Chatserver model using socket mutilthread

tuan7_chatserver_model.cpp

// ChatServer.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <stdio.h>
#include <winsock2.h>
#include <iostream>
#include<string>
#include<vector>


#pragma comment(lib, "ws2_32")
#pragma warning(disable:4996)

using namespace std;

const char* errorSyntax = "SYNTAX ERROR\n";
const char* errorCnt = "[CONNECT] ERROR \- Dang nhap that bai\n";
const char* CntMsg = "[CONNECT] OK \- Dang nhap thanh cong\n";
const char* errorDisconnect = "[DISCONNECT] ERROR \- Dang xuat that bai\n";
const char* disconnectMsg = "Disconnecting...\n";
const char* sendErr = "[SEND] ERROR \- Gui tin nhan that bai\n";
const char* sendOk = "[SEND] OK \- Gui tin nhan thanh cong\n";
const char* helloMsg = "Dang nhap theo cu phap [CONNECT] ID\n";
const char* listOk = "[LIST] OK \- Lay danh sach thanh cong\n";

CRITICAL_SECTION cs;

char* ids[64];
SOCKET clients[64];
int numClients = 0;

vector<string> useridExist{ "user1","user2","user3" };//mảng các tài khoản đã tồn tại

DWORD WINAPI ClientThread(LPVOID);
void removeClient(int);

bool isExistUser(string user) {//hàm kiểm tra xem user có tồn tại chưa?
	for (int i = 0; i < useridExist.size(); i++)
		if (useridExist[i] == user)
			return true;
	return false;
}

int main()
{
	WSADATA wsa;
	WSAStartup(MAKEWORD(2, 2), &wsa);

	InitializeCriticalSection(&cs);

	SOCKADDR_IN addr;
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	addr.sin_port = htons(9000);

	SOCKET listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	bind(listener, (SOCKADDR*)&addr, sizeof(addr));
	listen(listener, 5);

	while (1)
	{
		printf("Dang cho cac ket noi...\n");
		SOCKET client = accept(listener, NULL, NULL);
		printf("Ket noi moi: %d", client);

		CreateThread(0, 0, ClientThread, &client, 0, 0);
	}

	DeleteCriticalSection(&cs);
}

DWORD WINAPI ClientThread(LPVOID lpParam)
{
	SOCKET client = *(SOCKET*)lpParam;
	int indexOfClient;

	char buf[256];
	int ret;

	char cmd[16], id[32], tmp[32];
	char sendBuf[256];

	send(client, helloMsg, strlen(helloMsg), 0);

	// Thuc hien xac thuc client
	while (1)
	{
		ret = recv(client, buf, sizeof(buf), 0);
		if (ret <= 0)
		{
			closesocket(client);
			return 0;
		}

		buf[ret] = 0;
		printf("Received: %s\n", buf);

		// Kiem tra cu phap va id da ton tai chua
		ret = sscanf(buf, "%s %s %s", cmd, id, tmp);
		if (ret == 2)
		{
			if (strcmp(cmd, "[CONNECT]") == 0 && isExistUser(id) && strcmp(cmd, "ALL") != 0)
			{
				sprintf(sendBuf, "%s: %s %s", "[USER] CONNECT ", id, "\n");
				// Chuyen tiep tin nhan den cac client khac co user dang xuat
				for (int i = 0; i < numClients; i++)
					send(clients[i], sendBuf, strlen(sendBuf), 0);

				send(client, CntMsg, strlen(CntMsg), 0);

				EnterCriticalSection(&cs);

				ids[numClients] = id;
				indexOfClient = numClients;
				clients[numClients] = client;
				numClients++;

				LeaveCriticalSection(&cs);
				break;
			}
			else
				send(client, errorCnt, strlen(errorCnt), 0);//connect that bai
		}
		else
			send(client, errorCnt, strlen(errorCnt), 0);//connect that bai
	}

	// Thuc hien chuyen tiep tin nhan, dang xuat, lay danh sach
	while (1)
	{
		ret = recv(client, buf, sizeof(buf), 0);
		if (ret <= 0)
		{
			removeClient(indexOfClient);
			closesocket(client);
			return 0;
		}

		buf[ret] = 0;
		printf("Received: %s\n", buf);

		ret = sscanf(buf, "%s %s", cmd, tmp);

		if (ret == -1 || (strcmp(cmd, "[SEND]") != 0 && strcmp(cmd, "[DISCONNECT]") != 0 && strcmp(cmd, "[LIST]") != 0))
		{
			send(client, errorSyntax, strlen(errorSyntax), 0);
		}
		else if (strcmp(cmd, "[SEND]") == 0)
		{
			if (strcmp(tmp, "ALL") == 0)
			{
				sprintf(sendBuf, "%s %s: %s", "[MESSAGE_ALL]", id, buf + strlen(cmd) + strlen(tmp) + 1);
				// Chuyen tiep tin nhan den cac client khac
				for (int i = 0; i < numClients; i++)
					if (clients[i] != client) {
						send(clients[i], sendBuf, strlen(sendBuf), 0);
						if (ret != SOCKET_ERROR)
							send(client, sendOk, strlen(sendOk), 0);
						else
							send(client, sendErr, strlen(sendErr), 0);
					}
			}
			else
			{
				//Gui tin nhan den user chi dinh
				sprintf(sendBuf, "%s %s: %s", "[MESSAGE]", id, buf + strlen(cmd) + strlen(tmp) + 1);
				for (int i = 0; i < numClients; i++)
					if (strcmp(ids[i], tmp) == 0) {
						ret = send(clients[i], sendBuf, strlen(sendBuf), 0);
						if (ret != SOCKET_ERROR)
							send(client, sendOk, strlen(sendOk), 0);
						else
							send(client, sendErr, strlen(sendErr), 0);
					}
			}
		}
		else if (strcmp(cmd, "[DISCONNECT]") == 0)//Dang xuat
		{
			send(client, disconnectMsg, strlen(disconnectMsg), 0);//Dang dang xuat
			ret = closesocket(client);
			if (!ret)
			{
				removeClient(indexOfClient);
				// Chuyen tiep tin nhan den cac client khac co u◘ser dang xuat
				sprintf(sendBuf, "%s: %s %s", "[USER] DISCONNECT ", id, "\n");
				for (int i = 0; i < numClients; i++)
					send(clients[i], sendBuf, strlen(sendBuf), 0);
				return 0;
			}
			else
				send(client, errorDisconnect, strlen(errorDisconnect), 0);//Dang xuat that bai
		}
		else if (strcmp(cmd, "[LIST]") == 0)//Lay danh sach
		{
			string list = "[LIST] OK - Lay danh sach thanh cong: \n[";
			list += ids[0];
			for (int i = 1; i < numClients; i++)
			{
				list = list + "," + ids[i];
			}
			list += "]\n";
			const char* t = list.c_str();
			send(client, t, strlen(t), 0);
		}
	}
}

void removeClient(int i) {//ham xoa client theo chi so i trong mang
	if (i < numClients - 1)
	{
		clients[i] = clients[numClients - 1];
	}
	numClients--;
}