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Linux 4.3
[linux/fpc-iii.git] / net / netfilter / nft_compat.c
blob9c8fab00164b5b6f3e43b3fc6fe983e39f89e64e
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 static int nft_compat_chain_validate_dependency(const char *tablename,
27 const struct nft_chain *chain)
28 {
29 const struct nft_base_chain *basechain;
30
31 if (!tablename || !(chain->flags & NFT_BASE_CHAIN))
32 return 0;
33
34 basechain = nft_base_chain(chain);
35 if (strcmp(tablename, "nat") == 0 &&
36 basechain->type->type != NFT_CHAIN_T_NAT)
37 return -EINVAL;
38
39 return 0;
40 }
41
42 union nft_entry {
43 struct ipt_entry e4;
44 struct ip6t_entry e6;
45 struct ebt_entry ebt;
46 struct arpt_entry arp;
47 };
48
49 static inline void
50 nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
51 {
52 par->target = xt;
53 par->targinfo = xt_info;
54 par->hotdrop = false;
55 }
56
57 static void nft_target_eval_xt(const struct nft_expr *expr,
58 struct nft_regs *regs,
59 const struct nft_pktinfo *pkt)
60 {
61 void *info = nft_expr_priv(expr);
62 struct xt_target *target = expr->ops->data;
63 struct sk_buff *skb = pkt->skb;
64 int ret;
65
66 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
67
68 ret = target->target(skb, &pkt->xt);
69
70 if (pkt->xt.hotdrop)
71 ret = NF_DROP;
72
73 switch (ret) {
74 case XT_CONTINUE:
75 regs->verdict.code = NFT_CONTINUE;
76 break;
77 default:
78 regs->verdict.code = ret;
79 break;
80 }
81 }
82
83 static void nft_target_eval_bridge(const struct nft_expr *expr,
84 struct nft_regs *regs,
85 const struct nft_pktinfo *pkt)
86 {
87 void *info = nft_expr_priv(expr);
88 struct xt_target *target = expr->ops->data;
89 struct sk_buff *skb = pkt->skb;
90 int ret;
91
92 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
93
94 ret = target->target(skb, &pkt->xt);
95
96 if (pkt->xt.hotdrop)
97 ret = NF_DROP;
98
99 switch (ret) {
100 case EBT_ACCEPT:
101 regs->verdict.code = NF_ACCEPT;
102 break;
103 case EBT_DROP:
104 regs->verdict.code = NF_DROP;
105 break;
106 case EBT_CONTINUE:
107 regs->verdict.code = NFT_CONTINUE;
108 break;
109 case EBT_RETURN:
110 regs->verdict.code = NFT_RETURN;
111 break;
112 default:
113 regs->verdict.code = ret;
114 break;
115 }
116 }
117
118 static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
119 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
120 [NFTA_TARGET_REV] = { .type = NLA_U32 },
121 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
122 };
123
124 static void
125 nft_target_set_tgchk_param(struct xt_tgchk_param *par,
126 const struct nft_ctx *ctx,
127 struct xt_target *target, void *info,
128 union nft_entry *entry, u16 proto, bool inv)
129 {
130 par->net = ctx->net;
131 par->table = ctx->table->name;
132 switch (ctx->afi->family) {
133 case AF_INET:
134 entry->e4.ip.proto = proto;
135 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
136 break;
137 case AF_INET6:
138 if (proto)
139 entry->e6.ipv6.flags |= IP6T_F_PROTO;
140
141 entry->e6.ipv6.proto = proto;
142 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
143 break;
144 case NFPROTO_BRIDGE:
145 entry->ebt.ethproto = (__force __be16)proto;
146 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
147 break;
148 case NFPROTO_ARP:
149 break;
150 }
151 par->entryinfo = entry;
152 par->target = target;
153 par->targinfo = info;
154 if (ctx->chain->flags & NFT_BASE_CHAIN) {
155 const struct nft_base_chain *basechain =
156 nft_base_chain(ctx->chain);
157 const struct nf_hook_ops *ops = &basechain->ops[0];
158
159 par->hook_mask = 1 << ops->hooknum;
160 } else {
161 par->hook_mask = 0;
162 }
163 par->family = ctx->afi->family;
164 par->nft_compat = true;
165 }
166
167 static void target_compat_from_user(struct xt_target *t, void *in, void *out)
168 {
169 int pad;
170
171 memcpy(out, in, t->targetsize);
172 pad = XT_ALIGN(t->targetsize) - t->targetsize;
173 if (pad > 0)
174 memset(out + t->targetsize, 0, pad);
175 }
176
177 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
178 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
179 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
180 };
181
182 static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
183 {
184 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
185 u32 flags;
186 int err;
187
188 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
189 nft_rule_compat_policy);
190 if (err < 0)
191 return err;
192
193 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
194 return -EINVAL;
195
196 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
197 if (flags & ~NFT_RULE_COMPAT_F_MASK)
198 return -EINVAL;
199 if (flags & NFT_RULE_COMPAT_F_INV)
200 *inv = true;
201
202 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
203 return 0;
204 }
205
206 static int
207 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
208 const struct nlattr * const tb[])
209 {
210 void *info = nft_expr_priv(expr);
211 struct xt_target *target = expr->ops->data;
212 struct xt_tgchk_param par;
213 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
214 u16 proto = 0;
215 bool inv = false;
216 union nft_entry e = {};
217 int ret;
218
219 ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
220 if (ret < 0)
221 goto err;
222
223 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
224
225 if (ctx->nla[NFTA_RULE_COMPAT]) {
226 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
227 if (ret < 0)
228 goto err;
229 }
230
231 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
232
233 ret = xt_check_target(&par, size, proto, inv);
234 if (ret < 0)
235 goto err;
236
237 /* The standard target cannot be used */
238 if (target->target == NULL) {
239 ret = -EINVAL;
240 goto err;
241 }
242
243 return 0;
244 err:
245 module_put(target->me);
246 return ret;
247 }
248
249 static void
250 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
251 {
252 struct xt_target *target = expr->ops->data;
253 void *info = nft_expr_priv(expr);
254 struct xt_tgdtor_param par;
255
256 par.net = ctx->net;
257 par.target = target;
258 par.targinfo = info;
259 par.family = ctx->afi->family;
260 if (par.target->destroy != NULL)
261 par.target->destroy(&par);
262
263 module_put(target->me);
264 }
265
266 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
267 {
268 const struct xt_target *target = expr->ops->data;
269 void *info = nft_expr_priv(expr);
270
271 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
272 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
273 nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info))
274 goto nla_put_failure;
275
276 return 0;
277
278 nla_put_failure:
279 return -1;
280 }
281
282 static int nft_target_validate(const struct nft_ctx *ctx,
283 const struct nft_expr *expr,
284 const struct nft_data **data)
285 {
286 struct xt_target *target = expr->ops->data;
287 unsigned int hook_mask = 0;
288 int ret;
289
290 if (ctx->chain->flags & NFT_BASE_CHAIN) {
291 const struct nft_base_chain *basechain =
292 nft_base_chain(ctx->chain);
293 const struct nf_hook_ops *ops = &basechain->ops[0];
294
295 hook_mask = 1 << ops->hooknum;
296 if (!(hook_mask & target->hooks))
297 return -EINVAL;
298
299 ret = nft_compat_chain_validate_dependency(target->table,
300 ctx->chain);
301 if (ret < 0)
302 return ret;
303 }
304 return 0;
305 }
306
307 static void nft_match_eval(const struct nft_expr *expr,
308 struct nft_regs *regs,
309 const struct nft_pktinfo *pkt)
310 {
311 void *info = nft_expr_priv(expr);
312 struct xt_match *match = expr->ops->data;
313 struct sk_buff *skb = pkt->skb;
314 bool ret;
315
316 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
317
318 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
319
320 if (pkt->xt.hotdrop) {
321 regs->verdict.code = NF_DROP;
322 return;
323 }
324
325 switch (ret ? 1 : 0) {
326 case 1:
327 regs->verdict.code = NFT_CONTINUE;
328 break;
329 case 0:
330 regs->verdict.code = NFT_BREAK;
331 break;
332 }
333 }
334
335 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
336 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
337 [NFTA_MATCH_REV] = { .type = NLA_U32 },
338 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
339 };
340
341 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
342 static void
343 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
344 struct xt_match *match, void *info,
345 union nft_entry *entry, u16 proto, bool inv)
346 {
347 par->net = ctx->net;
348 par->table = ctx->table->name;
349 switch (ctx->afi->family) {
350 case AF_INET:
351 entry->e4.ip.proto = proto;
352 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
353 break;
354 case AF_INET6:
355 if (proto)
356 entry->e6.ipv6.flags |= IP6T_F_PROTO;
357
358 entry->e6.ipv6.proto = proto;
359 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
360 break;
361 case NFPROTO_BRIDGE:
362 entry->ebt.ethproto = (__force __be16)proto;
363 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
364 break;
365 case NFPROTO_ARP:
366 break;
367 }
368 par->entryinfo = entry;
369 par->match = match;
370 par->matchinfo = info;
371 if (ctx->chain->flags & NFT_BASE_CHAIN) {
372 const struct nft_base_chain *basechain =
373 nft_base_chain(ctx->chain);
374 const struct nf_hook_ops *ops = &basechain->ops[0];
375
376 par->hook_mask = 1 << ops->hooknum;
377 } else {
378 par->hook_mask = 0;
379 }
380 par->family = ctx->afi->family;
381 par->nft_compat = true;
382 }
383
384 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
385 {
386 int pad;
387
388 memcpy(out, in, m->matchsize);
389 pad = XT_ALIGN(m->matchsize) - m->matchsize;
390 if (pad > 0)
391 memset(out + m->matchsize, 0, pad);
392 }
393
394 static int
395 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
396 const struct nlattr * const tb[])
397 {
398 void *info = nft_expr_priv(expr);
399 struct xt_match *match = expr->ops->data;
400 struct xt_mtchk_param par;
401 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
402 u16 proto = 0;
403 bool inv = false;
404 union nft_entry e = {};
405 int ret;
406
407 ret = nft_compat_chain_validate_dependency(match->table, ctx->chain);
408 if (ret < 0)
409 goto err;
410
411 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
412
413 if (ctx->nla[NFTA_RULE_COMPAT]) {
414 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
415 if (ret < 0)
416 goto err;
417 }
418
419 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
420
421 ret = xt_check_match(&par, size, proto, inv);
422 if (ret < 0)
423 goto err;
424
425 return 0;
426 err:
427 module_put(match->me);
428 return ret;
429 }
430
431 static void
432 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
433 {
434 struct xt_match *match = expr->ops->data;
435 void *info = nft_expr_priv(expr);
436 struct xt_mtdtor_param par;
437
438 par.net = ctx->net;
439 par.match = match;
440 par.matchinfo = info;
441 par.family = ctx->afi->family;
442 if (par.match->destroy != NULL)
443 par.match->destroy(&par);
444
445 module_put(match->me);
446 }
447
448 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
449 {
450 void *info = nft_expr_priv(expr);
451 struct xt_match *match = expr->ops->data;
452
453 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
454 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
455 nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info))
456 goto nla_put_failure;
457
458 return 0;
459
460 nla_put_failure:
461 return -1;
462 }
463
464 static int nft_match_validate(const struct nft_ctx *ctx,
465 const struct nft_expr *expr,
466 const struct nft_data **data)
467 {
468 struct xt_match *match = expr->ops->data;
469 unsigned int hook_mask = 0;
470 int ret;
471
472 if (ctx->chain->flags & NFT_BASE_CHAIN) {
473 const struct nft_base_chain *basechain =
474 nft_base_chain(ctx->chain);
475 const struct nf_hook_ops *ops = &basechain->ops[0];
476
477 hook_mask = 1 << ops->hooknum;
478 if (!(hook_mask & match->hooks))
479 return -EINVAL;
480
481 ret = nft_compat_chain_validate_dependency(match->table,
482 ctx->chain);
483 if (ret < 0)
484 return ret;
485 }
486 return 0;
487 }
488
489 static int
490 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
491 int event, u16 family, const char *name,
492 int rev, int target)
493 {
494 struct nlmsghdr *nlh;
495 struct nfgenmsg *nfmsg;
496 unsigned int flags = portid ? NLM_F_MULTI : 0;
497
498 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
499 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
500 if (nlh == NULL)
501 goto nlmsg_failure;
502
503 nfmsg = nlmsg_data(nlh);
504 nfmsg->nfgen_family = family;
505 nfmsg->version = NFNETLINK_V0;
506 nfmsg->res_id = 0;
507
508 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
509 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
510 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
511 goto nla_put_failure;
512
513 nlmsg_end(skb, nlh);
514 return skb->len;
515
516 nlmsg_failure:
517 nla_put_failure:
518 nlmsg_cancel(skb, nlh);
519 return -1;
520 }
521
522 static int
523 nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
524 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
525 {
526 int ret = 0, target;
527 struct nfgenmsg *nfmsg;
528 const char *fmt;
529 const char *name;
530 u32 rev;
531 struct sk_buff *skb2;
532
533 if (tb[NFTA_COMPAT_NAME] == NULL ||
534 tb[NFTA_COMPAT_REV] == NULL ||
535 tb[NFTA_COMPAT_TYPE] == NULL)
536 return -EINVAL;
537
538 name = nla_data(tb[NFTA_COMPAT_NAME]);
539 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
540 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
541
542 nfmsg = nlmsg_data(nlh);
543
544 switch(nfmsg->nfgen_family) {
545 case AF_INET:
546 fmt = "ipt_%s";
547 break;
548 case AF_INET6:
549 fmt = "ip6t_%s";
550 break;
551 case NFPROTO_BRIDGE:
552 fmt = "ebt_%s";
553 break;
554 case NFPROTO_ARP:
555 fmt = "arpt_%s";
556 break;
557 default:
558 pr_err("nft_compat: unsupported protocol %d\n",
559 nfmsg->nfgen_family);
560 return -EINVAL;
561 }
562
563 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
564 rev, target, &ret),
565 fmt, name);
566
567 if (ret < 0)
568 return ret;
569
570 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
571 if (skb2 == NULL)
572 return -ENOMEM;
573
574 /* include the best revision for this extension in the message */
575 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
576 nlh->nlmsg_seq,
577 NFNL_MSG_TYPE(nlh->nlmsg_type),
578 NFNL_MSG_COMPAT_GET,
579 nfmsg->nfgen_family,
580 name, ret, target) <= 0) {
581 kfree_skb(skb2);
582 return -ENOSPC;
583 }
584
585 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
586 MSG_DONTWAIT);
587 if (ret > 0)
588 ret = 0;
589
590 return ret == -EAGAIN ? -ENOBUFS : ret;
591 }
592
593 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
594 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
595 .len = NFT_COMPAT_NAME_MAX-1 },
596 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
597 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
598 };
599
600 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
601 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
602 .attr_count = NFTA_COMPAT_MAX,
603 .policy = nfnl_compat_policy_get },
604 };
605
606 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
607 .name = "nft-compat",
608 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
609 .cb_count = NFNL_MSG_COMPAT_MAX,
610 .cb = nfnl_nft_compat_cb,
611 };
612
613 static LIST_HEAD(nft_match_list);
614
615 struct nft_xt {
616 struct list_head head;
617 struct nft_expr_ops ops;
618 };
619
620 static struct nft_expr_type nft_match_type;
621
622 static bool nft_match_cmp(const struct xt_match *match,
623 const char *name, u32 rev, u32 family)
624 {
625 return strcmp(match->name, name) == 0 && match->revision == rev &&
626 (match->family == NFPROTO_UNSPEC || match->family == family);
627 }
628
629 static const struct nft_expr_ops *
630 nft_match_select_ops(const struct nft_ctx *ctx,
631 const struct nlattr * const tb[])
632 {
633 struct nft_xt *nft_match;
634 struct xt_match *match;
635 char *mt_name;
636 u32 rev, family;
637
638 if (tb[NFTA_MATCH_NAME] == NULL ||
639 tb[NFTA_MATCH_REV] == NULL ||
640 tb[NFTA_MATCH_INFO] == NULL)
641 return ERR_PTR(-EINVAL);
642
643 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
644 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
645 family = ctx->afi->family;
646
647 /* Re-use the existing match if it's already loaded. */
648 list_for_each_entry(nft_match, &nft_match_list, head) {
649 struct xt_match *match = nft_match->ops.data;
650
651 if (nft_match_cmp(match, mt_name, rev, family)) {
652 if (!try_module_get(match->me))
653 return ERR_PTR(-ENOENT);
654
655 return &nft_match->ops;
656 }
657 }
658
659 match = xt_request_find_match(family, mt_name, rev);
660 if (IS_ERR(match))
661 return ERR_PTR(-ENOENT);
662
663 /* This is the first time we use this match, allocate operations */
664 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
665 if (nft_match == NULL)
666 return ERR_PTR(-ENOMEM);
667
668 nft_match->ops.type = &nft_match_type;
669 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
670 nft_match->ops.eval = nft_match_eval;
671 nft_match->ops.init = nft_match_init;
672 nft_match->ops.destroy = nft_match_destroy;
673 nft_match->ops.dump = nft_match_dump;
674 nft_match->ops.validate = nft_match_validate;
675 nft_match->ops.data = match;
676
677 list_add(&nft_match->head, &nft_match_list);
678
679 return &nft_match->ops;
680 }
681
682 static void nft_match_release(void)
683 {
684 struct nft_xt *nft_match, *tmp;
685
686 list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
687 kfree(nft_match);
688 }
689
690 static struct nft_expr_type nft_match_type __read_mostly = {
691 .name = "match",
692 .select_ops = nft_match_select_ops,
693 .policy = nft_match_policy,
694 .maxattr = NFTA_MATCH_MAX,
695 .owner = THIS_MODULE,
696 };
697
698 static LIST_HEAD(nft_target_list);
699
700 static struct nft_expr_type nft_target_type;
701
702 static bool nft_target_cmp(const struct xt_target *tg,
703 const char *name, u32 rev, u32 family)
704 {
705 return strcmp(tg->name, name) == 0 && tg->revision == rev &&
706 (tg->family == NFPROTO_UNSPEC || tg->family == family);
707 }
708
709 static const struct nft_expr_ops *
710 nft_target_select_ops(const struct nft_ctx *ctx,
711 const struct nlattr * const tb[])
712 {
713 struct nft_xt *nft_target;
714 struct xt_target *target;
715 char *tg_name;
716 u32 rev, family;
717
718 if (tb[NFTA_TARGET_NAME] == NULL ||
719 tb[NFTA_TARGET_REV] == NULL ||
720 tb[NFTA_TARGET_INFO] == NULL)
721 return ERR_PTR(-EINVAL);
722
723 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
724 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
725 family = ctx->afi->family;
726
727 /* Re-use the existing target if it's already loaded. */
728 list_for_each_entry(nft_target, &nft_target_list, head) {
729 struct xt_target *target = nft_target->ops.data;
730
731 if (nft_target_cmp(target, tg_name, rev, family)) {
732 if (!try_module_get(target->me))
733 return ERR_PTR(-ENOENT);
734
735 return &nft_target->ops;
736 }
737 }
738
739 target = xt_request_find_target(family, tg_name, rev);
740 if (IS_ERR(target))
741 return ERR_PTR(-ENOENT);
742
743 /* This is the first time we use this target, allocate operations */
744 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
745 if (nft_target == NULL)
746 return ERR_PTR(-ENOMEM);
747
748 nft_target->ops.type = &nft_target_type;
749 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
750 nft_target->ops.init = nft_target_init;
751 nft_target->ops.destroy = nft_target_destroy;
752 nft_target->ops.dump = nft_target_dump;
753 nft_target->ops.validate = nft_target_validate;
754 nft_target->ops.data = target;
755
756 if (family == NFPROTO_BRIDGE)
757 nft_target->ops.eval = nft_target_eval_bridge;
758 else
759 nft_target->ops.eval = nft_target_eval_xt;
760
761 list_add(&nft_target->head, &nft_target_list);
762
763 return &nft_target->ops;
764 }
765
766 static void nft_target_release(void)
767 {
768 struct nft_xt *nft_target, *tmp;
769
770 list_for_each_entry_safe(nft_target, tmp, &nft_target_list, head)
771 kfree(nft_target);
772 }
773
774 static struct nft_expr_type nft_target_type __read_mostly = {
775 .name = "target",
776 .select_ops = nft_target_select_ops,
777 .policy = nft_target_policy,
778 .maxattr = NFTA_TARGET_MAX,
779 .owner = THIS_MODULE,
780 };
781
782 static int __init nft_compat_module_init(void)
783 {
784 int ret;
785
786 ret = nft_register_expr(&nft_match_type);
787 if (ret < 0)
788 return ret;
789
790 ret = nft_register_expr(&nft_target_type);
791 if (ret < 0)
792 goto err_match;
793
794 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
795 if (ret < 0) {
796 pr_err("nft_compat: cannot register with nfnetlink.\n");
797 goto err_target;
798 }
799
800 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
801
802 return ret;
803
804 err_target:
805 nft_unregister_expr(&nft_target_type);
806 err_match:
807 nft_unregister_expr(&nft_match_type);
808 return ret;
809 }
810
811 static void __exit nft_compat_module_exit(void)
812 {
813 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
814 nft_unregister_expr(&nft_target_type);
815 nft_unregister_expr(&nft_match_type);
816 nft_match_release();
817 nft_target_release();
818 }
819
820 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
821
822 module_init(nft_compat_module_init);
823 module_exit(nft_compat_module_exit);
824
825 MODULE_LICENSE("GPL");
826 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
827 MODULE_ALIAS_NFT_EXPR("match");
828 MODULE_ALIAS_NFT_EXPR("target");
Linux with added FPC-III support