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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* NOTICE: This is a clean room re-implementation of libnl */
#include <errno.h>
#include "netlink/netlink.h"
#include "netlink/msg.h"
#include "netlink/attr.h"
#include "netlink-types.h"
/* Return payload of string attribute. */
char *nla_get_string(struct nlattr *nla)
{
return (char *) nla_data(nla);
}
/* Return payload of 16 bit integer attribute. */
uint16_t nla_get_u16(struct nlattr *nla)
{
return *((uint16_t *) nla_data(nla));
}
/* Return payload of 32 bit integer attribute. */
uint32_t nla_get_u32(struct nlattr *nla)
{
return *((uint32_t *) nla_data(nla));
}
/* Return value of 8 bit integer attribute. */
uint8_t nla_get_u8(struct nlattr *nla)
{
return *((uint8_t *) nla_data(nla));
}
/* Return payload of uint64_t attribute. */
uint64_t nla_get_u64(struct nlattr *nla)
{
uint64_t tmp;
nla_memcpy(&tmp, nla, sizeof(tmp));
return tmp;
}
/* Head of payload */
void *nla_data(const struct nlattr *nla)
{
return (void *) ((char *) nla + NLA_HDRLEN);
}
/* Return length of the payload . */
int nla_len(const struct nlattr *nla)
{
return nla->nla_len - NLA_HDRLEN;
}
int nla_padlen(int payload)
{
return NLA_ALIGN(payload) - payload;
}
/* Start a new level of nested attributes. */
struct nlattr *nla_nest_start(struct nl_msg *msg, int attrtype)
{
struct nlattr *start = (struct nlattr *)nlmsg_tail(msg->nm_nlh);
int rc;
rc = nla_put(msg, attrtype, 0, NULL);
if (rc < 0)
return NULL;
return start;
}
/* Finalize nesting of attributes. */
int nla_nest_end(struct nl_msg *msg, struct nlattr *start)
{
/* Set attribute size */
start->nla_len = (unsigned char *)nlmsg_tail(nlmsg_hdr(msg)) -
(unsigned char *)start;
return 0;
}
/* Return next attribute in a stream of attributes. */
struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
{
struct nlattr *next_nla = NULL;
if (nla->nla_len >= sizeof(struct nlattr) &&
nla->nla_len <= *remaining){
next_nla = (struct nlattr *) \
((char *) nla + NLA_ALIGN(nla->nla_len));
*remaining = *remaining - NLA_ALIGN(nla->nla_len);
}
return next_nla;
}
/* Check if the attribute header and payload can be accessed safely. */
int nla_ok(const struct nlattr *nla, int remaining)
{
return remaining > 0 &&
nla->nla_len >= sizeof(struct nlattr) &&
sizeof(struct nlattr) <= (unsigned int) remaining &&
nla->nla_len <= remaining;
}
/* Create attribute index based on a stream of attributes. */
/* NOTE: Policy not used ! */
int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
int len, struct nla_policy *policy)
{
struct nlattr *pos;
int rem;
/* First clear table */
memset(tb, 0, (maxtype + 1) * sizeof(struct nlattr *));
nla_for_each_attr(pos, head, len, rem) {
int type = nla_type(pos);
if ((type <= maxtype) && (type != 0))
tb[type] = pos;
}
return 0;
}
/* Create attribute index based on nested attribute. */
int nla_parse_nested(struct nlattr *tb[], int maxtype,
struct nlattr *nla, struct nla_policy *policy)
{
return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
}
/* Add a unspecific attribute to netlink message. */
int nla_put(struct nl_msg *msg, int attrtype, int datalen, const void *data)
{
struct nlattr *nla;
/* Reserve space and init nla header */
nla = nla_reserve(msg, attrtype, datalen);
if (nla) {
memcpy(nla_data(nla), data, datalen);
return 0;
}
return -EINVAL;
}
/* Add nested attributes to netlink message. */
/* Takes the attributes found in the nested message and appends them
* to the message msg nested in a container of the type attrtype. The
* nested message may not have a family specific header */
int nla_put_nested(struct nl_msg *msg, int attrtype, struct nl_msg *nested)
{
int rc;
rc = nla_put(msg, attrtype, nlmsg_attrlen(nlmsg_hdr(nested), 0),
nlmsg_attrdata(nlmsg_hdr(nested), 0));
return rc;
}
/* Return type of the attribute. */
int nla_type(const struct nlattr *nla)
{
return (int)nla->nla_type & NLA_TYPE_MASK;
}
/* Reserves room for an attribute in specified netlink message and fills
* in the attribute header (type,length). Return NULL if insufficient space */
struct nlattr *nla_reserve(struct nl_msg *msg, int attrtype, int data_len)
{
struct nlattr *nla;
const unsigned int NEW_SIZE = NLMSG_ALIGN(msg->nm_nlh->nlmsg_len) +
NLA_ALIGN(NLA_HDRLEN + data_len);
/* Check enough space for attribute */
if (NEW_SIZE > msg->nm_size)
return NULL;
nla = (struct nlattr *)nlmsg_tail(msg->nm_nlh);
nla->nla_type = attrtype;
nla->nla_len = NLA_HDRLEN + data_len;
memset((unsigned char *)nla + nla->nla_len, 0, nla_padlen(data_len));
msg->nm_nlh->nlmsg_len = NEW_SIZE;
return nla;
}
/* Copy attribute payload to another memory area. */
int nla_memcpy(void *dest, struct nlattr *src, int count)
{
if (!src || !dest)
return 0;
if (count > nla_len(src))
count = nla_len(src);
memcpy(dest, nla_data(src), count);
return count;
}
|