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Groups > linux.kernel > #1244271
| From | Andreas Gruenbacher <andreas.gruenbacher@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v10 14/46] richacl: Check if an acl is equivalent to a file mode |
| Date | 2015-10-12 01:10 +0200 |
| Message-ID | <qixUD-61y-53@gated-at.bofh.it> (permalink) |
| References | <qixKV-5z8-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Andreas Gruenbacher <agruenba@redhat.com>
ACLs are considered equivalent to file modes if they only consist of
owner@, group@, and everyone@ entries, the owner@ permissions do not
depend on whether the owner is a member in the owning group, and no
inheritance flags are set. This test is used to avoid storing richacls
if the acl can be computed from the file permission bits.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
---
fs/richacl_base.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/richacl.h | 1 +
2 files changed, 105 insertions(+)
diff --git a/fs/richacl_base.c b/fs/richacl_base.c
index 764d73a..f4b8d3c 100644
--- a/fs/richacl_base.c
+++ b/fs/richacl_base.c
@@ -382,3 +382,107 @@ __richacl_chmod(struct richacl *acl, umode_t mode)
return clone;
}
EXPORT_SYMBOL_GPL(__richacl_chmod);
+
+/**
+ * richacl_equiv_mode - compute the mode equivalent of @acl
+ *
+ * An acl is considered equivalent to a file mode if it only consists of
+ * owner@, group@, and everyone@ entries and the owner@ permissions do not
+ * depend on whether the owner is a member in the owning group.
+ */
+int
+richacl_equiv_mode(const struct richacl *acl, umode_t *mode_p)
+{
+ umode_t mode = *mode_p;
+
+ /*
+ * The RICHACE_DELETE_CHILD flag is meaningless for non-directories, so
+ * we ignore it.
+ */
+ unsigned int x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD;
+ struct {
+ unsigned int allowed;
+ unsigned int defined; /* allowed or denied */
+ } owner = {
+ .defined = RICHACE_POSIX_ALWAYS_ALLOWED |
+ RICHACE_POSIX_OWNER_ALLOWED | x,
+ }, group = {
+ .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x,
+ }, everyone = {
+ .defined = RICHACE_POSIX_ALWAYS_ALLOWED | x,
+ };
+ const struct richace *ace;
+
+ if (acl->a_flags & ~(RICHACL_WRITE_THROUGH | RICHACL_MASKED))
+ return -1;
+
+ richacl_for_each_entry(ace, acl) {
+ if (ace->e_flags & ~RICHACE_SPECIAL_WHO)
+ return -1;
+
+ if (richace_is_owner(ace) || richace_is_everyone(ace)) {
+ x = ace->e_mask & ~owner.defined;
+ if (richace_is_allow(ace)) {
+ unsigned int group_denied =
+ group.defined & ~group.allowed;
+
+ if (x & group_denied)
+ return -1;
+ owner.allowed |= x;
+ } else /* if (richace_is_deny(ace)) */ {
+ if (x & group.allowed)
+ return -1;
+ }
+ owner.defined |= x;
+
+ if (richace_is_everyone(ace)) {
+ x = ace->e_mask;
+ if (richace_is_allow(ace)) {
+ group.allowed |=
+ x & ~group.defined;
+ everyone.allowed |=
+ x & ~everyone.defined;
+ }
+ group.defined |= x;
+ everyone.defined |= x;
+ }
+ } else if (richace_is_group(ace)) {
+ x = ace->e_mask & ~group.defined;
+ if (richace_is_allow(ace))
+ group.allowed |= x;
+ group.defined |= x;
+ } else
+ return -1;
+ }
+
+ if (group.allowed & ~owner.defined)
+ return -1;
+
+ if (acl->a_flags & RICHACL_MASKED) {
+ if (acl->a_flags & RICHACL_WRITE_THROUGH) {
+ owner.allowed = acl->a_owner_mask;
+ everyone.allowed = acl->a_other_mask;
+ } else {
+ owner.allowed &= acl->a_owner_mask;
+ everyone.allowed &= acl->a_other_mask;
+ }
+ group.allowed &= acl->a_group_mask;
+ }
+
+ mode = (mode & ~S_IRWXUGO) |
+ (richacl_mask_to_mode(owner.allowed) << 6) |
+ (richacl_mask_to_mode(group.allowed) << 3) |
+ richacl_mask_to_mode(everyone.allowed);
+
+ /* Mask flags we can ignore */
+ x = S_ISDIR(mode) ? 0 : RICHACE_DELETE_CHILD;
+
+ if (((richacl_mode_to_mask(mode >> 6) ^ owner.allowed) & ~x) ||
+ ((richacl_mode_to_mask(mode >> 3) ^ group.allowed) & ~x) ||
+ ((richacl_mode_to_mask(mode) ^ everyone.allowed) & ~x))
+ return -1;
+
+ *mode_p = mode;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(richacl_equiv_mode);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index 152000c..9561db0 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -304,6 +304,7 @@ extern unsigned int richacl_mode_to_mask(umode_t);
extern unsigned int richacl_want_to_mask(unsigned int);
extern void richacl_compute_max_masks(struct richacl *);
extern struct richacl *__richacl_chmod(struct richacl *, umode_t);
+extern int richacl_equiv_mode(const struct richacl *, umode_t *);
/* richacl_inode.c */
extern int richacl_permission(struct inode *, const struct richacl *, int);
--
2.5.0
--
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[PATCH v10 00/46] Richacls Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:00 +0200
[PATCH v10 37/46] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 35/46] nfsd: Add richacl support Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 27/46] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 17/46] richacl: xattr mapping functions Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 23/46] xfs: Make xfs_set_mode non-static Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
Re: [PATCH v10 23/46] xfs: Make xfs_set_mode non-static Dave Chinner <david@fromorbit.com> - 2015-10-12 01:50 +0200
[PATCH v10 43/46] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 24/46] xfs: Add richacl support Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Dave Chinner <david@fromorbit.com> - 2015-10-12 02:20 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 04:00 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Dave Chinner <david@fromorbit.com> - 2015-10-12 06:10 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-12 08:00 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-10-13 21:30 +0200
Re: [PATCH v10 24/46] xfs: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-13 15:40 +0200
[PATCH v10 28/46] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 30/46] richacl: Isolate the owner and group classes Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 19/46] vfs: Add richacl permission checking Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 26/46] richacl: Move everyone@ aces down the acl Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 18/46] richacl: Add richacl xattr handler Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 42/46] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 36/46] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 13/46] richacl: Update the file masks in chmod() Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 32/46] richacl: Create richacl from mode values Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 22/46] xfs: Fix error path in xfs_get_acl Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 20/46] ext4: Add richacl support Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 11/46] vfs: Add get_richacl and set_richacl inode operations Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 14/46] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 33/46] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 38/46] richacl: Add support for unmapped identifiers Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
Re: [PATCH v10 38/46] richacl: Add support for unmapped identifiers Dave Chinner <david@fromorbit.com> - 2015-10-12 02:30 +0200
Re: [PATCH v10 38/46] richacl: Add support for unmapped identifiers Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 04:00 +0200
[PATCH v10 29/46] richacl: Set the other permissions to the other mask Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 45/46] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 41/46] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 46/46] richacl: uapi header split Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 44/46] nfs: Add richacl support Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
Re: [PATCH v10 44/46] nfs: Add richacl support Anna Schumaker <Anna.Schumaker@netapp.com> - 2015-10-12 16:40 +0200
Re: [PATCH v10 44/46] nfs: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-12 21:50 +0200
[PATCH v10 21/46] ext4: Add richacl feature flag Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 25/46] richacl: acl editing helper functions Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 15/46] richacl: Create-time inheritance Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 31/46] richacl: Apply the file masks to a richacl Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:10 +0200
[PATCH v10 40/46] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:20 +0200
[PATCH v10 39/46] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:20 +0200
[PATCH v10 34/46] nfsd: Use richacls as internal acl representation Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:20 +0200
[PATCH v10 16/46] richacl: Automatic Inheritance Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:30 +0200
[PATCH v10 03/46] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 12/46] vfs: Cache richacl in struct inode Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 09/46] richacl: Permission check algorithm Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 10/46] vfs: Cache base_acl objects in inodes Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 08/46] richacl: Compute maximum file masks from an acl Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 04/46] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 05/46] vfs: Add permission flags for setting file attributes Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 02/46] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:40 +0200
[PATCH v10 01/46] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:50 +0200
[PATCH v10 07/46] richacl: Permission mapping functions Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:50 +0200
[PATCH v10 06/46] richacl: In-memory representation and helper functions Andreas Gruenbacher <andreas.gruenbacher@gmail.com> - 2015-10-12 01:50 +0200
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