fs/hfsplus/xattr_security.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/hfsplus/xattr_trusted.c
   4  *
   5  * Vyacheslav Dubeyko <slava@dubeyko.com>
   6  *
   7  * Handler for storing security labels as extended attributes.
   8  */
   9
  10 #include <linux/security.h>
  11 #include <linux/nls.h>
  12
  13 #include "hfsplus_fs.h"
  14 #include "xattr.h"
  15
  16 static int hfsplus_security_getxattr(const struct xattr_handler *handler,
  17                                      struct dentry *unused, struct inode *inode,
  18                                      const char *name, void *buffer, size_t size)
  19 {
  20         return hfsplus_getxattr(inode, name, buffer, size,
  21                                 XATTR_SECURITY_PREFIX,
  22                                 XATTR_SECURITY_PREFIX_LEN);
  23 }
  24
  25 static int hfsplus_security_setxattr(const struct xattr_handler *handler,
  26                                      struct user_namespace *mnt_userns,
  27                                      struct dentry *unused, struct inode *inode,
  28                                      const char *name, const void *buffer,
  29                                      size_t size, int flags)
  30 {
  31         return hfsplus_setxattr(inode, name, buffer, size, flags,
  32                                 XATTR_SECURITY_PREFIX,
  33                                 XATTR_SECURITY_PREFIX_LEN);
  34 }
  35
  36 static int hfsplus_initxattrs(struct inode *inode,
  37                                 const struct xattr *xattr_array,
  38                                 void *fs_info)
  39 {
  40         const struct xattr *xattr;
  41         char *xattr_name;
  42         int err = 0;
  43
  44         xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
  45                 GFP_KERNEL);
  46         if (!xattr_name)
  47                 return -ENOMEM;
  48         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  49
  50                 if (!strcmp(xattr->name, ""))
  51                         continue;
  52
  53                 strcpy(xattr_name, XATTR_SECURITY_PREFIX);
  54                 strcpy(xattr_name +
  55                         XATTR_SECURITY_PREFIX_LEN, xattr->name);
  56                 memset(xattr_name +
  57                         XATTR_SECURITY_PREFIX_LEN + strlen(xattr->name), 0, 1);
  58
  59                 err = __hfsplus_setxattr(inode, xattr_name,
  60                                         xattr->value, xattr->value_len, 0);
  61                 if (err)
  62                         break;
  63         }
  64         kfree(xattr_name);
  65         return err;
  66 }
  67
  68 int hfsplus_init_security(struct inode *inode, struct inode *dir,
  69                                 const struct qstr *qstr)
  70 {
  71         return security_inode_init_security(inode, dir, qstr,
  72                                         &hfsplus_initxattrs, NULL);
  73 }
  74
  75 const struct xattr_handler hfsplus_xattr_security_handler = {
  76         .prefix = XATTR_SECURITY_PREFIX,
  77         .get    = hfsplus_security_getxattr,
  78         .set    = hfsplus_security_setxattr,
  79 };