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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
4 *
5 * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/netlink.h>
12#include <linux/netfilter.h>
13#include <linux/netfilter/nfnetlink.h>
14#include <linux/netfilter/nf_tables.h>
15#include <linux/netfilter/nf_tables_compat.h>
16#include <linux/netfilter/x_tables.h>
17#include <linux/netfilter_ipv4/ip_tables.h>
18#include <linux/netfilter_ipv6/ip6_tables.h>
19#include <linux/netfilter_bridge/ebtables.h>
20#include <linux/netfilter_arp/arp_tables.h>
21#include <net/netfilter/nf_tables.h>
22#include <net/netfilter/nf_log.h>
23
24/* Used for matches where *info is larger than X byte */
25#define NFT_MATCH_LARGE_THRESH 192
26
27struct nft_xt_match_priv {
28 void *info;
29};
30
31static int nft_compat_chain_validate_dependency(const struct nft_ctx *ctx,
32 const char *tablename)
33{
34 enum nft_chain_types type = NFT_CHAIN_T_DEFAULT;
35 const struct nft_chain *chain = ctx->chain;
36 const struct nft_base_chain *basechain;
37
38 if (!tablename ||
39 !nft_is_base_chain(chain))
40 return 0;
41
42 basechain = nft_base_chain(chain);
43 if (strcmp(tablename, "nat") == 0) {
44 if (ctx->family != NFPROTO_BRIDGE)
45 type = NFT_CHAIN_T_NAT;
46 if (basechain->type->type != type)
47 return -EINVAL;
48 }
49
50 return 0;
51}
52
53union nft_entry {
54 struct ipt_entry e4;
55 struct ip6t_entry e6;
56 struct ebt_entry ebt;
57 struct arpt_entry arp;
58};
59
60static inline void
61nft_compat_set_par(struct xt_action_param *par,
62 const struct nft_pktinfo *pkt,
63 const void *xt, const void *xt_info)
64{
65 par->state = pkt->state;
66 par->thoff = nft_thoff(pkt);
67 par->fragoff = pkt->fragoff;
68 par->target = xt;
69 par->targinfo = xt_info;
70 par->hotdrop = false;
71}
72
73static void nft_target_eval_xt(const struct nft_expr *expr,
74 struct nft_regs *regs,
75 const struct nft_pktinfo *pkt)
76{
77 void *info = nft_expr_priv(expr);
78 struct xt_target *target = expr->ops->data;
79 struct sk_buff *skb = pkt->skb;
80 struct xt_action_param xt;
81 int ret;
82
83 nft_compat_set_par(&xt, pkt, target, info);
84
85 ret = target->target(skb, &xt);
86
87 if (xt.hotdrop)
88 ret = NF_DROP;
89
90 switch (ret) {
91 case XT_CONTINUE:
92 regs->verdict.code = NFT_CONTINUE;
93 break;
94 default:
95 regs->verdict.code = ret;
96 break;
97 }
98}
99
100static void nft_target_eval_bridge(const struct nft_expr *expr,
101 struct nft_regs *regs,
102 const struct nft_pktinfo *pkt)
103{
104 void *info = nft_expr_priv(expr);
105 struct xt_target *target = expr->ops->data;
106 struct sk_buff *skb = pkt->skb;
107 struct xt_action_param xt;
108 int ret;
109
110 nft_compat_set_par(&xt, pkt, target, info);
111
112 ret = target->target(skb, &xt);
113
114 if (xt.hotdrop)
115 ret = NF_DROP;
116
117 switch (ret) {
118 case EBT_ACCEPT:
119 regs->verdict.code = NF_ACCEPT;
120 break;
121 case EBT_DROP:
122 regs->verdict.code = NF_DROP;
123 break;
124 case EBT_CONTINUE:
125 regs->verdict.code = NFT_CONTINUE;
126 break;
127 case EBT_RETURN:
128 regs->verdict.code = NFT_RETURN;
129 break;
130 default:
131 regs->verdict.code = ret;
132 break;
133 }
134}
135
136static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
137 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
138 [NFTA_TARGET_REV] = { .type = NLA_U32 },
139 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
140};
141
142static void
143nft_target_set_tgchk_param(struct xt_tgchk_param *par,
144 const struct nft_ctx *ctx,
145 struct xt_target *target, void *info,
146 union nft_entry *entry, u16 proto, bool inv)
147{
148 par->net = ctx->net;
149 par->table = ctx->table->name;
150 switch (ctx->family) {
151 case AF_INET:
152 entry->e4.ip.proto = proto;
153 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
154 break;
155 case AF_INET6:
156 if (proto)
157 entry->e6.ipv6.flags |= IP6T_F_PROTO;
158
159 entry->e6.ipv6.proto = proto;
160 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
161 break;
162 case NFPROTO_BRIDGE:
163 entry->ebt.ethproto = (__force __be16)proto;
164 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
165 break;
166 case NFPROTO_ARP:
167 break;
168 }
169 par->entryinfo = entry;
170 par->target = target;
171 par->targinfo = info;
172 if (nft_is_base_chain(ctx->chain)) {
173 const struct nft_base_chain *basechain =
174 nft_base_chain(ctx->chain);
175 const struct nf_hook_ops *ops = &basechain->ops;
176
177 par->hook_mask = 1 << ops->hooknum;
178 } else {
179 par->hook_mask = 0;
180 }
181 par->family = ctx->family;
182 par->nft_compat = true;
183}
184
185static void target_compat_from_user(struct xt_target *t, void *in, void *out)
186{
187 int pad;
188
189 memcpy(out, in, t->targetsize);
190 pad = XT_ALIGN(t->targetsize) - t->targetsize;
191 if (pad > 0)
192 memset(out + t->targetsize, 0, pad);
193}
194
195static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
196 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
197 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
198};
199
200static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
201{
202 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
203 u32 flags;
204 int err;
205
206 err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_MAX, attr,
207 nft_rule_compat_policy, NULL);
208 if (err < 0)
209 return err;
210
211 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
212 return -EINVAL;
213
214 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
215 if (flags & ~NFT_RULE_COMPAT_F_MASK)
216 return -EINVAL;
217 if (flags & NFT_RULE_COMPAT_F_INV)
218 *inv = true;
219
220 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
221 return 0;
222}
223
224static void nft_compat_wait_for_destructors(void)
225{
226 /* xtables matches or targets can have side effects, e.g.
227 * creation/destruction of /proc files.
228 * The xt ->destroy functions are run asynchronously from
229 * work queue. If we have pending invocations we thus
230 * need to wait for those to finish.
231 */
232 nf_tables_trans_destroy_flush_work();
233}
234
235static int
236nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
237 const struct nlattr * const tb[])
238{
239 void *info = nft_expr_priv(expr);
240 struct xt_target *target = expr->ops->data;
241 struct xt_tgchk_param par;
242 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
243 u16 proto = 0;
244 bool inv = false;
245 union nft_entry e = {};
246 int ret;
247
248 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
249
250 if (ctx->nla[NFTA_RULE_COMPAT]) {
251 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
252 if (ret < 0)
253 return ret;
254 }
255
256 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
257
258 nft_compat_wait_for_destructors();
259
260 ret = xt_check_target(&par, size, proto, inv);
261 if (ret < 0) {
262 if (ret == -ENOENT) {
263 const char *modname = NULL;
264
265 if (strcmp(target->name, "LOG") == 0)
266 modname = "nf_log_syslog";
267 else if (strcmp(target->name, "NFLOG") == 0)
268 modname = "nfnetlink_log";
269
270 if (modname &&
271 nft_request_module(ctx->net, "%s", modname) == -EAGAIN)
272 return -EAGAIN;
273 }
274
275 return ret;
276 }
277
278 /* The standard target cannot be used */
279 if (!target->target)
280 return -EINVAL;
281
282 return 0;
283}
284
285static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr)
286{
287 module_put(me);
288 kfree(expr->ops);
289}
290
291static void
292nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
293{
294 struct xt_target *target = expr->ops->data;
295 void *info = nft_expr_priv(expr);
296 struct module *me = target->me;
297 struct xt_tgdtor_param par;
298
299 par.net = ctx->net;
300 par.target = target;
301 par.targinfo = info;
302 par.family = ctx->family;
303 if (par.target->destroy != NULL)
304 par.target->destroy(&par);
305
306 __nft_mt_tg_destroy(me, expr);
307}
308
309static int nft_extension_dump_info(struct sk_buff *skb, int attr,
310 const void *info,
311 unsigned int size, unsigned int user_size)
312{
313 unsigned int info_size, aligned_size = XT_ALIGN(size);
314 struct nlattr *nla;
315
316 nla = nla_reserve(skb, attr, aligned_size);
317 if (!nla)
318 return -1;
319
320 info_size = user_size ? : size;
321 memcpy(nla_data(nla), info, info_size);
322 memset(nla_data(nla) + info_size, 0, aligned_size - info_size);
323
324 return 0;
325}
326
327static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
328{
329 const struct xt_target *target = expr->ops->data;
330 void *info = nft_expr_priv(expr);
331
332 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
333 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
334 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info,
335 target->targetsize, target->usersize))
336 goto nla_put_failure;
337
338 return 0;
339
340nla_put_failure:
341 return -1;
342}
343
344static int nft_target_validate(const struct nft_ctx *ctx,
345 const struct nft_expr *expr,
346 const struct nft_data **data)
347{
348 struct xt_target *target = expr->ops->data;
349 unsigned int hook_mask = 0;
350 int ret;
351
352 if (nft_is_base_chain(ctx->chain)) {
353 const struct nft_base_chain *basechain =
354 nft_base_chain(ctx->chain);
355 const struct nf_hook_ops *ops = &basechain->ops;
356
357 hook_mask = 1 << ops->hooknum;
358 if (target->hooks && !(hook_mask & target->hooks))
359 return -EINVAL;
360
361 ret = nft_compat_chain_validate_dependency(ctx, target->table);
362 if (ret < 0)
363 return ret;
364 }
365 return 0;
366}
367
368static void __nft_match_eval(const struct nft_expr *expr,
369 struct nft_regs *regs,
370 const struct nft_pktinfo *pkt,
371 void *info)
372{
373 struct xt_match *match = expr->ops->data;
374 struct sk_buff *skb = pkt->skb;
375 struct xt_action_param xt;
376 bool ret;
377
378 nft_compat_set_par(&xt, pkt, match, info);
379
380 ret = match->match(skb, &xt);
381
382 if (xt.hotdrop) {
383 regs->verdict.code = NF_DROP;
384 return;
385 }
386
387 switch (ret ? 1 : 0) {
388 case 1:
389 regs->verdict.code = NFT_CONTINUE;
390 break;
391 case 0:
392 regs->verdict.code = NFT_BREAK;
393 break;
394 }
395}
396
397static void nft_match_large_eval(const struct nft_expr *expr,
398 struct nft_regs *regs,
399 const struct nft_pktinfo *pkt)
400{
401 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
402
403 __nft_match_eval(expr, regs, pkt, priv->info);
404}
405
406static void nft_match_eval(const struct nft_expr *expr,
407 struct nft_regs *regs,
408 const struct nft_pktinfo *pkt)
409{
410 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr));
411}
412
413static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
414 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
415 [NFTA_MATCH_REV] = { .type = NLA_U32 },
416 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
417};
418
419/* struct xt_mtchk_param and xt_tgchk_param look very similar */
420static void
421nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
422 struct xt_match *match, void *info,
423 union nft_entry *entry, u16 proto, bool inv)
424{
425 par->net = ctx->net;
426 par->table = ctx->table->name;
427 switch (ctx->family) {
428 case AF_INET:
429 entry->e4.ip.proto = proto;
430 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
431 break;
432 case AF_INET6:
433 if (proto)
434 entry->e6.ipv6.flags |= IP6T_F_PROTO;
435
436 entry->e6.ipv6.proto = proto;
437 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
438 break;
439 case NFPROTO_BRIDGE:
440 entry->ebt.ethproto = (__force __be16)proto;
441 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
442 break;
443 case NFPROTO_ARP:
444 break;
445 }
446 par->entryinfo = entry;
447 par->match = match;
448 par->matchinfo = info;
449 if (nft_is_base_chain(ctx->chain)) {
450 const struct nft_base_chain *basechain =
451 nft_base_chain(ctx->chain);
452 const struct nf_hook_ops *ops = &basechain->ops;
453
454 par->hook_mask = 1 << ops->hooknum;
455 } else {
456 par->hook_mask = 0;
457 }
458 par->family = ctx->family;
459 par->nft_compat = true;
460}
461
462static void match_compat_from_user(struct xt_match *m, void *in, void *out)
463{
464 int pad;
465
466 memcpy(out, in, m->matchsize);
467 pad = XT_ALIGN(m->matchsize) - m->matchsize;
468 if (pad > 0)
469 memset(out + m->matchsize, 0, pad);
470}
471
472static int
473__nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
474 const struct nlattr * const tb[],
475 void *info)
476{
477 struct xt_match *match = expr->ops->data;
478 struct xt_mtchk_param par;
479 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
480 u16 proto = 0;
481 bool inv = false;
482 union nft_entry e = {};
483 int ret;
484
485 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
486
487 if (ctx->nla[NFTA_RULE_COMPAT]) {
488 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
489 if (ret < 0)
490 return ret;
491 }
492
493 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
494
495 nft_compat_wait_for_destructors();
496
497 return xt_check_match(&par, size, proto, inv);
498}
499
500static int
501nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
502 const struct nlattr * const tb[])
503{
504 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr));
505}
506
507static int
508nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
509 const struct nlattr * const tb[])
510{
511 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
512 struct xt_match *m = expr->ops->data;
513 int ret;
514
515 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL);
516 if (!priv->info)
517 return -ENOMEM;
518
519 ret = __nft_match_init(ctx, expr, tb, priv->info);
520 if (ret)
521 kfree(priv->info);
522 return ret;
523}
524
525static void
526__nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
527 void *info)
528{
529 struct xt_match *match = expr->ops->data;
530 struct module *me = match->me;
531 struct xt_mtdtor_param par;
532
533 par.net = ctx->net;
534 par.match = match;
535 par.matchinfo = info;
536 par.family = ctx->family;
537 if (par.match->destroy != NULL)
538 par.match->destroy(&par);
539
540 __nft_mt_tg_destroy(me, expr);
541}
542
543static void
544nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
545{
546 __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
547}
548
549static void
550nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
551{
552 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
553
554 __nft_match_destroy(ctx, expr, priv->info);
555 kfree(priv->info);
556}
557
558static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr,
559 void *info)
560{
561 struct xt_match *match = expr->ops->data;
562
563 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
564 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
565 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info,
566 match->matchsize, match->usersize))
567 goto nla_put_failure;
568
569 return 0;
570
571nla_put_failure:
572 return -1;
573}
574
575static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
576{
577 return __nft_match_dump(skb, expr, nft_expr_priv(expr));
578}
579
580static int nft_match_large_dump(struct sk_buff *skb, const struct nft_expr *e)
581{
582 struct nft_xt_match_priv *priv = nft_expr_priv(e);
583
584 return __nft_match_dump(skb, e, priv->info);
585}
586
587static int nft_match_validate(const struct nft_ctx *ctx,
588 const struct nft_expr *expr,
589 const struct nft_data **data)
590{
591 struct xt_match *match = expr->ops->data;
592 unsigned int hook_mask = 0;
593 int ret;
594
595 if (nft_is_base_chain(ctx->chain)) {
596 const struct nft_base_chain *basechain =
597 nft_base_chain(ctx->chain);
598 const struct nf_hook_ops *ops = &basechain->ops;
599
600 hook_mask = 1 << ops->hooknum;
601 if (match->hooks && !(hook_mask & match->hooks))
602 return -EINVAL;
603
604 ret = nft_compat_chain_validate_dependency(ctx, match->table);
605 if (ret < 0)
606 return ret;
607 }
608 return 0;
609}
610
611static int
612nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
613 int event, u16 family, const char *name,
614 int rev, int target)
615{
616 struct nlmsghdr *nlh;
617 unsigned int flags = portid ? NLM_F_MULTI : 0;
618
619 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event);
620 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family,
621 NFNETLINK_V0, 0);
622 if (!nlh)
623 goto nlmsg_failure;
624
625 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
626 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
627 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
628 goto nla_put_failure;
629
630 nlmsg_end(skb, nlh);
631 return skb->len;
632
633nlmsg_failure:
634nla_put_failure:
635 nlmsg_cancel(skb, nlh);
636 return -1;
637}
638
639static int nfnl_compat_get_rcu(struct sk_buff *skb,
640 const struct nfnl_info *info,
641 const struct nlattr * const tb[])
642{
643 u8 family = info->nfmsg->nfgen_family;
644 const char *name, *fmt;
645 struct sk_buff *skb2;
646 int ret = 0, target;
647 u32 rev;
648
649 if (tb[NFTA_COMPAT_NAME] == NULL ||
650 tb[NFTA_COMPAT_REV] == NULL ||
651 tb[NFTA_COMPAT_TYPE] == NULL)
652 return -EINVAL;
653
654 name = nla_data(tb[NFTA_COMPAT_NAME]);
655 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
656 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
657
658 switch(family) {
659 case AF_INET:
660 fmt = "ipt_%s";
661 break;
662 case AF_INET6:
663 fmt = "ip6t_%s";
664 break;
665 case NFPROTO_BRIDGE:
666 fmt = "ebt_%s";
667 break;
668 case NFPROTO_ARP:
669 fmt = "arpt_%s";
670 break;
671 default:
672 pr_err("nft_compat: unsupported protocol %d\n", family);
673 return -EINVAL;
674 }
675
676 if (!try_module_get(THIS_MODULE))
677 return -EINVAL;
678
679 rcu_read_unlock();
680 try_then_request_module(xt_find_revision(family, name, rev, target, &ret),
681 fmt, name);
682 if (ret < 0)
683 goto out_put;
684
685 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
686 if (skb2 == NULL) {
687 ret = -ENOMEM;
688 goto out_put;
689 }
690
691 /* include the best revision for this extension in the message */
692 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
693 info->nlh->nlmsg_seq,
694 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
695 NFNL_MSG_COMPAT_GET,
696 family, name, ret, target) <= 0) {
697 kfree_skb(skb2);
698 goto out_put;
699 }
700
701 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
702out_put:
703 rcu_read_lock();
704 module_put(THIS_MODULE);
705
706 return ret;
707}
708
709static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
710 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
711 .len = NFT_COMPAT_NAME_MAX-1 },
712 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
713 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
714};
715
716static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
717 [NFNL_MSG_COMPAT_GET] = {
718 .call = nfnl_compat_get_rcu,
719 .type = NFNL_CB_RCU,
720 .attr_count = NFTA_COMPAT_MAX,
721 .policy = nfnl_compat_policy_get
722 },
723};
724
725static const struct nfnetlink_subsystem nfnl_compat_subsys = {
726 .name = "nft-compat",
727 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
728 .cb_count = NFNL_MSG_COMPAT_MAX,
729 .cb = nfnl_nft_compat_cb,
730};
731
732static struct nft_expr_type nft_match_type;
733
734static const struct nft_expr_ops *
735nft_match_select_ops(const struct nft_ctx *ctx,
736 const struct nlattr * const tb[])
737{
738 struct nft_expr_ops *ops;
739 struct xt_match *match;
740 unsigned int matchsize;
741 char *mt_name;
742 u32 rev, family;
743 int err;
744
745 if (tb[NFTA_MATCH_NAME] == NULL ||
746 tb[NFTA_MATCH_REV] == NULL ||
747 tb[NFTA_MATCH_INFO] == NULL)
748 return ERR_PTR(-EINVAL);
749
750 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
751 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
752 family = ctx->family;
753
754 match = xt_request_find_match(family, mt_name, rev);
755 if (IS_ERR(match))
756 return ERR_PTR(-ENOENT);
757
758 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
759 err = -EINVAL;
760 goto err;
761 }
762
763 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
764 if (!ops) {
765 err = -ENOMEM;
766 goto err;
767 }
768
769 ops->type = &nft_match_type;
770 ops->eval = nft_match_eval;
771 ops->init = nft_match_init;
772 ops->destroy = nft_match_destroy;
773 ops->dump = nft_match_dump;
774 ops->validate = nft_match_validate;
775 ops->data = match;
776
777 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
778 if (matchsize > NFT_MATCH_LARGE_THRESH) {
779 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv));
780
781 ops->eval = nft_match_large_eval;
782 ops->init = nft_match_large_init;
783 ops->destroy = nft_match_large_destroy;
784 ops->dump = nft_match_large_dump;
785 }
786
787 ops->size = matchsize;
788
789 return ops;
790err:
791 module_put(match->me);
792 return ERR_PTR(err);
793}
794
795static void nft_match_release_ops(const struct nft_expr_ops *ops)
796{
797 struct xt_match *match = ops->data;
798
799 module_put(match->me);
800 kfree(ops);
801}
802
803static struct nft_expr_type nft_match_type __read_mostly = {
804 .name = "match",
805 .select_ops = nft_match_select_ops,
806 .release_ops = nft_match_release_ops,
807 .policy = nft_match_policy,
808 .maxattr = NFTA_MATCH_MAX,
809 .owner = THIS_MODULE,
810};
811
812static struct nft_expr_type nft_target_type;
813
814static const struct nft_expr_ops *
815nft_target_select_ops(const struct nft_ctx *ctx,
816 const struct nlattr * const tb[])
817{
818 struct nft_expr_ops *ops;
819 struct xt_target *target;
820 char *tg_name;
821 u32 rev, family;
822 int err;
823
824 if (tb[NFTA_TARGET_NAME] == NULL ||
825 tb[NFTA_TARGET_REV] == NULL ||
826 tb[NFTA_TARGET_INFO] == NULL)
827 return ERR_PTR(-EINVAL);
828
829 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
830 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
831 family = ctx->family;
832
833 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 ||
834 strcmp(tg_name, XT_STANDARD_TARGET) == 0 ||
835 strcmp(tg_name, "standard") == 0)
836 return ERR_PTR(-EINVAL);
837
838 target = xt_request_find_target(family, tg_name, rev);
839 if (IS_ERR(target))
840 return ERR_PTR(-ENOENT);
841
842 if (!target->target) {
843 err = -EINVAL;
844 goto err;
845 }
846
847 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
848 err = -EINVAL;
849 goto err;
850 }
851
852 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
853 if (!ops) {
854 err = -ENOMEM;
855 goto err;
856 }
857
858 ops->type = &nft_target_type;
859 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
860 ops->init = nft_target_init;
861 ops->destroy = nft_target_destroy;
862 ops->dump = nft_target_dump;
863 ops->validate = nft_target_validate;
864 ops->data = target;
865
866 if (family == NFPROTO_BRIDGE)
867 ops->eval = nft_target_eval_bridge;
868 else
869 ops->eval = nft_target_eval_xt;
870
871 return ops;
872err:
873 module_put(target->me);
874 return ERR_PTR(err);
875}
876
877static void nft_target_release_ops(const struct nft_expr_ops *ops)
878{
879 struct xt_target *target = ops->data;
880
881 module_put(target->me);
882 kfree(ops);
883}
884
885static struct nft_expr_type nft_target_type __read_mostly = {
886 .name = "target",
887 .select_ops = nft_target_select_ops,
888 .release_ops = nft_target_release_ops,
889 .policy = nft_target_policy,
890 .maxattr = NFTA_TARGET_MAX,
891 .owner = THIS_MODULE,
892};
893
894static int __init nft_compat_module_init(void)
895{
896 int ret;
897
898 ret = nft_register_expr(&nft_match_type);
899 if (ret < 0)
900 return ret;
901
902 ret = nft_register_expr(&nft_target_type);
903 if (ret < 0)
904 goto err_match;
905
906 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
907 if (ret < 0) {
908 pr_err("nft_compat: cannot register with nfnetlink.\n");
909 goto err_target;
910 }
911
912 return ret;
913err_target:
914 nft_unregister_expr(&nft_target_type);
915err_match:
916 nft_unregister_expr(&nft_match_type);
917 return ret;
918}
919
920static void __exit nft_compat_module_exit(void)
921{
922 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
923 nft_unregister_expr(&nft_target_type);
924 nft_unregister_expr(&nft_match_type);
925}
926
927MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
928
929module_init(nft_compat_module_init);
930module_exit(nft_compat_module_exit);
931
932MODULE_LICENSE("GPL");
933MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
934MODULE_ALIAS_NFT_EXPR("match");
935MODULE_ALIAS_NFT_EXPR("target");
936MODULE_DESCRIPTION("x_tables over nftables support");
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 <asm/uaccess.h> /* for set_fs */
23#include <net/netfilter/nf_tables.h>
24
25union nft_entry {
26 struct ipt_entry e4;
27 struct ip6t_entry e6;
28};
29
30static inline void
31nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
32{
33 par->target = xt;
34 par->targinfo = xt_info;
35 par->hotdrop = false;
36}
37
38static void nft_target_eval(const struct nft_expr *expr,
39 struct nft_data data[NFT_REG_MAX + 1],
40 const struct nft_pktinfo *pkt)
41{
42 void *info = nft_expr_priv(expr);
43 struct xt_target *target = expr->ops->data;
44 struct sk_buff *skb = pkt->skb;
45 int ret;
46
47 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
48
49 ret = target->target(skb, &pkt->xt);
50
51 if (pkt->xt.hotdrop)
52 ret = NF_DROP;
53
54 switch(ret) {
55 case XT_CONTINUE:
56 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
57 break;
58 default:
59 data[NFT_REG_VERDICT].verdict = ret;
60 break;
61 }
62 return;
63}
64
65static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
66 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
67 [NFTA_TARGET_REV] = { .type = NLA_U32 },
68 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
69};
70
71static void
72nft_target_set_tgchk_param(struct xt_tgchk_param *par,
73 const struct nft_ctx *ctx,
74 struct xt_target *target, void *info,
75 union nft_entry *entry, u8 proto, bool inv)
76{
77 par->net = &init_net;
78 par->table = ctx->table->name;
79 switch (ctx->afi->family) {
80 case AF_INET:
81 entry->e4.ip.proto = proto;
82 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
83 break;
84 case AF_INET6:
85 entry->e6.ipv6.proto = proto;
86 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
87 break;
88 }
89 par->entryinfo = entry;
90 par->target = target;
91 par->targinfo = info;
92 if (ctx->chain->flags & NFT_BASE_CHAIN) {
93 const struct nft_base_chain *basechain =
94 nft_base_chain(ctx->chain);
95 const struct nf_hook_ops *ops = &basechain->ops[0];
96
97 par->hook_mask = 1 << ops->hooknum;
98 }
99 par->family = ctx->afi->family;
100}
101
102static void target_compat_from_user(struct xt_target *t, void *in, void *out)
103{
104#ifdef CONFIG_COMPAT
105 if (t->compat_from_user) {
106 int pad;
107
108 t->compat_from_user(out, in);
109 pad = XT_ALIGN(t->targetsize) - t->targetsize;
110 if (pad > 0)
111 memset(out + t->targetsize, 0, pad);
112 } else
113#endif
114 memcpy(out, in, XT_ALIGN(t->targetsize));
115}
116
117static inline int nft_compat_target_offset(struct xt_target *target)
118{
119#ifdef CONFIG_COMPAT
120 return xt_compat_target_offset(target);
121#else
122 return 0;
123#endif
124}
125
126static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
127 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
128 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
129};
130
131static int nft_parse_compat(const struct nlattr *attr, u8 *proto, bool *inv)
132{
133 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
134 u32 flags;
135 int err;
136
137 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
138 nft_rule_compat_policy);
139 if (err < 0)
140 return err;
141
142 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
143 return -EINVAL;
144
145 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
146 if (flags & ~NFT_RULE_COMPAT_F_MASK)
147 return -EINVAL;
148 if (flags & NFT_RULE_COMPAT_F_INV)
149 *inv = true;
150
151 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
152 return 0;
153}
154
155static int
156nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
157 const struct nlattr * const tb[])
158{
159 void *info = nft_expr_priv(expr);
160 struct xt_target *target = expr->ops->data;
161 struct xt_tgchk_param par;
162 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
163 u8 proto = 0;
164 bool inv = false;
165 union nft_entry e = {};
166 int ret;
167
168 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
169
170 if (ctx->nla[NFTA_RULE_COMPAT]) {
171 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
172 if (ret < 0)
173 goto err;
174 }
175
176 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
177
178 ret = xt_check_target(&par, size, proto, inv);
179 if (ret < 0)
180 goto err;
181
182 /* The standard target cannot be used */
183 if (target->target == NULL) {
184 ret = -EINVAL;
185 goto err;
186 }
187
188 return 0;
189err:
190 module_put(target->me);
191 return ret;
192}
193
194static void
195nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
196{
197 struct xt_target *target = expr->ops->data;
198
199 module_put(target->me);
200}
201
202static int
203target_dump_info(struct sk_buff *skb, const struct xt_target *t, const void *in)
204{
205 int ret;
206
207#ifdef CONFIG_COMPAT
208 if (t->compat_to_user) {
209 mm_segment_t old_fs;
210 void *out;
211
212 out = kmalloc(XT_ALIGN(t->targetsize), GFP_ATOMIC);
213 if (out == NULL)
214 return -ENOMEM;
215
216 /* We want to reuse existing compat_to_user */
217 old_fs = get_fs();
218 set_fs(KERNEL_DS);
219 t->compat_to_user(out, in);
220 set_fs(old_fs);
221 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), out);
222 kfree(out);
223 } else
224#endif
225 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), in);
226
227 return ret;
228}
229
230static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
231{
232 const struct xt_target *target = expr->ops->data;
233 void *info = nft_expr_priv(expr);
234
235 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
236 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
237 target_dump_info(skb, target, info))
238 goto nla_put_failure;
239
240 return 0;
241
242nla_put_failure:
243 return -1;
244}
245
246static int nft_target_validate(const struct nft_ctx *ctx,
247 const struct nft_expr *expr,
248 const struct nft_data **data)
249{
250 struct xt_target *target = expr->ops->data;
251 unsigned int hook_mask = 0;
252
253 if (ctx->chain->flags & NFT_BASE_CHAIN) {
254 const struct nft_base_chain *basechain =
255 nft_base_chain(ctx->chain);
256 const struct nf_hook_ops *ops = &basechain->ops[0];
257
258 hook_mask = 1 << ops->hooknum;
259 if (hook_mask & target->hooks)
260 return 0;
261
262 /* This target is being called from an invalid chain */
263 return -EINVAL;
264 }
265 return 0;
266}
267
268static void nft_match_eval(const struct nft_expr *expr,
269 struct nft_data data[NFT_REG_MAX + 1],
270 const struct nft_pktinfo *pkt)
271{
272 void *info = nft_expr_priv(expr);
273 struct xt_match *match = expr->ops->data;
274 struct sk_buff *skb = pkt->skb;
275 bool ret;
276
277 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
278
279 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
280
281 if (pkt->xt.hotdrop) {
282 data[NFT_REG_VERDICT].verdict = NF_DROP;
283 return;
284 }
285
286 switch(ret) {
287 case true:
288 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
289 break;
290 case false:
291 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
292 break;
293 }
294}
295
296static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
297 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
298 [NFTA_MATCH_REV] = { .type = NLA_U32 },
299 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
300};
301
302/* struct xt_mtchk_param and xt_tgchk_param look very similar */
303static void
304nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
305 struct xt_match *match, void *info,
306 union nft_entry *entry, u8 proto, bool inv)
307{
308 par->net = &init_net;
309 par->table = ctx->table->name;
310 switch (ctx->afi->family) {
311 case AF_INET:
312 entry->e4.ip.proto = proto;
313 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
314 break;
315 case AF_INET6:
316 entry->e6.ipv6.proto = proto;
317 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
318 break;
319 }
320 par->entryinfo = entry;
321 par->match = match;
322 par->matchinfo = info;
323 if (ctx->chain->flags & NFT_BASE_CHAIN) {
324 const struct nft_base_chain *basechain =
325 nft_base_chain(ctx->chain);
326 const struct nf_hook_ops *ops = &basechain->ops[0];
327
328 par->hook_mask = 1 << ops->hooknum;
329 }
330 par->family = ctx->afi->family;
331}
332
333static void match_compat_from_user(struct xt_match *m, void *in, void *out)
334{
335#ifdef CONFIG_COMPAT
336 if (m->compat_from_user) {
337 int pad;
338
339 m->compat_from_user(out, in);
340 pad = XT_ALIGN(m->matchsize) - m->matchsize;
341 if (pad > 0)
342 memset(out + m->matchsize, 0, pad);
343 } else
344#endif
345 memcpy(out, in, XT_ALIGN(m->matchsize));
346}
347
348static int
349nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
350 const struct nlattr * const tb[])
351{
352 void *info = nft_expr_priv(expr);
353 struct xt_match *match = expr->ops->data;
354 struct xt_mtchk_param par;
355 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
356 u8 proto = 0;
357 bool inv = false;
358 union nft_entry e = {};
359 int ret;
360
361 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
362
363 if (ctx->nla[NFTA_RULE_COMPAT]) {
364 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
365 if (ret < 0)
366 goto err;
367 }
368
369 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
370
371 ret = xt_check_match(&par, size, proto, inv);
372 if (ret < 0)
373 goto err;
374
375 return 0;
376err:
377 module_put(match->me);
378 return ret;
379}
380
381static void
382nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
383{
384 struct xt_match *match = expr->ops->data;
385
386 module_put(match->me);
387}
388
389static int
390match_dump_info(struct sk_buff *skb, const struct xt_match *m, const void *in)
391{
392 int ret;
393
394#ifdef CONFIG_COMPAT
395 if (m->compat_to_user) {
396 mm_segment_t old_fs;
397 void *out;
398
399 out = kmalloc(XT_ALIGN(m->matchsize), GFP_ATOMIC);
400 if (out == NULL)
401 return -ENOMEM;
402
403 /* We want to reuse existing compat_to_user */
404 old_fs = get_fs();
405 set_fs(KERNEL_DS);
406 m->compat_to_user(out, in);
407 set_fs(old_fs);
408 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), out);
409 kfree(out);
410 } else
411#endif
412 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), in);
413
414 return ret;
415}
416
417static inline int nft_compat_match_offset(struct xt_match *match)
418{
419#ifdef CONFIG_COMPAT
420 return xt_compat_match_offset(match);
421#else
422 return 0;
423#endif
424}
425
426static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
427{
428 void *info = nft_expr_priv(expr);
429 struct xt_match *match = expr->ops->data;
430
431 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
432 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
433 match_dump_info(skb, match, info))
434 goto nla_put_failure;
435
436 return 0;
437
438nla_put_failure:
439 return -1;
440}
441
442static int nft_match_validate(const struct nft_ctx *ctx,
443 const struct nft_expr *expr,
444 const struct nft_data **data)
445{
446 struct xt_match *match = expr->ops->data;
447 unsigned int hook_mask = 0;
448
449 if (ctx->chain->flags & NFT_BASE_CHAIN) {
450 const struct nft_base_chain *basechain =
451 nft_base_chain(ctx->chain);
452 const struct nf_hook_ops *ops = &basechain->ops[0];
453
454 hook_mask = 1 << ops->hooknum;
455 if (hook_mask & match->hooks)
456 return 0;
457
458 /* This match is being called from an invalid chain */
459 return -EINVAL;
460 }
461 return 0;
462}
463
464static int
465nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
466 int event, u16 family, const char *name,
467 int rev, int target)
468{
469 struct nlmsghdr *nlh;
470 struct nfgenmsg *nfmsg;
471 unsigned int flags = portid ? NLM_F_MULTI : 0;
472
473 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
474 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
475 if (nlh == NULL)
476 goto nlmsg_failure;
477
478 nfmsg = nlmsg_data(nlh);
479 nfmsg->nfgen_family = family;
480 nfmsg->version = NFNETLINK_V0;
481 nfmsg->res_id = 0;
482
483 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
484 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
485 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
486 goto nla_put_failure;
487
488 nlmsg_end(skb, nlh);
489 return skb->len;
490
491nlmsg_failure:
492nla_put_failure:
493 nlmsg_cancel(skb, nlh);
494 return -1;
495}
496
497static int
498nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
499 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
500{
501 int ret = 0, target;
502 struct nfgenmsg *nfmsg;
503 const char *fmt;
504 const char *name;
505 u32 rev;
506 struct sk_buff *skb2;
507
508 if (tb[NFTA_COMPAT_NAME] == NULL ||
509 tb[NFTA_COMPAT_REV] == NULL ||
510 tb[NFTA_COMPAT_TYPE] == NULL)
511 return -EINVAL;
512
513 name = nla_data(tb[NFTA_COMPAT_NAME]);
514 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
515 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
516
517 nfmsg = nlmsg_data(nlh);
518
519 switch(nfmsg->nfgen_family) {
520 case AF_INET:
521 fmt = "ipt_%s";
522 break;
523 case AF_INET6:
524 fmt = "ip6t_%s";
525 break;
526 default:
527 pr_err("nft_compat: unsupported protocol %d\n",
528 nfmsg->nfgen_family);
529 return -EINVAL;
530 }
531
532 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
533 rev, target, &ret),
534 fmt, name);
535
536 if (ret < 0)
537 return ret;
538
539 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
540 if (skb2 == NULL)
541 return -ENOMEM;
542
543 /* include the best revision for this extension in the message */
544 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
545 nlh->nlmsg_seq,
546 NFNL_MSG_TYPE(nlh->nlmsg_type),
547 NFNL_MSG_COMPAT_GET,
548 nfmsg->nfgen_family,
549 name, ret, target) <= 0) {
550 kfree_skb(skb2);
551 return -ENOSPC;
552 }
553
554 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
555 MSG_DONTWAIT);
556 if (ret > 0)
557 ret = 0;
558
559 return ret == -EAGAIN ? -ENOBUFS : ret;
560}
561
562static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
563 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
564 .len = NFT_COMPAT_NAME_MAX-1 },
565 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
566 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
567};
568
569static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
570 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
571 .attr_count = NFTA_COMPAT_MAX,
572 .policy = nfnl_compat_policy_get },
573};
574
575static const struct nfnetlink_subsystem nfnl_compat_subsys = {
576 .name = "nft-compat",
577 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
578 .cb_count = NFNL_MSG_COMPAT_MAX,
579 .cb = nfnl_nft_compat_cb,
580};
581
582static LIST_HEAD(nft_match_list);
583
584struct nft_xt {
585 struct list_head head;
586 struct nft_expr_ops ops;
587};
588
589static struct nft_expr_type nft_match_type;
590
591static const struct nft_expr_ops *
592nft_match_select_ops(const struct nft_ctx *ctx,
593 const struct nlattr * const tb[])
594{
595 struct nft_xt *nft_match;
596 struct xt_match *match;
597 char *mt_name;
598 __u32 rev, family;
599
600 if (tb[NFTA_MATCH_NAME] == NULL ||
601 tb[NFTA_MATCH_REV] == NULL ||
602 tb[NFTA_MATCH_INFO] == NULL)
603 return ERR_PTR(-EINVAL);
604
605 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
606 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
607 family = ctx->afi->family;
608
609 /* Re-use the existing match if it's already loaded. */
610 list_for_each_entry(nft_match, &nft_match_list, head) {
611 struct xt_match *match = nft_match->ops.data;
612
613 if (strcmp(match->name, mt_name) == 0 &&
614 match->revision == rev && match->family == family)
615 return &nft_match->ops;
616 }
617
618 match = xt_request_find_match(family, mt_name, rev);
619 if (IS_ERR(match))
620 return ERR_PTR(-ENOENT);
621
622 /* This is the first time we use this match, allocate operations */
623 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
624 if (nft_match == NULL)
625 return ERR_PTR(-ENOMEM);
626
627 nft_match->ops.type = &nft_match_type;
628 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize) +
629 nft_compat_match_offset(match));
630 nft_match->ops.eval = nft_match_eval;
631 nft_match->ops.init = nft_match_init;
632 nft_match->ops.destroy = nft_match_destroy;
633 nft_match->ops.dump = nft_match_dump;
634 nft_match->ops.validate = nft_match_validate;
635 nft_match->ops.data = match;
636
637 list_add(&nft_match->head, &nft_match_list);
638
639 return &nft_match->ops;
640}
641
642static void nft_match_release(void)
643{
644 struct nft_xt *nft_match, *tmp;
645
646 list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
647 kfree(nft_match);
648}
649
650static struct nft_expr_type nft_match_type __read_mostly = {
651 .name = "match",
652 .select_ops = nft_match_select_ops,
653 .policy = nft_match_policy,
654 .maxattr = NFTA_MATCH_MAX,
655 .owner = THIS_MODULE,
656};
657
658static LIST_HEAD(nft_target_list);
659
660static struct nft_expr_type nft_target_type;
661
662static const struct nft_expr_ops *
663nft_target_select_ops(const struct nft_ctx *ctx,
664 const struct nlattr * const tb[])
665{
666 struct nft_xt *nft_target;
667 struct xt_target *target;
668 char *tg_name;
669 __u32 rev, family;
670
671 if (tb[NFTA_TARGET_NAME] == NULL ||
672 tb[NFTA_TARGET_REV] == NULL ||
673 tb[NFTA_TARGET_INFO] == NULL)
674 return ERR_PTR(-EINVAL);
675
676 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
677 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
678 family = ctx->afi->family;
679
680 /* Re-use the existing target if it's already loaded. */
681 list_for_each_entry(nft_target, &nft_match_list, head) {
682 struct xt_target *target = nft_target->ops.data;
683
684 if (strcmp(target->name, tg_name) == 0 &&
685 target->revision == rev && target->family == family)
686 return &nft_target->ops;
687 }
688
689 target = xt_request_find_target(family, tg_name, rev);
690 if (IS_ERR(target))
691 return ERR_PTR(-ENOENT);
692
693 /* This is the first time we use this target, allocate operations */
694 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
695 if (nft_target == NULL)
696 return ERR_PTR(-ENOMEM);
697
698 nft_target->ops.type = &nft_target_type;
699 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize) +
700 nft_compat_target_offset(target));
701 nft_target->ops.eval = nft_target_eval;
702 nft_target->ops.init = nft_target_init;
703 nft_target->ops.destroy = nft_target_destroy;
704 nft_target->ops.dump = nft_target_dump;
705 nft_target->ops.validate = nft_target_validate;
706 nft_target->ops.data = target;
707
708 list_add(&nft_target->head, &nft_target_list);
709
710 return &nft_target->ops;
711}
712
713static void nft_target_release(void)
714{
715 struct nft_xt *nft_target, *tmp;
716
717 list_for_each_entry_safe(nft_target, tmp, &nft_target_list, head)
718 kfree(nft_target);
719}
720
721static struct nft_expr_type nft_target_type __read_mostly = {
722 .name = "target",
723 .select_ops = nft_target_select_ops,
724 .policy = nft_target_policy,
725 .maxattr = NFTA_TARGET_MAX,
726 .owner = THIS_MODULE,
727};
728
729static int __init nft_compat_module_init(void)
730{
731 int ret;
732
733 ret = nft_register_expr(&nft_match_type);
734 if (ret < 0)
735 return ret;
736
737 ret = nft_register_expr(&nft_target_type);
738 if (ret < 0)
739 goto err_match;
740
741 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
742 if (ret < 0) {
743 pr_err("nft_compat: cannot register with nfnetlink.\n");
744 goto err_target;
745 }
746
747 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
748
749 return ret;
750
751err_target:
752 nft_unregister_expr(&nft_target_type);
753err_match:
754 nft_unregister_expr(&nft_match_type);
755 return ret;
756}
757
758static void __exit nft_compat_module_exit(void)
759{
760 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
761 nft_unregister_expr(&nft_target_type);
762 nft_unregister_expr(&nft_match_type);
763 nft_match_release();
764 nft_target_release();
765}
766
767MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
768
769module_init(nft_compat_module_init);
770module_exit(nft_compat_module_exit);
771
772MODULE_LICENSE("GPL");
773MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
774MODULE_ALIAS_NFT_EXPR("match");
775MODULE_ALIAS_NFT_EXPR("target");