[PATCH net-next v4 7/7] ipv6: Document enforce_ext_hdr_order sysctl
From: Tom Herbert <hidden>
Date: 2026-01-21 21:50:05
Subsystem:
documentation, networking [general], the rest · Maintainers:
Jonathan Corbet, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Document the enforce_ext_hdr_order sysctl that controls whether Extension Header order is enforced on receive. Signed-off-by: Tom Herbert <redacted> --- Documentation/networking/ip-sysctl.rst | 29 ++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 5051fe653c96..f8fa9f67b2ed 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst@@ -2581,6 +2581,35 @@ ioam6_id_wide - LONG INTEGER Default: 0xFFFFFFFFFFFFFF +enforce_ext_hdr_order - BOOLEAN + Enforce recommended Extension Header ordering in RFC8200. + If the sysctl is set to 1 then the ordering the ordering is + enforced in received packets and each Extension Header + may be present at most once per packet. If the sysctl is + set to 0 then ordering is not enforced and Extension Headers + may be present in any order and have any number of + occurences per packet (except for Hop-by-Hop Options). Also, + if the sysctl is set then Destination Options before the + Routing header are disllowed. + + The Extension Header order is: + + IPv6 header + Hop-by-Hop Options header + Routing header + Fragment header + Authentication header + Encapsulating Security Payload header + Destination Options header + Upper-Layer header + + Possible values: + + - 0 (disabled) + - 1 (enabled) + + Default: 1 (enabled) + IPv6 Fragmentation: ip6frag_high_thresh - INTEGER
--
2.43.0