【计算机网络】应用层HTTP协议

https://www.baidu.com/s?ie=utf-8&f=8&rsv_bp=1&rsv_idx=1&tn=baidu&wd=C%2B%2B&fenlei=256&oq=

#pragma once
#include <iostream>
#include <fstream>
#include <string>
#include <cassert>
#include <cstring>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <unistd.h>
#define CRLF "\r\n"
#define SPACE " "
#define SPACE_LEN strlen(SPACE)
#define HOME_PAGE "index.html"
#define ROOT_PATH "wwwroot"
std::string ReadFile(const std::string &path)
{
    std::ifstream in(path, std::ifstream::binary);
    if (!in.is_open())
    {
        return "404 NOT FOUND";
    }
    std::string content;
    std::string line;
    while (std::getline(in, line))
    {
        content += line;
    }
    in.close();
    return content;
}
std::string GetPath(std::string request)
{
    std::size_t pos = request.find(CRLF);
    if(pos == std::string::npos)
    {
        return nullptr;
    }
    // 获取第一行：GET PATH HTTP/1.1 
    std::string line = request.substr(0, pos);
    std::size_t first_space = line.find(SPACE);
    if(first_space == std::string::npos)
    {
        return nullptr;
    }
    std::size_t second_space = line.rfind(SPACE);
    if(second_space == std::string::npos)
    {
        return nullptr;
    }
    std::string path = line.substr(first_space + SPACE_LEN, second_space - (SPACE_LEN + first_space));
    if(path[0] == '/' && path.size() == 1)
        path += HOME_PAGE;
    return path;
}
void _handlerHttpRequest_(int sock)
{
    char buf[1024 * 10] = {0};
    ssize_t read_size = read(sock, buf, sizeof buf);
    if (read_size > 0)
    {
        std::cout << buf;
    }
    // std::string response = "HTTP/1.1 302 Temporarily Moved\r\n"; // 临时重定向
    std::string response = "HTTP/1.1 301 Permanently Moved\r\n"; // 永久重定向
    response += "Location: https://www.baidu.com/\r\n";
    response += "\r\n";
    // write(sock, response.c_str(), response.size());
    send(sock, response.c_str(), response.size(), 0);
}
void handlerHttpRequest(int sock)
{
    char buf[1024 * 10] = {0};
    ssize_t read_size = read(sock, buf, sizeof buf);
    if (read_size > 0)
    {
        std::cout << buf;
    }
    // 获取请求中的路径
    std::string path = GetPath(buf);
    // 请求的文件路径在请求行中，第二个字段就是要访问的文件
    //  GET PATH HTTP/1.1
    std::string resource = ROOT_PATH;
    resource += path;
    //debug
    std::cout << resource << std::endl;
    // 获取文件后缀
    std::size_t pos = resource.find(".");
    std::string suffix = resource.substr(pos);
    // 读取文件内容
    std::string html = ReadFile(resource);
    // 回响
    std::string response;
    response = "HTTP/1.0 200 OK\r\n";
    if (suffix == ".jpg")
        response += "Content-Type: image/jpeg\r\n";
    else
        response += "Content-Type: text/html\r\n";
    response += ("Content-Length: " + std::to_string(html.size()) + "\r\n");
    // 添加cookie
    response += "Set-Cookie: this is my cookie content;\r\n";
    response += "\r\n";
    response += html;
    send(sock, response.c_str(), response.size(), 0);
}
class Server
{
public:
    Server(uint16_t port, const std::string &ip = "")
        : _listenSock(-1), _port(port), _ip(ip), _quit(false)
    {
        signal(SIGCHLD, SIG_IGN);
    }
    ~Server()
    {
        if (_listenSock >= 0)
        {
            close(_listenSock);
        }
    }
public:
    void init()
    {
        // 创建socket
        _listenSock = socket(AF_INET, SOCK_STREAM, 0);
        if (_listenSock < 0)
        {
            std::cerr << "socket error" << std::endl;
            exit(1);
        }
        // 填充信息
        sockaddr_in addr;
        memset(&addr, 0, sizeof(addr));
        addr.sin_family = PF_INET;
        addr.sin_port = htons(_port);
        addr.sin_addr.s_addr = _ip.empty() ? htonl(INADDR_ANY) : inet_addr(_ip.c_str());
        // bind
        if (bind(_listenSock, (const sockaddr *)&addr, sizeof(addr)) < 0)
        {
            std::cerr << "bind error" << std::endl;
            exit(2);
        }
        // 监听
        if (listen(_listenSock, 5) < 0)
        {
            std::cerr << "listen error" << std::endl;
            exit(3);
        }
    }
    void loop()
    {
        while (!_quit)
        {
            sockaddr_in peer;
            socklen_t len = sizeof(peer);
            int peer_sock = accept(_listenSock, (sockaddr *)&peer, &len);
            if (peer_sock < 0)
            {
                std::cerr << "accept error" << std::endl;
                exit(4);
            }
            // 多进程版
            pid_t id = fork();
            if (id > 0)
            {
                // 父进程
                close(peer_sock);
            }
            else if (id == 0)
            {
                // 子进程
                close(_listenSock);
                handlerHttpRequest(peer_sock);
                close(peer_sock);
                exit(0);
            }
            else
            {
                std::cerr << "fork error" << std::endl;
                exit(5);
            }
        }
    }
    bool quitServer()
    {
        _quit = true;
        return true;
    }
private:
    int _listenSock; // sock
    uint16_t _port;  // 服务器端口
    std::string _ip; // IP地址
    bool _quit;      // 安全退出的标志
};

#include <iostream>
#include "Server.hpp"
static void Usage(std::string proc)
{
    std::cerr << "Usage:\n\t" << proc << " port" << std::endl;
    std::cerr << "example:\n\t" << proc << " 8080\n"
              << std::endl;
}
int main(int argc, char* argv[])
{
    if(argc != 2)
    {
        Usage(argv[0]);
        exit(-1);
    }
    uint16_t port = atoi(argv[1]);
    Server server(port);
    server.init();
    server.loop();
    return 0;
}

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>我的测试</title>
</head>
<body>
    <p> This is my httpServer!</p>
</body>
</html>