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Groups > linux.kernel > #1233757
| From | Andreas Gruenbacher <agruenba@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v8 14/41] richacl: Create-time inheritance |
| Date | 2015-09-28 00:20 +0200 |
| Message-ID | <qdssx-3tp-9@gated-at.bofh.it> (permalink) |
| References | <qdsiR-3hB-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
When a new file is created, it can inherit an acl from its parent
directory; this is similar to how default acls work in POSIX (draft)
ACLs.
As with POSIX ACLs, if a file inherits an acl from its parent directory,
the intersection between the create mode and the permissions granted by
the inherited acl determines the file masks and file permission bits,
and the umask is ignored.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
---
fs/richacl_base.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/richacl_inode.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/richacl.h | 2 ++
3 files changed, 135 insertions(+)
diff --git a/fs/richacl_base.c b/fs/richacl_base.c
index 106e988..c1490c7 100644
--- a/fs/richacl_base.c
+++ b/fs/richacl_base.c
@@ -483,3 +483,71 @@ richacl_equiv_mode(const struct richacl *acl, mode_t *mode_p)
return 0;
}
EXPORT_SYMBOL_GPL(richacl_equiv_mode);
+
+/**
+ * richacl_inherit - compute the inherited acl of a new file
+ * @dir_acl: acl of the containing directory
+ * @isdir: inherit by a directory or non-directory?
+ *
+ * A directory can have acl entries which files and/or directories created
+ * inside the directory will inherit. This function computes the acl for such
+ * a new file. If there is no inheritable acl, it will return %NULL.
+ */
+struct richacl *
+richacl_inherit(const struct richacl *dir_acl, int isdir)
+{
+ const struct richace *dir_ace;
+ struct richacl *acl = NULL;
+ struct richace *ace;
+ int count = 0;
+
+ if (isdir) {
+ richacl_for_each_entry(dir_ace, dir_acl) {
+ if (!richace_is_inheritable(dir_ace))
+ continue;
+ count++;
+ }
+ if (!count)
+ return NULL;
+ acl = richacl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ ace = acl->a_entries;
+ richacl_for_each_entry(dir_ace, dir_acl) {
+ if (!richace_is_inheritable(dir_ace))
+ continue;
+ richace_copy(ace, dir_ace);
+ if (dir_ace->e_flags & RICHACE_NO_PROPAGATE_INHERIT_ACE)
+ ace->e_flags &= ~RICHACE_INHERITANCE_FLAGS;
+ else if (!(dir_ace->e_flags & RICHACE_DIRECTORY_INHERIT_ACE))
+ ace->e_flags |= RICHACE_INHERIT_ONLY_ACE;
+ ace++;
+ }
+ } else {
+ richacl_for_each_entry(dir_ace, dir_acl) {
+ if (!(dir_ace->e_flags & RICHACE_FILE_INHERIT_ACE))
+ continue;
+ count++;
+ }
+ if (!count)
+ return NULL;
+ acl = richacl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ ace = acl->a_entries;
+ richacl_for_each_entry(dir_ace, dir_acl) {
+ if (!(dir_ace->e_flags & RICHACE_FILE_INHERIT_ACE))
+ continue;
+ richace_copy(ace, dir_ace);
+ ace->e_flags &= ~RICHACE_INHERITANCE_FLAGS;
+ /*
+ * RICHACE_DELETE_CHILD is meaningless for
+ * non-directories, so clear it.
+ */
+ ace->e_mask &= ~RICHACE_DELETE_CHILD;
+ ace++;
+ }
+ }
+
+ return acl;
+}
diff --git a/fs/richacl_inode.c b/fs/richacl_inode.c
index dcf8fb1..737f054 100644
--- a/fs/richacl_inode.c
+++ b/fs/richacl_inode.c
@@ -221,3 +221,68 @@ out:
return denied ? -EACCES : 0;
}
EXPORT_SYMBOL_GPL(richacl_permission);
+
+/**
+ * richacl_inherit_inode - compute inherited acl and file mode
+ * @dir_acl: acl of the containing directory
+ * @inode: inode of the new file (create mode in i_mode)
+ *
+ * The file permission bits in inode->i_mode must be set to the create mode by
+ * the caller.
+ *
+ * If there is an inheritable acl, the maximum permissions that the acl grants
+ * will be computed and permissions not granted by the acl will be removed from
+ * inode->i_mode. If there is no inheritable acl, the umask will be applied
+ * instead.
+ */
+static struct richacl *
+richacl_inherit_inode(const struct richacl *dir_acl, struct inode *inode)
+{
+ struct richacl *acl;
+ mode_t mask;
+
+ acl = richacl_inherit(dir_acl, S_ISDIR(inode->i_mode));
+ if (acl) {
+ mask = inode->i_mode;
+ if (richacl_equiv_mode(acl, &mask) == 0) {
+ richacl_put(acl);
+ acl = NULL;
+ } else {
+ richacl_compute_max_masks(acl);
+ /*
+ * Ensure that the acl will not grant any permissions
+ * beyond the create mode.
+ */
+ acl->a_flags |= RICHACL_MASKED;
+ acl->a_owner_mask &=
+ richacl_mode_to_mask(inode->i_mode >> 6);
+ acl->a_group_mask &=
+ richacl_mode_to_mask(inode->i_mode >> 3);
+ acl->a_other_mask &=
+ richacl_mode_to_mask(inode->i_mode);
+ mask = ~S_IRWXUGO | richacl_masks_to_mode(acl);
+ }
+ } else
+ mask = ~current_umask();
+
+ inode->i_mode &= mask;
+ return acl;
+}
+
+struct richacl *richacl_create(struct inode *inode, struct inode *dir)
+{
+ struct richacl *dir_acl, *acl = NULL;
+
+ if (S_ISLNK(inode->i_mode))
+ return NULL;
+ dir_acl = get_richacl(dir);
+ if (dir_acl) {
+ if (IS_ERR(dir_acl))
+ return dir_acl;
+ acl = richacl_inherit_inode(dir_acl, inode);
+ richacl_put(dir_acl);
+ } else
+ inode->i_mode &= ~current_umask();
+ return acl;
+}
+EXPORT_SYMBOL_GPL(richacl_create);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index 6535ce5..9bf95c2 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -305,8 +305,10 @@ extern unsigned int richacl_want_to_mask(unsigned int);
extern void richacl_compute_max_masks(struct richacl *);
extern struct richacl *richacl_chmod(struct richacl *, mode_t);
extern int richacl_equiv_mode(const struct richacl *, mode_t *);
+extern struct richacl *richacl_inherit(const struct richacl *, int);
/* richacl_inode.c */
extern int richacl_permission(struct inode *, const struct richacl *, int);
+extern struct richacl *richacl_create(struct inode *, struct inode *);
#endif /* __RICHACL_H */
--
2.4.3
--
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[PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:10 +0200
[PATCH v8 31/41] nfsd: Add support for the v4.1 dacl attribute Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 15/41] richacl: Automatic Inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 03/41] vfs: Add MAY_DELETE_SELF and MAY_DELETE_CHILD permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 12/41] vfs: Cache richacl in struct inode Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 14/41] richacl: Create-time inheritance Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 33/41] richacl: Add support for unmapped identifiers Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 06/41] richacl: In-memory representation and helper functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
Re: [PATCH v8 09/41] richacl: Update the file masks in chmod() "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 17:30 +0200
Re: [PATCH v8 09/41] richacl: Update the file masks in chmod() Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-29 01:50 +0200
[PATCH v8 13/41] richacl: Check if an acl is equivalent to a file mode Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 27/41] richacl: Create richacl from mode values Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 19/41] ext4: Add richacl feature flag Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 21/41] richacl: Move everyone@ aces down the acl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 20/41] richacl: acl editing helper functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 32/41] nfsd: Add support for the MAY_CREATE_{FILE,DIR} permissions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 26/41] richacl: Apply the file masks to a richacl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 01/41] vfs: Add IS_ACL() and IS_RICHACL() tests Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 41/41] richacl: uapi header split Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 18/41] ext4: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 17/41] vfs: Add richacl permission checking Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 35/41] sunrpc: Allow to demand-allocate pages to encode into Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 38/41] nfs: Remove unused xdr page offsets in getacl/setacl arguments Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 36/41] sunrpc: Add xdr_init_encode_pages Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 16/41] richacl: xattr mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 25/41] richacl: Isolate the owner and group classes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 40/41] nfs: Add support for the v4.1 dacl attribute Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 11/41] vfs: Cache base_acl objects in inodes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 08/41] richacl: Compute maximum file masks from an acl Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 34/41] ext4: Don't allow unmapped identifiers in richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 05/41] vfs: Add permission flags for setting file attributes Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 28/41] nfsd: Keep list of acls to dispose of in compoundargs Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 04/41] vfs: Make the inode passed to inode_change_ok non-const Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 22/41] richacl: Propagate everyone@ permissions to other aces Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 37/41] nfs: Fix GETATTR bitmap verification Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 29/41] nfsd: Use richacls as internal acl representation Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 39/41] nfs: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:20 +0200
[PATCH v8 24/41] richacl: Set the other permissions to the other mask Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 23/41] richacl: Set the owner permissions to the owner mask Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 30/41] nfsd: Add richacl support Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:30 +0200
[PATCH v8 07/41] richacl: Permission mapping functions Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:40 +0200
[PATCH v8 10/41] richacl: Permission check algorithm Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:40 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:10 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 18:30 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:30 +0200
Re: [PATCH v8 10/41] richacl: Permission check algorithm Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 19:00 +0200
[PATCH v8 02/41] vfs: Add MAY_CREATE_FILE and MAY_CREATE_DIR permission flags Andreas Gruenbacher <agruenba@redhat.com> - 2015-09-28 00:50 +0200
Re: [PATCH v8 00/41] Richacls "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 18:40 +0200
Re: [PATCH v8 00/41] Richacls Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-28 19:20 +0200
Re: [PATCH v8 00/41] Richacls "J. Bruce Fields" <bfields@fieldses.org> - 2015-09-28 19:50 +0200
Re: [PATCH v8 00/41] Richacls Andreas Grünbacher <andreas.gruenbacher@gmail.com> - 2015-09-29 17:00 +0200
Re: [PATCH v8 00/41] Richacls Christoph Hellwig <hch@infradead.org> - 2015-10-04 08:30 +0200
Re: [PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-05 20:50 +0200
Re: [PATCH v8 00/41] Richacls Austin S Hemmelgarn <ahferroin7@gmail.com> - 2015-10-05 21:00 +0200
Re: [PATCH v8 00/41] Richacls Dave Chinner <david@fromorbit.com> - 2015-10-05 23:20 +0200
Re: [PATCH v8 00/41] Richacls Andreas Gruenbacher <agruenba@redhat.com> - 2015-10-06 00:10 +0200
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