From d6976e0558a7468c02ba5c8aedea468adf2a0eca Mon Sep 17 00:00:00 2001
From: Marko Zec <zec@FreeBSD.org>
Date: Fri, 28 Aug 2009 19:18:20 +0000
Subject: [PATCH] MFC r196504:

  When moving ifnets from one vnet to another, and the ifnet
  has ifaddresses of AF_LINK type which thus have an embedded
  if_index "backpointer", we must update that if_index backpointer
  to reflect the new if_index that our ifnet just got assigned.

  This change affects only options VIMAGE builds.

  Submitted by: bz
  Reviewed by:  bz
  Approved by:  re (rwatson), julian (mentor)

Approved by:	re (rwatson)
---
 sys/net/if.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sys/net/if.c b/sys/net/if.c
index 5d108981cdde..e42dddfadadd 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -570,6 +570,21 @@ if_attach_internal(struct ifnet *ifp, int vmove)
 		/* Reliably crash if used uninitialized. */
 		ifp->if_broadcastaddr = NULL;
 	}
+#ifdef VIMAGE
+	else {
+		/*
+		 * Update the interface index in the link layer address
+		 * of the interface.
+		 */
+		for (ifa = ifp->if_addr; ifa != NULL;
+		    ifa = TAILQ_NEXT(ifa, ifa_link)) {
+			if (ifa->ifa_addr->sa_family == AF_LINK) {
+				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
+				sdl->sdl_index = ifp->if_index;
+			}
+		}
+	}
+#endif
 
 	IFNET_WLOCK();
 	TAILQ_INSERT_TAIL(&V_ifnet, ifp, if_link);