Überlauf bei int64

[jaenicke]

Oder schlicht so:

Delphi-Quellcode:

uses
  Winapi.Winsock;

function IPToCardinal(const AIP: string): Cardinal;
begin
  Result := ntohl(inet_addr(PAnsiChar(AnsiString(AIP))));
end;

Alternativ, wenn es manuell passieren soll (ohne Fehlerbehandlung):

Delphi-Quellcode:

function IPToCardinal2(const AIP: string): Cardinal;
var
  Value, Octet: Cardinal;
  i, ShlValue: Integer;
begin
  Result := 0;
  Value := 0;
  ShlValue := 24;
  for i := 1 to Length(AIP) do
  begin
    if AIP[i] = '.' then
    begin
      Result := Result or (Value shl ShlValue);
      Value := 0;
      ShlValue := ShlValue - 8;
    end
    else
      Value := Value * 10 + (Ord(AIP[i]) - Ord('0'));
  end;
  Result := Result or Value;
end;

[Kas Ob.]

Hi,

Away from the answers above, your code doesn't validate the input for valid IP address and will always result in something, so i suggest to replace the converting part and building with something like this:

Delphi-Quellcode:

    {if TryStrToInt(v1, i1) then
    if TryStrToInt(v2, i2) then
      if TryStrToInt(v3, i3) then
        if TryStrToInt(v4, i4) then
        begin
          Result := i1 * 16777216 + // Corrected from 16777246
                   i2 * 65536 +
                   i3 * 256 +
                   i4;
        end ;  }
  i1 := StrToIntDef(v1, -1);
  i2 := StrToIntDef(v2, -1);
  i3 := StrToIntDef(v3, -1);
  i4 := StrToIntDef(v4, -1);

  if Cardinal(i1 or i2 or i3 or i4) > 255 then      //  bit manipulation if any has higher bit than 8 then invalid (this includes negatives)
    begin
      raise Exception.Create('Invalid IP address');
    end;

  Result := i1 shl 24 or i2 shl 16 or i3 shl 8 or i4;
  // or
  //Result := i1 shl 24 + i2 shl 16 + i3 shl 8 + i4;

[Rollo62]

TLDR;
Es sollten doch die Octets auch auf Überlauf überprüft werden, also so ungefähr:

Edit: Ok, DeddyH hatte die Prüfung auch schon vorgeschlagen ...

Code:

function IP2Int(const value: string): Int64;
var
  parts: TArray<string>;
  i, octet: Integer;
begin
  Result := 0;
  parts := value.Split(['.']);
  if Length(parts) <> 4 then
    Exit;
  for i := 0 to 3 do
  begin
    if not TryStrToInt(parts[i], octet) then
      Exit;
    if (octet < 0) or (octet > 255) then   //<== Check this
      Exit;
    Result := (Result shl 8) + octet;
  end;
end;