1/* acl.c - access control lists 2 3 Copyright (C) 2002, 2003, 2005, 2006, 2007 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 18 Written by Paul Eggert and Andreas Gruenbacher. */ 19 20#include <config.h> 21 22#include "acl.h" 23 24#include "acl-internal.h" 25 26/* If DESC is a valid file descriptor use fchmod to change the 27 file's mode to MODE on systems that have fchown. On systems 28 that don't have fchown and if DESC is invalid, use chown on 29 NAME instead. */ 30 31int 32chmod_or_fchmod (const char *name, int desc, mode_t mode) 33{ 34 if (HAVE_FCHMOD && desc != -1) 35 return fchmod (desc, mode); 36 else 37 return chmod (name, mode); 38} 39 40/* Copy access control lists from one file to another. If SOURCE_DESC is 41 a valid file descriptor, use file descriptor operations, else use 42 filename based operations on SRC_NAME. Likewise for DEST_DESC and 43 DEST_NAME. 44 If access control lists are not available, fchmod the target file to 45 MODE. Also sets the non-permission bits of the destination file 46 (S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set. 47 System call return value semantics. */ 48 49int 50copy_acl (const char *src_name, int source_desc, const char *dst_name, 51 int dest_desc, mode_t mode) 52{ 53 int ret; 54 55#if USE_ACL && HAVE_ACL_GET_FILE && HAVE_ACL_SET_FILE && HAVE_ACL_FREE 56 /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */ 57 58 acl_t acl; 59 if (HAVE_ACL_GET_FD && source_desc != -1) 60 acl = acl_get_fd (source_desc); 61 else 62 acl = acl_get_file (src_name, ACL_TYPE_ACCESS); 63 if (acl == NULL) 64 { 65 if (ACL_NOT_WELL_SUPPORTED (errno)) 66 return set_acl (dst_name, dest_desc, mode); 67 else 68 { 69 error (0, errno, "%s", quote (src_name)); 70 return -1; 71 } 72 } 73 74 if (HAVE_ACL_SET_FD && dest_desc != -1) 75 ret = acl_set_fd (dest_desc, acl); 76 else 77 ret = acl_set_file (dst_name, ACL_TYPE_ACCESS, acl); 78 if (ret != 0) 79 { 80 int saved_errno = errno; 81 82 if (ACL_NOT_WELL_SUPPORTED (errno)) 83 { 84 int n = acl_entries (acl); 85 86 acl_free (acl); 87 /* On most hosts an ACL is trivial if n == 3, and it cannot be 88 less than 3. On IRIX 6.5 it is also trivial if n == -1. 89 For simplicity and safety, assume the ACL is trivial if n <= 3. 90 Also see file-has-acl.c for some of the other possibilities; 91 it's not clear whether that complexity is needed here. */ 92 if (n <= 3) 93 { 94 if (chmod_or_fchmod (dst_name, dest_desc, mode) != 0) 95 saved_errno = errno; 96 else 97 return 0; 98 } 99 else 100 chmod_or_fchmod (dst_name, dest_desc, mode); 101 } 102 else 103 { 104 acl_free (acl); 105 chmod_or_fchmod (dst_name, dest_desc, mode); 106 } 107 error (0, saved_errno, _("preserving permissions for %s"), 108 quote (dst_name)); 109 return -1; 110 } 111 else 112 acl_free (acl); 113 114 if (mode & (S_ISUID | S_ISGID | S_ISVTX)) 115 { 116 /* We did not call chmod so far, so the special bits have not yet 117 been set. */ 118 119 if (chmod_or_fchmod (dst_name, dest_desc, mode) != 0) 120 { 121 error (0, errno, _("preserving permissions for %s"), 122 quote (dst_name)); 123 return -1; 124 } 125 } 126 127 if (S_ISDIR (mode)) 128 { 129 acl = acl_get_file (src_name, ACL_TYPE_DEFAULT); 130 if (acl == NULL) 131 { 132 error (0, errno, "%s", quote (src_name)); 133 return -1; 134 } 135 136 if (acl_set_file (dst_name, ACL_TYPE_DEFAULT, acl)) 137 { 138 error (0, errno, _("preserving permissions for %s"), 139 quote (dst_name)); 140 acl_free (acl); 141 return -1; 142 } 143 else 144 acl_free (acl); 145 } 146 return 0; 147#else 148 ret = chmod_or_fchmod (dst_name, dest_desc, mode); 149 if (ret != 0) 150 error (0, errno, _("preserving permissions for %s"), quote (dst_name)); 151 return ret; 152#endif 153} 154 155/* Set the access control lists of a file. If DESC is a valid file 156 descriptor, use file descriptor operations where available, else use 157 filename based operations on NAME. If access control lists are not 158 available, fchmod the target file to MODE. Also sets the 159 non-permission bits of the destination file (S_ISUID, S_ISGID, S_ISVTX) 160 to those from MODE if any are set. System call return value 161 semantics. */ 162 163int 164set_acl (char const *name, int desc, mode_t mode) 165{ 166#if USE_ACL && HAVE_ACL_SET_FILE && HAVE_ACL_FREE 167 /* POSIX 1003.1e draft 17 (abandoned) specific version. */ 168 169 /* We must also have have_acl_from_text and acl_delete_def_file. 170 (acl_delete_def_file could be emulated with acl_init followed 171 by acl_set_file, but acl_set_file with an empty acl is 172 unspecified.) */ 173 174# ifndef HAVE_ACL_FROM_TEXT 175# error Must have acl_from_text (see POSIX 1003.1e draft 17). 176# endif 177# ifndef HAVE_ACL_DELETE_DEF_FILE 178# error Must have acl_delete_def_file (see POSIX 1003.1e draft 17). 179# endif 180 181 acl_t acl; 182 int ret; 183 184 if (HAVE_ACL_FROM_MODE) 185 { 186 acl = acl_from_mode (mode); 187 if (!acl) 188 { 189 error (0, errno, "%s", quote (name)); 190 return -1; 191 } 192 } 193 else 194 { 195 char acl_text[] = "u::---,g::---,o::---"; 196 197 if (mode & S_IRUSR) acl_text[ 3] = 'r'; 198 if (mode & S_IWUSR) acl_text[ 4] = 'w'; 199 if (mode & S_IXUSR) acl_text[ 5] = 'x'; 200 if (mode & S_IRGRP) acl_text[10] = 'r'; 201 if (mode & S_IWGRP) acl_text[11] = 'w'; 202 if (mode & S_IXGRP) acl_text[12] = 'x'; 203 if (mode & S_IROTH) acl_text[17] = 'r'; 204 if (mode & S_IWOTH) acl_text[18] = 'w'; 205 if (mode & S_IXOTH) acl_text[19] = 'x'; 206 207 acl = acl_from_text (acl_text); 208 if (!acl) 209 { 210 error (0, errno, "%s", quote (name)); 211 return -1; 212 } 213 } 214 if (HAVE_ACL_SET_FD && desc != -1) 215 ret = acl_set_fd (desc, acl); 216 else 217 ret = acl_set_file (name, ACL_TYPE_ACCESS, acl); 218 if (ret != 0) 219 { 220 int saved_errno = errno; 221 acl_free (acl); 222 223 if (ACL_NOT_WELL_SUPPORTED (errno)) 224 { 225 if (chmod_or_fchmod (name, desc, mode) != 0) 226 saved_errno = errno; 227 else 228 return 0; 229 } 230 error (0, saved_errno, _("setting permissions for %s"), quote (name)); 231 return -1; 232 } 233 else 234 acl_free (acl); 235 236 if (S_ISDIR (mode) && acl_delete_def_file (name)) 237 { 238 error (0, errno, _("setting permissions for %s"), quote (name)); 239 return -1; 240 } 241 242 if (mode & (S_ISUID | S_ISGID | S_ISVTX)) 243 { 244 /* We did not call chmod so far, so the special bits have not yet 245 been set. */ 246 247 if (chmod_or_fchmod (name, desc, mode)) 248 { 249 error (0, errno, _("preserving permissions for %s"), quote (name)); 250 return -1; 251 } 252 } 253 return 0; 254#else 255 int ret = chmod_or_fchmod (name, desc, mode); 256 if (ret) 257 error (0, errno, _("setting permissions for %s"), quote (name)); 258 return ret; 259#endif 260} 261