prefix_set
prefix_set(&pr->pr_prefix, prefix, prefixlen);
prefix_set(&pr->pr_prefix, sin6->sin6_addr, pr->pr_prefix_len);
prefix_set(&pr->pr_prefix, pr->pr_prefix, pr->pr_prefix_len);
prefix_set(&((struct sockaddr_in6 *)&lifr.lifr_addr)->sin6_addr,
prefix_set(&adv_pr->adv_pr_prefix, prefix, prefixlen);
static void prefix_set(struct in6_addr *prefix, struct in6_addr addr,