1#include <linux/reiserfs_fs.h>
  2#include <linux/errno.h>
  3#include <linux/fs.h>
  4#include <linux/pagemap.h>
  5#include <linux/xattr.h>
  6#include <linux/slab.h>
  7#include <linux/reiserfs_xattr.h>
  8#include <linux/security.h>
  9#include <asm/uaccess.h>
 10
 11static int
 12security_get(struct dentry *dentry, const char *name, void *buffer, size_t size,
 13		int handler_flags)
 14{
 15	if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
 16		return -EINVAL;
 17
 18	if (IS_PRIVATE(dentry->d_inode))
 19		return -EPERM;
 20
 21	return reiserfs_xattr_get(dentry->d_inode, name, buffer, size);
 22}
 23
 24static int
 25security_set(struct dentry *dentry, const char *name, const void *buffer,
 26	     size_t size, int flags, int handler_flags)
 27{
 28	if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
 29		return -EINVAL;
 30
 31	if (IS_PRIVATE(dentry->d_inode))
 32		return -EPERM;
 33
 34	return reiserfs_xattr_set(dentry->d_inode, name, buffer, size, flags);
 35}
 36
 37static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
 38			    const char *name, size_t namelen, int handler_flags)
 39{
 40	const size_t len = namelen + 1;
 41
 42	if (IS_PRIVATE(dentry->d_inode))
 43		return 0;
 44
 45	if (list && len <= list_len) {
 46		memcpy(list, name, namelen);
 47		list[namelen] = '\0';
 48	}
 49
 50	return len;
 51}
 52
 53/* Initializes the security context for a new inode and returns the number
 54 * of blocks needed for the transaction. If successful, reiserfs_security
 55 * must be released using reiserfs_security_free when the caller is done. */
 56int reiserfs_security_init(struct inode *dir, struct inode *inode,
 57			   const struct qstr *qstr,
 58			   struct reiserfs_security_handle *sec)
 59{
 60	int blocks = 0;
 61	int error;
 62
 63	sec->name = NULL;
 64
 65	/* Don't add selinux attributes on xattrs - they'll never get used */
 66	if (IS_PRIVATE(dir))
 67		return 0;
 68
 69	error = security_inode_init_security(inode, dir, qstr, &sec->name,
 70					     &sec->value, &sec->length);
 71	if (error) {
 72		if (error == -EOPNOTSUPP)
 73			error = 0;
 74
 75		sec->name = NULL;
 76		sec->value = NULL;
 77		sec->length = 0;
 78		return error;
 79	}
 80
 81	if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
 82		blocks = reiserfs_xattr_jcreate_nblocks(inode) +
 83			 reiserfs_xattr_nblocks(inode, sec->length);
 84		/* We don't want to count the directories twice if we have
 85		 * a default ACL. */
 86		REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
 87	}
 88	return blocks;
 89}
 90
 91int reiserfs_security_write(struct reiserfs_transaction_handle *th,
 92			    struct inode *inode,
 93			    struct reiserfs_security_handle *sec)
 94{
 95	int error;
 96	if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
 97		return -EINVAL;
 98
 99	error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
100					  sec->length, XATTR_CREATE);
101	if (error == -ENODATA || error == -EOPNOTSUPP)
102		error = 0;
103
104	return error;
105}
106
107void reiserfs_security_free(struct reiserfs_security_handle *sec)
108{
109	kfree(sec->name);
110	kfree(sec->value);
111	sec->name = NULL;
112	sec->value = NULL;
113}
114
115const struct xattr_handler reiserfs_xattr_security_handler = {
116	.prefix = XATTR_SECURITY_PREFIX,
117	.get = security_get,
118	.set = security_set,
119	.list = security_list,
120};