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Lesson11:http协议

news 2025/7/28 1:52:33

前言

应用层:就是程序员基于socket接口之上编写的具体逻辑,做了很多工作,都是和文本处理有关的--- 协议分析与处理
http协议,一定会具有大量的文体分析和协议处理

如果用户想再url中包含url本身用来作为特殊字符的字符,url形式的时候,浏览器会自动给我们进行编码encode
一般服务端收到之后,需要进行转回特殊字符

快速构建http请求和响应的报文格式

HttpServer.cc

#include <iostream>
#include <memory>
#include <cassert>
#include <fstream>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>#include "HttpServer.hpp"
#include "Usage.hpp"
#include "Util.hpp"// 一般http都要有自己的web根目录
#define ROOT "./wwwroot" // ./wwwroot/index.html
// 如果客户端只请求了一个/,我们返回默认首页
#define HOMEPAGE "index.html"void HandlerHttpRequest(int sockfd)
{// 1. 读取请求 for testchar buffer[10240];ssize_t s = recv(sockfd, buffer, sizeof(buffer) - 1, 0);if (s > 0){buffer[s] = 0;// std::cout << buffer << "--------------------\n" << std::endl;}std::vector<std::string> vline;Util::cutString(buffer, "\n", &vline);std::vector<std::string> vblock;Util::cutString(vline[0], " ", &vblock);// 拿到请求行std::string file = vblock[1];// cilent想要的文件名std::string target = ROOT;if(file == "/") file = "/index.html";target += file;std::cout << target << std::endl;// 打开这个文件,再从这个文件中拿数据std::string content;std::ifstream in(target);if(in.is_open()){std::string line;while(std::getline(in, line)){content += line;}in.close();}std::string HttpResponse;if(content.empty()) {HttpResponse = "HTTP/1.1 404 NotFound\r\n";}else {HttpResponse = "HTTP/1.1 200 OK\r\n";}HttpResponse += "\r\n";HttpResponse += content;// 2. 试着构建一个http的响应send(sockfd, HttpResponse.c_str(), HttpResponse.size(), 0);
}int main(int argc, char *argv[])
{if (argc != 2){Usage(argv[0]);exit(0);}std::unique_ptr<HttpServer> httpserver(new HttpServer(atoi(argv[1]), HandlerHttpRequest));httpserver->Start();return 0;
}

HttpServer.hpp

#pragma once#include <iostream>
#include <signal.h>
#include <functional>
#include "Sock.hpp"class HttpServer
{
public:using func_t = std::function<void(int)>;// 包装器->函数
private:int listensock_;// 监听uint16_t port_;Sock sock;// 套接字func_t func_;
public:HttpServer(const uint16_t &port, func_t func): port_(port),func_(func){listensock_ = sock.Socket();sock.Bind(listensock_, port_);// 绑定sock.Listen(listensock_);// 监听}void Start(){signal(SIGCHLD, SIG_IGN);// 解决父进程需要进程等待的问题for( ; ; ){std::string clientIp;uint16_t clientPort = 0;int sockfd = sock.Accept(listensock_, &clientIp, &clientPort);if(sockfd < 0) continue;if(fork() == 0){close(listensock_);func_(sockfd);close(sockfd);exit(0);}close(sockfd);}}~HttpServer(){if(listensock_ >= 0) close(listensock_);}
};

Log.hpp

#pragma once#include <iostream>
#include <cstdio>
#include <cstdarg>
#include <ctime>
#include <string>// 日志是有日志级别的
#define DEBUG   0
#define NORMAL  1
#define WARNING 2
#define ERROR   3
#define FATAL   4const char *gLevelMap[] = {"DEBUG","NORMAL","WARNING","ERROR","FATAL"
};#define LOGFILE "./calculator.log"// 完整的日志功能，至少: 日志等级 时间 支持用户自定义(日志内容, 文件行，文件名)
void logMessage(int level, const char *format, ...)
{
#ifndef DEBUG_SHOWif(level== DEBUG) return;
#endifchar stdBuffer[1024]; //标准部分time_t timestamp = time(nullptr);snprintf(stdBuffer, sizeof stdBuffer, "[%s] [%ld] ", gLevelMap[level], timestamp);char logBuffer[1024]; //自定义部分va_list args;va_start(args, format);vsnprintf(logBuffer, sizeof logBuffer, format, args);va_end(args);FILE *fp = fopen(LOGFILE, "a");fprintf(fp, "%s%s\n", stdBuffer, logBuffer);fclose(fp);
}

makefile

HttpServer:HttpServer.ccg++ -o $@ $^ -std=c++11 -lpthread.PHONY:clean
clean:rm -f HttpServer

Sock.hpp

#pragma once#include <iostream>
#include <string>
#include <cstring>
#include <cerrno>
#include <cassert>
#include <unistd.h>
#include <memory>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <ctype.h>
#include "Log.hpp"class Sock
{
private:const static int gbacklog = 20;public:Sock() {}// 创建套接字int Socket(){int listensock = socket(AF_INET, SOCK_STREAM, 0);if (listensock < 0){logMessage(FATAL, "create socket error, %d:%s", errno, strerror(errno));exit(2);}logMessage(NORMAL, "create socket success, listensock: %d", listensock);return listensock;}// 绑定void Bind(int sock, uint16_t port, std::string ip = "0.0.0.0"){struct sockaddr_in local;memset(&local, 0, sizeof local);local.sin_family = AF_INET;local.sin_port = htons(port);inet_pton(AF_INET, ip.c_str(), &local.sin_addr);if (bind(sock, (struct sockaddr *)&local, sizeof(local)) < 0){logMessage(FATAL, "bind error, %d:%s", errno, strerror(errno));exit(3);}}// 监听void Listen(int sock){if (listen(sock, gbacklog) < 0){logMessage(FATAL, "listen error, %d:%s", errno, strerror(errno));exit(4);}logMessage(NORMAL, "init server success");}// 一般经验// const std::string &: 输入型参数// std::string *: 输出型参数// std::string &: 输入输出型参数int Accept(int listensock, std::string *ip, uint16_t *port){struct sockaddr_in src;socklen_t len = sizeof(src);int servicesock = accept(listensock, (struct sockaddr *)&src, &len);if (servicesock < 0){logMessage(ERROR, "accept error, %d:%s", errno, strerror(errno));// 转移return -1;}if(port) *port = ntohs(src.sin_port);if(ip) *ip = inet_ntoa(src.sin_addr);return servicesock;}// 连接bool Connect(int sock, const std::string &server_ip, const uint16_t &server_port){struct sockaddr_in server;memset(&server, 0, sizeof(server));server.sin_family = AF_INET;server.sin_port = htons(server_port);server.sin_addr.s_addr = inet_addr(server_ip.c_str());if(connect(sock, (struct sockaddr*)&server, sizeof(server)) == 0) return true;else return false;}~Sock() {}
};

Usage.hpp

#pragma once#include <iostream>
#include <string>void Usage(std::string proc)
{std::cout << "\nUsage: " << proc <<  " port\n" << std::endl;
}

Util.hpp

#pragma once#include <iostream>
#include <vector>class Util
{
public:// aaaa\r\nbbbbb\r\nccc\r\n\r\n// 按sep分割符,分割字符static void cutString(std::string s, const std::string &sep, std::vector<std::string> *out){std::size_t start = 0;while (start < s.size()){auto pos = s.find(sep, start);if (pos == std::string::npos) break;std::string sub = s.substr(start, pos - start);// std::cout << "----" << sub << std::endl;out->push_back(sub);start += sub.size();start += sep.size();}if(start < s.size()) {out->push_back(s.substr(start));}}
};