fec_insert
if (fec_insert(&ln->sent_map, &me->fec))
if (fec_insert(&ln->recv_map, &me->fec))
if (fec_insert(t, &lre->fec)) {
if (fec_insert(&ln->sent_wdraw, &lw->fec))
int fec_insert(struct fec_tree *, struct fec *);
if (fec_insert(&ft, &fn->fec))