cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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nlattr.h (4042B)

      1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
      2
      3/*
      4 * NETLINK      Netlink attributes
      5 *
      6 * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
      7 */
      8
      9#ifndef __LIBBPF_NLATTR_H
     10#define __LIBBPF_NLATTR_H
     11
     12#include <stdint.h>
     13#include <string.h>
     14#include <errno.h>
     15#include <linux/netlink.h>
     16#include <linux/rtnetlink.h>
     17
     18/* avoid multiple definition of netlink features */
     19#define __LINUX_NETLINK_H
     20
     21/**
     22 * Standard attribute types to specify validation policy
     23 */
     24enum {
     25	LIBBPF_NLA_UNSPEC,	/**< Unspecified type, binary data chunk */
     26	LIBBPF_NLA_U8,		/**< 8 bit integer */
     27	LIBBPF_NLA_U16,		/**< 16 bit integer */
     28	LIBBPF_NLA_U32,		/**< 32 bit integer */
     29	LIBBPF_NLA_U64,		/**< 64 bit integer */
     30	LIBBPF_NLA_STRING,	/**< NUL terminated character string */
     31	LIBBPF_NLA_FLAG,	/**< Flag */
     32	LIBBPF_NLA_MSECS,	/**< Micro seconds (64bit) */
     33	LIBBPF_NLA_NESTED,	/**< Nested attributes */
     34	__LIBBPF_NLA_TYPE_MAX,
     35};
     36
     37#define LIBBPF_NLA_TYPE_MAX (__LIBBPF_NLA_TYPE_MAX - 1)
     38
     39/**
     40 * @ingroup attr
     41 * Attribute validation policy.
     42 *
     43 * See section @core_doc{core_attr_parse,Attribute Parsing} for more details.
     44 */
     45struct libbpf_nla_policy {
     46	/** Type of attribute or LIBBPF_NLA_UNSPEC */
     47	uint16_t	type;
     48
     49	/** Minimal length of payload required */
     50	uint16_t	minlen;
     51
     52	/** Maximal length of payload allowed */
     53	uint16_t	maxlen;
     54};
     55
     56struct libbpf_nla_req {
     57	struct nlmsghdr nh;
     58	union {
     59		struct ifinfomsg ifinfo;
     60		struct tcmsg tc;
     61	};
     62	char buf[128];
     63};
     64
     65/**
     66 * @ingroup attr
     67 * Iterate over a stream of attributes
     68 * @arg pos	loop counter, set to current attribute
     69 * @arg head	head of attribute stream
     70 * @arg len	length of attribute stream
     71 * @arg rem	initialized to len, holds bytes currently remaining in stream
     72 */
     73#define libbpf_nla_for_each_attr(pos, head, len, rem) \
     74	for (pos = head, rem = len; \
     75	     nla_ok(pos, rem); \
     76	     pos = nla_next(pos, &(rem)))
     77
     78/**
     79 * libbpf_nla_data - head of payload
     80 * @nla: netlink attribute
     81 */
     82static inline void *libbpf_nla_data(const struct nlattr *nla)
     83{
     84	return (void *)nla + NLA_HDRLEN;
     85}
     86
     87static inline uint8_t libbpf_nla_getattr_u8(const struct nlattr *nla)
     88{
     89	return *(uint8_t *)libbpf_nla_data(nla);
     90}
     91
     92static inline uint32_t libbpf_nla_getattr_u32(const struct nlattr *nla)
     93{
     94	return *(uint32_t *)libbpf_nla_data(nla);
     95}
     96
     97static inline const char *libbpf_nla_getattr_str(const struct nlattr *nla)
     98{
     99	return (const char *)libbpf_nla_data(nla);
    100}
    101
    102/**
    103 * libbpf_nla_len - length of payload
    104 * @nla: netlink attribute
    105 */
    106static inline int libbpf_nla_len(const struct nlattr *nla)
    107{
    108	return nla->nla_len - NLA_HDRLEN;
    109}
    110
    111int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
    112		     int len, struct libbpf_nla_policy *policy);
    113int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
    114			    struct nlattr *nla,
    115			    struct libbpf_nla_policy *policy);
    116
    117int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh);
    118
    119static inline struct nlattr *nla_data(struct nlattr *nla)
    120{
    121	return (struct nlattr *)((void *)nla + NLA_HDRLEN);
    122}
    123
    124static inline struct nlattr *req_tail(struct libbpf_nla_req *req)
    125{
    126	return (struct nlattr *)((void *)req + NLMSG_ALIGN(req->nh.nlmsg_len));
    127}
    128
    129static inline int nlattr_add(struct libbpf_nla_req *req, int type,
    130			     const void *data, int len)
    131{
    132	struct nlattr *nla;
    133
    134	if (NLMSG_ALIGN(req->nh.nlmsg_len) + NLA_ALIGN(NLA_HDRLEN + len) > sizeof(*req))
    135		return -EMSGSIZE;
    136	if (!!data != !!len)
    137		return -EINVAL;
    138
    139	nla = req_tail(req);
    140	nla->nla_type = type;
    141	nla->nla_len = NLA_HDRLEN + len;
    142	if (data)
    143		memcpy(nla_data(nla), data, len);
    144	req->nh.nlmsg_len = NLMSG_ALIGN(req->nh.nlmsg_len) + NLA_ALIGN(nla->nla_len);
    145	return 0;
    146}
    147
    148static inline struct nlattr *nlattr_begin_nested(struct libbpf_nla_req *req, int type)
    149{
    150	struct nlattr *tail;
    151
    152	tail = req_tail(req);
    153	if (nlattr_add(req, type | NLA_F_NESTED, NULL, 0))
    154		return NULL;
    155	return tail;
    156}
    157
    158static inline void nlattr_end_nested(struct libbpf_nla_req *req,
    159				     struct nlattr *tail)
    160{
    161	tail->nla_len = (void *)req_tail(req) - (void *)tail;
    162}
    163
    164#endif /* __LIBBPF_NLATTR_H */