fs/ext3/xattr_security.c

   1 /*
   2  * linux/fs/ext3/xattr_security.c
   3  * Handler for storing security labels as extended attributes.
   4  */
   5
   6 #include <linux/security.h>
   7 #include "ext3.h"
   8 #include "xattr.h"
   9
  10 static size_t
  11 ext3_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 size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
  15         const size_t total_len = prefix_len + name_len + 1;
  16
  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 ext3_xattr_security_get(struct dentry *dentry, const char *name,
  28                 void *buffer, size_t size, int type)
  29 {
  30         if (strcmp(name, "") == 0)
  31                 return -EINVAL;
  32         return ext3_xattr_get(d_inode(dentry), EXT3_XATTR_INDEX_SECURITY,
  33                               name, buffer, size);
  34 }
  35
  36 static int
  37 ext3_xattr_security_set(struct dentry *dentry, const char *name,
  38                 const void *value, size_t size, int flags, int type)
  39 {
  40         if (strcmp(name, "") == 0)
  41                 return -EINVAL;
  42         return ext3_xattr_set(d_inode(dentry), EXT3_XATTR_INDEX_SECURITY,
  43                               name, value, size, flags);
  44 }
  45
  46 static int ext3_initxattrs(struct inode *inode,
  47                            const struct xattr *xattr_array,
  48                            void *fs_info)
  49 {
  50         const struct xattr *xattr;
  51         handle_t *handle = fs_info;
  52         int err = 0;
  53
  54         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  55                 err = ext3_xattr_set_handle(handle, inode,
  56                                             EXT3_XATTR_INDEX_SECURITY,
  57                                             xattr->name, xattr->value,
  58                                             xattr->value_len, 0);
  59                 if (err < 0)
  60                         break;
  61         }
  62         return err;
  63 }
  64
  65 int
  66 ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
  67                    const struct qstr *qstr)
  68 {
  69         return security_inode_init_security(inode, dir, qstr,
  70                                             &ext3_initxattrs, handle);
  71 }
  72
  73 const struct xattr_handler ext3_xattr_security_handler = {
  74         .prefix = XATTR_SECURITY_PREFIX,
  75         .list   = ext3_xattr_security_list,
  76         .get    = ext3_xattr_security_get,
  77         .set    = ext3_xattr_security_set,
  78 };