pf_anchor_compare
static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
RB_PROTOTYPE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare)
RB_PROTOTYPE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare)