From f3321a0eafbeda0e8ebfb420974d391d7904ed44 Mon Sep 17 00:00:00 2001
From: beware <beware@bircd.org>
Date: Mon, 12 Dec 2011 03:01:06 +0000
Subject: [PATCH] removed use of global vars in dnssync, should be reentrant
 safe

git-svn-id: file:///svnroot/lcore/trunk@111 b1de8a11-f9be-4011-bde0-cc7ace90066a
---
 dnssync.pas | 139 ++++++++++++++++++++++++++++------------------------
 1 file changed, 74 insertions(+), 65 deletions(-)

diff --git a/dnssync.pas b/dnssync.pas
index 9a0c2c1..d037a68 100644
--- a/dnssync.pas
+++ b/dnssync.pas
@@ -58,10 +58,6 @@ const
 
   toport='53';
 
-var
-  id:integer;
-
-  sendquerytime:array[0..numsock-1] of integer;
 implementation
 
 {$ifdef win32}
@@ -77,11 +73,7 @@ implementation
 
 
 {$ifdef syncdnscore}
-var
-  numsockused:integer;
-  fd:array[0..numsock-1] of integer;
-  state:array[0..numsock-1] of tdnsstate;
-  toaddr:array[0..numsock-1] of tbinip;
+
 
 {$ifdef win32}
   const
@@ -107,45 +99,43 @@ begin
 end;
 
 
-function sendquery(socknum:integer;const packet:tdnspacket;len:integer):boolean;
+type tdnsstatearr=array[0..numsock-1] of tdnsstate;
+
+procedure resolveloop(timeout:integer;var state:tdnsstatearr;numsockused:integer);
 var
-  ip       : tbinip;
-  port       : ansistring;
-  inaddr     : TInetSockAddrV;
-begin
-{  writeln('sendquery ',decodename(state.packet,state.packetlen,12,0,a),' ',state.requesttype);}
-  result := false;
-  if len = 0 then exit; {no packet}
+  selectresult   : integer;
+  fds            : fdset;
 
-  ip := getcurrentsystemnameserverbin(id);
+  endtime      : longint;
+  starttime    : longint;
+  wrapmode     : boolean;
+  currenttime  : integer;
 
-  {$ifdef ipv6}{$ifdef win32}
-  if toaddr[socknum].family = AF_INET6 then if (useaf = 0) then useaf := useaf_preferv6;
-  {$endif}{$endif}
+  lag            : ttimeval;
+  selecttimeout	 : ttimeval;
+  socknum:integer;
+  needprocessing:array[0..numsock-1] of boolean;
+  finished:array[0..numsock-1] of boolean;
+  a,b:integer;
 
-  port := toport;
-  toaddr[socknum] := ip;
-  makeinaddrv(toaddr[socknum],port,inaddr);
+  Src    : TInetSockAddrV;
+  Srcx   : {$ifdef win32}sockaddr_in{$else}TInetSockAddrV{$endif} absolute Src;
+  SrcLen : Integer;
+  fromip:tbinip;
+  fromport:ansistring;
+
+  fd:array[0..numsock-1] of integer;
+  toaddr:array[0..numsock-1] of tbinip;
+  id:integer;
+  sendquerytime:array[0..numsock-1] of integer;
 
-  sendto(fd[socknum],packet,len,0,inaddr,inaddrsize(inaddr));
-  sendquerytime[socknum] := getts;
-  result := true;
-end;
 
 procedure setupsocket;
 var
   inAddrtemp : TInetSockAddrV;
-  a:integer;
   biniptemp:tbinip;
-
+  a:integer;
 begin
-  //init both sockets smultaneously, always, so they get succesive fd's
-
-  {recreate sockets every time, reusing them will fail (hang) if the nameserver is changed
-  also changing the nameserver can't possibly work}
-  {if fd[0] > 0 then exit;}
-  for a := 0 to numsock-1 do if (fd[a] > 0) then closesocket(fd[a]);
-
   biniptemp := getcurrentsystemnameserverbin(id);
   //must get the DNS server here so we know to init v4 or v6
 
@@ -167,42 +157,53 @@ begin
   end;
 end;
 
-procedure resolveloop(timeout:integer);
+procedure cleanupsockets;
 var
-  selectresult   : integer;
-  fds            : fdset;
+  a:integer;
+begin
+  for a := 0 to numsockused-1 do closesocket(fd[a]);
+end;
 
-  endtime      : longint;
-  starttime    : longint;
-  wrapmode     : boolean;
-  currenttime  : integer;
+function sendquery(socknum:integer;const packet:tdnspacket;len:integer):boolean;
+var
+  ip       : tbinip;
+  port       : ansistring;
+  inaddr     : TInetSockAddrV;
+begin
+{  writeln('sendquery ',decodename(state.packet,state.packetlen,12,0,a),' ',state.requesttype);}
+  result := false;
+  if len = 0 then exit; {no packet}
 
-  lag            : ttimeval;
-  selecttimeout	 : ttimeval;
-  socknum:integer;
-  needprocessing:array[0..numsock-1] of boolean;
-  finished:array[0..numsock-1] of boolean;
-  a,b:integer;
+  ip := getcurrentsystemnameserverbin(id);
 
-  Src    : TInetSockAddrV;
-  Srcx   : {$ifdef win32}sockaddr_in{$else}TInetSockAddrV{$endif} absolute Src;
-  SrcLen : Integer;
-  fromip:tbinip;
-  fromport:ansistring;
+  {$ifdef ipv6}{$ifdef win32}
+  if toaddr[socknum].family = AF_INET6 then if (useaf = 0) then useaf := useaf_preferv6;
+  {$endif}{$endif}
+
+  port := toport;
+  toaddr[socknum] := ip;
+  makeinaddrv(toaddr[socknum],port,inaddr);
+
+  sendto(fd[socknum],packet,len,0,inaddr,inaddrsize(inaddr));
+  sendquerytime[socknum] := getts;
+  result := true;
+end;
 
 begin
   if timeout < mintimeout then timeout := defaulttimeout;
 
-    starttime := getts;
-    endtime := starttime + timeout;
-    if (endtime and tswrap)=0 then begin
-      wrapmode := false;
-    end else begin
-      wrapmode := true;
-    end;
-    endtime := endtime and tsmask;
+  starttime := getts;
+  endtime := starttime + timeout;
+  if (endtime and tswrap)=0 then begin
+    wrapmode := false;
+  end else begin
+    wrapmode := true;
+  end;
+  endtime := endtime and tsmask;
 
   setupsocket;
+
+
   for socknum := 0 to numsockused-1 do begin
     needprocessing[socknum] := true;
     finished[socknum] := false;
@@ -223,6 +224,7 @@ begin
             if finished[a] then inc(b);
           end;
           if (b = numsockused) then begin
+            cleanupsockets;
             exit;
           end;
           //onrequestdone(self,0);
@@ -282,6 +284,7 @@ begin
 
       reportlag(id,-1);
       if (currenttime >= endtime) and ((not wrapmode) or (currenttime < starttime)) then begin
+        cleanupsockets;
         exit;
       end else begin
         //resend
@@ -302,6 +305,10 @@ var
   a:integer;
   biniptemp:tbinip;
   l:tbiniplist;
+
+  numsockused:integer;
+  state:tdnsstatearr;
+
 begin
   ipstrtobin(name,biniptemp);
   if biniptemp.family <> 0 then begin
@@ -350,7 +357,7 @@ begin
     end;
     {$endif}
 
-    resolveloop(timeout);
+    resolveloop(timeout,state,numsockused);
 
     if (numsockused = 1) then begin
       biniplist_addlist(result,state[0].resultlist);
@@ -378,6 +385,8 @@ end;
 function reverselookup(ip:tbinip;timeout:integer):ansistring;
 var
   dummy : integer;
+  numsockused:integer;
+  state:tdnsstatearr;
 begin
   {$ifdef win32}
     if usewindns then begin
@@ -388,7 +397,7 @@ begin
   {$ifdef syncdnscore}
   setstate_reverse(ip,state[0]);
   numsockused := 1;
-  resolveloop(timeout);
+  resolveloop(timeout,state,numsockused);
   result := state[0].resultstr;
   {$endif}
 end;
-- 
2.30.2