tools/lib/bpf/nlattr.h

   1 /* SPDX-License-Identifier: LGPL-2.1 */
   2
   3 /*
   4  * NETLINK      Netlink attributes
   5  *
   6  *      This library is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU Lesser General Public
   8  *      License as published by the Free Software Foundation version 2.1
   9  *      of the License.
  10  *
  11  * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
  12  */
  13
  14 #ifndef __NLATTR_H
  15 #define __NLATTR_H
  16
  17 #include <stdint.h>
  18 #include <linux/netlink.h>
  19 /* avoid multiple definition of netlink features */
  20 #define __LINUX_NETLINK_H
  21
  22 /**
  23  * Standard attribute types to specify validation policy
  24  */
  25 enum {
  26         NLA_UNSPEC,     /**< Unspecified type, binary data chunk */
  27         NLA_U8,         /**< 8 bit integer */
  28         NLA_U16,        /**< 16 bit integer */
  29         NLA_U32,        /**< 32 bit integer */
  30         NLA_U64,        /**< 64 bit integer */
  31         NLA_STRING,     /**< NUL terminated character string */
  32         NLA_FLAG,       /**< Flag */
  33         NLA_MSECS,      /**< Micro seconds (64bit) */
  34         NLA_NESTED,     /**< Nested attributes */
  35         __NLA_TYPE_MAX,
  36 };
  37
  38 #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
  39
  40 /**
  41  * @ingroup attr
  42  * Attribute validation policy.
  43  *
  44  * See section @core_doc{core_attr_parse,Attribute Parsing} for more details.
  45  */
  46 struct nla_policy {
  47         /** Type of attribute or NLA_UNSPEC */
  48         uint16_t        type;
  49
  50         /** Minimal length of payload required */
  51         uint16_t        minlen;
  52
  53         /** Maximal length of payload allowed */
  54         uint16_t        maxlen;
  55 };
  56
  57 /**
  58  * @ingroup attr
  59  * Iterate over a stream of attributes
  60  * @arg pos     loop counter, set to current attribute
  61  * @arg head    head of attribute stream
  62  * @arg len     length of attribute stream
  63  * @arg rem     initialized to len, holds bytes currently remaining in stream
  64  */
  65 #define nla_for_each_attr(pos, head, len, rem) \
  66         for (pos = head, rem = len; \
  67              nla_ok(pos, rem); \
  68              pos = nla_next(pos, &(rem)))
  69
  70 int nla_dump_errormsg(struct nlmsghdr *nlh);
  71
  72 #endif /* __NLATTR_H */