When creating a richacl that represents a particular file mode, one approach is
to create one everyone@ allow entry and set the richacl masks according to the
file mode; when those masks are applied with richacl_apply_masks(), that
everyone@ allow entry gets transformed as needed. The other approach is to
compute the result after richacl_apply_masks() directly; this commit does that.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/richacl_compat.c | 85 ++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 68 insertions(+), 17 deletions(-)
diff --git a/fs/richacl_compat.c b/fs/richacl_compat.c
index 8ebe772..33fc50c 100644
--- a/fs/richacl_compat.c
+++ b/fs/richacl_compat.c
@@ -761,30 +761,81 @@ EXPORT_SYMBOL_GPL(richacl_apply_masks);
struct richacl *
richacl_from_mode_unmasked(mode_t mode)
{
+ unsigned int owner_mask = richacl_mode_to_mask(mode >> 6) |
+ RICHACE_POSIX_OWNER_ALLOWED;
+ unsigned int group_mask = richacl_mode_to_mask(mode >> 3);
+ unsigned int other_mask = richacl_mode_to_mask(mode);
+ unsigned int denied;
+ unsigned int entries = 0;
struct richacl *acl;
struct richace *ace;
- acl = richacl_alloc(1, GFP_KERNEL);
+ /* RICHACE_DELETE_CHILD is meaningless for non-directories. */
+ if (!S_ISDIR(mode)) {
+ owner_mask &= ~RICHACE_DELETE_CHILD;
+ group_mask &= ~RICHACE_DELETE_CHILD;
+ other_mask &= ~RICHACE_DELETE_CHILD;
+ }
+
+ if (owner_mask & ~(group_mask & other_mask))
+ entries++; /* OWNER@ ALLOW entry needed */
+ denied = ~owner_mask & (group_mask | other_mask);
+ if (denied)
+ entries++; /* OWNER@ DENY entry needed */
+ if (group_mask & ~other_mask)
+ entries++; /* GROUP@ ALLOW entry needed */
+ denied = ~group_mask & other_mask;
+ if (denied)
+ entries++; /* GROUP@ DENY entry needed */
+ if (other_mask)
+ entries++; /* EVERYONE@ ALLOW entry needed */
+
+ acl = richacl_alloc(entries, GFP_KERNEL);
if (!acl)
return NULL;
- acl->a_flags = RICHACL_MASKED;
- acl->a_owner_mask = richacl_mode_to_mask(mode >> 6) |
- RICHACE_POSIX_OWNER_ALLOWED;
- acl->a_group_mask = richacl_mode_to_mask(mode >> 3);
- acl->a_other_mask = richacl_mode_to_mask(mode);
-
+ acl->a_owner_mask = owner_mask;
+ acl->a_group_mask = group_mask;
+ acl->a_other_mask = other_mask;
ace = acl->a_entries;
- ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE;
- ace->e_flags = RICHACE_SPECIAL_WHO;
- ace->e_mask = RICHACE_POSIX_ALWAYS_ALLOWED |
- RICHACE_POSIX_MODE_ALL |
- RICHACE_POSIX_OWNER_ALLOWED;
- /* RICHACE_DELETE_CHILD is meaningless for non-directories. */
- if (!S_ISDIR(mode))
- ace->e_mask &= ~RICHACE_DELETE_CHILD;
- ace->e_id.special = RICHACE_EVERYONE_SPECIAL_ID;
- return acl;
+ if (owner_mask & ~(group_mask & other_mask)) {
+ ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE;
+ ace->e_flags = RICHACE_SPECIAL_WHO;
+ ace->e_mask = owner_mask;
+ ace->e_id.special = RICHACE_OWNER_SPECIAL_ID;
+ ace++;
+ }
+ denied = ~owner_mask & (group_mask | other_mask);
+ if (denied) {
+ ace->e_type = RICHACE_ACCESS_DENIED_ACE_TYPE;
+ ace->e_flags = RICHACE_SPECIAL_WHO;
+ ace->e_mask = denied;
+ ace->e_id.special = RICHACE_OWNER_SPECIAL_ID;
+ ace++;
+ }
+ if (group_mask & ~other_mask) {
+ ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE;
+ ace->e_flags = RICHACE_SPECIAL_WHO;
+ ace->e_mask = group_mask;
+ ace->e_id.special = RICHACE_GROUP_SPECIAL_ID;
+ ace++;
+ }
+ denied = ~group_mask & other_mask;
+ if (denied) {
+ ace->e_type = RICHACE_ACCESS_DENIED_ACE_TYPE;
+ ace->e_flags = RICHACE_SPECIAL_WHO;
+ ace->e_mask = denied;
+ ace->e_id.special = RICHACE_GROUP_SPECIAL_ID;
+ ace++;
+ }
+ if (other_mask) {
+ ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE;
+ ace->e_flags = RICHACE_SPECIAL_WHO;
+ ace->e_mask = other_mask;
+ ace->e_id.special = RICHACE_EVERYONE_SPECIAL_ID;
+ ace++;
+ }
+ return acl;
}
EXPORT_SYMBOL_GPL(richacl_from_mode_unmasked);
--
2.1.0
--
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