sctp_cookie_echo_chunk
init_offset = offset += sizeof(struct sctp_cookie_echo_chunk);
init_offset = offset + sizeof(struct sctp_cookie_echo_chunk);
struct sctphdr *sh, struct sctp_cookie_echo_chunk *cp,
cookie_len < sizeof(struct sctp_cookie_echo_chunk) +
(struct sctp_cookie_echo_chunk *)ch, &inp,