From: Andreas Gruenbacher <agruenba@redhat.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
"Theodore Ts'o" <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
"J. Bruce Fields" <bfields@fieldses.org>,
Jeff Layton <jlayton@poochiereds.net>,
Trond Myklebust <trond.myklebust@primarydata.com>,
Anna Schumaker <anna.schumaker@netapp.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-api@vger.kernel.org
Subject: [PATCH v8 26/41] richacl: Apply the file masks to a richacl
Date: Mon, 28 Sep 2015 00:09:17 +0200 [thread overview]
Message-ID: <1443391772-10171-27-git-send-email-agruenba@redhat.com> (raw)
In-Reply-To: <1443391772-10171-1-git-send-email-agruenba@redhat.com>
Put all the pieces of the acl transformation puzzle together for
computing a richacl which has the file masks "applied" so that the
standard nfsv4 access check algorithm can be used on the richacl.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
---
fs/richacl_compat.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/richacl.h | 3 ++
2 files changed, 104 insertions(+)
diff --git a/fs/richacl_compat.c b/fs/richacl_compat.c
index 7e25343..c99274f 100644
--- a/fs/richacl_compat.c
+++ b/fs/richacl_compat.c
@@ -726,3 +726,104 @@ richacl_isolate_group_class(struct richacl_alloc *alloc, unsigned int deny)
}
return 0;
}
+
+/**
+ * __richacl_apply_masks - apply the file masks to all aces
+ * @alloc: acl and number of allocated entries
+ *
+ * Apply the owner mask to owner@ aces, the other mask to
+ * everyone@ aces, and the group mask to all other aces.
+ *
+ * The previous transformations have brought the acl into a
+ * form in which applying the masks will not lead to the
+ * accidental loss of permissions anymore.
+ */
+static int
+__richacl_apply_masks(struct richacl_alloc *alloc, kuid_t owner)
+{
+ struct richace *ace;
+
+ richacl_for_each_entry(ace, alloc->acl) {
+ unsigned int mask;
+
+ if (richace_is_inherit_only(ace) || !richace_is_allow(ace))
+ continue;
+ if (richace_is_owner(ace) ||
+ (richace_is_unix_user(ace) && uid_eq(owner, ace->e_id.uid)))
+ mask = alloc->acl->a_owner_mask;
+ else if (richace_is_everyone(ace))
+ mask = alloc->acl->a_other_mask;
+ else
+ mask = alloc->acl->a_group_mask;
+ if (richace_change_mask(alloc, &ace, ace->e_mask & mask))
+ return -1;
+ }
+ return 0;
+}
+
+/**
+ * richacl_apply_masks - apply the masks to the acl
+ *
+ * Transform @acl so that the standard NFSv4 permission check algorithm (which
+ * is not aware of file masks) will compute the same access decisions as the
+ * richacl permission check algorithm (which looks at the acl and the file
+ * masks).
+ *
+ * This algorithm is split into several steps:
+ *
+ * - Move everyone@ aces to the end of the acl. This simplifies the other
+ * transformations, and allows the everyone@ allow ace at the end of the
+ * acl to eventually allow permissions to the other class only.
+ *
+ * - Propagate everyone@ permissions up the acl. This transformation makes
+ * sure that the owner and group class aces won't lose any permissions when
+ * we apply the other mask to the everyone@ allow ace at the end of the acl.
+ *
+ * - Apply the file masks to all aces.
+ *
+ * - Make sure everyone is granted the other mask permissions. This step can
+ * elevate elevate permissions for the owner and group classes, which is
+ * corrected later.
+ *
+ * - Make sure that the group class is not granted any permissions from
+ * everyone@.
+ *
+ * - Make sure the owner is granted the owner mask permissions.
+ *
+ * - Make sure the owner is not granted any permissions beyond the owner
+ * mask from group class aces or from everyone@.
+ *
+ * NOTE: Depending on the acl and file masks, this algorithm can increase the
+ * number of aces by almost a factor of three in the worst case. This may make
+ * the acl too large for some purposes.
+ */
+int
+richacl_apply_masks(struct richacl **acl, kuid_t owner)
+{
+ if ((*acl)->a_flags & RICHACL_MASKED) {
+ struct richacl_alloc alloc = {
+ .acl = richacl_clone(*acl, GFP_KERNEL),
+ .count = (*acl)->a_count,
+ };
+ unsigned int added = 0;
+
+ if (!alloc.acl)
+ return -ENOMEM;
+ if (richacl_move_everyone_aces_down(&alloc) ||
+ richacl_propagate_everyone(&alloc) ||
+ __richacl_apply_masks(&alloc, owner) ||
+ richacl_set_other_permissions(&alloc, &added) ||
+ richacl_isolate_group_class(&alloc, added) ||
+ richacl_set_owner_permissions(&alloc) ||
+ richacl_isolate_owner_class(&alloc)) {
+ richacl_put(alloc.acl);
+ return -ENOMEM;
+ }
+
+ alloc.acl->a_flags &= ~(RICHACL_WRITE_THROUGH | RICHACL_MASKED);
+ richacl_put(*acl);
+ *acl = alloc.acl;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(richacl_apply_masks);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index 832b06c..a945f3c 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -332,4 +332,7 @@ extern struct richacl *richacl_inherit(const struct richacl *, int);
extern int richacl_permission(struct inode *, const struct richacl *, int);
extern struct richacl *richacl_create(struct inode *, struct inode *);
+/* richacl_compat.c */
+extern int richacl_apply_masks(struct richacl **, kuid_t);
+
#endif /* __RICHACL_H */
--
2.4.3
next prev parent reply other threads:[~2015-09-27 22:12 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-27 22:08 [PATCH v8 00/41] Richacls Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 01/41] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 02/41] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 03/41] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD " Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 04/41] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 05/41] vfs: Add permission flags for setting file attributes Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 06/41] richacl: In-memory representation and helper functions Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 07/41] richacl: Permission mapping functions Andreas Gruenbacher
2015-09-27 22:08 ` [PATCH v8 08/41] richacl: Compute maximum file masks from an acl Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher
2015-09-28 15:28 ` J. Bruce Fields
2015-09-28 23:42 ` Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 10/41] richacl: Permission check algorithm Andreas Gruenbacher
2015-09-28 16:08 ` J. Bruce Fields
2015-09-28 16:25 ` Andreas Grünbacher
2015-09-28 16:29 ` J. Bruce Fields
2015-09-28 16:51 ` Andreas Grünbacher
2015-09-27 22:09 ` [PATCH v8 11/41] vfs: Cache base_acl objects in inodes Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 12/41] vfs: Cache richacl in struct inode Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 13/41] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 14/41] richacl: Create-time inheritance Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 15/41] richacl: Automatic Inheritance Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 16/41] richacl: xattr mapping functions Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 17/41] vfs: Add richacl permission checking Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 18/41] ext4: Add richacl support Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 19/41] ext4: Add richacl feature flag Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 20/41] richacl: acl editing helper functions Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 21/41] richacl: Move everyone@ aces down the acl Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 22/41] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 23/41] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 24/41] richacl: Set the other permissions to the other mask Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 25/41] richacl: Isolate the owner and group classes Andreas Gruenbacher
2015-09-27 22:09 ` Andreas Gruenbacher [this message]
2015-09-27 22:09 ` [PATCH v8 27/41] richacl: Create richacl from mode values Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 28/41] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 29/41] nfsd: Use richacls as internal acl representation Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 30/41] nfsd: Add richacl support Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 31/41] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 32/41] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 33/41] richacl: Add support for unmapped identifiers Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 34/41] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 35/41] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 36/41] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 37/41] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 38/41] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 39/41] nfs: Add richacl support Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 40/41] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher
2015-09-27 22:09 ` [PATCH v8 41/41] richacl: uapi header split Andreas Gruenbacher
2015-09-28 16:35 ` [PATCH v8 00/41] Richacls J. Bruce Fields
2015-09-28 17:10 ` Andreas Grünbacher
2015-09-28 17:46 ` J. Bruce Fields
2015-09-29 14:54 ` Andreas Grünbacher
2015-10-16 18:12 ` Andreas Gruenbacher
2015-10-04 6:23 ` Christoph Hellwig
2015-10-05 18:45 ` Andreas Gruenbacher
2015-10-05 18:58 ` Austin S Hemmelgarn
2015-10-06 9:49 ` Christoph Hellwig
2015-10-06 13:12 ` Andreas Gruenbacher
2015-10-06 20:26 ` Andreas Dilger
2015-10-06 20:55 ` Steve French
2015-10-07 7:50 ` Christoph Hellwig
2015-10-07 13:38 ` Andreas Gruenbacher
2015-10-07 15:15 ` Steve French
2015-10-05 21:17 ` Dave Chinner
2015-10-05 22:01 ` Andreas Gruenbacher
2015-10-06 1:20 ` Dave Chinner
2015-10-06 9:49 ` James Morris
2015-10-06 12:24 ` Andreas Grünbacher
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