diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/renameat.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/renameat.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/renameat.c b/sysdeps/unix/sysv/linux/renameat.c new file mode 100644 index 0000000000..31662ea053 --- /dev/null +++ b/sysdeps/unix/sysv/linux/renameat.c @@ -0,0 +1,121 @@ +/* Copyright (C) 2005 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 <sysdep.h> + + +/* 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; +{ + 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); + + int result = INTERNAL_SYSCALL (rename, err, 2, old, new); + + if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 0)) + { + int errval = INTERNAL_SYSCALL_ERRNO (result, err); + if (errval == ENOTDIR && (bufnew != NULL || bufold != NULL)) + { + /* This can mean either the file descriptor is invalid or + /proc is not mounted. */ + struct stat64 st; + + if (bufnew != NULL) + { + if (__fxstat64 (_STAT_VER, newfd, &st) != 0) + /* errno is already set correctly. */ + return -1; + + /* 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 (bufold != NULL) + { + if (__fxstat64 (_STAT_VER, oldfd, &st) != 0) + /* errno is already set correctly. */ + return -1; + + /* 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; + } + } + + out: + __set_errno (errval); + result = -1; + } + + return result; +} |