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用C语言在windows中写http/https代理服务器

1.用C语言写一个tcp服务器

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/*
一、服务器
0.初始化socket
1.创建socket
2.绑定地址与端口
3.监听
4.接受来自客户端的连接
5.接收消息->循环接收消息
6.关闭socket
*/
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>

#pragma comment(lib, "ws2_32.lib")

#define d_addr 127.0.0.1
#define d_port 8080

void Start();
int main(int argc,char**argv)
{
	Start();
	_getche();
	return 0;
}
//0.初始化socket
void InitWSA()
{
	WSADATA wsaData;
	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
	{
		printf("Failed to initialize WinSock. Error Code: %d\n", WSAGetLastError());
		return 1;
	}
}
//1.创建socket
SOCKET CreateSocket()
{
	SOCKET serverSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (serverSocket == INVALID_SOCKET) {
		printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
		WSACleanup();
		return 1;
	}
	return serverSocket;
}
//2.绑定地址与端口
void BindAddr(SOCKET serverSocket)
{
	struct sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口
	addr.sin_port = htons(d_port); // 服务器端口
	int statue = bind(serverSocket, (struct sockaddr*)&addr,sizeof(addr));
	if (statue == SOCKET_ERROR) {
		printf("Bind failed. Error Code: %d\n", WSAGetLastError());
		closesocket(serverSocket);
		WSACleanup();
		return 1;
	}
	return;
}
//3.监听连接
void ListenSocket(SOCKET serverSocket)
{
	listen(serverSocket, 3);
	printf("Waiting for incoming connections...\n");
	return;
}
//4.接受来自客户端的连接
SOCKET AcceptConnect(SOCKET serverSocket)
{
	struct sockaddr_in clientAddr;
	int clientSize = sizeof(clientAddr);
	SOCKET clientSocket = accept(serverSocket, (struct sockaddr*)&clientAddr, &clientSize);
	if (serverSocket == INVALID_SOCKET) {
		printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
		WSACleanup();
		return 1;
	}
	char clientIP[INET_ADDRSTRLEN]; // 用于存储客户端 IP 地址
	inet_ntop(AF_INET, &clientAddr.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
	printf("Connection accepted from %s:%d\n", clientIP, ntohs(clientAddr.sin_port));
	return clientSocket;
}
//5.接收消息->循环接收消息
void ReciveMessage(SOCKET clientSocket)
{
	char buffer[1024];
	int recvSize;
	// 接收消息
	while ((recvSize = recv(clientSocket, buffer, sizeof(buffer) - 1, 0)) > 0) {
		buffer[recvSize] = '\0'; // 添加字符串结束符
		printf("Received message: %s\n", buffer);
	}
	if (recvSize == SOCKET_ERROR) {
		printf("Receive failed. Error Code: %d\n", WSAGetLastError());
	}
}
//6.关闭socket
void CloseSocket(SOCKET serverSocket, SOCKET clientSocket)
{
	closesocket(clientSocket);
	closesocket(serverSocket);
	WSACleanup();
	return;
}
void Start()
{
	InitWSA();
	SOCKET serverSocket = CreateSocket();
	BindAddr(serverSocket);
	ListenSocket( serverSocket);
	SOCKET clientSocket =AcceptConnect( serverSocket);
	ReciveMessage( clientSocket);
	CloseSocket(serverSocket,  clientSocket);
	return;
}

2.修改程序，修改为http服务器

  1. 创建一个html文件命名为index.html,存放在程序的当前目录
  2. 编写http_server.c
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//http_server.c
#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <WinSock2.h>
#pragma comment(lib,"ws2_32.lib")

int main()
{
	//开启网络权限
	WSAData wsaData;
	WSAStartup(MAKEWORD(2, 2), &wsaData);

	SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);

	struct sockaddr_in local;
	local.sin_family = AF_INET;
	local.sin_addr.S_un.S_addr = INADDR_ANY;
	local.sin_port = htons(9090);

	bind(sock, (struct sockaddr*)&local, sizeof(struct sockaddr));
	listen(sock, 20);

	int sockfd = accept(sock, NULL, NULL);

	char buff[1024] = { 0 };
	recv(sockfd, buff, 1024, 0);

	printf("%s\n", buff);

	FILE* fp = fopen("index.html", "rb+");
	fseek(fp, 0, SEEK_END);
	int FileSize = ftell(fp);
	fseek(fp, 0, SEEK_SET);
	char* FileCent = (char*)malloc(FileSize);
	fread(FileCent, FileSize, 1, fp);
	fclose(fp);

	char HttpHead[512] = { 0 };
	sprintf(HttpHead, "HTTP/1.0 200 OK\r\nContent-Type: text/html\r\nTransfer-Encoding: chunked\r\nConnection: Keep-Alive\r\nAccept-Ranges:bytes\r\nContent-Length:%d\r\n\r\n", FileSize);

	send(sockfd, HttpHead, strlen(HttpHead), 0);
	send(sockfd, FileCent, FileSize, 0);

	closesocket(sockfd);
	closesocket(sock);

	return 0;
}

3.C语言在windows中写一个http代理服务器

1.http.c

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//http.c
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#pragma comment(lib, "Ws2_32.lib") // 链接 Winsock 库

#define BUFFER_SIZE 4096

// 处理客户端请求的函数
DWORD WINAPI handle_client(void* arg) {
    SOCKET client_sock = *((SOCKET*)arg);
    free(arg);  // 释放内存
    char buffer[BUFFER_SIZE];
    char method[16], url[256], protocol[16];
    char host[128], path[256];
    SOCKET server_sock;
    struct addrinfo hints, * result;

    while (1) {
        // 接收客户端请求
        int received = recv(client_sock, buffer, BUFFER_SIZE - 1, 0);
        if (received <= 0) {
            printf("Client disconnected or error occurred\n");
            break;
        }
        buffer[received] = '\0';

        // 解析 HTTP 请求行
        if (sscanf(buffer, "%s %s %s", method, url, protocol) != 3) {
            fprintf(stderr, "Invalid request: %s\n", buffer);
            break;
        }

        // 检查是否为 GET 方法
        if (strcmp(method, "GET") != 0) {
            fprintf(stderr, "Only GET method is supported\n");
            break;
        }

        // 提取主机名和路径
        if (sscanf(url, "http://%[^/]%s", host, path) != 2) {
            strcpy(path, "/"); // 如果路径为空，则设置为根路径
        }

        // 设置地址信息
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_INET;
        hints.ai_socktype = SOCK_STREAM;
        if (getaddrinfo(host, "80", &hints, &result) != 0) {
            fprintf(stderr, "Failed to resolve host: %s\n", host);
            break;
        }

        // 创建服务器 socket
        server_sock = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
        if (server_sock == INVALID_SOCKET) {
            perror("Failed to create server socket");
            freeaddrinfo(result);
            break;
        }

        // 连接目标服务器
        if (connect(server_sock, result->ai_addr, (int)result->ai_addrlen) == SOCKET_ERROR) {
            perror("Failed to connect to server");
            freeaddrinfo(result);
            closesocket(server_sock);
            break;
        }
        freeaddrinfo(result);

        // 构建并发送代理的 HTTP 请求
        snprintf(buffer, BUFFER_SIZE,
            "GET %s %s\r\n"
            "Host: %s\r\n"
            "Connection: close\r\n"
            "User-Agent: ProxyServer/1.0\r\n\r\n",
            path, protocol, host);

        if (send(server_sock, buffer, strlen(buffer), 0) == SOCKET_ERROR) {
            perror("Failed to send request to server");
            closesocket(server_sock);
            break;
        }

        // 转发服务器响应给客户端
        while ((received = recv(server_sock, buffer, BUFFER_SIZE, 0)) > 0) {
            if (send(client_sock, buffer, received, 0) == SOCKET_ERROR) {
                perror("Failed to send data to client");
                break;
            }
        }

        if (received < 0) {
            perror("Error receiving data from server");
        }

        closesocket(server_sock); // 关闭服务器连接
    }

    closesocket(client_sock); // 关闭客户端连接
    return 0;
}

int main(int argc, char* argv[]) {
    WSADATA wsaData;
    SOCKET proxy_sock, client_sock;
    struct sockaddr_in proxy_addr, client_addr;
    int client_len;

    if (argc != 2) {
        fprintf(stderr, "Usage: %s <port>\n", argv[0]);
        return 1;
    }

    int port = atoi(argv[1]);

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        fprintf(stderr, "Failed to initialize Winsock\n");
        return 1;
    }

    // 创建代理服务器 socket
    proxy_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (proxy_sock == INVALID_SOCKET) {
        perror("Failed to create proxy socket");
        WSACleanup();
        return 1;
    }

    // 配置代理地址
    memset(&proxy_addr, 0, sizeof(proxy_addr));
    proxy_addr.sin_family = AF_INET;
    proxy_addr.sin_addr.s_addr = INADDR_ANY;
    proxy_addr.sin_port = htons(port);

    // 绑定并监听
    if (bind(proxy_sock, (struct sockaddr*)&proxy_addr, sizeof(proxy_addr)) == SOCKET_ERROR) {
        perror("Failed to bind proxy socket");
        closesocket(proxy_sock);
        WSACleanup();
        return 1;
    }

    if (listen(proxy_sock, 10) == SOCKET_ERROR) {
        perror("Failed to listen on proxy socket");
        closesocket(proxy_sock);
        WSACleanup();
        return 1;
    }

    printf("Proxy server is running on port %d...\n", port);

    // 接受并处理客户端请求
    while (1) {
        client_len = sizeof(client_addr);
        client_sock = accept(proxy_sock, (struct sockaddr*)&client_addr, &client_len);
        if (client_sock == INVALID_SOCKET) {
            perror("Failed to accept client connection");
            continue;
        }

        // 为每个客户端连接创建一个新的线程
        HANDLE client_thread;
        SOCKET* client_sock_ptr = malloc(sizeof(SOCKET));
        *client_sock_ptr = client_sock;

        client_thread = CreateThread(NULL, 0, handle_client, client_sock_ptr, 0, NULL);
        if (client_thread == NULL) {
            perror("Failed to create thread");
            closesocket(client_sock);
            free(client_sock_ptr);
        }
        else {
            CloseHandle(client_thread); // 关闭线程句柄，线程自动清理
        }
    }

    // 关闭代理服务器
    closesocket(proxy_sock);
    WSACleanup();
    return 0;
}

2. 运行结果

  1. 在服务器中运行http.exe，此时服务器ip为10.0.4.1。

    1
    .\http.exe 8080

  2. 在本机中设置http代理10.0.4.1:8080。

  3. 运行成功

4.C语言在windows中写一个https代理服务器

1.https.c

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//https.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <windows.h>

#define BUF_SIZE 8192
#define LISTEN_PORT 8080
#define INET_ADDRSTRLEN 16  // Windows 没有定义这个常量，我们手动定义

#pragma comment(lib, "ws2_32.lib")  // 链接 Winsock 库

// 初始化 Winsock
int init_winsock() {
    WSADATA wsaData;
    return WSAStartup(MAKEWORD(2, 2), &wsaData);
}

// 解析 HTTP 请求头，获取目标主机和端口
int parse_http_request(SOCKET client_sock, char* host, int* port, int* is_https) {
    char buffer[BUF_SIZE];
    int total_len = 0;
    int len = 0;

    // 循环读取客户端发送的完整 HTTP 请求
    while ((len = recv(client_sock, buffer + total_len, sizeof(buffer) - total_len - 1, 0)) > 0) {
        total_len += len;
        buffer[total_len] = '\0'; // 确保字符串终止符

        printf("Received %d bytes, total length = %d\n", len, total_len);
        printf("Partial Request:\n%s\n", buffer);


        // 判断是否读取完整的请求头（以 "\r\n\r\n" 结束）
        if (strstr(buffer, "\r\n\r\n") != NULL) {
            break;
        }
    }

    if (len <= 0) {
        fprintf(stderr, "Failed to read HTTP request from client\n");
        closesocket(client_sock);
        return;
    }

    // 输出完整的 HTTP 请求
    printf("Full HTTP Request:\n%s\n", buffer);

    // 判断是否为 HTTPS 请求（CONNECT 请求）
    if (strncmp(buffer, "CONNECT", 7) == 0) {
        *is_https = 1;
        char* start = buffer + 8;
        char* end = strchr(start, ' ');
        if (!end) return -1;

        *end = '\0';
        char* colon = strchr(start, ':');
        if (colon) {
            *colon = '\0';
            strcpy_s(host, strlen(host)+1, start);  // 使用 strcpy_s 防止溢出
            *port = atoi(colon + 1);
        }
        else {
            strcpy_s(host, strlen(host)+1, start);  // 使用 strcpy_s 防止溢出
            *port = 443;  // 默认 HTTPS 端口
        }
    }
    else
    {
        *is_https = 0;
        const char* Errorinfo = " 400 Not Support\r";
        printf("%s\n", Errorinfo);
        return 0;
    }

    return 0;
}
// 定义一个结构体，用来存储 socket
typedef struct {
    SOCKET client_sock;
    SOCKET remote_sock;
} SocketPair;

// 数据转发函数
void forward_data(SocketPair* sockets) {
    SOCKET src_sock = sockets->client_sock;
    SOCKET dst_sock = sockets->remote_sock;
    char buffer[BUF_SIZE];
    int n;

    while ((n = recv(src_sock, buffer, BUF_SIZE, 0)) > 0) {
        printf("Forwarding %d bytes from source to destination\n", n);  // 调试信息
        if (send(dst_sock, buffer, n, 0) <= 0) {
            perror("Forwarding error");
            break;
        }
    }
}



// 处理客户端连接
void handle_client(SOCKET client_sock) {
    char host[256];
    int port;
    int is_https = 0;

    if (parse_http_request(client_sock, host, &port, &is_https) < 0) {
        fprintf(stderr, "Failed to parse request\n");
        closesocket(client_sock);
        return;
    }
    if (!is_https)return;
    printf("Connecting to %s:%d\n", host, port);

    // 建立与目标服务器的连接
    SOCKET remote_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (remote_sock == INVALID_SOCKET) {
        perror("Socket creation failed");
        closesocket(client_sock);
        return;
    }

    struct sockaddr_in remote_addr;
    remote_addr.sin_family = AF_INET;
    remote_addr.sin_port = htons(port);

    struct hostent* server = gethostbyname(host);
    if (!server) {
        fprintf(stderr, "No such host: %s\n", host);
        closesocket(client_sock);
        closesocket(remote_sock);
        return;
    }
    memcpy(&remote_addr.sin_addr.s_addr, server->h_addr, server->h_length);

    if (connect(remote_sock, (struct sockaddr*)&remote_addr, sizeof(remote_addr)) == SOCKET_ERROR) {
        perror("Failed to connect to remote server");
        closesocket(client_sock);
        closesocket(remote_sock);
        return;
    }

    if (is_https) {
        // 发送 HTTP 200 响应，表示隧道已建立
        const char* tunnel_established = "HTTP/1.1 200 Connection Established\r\n\r\n";
        send(client_sock, tunnel_established, strlen(tunnel_established), 0);
        printf("Tunnel established for HTTPS\n");
    } 

    // 创建 SocketPair 结构体，并传递给线程
    SocketPair sockets1 = { client_sock, remote_sock };
    SocketPair sockets2 = { remote_sock, client_sock };

    // 创建线程并传递 SocketPair 结构体指针
    HANDLE thread1 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)forward_data, &sockets1, 0, NULL);
    HANDLE thread2 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)forward_data, &sockets2, 0, NULL);

    // 等待线程完成
    if (thread1 != NULL) {
        WaitForSingleObject(thread1, INFINITE);
        CloseHandle(thread1);
    }
    if (thread2 != NULL) {
        WaitForSingleObject(thread2, INFINITE);
        CloseHandle(thread2);
    }

    // 关闭连接
    closesocket(client_sock);
    closesocket(remote_sock);
}


// 服务器主程序
int main() {
    if (init_winsock() != 0) {
        fprintf(stderr, "Winsock initialization failed\n");
        return 1;
    }

    SOCKET server_sock;
    struct sockaddr_in server_addr, client_addr;
    int client_len = sizeof(client_addr);

    // 创建服务器 socket
    server_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (server_sock == INVALID_SOCKET) {
        perror("Socket creation failed");
        WSACleanup();
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(LISTEN_PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    // 绑定端口
    if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == SOCKET_ERROR) {
        perror("Bind failed");
        closesocket(server_sock);
        WSACleanup();
        return 1;
    }

    if (listen(server_sock, 10) == SOCKET_ERROR) {
        perror("Listen failed");
        closesocket(server_sock);
        WSACleanup();
        return 1;
    }

    printf("Proxy server listening on port %d...\n", LISTEN_PORT);

    while (1) {
        SOCKET client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &client_len);
        if (client_sock == INVALID_SOCKET) {
            perror("Accept failed");
            continue;
        }

        // 使用 WSAAddressToString 来替代 InetNtop
        char ip_str[INET_ADDRSTRLEN];
        DWORD ip_str_len = INET_ADDRSTRLEN;
        if (WSAAddressToString((struct sockaddr*)&client_addr, sizeof(client_addr), NULL, ip_str, &ip_str_len) == SOCKET_ERROR) {
            fprintf(stderr, "Failed to convert IP address: %d\n", WSAGetLastError());
            closesocket(client_sock);
            continue;
        }

        printf("Accepted connection from %s:%d\n", ip_str, ntohs(client_addr.sin_port));

        // 为每个客户端连接创建新的线程
        HANDLE thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)handle_client, (LPVOID)client_sock, 0, NULL);
        if (thread == NULL) {
            fprintf(stderr, "Failed to create thread: %d\n", GetLastError());
            closesocket(client_sock);
        }
    }

    closesocket(server_sock);
    WSACleanup();
    return 0;
}

2. 运行结果

  1. 在服务器中运行https.exe，此时服务器ip为10.0.4.1
  2. 在本机中设置https代理10.0.4.1:8080。
  3. 运行成功

5 .使用C语言在windows平台中写一个代理服务器，同时支持http/https协议

cproxy.c

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//cproxy.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>

#define BUF_SIZE 8192
#define LISTEN_PORT 8080
#define INET_ADDRSTRLEN 16  // Windows 没有定义这个常量，我们手动定义

#pragma comment(lib, "Ws2_32.lib") // 链接 Winsock 库

// 初始化 Winsock
int init_winsock() {
    WSADATA wsaData;
    return WSAStartup(MAKEWORD(2, 2), &wsaData);
}

// 定义一个结构体，用来存储 socket
typedef struct {
    SOCKET client_sock;
    SOCKET remote_sock;
} SocketPair;

// 数据转发函数
DWORD WINAPI forward_data(void* arg) {
    SocketPair* sockets = (SocketPair*)arg;
    SOCKET src_sock = sockets->client_sock;
    SOCKET dst_sock = sockets->remote_sock;
    char buffer[BUF_SIZE];
    int n;

    while ((n = recv(src_sock, buffer, BUF_SIZE, 0)) > 0) {
        if (send(dst_sock, buffer, n, 0) <= 0) {
            perror("Forwarding error");
            break;
        }
    }
    free(sockets);
    return 0;
}

// 解析 HTTP 请求头，获取目标主机和端口
int parse_http_request(SOCKET client_sock, char* host, int* port, int* is_https, char* path) {
    char buffer[BUF_SIZE];
    int total_len = 0;
    int len;

    while ((len = recv(client_sock, buffer + total_len, sizeof(buffer) - total_len - 1, 0)) > 0) {
        total_len += len;
        buffer[total_len] = '\0';

        if (strstr(buffer, "\r\n\r\n") != NULL) {
            break;
        }
    }

    if (len <= 0) {
        return -1;
    }

    if (strncmp(buffer, "CONNECT", 7) == 0) {
        *is_https = 1;
        sscanf_s(buffer, "CONNECT %[^:]:%d", host, (unsigned)_countof(host), port);

    }
    else {
        *is_https = 0;
        sscanf_s(buffer, "CONNECT %[^:]:%d", host, (unsigned)_countof(host), path);
        *port = 80;
    }
    return 0;
}

// 处理客户端连接
void handle_client(SOCKET client_sock) {
    char host[256];
    int port;
    int is_https = 0;
    char path[256] = "/";

    if (parse_http_request(client_sock, host, &port, &is_https, path) < 0) {
        fprintf(stderr, "Failed to parse request\n");
        closesocket(client_sock);
        return;
    }

    printf("Connecting to %s:%d\n", host, port);

    SOCKET remote_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (remote_sock == INVALID_SOCKET) {
        perror("Socket creation failed");
        closesocket(client_sock);
        return;
    }

    struct addrinfo hints, * result;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;

    if (getaddrinfo(host, is_https ? "443" : "80", &hints, &result) != 0) {
        fprintf(stderr, "Failed to resolve host: %s\n", host);
        closesocket(client_sock);
        closesocket(remote_sock);
        return;
    }

    if (connect(remote_sock, result->ai_addr, (int)result->ai_addrlen) == SOCKET_ERROR) {
        perror("Failed to connect to remote server");
        freeaddrinfo(result);
        closesocket(client_sock);
        closesocket(remote_sock);
        return;
    }
    freeaddrinfo(result);

    if (is_https) {
        const char* response = "HTTP/1.1 200 Connection Established\r\n\r\n";
        send(client_sock, response, strlen(response), 0);
    }
    else {
        char request[BUF_SIZE];
        snprintf(request, BUF_SIZE,
            "GET %s HTTP/1.1\r\n"
            "Host: %s\r\n"
            "Connection: close\r\n\r\n",
            path, host);
        send(remote_sock, request, strlen(request), 0);
    }

    SocketPair* sockets1 = malloc(sizeof(SocketPair));
    SocketPair* sockets2 = malloc(sizeof(SocketPair));

    sockets1->client_sock = client_sock;
    sockets1->remote_sock = remote_sock;
    sockets2->client_sock = remote_sock;
    sockets2->remote_sock = client_sock;

    HANDLE thread1 = CreateThread(NULL, 0, forward_data, sockets1, 0, NULL);
    HANDLE thread2 = CreateThread(NULL, 0, forward_data, sockets2, 0, NULL);

    WaitForSingleObject(thread1, INFINITE);
    WaitForSingleObject(thread2, INFINITE);

    CloseHandle(thread1);
    CloseHandle(thread2);
    closesocket(client_sock);
    closesocket(remote_sock);
}

// 服务器主程序
int main() {
    if (init_winsock() != 0) {
        fprintf(stderr, "Winsock initialization failed\n");
        return 1;
    }

    SOCKET server_sock;
    struct sockaddr_in server_addr, client_addr;
    int client_len = sizeof(client_addr);

    server_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (server_sock == INVALID_SOCKET) {
        perror("Socket creation failed");
        WSACleanup();
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(LISTEN_PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == SOCKET_ERROR) {
        perror("Bind failed");
        closesocket(server_sock);
        WSACleanup();
        return 1;
    }

    if (listen(server_sock, 10) == SOCKET_ERROR) {
        perror("Listen failed");
        closesocket(server_sock);
        WSACleanup();
        return 1;
    }

    printf("Proxy server listening on port %d...\n", LISTEN_PORT);

    while (1) {
        SOCKET client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &client_len);
        if (client_sock == INVALID_SOCKET) {
            perror("Accept failed");
            continue;
        }

        HANDLE thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)handle_client, (LPVOID)client_sock, 0, NULL);
        if (thread == NULL) {
            fprintf(stderr, "Failed to create thread\n");
            closesocket(client_sock);
        }
        else {
            CloseHandle(thread);
        }
    }

    closesocket(server_sock);
    WSACleanup();
    return 0;
}

用C语言在Linux中写http代理服务器

1.用C语言在Linux中写http代理服务器

访问http://info.cern.ch

其他的一些http网站

1
2
http://www.auiou.com/relevant/00000909.jsp
http://www.moe.gov.cn/

Linuxhttp.c

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#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include <pthread.h>
#include <netinet/in.h>
#include <signal.h>

#define BUFFER_SIZE 4096
#define TIMEOUT_SECONDS 5 // 设置超时为5秒

// 处理客户端请求
void* handle_client(void* arg) {
    int client_sock = *((int*)arg);
    free(arg);  // 释放内存
    char buffer[BUFFER_SIZE];
    char method[16], url[256], protocol[16];
    char host[128], path[256];
    int server_sock;
    struct sockaddr_in server_addr;

    // 设置信号处理，捕获 SIGPIPE
    signal(SIGPIPE, SIG_IGN);

    while (1) { // 循环处理客户端请求
        // 接收客户端请求
        int received = recv(client_sock, buffer, BUFFER_SIZE - 1, 0);
        if (received < 0) {
            perror("Failed to receive data from client");
            break;  // 如果接收失败，退出循环
        }
        if (received == 0) {
            printf("Client closed connection\n");
            break; // 客户端关闭连接，跳出循环
        }

        buffer[received] = '\0';

        // 解析 HTTP 请求行
        if (sscanf(buffer, "%s %s %s", method, url, protocol) != 3) {
            fprintf(stderr, "Invalid request: %s\n", buffer);
            break;
        }

        // 检查是否为 GET 方法
        if (strcmp(method, "GET") != 0) {
            fprintf(stderr, "Only GET method is supported\n");
            break;
        }

        // 提取主机名和路径
        if (sscanf(url, "http://%[^/]%s", host, path) != 2) {
            strcpy(path, "/"); // 如果路径为空，则设置为根路径
        }

        // 创建连接到目标服务器的 socket
        server_sock = socket(AF_INET, SOCK_STREAM, 0);
        if (server_sock < 0) {
            perror("Failed to create socket to server");
            break;  // 如果无法创建 socket，退出循环
        }

        // 解析目标主机 IP
        struct hostent* server = gethostbyname(host);
        if (!server) {
            fprintf(stderr, "No such host: %s\n", host);
            break; // 如果无法解析主机名，退出循环
        }

        memset(&server_addr, 0, sizeof(server_addr));
        server_addr.sin_family = AF_INET;
        server_addr.sin_port = htons(80);
        memcpy(&server_addr.sin_addr.s_addr, server->h_addr, server->h_length);

        // 连接到目标服务器
        if (connect(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
            perror("Failed to connect to server");
            break; // 如果连接失败，退出循环
        }

        // 构建并发送代理的 HTTP 请求
        snprintf(buffer, BUFFER_SIZE,
            "GET %s %s\r\n"
            "Host: %s\r\n"
            "Connection: close\r\n"
            "User-Agent: ProxyServer/1.0\r\n\r\n",
            path, protocol, host);

        if (send(server_sock, buffer, strlen(buffer), 0) < 0) {
            perror("Failed to send request to server");
            break; // 如果发送请求失败，退出循环
        }

        // 转发服务器响应给客户端
        while ((received = recv(server_sock, buffer, BUFFER_SIZE, 0)) > 0) {
            if (send(client_sock, buffer, received, 0) < 0) {
                perror("Failed to send data to client");
                break; // 如果发送数据失败，退出循环
            }
        }

        if (received < 0) {
            perror("Error receiving data from server");
        }

        // 关闭服务器连接
        close(server_sock);
    }

    // 关闭客户端连接
    close(client_sock);
    return NULL;
}

int main(int argc, char* argv[]) {
    int proxy_sock, client_sock;
    struct sockaddr_in proxy_addr, client_addr;
    socklen_t client_len;

    if (argc != 2) {
        fprintf(stderr, "Usage: %s <port>\n", argv[0]);
        return 1;
    }

    int port = atoi(argv[1]);

    // 创建代理服务器 socket
    proxy_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (proxy_sock < 0) {
        perror("Failed to create proxy socket");
        return 1;
    }

    memset(&proxy_addr, 0, sizeof(proxy_addr));
    proxy_addr.sin_family = AF_INET;
    proxy_addr.sin_addr.s_addr = INADDR_ANY;
    proxy_addr.sin_port = htons(port);

    // 绑定并监听
    if (bind(proxy_sock, (struct sockaddr*)&proxy_addr, sizeof(proxy_addr)) < 0) {
        perror("Failed to bind proxy socket");
        close(proxy_sock);
        return 1;
    }

    if (listen(proxy_sock, 10) < 0) {
        perror("Failed to listen on proxy socket");
        close(proxy_sock);
        return 1;
    }

    printf("Proxy server is running on port %d...\n", port);

    // 接受并处理客户端请求
    while ((client_sock = accept(proxy_sock, (struct sockaddr*)&client_addr, &client_len)) >= 0) {
        // 为每个客户端连接创建一个新的线程
        pthread_t client_thread;
        int* client_sock_ptr = malloc(sizeof(int));
        *client_sock_ptr = client_sock;
        if (pthread_create(&client_thread, NULL, handle_client, client_sock_ptr) != 0) {
            perror("Failed to create thread");
            close(client_sock);
        } else {
            // Detach thread so it cleans up after itself
            pthread_detach(client_thread);
        }
    }

    // 关闭代理服务器
    close(proxy_sock);
    return 0;
}

2.用C语言在Linux中写https代理服务器

linuxhttps.c

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//linuxhttps.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <netdb.h> // 解决 gethostbyname 和 struct hostent 的定义问题


#define BUF_SIZE 8192
#define LISTEN_PORT 8080

// 读取 HTTP 请求头，获取目标主机和端口
int parse_http_request(int client_sock, char *host, int *port, int *is_https) {
    char buffer[BUF_SIZE];
    int len = recv(client_sock, buffer, sizeof(buffer) - 1, 0);
    if (len <= 0) return -1;

    buffer[len] = '\0';
    printf("Received Request:\n%s", buffer);

    if (strncmp(buffer, "CONNECT", 7) == 0) { // HTTPS 隧道请求
        *is_https = 1;
        char *start = buffer + 8;
        char *end = strchr(start, ' ');
        if (!end) return -1;

        *end = '\0';
        char *colon = strchr(start, ':');
        if (colon) {
            *colon = '\0';
            strcpy(host, start);
            *port = atoi(colon + 1);
        } else {
            strcpy(host, start);
            *port = 443; // 默认 HTTPS 端口
        }
    } else { // 其他 请求
        *is_https = 0;
        const char* Errorinfo = " 400 Not Support\r";
        printf("%s\n", Errorinfo);
        return 0;

    }

    return 0;
}

// 数据转发函数
void forward_data(int src_sock, int dst_sock) {
    char buffer[BUF_SIZE];
    ssize_t n;

    while ((n = recv(src_sock, buffer, BUF_SIZE, 0)) > 0) {
        if (send(dst_sock, buffer, n, 0) <= 0) {
            perror("Forwarding error");
            break;
        }
    }
}

// 处理客户端连接
void handle_client(int client_sock) {
    char host[256];
    int port;
    int is_https = 0;

    if (parse_http_request(client_sock, host, &port, &is_https) < 0) {
        fprintf(stderr, "Failed to parse request\n");
        close(client_sock);
        return;
    }
    
     if (!is_https)return;
    printf("Connecting to %s:%d\n", host, port);

    // 建立与目标服务器的连接
    int remote_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (remote_sock < 0) {
        perror("Socket creation failed");
        close(client_sock);
        return;
    }

    struct sockaddr_in remote_addr;
    remote_addr.sin_family = AF_INET;
    remote_addr.sin_port = htons(port);

    struct hostent *server = gethostbyname(host);
    if (!server) {
        fprintf(stderr, "No such host: %s\n", host);
        close(client_sock);
        close(remote_sock);
        return;
    }
    memcpy(&remote_addr.sin_addr.s_addr, server->h_addr, server->h_length);

    if (connect(remote_sock, (struct sockaddr *)&remote_addr, sizeof(remote_addr)) < 0) {
        perror("Failed to connect to remote server");
        close(client_sock);
        close(remote_sock);
        return;
    }

    if (is_https) {
        // 发送 HTTP 200 响应，表示隧道已建立
        const char *tunnel_established = "HTTP/1.1 200 Connection Established\r\n\r\n";
        send(client_sock, tunnel_established, strlen(tunnel_established), 0);
    }

    // 数据转发，分别处理两个方向
    if (fork() == 0) {
        forward_data(client_sock, remote_sock); // 客户端 -> 目标服务器
        exit(0);
    }
    if (fork() == 0) {
        forward_data(remote_sock, client_sock); // 目标服务器 -> 客户端
        exit(0);
    }

    close(client_sock);
    close(remote_sock);
    wait(NULL);
    wait(NULL);
}

int main() {
    int server_sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_len = sizeof(client_addr);

    // 创建服务器 socket
    server_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (server_sock < 0) {
        perror("Socket creation failed");
        exit(1);
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(LISTEN_PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    // 绑定端口
    if (bind(server_sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("Bind failed");
        close(server_sock);
        exit(1);
    }

    if (listen(server_sock, 10) < 0) {
        perror("Listen failed");
        close(server_sock);
        exit(1);
    }

    printf("Proxy server listening on port %d...\n", LISTEN_PORT);

    while (1) {
        int client_sock = accept(server_sock, (struct sockaddr *)&client_addr, &client_len);
        if (client_sock < 0) {
            perror("Accept failed");
            continue;
        }

        printf("Accepted connection from %s:%d\n",
               inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

        if (fork() == 0) { // 创建子进程处理客户端
            close(server_sock);
            handle_client(client_sock);
            exit(0);
        }
        close(client_sock);
    }

    close(server_sock);
    return 0;
}

3.使用C语言在Linux平台中写一个代理服务器，同时支持http/https协议

linux_cproxy.c

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//linux_cproxy.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <netdb.h>

#define BUF_SIZE 8192
#define LISTEN_PORT 8080

typedef struct {
    int client_sock;
    int remote_sock;
} SocketPair;

// 在 forward_data 函数中确保释放内存
void* forward_data(void* arg) {
    SocketPair* sockets = (SocketPair*)arg;
    int src_sock = sockets->client_sock;
    int dst_sock = sockets->remote_sock;
    char buffer[BUF_SIZE];
    int n;

    while ((n = recv(src_sock, buffer, BUF_SIZE, 0)) > 0) {
        if (send(dst_sock, buffer, n, 0) <= 0) {
            perror("Forwarding error");
            break;
        }
    }
    close(src_sock); // 关闭源套接字
    close(dst_sock); // 关闭目标套接字
    free(sockets);   // 释放内存
    return NULL;
}

int parse_http_request(int client_sock, char* host, int* port, int* is_https, char* path) {
    char buffer[BUF_SIZE];
    int total_len = 0;
    int len;

    while ((len = recv(client_sock, buffer + total_len, sizeof(buffer) - total_len - 1, 0)) > 0) {
        total_len += len;
        buffer[total_len] = '\0';

        if (strstr(buffer, "\r\n\r\n") != NULL) {
            break;
        }
    }

    if (len <= 0) {
        return -1;
    }

   if (strncmp(buffer, "CONNECT", 7) == 0) {
        *is_https = 1;
        if (sscanf(buffer, "CONNECT %[^:]:%d", host, port) != 2) {
            return -1; // 解析失败
        }
    } else {
        *is_https = 0;
        if (sscanf(buffer, "GET http://%[^/]%s", host, path) != 2) {
            return -1; // 解析失败
        }
        *port = 80;
    }
    return 0;
}

void handle_client(int client_sock) {
    char host[256];
    int port;
    int is_https = 0;
    char path[256] = "/";

    if (parse_http_request(client_sock, host, &port, &is_https, path) < 0) {
        fprintf(stderr, "Failed to parse request\n");
        close(client_sock);
        return;
    }

    printf("Connecting to %s:%d\n", host, port);

    int remote_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (remote_sock < 0) {
        perror("Socket creation failed");
        close(client_sock);
        return;
    }

    struct addrinfo hints, *result;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;

    if (getaddrinfo(host, is_https ?     "443" : "80", &hints, &result) != 0) {
        fprintf(stderr, "Failed to resolve host: %s\n", host);
        close(client_sock);
        close(remote_sock);
        return;
    }

    if (connect(remote_sock, result->ai_addr, result->ai_addrlen) < 0) {
        perror("Failed to connect to remote server");
        freeaddrinfo(result);
        close(client_sock);
        close(remote_sock);
        return;
    }
    freeaddrinfo(result);

    if (is_https) {
        const char* response = "HTTP/1.1 200 Connection Established\r\n\r\n";
        send(client_sock, response, strlen(response), 0);
    } else {
        char request[BUF_SIZE];
        snprintf(request, BUF_SIZE,
            "GET %s HTTP/1.1\r\n"
            "Host: %s\r\n"
            "Connection: close\r\n\r\n",
            path, host);
        send(remote_sock, request, strlen(request), 0);
    }

    SocketPair* sockets1 = malloc(sizeof(SocketPair));
    SocketPair* sockets2 = malloc(sizeof(SocketPair));

    if (sockets1 == NULL || sockets2 == NULL) {
        perror("Failed to allocate memory for socket pairs");
        close(client_sock);
        close(remote_sock);
        return;
    }

    sockets1->client_sock = client_sock;
    sockets1->remote_sock = remote_sock;
    sockets2->client_sock = remote_sock;
    sockets2->remote_sock = client_sock;

    pthread_t thread1, thread2;
    if (pthread_create(&thread1, NULL, forward_data, sockets1) != 0) {
        perror("Failed to create thread for forwarding data from client to remote");
        free(sockets1);
        free(sockets2);
        close(client_sock);
        close(remote_sock);
        return;
    }

    if (pthread_create(&thread2, NULL, forward_data, sockets2) != 0) {
        perror("Failed to create thread for forwarding data from remote to client");
        free(sockets1);
        free(sockets2);
        close(client_sock);
        close(remote_sock);
        return;
    }

    pthread_detach(thread1);
    pthread_detach(thread2);
}

// 服务器主程序
int main() {
    int server_sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_len = sizeof(client_addr);

    server_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (server_sock < 0) {
        perror("Socket creation failed");
        return 1;
    }

    // 设置 SO_REUSEADDR 选项
    int opt = 1;
    if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
        perror("setsockopt failed");
        close(server_sock);
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(LISTEN_PORT);
    server_addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("Bind failed");
        close(server_sock);
        return 1;
    }

    if (listen(server_sock, 10) < 0) {
        perror("Listen failed");
        close(server_sock);
        return 1;
    }

    printf("Proxy server listening on port %d...\n", LISTEN_PORT);

    while (1) {
        int client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &client_len);
        if (client_sock < 0) {
            perror("Accept failed");
            continue;
        }

        // 创建一个新线程来处理客户端连接
        pthread_t thread;
        if (pthread_create(&thread, NULL, (void* (*)(void*))handle_client, (void*)(intptr_t)client_sock) != 0) {
            fprintf(stderr, "Failed to create thread\n");
            close(client_sock);
        } else {
            pthread_detach(thread); // 使线程在结束时自动释放资源
        }
    }

    close(server_sock);
    return 0;
}