lkml.org 
[lkml]   [2005]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH 3/3] Access Control Lists for /dev/pts
/dev/pts is somewhat special: there are no directories, and so we
don't need default acls.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>

Index: linux-2.6.11-rc2-mm2/fs/devpts/inode.c
===================================================================
--- linux-2.6.11-rc2-mm2.orig/fs/devpts/inode.c
+++ linux-2.6.11-rc2-mm2/fs/devpts/inode.c
@@ -19,15 +19,43 @@
#include <linux/tty.h>
#include <linux/devpts_fs.h>
#include <linux/xattr.h>
+#include <linux/generic_acl.h>

#define DEVPTS_SUPER_MAGIC 0x1cd1

+#ifdef CONFIG_DEVPTS_POSIX_ACL
+static struct inode *
+devpts_alloc_inode(struct super_block *sb)
+{
+ struct devpts_inode_info *ei;
+ ei = kmalloc(sizeof(*ei), SLAB_KERNEL);
+ if (!ei)
+ return NULL;
+ inode_init_once(&ei->vfs_inode);
+ ei->i_acl = NULL;
+ return &ei->vfs_inode;
+}
+
+static void
+devpts_destroy_inode(struct inode *inode)
+{
+ struct devpts_inode_info *ei = DEVPTS_I(inode);
+ if (ei->i_acl)
+ posix_acl_release(ei->i_acl);
+ kfree(ei);
+}
+#endif /* CONFIG_DEVPTS_POSIX_ACL */
+
extern struct xattr_handler devpts_xattr_security_handler;
+extern struct xattr_handler devpts_xattr_acl_access_handler;

static struct xattr_handler *devpts_xattr_handlers[] = {
#ifdef CONFIG_DEVPTS_FS_SECURITY
&devpts_xattr_security_handler,
#endif
+#ifdef CONFIG_DEVPTS_POSIX_ACL
+ &devpts_xattr_acl_access_handler,
+#endif
NULL
};

@@ -38,6 +66,10 @@ static struct inode_operations devpts_fi
.listxattr = generic_listxattr,
.removexattr = generic_removexattr,
#endif
+#ifdef CONFIG_DEVPTS_POSIX_ACL
+ .setattr = devpts_setattr,
+ .permission = devpts_permission,
+#endif
};

static struct vfsmount *devpts_mnt;
@@ -89,6 +121,10 @@ static int devpts_remount(struct super_b
}

static struct super_operations devpts_sops = {
+#ifdef CONFIG_DEVPTS_POSIX_ACL
+ .alloc_inode = devpts_alloc_inode,
+ .destroy_inode = devpts_destroy_inode,
+#endif
.statfs = simple_statfs,
.remount_fs = devpts_remount,
};
@@ -117,6 +153,9 @@ devpts_fill_super(struct super_block *s,
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_nlink = 2;
+#ifdef CONFIG_TMPFS_POSIX_ACL
+ s->s_flags |= MS_POSIXACL;
+#endif

devpts_root = s->s_root = d_alloc_root(inode);
if (s->s_root)
Index: linux-2.6.11-rc2-mm2/fs/devpts/Makefile
===================================================================
--- linux-2.6.11-rc2-mm2.orig/fs/devpts/Makefile
+++ linux-2.6.11-rc2-mm2/fs/devpts/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_UNIX98_PTYS) += devpts.o

devpts-$(CONFIG_UNIX98_PTYS) := inode.o
devpts-$(CONFIG_DEVPTS_FS_SECURITY) += xattr_security.o
+devpts-$(CONFIG_DEVPTS_POSIX_ACL) += acl.o
Index: linux-2.6.11-rc2-mm2/include/linux/devpts_fs.h
===================================================================
--- linux-2.6.11-rc2-mm2.orig/include/linux/devpts_fs.h
+++ linux-2.6.11-rc2-mm2/include/linux/devpts_fs.h
@@ -17,6 +17,23 @@

#ifdef CONFIG_UNIX98_PTYS

+#ifdef CONFIG_DEVPTS_POSIX_ACL
+struct devpts_inode_info {
+ struct posix_acl *i_acl;
+ struct inode vfs_inode;
+};
+
+static inline struct devpts_inode_info *DEVPTS_I(struct inode *inode)
+{
+ return container_of(inode, struct devpts_inode_info, vfs_inode);
+}
+
+/* acl.c */
+int devpts_setattr(struct dentry *, struct iattr *);
+int devpts_permission(struct inode *, int, struct nameidata *);
+#endif /* CONFIG_DEVPTS_POSIX_ACL */
+
+/* inode.c */
int devpts_pty_new(struct tty_struct *tty); /* mknod in devpts */
struct tty_struct *devpts_get_tty(int number); /* get tty structure */
void devpts_pty_kill(int number); /* unlink */
Index: linux-2.6.11-rc2-mm2/fs/Kconfig
===================================================================
--- linux-2.6.11-rc2-mm2.orig/fs/Kconfig
+++ linux-2.6.11-rc2-mm2/fs/Kconfig
@@ -850,6 +850,19 @@ config DEVPTS_FS_XATTR

If unsure, say N.

+config DEVPTS_POSIX_ACL
+ bool "/dev/pts POSIX Access Control Lists"
+ depends on DEVPTS_FS_XATTR
+ select GENERIC_ACL
+ help
+ POSIX Access Control Lists (ACLs) support permissions for users and
+ groups beyond the owner/group/world scheme.
+
+ To learn more about Access Control Lists, visit the POSIX ACLs for
+ Linux website <http://acl.bestbits.at/>.
+
+ If you don't know what Access Control Lists are, say N.
+
config DEVPTS_FS_SECURITY
bool "/dev/pts Security Labels"
depends on DEVPTS_FS_XATTR
Index: linux-2.6.11-rc2-mm2/fs/devpts/acl.c
===================================================================
--- /dev/null
+++ linux-2.6.11-rc2-mm2/fs/devpts/acl.c
@@ -0,0 +1,112 @@
+/*
+ * fs/devpts/acl.c
+ *
+ * (C) 2005 Andreas Gruenbacher <agruen@suse.de>
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/fs.h>
+#include <linux/tty.h>
+#include <linux/devpts_fs.h>
+#include <linux/xattr.h>
+#include <linux/generic_acl.h>
+
+static struct posix_acl *
+devpts_get_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl = NULL;
+
+ spin_lock(&inode->i_lock);
+ if (type == ACL_TYPE_ACCESS)
+ acl = posix_acl_dup(DEVPTS_I(inode)->i_acl);
+ spin_unlock(&inode->i_lock);
+
+ return acl;
+}
+
+static void
+devpts_set_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+ spin_lock(&inode->i_lock);
+ if (type == ACL_TYPE_ACCESS) {
+ if (DEVPTS_I(inode)->i_acl)
+ posix_acl_release(DEVPTS_I(inode)->i_acl);
+ DEVPTS_I(inode)->i_acl = posix_acl_dup(acl);
+ }
+ spin_unlock(&inode->i_lock);
+}
+
+struct generic_acl_operations devpts_acl_ops = {
+ .getacl = devpts_get_acl,
+ .setacl = devpts_set_acl,
+};
+
+static size_t
+devpts_list_acl_access(struct inode *inode, char *list, size_t list_size,
+ const char *name, size_t name_len)
+{
+ return generic_acl_list(inode, &devpts_acl_ops, ACL_TYPE_ACCESS,
+ list, list_size);
+}
+
+static int
+devpts_get_acl_access(struct inode *inode, const char *name, void *buffer,
+ size_t size)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return generic_acl_get(inode, &devpts_acl_ops, ACL_TYPE_ACCESS, buffer,
+ size);
+}
+
+static int
+devpts_set_acl_access(struct inode *inode, const char *name, const void *value,
+ size_t size, int flags)
+{
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ return generic_acl_set(inode, &devpts_acl_ops, ACL_TYPE_ACCESS, value,
+ size);
+}
+
+struct xattr_handler devpts_xattr_acl_access_handler = {
+ .prefix = XATTR_NAME_ACL_ACCESS,
+ .list = devpts_list_acl_access,
+ .get = devpts_get_acl_access,
+ .set = devpts_set_acl_access,
+};
+
+int
+devpts_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+ error = inode_setattr(inode, iattr);
+ if (!error && (iattr->ia_valid & ATTR_MODE))
+ error = generic_acl_chmod(inode, &devpts_acl_ops);
+ return error;
+}
+
+static int
+devpts_check_acl(struct inode *inode, int mask)
+{
+ struct posix_acl *acl = devpts_get_acl(inode, ACL_TYPE_ACCESS);
+
+ if (acl) {
+ int error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ return error;
+ }
+ return -EAGAIN;
+}
+
+int
+devpts_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+ return generic_permission(inode, mask, devpts_check_acl);
+}
--
Andreas Gruenbacher <agruen@suse.de>
SUSE Labs, SUSE LINUX PRODUCTS GMBH

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:10    [from the cache]
©2003-2011 Jasper Spaans