVEDIR erroneously ignores ".." on Darwin 14. + + Solve these in a similar manner to unlink. */ + +int +rpl_unlinkat (int fd, char const *name, int flag) +{ + size_t len; + int result = 0; + /* rmdir behavior has no problems with trailing slash. */ + if (flag & AT_REMOVEDIR) + return unlinkat (fd, name, flag); + + len = strlen (name); + if (len && ISSLASH (name[len - 1])) + { + /* See the lengthy comment in unlink.c why we disobey the POSIX + rule of letting unlink("link-to-dir/") attempt to unlink a + directory. */ + struct stat st; + result = fstatat (fd, name, &st, AT_SYMLINK_NOFOLLOW); + if (result == 0 || errno == EOVERFLOW) + { + /* Trailing NUL will overwrite the trailing slash. */ + char *short_name = malloc (len); + if (!short_name) + { + errno = EPERM; + return -1; + } + memcpy (short_name, name, len); + while (len && ISSLASH (short_name[len - 1])) + short_name[--len] = '\0'; + if (len && (fstatat (fd, short_name, &st, AT_SYMLINK_NOFOLLOW) + || S_ISLNK (st.st_mode))) + { + free (short_name); + errno = EPERM; + return -1; + } + free (short_name); + result = 0; + } + } + if (!result) + { +# if UNLINK_PARENT_BUG + if (len >= 2 && name[len - 1] == '.' && name[len - 2] == '.' + && (len == 2 || ISSLASH (name[len - 3]))) + { + errno = EISDIR; /* could also use EPERM */ + return -1; + } +# endif + result = unlinkat (fd, name, flag); + } + return result; +} + +#else /* !HAVE_UNLINKAT */ + +/* Replacement for Solaris' function by the same name. + + First, try to simulate it via (unlink|rmdir) ("/proc/self/fd/FD/FILE"). + Failing that, simulate it via save_cwd/fchdir/(unlink|rmdir)/restore_cwd. + If either the save_cwd or the restore_cwd fails (relatively unlikely), + then give a diagnostic and exit nonzero. + Otherwise, this function works just like Solaris' unlinkat. */ + +# define AT_FUNC_NAME unlinkat +# define AT_FUNC_F1 rmdir +# define AT_FUNC_F2 unlink +# define AT_FUNC_USE_F1_COND AT_REMOVEDIR +# define AT_FUNC_POST_FILE_PARAM_DECLS , int flag +# define AT_FUNC_POST_FILE_ARGS /* empty */ +# include "at-func.c" +# undef AT_FUNC_NAME +# undef AT_FUNC_F1 +# undef AT_FUNC_F2 +# undef AT_FUNC_USE_F1_COND +# undef AT_FUNC_POST_FILE_PARAM_DECLS +# undef AT_FUNC_POST_FILE_ARGS + +#endif /* !HAVE_UNLINKAT */ -- cgit v1.2.3