diff options
Diffstat (limited to 'lib/acl.c')
| -rw-r--r-- | lib/acl.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/lib/acl.c b/lib/acl.c new file mode 100644 index 0000000..803be0d --- /dev/null +++ b/lib/acl.c @@ -0,0 +1,407 @@ +/* acl.c - access control lists + + Copyright (C) 2002, 2003, 2005, 2006 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 2, 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, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + + Written by Paul Eggert and Andreas Gruenbacher. */ + +#include <config.h> + +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#ifndef S_ISLNK +# define S_ISLNK(Mode) 0 +#endif + +#ifdef HAVE_ACL_LIBACL_H +# include <acl/libacl.h> +#endif + +#include "acl.h" +#include "error.h" +#include "quote.h" + +#include <errno.h> +#ifndef ENOSYS +# define ENOSYS (-1) +#endif +#ifndef ENOTSUP +# define ENOTSUP (-1) +#endif + +#if ENABLE_NLS +# include <libintl.h> +# define _(Text) gettext (Text) +#else +# define _(Text) Text +#endif + +#ifndef HAVE_FCHMOD +# define HAVE_FCHMOD false +# define fchmod(fd, mode) (-1) +#endif + +/* POSIX 1003.1e (draft 17) */ +#ifndef HAVE_ACL_GET_FD +# define HAVE_ACL_GET_FD false +# define acl_get_fd(fd) (NULL) +#endif + +/* POSIX 1003.1e (draft 17) */ +#ifndef HAVE_ACL_SET_FD +# define HAVE_ACL_SET_FD false +# define acl_set_fd(fd, acl) (-1) +#endif + +/* Linux-specific */ +#ifndef HAVE_ACL_EXTENDED_FILE +# define HAVE_ACL_EXTENDED_FILE false +# define acl_extended_file(name) (-1) +#endif + +/* Linux-specific */ +#ifndef HAVE_ACL_FROM_MODE +# define HAVE_ACL_FROM_MODE false +# define acl_from_mode(mode) (NULL) +#endif + +/* We detect the presence of POSIX 1003.1e (draft 17 -- abandoned) support + by checking for HAVE_ACL_GET_FILE, HAVE_ACL_SET_FILE, and HAVE_ACL_FREE. + Systems that have acl_get_file, acl_set_file, and acl_free must also + have acl_to_text, acl_from_text, and acl_delete_def_file (all defined + in the draft); systems that don't would hit #error statements here. */ + +#if USE_ACL && HAVE_ACL_GET_FILE && !HAVE_ACL_ENTRIES +# ifndef HAVE_ACL_TO_TEXT +# error Must have acl_to_text (see POSIX 1003.1e draft 17). +# endif + +/* Return the number of entries in ACL. Linux implements acl_entries + as a more efficient extension than using this workaround. */ + +static int +acl_entries (acl_t acl) +{ + char *text = acl_to_text (acl, NULL), *t; + int entries; + if (text == NULL) + return -1; + for (entries = 0, t = text; ; t++, entries++) { + t = strchr (t, '\n'); + if (t == NULL) + break; + } + acl_free (text); + return entries; +} +#endif + +/* If DESC is a valid file descriptor use fchmod to change the + file's mode to MODE on systems that have fchown. On systems + that don't have fchown and if DESC is invalid, use chown on + NAME instead. */ + +int +chmod_or_fchmod (const char *name, int desc, mode_t mode) +{ + if (HAVE_FCHMOD && desc != -1) + return fchmod (desc, mode); + else + return chmod (name, mode); +} + +/* Return 1 if NAME has a nontrivial access control list, 0 if + NAME only has no or a base access control list, and -1 on + error. SB must be set to the stat buffer of FILE. */ + +int +file_has_acl (char const *name, struct stat const *sb) +{ +#if USE_ACL && HAVE_ACL && defined GETACLCNT + /* This implementation should work on recent-enough versions of HP-UX, + Solaris, and Unixware. */ + +# ifndef MIN_ACL_ENTRIES +# define MIN_ACL_ENTRIES 4 +# endif + + if (! S_ISLNK (sb->st_mode)) + { + int n = acl (name, GETACLCNT, 0, NULL); + return n < 0 ? (errno == ENOSYS ? 0 : -1) : (MIN_ACL_ENTRIES < n); + } +#elif USE_ACL && HAVE_ACL_GET_FILE && HAVE_ACL_FREE + /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */ + + if (! S_ISLNK (sb->st_mode)) + { + int ret; + + if (HAVE_ACL_EXTENDED_FILE) + ret = acl_extended_file (name); + else + { + acl_t acl = acl_get_file (name, ACL_TYPE_ACCESS); + if (acl) + { + ret = (3 < acl_entries (acl)); + acl_free (acl); + if (ret == 0 && S_ISDIR (sb->st_mode)) + { + acl = acl_get_file (name, ACL_TYPE_DEFAULT); + if (acl) + { + ret = (0 < acl_entries (acl)); + acl_free (acl); + } + else + ret = -1; + } + } + else + ret = -1; + } + if (ret < 0) + return (errno == ENOSYS || errno == ENOTSUP) ? 0 : -1; + return ret; + } +#endif + + /* FIXME: Add support for AIX, Irix, and Tru64. Please see Samba's + source/lib/sysacls.c file for fix-related ideas. */ + + return 0; +} + +/* Copy access control lists from one file to another. If SOURCE_DESC is + a valid file descriptor, use file descriptor operations, else use + filename based operations on SRC_NAME. Likewise for DEST_DESC and + DEST_NAME. + If access control lists are not available, fchmod the target file to + MODE. Also sets the non-permission bits of the destination file + (S_ISUID, S_ISGID, S_ISVTX) to those from MODE if any are set. + System call return value semantics. */ + +int +copy_acl (const char *src_name, int source_desc, const char *dst_name, + int dest_desc, mode_t mode) +{ + int ret; + +#if USE_ACL && HAVE_ACL_GET_FILE && HAVE_ACL_SET_FILE && HAVE_ACL_FREE + /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */ + + acl_t acl; + if (HAVE_ACL_GET_FD && source_desc != -1) + acl = acl_get_fd (source_desc); + else + acl = acl_get_file (src_name, ACL_TYPE_ACCESS); + if (acl == NULL) + { + if (errno == ENOSYS || errno == ENOTSUP) + return set_acl (dst_name, dest_desc, mode); + else + { + error (0, errno, "%s", quote (src_name)); + return -1; + } + } + + if (HAVE_ACL_SET_FD && dest_desc != -1) + ret = acl_set_fd (dest_desc, acl); + else + ret = acl_set_file (dst_name, ACL_TYPE_ACCESS, acl); + if (ret != 0) + { + int saved_errno = errno; + + if (errno == ENOSYS || errno == ENOTSUP) + { + int n = acl_entries (acl); + + acl_free (acl); + if (n == 3) + { + if (chmod_or_fchmod (dst_name, dest_desc, mode) != 0) + saved_errno = errno; + else + return 0; + } + else + chmod_or_fchmod (dst_name, dest_desc, mode); + } + else + { + acl_free (acl); + chmod_or_fchmod (dst_name, dest_desc, mode); + } + error (0, saved_errno, _("preserving permissions for %s"), + quote (dst_name)); + return -1; + } + else + acl_free (acl); + + if (mode & (S_ISUID | S_ISGID | S_ISVTX)) + { + /* We did not call chmod so far, so the special bits have not yet + been set. */ + + if (chmod_or_fchmod (dst_name, dest_desc, mode) != 0) + { + error (0, errno, _("preserving permissions for %s"), + quote (dst_name)); + return -1; + } + } + + if (S_ISDIR (mode)) + { + acl = acl_get_file (src_name, ACL_TYPE_DEFAULT); + if (acl == NULL) + { + error (0, errno, "%s", quote (src_name)); + return -1; + } + + if (acl_set_file (dst_name, ACL_TYPE_DEFAULT, acl)) + { + error (0, errno, _("preserving permissions for %s"), + quote (dst_name)); + acl_free (acl); + return -1; + } + else + acl_free (acl); + } + return 0; +#else + ret = chmod_or_fchmod (dst_name, dest_desc, mode); + if (ret != 0) + error (0, errno, _("preserving permissions for %s"), quote (dst_name)); + return ret; +#endif +} + +/* Set the access control lists of a file. If DESC is a valid file + descriptor, use file descriptor operations where available, else use + filename based operations on NAME. If access control lists are not + available, fchmod the target file to MODE. Also sets the + non-permission bits of the destination file (S_ISUID, S_ISGID, S_ISVTX) + to those from MODE if any are set. System call return value + semantics. */ + +int +set_acl (char const *name, int desc, mode_t mode) +{ +#if USE_ACL && HAVE_ACL_SET_FILE && HAVE_ACL_FREE + /* POSIX 1003.1e draft 17 (abandoned) specific version. */ + + /* We must also have have_acl_from_text and acl_delete_def_file. + (acl_delete_def_file could be emulated with acl_init followed + by acl_set_file, but acl_set_file with an empty acl is + unspecified.) */ + +# ifndef HAVE_ACL_FROM_TEXT +# error Must have acl_from_text (see POSIX 1003.1e draft 17). +# endif +# ifndef HAVE_ACL_DELETE_DEF_FILE +# error Must have acl_delete_def_file (see POSIX 1003.1e draft 17). +# endif + + acl_t acl; + int ret; + + if (HAVE_ACL_FROM_MODE) + { + acl = acl_from_mode (mode); + if (!acl) + { + error (0, errno, "%s", quote (name)); + return -1; + } + } + else + { + char acl_text[] = "u::---,g::---,o::---"; + + if (mode & S_IRUSR) acl_text[ 3] = 'r'; + if (mode & S_IWUSR) acl_text[ 4] = 'w'; + if (mode & S_IXUSR) acl_text[ 5] = 'x'; + if (mode & S_IRGRP) acl_text[10] = 'r'; + if (mode & S_IWGRP) acl_text[11] = 'w'; + if (mode & S_IXGRP) acl_text[12] = 'x'; + if (mode & S_IROTH) acl_text[17] = 'r'; + if (mode & S_IWOTH) acl_text[18] = 'w'; + if (mode & S_IXOTH) acl_text[19] = 'x'; + + acl = acl_from_text (acl_text); + if (!acl) + { + error (0, errno, "%s", quote (name)); + return -1; + } + } + if (HAVE_ACL_SET_FD && desc != -1) + ret = acl_set_fd (desc, acl); + else + ret = acl_set_file (name, ACL_TYPE_ACCESS, acl); + if (ret != 0) + { + int saved_errno = errno; + acl_free (acl); + + if (errno == ENOTSUP || errno == ENOSYS) + { + if (chmod_or_fchmod (name, desc, mode) != 0) + saved_errno = errno; + else + return 0; + } + error (0, saved_errno, _("setting permissions for %s"), quote (name)); + return -1; + } + else + acl_free (acl); + + if (S_ISDIR (mode) && acl_delete_def_file (name)) + { + error (0, errno, _("setting permissions for %s"), quote (name)); + return -1; + } + + if (mode & (S_ISUID | S_ISGID | S_ISVTX)) + { + /* We did not call chmod so far, so the special bits have not yet + been set. */ + + if (chmod_or_fchmod (name, desc, mode)) + { + error (0, errno, _("preserving permissions for %s"), quote (name)); + return -1; + } + } + return 0; +#else + int ret = chmod_or_fchmod (name, desc, mode); + if (ret) + error (0, errno, _("setting permissions for %s"), quote (name)); + return ret; +#endif +} |