Middle of parsing incoming datagrams.

[adns.git] / src / reply.c

diff --git a/src/reply.c b/src/reply.c
index 63b7033892a2b5e38faf93109f07bc911556948e..6aacd2b820c160c9706e5919c0a00a80b98aa3a6 100644 (file)
--- a/src/reply.c
+++ b/src/reply.c
@@ -2,7 +2,83 @@
 
 #include "internal.h"
 
+typedef enum {
+  rcode_noerror,
+  rcode_formaterror,
+  rcode_serverfail,
+  rcode_nxdomain,
+  rcode_notimp,
+  rcode_refused
+} dns_rcode;
+
 void adns__procdgram(adns_state ads, const byte *dgram, int len, int serv) {
-  /* FIXME do something with incoming datagrams */
+  unsigned char *rpp;
+  
+  if (len<12) {
+    adns__diag(ads,serv,"received datagram too short for message header (%d)",len);
+    return;
+  }
+  id= GFREPLYW;
+  f1= GFREPLYB;
+  f2= GFREPLYB;
+  qdcount= GFREPLYW;
+  ancount= GFREPLYW;
+  nscount= GFREPLYW;
+  arcount= GFREPLYW;
+
+  if (f1&0x80) {
+    adns__diag(ads,serv,"server sent us a query, not a response");
+    return;
+  }
+  if (f1&0x70) {
+    adns__diag(ads,serv,"server sent us unknown opcode %d (wanted 0=QUERY)",
+              (f1>>4)&0x70);
+    return;
+  }
+  if (!qdcount) {
+    adns__diag(ads,serv,"server sent reply without quoting our question");
+    return;
+  } else if (qdcount>1) {
+    adns__diag(ads,serv,"server claimed to answer %d questions with one message",
+              qdcount);
+    return;
+  }
+  for (qu= ads->timew; qu= nqu; qu++) {
+    nqu= qu->next;
+    if (qu->id != id) continue;
+    if (len < qu->querylen) continue;
+    if (memcmp(qu->querymsg+12,rpp,qu->querylen-12)) continue;
+    break;
+  }
+  if (!qu) {
+    adns__debug(ads,serv,"reply not found (id=%02x)",id);
+    return;
+  }
+  if (!(f2&0x80)) {
+    adns__diag(ads,serv,"server is not willing to do recursive lookups for us");
+    adns__query_fail(ads,qu,adns_s_norecurse);
+    return;
+  }
+  if (!(f1&0x01)) {
+    adns__diag(ads,serv,"server thinks we didn't ask for recursive lookup");
+    adns__query_fail(ads,qu,adns_s_serverfaulty);
+    return;
+  }
+  switch (f1&0x0f) {
+  case 0: /* NOERROR */
+    break;
+  case 1: /* Format error */
+    adns__diag(ads,serv,"server cannot understand our query (Format Error)");
+    adns__query_fail(ads,qu,adns_s_serverfaulty);
+    return;
+  case 2: /* Server failure */
+    adns__query_fail(ads,qu,adns_s_serverfailure);
+    return;
+  case 3: /* Name Error */
+  
+  qr= f1&0x80;
+  
+             
   adns__diag(ads,serv,"received datagram size %d",len);
+
 }