libnftnl 1.2.9
fwd.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
4 */
5
6#include <stdio.h>
7#include <stdint.h>
8#include <string.h>
9#include <arpa/inet.h>
10#include <errno.h>
11#include "internal.h"
12#include <libmnl/libmnl.h>
13#include <linux/netfilter/nf_tables.h>
14#include <libnftnl/expr.h>
15#include <libnftnl/rule.h>
16#include "expr_ops.h"
17#include "data_reg.h"
18
20 enum nft_registers sreg_dev;
21 enum nft_registers sreg_addr;
22 uint32_t nfproto;
23};
24
25static int nftnl_expr_fwd_set(struct nftnl_expr *e, uint16_t type,
26 const void *data, uint32_t data_len)
27{
28 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
29
30 switch (type) {
31 case NFTNL_EXPR_FWD_SREG_DEV:
32 memcpy(&fwd->sreg_dev, data, data_len);
33 break;
34 case NFTNL_EXPR_FWD_SREG_ADDR:
35 memcpy(&fwd->sreg_addr, data, data_len);
36 break;
37 case NFTNL_EXPR_FWD_NFPROTO:
38 memcpy(&fwd->nfproto, data, data_len);
39 break;
40 }
41 return 0;
42}
43
44static const void *nftnl_expr_fwd_get(const struct nftnl_expr *e,
45 uint16_t type, uint32_t *data_len)
46{
47 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
48
49 switch (type) {
50 case NFTNL_EXPR_FWD_SREG_DEV:
51 *data_len = sizeof(fwd->sreg_dev);
52 return &fwd->sreg_dev;
53 case NFTNL_EXPR_FWD_SREG_ADDR:
54 *data_len = sizeof(fwd->sreg_addr);
55 return &fwd->sreg_addr;
56 case NFTNL_EXPR_FWD_NFPROTO:
57 *data_len = sizeof(fwd->nfproto);
58 return &fwd->nfproto;
59 }
60 return NULL;
61}
62
63static int nftnl_expr_fwd_cb(const struct nlattr *attr, void *data)
64{
65 const struct nlattr **tb = data;
66 int type = mnl_attr_get_type(attr);
67
68 if (mnl_attr_type_valid(attr, NFTA_FWD_MAX) < 0)
69 return MNL_CB_OK;
70
71 switch (type) {
72 case NFTA_FWD_SREG_DEV:
73 case NFTA_FWD_SREG_ADDR:
74 case NFTA_FWD_NFPROTO:
75 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
76 abi_breakage();
77 break;
78 }
79
80 tb[type] = attr;
81 return MNL_CB_OK;
82}
83
84static void nftnl_expr_fwd_build(struct nlmsghdr *nlh,
85 const struct nftnl_expr *e)
86{
87 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
88
89 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV))
90 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_DEV, htonl(fwd->sreg_dev));
91 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR))
92 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_ADDR, htonl(fwd->sreg_addr));
93 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO))
94 mnl_attr_put_u32(nlh, NFTA_FWD_NFPROTO, htonl(fwd->nfproto));
95}
96
97static int nftnl_expr_fwd_parse(struct nftnl_expr *e, struct nlattr *attr)
98{
99 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
100 struct nlattr *tb[NFTA_FWD_MAX + 1] = {};
101 int ret = 0;
102
103 if (mnl_attr_parse_nested(attr, nftnl_expr_fwd_cb, tb) < 0)
104 return -1;
105
106 if (tb[NFTA_FWD_SREG_DEV]) {
107 fwd->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_DEV]));
108 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_DEV);
109 }
110 if (tb[NFTA_FWD_SREG_ADDR]) {
111 fwd->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_ADDR]));
112 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_ADDR);
113 }
114 if (tb[NFTA_FWD_NFPROTO]) {
115 fwd->nfproto = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_NFPROTO]));
116 e->flags |= (1 << NFTNL_EXPR_FWD_NFPROTO);
117 }
118
119 return ret;
120}
121
122static int nftnl_expr_fwd_snprintf(char *buf, size_t remain,
123 uint32_t flags, const struct nftnl_expr *e)
124{
125 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
126 int offset = 0, ret;
127
128 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) {
129 ret = snprintf(buf + offset, remain, "sreg_dev %u ",
130 fwd->sreg_dev);
131 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
132 }
133 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) {
134 ret = snprintf(buf + offset, remain, "sreg_addr %u ",
135 fwd->sreg_addr);
136 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
137 }
138 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) {
139 ret = snprintf(buf + offset, remain, "nfproto %u ",
140 fwd->nfproto);
141 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
142 }
143
144 return offset;
145}
146
147static struct attr_policy fwd_attr_policy[__NFTNL_EXPR_FWD_MAX] = {
148 [NFTNL_EXPR_FWD_SREG_DEV] = { .maxlen = sizeof(uint32_t) },
149 [NFTNL_EXPR_FWD_SREG_ADDR] = { .maxlen = sizeof(uint32_t) },
150 [NFTNL_EXPR_FWD_NFPROTO] = { .maxlen = sizeof(uint32_t) },
151};
152
153struct expr_ops expr_ops_fwd = {
154 .name = "fwd",
155 .alloc_len = sizeof(struct nftnl_expr_fwd),
156 .nftnl_max_attr = __NFTNL_EXPR_FWD_MAX - 1,
157 .attr_policy = fwd_attr_policy,
158 .set = nftnl_expr_fwd_set,
159 .get = nftnl_expr_fwd_get,
160 .parse = nftnl_expr_fwd_parse,
161 .build = nftnl_expr_fwd_build,
162 .output = nftnl_expr_fwd_snprintf,
163};