| /* Work around rename bugs in some systems. |
| |
| Copyright (C) 2001-2003, 2005-2006, 2009-2021 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 <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by Volker Borchert, Eric Blake. */ |
| |
| #include <config.h> |
| |
| #include <stdio.h> |
| |
| #undef rename |
| |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| /* The mingw rename has problems with trailing slashes; it also |
| requires use of native Windows calls to allow atomic renames over |
| existing files. */ |
| |
| # include <errno.h> |
| # include <stdbool.h> |
| # include <stdlib.h> |
| # include <sys/stat.h> |
| # include <unistd.h> |
| |
| # define WIN32_LEAN_AND_MEAN |
| # include <windows.h> |
| |
| # include "dirname.h" |
| |
| /* Don't assume that UNICODE is not defined. */ |
| # undef MoveFileEx |
| # define MoveFileEx MoveFileExA |
| |
| /* Rename the file SRC to DST. This replacement is necessary on |
| Windows, on which the system rename function will not replace |
| an existing DST. */ |
| int |
| rpl_rename (char const *src, char const *dst) |
| { |
| int error; |
| size_t src_len = strlen (src); |
| size_t dst_len = strlen (dst); |
| char *src_base = last_component (src); |
| char *dst_base = last_component (dst); |
| bool src_slash; |
| bool dst_slash; |
| bool dst_exists; |
| struct stat src_st; |
| struct stat dst_st; |
| |
| /* Filter out dot as last component. */ |
| if (!src_len || !dst_len) |
| { |
| errno = ENOENT; |
| return -1; |
| } |
| if (*src_base == '.') |
| { |
| size_t len = base_len (src_base); |
| if (len == 1 || (len == 2 && src_base[1] == '.')) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| } |
| if (*dst_base == '.') |
| { |
| size_t len = base_len (dst_base); |
| if (len == 1 || (len == 2 && dst_base[1] == '.')) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| } |
| |
| /* Presence of a trailing slash requires directory semantics. If |
| the source does not exist, or if the destination cannot be turned |
| into a directory, give up now. Otherwise, strip trailing slashes |
| before calling rename. There are no symlinks on mingw, so stat |
| works instead of lstat. */ |
| src_slash = ISSLASH (src[src_len - 1]); |
| dst_slash = ISSLASH (dst[dst_len - 1]); |
| if (stat (src, &src_st)) |
| return -1; |
| if (stat (dst, &dst_st)) |
| { |
| if (errno != ENOENT || (!S_ISDIR (src_st.st_mode) && dst_slash)) |
| return -1; |
| dst_exists = false; |
| } |
| else |
| { |
| if (S_ISDIR (dst_st.st_mode) != S_ISDIR (src_st.st_mode)) |
| { |
| errno = S_ISDIR (dst_st.st_mode) ? EISDIR : ENOTDIR; |
| return -1; |
| } |
| dst_exists = true; |
| } |
| |
| /* There are no symlinks, so if a file existed with a trailing |
| slash, it must be a directory, and we don't have to worry about |
| stripping strip trailing slash. However, mingw refuses to |
| replace an existing empty directory, so we have to help it out. |
| And canonicalize_file_name is not yet ported to mingw; however, |
| for directories, getcwd works as a viable alternative. Ensure |
| that we can get back to where we started before using it; later |
| attempts to return are fatal. Note that we can end up losing a |
| directory if rename then fails, but it was empty, so not much |
| damage was done. */ |
| if (dst_exists && S_ISDIR (dst_st.st_mode)) |
| { |
| char *cwd = getcwd (NULL, 0); |
| char *src_temp; |
| char *dst_temp; |
| if (!cwd || chdir (cwd)) |
| return -1; |
| if (IS_ABSOLUTE_FILE_NAME (src)) |
| { |
| dst_temp = chdir (dst) ? NULL : getcwd (NULL, 0); |
| src_temp = chdir (src) ? NULL : getcwd (NULL, 0); |
| } |
| else |
| { |
| src_temp = chdir (src) ? NULL : getcwd (NULL, 0); |
| if (!IS_ABSOLUTE_FILE_NAME (dst) && chdir (cwd)) |
| abort (); |
| dst_temp = chdir (dst) ? NULL : getcwd (NULL, 0); |
| } |
| if (chdir (cwd)) |
| abort (); |
| free (cwd); |
| if (!src_temp || !dst_temp) |
| { |
| free (src_temp); |
| free (dst_temp); |
| errno = ENOMEM; |
| return -1; |
| } |
| src_len = strlen (src_temp); |
| if (strncmp (src_temp, dst_temp, src_len) == 0 |
| && (ISSLASH (dst_temp[src_len]) || dst_temp[src_len] == '\0')) |
| { |
| error = dst_temp[src_len]; |
| free (src_temp); |
| free (dst_temp); |
| if (error) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| if (rmdir (dst)) |
| { |
| error = errno; |
| free (src_temp); |
| free (dst_temp); |
| errno = error; |
| return -1; |
| } |
| free (src_temp); |
| free (dst_temp); |
| } |
| |
| /* MoveFileEx works if SRC is a directory without any flags, but |
| fails with MOVEFILE_REPLACE_EXISTING, so try without flags first. |
| Thankfully, MoveFileEx handles hard links correctly, even though |
| rename() does not. */ |
| if (MoveFileEx (src, dst, 0)) |
| return 0; |
| |
| /* Retry with MOVEFILE_REPLACE_EXISTING if the move failed |
| due to the destination already existing. */ |
| error = GetLastError (); |
| if (error == ERROR_FILE_EXISTS || error == ERROR_ALREADY_EXISTS) |
| { |
| if (MoveFileEx (src, dst, MOVEFILE_REPLACE_EXISTING)) |
| return 0; |
| |
| error = GetLastError (); |
| } |
| |
| switch (error) |
| { |
| case ERROR_FILE_NOT_FOUND: |
| case ERROR_PATH_NOT_FOUND: |
| case ERROR_BAD_PATHNAME: |
| case ERROR_DIRECTORY: |
| errno = ENOENT; |
| break; |
| |
| case ERROR_ACCESS_DENIED: |
| case ERROR_SHARING_VIOLATION: |
| errno = EACCES; |
| break; |
| |
| case ERROR_OUTOFMEMORY: |
| errno = ENOMEM; |
| break; |
| |
| case ERROR_CURRENT_DIRECTORY: |
| errno = EBUSY; |
| break; |
| |
| case ERROR_NOT_SAME_DEVICE: |
| errno = EXDEV; |
| break; |
| |
| case ERROR_WRITE_PROTECT: |
| errno = EROFS; |
| break; |
| |
| case ERROR_WRITE_FAULT: |
| case ERROR_READ_FAULT: |
| case ERROR_GEN_FAILURE: |
| errno = EIO; |
| break; |
| |
| case ERROR_HANDLE_DISK_FULL: |
| case ERROR_DISK_FULL: |
| case ERROR_DISK_TOO_FRAGMENTED: |
| errno = ENOSPC; |
| break; |
| |
| case ERROR_FILE_EXISTS: |
| case ERROR_ALREADY_EXISTS: |
| errno = EEXIST; |
| break; |
| |
| case ERROR_BUFFER_OVERFLOW: |
| case ERROR_FILENAME_EXCED_RANGE: |
| errno = ENAMETOOLONG; |
| break; |
| |
| case ERROR_INVALID_NAME: |
| case ERROR_DELETE_PENDING: |
| errno = EPERM; /* ? */ |
| break; |
| |
| # ifndef ERROR_FILE_TOO_LARGE |
| /* This value is documented but not defined in all versions of windows.h. */ |
| # define ERROR_FILE_TOO_LARGE 223 |
| # endif |
| case ERROR_FILE_TOO_LARGE: |
| errno = EFBIG; |
| break; |
| |
| default: |
| errno = EINVAL; |
| break; |
| } |
| |
| return -1; |
| } |
| |
| #else /* ! W32 platform */ |
| |
| # include <errno.h> |
| # include <stdio.h> |
| # include <stdlib.h> |
| # include <string.h> |
| # include <sys/stat.h> |
| # include <unistd.h> |
| |
| # include "dirname.h" |
| # include "same-inode.h" |
| |
| /* Rename the file SRC to DST, fixing any trailing slash bugs. */ |
| |
| int |
| rpl_rename (char const *src, char const *dst) |
| { |
| size_t src_len = strlen (src); |
| size_t dst_len = strlen (dst); |
| char *src_temp = (char *) src; |
| char *dst_temp = (char *) dst; |
| bool src_slash; |
| bool dst_slash; |
| bool dst_exists _GL_UNUSED; |
| int ret_val = -1; |
| int rename_errno = ENOTDIR; |
| struct stat src_st; |
| struct stat dst_st; |
| |
| if (!src_len || !dst_len) |
| return rename (src, dst); /* Let strace see the ENOENT failure. */ |
| |
| # if RENAME_DEST_EXISTS_BUG |
| { |
| char *src_base = last_component (src); |
| char *dst_base = last_component (dst); |
| if (*src_base == '.') |
| { |
| size_t len = base_len (src_base); |
| if (len == 1 || (len == 2 && src_base[1] == '.')) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| } |
| if (*dst_base == '.') |
| { |
| size_t len = base_len (dst_base); |
| if (len == 1 || (len == 2 && dst_base[1] == '.')) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| } |
| } |
| # endif /* RENAME_DEST_EXISTS_BUG */ |
| |
| src_slash = src[src_len - 1] == '/'; |
| dst_slash = dst[dst_len - 1] == '/'; |
| |
| # if !RENAME_HARD_LINK_BUG && !RENAME_DEST_EXISTS_BUG |
| /* If there are no trailing slashes, then trust the native |
| implementation unless we also suspect issues with hard link |
| detection or file/directory conflicts. */ |
| if (!src_slash && !dst_slash) |
| return rename (src, dst); |
| # endif /* !RENAME_HARD_LINK_BUG && !RENAME_DEST_EXISTS_BUG */ |
| |
| /* Presence of a trailing slash requires directory semantics. If |
| the source does not exist, or if the destination cannot be turned |
| into a directory, give up now. Otherwise, strip trailing slashes |
| before calling rename. */ |
| if (lstat (src, &src_st)) |
| return -1; |
| if (lstat (dst, &dst_st)) |
| { |
| if (errno != ENOENT || (!S_ISDIR (src_st.st_mode) && dst_slash)) |
| return -1; |
| dst_exists = false; |
| } |
| else |
| { |
| if (S_ISDIR (dst_st.st_mode) != S_ISDIR (src_st.st_mode)) |
| { |
| errno = S_ISDIR (dst_st.st_mode) ? EISDIR : ENOTDIR; |
| return -1; |
| } |
| # if RENAME_HARD_LINK_BUG |
| if (SAME_INODE (src_st, dst_st)) |
| return 0; |
| # endif /* RENAME_HARD_LINK_BUG */ |
| dst_exists = true; |
| } |
| |
| # if (RENAME_TRAILING_SLASH_SOURCE_BUG || RENAME_DEST_EXISTS_BUG \ |
| || RENAME_HARD_LINK_BUG) |
| /* If the only bug was that a trailing slash was allowed on a |
| non-existing file destination, as in Solaris 10, then we've |
| already covered that situation. But if there is any problem with |
| a trailing slash on an existing source or destination, as in |
| Solaris 9, or if a directory can overwrite a symlink, as on |
| Cygwin 1.5, or if directories cannot be created with trailing |
| slash, as on NetBSD 1.6, then we must strip the offending slash |
| and check that we have not encountered a symlink instead of a |
| directory. |
| |
| Stripping a trailing slash interferes with POSIX semantics, where |
| rename behavior on a symlink with a trailing slash operates on |
| the corresponding target directory. We prefer the GNU semantics |
| of rejecting any use of a symlink with trailing slash, but do not |
| enforce them, since Solaris 10 is able to obey POSIX semantics |
| and there might be clients expecting it, as counter-intuitive as |
| those semantics are. |
| |
| Technically, we could also follow the POSIX behavior by chasing a |
| readlink trail, but that is harder to implement. */ |
| if (src_slash) |
| { |
| src_temp = strdup (src); |
| if (!src_temp) |
| { |
| /* Rather than rely on strdup-posix, we set errno ourselves. */ |
| rename_errno = ENOMEM; |
| goto out; |
| } |
| strip_trailing_slashes (src_temp); |
| if (lstat (src_temp, &src_st)) |
| { |
| rename_errno = errno; |
| goto out; |
| } |
| if (S_ISLNK (src_st.st_mode)) |
| goto out; |
| } |
| if (dst_slash) |
| { |
| dst_temp = strdup (dst); |
| if (!dst_temp) |
| { |
| rename_errno = ENOMEM; |
| goto out; |
| } |
| strip_trailing_slashes (dst_temp); |
| if (lstat (dst_temp, &dst_st)) |
| { |
| if (errno != ENOENT) |
| { |
| rename_errno = errno; |
| goto out; |
| } |
| } |
| else if (S_ISLNK (dst_st.st_mode)) |
| goto out; |
| } |
| # endif /* RENAME_TRAILING_SLASH_SOURCE_BUG || RENAME_DEST_EXISTS_BUG |
| || RENAME_HARD_LINK_BUG */ |
| |
| # if RENAME_DEST_EXISTS_BUG |
| /* Cygwin 1.5 sometimes behaves oddly when moving a non-empty |
| directory on top of an empty one (the old directory name can |
| reappear if the new directory tree is removed). Work around this |
| by removing the target first, but don't remove the target if it |
| is a subdirectory of the source. Note that we can end up losing |
| a directory if rename then fails, but it was empty, so not much |
| damage was done. */ |
| if (dst_exists && S_ISDIR (dst_st.st_mode)) |
| { |
| if (src_st.st_dev != dst_st.st_dev) |
| { |
| rename_errno = EXDEV; |
| goto out; |
| } |
| if (src_temp != src) |
| free (src_temp); |
| src_temp = canonicalize_file_name (src); |
| if (dst_temp != dst) |
| free (dst_temp); |
| dst_temp = canonicalize_file_name (dst); |
| if (!src_temp || !dst_temp) |
| { |
| rename_errno = ENOMEM; |
| goto out; |
| } |
| src_len = strlen (src_temp); |
| if (strncmp (src_temp, dst_temp, src_len) == 0 |
| && dst_temp[src_len] == '/') |
| { |
| rename_errno = EINVAL; |
| goto out; |
| } |
| if (rmdir (dst)) |
| { |
| rename_errno = errno; |
| goto out; |
| } |
| } |
| # endif /* RENAME_DEST_EXISTS_BUG */ |
| |
| ret_val = rename (src_temp, dst_temp); |
| rename_errno = errno; |
| |
| out: _GL_UNUSED_LABEL; |
| |
| if (src_temp != src) |
| free (src_temp); |
| if (dst_temp != dst) |
| free (dst_temp); |
| errno = rename_errno; |
| return ret_val; |
| } |
| #endif /* ! W32 platform */ |
