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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] = NLA_POLICY_MAX(NLA_BE32, 255),
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 l4proto;
204 u32 flags;
205 int err;
206
207 err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_MAX, attr,
208 nft_rule_compat_policy, NULL);
209 if (err < 0)
210 return err;
211
212 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
213 return -EINVAL;
214
215 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
216 if (flags & NFT_RULE_COMPAT_F_UNUSED ||
217 flags & ~NFT_RULE_COMPAT_F_MASK)
218 return -EINVAL;
219 if (flags & NFT_RULE_COMPAT_F_INV)
220 *inv = true;
221
222 l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
223 if (l4proto > U16_MAX)
224 return -EINVAL;
225
226 *proto = l4proto;
227
228 return 0;
229}
230
231static void nft_compat_wait_for_destructors(void)
232{
233 /* xtables matches or targets can have side effects, e.g.
234 * creation/destruction of /proc files.
235 * The xt ->destroy functions are run asynchronously from
236 * work queue. If we have pending invocations we thus
237 * need to wait for those to finish.
238 */
239 nf_tables_trans_destroy_flush_work();
240}
241
242static int
243nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
244 const struct nlattr * const tb[])
245{
246 void *info = nft_expr_priv(expr);
247 struct xt_target *target = expr->ops->data;
248 struct xt_tgchk_param par;
249 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
250 u16 proto = 0;
251 bool inv = false;
252 union nft_entry e = {};
253 int ret;
254
255 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
256
257 if (ctx->nla[NFTA_RULE_COMPAT]) {
258 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
259 if (ret < 0)
260 return ret;
261 }
262
263 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
264
265 nft_compat_wait_for_destructors();
266
267 ret = xt_check_target(&par, size, proto, inv);
268 if (ret < 0) {
269 if (ret == -ENOENT) {
270 const char *modname = NULL;
271
272 if (strcmp(target->name, "LOG") == 0)
273 modname = "nf_log_syslog";
274 else if (strcmp(target->name, "NFLOG") == 0)
275 modname = "nfnetlink_log";
276
277 if (modname &&
278 nft_request_module(ctx->net, "%s", modname) == -EAGAIN)
279 return -EAGAIN;
280 }
281
282 return ret;
283 }
284
285 /* The standard target cannot be used */
286 if (!target->target)
287 return -EINVAL;
288
289 return 0;
290}
291
292static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr)
293{
294 module_put(me);
295 kfree(expr->ops);
296}
297
298static void
299nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
300{
301 struct xt_target *target = expr->ops->data;
302 void *info = nft_expr_priv(expr);
303 struct module *me = target->me;
304 struct xt_tgdtor_param par;
305
306 par.net = ctx->net;
307 par.target = target;
308 par.targinfo = info;
309 par.family = ctx->family;
310 if (par.target->destroy != NULL)
311 par.target->destroy(&par);
312
313 __nft_mt_tg_destroy(me, expr);
314}
315
316static int nft_extension_dump_info(struct sk_buff *skb, int attr,
317 const void *info,
318 unsigned int size, unsigned int user_size)
319{
320 unsigned int info_size, aligned_size = XT_ALIGN(size);
321 struct nlattr *nla;
322
323 nla = nla_reserve(skb, attr, aligned_size);
324 if (!nla)
325 return -1;
326
327 info_size = user_size ? : size;
328 memcpy(nla_data(nla), info, info_size);
329 memset(nla_data(nla) + info_size, 0, aligned_size - info_size);
330
331 return 0;
332}
333
334static int nft_target_dump(struct sk_buff *skb,
335 const struct nft_expr *expr, bool reset)
336{
337 const struct xt_target *target = expr->ops->data;
338 void *info = nft_expr_priv(expr);
339
340 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
341 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
342 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info,
343 target->targetsize, target->usersize))
344 goto nla_put_failure;
345
346 return 0;
347
348nla_put_failure:
349 return -1;
350}
351
352static int nft_target_validate(const struct nft_ctx *ctx,
353 const struct nft_expr *expr)
354{
355 struct xt_target *target = expr->ops->data;
356 unsigned int hook_mask = 0;
357 int ret;
358
359 if (ctx->family != NFPROTO_IPV4 &&
360 ctx->family != NFPROTO_IPV6 &&
361 ctx->family != NFPROTO_INET &&
362 ctx->family != NFPROTO_BRIDGE &&
363 ctx->family != NFPROTO_ARP)
364 return -EOPNOTSUPP;
365
366 ret = nft_chain_validate_hooks(ctx->chain,
367 (1 << NF_INET_PRE_ROUTING) |
368 (1 << NF_INET_LOCAL_IN) |
369 (1 << NF_INET_FORWARD) |
370 (1 << NF_INET_LOCAL_OUT) |
371 (1 << NF_INET_POST_ROUTING));
372 if (ret)
373 return ret;
374
375 if (nft_is_base_chain(ctx->chain)) {
376 const struct nft_base_chain *basechain =
377 nft_base_chain(ctx->chain);
378 const struct nf_hook_ops *ops = &basechain->ops;
379
380 hook_mask = 1 << ops->hooknum;
381 if (target->hooks && !(hook_mask & target->hooks))
382 return -EINVAL;
383
384 ret = nft_compat_chain_validate_dependency(ctx, target->table);
385 if (ret < 0)
386 return ret;
387 }
388 return 0;
389}
390
391static void __nft_match_eval(const struct nft_expr *expr,
392 struct nft_regs *regs,
393 const struct nft_pktinfo *pkt,
394 void *info)
395{
396 struct xt_match *match = expr->ops->data;
397 struct sk_buff *skb = pkt->skb;
398 struct xt_action_param xt;
399 bool ret;
400
401 nft_compat_set_par(&xt, pkt, match, info);
402
403 ret = match->match(skb, &xt);
404
405 if (xt.hotdrop) {
406 regs->verdict.code = NF_DROP;
407 return;
408 }
409
410 switch (ret ? 1 : 0) {
411 case 1:
412 regs->verdict.code = NFT_CONTINUE;
413 break;
414 case 0:
415 regs->verdict.code = NFT_BREAK;
416 break;
417 }
418}
419
420static void nft_match_large_eval(const struct nft_expr *expr,
421 struct nft_regs *regs,
422 const struct nft_pktinfo *pkt)
423{
424 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
425
426 __nft_match_eval(expr, regs, pkt, priv->info);
427}
428
429static void nft_match_eval(const struct nft_expr *expr,
430 struct nft_regs *regs,
431 const struct nft_pktinfo *pkt)
432{
433 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr));
434}
435
436static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
437 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
438 [NFTA_MATCH_REV] = NLA_POLICY_MAX(NLA_BE32, 255),
439 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
440};
441
442/* struct xt_mtchk_param and xt_tgchk_param look very similar */
443static void
444nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
445 struct xt_match *match, void *info,
446 union nft_entry *entry, u16 proto, bool inv)
447{
448 par->net = ctx->net;
449 par->table = ctx->table->name;
450 switch (ctx->family) {
451 case AF_INET:
452 entry->e4.ip.proto = proto;
453 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
454 break;
455 case AF_INET6:
456 if (proto)
457 entry->e6.ipv6.flags |= IP6T_F_PROTO;
458
459 entry->e6.ipv6.proto = proto;
460 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
461 break;
462 case NFPROTO_BRIDGE:
463 entry->ebt.ethproto = (__force __be16)proto;
464 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
465 break;
466 case NFPROTO_ARP:
467 break;
468 }
469 par->entryinfo = entry;
470 par->match = match;
471 par->matchinfo = info;
472 if (nft_is_base_chain(ctx->chain)) {
473 const struct nft_base_chain *basechain =
474 nft_base_chain(ctx->chain);
475 const struct nf_hook_ops *ops = &basechain->ops;
476
477 par->hook_mask = 1 << ops->hooknum;
478 } else {
479 par->hook_mask = 0;
480 }
481 par->family = ctx->family;
482 par->nft_compat = true;
483}
484
485static void match_compat_from_user(struct xt_match *m, void *in, void *out)
486{
487 int pad;
488
489 memcpy(out, in, m->matchsize);
490 pad = XT_ALIGN(m->matchsize) - m->matchsize;
491 if (pad > 0)
492 memset(out + m->matchsize, 0, pad);
493}
494
495static int
496__nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
497 const struct nlattr * const tb[],
498 void *info)
499{
500 struct xt_match *match = expr->ops->data;
501 struct xt_mtchk_param par;
502 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
503 u16 proto = 0;
504 bool inv = false;
505 union nft_entry e = {};
506 int ret;
507
508 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
509
510 if (ctx->nla[NFTA_RULE_COMPAT]) {
511 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
512 if (ret < 0)
513 return ret;
514 }
515
516 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
517
518 nft_compat_wait_for_destructors();
519
520 return xt_check_match(&par, size, proto, inv);
521}
522
523static int
524nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
525 const struct nlattr * const tb[])
526{
527 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr));
528}
529
530static int
531nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
532 const struct nlattr * const tb[])
533{
534 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
535 struct xt_match *m = expr->ops->data;
536 int ret;
537
538 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL_ACCOUNT);
539 if (!priv->info)
540 return -ENOMEM;
541
542 ret = __nft_match_init(ctx, expr, tb, priv->info);
543 if (ret)
544 kfree(priv->info);
545 return ret;
546}
547
548static void
549__nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
550 void *info)
551{
552 struct xt_match *match = expr->ops->data;
553 struct module *me = match->me;
554 struct xt_mtdtor_param par;
555
556 par.net = ctx->net;
557 par.match = match;
558 par.matchinfo = info;
559 par.family = ctx->family;
560 if (par.match->destroy != NULL)
561 par.match->destroy(&par);
562
563 __nft_mt_tg_destroy(me, expr);
564}
565
566static void
567nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
568{
569 __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
570}
571
572static void
573nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
574{
575 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
576
577 __nft_match_destroy(ctx, expr, priv->info);
578 kfree(priv->info);
579}
580
581static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr,
582 void *info)
583{
584 struct xt_match *match = expr->ops->data;
585
586 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
587 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
588 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info,
589 match->matchsize, match->usersize))
590 goto nla_put_failure;
591
592 return 0;
593
594nla_put_failure:
595 return -1;
596}
597
598static int nft_match_dump(struct sk_buff *skb,
599 const struct nft_expr *expr, bool reset)
600{
601 return __nft_match_dump(skb, expr, nft_expr_priv(expr));
602}
603
604static int nft_match_large_dump(struct sk_buff *skb,
605 const struct nft_expr *e, bool reset)
606{
607 struct nft_xt_match_priv *priv = nft_expr_priv(e);
608
609 return __nft_match_dump(skb, e, priv->info);
610}
611
612static int nft_match_validate(const struct nft_ctx *ctx,
613 const struct nft_expr *expr)
614{
615 struct xt_match *match = expr->ops->data;
616 unsigned int hook_mask = 0;
617 int ret;
618
619 if (ctx->family != NFPROTO_IPV4 &&
620 ctx->family != NFPROTO_IPV6 &&
621 ctx->family != NFPROTO_INET &&
622 ctx->family != NFPROTO_BRIDGE &&
623 ctx->family != NFPROTO_ARP)
624 return -EOPNOTSUPP;
625
626 ret = nft_chain_validate_hooks(ctx->chain,
627 (1 << NF_INET_PRE_ROUTING) |
628 (1 << NF_INET_LOCAL_IN) |
629 (1 << NF_INET_FORWARD) |
630 (1 << NF_INET_LOCAL_OUT) |
631 (1 << NF_INET_POST_ROUTING));
632 if (ret)
633 return ret;
634
635 if (nft_is_base_chain(ctx->chain)) {
636 const struct nft_base_chain *basechain =
637 nft_base_chain(ctx->chain);
638 const struct nf_hook_ops *ops = &basechain->ops;
639
640 hook_mask = 1 << ops->hooknum;
641 if (match->hooks && !(hook_mask & match->hooks))
642 return -EINVAL;
643
644 ret = nft_compat_chain_validate_dependency(ctx, match->table);
645 if (ret < 0)
646 return ret;
647 }
648 return 0;
649}
650
651static int
652nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
653 int event, u16 family, const char *name,
654 int rev, int target)
655{
656 struct nlmsghdr *nlh;
657 unsigned int flags = portid ? NLM_F_MULTI : 0;
658
659 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event);
660 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family,
661 NFNETLINK_V0, 0);
662 if (!nlh)
663 goto nlmsg_failure;
664
665 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
666 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
667 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
668 goto nla_put_failure;
669
670 nlmsg_end(skb, nlh);
671 return skb->len;
672
673nlmsg_failure:
674nla_put_failure:
675 nlmsg_cancel(skb, nlh);
676 return -1;
677}
678
679static int nfnl_compat_get_rcu(struct sk_buff *skb,
680 const struct nfnl_info *info,
681 const struct nlattr * const tb[])
682{
683 u8 family = info->nfmsg->nfgen_family;
684 const char *name, *fmt;
685 struct sk_buff *skb2;
686 int ret = 0, target;
687 u32 rev;
688
689 if (tb[NFTA_COMPAT_NAME] == NULL ||
690 tb[NFTA_COMPAT_REV] == NULL ||
691 tb[NFTA_COMPAT_TYPE] == NULL)
692 return -EINVAL;
693
694 name = nla_data(tb[NFTA_COMPAT_NAME]);
695 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
696 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
697
698 switch(family) {
699 case AF_INET:
700 fmt = "ipt_%s";
701 break;
702 case AF_INET6:
703 fmt = "ip6t_%s";
704 break;
705 case NFPROTO_BRIDGE:
706 fmt = "ebt_%s";
707 break;
708 case NFPROTO_ARP:
709 fmt = "arpt_%s";
710 break;
711 default:
712 pr_err("nft_compat: unsupported protocol %d\n", family);
713 return -EINVAL;
714 }
715
716 if (!try_module_get(THIS_MODULE))
717 return -EINVAL;
718
719 rcu_read_unlock();
720 try_then_request_module(xt_find_revision(family, name, rev, target, &ret),
721 fmt, name);
722 if (ret < 0)
723 goto out_put;
724
725 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
726 if (skb2 == NULL) {
727 ret = -ENOMEM;
728 goto out_put;
729 }
730
731 /* include the best revision for this extension in the message */
732 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
733 info->nlh->nlmsg_seq,
734 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
735 NFNL_MSG_COMPAT_GET,
736 family, name, ret, target) <= 0) {
737 kfree_skb(skb2);
738 goto out_put;
739 }
740
741 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
742out_put:
743 rcu_read_lock();
744 module_put(THIS_MODULE);
745
746 return ret;
747}
748
749static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
750 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
751 .len = NFT_COMPAT_NAME_MAX-1 },
752 [NFTA_COMPAT_REV] = NLA_POLICY_MAX(NLA_BE32, 255),
753 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
754};
755
756static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
757 [NFNL_MSG_COMPAT_GET] = {
758 .call = nfnl_compat_get_rcu,
759 .type = NFNL_CB_RCU,
760 .attr_count = NFTA_COMPAT_MAX,
761 .policy = nfnl_compat_policy_get
762 },
763};
764
765static const struct nfnetlink_subsystem nfnl_compat_subsys = {
766 .name = "nft-compat",
767 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
768 .cb_count = NFNL_MSG_COMPAT_MAX,
769 .cb = nfnl_nft_compat_cb,
770};
771
772static struct nft_expr_type nft_match_type;
773
774static bool nft_match_reduce(struct nft_regs_track *track,
775 const struct nft_expr *expr)
776{
777 const struct xt_match *match = expr->ops->data;
778
779 return strcmp(match->name, "comment") == 0;
780}
781
782static const struct nft_expr_ops *
783nft_match_select_ops(const struct nft_ctx *ctx,
784 const struct nlattr * const tb[])
785{
786 struct nft_expr_ops *ops;
787 struct xt_match *match;
788 unsigned int matchsize;
789 char *mt_name;
790 u32 rev, family;
791 int err;
792
793 if (tb[NFTA_MATCH_NAME] == NULL ||
794 tb[NFTA_MATCH_REV] == NULL ||
795 tb[NFTA_MATCH_INFO] == NULL)
796 return ERR_PTR(-EINVAL);
797
798 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
799 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
800 family = ctx->family;
801
802 match = xt_request_find_match(family, mt_name, rev);
803 if (IS_ERR(match))
804 return ERR_PTR(-ENOENT);
805
806 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
807 err = -EINVAL;
808 goto err;
809 }
810
811 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL_ACCOUNT);
812 if (!ops) {
813 err = -ENOMEM;
814 goto err;
815 }
816
817 ops->type = &nft_match_type;
818 ops->eval = nft_match_eval;
819 ops->init = nft_match_init;
820 ops->destroy = nft_match_destroy;
821 ops->dump = nft_match_dump;
822 ops->validate = nft_match_validate;
823 ops->data = match;
824 ops->reduce = nft_match_reduce;
825
826 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
827 if (matchsize > NFT_MATCH_LARGE_THRESH) {
828 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv));
829
830 ops->eval = nft_match_large_eval;
831 ops->init = nft_match_large_init;
832 ops->destroy = nft_match_large_destroy;
833 ops->dump = nft_match_large_dump;
834 }
835
836 ops->size = matchsize;
837
838 return ops;
839err:
840 module_put(match->me);
841 return ERR_PTR(err);
842}
843
844static void nft_match_release_ops(const struct nft_expr_ops *ops)
845{
846 struct xt_match *match = ops->data;
847
848 module_put(match->me);
849 kfree(ops);
850}
851
852static struct nft_expr_type nft_match_type __read_mostly = {
853 .name = "match",
854 .select_ops = nft_match_select_ops,
855 .release_ops = nft_match_release_ops,
856 .policy = nft_match_policy,
857 .maxattr = NFTA_MATCH_MAX,
858 .owner = THIS_MODULE,
859};
860
861static struct nft_expr_type nft_target_type;
862
863static const struct nft_expr_ops *
864nft_target_select_ops(const struct nft_ctx *ctx,
865 const struct nlattr * const tb[])
866{
867 struct nft_expr_ops *ops;
868 struct xt_target *target;
869 char *tg_name;
870 u32 rev, family;
871 int err;
872
873 if (tb[NFTA_TARGET_NAME] == NULL ||
874 tb[NFTA_TARGET_REV] == NULL ||
875 tb[NFTA_TARGET_INFO] == NULL)
876 return ERR_PTR(-EINVAL);
877
878 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
879 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
880 family = ctx->family;
881
882 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 ||
883 strcmp(tg_name, XT_STANDARD_TARGET) == 0 ||
884 strcmp(tg_name, "standard") == 0)
885 return ERR_PTR(-EINVAL);
886
887 target = xt_request_find_target(family, tg_name, rev);
888 if (IS_ERR(target))
889 return ERR_PTR(-ENOENT);
890
891 if (!target->target) {
892 err = -EINVAL;
893 goto err;
894 }
895
896 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
897 err = -EINVAL;
898 goto err;
899 }
900
901 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL_ACCOUNT);
902 if (!ops) {
903 err = -ENOMEM;
904 goto err;
905 }
906
907 ops->type = &nft_target_type;
908 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
909 ops->init = nft_target_init;
910 ops->destroy = nft_target_destroy;
911 ops->dump = nft_target_dump;
912 ops->validate = nft_target_validate;
913 ops->data = target;
914 ops->reduce = NFT_REDUCE_READONLY;
915
916 if (family == NFPROTO_BRIDGE)
917 ops->eval = nft_target_eval_bridge;
918 else
919 ops->eval = nft_target_eval_xt;
920
921 return ops;
922err:
923 module_put(target->me);
924 return ERR_PTR(err);
925}
926
927static void nft_target_release_ops(const struct nft_expr_ops *ops)
928{
929 struct xt_target *target = ops->data;
930
931 module_put(target->me);
932 kfree(ops);
933}
934
935static struct nft_expr_type nft_target_type __read_mostly = {
936 .name = "target",
937 .select_ops = nft_target_select_ops,
938 .release_ops = nft_target_release_ops,
939 .policy = nft_target_policy,
940 .maxattr = NFTA_TARGET_MAX,
941 .owner = THIS_MODULE,
942};
943
944static int __init nft_compat_module_init(void)
945{
946 int ret;
947
948 ret = nft_register_expr(&nft_match_type);
949 if (ret < 0)
950 return ret;
951
952 ret = nft_register_expr(&nft_target_type);
953 if (ret < 0)
954 goto err_match;
955
956 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
957 if (ret < 0) {
958 pr_err("nft_compat: cannot register with nfnetlink.\n");
959 goto err_target;
960 }
961
962 return ret;
963err_target:
964 nft_unregister_expr(&nft_target_type);
965err_match:
966 nft_unregister_expr(&nft_match_type);
967 return ret;
968}
969
970static void __exit nft_compat_module_exit(void)
971{
972 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
973 nft_unregister_expr(&nft_target_type);
974 nft_unregister_expr(&nft_match_type);
975}
976
977MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
978
979module_init(nft_compat_module_init);
980module_exit(nft_compat_module_exit);
981
982MODULE_LICENSE("GPL");
983MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
984MODULE_ALIAS_NFT_EXPR("match");
985MODULE_ALIAS_NFT_EXPR("target");
986MODULE_DESCRIPTION("x_tables over nftables support");