Hello, I'm writing a small TCP client/server using Winsock and I'm stuck with errors upon calling send or recv. Am I missing something obvious?
#include <winsock2.h>
#include <windows.h>
#pragma comment(lib, "ws2_32")
#include <iostream>
#include <string>
#include <sstream>
#include <cstring>
using std::cout;
using std::endl;
using std::string;
using std::istringstream;
using std::ios;
bool stop = false;
SOCKET tcp_socket = INVALID_SOCKET;
enum program_mode { talk_mode, listen_mode };
void print_usage(void)
{
cout << " USAGE:" << endl;
cout << " Listen mode:" << endl;
cout << " tcpspeed PORT_NUMBER" << endl;
cout << endl;
cout << " Talk mode:" << endl;
cout << " tcpspeed TARGET_HOST PORT_NUMBER" << endl;
cout << endl;
cout << " ie:" << endl;
cout << " Listen mode: tcpspeed 1920" << endl;
cout << " Talk mode: tcpspeed www 342" << endl;
cout << " Talk mode: tcpspeed 10.200.67.1 950" << endl;
cout << endl;
}
bool verify_port(const string &port_string, unsigned long int &port_number)
{
for (size_t i = 0; i < port_string.length(); i++)
{
if (!isdigit(port_string[i]))
{
cout << " Invalid port: " << port_string << endl;
cout << " Ports are specified by numerals only." << endl;
return false;
}
}
istringstream iss(port_string);
iss >> port_number;
if (port_string.length() > 5 || port_number > 65535 || port_number == 0)
{
cout << " Invalid port: " << port_string << endl;
cout << " Port must be in the range of 1-65535" << endl;
return false;
}
return true;
}
bool init_winsock(void)
{
WSADATA wsa_data;
WORD ver_requested = MAKEWORD(2, 2);
if (WSAStartup(ver_requested, &wsa_data))
{
cout << "Could not initialize Winsock 2.2.";
return false;
}
if (LOBYTE(wsa_data.wVersion) != 2 || HIBYTE(wsa_data.wVersion) != 2)
{
cout << "Required version of Winsock (2.2) not available.";
return false;
}
return true;
}
BOOL console_control_handler(DWORD control_type)
{
stop = true;
closesocket(tcp_socket);
return TRUE;
}
bool init_options(const int &argc, char **argv, enum program_mode &mode, string &target_host_string, long unsigned int &port_number)
{
if (!SetConsoleCtrlHandler((PHANDLER_ROUTINE)console_control_handler, TRUE))
{
cout << " Could not add console control handler." << endl;
return false;
}
if (!init_winsock())
return false;
string port_string = "";
if (2 == argc)
{
mode = listen_mode;
port_string = argv[1];
}
else if (3 == argc)
{
mode = talk_mode;
target_host_string = argv[1];
port_string = argv[2];
}
else
{
print_usage();
return false;
}
cout.setf(ios::fixed, ios::floatfield);
cout.precision(2);
return verify_port(port_string, port_number);
}
void cleanup(void)
{
// if the program was aborted, flush cout and print a final goodbye
if (stop)
{
cout.flush();
cout << endl << " Stopping." << endl;
}
// if the socket is still open, close it
if (INVALID_SOCKET != tcp_socket)
closesocket(tcp_socket);
// shut down winsock
WSACleanup();
// remove the console control handler
SetConsoleCtrlHandler((PHANDLER_ROUTINE)console_control_handler, FALSE);
}
int main(int argc, char **argv)
{
cout << endl << "tcpspeed 1.1 - TCP speed tester" << endl << "Copyright 2018, Shawn Halayka" << endl << endl;
program_mode mode = listen_mode;
string target_host_string = "";
long unsigned int port_number = 0;
const long unsigned int tx_buf_size = 1450;
char tx_buf[1450];
const long unsigned int rx_buf_size = 8196;
char rx_buf[8196];
// initialize winsock and all of the program's options
if (!init_options(argc, argv, mode, target_host_string, port_number))
{
cleanup();
return 1;
}
if (talk_mode == mode)
{
struct sockaddr_in their_addr;
struct hostent *he = 0;
he = gethostbyname(target_host_string.c_str());
if (NULL == he)
{
cout << " Could not resolve target host." << endl;
cleanup();
return 2;
}
their_addr.sin_family = AF_INET;
their_addr.sin_port = htons((unsigned short int)port_number);
their_addr.sin_addr = *((struct in_addr *)he->h_addr);
memset(&(their_addr.sin_zero), '\0', 8);
if (INVALID_SOCKET == (tcp_socket = socket(AF_INET, SOCK_STREAM, 0)))
{
cout << " Could not allocate a new socket." << endl;
cleanup();
return 3;
}
if (SOCKET_ERROR == connect(tcp_socket, (struct sockaddr *)&their_addr, sizeof(struct sockaddr))) // (tcp_socket = socket(AF_INET, SOCK_STREAM, 0)))
{
cout << " connect error." << endl;
cleanup();
return 3;
}
cout << " Sending on TCP port " << port_number << " - CTRL+C to exit." << endl;
while (!stop)
{
if (SOCKET_ERROR == (send(tcp_socket, tx_buf, tx_buf_size, 0)))
{
if (!stop)
cout << " send error " << WSAGetLastError() << endl;
break;
}
}
}
else if (listen_mode == mode)
{
struct sockaddr_in my_addr;
int sock_addr_len = sizeof(struct sockaddr);
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons((unsigned short int)port_number);
my_addr.sin_addr.s_addr = INADDR_ANY;
memset(&(my_addr.sin_zero), '\0', 8);
if (INVALID_SOCKET == (tcp_socket = socket(AF_INET, SOCK_STREAM, 0)))
{
cout << " Could not allocate a new socket." << endl;
cleanup();
return 4;
}
if (SOCKET_ERROR == bind(tcp_socket, (struct sockaddr *) &my_addr, sizeof(struct sockaddr)))
{
cout << " Could not bind socket to port " << port_number << "." << endl;
cleanup();
return 5;
}
if (SOCKET_ERROR == listen(tcp_socket, 0))
{
cout << " listen error." << endl;
cleanup();
return 6;
}
if (SOCKET_ERROR == accept(tcp_socket, (struct sockaddr *) &my_addr, &sock_addr_len))
{
cout << " accept error." << endl;
cleanup();
return 7;
}
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms737593(v=vs.85).aspx
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms737591(v=vs.85).aspx
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms741394(v=vs.85).aspx
//
cout << " Listening on TCP port " << port_number << " - CTRL+C to exit." << endl;
long unsigned int temp_bytes_received = 0;
while (!stop)
{
if (SOCKET_ERROR == (temp_bytes_received = recv(tcp_socket, rx_buf, rx_buf_size, 0)))
{
if (!stop)
{
cout << " recv error " << WSAGetLastError() << endl;
cleanup();
return 6;
}
}
}
}
cleanup();
return 0;
}
