[PATCH] xattr consolidation v3 - LSM

This patch replaces the dentry parameter with an inode in the LSM
inode_{set|get|list}security hooks, in keeping with the ext2/ext3 code. 
dentries are not needed here.
Signed-off-by: James Morris <jmorris@redhat.com>
Signed-off-by: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/security.h

@@ -396,13 +396,13 @@ struct swap_info_struct;
  * 	Return 0 if permission is granted.
  * @inode_getsecurity:
  *	Copy the extended attribute representation of the security label 
- *	associated with @name for @dentry into @buffer.  @buffer may be 
+ *	associated with @name for @inode into @buffer.  @buffer may be
  *	NULL to request the size of the buffer required.  @size indicates
  *	the size of @buffer in bytes.  Note that @name is the remainder
  *	of the attribute name after the security. prefix has been removed.
  *	Return number of bytes used/required on success.
  * @inode_setsecurity:
- *	Set the security label associated with @name for @dentry from the 
+ *	Set the security label associated with @name for @inode from the
  *	extended attribute value @value.  @size indicates the size of the
  *	@value in bytes.  @flags may be XATTR_CREATE, XATTR_REPLACE, or 0.
  *	Note that @name is the remainder of the attribute name after the 
@@ -410,8 +410,9 @@ struct swap_info_struct;
  *	Return 0 on success.
  * @inode_listsecurity:
  *	Copy the extended attribute names for the security labels
- *	associated with @dentry into @buffer.  @buffer may be NULL to 
- *	request the size of the buffer required.  
+ *	associated with @inode into @buffer.  The maximum size of @buffer
+ *	is specified by @buffer_size.  @buffer may be NULL to request
+ *	the size of the buffer required.
  *	Returns number of bytes used/required on success.
  *
  * Security hooks for file operations
@@ -1109,9 +1110,9 @@ struct security_operations {
 	int (*inode_getxattr) (struct dentry *dentry, char *name);
 	int (*inode_listxattr) (struct dentry *dentry);
 	int (*inode_removexattr) (struct dentry *dentry, char *name);
-  	int (*inode_getsecurity)(struct dentry *dentry, const char *name, void *buffer, size_t size);
-  	int (*inode_setsecurity)(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
-  	int (*inode_listsecurity)(struct dentry *dentry, char *buffer);
+  	int (*inode_getsecurity)(struct inode *inode, const char *name, void *buffer, size_t size);
+  	int (*inode_setsecurity)(struct inode *inode, const char *name, const void *value, size_t size, int flags);
+  	int (*inode_listsecurity)(struct inode *inode, char *buffer, size_t buffer_size);
 
 	int (*file_permission) (struct file * file, int mask);
 	int (*file_alloc_security) (struct file * file);
@@ -1576,19 +1577,19 @@ static inline int security_inode_removexattr (struct dentry *dentry, char *name)
 	return security_ops->inode_removexattr (dentry, name);
 }
 
-static inline int security_inode_getsecurity(struct dentry *dentry, const char *name, void *buffer, size_t size)
+static inline int security_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
 {
-	return security_ops->inode_getsecurity(dentry, name, buffer, size);
+	return security_ops->inode_getsecurity(inode, name, buffer, size);
 }
 
-static inline int security_inode_setsecurity(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) 
+static inline int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags)
 {
-	return security_ops->inode_setsecurity(dentry, name, value, size, flags);
+	return security_ops->inode_setsecurity(inode, name, value, size, flags);
 }
 
-static inline int security_inode_listsecurity(struct dentry *dentry, char *buffer)
+static inline int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
 {
-	return security_ops->inode_listsecurity(dentry, buffer);
+	return security_ops->inode_listsecurity(inode, buffer, buffer_size);
 }
 
 static inline int security_file_permission (struct file *file, int mask)
@@ -2215,17 +2216,17 @@ static inline int security_inode_removexattr (struct dentry *dentry, char *name)
 	return cap_inode_removexattr(dentry, name);
 }
 
-static inline int security_inode_getsecurity(struct dentry *dentry, const char *name, void *buffer, size_t size)
+static inline int security_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline int security_inode_setsecurity(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) 
+static inline int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags)
 {
 	return -EOPNOTSUPP;
 }
 
-static inline int security_inode_listsecurity(struct dentry *dentry, char *buffer)
+static inline int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
 {
 	return 0;
 }

security/dummy.c

@@ -447,17 +447,17 @@ static int dummy_inode_removexattr (struct dentry *dentry, char *name)
 	return 0;
 }
 
-static int dummy_inode_getsecurity(struct dentry *dentry, const char *name, void *buffer, size_t size)
+static int dummy_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
 {
 	return -EOPNOTSUPP;
 }
 
-static int dummy_inode_setsecurity(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) 
+static int dummy_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags)
 {
 	return -EOPNOTSUPP;
 }
 
-static int dummy_inode_listsecurity(struct dentry *dentry, char *buffer)
+static int dummy_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
 {
 	return 0;
 }

security/selinux/hooks.c

@@ -2332,9 +2332,8 @@ static int selinux_inode_removexattr (struct dentry *dentry, char *name)
 	return -EACCES;
 }
 
-static int selinux_inode_getsecurity(struct dentry *dentry, const char *name, void *buffer, size_t size)
+static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size)
 {
-	struct inode *inode = dentry->d_inode;
 	struct inode_security_struct *isec = inode->i_security;
 	char *context;
 	unsigned len;
@@ -2362,10 +2361,9 @@ static int selinux_inode_getsecurity(struct dentry *dentry, const char *name, vo
 	return len;
 }
 
-static int selinux_inode_setsecurity(struct dentry *dentry, const char *name,
+static int selinux_inode_setsecurity(struct inode *inode, const char *name,
                                      const void *value, size_t size, int flags)
 {
-	struct inode *inode = dentry->d_inode;
 	struct inode_security_struct *isec = inode->i_security;
 	u32 newsid;
 	int rc;
@@ -2384,10 +2382,10 @@ static int selinux_inode_setsecurity(struct dentry *dentry, const char *name,
 	return 0;
 }
 
-static int selinux_inode_listsecurity(struct dentry *dentry, char *buffer)
+static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
 {
 	const int len = sizeof(XATTR_NAME_SELINUX);
-	if (buffer)
+	if (buffer && len <= buffer_size)
 		memcpy(buffer, XATTR_NAME_SELINUX, len);
 	return len;
 }