From: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-api@vger.kernel.org, linux-cifs@vger.kernel.org,
linux-security-module@vger.kernel.org,
Andreas Gruenbacher <agruenba@redhat.com>
Subject: [RFC v6 27/40] richacl: Create richacl from mode values
Date: Tue, 4 Aug 2015 13:53:25 +0200 [thread overview]
Message-ID: <1438689218-6921-28-git-send-email-agruenba@redhat.com> (raw)
In-Reply-To: <1438689218-6921-1-git-send-email-agruenba@redhat.com>
A file can have "no acl" in the sense that only the file mode permission
bits determine access. In that case, the getxattr system call fails with
errno == ENODATA (No such attribute).
Over the NFSv4 protocol, a file always has an acl, and we convert the file
mode permission bits into an equivalent acl with richacl_from_mode. Such
"trivial" acls can be converted back to a file mode with
richacl_equiv_mode.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
fs/richacl_compat.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/richacl.h | 1 +
2 files changed, 89 insertions(+)
diff --git a/fs/richacl_compat.c b/fs/richacl_compat.c
index e552c95..50839a1 100644
--- a/fs/richacl_compat.c
+++ b/fs/richacl_compat.c
@@ -839,3 +839,91 @@ richacl_apply_masks(struct richacl **acl, kuid_t owner)
return 0;
}
EXPORT_SYMBOL_GPL(richacl_apply_masks);
+
+/**
+ * richacl_from_mode - create an acl which corresponds to @mode
+ *
+ * The resulting acl doesn't have the RICHACL_MASKED flag set.
+ *
+ * @mode: file mode including the file type
+ */
+struct richacl *
+richacl_from_mode(mode_t mode)
+{
+ unsigned int owner_mask = richacl_mode_to_mask(mode >> 6);
+ 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;
+
+ /* 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;
+ }
+
+ denied = ~owner_mask & (group_mask | other_mask);
+ if (denied)
+ entries++; /* owner@ deny entry needed */
+ if (owner_mask & ~(group_mask & other_mask))
+ entries++; /* owner@ allow entry needed */
+ denied = ~group_mask & other_mask;
+ if (denied)
+ entries++; /* group@ deny entry needed */
+ if (group_mask & ~other_mask)
+ entries++; /* group@ allow entry needed */
+ if (other_mask)
+ entries++; /* everyone@ allow entry needed */
+
+ acl = richacl_alloc(entries, GFP_KERNEL);
+ if (!acl)
+ return NULL;
+ acl->a_owner_mask = owner_mask;
+ acl->a_group_mask = group_mask;
+ acl->a_other_mask = other_mask;
+ ace = acl->a_entries;
+
+ 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 (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 = ~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 (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++;
+ }
+ 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);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index 8723ec9..fce5d84 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -340,5 +340,6 @@ extern struct richacl *richacl_create(struct inode *, struct inode *);
/* richacl_compat.c */
extern int richacl_apply_masks(struct richacl **, kuid_t);
+extern struct richacl *richacl_from_mode(mode_t);
#endif /* __RICHACL_H */
--
2.5.0
next prev parent reply other threads:[~2015-08-04 12:01 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-04 11:52 [RFC v6 00/40] Richacls Andreas Gruenbacher
2015-08-04 11:52 ` [RFC v6 01/40] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher
2015-08-28 20:34 ` J. Bruce Fields
2015-08-04 11:53 ` [RFC v6 02/40] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher
2015-09-02 18:53 ` J. Bruce Fields
2015-09-02 19:06 ` Andreas Gruenbacher
2015-09-02 19:20 ` J. Bruce Fields
2015-09-02 20:23 ` Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 03/40] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD " Andreas Gruenbacher
2015-08-28 20:44 ` J. Bruce Fields
2015-08-28 21:08 ` Andreas Gruenbacher
2015-08-28 21:36 ` Andy Lutomirski
2015-08-28 21:54 ` Andreas Grünbacher
2015-08-29 1:04 ` Andy Lutomirski
2015-08-28 21:57 ` J. Bruce Fields
2015-08-04 11:53 ` [RFC v6 04/40] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 05/40] vfs: Add permission flags for setting file attributes Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 06/40] richacl: In-memory representation and helper functions Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 07/40] richacl: Permission mapping functions Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 08/40] richacl: Compute maximum file masks from an acl Andreas Gruenbacher
2015-09-02 19:54 ` J. Bruce Fields
2015-09-02 19:54 ` J. Bruce Fields
2015-09-02 20:38 ` Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 09/40] richacl: Update the file masks in chmod() Andreas Gruenbacher
2015-09-01 21:38 ` J. Bruce Fields
2015-09-02 6:08 ` Andreas Grünbacher
2015-08-04 11:53 ` [RFC v6 10/40] richacl: Permission check algorithm Andreas Gruenbacher
2015-08-28 21:49 ` J. Bruce Fields
2015-08-28 22:06 ` Andreas Grünbacher
2015-08-31 15:23 ` J. Bruce Fields
2015-08-04 11:53 ` [RFC v6 11/40] vfs: Cache base_acl objects in inodes Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 12/40] vfs: Cache richacl in struct inode Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 13/40] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 14/40] richacl: Create-time inheritance Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 15/40] richacl: Automatic Inheritance Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 16/40] richacl: xattr mapping functions Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 17/40] vfs: Add richacl permission checking Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 18/40] ext4: Add richacl support Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 19/40] ext4: Add richacl feature flag Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 20/40] richacl: acl editing helper functions Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 21/40] richacl: Move everyone@ aces down the acl Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 22/40] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 23/40] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 24/40] richacl: Set the other permissions to the other mask Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 25/40] richacl: Isolate the owner and group classes Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 26/40] richacl: Apply the file masks to a richacl Andreas Gruenbacher
2015-08-04 11:53 ` Andreas Gruenbacher [this message]
2015-08-04 11:53 ` [RFC v6 28/40] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 29/40] nfsd: Use richacls as internal acl representation Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 30/40] nfsd: Add richacl support Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 31/40] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 32/40] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 33/40] richacl: Add support for unmapped identifiers Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 34/40] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 35/40] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 36/40] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 37/40] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 38/40] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 39/40] nfs: Add richacl support Andreas Gruenbacher
2015-08-04 11:53 ` [RFC v6 40/40] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher
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