libnftnl 1.2.6
expr/tunnel.c
1/*
2 * (C) 2018 by 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 <linux/netfilter/nf_tables.h>
16
17#include "internal.h"
18#include <libmnl/libmnl.h>
19#include <libnftnl/expr.h>
20#include <libnftnl/rule.h>
21
23 enum nft_tunnel_keys key;
24 enum nft_registers dreg;
25};
26
27static int nftnl_expr_tunnel_set(struct nftnl_expr *e, uint16_t type,
28 const void *data, uint32_t data_len)
29{
30 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
31
32 switch(type) {
33 case NFTNL_EXPR_TUNNEL_KEY:
34 memcpy(&tunnel->key, data, sizeof(tunnel->key));
35 break;
36 case NFTNL_EXPR_TUNNEL_DREG:
37 memcpy(&tunnel->dreg, data, sizeof(tunnel->dreg));
38 break;
39 default:
40 return -1;
41 }
42 return 0;
43}
44
45static const void *
46nftnl_expr_tunnel_get(const struct nftnl_expr *e, uint16_t type,
47 uint32_t *data_len)
48{
49 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
50
51 switch(type) {
52 case NFTNL_EXPR_TUNNEL_KEY:
53 *data_len = sizeof(tunnel->key);
54 return &tunnel->key;
55 case NFTNL_EXPR_TUNNEL_DREG:
56 *data_len = sizeof(tunnel->dreg);
57 return &tunnel->dreg;
58 }
59 return NULL;
60}
61
62static int nftnl_expr_tunnel_cb(const struct nlattr *attr, void *data)
63{
64 const struct nlattr **tb = data;
65 int type = mnl_attr_get_type(attr);
66
67 if (mnl_attr_type_valid(attr, NFTA_TUNNEL_MAX) < 0)
68 return MNL_CB_OK;
69
70 switch(type) {
71 case NFTA_TUNNEL_KEY:
72 case NFTA_TUNNEL_DREG:
73 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
74 abi_breakage();
75 break;
76 }
77
78 tb[type] = attr;
79 return MNL_CB_OK;
80}
81
82static void
83nftnl_expr_tunnel_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
84{
85 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
86
87 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_KEY))
88 mnl_attr_put_u32(nlh, NFTA_TUNNEL_KEY, htonl(tunnel->key));
89 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG))
90 mnl_attr_put_u32(nlh, NFTA_TUNNEL_DREG, htonl(tunnel->dreg));
91}
92
93static int
94nftnl_expr_tunnel_parse(struct nftnl_expr *e, struct nlattr *attr)
95{
96 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
97 struct nlattr *tb[NFTA_TUNNEL_MAX + 1] = {};
98
99 if (mnl_attr_parse_nested(attr, nftnl_expr_tunnel_cb, tb) < 0)
100 return -1;
101
102 if (tb[NFTA_TUNNEL_KEY]) {
103 tunnel->key = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_KEY]));
104 e->flags |= (1 << NFTNL_EXPR_TUNNEL_KEY);
105 }
106 if (tb[NFTA_TUNNEL_DREG]) {
107 tunnel->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_DREG]));
108 e->flags |= (1 << NFTNL_EXPR_TUNNEL_DREG);
109 }
110
111 return 0;
112}
113
114static const char *tunnel_key2str_array[NFT_TUNNEL_MAX + 1] = {
115 [NFT_TUNNEL_PATH] = "path",
116 [NFT_TUNNEL_ID] = "id",
117};
118
119static const char *tunnel_key2str(uint8_t key)
120{
121 if (key <= NFT_TUNNEL_MAX)
122 return tunnel_key2str_array[key];
123
124 return "unknown";
125}
126
127static int
128nftnl_expr_tunnel_snprintf(char *buf, size_t len,
129 uint32_t flags, const struct nftnl_expr *e)
130{
131 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
132
133 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG)) {
134 return snprintf(buf, len, "load %s => reg %u ",
135 tunnel_key2str(tunnel->key), tunnel->dreg);
136 }
137 return 0;
138}
139
140struct expr_ops expr_ops_tunnel = {
141 .name = "tunnel",
142 .alloc_len = sizeof(struct nftnl_expr_tunnel),
143 .max_attr = NFTA_TUNNEL_MAX,
144 .set = nftnl_expr_tunnel_set,
145 .get = nftnl_expr_tunnel_get,
146 .parse = nftnl_expr_tunnel_parse,
147 .build = nftnl_expr_tunnel_build,
148 .output = nftnl_expr_tunnel_snprintf,
149};