diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/renameat.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/renameat.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/renameat.c b/sysdeps/unix/sysv/linux/renameat.c new file mode 100644 index 0000000..86bb75a --- /dev/null +++ b/sysdeps/unix/sysv/linux/renameat.c @@ -0,0 +1,184 @@ +/* Copyright (C) 2005, 2006 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <string.h> +#include <kernel-features.h> +#include <sysdep.h> + + +#ifndef __ASSUME_ATFCTS +void +attribute_hidden +__atfct_seterrno_2 (int errval, int fd1, const char *buf1, int fd2, + const char *buf2) +{ + if (buf1 != NULL || buf2 != NULL) + { + struct stat64 st; + + if (errval == ENOTDIR) + { + /* This can mean either the file descriptor is invalid or + /proc is not mounted. */ + if (buf1 != NULL) + { + if (__fxstat64 (_STAT_VER, fd1, &st) != 0) + /* errno is already set correctly. */ + return; + + /* If /proc is not mounted there is nothing we can do. */ + if (S_ISDIR (st.st_mode) + && (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0 + || !S_ISDIR (st.st_mode))) + { + errval = ENOSYS; + goto out; + } + } + + if (buf2 != NULL) + { + if (__fxstat64 (_STAT_VER, fd2, &st) != 0) + /* errno is already set correctly. */ + return; + + /* If /proc is not mounted there is nothing we can do. */ + if (S_ISDIR (st.st_mode) + && (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0 + || !S_ISDIR (st.st_mode))) + errval = ENOSYS; + } + } + else if (errval == ENOENT) + { + /* This could mean the file descriptor is not valid. We + reuse BUF for the stat call. Find the slash after the + file descriptor number. */ + if (buf1 != NULL) + { + *(char *) strchr (buf1 + sizeof "/proc/self/fd", '/') = '\0'; + + int e = __lxstat64 (_STAT_VER, buf1, &st); + if ((e == -1 && errno == ENOENT) + ||(e == 0 && !S_ISLNK (st.st_mode))) + { + errval = EBADF; + goto out; + } + } + + if (buf2 != NULL) + { + *(char *) strchr (buf2 + sizeof "/proc/self/fd", '/') = '\0'; + + int e = __lxstat64 (_STAT_VER, buf2, &st); + if ((e == -1 && errno == ENOENT) + ||(e == 0 && !S_ISLNK (st.st_mode))) + errval = EBADF; + } + } + } + + out: + __set_errno (errval); +} +#endif + + +/* Rename the file OLD relative to OLDFD to NEW relative to NEWFD. */ +int +renameat (oldfd, old, newfd, new) + int oldfd; + const char *old; + int newfd; + const char *new; +{ + int result; + +#ifdef __NR_renameat +# ifndef __ASSUME_ATFCTS + if (__have_atfcts >= 0) +# endif + { + result = INLINE_SYSCALL (renameat, 4, oldfd, old, newfd, new); +# ifndef __ASSUME_ATFCTS + if (result == -1 && errno == ENOSYS) + __have_atfcts = -1; + else +# endif + return result; + } +#endif + +#ifndef __ASSUME_ATFCTS + static const char procfd[] = "/proc/self/fd/%d/%s"; + char *bufold = NULL; + + if (oldfd != AT_FDCWD && old[0] != '/') + { + size_t filelen = strlen (old); + /* Buffer for the path name we are going to use. It consists of + - the string /proc/self/fd/ + - the file descriptor number + - the file name provided. + The final NUL is included in the sizeof. A bit of overhead + due to the format elements compensates for possible negative + numbers. */ + size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen; + bufold = alloca (buflen); + + __snprintf (bufold, buflen, procfd, oldfd, old); + old = bufold; + } + + char *bufnew = NULL; + + if (newfd != AT_FDCWD && new[0] != '/') + { + size_t filelen = strlen (new); + /* Buffer for the path name we are going to use. It consists of + - the string /proc/self/fd/ + - the file descriptor number + - the file name provided. + The final NUL is included in the sizeof. A bit of overhead + due to the format elements compensates for possible negative + numbers. */ + size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen; + bufnew = alloca (buflen); + + __snprintf (bufnew, buflen, procfd, newfd, new); + new = bufnew; + } + + INTERNAL_SYSCALL_DECL (err); + + result = INTERNAL_SYSCALL (rename, err, 2, old, new); + + if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0)) + { + __atfct_seterrno_2 (INTERNAL_SYSCALL_ERRNO (result, err), newfd, bufnew, + oldfd, bufold); + result = -1; + } + + return result; +#endif +} |