bee11dc78f
This patch moves nft_reject_ipv4 to nft_reject and adds support for IPv6 protocol. This patch uses functions included in nf_reject.h to implement reject by TCP reset. The code has to be build as a module if NF_TABLES_IPV6 is also a module to avoid compilation error due to usage of IPv6 functions. This has been done in Kconfig by using the construct: depends on NF_TABLES_IPV6 || !NF_TABLES_IPV6 This seems a bit weird in terms of syntax but works perfectly. Signed-off-by: Eric Leblond <eric@regit.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
145 lines
3.6 KiB
C
145 lines
3.6 KiB
C
/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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* Copyright (c) 2013 Eric Leblond <eric@regit.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/icmp.h>
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#include <net/netfilter/ipv4/nf_reject.h>
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#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
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#include <net/netfilter/ipv6/nf_reject.h>
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#endif
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struct nft_reject {
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enum nft_reject_types type:8;
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u8 icmp_code;
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u8 family;
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};
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static void nft_reject_eval(const struct nft_expr *expr,
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struct nft_data data[NFT_REG_MAX + 1],
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const struct nft_pktinfo *pkt)
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{
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struct nft_reject *priv = nft_expr_priv(expr);
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struct net *net = dev_net((pkt->in != NULL) ? pkt->in : pkt->out);
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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if (priv->family == NFPROTO_IPV4)
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nf_send_unreach(pkt->skb, priv->icmp_code);
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#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
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else if (priv->family == NFPROTO_IPV6)
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nf_send_unreach6(net, pkt->skb, priv->icmp_code,
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pkt->hooknum);
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#endif
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break;
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case NFT_REJECT_TCP_RST:
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if (priv->family == NFPROTO_IPV4)
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nf_send_reset(pkt->skb, pkt->hooknum);
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#if IS_ENABLED(CONFIG_NF_TABLES_IPV6)
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else if (priv->family == NFPROTO_IPV6)
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nf_send_reset6(net, pkt->skb, pkt->hooknum);
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#endif
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break;
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}
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data[NFT_REG_VERDICT].verdict = NF_DROP;
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}
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static const struct nla_policy nft_reject_policy[NFTA_REJECT_MAX + 1] = {
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[NFTA_REJECT_TYPE] = { .type = NLA_U32 },
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[NFTA_REJECT_ICMP_CODE] = { .type = NLA_U8 },
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};
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static int nft_reject_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_reject *priv = nft_expr_priv(expr);
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if (tb[NFTA_REJECT_TYPE] == NULL)
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return -EINVAL;
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priv->family = ctx->afi->family;
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priv->type = ntohl(nla_get_be32(tb[NFTA_REJECT_TYPE]));
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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if (tb[NFTA_REJECT_ICMP_CODE] == NULL)
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return -EINVAL;
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priv->icmp_code = nla_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
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case NFT_REJECT_TCP_RST:
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static int nft_reject_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_reject *priv = nft_expr_priv(expr);
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if (nla_put_be32(skb, NFTA_REJECT_TYPE, htonl(priv->type)))
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goto nla_put_failure;
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switch (priv->type) {
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case NFT_REJECT_ICMP_UNREACH:
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if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
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goto nla_put_failure;
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break;
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}
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct nft_expr_type nft_reject_type;
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static const struct nft_expr_ops nft_reject_ops = {
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.type = &nft_reject_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_reject)),
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.eval = nft_reject_eval,
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.init = nft_reject_init,
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.dump = nft_reject_dump,
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};
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static struct nft_expr_type nft_reject_type __read_mostly = {
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.name = "reject",
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.ops = &nft_reject_ops,
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.policy = nft_reject_policy,
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.maxattr = NFTA_REJECT_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_reject_module_init(void)
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{
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return nft_register_expr(&nft_reject_type);
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}
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static void __exit nft_reject_module_exit(void)
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{
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nft_unregister_expr(&nft_reject_type);
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}
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module_init(nft_reject_module_init);
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module_exit(nft_reject_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_ALIAS_NFT_EXPR("reject");
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