libnftnl 1.2.6
meta.c
1/*
2 * (C) 2012 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 * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
10 */
11
12#include <stdio.h>
13#include <stdint.h>
14#include <string.h>
15#include <arpa/inet.h>
16#include <errno.h>
17#include <linux/netfilter/nf_tables.h>
18
19#include "internal.h"
20#include <libmnl/libmnl.h>
21#include <libnftnl/expr.h>
22#include <libnftnl/rule.h>
23
24#ifndef NFT_META_MAX
25#define NFT_META_MAX (NFT_META_BRI_BROUTE + 1)
26#endif
27
29 enum nft_meta_keys key;
30 enum nft_registers dreg;
31 enum nft_registers sreg;
32};
33
34static int
35nftnl_expr_meta_set(struct nftnl_expr *e, uint16_t type,
36 const void *data, uint32_t data_len)
37{
38 struct nftnl_expr_meta *meta = nftnl_expr_data(e);
39
40 switch(type) {
41 case NFTNL_EXPR_META_KEY:
42 memcpy(&meta->key, data, sizeof(meta->key));
43 break;
44 case NFTNL_EXPR_META_DREG:
45 memcpy(&meta->dreg, data, sizeof(meta->dreg));
46 break;
47 case NFTNL_EXPR_META_SREG:
48 memcpy(&meta->sreg, data, sizeof(meta->sreg));
49 break;
50 default:
51 return -1;
52 }
53 return 0;
54}
55
56static const void *
57nftnl_expr_meta_get(const struct nftnl_expr *e, uint16_t type,
58 uint32_t *data_len)
59{
60 struct nftnl_expr_meta *meta = nftnl_expr_data(e);
61
62 switch(type) {
63 case NFTNL_EXPR_META_KEY:
64 *data_len = sizeof(meta->key);
65 return &meta->key;
66 case NFTNL_EXPR_META_DREG:
67 *data_len = sizeof(meta->dreg);
68 return &meta->dreg;
69 case NFTNL_EXPR_META_SREG:
70 *data_len = sizeof(meta->sreg);
71 return &meta->sreg;
72 }
73 return NULL;
74}
75
76static int nftnl_expr_meta_cb(const struct nlattr *attr, void *data)
77{
78 const struct nlattr **tb = data;
79 int type = mnl_attr_get_type(attr);
80
81 if (mnl_attr_type_valid(attr, NFTA_META_MAX) < 0)
82 return MNL_CB_OK;
83
84 switch(type) {
85 case NFTA_META_KEY:
86 case NFTA_META_DREG:
87 case NFTA_META_SREG:
88 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
89 abi_breakage();
90 break;
91 }
92
93 tb[type] = attr;
94 return MNL_CB_OK;
95}
96
97static void
98nftnl_expr_meta_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
99{
100 struct nftnl_expr_meta *meta = nftnl_expr_data(e);
101
102 if (e->flags & (1 << NFTNL_EXPR_META_KEY))
103 mnl_attr_put_u32(nlh, NFTA_META_KEY, htonl(meta->key));
104 if (e->flags & (1 << NFTNL_EXPR_META_DREG))
105 mnl_attr_put_u32(nlh, NFTA_META_DREG, htonl(meta->dreg));
106 if (e->flags & (1 << NFTNL_EXPR_META_SREG))
107 mnl_attr_put_u32(nlh, NFTA_META_SREG, htonl(meta->sreg));
108}
109
110static int
111nftnl_expr_meta_parse(struct nftnl_expr *e, struct nlattr *attr)
112{
113 struct nftnl_expr_meta *meta = nftnl_expr_data(e);
114 struct nlattr *tb[NFTA_META_MAX+1] = {};
115
116 if (mnl_attr_parse_nested(attr, nftnl_expr_meta_cb, tb) < 0)
117 return -1;
118
119 if (tb[NFTA_META_KEY]) {
120 meta->key = ntohl(mnl_attr_get_u32(tb[NFTA_META_KEY]));
121 e->flags |= (1 << NFTNL_EXPR_META_KEY);
122 }
123 if (tb[NFTA_META_DREG]) {
124 meta->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_META_DREG]));
125 e->flags |= (1 << NFTNL_EXPR_META_DREG);
126 }
127 if (tb[NFTA_META_SREG]) {
128 meta->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_META_SREG]));
129 e->flags |= (1 << NFTNL_EXPR_META_SREG);
130 }
131
132 return 0;
133}
134
135static const char *meta_key2str_array[NFT_META_MAX] = {
136 [NFT_META_LEN] = "len",
137 [NFT_META_PROTOCOL] = "protocol",
138 [NFT_META_NFPROTO] = "nfproto",
139 [NFT_META_L4PROTO] = "l4proto",
140 [NFT_META_PRIORITY] = "priority",
141 [NFT_META_MARK] = "mark",
142 [NFT_META_IIF] = "iif",
143 [NFT_META_OIF] = "oif",
144 [NFT_META_IIFNAME] = "iifname",
145 [NFT_META_OIFNAME] = "oifname",
146 [NFT_META_IIFTYPE] = "iiftype",
147 [NFT_META_OIFTYPE] = "oiftype",
148 [NFT_META_SKUID] = "skuid",
149 [NFT_META_SKGID] = "skgid",
150 [NFT_META_NFTRACE] = "nftrace",
151 [NFT_META_RTCLASSID] = "rtclassid",
152 [NFT_META_SECMARK] = "secmark",
153 [NFT_META_BRI_IIFNAME] = "bri_iifname",
154 [NFT_META_BRI_OIFNAME] = "bri_oifname",
155 [NFT_META_PKTTYPE] = "pkttype",
156 [NFT_META_CPU] = "cpu",
157 [NFT_META_IIFGROUP] = "iifgroup",
158 [NFT_META_OIFGROUP] = "oifgroup",
159 [NFT_META_CGROUP] = "cgroup",
160 [NFT_META_PRANDOM] = "prandom",
161 [NFT_META_SECPATH] = "secpath",
162 [NFT_META_IIFKIND] = "iifkind",
163 [NFT_META_OIFKIND] = "oifkind",
164 [NFT_META_BRI_IIFPVID] = "bri_iifpvid",
165 [NFT_META_BRI_IIFVPROTO] = "bri_iifvproto",
166 [NFT_META_TIME_NS] = "time",
167 [NFT_META_TIME_DAY] = "day",
168 [NFT_META_TIME_HOUR] = "hour",
169 [NFT_META_SDIF] = "sdif",
170 [NFT_META_SDIFNAME] = "sdifname",
171 [NFT_META_BRI_BROUTE] = "broute",
172};
173
174static const char *meta_key2str(uint8_t key)
175{
176 if (key < NFT_META_MAX)
177 return meta_key2str_array[key];
178
179 return "unknown";
180}
181
182static inline int str2meta_key(const char *str)
183{
184 int i;
185
186 for (i = 0; i < NFT_META_MAX; i++) {
187 if (strcmp(str, meta_key2str_array[i]) == 0)
188 return i;
189 }
190
191 errno = EINVAL;
192 return -1;
193}
194
195static int
196nftnl_expr_meta_snprintf(char *buf, size_t len,
197 uint32_t flags, const struct nftnl_expr *e)
198{
199 struct nftnl_expr_meta *meta = nftnl_expr_data(e);
200
201 if (e->flags & (1 << NFTNL_EXPR_META_SREG)) {
202 return snprintf(buf, len, "set %s with reg %u ",
203 meta_key2str(meta->key), meta->sreg);
204 }
205 if (e->flags & (1 << NFTNL_EXPR_META_DREG)) {
206 return snprintf(buf, len, "load %s => reg %u ",
207 meta_key2str(meta->key), meta->dreg);
208 }
209 return 0;
210}
211
212struct expr_ops expr_ops_meta = {
213 .name = "meta",
214 .alloc_len = sizeof(struct nftnl_expr_meta),
215 .max_attr = NFTA_META_MAX,
216 .set = nftnl_expr_meta_set,
217 .get = nftnl_expr_meta_get,
218 .parse = nftnl_expr_meta_parse,
219 .build = nftnl_expr_meta_build,
220 .output = nftnl_expr_meta_snprintf,
221};