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