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 <net/netfilter/nf_tables.h>
27 } table_to_chaintype[] = {
28 { "filter", NFT_CHAIN_T_DEFAULT },
29 { "raw", NFT_CHAIN_T_DEFAULT },
30 { "security", NFT_CHAIN_T_DEFAULT },
31 { "mangle", NFT_CHAIN_T_ROUTE },
32 { "nat", NFT_CHAIN_T_NAT },
36 static int nft_compat_table_to_chaintype(const char *table)
40 for (i = 0; table_to_chaintype[i].name != NULL; i++) {
41 if (strcmp(table_to_chaintype[i].name, table) == 0)
42 return table_to_chaintype[i].type;
48 static int nft_compat_chain_validate_dependency(const char *tablename,
49 const struct nft_chain *chain)
51 enum nft_chain_type type;
52 const struct nft_base_chain *basechain;
54 if (!tablename || !(chain->flags & NFT_BASE_CHAIN))
57 type = nft_compat_table_to_chaintype(tablename);
61 basechain = nft_base_chain(chain);
62 if (basechain->type->type != type)
74 nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
77 par->targinfo = xt_info;
81 static void nft_target_eval(const struct nft_expr *expr,
82 struct nft_data data[NFT_REG_MAX + 1],
83 const struct nft_pktinfo *pkt)
85 void *info = nft_expr_priv(expr);
86 struct xt_target *target = expr->ops->data;
87 struct sk_buff *skb = pkt->skb;
90 nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
92 ret = target->target(skb, &pkt->xt);
99 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
102 data[NFT_REG_VERDICT].verdict = ret;
108 static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
109 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
110 [NFTA_TARGET_REV] = { .type = NLA_U32 },
111 [NFTA_TARGET_INFO] = { .type = NLA_BINARY },
115 nft_target_set_tgchk_param(struct xt_tgchk_param *par,
116 const struct nft_ctx *ctx,
117 struct xt_target *target, void *info,
118 union nft_entry *entry, u8 proto, bool inv)
120 par->net = &init_net;
121 par->table = ctx->table->name;
122 switch (ctx->afi->family) {
124 entry->e4.ip.proto = proto;
125 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
128 entry->e6.ipv6.proto = proto;
129 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
132 par->entryinfo = entry;
133 par->target = target;
134 par->targinfo = info;
135 if (ctx->chain->flags & NFT_BASE_CHAIN) {
136 const struct nft_base_chain *basechain =
137 nft_base_chain(ctx->chain);
138 const struct nf_hook_ops *ops = &basechain->ops[0];
140 par->hook_mask = 1 << ops->hooknum;
144 par->family = ctx->afi->family;
147 static void target_compat_from_user(struct xt_target *t, void *in, void *out)
151 memcpy(out, in, t->targetsize);
152 pad = XT_ALIGN(t->targetsize) - t->targetsize;
154 memset(out + t->targetsize, 0, pad);
157 static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
158 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
159 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
162 static int nft_parse_compat(const struct nlattr *attr, u8 *proto, bool *inv)
164 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
168 err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
169 nft_rule_compat_policy);
173 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
176 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
177 if (flags & ~NFT_RULE_COMPAT_F_MASK)
179 if (flags & NFT_RULE_COMPAT_F_INV)
182 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
187 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
188 const struct nlattr * const tb[])
190 void *info = nft_expr_priv(expr);
191 struct xt_target *target = expr->ops->data;
192 struct xt_tgchk_param par;
193 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
196 union nft_entry e = {};
199 ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
203 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
205 if (ctx->nla[NFTA_RULE_COMPAT]) {
206 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
211 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
213 ret = xt_check_target(&par, size, proto, inv);
217 /* The standard target cannot be used */
218 if (target->target == NULL) {
225 module_put(target->me);
230 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
232 struct xt_target *target = expr->ops->data;
233 void *info = nft_expr_priv(expr);
234 struct xt_tgdtor_param par;
239 par.family = ctx->afi->family;
240 if (par.target->destroy != NULL)
241 par.target->destroy(&par);
243 module_put(target->me);
246 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
248 const struct xt_target *target = expr->ops->data;
249 void *info = nft_expr_priv(expr);
251 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
252 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
253 nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info))
254 goto nla_put_failure;
262 static int nft_target_validate(const struct nft_ctx *ctx,
263 const struct nft_expr *expr,
264 const struct nft_data **data)
266 struct xt_target *target = expr->ops->data;
267 unsigned int hook_mask = 0;
270 if (ctx->chain->flags & NFT_BASE_CHAIN) {
271 const struct nft_base_chain *basechain =
272 nft_base_chain(ctx->chain);
273 const struct nf_hook_ops *ops = &basechain->ops[0];
275 hook_mask = 1 << ops->hooknum;
276 if (!(hook_mask & target->hooks))
279 ret = nft_compat_chain_validate_dependency(target->table,
287 static void nft_match_eval(const struct nft_expr *expr,
288 struct nft_data data[NFT_REG_MAX + 1],
289 const struct nft_pktinfo *pkt)
291 void *info = nft_expr_priv(expr);
292 struct xt_match *match = expr->ops->data;
293 struct sk_buff *skb = pkt->skb;
296 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
298 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
300 if (pkt->xt.hotdrop) {
301 data[NFT_REG_VERDICT].verdict = NF_DROP;
307 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
310 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
315 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
316 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
317 [NFTA_MATCH_REV] = { .type = NLA_U32 },
318 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
321 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
323 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
324 struct xt_match *match, void *info,
325 union nft_entry *entry, u8 proto, bool inv)
327 par->net = &init_net;
328 par->table = ctx->table->name;
329 switch (ctx->afi->family) {
331 entry->e4.ip.proto = proto;
332 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
335 entry->e6.ipv6.proto = proto;
336 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
339 par->entryinfo = entry;
341 par->matchinfo = info;
342 if (ctx->chain->flags & NFT_BASE_CHAIN) {
343 const struct nft_base_chain *basechain =
344 nft_base_chain(ctx->chain);
345 const struct nf_hook_ops *ops = &basechain->ops[0];
347 par->hook_mask = 1 << ops->hooknum;
351 par->family = ctx->afi->family;
354 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
358 memcpy(out, in, m->matchsize);
359 pad = XT_ALIGN(m->matchsize) - m->matchsize;
361 memset(out + m->matchsize, 0, pad);
365 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
366 const struct nlattr * const tb[])
368 void *info = nft_expr_priv(expr);
369 struct xt_match *match = expr->ops->data;
370 struct xt_mtchk_param par;
371 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
374 union nft_entry e = {};
377 ret = nft_compat_chain_validate_dependency(match->name, ctx->chain);
381 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
383 if (ctx->nla[NFTA_RULE_COMPAT]) {
384 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
389 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
391 ret = xt_check_match(&par, size, proto, inv);
397 module_put(match->me);
402 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
404 struct xt_match *match = expr->ops->data;
405 void *info = nft_expr_priv(expr);
406 struct xt_mtdtor_param par;
410 par.matchinfo = info;
411 par.family = ctx->afi->family;
412 if (par.match->destroy != NULL)
413 par.match->destroy(&par);
415 module_put(match->me);
418 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
420 void *info = nft_expr_priv(expr);
421 struct xt_match *match = expr->ops->data;
423 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
424 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
425 nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info))
426 goto nla_put_failure;
434 static int nft_match_validate(const struct nft_ctx *ctx,
435 const struct nft_expr *expr,
436 const struct nft_data **data)
438 struct xt_match *match = expr->ops->data;
439 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[0];
447 hook_mask = 1 << ops->hooknum;
448 if (!(hook_mask & match->hooks))
451 ret = nft_compat_chain_validate_dependency(match->name,
460 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
461 int event, u16 family, const char *name,
464 struct nlmsghdr *nlh;
465 struct nfgenmsg *nfmsg;
466 unsigned int flags = portid ? NLM_F_MULTI : 0;
468 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
469 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
473 nfmsg = nlmsg_data(nlh);
474 nfmsg->nfgen_family = family;
475 nfmsg->version = NFNETLINK_V0;
478 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
479 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
480 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
481 goto nla_put_failure;
488 nlmsg_cancel(skb, nlh);
493 nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
494 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
497 struct nfgenmsg *nfmsg;
501 struct sk_buff *skb2;
503 if (tb[NFTA_COMPAT_NAME] == NULL ||
504 tb[NFTA_COMPAT_REV] == NULL ||
505 tb[NFTA_COMPAT_TYPE] == NULL)
508 name = nla_data(tb[NFTA_COMPAT_NAME]);
509 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
510 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
512 nfmsg = nlmsg_data(nlh);
514 switch(nfmsg->nfgen_family) {
522 pr_err("nft_compat: unsupported protocol %d\n",
523 nfmsg->nfgen_family);
527 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
534 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
538 /* include the best revision for this extension in the message */
539 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
541 NFNL_MSG_TYPE(nlh->nlmsg_type),
544 name, ret, target) <= 0) {
549 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
554 return ret == -EAGAIN ? -ENOBUFS : ret;
557 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
558 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
559 .len = NFT_COMPAT_NAME_MAX-1 },
560 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
561 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
564 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
565 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
566 .attr_count = NFTA_COMPAT_MAX,
567 .policy = nfnl_compat_policy_get },
570 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
571 .name = "nft-compat",
572 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
573 .cb_count = NFNL_MSG_COMPAT_MAX,
574 .cb = nfnl_nft_compat_cb,
577 static LIST_HEAD(nft_match_list);
580 struct list_head head;
581 struct nft_expr_ops ops;
584 static struct nft_expr_type nft_match_type;
586 static const struct nft_expr_ops *
587 nft_match_select_ops(const struct nft_ctx *ctx,
588 const struct nlattr * const tb[])
590 struct nft_xt *nft_match;
591 struct xt_match *match;
595 if (tb[NFTA_MATCH_NAME] == NULL ||
596 tb[NFTA_MATCH_REV] == NULL ||
597 tb[NFTA_MATCH_INFO] == NULL)
598 return ERR_PTR(-EINVAL);
600 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
601 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
602 family = ctx->afi->family;
604 /* Re-use the existing match if it's already loaded. */
605 list_for_each_entry(nft_match, &nft_match_list, head) {
606 struct xt_match *match = nft_match->ops.data;
608 if (strcmp(match->name, mt_name) == 0 &&
609 match->revision == rev && match->family == family)
610 return &nft_match->ops;
613 match = xt_request_find_match(family, mt_name, rev);
615 return ERR_PTR(-ENOENT);
617 /* This is the first time we use this match, allocate operations */
618 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
619 if (nft_match == NULL)
620 return ERR_PTR(-ENOMEM);
622 nft_match->ops.type = &nft_match_type;
623 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
624 nft_match->ops.eval = nft_match_eval;
625 nft_match->ops.init = nft_match_init;
626 nft_match->ops.destroy = nft_match_destroy;
627 nft_match->ops.dump = nft_match_dump;
628 nft_match->ops.validate = nft_match_validate;
629 nft_match->ops.data = match;
631 list_add(&nft_match->head, &nft_match_list);
633 return &nft_match->ops;
636 static void nft_match_release(void)
638 struct nft_xt *nft_match, *tmp;
640 list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
644 static struct nft_expr_type nft_match_type __read_mostly = {
646 .select_ops = nft_match_select_ops,
647 .policy = nft_match_policy,
648 .maxattr = NFTA_MATCH_MAX,
649 .owner = THIS_MODULE,
652 static LIST_HEAD(nft_target_list);
654 static struct nft_expr_type nft_target_type;
656 static const struct nft_expr_ops *
657 nft_target_select_ops(const struct nft_ctx *ctx,
658 const struct nlattr * const tb[])
660 struct nft_xt *nft_target;
661 struct xt_target *target;
665 if (tb[NFTA_TARGET_NAME] == NULL ||
666 tb[NFTA_TARGET_REV] == NULL ||
667 tb[NFTA_TARGET_INFO] == NULL)
668 return ERR_PTR(-EINVAL);
670 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
671 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
672 family = ctx->afi->family;
674 /* Re-use the existing target if it's already loaded. */
675 list_for_each_entry(nft_target, &nft_target_list, head) {
676 struct xt_target *target = nft_target->ops.data;
678 if (strcmp(target->name, tg_name) == 0 &&
679 target->revision == rev && target->family == family)
680 return &nft_target->ops;
683 target = xt_request_find_target(family, tg_name, rev);
685 return ERR_PTR(-ENOENT);
687 /* This is the first time we use this target, allocate operations */
688 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
689 if (nft_target == NULL)
690 return ERR_PTR(-ENOMEM);
692 nft_target->ops.type = &nft_target_type;
693 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
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, *tmp;
710 list_for_each_entry_safe(nft_target, tmp, &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");