From f630e43a215a3129d0c1173cae0bce6ea4855cf7 Mon Sep 17 00:00:00 2001 From: YOSHIFUJI Hideaki Date: Thu, 19 Jun 2008 16:33:57 -0700 Subject: [PATCH] ipv6: Drop packets for loopback address from outside of the box. [ Based upon original report and patch by Karsten Keil. Karsten has verified that this fixes the TAHI test case "ICMPv6 test v6LC.5.1.2 Part F". -DaveM ] Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- include/net/ipv6.h | 6 ++++++ net/ipv6/ip6_input.c | 9 +++++++++ 2 files changed, 15 insertions(+) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index e0a612bc9c4..f422f7218e1 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -367,6 +367,12 @@ static inline int ipv6_addr_any(const struct in6_addr *a) a->s6_addr32[2] | a->s6_addr32[3] ) == 0); } +static inline int ipv6_addr_loopback(const struct in6_addr *a) +{ + return ((a->s6_addr32[0] | a->s6_addr32[1] | + a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0); +} + static inline int ipv6_addr_v4mapped(const struct in6_addr *a) { return ((a->s6_addr32[0] | a->s6_addr32[1] | diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 4e5c8615832..17eb48b8e32 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -102,6 +102,15 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt if (hdr->version != 6) goto err; + /* + * RFC4291 2.5.3 + * A packet received on an interface with a destination address + * of loopback must be dropped. + */ + if (!(dev->flags & IFF_LOOPBACK) && + ipv6_addr_loopback(&hdr->daddr)) + goto err; + skb->transport_header = skb->network_header + sizeof(*hdr); IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); -- 2.41.0