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
|
#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_synproxy {
uint16_t mss;
uint8_t wscale;
uint32_t flags;
};
static int nftnl_expr_synproxy_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_synproxy *synproxy = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_SYNPROXY_MSS:
memcpy(&synproxy->mss, data, sizeof(synproxy->mss));
break;
case NFTNL_EXPR_SYNPROXY_WSCALE:
memcpy(&synproxy->wscale, data, sizeof(synproxy->wscale));
break;
case NFTNL_EXPR_SYNPROXY_FLAGS:
memcpy(&synproxy->flags, data, sizeof(synproxy->flags));
break;
}
return 0;
}
static const void *
nftnl_expr_synproxy_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_synproxy *synproxy = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_SYNPROXY_MSS:
*data_len = sizeof(synproxy->mss);
return &synproxy->mss;
case NFTNL_EXPR_SYNPROXY_WSCALE:
*data_len = sizeof(synproxy->wscale);
return &synproxy->wscale;
case NFTNL_EXPR_SYNPROXY_FLAGS:
*data_len = sizeof(synproxy->flags);
return &synproxy->flags;
}
return NULL;
}
static int nftnl_expr_synproxy_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_SYNPROXY_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTNL_EXPR_SYNPROXY_MSS:
if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
abi_breakage();
break;
case NFTNL_EXPR_SYNPROXY_WSCALE:
if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
abi_breakage();
break;
case NFTNL_EXPR_SYNPROXY_FLAGS:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_synproxy_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_synproxy *synproxy = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_SYNPROXY_MSS))
mnl_attr_put_u16(nlh, NFTNL_EXPR_SYNPROXY_MSS,
htons(synproxy->mss));
if (e->flags & (1 << NFTNL_EXPR_SYNPROXY_WSCALE))
mnl_attr_put_u8(nlh, NFTNL_EXPR_SYNPROXY_WSCALE,
synproxy->wscale);
if (e->flags & (1 << NFTNL_EXPR_SYNPROXY_FLAGS))
mnl_attr_put_u32(nlh, NFTNL_EXPR_SYNPROXY_FLAGS,
htonl(synproxy->flags));
}
static int
nftnl_expr_synproxy_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_synproxy *synproxy = nftnl_expr_data(e);
struct nlattr *tb[NFTA_SYNPROXY_MAX + 1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_synproxy_cb, tb) < 0)
return -1;
if (tb[NFTA_SYNPROXY_MSS]) {
synproxy->mss = ntohs(mnl_attr_get_u16(tb[NFTA_SYNPROXY_MSS]));
e->flags |= (1 << NFTNL_EXPR_SYNPROXY_MSS);
}
if (tb[NFTA_SYNPROXY_WSCALE]) {
synproxy->wscale = mnl_attr_get_u8(tb[NFTA_SYNPROXY_WSCALE]);
e->flags |= (1 << NFTNL_EXPR_SYNPROXY_WSCALE);
}
if (tb[NFTA_SYNPROXY_FLAGS]) {
synproxy->flags = ntohl(mnl_attr_get_u32(tb[NFTA_SYNPROXY_FLAGS]));
e->flags |= (1 << NFTNL_EXPR_SYNPROXY_FLAGS);
}
return 0;
}
static int
nftnl_expr_synproxy_snprintf(char *buf, size_t len,
uint32_t flags, const struct nftnl_expr *e)
{
struct nftnl_expr_synproxy *synproxy = nftnl_expr_data(e);
int ret, offset = 0;
if (e->flags & (1 << NFTNL_EXPR_SYNPROXY_MSS) &&
e->flags & (1 << NFTNL_EXPR_SYNPROXY_WSCALE)) {
ret = snprintf(buf, len, "mss %u wscale %u ", synproxy->mss,
synproxy->wscale);
SNPRINTF_BUFFER_SIZE(ret, len, offset);
}
return offset;
}
struct expr_ops expr_ops_synproxy = {
.name = "synproxy",
.alloc_len = sizeof(struct nftnl_expr_synproxy),
.max_attr = NFTA_SYNPROXY_MAX,
.set = nftnl_expr_synproxy_set,
.get = nftnl_expr_synproxy_get,
.parse = nftnl_expr_synproxy_parse,
.build = nftnl_expr_synproxy_build,
.snprintf = nftnl_expr_synproxy_snprintf,
};
|
