rip6
if (len < sizeof(struct rip6)) {
nn = (len - sizeof(struct rip6) + sizeof(struct netinfo6)) /
rp = (struct rip6 *)buf;
struct rip6 *ripbuf; /* packet buffer for sending */
(sizeof(struct rip6) + ((n)-1) * sizeof(struct netinfo6))
sizeof(struct rip6) + sizeof(struct netinfo6)) /
sizeof(struct rip6) + sizeof(struct netinfo6)) /
struct rip6 *rp;
const struct rip6 *rp = (struct rip6 *)dat;
(sizeof(struct rip6) - sizeof(struct netinfo6));