Linux网络 应用层协议 HTTP

• 用途：用于传输实体的主体，通常用于提交表单数据。
• 示例：POST /submit.cgi HTTP/1.1
• 特性：可以发送大量的数据给服务器，并且数据包含在请求体中。

PUT 方法

• 用途：用于传输文件，将请求报文主体中的文件保存到请求 URL 指定的位置。
• 示例：PUT /example.html HTTP/1.1
• 特性：不太常用，但在某些情况下，如 RESTful API 中，用于更新资源。

HEAD 方法

• 用途：与 GET 方法类似，但不返回报文主体部分，仅返回响应头。
• 示例：HEAD /index.html HTTP/1.1
• 特性：用于确认 URL 的有效性及资源更新的日期时间等。

• HTTP 状态码 301（永久重定向）：

HTTP/1.1 301 Moved Permanently\r\n
Location: https://www.new-url.com\r\n

HTTP/1.1 302 Found\r\n
Location: https://www.new-url.com\r\n

#pragma once
#include <string>
#include <iostream>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <cstring>
using namespace std;
class InetAddr
{
public:InetAddr(){}InetAddr(int port, string ip = ""): _port(port), _ip(ip){bzero(&_sockaddr, sizeof(_sockaddr));_sockaddr.sin_family = AF_INET;_sockaddr.sin_port = htons(_port);if (_ip.empty())_sockaddr.sin_addr.s_addr = INADDR_ANY;else_sockaddr.sin_addr.s_addr = inet_addr(_ip.c_str());}InetAddr(const struct sockaddr_in &sockaddr){_port = ntohs(sockaddr.sin_port);char buf[64];_ip = inet_ntop(AF_INET, &sockaddr.sin_addr, buf, sizeof(buf));}bool operator==(const InetAddr &other){return _ip == other._ip;}InetAddr operator=(const InetAddr &other){_ip = other._ip;_port = other._port;_sockaddr = other._sockaddr;return *this;}struct sockaddr *getSockaddr(){return (struct sockaddr *)&_sockaddr;}int getSockaddrLen(){return sizeof(_sockaddr);}const string &getIp(){return _ip;}int getPort(){return _port;}void SetAddr(const struct sockaddr_in &client){_sockaddr = client;_port = ntohs(client.sin_port);char buf[64];_ip = inet_ntop(AF_INET, &client.sin_addr, buf, sizeof(buf));}private:string _ip;int _port;struct sockaddr_in _sockaddr;
};

enum
{SOCKET_ERROR=1,BIND_ERROR,LISTEN_ERROR,ACCEPT_ERROR,CONNECT_ERROR
};

Socket.hpp

#pragma once
#include <iostream>
#include <string>
#include <memory>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include "Common.hpp"
#include "InetAddr.hpp"
using namespace std;
class Socket; // 前置声明
using SockPtr = shared_ptr<Socket>;
#define glistensockfd -1
#define gbacklog 8
// 基类，规定创建socket方法
class Socket
{
public:// 创建listensockfdSocket() = default;virtual ~Socket() = default;virtual void SocketOrDie() = 0;virtual void SetSockOpt() = 0;virtual bool BindOrDie(int port) = 0;virtual bool ListenOrDie() = 0;virtual SockPtr Accepter(InetAddr *client) = 0;virtual void Close() = 0;virtual int Recv(string *out_str) = 0;virtual int Send(const string &in_str) = 0;virtual int Fd() = 0;// 创建TcpSocket的固定方法void BuildTcpSocketMethod(int port){SocketOrDie();SetSockOpt();BindOrDie(port);ListenOrDie();}// 创建UdpSocket的固定方法void BuildUdpSocketMethod(int port){SocketOrDie();SetSockOpt();BindOrDie(port);}
};class TcpSocket : public Socket
{
public:TcpSocket() : _listensockfd(glistensockfd){}TcpSocket(int listensockfd): _listensockfd(listensockfd){}virtual ~TcpSocket(){}// 创建listensockfdvirtual void SocketOrDie() override{_listensockfd = socket(AF_INET, SOCK_STREAM, 0);if (_listensockfd < 0){cout << "socket error" << endl;exit(SOCKET_ERROR);}cout << "socket create success" << endl;}virtual void SetSockOpt() override{int opt = 1;// 保证服务器异常断开后可以立即重启，不会有bind问题setsockopt(_listensockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));}virtual bool BindOrDie(int port) override{if (_listensockfd == glistensockfd)return false;// 填充网络信息struct sockaddr_in local;local.sin_family = AF_INET;local.sin_port = htons(port);local.sin_addr.s_addr = INADDR_ANY;int n = bind(_listensockfd, (struct sockaddr *)&local, sizeof(local));if (n < 0){cout << "bind error" << endl;exit(BIND_ERROR);}cout << "bind success" << endl;return true;}virtual bool ListenOrDie() override{if (_listensockfd == glistensockfd)return false;int n = listen(_listensockfd, gbacklog);if (n < 0){cout << "listen error" << endl;exit(LISTEN_ERROR);}cout << "listen success" << endl;return true;}// 1.文件描述符 2.client infovirtual SockPtr Accepter(InetAddr *client) override{if (client == nullptr)return nullptr;struct sockaddr_in peer;socklen_t len = sizeof(peer);int sockfd = accept(_listensockfd, (struct sockaddr *)&peer, &len);if (sockfd < 0){cout << "accep error" << endl;return nullptr;}client->SetAddr(peer);return make_shared<TcpSocket>(sockfd);}virtual void Close() override{if (_listensockfd == glistensockfd)return;close(_listensockfd);}virtual int Recv(string *out_str) override{char buffer[4096*2];int sz = recv(_listensockfd, buffer, sizeof(buffer) - 1, 0);if (sz > 0){buffer[sz] = 0;*out_str = buffer;}return sz;}virtual int Send(const string &in_str) override{int sz = send(_listensockfd, in_str.c_str(), in_str.size(), 0);return sz;}virtual int Fd() override{return _listensockfd;}private:int _listensockfd;
};class UdpSocket : public Socket
{
public:UdpSocket(int sockfd = glistensockfd): _sockfd(sockfd){}// 创建listensockfdvirtual void SocketOrDie() override{_sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (_sockfd < 0){cout << "socket error" << endl;exit(SOCKET_ERROR);}cout << "socket create success" << endl;}virtual void SetSockOpt() override{int opt = 1;setsockopt(_sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));}virtual bool BindOrDie(int port) override{struct sockaddr_in local;bzero(&local, sizeof(local));local.sin_family = AF_INET;local.sin_port = htons(port);local.sin_addr.s_addr = INADDR_ANY;int n = bind(_sockfd, (struct sockaddr *)&local, sizeof(local));if (n < 0){cout << "bind error" << endl;exit(BIND_ERROR);}cout << "bind success" << endl;return true;}virtual void Close() override{if (_sockfd == glistensockfd)return;close(_sockfd);}virtual int Recv(string *out_str){char buffer[4096];socklen_t len = sizeof(_peer);int sz = recvfrom(_sockfd, buffer, sizeof(buffer) - 1, 0, (struct sockaddr *)&_peer, &len);if (sz > 0){buffer[sz] = 0;*out_str = buffer;}return sz;}virtual int Send(const string &in_str) override{int sz = sendto(_sockfd, in_str.c_str(), in_str.size(), 0, (struct sockaddr *)&_peer, sizeof(_peer));return sz;}virtual int Fd() override{return _sockfd;}private:int _sockfd;struct sockaddr_in _peer;
};

TcpServer.hpp

#pragma once
#include <iostream>
#include <functional>
#include <memory>
#include "Socket.hpp"
#include "InetAddr.hpp"
#include <unistd.h>
#include <sys/wait.h>
using namespace std;#define BACKLOG 8
using handler_t = function<void(SockPtr, InetAddr)>;
using task_t = function<void()>;
static const uint16_t gport = 8080;// 只负责IO，不对协议进行处理
class TcpServer
{
public:TcpServer(uint16_t port = gport): _port(port), _isrunning(false), _listensockfd(make_unique<TcpSocket>()){}void InitServer(handler_t handler){_handler = handler;_listensockfd->BuildTcpSocketMethod(_port);}void Loop(){_isrunning = true;while (_isrunning){// 1.AcceptInetAddr client;auto sockfd = _listensockfd->Accepter(&client);if (sockfd == nullptr)continue;// 2.IO处理cout << "get a new client,info is: " << client.getIp() << ":" << client.getPort() << endl;// 3.交给孙子进程执行任务pid_t id = fork();if (id == 0){_listensockfd->Close();if (fork() > 0)exit(0);_handler(sockfd, client);exit(0);}sockfd->Close();waitpid(id, nullptr, 0);}_isrunning = false;}void Stop(){_isrunning = false;}~TcpServer(){_listensockfd->Close();}private:// int _listensockfd; // 监听socketunique_ptr<Socket> _listensockfd;uint16_t _port;bool _isrunning;// 处理上层任务的入口handler_t _handler;
};

Daemon.hpp

#pragma once
#include <iostream>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>using namespace std;
#define ROOT "/"
#define devnull "/dev/null"
void Daemon(bool ischdir, bool isclose)
{// 守护进程要屏蔽特定的异常信号signal(SIGCHLD, SIG_IGN);signal(SIGPIPE, SIG_IGN);// 成为非组长if (fork() > 0)exit(0);// 建立新会话setsid();// 每一个进程都有自己的CWD，是否将当前进程的CWD更改成为 / 根目录if (ischdir)chdir(ROOT);// 变成守护进程，不需要与用户的输入输出，错误相关联if (isclose){close(0);close(1);close(2);}else{int fd = open(devnull, O_WRONLY);if (fd > 0){// 重定向dup2(fd, 0);dup2(fd, 1);dup2(fd, 2);close(fd);}}
}

HttpProtocol.hpp

#pragma once
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
#include <fstream>
#include <sstream>
using namespace std;
const string Sep = "\r\n";
const string LineSep = " ";
const string HeaderLineSep = ": ";
const string BlankLine = Sep;
const string http_version = "HTTP/1.0";
const string defaulthomepage = "shop";
const string firstpage = "page/index.html";
const string page404 = "shop/page/404.html";class HttpRequest
{
public:bool IsHasArgs(){return _isexec;}// GET /favicon.ico HTTP/1.1\r\n// Host: 8.137.19.140:8080// Connection: keep-alive// User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0// Accept: image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8// Referer: http://8.137.19.140:8080/?msg=i_have_sent_a_message_he_he_he_he_he_he_he_he_he_he_he_he_he_he_he_he_he_he// Accept-Language: zh-CN,zh;q=0.9,en;q=0.8,en-GB;q=0.7,en-US;q=0.6// dnt: 1// sec-gpc: 1//bool SplitString(const string &header, const string &sep, string *key, string *value){auto pos = header.find(sep);if (pos == string::npos)return false;*key = header.substr(0, pos);*value = header.substr(pos + sep.size());return true;}void ParseHeaderkv(){string key, value;for (auto &header : _request_header){if (SplitString(header, HeaderLineSep, &key, &value)){_headerkv[key] = value;}}}bool ParseOneLine(string &str, string *out_str, const string &sep){auto pos = str.find(sep);if (pos == string::npos)return false;*out_str = str.substr(0, pos);str.erase(0, pos + sep.size());return true;}// 处理请求报头bool ParseHeader(string &request_str){string line;while (true){bool ret = ParseOneLine(request_str, &line, Sep);if (ret && !line.empty()){_request_header.push_back(line);}else if (ret && line.empty()){_blank_line = BlankLine;break;}elsereturn false;}ParseHeaderkv();return true;}// 处理请求行//  GET /favicon.ico HTTP/1.1\r\nvoid ParseRequestLine(string &request_line){stringstream ss(request_line);ss >> _method >> _url >> _version;}void Deserialize(string &request_str){if (ParseOneLine(request_str, &_request_line, Sep)){// 提取请求行中的详细字段ParseRequestLine(_request_line);ParseHeader(request_str);_body = request_str;// 分析请求是否含有参数if (_method == "POST"){_isexec = true; // 参数在正文_args = _body;_path = _url;cout << "POST: _path: " << _path << endl;cout << "POST: _args: " << _args << endl;}else if (_method == "GET"){// /login?name=zhang&passwd=123456auto pos = _url.find("?");if (pos != string::npos){_isexec = true;_path = _url.substr(0, pos);_args = _url.substr(pos + 1);cout << "POST: _path: " << _path << endl;cout << "POST: _args: " << _args << endl;}}}}string GetContent(const string &path){// 由于传输的数据可能是文件，图片，视频等// 所以需要通过二进制文件方式获取string content;ifstream in(path, ios::binary);if (!in.is_open())return "";in.seekg(0, in.end);int filesz = in.tellg();in.seekg(0, in.beg);content.resize(filesz);in.read((char *)content.c_str(), filesz);in.close();cout << "content length: " << content.size() << endl;return content;}void Print(){cout << "HttpRequest: " << endl;cout << "_method: " << _method << endl;cout << "_url: " << _url << endl;cout << "_version: " << _version << endl;for (auto &kv : _headerkv){cout << kv.first << " # " << kv.second << endl;}cout << "_blank_line: " << _blank_line << endl;cout << "_body: " << _body << endl;}string Url(){return _url;}void SetUrl(const string &newurl){_url = newurl;}string Path(){return _path;}string Args(){return _args;}string Suffix(){auto pos = _path.find(".");if (pos == string::npos)return ".html";elsereturn _path.substr(pos);}private:string _request_line;vector<string> _request_header;string _blank_line = BlankLine;string _body;// 在反序列化中我们需要细化解析出来的字段string _method;string _url; // 如果请求方法为GET，则url中存在路径和参数两部分string _path;string _args;string _version;unordered_map<string, string> _headerkv;bool _isexec = false;
};class HttpResponse
{
public:void Build(HttpRequest &req){string url = defaulthomepage + req.Url();if (url.back() == '/'){url += firstpage;}cout << "-------客户端正在请求：" << url << endl;req.Print();cout << "---------------------------" << endl;_content = req.GetContent(url);if (_content.empty()){// 用户请求的资源不存在_status_code = 404;_content = req.GetContent(page404);}else{_status_code = 200;}_status_desc = CodeToDesc(_status_code);if (!_content.empty()){SetHeader("Content-Length", to_string(_content.size()));}string mime_type = SuffixToDesc(req.Suffix());SetHeader("Content-Type", mime_type);_body = _content;}void SetHeader(const string &k, const string &v){_header_kv[k] = v;}void SetCode(int code){_status_code = code;_status_desc = CodeToDesc(_status_code);}void SetBody(const string &body){_body = body;}void Serialize(string *response_str){_response_line = _version + LineSep + to_string(_status_code) + LineSep + _status_desc + Sep;for (auto &header : _header_kv){_response_header.push_back(header.first + HeaderLineSep + header.second);}*response_str = _response_line;for (auto &line : _response_header){*response_str += (line + Sep);}*response_str += _blank_line;*response_str += _body;}private:string CodeToDesc(const int &code){switch (code){case 200:return "OK";case 404:return "Not Found";case 301:return "Moved Permanently";case 302:return "Found";default:return "";}}string SuffixToDesc(const string &suffix){if (suffix == ".html")return "text/html";else if (suffix == ".jpg")return "application/x-jpg";elsereturn "text/html";}private:string _version = http_version;int _status_code;string _status_desc;string _content;unordered_map<string, string> _header_kv;// 最终的四部分构建应答string _response_line;vector<string> _response_header;string _blank_line = BlankLine;string _body;
};

HttpServer.hpp

#pragma once
#include "TcpServer.hpp"
#include "HttpProtocol.hpp"using http_handler_t = function<void(HttpRequest &, HttpResponse &)>;
class HttpServer
{
public:HttpServer(int port): _tsvr(make_unique<TcpServer>(port)){}void Resgiter(string funcname, http_handler_t func){_route[funcname] = func;}bool SafeCheck(const string &service){auto iter = _route.find(service);return iter != _route.end();}void HandlerHttpRequest(SockPtr sockfd, InetAddr client){cout << "HttpServer: get a new client: " << sockfd->Fd()<< "info: " << client.getIp() << ":" << client.getPort() << endl;string http_request;sockfd->Recv(&http_request);HttpRequest req;req.Deserialize(http_request);HttpResponse resp;// 请求分为两类。1.静态资源 2.携带参数if (req.IsHasArgs()){string service = req.Path();if (SafeCheck(service))_route[service](req, resp);elseresp.Build(req);}else{resp.Build(req);}string resp_str;resp.Serialize(&resp_str);sockfd->Send(resp_str);}void Start(){_tsvr->InitServer([&](SockPtr sockfd, InetAddr client){ this->HandlerHttpRequest(sockfd, client); });_tsvr->Loop();}private:unique_ptr<TcpServer> _tsvr;unordered_map<string, http_handler_t> _route; // 功能路由
};

HttpServermain.cc

#include "HttpServer.hpp"
#include "Daemon.hpp"
#include <functional>
#include <unistd.h>
#include <memory>
void Login(HttpRequest &req, HttpResponse &resp)
{// req.Path(): /login// 根据req，动态构建username=lisi&password=12345cout << "进入登录模块" << req.Path() << ", " << req.Args();// 1. 解析参数格式，得到要的参数// 2. 访问数据库，验证对应的用户是否是合法的用户，其他工作....// 3. 登录成功
}void Register(HttpRequest &req, HttpResponse &resp)
{// 根据req，动态构建respcout << "进入注册模块" << req.Path() << ", " << req.Args();
}void Search(HttpRequest &req, HttpResponse &resp)
{// 根据req，动态构建respcout << "进入搜索模块" << req.Path() << ", " << req.Args();
}void Test(HttpRequest &req, HttpResponse &resp)
{// 根据req，动态构建respcout << "进入测试模块" << req.Path() << ", " << req.Args();
}
int main(int argc, char *argv[])
{if (argc != 2){std::cout << "Usage: " << argv[0] << " port" << std::endl;return 1;}int port = stoi(argv[1]);// 变成守护进程Daemon(false, false);auto server = make_unique<HttpServer>(port);server->Resgiter("/login",Login);server->Resgiter("/register", Register);server->Resgiter("/search", Search);server->Resgiter("/test", Test);server->Start();return 0;
}

makefile

server:HttpServermain.ccg++ -o $@ $^ -std=c++17 -lpthread -ljsoncpp
.PHONY:clean
clean:rm -f server