extern dns_address *dns_address_from_rr(dns_answer *, dns_record *);
extern int dns_basic_lookup(dns_answer *, const uschar *, int);
extern void dns_build_reverse(const uschar *, uschar *);
extern dns_address *dns_address_from_rr(dns_answer *, dns_record *);
extern int dns_basic_lookup(dns_answer *, const uschar *, int);
extern void dns_build_reverse(const uschar *, uschar *);