From b13c5b5db2ac06e526e011e6044a33d88fca40b4 Mon Sep 17 00:00:00 2001
From: "Alexander V. Chernikov" <melifaro@FreeBSD.org>
Date: Mon, 9 Nov 2015 10:11:14 +0000
Subject: [PATCH] Use lladdr_event to propagate gratiotus arp.

Differential Revision:	https://reviews.freebsd.org/D4019
---
 sys/net/if.c             | 13 ++-----------
 sys/net/if_vlan.c        |  7 +++++--
 sys/netgraph/ng_eiface.c |  3 ++-
 sys/netgraph/ng_ether.c  |  3 ++-
 sys/netinet/if_ether.c   | 31 +++++++++++++++++++++++++++++++
 5 files changed, 42 insertions(+), 15 deletions(-)

diff --git a/sys/net/if.c b/sys/net/if.c
index 118e63b06589..74c30d0159dc 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -2512,7 +2512,8 @@ ifhwioctl(u_long cmd, struct ifnet *ifp, caddr_t data, struct thread *td)
 			return (error);
 		error = if_setlladdr(ifp,
 		    ifr->ifr_addr.sa_data, ifr->ifr_addr.sa_len);
-		EVENTHANDLER_INVOKE(iflladdr_event, ifp);
+		if (error == 0)
+			EVENTHANDLER_INVOKE(iflladdr_event, ifp);
 		break;
 
 	case SIOCAIFGROUP:
@@ -3375,16 +3376,6 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
 			ifr.ifr_flagshigh = ifp->if_flags >> 16;
 			(*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, (caddr_t)&ifr);
 		}
-#ifdef INET
-		/*
-		 * Also send gratuitous ARPs to notify other nodes about
-		 * the address change.
-		 */
-		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-			if (ifa->ifa_addr->sa_family == AF_INET)
-				arp_ifinit(ifp, ifa);
-		}
-#endif
 	}
 	return (0);
 }
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 462c9078fbc1..dc079750b61e 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -523,7 +523,7 @@ vlan_iflladdr(void *arg __unused, struct ifnet *ifp)
 #ifndef VLAN_ARRAY
 	struct ifvlan *next;
 #endif
-	int i;
+	int error, i;
 
 	/*
 	 * Check if it's a trunk interface first of all
@@ -544,8 +544,11 @@ vlan_iflladdr(void *arg __unused, struct ifnet *ifp)
 		LIST_FOREACH_SAFE(ifv, &ifp->if_vlantrunk->hash[i], ifv_list, next) {
 #endif /* VLAN_ARRAY */
 			VLAN_UNLOCK();
-			if_setlladdr(ifv->ifv_ifp, IF_LLADDR(ifp),
+			error = if_setlladdr(ifv->ifv_ifp, IF_LLADDR(ifp),
 			    ifp->if_addrlen);
+			if (error == 0)
+				EVENTHANDLER_INVOKE(iflladdr_event,
+				    ifv->ifv_ifp);
 			VLAN_LOCK();
 		}
 	VLAN_UNLOCK();
diff --git a/sys/netgraph/ng_eiface.c b/sys/netgraph/ng_eiface.c
index ae573da02541..ab7071914f6e 100644
--- a/sys/netgraph/ng_eiface.c
+++ b/sys/netgraph/ng_eiface.c
@@ -489,7 +489,8 @@ ng_eiface_rcvmsg(node_p node, item_p item, hook_p lasthook)
 			}
 			error = if_setlladdr(priv->ifp,
 			    (u_char *)msg->data, ETHER_ADDR_LEN);
-			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
+			if (error == 0)
+				EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
 			break;
 		    }
 
diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c
index fcde08c07092..63179a5edd10 100644
--- a/sys/netgraph/ng_ether.c
+++ b/sys/netgraph/ng_ether.c
@@ -534,7 +534,8 @@ ng_ether_rcvmsg(node_p node, item_p item, hook_p lasthook)
 			}
 			error = if_setlladdr(priv->ifp,
 			    (u_char *)msg->data, ETHER_ADDR_LEN);
-			EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
+			if (error == 0)
+				EVENTHANDLER_INVOKE(iflladdr_event, priv->ifp);
 			break;
 		    }
 		case NGM_ETHER_GET_PROMISC:
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index f9d3612b046a..fd005c795456 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -142,7 +142,9 @@ static void	in_arpinput(struct mbuf *);
 static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr,
     struct ifnet *ifp, int bridged, struct llentry *la);
 static void arp_mark_lle_reachable(struct llentry *la);
+static void arp_iflladdr(void *arg __unused, struct ifnet *ifp);
 
+static eventhandler_tag iflladdr_tag;
 
 static const struct netisr_handler arp_nh = {
 	.nh_name = "arp",
@@ -1150,10 +1152,39 @@ arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
 	ifa->ifa_rtrequest = NULL;
 }
 
+/*
+ * Sends gratuitous ARPs for each ifaddr to notify other
+ * nodes about the address change.
+ */
+static __noinline void
+arp_handle_ifllchange(struct ifnet *ifp)
+{
+	struct ifaddr *ifa;
+
+	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+		if (ifa->ifa_addr->sa_family == AF_INET)
+			arp_ifinit(ifp, ifa);
+	}
+}
+
+/*
+ * A handler for interface link layer address change event.
+ */
+static __noinline void
+arp_iflladdr(void *arg __unused, struct ifnet *ifp)
+{
+
+	if ((ifp->if_flags & IFF_UP) != 0)
+		arp_handle_ifllchange(ifp);
+}
+
 static void
 arp_init(void)
 {
 
 	netisr_register(&arp_nh);
+	if (IS_DEFAULT_VNET(curvnet))
+		iflladdr_tag = EVENTHANDLER_REGISTER(iflladdr_event,
+		    arp_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
 }
 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);