commit a71b668dd325b7ef7d520ec94d8519fec1a281b4
author Ravinder Konka <rkonka@codeaurora.org> Thu Apr 09 11:42:00 2015 +0530
committer Mohammed Javid <mjavid@codeaurora.org> Thu Oct 12 18:39:26 2017 +0530
tree ee438818bd9f92442104ba20d408e1870e729823
parent f526258c529fcdf0c6b9d3047df5beac2420aac6

net: core: Send ARP probe and trigger RTM_NEWNEIGH

Send ARP probe and generate RTM_NEWNEIGH if the neighbor
state is not NUD_REACHABLE. Also featurize changes for
sending neighbor probe.

Change-Id: I633285b8e0cbcd49291d5e52136f11e20f2388bc
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>

include/net/neighbour.h

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 8b68384..ddfb742 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -62,6 +62,7 @@
 	NEIGH_VAR_GC_THRESH1,
 	NEIGH_VAR_GC_THRESH2,
 	NEIGH_VAR_GC_THRESH3,
+	NEIGH_VAR_PROBE,
 	NEIGH_VAR_MAX
 };
 

net/core/neighbour.c

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 227c249..62893eb 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -56,6 +56,7 @@
 static void neigh_update_notify(struct neighbour *neigh);
 static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 
+static unsigned int neigh_probe_enable;
 #ifdef CONFIG_PROC_FS
 static const struct file_operations neigh_stat_seq_fops;
 #endif
@@ -1258,9 +1259,20 @@
 {
 	struct neighbour *neigh = __neigh_lookup(tbl, saddr, dev,
 						 lladdr || !dev->addr_len);
-	if (neigh)
-		neigh_update(neigh, lladdr, NUD_STALE,
-			     NEIGH_UPDATE_F_OVERRIDE);
+	if (neigh) {
+		if (neigh_probe_enable) {
+			if (!(neigh->nud_state == NUD_REACHABLE)) {
+				neigh_update(neigh, lladdr, NUD_STALE,
+					     NEIGH_UPDATE_F_OVERRIDE);
+				write_lock(&neigh->lock);
+				neigh_probe(neigh);
+				neigh_update_notify(neigh);
+			}
+		} else {
+			neigh_update(neigh, lladdr, NUD_STALE,
+				     NEIGH_UPDATE_F_OVERRIDE);
+		}
+	}
 	return neigh;
 }
 EXPORT_SYMBOL(neigh_event_ns);
@@ -3107,6 +3119,12 @@
 			.extra2		= &int_max,
 			.proc_handler	= proc_dointvec_minmax,
 		},
+		[NEIGH_VAR_PROBE] = {
+			.procname	= "neigh_probe",
+			.maxlen		= sizeof(int),
+			.mode		= 0644,
+			.proc_handler	= proc_dointvec,
+		},
 		{},
 	},
 };
@@ -3142,6 +3160,7 @@
 		t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1;
 		t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2;
 		t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3;
+		t->neigh_vars[NEIGH_VAR_PROBE].data  = &neigh_probe_enable;
 	}
 
 	if (handler) {