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authorFlorian Westphal <fw@strlen.de>2013-04-17 22:45:24 +0000
committerPablo Neira Ayuso <pablo@netfilter.org>2013-04-19 00:11:59 +0200
commitf83a7ea2075ca896f2dbf07672bac9cf3682ff74 (patch)
treece21e50675072ee54018788ddea8b234daad4af4
parent5add189a125e6b497e31bffdaaed8145ec6d4984 (diff)
downloadvexpress-lsk-f83a7ea2075ca896f2dbf07672bac9cf3682ff74.tar.gz
netfilter: xt_rpfilter: skip locally generated broadcast/multicast, too
Alex Efros reported rpfilter module doesn't match following packets: IN=br.qemu SRC=192.168.2.1 DST=192.168.2.255 [ .. ] (netfilter bugzilla #814). Problem is that network stack arranges for the locally generated broadcasts to appear on the interface they were sent out, so the IFF_LOOPBACK check doesn't trigger. As -m rpfilter is restricted to PREROUTING, we can check for existing rtable instead, it catches locally-generated broad/multicast case, too. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--net/ipv4/netfilter/ipt_rpfilter.c8
-rw-r--r--net/ipv6/netfilter/ip6t_rpfilter.c8
2 files changed, 14 insertions, 2 deletions
diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c
index c30130062cd..c49dcd0284a 100644
--- a/net/ipv4/netfilter/ipt_rpfilter.c
+++ b/net/ipv4/netfilter/ipt_rpfilter.c
@@ -66,6 +66,12 @@ static bool rpfilter_lookup_reverse(struct flowi4 *fl4,
return dev_match;
}
+static bool rpfilter_is_local(const struct sk_buff *skb)
+{
+ const struct rtable *rt = skb_rtable(skb);
+ return rt && (rt->rt_flags & RTCF_LOCAL);
+}
+
static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_rpfilter_info *info;
@@ -76,7 +82,7 @@ static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
info = par->matchinfo;
invert = info->flags & XT_RPFILTER_INVERT;
- if (par->in->flags & IFF_LOOPBACK)
+ if (rpfilter_is_local(skb))
return true ^ invert;
iph = ip_hdr(skb);
diff --git a/net/ipv6/netfilter/ip6t_rpfilter.c b/net/ipv6/netfilter/ip6t_rpfilter.c
index 5060d54199a..e0983f3648a 100644
--- a/net/ipv6/netfilter/ip6t_rpfilter.c
+++ b/net/ipv6/netfilter/ip6t_rpfilter.c
@@ -71,6 +71,12 @@ static bool rpfilter_lookup_reverse6(const struct sk_buff *skb,
return ret;
}
+static bool rpfilter_is_local(const struct sk_buff *skb)
+{
+ const struct rt6_info *rt = (const void *) skb_dst(skb);
+ return rt && (rt->rt6i_flags & RTF_LOCAL);
+}
+
static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_rpfilter_info *info = par->matchinfo;
@@ -78,7 +84,7 @@ static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
struct ipv6hdr *iph;
bool invert = info->flags & XT_RPFILTER_INVERT;
- if (par->in->flags & IFF_LOOPBACK)
+ if (rpfilter_is_local(skb))
return true ^ invert;
iph = ipv6_hdr(skb);