--- busybox-1.13.1/include/libbb.h	Sun Nov  9 18:28:17 2008
+++ busybox-1.13.1-bindtodevice/include/libbb.h	Wed Dec 10 12:10:30 2008
@@ -437,6 +437,7 @@
  * Turn it on before you call bind(). */
 void setsockopt_reuseaddr(int fd) FAST_FUNC; /* On Linux this never fails. */
 int setsockopt_broadcast(int fd) FAST_FUNC;
+int setsockopt_bindtodevice(int fd, const char *iface) FAST_FUNC;
 /* NB: returns port in host byte order */
 unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port) FAST_FUNC;
 typedef struct len_and_sockaddr {
--- busybox-1.13.1/libbb/xconnect.c	Sun Nov  9 18:28:09 2008
+++ busybox-1.13.1-bindtodevice/libbb/xconnect.c	Wed Dec 10 23:20:29 2008
@@ -7,6 +7,7 @@
  */
 
 #include <netinet/in.h>
+#include <net/if.h>
 #include "libbb.h"
 
 void FAST_FUNC setsockopt_reuseaddr(int fd)
@@ -17,6 +18,20 @@
 {
 	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
 }
+int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
+{
+	int r;
+	struct ifreq ifr;
+	strncpy(ifr.ifr_name, iface, IFNAMSIZ);
+	/* Actually, ifr_name is at offset 0, and in practice
+	 * just giving char[IFNAMSIZ] instead of struct ifreq works too.
+	 * But just in case it's not true on some obscure arch... */
+	r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
+	if (r)
+		bb_perror_msg("can't bind to interface %s", iface);
+	return r;
+}
+
 
 void FAST_FUNC xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
 {
--- busybox-1.13.1/networking/arping.c	Sun Nov  9 18:27:59 2008
+++ busybox-1.13.1-bindtodevice/networking/arping.c	Wed Dec 10 12:10:30 2008
@@ -322,8 +322,7 @@
 		struct sockaddr_in saddr;
 		int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0);
 
-		if (setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device) + 1) == -1)
-			bb_perror_msg("cannot bind to device %s", device);
+		setsockopt_bindtodevice(probe_fd, device);
 		memset(&saddr, 0, sizeof(saddr));
 		saddr.sin_family = AF_INET;
 		if (src.s_addr) {
--- busybox-1.13.1/networking/ping.c	Sun Nov  9 18:27:59 2008
+++ busybox-1.13.1-bindtodevice/networking/ping.c	Wed Dec 10 12:10:30 2008
@@ -572,7 +572,7 @@
 		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
 	}
 	if (str_I)
-		setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, str_I, strlen(str_I) + 1);
+		setsockopt_bindtodevice(pingsock, str_I);
 
 	/* enable broadcast pings */
 	setsockopt_broadcast(pingsock);
@@ -622,7 +622,7 @@
 	if (source_lsa)
 		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
 	if (str_I)
-		setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, str_I, strlen(str_I) + 1);
+		setsockopt_bindtodevice(pingsock, str_I);
 
 #ifdef ICMP6_FILTER
 	{
--- busybox-1.13.1/networking/udhcp/socket.c	Sun Nov  9 18:27:58 2008
+++ busybox-1.13.1-bindtodevice/networking/udhcp/socket.c	Wed Dec 10 12:10:30 2008
@@ -98,8 +98,8 @@
 		bb_perror_msg_and_die("SO_BROADCAST");
 
 	/* NB: bug 1032 says this doesn't work on ethernet aliases (ethN:M) */
-	if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &inf, strlen(inf) + 1) == -1)
-		bb_perror_msg_and_die("SO_BINDTODEVICE");
+	if (setsockopt_bindtodevice(fd, inf))
+		xfunc_die(); /* warning is already printed */
 
 	memset(&addr, 0, sizeof(addr));
 	addr.sin_family = AF_INET;