From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Linus=20L=C3=BCssing?= Subject: [PATCH] bridge: prevent flooding IPv6 packets that do not have a listener Date: Fri, 21 Jun 2013 13:53:58 +0200 Message-ID: <1371815638-5618-1-git-send-email-linus.luessing@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Stephen Hemminger , netdev@vger.kernel.org, =?UTF-8?q?Linus=20L=C3=BCssing?= , "David S. Miller" , linux-kernel@vger.kernel.org To: bridge@lists.linux-foundation.org Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bridge-bounces@lists.linux-foundation.org Errors-To: bridge-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org Currently if there is no listener for a certain group then IPv6 packets for that group are flooded on all ports, even though there might be no host and router interested in it on a port. With this commit they are only forwarded to ports with a multicast router. Just like commit bd4265fe36 ("bridge: Only flood unregistered groups to routers") did for IPv4, let's do the same for IPv6 with the same reasoning. Signed-off-by: Linus L=C3=BCssing --- net/bridge/br_multicast.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 81f2389..8bdfaf5 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1465,8 +1465,14 @@ static int br_multicast_ipv6_rcv(struct net_bridge= *br, * - MLD has always Router Alert hop-by-hop option * - But we do not support jumbrograms. */ - if (ip6h->version !=3D 6 || - ip6h->nexthdr !=3D IPPROTO_HOPOPTS || + if (ip6h->version !=3D 6) + return 0; + + /* Prevent flooding this packet if there is no listener present */ + if (ipv6_is_transient_multicast(&ip6h->daddr)) + BR_INPUT_SKB_CB(skb)->mrouters_only =3D 1; + + if (ip6h->nexthdr !=3D IPPROTO_HOPOPTS || ip6h->payload_len =3D=3D 0) return 0; =20 --=20 1.7.10.4