C++ , Send() function sends extra bytes - c++

Question

I am having trouble with a Winsock2 wrapper classes (client-server) and after countless hours of scratching-my-head-in-confusion, I decided it would be better if I asked your opinion.
To be more specific, the problem is that every time I use my Send() function, both the client and the server (not always!) send one or two extra bytes!
For example I use SendBytes("Hello") and the Recv function returns "Hello•" with a '•' or other random characters at the end of the character array.
//main.cpp (Client)
#include "Socket.h"
int main()
{
NetworkService::Client cService = NetworkService::Client();
int res = cService.Initialize("127.0.0.1","20248");
if(res == 0){
int local = cService.SendBytes("Hello!");
printf("Bytes Sent: %ld\n", local);
cService.Shutdown();
char* temp = cService.Recv();
printf("String Recieved: %s - Size: %d",temp,strlen(temp));
printf("\nSTRLEN: %d",strlen("X5"));
}
else{
cService.Clean();
}
cService.Close();
while(!kbhit());
return 0;
}
Of course, the server sends the string "X5" and the client prints the strlens ...
//The result with "X5" as the dummy text:
String Recieved: X5? - Size: 3 //Notice the extra '?' character
STRLEN: 2
Send // Recieve Functions
int NetworkService::Client::SendBytes(char* lData){
int local = send( ConnectSocket, lData, (int)strlen(lData), 0 );
if (local == SOCKET_ERROR) {
Close();
return WSAGetLastError();
}
return local;
}
char* NetworkService::Client::Recv(){
recv(ConnectSocket, recvbuf , recvbuflen, 0);
return recvbuf;
}
Help would be appreciated ^_^.

Answer 1

Excuse me, but
int local;
(...)
return (int*)local;
What you were trying to achieve? There are many serious problems in your code.

Answer 2

This is not the way you send data over the network. There are too many errors.
IF you want to send null-terminated strings over the network:
int local = send( ConnectSocket, lData, (int)strlen(lData), 0 );
as everyone said, you don't actually send the null terminator. You would have sent it if you added 1 to the length. Moreover, with long strings, the send() function doesn't guarantee you to send the whole string at once. You have to check for that and resend the missing part.
recv(ConnectSocket, recvbuf , recvbuflen, 0);
You don't check the return value, so you can't know the length of the received string. As you don't send the null byte, the received data is not null-terminated. Also, if null terminator is the only delimiter of more data you send, you'll have to read byte-by-byte (not efficient) not to miss the null terminator to know when to finish. An alternative would be to make your own buffering scheme (so the next read would partially return the result of the previous), or change the protocol to make length of the transported data known beforehand. Also, the same remark about partial reads as with the send function applies here.
BTW returning a static/global buffer is not a sign of good code.

Answer 3

You don't really check the return value of recv.
There is a do-while but it doesn't do anything. You return from the function without proper error handling even when recv fails, but you will never know it.
Also you don't send the terminating \0 which isn't necessary bad, depends on what you're trying to do, for example you can add that after receiving.