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![Miaohe Lin](/assets/img/avatar_default.png)
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>
150 lines
3.9 KiB
C
150 lines
3.9 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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#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/route.h>
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#include <net/ip6_fib.h>
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#include <net/ip6_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("Xtables: IPv6 reverse path filter match");
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static bool rpfilter_addr_unicast(const struct in6_addr *addr)
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{
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int addr_type = ipv6_addr_type(addr);
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return addr_type & IPV6_ADDR_UNICAST;
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}
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static bool rpfilter_addr_linklocal(const struct in6_addr *addr)
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{
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int addr_type = ipv6_addr_type(addr);
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return addr_type & IPV6_ADDR_LINKLOCAL;
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}
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static bool rpfilter_lookup_reverse6(struct net *net, const struct sk_buff *skb,
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const struct net_device *dev, u8 flags)
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{
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struct rt6_info *rt;
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struct ipv6hdr *iph = ipv6_hdr(skb);
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bool ret = false;
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struct flowi6 fl6 = {
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.flowi6_iif = LOOPBACK_IFINDEX,
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.flowlabel = (* (__be32 *) iph) & IPV6_FLOWINFO_MASK,
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.flowi6_proto = iph->nexthdr,
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.daddr = iph->saddr,
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};
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int lookup_flags;
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if (rpfilter_addr_unicast(&iph->daddr)) {
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memcpy(&fl6.saddr, &iph->daddr, sizeof(struct in6_addr));
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lookup_flags = RT6_LOOKUP_F_HAS_SADDR;
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} else {
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lookup_flags = 0;
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}
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fl6.flowi6_mark = flags & XT_RPFILTER_VALID_MARK ? skb->mark : 0;
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if (rpfilter_addr_linklocal(&iph->saddr)) {
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lookup_flags |= RT6_LOOKUP_F_IFACE;
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fl6.flowi6_oif = dev->ifindex;
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/* Set flowi6_oif for vrf devices to lookup route in l3mdev domain. */
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} else if (netif_is_l3_master(dev) || netif_is_l3_slave(dev) ||
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(flags & XT_RPFILTER_LOOSE) == 0)
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fl6.flowi6_oif = dev->ifindex;
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rt = (void *)ip6_route_lookup(net, &fl6, skb, lookup_flags);
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if (rt->dst.error)
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goto out;
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if (rt->rt6i_flags & (RTF_REJECT|RTF_ANYCAST))
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goto out;
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if (rt->rt6i_flags & RTF_LOCAL) {
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ret = flags & XT_RPFILTER_ACCEPT_LOCAL;
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goto out;
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}
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if (rt->rt6i_idev->dev == dev ||
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l3mdev_master_ifindex_rcu(rt->rt6i_idev->dev) == dev->ifindex ||
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(flags & XT_RPFILTER_LOOSE))
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ret = true;
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out:
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ip6_rt_put(rt);
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return ret;
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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 = par->matchinfo;
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int saddrtype;
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struct ipv6hdr *iph;
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bool 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 = ipv6_hdr(skb);
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saddrtype = ipv6_addr_type(&iph->saddr);
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if (unlikely(saddrtype == IPV6_ADDR_ANY))
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return true ^ invert; /* not routable: forward path will drop it */
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return rpfilter_lookup_reverse6(xt_net(par), skb, xt_in(par),
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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_IPV6,
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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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