1 /*
2 * Copyright (C) 2022 HiHope Open Source Organization .
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http:// www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 *
14 * limitations under the License.
15 */
16 #include <errno.h>
17 #include <stdio.h>
18 #include <unistd.h>
19
20 #include "net_demo.h"
21 #include "net_common.h"
22
23 static char request[] = "Hello.";
24 static char response[128] = "";
25
UdpClientTest(const char * host,unsigned short port)26 void UdpClientTest(const char* host, unsigned short port)
27 {
28 ssize_t retval = 0;
29 int sockfd = socket(AF_INET, SOCK_DGRAM, 0); // UDP socket
30
31 struct sockaddr_in toAddr = {0};
32 toAddr.sin_family = AF_INET;
33 toAddr.sin_port = htons(port); // 端口号，从主机字节序转为网络字节序
34 if (inet_pton(AF_INET, host, &toAddr.sin_addr) <= 0) { // 将主机IP地址从“点分十进制”字符串 转化为 标准格式（32位整数）
35 printf("inet_pton failed!\r\n");
36 printf("do_cleanup...\r\n");
37 close(sockfd);
38 }
39
40 // UDP socket 是 “无连接的” ，因此每次发送都必须先指定目标主机和端口，主机可以是多播地址
41 retval = sendto(sockfd, request, sizeof(request), 0, (struct sockaddr *)&toAddr, sizeof(toAddr));
42 if (retval < 0) {
43 printf("sendto failed!\r\n");
44 printf("do_cleanup...\r\n");
45 close(sockfd);
46 }
47 printf("send UDP message {%s} %ld done!\r\n", request, retval);
48
49 struct sockaddr_in fromAddr = {0};
50 socklen_t fromLen = sizeof(fromAddr);
51
52 // UDP socket 是 “无连接的” ，因此每次接收时前并不知道消息来自何处，通过 fromAddr 参数可以得到发送方的信息（主机、端口号）
53 retval = recvfrom(sockfd, &response, sizeof(response), 0, (struct sockaddr *)&fromAddr, &fromLen);
54 if (retval <= 0) {
55 printf("recvfrom failed or abort, %ld, %d!\r\n", retval, errno);
56 printf("do_cleanup...\r\n");
57 close(sockfd);
58 }
59 response[retval] = '\0';
60 printf("recv UDP message {%s} %ld done!\r\n", response, retval);
61 printf("peer info: ipaddr = %s, port = %d\r\n", inet_ntoa(fromAddr.sin_addr), ntohs(fromAddr.sin_port));
62 CLIENT_TEST_DEMO(UdpClientTest);