idnntpserver.pas

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      if LAccept then
      begin
        ASender.Reply.SetReply(335,'News to me!  <CRLF.CRLF> to end.'); {do not localize}
        ASender.SendReply;
        LErrorText := '';
        OnPost(TIdNNTPContext(ASender.Context), LAccept, LErrorText);
        ASender.Reply.SetReply(iif(LAccept, 235, 436), LErrorText);
      end
      else
      begin
        ASender.Reply.NumericCode := 435;
      end;
    end;
  end else ASender.Reply.NumericCode := 500;
end;

procedure TIdNNTPServer.CommandLast(ASender: TIdCommand);
var
  LMsgNo: Integer;
  LThread: TIdNNTPContext;
  LMsgID : String;
begin
  if Assigned(OnPrevArticle) then begin
    if SecLayerOk(ASender) then
    begin
      Exit;
    end;
    if not AuthOk(ASender) then begin
      LThread := TIdNNTPContext(ASender.Context);
      //we do this in a round about way in case there is no previous article at all
      LMsgNo := LThread.CurrentArticle;
      LMsgID := RawNavigate(LThread,OnPrevArticle);
      if LMsgID<>'' then begin
        ASender.Reply.SetReply(223, IntToStr(LMsgNo) + ' ' + LMsgID +
          ' article retrieved - request text separately');  {do not localize}
      end else begin
        ASender.Reply.NumericCode := 430;
      end;
    end;
  end else ASender.Reply.NumericCode := 500;
end;

(*
3.6.  The LIST command

3.6.1.  LIST

   LIST

   Returns a list of valid newsgroups and associated information.  Each
   newsgroup is sent as a line of text in the following format:

      group last first p

   where <group> is the name of the newsgroup, <last> is the number of
   the last known article currently in that newsgroup, <first> is the
   number of the first article currently in the newsgroup, and <p> is
   either 'y' or 'n' indicating whether posting to this newsgroup is
   allowed ('y') or prohibited ('n').

   The <first> and <last> fields will always be numeric.  They may have
   leading zeros.  If the <last> field evaluates to less than the
   <first> field, there are no articles currently on file in the
   newsgroup.

   Note that posting may still be prohibited to a client even though the
   LIST command indicates that posting is permitted to a particular
   newsgroup. See the POST command for an explanation of client
   prohibitions.  The posting flag exists for each newsgroup because
   some newsgroups are moderated or are digests, and therefore cannot be
   posted to; that is, articles posted to them must be mailed to a
   moderator who will post them for the submitter.  This is independent
   of the posting permission granted to a client by the NNTP server.

   Please note that an empty list (i.e., the text body returned by this
   command consists only of the terminating period) is a possible valid
   response, and indicates that there are currently no valid newsgroups.

3.6.2.  Responses

   215 list of newsgroups follows
*)
procedure TIdNNTPServer.CommandList(ASender: TIdCommand);
begin
  if SecLayerOk(ASender) then
  begin
    Exit;
  end;
  if not AuthOk(ASender) then begin
    ASender.SendReply;
    DoListGroups(TIdNNTPContext(ASender.Context));
    ASender.Context.Connection.IOHandler.WriteLn('.');
  end;
end;

procedure TIdNNTPServer.CommandListGroup(ASender: TIdCommand);
var LThrd : TIdNNTPContext;
    LGroup : String;
    LFirstIdx : Integer;
    LCanJoin : Boolean;
begin
  if Assigned(FOnCheckListGroup) and Assigned(FOnListGroup) then begin
    if SecLayerOk(ASender) then
    begin
      Exit;
    end;
    if AuthOk(ASender)=False then begin
      ASender.Reply.NumericCode := 502;
    end;
    LThrd := TIdNNTPContext ( ASender.Context );
    LGroup := Trim(ASender.UnparsedParams);
    if Length(LGroup)>0 then
    begin
      LGroup := LThrd.CurrentGroup;
    end;
    FOnCheckListGroup(LThrd,LGroup,LCanJoin,LFirstIdx);
    if LCanJoin then
    begin
      LThrd.FCurrentGroup := LGroup;
      LThrd.FCurrentArticle := LFirstIdx;
      ASender.SendReply;
      FOnListGroup(LThrd);
      ASender.Context.Connection.IOHandler.WriteLn('.');
    end
    else
    begin
      ASender.Reply.SetReply(412,'Not currently in newsgroup'); {do not localize}
    end;
  end else ASender.Reply.NumericCode := 500;
end;

procedure TIdNNTPServer.CommandModeReader(ASender: TIdCommand);
(*
2.3 MODE READER

   MODE READER is used by the client to indicate to the server that it
   is a news reading client.  Some implementations make use of this
   information to reconfigure themselves for better performance in
   responding to news reader commands.  This command can be contrasted
   with the SLAVE command in RFC 977, which was not widely implemented.
   MODE READER was first available in INN.

2.3.1 Responses

      200 Hello, you can post
      201 Hello, you can't post
*)
begin
    if SecLayerOk(ASender) then
    begin
      Exit;
    end;
  TIdNNTPContext(ASender.Context).FModeReader := True;
  ASender.Reply.NumericCode := 200;
end;

(*
3.7.  The NEWGROUPS command

3.7.1.  NEWGROUPS

   NEWGROUPS date time [GMT] [<distributions>]

   A list of newsgroups created since <date and time> will be listed in
   the same format as the LIST command.

   The date is sent as 6 digits in the format YYMMDD, where YY is the
   last two digits of the year, MM is the two digits of the month (with
   leading zero, if appropriate), and DD is the day of the month (with
   leading zero, if appropriate).  The closest century is assumed as
   part of the year (i.e., 86 specifies 1986, 30 specifies 2030, 99 is
   1999, 00 is 2000).

   Time must also be specified.  It must be as 6 digits HHMMSS with HH
   being hours on the 24-hour clock, MM minutes 00-59, and SS seconds
   00-59.  The time is assumed to be in the server's timezone unless the
   token "GMT" appears, in which case both time and date are evaluated
   at the 0 meridian.

   The optional parameter "distributions" is a list of distribution
   groups, enclosed in angle brackets.  If specified, the distribution
   portion of a new newsgroup (e.g, 'net' in 'net.wombat') will be
   examined for a match with the distribution categories listed, and
   only those new newsgroups which match will be listed.  If more than
   one distribution group is to be listed, they must be separated by
   commas within the angle brackets.

   Please note that an empty list (i.e., the text body returned by this
   command consists only of the terminating period) is a possible valid
   response, and indicates that there are currently no new newsgroups.

3.7.2.  Responses

   231 list of new newsgroups follows
*)
procedure TIdNNTPServer.CommandNewGroups(ASender: TIdCommand);
var LDate : TDateTime;
    LDist : String;
begin
    if SecLayerOk(ASender) then
    begin
      Exit;
    end;
  if AuthOk(ASender) then begin
    Exit;
  end;
  if (ASender.Params.Count > 1) and (Assigned(FOnListNewGroups)) then
  begin
    LDist := '';
    LDate := NNTPDateTimeToDateTime( ASender.Params[0] );
    LDate := LDate + NNTPTimeToTime( ASender.Params[1] );
    if ASender.Params.Count > 2 then
    begin
      if (UpperCase(ASender.Params[2]) = 'GMT') then {Do not translate}
      begin
        LDate := LDate + OffSetFromUTC;
        if (ASender.Params.Count > 3) then
        begin
          LDist := ASender.Params[3];
        end;
      end
      else
      begin
        LDist := ASender.Params[2];
      end;
    end;
    ASender.SendReply;
    FOnListNewGroups(TIdNNTPContext(ASender.Context), LDate, LDist);
    ASender.Context.Connection.IOHandler.WriteLn('.');
  end else ASender.Reply.NumericCode := 500;
end;

procedure TIdNNTPServer.CommandNewNews(ASender: TIdCommand);
var LDate : TDateTime;
    LDist : String;
begin
    if SecLayerOk(ASender) then
    begin
      Exit;
    end;
  if AuthOk(ASender) then begin
    Exit;
  end;
  if (ASender.Params.Count > 2) and (Assigned(FOnNewNews)) then
  begin
    //0 - newsgroup
    //1 - date
    //2 - time
    //3 - GMT or distributions
    //4 - distributions if 3 was GMT
    LDist := '';
    LDate := NNTPDateTimeToDateTime( ASender.Params[1] );
    LDate := LDate + NNTPTimeToTime( ASender.Params[2] );
    if (ASender.Params.Count > 3) then
    begin
      if (UpperCase(ASender.Params[3]) = 'GMT') then {Do not translate}
      begin
        LDate := LDate + OffSetFromUTC;
        if (ASender.Params.Count > 4) then
        begin
          LDist := ASender.Params[4];
        end;
      end
      else
      begin
        LDist := ASender.Params[3];
      end;
    end;
    ASender.SendReply;
    FOnNewNews( TIdNNTPContext(ASender.Context), ASender.Params[0], LDate, LDist );
    ASender.Context.Connection.IOHandler.WriteLn('.');
  end else ASender.Reply.NumericCode := 500;
end;

procedure TIdNNTPServer.CommandNext(ASender: TIdCommand);
var
  LMsgNo: Integer;
  LThread: TIdNNTPContext;
  LMsgID : String;
begin
  if Assigned(OnPrevArticle) then begin
      if SecLayerOk(ASender) then
    begin
      Exit;
    end;
    if AuthOk(ASender) then begin
      Exit;
    end;
    LThread := TIdNNTPContext(ASender.Context);
    //we do this in a round about way in case there is no previous article at all
    LMsgNo := LThread.CurrentArticle;
    LMsgID := RawNavigate(LThread,OnPrevArticle);
    if LMsgID<>'' then begin
      ASender.Reply.SetReply(223, IntToStr(LMsgNo) + ' ' + LMsgID +
        ' article retrieved - request text separately'); {do not localize}
    end else begin
      ASender.Reply.NumericCode := 430;
    end;
  end;
end;

(*
3.10.  The POST command

3.10.1.  POST

   POST

   If posting is allowed, response code 340 is returned to indicate that
   the article to be posted should be sent. Response code 440 indicates
   that posting is prohibited for some installation-dependent reason.

   If posting is permitted, the article should be presented in the
   format specified by RFC850, and should include all required header
   lines. After the article's header and body have been completely sent
   by the client to the server, a further response code will be returned
   to indicate success or failure of the posting attempt.

   The text forming the header and body of the message to be posted
   should be sent by the client using the conventions for text received
   from the news server:  A single period (".") on a line indicates the
   end of the text, with lines starting with a period in the original
   text having that period doubled during transmission.

   No attempt shall be made by the server to filter characters, fold or
   limit lines, or otherwise process incoming text.  It is our intent
   that the server just pass the incoming message to be posted to the
   server installation's news posting software, which is separate from
   this specification.  See RFC850 for more details.

   Since most installations will want the client news program to allow
   the user to prepare his message using some sort of text editor, and
   transmit it to the server for posting only after it is composed, the
   client program should take note of the herald message that greeted it
   when the connection was first established. This message indicates
   whether postings from that client are permitted or not, and can be
   used to caution the user that his access is read-only if that is the
   case. This will prevent the user from wasting a good deal of time
   composing a message only to find posting of the message was denied.
   The method and determination of which clients and hosts may post is
   installation dependent and is not covered by this specification.

3.10.2.  Responses

   240 article posted ok
   340 send article to be posted. End with <CR-LF>.<CR-LF>
   440 posting not allowed
   441 posting failed

   (for reference, one of the following codes will be sent upon initial
   connection; the client program should determine whether posting is
   generally permitted from these:) 200 server ready - posting allowed
   201 server ready - no posting allowed
*)
procedure TIdNNTPServer.CommandPost(ASender: TIdCommand);
var
  LCanPost: Boolean;
  LErrorText: string;
  LPostOk: Boolean;
  LReply: TIdReplyRFC;
begin
  if SecLayerOk(ASender) then begin
    Exit;
  end;
  if AuthOk(ASender) then begin
    Exit;
  end;
  LCanPost := Assigned(OnPost);
  LReply := TIdReplyRFC.Create(nil);
  try
    LReply.NumericCode := iif(LCanPost, 340, 440);
    ReplyTexts.UpdateText(LReply);
    ASender.Context.Connection.IOHandler.Write(LReply.FormattedReply);
  finally
    FreeAndNil(LReply);