X-Git-Url: https://git.distorted.org.uk/~mdw/adns/blobdiff_plain/b9de380c1e587b6c5828cb9de796746024946880..d3eea6424e9ba051c0e72b3c39cd826fda168762:/src/reply.c

diff --git a/src/reply.c b/src/reply.c
index b6218c1..39337e8 100644
--- a/src/reply.c
+++ b/src/reply.c
@@ -2,141 +2,26 @@
 
 #include "internal.h"
 
-typedef enum {
-  rcode_noerror,
-  rcode_formaterror,
-  rcode_servfail,
-  rcode_nxdomain,
-  rcode_notimp,
-  rcode_refused
-} dns_rcode;
-
-#define GETIL_B(cb) (dgram[*(cb)++])
-#define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
-#define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
-
-static void vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
-  char qbuf[10];
-  int i;
-  
-  while (len) {
-    qbuf[0]= 0;
-    for (i=0; i<len; i++) {
-      ch= buf[i];
-      if (ch == '.' || ch == '"' || ch == '(' || ch == ')' ||
-	  ch == '@' || ch == ';' || ch == '$') {
-	sprintf(qbuf,"\\%c",ch);
-	break;
-      } else if (ch <= ' ' || ch >= 127) {
-	sprintf(qbuf,"\\%03o",ch);
-	break;
-      }
-    }
-    if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
-      return adns_s_nolocalmem;
-    buf+= i; len-= i;
-  }
-}
-
-static adns_status get_domain_perm(adns_state ads, adns_query qu, int serv,
-				   const byte *dgram, int dglen,
-				   int *cbyte_io, int max, char **domain_r) {
-  /* Returns 0     for OK (*domain_r set) or truncated (*domain_r null)
-   *      or any other adns_s_* value.
-   */
-  int cbyte, sused, lablen;
-
-  /* If we follow a pointer we set cbyte_io to 0 to indicate that
-   * we've lost our original starting and ending points; we don't
-   * put the end of the pointed-to thing into the original *cbyte_io.
-   */
-  cbyte= *cbyte_io;
-  sused= qu->ans.used;
-  *domain_r= 0;
-  for (;;) {
-    if (cbyte>=max) goto x_truncated;
-    lablen= GET_B(cbyte);
-    if (!lablen) break;
-    if (lablen&0x0c000) {
-      if ((lablen&0x0c000) != 0x0c0000) return adns_s_unknownreply;
-      if (cbyte_io) { *cbyte_io= cbyte; cbyte_io= 0; }
-      cbyte= (lablen&0x3fff) + DNS_HDR_SIZE;
-      max= dglen;
-      continue;
-    }
-    if (cbyte+lablen>=max) bgoto x_truncated;
-    if (qu->ans.used != sused)
-      if (!adns__vbuf_append(&qu->ans,".",1)) return adns_s_nolocalmem;
-    if (qu->flags & adns_qf_anyquote) {
-      if (!vbuf__append_quoted1035(&qu->ans,dgram+cbyte,lablen))
-	return adns_s_nolocalmem;
-    } else {
-      if (!ctype_isalpha(dgram[cbyte])) return adns_s_invaliddomain;
-      for (i= cbyte+1; i<cbyte+lablen; i++) {
-	ch= dgram[cbyte];
-	if (ch != '-' && !ctype_isalpha(ch) && !ctype_isdigit(ch))
-	  return adns_s_invaliddomain;
-      }
-      if (!adns__vbuf_append(&qu->ans,dgram+cbyte,lablen))
-	return adns_s_nolocalmem;
-    }
-  }
-  if (cbyte_io) *cbyte_io= cbyte;
-  if (!adns__vbuf_append(&qu->ans,"",1)) return adns_s_nolocalmem;
-  *domain_r= qu->ans.buf+sused;
-  return adns_s_ok;
-
- x_truncated:
-  return cbyte_io ? -1 : adns_s_serverfaulty;
+static void cname_recurse(adns_state ads, adns_query qu, adns_queryflags xflags) {
+  abort(); /* FIXME */
 }
     
-static adns_status get_domain_temp(adns_state ads, adns_query qu, int serv,
-				   const byte *dgram, int dglen,
-				   int *cbyte_io, int max, char **domain_r) {
-  int sused;
+void adns__procdgram(adns_state ads, const byte *dgram, int dglen,
+		     int serv, struct timeval now) {
+  int cbyte, rrstart, wantedrrs, rri, foundsoa, foundns;
+  int id, f1, f2, qdcount, ancount, nscount, arcount, flg_ra, flg_tc;
+  int rrtype, rrclass, rdlength, rdstart, ownermatched, ownerstart;
+  int anstart, nsstart, arstart;
+  int currentrrs;
+  adns_query qu, nqu;
+  dns_rcode rcode;
   adns_status st;
-
-  sused= qu->ans.used;
-  st= get_domain_perm(ads,qu,serv,dgram,dglen,cbyte_io,max,domain_r);
-  qu->ans.used= sused;
-  return st;
-}
-
-/* fixme: sensible comparison of owners */
-
-static adns_status get_rr_temp(adns_state ads, adns_query qu, int serv,
-			       const byte *dgram, int dglen,
-			       int *cbyte_io,
-			       int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
-			       char **owner_r) {
-  int cbyte, tmp, rdlen;
-
-  cbyte= *cbyte_io;
-  st= get_domain_temp(ads,qu,serv,dgram,dglen,&cbyte,dglen,owner_r);
-  if (st) return st;
-  
-  if (cbyte+10>len) goto x_truncated;
-  GET_W(cbyte,tmp); if (type_r) *type_r= tmp;
-  GET_W(cbyte,tmp); if (class_r) *class_r= tmp;
-  cbyte+= 4; /* we skip the TTL */
-  GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= tmp;
-  if (rdstart_r) *rdstart_r= cbyte;
-  cbyte+= rdlen;
-  if (cbyte>dglen) goto x_truncated;
-  *cbyte_io= cbyte;
-  return adns_s_ok;
-
- x_truncated:
-  *owner_r= 0; return 0;;
-}
-    
-void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
-  int cbyte, anstart, rrstart, lablen, wantedrrs, get_t;
+  adns_answer *ans;
 
   cbyte= 0;
   
-  if (dglen<DNS_HDR_SIZE) {
-    adns__diag(ads,serv,"received datagram too short for message header (%d)",len);
+  if (dglen<DNS_HDRSIZE) {
+    adns__diag(ads,serv,"received datagram too short for message header (%d)",dglen);
     return;
   }
   GET_W(cbyte,id);
@@ -146,7 +31,10 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
   GET_W(cbyte,ancount);
   GET_W(cbyte,nscount);
   GET_W(cbyte,arcount);
-  assert(cbyte == DNS_HDR_SIZE);
+  assert(cbyte == DNS_HDRSIZE);
+
+  flg_tc= f1&0x20;
+  flg_ra= f2&0x80;
 
   if (f1&0x80) {
     adns__diag(ads,serv,"server sent us a query, not a response");
@@ -165,19 +53,24 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
 	       qdcount);
     return;
   }
-  for (qu= ads->timew; qu= nqu; qu++) {
+  for (qu= ads->timew.head; qu; qu= nqu) {
     nqu= qu->next;
     if (qu->id != id) continue;
-    if (len < qu->querylen) continue;
-    if (memcmp(qu->querymsg+DNSHDRSIZE,dgram+DNSHDRSIZE,qu->querylen-DNSHDRSIZE))
+    if (dglen < qu->querylen) continue;
+    if (memcmp(qu->querymsg+DNS_HDRSIZE,dgram+DNS_HDRSIZE,qu->querylen-DNS_HDRSIZE))
       continue;
     break;
   }
+  assert(qu->cnameoff == -1);
   anstart= qu->querylen;
   if (!qu) {
     adns__debug(ads,serv,"reply not found (id=%02x)",id);
     return;
   }
+
+  LIST_UNLINK(ads->timew,qu);
+  /* We're definitely going to do something with this query now */
+  
   if (!(f1&0x01)) {
     adns__diag(ads,serv,"server thinks we didn't ask for recursive lookup");
     adns__query_fail(ads,qu,adns_s_serverfaulty);
@@ -193,8 +86,8 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
     adns__warn(ads,serv,"server cannot understand our query (Format Error)");
     adns__query_fail(ads,qu,adns_s_serverfaulty);
     return;
-  case rcode_servfail;
-    adns__query_fail(ads,qu,adns_s_serverfailure);
+  case rcode_servfail:
+    adns__query_fail(ads,qu,adns_s_servfail);
     return;
   case rcode_notimp:
     adns__warn(ads,serv,"server claims not to implement our query");
@@ -216,28 +109,50 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
   wantedrrs= 0;
   for (rri= 0; rri<ancount; rri++) {
     rrstart= cbyte;
-    st= get_rr_temp(ads,qu,serv,
-		    dgram,dglen,
-		    &cbyte,
-		    &rrtype,&rrclass,&rdlength,&cowner);
+    if (qu->cnameoff >= 0) {
+      st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
+			    &rrtype,&rrclass,&rdlength,&rdstart,
+			    dgram,dglen,qu->cnameoff, &ownermatched);
+    } else {
+      st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
+			    &rrtype,&rrclass,&rdlength,&rdstart,
+			    qu->querymsg,qu->querylen,DNS_HDRSIZE, &ownermatched);
+    }
     if (st) adns__query_fail(ads,qu,st);
+    if (rrtype == -1) goto x_truncated;
+
     if (rrclass != DNS_CLASS_IN) {
-      adns__diag(ads,serv,"ignoring RR with wrong class %d (expected IN=%d)",
+      adns__diag(ads,serv,"ignoring answer RR with wrong class %d (expected IN=%d)",
 		 rrclass,DNS_CLASS_IN);
       continue;
     }
-    if (strcmp_quoted1035(cowner, qu->cname ? qu->cname : qu->owner)) {
-      adns__debug(ads,serv,"ignoring answer RR with irrelevant owner \"%s\"",cowner);
+    if (!ownermatched) {
+      if (ads->iflags & adns_if_debug) {
+	st= adns__get_domain_temp(ads,qu,serv, dgram,dglen,&rrstart,dglen, &ownerstart);
+	if (st)
+	  adns__debug(ads,serv, "ignoring RR with an irrelevant owner"
+		      " whose format is bad, code %d",st);
+	else if (ownerstart>=0)
+	  adns__debug(ads,serv, "ignoring RR with an irrelevant owner"
+		      " \"%s\"", qu->ans.buf+ownerstart);
+	else
+	  adns__debug(ads,serv,"ignoring RR with an irrelevant truncated owner");
+      }
       continue;
     }
-    if (!qu->cname &&
-	(qu->type & adns__rrt_typemask) != adns_cname &&
-	rrtype == adns_cname) { /* Ignore second and subsequent CNAMEs */
-      qu->cname= get_domain_perm(ads,qu,dgram,len,rdstart,rdstart+rdlength);
-	/* If we find the answer section truncated after this point we restart
-	 * the query at the CNAME; otherwise we can use it as-is.
-	 */
-    } else if (rrtype == (qu->type & adns__rrt_typemask)) {
+    if (qu->cnameoff<0 &&
+	(qu->typei->type & adns__rrt_typemask) != adns_r_cname &&
+	rrtype == adns_r_cname) { /* Ignore second and subsequent CNAMEs */
+      st= adns__get_domain_perm(ads,qu,serv, dgram,dglen,
+				&rdstart,rdstart+rdlength,&qu->cnameoff);
+      if (st) { adns__query_fail(ads,qu,st); return; }
+      if (qu->cnameoff==-1) goto x_truncated;
+      /* If we find the answer section truncated after this point we restart
+       * the query at the CNAME; if beforehand then we obviously have to use
+       * TCP.  If there is no truncation we can use the whole answer if
+       * it contains the relevant info.
+       */
+    } else if (rrtype == (qu->typei->type & adns__rrt_typemask)) {
       wantedrrs++;
     } else {
       adns__debug(ads,serv,"ignoring answer RR with irrelevant type %d",rrtype);
@@ -251,48 +166,94 @@ void adns__procdgram(adns_state ads, const byte *dgram, int dglen, int serv) {
     /* Oops, NODATA or NXDOMAIN or perhaps a referral (which would be a problem) */
     
     if (rcode == rcode_nxdomain) {
-      adnns__query_finish(ads,qu,adns_s_nxdomain);
+      adns__query_finish(ads,qu,adns_s_nxdomain);
       return;
     }
 
     /* RFC2308: NODATA has _either_ a SOA _or_ _no_ NS records in authority section */
+    foundsoa= 0; foundns= 0;
     for (rri= 0; rri<nscount; rri++) {
-      
+      rrstart= cbyte;
+      st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
+			    &rrtype,&rrclass, &rdlength,&rdstart, 0,0,0,0);
+      if (st) { adns__query_fail(ads,qu,st); return; }
+      if (rrtype==-1) goto x_truncated;
+      if (rrclass != DNS_CLASS_IN) {
+	adns__diag(ads,serv,"ignoring authority RR with wrong class %d (expected IN=%d)",
+		   rrclass,DNS_CLASS_IN);
+	continue;
+      }
+      if (rrtype == adns_r_soa_raw) { foundsoa= 1; break; }
+      else if (rrtype == adns_r_ns_raw) { foundns= 1; }
     }
-    } else {
-      
-    
-  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);
+
+    if (foundsoa || !foundns) {
+      /* Aha !  A NODATA response, good. */
+      adns__query_finish(ads,qu,adns_s_nodata);
+      return;
+    }
+
+    /* Now what ?  No relevant answers, no SOA, and at least some NS's.
+     * Looks like a referral.  Just one last chance ... if we came across
+     * a CNAME then perhaps we should do our own CNAME lookup.
+     */
+    if (qu->cnameoff != -1) { cname_recurse(ads,qu,0); return; }
+
+    /* Bloody hell, I thought we asked for recursion ? */
+    if (!flg_ra) {
+      adns__diag(ads,serv,"server is not willing to do recursive lookups for us");
+      adns__query_fail(ads,qu,adns_s_norecurse);
+      return;
+    }
+    adns__diag(ads,serv,"server claims to do recursion, but gave us a referral");
+    adns__query_fail(ads,qu,adns_s_serverfaulty);
     return;
   }
 
-  
-	) {
-    if (type 
-      if (cbyte+lab
-      if (anstart > dgend) { truncated(ads,qu,f1); return; }
-  }
-    for    
+  /* Now, we have some RRs which we wanted. */
 
-    /* Look for CNAMEs in the answer section */
+  qu->rrsoff= adns__vbuf_malloc(&qu->ans,qu->typei->rrsz*wantedrrs);
+  if (qu->rrsoff == -1) adns__query_fail(ads,qu,adns_s_nolocalmem);
 
+  cbyte= anstart;
+  currentrrs= 0;
+  arstart= -1;
+  for (rri=0; rri<ancount; rri++) {
+    st= adns__get_rr_temp(ads,qu,serv, dgram,dglen,&cbyte,
+			  &rrtype,&rrclass, &rdlength,&rdstart, 0,0,0,0);
+    assert(!st); assert(rrtype != -1);
+    if (rrclass != DNS_CLASS_IN ||
+	rrtype != (qu->typei->type & adns__rrt_typemask))
+      continue;
+    assert(currentrrs<wantedrrs);
+    st= qu->typei->get_fn(ads,qu,serv, dgram,dglen, &rdstart,rdstart+rdlength,
+			  nsstart,arcount,&arstart, qu->rrsoff,&currentrrs);
+    if (st) { adns__query_fail(ads,qu,st); return; }
+    if (currentrrs==-1) goto x_truncated;
   }
-  
-    
-    adns__diag(ads,serv,"server refused our query");
-    
-    case rcode_
-    
-  case 0: /* NOERROR 
-    break;
-  case 1: /* Format error */
-  case 3: /* Name Error */
-  
-  qr= f1&0x80;
-  
-	      
-  adns__diag(ads,serv,"received datagram size %d",len);
 
+  /* This may have generated some child queries ... */
+  if (qu->children.head) {
+    qu->state= query_child;
+    LIST_LINK_TAIL(ads->childw,qu);
+    return;
+  }
+
+  adns__query_finish(ads,qu,adns_s_ok);
+  return;
+
+x_truncated:
+  if (!flg_tc) {
+    adns__diag(ads,serv,"server sent datagram which points outside itself");
+    adns__query_fail(ads,qu,adns_s_serverfaulty);
+    return;
+  }
+  if (qu->cnameoff != -1) { cname_recurse(ads,qu,adns_qf_usevc); return; }
+  qu->cnameoff= -1;
+  qu->rrsoff= -1;
+  ans= (adns_answer*)qu->ans.buf;
+  ans->nrrs= 0;
+  qu->ans.used= sizeof(adns_answer);
+  qu->flags |= adns_qf_usevc;
+  adns__query_udp(ads,qu,now);
 }