【在Linux世界中追寻伟大的One Piece】Socket编程TCP

#pragma once
#include <iostream>

class nocopy
{
public:
	nocopy() {}

	nocopy(const nocopy&) = delete;
	const nocopy& operator = (const nocopy&) = delete;

	~nocopy() {}
};

#pragma once
#include <iostream>
#include <string>
#include <cerrno>
#include <cstring>
#include <cstdlib>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "Log.hpp"
#include "nocopy.hpp"
#include "Comm.hpp"

const static int default_backlog = 6; // TODO
class TcpServer : public nocopy
{
public:
	TcpServer(uint16_t port) : _port(port), _isrunning(false)
	{
	}

	// 都是固定套路
	void Init()
	{
		// 1. 创建 socket, file fd, 本质是文件
		_listensock = socket(AF_INET, SOCK_STREAM, 0);
		if (_listensock < 0)
		{
			lg.LogMessage(Fatal, "create socket error, errnocode: % d, error string : % s\n", errno, strerror(errno));
			exit(Fatal);
		}

		int opt = 1;
		setsockopt(_listensock, SOL_SOCKET, SO_REUSEADDR |
		SO_REUSEPORT, &opt, sizeof(opt));

		lg.LogMessage(Debug, "create socket success,
			sockfd: % d\n", _listensock);

		// 2. 填充本地网络信息并 bind
		struct sockaddr_in local;
		memset(&local, 0, sizeof(local));
		local.sin_family = AF_INET;
		local.sin_port = htons(_port);
		local.sin_addr.s_addr = htonl(INADDR_ANY);

		// 2.1 bind
		if (bind(_listensock, CONV(&local), sizeof(local)) != 0)
		{
			lg.LogMessage(Fatal, "bind socket error, errno
				code: % d, error string : % s\n", errno, strerror(errno));
				exit(Bind_Err);
		}

		lg.LogMessage(Debug, "bind socket success, sockfd: %d\n",
			_listensock);

		// 3. 设置 socket 为监听状态，tcp 特有的
		if (listen(_listensock, default_backlog) != 0)
		{
			lg.LogMessage(Fatal, "listen socket error, errno
				code: % d, error string : % s\n", errno, strerror(errno));
				exit(Listen_Err);
		}
		lg.LogMessage(Debug, "listen socket success,
			sockfd: % d\n", _listensock);
	}

	// Tcp 连接全双工通信的.
	void Service(int sockfd)
	{
		char buffer[1024];
		// 一直进行 IO
		while (true)
		{
			ssize_t n = read(sockfd, buffer, sizeof(buffer) - 1);
			if (n > 0)
			{
				buffer[n] = 0;
				std::cout << "client say# " << buffer <<
					std::endl;

				std::string echo_string = "server echo# ";
				echo_string += buffer;
				write(sockfd, echo_string.c_str(),
					echo_string.size());
			}
			else if (n == 0) // read 如果返回值是 0，表示读到了文件结尾(对端关闭了连接！)
			{
				lg.LogMessage(Info, "client quit...\n");

				break;
			}
			else
			{
				lg.LogMessage(Error, "read socket error, errno
					code: % d, error string : % s\n", errno, strerror(errno));
					break;
			}
		}
	}

	void Start()
	{
		_isrunning = true;
		while (_isrunning)
		{
			// 4. 获取连接
			struct sockaddr_in peer;
			socklen_t len = sizeof(peer);

			int sockfd = accept(_listensock, CONV(&peer), &len);
			if (sockfd < 0)
			{
				lg.LogMessage(Warning, "accept socket error, errno
					code: % d, error string : % s\n", errno, strerror(errno));
					continue;
			}

			lg.LogMessage(Debug, "accept success, get n new
			sockfd: % d\n", sockfd);
			// 5. 提供服务, v1~v4
			// v1
			// Service(sockfd);
			close(sockfd);
		}
	}

	~TcpServer()
	{
	}
private:
	uint16_t _port;
	int _listensock; // TODO
	bool _isrunning;
};

#pragma once
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

enum 
{
	Usage_Err = 1,
	Socket_Err,
	Bind_Err,
	Listen_Err
};

#define CONV(addr_ptr) ((struct sockaddr *)addr_ptr)

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "Comm.hpp"
using namespace std;

void Usage(const std::string& process)
{
	std::cout << "Usage: " << process << " server_ip server_port"
		<< std::endl;
}

// ./tcp_client serverip serverport
int main(int argc, char* argv[])
{
	if (argc != 3)
	{
		Usage(argv[0]);

		return 1;
	}

	std::string serverip = argv[1];
	uint16_t serverport = stoi(argv[2]);

	// 1. 创建 socket
	int sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0)
	{
		cerr << "socket error" << endl;

		return 1;
	}

	// 2. 要不要 bind？必须要有 Ip 和 Port, 需要 bind，但是不需要用户显示的 bind，client 系统随机端口
	// 发起连接的时候，client 会被 OS 自动进行本地绑定
	// 
	// 2. connect
	struct sockaddr_in server;
	memset(&server, 0, sizeof(server));
	server.sin_family = AF_INET;
	server.sin_port = htons(serverport);

	// p:process(进程), n(网络) -- 不太准确，但是好记忆
	inet_pton(AF_INET, serverip.c_str(), &server.sin_addr); // 1. 字符串 ip->4 字节 IP 2. 网络序列
	int n = connect(sockfd, CONV(&server), sizeof(server)); // 自动进行 bind 哦！
	if (n < 0)
	{
		cerr << "connect error" << endl;

		return 2;
	}

	// 并没有向 server 一样，产生新的 sockfd.未来我们就用 connect 成功的sockfd 进行通信即可.
	while (true)
	{
		string inbuffer;
		cout << "Please Enter# ";
		getline(cin, inbuffer);
		ssize_t n = write(sockfd, inbuffer.c_str(),
			inbuffer.size());
		if (n > 0)
		{
			char buffer[1024];
			ssize_t m = read(sockfd, buffer, sizeof(buffer) - 1);
			if (m > 0)
			{
				buffer[m] = 0;
				cout << "get a echo messsge -> " << buffer <<
					endl;
			}
			else if (m == 0 || m < 0)
			{
				break;
			}
		}
		else
		{
			break;
		}
	}

	close(sockfd);

	return 0;
}