Three more helper functions and the DNS action is done.

examples/dns.h

@@ -1,7 +1,8 @@
+typedef int bool;
 struct dns_header {
   uint16_t id;
-  boolean qr, aa, tc, rd, ra;
-  char opcode, z, rcode;
+  bool qr, aa, tc, rd, ra;
+  char opcode, rcode;
   size_t question_count;
   size_t answer_count;
   size_t authority_count;
@@ -19,14 +20,54 @@ struct dns_rr {
   uint32_t ttl; // cmos is also acceptable.
   uint16_t rdlength;
   union {
-    // various types of rdata-specific data here...
+    char* cname;
+    struct {
+      uint8_t* cpu;
+      uint8_t* os;
+    } hinfo;
+    char* mb;
+    char* md;
+    char* mf;
+    char* mg;
+    struct {
+      char* rmailbx;
+      char* emailbx;
+    } minfo;
+    char* mr;
+    struct {
+      uint16_t preference;
+      char* exchange;
+    } mx;
+    uint8_t* null;
+    char* ns;
+    char* ptr;
+    struct {
+      char* mname;
+      char* rname;
+      uint32_t serial;
+      uint32_t refresh;
+      uint32_t retry;
+      uint32_t expire;
+      uint32_t minimum;
+    } soa;
+    struct {
+      size_t count;
+      uint8_t** txt_data;
+    } txt;
+    uint32_t a;
+    struct {
+      uint32_t address;
+      uint8_t protocol;
+      size_t len;
+      uint8_t** bit_map;
+    } wks;
   };
 };
 
 typedef struct dns_message {
   struct dns_header header;
-  struct dns_question *questions; // end all these with null, just to be sure.
+  struct dns_question *questions;
   struct dns_rr *answers;
   struct dns_rr *authority;
   struct dns_rr *additional;
-}
+} dns_message_t;