IFADDR_STR_LEN
ret = fread(ifaddr, 1, IFADDR_STR_LEN, f);
if (!ASSERT_EQ(ret, IFADDR_STR_LEN, "fread ifaddr")) {
char src_fwd_addr[IFADDR_STR_LEN+1] = {};
char src_addr[IFADDR_STR_LEN + 1] = {};