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Linux 4.19.133
[linux/fpc-iii.git] / net / netfilter / nft_compat.c
blob469f9da5073bf61ea7ac50ea02deeea4b4400d15
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 /* Used for matches where *info is larger than X byte */
27 #define NFT_MATCH_LARGE_THRESH 192
28
29 struct nft_xt_match_priv {
30 void *info;
31 };
32
33 static int nft_compat_chain_validate_dependency(const struct nft_ctx *ctx,
34 const char *tablename)
35 {
36 enum nft_chain_types type = NFT_CHAIN_T_DEFAULT;
37 const struct nft_chain *chain = ctx->chain;
38 const struct nft_base_chain *basechain;
39
40 if (!tablename ||
41 !nft_is_base_chain(chain))
42 return 0;
43
44 basechain = nft_base_chain(chain);
45 if (strcmp(tablename, "nat") == 0) {
46 if (ctx->family != NFPROTO_BRIDGE)
47 type = NFT_CHAIN_T_NAT;
48 if (basechain->type->type != type)
49 return -EINVAL;
50 }
51
52 return 0;
53 }
54
55 union nft_entry {
56 struct ipt_entry e4;
57 struct ip6t_entry e6;
58 struct ebt_entry ebt;
59 struct arpt_entry arp;
60 };
61
62 static inline void
63 nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
64 {
65 par->target = xt;
66 par->targinfo = xt_info;
67 par->hotdrop = false;
68 }
69
70 static void nft_target_eval_xt(const struct nft_expr *expr,
71 struct nft_regs *regs,
72 const struct nft_pktinfo *pkt)
73 {
74 void *info = nft_expr_priv(expr);
75 struct xt_target *target = expr->ops->data;
76 struct sk_buff *skb = pkt->skb;
77 int ret;
78
79 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
80
81 ret = target->target(skb, &pkt->xt);
82
83 if (pkt->xt.hotdrop)
84 ret = NF_DROP;
85
86 switch (ret) {
87 case XT_CONTINUE:
88 regs->verdict.code = NFT_CONTINUE;
89 break;
90 default:
91 regs->verdict.code = ret;
92 break;
93 }
94 }
95
96 static void nft_target_eval_bridge(const struct nft_expr *expr,
97 struct nft_regs *regs,
98 const struct nft_pktinfo *pkt)
99 {
100 void *info = nft_expr_priv(expr);
101 struct xt_target *target = expr->ops->data;
102 struct sk_buff *skb = pkt->skb;
103 int ret;
104
105 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
106
107 ret = target->target(skb, &pkt->xt);
108
109 if (pkt->xt.hotdrop)
110 ret = NF_DROP;
111
112 switch (ret) {
113 case EBT_ACCEPT:
114 regs->verdict.code = NF_ACCEPT;
115 break;
116 case EBT_DROP:
117 regs->verdict.code = NF_DROP;
118 break;
119 case EBT_CONTINUE:
120 regs->verdict.code = NFT_CONTINUE;
121 break;
122 case EBT_RETURN:
123 regs->verdict.code = NFT_RETURN;
124 break;
125 default:
126 regs->verdict.code = ret;
127 break;
128 }
129 }
130
131 static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
132 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
133 [NFTA_TARGET_REV] = { .type = NLA_U32 },
134 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
135 };
136
137 static void
138 nft_target_set_tgchk_param(struct xt_tgchk_param *par,
139 const struct nft_ctx *ctx,
140 struct xt_target *target, void *info,
141 union nft_entry *entry, u16 proto, bool inv)
142 {
143 par->net = ctx->net;
144 par->table = ctx->table->name;
145 switch (ctx->family) {
146 case AF_INET:
147 entry->e4.ip.proto = proto;
148 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
149 break;
150 case AF_INET6:
151 if (proto)
152 entry->e6.ipv6.flags |= IP6T_F_PROTO;
153
154 entry->e6.ipv6.proto = proto;
155 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
156 break;
157 case NFPROTO_BRIDGE:
158 entry->ebt.ethproto = (__force __be16)proto;
159 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
160 break;
161 case NFPROTO_ARP:
162 break;
163 }
164 par->entryinfo = entry;
165 par->target = target;
166 par->targinfo = info;
167 if (nft_is_base_chain(ctx->chain)) {
168 const struct nft_base_chain *basechain =
169 nft_base_chain(ctx->chain);
170 const struct nf_hook_ops *ops = &basechain->ops;
171
172 par->hook_mask = 1 << ops->hooknum;
173 } else {
174 par->hook_mask = 0;
175 }
176 par->family = ctx->family;
177 par->nft_compat = true;
178 }
179
180 static void target_compat_from_user(struct xt_target *t, void *in, void *out)
181 {
182 int pad;
183
184 memcpy(out, in, t->targetsize);
185 pad = XT_ALIGN(t->targetsize) - t->targetsize;
186 if (pad > 0)
187 memset(out + t->targetsize, 0, pad);
188 }
189
190 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
191 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
192 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
193 };
194
195 static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
196 {
197 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
198 u32 flags;
199 int err;
200
201 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
202 nft_rule_compat_policy, NULL);
203 if (err < 0)
204 return err;
205
206 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
207 return -EINVAL;
208
209 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
210 if (flags & ~NFT_RULE_COMPAT_F_MASK)
211 return -EINVAL;
212 if (flags & NFT_RULE_COMPAT_F_INV)
213 *inv = true;
214
215 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
216 return 0;
217 }
218
219 static int
220 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
221 const struct nlattr * const tb[])
222 {
223 void *info = nft_expr_priv(expr);
224 struct xt_target *target = expr->ops->data;
225 struct xt_tgchk_param par;
226 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
227 u16 proto = 0;
228 bool inv = false;
229 union nft_entry e = {};
230 int ret;
231
232 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
233
234 if (ctx->nla[NFTA_RULE_COMPAT]) {
235 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
236 if (ret < 0)
237 return ret;
238 }
239
240 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
241
242 ret = xt_check_target(&par, size, proto, inv);
243 if (ret < 0)
244 return ret;
245
246 /* The standard target cannot be used */
247 if (!target->target)
248 return -EINVAL;
249
250 return 0;
251 }
252
253 static void
254 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
255 {
256 struct xt_target *target = expr->ops->data;
257 void *info = nft_expr_priv(expr);
258 struct module *me = target->me;
259 struct xt_tgdtor_param par;
260
261 par.net = ctx->net;
262 par.target = target;
263 par.targinfo = info;
264 par.family = ctx->family;
265 if (par.target->destroy != NULL)
266 par.target->destroy(&par);
267
268 module_put(me);
269 kfree(expr->ops);
270 }
271
272 static int nft_extension_dump_info(struct sk_buff *skb, int attr,
273 const void *info,
274 unsigned int size, unsigned int user_size)
275 {
276 unsigned int info_size, aligned_size = XT_ALIGN(size);
277 struct nlattr *nla;
278
279 nla = nla_reserve(skb, attr, aligned_size);
280 if (!nla)
281 return -1;
282
283 info_size = user_size ? : size;
284 memcpy(nla_data(nla), info, info_size);
285 memset(nla_data(nla) + info_size, 0, aligned_size - info_size);
286
287 return 0;
288 }
289
290 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
291 {
292 const struct xt_target *target = expr->ops->data;
293 void *info = nft_expr_priv(expr);
294
295 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
296 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
297 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info,
298 target->targetsize, target->usersize))
299 goto nla_put_failure;
300
301 return 0;
302
303 nla_put_failure:
304 return -1;
305 }
306
307 static int nft_target_validate(const struct nft_ctx *ctx,
308 const struct nft_expr *expr,
309 const struct nft_data **data)
310 {
311 struct xt_target *target = expr->ops->data;
312 unsigned int hook_mask = 0;
313 int ret;
314
315 if (nft_is_base_chain(ctx->chain)) {
316 const struct nft_base_chain *basechain =
317 nft_base_chain(ctx->chain);
318 const struct nf_hook_ops *ops = &basechain->ops;
319
320 hook_mask = 1 << ops->hooknum;
321 if (target->hooks && !(hook_mask & target->hooks))
322 return -EINVAL;
323
324 ret = nft_compat_chain_validate_dependency(ctx, target->table);
325 if (ret < 0)
326 return ret;
327 }
328 return 0;
329 }
330
331 static void __nft_match_eval(const struct nft_expr *expr,
332 struct nft_regs *regs,
333 const struct nft_pktinfo *pkt,
334 void *info)
335 {
336 struct xt_match *match = expr->ops->data;
337 struct sk_buff *skb = pkt->skb;
338 bool ret;
339
340 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
341
342 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
343
344 if (pkt->xt.hotdrop) {
345 regs->verdict.code = NF_DROP;
346 return;
347 }
348
349 switch (ret ? 1 : 0) {
350 case 1:
351 regs->verdict.code = NFT_CONTINUE;
352 break;
353 case 0:
354 regs->verdict.code = NFT_BREAK;
355 break;
356 }
357 }
358
359 static void nft_match_large_eval(const struct nft_expr *expr,
360 struct nft_regs *regs,
361 const struct nft_pktinfo *pkt)
362 {
363 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
364
365 __nft_match_eval(expr, regs, pkt, priv->info);
366 }
367
368 static void nft_match_eval(const struct nft_expr *expr,
369 struct nft_regs *regs,
370 const struct nft_pktinfo *pkt)
371 {
372 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr));
373 }
374
375 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
376 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
377 [NFTA_MATCH_REV] = { .type = NLA_U32 },
378 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
379 };
380
381 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
382 static void
383 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
384 struct xt_match *match, void *info,
385 union nft_entry *entry, u16 proto, bool inv)
386 {
387 par->net = ctx->net;
388 par->table = ctx->table->name;
389 switch (ctx->family) {
390 case AF_INET:
391 entry->e4.ip.proto = proto;
392 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
393 break;
394 case AF_INET6:
395 if (proto)
396 entry->e6.ipv6.flags |= IP6T_F_PROTO;
397
398 entry->e6.ipv6.proto = proto;
399 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
400 break;
401 case NFPROTO_BRIDGE:
402 entry->ebt.ethproto = (__force __be16)proto;
403 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
404 break;
405 case NFPROTO_ARP:
406 break;
407 }
408 par->entryinfo = entry;
409 par->match = match;
410 par->matchinfo = info;
411 if (nft_is_base_chain(ctx->chain)) {
412 const struct nft_base_chain *basechain =
413 nft_base_chain(ctx->chain);
414 const struct nf_hook_ops *ops = &basechain->ops;
415
416 par->hook_mask = 1 << ops->hooknum;
417 } else {
418 par->hook_mask = 0;
419 }
420 par->family = ctx->family;
421 par->nft_compat = true;
422 }
423
424 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
425 {
426 int pad;
427
428 memcpy(out, in, m->matchsize);
429 pad = XT_ALIGN(m->matchsize) - m->matchsize;
430 if (pad > 0)
431 memset(out + m->matchsize, 0, pad);
432 }
433
434 static int
435 __nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
436 const struct nlattr * const tb[],
437 void *info)
438 {
439 struct xt_match *match = expr->ops->data;
440 struct xt_mtchk_param par;
441 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
442 u16 proto = 0;
443 bool inv = false;
444 union nft_entry e = {};
445 int ret;
446
447 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
448
449 if (ctx->nla[NFTA_RULE_COMPAT]) {
450 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
451 if (ret < 0)
452 return ret;
453 }
454
455 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
456
457 return xt_check_match(&par, size, proto, inv);
458 }
459
460 static int
461 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
462 const struct nlattr * const tb[])
463 {
464 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr));
465 }
466
467 static int
468 nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
469 const struct nlattr * const tb[])
470 {
471 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
472 struct xt_match *m = expr->ops->data;
473 int ret;
474
475 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL);
476 if (!priv->info)
477 return -ENOMEM;
478
479 ret = __nft_match_init(ctx, expr, tb, priv->info);
480 if (ret)
481 kfree(priv->info);
482 return ret;
483 }
484
485 static void
486 __nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
487 void *info)
488 {
489 struct xt_match *match = expr->ops->data;
490 struct module *me = match->me;
491 struct xt_mtdtor_param par;
492
493 par.net = ctx->net;
494 par.match = match;
495 par.matchinfo = info;
496 par.family = ctx->family;
497 if (par.match->destroy != NULL)
498 par.match->destroy(&par);
499
500 module_put(me);
501 kfree(expr->ops);
502 }
503
504 static void
505 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
506 {
507 __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
508 }
509
510 static void
511 nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
512 {
513 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
514
515 __nft_match_destroy(ctx, expr, priv->info);
516 kfree(priv->info);
517 }
518
519 static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr,
520 void *info)
521 {
522 struct xt_match *match = expr->ops->data;
523
524 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
525 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
526 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info,
527 match->matchsize, match->usersize))
528 goto nla_put_failure;
529
530 return 0;
531
532 nla_put_failure:
533 return -1;
534 }
535
536 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
537 {
538 return __nft_match_dump(skb, expr, nft_expr_priv(expr));
539 }
540
541 static int nft_match_large_dump(struct sk_buff *skb, const struct nft_expr *e)
542 {
543 struct nft_xt_match_priv *priv = nft_expr_priv(e);
544
545 return __nft_match_dump(skb, e, priv->info);
546 }
547
548 static int nft_match_validate(const struct nft_ctx *ctx,
549 const struct nft_expr *expr,
550 const struct nft_data **data)
551 {
552 struct xt_match *match = expr->ops->data;
553 unsigned int hook_mask = 0;
554 int ret;
555
556 if (nft_is_base_chain(ctx->chain)) {
557 const struct nft_base_chain *basechain =
558 nft_base_chain(ctx->chain);
559 const struct nf_hook_ops *ops = &basechain->ops;
560
561 hook_mask = 1 << ops->hooknum;
562 if (match->hooks && !(hook_mask & match->hooks))
563 return -EINVAL;
564
565 ret = nft_compat_chain_validate_dependency(ctx, match->table);
566 if (ret < 0)
567 return ret;
568 }
569 return 0;
570 }
571
572 static int
573 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
574 int event, u16 family, const char *name,
575 int rev, int target)
576 {
577 struct nlmsghdr *nlh;
578 struct nfgenmsg *nfmsg;
579 unsigned int flags = portid ? NLM_F_MULTI : 0;
580
581 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event);
582 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
583 if (nlh == NULL)
584 goto nlmsg_failure;
585
586 nfmsg = nlmsg_data(nlh);
587 nfmsg->nfgen_family = family;
588 nfmsg->version = NFNETLINK_V0;
589 nfmsg->res_id = 0;
590
591 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
592 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
593 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
594 goto nla_put_failure;
595
596 nlmsg_end(skb, nlh);
597 return skb->len;
598
599 nlmsg_failure:
600 nla_put_failure:
601 nlmsg_cancel(skb, nlh);
602 return -1;
603 }
604
605 static int nfnl_compat_get_rcu(struct net *net, struct sock *nfnl,
606 struct sk_buff *skb, const struct nlmsghdr *nlh,
607 const struct nlattr * const tb[],
608 struct netlink_ext_ack *extack)
609 {
610 int ret = 0, target;
611 struct nfgenmsg *nfmsg;
612 const char *fmt;
613 const char *name;
614 u32 rev;
615 struct sk_buff *skb2;
616
617 if (tb[NFTA_COMPAT_NAME] == NULL ||
618 tb[NFTA_COMPAT_REV] == NULL ||
619 tb[NFTA_COMPAT_TYPE] == NULL)
620 return -EINVAL;
621
622 name = nla_data(tb[NFTA_COMPAT_NAME]);
623 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
624 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
625
626 nfmsg = nlmsg_data(nlh);
627
628 switch(nfmsg->nfgen_family) {
629 case AF_INET:
630 fmt = "ipt_%s";
631 break;
632 case AF_INET6:
633 fmt = "ip6t_%s";
634 break;
635 case NFPROTO_BRIDGE:
636 fmt = "ebt_%s";
637 break;
638 case NFPROTO_ARP:
639 fmt = "arpt_%s";
640 break;
641 default:
642 pr_err("nft_compat: unsupported protocol %d\n",
643 nfmsg->nfgen_family);
644 return -EINVAL;
645 }
646
647 if (!try_module_get(THIS_MODULE))
648 return -EINVAL;
649
650 rcu_read_unlock();
651 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
652 rev, target, &ret),
653 fmt, name);
654 if (ret < 0)
655 goto out_put;
656
657 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
658 if (skb2 == NULL) {
659 ret = -ENOMEM;
660 goto out_put;
661 }
662
663 /* include the best revision for this extension in the message */
664 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
665 nlh->nlmsg_seq,
666 NFNL_MSG_TYPE(nlh->nlmsg_type),
667 NFNL_MSG_COMPAT_GET,
668 nfmsg->nfgen_family,
669 name, ret, target) <= 0) {
670 kfree_skb(skb2);
671 goto out_put;
672 }
673
674 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
675 MSG_DONTWAIT);
676 if (ret > 0)
677 ret = 0;
678 out_put:
679 rcu_read_lock();
680 module_put(THIS_MODULE);
681 return ret == -EAGAIN ? -ENOBUFS : ret;
682 }
683
684 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
685 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
686 .len = NFT_COMPAT_NAME_MAX-1 },
687 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
688 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
689 };
690
691 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
692 [NFNL_MSG_COMPAT_GET] = { .call_rcu = nfnl_compat_get_rcu,
693 .attr_count = NFTA_COMPAT_MAX,
694 .policy = nfnl_compat_policy_get },
695 };
696
697 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
698 .name = "nft-compat",
699 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
700 .cb_count = NFNL_MSG_COMPAT_MAX,
701 .cb = nfnl_nft_compat_cb,
702 };
703
704 static struct nft_expr_type nft_match_type;
705
706 static const struct nft_expr_ops *
707 nft_match_select_ops(const struct nft_ctx *ctx,
708 const struct nlattr * const tb[])
709 {
710 struct nft_expr_ops *ops;
711 struct xt_match *match;
712 unsigned int matchsize;
713 char *mt_name;
714 u32 rev, family;
715 int err;
716
717 if (tb[NFTA_MATCH_NAME] == NULL ||
718 tb[NFTA_MATCH_REV] == NULL ||
719 tb[NFTA_MATCH_INFO] == NULL)
720 return ERR_PTR(-EINVAL);
721
722 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
723 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
724 family = ctx->family;
725
726 match = xt_request_find_match(family, mt_name, rev);
727 if (IS_ERR(match))
728 return ERR_PTR(-ENOENT);
729
730 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
731 err = -EINVAL;
732 goto err;
733 }
734
735 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
736 if (!ops) {
737 err = -ENOMEM;
738 goto err;
739 }
740
741 ops->type = &nft_match_type;
742 ops->eval = nft_match_eval;
743 ops->init = nft_match_init;
744 ops->destroy = nft_match_destroy;
745 ops->dump = nft_match_dump;
746 ops->validate = nft_match_validate;
747 ops->data = match;
748
749 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
750 if (matchsize > NFT_MATCH_LARGE_THRESH) {
751 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv));
752
753 ops->eval = nft_match_large_eval;
754 ops->init = nft_match_large_init;
755 ops->destroy = nft_match_large_destroy;
756 ops->dump = nft_match_large_dump;
757 }
758
759 ops->size = matchsize;
760
761 return ops;
762 err:
763 module_put(match->me);
764 return ERR_PTR(err);
765 }
766
767 static void nft_match_release_ops(const struct nft_expr_ops *ops)
768 {
769 struct xt_match *match = ops->data;
770
771 module_put(match->me);
772 kfree(ops);
773 }
774
775 static struct nft_expr_type nft_match_type __read_mostly = {
776 .name = "match",
777 .select_ops = nft_match_select_ops,
778 .release_ops = nft_match_release_ops,
779 .policy = nft_match_policy,
780 .maxattr = NFTA_MATCH_MAX,
781 .owner = THIS_MODULE,
782 };
783
784 static struct nft_expr_type nft_target_type;
785
786 static const struct nft_expr_ops *
787 nft_target_select_ops(const struct nft_ctx *ctx,
788 const struct nlattr * const tb[])
789 {
790 struct nft_expr_ops *ops;
791 struct xt_target *target;
792 char *tg_name;
793 u32 rev, family;
794 int err;
795
796 if (tb[NFTA_TARGET_NAME] == NULL ||
797 tb[NFTA_TARGET_REV] == NULL ||
798 tb[NFTA_TARGET_INFO] == NULL)
799 return ERR_PTR(-EINVAL);
800
801 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
802 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
803 family = ctx->family;
804
805 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 ||
806 strcmp(tg_name, XT_STANDARD_TARGET) == 0 ||
807 strcmp(tg_name, "standard") == 0)
808 return ERR_PTR(-EINVAL);
809
810 target = xt_request_find_target(family, tg_name, rev);
811 if (IS_ERR(target))
812 return ERR_PTR(-ENOENT);
813
814 if (!target->target) {
815 err = -EINVAL;
816 goto err;
817 }
818
819 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
820 err = -EINVAL;
821 goto err;
822 }
823
824 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
825 if (!ops) {
826 err = -ENOMEM;
827 goto err;
828 }
829
830 ops->type = &nft_target_type;
831 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
832 ops->init = nft_target_init;
833 ops->destroy = nft_target_destroy;
834 ops->dump = nft_target_dump;
835 ops->validate = nft_target_validate;
836 ops->data = target;
837
838 if (family == NFPROTO_BRIDGE)
839 ops->eval = nft_target_eval_bridge;
840 else
841 ops->eval = nft_target_eval_xt;
842
843 return ops;
844 err:
845 module_put(target->me);
846 return ERR_PTR(err);
847 }
848
849 static void nft_target_release_ops(const struct nft_expr_ops *ops)
850 {
851 struct xt_target *target = ops->data;
852
853 module_put(target->me);
854 kfree(ops);
855 }
856
857 static struct nft_expr_type nft_target_type __read_mostly = {
858 .name = "target",
859 .select_ops = nft_target_select_ops,
860 .release_ops = nft_target_release_ops,
861 .policy = nft_target_policy,
862 .maxattr = NFTA_TARGET_MAX,
863 .owner = THIS_MODULE,
864 };
865
866 static int __init nft_compat_module_init(void)
867 {
868 int ret;
869
870 ret = nft_register_expr(&nft_match_type);
871 if (ret < 0)
872 return ret;
873
874 ret = nft_register_expr(&nft_target_type);
875 if (ret < 0)
876 goto err_match;
877
878 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
879 if (ret < 0) {
880 pr_err("nft_compat: cannot register with nfnetlink.\n");
881 goto err_target;
882 }
883
884 return ret;
885 err_target:
886 nft_unregister_expr(&nft_target_type);
887 err_match:
888 nft_unregister_expr(&nft_match_type);
889 return ret;
890 }
891
892 static void __exit nft_compat_module_exit(void)
893 {
894 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
895 nft_unregister_expr(&nft_target_type);
896 nft_unregister_expr(&nft_match_type);
897 }
898
899 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
900
901 module_init(nft_compat_module_init);
902 module_exit(nft_compat_module_exit);
903
904 MODULE_LICENSE("GPL");
905 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
906 MODULE_ALIAS_NFT_EXPR("match");
907 MODULE_ALIAS_NFT_EXPR("target");
Linux with added FPC-III support