Title: ip packet structure
Question: ip packet structure
Mahir DEMR (Nov 19 2001 1:18PM)
hi;
i want to get the packet in the network.and split that packet get the packet Destination ip, source ip ..
this program my project not for hacker or cracker.i am not hacker.i am university student.please help me.
I also would like to know this..., if you are not willing to post this information on your website, i was hoping that you em@il the source code..., this would be much apprecaited
Answer:
if i knew the answer..., i would gladly post it.
But..., get this up ya!.
function TMain.checkips(address: string): string;
var Num, X: Integer;
Cpy1: String;
begin
if chk1.Checked = false then
begin
Cpy1 := address;
X := StrLen(PChar(Cpy1));
if X = 7 then
begin
Cpy := '';
for Num := 0 to X do
begin
if Copy(Cpy1, 1, 1) = '1' then
begin
Cpy := Cpy + '1';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '2' then
begin
Cpy := Cpy + '2';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '3' then
begin
Cpy := Cpy + '3';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '4' then
begin
Cpy := Cpy + '4';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '5' then
begin
Cpy := Cpy + '5';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '6' then
begin
Cpy := Cpy + '6';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '7' then
begin
Cpy := Cpy + '7';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '8' then
begin
Cpy := Cpy + '8';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '9' then
begin
Cpy := Cpy + '9';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '0' then
begin
Cpy := Cpy + '0';
Delete(Cpy1, 1, 1);
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
else if Copy(Cpy1, 1, 1) = '.' then
begin
Cpy := Cpy + '.';
Delete(Cpy1, 1, 1);
if IPCnt = 0 then
begin
Result := '#005';
Break;
end
else
begin
IPCnt := Succ(IPCnt);
if StrLen(PChar(Cpy1)) begin
Result := Cpy;
Break;
end
end
end
else
begin
Result := '#001';
Break;
end
end
end
else
begin
Result := '#002';
end
end
else
begin
Result := address;
end
end;
function TMain.checkipex(address: string): string;
var X, Y, Z, Num: Integer;
Cpy1, Cpy2, Chk: String;
begin
Cpy1 := Trim(address);
Chk := checkips(Cpy1);
IPCnt := 0;
if Chk = '#001' then
begin
Result := '#001';
end
else if Chk = '#002' then
begin
Result := '#002';
end
else if Chk = '#005' then
begin
Result := '#005';
end
else
begin
X := StrLen(PChar(Chk));
for Num := 0 to X do
begin
X := StrLen(PChar(Chk));
if X = 1 then
begin
Y := Pos('.', Chk);
if Y = 3 then
begin
Cpy2 := Copy(Chk, 1, Y -1);
Delete(Chk, 1, Y);
Z := StrToInt(Cpy2);
if Z = 256 then
begin
Result := '#003';
Break;
end
else
begin
IPCnt := Succ(IPCnt);
end
end
else if Y = 0 then
begin
Cpy2 := Copy(Chk, 1, X);
Delete(Chk, 1, X);
Z := StrToInt(Cpy2);
if Z = 256 then
begin
Result := '#003';
Break;
end
else
begin
IPCnt := Succ(IPCnt);
end
end
else
begin
Cpy2 := Copy(Chk, 1, Y -1);
Delete(Chk, 1, Y);
Z := StrToInt(Cpy2);
if Z = 256 then
begin
Result := '#003';
Break;
end
else if Z = 0 then
begin
if IPCnt = 0 then
begin
Result := '#004';
Break;
end
end
else
begin
IPCnt := Succ(IPCnt);
end
end
end
else
begin
Result := address;
end
end
end
end;
checkip results (please do not directly call
this procedure, use checkipex instead) :
#001 = Invalid character
#002 = Invalid ip
checkipex results :
#001 = Invalid character
#002 = Invalid ip
#003 = Ip address has a value greater than 255
#004 = Ip address begins with 0
#005 = Ip address begins with .
Umm..., sorry if i haven't declared all of the variables in this code (Some may be globally declared).
I don't think i can explain it any better than that..., i hope someone finds some use for it, i know i did...