b575b24b8e
When firewalld is enabled with ipv4/ipv6 rpfilter, vrf ipv4/ipv6 packets will be dropped. Vrf device will pass through netfilter hook twice. One with enslaved device and another one with l3 master device. So in device may dismatch witch out device because out device is always enslaved device.So failed with the check of the rpfilter and drop the packets by mistake. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
127 lines
3.3 KiB
C
127 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2011 Florian Westphal <fw@strlen.de>
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*
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* based on fib_frontend.c; Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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#include <net/ip_fib.h>
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#include <net/route.h>
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#include <linux/netfilter/xt_rpfilter.h>
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#include <linux/netfilter/x_tables.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
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MODULE_DESCRIPTION("iptables: ipv4 reverse path filter match");
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/* don't try to find route from mcast/bcast/zeronet */
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static __be32 rpfilter_get_saddr(__be32 addr)
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{
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if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr) ||
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ipv4_is_zeronet(addr))
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return 0;
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return addr;
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}
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static bool rpfilter_lookup_reverse(struct net *net, struct flowi4 *fl4,
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const struct net_device *dev, u8 flags)
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{
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struct fib_result res;
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int ret __maybe_unused;
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if (fib_lookup(net, fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE))
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return false;
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if (res.type != RTN_UNICAST) {
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if (res.type != RTN_LOCAL || !(flags & XT_RPFILTER_ACCEPT_LOCAL))
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return false;
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}
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return fib_info_nh_uses_dev(res.fi, dev) || flags & XT_RPFILTER_LOOSE;
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}
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static bool
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rpfilter_is_loopback(const struct sk_buff *skb, const struct net_device *in)
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{
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return skb->pkt_type == PACKET_LOOPBACK || in->flags & IFF_LOOPBACK;
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}
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static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct xt_rpfilter_info *info;
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const struct iphdr *iph;
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struct flowi4 flow;
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bool invert;
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info = par->matchinfo;
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invert = info->flags & XT_RPFILTER_INVERT;
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if (rpfilter_is_loopback(skb, xt_in(par)))
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return true ^ invert;
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iph = ip_hdr(skb);
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if (ipv4_is_zeronet(iph->saddr)) {
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if (ipv4_is_lbcast(iph->daddr) ||
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ipv4_is_local_multicast(iph->daddr))
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return true ^ invert;
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}
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memset(&flow, 0, sizeof(flow));
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flow.flowi4_iif = LOOPBACK_IFINDEX;
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flow.daddr = iph->saddr;
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flow.saddr = rpfilter_get_saddr(iph->daddr);
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flow.flowi4_mark = info->flags & XT_RPFILTER_VALID_MARK ? skb->mark : 0;
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flow.flowi4_tos = RT_TOS(iph->tos);
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flow.flowi4_scope = RT_SCOPE_UNIVERSE;
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flow.flowi4_oif = l3mdev_master_ifindex_rcu(xt_in(par));
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return rpfilter_lookup_reverse(xt_net(par), &flow, xt_in(par), info->flags) ^ invert;
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}
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static int rpfilter_check(const struct xt_mtchk_param *par)
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{
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const struct xt_rpfilter_info *info = par->matchinfo;
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unsigned int options = ~XT_RPFILTER_OPTION_MASK;
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if (info->flags & options) {
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pr_info_ratelimited("unknown options\n");
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return -EINVAL;
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}
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if (strcmp(par->table, "mangle") != 0 &&
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strcmp(par->table, "raw") != 0) {
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pr_info_ratelimited("only valid in \'raw\' or \'mangle\' table, not \'%s\'\n",
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par->table);
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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 struct xt_match rpfilter_mt_reg __read_mostly = {
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.name = "rpfilter",
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.family = NFPROTO_IPV4,
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.checkentry = rpfilter_check,
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.match = rpfilter_mt,
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.matchsize = sizeof(struct xt_rpfilter_info),
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.hooks = (1 << NF_INET_PRE_ROUTING),
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.me = THIS_MODULE
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};
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static int __init rpfilter_mt_init(void)
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{
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return xt_register_match(&rpfilter_mt_reg);
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}
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static void __exit rpfilter_mt_exit(void)
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{
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xt_unregister_match(&rpfilter_mt_reg);
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}
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module_init(rpfilter_mt_init);
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module_exit(rpfilter_mt_exit);
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