From 5bb1ab09e4f6287c0b6c9cdbd463147cbd003f54 Mon Sep 17 00:00:00 2001 From: David L Stevens Date: Wed, 9 May 2007 13:53:44 -0700 Subject: [PATCH] [IPV6]: Send ICMPv6 error on scope violations. When an IPv6 router is forwarding a packet with a link-local scope source address off-link, RFC 4007 requires it to send an ICMPv6 destination unreachable with code 2 ("not neighbor"), but Linux doesn't. Fix below. Signed-off-by: David L Stevens Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index f508171bab73..4704b5fc3085 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -463,10 +463,17 @@ int ip6_forward(struct sk_buff *skb) */ if (xrlim_allow(dst, 1*HZ)) ndisc_send_redirect(skb, n, target); - } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK - |IPV6_ADDR_LINKLOCAL)) { + } else { + int addrtype = ipv6_addr_type(&hdr->saddr); + /* This check is security critical. */ - goto error; + if (addrtype & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK)) + goto error; + if (addrtype & IPV6_ADDR_LINKLOCAL) { + icmpv6_send(skb, ICMPV6_DEST_UNREACH, + ICMPV6_NOT_NEIGHBOUR, 0, skb->dev); + goto error; + } } if (skb->len > dst_mtu(dst)) { -- GitLab