Date: Thu, 17 Jun 2021 08:21:44 GMT From: Lutz Donnerhacke <donner@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 9d30353cb494 - stable/11 - Do not forward datagrams originated by link-local addresses Message-ID: <202106170821.15H8Lid0082844@gitrepo.freebsd.org>
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The branch stable/11 has been updated by donner: URL: https://cgit.FreeBSD.org/src/commit/?id=9d30353cb49467ba2b672673a5765588c4e857ec commit 9d30353cb49467ba2b672673a5765588c4e857ec Author: Zhenlei Huang <zlei.huang@gmail.com> AuthorDate: 2021-05-18 20:51:37 +0000 Commit: Lutz Donnerhacke <donner@FreeBSD.org> CommitDate: 2021-06-17 08:21:00 +0000 Do not forward datagrams originated by link-local addresses The current implement of ip_input() reject packets destined for 169.254.0.0/16, but not those original from 169.254.0.0/16 link-local addresses. Fix to fully respect RFC 3927 section 2.7. PR: 255388 Reviewed by: donner, rgrimes, karels Differential Revision: https://reviews.freebsd.org/D29968 Reviewed by: rgrimes, donner, karels, marcus, emaste Differential Revision: https://reviews.freebsd.org/D30374 (cherry picked from commit 3d846e48227e2e78c1e7b35145f57353ffda56ba) (cherry picked from commit 03b0505b8fe848f33f2f38fe89dd5538908c847e) --- sys/netinet/ip_input.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c index 0f14889f355d..53978fd0fe6c 100644 --- a/sys/netinet/ip_input.c +++ b/sys/netinet/ip_input.c @@ -733,14 +733,12 @@ passin: IF_ADDR_RUNLOCK(ifp); ia = NULL; } - /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */ - if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { - IPSTAT_INC(ips_cantforward); - m_freem(m); - return; - } if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { - if (V_ip_mrouter) { + /* + * RFC 3927 2.7: Do not forward multicast packets from + * IN_LINKLOCAL. + */ + if (V_ip_mrouter && !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) { /* * If we are acting as a multicast router, all * incoming multicast packets are passed to the @@ -775,6 +773,13 @@ passin: goto ours; if (ip->ip_dst.s_addr == INADDR_ANY) goto ours; + /* RFC 3927 2.7: Do not forward packets to or from IN_LINKLOCAL. */ + if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) || + IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) { + IPSTAT_INC(ips_cantforward); + m_freem(m); + return; + } /* * Not for us; forward if possible and desirable.
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