X-Git-Url: http://www.lcore.org/git/lcore.git/blobdiff_plain/9eaeac69829469108bce954ccce0710bbdb27fb3..refs/heads/master:/dnscore.pas?ds=sidebyside

diff --git a/dnscore.pas b/dnscore.pas
index 7cbb828..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);
 
@@ -188,7 +191,8 @@ procedure populatednsserverlist;
 procedure cleardnsservercache;
 
 var
-  dnsserverlist : tstringlist;
+  dnsserverlist : tbiniplist;
+  dnsserverlag:tlist;
 //  currentdnsserverno : integer;
 
 
@@ -196,6 +200,7 @@ var
 //id to the id of that nameserver. id should later be used to report how laggy
 //the servers response was and if it was timed out.
 function getcurrentsystemnameserver(var id:integer) :ansistring;
+function getcurrentsystemnameserverbin(var id:integer) :tbinip;
 procedure reportlag(id:integer;lag:integer); //lag should be in microseconds and should be -1 to report a timeout
 
 //var
@@ -204,7 +209,6 @@ procedure reportlag(id:integer;lag:integer); //lag should be in microseconds and
 
 
 {$ifdef ipv6}
-function getv6localips:tbiniplist;
 procedure initpreferredmode;
 
 var
@@ -220,10 +224,7 @@ function getquerytype(s:ansistring):integer;
 implementation
 
 uses
-  {$ifdef win32}
-    windows,winsock,
-  {$endif}
-
+  lcorelocalips,
   sysutils;
 
 
@@ -504,7 +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;
 
@@ -593,7 +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';
@@ -606,132 +610,59 @@ recursed:
 failure:
   setstate_failure(state);
 end;
-{$ifdef win32}
-  const
-    MAX_HOSTNAME_LEN = 132;
-    MAX_DOMAIN_NAME_LEN = 132;
-    MAX_SCOPE_ID_LEN = 260    ;
-    MAX_ADAPTER_NAME_LENGTH = 260;
-    MAX_ADAPTER_ADDRESS_LENGTH = 8;
-    MAX_ADAPTER_DESCRIPTION_LENGTH = 132;
-    ERROR_BUFFER_OVERFLOW = 111;
-    MIB_IF_TYPE_ETHERNET = 6;
-    MIB_IF_TYPE_TOKENRING = 9;
-    MIB_IF_TYPE_FDDI = 15;
-    MIB_IF_TYPE_PPP = 23;
-    MIB_IF_TYPE_LOOPBACK = 24;
-    MIB_IF_TYPE_SLIP = 28;
-
-
-  type
-    tip_addr_string=packed record
-      Next :pointer;
-      IpAddress : array[0..15] of ansichar;
-      ipmask    : array[0..15] of ansichar;
-      context   : dword;
-    end;
-    pip_addr_string=^tip_addr_string;
-    tFIXED_INFO=packed record
-       HostName         : array[0..MAX_HOSTNAME_LEN-1] of ansichar;
-       DomainName       : array[0..MAX_DOMAIN_NAME_LEN-1] of ansichar;
-       currentdnsserver : pip_addr_string;
-       dnsserverlist    : tip_addr_string;
-       nodetype         : longint;
-       ScopeId          : array[0..MAX_SCOPE_ID_LEN + 4] of ansichar;
-       enablerouting    : longbool;
-       enableproxy      : longbool;
-       enabledns        : longbool;
-    end;
-    pFIXED_INFO=^tFIXED_INFO;
 
-  var
-    iphlpapi : thandle;
-    getnetworkparams : function(pFixedInfo : PFIXED_INFO;OutBufLen : plongint) : longint;stdcall;
-{$endif}
+
 procedure populatednsserverlist;
 var
-  {$ifdef win32}
-    fixed_info : pfixed_info;
-    fixed_info_len : longint;
-    currentdnsserver : pip_addr_string;
-  {$else}
-    t:textfile;
-    s:ansistring;
-    a:integer;
-  {$endif}
+  a:integer;
 begin
-  //result := '';
-  if assigned(dnsserverlist) then begin
-    dnsserverlist.clear;
+  if assigned(dnsserverlag) then begin
+    dnsserverlag.clear;
   end else begin
-    dnsserverlist := tstringlist.Create;
+    dnsserverlag := tlist.Create;
   end;
-  {$ifdef win32}
-    if iphlpapi=0 then iphlpapi := loadlibrary('iphlpapi.dll');
-    if not assigned(getnetworkparams) then @getnetworkparams := getprocaddress(iphlpapi,'GetNetworkParams');
-    if not assigned(getnetworkparams) then exit;
-    fixed_info_len := 0;
-    if GetNetworkParams(nil,@fixed_info_len)<>ERROR_BUFFER_OVERFLOW then exit;
-    //fixed_info_len :=sizeof(tfixed_info);
-    getmem(fixed_info,fixed_info_len);
-    if GetNetworkParams(fixed_info,@fixed_info_len)<>0 then begin
-      freemem(fixed_info);
-      exit;
-    end;
-    currentdnsserver := @(fixed_info.dnsserverlist);
-    while assigned(currentdnsserver) do begin
-      dnsserverlist.Add(currentdnsserver.IpAddress);
-      currentdnsserver := currentdnsserver.next;
-    end;
-    freemem(fixed_info);
-  {$else}
-    filemode := 0;
-    assignfile(t,'/etc/resolv.conf');
-    {$i-}reset(t);{$i+}
-    if ioresult <> 0 then exit;
-
-    while not eof(t) do begin
-      readln(t,s);
-      if not (copy(s,1,10) = 'nameserver') then continue;
-      s := copy(s,11,500);
-      while s <> '' do begin
-        if (s[1] = #32) or (s[1] = #9) then s := copy(s,2,500) else break;
-      end;
-      a := pos(' ',s);
-      if a <> 0 then s := copy(s,1,a-1);
-      a := pos(#9,s);
-      if a <> 0 then s := copy(s,1,a-1);
-      //result := s;
-      //if result <> '' then break;
-      dnsserverlist.Add(s);
-    end;
-    close(t);
-  {$endif}
+
+  dnsserverlist := getsystemdnsservers;
+  for a := biniplist_getcount(dnsserverlist)-1 downto 0 do dnsserverlag.Add(nil);
 end;
 
 procedure cleardnsservercache;
 begin
-  if assigned(dnsserverlist) then begin
-    dnsserverlist.destroy;
-    dnsserverlist := nil;
+  if assigned(dnsserverlag) then begin
+    dnsserverlag.destroy;
+    dnsserverlag := nil;
+    dnsserverlist := '';
   end;
 end;
 
-function getcurrentsystemnameserver(var id:integer):ansistring;
+function getcurrentsystemnameserverbin(var id:integer):tbinip;
 var
   counter : integer;
-
 begin
-  if not assigned(dnsserverlist) then populatednsserverlist;
-  if dnsserverlist.count=0 then raise exception.create('no dns servers availible');
-  id := 0;
-  if dnsserverlist.count >1 then begin
+  {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);
+    if result.family <> 0 then begin
+      id := -1;
+      exit;
+    end;
+  end;
 
-    for counter := 1 to dnsserverlist.count-1 do begin
-      if taddrint(dnsserverlist.objects[counter]) < taddrint(dnsserverlist.objects[id]) then id := counter;
+  if not assigned(dnsserverlag) then populatednsserverlist;
+  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
+      if taddrint(dnsserverlag[counter]) < taddrint(dnsserverlag[id]) then id := counter;
     end;
   end;
-  result := dnsserverlist[id]
+  result := biniplist_get(dnsserverlist,id);
+end;
+
+function getcurrentsystemnameserver(var id:integer):ansistring;
+begin
+  result := ipbintostr(getcurrentsystemnameserverbin(id));
 end;
 
 procedure reportlag(id:integer;lag:integer); //lag should be in microseconds and should be -1 to report a timeout
@@ -739,105 +670,30 @@ var
   counter : integer;
   temp : integer;
 begin
-  if (id < 0) or (id >= dnsserverlist.count) then exit;
+  if (id < 0) or (id >= dnsserverlag.count) then exit;
   if lag = -1 then lag := timeoutlag;
-  for counter := 0 to dnsserverlist.count-1 do begin
-    temp := taddrint(dnsserverlist.objects[counter]) *15;
+  for counter := 0 to dnsserverlag.count-1 do begin
+    temp := taddrint(dnsserverlag[counter]) *15;
     if counter=id then temp := temp + lag;
-    dnsserverlist.objects[counter] := tobject(temp div 16);
+    dnsserverlag[counter] := tobject(temp div 16);
   end;
 
 end;
 
 
-
 {$ifdef ipv6}
 
-{$ifdef linux}
-function getv6localips:tbiniplist;
-var
-  t:textfile;
-  s,s2:ansistring;
-  ip:tbinip;
-  a:integer;
-begin
-  result := biniplist_new;
-
-  assignfile(t,'/proc/net/if_inet6');
-  {$i-}reset(t);{$i+}
-  if ioresult <> 0 then exit; {none found, return empty list}
-
-  while not eof(t) do begin
-    readln(t,s);
-    s2 := '';
-    for a := 0 to 7 do begin
-      if (s2 <> '') then s2 := s2 + ':';
-      s2 := s2 + copy(s,(a shl 2)+1,4);
-    end;
-    ipstrtobin(s2,ip);
-    if ip.family <> 0 then biniplist_add(result,ip);
-  end;
-  closefile(t);
-end;
-
-{$else}
-
-{the following code's purpose is to determine what IP windows would come from, to reach an IP
-it can be abused to find if there's any global v6 IPs, getaddrinfo seems unreliable (not working on XP atleast)
-}
-const
-  SIO_ROUTING_INTERFACE_QUERY = $c8000014;
-  function WSAIoctl(s: TSocket; code:integer; const Buf; len: Integer; var output; outlen:integer; var outreturned: Integer; overlapped:pointer; completion: pointer): Integer; stdcall; external 'ws2_32.dll' name 'WSAIoctl';
-
-function getlocalipforip(const ip:tbinip):tbinip;
-var
-  handle:integer;
-  a,b:integer;
-  inaddrv,inaddrv2:tinetsockaddrv;
-  srcx:winsock.tsockaddr absolute inaddrv2;
-begin
-  makeinaddrv(ip,'0',inaddrv);
-  handle := Socket(inaddrv.inaddr.family,SOCK_DGRAM,IPPROTO_UDP);
-  if WSAIoctl(handle, SIO_ROUTING_INTERFACE_QUERY, inaddrv, sizeof(inaddrv), inaddrv2, sizeof(inaddrv2), a, nil, nil) <> 0
-  then raise exception.create('getlocalipforip failed with error: '+inttostr(wsagetlasterror));
-  result := inaddrvtobinip(inaddrv2);
-  closesocket(handle);
-end;
-
-function getv6localips:tbiniplist;
-begin
-  result := biniplist_new;
-  {this IP is chosen because it's the first normal global v6 IP that has no special purpose}
-  biniplist_add(result,getlocalipforip(ipstrtobinf('2001:200::')));
-end;
-{$endif}
-
 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}