sctp_get_valid_addr
extern in6_addr_t sctp_get_valid_addr(sctp_t *, boolean_t, boolean_t *);
ipaddr = sctp_get_valid_addr(sctp, B_FALSE, &saddr_set);
ipaddr = sctp_get_valid_addr(sctp, B_TRUE, &saddr_set);
fp->sf_saddr = sctp_get_valid_addr(sctp, v6, &addr_set);