1 /* Create an inode relative to an open directory. 2 Copyright (C) 2009-2021 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* written by Eric Blake */ 18 19 #include <config.h> 20 21 /* Specification. */ 22 #include <sys/stat.h> 23 24 #include <stdlib.h> 25 26 #if HAVE_MKNODAT 27 28 # include <errno.h> 29 # include <fcntl.h> 30 # include <string.h> 31 32 int 33 rpl_mknodat (int fd, char const *file, mode_t mode, dev_t dev) /* */ 34 #undef mknodat 35 { 36 /* Use the original mknodat(), but correct the trailing slash handling. */ 37 size_t len = strlen (file); 38 if (len && file[len - 1] == '/') 39 { 40 struct stat st; 41 42 if (fstatat (fd, file, &st, AT_SYMLINK_NOFOLLOW) < 0) 43 { 44 if (errno == EOVERFLOW) 45 /* It's surely a file, not a directory. */ 46 errno = ENOTDIR; 47 } 48 else 49 { 50 /* It's a directory, otherwise fstatat() would have reported an error 51 ENOTDIR. */ 52 errno = EEXIST; 53 } 54 return -1; 55 } 56 57 return mknodat (fd, file, mode, dev); 58 } 59 60 #else 61 62 # if !HAVE_MKNOD 63 64 # include <errno.h> 65 66 /* Mingw lacks mknod, so this wrapper is trivial. */ 67 68 int 69 mknodat (_GL_UNUSED int fd, _GL_UNUSED char const *path, /* */ 70 _GL_UNUSED mode_t mode, _GL_UNUSED dev_t dev) 71 { 72 errno = ENOSYS; 73 return -1; 74 } 75 76 # else 77 78 /* Create a file system node FILE relative to directory FD, with 79 access permissions and file type in MODE, and device type in DEV. 80 Usually, non-root applications can only create named fifos, with 81 DEV set to 0. If possible, create the node without changing the 82 working directory. Otherwise, resort to using save_cwd/fchdir, 83 then mknod/restore_cwd. If either the save_cwd or the restore_cwd 84 fails, then give a diagnostic and exit nonzero. */ 85 86 # define AT_FUNC_NAME mknodat 87 # define AT_FUNC_F1 mknod 88 # define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode, dev_t dev 89 # define AT_FUNC_POST_FILE_ARGS , mode, dev 90 # include "at-func.c" 91 # undef AT_FUNC_NAME 92 # undef AT_FUNC_F1 93 # undef AT_FUNC_POST_FILE_PARAM_DECLS 94 # undef AT_FUNC_POST_FILE_ARGS 95 96 # endif 97 98 #endif