From 74ff87cd16e4ebc65b6e80235869bf44b94ce64f Mon Sep 17 00:00:00 2001 From: "Bjoern A. Zeeb" Date: Fri, 6 Dec 2019 16:53:42 +0000 Subject: [PATCH] Update comment. Update the comment related to SIIT and v4mapped addresses being rejected by us when coming from the wire given we have supported IPv6-only kernels for a few years now. See also draft-itojun-v6ops-v4mapped-harmful. Suggested by: melifaro MFC after: 2 weeks --- sys/netinet6/ip6_input.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c index 431941dcad1..4044d590b4b 100644 --- a/sys/netinet6/ip6_input.c +++ b/sys/netinet6/ip6_input.c @@ -677,11 +677,10 @@ ip6_input(struct mbuf *m) * and bypass security checks (act as if it was from 127.0.0.1 by using * IPv6 src ::ffff:127.0.0.1). Be cautious. * - * This check chokes if we are in an SIIT cloud. As none of BSDs - * support IPv4-less kernel compilation, we cannot support SIIT - * environment at all. So, it makes more sense for us to reject any - * malicious packets for non-SIIT environment, than try to do a - * partial support for SIIT environment. + * We have supported IPv6-only kernels for a few years and this issue + * has not come up. The world seems to move mostly towards not using + * v4mapped on the wire, so it makes sense for us to keep rejecting + * any such packets. */ if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {