Привет, я пишу эхо-клиент, и по какой-то причине функция connectsock возвращает ошибку и возвращает INVALID_SOCKET. Я не могу понять, почему это так. Может кто-нибудь сказать мне, почему
/*********************************
* echo1.cpp *
* *
* Echo client - version 1 *
**********************************/
#include <winsock2.h>
#pragma comment(lib, "ws2_32.lib")
#include <string>
#include <iostream>
using namespace std;
const int MAXBUF = 128;
const int MAXNAME = 80;
SOCKET connectsock (char*, char*, char*);
int main (int argc, char **argv)
{
char msg[MAXBUF] = "";
char buf[MAXBUF] = "";
char host[MAXNAME] = "";
char service[MAXNAME] = "";
int len;
SOCKET s;
/* Must always initialize the Windows Sockets TCP/IP library */
WORD wVersion = 0x0202;
WSADATA wsaData;
int iResult = WSAStartup( wVersion, &wsaData);
if (iResult != 0)
{
cout << "Unable to initialize Windows Socket library." << endl;
return 0;
}
string hostaddress = argv[1];
if(argv[2] == NULL)
{
strcpy_s(service, MAXNAME, "7");
}
else
{
strcpy_s(service, MAXNAME, argv[2]);
}
strcpy_s( host, MAXNAME, hostaddress.c_str() );
s = connectsock(host, service, "tcp");
if (s != INVALID_SOCKET)
{
cout <<"Message?";
cin.getline(msg, MAXBUF);
// Now, let's try to send the message to the remote machine
len = send(s, msg, (int) strlen(msg), 0);
if (len > 0)
{
cout << "Number of bytes sent: " << len << endl;
cout << endl;
}
else
{
cout << "Unable to send message to remote machine." << endl;
return 0;
}
// Message was sent. Is there a reply from the remote machine?
len = recv(s, buf, sizeof(buf), 0);
if (len > 0)
{
cout << "Received message: ";
for (int i=0; i<len; i++) cout << buf[i];
cout << endl;
cout << "Number of bytes received: " << len << endl << endl;
}
cout << endl << endl;
/* Close the socket (and thus the connection) */
shutdown(s,1);
closesocket(s);
}
WSACleanup();
}
/*------------------------------------------------------------------
* connectsock - allocate & connect a remote socket using TCP or UDP
*------------------------------------------------------------------
*/
SOCKET connectsock (char *host, char *service, char *protocol)
{
struct hostent *phe;
struct servent *pse;
short port;
int ihost;
port = htons( (u_short) atoi(service)); // 1st try to convert string to integer
if (port == 0)
{ // if that doesn't work, call service function
pse = getservbyname(service,NULL);
if (pse)
{
port = pse->s_port;
}
else
{
cout << "Invalid service request." << endl;
return INVALID_SOCKET;
}
}
/*
cout << "Service: " << service << endl;
cout << "Port: " << htons(port) << endl;
*/
ihost = inet_addr(host);
if (ihost == INADDR_NONE)
{
phe = gethostbyname(host);
if (phe)
{
memmove(&ihost, phe->h_addr, phe->h_length);
}
else
{
cout << "Invalid Host." << endl;
return INVALID_SOCKET;
}
}
/*
cout << "Network address for hostname: " << host << endl;
cout << "32-bit address in Network Byte Order: " << ihost << endl;
cout << "32-bit address in Host Byte Order: " << ntohl(ihost) << endl;
struct in_addr in;
in.S_un.S_addr = ihost;
cout << "Address as dotted decimal: " << inet_ntoa(in) << endl;
*/
struct sockaddr_in remote;
SOCKET s;
if (_stricmp(protocol, "tcp") == 0)
{
s = socket(AF_INET, SOCK_STREAM, 0);
if (s < 0 || s == INVALID_SOCKET)
{
cout << "Cannot create socket" << endl;
return INVALID_SOCKET;
}
memset(&remote, 0, sizeof(remote));
remote.sin_family = AF_INET;
remote.sin_port = htons( (u_short) atoi(service));
remote.sin_addr.s_addr = inet_addr(host);
int status = connect(s, (LPSOCKADDR) &remote, sizeof(SOCKADDR));
if (status == SOCKET_ERROR)
{
cout << "Remote host/service not found - or connection refused" << endl;
return INVALID_SOCKET;
}
}
else if (_stricmp(protocol,"udp") == 0)
{
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0 || s == INVALID_SOCKET)
{
cout << "Cannot create socket" << endl;
return INVALID_SOCKET;
}
}
else
{ // Unknown or unsupported protocol request
cout << "Invalid Protocol" << endl;
return INVALID_SOCKET;
}
return s;
}