udhcpc6: additional fix for ppp interface type

Invent a fictitious MAC only once

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/udhcp/d6_socket.c b/networking/udhcp/d6_socket.c
index f9082ee9d3a83f432016ecdac2821871fd44c6a0..315c8d98a33e92241f2b0fa060fc9e094a9054ae 100644 (file)
--- a/networking/udhcp/d6_socket.c
+++ b/networking/udhcp/d6_socket.c
@@ -69,8 +69,12 @@ int FAST_FUNC d6_read_interface(const char *interface, int *ifindex, struct in6_
                if (ioctl(fd, SIOCGIFINDEX, &ifr) == 0) {
                        *ifindex = ifr.ifr_ifindex;
                        log2("ifindex %d", *ifindex);
-                       ((uint32_t*)mac)[0] = rand();
-                       ((uint16_t*)mac)[2] = rand();
+                       if (((uint32_t*)mac)[0] == 0) {
+                               /* invent a fictitious MAC (once) */
+                               ((uint32_t*)mac)[0] = rand();
+                               ((uint16_t*)mac)[2] = rand();
+                               mac[0] &= 0xfc; /* make sure it's not bcast */
+                       }
                        retval &= (3 - (1<<0));
                }
                close(fd);