kk Blog —— 通用基础

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define BUF_LEN 2048
#define PORT 8080

int main(int argc, char *argv[])
{
	int serv_sock = -1, client_sock = -1;
	socklen_t addr_len = 0;
	struct sockaddr_in6 local_addr = {0}, client_addr = {0};
	char buf[BUF_LEN] = {0};
	int err = -1;

	/* 建立socket */
	serv_sock = socket(PF_INET6, SOCK_STREAM, 0);
	if (-1 == serv_sock) {
		perror("socket error: ");
		return -1;
	}

	/* 填充地址结构 */
	local_addr.sin6_family = AF_INET6;
	local_addr.sin6_port = htons(PORT);
	local_addr.sin6_addr = in6addr_any;

	/* 绑定地址 */
	err = bind(serv_sock, (struct sockaddr *)&local_addr, sizeof(struct sockaddr_in6));
	if (-1 == err) {
		perror("bind error: ");
		close(serv_sock);
		return -1;
	}

	/* 监听 */
	err = listen(serv_sock, 5);
	if (-1 == err) {
		perror("listen error: ");
		close(serv_sock);
		return -1;
	}

	/* 循环等待客户连接请求 */
	while (1) {
		memset(&client_addr, 0x0, sizeof(client_addr));
		addr_len = sizeof(struct sockaddr_in6);
		client_sock = accept(serv_sock, (struct sockaddr *)&client_addr, &addr_len);
		if (-1 == client_sock) {
			perror("accept error:");
			close(serv_sock);
			return -1;
		}

		/* 转换client地址为字符串并打印 */
		inet_ntop(AF_INET6, &client_addr.sin6_addr, buf, BUF_LEN);
		printf("A clinet connected, ip: %s, port %d\n", buf, ntohs(client_addr.sin6_port));

		/* 接收消息 */
		memset(buf, 0x0, BUF_LEN);
		err = recv(client_sock, buf, BUF_LEN, 0);
		if (err < 0) {
			perror("recv error:");
			close(serv_sock);
			close(client_sock);
			return -1;
		}
		printf("recv %d bytes: %s\n", err, buf);

		/* 回送消息 */
		err = send(client_sock, buf, strlen(buf), 0);
		if (err < 0) {
			perror("send error:");
			close(serv_sock);
			close(client_sock);
			return -1;
		}

		/* 关闭这个client连接 */
		close(client_sock);
	}
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define BUF_LEN 2048
#define PORT 8080

int main(int argc, char *argv[])
{
	int sock = -1;
	socklen_t addr_len = 0;
	struct sockaddr_in6 serv_addr = {0};
	char buf[BUF_LEN] = {0};
	int err = -1;

	/* 建立socket */
	sock = socket(AF_INET6, SOCK_STREAM, 0);
	if (-1 == sock) {
		perror("socket error: ");
		return -1;
	}

	memset(&serv_addr, 0x0, sizeof(serv_addr));
	/* 填充地址结构 */
	serv_addr.sin6_family = AF_INET6;
	serv_addr.sin6_port = htons(PORT);

	//serv_addr.sin6_addr = in6addr_loopback;  /* 连接到环回地址 */

	//inet_pton(AF_INET6, "2002:da80:e000::1:1:9", &serv_addr.sin6_addr);

	//inet_pton(AF_INET6, "::ffff:c0a8:0208", &serv_addr.sin6_addr);
	//inet_pton(AF_INET6, "::c0a8:0205", &serv_addr.sin6_addr);

	// connect到链路本地地址，需要设置sin6_scope_id，用`ip addr show`获取
	serv_addr.sin6_scope_id = 2;
	inet_pton(AF_INET6, "fe80::a00:27ff:fea0:67d6", &serv_addr.sin6_addr);

	addr_len = sizeof(serv_addr);
	err = connect(sock, (struct sockaddr *)&serv_addr, addr_len);
	if (-1 == err) {
		perror("connect error:");
		close(sock);
		return -1;
	}

	/* 发送消息 */
	memset(buf, 0x0, BUF_LEN);
	snprintf(buf, BUF_LEN - 1, "hello server, I'm client\n");
	err = send(sock, buf, strlen(buf), 0);
	if (err < 0) {
		perror("send error:");
		close(sock);
		return -1;
	}

	/* 接收消息 */
	memset(buf, 0x0, BUF_LEN);
	err = recv(sock, buf, BUF_LEN, 0);
	if (err < 0) {
		perror("recv error:");
		close(sock);
		return -1;
	}
	printf("recv %d bytes: %s\n", err, buf);

	close(sock);

	return 0;
}