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(const struct xattr_handler *handler,
  12                          struct dentry *dentry, char *list, size_t list_size,
  13                          const char *name, size_t name_len)
  14 {
  15         const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
  16         const size_t total_len = prefix_len + name_len + 1;
  17
  18         if (list && total_len <= list_size) {
  19                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
  20                 memcpy(list+prefix_len, name, name_len);
  21                 list[prefix_len + name_len] = '\0';
  22         }
  23         return total_len;
  24 }
  25
  26 static int
  27 ext2_xattr_security_get(const struct xattr_handler *handler,
  28                         struct dentry *dentry, const char *name,
  29                         void *buffer, size_t size)
  30 {
  31         if (strcmp(name, "") == 0)
  32                 return -EINVAL;
  33         return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
  34                               buffer, size);
  35 }
  36
  37 static int
  38 ext2_xattr_security_set(const struct xattr_handler *handler,
  39                         struct dentry *dentry, const char *name,
  40                         const void *value, size_t size, int flags)
  41 {
  42         if (strcmp(name, "") == 0)
  43                 return -EINVAL;
  44         return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
  45                               value, size, flags);
  46 }
  47
  48 static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
  49                            void *fs_info)
  50 {
  51         const struct xattr *xattr;
  52         int err = 0;
  53
  54         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  55                 err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
  56                                      xattr->name, xattr->value,
  57                                      xattr->value_len, 0);
  58                 if (err < 0)
  59                         break;
  60         }
  61         return err;
  62 }
  63
  64 int
  65 ext2_init_security(struct inode *inode, struct inode *dir,
  66                    const struct qstr *qstr)
  67 {
  68         return security_inode_init_security(inode, dir, qstr,
  69                                             &ext2_initxattrs, NULL);
  70 }
  71
  72 const struct xattr_handler ext2_xattr_security_handler = {
  73         .prefix = XATTR_SECURITY_PREFIX,
  74         .list   = ext2_xattr_security_list,
  75         .get    = ext2_xattr_security_get,
  76         .set    = ext2_xattr_security_set,
  77 };