sctp_pad_lastmbuf
lm = sctp_pad_lastmbuf(chk->data, pads, chk->last_mbuf);
if (sctp_pad_lastmbuf(cookie, pad, NULL) == NULL) {
sctp_pad_lastmbuf(outchain, 4 - (chk_length % 4), NULL);
struct mbuf *sctp_pad_lastmbuf(struct mbuf *, int, struct mbuf *);