ip, neigh: Add missing NTF_USE support

Currently, ip neigh does not support the NTF_USE flag. Similar to other flags
such as extern_learn, add cmdline support. The flag dump support is explicitly
missing here, since the kernel does not propagate the flag back to user space.

Usage example:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE
  [...]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/ip/ipneigh.c b/ip/ipneigh.c
index a8006f94ab87243d34138ec244f415aa3afd1e83..874c90335208c30026129777011d31f40b2f7ea2 100644 (file)
--- a/ip/ipneigh.c
+++ b/ip/ipneigh.c
@@ -51,7 +51,7 @@ static void usage(void)
        fprintf(stderr,
                "Usage: ip neigh { add | del | change | replace }\n"
                "                { ADDR [ lladdr LLADDR ] [ nud STATE ] proxy ADDR }\n"
-               "                [ dev DEV ] [ router ] [ extern_learn ] [ protocol PROTO ]\n"
+               "                [ dev DEV ] [ router ] [ use ] [ extern_learn ] [ protocol PROTO ]\n"
                "\n"
                "       ip neigh { show | flush } [ proxy ] [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n"
                "                                 [ vrf NAME ] [ nomaster ]\n"
@@ -148,6 +148,8 @@ static int ipneigh_modify(int cmd, int flags, int argc, char **argv)
                        req.ndm.ndm_flags |= NTF_PROXY;
                } else if (strcmp(*argv, "router") == 0) {
                        req.ndm.ndm_flags |= NTF_ROUTER;
+               } else if (strcmp(*argv, "use") == 0) {
+                       req.ndm.ndm_flags |= NTF_USE;
                } else if (matches(*argv, "extern_learn") == 0) {
                        req.ndm.ndm_flags |= NTF_EXT_LEARNED;
                } else if (strcmp(*argv, "dev") == 0) {

diff --git a/man/man8/ip-neighbour.8 b/man/man8/ip-neighbour.8
index 028629641694587eef32eb16b2bdbdab0853c911..3001cd010c5a0628ea6a351dd66efc1557c6f9f7 100644 (file)
--- a/man/man8/ip-neighbour.8
+++ b/man/man8/ip-neighbour.8
@@ -25,6 +25,7 @@ ip-neighbour \- neighbour/arp tables management.
 .B  dev
 .IR DEV " ] [ "
 .BR router " ] [ "
+.BR use " ] [ "
 .BR extern_learn " ]"
 
 .ti -8
@@ -92,6 +93,13 @@ indicates whether we are proxying for this neighbour entry
 .BI router
 indicates whether neighbour is a router
 
+.TP
+.BI use
+this neigh entry is in "use". This option can be used to indicate to
+the kernel that a controller is using this dynamic entry. If the entry
+does not exist, the kernel will resolve it. If it exists, an attempt
+to refresh the neighbor entry will be triggered.
+
 .TP
 .BI extern_learn
 this neigh entry was learned externally. This option can be used to