/* SPDX-License-Identifier: LGPL-2.1 */
/*
* NETLINK Netlink attributes
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
*/
#ifndef __NLATTR_H
#define __NLATTR_H
#include <stdint.h>
#include <linux/netlink.h>
/* avoid multiple definition of netlink features */
#define __LINUX_NETLINK_H
/**
* Standard attribute types to specify validation policy
*/
enum {
NLA_UNSPEC, /**< Unspecified type, binary data chunk */
NLA_U8, /**< 8 bit integer */
NLA_U16, /**< 16 bit integer */
NLA_U32, /**< 32 bit integer */
NLA_U64, /**< 64 bit integer */
NLA_STRING, /**< NUL terminated character string */
NLA_FLAG, /**< Flag */
NLA_MSECS, /**< Micro seconds (64bit) */
NLA_NESTED, /**< Nested attributes */
__NLA_TYPE_MAX,
};
#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
/**
* @ingroup attr
* Attribute validation policy.
*
* See section @core_doc{core_attr_parse,Attribute Parsing} for more details.
*/
struct nla_policy {
/** Type of attribute or NLA_UNSPEC */
uint16_t type;
/** Minimal length of payload required */
uint16_t minlen;
/** Maximal length of payload allowed */
uint16_t maxlen;
};
/**
* @ingroup attr
* Iterate over a stream of attributes
* @arg pos loop counter, set to current attribute
* @arg head head of attribute stream
* @arg len length of attribute stream
* @arg rem initialized to len, holds bytes currently remaining in stream
*/
#define nla_for_each_attr(pos, head, len, rem) \
for (pos = head, rem = len; \
nla_ok(pos, rem); \
pos = nla_next(pos, &(rem)))
/**
* nla_data - head of payload
* @nla: netlink attribute
*/
static inline void *nla_data(const struct nlattr *nla)
{
return (char *) nla + NLA_HDRLEN;
}
static inline uint8_t nla_getattr_u8(const struct nlattr *nla)
{
return *(uint8_t *)nla_data(nla);
}
static inline uint32_t nla_getattr_u32(const struct nlattr *nla)
{
return *(uint32_t *)nla_data(nla);
}
static inline const char *nla_getattr_str(const struct nlattr *nla)
{
return (const char *)nla_data(nla);
}
/**
* nla_len - length of payload
* @nla: netlink attribute
*/
static inline int nla_len(const struct nlattr *nla)
{
return nla->nla_len - NLA_HDRLEN;
}
int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
struct nla_policy *policy);
int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla,
struct nla_policy *policy);
int nla_dump_errormsg(struct nlmsghdr *nlh);
#endif /* __NLATTR_H */
