X-Git-Url: http://www.lcore.org/git/lcore.git/blobdiff_plain/eaa75975b23ce60360526c08628f2b0651c95167..69598fec083b67c8567293c7b8a397b64175bd45:/dnscore.pas?ds=inline

diff --git a/dnscore.pas b/dnscore.pas
index fa9eee2..08f99d1 100644
--- a/dnscore.pas
+++ b/dnscore.pas
@@ -6,12 +6,12 @@
 {
 
   code wanting to use this dns system should act as follows (note: app
-  developers will probablly want to use dnsasync or dnssync or write a similar
-  wrapper unit of thier own).
+  developers will probably want to use dnsasync or dnssync or write a similar
+  wrapper unit of their own).
 
   for normal lookups call setstate_forward or setstate_reverse to set up the
   state, for more obscure lookups use setstate_request_init and fill in other
-  relavent state manually.
+  relevant state manually.
 
   call state_process which will do processing on the information in the state
   and return an action
@@ -20,7 +20,7 @@
   action_sendpacket means that dnscore wants the code that calls it to send
   the packet in sendpacket/sendpacketlen and then start (or go back to) listening
   for
-  action_done means the request has completed (either suceeded or failed)
+  action_done means the request has completed (either succeeded or failed)
 
   callers should resend the last packet they tried to send if they have not
   been asked to send a new packet for more than some timeout value they choose.
@@ -32,23 +32,23 @@
   following ways.
 
   on failure state.resultstr will be an empty string and state.resultbin will
-  be zeroed out (easilly detected by the fact that it will have a family of 0)
+  be zeroed out (easily detected by the fact that it will have a family of 0)
 
   on success for a A or AAAA lookup state.resultstr will be an empty string
-  and state.resultbin will contain the result (note: AAAA lookups require IPV6
+  and state.resultbin will contain the result (note: AAAA lookups require IPv6
   enabled).
 
-  if an A lookup fails and the code is built with ipv6 enabled then the code
+  if an A lookup fails and the code is built with IPv6 enabled then the code
   will return any AAAA records with the same name. The reverse does not apply
-  so if an application preffers IPV6 but wants IPV4 results as well it must
-  check them seperately.
+  so if an application prefers IPv6 but wants IPv4 results as well it must
+  check them separately.
 
   on success for any other type of lookup state.resultstr will be an empty
 
   note the state contains ansistrings, setstate_init with a null name parameter
-  can be used to clean theese up if required.
+  can be used to clean these up if required.
 
-  callers may use setstate_failure to mark the state as failed themseleves
+  callers may use setstate_failure to mark the state as failed themselves
   before passing it on to other code, for example this may be done in the event
   of a timeout.
 }
@@ -62,7 +62,7 @@ interface
 
 uses binipstuff,classes,pgtypes,lcorernd;
 
-var usewindns : boolean = {$ifdef win32}true{$else}false{$endif};
+var usewindns : boolean = {$ifdef mswindows}true{$else}false{$endif};
 {hint to users of this unit that they should use windows dns instead.
 May be disabled by applications if desired. (e.g. if setting a custom
 dnsserverlist).
@@ -106,7 +106,10 @@ const
   querytype_txt=16;
   querytype_spf=99;
   maxrecursion=50;
-  maxrrofakind=20;
+  maxrrofakind=32;
+  {the maximum number of RR of a kind of purely an extra sanity check and could be omitted.
+  before, i set it to 20, but valid replies can have more. dnscore only does udp requests,
+  and ordinary DNS, so up to 512 bytes. the maximum number of A records that fits seems to be 29}
 
   retryafter=300000; //microseconds must be less than one second;
   timeoutlag=1000000000; // penalty value to be treated as lag in the event of a timeout (microseconds)
@@ -159,7 +162,7 @@ type
   end;
 
 //commenting out functions from interface that do not have documented semantics
-//and probablly should not be called from outside this unit, reenable them
+//and probably should not be called from outside this unit, reenable them
 //if you must but please document them at the same time --plugwash
 
 //function buildrequest(const name:string;var packet:tdnspacket;requesttype:word):integer;
@@ -169,7 +172,7 @@ function makereversename(const binip:tbinip):ansistring;
 
 procedure setstate_request_init(const name:ansistring;var state:tdnsstate);
 
-//set up state for a foward lookup. A family value of AF_INET6 will give only
+//set up state for a forward lookup. A family value of AF_INET6 will give only
 //ipv6 results. Any other value will give only ipv4 results
 procedure setstate_forward(const name:ansistring;var state:tdnsstate;family:integer);
 
@@ -502,7 +505,10 @@ begin
     state.numrr2 := 0;
     for a := 0 to 3 do begin
       state.numrr1[a] := htons(state.recvpacket.rrcount[a]);
-      if state.numrr1[a] > maxrrofakind then goto failure;
+      if state.numrr1[a] > maxrrofakind then begin
+        failurereason := 'exceeded maximum RR of a kind';
+        goto failure;
+      end;
       inc(state.numrr2,state.numrr1[a]);
     end;
 
@@ -591,7 +597,7 @@ recursed:
     goto failure;
   end;
 
-  {do /ets/hosts lookup here}
+  {do /etc/hosts lookup here}
   state.sendpacketlen := buildrequest(state.queryname,state.sendpacket,state.requesttype);
   if state.sendpacketlen = 0 then begin
     failurereason := 'building request packet failed';
@@ -633,7 +639,7 @@ function getcurrentsystemnameserverbin(var id:integer):tbinip;
 var
   counter : integer;
 begin
-  {override the name server choice here, instead of overriding it whereever it's called
+  {override the name server choice here, instead of overriding it wherever it's called
   setting ID to -1 causes it to be ignored in reportlag}
   if (overridednsserver <> '') then begin
     result := ipstrtobinf(overridednsserver);
@@ -644,7 +650,7 @@ begin
   end;
 
   if not assigned(dnsserverlag) then populatednsserverlist;
-  if dnsserverlag.count=0 then raise exception.create('no dns servers availible');
+  if dnsserverlag.count=0 then raise exception.create('no dns servers available');
   id := 0;
   if dnsserverlag.count >1 then begin
     for counter := dnsserverlag.count-1 downto 1 do begin
@@ -678,31 +684,16 @@ end;
 {$ifdef ipv6}
 
 procedure initpreferredmode;
-var
-  l:tbiniplist;
-  a:integer;
-  ip:tbinip;
-  ipmask_global,ipmask_6to4,ipmask_teredo:tbinip;
-
 begin
   if preferredmodeinited then exit;
   if useaf <> useaf_default then exit;
-  l := getv6localips;
-  if biniplist_getcount(l) = 0 then exit;
-  useaf := useaf_preferv4;
-  ipstrtobin('2000::',ipmask_global);
-  ipstrtobin('2001::',ipmask_teredo);
-  ipstrtobin('2002::',ipmask_6to4);
-  {if there is any v6 IP which is globally routable and not 6to4 and not teredo, prefer v6}
-  for a := biniplist_getcount(l)-1 downto 0 do begin
-    ip := biniplist_get(l,a);
-    if not comparebinipmask(ip,ipmask_global,3) then continue;
-    if comparebinipmask(ip,ipmask_teredo,32) then continue;
-    if comparebinipmask(ip,ipmask_6to4,16) then continue;
-    useaf := useaf_preferv6;
-    preferredmodeinited := true;
-    exit;
-  end;
+
+  if (have_ipv6_connectivity) then
+    useaf := useaf_preferv6
+  else
+    useaf := useaf_preferv4;
+
+  preferredmodeinited := true;
 end;
 
 {$endif}