From 003f21868b2b0b4d09eb6b1f4abe0a8fbc03e859 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 28 Sep 2026 12:07:58 -0700 Subject: llc: move the type 2 sockets out of tree 802.2 LLC is only used in tree by protocols which need the connectionless type 1 subset: STP, which carries the bridge's BPDUs, GARP, which sends its own UI PDUs, and SNAP. The llc2 module on top of the core - the type 2 connection state machine, the type 1 SAP state machine, the station component and the PF_LLC socket family - has no in-kernel users and nobody who can test it; what we get instead is a slow trickle of drive-by fixes. There was a recent patch from Ernestas Kulik indicating potential real life use, but it was new/experimental and that person is not responding to off-list pings. Let LLC2 follow AX.25, hamradio and AppleTalk out of the Linux tree. We will maintain the code at: github.com/linux-netdev/mod-orphan for anyone interested in playing with it. PF_LLC goes in full, both the class two SOCK_STREAM and the class one SOCK_DGRAM half, and so do /proc/net/llc/ and /proc/sys/net/llc/. Note that the kernel also stops answering XID and TEST commands, addressed to a SAP or to the station - those are type 1, but they lived in the module, and they got answered whether or not any socket was open. Nothing in tree asks for them; what the core keeps is SAP registration and the UI path the in-tree users need. Retain the uAPI for now, like we did for AppleTalk. Only the socket ABI half of it is vestigial: STP, GARP, the bridge and openvswitch use the SAP numbers it defines. Cleaning up what the core no longer needs follows in the next patch. Signed-off-by: Jakub Kicinski Link: https://patch.msgid.link/20260928190800.2521749-2-kuba@kernel.org Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni --- include/linux/llc.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/llc.h b/include/linux/llc.h index 944e9e213112..c03bb12bcc9c 100644 --- a/include/linux/llc.h +++ b/include/linux/llc.h @@ -9,9 +9,4 @@ #include -#define LLC_SAP_DYN_START 0xC0 -#define LLC_SAP_DYN_STOP 0xDE -#define LLC_SAP_DYN_TRIES 4 - -#define llc_ui_skb_cb(__skb) ((struct sockaddr_llc *)&((__skb)->cb[0])) #endif /* __LINUX_LLC_H */ -- cgit v1.2.3