]>
Commit | Line | Data |
---|---|---|
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 version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This software has been sponsored by Sophos Astaro <http://www.sophos.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/nfnetlink.h> | |
17 | #include <linux/netfilter/nf_tables.h> | |
18 | #include <linux/netfilter/nf_tables_compat.h> | |
19 | #include <linux/netfilter/x_tables.h> | |
20 | #include <linux/netfilter_ipv4/ip_tables.h> | |
21 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
22 | #include <linux/netfilter_bridge/ebtables.h> | |
23 | #include <linux/netfilter_arp/arp_tables.h> | |
24 | #include <net/netfilter/nf_tables.h> | |
25 | ||
26 | struct nft_xt { | |
27 | struct list_head head; | |
28 | struct nft_expr_ops ops; | |
29 | unsigned int refcnt; | |
30 | }; | |
31 | ||
32 | static void nft_xt_put(struct nft_xt *xt) | |
33 | { | |
34 | if (--xt->refcnt == 0) { | |
35 | list_del(&xt->head); | |
36 | kfree(xt); | |
37 | } | |
38 | } | |
39 | ||
40 | static int nft_compat_chain_validate_dependency(const char *tablename, | |
41 | const struct nft_chain *chain) | |
42 | { | |
43 | const struct nft_base_chain *basechain; | |
44 | ||
45 | if (!tablename || !(chain->flags & NFT_BASE_CHAIN)) | |
46 | return 0; | |
47 | ||
48 | basechain = nft_base_chain(chain); | |
49 | if (strcmp(tablename, "nat") == 0 && | |
50 | basechain->type->type != NFT_CHAIN_T_NAT) | |
51 | return -EINVAL; | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | union nft_entry { | |
57 | struct ipt_entry e4; | |
58 | struct ip6t_entry e6; | |
59 | struct ebt_entry ebt; | |
60 | struct arpt_entry arp; | |
61 | }; | |
62 | ||
63 | static inline void | |
64 | nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info) | |
65 | { | |
66 | par->target = xt; | |
67 | par->targinfo = xt_info; | |
68 | par->hotdrop = false; | |
69 | } | |
70 | ||
71 | static void nft_target_eval_xt(const struct nft_expr *expr, | |
72 | struct nft_regs *regs, | |
73 | const struct nft_pktinfo *pkt) | |
74 | { | |
75 | void *info = nft_expr_priv(expr); | |
76 | struct xt_target *target = expr->ops->data; | |
77 | struct sk_buff *skb = pkt->skb; | |
78 | int ret; | |
79 | ||
80 | nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info); | |
81 | ||
82 | ret = target->target(skb, &pkt->xt); | |
83 | ||
84 | if (pkt->xt.hotdrop) | |
85 | ret = NF_DROP; | |
86 | ||
87 | switch (ret) { | |
88 | case XT_CONTINUE: | |
89 | regs->verdict.code = NFT_CONTINUE; | |
90 | break; | |
91 | default: | |
92 | regs->verdict.code = ret; | |
93 | break; | |
94 | } | |
95 | } | |
96 | ||
97 | static void nft_target_eval_bridge(const struct nft_expr *expr, | |
98 | struct nft_regs *regs, | |
99 | const struct nft_pktinfo *pkt) | |
100 | { | |
101 | void *info = nft_expr_priv(expr); | |
102 | struct xt_target *target = expr->ops->data; | |
103 | struct sk_buff *skb = pkt->skb; | |
104 | int ret; | |
105 | ||
106 | nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info); | |
107 | ||
108 | ret = target->target(skb, &pkt->xt); | |
109 | ||
110 | if (pkt->xt.hotdrop) | |
111 | ret = NF_DROP; | |
112 | ||
113 | switch (ret) { | |
114 | case EBT_ACCEPT: | |
115 | regs->verdict.code = NF_ACCEPT; | |
116 | break; | |
117 | case EBT_DROP: | |
118 | regs->verdict.code = NF_DROP; | |
119 | break; | |
120 | case EBT_CONTINUE: | |
121 | regs->verdict.code = NFT_CONTINUE; | |
122 | break; | |
123 | case EBT_RETURN: | |
124 | regs->verdict.code = NFT_RETURN; | |
125 | break; | |
126 | default: | |
127 | regs->verdict.code = ret; | |
128 | break; | |
129 | } | |
130 | } | |
131 | ||
132 | static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = { | |
133 | [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING }, | |
134 | [NFTA_TARGET_REV] = { .type = NLA_U32 }, | |
135 | [NFTA_TARGET_INFO] = { .type = NLA_BINARY }, | |
136 | }; | |
137 | ||
138 | static void | |
139 | nft_target_set_tgchk_param(struct xt_tgchk_param *par, | |
140 | const struct nft_ctx *ctx, | |
141 | struct xt_target *target, void *info, | |
142 | union nft_entry *entry, u16 proto, bool inv) | |
143 | { | |
144 | par->net = ctx->net; | |
145 | par->table = ctx->table->name; | |
146 | switch (ctx->afi->family) { | |
147 | case AF_INET: | |
148 | entry->e4.ip.proto = proto; | |
149 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; | |
150 | break; | |
151 | case AF_INET6: | |
152 | if (proto) | |
153 | entry->e6.ipv6.flags |= IP6T_F_PROTO; | |
154 | ||
155 | entry->e6.ipv6.proto = proto; | |
156 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; | |
157 | break; | |
158 | case NFPROTO_BRIDGE: | |
159 | entry->ebt.ethproto = (__force __be16)proto; | |
160 | entry->ebt.invflags = inv ? EBT_IPROTO : 0; | |
161 | break; | |
162 | case NFPROTO_ARP: | |
163 | break; | |
164 | } | |
165 | par->entryinfo = entry; | |
166 | par->target = target; | |
167 | par->targinfo = info; | |
168 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
169 | const struct nft_base_chain *basechain = | |
170 | nft_base_chain(ctx->chain); | |
171 | const struct nf_hook_ops *ops = &basechain->ops[0]; | |
172 | ||
173 | par->hook_mask = 1 << ops->hooknum; | |
174 | } else { | |
175 | par->hook_mask = 0; | |
176 | } | |
177 | par->family = ctx->afi->family; | |
178 | par->nft_compat = true; | |
179 | } | |
180 | ||
181 | static void target_compat_from_user(struct xt_target *t, void *in, void *out) | |
182 | { | |
183 | int pad; | |
184 | ||
185 | memcpy(out, in, t->targetsize); | |
186 | pad = XT_ALIGN(t->targetsize) - t->targetsize; | |
187 | if (pad > 0) | |
188 | memset(out + t->targetsize, 0, pad); | |
189 | } | |
190 | ||
191 | static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = { | |
192 | [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 }, | |
193 | [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, | |
194 | }; | |
195 | ||
196 | static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) | |
197 | { | |
198 | struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; | |
199 | u32 flags; | |
200 | int err; | |
201 | ||
202 | err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr, | |
203 | nft_rule_compat_policy); | |
204 | if (err < 0) | |
205 | return err; | |
206 | ||
207 | if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS]) | |
208 | return -EINVAL; | |
209 | ||
210 | flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS])); | |
211 | if (flags & ~NFT_RULE_COMPAT_F_MASK) | |
212 | return -EINVAL; | |
213 | if (flags & NFT_RULE_COMPAT_F_INV) | |
214 | *inv = true; | |
215 | ||
216 | *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static int | |
221 | nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
222 | const struct nlattr * const tb[]) | |
223 | { | |
224 | void *info = nft_expr_priv(expr); | |
225 | struct xt_target *target = expr->ops->data; | |
226 | struct xt_tgchk_param par; | |
227 | size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO])); | |
228 | u16 proto = 0; | |
229 | bool inv = false; | |
230 | union nft_entry e = {}; | |
231 | int ret; | |
232 | ||
233 | ret = nft_compat_chain_validate_dependency(target->table, ctx->chain); | |
234 | if (ret < 0) | |
235 | goto err; | |
236 | ||
237 | target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info); | |
238 | ||
239 | if (ctx->nla[NFTA_RULE_COMPAT]) { | |
240 | ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); | |
241 | if (ret < 0) | |
242 | goto err; | |
243 | } | |
244 | ||
245 | nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv); | |
246 | ||
247 | ret = xt_check_target(&par, size, proto, inv); | |
248 | if (ret < 0) | |
249 | goto err; | |
250 | ||
251 | /* The standard target cannot be used */ | |
252 | if (target->target == NULL) { | |
253 | ret = -EINVAL; | |
254 | goto err; | |
255 | } | |
256 | ||
257 | return 0; | |
258 | err: | |
259 | module_put(target->me); | |
260 | return ret; | |
261 | } | |
262 | ||
263 | static void | |
264 | nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) | |
265 | { | |
266 | struct xt_target *target = expr->ops->data; | |
267 | void *info = nft_expr_priv(expr); | |
268 | struct xt_tgdtor_param par; | |
269 | ||
270 | par.net = ctx->net; | |
271 | par.target = target; | |
272 | par.targinfo = info; | |
273 | par.family = ctx->afi->family; | |
274 | if (par.target->destroy != NULL) | |
275 | par.target->destroy(&par); | |
276 | ||
277 | nft_xt_put(container_of(expr->ops, struct nft_xt, ops)); | |
278 | module_put(target->me); | |
279 | } | |
280 | ||
281 | static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
282 | { | |
283 | const struct xt_target *target = expr->ops->data; | |
284 | void *info = nft_expr_priv(expr); | |
285 | ||
286 | if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) || | |
287 | nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) || | |
288 | nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info)) | |
289 | goto nla_put_failure; | |
290 | ||
291 | return 0; | |
292 | ||
293 | nla_put_failure: | |
294 | return -1; | |
295 | } | |
296 | ||
297 | static int nft_target_validate(const struct nft_ctx *ctx, | |
298 | const struct nft_expr *expr, | |
299 | const struct nft_data **data) | |
300 | { | |
301 | struct xt_target *target = expr->ops->data; | |
302 | unsigned int hook_mask = 0; | |
303 | int ret; | |
304 | ||
305 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
306 | const struct nft_base_chain *basechain = | |
307 | nft_base_chain(ctx->chain); | |
308 | const struct nf_hook_ops *ops = &basechain->ops[0]; | |
309 | ||
310 | hook_mask = 1 << ops->hooknum; | |
311 | if (!(hook_mask & target->hooks)) | |
312 | return -EINVAL; | |
313 | ||
314 | ret = nft_compat_chain_validate_dependency(target->table, | |
315 | ctx->chain); | |
316 | if (ret < 0) | |
317 | return ret; | |
318 | } | |
319 | return 0; | |
320 | } | |
321 | ||
322 | static void nft_match_eval(const struct nft_expr *expr, | |
323 | struct nft_regs *regs, | |
324 | const struct nft_pktinfo *pkt) | |
325 | { | |
326 | void *info = nft_expr_priv(expr); | |
327 | struct xt_match *match = expr->ops->data; | |
328 | struct sk_buff *skb = pkt->skb; | |
329 | bool ret; | |
330 | ||
331 | nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info); | |
332 | ||
333 | ret = match->match(skb, (struct xt_action_param *)&pkt->xt); | |
334 | ||
335 | if (pkt->xt.hotdrop) { | |
336 | regs->verdict.code = NF_DROP; | |
337 | return; | |
338 | } | |
339 | ||
340 | switch (ret ? 1 : 0) { | |
341 | case 1: | |
342 | regs->verdict.code = NFT_CONTINUE; | |
343 | break; | |
344 | case 0: | |
345 | regs->verdict.code = NFT_BREAK; | |
346 | break; | |
347 | } | |
348 | } | |
349 | ||
350 | static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = { | |
351 | [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING }, | |
352 | [NFTA_MATCH_REV] = { .type = NLA_U32 }, | |
353 | [NFTA_MATCH_INFO] = { .type = NLA_BINARY }, | |
354 | }; | |
355 | ||
356 | /* struct xt_mtchk_param and xt_tgchk_param look very similar */ | |
357 | static void | |
358 | nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx, | |
359 | struct xt_match *match, void *info, | |
360 | union nft_entry *entry, u16 proto, bool inv) | |
361 | { | |
362 | par->net = ctx->net; | |
363 | par->table = ctx->table->name; | |
364 | switch (ctx->afi->family) { | |
365 | case AF_INET: | |
366 | entry->e4.ip.proto = proto; | |
367 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; | |
368 | break; | |
369 | case AF_INET6: | |
370 | if (proto) | |
371 | entry->e6.ipv6.flags |= IP6T_F_PROTO; | |
372 | ||
373 | entry->e6.ipv6.proto = proto; | |
374 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; | |
375 | break; | |
376 | case NFPROTO_BRIDGE: | |
377 | entry->ebt.ethproto = (__force __be16)proto; | |
378 | entry->ebt.invflags = inv ? EBT_IPROTO : 0; | |
379 | break; | |
380 | case NFPROTO_ARP: | |
381 | break; | |
382 | } | |
383 | par->entryinfo = entry; | |
384 | par->match = match; | |
385 | par->matchinfo = info; | |
386 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
387 | const struct nft_base_chain *basechain = | |
388 | nft_base_chain(ctx->chain); | |
389 | const struct nf_hook_ops *ops = &basechain->ops[0]; | |
390 | ||
391 | par->hook_mask = 1 << ops->hooknum; | |
392 | } else { | |
393 | par->hook_mask = 0; | |
394 | } | |
395 | par->family = ctx->afi->family; | |
396 | par->nft_compat = true; | |
397 | } | |
398 | ||
399 | static void match_compat_from_user(struct xt_match *m, void *in, void *out) | |
400 | { | |
401 | int pad; | |
402 | ||
403 | memcpy(out, in, m->matchsize); | |
404 | pad = XT_ALIGN(m->matchsize) - m->matchsize; | |
405 | if (pad > 0) | |
406 | memset(out + m->matchsize, 0, pad); | |
407 | } | |
408 | ||
409 | static int | |
410 | nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
411 | const struct nlattr * const tb[]) | |
412 | { | |
413 | void *info = nft_expr_priv(expr); | |
414 | struct xt_match *match = expr->ops->data; | |
415 | struct xt_mtchk_param par; | |
416 | size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO])); | |
417 | u16 proto = 0; | |
418 | bool inv = false; | |
419 | union nft_entry e = {}; | |
420 | int ret; | |
421 | ||
422 | ret = nft_compat_chain_validate_dependency(match->table, ctx->chain); | |
423 | if (ret < 0) | |
424 | goto err; | |
425 | ||
426 | match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info); | |
427 | ||
428 | if (ctx->nla[NFTA_RULE_COMPAT]) { | |
429 | ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); | |
430 | if (ret < 0) | |
431 | goto err; | |
432 | } | |
433 | ||
434 | nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv); | |
435 | ||
436 | ret = xt_check_match(&par, size, proto, inv); | |
437 | if (ret < 0) | |
438 | goto err; | |
439 | ||
440 | return 0; | |
441 | err: | |
442 | module_put(match->me); | |
443 | return ret; | |
444 | } | |
445 | ||
446 | static void | |
447 | nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) | |
448 | { | |
449 | struct xt_match *match = expr->ops->data; | |
450 | void *info = nft_expr_priv(expr); | |
451 | struct xt_mtdtor_param par; | |
452 | ||
453 | par.net = ctx->net; | |
454 | par.match = match; | |
455 | par.matchinfo = info; | |
456 | par.family = ctx->afi->family; | |
457 | if (par.match->destroy != NULL) | |
458 | par.match->destroy(&par); | |
459 | ||
460 | nft_xt_put(container_of(expr->ops, struct nft_xt, ops)); | |
461 | module_put(match->me); | |
462 | } | |
463 | ||
464 | static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
465 | { | |
466 | void *info = nft_expr_priv(expr); | |
467 | struct xt_match *match = expr->ops->data; | |
468 | ||
469 | if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) || | |
470 | nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) || | |
471 | nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info)) | |
472 | goto nla_put_failure; | |
473 | ||
474 | return 0; | |
475 | ||
476 | nla_put_failure: | |
477 | return -1; | |
478 | } | |
479 | ||
480 | static int nft_match_validate(const struct nft_ctx *ctx, | |
481 | const struct nft_expr *expr, | |
482 | const struct nft_data **data) | |
483 | { | |
484 | struct xt_match *match = expr->ops->data; | |
485 | unsigned int hook_mask = 0; | |
486 | int ret; | |
487 | ||
488 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
489 | const struct nft_base_chain *basechain = | |
490 | nft_base_chain(ctx->chain); | |
491 | const struct nf_hook_ops *ops = &basechain->ops[0]; | |
492 | ||
493 | hook_mask = 1 << ops->hooknum; | |
494 | if (!(hook_mask & match->hooks)) | |
495 | return -EINVAL; | |
496 | ||
497 | ret = nft_compat_chain_validate_dependency(match->table, | |
498 | ctx->chain); | |
499 | if (ret < 0) | |
500 | return ret; | |
501 | } | |
502 | return 0; | |
503 | } | |
504 | ||
505 | static int | |
506 | nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, | |
507 | int event, u16 family, const char *name, | |
508 | int rev, int target) | |
509 | { | |
510 | struct nlmsghdr *nlh; | |
511 | struct nfgenmsg *nfmsg; | |
512 | unsigned int flags = portid ? NLM_F_MULTI : 0; | |
513 | ||
514 | event |= NFNL_SUBSYS_NFT_COMPAT << 8; | |
515 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); | |
516 | if (nlh == NULL) | |
517 | goto nlmsg_failure; | |
518 | ||
519 | nfmsg = nlmsg_data(nlh); | |
520 | nfmsg->nfgen_family = family; | |
521 | nfmsg->version = NFNETLINK_V0; | |
522 | nfmsg->res_id = 0; | |
523 | ||
524 | if (nla_put_string(skb, NFTA_COMPAT_NAME, name) || | |
525 | nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) || | |
526 | nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target))) | |
527 | goto nla_put_failure; | |
528 | ||
529 | nlmsg_end(skb, nlh); | |
530 | return skb->len; | |
531 | ||
532 | nlmsg_failure: | |
533 | nla_put_failure: | |
534 | nlmsg_cancel(skb, nlh); | |
535 | return -1; | |
536 | } | |
537 | ||
538 | static int nfnl_compat_get(struct net *net, struct sock *nfnl, | |
539 | struct sk_buff *skb, const struct nlmsghdr *nlh, | |
540 | const struct nlattr * const tb[]) | |
541 | { | |
542 | int ret = 0, target; | |
543 | struct nfgenmsg *nfmsg; | |
544 | const char *fmt; | |
545 | const char *name; | |
546 | u32 rev; | |
547 | struct sk_buff *skb2; | |
548 | ||
549 | if (tb[NFTA_COMPAT_NAME] == NULL || | |
550 | tb[NFTA_COMPAT_REV] == NULL || | |
551 | tb[NFTA_COMPAT_TYPE] == NULL) | |
552 | return -EINVAL; | |
553 | ||
554 | name = nla_data(tb[NFTA_COMPAT_NAME]); | |
555 | rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV])); | |
556 | target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE])); | |
557 | ||
558 | nfmsg = nlmsg_data(nlh); | |
559 | ||
560 | switch(nfmsg->nfgen_family) { | |
561 | case AF_INET: | |
562 | fmt = "ipt_%s"; | |
563 | break; | |
564 | case AF_INET6: | |
565 | fmt = "ip6t_%s"; | |
566 | break; | |
567 | case NFPROTO_BRIDGE: | |
568 | fmt = "ebt_%s"; | |
569 | break; | |
570 | case NFPROTO_ARP: | |
571 | fmt = "arpt_%s"; | |
572 | break; | |
573 | default: | |
574 | pr_err("nft_compat: unsupported protocol %d\n", | |
575 | nfmsg->nfgen_family); | |
576 | return -EINVAL; | |
577 | } | |
578 | ||
579 | try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name, | |
580 | rev, target, &ret), | |
581 | fmt, name); | |
582 | ||
583 | if (ret < 0) | |
584 | return ret; | |
585 | ||
586 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
587 | if (skb2 == NULL) | |
588 | return -ENOMEM; | |
589 | ||
590 | /* include the best revision for this extension in the message */ | |
591 | if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid, | |
592 | nlh->nlmsg_seq, | |
593 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
594 | NFNL_MSG_COMPAT_GET, | |
595 | nfmsg->nfgen_family, | |
596 | name, ret, target) <= 0) { | |
597 | kfree_skb(skb2); | |
598 | return -ENOSPC; | |
599 | } | |
600 | ||
601 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, | |
602 | MSG_DONTWAIT); | |
603 | if (ret > 0) | |
604 | ret = 0; | |
605 | ||
606 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
607 | } | |
608 | ||
609 | static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { | |
610 | [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING, | |
611 | .len = NFT_COMPAT_NAME_MAX-1 }, | |
612 | [NFTA_COMPAT_REV] = { .type = NLA_U32 }, | |
613 | [NFTA_COMPAT_TYPE] = { .type = NLA_U32 }, | |
614 | }; | |
615 | ||
616 | static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = { | |
617 | [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get, | |
618 | .attr_count = NFTA_COMPAT_MAX, | |
619 | .policy = nfnl_compat_policy_get }, | |
620 | }; | |
621 | ||
622 | static const struct nfnetlink_subsystem nfnl_compat_subsys = { | |
623 | .name = "nft-compat", | |
624 | .subsys_id = NFNL_SUBSYS_NFT_COMPAT, | |
625 | .cb_count = NFNL_MSG_COMPAT_MAX, | |
626 | .cb = nfnl_nft_compat_cb, | |
627 | }; | |
628 | ||
629 | static LIST_HEAD(nft_match_list); | |
630 | ||
631 | static struct nft_expr_type nft_match_type; | |
632 | ||
633 | static bool nft_match_cmp(const struct xt_match *match, | |
634 | const char *name, u32 rev, u32 family) | |
635 | { | |
636 | return strcmp(match->name, name) == 0 && match->revision == rev && | |
637 | (match->family == NFPROTO_UNSPEC || match->family == family); | |
638 | } | |
639 | ||
640 | static const struct nft_expr_ops * | |
641 | nft_match_select_ops(const struct nft_ctx *ctx, | |
642 | const struct nlattr * const tb[]) | |
643 | { | |
644 | struct nft_xt *nft_match; | |
645 | struct xt_match *match; | |
646 | char *mt_name; | |
647 | u32 rev, family; | |
648 | int err; | |
649 | ||
650 | if (tb[NFTA_MATCH_NAME] == NULL || | |
651 | tb[NFTA_MATCH_REV] == NULL || | |
652 | tb[NFTA_MATCH_INFO] == NULL) | |
653 | return ERR_PTR(-EINVAL); | |
654 | ||
655 | mt_name = nla_data(tb[NFTA_MATCH_NAME]); | |
656 | rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV])); | |
657 | family = ctx->afi->family; | |
658 | ||
659 | /* Re-use the existing match if it's already loaded. */ | |
660 | list_for_each_entry(nft_match, &nft_match_list, head) { | |
661 | struct xt_match *match = nft_match->ops.data; | |
662 | ||
663 | if (nft_match_cmp(match, mt_name, rev, family)) { | |
664 | if (!try_module_get(match->me)) | |
665 | return ERR_PTR(-ENOENT); | |
666 | ||
667 | nft_match->refcnt++; | |
668 | return &nft_match->ops; | |
669 | } | |
670 | } | |
671 | ||
672 | match = xt_request_find_match(family, mt_name, rev); | |
673 | if (IS_ERR(match)) | |
674 | return ERR_PTR(-ENOENT); | |
675 | ||
676 | if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) { | |
677 | err = -EINVAL; | |
678 | goto err; | |
679 | } | |
680 | ||
681 | /* This is the first time we use this match, allocate operations */ | |
682 | nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL); | |
683 | if (nft_match == NULL) { | |
684 | err = -ENOMEM; | |
685 | goto err; | |
686 | } | |
687 | ||
688 | nft_match->refcnt = 1; | |
689 | nft_match->ops.type = &nft_match_type; | |
690 | nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize)); | |
691 | nft_match->ops.eval = nft_match_eval; | |
692 | nft_match->ops.init = nft_match_init; | |
693 | nft_match->ops.destroy = nft_match_destroy; | |
694 | nft_match->ops.dump = nft_match_dump; | |
695 | nft_match->ops.validate = nft_match_validate; | |
696 | nft_match->ops.data = match; | |
697 | ||
698 | list_add(&nft_match->head, &nft_match_list); | |
699 | ||
700 | return &nft_match->ops; | |
701 | err: | |
702 | module_put(match->me); | |
703 | return ERR_PTR(err); | |
704 | } | |
705 | ||
706 | static struct nft_expr_type nft_match_type __read_mostly = { | |
707 | .name = "match", | |
708 | .select_ops = nft_match_select_ops, | |
709 | .policy = nft_match_policy, | |
710 | .maxattr = NFTA_MATCH_MAX, | |
711 | .owner = THIS_MODULE, | |
712 | }; | |
713 | ||
714 | static LIST_HEAD(nft_target_list); | |
715 | ||
716 | static struct nft_expr_type nft_target_type; | |
717 | ||
718 | static bool nft_target_cmp(const struct xt_target *tg, | |
719 | const char *name, u32 rev, u32 family) | |
720 | { | |
721 | return strcmp(tg->name, name) == 0 && tg->revision == rev && | |
722 | (tg->family == NFPROTO_UNSPEC || tg->family == family); | |
723 | } | |
724 | ||
725 | static const struct nft_expr_ops * | |
726 | nft_target_select_ops(const struct nft_ctx *ctx, | |
727 | const struct nlattr * const tb[]) | |
728 | { | |
729 | struct nft_xt *nft_target; | |
730 | struct xt_target *target; | |
731 | char *tg_name; | |
732 | u32 rev, family; | |
733 | int err; | |
734 | ||
735 | if (tb[NFTA_TARGET_NAME] == NULL || | |
736 | tb[NFTA_TARGET_REV] == NULL || | |
737 | tb[NFTA_TARGET_INFO] == NULL) | |
738 | return ERR_PTR(-EINVAL); | |
739 | ||
740 | tg_name = nla_data(tb[NFTA_TARGET_NAME]); | |
741 | rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); | |
742 | family = ctx->afi->family; | |
743 | ||
744 | /* Re-use the existing target if it's already loaded. */ | |
745 | list_for_each_entry(nft_target, &nft_target_list, head) { | |
746 | struct xt_target *target = nft_target->ops.data; | |
747 | ||
748 | if (nft_target_cmp(target, tg_name, rev, family)) { | |
749 | if (!try_module_get(target->me)) | |
750 | return ERR_PTR(-ENOENT); | |
751 | ||
752 | nft_target->refcnt++; | |
753 | return &nft_target->ops; | |
754 | } | |
755 | } | |
756 | ||
757 | target = xt_request_find_target(family, tg_name, rev); | |
758 | if (IS_ERR(target)) | |
759 | return ERR_PTR(-ENOENT); | |
760 | ||
761 | if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) { | |
762 | err = -EINVAL; | |
763 | goto err; | |
764 | } | |
765 | ||
766 | /* This is the first time we use this target, allocate operations */ | |
767 | nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL); | |
768 | if (nft_target == NULL) { | |
769 | err = -ENOMEM; | |
770 | goto err; | |
771 | } | |
772 | ||
773 | nft_target->refcnt = 1; | |
774 | nft_target->ops.type = &nft_target_type; | |
775 | nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize)); | |
776 | nft_target->ops.init = nft_target_init; | |
777 | nft_target->ops.destroy = nft_target_destroy; | |
778 | nft_target->ops.dump = nft_target_dump; | |
779 | nft_target->ops.validate = nft_target_validate; | |
780 | nft_target->ops.data = target; | |
781 | ||
782 | if (family == NFPROTO_BRIDGE) | |
783 | nft_target->ops.eval = nft_target_eval_bridge; | |
784 | else | |
785 | nft_target->ops.eval = nft_target_eval_xt; | |
786 | ||
787 | list_add(&nft_target->head, &nft_target_list); | |
788 | ||
789 | return &nft_target->ops; | |
790 | err: | |
791 | module_put(target->me); | |
792 | return ERR_PTR(err); | |
793 | } | |
794 | ||
795 | static struct nft_expr_type nft_target_type __read_mostly = { | |
796 | .name = "target", | |
797 | .select_ops = nft_target_select_ops, | |
798 | .policy = nft_target_policy, | |
799 | .maxattr = NFTA_TARGET_MAX, | |
800 | .owner = THIS_MODULE, | |
801 | }; | |
802 | ||
803 | static int __init nft_compat_module_init(void) | |
804 | { | |
805 | int ret; | |
806 | ||
807 | ret = nft_register_expr(&nft_match_type); | |
808 | if (ret < 0) | |
809 | return ret; | |
810 | ||
811 | ret = nft_register_expr(&nft_target_type); | |
812 | if (ret < 0) | |
813 | goto err_match; | |
814 | ||
815 | ret = nfnetlink_subsys_register(&nfnl_compat_subsys); | |
816 | if (ret < 0) { | |
817 | pr_err("nft_compat: cannot register with nfnetlink.\n"); | |
818 | goto err_target; | |
819 | } | |
820 | ||
821 | pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n"); | |
822 | ||
823 | return ret; | |
824 | ||
825 | err_target: | |
826 | nft_unregister_expr(&nft_target_type); | |
827 | err_match: | |
828 | nft_unregister_expr(&nft_match_type); | |
829 | return ret; | |
830 | } | |
831 | ||
832 | static void __exit nft_compat_module_exit(void) | |
833 | { | |
834 | nfnetlink_subsys_unregister(&nfnl_compat_subsys); | |
835 | nft_unregister_expr(&nft_target_type); | |
836 | nft_unregister_expr(&nft_match_type); | |
837 | } | |
838 | ||
839 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT); | |
840 | ||
841 | module_init(nft_compat_module_init); | |
842 | module_exit(nft_compat_module_exit); | |
843 | ||
844 | MODULE_LICENSE("GPL"); | |
845 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
846 | MODULE_ALIAS_NFT_EXPR("match"); | |
847 | MODULE_ALIAS_NFT_EXPR("target"); |