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NFS: Don't clear desc->pg_moreio in nfs_do_recoalesce()
[linux/fpc-iii.git] / net / netfilter / nft_compat.c
blob7f29cfc76349f56d7408f4519213a98d564ab135
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 }
165
166 static void target_compat_from_user(struct xt_target *t, void *in, void *out)
167 {
168 int pad;
169
170 memcpy(out, in, t->targetsize);
171 pad = XT_ALIGN(t->targetsize) - t->targetsize;
172 if (pad > 0)
173 memset(out + t->targetsize, 0, pad);
174 }
175
176 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
177 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
178 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
179 };
180
181 static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
182 {
183 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
184 u32 flags;
185 int err;
186
187 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
188 nft_rule_compat_policy);
189 if (err < 0)
190 return err;
191
192 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
193 return -EINVAL;
194
195 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
196 if (flags & ~NFT_RULE_COMPAT_F_MASK)
197 return -EINVAL;
198 if (flags & NFT_RULE_COMPAT_F_INV)
199 *inv = true;
200
201 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
202 return 0;
203 }
204
205 static int
206 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
207 const struct nlattr * const tb[])
208 {
209 void *info = nft_expr_priv(expr);
210 struct xt_target *target = expr->ops->data;
211 struct xt_tgchk_param par;
212 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
213 u16 proto = 0;
214 bool inv = false;
215 union nft_entry e = {};
216 int ret;
217
218 ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
219 if (ret < 0)
220 goto err;
221
222 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
223
224 if (ctx->nla[NFTA_RULE_COMPAT]) {
225 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
226 if (ret < 0)
227 goto err;
228 }
229
230 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
231
232 ret = xt_check_target(&par, size, proto, inv);
233 if (ret < 0)
234 goto err;
235
236 /* The standard target cannot be used */
237 if (target->target == NULL) {
238 ret = -EINVAL;
239 goto err;
240 }
241
242 return 0;
243 err:
244 module_put(target->me);
245 return ret;
246 }
247
248 static void
249 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
250 {
251 struct xt_target *target = expr->ops->data;
252 void *info = nft_expr_priv(expr);
253 struct xt_tgdtor_param par;
254
255 par.net = ctx->net;
256 par.target = target;
257 par.targinfo = info;
258 par.family = ctx->afi->family;
259 if (par.target->destroy != NULL)
260 par.target->destroy(&par);
261
262 module_put(target->me);
263 }
264
265 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
266 {
267 const struct xt_target *target = expr->ops->data;
268 void *info = nft_expr_priv(expr);
269
270 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
271 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
272 nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info))
273 goto nla_put_failure;
274
275 return 0;
276
277 nla_put_failure:
278 return -1;
279 }
280
281 static int nft_target_validate(const struct nft_ctx *ctx,
282 const struct nft_expr *expr,
283 const struct nft_data **data)
284 {
285 struct xt_target *target = expr->ops->data;
286 unsigned int hook_mask = 0;
287 int ret;
288
289 if (ctx->chain->flags & NFT_BASE_CHAIN) {
290 const struct nft_base_chain *basechain =
291 nft_base_chain(ctx->chain);
292 const struct nf_hook_ops *ops = &basechain->ops[0];
293
294 hook_mask = 1 << ops->hooknum;
295 if (!(hook_mask & target->hooks))
296 return -EINVAL;
297
298 ret = nft_compat_chain_validate_dependency(target->table,
299 ctx->chain);
300 if (ret < 0)
301 return ret;
302 }
303 return 0;
304 }
305
306 static void nft_match_eval(const struct nft_expr *expr,
307 struct nft_regs *regs,
308 const struct nft_pktinfo *pkt)
309 {
310 void *info = nft_expr_priv(expr);
311 struct xt_match *match = expr->ops->data;
312 struct sk_buff *skb = pkt->skb;
313 bool ret;
314
315 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
316
317 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
318
319 if (pkt->xt.hotdrop) {
320 regs->verdict.code = NF_DROP;
321 return;
322 }
323
324 switch (ret ? 1 : 0) {
325 case 1:
326 regs->verdict.code = NFT_CONTINUE;
327 break;
328 case 0:
329 regs->verdict.code = NFT_BREAK;
330 break;
331 }
332 }
333
334 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
335 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
336 [NFTA_MATCH_REV] = { .type = NLA_U32 },
337 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
338 };
339
340 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
341 static void
342 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
343 struct xt_match *match, void *info,
344 union nft_entry *entry, u16 proto, bool inv)
345 {
346 par->net = ctx->net;
347 par->table = ctx->table->name;
348 switch (ctx->afi->family) {
349 case AF_INET:
350 entry->e4.ip.proto = proto;
351 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
352 break;
353 case AF_INET6:
354 if (proto)
355 entry->e6.ipv6.flags |= IP6T_F_PROTO;
356
357 entry->e6.ipv6.proto = proto;
358 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
359 break;
360 case NFPROTO_BRIDGE:
361 entry->ebt.ethproto = (__force __be16)proto;
362 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
363 break;
364 case NFPROTO_ARP:
365 break;
366 }
367 par->entryinfo = entry;
368 par->match = match;
369 par->matchinfo = info;
370 if (ctx->chain->flags & NFT_BASE_CHAIN) {
371 const struct nft_base_chain *basechain =
372 nft_base_chain(ctx->chain);
373 const struct nf_hook_ops *ops = &basechain->ops[0];
374
375 par->hook_mask = 1 << ops->hooknum;
376 } else {
377 par->hook_mask = 0;
378 }
379 par->family = ctx->afi->family;
380 }
381
382 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
383 {
384 int pad;
385
386 memcpy(out, in, m->matchsize);
387 pad = XT_ALIGN(m->matchsize) - m->matchsize;
388 if (pad > 0)
389 memset(out + m->matchsize, 0, pad);
390 }
391
392 static int
393 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
394 const struct nlattr * const tb[])
395 {
396 void *info = nft_expr_priv(expr);
397 struct xt_match *match = expr->ops->data;
398 struct xt_mtchk_param par;
399 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
400 u16 proto = 0;
401 bool inv = false;
402 union nft_entry e = {};
403 int ret;
404
405 ret = nft_compat_chain_validate_dependency(match->table, ctx->chain);
406 if (ret < 0)
407 goto err;
408
409 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
410
411 if (ctx->nla[NFTA_RULE_COMPAT]) {
412 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
413 if (ret < 0)
414 goto err;
415 }
416
417 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
418
419 ret = xt_check_match(&par, size, proto, inv);
420 if (ret < 0)
421 goto err;
422
423 return 0;
424 err:
425 module_put(match->me);
426 return ret;
427 }
428
429 static void
430 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
431 {
432 struct xt_match *match = expr->ops->data;
433 void *info = nft_expr_priv(expr);
434 struct xt_mtdtor_param par;
435
436 par.net = ctx->net;
437 par.match = match;
438 par.matchinfo = info;
439 par.family = ctx->afi->family;
440 if (par.match->destroy != NULL)
441 par.match->destroy(&par);
442
443 module_put(match->me);
444 }
445
446 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
447 {
448 void *info = nft_expr_priv(expr);
449 struct xt_match *match = expr->ops->data;
450
451 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
452 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
453 nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info))
454 goto nla_put_failure;
455
456 return 0;
457
458 nla_put_failure:
459 return -1;
460 }
461
462 static int nft_match_validate(const struct nft_ctx *ctx,
463 const struct nft_expr *expr,
464 const struct nft_data **data)
465 {
466 struct xt_match *match = expr->ops->data;
467 unsigned int hook_mask = 0;
468 int ret;
469
470 if (ctx->chain->flags & NFT_BASE_CHAIN) {
471 const struct nft_base_chain *basechain =
472 nft_base_chain(ctx->chain);
473 const struct nf_hook_ops *ops = &basechain->ops[0];
474
475 hook_mask = 1 << ops->hooknum;
476 if (!(hook_mask & match->hooks))
477 return -EINVAL;
478
479 ret = nft_compat_chain_validate_dependency(match->table,
480 ctx->chain);
481 if (ret < 0)
482 return ret;
483 }
484 return 0;
485 }
486
487 static int
488 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
489 int event, u16 family, const char *name,
490 int rev, int target)
491 {
492 struct nlmsghdr *nlh;
493 struct nfgenmsg *nfmsg;
494 unsigned int flags = portid ? NLM_F_MULTI : 0;
495
496 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
497 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
498 if (nlh == NULL)
499 goto nlmsg_failure;
500
501 nfmsg = nlmsg_data(nlh);
502 nfmsg->nfgen_family = family;
503 nfmsg->version = NFNETLINK_V0;
504 nfmsg->res_id = 0;
505
506 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
507 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
508 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
509 goto nla_put_failure;
510
511 nlmsg_end(skb, nlh);
512 return skb->len;
513
514 nlmsg_failure:
515 nla_put_failure:
516 nlmsg_cancel(skb, nlh);
517 return -1;
518 }
519
520 static int
521 nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
522 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
523 {
524 int ret = 0, target;
525 struct nfgenmsg *nfmsg;
526 const char *fmt;
527 const char *name;
528 u32 rev;
529 struct sk_buff *skb2;
530
531 if (tb[NFTA_COMPAT_NAME] == NULL ||
532 tb[NFTA_COMPAT_REV] == NULL ||
533 tb[NFTA_COMPAT_TYPE] == NULL)
534 return -EINVAL;
535
536 name = nla_data(tb[NFTA_COMPAT_NAME]);
537 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
538 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
539
540 nfmsg = nlmsg_data(nlh);
541
542 switch(nfmsg->nfgen_family) {
543 case AF_INET:
544 fmt = "ipt_%s";
545 break;
546 case AF_INET6:
547 fmt = "ip6t_%s";
548 break;
549 case NFPROTO_BRIDGE:
550 fmt = "ebt_%s";
551 break;
552 case NFPROTO_ARP:
553 fmt = "arpt_%s";
554 break;
555 default:
556 pr_err("nft_compat: unsupported protocol %d\n",
557 nfmsg->nfgen_family);
558 return -EINVAL;
559 }
560
561 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
562 rev, target, &ret),
563 fmt, name);
564
565 if (ret < 0)
566 return ret;
567
568 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
569 if (skb2 == NULL)
570 return -ENOMEM;
571
572 /* include the best revision for this extension in the message */
573 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
574 nlh->nlmsg_seq,
575 NFNL_MSG_TYPE(nlh->nlmsg_type),
576 NFNL_MSG_COMPAT_GET,
577 nfmsg->nfgen_family,
578 name, ret, target) <= 0) {
579 kfree_skb(skb2);
580 return -ENOSPC;
581 }
582
583 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
584 MSG_DONTWAIT);
585 if (ret > 0)
586 ret = 0;
587
588 return ret == -EAGAIN ? -ENOBUFS : ret;
589 }
590
591 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
592 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
593 .len = NFT_COMPAT_NAME_MAX-1 },
594 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
595 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
596 };
597
598 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
599 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
600 .attr_count = NFTA_COMPAT_MAX,
601 .policy = nfnl_compat_policy_get },
602 };
603
604 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
605 .name = "nft-compat",
606 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
607 .cb_count = NFNL_MSG_COMPAT_MAX,
608 .cb = nfnl_nft_compat_cb,
609 };
610
611 static LIST_HEAD(nft_match_list);
612
613 struct nft_xt {
614 struct list_head head;
615 struct nft_expr_ops ops;
616 };
617
618 static struct nft_expr_type nft_match_type;
619
620 static const struct nft_expr_ops *
621 nft_match_select_ops(const struct nft_ctx *ctx,
622 const struct nlattr * const tb[])
623 {
624 struct nft_xt *nft_match;
625 struct xt_match *match;
626 char *mt_name;
627 __u32 rev, family;
628
629 if (tb[NFTA_MATCH_NAME] == NULL ||
630 tb[NFTA_MATCH_REV] == NULL ||
631 tb[NFTA_MATCH_INFO] == NULL)
632 return ERR_PTR(-EINVAL);
633
634 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
635 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
636 family = ctx->afi->family;
637
638 /* Re-use the existing match if it's already loaded. */
639 list_for_each_entry(nft_match, &nft_match_list, head) {
640 struct xt_match *match = nft_match->ops.data;
641
642 if (strcmp(match->name, mt_name) == 0 &&
643 match->revision == rev && match->family == family) {
644 if (!try_module_get(match->me))
645 return ERR_PTR(-ENOENT);
646
647 return &nft_match->ops;
648 }
649 }
650
651 match = xt_request_find_match(family, mt_name, rev);
652 if (IS_ERR(match))
653 return ERR_PTR(-ENOENT);
654
655 /* This is the first time we use this match, allocate operations */
656 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
657 if (nft_match == NULL)
658 return ERR_PTR(-ENOMEM);
659
660 nft_match->ops.type = &nft_match_type;
661 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
662 nft_match->ops.eval = nft_match_eval;
663 nft_match->ops.init = nft_match_init;
664 nft_match->ops.destroy = nft_match_destroy;
665 nft_match->ops.dump = nft_match_dump;
666 nft_match->ops.validate = nft_match_validate;
667 nft_match->ops.data = match;
668
669 list_add(&nft_match->head, &nft_match_list);
670
671 return &nft_match->ops;
672 }
673
674 static void nft_match_release(void)
675 {
676 struct nft_xt *nft_match, *tmp;
677
678 list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
679 kfree(nft_match);
680 }
681
682 static struct nft_expr_type nft_match_type __read_mostly = {
683 .name = "match",
684 .select_ops = nft_match_select_ops,
685 .policy = nft_match_policy,
686 .maxattr = NFTA_MATCH_MAX,
687 .owner = THIS_MODULE,
688 };
689
690 static LIST_HEAD(nft_target_list);
691
692 static struct nft_expr_type nft_target_type;
693
694 static const struct nft_expr_ops *
695 nft_target_select_ops(const struct nft_ctx *ctx,
696 const struct nlattr * const tb[])
697 {
698 struct nft_xt *nft_target;
699 struct xt_target *target;
700 char *tg_name;
701 __u32 rev, family;
702
703 if (tb[NFTA_TARGET_NAME] == NULL ||
704 tb[NFTA_TARGET_REV] == NULL ||
705 tb[NFTA_TARGET_INFO] == NULL)
706 return ERR_PTR(-EINVAL);
707
708 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
709 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
710 family = ctx->afi->family;
711
712 /* Re-use the existing target if it's already loaded. */
713 list_for_each_entry(nft_target, &nft_target_list, head) {
714 struct xt_target *target = nft_target->ops.data;
715
716 if (strcmp(target->name, tg_name) == 0 &&
717 target->revision == rev && target->family == family) {
718 if (!try_module_get(target->me))
719 return ERR_PTR(-ENOENT);
720
721 return &nft_target->ops;
722 }
723 }
724
725 target = xt_request_find_target(family, tg_name, rev);
726 if (IS_ERR(target))
727 return ERR_PTR(-ENOENT);
728
729 /* This is the first time we use this target, allocate operations */
730 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
731 if (nft_target == NULL)
732 return ERR_PTR(-ENOMEM);
733
734 nft_target->ops.type = &nft_target_type;
735 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
736 nft_target->ops.init = nft_target_init;
737 nft_target->ops.destroy = nft_target_destroy;
738 nft_target->ops.dump = nft_target_dump;
739 nft_target->ops.validate = nft_target_validate;
740 nft_target->ops.data = target;
741
742 if (family == NFPROTO_BRIDGE)
743 nft_target->ops.eval = nft_target_eval_bridge;
744 else
745 nft_target->ops.eval = nft_target_eval_xt;
746
747 list_add(&nft_target->head, &nft_target_list);
748
749 return &nft_target->ops;
750 }
751
752 static void nft_target_release(void)
753 {
754 struct nft_xt *nft_target, *tmp;
755
756 list_for_each_entry_safe(nft_target, tmp, &nft_target_list, head)
757 kfree(nft_target);
758 }
759
760 static struct nft_expr_type nft_target_type __read_mostly = {
761 .name = "target",
762 .select_ops = nft_target_select_ops,
763 .policy = nft_target_policy,
764 .maxattr = NFTA_TARGET_MAX,
765 .owner = THIS_MODULE,
766 };
767
768 static int __init nft_compat_module_init(void)
769 {
770 int ret;
771
772 ret = nft_register_expr(&nft_match_type);
773 if (ret < 0)
774 return ret;
775
776 ret = nft_register_expr(&nft_target_type);
777 if (ret < 0)
778 goto err_match;
779
780 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
781 if (ret < 0) {
782 pr_err("nft_compat: cannot register with nfnetlink.\n");
783 goto err_target;
784 }
785
786 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
787
788 return ret;
789
790 err_target:
791 nft_unregister_expr(&nft_target_type);
792 err_match:
793 nft_unregister_expr(&nft_match_type);
794 return ret;
795 }
796
797 static void __exit nft_compat_module_exit(void)
798 {
799 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
800 nft_unregister_expr(&nft_target_type);
801 nft_unregister_expr(&nft_match_type);
802 nft_match_release();
803 nft_target_release();
804 }
805
806 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
807
808 module_init(nft_compat_module_init);
809 module_exit(nft_compat_module_exit);
810
811 MODULE_LICENSE("GPL");
812 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
813 MODULE_ALIAS_NFT_EXPR("match");
814 MODULE_ALIAS_NFT_EXPR("target");
Linux with added FPC-III support