1/* mkdir-p.c -- Ensure that a directory and its parents exist. 2 3 Copyright (C) 1990, 1997-2000, 2002-2007, 2009-2010 Free Software 4 Foundation, Inc. 5 6 This program is free software: you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 18 19/* Written by Paul Eggert, David MacKenzie, and Jim Meyering. */ 20 21#include <config.h> 22 23#include "mkdir-p.h" 24 25#include <errno.h> 26#include <sys/stat.h> 27#include <unistd.h> 28 29#include "gettext.h" 30#define _(msgid) gettext (msgid) 31 32#include "dirchownmod.h" 33#include "dirname.h" 34#include "error.h" 35#include "quote.h" 36#include "mkancesdirs.h" 37#include "savewd.h" 38 39#ifndef HAVE_FCHMOD 40# define HAVE_FCHMOD false 41#endif 42 43/* Ensure that the directory DIR exists. 44 45 WD is the working directory, as in savewd.c. 46 47 If MAKE_ANCESTOR is not null, create any ancestor directories that 48 don't already exist, by invoking MAKE_ANCESTOR (DIR, ANCESTOR, OPTIONS). 49 This function should return zero if successful, -1 (setting errno) 50 otherwise. In this case, DIR may be modified by storing '\0' bytes 51 into it, to access the ancestor directories, and this modification 52 is retained on return if the ancestor directories could not be 53 created. 54 55 Create DIR as a new directory with using mkdir with permissions 56 MODE. It is also OK if MAKE_ANCESTOR is not null and a 57 directory DIR already exists. 58 59 Call ANNOUNCE (DIR, OPTIONS) just after successfully making DIR, 60 even if some of the following actions fail. 61 62 Set DIR's owner to OWNER and group to GROUP, but leave the owner 63 alone if OWNER is (uid_t) -1, and similarly for GROUP. 64 65 Set DIR's mode bits to MODE, except preserve any of the bits that 66 correspond to zero bits in MODE_BITS. In other words, MODE_BITS is 67 a mask that specifies which of DIR's mode bits should be set or 68 cleared. MODE should be a subset of MODE_BITS, which in turn 69 should be a subset of CHMOD_MODE_BITS. Changing the mode in this 70 way is necessary if DIR already existed or if MODE and MODE_BITS 71 specify non-permissions bits like S_ISUID. 72 73 However, if PRESERVE_EXISTING is true and DIR already exists, 74 do not attempt to set DIR's ownership and file mode bits. 75 76 This implementation assumes the current umask is zero. 77 78 Return true if DIR exists as a directory with the proper ownership 79 and file mode bits when done, or if a child process has been 80 dispatched to do the real work (though the child process may not 81 have finished yet -- it is the caller's responsibility to handle 82 this). Report a diagnostic and return false on failure, storing 83 '\0' into *DIR if an ancestor directory had problems. */ 84 85bool 86make_dir_parents (char *dir, 87 struct savewd *wd, 88 int (*make_ancestor) (char const *, char const *, void *), 89 void *options, 90 mode_t mode, 91 void (*announce) (char const *, void *), 92 mode_t mode_bits, 93 uid_t owner, 94 gid_t group, 95 bool preserve_existing) 96{ 97 int mkdir_errno = (IS_ABSOLUTE_FILE_NAME (dir) ? 0 : savewd_errno (wd)); 98 99 if (mkdir_errno == 0) 100 { 101 ptrdiff_t prefix_len = 0; 102 int savewd_chdir_options = (HAVE_FCHMOD ? SAVEWD_CHDIR_SKIP_READABLE : 0); 103 104 if (make_ancestor) 105 { 106 prefix_len = mkancesdirs (dir, wd, make_ancestor, options); 107 if (prefix_len < 0) 108 { 109 if (prefix_len < -1) 110 return true; 111 mkdir_errno = errno; 112 } 113 } 114 115 if (0 <= prefix_len) 116 { 117 /* If the ownership might change, or if the directory will be 118 writeable to other users and its special mode bits may 119 change after the directory is created, create it with 120 more restrictive permissions at first, so unauthorized 121 users cannot nip in before the directory is ready. */ 122 bool keep_owner = owner == (uid_t) -1 && group == (gid_t) -1; 123 bool keep_special_mode_bits = 124 ((mode_bits & (S_ISUID | S_ISGID)) | (mode & S_ISVTX)) == 0; 125 mode_t mkdir_mode = mode; 126 if (! keep_owner) 127 mkdir_mode &= ~ (S_IRWXG | S_IRWXO); 128 else if (! keep_special_mode_bits) 129 mkdir_mode &= ~ (S_IWGRP | S_IWOTH); 130 131 if (mkdir (dir + prefix_len, mkdir_mode) == 0) 132 { 133 announce (dir, options); 134 preserve_existing = keep_owner & keep_special_mode_bits; 135 savewd_chdir_options |= 136 (SAVEWD_CHDIR_NOFOLLOW 137 | (mode & S_IRUSR ? SAVEWD_CHDIR_READABLE : 0)); 138 } 139 else 140 { 141 mkdir_errno = errno; 142 mkdir_mode = -1; 143 } 144 145 if (preserve_existing) 146 { 147 struct stat st; 148 if (mkdir_errno == 0 149 || (mkdir_errno != ENOENT && make_ancestor 150 && stat (dir + prefix_len, &st) == 0 151 && S_ISDIR (st.st_mode))) 152 return true; 153 } 154 else 155 { 156 int open_result[2]; 157 int chdir_result = 158 savewd_chdir (wd, dir + prefix_len, 159 savewd_chdir_options, open_result); 160 if (chdir_result < -1) 161 return true; 162 else 163 { 164 bool chdir_ok = (chdir_result == 0); 165 int chdir_errno = errno; 166 int fd = open_result[0]; 167 bool chdir_failed_unexpectedly = 168 (mkdir_errno == 0 169 && ((! chdir_ok && (mode & S_IXUSR)) 170 || (fd < 0 && (mode & S_IRUSR)))); 171 172 if (chdir_failed_unexpectedly) 173 { 174 /* No need to save errno here; it's irrelevant. */ 175 if (0 <= fd) 176 close (fd); 177 } 178 else 179 { 180 char const *subdir = (chdir_ok ? "." : dir + prefix_len); 181 if (dirchownmod (fd, subdir, mkdir_mode, owner, group, 182 mode, mode_bits) 183 == 0) 184 return true; 185 } 186 187 if (mkdir_errno == 0 188 || (mkdir_errno != ENOENT && make_ancestor 189 && errno != ENOTDIR)) 190 { 191 error (0, 192 (! chdir_failed_unexpectedly ? errno 193 : ! chdir_ok && (mode & S_IXUSR) ? chdir_errno 194 : open_result[1]), 195 _(keep_owner 196 ? "cannot change permissions of %s" 197 : "cannot change owner and permissions of %s"), 198 quote (dir)); 199 return false; 200 } 201 } 202 } 203 } 204 } 205 206 error (0, mkdir_errno, _("cannot create directory %s"), quote (dir)); 207 return false; 208} 209