fs/ext2/xattr_security.c

   1 /*
   2  * linux/fs/ext2/xattr_security.c
   3  * Handler for storing security labels as extended attributes.
   4  */
   5
   6 #include "ext2.h"
   7 #include <linux/security.h>
   8 #include "xattr.h"
   9
  10 static size_t
  11 ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
  12                          const char *name, size_t name_len, int type)
  13 {
  14         const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
  15         const size_t total_len = prefix_len + name_len + 1;
  16
  17         if (list && total_len <= list_size) {
  18                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
  19                 memcpy(list+prefix_len, name, name_len);
  20                 list[prefix_len + name_len] = '\0';
  21         }
  22         return total_len;
  23 }
  24
  25 static int
  26 ext2_xattr_security_get(struct dentry *dentry, const char *name,
  27                        void *buffer, size_t size, int type)
  28 {
  29         if (strcmp(name, "") == 0)
  30                 return -EINVAL;
  31         return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
  32                               buffer, size);
  33 }
  34
  35 static int
  36 ext2_xattr_security_set(struct dentry *dentry, const char *name,
  37                 const void *value, size_t size, int flags, int type)
  38 {
  39         if (strcmp(name, "") == 0)
  40                 return -EINVAL;
  41         return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
  42                               value, size, flags);
  43 }
  44
  45 static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
  46                            void *fs_info)
  47 {
  48         const struct xattr *xattr;
  49         int err = 0;
  50
  51         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  52                 err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
  53                                      xattr->name, xattr->value,
  54                                      xattr->value_len, 0);
  55                 if (err < 0)
  56                         break;
  57         }
  58         return err;
  59 }
  60
  61 int
  62 ext2_init_security(struct inode *inode, struct inode *dir,
  63                    const struct qstr *qstr)
  64 {
  65         return security_inode_init_security(inode, dir, qstr,
  66                                             &ext2_initxattrs, NULL);
  67 }
  68
  69 const struct xattr_handler ext2_xattr_security_handler = {
  70         .prefix = XATTR_SECURITY_PREFIX,
  71         .list   = ext2_xattr_security_list,
  72         .get    = ext2_xattr_security_get,
  73         .set    = ext2_xattr_security_set,
  74 };