dhcprelay: new applet

1 files changed, 17 insertions, 13 deletions

diff --git a/networking/udhcp/socket.c b/networking/udhcp/socket.c
index ea2913172..c19131d65 100644
--- a/networking/udhcp/socket.c
+++ b/networking/udhcp/socket.c
@@ -63,23 +63,27 @@ int read_interface(char *interface, int *ifindex, uint32_t *addr, uint8_t *arp)
                 DEBUG("%s (our ip) = %s", ifr.ifr_name, inet_ntoa(our_ip->sin_addr));
         }
 
-        if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
-                bb_perror_msg("SIOCGIFINDEX failed");
-                close(fd);
-                return -1;
+        if (ifindex) {
+                if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
+                        bb_perror_msg("SIOCGIFINDEX failed");
+                        close(fd);
+                        return -1;
+                }
+                DEBUG("adapter index %d", ifr.ifr_ifindex);
+                *ifindex = ifr.ifr_ifindex;
         }
 
-        DEBUG("adapter index %d", ifr.ifr_ifindex);
-        *ifindex = ifr.ifr_ifindex;
-        if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0) {
-                bb_perror_msg("SIOCGIFHWADDR failed");
-                close(fd);
-                return -1;
+        if (arp) {
+                if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0) {
+                        bb_perror_msg("SIOCGIFHWADDR failed");
+                        close(fd);
+                        return -1;
+                }
+                memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
+                DEBUG("adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
+                        arp[0], arp[1], arp[2], arp[3], arp[4], arp[5]);
         }
 
-        memcpy(arp, ifr.ifr_hwaddr.sa_data, 6);
-        DEBUG("adapter hardware address %02x:%02x:%02x:%02x:%02x:%02x",
-                arp[0], arp[1], arp[2], arp[3], arp[4], arp[5]);
         return 0;
 }