Index: ndp.c
===================================================================
RCS file: /cvs/src/usr.sbin/ndp/ndp.c,v
retrieving revision 1.87
diff -u -p -r1.87 ndp.c
--- ndp.c	25 Oct 2017 12:09:07 -0000	1.87
+++ ndp.c	1 Mar 2018 22:58:05 -0000
@@ -137,6 +137,7 @@ int rtget(struct sockaddr_in6 **, struct
 void ifinfo(char *);
 static char *sec2str(time_t);
 static void ts_print(const struct timeval *);
+static int sdl_isether(const struct sockaddr_dl *);
 static int rdomain;
 
 static char *rtpref_str[] = {
@@ -376,15 +377,10 @@ set(int argc, char **argv)
 	}
 
 	if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr)) {
-		if (sdl->sdl_family == AF_LINK &&
+		if (sdl_isether(sdl) &&
 		    (rtm->rtm_flags & RTF_LLINFO) &&
-		    !(rtm->rtm_flags & RTF_GATEWAY)) {
-			switch (sdl->sdl_type) {
-			case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
-			case IFT_ISO88024: case IFT_ISO88025:
-				goto overwrite;
-			}
-		}
+		    !(rtm->rtm_flags & RTF_GATEWAY))
+			goto overwrite;
 		/*
 		 * IPv4 arp command retries with sin_other = SIN_PROXY here.
 		 */
@@ -392,11 +388,11 @@ set(int argc, char **argv)
 		return 1;
 	}
 
-overwrite:
-	if (sdl->sdl_family != AF_LINK) {
+	if (!sdl_isether(sdl)) {
 		printf("cannot intuit interface index and type for %s\n", host);
 		return (1);
 	}
+overwrite:
 	sdl_m.sdl_type = sdl->sdl_type;
 	sdl_m.sdl_index = sdl->sdl_index;
 	return (rtmsg(RTM_ADD));
@@ -477,7 +473,7 @@ delete(char *host)
 	}
 
 	if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr)) {
-		if (sdl->sdl_family == AF_LINK && rtm->rtm_flags & RTF_LLINFO) {
+		if (sdl_isether(sdl) && rtm->rtm_flags & RTF_LLINFO) {
 			if (rtm->rtm_flags & RTF_LOCAL)
 				return (0);
 			if (!(rtm->rtm_flags & RTF_GATEWAY))
@@ -490,11 +486,11 @@ delete(char *host)
 		return 1;
 	}
 
-delete:
-	if (sdl->sdl_family != AF_LINK) {
+	if (!sdl_isether(sdl)) {
 		printf("cannot locate %s\n", host);
 		return (1);
 	}
+delete:
 	if (rtmsg(RTM_DELETE) == 0) {
 		struct sockaddr_in6 s6 = *sin; /* XXX: for safety */
 
@@ -590,7 +586,7 @@ again:;
 		 * What is to be fixed is not ndp, but such routing software
 		 * (and the kernel workaround)...
 		 */
-		if (sdl->sdl_family != AF_LINK)
+		if (!sdl_isether(sdl))
 			continue;
 
 		if (!(rtm->rtm_flags & RTF_HOST))
@@ -961,4 +957,27 @@ ts_print(const struct timeval *tvp)
 	s = (tvp->tv_sec + thiszone) % 86400;
 	(void)printf("%02d:%02d:%02d.%06u ",
 	    s / 3600, (s % 3600) / 60, s % 60, (u_int32_t)tvp->tv_usec);
+}
+
+static int
+sdl_isether(const struct sockaddr_dl *sdl)
+{
+	if (sdl->sdl_family != AF_LINK)
+		return (0);
+
+	switch (sdl->sdl_type) {
+	case IFT_ETHER:
+	case IFT_CARP:
+	case IFT_XETHER:
+	case IFT_FDDI:
+	case IFT_ISO88023:
+	case IFT_ISO88024:
+	case IFT_ISO88025:
+		break;
+
+	default:
+		return (0);
+	}
+
+	return (1);
 }