+#define HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
+
+static int get_mac(struct ether_addr *mac) {
+ int r;
+
+ uint8_t result[8];
+ size_t l, sz;
+ uint8_t *v;
+
+ l = strlen(arg_machine);
+ sz = sizeof(sd_id128_t) + l;
+ v = alloca(sz);
+
+ /* fetch some persistent data unique to the host */
+ r = sd_id128_get_machine((sd_id128_t*) v);
+ if (r < 0)
+ return r;
+
+ /* combine with some data unique (on this host) to this
+ * container instance */
+ memcpy(v + sizeof(sd_id128_t), arg_machine, l);
+
+ /* Let's hash the host machine ID plus the container name. We
+ * use a fixed, but originally randomly created hash key here. */
+ siphash24(result, v, sz, HASH_KEY.bytes);
+
+ assert_cc(ETH_ALEN <= sizeof(result));
+ memcpy(mac->ether_addr_octet, result, ETH_ALEN);
+
+ /* see eth_random_addr in the kernel */
+ mac->ether_addr_octet[0] &= 0xfe; /* clear multicast bit */
+ mac->ether_addr_octet[0] |= 0x02; /* set local assignment bit (IEEE802) */
+
+ return 0;
+}
+