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