X-Git-Url: http://www.lcore.org/git/lcore.git/blobdiff_plain/85ef2ce64f0cc31a063fccea69fdcc7281d51548..90c7057fc0ae5d85a6443e7633642ef43553ab28:/dnscore.pas diff --git a/dnscore.pas b/dnscore.pas old mode 100755 new mode 100644 index 4cb52e2..6864398 --- a/dnscore.pas +++ b/dnscore.pas @@ -28,7 +28,7 @@ when a packet is received the application should put the packet in recvbuf/recvbuflen , set state.parsepacket and call state_process again - once the app gets action_done it can determine sucess or failure in the + once the app gets action_done it can determine success or failure in the following ways. on failure state.resultstr will be an empty string and state.resultbin will @@ -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). @@ -85,7 +85,7 @@ var useaf:integer = useaf_default; { (temporarily) use a different nameserver, regardless of the dnsserverlist } -var overridednsserver:string; +var overridednsserver:ansistring; const maxnamelength=127; @@ -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) @@ -125,16 +128,16 @@ type tdnsstate=record id:word; recursioncount:integer; - queryname:string; + queryname:ansistring; requesttype:word; parsepacket:boolean; - resultstr:string; + resultstr:ansistring; resultbin:tbinip; resultlist:tbiniplist; resultaction:integer; numrr1:array[0..3] of integer; numrr2:integer; - rrdata:string; + rrdata:ansistring; sendpacketlen:integer; sendpacket:tdnspacket; recvpacketlen:integer; @@ -165,20 +168,20 @@ type //function buildrequest(const name:string;var packet:tdnspacket;requesttype:word):integer; //returns the DNS name used to reverse look up an IP, such as 4.3.2.1.in-addr.arpa for 1.2.3.4 -function makereversename(const binip:tbinip):string; +function makereversename(const binip:tbinip):ansistring; -procedure setstate_request_init(const name:string;var state:tdnsstate); +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 //ipv6 results. Any other value will give only ipv4 results -procedure setstate_forward(const name:string;var state:tdnsstate;family:integer); +procedure setstate_forward(const name:ansistring;var state:tdnsstate;family:integer); procedure setstate_reverse(const binip:tbinip;var state:tdnsstate); procedure setstate_failure(var state:tdnsstate); //procedure setstate_return(const rrp:trrpointer;len:integer;var state:tdnsstate); //for custom raw lookups such as TXT, as desired by the user -procedure setstate_custom(const name:string; requesttype:integer; var state:tdnsstate); +procedure setstate_custom(const name:ansistring; requesttype:integer; var state:tdnsstate); procedure state_process(var state:tdnsstate); @@ -188,14 +191,16 @@ procedure populatednsserverlist; procedure cleardnsservercache; var - dnsserverlist : tstringlist; + dnsserverlist : tbiniplist; + dnsserverlag:tlist; // currentdnsserverno : integer; //getcurrentsystemnameserver returns the nameserver the app should use and sets //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) :string; +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 {$ifdef ipv6} -function getv6localips:tbiniplist; procedure initpreferredmode; var @@ -213,22 +217,19 @@ var {$endif} var - failurereason:string; + failurereason:ansistring; -function getquerytype(s:string):integer; +function getquerytype(s:ansistring):integer; implementation uses - {$ifdef win32} - windows, - {$endif} - + lcorelocalips, sysutils; -function getquerytype(s:string):integer; +function getquerytype(s:ansistring):integer; begin s := uppercase(s); result := 0; @@ -244,10 +245,10 @@ begin if (s = 'SPF') then result := querytype_spf; end; -function buildrequest(const name:string;var packet:tdnspacket;requesttype:word):integer; +function buildrequest(const name:ansistring;var packet:tdnspacket;requesttype:word):integer; var a,b:integer; - s:string; + s:ansistring; arr:array[0..sizeof(packet)-1] of byte absolute packet; begin { writeln('buildrequest: name: ',name);} @@ -289,9 +290,9 @@ begin arr[result-4] := requesttype shr 8; end; -function makereversename(const binip:tbinip):string; +function makereversename(const binip:tbinip):ansistring; var - name:string; + name:ansistring; a,b:integer; begin name := ''; @@ -323,10 +324,10 @@ doesnt read beyond len. empty result + non null failurereason: failure empty result + null failurereason: internal use } -function decodename(const packet:tdnspacket;len,start,recursion:integer;var numread:integer):string; +function decodename(const packet:tdnspacket;len,start,recursion:integer;var numread:integer):ansistring; var arr:array[0..sizeof(packet)-1] of byte absolute packet; - s:string; + s:ansistring; a,b:integer; begin numread := 0; @@ -367,7 +368,7 @@ begin failurereason := 'decoding name: got out of range2'; exit; end; - result := result + char(arr[a]); + result := result + ansichar(arr[a]); end; inc(numread,b+1); @@ -385,7 +386,7 @@ end; {==============================================================================} -function getrawfromrr(const rrp:trrpointer;len:integer):string; +function getrawfromrr(const rrp:trrpointer;len:integer):ansistring; begin setlength(result,htons(trr(rrp.p^).datalen)); uniquestring(result); @@ -441,7 +442,7 @@ begin end; end; -procedure setstate_request_init(const name:string;var state:tdnsstate); +procedure setstate_request_init(const name:ansistring;var state:tdnsstate); begin {destroy things properly} state.resultstr := ''; @@ -452,7 +453,7 @@ begin state.parsepacket := false; end; -procedure setstate_forward(const name:string;var state:tdnsstate;family:integer); +procedure setstate_forward(const name:ansistring;var state:tdnsstate;family:integer); begin setstate_request_init(name,state); state.forwardfamily := family; @@ -468,7 +469,7 @@ begin state.requesttype := querytype_ptr; end; -procedure setstate_custom(const name:string; requesttype:integer; var state:tdnsstate); +procedure setstate_custom(const name:ansistring; requesttype:integer; var state:tdnsstate); begin setstate_request_init(name,state); state.requesttype := requesttype; @@ -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; @@ -606,132 +610,59 @@ recursed: failure: setstate_failure(state); end; -{$ifdef win32} - const - MAX_HOSTNAME_LEN = 132; - MAX_DOMAIN_NAME_LEN = 132; - MAX_SCOPE_ID_LEN = 260 ; - MAX_ADAPTER_NAME_LENGTH = 260; - MAX_ADAPTER_ADDRESS_LENGTH = 8; - MAX_ADAPTER_DESCRIPTION_LENGTH = 132; - ERROR_BUFFER_OVERFLOW = 111; - MIB_IF_TYPE_ETHERNET = 6; - MIB_IF_TYPE_TOKENRING = 9; - MIB_IF_TYPE_FDDI = 15; - MIB_IF_TYPE_PPP = 23; - MIB_IF_TYPE_LOOPBACK = 24; - MIB_IF_TYPE_SLIP = 28; - - - type - tip_addr_string=packed record - Next :pointer; - IpAddress : array[0..15] of char; - ipmask : array[0..15] of char; - context : dword; - end; - pip_addr_string=^tip_addr_string; - tFIXED_INFO=packed record - HostName : array[0..MAX_HOSTNAME_LEN-1] of char; - DomainName : array[0..MAX_DOMAIN_NAME_LEN-1] of char; - currentdnsserver : pip_addr_string; - dnsserverlist : tip_addr_string; - nodetype : longint; - ScopeId : array[0..MAX_SCOPE_ID_LEN + 4] of char; - enablerouting : longbool; - enableproxy : longbool; - enabledns : longbool; - end; - pFIXED_INFO=^tFIXED_INFO; - var - iphlpapi : thandle; - getnetworkparams : function(pFixedInfo : PFIXED_INFO;OutBufLen : plongint) : longint;stdcall; -{$endif} + procedure populatednsserverlist; var - {$ifdef win32} - fixed_info : pfixed_info; - fixed_info_len : longint; - currentdnsserver : pip_addr_string; - {$else} - t:textfile; - s:string; - 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):string; +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 whereever 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 availible'); + 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 @@ -739,54 +670,19 @@ 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:string; - 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; - -{$else} -function getv6localips:tbiniplist; -begin - result := biniplist_new; -end; -{$endif} - procedure initpreferredmode; var l:tbiniplist;