deal with funny SIOCSETMPWCFG ioctl, carefully

commands.c

@@ -678,6 +678,8 @@ interface(int argc, char **argv, char *modhvar)
 		bridge = 0; 
 	}
 
+	imr_init(ifname);
+
 	if (modhvar) {
 		/* direct rcfile -i or -c initialization */
 		char *argp;

externs.h

@@ -372,6 +372,7 @@ int parse_ipv6(char *, struct in6_addr *);
 #define ROUNDMBPS(bps) ((float)bps == ((bps / 1000 / 1000) * 1000 * 1000))
 #define ROUNDKBPS(bps) ((float)bps == ((bps / 1000) * 1000))
 #define ROUNDKBYTES(bytes) ((float)bytes == ((bytes / 1024) * 1024))
+void imr_init(char *);
 int is_valid_ifname(char *);
 int show_int(int, char **);
 int get_rdomain(int, char *);

if.c

@@ -55,6 +55,7 @@ void printifhwfeatures(int, char *);
 void show_vnet_parent(int, char *);
 
 static struct ifmpwreq imrsave;
+static char imrif[IFNAMSIZ];
 
 static const struct {
 	char *name;
@@ -86,6 +87,14 @@ static const struct {
 	{ "Unspecified",		IFT_OTHER },
 };
 
+void imr_init(char *ifname)
+{
+	if (strcmp(ifname, imrif) == 0)
+			return;
+	strlcpy (imrif, ifname, IFNAMSIZ);
+	memset (&imrsave, 0, sizeof(imrsave));
+}
+
 int
 show_int(int argc, char **argv)
 {
@@ -1317,8 +1326,8 @@ intmpw(char *ifname, int ifs, int argc, char **argv)
 	    imrsave.imr_rshim.shim_label == 0) {
 		if (imr.imr_lshim.shim_label == 0 ||
 		    imr.imr_rshim.shim_label == 0) {
-			printf("%% mpw local / remote label not specified\n");
-			/*return 0;*/
+			/*printf("%% mpw local / remote label not specified\n");*/
+			return 0;
 		}
 		imrsave.imr_lshim.shim_label = imr.imr_lshim.shim_label;
 		imrsave.imr_rshim.shim_label = imr.imr_rshim.shim_label;
@@ -1328,8 +1337,8 @@ intmpw(char *ifname, int ifs, int argc, char **argv)
 	sinn = (struct sockaddr_in *) &imr.imr_nexthop;
 	if (sin->sin_addr.s_addr == 0) {
 		if (sinn->sin_addr.s_addr == 0) {
-			printf("%% mpw neighbor address not specified\n");
-			/*return 0;*/
+			/*printf("%% mpw neighbor address not specified\n");*/
+			return 0;
 		}
 
 		sin->sin_family = sinn->sin_family;