libnftnl 1.2.6
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, sizeof(fwd->sreg_dev));
37 break;
38 case NFTNL_EXPR_FWD_SREG_ADDR:
39 memcpy(&fwd->sreg_addr, data, sizeof(fwd->sreg_addr));
40 break;
41 case NFTNL_EXPR_FWD_NFPROTO:
42 memcpy(&fwd->nfproto, data, sizeof(fwd->nfproto));
43 break;
44 default:
45 return -1;
46 }
47 return 0;
48}
49
50static const void *nftnl_expr_fwd_get(const struct nftnl_expr *e,
51 uint16_t type, uint32_t *data_len)
52{
53 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
54
55 switch (type) {
56 case NFTNL_EXPR_FWD_SREG_DEV:
57 *data_len = sizeof(fwd->sreg_dev);
58 return &fwd->sreg_dev;
59 case NFTNL_EXPR_FWD_SREG_ADDR:
60 *data_len = sizeof(fwd->sreg_addr);
61 return &fwd->sreg_addr;
62 case NFTNL_EXPR_FWD_NFPROTO:
63 *data_len = sizeof(fwd->nfproto);
64 return &fwd->nfproto;
65 }
66 return NULL;
67}
68
69static int nftnl_expr_fwd_cb(const struct nlattr *attr, void *data)
70{
71 const struct nlattr **tb = data;
72 int type = mnl_attr_get_type(attr);
73
74 if (mnl_attr_type_valid(attr, NFTA_FWD_MAX) < 0)
75 return MNL_CB_OK;
76
77 switch (type) {
78 case NFTA_FWD_SREG_DEV:
79 case NFTA_FWD_SREG_ADDR:
80 case NFTA_FWD_NFPROTO:
81 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
82 abi_breakage();
83 break;
84 }
85
86 tb[type] = attr;
87 return MNL_CB_OK;
88}
89
90static void nftnl_expr_fwd_build(struct nlmsghdr *nlh,
91 const struct nftnl_expr *e)
92{
93 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
94
95 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV))
96 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_DEV, htonl(fwd->sreg_dev));
97 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR))
98 mnl_attr_put_u32(nlh, NFTA_FWD_SREG_ADDR, htonl(fwd->sreg_addr));
99 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO))
100 mnl_attr_put_u32(nlh, NFTA_FWD_NFPROTO, htonl(fwd->nfproto));
101}
102
103static int nftnl_expr_fwd_parse(struct nftnl_expr *e, struct nlattr *attr)
104{
105 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
106 struct nlattr *tb[NFTA_FWD_MAX + 1] = {};
107 int ret = 0;
108
109 if (mnl_attr_parse_nested(attr, nftnl_expr_fwd_cb, tb) < 0)
110 return -1;
111
112 if (tb[NFTA_FWD_SREG_DEV]) {
113 fwd->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_DEV]));
114 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_DEV);
115 }
116 if (tb[NFTA_FWD_SREG_ADDR]) {
117 fwd->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_ADDR]));
118 e->flags |= (1 << NFTNL_EXPR_FWD_SREG_ADDR);
119 }
120 if (tb[NFTA_FWD_NFPROTO]) {
121 fwd->nfproto = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_NFPROTO]));
122 e->flags |= (1 << NFTNL_EXPR_FWD_NFPROTO);
123 }
124
125 return ret;
126}
127
128static int nftnl_expr_fwd_snprintf(char *buf, size_t remain,
129 uint32_t flags, const struct nftnl_expr *e)
130{
131 struct nftnl_expr_fwd *fwd = nftnl_expr_data(e);
132 int offset = 0, ret;
133
134 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) {
135 ret = snprintf(buf + offset, remain, "sreg_dev %u ",
136 fwd->sreg_dev);
137 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
138 }
139 if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) {
140 ret = snprintf(buf + offset, remain, "sreg_addr %u ",
141 fwd->sreg_addr);
142 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
143 }
144 if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) {
145 ret = snprintf(buf + offset, remain, "nfproto %u ",
146 fwd->nfproto);
147 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
148 }
149
150 return offset;
151}
152
153struct expr_ops expr_ops_fwd = {
154 .name = "fwd",
155 .alloc_len = sizeof(struct nftnl_expr_fwd),
156 .max_attr = NFTA_FWD_MAX,
157 .set = nftnl_expr_fwd_set,
158 .get = nftnl_expr_fwd_get,
159 .parse = nftnl_expr_fwd_parse,
160 .build = nftnl_expr_fwd_build,
161 .output = nftnl_expr_fwd_snprintf,
162};