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/netfilter/xt_addrtype.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) (limited to 'net/netfilter/xt_addrtype.c') diff --git a/net/netfilter/xt_addrtype.c b/net/netfilter/xt_addrtype.c index 49c5ff7f6dd6..68ff29f60867 100644 --- a/net/netfilter/xt_addrtype.c +++ b/net/netfilter/xt_addrtype.c @@ -22,6 +22,7 @@ #include #endif +#include #include #include @@ -33,12 +34,12 @@ MODULE_ALIAS("ip6t_addrtype"); #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) static u32 match_lookup_rt6(struct net *net, const struct net_device *dev, - const struct in6_addr *addr) + const struct in6_addr *addr, u16 mask) { const struct nf_afinfo *afinfo; struct flowi6 flow; struct rt6_info *rt; - u32 ret; + u32 ret = 0; int route_err; memset(&flow, 0, sizeof(flow)); @@ -49,12 +50,19 @@ static u32 match_lookup_rt6(struct net *net, const struct net_device *dev, rcu_read_lock(); afinfo = nf_get_afinfo(NFPROTO_IPV6); - if (afinfo != NULL) + if (afinfo != NULL) { + const struct nf_ipv6_ops *v6ops; + + if (dev && (mask & XT_ADDRTYPE_LOCAL)) { + v6ops = nf_get_ipv6_ops(); + if (v6ops && v6ops->chk_addr(net, addr, dev, true)) + ret = XT_ADDRTYPE_LOCAL; + } route_err = afinfo->route(net, (struct dst_entry **)&rt, - flowi6_to_flowi(&flow), !!dev); - else + flowi6_to_flowi(&flow), false); + } else { route_err = 1; - + } rcu_read_unlock(); if (route_err) @@ -62,15 +70,12 @@ static u32 match_lookup_rt6(struct net *net, const struct net_device *dev, if (rt->rt6i_flags & RTF_REJECT) ret = XT_ADDRTYPE_UNREACHABLE; - else - ret = 0; - if (rt->rt6i_flags & RTF_LOCAL) + if (dev == NULL && rt->rt6i_flags & RTF_LOCAL) ret |= XT_ADDRTYPE_LOCAL; if (rt->rt6i_flags & RTF_ANYCAST) ret |= XT_ADDRTYPE_ANYCAST; - dst_release(&rt->dst); return ret; } @@ -90,7 +95,7 @@ static bool match_type6(struct net *net, const struct net_device *dev, if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST | XT_ADDRTYPE_UNREACHABLE) & mask) - return !!(mask & match_lookup_rt6(net, dev, addr)); + return !!(mask & match_lookup_rt6(net, dev, addr, mask)); return true; } -- cgit v1.2.1