From 2a7851bffb008ff4882eee673da74718997b4265 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 17 May 2013 03:56:10 +0000 Subject: netfilter: add nf_ipv6_ops hook to fix xt_addrtype with IPv6 Quoting https://bugzilla.netfilter.org/show_bug.cgi?id=812: [ ip6tables -m addrtype ] When I tried to use in the nat/PREROUTING it messes up the routing cache even if the rule didn't matched at all. [..] If I remove the --limit-iface-in from the non-working scenario, so just use the -m addrtype --dst-type LOCAL it works! This happens when LOCAL type matching is requested with --limit-iface-in, and the default ipv6 route is via the interface the packet we test arrived on. Because xt_addrtype uses ip6_route_output, the ipv6 routing implementation creates an unwanted cached entry, and the packet won't make it to the real/expected destination. Silently ignoring --limit-iface-in makes the routing work but it breaks rule matching (--dst-type LOCAL with limit-iface-in is supposed to only match if the dst address is configured on the incoming interface; without --limit-iface-in it will match if the address is reachable via lo). The test should call ipv6_chk_addr() instead. However, this would add a link-time dependency on ipv6. There are two possible solutions: 1) Revert the commit that moved ipt_addrtype to xt_addrtype, and put ipv6 specific code into ip6t_addrtype. 2) add new "nf_ipv6_ops" struct to register pointers to ipv6 functions. While the former might seem preferable, Pablo pointed out that there are more xt modules with link-time dependeny issues regarding ipv6, so lets go for 2). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv6/addrconf.c | 2 +- net/ipv6/netfilter.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index d1ab6ab29a55..d1b2d8034b54 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1487,7 +1487,7 @@ static int ipv6_count_addresses(struct inet6_dev *idev) } int ipv6_chk_addr(struct net *net, const struct in6_addr *addr, - struct net_device *dev, int strict) + const struct net_device *dev, int strict) { struct inet6_ifaddr *ifp; unsigned int hash = inet6_addr_hash(addr); diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 72836f40b730..95f3f1da0d7f 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -186,6 +187,10 @@ static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, return csum; }; +static const struct nf_ipv6_ops ipv6ops = { + .chk_addr = ipv6_chk_addr, +}; + static const struct nf_afinfo nf_ip6_afinfo = { .family = AF_INET6, .checksum = nf_ip6_checksum, @@ -198,6 +203,7 @@ static const struct nf_afinfo nf_ip6_afinfo = { int __init ipv6_netfilter_init(void) { + RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops); return nf_register_afinfo(&nf_ip6_afinfo); } @@ -206,5 +212,6 @@ int __init ipv6_netfilter_init(void) */ void ipv6_netfilter_fini(void) { + RCU_INIT_POINTER(nf_ipv6_ops, NULL); nf_unregister_afinfo(&nf_ip6_afinfo); } -- cgit v1.2.3