libnftnl 1.2.8
tproxy.c
1/*
2 * Copyright (c) 2018 Máté Eckl <ecklm94@gmail.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published
6 * by the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 */
9
10#include "internal.h"
11
12#include <stdio.h>
13#include <stdint.h>
14#include <limits.h>
15#include <string.h>
16#include <errno.h>
17#include <arpa/inet.h>
18#include <libmnl/libmnl.h>
19#include <linux/netfilter/nf_tables.h>
20#include <libnftnl/expr.h>
21#include <libnftnl/rule.h>
22
24 enum nft_registers sreg_addr;
25 enum nft_registers sreg_port;
26 int family;
27};
28
29static int
30nftnl_expr_tproxy_set(struct nftnl_expr *e, uint16_t type,
31 const void *data, uint32_t data_len)
32{
33 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
34
35 switch(type) {
36 case NFTNL_EXPR_TPROXY_FAMILY:
37 memcpy(&tproxy->family, data, data_len);
38 break;
39 case NFTNL_EXPR_TPROXY_REG_ADDR:
40 memcpy(&tproxy->sreg_addr, data, data_len);
41 break;
42 case NFTNL_EXPR_TPROXY_REG_PORT:
43 memcpy(&tproxy->sreg_port, data, data_len);
44 break;
45 }
46
47 return 0;
48}
49
50static const void *
51nftnl_expr_tproxy_get(const struct nftnl_expr *e, uint16_t type,
52 uint32_t *data_len)
53{
54 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
55
56 switch(type) {
57 case NFTNL_EXPR_TPROXY_FAMILY:
58 *data_len = sizeof(tproxy->family);
59 return &tproxy->family;
60 case NFTNL_EXPR_TPROXY_REG_ADDR:
61 *data_len = sizeof(tproxy->sreg_addr);
62 return &tproxy->sreg_addr;
63 case NFTNL_EXPR_TPROXY_REG_PORT:
64 *data_len = sizeof(tproxy->sreg_port);
65 return &tproxy->sreg_port;
66 }
67 return NULL;
68}
69
70static int nftnl_expr_tproxy_cb(const struct nlattr *attr, void *data)
71{
72 const struct nlattr **tb = data;
73 int type = mnl_attr_get_type(attr);
74
75 if (mnl_attr_type_valid(attr, NFTA_TPROXY_MAX) < 0)
76 return MNL_CB_OK;
77
78 switch(type) {
79 case NFTA_TPROXY_FAMILY:
80 case NFTA_TPROXY_REG_ADDR:
81 case NFTA_TPROXY_REG_PORT:
82 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
83 abi_breakage();
84 break;
85 }
86
87 tb[type] = attr;
88 return MNL_CB_OK;
89}
90
91static int
92nftnl_expr_tproxy_parse(struct nftnl_expr *e, struct nlattr *attr)
93{
94 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
95 struct nlattr *tb[NFTA_TPROXY_MAX + 1] = {};
96
97 if (mnl_attr_parse_nested(attr, nftnl_expr_tproxy_cb, tb) < 0)
98 return -1;
99
100 if (tb[NFTA_TPROXY_FAMILY]) {
101 tproxy->family = ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_FAMILY]));
102 e->flags |= (1 << NFTNL_EXPR_TPROXY_FAMILY);
103 }
104 if (tb[NFTA_TPROXY_REG_ADDR]) {
105 tproxy->sreg_addr =
106 ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_ADDR]));
107 e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_ADDR);
108 }
109 if (tb[NFTA_TPROXY_REG_PORT]) {
110 tproxy->sreg_port =
111 ntohl(mnl_attr_get_u32(tb[NFTA_TPROXY_REG_PORT]));
112 e->flags |= (1 << NFTNL_EXPR_TPROXY_REG_PORT);
113 }
114
115 return 0;
116}
117
118static void
119nftnl_expr_tproxy_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
120{
121 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
122
123 if (e->flags & (1 << NFTNL_EXPR_TPROXY_FAMILY))
124 mnl_attr_put_u32(nlh, NFTA_TPROXY_FAMILY, htonl(tproxy->family));
125
126 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR))
127 mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_ADDR,
128 htonl(tproxy->sreg_addr));
129
130 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT))
131 mnl_attr_put_u32(nlh, NFTA_TPROXY_REG_PORT,
132 htonl(tproxy->sreg_port));
133}
134
135static int
136nftnl_expr_tproxy_snprintf(char *buf, size_t remain,
137 uint32_t flags, const struct nftnl_expr *e)
138{
139 struct nftnl_expr_tproxy *tproxy = nftnl_expr_data(e);
140 int offset = 0, ret = 0;
141
142 if (tproxy->family != NFTA_TPROXY_UNSPEC) {
143 ret = snprintf(buf + offset, remain, "%s ",
144 nftnl_family2str(tproxy->family));
145 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
146 }
147
148 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_ADDR)) {
149 ret = snprintf(buf + offset, remain,
150 "addr reg %u ", tproxy->sreg_addr);
151 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
152 }
153
154 if (e->flags & (1 << NFTNL_EXPR_TPROXY_REG_PORT)) {
155 ret = snprintf(buf + offset, remain,
156 "port reg %u ", tproxy->sreg_port);
157 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
158 }
159
160 return offset;
161}
162
163static struct attr_policy tproxy_attr_policy[__NFTNL_EXPR_TPROXY_MAX] = {
164 [NFTNL_EXPR_TPROXY_FAMILY] = { .maxlen = sizeof(uint32_t) },
165 [NFTNL_EXPR_TPROXY_REG_ADDR] = { .maxlen = sizeof(uint32_t) },
166 [NFTNL_EXPR_TPROXY_REG_PORT] = { .maxlen = sizeof(uint32_t) },
167};
168
169struct expr_ops expr_ops_tproxy = {
170 .name = "tproxy",
171 .alloc_len = sizeof(struct nftnl_expr_tproxy),
172 .nftnl_max_attr = __NFTNL_EXPR_TPROXY_MAX - 1,
173 .attr_policy = tproxy_attr_policy,
174 .set = nftnl_expr_tproxy_set,
175 .get = nftnl_expr_tproxy_get,
176 .parse = nftnl_expr_tproxy_parse,
177 .build = nftnl_expr_tproxy_build,
178 .output = nftnl_expr_tproxy_snprintf,
179};