Export the functionality of SIOCSIFLLADDR with if_setlladdr()

and add some more rigorous sanity checking in the process.

Reviewed by:	freebsd-net

2 files changed, 51 insertions, 25 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index d7feb3c..829ede2 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -54,6 +54,7 @@
 #include <net/if.h>
 #include <net/if_arp.h>
 #include <net/if_dl.h>
+#include <net/if_types.h>
 #include <net/radix.h>
 #include <net/route.h>
 
@@ -762,8 +763,6 @@ ifioctl(so, cmd, data, p)
 {
 	register struct ifnet *ifp;
 	register struct ifreq *ifr;
-	register struct ifaddr *ifa;
-	struct sockaddr_dl *sdl;
 	struct ifstat *ifs;
 	int error;
 	short oif_flags;
@@ -917,29 +916,9 @@ ifioctl(so, cmd, data, p)
 		error = suser(p);
 		if (error)
 			return (error);
-		ifa = ifnet_addrs[ifp->if_index - 1];
-		if (ifa == NULL)
-			return(EINVAL);
-		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
-		if (sdl == NULL)
-			return(EINVAL);
-		bcopy(ifr->ifr_addr.sa_data,
-		    ((struct arpcom *)ifp->if_softc)->ac_enaddr,
-		    ifr->ifr_addr.sa_len);
-		bcopy(ifr->ifr_addr.sa_data, LLADDR(sdl),
-		    ifr->ifr_addr.sa_len);
-		/*
-		 * If the interface is already up, we need
-		 * to re-init it in order to reprogram its
-		 * address filter.
-		 */
-		if (ifp->if_flags & IFF_UP) {
-			ifp->if_flags &= ~IFF_UP;
-			(*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, NULL);
-			ifp->if_flags |= IFF_UP;
-			(*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, NULL);
-		}
-		return(0);
+		return if_setlladdr(ifp,
+		    ifr->ifr_addr.sa_data, ifr->ifr_addr.sa_len);
+
 	default:
 		oif_flags = ifp->if_flags;
 		if (so->so_proto == 0)
@@ -1339,6 +1318,52 @@ if_delmulti(ifp, sa)
 	return 0;
 }
 
+/*
+ * Set the link layer address on an interface.
+ *
+ * At this time we only support certain types of interfaces,
+ * and we don't allow the length of the address to change.
+ */
+int
+if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
+{
+	struct sockaddr_dl *sdl;
+	struct ifaddr *ifa;
+
+	ifa = ifnet_addrs[ifp->if_index - 1];
+	if (ifa == NULL)
+		return (EINVAL);
+	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
+	if (sdl == NULL)
+		return (EINVAL);
+	if (len != sdl->sdl_alen)	/* don't allow length to change */
+		return (EINVAL);
+	switch (ifp->if_type) {
+	case IFT_ETHER:			/* these types use struct arpcom */
+	case IFT_FDDI:
+	case IFT_XETHER:
+	case IFT_ISO88025:
+	case IFT_PROPVIRTUAL:		/* XXX waiting for IFT_8021_VLAN */
+		bcopy(lladdr, ((struct arpcom *)ifp->if_softc)->ac_enaddr, len);
+		bcopy(lladdr, LLADDR(sdl), len);
+		break;
+	default:
+		return (ENODEV);
+	}
+	/*
+	 * If the interface is already up, we need
+	 * to re-init it in order to reprogram its
+	 * address filter.
+	 */
+	if ((ifp->if_flags & IFF_UP) != 0) {
+		ifp->if_flags &= ~IFF_UP;
+		(*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, NULL);
+		ifp->if_flags |= IFF_UP;
+		(*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, NULL);
+	}
+	return (0);
+}
+
 struct ifmultiaddr *
 ifmaof_ifpforaddr(sa, ifp)
 	struct sockaddr *sa;
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index e6f0785..d16fc00 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -340,6 +340,7 @@ int	if_delmulti __P((struct ifnet *, struct sockaddr *));
 void	if_detach __P((struct ifnet *));
 void	if_down __P((struct ifnet *));
 void	if_route __P((struct ifnet *, int flag, int fam));
+int	if_setlladdr __P((struct ifnet *, const u_char *, int));
 void	if_unroute __P((struct ifnet *, int flag, int fam));
 void	if_up __P((struct ifnet *));
 /*void	ifinit __P((void));*/ /* declared in systm.h for main() */