libnftnl 1.2.9
expr/tunnel.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2018 by 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 <linux/netfilter/nf_tables.h>
12
13#include "internal.h"
14#include <libmnl/libmnl.h>
15#include <libnftnl/expr.h>
16#include <libnftnl/rule.h>
17
19 enum nft_tunnel_keys key;
20 enum nft_registers dreg;
21};
22
23static int nftnl_expr_tunnel_set(struct nftnl_expr *e, uint16_t type,
24 const void *data, uint32_t data_len)
25{
26 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
27
28 switch(type) {
29 case NFTNL_EXPR_TUNNEL_KEY:
30 memcpy(&tunnel->key, data, data_len);
31 break;
32 case NFTNL_EXPR_TUNNEL_DREG:
33 memcpy(&tunnel->dreg, data, data_len);
34 break;
35 }
36 return 0;
37}
38
39static const void *
40nftnl_expr_tunnel_get(const struct nftnl_expr *e, uint16_t type,
41 uint32_t *data_len)
42{
43 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
44
45 switch(type) {
46 case NFTNL_EXPR_TUNNEL_KEY:
47 *data_len = sizeof(tunnel->key);
48 return &tunnel->key;
49 case NFTNL_EXPR_TUNNEL_DREG:
50 *data_len = sizeof(tunnel->dreg);
51 return &tunnel->dreg;
52 }
53 return NULL;
54}
55
56static int nftnl_expr_tunnel_cb(const struct nlattr *attr, void *data)
57{
58 const struct nlattr **tb = data;
59 int type = mnl_attr_get_type(attr);
60
61 if (mnl_attr_type_valid(attr, NFTA_TUNNEL_MAX) < 0)
62 return MNL_CB_OK;
63
64 switch(type) {
65 case NFTA_TUNNEL_KEY:
66 case NFTA_TUNNEL_DREG:
67 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
68 abi_breakage();
69 break;
70 }
71
72 tb[type] = attr;
73 return MNL_CB_OK;
74}
75
76static void
77nftnl_expr_tunnel_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
78{
79 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
80
81 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_KEY))
82 mnl_attr_put_u32(nlh, NFTA_TUNNEL_KEY, htonl(tunnel->key));
83 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG))
84 mnl_attr_put_u32(nlh, NFTA_TUNNEL_DREG, htonl(tunnel->dreg));
85}
86
87static int
88nftnl_expr_tunnel_parse(struct nftnl_expr *e, struct nlattr *attr)
89{
90 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
91 struct nlattr *tb[NFTA_TUNNEL_MAX + 1] = {};
92
93 if (mnl_attr_parse_nested(attr, nftnl_expr_tunnel_cb, tb) < 0)
94 return -1;
95
96 if (tb[NFTA_TUNNEL_KEY]) {
97 tunnel->key = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_KEY]));
98 e->flags |= (1 << NFTNL_EXPR_TUNNEL_KEY);
99 }
100 if (tb[NFTA_TUNNEL_DREG]) {
101 tunnel->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_DREG]));
102 e->flags |= (1 << NFTNL_EXPR_TUNNEL_DREG);
103 }
104
105 return 0;
106}
107
108static const char *tunnel_key2str_array[NFT_TUNNEL_MAX + 1] = {
109 [NFT_TUNNEL_PATH] = "path",
110 [NFT_TUNNEL_ID] = "id",
111};
112
113static const char *tunnel_key2str(uint8_t key)
114{
115 if (key <= NFT_TUNNEL_MAX)
116 return tunnel_key2str_array[key];
117
118 return "unknown";
119}
120
121static int
122nftnl_expr_tunnel_snprintf(char *buf, size_t len,
123 uint32_t flags, const struct nftnl_expr *e)
124{
125 struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
126
127 if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG)) {
128 return snprintf(buf, len, "load %s => reg %u ",
129 tunnel_key2str(tunnel->key), tunnel->dreg);
130 }
131 return 0;
132}
133
134static struct attr_policy tunnel_attr_policy[__NFTNL_EXPR_TUNNEL_MAX] = {
135 [NFTNL_EXPR_TUNNEL_KEY] = { .maxlen = sizeof(uint32_t) },
136 [NFTNL_EXPR_TUNNEL_DREG] = { .maxlen = sizeof(uint32_t) },
137};
138
139struct expr_ops expr_ops_tunnel = {
140 .name = "tunnel",
141 .alloc_len = sizeof(struct nftnl_expr_tunnel),
142 .nftnl_max_attr = __NFTNL_EXPR_TUNNEL_MAX - 1,
143 .attr_policy = tunnel_attr_policy,
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};