libnftnl 1.2.8
fwd.c
1/*
2 * (C) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
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 <stdio.h>
11#include <stdint.h>
12#include <string.h>
13#include <arpa/inet.h>
14#include <errno.h>
15#include "internal.h"
16#include <libmnl/libmnl.h>
17#include <linux/netfilter/nf_tables.h>
18#include <libnftnl/expr.h>
19#include <libnftnl/rule.h>
20#include "expr_ops.h"
21#include "data_reg.h"
22
24 enum nft_registers sreg_dev;
25 enum nft_registers sreg_addr;
26 uint32_t nfproto;
27};
28
29static int nftnl_expr_fwd_set(struct nftnl_expr *e, uint16_t type,
30 const void *data, uint32_t data_len)
31{
32 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
33
34 switch (type) {
35 case NFTNL_EXPR_FWD_SREG_DEV:
36 memcpy(&fwd->sreg_dev, data, data_len);
37 break;
38 case NFTNL_EXPR_FWD_SREG_ADDR:
39 memcpy(&fwd->sreg_addr, data, data_len);
40 break;
41 case NFTNL_EXPR_FWD_NFPROTO:
42 memcpy(&fwd->nfproto, data, data_len);
43 break;
44 }
45 return 0;
46}
47
48static const void *nftnl_expr_fwd_get(const struct nftnl_expr *e,
49 uint16_t type, uint32_t *data_len)
50{
51 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
52
53 switch (type) {
54 case NFTNL_EXPR_FWD_SREG_DEV:
55 *data_len = sizeof(fwd->sreg_dev);
56 return &fwd->sreg_dev;
57 case NFTNL_EXPR_FWD_SREG_ADDR:
58 *data_len = sizeof(fwd->sreg_addr);
59 return &fwd->sreg_addr;
60 case NFTNL_EXPR_FWD_NFPROTO:
61 *data_len = sizeof(fwd->nfproto);
62 return &fwd->nfproto;
63 }
64 return NULL;
65}
66
67static int nftnl_expr_fwd_cb(const struct nlattr *attr, void *data)
68{
69 const struct nlattr **tb = data;
70 int type = mnl_attr_get_type(attr);
71
72 if (mnl_attr_type_valid(attr, NFTA_FWD_MAX) < 0)
73 return MNL_CB_OK;
74
75 switch (type) {
76 case NFTA_FWD_SREG_DEV:
77 case NFTA_FWD_SREG_ADDR:
78 case NFTA_FWD_NFPROTO:
79 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
80 abi_breakage();
81 break;
82 }
83
84 tb[type] = attr;
85 return MNL_CB_OK;
86}
87
88static void nftnl_expr_fwd_build(struct nlmsghdr *nlh,
89 const struct nftnl_expr *e)
90{
91 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
92
93 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV))
94 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_DEV, htonl(fwd->sreg_dev));
95 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR))
96 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_ADDR, htonl(fwd->sreg_addr));
97 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO))
98 mnl_attr_put_u32(nlh, NFTA_FWD_NFPROTO, htonl(fwd->nfproto));
99}
100
101static int nftnl_expr_fwd_parse(struct nftnl_expr *e, struct nlattr *attr)
102{
103 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
104 struct nlattr *tb[NFTA_FWD_MAX + 1] = {};
105 int ret = 0;
106
107 if (mnl_attr_parse_nested(attr, nftnl_expr_fwd_cb, tb) < 0)
108 return -1;
109
110 if (tb[NFTA_FWD_SREG_DEV]) {
111 fwd->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_DEV]));
112 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_DEV);
113 }
114 if (tb[NFTA_FWD_SREG_ADDR]) {
115 fwd->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_ADDR]));
116 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_ADDR);
117 }
118 if (tb[NFTA_FWD_NFPROTO]) {
119 fwd->nfproto = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_NFPROTO]));
120 e->flags |= (1 << NFTNL_EXPR_FWD_NFPROTO);
121 }
122
123 return ret;
124}
125
126static int nftnl_expr_fwd_snprintf(char *buf, size_t remain,
127 uint32_t flags, const struct nftnl_expr *e)
128{
129 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
130 int offset = 0, ret;
131
132 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) {
133 ret = snprintf(buf + offset, remain, "sreg_dev %u ",
134 fwd->sreg_dev);
135 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
136 }
137 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) {
138 ret = snprintf(buf + offset, remain, "sreg_addr %u ",
139 fwd->sreg_addr);
140 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
141 }
142 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) {
143 ret = snprintf(buf + offset, remain, "nfproto %u ",
144 fwd->nfproto);
145 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
146 }
147
148 return offset;
149}
150
151static struct attr_policy fwd_attr_policy[__NFTNL_EXPR_FWD_MAX] = {
152 [NFTNL_EXPR_FWD_SREG_DEV] = { .maxlen = sizeof(uint32_t) },
153 [NFTNL_EXPR_FWD_SREG_ADDR] = { .maxlen = sizeof(uint32_t) },
154 [NFTNL_EXPR_FWD_NFPROTO] = { .maxlen = sizeof(uint32_t) },
155};
156
157struct expr_ops expr_ops_fwd = {
158 .name = "fwd",
159 .alloc_len = sizeof(struct nftnl_expr_fwd),
160 .nftnl_max_attr = __NFTNL_EXPR_FWD_MAX - 1,
161 .attr_policy = fwd_attr_policy,
162 .set = nftnl_expr_fwd_set,
163 .get = nftnl_expr_fwd_get,
164 .parse = nftnl_expr_fwd_parse,
165 .build = nftnl_expr_fwd_build,
166 .output = nftnl_expr_fwd_snprintf,
167};