From 1ac42adcb600bbbbe94ee43a4fcc8f3061817600 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Tue, 1 Jul 2025 17:42:16 +0300 Subject: [PATCH] ip neigh: Add support for "extern_valid" flag Add support for the recently added "extern_valid" flag that can be used to indicate to the kernel that a neighbor entry was learned and determined to be valid externally. The kernel will not remove or invalidate the entry, but it can probe the entry and notify user space when the entry becomes reachable. The kernel will return the entry to stale state if it did not receive a confirmation after probing the entry. Example usage and output: # ip neigh add 192.0.2.1 nud none dev br0.10 extern_valid Error: Cannot create externally validated neighbor with an invalid state. # ip neigh add 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid $ ip neigh show dev br0.10 192.0.2.1 lladdr 00:11:22:33:44:55 extern_valid STALE $ ip -j -p neigh show dev br0.10 [ { "dst": "192.0.2.1", "lladdr": "00:11:22:33:44:55", "extern_valid": null, "state": [ "STALE" ] } ] Signed-off-by: Ido Schimmel Signed-off-by: David Ahern --- ip/ipneigh.c | 6 +++++- man/man8/ip-neighbour.8 | 10 +++++++++- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/ip/ipneigh.c b/ip/ipneigh.c index bd7f44e10..e678545ad 100644 --- a/ip/ipneigh.c +++ b/ip/ipneigh.c @@ -47,7 +47,7 @@ static void usage(void) "Usage: ip neigh { add | del | change | replace }\n" " { ADDR [ lladdr LLADDR ] [ nud STATE ] proxy ADDR }\n" " [ dev DEV ] [ router ] [ use ] [ managed ] [ extern_learn ]\n" - " [ protocol PROTO ]\n" + " [ extern_valid ] [ protocol PROTO ]\n" "\n" " ip neigh { show | flush } [ proxy ] [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n" " [ vrf NAME ] [ nomaster ]\n" @@ -152,6 +152,8 @@ static int ipneigh_modify(int cmd, int flags, int argc, char **argv) req.ndm.ndm_state = NUD_NONE; } else if (matches(*argv, "extern_learn") == 0) { req.ndm.ndm_flags |= NTF_EXT_LEARNED; + } else if (strcmp(*argv, "extern_valid") == 0) { + ext_flags |= NTF_EXT_EXT_VALIDATED; } else if (strcmp(*argv, "dev") == 0) { NEXT_ARG(); dev = *argv; @@ -446,6 +448,8 @@ int print_neigh(struct nlmsghdr *n, void *arg) print_null(PRINT_ANY, "extern_learn", "%s ", "extern_learn"); if (r->ndm_flags & NTF_OFFLOADED) print_null(PRINT_ANY, "offload", "%s ", "offload"); + if (ext_flags & NTF_EXT_EXT_VALIDATED) + print_null(PRINT_ANY, "extern_valid", "%s ", "extern_valid"); if (show_stats) { if (tb[NDA_CACHEINFO]) diff --git a/man/man8/ip-neighbour.8 b/man/man8/ip-neighbour.8 index 6fed47ced..1f890c0d0 100644 --- a/man/man8/ip-neighbour.8 +++ b/man/man8/ip-neighbour.8 @@ -27,7 +27,8 @@ ip-neighbour \- neighbour/arp tables management. .BR router " ] [ " .BR use " ] [ " .BR managed " ] [ " -.BR extern_learn " ]" +.BR extern_learn " ] [ " +.BR extern_valid " ]" .ti -8 .BR "ip neigh" " { " show " | " flush " } [ " proxy " ] [ " to @@ -115,6 +116,13 @@ this neigh entry was learned externally. This option can be used to indicate to the kernel that this is a controller learnt dynamic entry. Kernel will not gc such an entry. +.TP +.BI extern_valid +this neigh entry was learned and determined to be valid externally. The kernel +will not remove or invalidate the entry, but it can probe the entry and notify +user space when the entry becomes reachable. The kernel will return the entry +to stale state if it did not receive a confirmation after probing the entry. + .TP .BI lladdr " LLADDRESS" the link layer address of the neighbour. -- 2.47.2