libnftnl 1.2.9
tproxy.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright (c) 2018 Máté Eckl <ecklm94@gmail.com>
4 */
5
6#include "internal.h"
7
8#include <stdio.h>
9#include <stdint.h>
10#include <limits.h>
11#include <string.h>
12#include <errno.h>
13#include <arpa/inet.h>
14#include <libmnl/libmnl.h>
15#include <linux/netfilter/nf_tables.h>
16#include <libnftnl/expr.h>
17#include <libnftnl/rule.h>
18
20 enum nft_registers sreg_addr;
21 enum nft_registers sreg_port;
22 int family;
23};
24
25static int
26nftnl_expr_tproxy_set(struct nftnl_expr *e, uint16_t type,
27 const void *data, uint32_t data_len)
28{
29 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
30
31 switch(type) {
32 case NFTNL_EXPR_TPROXY_FAMILY:
33 memcpy(&tproxy->family, data, data_len);
34 break;
35 case NFTNL_EXPR_TPROXY_REG_ADDR:
36 memcpy(&tproxy->sreg_addr, data, data_len);
37 break;
38 case NFTNL_EXPR_TPROXY_REG_PORT:
39 memcpy(&tproxy->sreg_port, data, data_len);
40 break;
41 }
42
43 return 0;
44}
45
46static const void *
47nftnl_expr_tproxy_get(const struct nftnl_expr *e, uint16_t type,
48 uint32_t *data_len)
49{
50 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
51
52 switch(type) {
53 case NFTNL_EXPR_TPROXY_FAMILY:
54 *data_len = sizeof(tproxy->family);
55 return &tproxy->family;
56 case NFTNL_EXPR_TPROXY_REG_ADDR:
57 *data_len = sizeof(tproxy->sreg_addr);
58 return &tproxy->sreg_addr;
59 case NFTNL_EXPR_TPROXY_REG_PORT:
60 *data_len = sizeof(tproxy->sreg_port);
61 return &tproxy->sreg_port;
62 }
63 return NULL;
64}
65
66static int nftnl_expr_tproxy_cb(const struct nlattr *attr, void *data)
67{
68 const struct nlattr **tb = data;
69 int type = mnl_attr_get_type(attr);
70
71 if (mnl_attr_type_valid(attr, NFTA_TPROXY_MAX) < 0)
72 return MNL_CB_OK;
73
74 switch(type) {
75 case NFTA_TPROXY_FAMILY:
76 case NFTA_TPROXY_REG_ADDR:
77 case NFTA_TPROXY_REG_PORT:
78 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
79 abi_breakage();
80 break;
81 }
82
83 tb[type] = attr;
84 return MNL_CB_OK;
85}
86
87static int
88nftnl_expr_tproxy_parse(struct nftnl_expr *e, struct nlattr *attr)
89{
90 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
91 struct nlattr *tb[NFTA_TPROXY_MAX + 1] = {};
92
93 if (mnl_attr_parse_nested(attr, nftnl_expr_tproxy_cb, tb) < 0)
94 return -1;
95
96 if (tb[NFTA_TPROXY_FAMILY]) {
97 tproxy->family = ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_FAMILY]));
98 e->flags |= (1 << NFTNL_EXPR_TPROXY_FAMILY);
99 }
100 if (tb[NFTA_TPROXY_REG_ADDR]) {
101 tproxy->sreg_addr =
102 ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_ADDR]));
103 e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_ADDR);
104 }
105 if (tb[NFTA_TPROXY_REG_PORT]) {
106 tproxy->sreg_port =
107 ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_PORT]));
108 e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_PORT);
109 }
110
111 return 0;
112}
113
114static void
115nftnl_expr_tproxy_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
116{
117 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
118
119 if (e->flags & (1 << NFTNL_EXPR_TPROXY_FAMILY))
120 mnl_attr_put_u32(nlh, NFTA_TPROXY_FAMILY, htonl(tproxy->family));
121
122 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR))
123 mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_ADDR,
124 htonl(tproxy->sreg_addr));
125
126 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT))
127 mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_PORT,
128 htonl(tproxy->sreg_port));
129}
130
131static int
132nftnl_expr_tproxy_snprintf(char *buf, size_t remain,
133 uint32_t flags, const struct nftnl_expr *e)
134{
135 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
136 int offset = 0, ret = 0;
137
138 if (tproxy->family != NFTA_TPROXY_UNSPEC) {
139 ret = snprintf(buf + offset, remain, "%s ",
140 nftnl_family2str(tproxy->family));
141 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
142 }
143
144 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR)) {
145 ret = snprintf(buf + offset, remain,
146 "addr reg %u ", tproxy->sreg_addr);
147 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
148 }
149
150 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT)) {
151 ret = snprintf(buf + offset, remain,
152 "port reg %u ", tproxy->sreg_port);
153 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
154 }
155
156 return offset;
157}
158
159static struct attr_policy tproxy_attr_policy[__NFTNL_EXPR_TPROXY_MAX] = {
160 [NFTNL_EXPR_TPROXY_FAMILY] = { .maxlen = sizeof(uint32_t) },
161 [NFTNL_EXPR_TPROXY_REG_ADDR] = { .maxlen = sizeof(uint32_t) },
162 [NFTNL_EXPR_TPROXY_REG_PORT] = { .maxlen = sizeof(uint32_t) },
163};
164
165struct expr_ops expr_ops_tproxy = {
166 .name = "tproxy",
167 .alloc_len = sizeof(struct nftnl_expr_tproxy),
168 .nftnl_max_attr = __NFTNL_EXPR_TPROXY_MAX - 1,
169 .attr_policy = tproxy_attr_policy,
170 .set = nftnl_expr_tproxy_set,
171 .get = nftnl_expr_tproxy_get,
172 .parse = nftnl_expr_tproxy_parse,
173 .build = nftnl_expr_tproxy_build,
174 .output = nftnl_expr_tproxy_snprintf,
175};