Merge branch 'net-hsr-prp-redbox-prp-san-support'

Xin Xie says:

====================
net: hsr: PRP RedBox (PRP-SAN) support

This series adds PRP RedBox support to the hsr driver: a PRP node that
proxies one or more SANs sitting behind an interlink port (IEC 62439-3,
PRP-SAN). HSR-SAN has been supported since commit 5055cccfc2 ("net: hsr:
Provide RedBox support (HSR-SAN)"); this extends the equivalent capability
to PRP, reusing the existing protocol-neutral proxy machinery
(proxy_node_db, hsr_proxy_announce(), hsr_prune_proxy_nodes()).

A SAN behind the interlink does bidirectional unicast with peers on the PRP
network, its source MAC is preserved on the wire, the PRP RCT is correct,
and the RedBox announces each proxied SAN with the RedBox-MAC TLV (Type 30)
in its supervision frames.

The series is bisect-safe: the datapath, duplicate discard and supervision
support are added first; the rtnetlink rejection of "type hsr ... interlink
<dev> proto 1" is removed only in patch 3, once the feature is complete.

Design notes:

 - prp_drop_frame() does not walk the node tables. The destination
   classification (PRP-network node vs proxied SAN) is resolved once per
   frame in fill_frame_info() and cached in struct hsr_frame_info, so the
   per egress-port drop decision is O(1) in the softIRQ path. The
   classification is gated on PRP RedBox devices (prot_version == PRP_V1 &&
   hsr->redbox), so HSR RedBox traffic is not affected.

 - The LAN A/B duplicate test is factored into prp_is_lan_dup() so the new
   PRP interlink rules in prp_drop_frame() do not change hsr_drop_frame()
   behaviour, including the NETIF_F_HW_HSR_FWD path. This is software PRP
   RedBox only; it adds no new hardware-offload contract.

 - The supervision emitter uses pre-reserved tailroom (hsr_init_skb() +
   skb_put()) on the existing GFP_ATOMIC path; no skb_linearize() or
   pskb_expand_head(). The RedBox-MAC TLV is followed by an explicit EOT
   (Type 0, Length 0); padding via skb_put_padto(ETH_ZLEN) and the 6-byte
   PRP RCT remain at the absolute tail of the egress frame.

 - The hsr_get_node() hsr_ethhdr length guard is relaxed only for PRP
   supervision frames (prot_version == PRP_V1 && ETH_P_PRP && is_sup), which
   are untagged with mac_len == ETH_HLEN. HSR (ETH_P_HSR) supervision is
   front-tagged and keeps the original length requirement, so HSR
   malformed-frame filtering is unchanged.
====================

Link: https://patch.msgid.link/20260717201457.54-1-xiexinet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2026-07-27 17:46:47 -07:00
commit d5990d2a86
8 changed files with 204 additions and 25 deletions