pf_find_or_create_ruleset
rs = pf_find_or_create_ruleset(ta);
rs = pf_find_or_create_ruleset(pr.anchor_call);
if ((ruleset = pf_find_or_create_ruleset(PF_RESERVED_ANCHOR)) == NULL) {
rs = pf_find_or_create_ruleset(anchor);
ruleset = pf_find_or_create_ruleset(path);
rs = pf_find_or_create_ruleset(trs->pfrt_anchor);
rs = pf_find_or_create_ruleset(tbl->pfrt_anchor);
struct pf_ruleset *pf_find_or_create_ruleset(const char *);