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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
|
/*
* (C) 2016 by Laura Garcia <nevola@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <linux/netfilter/nf_tables.h>
#include "internal.h"
#include <libmnl/libmnl.h>
#include <libnftnl/expr.h>
#include <libnftnl/rule.h>
struct nftnl_expr_hash {
enum nft_hash_types type;
enum nft_registers sreg;
enum nft_registers dreg;
unsigned int len;
unsigned int modulus;
unsigned int seed;
unsigned int offset;
struct {
const char *name;
uint32_t id;
} map;
};
static int
nftnl_expr_hash_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_hash *hash = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_HASH_SREG:
memcpy(&hash->sreg, data, sizeof(hash->sreg));
break;
case NFTNL_EXPR_HASH_DREG:
memcpy(&hash->dreg, data, sizeof(hash->dreg));
break;
case NFTNL_EXPR_HASH_LEN:
memcpy(&hash->len, data, sizeof(hash->len));
break;
case NFTNL_EXPR_HASH_MODULUS:
memcpy(&hash->modulus, data, sizeof(hash->modulus));
break;
case NFTNL_EXPR_HASH_SEED:
memcpy(&hash->seed, data, sizeof(hash->seed));
break;
case NFTNL_EXPR_HASH_OFFSET:
memcpy(&hash->offset, data, sizeof(hash->offset));
break;
case NFTNL_EXPR_HASH_TYPE:
memcpy(&hash->type, data, sizeof(hash->type));
break;
case NFTNL_EXPR_HASH_SET_NAME:
hash->map.name = strdup(data);
if (!hash->map.name)
return -1;
break;
case NFTNL_EXPR_HASH_SET_ID:
memcpy(&hash->map.id, data, sizeof(hash->map.id));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_hash_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_hash *hash = nftnl_expr_data(e);
switch (type) {
case NFTNL_EXPR_HASH_SREG:
*data_len = sizeof(hash->sreg);
return &hash->sreg;
case NFTNL_EXPR_HASH_DREG:
*data_len = sizeof(hash->dreg);
return &hash->dreg;
case NFTNL_EXPR_HASH_LEN:
*data_len = sizeof(hash->len);
return &hash->len;
case NFTNL_EXPR_HASH_MODULUS:
*data_len = sizeof(hash->modulus);
return &hash->modulus;
case NFTNL_EXPR_HASH_SEED:
*data_len = sizeof(hash->seed);
return &hash->seed;
case NFTNL_EXPR_HASH_OFFSET:
*data_len = sizeof(hash->offset);
return &hash->offset;
case NFTNL_EXPR_HASH_TYPE:
*data_len = sizeof(hash->type);
return &hash->type;
case NFTNL_EXPR_HASH_SET_NAME:
*data_len = strlen(hash->map.name) + 1;
return hash->map.name;
case NFTNL_EXPR_HASH_SET_ID:
*data_len = sizeof(hash->map.id);
return &hash->map.id;
}
return NULL;
}
static int nftnl_expr_hash_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, NFTA_HASH_MAX) < 0)
return MNL_CB_OK;
switch (type) {
case NFTA_HASH_SREG:
case NFTA_HASH_DREG:
case NFTA_HASH_LEN:
case NFTA_HASH_MODULUS:
case NFTA_HASH_SEED:
case NFTA_HASH_OFFSET:
case NFTA_HASH_TYPE:
case NFTA_HASH_SET_ID:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
case NFTA_HASH_SET_NAME:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_hash_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_hash *hash = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_HASH_SREG))
mnl_attr_put_u32(nlh, NFTA_HASH_SREG, htonl(hash->sreg));
if (e->flags & (1 << NFTNL_EXPR_HASH_DREG))
mnl_attr_put_u32(nlh, NFTA_HASH_DREG, htonl(hash->dreg));
if (e->flags & (1 << NFTNL_EXPR_HASH_LEN))
mnl_attr_put_u32(nlh, NFTA_HASH_LEN, htonl(hash->len));
if (e->flags & (1 << NFTNL_EXPR_HASH_MODULUS))
mnl_attr_put_u32(nlh, NFTA_HASH_MODULUS, htonl(hash->modulus));
if (e->flags & (1 << NFTNL_EXPR_HASH_SEED))
mnl_attr_put_u32(nlh, NFTA_HASH_SEED, htonl(hash->seed));
if (e->flags & (1 << NFTNL_EXPR_HASH_OFFSET))
mnl_attr_put_u32(nlh, NFTA_HASH_OFFSET, htonl(hash->offset));
if (e->flags & (1 << NFTNL_EXPR_HASH_TYPE))
mnl_attr_put_u32(nlh, NFTA_HASH_TYPE, htonl(hash->type));
if (e->flags & (1 << NFTNL_EXPR_HASH_SET_NAME))
mnl_attr_put_str(nlh, NFTA_HASH_SET_NAME, hash->map.name);
if (e->flags & (1 << NFTNL_EXPR_HASH_SET_ID))
mnl_attr_put_u32(nlh, NFTA_HASH_SET_ID, htonl(hash->map.id));
}
static int
nftnl_expr_hash_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_hash *hash = nftnl_expr_data(e);
struct nlattr *tb[NFTA_HASH_MAX+1] = {};
int ret = 0;
if (mnl_attr_parse_nested(attr, nftnl_expr_hash_cb, tb) < 0)
return -1;
if (tb[NFTA_HASH_SREG]) {
hash->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SREG]));
e->flags |= (1 << NFTNL_EXPR_HASH_SREG);
}
if (tb[NFTA_HASH_DREG]) {
hash->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_DREG]));
e->flags |= (1 << NFTNL_EXPR_HASH_DREG);
}
if (tb[NFTA_HASH_LEN]) {
hash->len = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_LEN]));
e->flags |= (1 << NFTNL_EXPR_HASH_LEN);
}
if (tb[NFTA_HASH_MODULUS]) {
hash->modulus = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_MODULUS]));
e->flags |= (1 << NFTNL_EXPR_HASH_MODULUS);
}
if (tb[NFTA_HASH_SEED]) {
hash->seed = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SEED]));
e->flags |= (1 << NFTNL_EXPR_HASH_SEED);
}
if (tb[NFTA_HASH_OFFSET]) {
hash->offset = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_OFFSET]));
e->flags |= (1 << NFTNL_EXPR_HASH_OFFSET);
}
if (tb[NFTA_HASH_TYPE]) {
hash->type = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_TYPE]));
e->flags |= (1 << NFTNL_EXPR_HASH_TYPE);
}
if (tb[NFTA_HASH_SET_NAME]) {
hash->map.name =
strdup(mnl_attr_get_str(tb[NFTA_HASH_SET_NAME]));
e->flags |= (1 << NFTNL_EXPR_HASH_SET_NAME);
}
if (tb[NFTA_HASH_SET_ID]) {
hash->map.id =
ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SET_ID]));
e->flags |= (1 << NFTNL_EXPR_HASH_SET_ID);
}
return ret;
}
static int
nftnl_expr_hash_snprintf_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
struct nftnl_expr_hash *hash = nftnl_expr_data(e);
int remain = size, offset = 0, ret;
switch (hash->type) {
case NFT_HASH_SYM:
ret =
snprintf(buf, remain, "reg %u = symhash() %% mod %u ",
hash->dreg,
hash->modulus);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
break;
case NFT_HASH_JENKINS:
default:
ret =
snprintf(buf, remain,
"reg %u = jhash(reg %u, %u, 0x%x) %% mod %u ",
hash->dreg, hash->sreg, hash->len, hash->seed,
hash->modulus);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
break;
}
if (hash->offset) {
ret = snprintf(buf + offset, remain, "offset %u ",
hash->offset);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (hash->map.id) {
ret = snprintf(buf + offset, remain, "set %s id %u ",
hash->map.name, hash->map.id);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
return offset;
}
static int
nftnl_expr_hash_snprintf(char *buf, size_t len, uint32_t type,
uint32_t flags, const struct nftnl_expr *e)
{
switch (type) {
case NFTNL_OUTPUT_DEFAULT:
return nftnl_expr_hash_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
struct expr_ops expr_ops_hash = {
.name = "hash",
.alloc_len = sizeof(struct nftnl_expr_hash),
.max_attr = NFTA_HASH_MAX,
.set = nftnl_expr_hash_set,
.get = nftnl_expr_hash_get,
.parse = nftnl_expr_hash_parse,
.build = nftnl_expr_hash_build,
.snprintf = nftnl_expr_hash_snprintf,
};
|
