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1 | /* | |
2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> | |
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 version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/netfilter/nf_tables.h> | |
17 | #include <net/netfilter/nf_tables.h> | |
18 | #include <net/netfilter/nf_conntrack.h> | |
19 | #include <net/netfilter/nf_conntrack_tuple.h> | |
20 | #include <net/netfilter/nf_conntrack_helper.h> | |
21 | #include <net/netfilter/nf_conntrack_ecache.h> | |
22 | ||
23 | struct nft_ct { | |
24 | enum nft_ct_keys key:8; | |
25 | enum ip_conntrack_dir dir:8; | |
26 | union{ | |
27 | enum nft_registers dreg:8; | |
28 | enum nft_registers sreg:8; | |
29 | }; | |
30 | uint8_t family; | |
31 | }; | |
32 | ||
33 | static void nft_ct_get_eval(const struct nft_expr *expr, | |
34 | struct nft_data data[NFT_REG_MAX + 1], | |
35 | const struct nft_pktinfo *pkt) | |
36 | { | |
37 | const struct nft_ct *priv = nft_expr_priv(expr); | |
38 | struct nft_data *dest = &data[priv->dreg]; | |
39 | enum ip_conntrack_info ctinfo; | |
40 | const struct nf_conn *ct; | |
41 | const struct nf_conn_help *help; | |
42 | const struct nf_conntrack_tuple *tuple; | |
43 | const struct nf_conntrack_helper *helper; | |
44 | long diff; | |
45 | unsigned int state; | |
46 | ||
47 | ct = nf_ct_get(pkt->skb, &ctinfo); | |
48 | ||
49 | switch (priv->key) { | |
50 | case NFT_CT_STATE: | |
51 | if (ct == NULL) | |
52 | state = NF_CT_STATE_INVALID_BIT; | |
53 | else if (nf_ct_is_untracked(ct)) | |
54 | state = NF_CT_STATE_UNTRACKED_BIT; | |
55 | else | |
56 | state = NF_CT_STATE_BIT(ctinfo); | |
57 | dest->data[0] = state; | |
58 | return; | |
59 | } | |
60 | ||
61 | if (ct == NULL) | |
62 | goto err; | |
63 | ||
64 | switch (priv->key) { | |
65 | case NFT_CT_DIRECTION: | |
66 | dest->data[0] = CTINFO2DIR(ctinfo); | |
67 | return; | |
68 | case NFT_CT_STATUS: | |
69 | dest->data[0] = ct->status; | |
70 | return; | |
71 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
72 | case NFT_CT_MARK: | |
73 | dest->data[0] = ct->mark; | |
74 | return; | |
75 | #endif | |
76 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
77 | case NFT_CT_SECMARK: | |
78 | dest->data[0] = ct->secmark; | |
79 | return; | |
80 | #endif | |
81 | case NFT_CT_EXPIRATION: | |
82 | diff = (long)jiffies - (long)ct->timeout.expires; | |
83 | if (diff < 0) | |
84 | diff = 0; | |
85 | dest->data[0] = jiffies_to_msecs(diff); | |
86 | return; | |
87 | case NFT_CT_HELPER: | |
88 | if (ct->master == NULL) | |
89 | goto err; | |
90 | help = nfct_help(ct->master); | |
91 | if (help == NULL) | |
92 | goto err; | |
93 | helper = rcu_dereference(help->helper); | |
94 | if (helper == NULL) | |
95 | goto err; | |
96 | if (strlen(helper->name) >= sizeof(dest->data)) | |
97 | goto err; | |
98 | strncpy((char *)dest->data, helper->name, sizeof(dest->data)); | |
99 | return; | |
100 | } | |
101 | ||
102 | tuple = &ct->tuplehash[priv->dir].tuple; | |
103 | switch (priv->key) { | |
104 | case NFT_CT_L3PROTOCOL: | |
105 | dest->data[0] = nf_ct_l3num(ct); | |
106 | return; | |
107 | case NFT_CT_SRC: | |
108 | memcpy(dest->data, tuple->src.u3.all, | |
109 | nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); | |
110 | return; | |
111 | case NFT_CT_DST: | |
112 | memcpy(dest->data, tuple->dst.u3.all, | |
113 | nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); | |
114 | return; | |
115 | case NFT_CT_PROTOCOL: | |
116 | dest->data[0] = nf_ct_protonum(ct); | |
117 | return; | |
118 | case NFT_CT_PROTO_SRC: | |
119 | dest->data[0] = (__force __u16)tuple->src.u.all; | |
120 | return; | |
121 | case NFT_CT_PROTO_DST: | |
122 | dest->data[0] = (__force __u16)tuple->dst.u.all; | |
123 | return; | |
124 | } | |
125 | return; | |
126 | err: | |
127 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; | |
128 | } | |
129 | ||
130 | static void nft_ct_set_eval(const struct nft_expr *expr, | |
131 | struct nft_data data[NFT_REG_MAX + 1], | |
132 | const struct nft_pktinfo *pkt) | |
133 | { | |
134 | const struct nft_ct *priv = nft_expr_priv(expr); | |
135 | struct sk_buff *skb = pkt->skb; | |
136 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
137 | u32 value = data[priv->sreg].data[0]; | |
138 | #endif | |
139 | enum ip_conntrack_info ctinfo; | |
140 | struct nf_conn *ct; | |
141 | ||
142 | ct = nf_ct_get(skb, &ctinfo); | |
143 | if (ct == NULL) | |
144 | return; | |
145 | ||
146 | switch (priv->key) { | |
147 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
148 | case NFT_CT_MARK: | |
149 | if (ct->mark != value) { | |
150 | ct->mark = value; | |
151 | nf_conntrack_event_cache(IPCT_MARK, ct); | |
152 | } | |
153 | break; | |
154 | #endif | |
155 | } | |
156 | } | |
157 | ||
158 | static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = { | |
159 | [NFTA_CT_DREG] = { .type = NLA_U32 }, | |
160 | [NFTA_CT_KEY] = { .type = NLA_U32 }, | |
161 | [NFTA_CT_DIRECTION] = { .type = NLA_U8 }, | |
162 | [NFTA_CT_SREG] = { .type = NLA_U32 }, | |
163 | }; | |
164 | ||
165 | static int nft_ct_l3proto_try_module_get(uint8_t family) | |
166 | { | |
167 | int err; | |
168 | ||
169 | if (family == NFPROTO_INET) { | |
170 | err = nf_ct_l3proto_try_module_get(NFPROTO_IPV4); | |
171 | if (err < 0) | |
172 | goto err1; | |
173 | err = nf_ct_l3proto_try_module_get(NFPROTO_IPV6); | |
174 | if (err < 0) | |
175 | goto err2; | |
176 | } else { | |
177 | err = nf_ct_l3proto_try_module_get(family); | |
178 | if (err < 0) | |
179 | goto err1; | |
180 | } | |
181 | return 0; | |
182 | ||
183 | err2: | |
184 | nf_ct_l3proto_module_put(NFPROTO_IPV4); | |
185 | err1: | |
186 | return err; | |
187 | } | |
188 | ||
189 | static void nft_ct_l3proto_module_put(uint8_t family) | |
190 | { | |
191 | if (family == NFPROTO_INET) { | |
192 | nf_ct_l3proto_module_put(NFPROTO_IPV4); | |
193 | nf_ct_l3proto_module_put(NFPROTO_IPV6); | |
194 | } else | |
195 | nf_ct_l3proto_module_put(family); | |
196 | } | |
197 | ||
198 | static int nft_ct_init_validate_get(const struct nft_expr *expr, | |
199 | const struct nlattr * const tb[]) | |
200 | { | |
201 | struct nft_ct *priv = nft_expr_priv(expr); | |
202 | ||
203 | if (tb[NFTA_CT_DIRECTION] != NULL) { | |
204 | priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]); | |
205 | switch (priv->dir) { | |
206 | case IP_CT_DIR_ORIGINAL: | |
207 | case IP_CT_DIR_REPLY: | |
208 | break; | |
209 | default: | |
210 | return -EINVAL; | |
211 | } | |
212 | } | |
213 | ||
214 | switch (priv->key) { | |
215 | case NFT_CT_STATE: | |
216 | case NFT_CT_DIRECTION: | |
217 | case NFT_CT_STATUS: | |
218 | #ifdef CONFIG_NF_CONNTRACK_MARK | |
219 | case NFT_CT_MARK: | |
220 | #endif | |
221 | #ifdef CONFIG_NF_CONNTRACK_SECMARK | |
222 | case NFT_CT_SECMARK: | |
223 | #endif | |
224 | case NFT_CT_EXPIRATION: | |
225 | case NFT_CT_HELPER: | |
226 | if (tb[NFTA_CT_DIRECTION] != NULL) | |
227 | return -EINVAL; | |
228 | break; | |
229 | case NFT_CT_L3PROTOCOL: | |
230 | case NFT_CT_PROTOCOL: | |
231 | case NFT_CT_SRC: | |
232 | case NFT_CT_DST: | |
233 | case NFT_CT_PROTO_SRC: | |
234 | case NFT_CT_PROTO_DST: | |
235 | if (tb[NFTA_CT_DIRECTION] == NULL) | |
236 | return -EINVAL; | |
237 | break; | |
238 | default: | |
239 | return -EOPNOTSUPP; | |
240 | } | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
245 | static int nft_ct_init_validate_set(uint32_t key) | |
246 | { | |
247 | switch (key) { | |
248 | case NFT_CT_MARK: | |
249 | break; | |
250 | default: | |
251 | return -EOPNOTSUPP; | |
252 | } | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | static int nft_ct_init(const struct nft_ctx *ctx, | |
258 | const struct nft_expr *expr, | |
259 | const struct nlattr * const tb[]) | |
260 | { | |
261 | struct nft_ct *priv = nft_expr_priv(expr); | |
262 | int err; | |
263 | ||
264 | priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY])); | |
265 | ||
266 | if (tb[NFTA_CT_DREG]) { | |
267 | err = nft_ct_init_validate_get(expr, tb); | |
268 | if (err < 0) | |
269 | return err; | |
270 | ||
271 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_CT_DREG])); | |
272 | err = nft_validate_output_register(priv->dreg); | |
273 | if (err < 0) | |
274 | return err; | |
275 | ||
276 | err = nft_validate_data_load(ctx, priv->dreg, NULL, | |
277 | NFT_DATA_VALUE); | |
278 | if (err < 0) | |
279 | return err; | |
280 | } else { | |
281 | err = nft_ct_init_validate_set(priv->key); | |
282 | if (err < 0) | |
283 | return err; | |
284 | ||
285 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CT_SREG])); | |
286 | err = nft_validate_input_register(priv->sreg); | |
287 | if (err < 0) | |
288 | return err; | |
289 | } | |
290 | ||
291 | err = nft_ct_l3proto_try_module_get(ctx->afi->family); | |
292 | if (err < 0) | |
293 | return err; | |
294 | ||
295 | priv->family = ctx->afi->family; | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | static void nft_ct_destroy(const struct nft_expr *expr) | |
301 | { | |
302 | struct nft_ct *priv = nft_expr_priv(expr); | |
303 | ||
304 | nft_ct_l3proto_module_put(priv->family); | |
305 | } | |
306 | ||
307 | static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
308 | { | |
309 | const struct nft_ct *priv = nft_expr_priv(expr); | |
310 | ||
311 | if (nla_put_be32(skb, NFTA_CT_DREG, htonl(priv->dreg))) | |
312 | goto nla_put_failure; | |
313 | if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) | |
314 | goto nla_put_failure; | |
315 | ||
316 | switch (priv->key) { | |
317 | case NFT_CT_PROTOCOL: | |
318 | case NFT_CT_SRC: | |
319 | case NFT_CT_DST: | |
320 | case NFT_CT_PROTO_SRC: | |
321 | case NFT_CT_PROTO_DST: | |
322 | if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir)) | |
323 | goto nla_put_failure; | |
324 | default: | |
325 | break; | |
326 | } | |
327 | ||
328 | return 0; | |
329 | ||
330 | nla_put_failure: | |
331 | return -1; | |
332 | } | |
333 | ||
334 | static int nft_ct_set_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
335 | { | |
336 | const struct nft_ct *priv = nft_expr_priv(expr); | |
337 | ||
338 | if (nla_put_be32(skb, NFTA_CT_SREG, htonl(priv->sreg))) | |
339 | goto nla_put_failure; | |
340 | if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) | |
341 | goto nla_put_failure; | |
342 | return 0; | |
343 | ||
344 | nla_put_failure: | |
345 | return -1; | |
346 | } | |
347 | ||
348 | static struct nft_expr_type nft_ct_type; | |
349 | static const struct nft_expr_ops nft_ct_get_ops = { | |
350 | .type = &nft_ct_type, | |
351 | .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), | |
352 | .eval = nft_ct_get_eval, | |
353 | .init = nft_ct_init, | |
354 | .destroy = nft_ct_destroy, | |
355 | .dump = nft_ct_get_dump, | |
356 | }; | |
357 | ||
358 | static const struct nft_expr_ops nft_ct_set_ops = { | |
359 | .type = &nft_ct_type, | |
360 | .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), | |
361 | .eval = nft_ct_set_eval, | |
362 | .init = nft_ct_init, | |
363 | .destroy = nft_ct_destroy, | |
364 | .dump = nft_ct_set_dump, | |
365 | }; | |
366 | ||
367 | static const struct nft_expr_ops * | |
368 | nft_ct_select_ops(const struct nft_ctx *ctx, | |
369 | const struct nlattr * const tb[]) | |
370 | { | |
371 | if (tb[NFTA_CT_KEY] == NULL) | |
372 | return ERR_PTR(-EINVAL); | |
373 | ||
374 | if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG]) | |
375 | return ERR_PTR(-EINVAL); | |
376 | ||
377 | if (tb[NFTA_CT_DREG]) | |
378 | return &nft_ct_get_ops; | |
379 | ||
380 | if (tb[NFTA_CT_SREG]) | |
381 | return &nft_ct_set_ops; | |
382 | ||
383 | return ERR_PTR(-EINVAL); | |
384 | } | |
385 | ||
386 | static struct nft_expr_type nft_ct_type __read_mostly = { | |
387 | .name = "ct", | |
388 | .select_ops = &nft_ct_select_ops, | |
389 | .policy = nft_ct_policy, | |
390 | .maxattr = NFTA_CT_MAX, | |
391 | .owner = THIS_MODULE, | |
392 | }; | |
393 | ||
394 | static int __init nft_ct_module_init(void) | |
395 | { | |
396 | return nft_register_expr(&nft_ct_type); | |
397 | } | |
398 | ||
399 | static void __exit nft_ct_module_exit(void) | |
400 | { | |
401 | nft_unregister_expr(&nft_ct_type); | |
402 | } | |
403 | ||
404 | module_init(nft_ct_module_init); | |
405 | module_exit(nft_ct_module_exit); | |
406 | ||
407 | MODULE_LICENSE("GPL"); | |
408 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
409 | MODULE_ALIAS_NFT_EXPR("ct"); |