[PATCH V2] IPv6 : add multicast routing verify which net_device is lo
From: Gao feng <hidden>
Date: 2011-12-20 11:09:38
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
In currently routing subsystem, when we lookup a multicast routing to send muticast packets to outside, rt6_device_match will return the rt6_info which it's match first. If we add a multicast route on loopback devices beforce the others interface, rt6_device_match will retrun the rt6_info which rt6i_dev->name is "lo". But, obviously, we can't send a muticast packet to outside using loopback devices. It case all multicast packets blocking. Commit 4af04aba93f47699e disabled kernel add multicast route on lo automatically. However, we can't surmise the routing-add order or interdict add multicast routing on loopback devices in user space. The bug still exist. So, i think, more stronger routing subsystem is necessary. Signed-off-by: Wang xingtong <redacted> --- net/ipv6/route.c | 19 ++++++++++++++++--- 1 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b582a0a..d6663ca 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -334,9 +334,16 @@ static inline struct rt6_info *rt6_device_match(struct net *net, struct rt6_info *local = NULL; struct rt6_info *sprt; - if (!oif && ipv6_addr_any(saddr)) + if (!oif && ipv6_addr_any(saddr)){ + if (unlikely(rt->rt6i_dev->flags & IFF_LOOPBACK && + ipv6_addr_is_multicast(&rt->rt6i_dst.addr))){ + rt=rt->dst.rt6_next; + goto match; + } goto out; + } +match: for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) { struct net_device *dev = sprt->rt6i_dev;
@@ -355,9 +362,15 @@ static inline struct rt6_info *rt6_device_match(struct net *net, local = sprt; } } else { - if (ipv6_chk_addr(net, saddr, dev, - flags & RT6_LOOKUP_F_IFACE)) + if (ipv6_addr_any(saddr)){ + if (unlikely(rt->rt6i_dev->flags & IFF_LOOPBACK && + ipv6_addr_is_multicast(&rt->rt6i_dst.addr))) + continue; return sprt; + } + else if (ipv6_chk_addr(net, saddr, dev, + flags & RT6_LOOKUP_F_IFACE)) + return sprt; } }
--
1.7.1