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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
26struct nft_xt {
27 struct list_head head;
28 struct nft_expr_ops ops;
29 unsigned int refcnt;
30};
31
32static void nft_xt_put(struct nft_xt *xt)
33{
34 if (--xt->refcnt == 0) {
35 list_del(&xt->head);
36 kfree(xt);
37 }
38}
39
40static int nft_compat_chain_validate_dependency(const char *tablename,
41 const struct nft_chain *chain)
42{
43 const struct nft_base_chain *basechain;
44
45 if (!tablename || !(chain->flags & NFT_BASE_CHAIN))
46 return 0;
47
48 basechain = nft_base_chain(chain);
49 if (strcmp(tablename, "nat") == 0 &&
50 basechain->type->type != NFT_CHAIN_T_NAT)
51 return -EINVAL;
52
53 return 0;
54}
55
56union nft_entry {
57 struct ipt_entry e4;
58 struct ip6t_entry e6;
59 struct ebt_entry ebt;
60 struct arpt_entry arp;
61};
62
63static inline void
64nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
65{
66 par->target = xt;
67 par->targinfo = xt_info;
68 par->hotdrop = false;
69}
70
71static void nft_target_eval_xt(const struct nft_expr *expr,
72 struct nft_regs *regs,
73 const struct nft_pktinfo *pkt)
74{
75 void *info = nft_expr_priv(expr);
76 struct xt_target *target = expr->ops->data;
77 struct sk_buff *skb = pkt->skb;
78 int ret;
79
80 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
81
82 ret = target->target(skb, &pkt->xt);
83
84 if (pkt->xt.hotdrop)
85 ret = NF_DROP;
86
87 switch (ret) {
88 case XT_CONTINUE:
89 regs->verdict.code = NFT_CONTINUE;
90 break;
91 default:
92 regs->verdict.code = ret;
93 break;
94 }
95}
96
97static void nft_target_eval_bridge(const struct nft_expr *expr,
98 struct nft_regs *regs,
99 const struct nft_pktinfo *pkt)
100{
101 void *info = nft_expr_priv(expr);
102 struct xt_target *target = expr->ops->data;
103 struct sk_buff *skb = pkt->skb;
104 int ret;
105
106 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
107
108 ret = target->target(skb, &pkt->xt);
109
110 if (pkt->xt.hotdrop)
111 ret = NF_DROP;
112
113 switch (ret) {
114 case EBT_ACCEPT:
115 regs->verdict.code = NF_ACCEPT;
116 break;
117 case EBT_DROP:
118 regs->verdict.code = NF_DROP;
119 break;
120 case EBT_CONTINUE:
121 regs->verdict.code = NFT_CONTINUE;
122 break;
123 case EBT_RETURN:
124 regs->verdict.code = NFT_RETURN;
125 break;
126 default:
127 regs->verdict.code = ret;
128 break;
129 }
130}
131
132static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
133 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
134 [NFTA_TARGET_REV] = { .type = NLA_U32 },
135 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
136};
137
138static void
139nft_target_set_tgchk_param(struct xt_tgchk_param *par,
140 const struct nft_ctx *ctx,
141 struct xt_target *target, void *info,
142 union nft_entry *entry, u16 proto, bool inv)
143{
144 par->net = ctx->net;
145 par->table = ctx->table->name;
146 switch (ctx->afi->family) {
147 case AF_INET:
148 entry->e4.ip.proto = proto;
149 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
150 break;
151 case AF_INET6:
152 if (proto)
153 entry->e6.ipv6.flags |= IP6T_F_PROTO;
154
155 entry->e6.ipv6.proto = proto;
156 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
157 break;
158 case NFPROTO_BRIDGE:
159 entry->ebt.ethproto = (__force __be16)proto;
160 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
161 break;
162 case NFPROTO_ARP:
163 break;
164 }
165 par->entryinfo = entry;
166 par->target = target;
167 par->targinfo = info;
168 if (ctx->chain->flags & NFT_BASE_CHAIN) {
169 const struct nft_base_chain *basechain =
170 nft_base_chain(ctx->chain);
171 const struct nf_hook_ops *ops = &basechain->ops[0];
172
173 par->hook_mask = 1 << ops->hooknum;
174 } else {
175 par->hook_mask = 0;
176 }
177 par->family = ctx->afi->family;
178 par->nft_compat = true;
179}
180
181static void target_compat_from_user(struct xt_target *t, void *in, void *out)
182{
183 int pad;
184
185 memcpy(out, in, t->targetsize);
186 pad = XT_ALIGN(t->targetsize) - t->targetsize;
187 if (pad > 0)
188 memset(out + t->targetsize, 0, pad);
189}
190
191static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
192 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
193 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
194};
195
196static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
197{
198 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
199 u32 flags;
200 int err;
201
202 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
203 nft_rule_compat_policy);
204 if (err < 0)
205 return err;
206
207 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
208 return -EINVAL;
209
210 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
211 if (flags & ~NFT_RULE_COMPAT_F_MASK)
212 return -EINVAL;
213 if (flags & NFT_RULE_COMPAT_F_INV)
214 *inv = true;
215
216 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
217 return 0;
218}
219
220static int
221nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
222 const struct nlattr * const tb[])
223{
224 void *info = nft_expr_priv(expr);
225 struct xt_target *target = expr->ops->data;
226 struct xt_tgchk_param par;
227 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
228 u16 proto = 0;
229 bool inv = false;
230 union nft_entry e = {};
231 int ret;
232
233 ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
234 if (ret < 0)
235 goto err;
236
237 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
238
239 if (ctx->nla[NFTA_RULE_COMPAT]) {
240 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
241 if (ret < 0)
242 goto err;
243 }
244
245 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
246
247 ret = xt_check_target(&par, size, proto, inv);
248 if (ret < 0)
249 goto err;
250
251 /* The standard target cannot be used */
252 if (target->target == NULL) {
253 ret = -EINVAL;
254 goto err;
255 }
256
257 return 0;
258err:
259 module_put(target->me);
260 return ret;
261}
262
263static void
264nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
265{
266 struct xt_target *target = expr->ops->data;
267 void *info = nft_expr_priv(expr);
268 struct xt_tgdtor_param par;
269
270 par.net = ctx->net;
271 par.target = target;
272 par.targinfo = info;
273 par.family = ctx->afi->family;
274 if (par.target->destroy != NULL)
275 par.target->destroy(&par);
276
277 nft_xt_put(container_of(expr->ops, struct nft_xt, ops));
278 module_put(target->me);
279}
280
281static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
282{
283 const struct xt_target *target = expr->ops->data;
284 void *info = nft_expr_priv(expr);
285
286 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
287 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
288 nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info))
289 goto nla_put_failure;
290
291 return 0;
292
293nla_put_failure:
294 return -1;
295}
296
297static int nft_target_validate(const struct nft_ctx *ctx,
298 const struct nft_expr *expr,
299 const struct nft_data **data)
300{
301 struct xt_target *target = expr->ops->data;
302 unsigned int hook_mask = 0;
303 int ret;
304
305 if (ctx->chain->flags & NFT_BASE_CHAIN) {
306 const struct nft_base_chain *basechain =
307 nft_base_chain(ctx->chain);
308 const struct nf_hook_ops *ops = &basechain->ops[0];
309
310 hook_mask = 1 << ops->hooknum;
311 if (!(hook_mask & target->hooks))
312 return -EINVAL;
313
314 ret = nft_compat_chain_validate_dependency(target->table,
315 ctx->chain);
316 if (ret < 0)
317 return ret;
318 }
319 return 0;
320}
321
322static void nft_match_eval(const struct nft_expr *expr,
323 struct nft_regs *regs,
324 const struct nft_pktinfo *pkt)
325{
326 void *info = nft_expr_priv(expr);
327 struct xt_match *match = expr->ops->data;
328 struct sk_buff *skb = pkt->skb;
329 bool ret;
330
331 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
332
333 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
334
335 if (pkt->xt.hotdrop) {
336 regs->verdict.code = NF_DROP;
337 return;
338 }
339
340 switch (ret ? 1 : 0) {
341 case 1:
342 regs->verdict.code = NFT_CONTINUE;
343 break;
344 case 0:
345 regs->verdict.code = NFT_BREAK;
346 break;
347 }
348}
349
350static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
351 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
352 [NFTA_MATCH_REV] = { .type = NLA_U32 },
353 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
354};
355
356/* struct xt_mtchk_param and xt_tgchk_param look very similar */
357static void
358nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
359 struct xt_match *match, void *info,
360 union nft_entry *entry, u16 proto, bool inv)
361{
362 par->net = ctx->net;
363 par->table = ctx->table->name;
364 switch (ctx->afi->family) {
365 case AF_INET:
366 entry->e4.ip.proto = proto;
367 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
368 break;
369 case AF_INET6:
370 if (proto)
371 entry->e6.ipv6.flags |= IP6T_F_PROTO;
372
373 entry->e6.ipv6.proto = proto;
374 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
375 break;
376 case NFPROTO_BRIDGE:
377 entry->ebt.ethproto = (__force __be16)proto;
378 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
379 break;
380 case NFPROTO_ARP:
381 break;
382 }
383 par->entryinfo = entry;
384 par->match = match;
385 par->matchinfo = info;
386 if (ctx->chain->flags & NFT_BASE_CHAIN) {
387 const struct nft_base_chain *basechain =
388 nft_base_chain(ctx->chain);
389 const struct nf_hook_ops *ops = &basechain->ops[0];
390
391 par->hook_mask = 1 << ops->hooknum;
392 } else {
393 par->hook_mask = 0;
394 }
395 par->family = ctx->afi->family;
396 par->nft_compat = true;
397}
398
399static void match_compat_from_user(struct xt_match *m, void *in, void *out)
400{
401 int pad;
402
403 memcpy(out, in, m->matchsize);
404 pad = XT_ALIGN(m->matchsize) - m->matchsize;
405 if (pad > 0)
406 memset(out + m->matchsize, 0, pad);
407}
408
409static int
410nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
411 const struct nlattr * const tb[])
412{
413 void *info = nft_expr_priv(expr);
414 struct xt_match *match = expr->ops->data;
415 struct xt_mtchk_param par;
416 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
417 u16 proto = 0;
418 bool inv = false;
419 union nft_entry e = {};
420 int ret;
421
422 ret = nft_compat_chain_validate_dependency(match->table, ctx->chain);
423 if (ret < 0)
424 goto err;
425
426 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
427
428 if (ctx->nla[NFTA_RULE_COMPAT]) {
429 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
430 if (ret < 0)
431 goto err;
432 }
433
434 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
435
436 ret = xt_check_match(&par, size, proto, inv);
437 if (ret < 0)
438 goto err;
439
440 return 0;
441err:
442 module_put(match->me);
443 return ret;
444}
445
446static void
447nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
448{
449 struct xt_match *match = expr->ops->data;
450 void *info = nft_expr_priv(expr);
451 struct xt_mtdtor_param par;
452
453 par.net = ctx->net;
454 par.match = match;
455 par.matchinfo = info;
456 par.family = ctx->afi->family;
457 if (par.match->destroy != NULL)
458 par.match->destroy(&par);
459
460 nft_xt_put(container_of(expr->ops, struct nft_xt, ops));
461 module_put(match->me);
462}
463
464static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
465{
466 void *info = nft_expr_priv(expr);
467 struct xt_match *match = expr->ops->data;
468
469 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
470 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
471 nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info))
472 goto nla_put_failure;
473
474 return 0;
475
476nla_put_failure:
477 return -1;
478}
479
480static int nft_match_validate(const struct nft_ctx *ctx,
481 const struct nft_expr *expr,
482 const struct nft_data **data)
483{
484 struct xt_match *match = expr->ops->data;
485 unsigned int hook_mask = 0;
486 int ret;
487
488 if (ctx->chain->flags & NFT_BASE_CHAIN) {
489 const struct nft_base_chain *basechain =
490 nft_base_chain(ctx->chain);
491 const struct nf_hook_ops *ops = &basechain->ops[0];
492
493 hook_mask = 1 << ops->hooknum;
494 if (!(hook_mask & match->hooks))
495 return -EINVAL;
496
497 ret = nft_compat_chain_validate_dependency(match->table,
498 ctx->chain);
499 if (ret < 0)
500 return ret;
501 }
502 return 0;
503}
504
505static int
506nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
507 int event, u16 family, const char *name,
508 int rev, int target)
509{
510 struct nlmsghdr *nlh;
511 struct nfgenmsg *nfmsg;
512 unsigned int flags = portid ? NLM_F_MULTI : 0;
513
514 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
515 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
516 if (nlh == NULL)
517 goto nlmsg_failure;
518
519 nfmsg = nlmsg_data(nlh);
520 nfmsg->nfgen_family = family;
521 nfmsg->version = NFNETLINK_V0;
522 nfmsg->res_id = 0;
523
524 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
525 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
526 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
527 goto nla_put_failure;
528
529 nlmsg_end(skb, nlh);
530 return skb->len;
531
532nlmsg_failure:
533nla_put_failure:
534 nlmsg_cancel(skb, nlh);
535 return -1;
536}
537
538static int nfnl_compat_get(struct net *net, struct sock *nfnl,
539 struct sk_buff *skb, const struct nlmsghdr *nlh,
540 const struct nlattr * const tb[])
541{
542 int ret = 0, target;
543 struct nfgenmsg *nfmsg;
544 const char *fmt;
545 const char *name;
546 u32 rev;
547 struct sk_buff *skb2;
548
549 if (tb[NFTA_COMPAT_NAME] == NULL ||
550 tb[NFTA_COMPAT_REV] == NULL ||
551 tb[NFTA_COMPAT_TYPE] == NULL)
552 return -EINVAL;
553
554 name = nla_data(tb[NFTA_COMPAT_NAME]);
555 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
556 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
557
558 nfmsg = nlmsg_data(nlh);
559
560 switch(nfmsg->nfgen_family) {
561 case AF_INET:
562 fmt = "ipt_%s";
563 break;
564 case AF_INET6:
565 fmt = "ip6t_%s";
566 break;
567 case NFPROTO_BRIDGE:
568 fmt = "ebt_%s";
569 break;
570 case NFPROTO_ARP:
571 fmt = "arpt_%s";
572 break;
573 default:
574 pr_err("nft_compat: unsupported protocol %d\n",
575 nfmsg->nfgen_family);
576 return -EINVAL;
577 }
578
579 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
580 rev, target, &ret),
581 fmt, name);
582
583 if (ret < 0)
584 return ret;
585
586 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
587 if (skb2 == NULL)
588 return -ENOMEM;
589
590 /* include the best revision for this extension in the message */
591 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
592 nlh->nlmsg_seq,
593 NFNL_MSG_TYPE(nlh->nlmsg_type),
594 NFNL_MSG_COMPAT_GET,
595 nfmsg->nfgen_family,
596 name, ret, target) <= 0) {
597 kfree_skb(skb2);
598 return -ENOSPC;
599 }
600
601 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
602 MSG_DONTWAIT);
603 if (ret > 0)
604 ret = 0;
605
606 return ret == -EAGAIN ? -ENOBUFS : ret;
607}
608
609static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
610 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
611 .len = NFT_COMPAT_NAME_MAX-1 },
612 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
613 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
614};
615
616static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
617 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
618 .attr_count = NFTA_COMPAT_MAX,
619 .policy = nfnl_compat_policy_get },
620};
621
622static const struct nfnetlink_subsystem nfnl_compat_subsys = {
623 .name = "nft-compat",
624 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
625 .cb_count = NFNL_MSG_COMPAT_MAX,
626 .cb = nfnl_nft_compat_cb,
627};
628
629static LIST_HEAD(nft_match_list);
630
631static struct nft_expr_type nft_match_type;
632
633static bool nft_match_cmp(const struct xt_match *match,
634 const char *name, u32 rev, u32 family)
635{
636 return strcmp(match->name, name) == 0 && match->revision == rev &&
637 (match->family == NFPROTO_UNSPEC || match->family == family);
638}
639
640static const struct nft_expr_ops *
641nft_match_select_ops(const struct nft_ctx *ctx,
642 const struct nlattr * const tb[])
643{
644 struct nft_xt *nft_match;
645 struct xt_match *match;
646 char *mt_name;
647 u32 rev, family;
648 int err;
649
650 if (tb[NFTA_MATCH_NAME] == NULL ||
651 tb[NFTA_MATCH_REV] == NULL ||
652 tb[NFTA_MATCH_INFO] == NULL)
653 return ERR_PTR(-EINVAL);
654
655 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
656 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
657 family = ctx->afi->family;
658
659 /* Re-use the existing match if it's already loaded. */
660 list_for_each_entry(nft_match, &nft_match_list, head) {
661 struct xt_match *match = nft_match->ops.data;
662
663 if (nft_match_cmp(match, mt_name, rev, family)) {
664 if (!try_module_get(match->me))
665 return ERR_PTR(-ENOENT);
666
667 nft_match->refcnt++;
668 return &nft_match->ops;
669 }
670 }
671
672 match = xt_request_find_match(family, mt_name, rev);
673 if (IS_ERR(match))
674 return ERR_PTR(-ENOENT);
675
676 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
677 err = -EINVAL;
678 goto err;
679 }
680
681 /* This is the first time we use this match, allocate operations */
682 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
683 if (nft_match == NULL) {
684 err = -ENOMEM;
685 goto err;
686 }
687
688 nft_match->refcnt = 1;
689 nft_match->ops.type = &nft_match_type;
690 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
691 nft_match->ops.eval = nft_match_eval;
692 nft_match->ops.init = nft_match_init;
693 nft_match->ops.destroy = nft_match_destroy;
694 nft_match->ops.dump = nft_match_dump;
695 nft_match->ops.validate = nft_match_validate;
696 nft_match->ops.data = match;
697
698 list_add(&nft_match->head, &nft_match_list);
699
700 return &nft_match->ops;
701err:
702 module_put(match->me);
703 return ERR_PTR(err);
704}
705
706static struct nft_expr_type nft_match_type __read_mostly = {
707 .name = "match",
708 .select_ops = nft_match_select_ops,
709 .policy = nft_match_policy,
710 .maxattr = NFTA_MATCH_MAX,
711 .owner = THIS_MODULE,
712};
713
714static LIST_HEAD(nft_target_list);
715
716static struct nft_expr_type nft_target_type;
717
718static bool nft_target_cmp(const struct xt_target *tg,
719 const char *name, u32 rev, u32 family)
720{
721 return strcmp(tg->name, name) == 0 && tg->revision == rev &&
722 (tg->family == NFPROTO_UNSPEC || tg->family == family);
723}
724
725static const struct nft_expr_ops *
726nft_target_select_ops(const struct nft_ctx *ctx,
727 const struct nlattr * const tb[])
728{
729 struct nft_xt *nft_target;
730 struct xt_target *target;
731 char *tg_name;
732 u32 rev, family;
733 int err;
734
735 if (tb[NFTA_TARGET_NAME] == NULL ||
736 tb[NFTA_TARGET_REV] == NULL ||
737 tb[NFTA_TARGET_INFO] == NULL)
738 return ERR_PTR(-EINVAL);
739
740 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
741 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
742 family = ctx->afi->family;
743
744 /* Re-use the existing target if it's already loaded. */
745 list_for_each_entry(nft_target, &nft_target_list, head) {
746 struct xt_target *target = nft_target->ops.data;
747
748 if (nft_target_cmp(target, tg_name, rev, family)) {
749 if (!try_module_get(target->me))
750 return ERR_PTR(-ENOENT);
751
752 nft_target->refcnt++;
753 return &nft_target->ops;
754 }
755 }
756
757 target = xt_request_find_target(family, tg_name, rev);
758 if (IS_ERR(target))
759 return ERR_PTR(-ENOENT);
760
761 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
762 err = -EINVAL;
763 goto err;
764 }
765
766 /* This is the first time we use this target, allocate operations */
767 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
768 if (nft_target == NULL) {
769 err = -ENOMEM;
770 goto err;
771 }
772
773 nft_target->refcnt = 1;
774 nft_target->ops.type = &nft_target_type;
775 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
776 nft_target->ops.init = nft_target_init;
777 nft_target->ops.destroy = nft_target_destroy;
778 nft_target->ops.dump = nft_target_dump;
779 nft_target->ops.validate = nft_target_validate;
780 nft_target->ops.data = target;
781
782 if (family == NFPROTO_BRIDGE)
783 nft_target->ops.eval = nft_target_eval_bridge;
784 else
785 nft_target->ops.eval = nft_target_eval_xt;
786
787 list_add(&nft_target->head, &nft_target_list);
788
789 return &nft_target->ops;
790err:
791 module_put(target->me);
792 return ERR_PTR(err);
793}
794
795static struct nft_expr_type nft_target_type __read_mostly = {
796 .name = "target",
797 .select_ops = nft_target_select_ops,
798 .policy = nft_target_policy,
799 .maxattr = NFTA_TARGET_MAX,
800 .owner = THIS_MODULE,
801};
802
803static int __init nft_compat_module_init(void)
804{
805 int ret;
806
807 ret = nft_register_expr(&nft_match_type);
808 if (ret < 0)
809 return ret;
810
811 ret = nft_register_expr(&nft_target_type);
812 if (ret < 0)
813 goto err_match;
814
815 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
816 if (ret < 0) {
817 pr_err("nft_compat: cannot register with nfnetlink.\n");
818 goto err_target;
819 }
820
821 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
822
823 return ret;
824
825err_target:
826 nft_unregister_expr(&nft_target_type);
827err_match:
828 nft_unregister_expr(&nft_match_type);
829 return ret;
830}
831
832static void __exit nft_compat_module_exit(void)
833{
834 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
835 nft_unregister_expr(&nft_target_type);
836 nft_unregister_expr(&nft_match_type);
837}
838
839MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
840
841module_init(nft_compat_module_init);
842module_exit(nft_compat_module_exit);
843
844MODULE_LICENSE("GPL");
845MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
846MODULE_ALIAS_NFT_EXPR("match");
847MODULE_ALIAS_NFT_EXPR("target");
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,
328 const struct nft_expr *expr, bool reset)
329{
330 const struct xt_target *target = expr->ops->data;
331 void *info = nft_expr_priv(expr);
332
333 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
334 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
335 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info,
336 target->targetsize, target->usersize))
337 goto nla_put_failure;
338
339 return 0;
340
341nla_put_failure:
342 return -1;
343}
344
345static int nft_target_validate(const struct nft_ctx *ctx,
346 const struct nft_expr *expr,
347 const struct nft_data **data)
348{
349 struct xt_target *target = expr->ops->data;
350 unsigned int hook_mask = 0;
351 int ret;
352
353 if (nft_is_base_chain(ctx->chain)) {
354 const struct nft_base_chain *basechain =
355 nft_base_chain(ctx->chain);
356 const struct nf_hook_ops *ops = &basechain->ops;
357
358 hook_mask = 1 << ops->hooknum;
359 if (target->hooks && !(hook_mask & target->hooks))
360 return -EINVAL;
361
362 ret = nft_compat_chain_validate_dependency(ctx, target->table);
363 if (ret < 0)
364 return ret;
365 }
366 return 0;
367}
368
369static void __nft_match_eval(const struct nft_expr *expr,
370 struct nft_regs *regs,
371 const struct nft_pktinfo *pkt,
372 void *info)
373{
374 struct xt_match *match = expr->ops->data;
375 struct sk_buff *skb = pkt->skb;
376 struct xt_action_param xt;
377 bool ret;
378
379 nft_compat_set_par(&xt, pkt, match, info);
380
381 ret = match->match(skb, &xt);
382
383 if (xt.hotdrop) {
384 regs->verdict.code = NF_DROP;
385 return;
386 }
387
388 switch (ret ? 1 : 0) {
389 case 1:
390 regs->verdict.code = NFT_CONTINUE;
391 break;
392 case 0:
393 regs->verdict.code = NFT_BREAK;
394 break;
395 }
396}
397
398static void nft_match_large_eval(const struct nft_expr *expr,
399 struct nft_regs *regs,
400 const struct nft_pktinfo *pkt)
401{
402 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
403
404 __nft_match_eval(expr, regs, pkt, priv->info);
405}
406
407static void nft_match_eval(const struct nft_expr *expr,
408 struct nft_regs *regs,
409 const struct nft_pktinfo *pkt)
410{
411 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr));
412}
413
414static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
415 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
416 [NFTA_MATCH_REV] = { .type = NLA_U32 },
417 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
418};
419
420/* struct xt_mtchk_param and xt_tgchk_param look very similar */
421static void
422nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
423 struct xt_match *match, void *info,
424 union nft_entry *entry, u16 proto, bool inv)
425{
426 par->net = ctx->net;
427 par->table = ctx->table->name;
428 switch (ctx->family) {
429 case AF_INET:
430 entry->e4.ip.proto = proto;
431 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
432 break;
433 case AF_INET6:
434 if (proto)
435 entry->e6.ipv6.flags |= IP6T_F_PROTO;
436
437 entry->e6.ipv6.proto = proto;
438 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
439 break;
440 case NFPROTO_BRIDGE:
441 entry->ebt.ethproto = (__force __be16)proto;
442 entry->ebt.invflags = inv ? EBT_IPROTO : 0;
443 break;
444 case NFPROTO_ARP:
445 break;
446 }
447 par->entryinfo = entry;
448 par->match = match;
449 par->matchinfo = info;
450 if (nft_is_base_chain(ctx->chain)) {
451 const struct nft_base_chain *basechain =
452 nft_base_chain(ctx->chain);
453 const struct nf_hook_ops *ops = &basechain->ops;
454
455 par->hook_mask = 1 << ops->hooknum;
456 } else {
457 par->hook_mask = 0;
458 }
459 par->family = ctx->family;
460 par->nft_compat = true;
461}
462
463static void match_compat_from_user(struct xt_match *m, void *in, void *out)
464{
465 int pad;
466
467 memcpy(out, in, m->matchsize);
468 pad = XT_ALIGN(m->matchsize) - m->matchsize;
469 if (pad > 0)
470 memset(out + m->matchsize, 0, pad);
471}
472
473static int
474__nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
475 const struct nlattr * const tb[],
476 void *info)
477{
478 struct xt_match *match = expr->ops->data;
479 struct xt_mtchk_param par;
480 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
481 u16 proto = 0;
482 bool inv = false;
483 union nft_entry e = {};
484 int ret;
485
486 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
487
488 if (ctx->nla[NFTA_RULE_COMPAT]) {
489 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
490 if (ret < 0)
491 return ret;
492 }
493
494 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
495
496 nft_compat_wait_for_destructors();
497
498 return xt_check_match(&par, size, proto, inv);
499}
500
501static int
502nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
503 const struct nlattr * const tb[])
504{
505 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr));
506}
507
508static int
509nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
510 const struct nlattr * const tb[])
511{
512 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
513 struct xt_match *m = expr->ops->data;
514 int ret;
515
516 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL);
517 if (!priv->info)
518 return -ENOMEM;
519
520 ret = __nft_match_init(ctx, expr, tb, priv->info);
521 if (ret)
522 kfree(priv->info);
523 return ret;
524}
525
526static void
527__nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr,
528 void *info)
529{
530 struct xt_match *match = expr->ops->data;
531 struct module *me = match->me;
532 struct xt_mtdtor_param par;
533
534 par.net = ctx->net;
535 par.match = match;
536 par.matchinfo = info;
537 par.family = ctx->family;
538 if (par.match->destroy != NULL)
539 par.match->destroy(&par);
540
541 __nft_mt_tg_destroy(me, expr);
542}
543
544static void
545nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
546{
547 __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
548}
549
550static void
551nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
552{
553 struct nft_xt_match_priv *priv = nft_expr_priv(expr);
554
555 __nft_match_destroy(ctx, expr, priv->info);
556 kfree(priv->info);
557}
558
559static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr,
560 void *info)
561{
562 struct xt_match *match = expr->ops->data;
563
564 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
565 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
566 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info,
567 match->matchsize, match->usersize))
568 goto nla_put_failure;
569
570 return 0;
571
572nla_put_failure:
573 return -1;
574}
575
576static int nft_match_dump(struct sk_buff *skb,
577 const struct nft_expr *expr, bool reset)
578{
579 return __nft_match_dump(skb, expr, nft_expr_priv(expr));
580}
581
582static int nft_match_large_dump(struct sk_buff *skb,
583 const struct nft_expr *e, bool reset)
584{
585 struct nft_xt_match_priv *priv = nft_expr_priv(e);
586
587 return __nft_match_dump(skb, e, priv->info);
588}
589
590static int nft_match_validate(const struct nft_ctx *ctx,
591 const struct nft_expr *expr,
592 const struct nft_data **data)
593{
594 struct xt_match *match = expr->ops->data;
595 unsigned int hook_mask = 0;
596 int ret;
597
598 if (nft_is_base_chain(ctx->chain)) {
599 const struct nft_base_chain *basechain =
600 nft_base_chain(ctx->chain);
601 const struct nf_hook_ops *ops = &basechain->ops;
602
603 hook_mask = 1 << ops->hooknum;
604 if (match->hooks && !(hook_mask & match->hooks))
605 return -EINVAL;
606
607 ret = nft_compat_chain_validate_dependency(ctx, match->table);
608 if (ret < 0)
609 return ret;
610 }
611 return 0;
612}
613
614static int
615nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
616 int event, u16 family, const char *name,
617 int rev, int target)
618{
619 struct nlmsghdr *nlh;
620 unsigned int flags = portid ? NLM_F_MULTI : 0;
621
622 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event);
623 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family,
624 NFNETLINK_V0, 0);
625 if (!nlh)
626 goto nlmsg_failure;
627
628 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
629 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
630 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
631 goto nla_put_failure;
632
633 nlmsg_end(skb, nlh);
634 return skb->len;
635
636nlmsg_failure:
637nla_put_failure:
638 nlmsg_cancel(skb, nlh);
639 return -1;
640}
641
642static int nfnl_compat_get_rcu(struct sk_buff *skb,
643 const struct nfnl_info *info,
644 const struct nlattr * const tb[])
645{
646 u8 family = info->nfmsg->nfgen_family;
647 const char *name, *fmt;
648 struct sk_buff *skb2;
649 int ret = 0, target;
650 u32 rev;
651
652 if (tb[NFTA_COMPAT_NAME] == NULL ||
653 tb[NFTA_COMPAT_REV] == NULL ||
654 tb[NFTA_COMPAT_TYPE] == NULL)
655 return -EINVAL;
656
657 name = nla_data(tb[NFTA_COMPAT_NAME]);
658 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
659 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
660
661 switch(family) {
662 case AF_INET:
663 fmt = "ipt_%s";
664 break;
665 case AF_INET6:
666 fmt = "ip6t_%s";
667 break;
668 case NFPROTO_BRIDGE:
669 fmt = "ebt_%s";
670 break;
671 case NFPROTO_ARP:
672 fmt = "arpt_%s";
673 break;
674 default:
675 pr_err("nft_compat: unsupported protocol %d\n", family);
676 return -EINVAL;
677 }
678
679 if (!try_module_get(THIS_MODULE))
680 return -EINVAL;
681
682 rcu_read_unlock();
683 try_then_request_module(xt_find_revision(family, name, rev, target, &ret),
684 fmt, name);
685 if (ret < 0)
686 goto out_put;
687
688 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
689 if (skb2 == NULL) {
690 ret = -ENOMEM;
691 goto out_put;
692 }
693
694 /* include the best revision for this extension in the message */
695 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
696 info->nlh->nlmsg_seq,
697 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
698 NFNL_MSG_COMPAT_GET,
699 family, name, ret, target) <= 0) {
700 kfree_skb(skb2);
701 goto out_put;
702 }
703
704 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
705out_put:
706 rcu_read_lock();
707 module_put(THIS_MODULE);
708
709 return ret;
710}
711
712static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
713 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
714 .len = NFT_COMPAT_NAME_MAX-1 },
715 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
716 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
717};
718
719static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
720 [NFNL_MSG_COMPAT_GET] = {
721 .call = nfnl_compat_get_rcu,
722 .type = NFNL_CB_RCU,
723 .attr_count = NFTA_COMPAT_MAX,
724 .policy = nfnl_compat_policy_get
725 },
726};
727
728static const struct nfnetlink_subsystem nfnl_compat_subsys = {
729 .name = "nft-compat",
730 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
731 .cb_count = NFNL_MSG_COMPAT_MAX,
732 .cb = nfnl_nft_compat_cb,
733};
734
735static struct nft_expr_type nft_match_type;
736
737static bool nft_match_reduce(struct nft_regs_track *track,
738 const struct nft_expr *expr)
739{
740 const struct xt_match *match = expr->ops->data;
741
742 return strcmp(match->name, "comment") == 0;
743}
744
745static const struct nft_expr_ops *
746nft_match_select_ops(const struct nft_ctx *ctx,
747 const struct nlattr * const tb[])
748{
749 struct nft_expr_ops *ops;
750 struct xt_match *match;
751 unsigned int matchsize;
752 char *mt_name;
753 u32 rev, family;
754 int err;
755
756 if (tb[NFTA_MATCH_NAME] == NULL ||
757 tb[NFTA_MATCH_REV] == NULL ||
758 tb[NFTA_MATCH_INFO] == NULL)
759 return ERR_PTR(-EINVAL);
760
761 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
762 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
763 family = ctx->family;
764
765 match = xt_request_find_match(family, mt_name, rev);
766 if (IS_ERR(match))
767 return ERR_PTR(-ENOENT);
768
769 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
770 err = -EINVAL;
771 goto err;
772 }
773
774 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
775 if (!ops) {
776 err = -ENOMEM;
777 goto err;
778 }
779
780 ops->type = &nft_match_type;
781 ops->eval = nft_match_eval;
782 ops->init = nft_match_init;
783 ops->destroy = nft_match_destroy;
784 ops->dump = nft_match_dump;
785 ops->validate = nft_match_validate;
786 ops->data = match;
787 ops->reduce = nft_match_reduce;
788
789 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
790 if (matchsize > NFT_MATCH_LARGE_THRESH) {
791 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv));
792
793 ops->eval = nft_match_large_eval;
794 ops->init = nft_match_large_init;
795 ops->destroy = nft_match_large_destroy;
796 ops->dump = nft_match_large_dump;
797 }
798
799 ops->size = matchsize;
800
801 return ops;
802err:
803 module_put(match->me);
804 return ERR_PTR(err);
805}
806
807static void nft_match_release_ops(const struct nft_expr_ops *ops)
808{
809 struct xt_match *match = ops->data;
810
811 module_put(match->me);
812 kfree(ops);
813}
814
815static struct nft_expr_type nft_match_type __read_mostly = {
816 .name = "match",
817 .select_ops = nft_match_select_ops,
818 .release_ops = nft_match_release_ops,
819 .policy = nft_match_policy,
820 .maxattr = NFTA_MATCH_MAX,
821 .owner = THIS_MODULE,
822};
823
824static struct nft_expr_type nft_target_type;
825
826static const struct nft_expr_ops *
827nft_target_select_ops(const struct nft_ctx *ctx,
828 const struct nlattr * const tb[])
829{
830 struct nft_expr_ops *ops;
831 struct xt_target *target;
832 char *tg_name;
833 u32 rev, family;
834 int err;
835
836 if (tb[NFTA_TARGET_NAME] == NULL ||
837 tb[NFTA_TARGET_REV] == NULL ||
838 tb[NFTA_TARGET_INFO] == NULL)
839 return ERR_PTR(-EINVAL);
840
841 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
842 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
843 family = ctx->family;
844
845 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 ||
846 strcmp(tg_name, XT_STANDARD_TARGET) == 0 ||
847 strcmp(tg_name, "standard") == 0)
848 return ERR_PTR(-EINVAL);
849
850 target = xt_request_find_target(family, tg_name, rev);
851 if (IS_ERR(target))
852 return ERR_PTR(-ENOENT);
853
854 if (!target->target) {
855 err = -EINVAL;
856 goto err;
857 }
858
859 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
860 err = -EINVAL;
861 goto err;
862 }
863
864 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL);
865 if (!ops) {
866 err = -ENOMEM;
867 goto err;
868 }
869
870 ops->type = &nft_target_type;
871 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
872 ops->init = nft_target_init;
873 ops->destroy = nft_target_destroy;
874 ops->dump = nft_target_dump;
875 ops->validate = nft_target_validate;
876 ops->data = target;
877 ops->reduce = NFT_REDUCE_READONLY;
878
879 if (family == NFPROTO_BRIDGE)
880 ops->eval = nft_target_eval_bridge;
881 else
882 ops->eval = nft_target_eval_xt;
883
884 return ops;
885err:
886 module_put(target->me);
887 return ERR_PTR(err);
888}
889
890static void nft_target_release_ops(const struct nft_expr_ops *ops)
891{
892 struct xt_target *target = ops->data;
893
894 module_put(target->me);
895 kfree(ops);
896}
897
898static struct nft_expr_type nft_target_type __read_mostly = {
899 .name = "target",
900 .select_ops = nft_target_select_ops,
901 .release_ops = nft_target_release_ops,
902 .policy = nft_target_policy,
903 .maxattr = NFTA_TARGET_MAX,
904 .owner = THIS_MODULE,
905};
906
907static int __init nft_compat_module_init(void)
908{
909 int ret;
910
911 ret = nft_register_expr(&nft_match_type);
912 if (ret < 0)
913 return ret;
914
915 ret = nft_register_expr(&nft_target_type);
916 if (ret < 0)
917 goto err_match;
918
919 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
920 if (ret < 0) {
921 pr_err("nft_compat: cannot register with nfnetlink.\n");
922 goto err_target;
923 }
924
925 return ret;
926err_target:
927 nft_unregister_expr(&nft_target_type);
928err_match:
929 nft_unregister_expr(&nft_match_type);
930 return ret;
931}
932
933static void __exit nft_compat_module_exit(void)
934{
935 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
936 nft_unregister_expr(&nft_target_type);
937 nft_unregister_expr(&nft_match_type);
938}
939
940MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
941
942module_init(nft_compat_module_init);
943module_exit(nft_compat_module_exit);
944
945MODULE_LICENSE("GPL");
946MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
947MODULE_ALIAS_NFT_EXPR("match");
948MODULE_ALIAS_NFT_EXPR("target");
949MODULE_DESCRIPTION("x_tables over nftables support");