From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: stable@vger.kernel.org, davem@davemloft.net
Subject: [-stable-3.8.y 8/9] netfilter: xt_rpfilter: skip locally generated broadcast/multicast, too
Date: Tue, 7 May 2013 01:05:27 +0200 [thread overview]
Message-ID: <1367881528-15524-8-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1367881528-15524-1-git-send-email-pablo@netfilter.org>
From: Florian Westphal <fw@strlen.de>
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>
[ git cherry-pick f83a7ea ]
---
net/ipv4/netfilter/ipt_rpfilter.c | 8 +++++++-
net/ipv6/netfilter/ip6t_rpfilter.c | 8 +++++++-
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c
index c301300..c49dcd0 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 5060d54..e0983f3 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);
--
1.7.10.4
next prev parent reply other threads:[~2013-05-06 23:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-06 23:05 [-stable-3.8.y 1/9] ipvs: ip_vs_sip_fill_param() BUG: bad check of return value Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 2/9] netfilter: nf_nat: fix race when unloading protocol modules Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 3/9] netfilter: ipset: list:set: fix reference counter update Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 4/9] netfilter: nf_ct_sip: don't drop packets with offsets pointing outside the packet Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 5/9] netfilter: ipset: "Directory not empty" error message Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 6/9] netfilter: nf_ct_helper: don't discard helper if it is actually the same Pablo Neira Ayuso
2013-05-06 23:05 ` [-stable-3.8.y 7/9] netfilter: ctnetlink: don't permit ct creation with random tuple Pablo Neira Ayuso
2013-05-06 23:05 ` Pablo Neira Ayuso [this message]
2013-05-06 23:05 ` [-stable-3.8.y 9/9] netfilter: ip6t_NPT: Fix translation for non-multiple of 32 prefix lengths Pablo Neira Ayuso
2013-05-08 22:36 ` [-stable-3.8.y 1/9] ipvs: ip_vs_sip_fill_param() BUG: bad check of return value Greg KH
2013-05-08 23:53 ` Pablo Neira Ayuso
2013-05-09 20:38 ` Greg KH
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