Tidy up pipe-to-parent code in DNS TCP path.

src/dnsmasq.h

@@ -537,6 +537,10 @@ struct crec {
 #define SRC_HOSTS     2
 #define SRC_AH        3
 
+#define PIPE_OP_RR      1  /* Resource record */
+#define PIPE_OP_END     2  /* Cache entry complete: commit */
+#define PIPE_OP_RESULT  3  /* validation result. */
+#define PIPE_OP_STATS   4  /* Update parent's stats */
 
 /* struct sockaddr is not large enough to hold any address,
    and specifically not big enough to hold an IPv6 address.
@@ -1354,6 +1358,9 @@ void cache_end_insert(void);
 void cache_start_insert(void);
 unsigned int cache_remove_uid(const unsigned int uid);
 int cache_recv_insert(time_t now, int fd);
+#ifdef HAVE_DNSSEC
+void cache_update_hwm(void);
+#endif
 struct crec *cache_insert(char *name, union all_addr *addr, unsigned short class, 
 			  time_t now, unsigned long ttl, unsigned int flags);
 void cache_reload(void);