2 * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
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.
8 * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/netlink.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter/nfnetlink.h>
17 #include <linux/netfilter/nf_tables.h>
18 #include <linux/netfilter/nf_tables_compat.h>
19 #include <linux/netfilter/x_tables.h>
20 #include <linux/netfilter_ipv4/ip_tables.h>
21 #include <linux/netfilter_ipv6/ip6_tables.h>
22 #include <asm/uaccess.h> /* for set_fs */
23 #include <net/netfilter/nf_tables.h>
31 nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
34 par->targinfo = xt_info;
38 static void nft_target_eval(const struct nft_expr *expr,
39 struct nft_data data[NFT_REG_MAX + 1],
40 const struct nft_pktinfo *pkt)
42 void *info = nft_expr_priv(expr);
43 struct xt_target *target = expr->ops->data;
44 struct sk_buff *skb = pkt->skb;
47 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
49 ret = target->target(skb, &pkt->xt);
56 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
59 data[NFT_REG_VERDICT].verdict = ret;
65 static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
66 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
67 [NFTA_TARGET_REV] = { .type = NLA_U32 },
68 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
72 nft_target_set_tgchk_param(struct xt_tgchk_param *par,
73 const struct nft_ctx *ctx,
74 struct xt_target *target, void *info,
75 union nft_entry *entry, u8 proto, bool inv)
78 par->table = ctx->table->name;
79 switch (ctx->afi->family) {
81 entry->e4.ip.proto = proto;
82 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
85 entry->e6.ipv6.proto = proto;
86 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
89 par->entryinfo = entry;
92 if (ctx->chain->flags & NFT_BASE_CHAIN) {
93 const struct nft_base_chain *basechain =
94 nft_base_chain(ctx->chain);
95 const struct nf_hook_ops *ops = &basechain->ops;
97 par->hook_mask = 1 << ops->hooknum;
99 par->family = ctx->afi->family;
102 static void target_compat_from_user(struct xt_target *t, void *in, void *out)
105 if (t->compat_from_user) {
108 t->compat_from_user(out, in);
109 pad = XT_ALIGN(t->targetsize) - t->targetsize;
111 memset(out + t->targetsize, 0, pad);
114 memcpy(out, in, XT_ALIGN(t->targetsize));
117 static inline int nft_compat_target_offset(struct xt_target *target)
120 return xt_compat_target_offset(target);
126 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
127 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
128 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
131 static u8 nft_parse_compat(const struct nlattr *attr, bool *inv)
133 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
137 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
138 nft_rule_compat_policy);
142 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
145 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
146 if (flags & ~NFT_RULE_COMPAT_F_MASK)
148 if (flags & NFT_RULE_COMPAT_F_INV)
151 return ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
155 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
156 const struct nlattr * const tb[])
158 void *info = nft_expr_priv(expr);
159 struct xt_target *target = expr->ops->data;
160 struct xt_tgchk_param par;
161 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
164 union nft_entry e = {};
167 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
169 if (ctx->nla[NFTA_RULE_COMPAT])
170 proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv);
172 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
174 ret = xt_check_target(&par, size, proto, inv);
178 /* The standard target cannot be used */
179 if (target->target == NULL) {
186 module_put(target->me);
191 nft_target_destroy(const struct nft_expr *expr)
193 struct xt_target *target = expr->ops->data;
195 module_put(target->me);
199 target_dump_info(struct sk_buff *skb, const struct xt_target *t, const void *in)
204 if (t->compat_to_user) {
208 out = kmalloc(XT_ALIGN(t->targetsize), GFP_ATOMIC);
212 /* We want to reuse existing compat_to_user */
215 t->compat_to_user(out, in);
217 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), out);
221 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), in);
226 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
228 const struct xt_target *target = expr->ops->data;
229 void *info = nft_expr_priv(expr);
231 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
232 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
233 target_dump_info(skb, target, info))
234 goto nla_put_failure;
242 static int nft_target_validate(const struct nft_ctx *ctx,
243 const struct nft_expr *expr,
244 const struct nft_data **data)
246 struct xt_target *target = expr->ops->data;
247 unsigned int hook_mask = 0;
249 if (ctx->chain->flags & NFT_BASE_CHAIN) {
250 const struct nft_base_chain *basechain =
251 nft_base_chain(ctx->chain);
252 const struct nf_hook_ops *ops = &basechain->ops;
254 hook_mask = 1 << ops->hooknum;
255 if (hook_mask & target->hooks)
258 /* This target is being called from an invalid chain */
264 static void nft_match_eval(const struct nft_expr *expr,
265 struct nft_data data[NFT_REG_MAX + 1],
266 const struct nft_pktinfo *pkt)
268 void *info = nft_expr_priv(expr);
269 struct xt_match *match = expr->ops->data;
270 struct sk_buff *skb = pkt->skb;
273 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
275 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
277 if (pkt->xt.hotdrop) {
278 data[NFT_REG_VERDICT].verdict = NF_DROP;
284 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
287 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
292 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
293 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
294 [NFTA_MATCH_REV] = { .type = NLA_U32 },
295 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
298 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
300 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
301 struct xt_match *match, void *info,
302 union nft_entry *entry, u8 proto, bool inv)
304 par->net = &init_net;
305 par->table = ctx->table->name;
306 switch (ctx->afi->family) {
308 entry->e4.ip.proto = proto;
309 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
312 entry->e6.ipv6.proto = proto;
313 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
316 par->entryinfo = entry;
318 par->matchinfo = info;
319 if (ctx->chain->flags & NFT_BASE_CHAIN) {
320 const struct nft_base_chain *basechain =
321 nft_base_chain(ctx->chain);
322 const struct nf_hook_ops *ops = &basechain->ops;
324 par->hook_mask = 1 << ops->hooknum;
326 par->family = ctx->afi->family;
329 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
332 if (m->compat_from_user) {
335 m->compat_from_user(out, in);
336 pad = XT_ALIGN(m->matchsize) - m->matchsize;
338 memset(out + m->matchsize, 0, pad);
341 memcpy(out, in, XT_ALIGN(m->matchsize));
345 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
346 const struct nlattr * const tb[])
348 void *info = nft_expr_priv(expr);
349 struct xt_match *match = expr->ops->data;
350 struct xt_mtchk_param par;
351 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
354 union nft_entry e = {};
357 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
359 if (ctx->nla[NFTA_RULE_COMPAT])
360 proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv);
362 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
364 ret = xt_check_match(&par, size, proto, inv);
370 module_put(match->me);
375 nft_match_destroy(const struct nft_expr *expr)
377 struct xt_match *match = expr->ops->data;
379 module_put(match->me);
383 match_dump_info(struct sk_buff *skb, const struct xt_match *m, const void *in)
388 if (m->compat_to_user) {
392 out = kmalloc(XT_ALIGN(m->matchsize), GFP_ATOMIC);
396 /* We want to reuse existing compat_to_user */
399 m->compat_to_user(out, in);
401 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), out);
405 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), in);
410 static inline int nft_compat_match_offset(struct xt_match *match)
413 return xt_compat_match_offset(match);
419 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
421 void *info = nft_expr_priv(expr);
422 struct xt_match *match = expr->ops->data;
424 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
425 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
426 match_dump_info(skb, match, info))
427 goto nla_put_failure;
435 static int nft_match_validate(const struct nft_ctx *ctx,
436 const struct nft_expr *expr,
437 const struct nft_data **data)
439 struct xt_match *match = expr->ops->data;
440 unsigned int hook_mask = 0;
442 if (ctx->chain->flags & NFT_BASE_CHAIN) {
443 const struct nft_base_chain *basechain =
444 nft_base_chain(ctx->chain);
445 const struct nf_hook_ops *ops = &basechain->ops;
447 hook_mask = 1 << ops->hooknum;
448 if (hook_mask & match->hooks)
451 /* This match is being called from an invalid chain */
458 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
459 int event, u16 family, const char *name,
462 struct nlmsghdr *nlh;
463 struct nfgenmsg *nfmsg;
464 unsigned int flags = portid ? NLM_F_MULTI : 0;
466 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
467 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
471 nfmsg = nlmsg_data(nlh);
472 nfmsg->nfgen_family = family;
473 nfmsg->version = NFNETLINK_V0;
476 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
477 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
478 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
479 goto nla_put_failure;
486 nlmsg_cancel(skb, nlh);
491 nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
492 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
495 struct nfgenmsg *nfmsg;
499 struct sk_buff *skb2;
501 if (tb[NFTA_COMPAT_NAME] == NULL ||
502 tb[NFTA_COMPAT_REV] == NULL ||
503 tb[NFTA_COMPAT_TYPE] == NULL)
506 name = nla_data(tb[NFTA_COMPAT_NAME]);
507 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
508 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
510 nfmsg = nlmsg_data(nlh);
512 switch(nfmsg->nfgen_family) {
520 pr_err("nft_compat: unsupported protocol %d\n",
521 nfmsg->nfgen_family);
525 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
532 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
536 /* include the best revision for this extension in the message */
537 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
539 NFNL_MSG_TYPE(nlh->nlmsg_type),
542 name, ret, target) <= 0) {
547 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
552 return ret == -EAGAIN ? -ENOBUFS : ret;
555 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
556 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
557 .len = NFT_COMPAT_NAME_MAX-1 },
558 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
559 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
562 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
563 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
564 .attr_count = NFTA_COMPAT_MAX,
565 .policy = nfnl_compat_policy_get },
568 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
569 .name = "nft-compat",
570 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
571 .cb_count = NFNL_MSG_COMPAT_MAX,
572 .cb = nfnl_nft_compat_cb,
575 static LIST_HEAD(nft_match_list);
578 struct list_head head;
579 struct nft_expr_ops ops;
582 static struct nft_expr_type nft_match_type;
584 static const struct nft_expr_ops *
585 nft_match_select_ops(const struct nft_ctx *ctx,
586 const struct nlattr * const tb[])
588 struct nft_xt *nft_match;
589 struct xt_match *match;
593 if (tb[NFTA_MATCH_NAME] == NULL ||
594 tb[NFTA_MATCH_REV] == NULL ||
595 tb[NFTA_MATCH_INFO] == NULL)
596 return ERR_PTR(-EINVAL);
598 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
599 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
600 family = ctx->afi->family;
602 /* Re-use the existing match if it's already loaded. */
603 list_for_each_entry(nft_match, &nft_match_list, head) {
604 struct xt_match *match = nft_match->ops.data;
606 if (strcmp(match->name, mt_name) == 0 &&
607 match->revision == rev && match->family == family)
608 return &nft_match->ops;
611 match = xt_request_find_match(family, mt_name, rev);
613 return ERR_PTR(-ENOENT);
615 /* This is the first time we use this match, allocate operations */
616 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
617 if (nft_match == NULL)
618 return ERR_PTR(-ENOMEM);
620 nft_match->ops.type = &nft_match_type;
621 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize) +
622 nft_compat_match_offset(match));
623 nft_match->ops.eval = nft_match_eval;
624 nft_match->ops.init = nft_match_init;
625 nft_match->ops.destroy = nft_match_destroy;
626 nft_match->ops.dump = nft_match_dump;
627 nft_match->ops.validate = nft_match_validate;
628 nft_match->ops.data = match;
630 list_add(&nft_match->head, &nft_match_list);
632 return &nft_match->ops;
635 static void nft_match_release(void)
637 struct nft_xt *nft_match;
639 list_for_each_entry(nft_match, &nft_match_list, head)
643 static struct nft_expr_type nft_match_type __read_mostly = {
645 .select_ops = nft_match_select_ops,
646 .policy = nft_match_policy,
647 .maxattr = NFTA_MATCH_MAX,
648 .owner = THIS_MODULE,
651 static LIST_HEAD(nft_target_list);
653 static struct nft_expr_type nft_target_type;
655 static const struct nft_expr_ops *
656 nft_target_select_ops(const struct nft_ctx *ctx,
657 const struct nlattr * const tb[])
659 struct nft_xt *nft_target;
660 struct xt_target *target;
664 if (tb[NFTA_TARGET_NAME] == NULL ||
665 tb[NFTA_TARGET_REV] == NULL ||
666 tb[NFTA_TARGET_INFO] == NULL)
667 return ERR_PTR(-EINVAL);
669 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
670 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
671 family = ctx->afi->family;
673 /* Re-use the existing target if it's already loaded. */
674 list_for_each_entry(nft_target, &nft_match_list, head) {
675 struct xt_target *target = nft_target->ops.data;
677 if (strcmp(target->name, tg_name) == 0 &&
678 target->revision == rev && target->family == family)
679 return &nft_target->ops;
682 target = xt_request_find_target(family, tg_name, rev);
684 return ERR_PTR(-ENOENT);
686 /* This is the first time we use this target, allocate operations */
687 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
688 if (nft_target == NULL)
689 return ERR_PTR(-ENOMEM);
691 nft_target->ops.type = &nft_target_type;
692 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize) +
693 nft_compat_target_offset(target));
694 nft_target->ops.eval = nft_target_eval;
695 nft_target->ops.init = nft_target_init;
696 nft_target->ops.destroy = nft_target_destroy;
697 nft_target->ops.dump = nft_target_dump;
698 nft_target->ops.validate = nft_target_validate;
699 nft_target->ops.data = target;
701 list_add(&nft_target->head, &nft_target_list);
703 return &nft_target->ops;
706 static void nft_target_release(void)
708 struct nft_xt *nft_target;
710 list_for_each_entry(nft_target, &nft_target_list, head)
714 static struct nft_expr_type nft_target_type __read_mostly = {
716 .select_ops = nft_target_select_ops,
717 .policy = nft_target_policy,
718 .maxattr = NFTA_TARGET_MAX,
719 .owner = THIS_MODULE,
722 static int __init nft_compat_module_init(void)
726 ret = nft_register_expr(&nft_match_type);
730 ret = nft_register_expr(&nft_target_type);
734 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
736 pr_err("nft_compat: cannot register with nfnetlink.\n");
740 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
745 nft_unregister_expr(&nft_target_type);
747 nft_unregister_expr(&nft_match_type);
751 static void __exit nft_compat_module_exit(void)
753 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
754 nft_unregister_expr(&nft_target_type);
755 nft_unregister_expr(&nft_match_type);
757 nft_target_release();
760 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
762 module_init(nft_compat_module_init);
763 module_exit(nft_compat_module_exit);
765 MODULE_LICENSE("GPL");
766 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
767 MODULE_ALIAS_NFT_EXPR("match");
768 MODULE_ALIAS_NFT_EXPR("target");