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Diffstat (limited to 'lib/acl-internal.c')
| -rw-r--r-- | lib/acl-internal.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/lib/acl-internal.c b/lib/acl-internal.c new file mode 100644 index 00000000..1a2f8c44 --- /dev/null +++ b/lib/acl-internal.c @@ -0,0 +1,500 @@ +/* Test whether a file has a nontrivial access control list. + + Copyright (C) 2002-2003, 2005-2015 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 <http://www.gnu.org/licenses/>. + + Written by Paul Eggert, Andreas Grünbacher, and Bruno Haible. */ + +#include <config.h> + +#include "acl.h" + +#include "acl-internal.h" + +#if USE_ACL && HAVE_ACL_GET_FILE + +# if HAVE_ACL_TYPE_EXTENDED /* Mac OS X */ + +/* ACL is an ACL, from a file, stored as type ACL_TYPE_EXTENDED. + Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial. */ +int +acl_extended_nontrivial (acl_t acl) +{ + /* acl is non-trivial if it is non-empty. */ + return (acl_entries (acl) > 0); +} + +# else /* Linux, FreeBSD, IRIX, Tru64 */ + +/* ACL is an ACL, from a file, stored as type ACL_TYPE_ACCESS. + Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. + Return -1 and set errno upon failure to determine it. */ +int +acl_access_nontrivial (acl_t acl) +{ + /* acl is non-trivial if it has some entries other than for "user::", + "group::", and "other::". Normally these three should be present + at least, allowing us to write + return (3 < acl_entries (acl)); + but the following code is more robust. */ +# if HAVE_ACL_FIRST_ENTRY /* Linux, FreeBSD */ + + acl_entry_t ace; + int got_one; + + for (got_one = acl_get_entry (acl, ACL_FIRST_ENTRY, &ace); + got_one > 0; + got_one = acl_get_entry (acl, ACL_NEXT_ENTRY, &ace)) + { + acl_tag_t tag; + if (acl_get_tag_type (ace, &tag) < 0) + return -1; + if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER)) + return 1; + } + return got_one; + +# elif HAVE_ACL_TO_SHORT_TEXT /* IRIX */ + /* Don't use acl_get_entry: it is undocumented. */ + + int count = acl->acl_cnt; + int i; + + for (i = 0; i < count; i++) + { + acl_entry_t ace = &acl->acl_entry[i]; + acl_tag_t tag = ace->ae_tag; + + if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ + || tag == ACL_OTHER_OBJ)) + return 1; + } + return 0; + +# elif HAVE_ACL_FREE_TEXT /* Tru64 */ + /* Don't use acl_get_entry: it takes only one argument and does not work. */ + + int count = acl->acl_num; + acl_entry_t ace; + + for (ace = acl->acl_first; count > 0; ace = ace->next, count--) + { + acl_tag_t tag; + acl_perm_t perm; + + tag = ace->entry->acl_type; + if (!(tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_OTHER)) + return 1; + + perm = ace->entry->acl_perm; + /* On Tru64, perm can also contain non-standard bits such as + PERM_INSERT, PERM_DELETE, PERM_MODIFY, PERM_LOOKUP, ... */ + if ((perm & ~(ACL_READ | ACL_WRITE | ACL_EXECUTE)) != 0) + return 1; + } + return 0; + +# else + + errno = ENOSYS; + return -1; +# endif +} + +# endif + +#elif USE_ACL && HAVE_FACL && defined GETACL /* Solaris, Cygwin, not HP-UX */ + +/* Test an ACL retrieved with GETACL. + Return 1 if the given ACL, consisting of COUNT entries, is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_nontrivial (int count, aclent_t *entries) +{ + int i; + + for (i = 0; i < count; i++) + { + aclent_t *ace = &entries[i]; + + /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat(). + If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat(). + We don't need to check ace->a_id in these cases. */ + if (!(ace->a_type == USER_OBJ + || ace->a_type == GROUP_OBJ + || ace->a_type == OTHER_OBJ + /* Note: Cygwin does not return a CLASS_OBJ ("mask:") entry + sometimes. */ + || ace->a_type == CLASS_OBJ)) + return 1; + } + return 0; +} + +# ifdef ACE_GETACL + +/* A shortcut for a bitmask. */ +# define NEW_ACE_WRITEA_DATA (NEW_ACE_WRITE_DATA | NEW_ACE_APPEND_DATA) + +/* Test an ACL retrieved with ACE_GETACL. + Return 1 if the given ACL, consisting of COUNT entries, is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_ace_nontrivial (int count, ace_t *entries) +{ + int i; + + /* The flags in the ace_t structure changed in a binary incompatible way + when ACL_NO_TRIVIAL etc. were introduced in <sys/acl.h> version 1.15. + How to distinguish the two conventions at runtime? + In the old convention, usually three ACEs have a_flags = ACE_OWNER / + ACE_GROUP / ACE_OTHER, in the range 0x0100..0x0400. In the new + convention, these values are not used. */ + int old_convention = 0; + + for (i = 0; i < count; i++) + if (entries[i].a_flags & (OLD_ACE_OWNER | OLD_ACE_GROUP | OLD_ACE_OTHER)) + { + old_convention = 1; + break; + } + + if (old_convention) + /* Running on Solaris 10. */ + for (i = 0; i < count; i++) + { + ace_t *ace = &entries[i]; + + /* Note: + If ace->a_flags = ACE_OWNER, ace->a_who is the st_uid from stat(). + If ace->a_flags = ACE_GROUP, ace->a_who is the st_gid from stat(). + We don't need to check ace->a_who in these cases. */ + if (!(ace->a_type == OLD_ALLOW + && (ace->a_flags == OLD_ACE_OWNER + || ace->a_flags == OLD_ACE_GROUP + || ace->a_flags == OLD_ACE_OTHER))) + return 1; + } + else + { + /* Running on Solaris 10 (newer version) or Solaris 11. */ + unsigned int access_masks[6] = + { + 0, /* owner@ deny */ + 0, /* owner@ allow */ + 0, /* group@ deny */ + 0, /* group@ allow */ + 0, /* everyone@ deny */ + 0 /* everyone@ allow */ + }; + + for (i = 0; i < count; i++) + { + ace_t *ace = &entries[i]; + unsigned int index1; + unsigned int index2; + + if (ace->a_type == NEW_ACE_ACCESS_ALLOWED_ACE_TYPE) + index1 = 1; + else if (ace->a_type == NEW_ACE_ACCESS_DENIED_ACE_TYPE) + index1 = 0; + else + return 1; + + if (ace->a_flags == NEW_ACE_OWNER) + index2 = 0; + else if (ace->a_flags == (NEW_ACE_GROUP | NEW_ACE_IDENTIFIER_GROUP)) + index2 = 2; + else if (ace->a_flags == NEW_ACE_EVERYONE) + index2 = 4; + else + return 1; + + access_masks[index1 + index2] |= ace->a_access_mask; + } + + /* The same bit shouldn't be both allowed and denied. */ + if (access_masks[0] & access_masks[1]) + return 1; + if (access_masks[2] & access_masks[3]) + return 1; + if (access_masks[4] & access_masks[5]) + return 1; + + /* Check minimum masks. */ + if ((NEW_ACE_WRITE_NAMED_ATTRS + | NEW_ACE_WRITE_ATTRIBUTES + | NEW_ACE_WRITE_ACL + | NEW_ACE_WRITE_OWNER) + & ~ access_masks[1]) + return 1; + access_masks[1] &= ~(NEW_ACE_WRITE_NAMED_ATTRS + | NEW_ACE_WRITE_ATTRIBUTES + | NEW_ACE_WRITE_ACL + | NEW_ACE_WRITE_OWNER); + if ((NEW_ACE_READ_NAMED_ATTRS + | NEW_ACE_READ_ATTRIBUTES + | NEW_ACE_READ_ACL + | NEW_ACE_SYNCHRONIZE) + & ~ access_masks[5]) + return 1; + access_masks[5] &= ~(NEW_ACE_READ_NAMED_ATTRS + | NEW_ACE_READ_ATTRIBUTES + | NEW_ACE_READ_ACL + | NEW_ACE_SYNCHRONIZE); + + /* Check the allowed or denied bits. */ + switch ((access_masks[0] | access_masks[1]) + & ~(NEW_ACE_READ_NAMED_ATTRS + | NEW_ACE_READ_ATTRIBUTES + | NEW_ACE_READ_ACL + | NEW_ACE_SYNCHRONIZE)) + { + case 0: + case NEW_ACE_READ_DATA: + case NEW_ACE_WRITEA_DATA: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA: + case NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + break; + default: + return 1; + } + switch ((access_masks[2] | access_masks[3]) + & ~(NEW_ACE_READ_NAMED_ATTRS + | NEW_ACE_READ_ATTRIBUTES + | NEW_ACE_READ_ACL + | NEW_ACE_SYNCHRONIZE)) + { + case 0: + case NEW_ACE_READ_DATA: + case NEW_ACE_WRITEA_DATA: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA: + case NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + break; + default: + return 1; + } + switch ((access_masks[4] | access_masks[5]) + & ~(NEW_ACE_WRITE_NAMED_ATTRS + | NEW_ACE_WRITE_ATTRIBUTES + | NEW_ACE_WRITE_ACL + | NEW_ACE_WRITE_OWNER)) + { + case 0: + case NEW_ACE_READ_DATA: + case NEW_ACE_WRITEA_DATA: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA: + case NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + case NEW_ACE_READ_DATA | NEW_ACE_WRITEA_DATA | NEW_ACE_EXECUTE: + break; + default: + return 1; + } + + /* Check that the NEW_ACE_WRITE_DATA and NEW_ACE_APPEND_DATA bits are + either both allowed or both denied. */ + if (((access_masks[0] & NEW_ACE_WRITE_DATA) != 0) + != ((access_masks[0] & NEW_ACE_APPEND_DATA) != 0)) + return 1; + if (((access_masks[2] & NEW_ACE_WRITE_DATA) != 0) + != ((access_masks[2] & NEW_ACE_APPEND_DATA) != 0)) + return 1; + if (((access_masks[4] & NEW_ACE_WRITE_DATA) != 0) + != ((access_masks[4] & NEW_ACE_APPEND_DATA) != 0)) + return 1; + } + + return 0; +} + +# endif + +#elif USE_ACL && HAVE_GETACL /* HP-UX */ + +/* Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_nontrivial (int count, struct acl_entry *entries) +{ + int i; + + if (count > 3) + return 1; + + for (i = 0; i < count; i++) + { + struct acl_entry *ace = &entries[i]; + + if (ace->uid != ACL_NSUSER && ace->gid != ACL_NSGROUP) + return 1; + } + return 0; +} + +# if HAVE_ACLV_H /* HP-UX >= 11.11 */ + +/* Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +aclv_nontrivial (int count, struct acl *entries) +{ + int i; + + for (i = 0; i < count; i++) + { + struct acl *ace = &entries[i]; + + /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat(). + If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat(). + We don't need to check ace->a_id in these cases. */ + if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */ + || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */ + || ace->a_type == CLASS_OBJ + || ace->a_type == OTHER_OBJ)) + return 1; + } + return 0; +} + +# endif + +#elif USE_ACL && (HAVE_ACLX_GET || HAVE_STATACL) /* AIX */ + +/* Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_nontrivial (struct acl *a) +{ + /* The normal way to iterate through an ACL is like this: + struct acl_entry *ace; + for (ace = a->acl_ext; ace != acl_last (a); ace = acl_nxt (ace)) + { + struct ace_id *aei; + switch (ace->ace_type) + { + case ACC_PERMIT: + case ACC_DENY: + case ACC_SPECIFY: + ...; + } + for (aei = ace->ace_id; aei != id_last (ace); aei = id_nxt (aei)) + ... + } + */ + return (acl_last (a) != a->acl_ext ? 1 : 0); +} + +# if HAVE_ACLX_GET && defined ACL_AIX_WIP /* newer AIX */ + +/* Return 1 if the given ACL is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_nfs4_nontrivial (nfs4_acl_int_t *a) +{ +# if 1 /* let's try this first */ + return (a->aclEntryN > 0 ? 1 : 0); +# else + int count = a->aclEntryN; + int i; + + for (i = 0; i < count; i++) + { + nfs4_ace_int_t *ace = &a->aclEntry[i]; + + if (!((ace->flags & ACE4_ID_SPECIAL) != 0 + && (ace->aceWho.special_whoid == ACE4_WHO_OWNER + || ace->aceWho.special_whoid == ACE4_WHO_GROUP + || ace->aceWho.special_whoid == ACE4_WHO_EVERYONE) + && ace->aceType == ACE4_ACCESS_ALLOWED_ACE_TYPE + && ace->aceFlags == 0 + && (ace->aceMask & ~(ACE4_READ_DATA | ACE4_LIST_DIRECTORY + | ACE4_WRITE_DATA | ACE4_ADD_FILE + | ACE4_EXECUTE)) == 0)) + return 1; + } + return 0; +# endif +} + +# endif + +#elif USE_ACL && HAVE_ACLSORT /* NonStop Kernel */ + +/* Test an ACL retrieved with ACL_GET. + Return 1 if the given ACL, consisting of COUNT entries, is non-trivial. + Return 0 if it is trivial, i.e. equivalent to a simple stat() mode. */ +int +acl_nontrivial (int count, struct acl *entries) +{ + int i; + + for (i = 0; i < count; i++) + { + struct acl *ace = &entries[i]; + + /* Note: If ace->a_type = USER_OBJ, ace->a_id is the st_uid from stat(). + If ace->a_type = GROUP_OBJ, ace->a_id is the st_gid from stat(). + We don't need to check ace->a_id in these cases. */ + if (!(ace->a_type == USER_OBJ /* no need to check ace->a_id here */ + || ace->a_type == GROUP_OBJ /* no need to check ace->a_id here */ + || ace->a_type == CLASS_OBJ + || ace->a_type == OTHER_OBJ)) + return 1; + } + return 0; +} + +#endif + +void +free_permission_context (struct permission_context *ctx) +{ +#ifdef USE_ACL +# if HAVE_ACL_GET_FILE /* Linux, FreeBSD, Mac OS X, IRIX, Tru64 */ + if (ctx->acl) + acl_free (ctx->acl); +# if !HAVE_ACL_TYPE_EXTENDED + if (ctx->default_acl) + acl_free (ctx->default_acl); +# endif + +# elif defined GETACL /* Solaris, Cygwin */ + free (ctx->entries); +# ifdef ACE_GETACL + free (ctx->ace_entries); +# endif + +# elif HAVE_GETACL /* HP-UX */ + +# if HAVE_ACLV_H +# endif + +# elif HAVE_STATACL /* older AIX */ + +# elif HAVE_ACLSORT /* NonStop Kernel */ + +# endif +#endif +} |