libnftnl 1.2.6
ct.c
1/*
2 * (C) 2012-2013 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 <string.h>
14#include <stdint.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
25 enum nft_ct_keys key;
26 enum nft_registers dreg;
27 enum nft_registers sreg;
28 uint8_t dir;
29};
30
31#define IP_CT_DIR_ORIGINAL 0
32#define IP_CT_DIR_REPLY 1
33
34static int
35nftnl_expr_ct_set(struct nftnl_expr *e, uint16_t type,
36 const void *data, uint32_t data_len)
37{
38 struct nftnl_expr_ct *ct = nftnl_expr_data(e);
39
40 switch(type) {
41 case NFTNL_EXPR_CT_KEY:
42 memcpy(&ct->key, data, sizeof(ct->key));
43 break;
44 case NFTNL_EXPR_CT_DIR:
45 memcpy(&ct->dir, data, sizeof(ct->dir));
46 break;
47 case NFTNL_EXPR_CT_DREG:
48 memcpy(&ct->dreg, data, sizeof(ct->dreg));
49 break;
50 case NFTNL_EXPR_CT_SREG:
51 memcpy(&ct->sreg, data, sizeof(ct->sreg));
52 break;
53 default:
54 return -1;
55 }
56 return 0;
57}
58
59static const void *
60nftnl_expr_ct_get(const struct nftnl_expr *e, uint16_t type,
61 uint32_t *data_len)
62{
63 struct nftnl_expr_ct *ct = nftnl_expr_data(e);
64
65 switch(type) {
66 case NFTNL_EXPR_CT_KEY:
67 *data_len = sizeof(ct->key);
68 return &ct->key;
69 case NFTNL_EXPR_CT_DIR:
70 *data_len = sizeof(ct->dir);
71 return &ct->dir;
72 case NFTNL_EXPR_CT_DREG:
73 *data_len = sizeof(ct->dreg);
74 return &ct->dreg;
75 case NFTNL_EXPR_CT_SREG:
76 *data_len = sizeof(ct->sreg);
77 return &ct->sreg;
78 }
79 return NULL;
80}
81
82static int nftnl_expr_ct_cb(const struct nlattr *attr, void *data)
83{
84 const struct nlattr **tb = data;
85 int type = mnl_attr_get_type(attr);
86
87 if (mnl_attr_type_valid(attr, NFTA_CT_MAX) < 0)
88 return MNL_CB_OK;
89
90 switch(type) {
91 case NFTA_CT_KEY:
92 case NFTA_CT_DREG:
93 case NFTA_CT_SREG:
94 if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
95 abi_breakage();
96 break;
97 case NFTA_CT_DIRECTION:
98 if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
99 abi_breakage();
100 break;
101 }
102
103 tb[type] = attr;
104 return MNL_CB_OK;
105}
106
107static void
108nftnl_expr_ct_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
109{
110 struct nftnl_expr_ct *ct = nftnl_expr_data(e);
111
112 if (e->flags & (1 << NFTNL_EXPR_CT_KEY))
113 mnl_attr_put_u32(nlh, NFTA_CT_KEY, htonl(ct->key));
114 if (e->flags & (1 << NFTNL_EXPR_CT_DREG))
115 mnl_attr_put_u32(nlh, NFTA_CT_DREG, htonl(ct->dreg));
116 if (e->flags & (1 << NFTNL_EXPR_CT_DIR))
117 mnl_attr_put_u8(nlh, NFTA_CT_DIRECTION, ct->dir);
118 if (e->flags & (1 << NFTNL_EXPR_CT_SREG))
119 mnl_attr_put_u32(nlh, NFTA_CT_SREG, htonl(ct->sreg));
120}
121
122static int
123nftnl_expr_ct_parse(struct nftnl_expr *e, struct nlattr *attr)
124{
125 struct nftnl_expr_ct *ct = nftnl_expr_data(e);
126 struct nlattr *tb[NFTA_CT_MAX+1] = {};
127
128 if (mnl_attr_parse_nested(attr, nftnl_expr_ct_cb, tb) < 0)
129 return -1;
130
131 if (tb[NFTA_CT_KEY]) {
132 ct->key = ntohl(mnl_attr_get_u32(tb[NFTA_CT_KEY]));
133 e->flags |= (1 << NFTNL_EXPR_CT_KEY);
134 }
135 if (tb[NFTA_CT_DREG]) {
136 ct->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_DREG]));
137 e->flags |= (1 << NFTNL_EXPR_CT_DREG);
138 }
139 if (tb[NFTA_CT_SREG]) {
140 ct->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_SREG]));
141 e->flags |= (1 << NFTNL_EXPR_CT_SREG);
142 }
143 if (tb[NFTA_CT_DIRECTION]) {
144 ct->dir = mnl_attr_get_u8(tb[NFTA_CT_DIRECTION]);
145 e->flags |= (1 << NFTNL_EXPR_CT_DIR);
146 }
147
148 return 0;
149}
150
151static const char *ctkey2str_array[NFT_CT_MAX + 1] = {
152 [NFT_CT_STATE] = "state",
153 [NFT_CT_DIRECTION] = "direction",
154 [NFT_CT_STATUS] = "status",
155 [NFT_CT_MARK] = "mark",
156 [NFT_CT_SECMARK] = "secmark",
157 [NFT_CT_EXPIRATION] = "expiration",
158 [NFT_CT_HELPER] = "helper",
159 [NFT_CT_L3PROTOCOL] = "l3protocol",
160 [NFT_CT_PROTOCOL] = "protocol",
161 [NFT_CT_SRC] = "src",
162 [NFT_CT_DST] = "dst",
163 [NFT_CT_PROTO_SRC] = "proto_src",
164 [NFT_CT_PROTO_DST] = "proto_dst",
165 [NFT_CT_LABELS] = "label",
166 [NFT_CT_PKTS] = "packets",
167 [NFT_CT_BYTES] = "bytes",
168 [NFT_CT_AVGPKT] = "avgpkt",
169 [NFT_CT_ZONE] = "zone",
170 [NFT_CT_EVENTMASK] = "event",
171 [NFT_CT_SRC_IP] = "src_ip",
172 [NFT_CT_DST_IP] = "dst_ip",
173 [NFT_CT_SRC_IP6] = "src_ip6",
174 [NFT_CT_DST_IP6] = "dst_ip6",
175 [NFT_CT_ID] = "id",
176};
177
178static const char *ctkey2str(uint32_t ctkey)
179{
180 if (ctkey >= NFT_CT_MAX)
181 return "unknown";
182
183 return ctkey2str_array[ctkey];
184}
185
186static inline int str2ctkey(const char *ctkey)
187{
188 int i;
189
190 for (i = 0; i < NFT_CT_MAX; i++) {
191 if (strcmp(ctkey2str_array[i], ctkey) == 0)
192 return i;
193 }
194
195 return -1;
196}
197
198static const char *ctdir2str(uint8_t ctdir)
199{
200 switch (ctdir) {
201 case IP_CT_DIR_ORIGINAL:
202 return "original";
203 case IP_CT_DIR_REPLY:
204 return "reply";
205 default:
206 return "unknown";
207 }
208}
209
210static inline int str2ctdir(const char *str, uint8_t *ctdir)
211{
212 if (strcmp(str, "original") == 0) {
213 *ctdir = IP_CT_DIR_ORIGINAL;
214 return 0;
215 }
216
217 if (strcmp(str, "reply") == 0) {
218 *ctdir = IP_CT_DIR_REPLY;
219 return 0;
220 }
221
222 return -1;
223}
224
225static int
226nftnl_expr_ct_snprintf(char *buf, size_t remain,
227 uint32_t flags, const struct nftnl_expr *e)
228{
229 struct nftnl_expr_ct *ct = nftnl_expr_data(e);
230 int ret, offset = 0;
231
232 if (e->flags & (1 << NFTNL_EXPR_CT_SREG)) {
233 ret = snprintf(buf, remain, "set %s with reg %u ",
234 ctkey2str(ct->key), ct->sreg);
235 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
236 }
237
238 if (e->flags & (1 << NFTNL_EXPR_CT_DREG)) {
239 ret = snprintf(buf, remain, "load %s => reg %u ",
240 ctkey2str(ct->key), ct->dreg);
241 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
242 }
243
244 if (nftnl_expr_is_set(e, NFTNL_EXPR_CT_DIR)) {
245 ret = snprintf(buf + offset, remain, ", dir %s ",
246 ctdir2str(ct->dir));
247 SNPRINTF_BUFFER_SIZE(ret, remain, offset);
248 }
249
250 return offset;
251}
252
253struct expr_ops expr_ops_ct = {
254 .name = "ct",
255 .alloc_len = sizeof(struct nftnl_expr_ct),
256 .max_attr = NFTA_CT_MAX,
257 .set = nftnl_expr_ct_set,
258 .get = nftnl_expr_ct_get,
259 .parse = nftnl_expr_ct_parse,
260 .build = nftnl_expr_ct_build,
261 .output = nftnl_expr_ct_snprintf,
262};