![\"menu-r.4af5f7ec.gif\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/07\/20250730102639-6889f35f38e7f.gif\")
<\/p>\n \u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：UDP（\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae）\u662f\u7528\u4e8e\u7f51\u7edc\u901a\u4fe1\u7684\u65e0\u8fde\u63a5\u534f\u8bae，\u76f8\u6bd4TCP\u66f4\u9002\u5408\u5b9e\u65f6\u5e94\u7528\u3002\u901a\u8fc7\u6b64UDP\u670d\u52a1\u5668\u548c\u5ba2\u6237\u7aef\u7684\u793a\u4f8b\u7a0b\u5e8f，\u5f00\u53d1\u8005\u53ef\u4ee5\u5b66\u4e60\u5982\u4f55\u5728\u5c40\u57df\u7f51\u5185\u5b9e\u73b0\u57fa\u7840\u7684\u6570\u636e\u4ea4\u6362\u3002\u793a\u4f8b\u6db5\u76d6\u4e86\u521b\u5efa\u5957\u63a5\u5b57\u3001\u7ed1\u5b9aIP\u7aef\u53e3\u3001\u6570\u636e\u63a5\u6536\u548c\u53d1\u9001\u7b49\u5173\u952e\u6b65\u9aa4，\u5e76\u5c55\u793a\u4e86\u5982\u4f55\u5904\u7406UDP\u7684\u4e0d\u53ef\u9760\u6027\u95ee\u9898\u3002 ![\"udp](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/07\/20250730102639-6889f35f95972.png\")
<\/p>\n
\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae（UDP）\u662f\u7f51\u7edc\u901a\u4fe1\u4e2d\u4e00\u4e2a\u8f7b\u91cf\u7ea7\u7684\u4f20\u8f93\u5c42\u534f\u8bae，\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u65e0\u9700\u5efa\u7acb\u8fde\u63a5\u5373\u53ef\u53d1\u9001\u6570\u636e\u5305\u7684\u65b9\u5f0f\u3002UDP\u4ee5\u5176\u9ad8\u6548\u6027\u548c\u7b80\u5355\u6027，\u5728\u7279\u5b9a\u573a\u666f\u4e0b\u6709\u7740\u5e7f\u6cdb\u7684\u5e94\u7528\u3002 <\/p>\n
UDP\u534f\u8bae\u7684\u4e3b\u8981\u7279\u6027\u5305\u62ec： – \u65e0\u8fde\u63a5 ：\u53d1\u9001\u6570\u636e\u524d\u65e0\u9700\u5efa\u7acb\u8fde\u63a5，\u53ef\u4ee5\u5feb\u901f\u53d1\u9001\u6570\u636e\u3002 – \u4f20\u8f93\u901f\u5ea6\u5feb ：\u7531\u4e8e\u7701\u7565\u4e86\u8fde\u63a5\u7684\u5efa\u7acb\u548c\u7ec8\u6b62\u8fc7\u7a0b，\u6570\u636e\u4f20\u8f93\u6548\u7387\u8f83\u9ad8\u3002 – \u65e0\u5e8f\u4f20\u8f93 ：UDP\u4e0d\u4fdd\u8bc1\u6570\u636e\u5305\u7684\u987a\u5e8f，\u5230\u8fbe\u987a\u5e8f\u53ef\u80fd\u4e0e\u53d1\u9001\u987a\u5e8f\u4e0d\u540c\u3002 – \u53ef\u9760\u6027\u4f4e ：UDP\u4e0d\u63d0\u4f9b\u786e\u8ba4\u673a\u5236，\u6570\u636e\u5305\u53ef\u80fd\u4f1a\u4e22\u5931\u6216\u91cd\u590d\u3002 – \u5f00\u9500\u5c0f ：UDP\u5934\u90e8\u4ec5\u5305\u542b8\u5b57\u8282\u7684\u63a7\u5236\u4fe1\u606f，\u5f00\u9500\u8f83\u5c0f\u3002 <\/p>\n
UDP\u534f\u8bae\u7279\u522b\u9002\u5408\u4ee5\u4e0b\u573a\u666f： – \u5b9e\u65f6\u5e94\u7528 ：\u5982\u89c6\u9891\u4f1a\u8bae\u3001\u5728\u7ebf\u6e38\u620f\u7b49，\u8fd9\u4e9b\u5e94\u7528\u53ef\u4ee5\u5bb9\u5fcd\u4e00\u5b9a\u7a0b\u5ea6\u7684\u6570\u636e\u4e22\u5931，\u4f46\u8981\u6c42\u4f4e\u5ef6\u8fdf\u3002 – \u65e0\u9700\u8fde\u63a5\u7ba1\u7406 ：\u5982DNS\u67e5\u8be2，\u8bf7\u6c42\u4e0e\u54cd\u5e94\u91cf\u5de8\u5927，\u6bcf\u6b21\u5efa\u7acb\u8fde\u63a5\u7684\u5f00\u9500\u4e0d\u5212\u7b97\u3002 – \u5e7f\u64ad\u6216\u591a\u64ad ：UDP\u652f\u6301\u4e00\u5bf9\u591a\u7684\u6570\u636e\u4f20\u8f93，\u9002\u5408\u5e7f\u64ad\u6216\u591a\u64ad\u7f51\u7edc\u670d\u52a1\u3002 – \u7b80\u5355\u534f\u8bae ：\u5bf9\u4e8e\u4e00\u4e9b\u7b80\u5355\u7684\u8bf7\u6c42-\u54cd\u5e94\u6a21\u5f0f\u7684\u534f\u8bae，\u5982TFTP（\u7b80\u5355\u6587\u4ef6\u4f20\u8f93\u534f\u8bae），UDP\u63d0\u4f9b\u4e86\u8db3\u591f\u7b80\u5355\u7684\u901a\u4fe1\u624b\u6bb5\u3002 <\/p>\n
\u901a\u8fc7\u7406\u89e3UDP\u7684\u7279\u6027\u4e0e\u9002\u7528\u573a\u666f，\u5f00\u53d1\u8005\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u9700\u6c42\u9009\u62e9\u6700\u5408\u9002\u7684\u7f51\u7edc\u901a\u4fe1\u534f\u8bae，\u4ee5\u8fbe\u5230\u6700\u4f73\u7684\u5e94\u7528\u6548\u679c\u3002\u5728\u63a5\u4e0b\u6765\u7684\u7ae0\u8282\u4e2d，\u6211\u4eec\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u5b9e\u73b0UDP\u670d\u52a1\u5668\u7aef\u548c\u5ba2\u6237\u7aef，\u4ee5\u53ca\u5982\u4f55\u5728\u5c40\u57df\u7f51\u5185\u914d\u7f6eUDP\u901a\u4fe1\u548c\u5904\u7406UDP\u901a\u4fe1\u7684\u4e0d\u53ef\u9760\u6027\u3002 <\/p>\n
\u5957\u63a5\u5b57\u662f\u7f51\u7edc\u901a\u4fe1\u7684\u57fa\u7840，\u5b83\u662f\u901a\u4fe1\u7684\u7aef\u70b9，\u80fd\u591f\u8ba9\u4f4d\u4e8e\u4e0d\u540c\u4e3b\u673a\u4e0a\u7684\u8fdb\u7a0b\u8fdb\u884c\u6570\u636e\u4ea4\u6362\u3002\u5957\u63a5\u5b57\u662f\u5e94\u7528\u5c42\u4e0eTCP\/IP\u534f\u8bae\u65cf\u901a\u4fe1\u7684\u4e2d\u95f4\u8f6f\u4ef6\u62bd\u8c61\u5c42，\u4f4d\u4e8e\u5e94\u7528\u5c42\u4e0e\u4f20\u8f93\u5c42\u4e4b\u95f4\u3002\u4ece\u7f16\u7a0b\u89d2\u5ea6\u6765\u770b，\u5957\u63a5\u5b57\u53ef\u4ee5\u770b\u4f5c\u662f\u4e24\u4e2a\u5e94\u7528\u5c42\u8fdb\u7a0b\u95f4\u8fdb\u884c\u53cc\u5411\u901a\u4fe1\u7684\u7aef\u70b9\u3002 <\/p>\n
\u5728UDP\u670d\u52a1\u5668\u7aef\u5f00\u53d1\u4e2d，\u9996\u5148\u9700\u8981\u521b\u5efa\u4e00\u4e2aUDP\u5957\u63a5\u5b57\u3002\u521b\u5efa\u5957\u63a5\u5b57\u540e，\u670d\u52a1\u5668\u7aef\u5c31\u53ef\u4ee5\u901a\u8fc7\u8fd9\u4e2a\u5957\u63a5\u5b57\u4e0e\u5ba2\u6237\u7aef\u8fdb\u884c\u6570\u636e\u7684\u53d1\u9001\u548c\u63a5\u6536\u64cd\u4f5c\u3002 <\/p>\n
\u521b\u5efaUDP\u5957\u63a5\u5b57\u901a\u5e38\u6d89\u53ca\u8c03\u7528 socket() \u51fd\u6570，\u5176\u539f\u578b\u5982\u4e0b： <\/p>\n
int socket(int domain, int type, int protocol);<\/p>\n
\u4ee5\u4e0b\u662f\u521b\u5efaUDP\u5957\u63a5\u5b57\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h><\/p>\n
int sockfd;
\nsockfd = socket(AF_INET, SOCK_DGRAM, 0);
\nif (sockfd < 0) {
\n perror("socket failed");
\n exit(EXIT_FAILURE);
\n}<\/p>\n
\u7f51\u7edc\u901a\u4fe1\u4e2d，\u7aef\u53e3\u662f\u903b\u8f91\u6982\u5ff5，\u5b83\u7528\u4e8e\u533a\u5206\u540c\u4e00\u4e3b\u673a\u4e0a\u7684\u591a\u4e2a\u7f51\u7edc\u670d\u52a1\u3002\u7aef\u53e3\u53f7\u662f\u4e00\u4e2a16\u4f4d\u65e0\u7b26\u53f7\u6574\u6570，\u8303\u56f4\u4ece0\u523065535\u3002\u5c0f\u4e8e1024\u7684\u7aef\u53e3\u901a\u5e38\u88ab\u8ba4\u4e3a\u662f\u201c\u719f\u77e5\u7aef\u53e3\u201d\u6216\u201c\u4fdd\u7559\u7aef\u53e3\u201d，\u7531\u7cfb\u7edf\u6216\u4e00\u4e9b\u670d\u52a1\u7a0b\u5e8f\u5360\u7528\u3002\u9ad8\u4e8e1024\u7684\u7aef\u53e3\u53f7\u53ef\u4ee5\u81ea\u7531\u9009\u62e9，\u7528\u4e8e\u4e00\u822c\u7684\u5e94\u7528\u7a0b\u5e8f\u901a\u4fe1\u3002 <\/p>\n
\u5728UDP\u670d\u52a1\u5668\u7aef\u5b9e\u73b0\u4e2d，\u9700\u8981\u9009\u62e9\u4e00\u4e2a\u7aef\u53e3\u5e76\u7ed1\u5b9a\u5230\u524d\u9762\u521b\u5efa\u7684\u5957\u63a5\u5b57\u4e0a\u3002\u5ba2\u6237\u7aef\u5c06\u4f7f\u7528\u8fd9\u4e2a\u7aef\u53e3\u5730\u5740\u6765\u5b9a\u4f4d\u670d\u52a1\u5668\u5e76\u53d1\u9001\u6570\u636e\u5305\u3002 <\/p>\n
\u7ed1\u5b9a\u7aef\u53e3\u5230\u5957\u63a5\u5b57\u53ef\u4ee5\u4f7f\u7528 bind() \u51fd\u6570\u5b8c\u6210，\u5176\u51fd\u6570\u539f\u578b\u4e3a： <\/p>\n
int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);<\/p>\n
\u4ee5\u4e0b\u662f\u7ed1\u5b9a\u7aef\u53e3\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
#include <netinet\/in.h>
\n#include <arpa\/inet.h><\/p>\n
struct sockaddr_in server_addr;
\nmemset(&server_addr, 0, sizeof(server_addr));
\nserver_addr.sin_family = AF_INET;
\nserver_addr.sin_addr.s_addr = htonl(INADDR_ANY); \/\/ \u63a5\u53d7\u4efb\u4f55\u5730\u5740
\nserver_addr.sin_port = htons(12345); \/\/ \u4f7f\u752812345\u7aef\u53e3<\/p>\n
if (bind(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
\n perror("bind failed");
\n exit(EXIT_FAILURE);
\n}<\/p>\n
UDP\u670d\u52a1\u5668\u7aef\u9700\u8981\u76d1\u542c\u6765\u81ea\u5ba2\u6237\u7aef\u7684\u6570\u636e\u5305\u3002\u7531\u4e8eUDP\u534f\u8bae\u662f\u57fa\u4e8e\u65e0\u8fde\u63a5\u7684\u534f\u8bae，\u670d\u52a1\u5668\u7aef\u4e0d\u9700\u8981\u50cfTCP\u90a3\u6837\u63a5\u53d7\u8fde\u63a5\u8bf7\u6c42，\u5b83\u53ea\u9700\u8981\u8bbe\u7f6e\u597d\u5957\u63a5\u5b57\u548c\u7aef\u53e3，\u7136\u540e\u4f7f\u7528 recvfrom() \u51fd\u6570\u8fdb\u884c\u6570\u636e\u7684\u76d1\u542c\u548c\u63a5\u6536\u3002 <\/p>\n
recvfrom() \u51fd\u6570\u539f\u578b\u5982\u4e0b： <\/p>\n
ssize_t recvfrom(int sockfd, void *buf, size_t len, int flags,
\n struct sockaddr *src_addr, socklen_t *addrlen);<\/p>\n
\u5728\u6570\u636e\u63a5\u6536\u9636\u6bb5，\u670d\u52a1\u5668\u9700\u8981\u6307\u5b9a\u4e00\u4e2a\u7f13\u51b2\u533a\u6765\u6682\u5b58\u63a5\u6536\u5230\u7684\u6570\u636e\u5305，\u540c\u65f6\u8fd8\u9700\u8981\u786e\u5b9a\u6570\u636e\u6765\u6e90，\u4ee5\u5224\u65ad\u662f\u5426\u9700\u8981\u54cd\u5e94\u3002\u4ee5\u4e0b\u662f\u63a5\u6536\u6570\u636e\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <stdio.h>
\n#include <string.h><\/p>\n
#define BUF_SIZE 1024<\/p>\n
char buf[BUF_SIZE];
\nstruct sockaddr_in clnt_addr;
\nsocklen_t clnt_addr_size = sizeof(clnt_addr);<\/p>\n
ssize_t str_len = recvfrom(sockfd, buf, BUF_SIZE, 0,
\n (struct sockaddr*)&clnt_addr, &clnt_addr_size);
\nif (str_len < 0) {
\n perror("recvfrom failed");
\n exit(EXIT_FAILURE);
\n}<\/p>\n
printf("Received message from %s:%d\\\\n",
\n inet_ntoa(clnt_addr.sin_addr), ntohs(clnt_addr.sin_port));
\nprintf("Message: %s\\\\n", buf);<\/p>\n
UDP\u6570\u636e\u5305\u4e0d\u50cfTCP\u90a3\u6837\u4fdd\u8bc1\u53ef\u9760\u6027\u548c\u987a\u5e8f，\u5b83\u4ec5\u4ec5\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u6570\u636e\u5305\u4f20\u8f93\u670d\u52a1\u3002\u6bcf\u4e2a\u6570\u636e\u5305\u90fd\u662f\u72ec\u7acb\u7684，\u5305\u542b\u4e00\u4e2a\u5b8c\u6574\u7684\u6d88\u606f\u3002\u53d1\u9001\u6570\u636e\u5305\u65f6，\u5982\u679c\u7f51\u7edc\u4e0d\u7a33\u5b9a，\u6570\u636e\u5305\u53ef\u80fd\u4f1a\u4e22\u5931\u3001\u4e71\u5e8f\u6216\u88ab\u590d\u5236\u3002 <\/p>\n
\u6570\u636e\u53d1\u9001\u4f7f\u7528 sendto() \u51fd\u6570，\u5176\u51fd\u6570\u539f\u578b\u5982\u4e0b： <\/p>\n
ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
\n const struct sockaddr *dest_addr, socklen_t addrlen);<\/p>\n
\u4ee5\u4e0b\u662f\u6570\u636e\u53d1\u9001\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
const char* message = "Hello Client!";
\nstruct sockaddr_in serv_addr;
\nmemset(&serv_addr, 0, sizeof(serv_addr));
\nserv_addr.sin_family = AF_INET;
\nserv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
\nserv_addr.sin_port = htons(12345);<\/p>\n
int send_len = sendto(sockfd, message, strlen(message), 0,
\n (struct sockaddr*)&serv_addr, sizeof(serv_addr));
\nif (send_len < 0) {
\n perror("sendto failed");
\n exit(EXIT_FAILURE);
\n}<\/p>\n
\u5728UDP\u670d\u52a1\u5668\u7aef\u7684\u5b9e\u73b0\u6b65\u9aa4\u4e2d，\u901a\u8fc7\u4e0a\u8ff0\u8be6\u7ec6\u7684\u4ee3\u7801\u5757\u3001\u53c2\u6570\u8bf4\u660e\u548c\u6267\u884c\u903b\u8f91，\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u521b\u5efa\u5957\u63a5\u5b57\u3001\u7ed1\u5b9aIP\u7aef\u53e3\u3001\u6570\u636e\u76d1\u542c\u4e0e\u63a5\u6536\u3001\u6570\u636e\u53d1\u9001\u7684\u5b8c\u6574\u8fc7\u7a0b\u3002\u8fd9\u4e9b\u6b65\u9aa4\u662f\u6784\u5efaUDP\u670d\u52a1\u5668\u7aef\u7684\u57fa\u7840，\u5bf9\u6bcf\u4e2a\u73af\u8282\u7684\u6df1\u5165\u7406\u89e3\u6709\u52a9\u4e8e\u5f00\u53d1\u7a33\u5b9a\u53ef\u9760\u7684UDP\u670d\u52a1\u3002 <\/p>\n
UDP\u5ba2\u6237\u7aef\u7684\u5b9e\u73b0\u662f\u7f51\u7edc\u901a\u4fe1\u4e2d\u7684\u91cd\u8981\u73af\u8282，\u5b83\u7684\u4f5c\u7528\u5728\u4e8e\u4e3b\u52a8\u8fde\u63a5\u670d\u52a1\u5668，\u8fdb\u884c\u6570\u636e\u7684\u53d1\u9001\u548c\u63a5\u6536\u3002\u672c\u7ae0\u8282\u5c06\u6df1\u5165\u63a2\u8ba8UDP\u5ba2\u6237\u7aef\u7684\u6784\u5efa\u8fc7\u7a0b，\u5305\u62ec\u5957\u63a5\u5b57\u7684\u521b\u5efa\u3001\u6570\u636e\u7684\u53d1\u9001\u4e0e\u63a5\u6536\u673a\u5236，\u4ee5\u53ca\u76f8\u5173\u4ee3\u7801\u5b9e\u8df5\u548c\u903b\u8f91\u5206\u6790\u3002 <\/p>\n
\u5728UDP\u901a\u4fe1\u6a21\u578b\u4e2d，\u5ba2\u6237\u7aef\u7684\u4f5c\u7528\u4e3b\u8981\u662f\u521d\u59cb\u5316\u4f1a\u8bdd\u548c\u53d1\u9001\u6570\u636e\u3002\u4e0d\u540c\u4e8e\u670d\u52a1\u5668\u7aef\u7684\u88ab\u52a8\u63a5\u53d7\u8fde\u63a5，\u5ba2\u6237\u7aef\u5957\u63a5\u5b57（Socket）\u9700\u8981\u4e3b\u52a8\u53d1\u8d77\u8fde\u63a5\u5230\u670d\u52a1\u5668\u3002\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u9700\u8981\u5177\u5907\u4ee5\u4e0b\u7279\u5f81： <\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u5178\u578b\u7684UDP\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u521b\u5efa\u7684\u4ee3\u7801\u5b9e\u8df5\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u4e3b\u8981\u6d89\u53ca\u5230 socket() \u548c connect() \u51fd\u6570\u3002 <\/p>\n
#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <stdio.h>
\n#include <string.h><\/p>\n
#define SERVER_IP "192.168.1.100"
\n#define SERVER_PORT 12345<\/p>\n
int main() {
\n int sockfd;
\n struct sockaddr_in serveraddr;<\/p>\n
\/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);
\n if (sockfd < 0) {
\n perror("socket creation failed");
\n return -1;
\n }<\/p>\n
\/\/ \u6e05\u96f6\u7ed3\u6784\u4f53
\n memset(&serveraddr, 0, sizeof(serveraddr));<\/p>\n
\/\/ \u8bbe\u7f6e\u670d\u52a1\u5668\u5730\u5740\u548c\u7aef\u53e3
\n serveraddr.sin_family = AF_INET;
\n serveraddr.sin_port = htons(SERVER_PORT);
\n serveraddr.sin_addr.s_addr = inet_addr(SERVER_IP);<\/p>\n
\/\/ \u8fde\u63a5\u670d\u52a1\u5668（\u53d1\u9001\u548c\u63a5\u6536\u6570\u636e\u65f6\u81ea\u52a8）
\n if (connect(sockfd, (const struct sockaddr *)&serveraddr, sizeof(serveraddr)) < 0) {
\n perror("connect failed");
\n close(sockfd);
\n return -1;
\n }<\/p>\n
\/\/ \u4e4b\u540e\u53ef\u4ee5\u4f7f\u7528sendto\u548crecvfrom\u8fdb\u884c\u6570\u636e\u53d1\u9001\u548c\u63a5\u6536
\n \/\/ …<\/p>\n
close(sockfd); \/\/ \u5173\u95ed\u5957\u63a5\u5b57
\n return 0;
\n}<\/p>\n
\u4ee3\u7801\u903b\u8f91\u5206\u6790 <\/p>\n
UDP\u5ba2\u6237\u7aef\u53d1\u9001\u6570\u636e\u901a\u5e38\u4f7f\u7528 sendto() \u51fd\u6570\u3002\u4e0b\u9762\u662f\u51fd\u6570\u539f\u578b\u548c\u4e00\u4e2a\u7b80\u5355\u7684\u4f7f\u7528\u793a\u4f8b： <\/p>\n
ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
\n const struct sockaddr *dest_addr, socklen_t addrlen);<\/p>\n
UDP\u5ba2\u6237\u7aef\u63a5\u6536\u6765\u81ea\u670d\u52a1\u5668\u7684\u6570\u636e，\u53ef\u4ee5\u4f7f\u7528 recvfrom() \u51fd\u6570\u3002\u51fd\u6570\u539f\u578b\u5982\u4e0b： <\/p>\n
ssize_t recvfrom(int sockfd, void *buf, size_t len, int flags,
\n struct sockaddr *src_addr, socklen_t *addrlen);<\/p>\n
\u4ee3\u7801\u5b9e\u8df5 <\/p>\n
\/\/ \u5047\u8bbe\u5df2\u5b58\u5728\u4e0a\u9762\u521b\u5efa\u7684sockfd
\nchar buffer[1024] = {0};
\nstruct sockaddr_in serveraddr;
\nsocklen_t len = sizeof(serveraddr);
\nssize_t n;<\/p>\n
\/\/ \u63a5\u6536\u6570\u636e
\nn = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&serveraddr, &len);
\nif (n < 0) {
\n perror("recvfrom failed");
\n close(sockfd);
\n return -1;
\n}<\/p>\n
printf("Received message: %s\\\\n", buffer);<\/p>\n
\u8be5\u56fe\u5c55\u793a\u4e86\u4e00\u4e2a\u5178\u578b\u7684UDP\u5ba2\u6237\u7aef\u7ed3\u6784\u3002\u5ba2\u6237\u7aef\u901a\u8fc7\u521d\u59cb\u5316\u5957\u63a5\u5b57，\u8fde\u63a5\u670d\u52a1\u5668\u540e，\u5c31\u53ef\u4ee5\u4f7f\u7528 sendto() \u548c recvfrom() \u51fd\u6570\u8fdb\u884c\u6570\u636e\u7684\u53d1\u9001\u548c\u63a5\u6536\u64cd\u4f5c\u3002 <\/p>\n
\u901a\u8fc7\u4e0a\u8ff0\u5185\u5bb9\u7684\u8ba8\u8bba，\u6211\u4eec\u53ef\u4ee5\u770b\u5230UDP\u5ba2\u6237\u7aef\u7684\u6784\u5efa\u5305\u62ec\u4e86\u5957\u63a5\u5b57\u521b\u5efa\u548c\u6570\u636e\u7684\u53d1\u9001\u4e0e\u63a5\u6536\u7b56\u7565\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d，\u8fd9\u79cd\u7ed3\u6784\u4e3a\u9700\u8981\u5feb\u901f\u3001\u65e0\u8fde\u63a5\u4f20\u8f93\u7684\u5e94\u7528\u63d0\u4f9b\u4e86\u4fbf\u5229\u3002\u5728\u4e0b\u4e00\u8282\u4e2d，\u6211\u4eec\u5c06\u7ee7\u7eed\u6df1\u5165\u4e86\u89e3\u5c40\u57df\u7f51\u4e2dUDP\u901a\u4fe1\u7684IP\u5730\u5740\u914d\u7f6e\u65b9\u6cd5\u3002 <\/p>\n
IP\u5730\u5740\u4f5c\u4e3a\u7f51\u7edc\u4e2d\u8bbe\u5907\u7684\u552f\u4e00\u6807\u8bc6，\u5176\u5728\u5c40\u57df\u7f51\u901a\u4fe1\u4e2d\u626e\u6f14\u7740\u81f3\u5173\u91cd\u8981\u7684\u89d2\u8272\u3002IP\u5730\u5740\u662f\u5206\u914d\u7ed9\u7f51\u7edc\u4e0a\u7684\u6bcf\u4e00\u53f0\u8ba1\u7b97\u673a\u6216\u5176\u4ed6\u8bbe\u5907\u7684\u552f\u4e00\u5730\u5740，\u5b83\u4f7f\u5f97\u7f51\u7edc\u4e2d\u7684\u8bbe\u5907\u53ef\u4ee5\u901a\u8fc7\u7f51\u7edc\u5c42\u8fdb\u884c\u901a\u4fe1\u3002IP\u5730\u5740\u7531\u56db\u4e2a8\u4f4d\u7684\u4e8c\u8fdb\u5236\u6570\u7ec4\u6210，\u5171\u670932\u4f4d，\u5206\u6210\u56db\u4e2a\u90e8\u5206，\u6bcf\u4e2a\u90e8\u52068\u4f4d，\u8868\u793a\u4e3a0~255\u4e4b\u95f4\u7684\u6570\u5b57\u3002 <\/p>\n
\u5e38\u89c1\u7684IP\u5730\u5740\u5206\u7c7b\u5982\u4e0b： – A\u7c7b\u5730\u5740：\u4ee50\u5f00\u5934，\u9996\u4f4d\u56fa\u5b9a，\u540e\u97627\u4f4d\u4e3a\u7f51\u7edc\u53f7，\u5269\u4f5924\u4f4d\u4e3a\u4e3b\u673a\u53f7\u3002 – B\u7c7b\u5730\u5740：\u4ee510\u5f00\u5934，\u524d\u4e24\u4f4d\u56fa\u5b9a，\u63a5\u4e0b\u676514\u4f4d\u4e3a\u7f51\u7edc\u53f7，\u5269\u4f5916\u4f4d\u4e3a\u4e3b\u673a\u53f7\u3002 – C\u7c7b\u5730\u5740：\u4ee5110\u5f00\u5934，\u524d\u4e09\u4f4d\u56fa\u5b9a，\u63a5\u4e0b\u676521\u4f4d\u4e3a\u7f51\u7edc\u53f7，\u5269\u4f598\u4f4d\u4e3a\u4e3b\u673a\u53f7\u3002 – D\u7c7b\u5730\u5740：\u4ee51110\u5f00\u5934，\u7528\u4e8e\u591a\u64ad\u5730\u5740\u3002 – E\u7c7b\u5730\u5740：\u4ee51111\u5f00\u5934，\u4fdd\u7559\u4f5c\u7814\u7a76\u4f7f\u7528\u3002 <\/p>\n
\u5728\u5c40\u57df\u7f51\u4e2d\u914d\u7f6eIP\u5730\u5740\u65f6，\u9700\u8981\u9075\u5faa\u4ee5\u4e0b\u539f\u5219，\u4ee5\u786e\u4fdd\u7f51\u7edc\u7684\u6b63\u5e38\u8fd0\u4f5c： – IP\u5730\u5740\u9700\u8981\u552f\u4e00：\u5728\u540c\u4e00\u5c40\u57df\u7f51\u5185，\u6bcf\u4e2a\u8bbe\u5907\u7684IP\u5730\u5740\u5fc5\u987b\u662f\u552f\u4e00\u7684\u3002 – \u5b50\u7f51\u63a9\u7801\u4e00\u81f4：\u540c\u4e00\u7f51\u7edc\u4e0b\u7684\u6240\u6709\u8bbe\u5907\u5fc5\u987b\u914d\u7f6e\u76f8\u540c\u7684\u5b50\u7f51\u63a9\u7801，\u4ee5\u786e\u4fdd\u5b83\u4eec\u4f4d\u4e8e\u540c\u4e00\u5b50\u7f51\u5185\u3002 – \u907f\u514d\u4f7f\u7528\u79c1\u6709IP\u5730\u5740\u51b2\u7a81：\u907f\u514d\u5c06\u5c40\u57df\u7f51\u5185\u7684\u8bbe\u5907\u914d\u7f6e\u4e3a\u516c\u7f51\u4e2d\u7684\u4fdd\u7559IP\u5730\u5740\u3002 – \u7f51\u5173\u4e0eDNS\u914d\u7f6e：\u6b63\u786e\u914d\u7f6e\u7f51\u5173\u5730\u5740\u53ef\u4ee5\u8ba9\u8bbe\u5907\u8bbf\u95ee\u5916\u90e8\u7f51\u7edc，\u800cDNS\u670d\u52a1\u5668\u5730\u5740\u5219\u4f7f\u5f97\u8bbe\u5907\u80fd\u89e3\u6790\u57df\u540d\u3002 <\/p>\n
\u9759\u6001IP\u5730\u5740\u914d\u7f6e\u662f\u6307\u624b\u52a8\u4e3a\u6bcf\u4e2a\u7f51\u7edc\u8bbe\u5907\u5206\u914d\u56fa\u5b9a\u7684IP\u5730\u5740\u3001\u5b50\u7f51\u63a9\u7801\u3001\u9ed8\u8ba4\u7f51\u5173\u548cDNS\u670d\u52a1\u5668\u5730\u5740\u3002\u4ee5\u4e0b\u662f\u9759\u6001IP\u5730\u5740\u914d\u7f6e\u7684\u6b65\u9aa4： <\/p>\n
\u52a8\u6001IP\u914d\u7f6e，\u53c8\u79f0\u4e3aDHCP（Dynamic Host Configuration Protocol）\u914d\u7f6e，\u662f\u5c40\u57df\u7f51\u4e2d\u81ea\u52a8\u5206\u914dIP\u5730\u5740\u7684\u4e00\u79cd\u65b9\u5f0f\u3002\u5f53\u8bbe\u5907\u8fde\u63a5\u5230\u7f51\u7edc\u65f6，DHCP\u670d\u52a1\u5668\u4f1a\u81ea\u52a8\u4e3a\u5176\u5206\u914d\u4e00\u4e2aIP\u5730\u5740\u3001\u5b50\u7f51\u63a9\u7801\u3001\u9ed8\u8ba4\u7f51\u5173\u548cDNS\u670d\u52a1\u5668\u5730\u5740\u3002\u8fd9\u4e00\u8fc7\u7a0b\u65e0\u9700\u7528\u6237\u624b\u52a8\u5e72\u9884，\u7b80\u5316\u4e86\u7f51\u7edc\u914d\u7f6e\u6d41\u7a0b\u3002\u4ee5\u4e0b\u662f\u52a8\u6001IP\u5730\u5740\u914d\u7f6e\u7684\u57fa\u672c\u539f\u7406： <\/p>\n
\u5728\u914d\u7f6e\u52a8\u6001IP\u65f6，\u786e\u4fdd\u7f51\u7edc\u5185\u5b58\u5728\u81f3\u5c11\u4e00\u4e2a\u6d3b\u8dc3\u7684DHCP\u670d\u52a1\u5668，\u4ee5\u4fdd\u8bc1\u8bbe\u5907\u80fd\u591f\u6210\u529f\u83b7\u5f97IP\u914d\u7f6e\u3002 <\/p>\n
\u63a5\u4e0b\u6765，\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8UDP\u901a\u4fe1\u4e2d\u4e0d\u53ef\u9760\u6027\u7684\u5904\u7406\u7b56\u7565，\u4ee5\u53ca\u793a\u4f8b\u4ee3\u7801\u7684\u7ed3\u6784，\u8fd9\u5c06\u4e3a\u8bfb\u8005\u63d0\u4f9b\u66f4\u5168\u9762\u7684UDP\u534f\u8bae\u5e94\u7528\u89c6\u89d2\u3002 <\/p>\n
\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae（UDP）\u662f\u4e00\u4e2a\u7b80\u5355\u3001\u65e0\u8fde\u63a5\u7684\u534f\u8bae，\u5176\u8bbe\u8ba1\u76ee\u6807\u662f\u63d0\u4f9b\u5c3d\u6700\u5927\u52aa\u529b\u4ea4\u4ed8\u7684\u4f20\u8f93\u670d\u52a1，\u8fd9\u610f\u5473\u7740\u5b83\u4e0d\u4fdd\u8bc1\u6570\u636e\u5305\u7684\u987a\u5e8f\u3001\u5b8c\u6574\u6027\u6216\u53ef\u9760\u6027\u3002UDP\u6570\u636e\u5305\u7684\u4e22\u5931\u3001\u91cd\u590d\u548c\u4e71\u5e8f\u662f\u53f8\u7a7a\u89c1\u60ef\u7684\u4e8b\u60c5，\u56e0\u4e3aUDP\u6ca1\u6709\u5185\u7f6e\u7684\u91cd\u4f20\u673a\u5236\u6216\u987a\u5e8f\u63a7\u5236，\u4e5f\u4e0d\u8fdb\u884c\u4efb\u4f55\u6d41\u91cf\u63a7\u5236\u6216\u62e5\u585e\u63a7\u5236\u3002 <\/p>\n
\u7531\u4e8eUDP\u7684\u8fd9\u79cd\u4e0d\u53ef\u9760\u6027，\u7f51\u7edc\u5e94\u7528\u5728\u8bbe\u8ba1\u65f6\u5fc5\u987b\u8003\u8651\u5230\u6570\u636e\u5305\u7684\u4e22\u5931\u548c\u4e71\u5e8f\u3002\u6bd4\u5982，\u5728\u5b9e\u65f6\u97f3\u89c6\u9891\u6d41\u5e94\u7528\u4e2d，\u97f3\u89c6\u9891\u6570\u636e\u5305\u7684\u4e22\u5931\u53ef\u80fd\u4f1a\u5bfc\u81f4\u77ed\u6682\u7684\u5361\u987f\u6216\u753b\u9762\u5931\u771f，\u4f46\u7528\u6237\u53ef\u80fd\u5e76\u4e0d\u4f1a\u5728\u610f\u8fd9\u4e9b\u5076\u5c14\u7684\u4e2d\u65ad，\u56e0\u4e3a\u5b9e\u73b0\u5b9e\u65f6\u6027\u6bd4\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027\u66f4\u91cd\u8981\u3002 <\/p>\n
\u5728\u5b9e\u9645\u5e94\u7528\u4e2d，UDP\u7684\u4e0d\u53ef\u9760\u6027\u53ef\u80fd\u5bf9\u591a\u79cd\u5e94\u7528\u4ea7\u751f\u5f71\u54cd\u3002\u4f8b\u5982： <\/p>\n
\u4e3a\u4e86\u5e94\u5bf9UDP\u6570\u636e\u5305\u53ef\u80fd\u7684\u4e22\u5931，\u5e94\u7528\u5c42\u53ef\u4ee5\u5b9e\u73b0\u8d85\u65f6\u91cd\u4f20\u673a\u5236\u3002\u8fd9\u662f\u4e00\u79cd\u7b80\u5355\u800c\u6709\u6548\u7684\u7b56\u7565，\u5b83\u7684\u5de5\u4f5c\u539f\u7406\u5982\u4e0b： <\/p>\n
\u5b9e\u73b0\u8d85\u65f6\u91cd\u4f20\u65f6，\u5f00\u53d1\u8005\u9700\u8981\u8003\u8651\u4ee5\u4e0b\u51e0\u70b9： <\/p>\n
\u9664\u4e86\u8d85\u65f6\u91cd\u4f20\u673a\u5236\u4e4b\u5916，\u5e94\u7528\u5c42\u8fd8\u5e94\u5b9e\u73b0\u6570\u636e\u5305\u786e\u8ba4\u673a\u5236\u6765\u68c0\u6d4b\u6570\u636e\u5305\u662f\u5426\u6210\u529f\u5230\u8fbe\u63a5\u6536\u65b9\u3002\u4e3b\u8981\u7684\u6b65\u9aa4\u5305\u62ec： <\/p>\n
\u5b9e\u73b0\u6570\u636e\u5305\u786e\u8ba4\u673a\u5236\u65f6，\u53ef\u4ee5\u8003\u8651\u4ee5\u4e0b\u5173\u952e\u70b9： <\/p>\n
\u4e0b\u9762\u662f\u4e00\u4e2a\u7b80\u5355\u7684UDP\u8d85\u65f6\u91cd\u4f20\u673a\u5236\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
import socket
\nimport time<\/p>\n
def send_data_with_retransmission(ip, port, data, timeout=3, retries=5):
\n # \u521b\u5efaUDP\u5957\u63a5\u5b57
\n sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
\n # \u8bbe\u7f6e\u5957\u63a5\u5b57\u7684\u8d85\u65f6\u65f6\u95f4
\n sock.settimeout(timeout)
\n data_sent = False
\n retry_count = 0<\/p>\n
while not data_sent and retry_count < retries:
\n try:
\n # \u53d1\u9001\u6570\u636e\u5305
\n sock.sendto(data.encode(), (ip, port))
\n # \u7b49\u5f85\u63a5\u6536\u786e\u8ba4
\n start_time = time.time()
\n while True:
\n try:
\n data, addr = sock.recvfrom(1024)
\n if data.decode() == 'ACK': # \u5047\u8bbe\u6536\u5230ACK\u8868\u793a\u786e\u8ba4\u6210\u529f
\n data_sent = True
\n break
\n except socket.timeout:
\n elapsed_time = time.time() – start_time
\n if elapsed_time >= timeout:
\n break
\n except socket.timeout:
\n retry_count += 1
\n print(f"Retrying… {retry_count}\/{retries}")
\n finally:
\n sock.settimeout(None) # \u53d6\u6d88\u8d85\u65f6\u8bbe\u7f6e，\u51c6\u5907\u4e0b\u4e00\u6b21\u53d1\u9001<\/p>\n
if data_sent:
\n print("Data sent successfully.")
\n else:
\n print("Maximum retries reached. Data might not have been sent.")<\/p>\n
sock.close()<\/p>\n
# \u4f7f\u7528\u51fd\u6570\u53d1\u9001\u6570\u636e
\nsend_data_with_retransmission('192.168.1.2', 12345, 'Hello UDP with retransmission!')<\/p>\n
\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u4e2d， send_data_with_retransmission \u51fd\u6570\u8d1f\u8d23\u53d1\u9001\u6570\u636e\u5e76\u5904\u7406\u53ef\u80fd\u7684\u4e22\u5305\u95ee\u9898\u3002\u5b83\u901a\u8fc7\u8bbe\u7f6e\u8d85\u65f6\u548c\u91cd\u8bd5\u6b21\u6570\u6765\u5c1d\u8bd5\u786e\u4fdd\u6570\u636e\u5305\u80fd\u591f\u6210\u529f\u5230\u8fbe\u76ee\u7684\u5730\u3002\u5982\u679c\u5728\u6307\u5b9a\u7684\u91cd\u8bd5\u6b21\u6570\u5185\u6536\u5230\u786e\u8ba4\u6d88\u606f，\u5219\u53d1\u9001\u6210\u529f；\u5426\u5219，\u53d1\u9001\u5931\u8d25\u3002 <\/p>\n
\u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d，\u6211\u4eec\u8bbe\u7f6e\u4e86\u4e24\u4e2a\u91cd\u8981\u7684\u8d85\u65f6\u673a\u5236：\u4e00\u4e2a\u662f\u7528\u4e8e\u53d1\u9001\u548c\u63a5\u6536\u6570\u636e\u7684\u8d85\u65f6\u65f6\u95f4（ timeout ），\u53e6\u4e00\u4e2a\u662f\u91cd\u8bd5\u95f4\u9694\u7684\u8d85\u65f6（\u901a\u8fc7\u5faa\u73af\u5185\u7684 time.sleep \u6765\u5b9e\u73b0）\u3002\u5f53\u53d1\u9001\u6570\u636e\u540e，\u5982\u679c\u6ca1\u6709\u5728\u6307\u5b9a\u7684\u8d85\u65f6\u65f6\u95f4\u5185\u6536\u5230\u786e\u8ba4\u6d88\u606f（ ACK ），\u6211\u4eec\u5c06\u589e\u52a0\u91cd\u8bd5\u6b21\u6570 retry_count \u5e76\u91cd\u65b0\u5c1d\u8bd5\u53d1\u9001\u6570\u636e\u5305\u3002\u6574\u4e2a\u8fc7\u7a0b\u5c06\u6301\u7eed，\u76f4\u5230\u8fbe\u5230\u6700\u5927\u91cd\u8bd5\u6b21\u6570 retries \u6216\u8005\u6210\u529f\u6536\u5230\u786e\u8ba4\u4e3a\u6b62\u3002 <\/p>\n
\u901a\u8fc7\u672c\u793a\u4f8b\u4ee3\u7801，\u53ef\u4ee5\u770b\u51fa，\u5373\u4f7f\u5728\u4e0d\u4fdd\u8bc1\u53ef\u9760\u4f20\u8f93\u7684UDP\u534f\u8bae\u4e2d，\u6211\u4eec\u4f9d\u7136\u53ef\u4ee5\u901a\u8fc7\u5728\u5e94\u7528\u5c42\u5b9e\u73b0\u8d85\u65f6\u91cd\u4f20\u673a\u5236\u548c\u786e\u8ba4\u673a\u5236\u6765\u63d0\u9ad8\u901a\u4fe1\u7684\u53ef\u9760\u6027\u3002\u8fd9\u8981\u6c42\u5f00\u53d1\u8005\u4e0d\u4ec5\u5bf9UDP\u534f\u8bae\u672c\u8eab\u6709\u6df1\u523b\u7406\u89e3，\u8fd8\u9700\u8981\u5728\u5e94\u7528\u5c42\u5b9e\u73b0\u590d\u6742\u7684\u903b\u8f91\u6765\u5f25\u8865\u534f\u8bae\u5c42\u7684\u4e0d\u8db3\u3002 <\/p>\n
\u5728UDP\u901a\u4fe1\u7a0b\u5e8f\u4e2d，\u901a\u5e38\u5305\u542b\u81f3\u5c11\u4e24\u4e2a\u6587\u4ef6：\u4e00\u4e2a\u662f\u5934\u6587\u4ef6（.h），\u5b83\u58f0\u660e\u4e86\u7a0b\u5e8f\u4e2d\u4f1a\u7528\u5230\u7684\u51fd\u6570\u548c\u6570\u636e\u7ed3\u6784；\u53e6\u4e00\u4e2a\u662f\u6e90\u4ee3\u7801\u6587\u4ef6（.c），\u5b83\u5b9e\u73b0\u4e86\u5934\u6587\u4ef6\u4e2d\u58f0\u660e\u7684\u529f\u80fd\u3002\u5bf9\u4e8eUDP\u670d\u52a1\u5668\u548c\u5ba2\u6237\u7aef\u7a0b\u5e8f，\u6211\u4eec\u901a\u5e38\u4f1a\u6709\u7c7b\u4f3c\u7684\u7ed3\u6784： <\/p>\n
\u8fd9\u79cd\u7ed3\u6784\u4fbf\u4e8e\u6a21\u5757\u5316\u7ba1\u7406，\u4e5f\u4f7f\u5f97\u4ee3\u7801\u6613\u4e8e\u7ef4\u62a4\u548c\u7406\u89e3\u3002 <\/p>\n
\u63a5\u4e0b\u6765，\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8\u670d\u52a1\u5668\u7aef\u548c\u5ba2\u6237\u7aef\u4ee3\u7801\u7684\u5b9e\u73b0\u7ec6\u8282\u3002 <\/p>\n
\u670d\u52a1\u5668\u7aef\u9996\u5148\u9700\u8981\u521b\u5efa\u4e00\u4e2aUDP\u5957\u63a5\u5b57，\u7136\u540e\u7ed1\u5b9a\u5230\u4e00\u4e2a\u7279\u5b9a\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u4e0a\u3002\u4ee5\u4e0b\u662f\u521b\u5efa\u548c\u7ed1\u5b9aUDP\u5957\u63a5\u5b57\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
#include <stdio.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <unistd.h><\/p>\n
#define SERVER_PORT 9876 \/\/ \u5b9a\u4e49\u670d\u52a1\u5668\u76d1\u542c\u7aef\u53e3\u53f7<\/p>\n
int main() {
\n int sockfd;
\n struct sockaddr_in serverAddr, clientAddr;
\n socklen_t clientAddrLen = sizeof(clientAddr);<\/p>\n
\/\/ \u521b\u5efa\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);
\n if (sockfd < 0) {
\n perror("socket creation failed");
\n exit(EXIT_FAILURE);
\n }<\/p>\n
\/\/ \u6e05\u7a7a\u5e76\u8bbe\u7f6e\u670d\u52a1\u5668\u5730\u5740\u7ed3\u6784\u4f53
\n memset(&serverAddr, 0, sizeof(serverAddr));
\n serverAddr.sin_family = AF_INET; \/\/ \u4f7f\u7528IPv4\u5730\u5740
\n serverAddr.sin_addr.s_addr = htonl(INADDR_ANY); \/\/ \u63a5\u53d7\u4efb\u4f55\u5730\u5740\u7684\u6570\u636e\u5305
\n serverAddr.sin_port = htons(SERVER_PORT); \/\/ \u8bbe\u7f6e\u7aef\u53e3\u53f7<\/p>\n
\/\/ \u7ed1\u5b9a\u5957\u63a5\u5b57\u5230\u670d\u52a1\u5668\u5730\u5740
\n if (bind(sockfd, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) < 0) {
\n perror("bind failed");
\n exit(EXIT_FAILURE);
\n }<\/p>\n
\/\/ \u5176\u4ed6\u4ee3\u7801，\u5982\u6570\u636e\u76d1\u542c\u4e0e\u63a5\u6536\u5904\u7406
\n \/\/ …<\/p>\n
close(sockfd); \/\/ \u5173\u95ed\u5957\u63a5\u5b57
\n return 0;
\n}<\/p>\n
\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u5757\u4e2d，\u6211\u4eec\u9996\u5148\u5b9a\u4e49\u4e86\u670d\u52a1\u5668\u76d1\u542c\u7aef\u53e3\u53f7 SERVER_PORT \u3002\u7136\u540e\u5728 main \u51fd\u6570\u4e2d\u521b\u5efa\u4e86\u4e00\u4e2aUDP\u5957\u63a5\u5b57，\u5e76\u68c0\u67e5\u521b\u5efa\u662f\u5426\u6210\u529f\u3002\u63a5\u7740，\u6211\u4eec\u58f0\u660e\u5e76\u521d\u59cb\u5316\u4e86 serverAddr \u7ed3\u6784\u4f53，\u8fd9\u4e2a\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u670d\u52a1\u5668\u76d1\u542c\u7684IP\u5730\u5740\u3001\u7aef\u53e3\u4fe1\u606f\u7b49\u3002\u901a\u8fc7 bind \u51fd\u6570，\u6211\u4eec\u5c06\u521b\u5efa\u7684\u5957\u63a5\u5b57\u7ed1\u5b9a\u5230\u4e86\u6307\u5b9a\u7684\u5730\u5740\u548c\u7aef\u53e3\u4e0a，\u6700\u540e\u5728\u6570\u636e\u5904\u7406\u5b8c\u6bd5\u540e\u5173\u95ed\u5957\u63a5\u5b57\u3002 <\/p>\n
\u63a5\u4e0b\u6765，\u6211\u4eec\u5c06\u5728\u4ee3\u7801\u4e2d\u5b9e\u73b0\u6570\u636e\u7684\u76d1\u542c\u4e0e\u63a5\u6536： <\/p>\n
\/\/ \u670d\u52a1\u5668\u7aef\u6570\u636e\u63a5\u6536
\nchar buffer[1024];
\nwhile (1) {
\n ssize_t numBytesReceived = recvfrom(sockfd, buffer, sizeof(buffer), 0,
\n (struct sockaddr *)&clientAddr, &clientAddrLen);
\n if (numBytesReceived < 0) {
\n perror("recvfrom failed");
\n break;
\n }
\n \/\/ \u8f93\u51fa\u63a5\u6536\u5230\u7684\u6570\u636e
\n printf("Received message from client: %s\\\\n", buffer);
\n \/\/ \u5904\u7406\u6570\u636e，\u4f8b\u5982\u56de\u9001\u5ba2\u6237\u7aef
\n sendto(sockfd, buffer, numBytesReceived, 0, (struct sockaddr *)&clientAddr, clientAddrLen);
\n}<\/p>\n
\u5728\u8fd9\u6bb5\u4ee3\u7801\u4e2d，\u6211\u4eec\u4f7f\u7528 recvfrom \u51fd\u6570\u6765\u76d1\u542c\u548c\u63a5\u6536\u6570\u636e\u3002 recvfrom \u51fd\u6570\u5c06\u4f1a\u963b\u585e\u7a0b\u5e8f\u7684\u6267\u884c\u76f4\u5230\u63a5\u6536\u5230\u6570\u636e\u3002\u63a5\u6536\u5230\u7684\u6570\u636e\u5b58\u50a8\u5728 buffer \u4e2d，\u7136\u540e\u6211\u4eec\u901a\u8fc7 sendto \u51fd\u6570\u5c06\u63a5\u6536\u5230\u7684\u6570\u636e\u56de\u53d1\u7ed9\u5ba2\u6237\u7aef\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d，\u60a8\u53ef\u80fd\u9700\u8981\u6839\u636e\u5e94\u7528\u7684\u5177\u4f53\u9700\u6c42\u6765\u89e3\u6790\u548c\u5904\u7406\u6570\u636e\u3002 <\/p>\n
\u5ba2\u6237\u7aef\u7684\u4ee3\u7801\u9996\u5148\u9700\u8981\u521b\u5efa\u4e00\u4e2aUDP\u5957\u63a5\u5b57，\u4ee3\u7801\u5982\u4e0b： <\/p>\n
#include <stdio.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <unistd.h><\/p>\n
#define SERVER_IP "127.0.0.1" \/\/ \u5b9a\u4e49\u670d\u52a1\u5668IP\u5730\u5740
\n#define SERVER_PORT 9876 \/\/ \u5b9a\u4e49\u670d\u52a1\u5668\u7aef\u53e3\u53f7<\/p>\n
int main() {
\n int sockfd;
\n struct sockaddr_in serverAddr;<\/p>\n
\/\/ \u521b\u5efa\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);
\n if (sockfd < 0) {
\n perror("socket creation failed");
\n exit(EXIT_FAILURE);
\n }<\/p>\n
\/\/ \u6e05\u7a7a\u5e76\u8bbe\u7f6e\u670d\u52a1\u5668\u5730\u5740\u7ed3\u6784\u4f53
\n memset(&serverAddr, 0, sizeof(serverAddr));
\n serverAddr.sin_family = AF_INET;
\n serverAddr.sin_port = htons(SERVER_PORT);
\n serverAddr.sin_addr.s_addr = inet_addr(SERVER_IP); \/\/ \u8bbe\u7f6e\u670d\u52a1\u5668IP\u5730\u5740<\/p>\n
\/\/ \u5176\u4ed6\u4ee3\u7801，\u5982\u6570\u636e\u53d1\u9001
\n \/\/ …<\/p>\n
close(sockfd); \/\/ \u5173\u95ed\u5957\u63a5\u5b57
\n return 0;
\n}<\/p>\n
\u8fd9\u91cc，\u6211\u4eec\u5b9a\u4e49\u4e86\u670d\u52a1\u5668\u7684IP\u5730\u5740\u548c\u7aef\u53e3\u53f7，\u5e76\u58f0\u660e\u4e86\u4e00\u4e2a serverAddr \u7ed3\u6784\u4f53\u6765\u5b58\u50a8\u8fd9\u4e9b\u4fe1\u606f\u3002 inet_addr \u51fd\u6570\u7528\u4e8e\u5c06IP\u5730\u5740\u4ece\u70b9\u5206\u5341\u8fdb\u5236\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u7f51\u7edc\u5b57\u8282\u5e8f\u7684\u6574\u6570\u503c\u3002\u5957\u63a5\u5b57\u521b\u5efa\u6210\u529f\u540e，\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u8be5\u5957\u63a5\u5b57\u6765\u53d1\u9001\u6570\u636e\u5230\u670d\u52a1\u5668\u3002 <\/p>\n
\u5ba2\u6237\u7aef\u901a\u8fc7UDP\u53d1\u9001\u6570\u636e\u5230\u670d\u52a1\u5668\u7684\u4ee3\u7801\u5982\u4e0b： <\/p>\n
\/\/ \u5ba2\u6237\u7aef\u6570\u636e\u53d1\u9001
\nconst char *message = "Hello, UDP Server!";
\nsendto(sockfd, message, strlen(message), 0, (struct sockaddr *)&serverAddr, sizeof(serverAddr));<\/p>\n
\u5728\u8fd9\u6bb5\u4ee3\u7801\u4e2d，\u6211\u4eec\u4f7f\u7528 sendto \u51fd\u6570\u5c06\u6570\u636e\u53d1\u9001\u5230\u670d\u52a1\u5668\u3002 sendto \u51fd\u6570\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u5957\u63a5\u5b57\u63cf\u8ff0\u7b26，\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u8981\u53d1\u9001\u7684\u6570\u636e\u7684\u6307\u9488，\u7b2c\u4e09\u4e2a\u53c2\u6570\u662f\u8981\u53d1\u9001\u7684\u5b57\u8282\u6570，\u540e\u7eed\u53c2\u6570\u5305\u542b\u4e86\u670d\u52a1\u5668\u7684\u5730\u5740\u4fe1\u606f\u3002 <\/p>\n
\u5ba2\u6237\u7aef\u7684UDP\u901a\u4fe1\u7a0b\u5e8f\u901a\u5e38\u8f83\u4e3a\u7b80\u5355，\u56e0\u4e3a\u4e0d\u9700\u8981\u76d1\u542c\u6765\u81ea\u670d\u52a1\u5668\u7684\u6570\u636e\u3002\u7136\u800c，\u5982\u679c\u5ba2\u6237\u7aef\u9700\u8981\u63a5\u6536\u670d\u52a1\u5668\u7684\u54cd\u5e94，\u53ef\u4ee5\u4f7f\u7528 recvfrom \u51fd\u6570，\u4e0e\u670d\u52a1\u5668\u7aef\u7c7b\u4f3c\u3002 <\/p>\n
\u901a\u8fc7\u4ee5\u4e0a\u793a\u4f8b，\u6211\u4eec\u53ef\u4ee5\u770b\u5230UDP\u7a0b\u5e8f\u7684\u57fa\u672c\u7ed3\u6784\u548c\u6570\u636e\u4f20\u8f93\u65b9\u5f0f\u3002\u5b9e\u8df5\u4e2d，\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u9700\u6c42\u5bf9\u4ee3\u7801\u8fdb\u884c\u4f18\u5316\u548c\u6269\u5c55\u3002 <\/p>\n
\u5f53\u6d89\u53ca\u5230UDP\u7a0b\u5e8f\u6027\u80fd\u4f18\u5316\u65f6，\u5408\u7406\u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f\u662f\u5173\u952e\u3002UDP\u7f13\u51b2\u533a\u592a\u5c0f\u53ef\u80fd\u65e0\u6cd5\u6709\u6548\u5904\u7406\u6570\u636e\u6d41，\u800c\u592a\u5927\u5219\u53ef\u80fd\u4f1a\u5bfc\u81f4\u5185\u5b58\u6d6a\u8d39\u6216\u6570\u636e\u5305\u7684\u5ef6\u8fdf\u5904\u7406\u3002\u53ef\u4ee5\u901a\u8fc7 socket \u9009\u9879\u8c03\u6574\u7f13\u51b2\u533a\u5927\u5c0f，\u4ee5\u8fbe\u5230\u6027\u80fd\u6700\u4f18\u3002 <\/p>\n
#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <stdio.h><\/p>\n
int main() {
\n int sockfd;
\n struct sockaddr_in addr;
\n int buffer_size = 65536; \/\/ 64KB\u7f13\u51b2\u533a<\/p>\n
\/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);<\/p>\n
\/\/ \u8bbe\u7f6e\u7f13\u51b2\u533a\u5927\u5c0f
\n if (setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &buffer_size, sizeof(buffer_size)) < 0) {
\n perror("setsockopt() error");
\n return -1;
\n }<\/p>\n
\/\/ \u5176\u4ed6\u4ee3\u7801，\u5982\u7ed1\u5b9a\u5730\u5740，\u53d1\u9001\/\u63a5\u6536\u6570\u636e\u7b49
\n \/\/ …<\/p>\n
return 0;
\n}<\/p>\n
\u5728\u5904\u7406\u9ad8\u5e76\u53d1\u7684UDP\u901a\u4fe1\u65f6，\u670d\u52a1\u5668\u7aef\u53ef\u80fd\u56e0\u4e3aI\/O\u963b\u585e\u800c\u5bfc\u81f4\u6027\u80fd\u4e0b\u964d\u3002\u901a\u8fc7\u5c06UDP\u5957\u63a5\u5b57\u8bbe\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f，\u53ef\u4ee5\u4f7f\u670d\u52a1\u5668\u5728\u5904\u7406\u591a\u4e2a\u5ba2\u6237\u7aef\u8bf7\u6c42\u65f6\u66f4\u52a0\u9ad8\u6548\u3002 <\/p>\n
#include <sys\/socket.h>
\n#include <fcntl.h>
\n#include <stdio.h><\/p>\n
int main() {
\n int sockfd;
\n int nonblock = 1;<\/p>\n
\/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);<\/p>\n
\/\/ \u8bbe\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\n if (fcntl(sockfd, F_SETFL, O_NONBLOCK) < 0) {
\n perror("fcntl() error");
\n return -1;
\n }<\/p>\n
\/\/ \u5176\u4ed6\u4ee3\u7801，\u5982\u7ed1\u5b9a\u5730\u5740，\u53d1\u9001\/\u63a5\u6536\u6570\u636e\u7b49
\n \/\/ …<\/p>\n
return 0;
\n}<\/p>\n
\u4e3a\u4e86\u63d0\u9ad8UDP\u670d\u52a1\u5668\u7684\u5e76\u53d1\u5904\u7406\u80fd\u529b，\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u591a\u7ebf\u7a0b\u6216\u591a\u8fdb\u7a0b\u7684\u65b9\u5f0f\u3002\u8fd9\u6837\u53ef\u4ee5\u540c\u65f6\u5904\u7406\u591a\u4e2a\u5ba2\u6237\u7aef\u7684\u6570\u636e，\u63d0\u9ad8\u670d\u52a1\u5668\u7684\u603b\u4f53\u541e\u5410\u91cf\u3002 <\/p>\n
#include <pthread.h>
\n#include <stdio.h>
\n#include <stdlib.h>
\n#include <sys\/types.h>
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <arpa\/inet.h>
\n#include <unistd.h><\/p>\n
void *thread_func(void *arg) {
\n int sockfd = (int)arg;
\n struct sockaddr_in addr;
\n char buffer[1024];
\n int len;<\/p>\n
\/\/ \u63a5\u6536\u6570\u636e
\n len = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr*)&addr, &len);<\/p>\n
\/\/ \u5904\u7406\u63a5\u6536\u5230\u7684\u6570\u636e
\n \/\/ …<\/p>\n
return NULL;
\n}<\/p>\n
int main() {
\n int sockfd;
\n pthread_t thread_id;
\n struct sockaddr_in addr;<\/p>\n
\/\/ \u521b\u5efaUDP\u5957\u63a5\u5b57
\n sockfd = socket(AF_INET, SOCK_DGRAM, 0);<\/p>\n
\/\/ \u5176\u4ed6\u4ee3\u7801，\u5982\u7ed1\u5b9a\u5730\u5740，\u8bbe\u7f6e\u975e\u963b\u585e\u7b49
\n \/\/ …<\/p>\n
\/\/ \u521b\u5efa\u7ebf\u7a0b\u5904\u7406\u63a5\u6536\u5230\u7684\u6570\u636e
\n if (pthread_create(&thread_id, NULL, thread_func, (void*)sockfd) < 0) {
\n perror("pthread_create() error");
\n return -1;
\n }<\/p>\n
\/\/ \u7b49\u5f85\u7ebf\u7a0b\u7ed3\u675f
\n pthread_join(thread_id, NULL);<\/p>\n
return 0;
\n}<\/p>\n
\u901a\u8fc7\u4e0a\u8ff0\u7ae0\u8282\u5185\u5bb9\u7684\u5c55\u5f00，\u6211\u4eec\u770b\u5230UDP\u7f16\u7a0b\u53ef\u4ee5\u6839\u636e\u4e0d\u540c\u7684\u6027\u80fd\u74f6\u9888，\u91c7\u7528\u4e0d\u540c\u7684\u4f18\u5316\u7b56\u7565\u3002\u63a5\u4e0b\u6765\u7684\u7ae0\u8282\u5c06\u6df1\u5165\u63a2\u8ba8UDP\u901a\u4fe1\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u7684\u5b89\u5168\u6027\u6311\u6218\u53ca\u5176\u5e94\u5bf9\u63aa\u65bd\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：UDP（\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae）\u662f\u7528\u4e8e\u7f51\u7edc\u901a\u4fe1\u7684\u65e0\u8fde\u63a5\u534f\u8bae，\u76f8\u6bd4TCP\u66f4\u9002\u5408\u5b9e\u65f6\u5e94\u7528\u3002\u901a\u8fc7\u6b64UDP\u670d\u52a1\u5668\u548c\u5ba2\u6237\u7aef\u7684\u793a\u4f8b\u7a0b\u5e8f，\u5f00\u53d1\u8005\u53ef\u4ee5\u5b66\u4e60\u5982\u4f55\u5728\u5c40\u57df\u7f51\u5185\u5b9e\u73b0\u57fa\u7840\u7684\u6570\u636e\u4ea4\u6362\u3002\u793a\u4f8b\u6db5\u76d6\u4e86\u521b\u5efa\u5957\u63a5\u5b57\u3001\u7ed1\u5b9aIP\u7aef\u53e3\u3001\u6570\u636e\u63a5\u6536\u548c\u53d1\u9001\u7b49\u5173\u952e\u6b65\u9aa4，\u5e76\u5c55\u793a\u4e86\u5982\u4f55\u5904\u7406UDP\u7684\u4e0d\u53ef\u9760\u6027\u95ee\u9898\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p><\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb692\u6b21\uff0c\u70b9\u8d5e11\u6b21\uff0c\u6536\u85cf15\u6b21\u3002\u7528\u6237\u6570\u636e\u62a5\u534f\u8bae\uff08UDP\uff09\u662f\u7f51\u7edc\u901a\u4fe1\u4e2d\u4e00\u4e2a\u8f7b\u91cf\u7ea7\u7684\u4f20\u8f93\u5c42\u534f\u8bae\uff0c\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u65e0\u9700\u5efa\u7acb\u8fde\u63a5\u5373\u53ef\u53d1\u9001\u6570\u636e\u5305\u7684\u65b9\u5f0f\u3002UDP\u4ee5\u5176\u9ad8\u6548\u6027\u548c\u7b80\u5355\u6027\uff0c\u5728\u7279\u5b9a\u573a\u666f\u4e0b\u6709\u7740\u5e7f\u6cdb\u7684\u5e94\u7528\u3002_udp\u5ba2\u6237\u7aef<\/p>\n","protected":false},"author":2,"featured_media":49462,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topic":[],"class_list":["post-49464","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server"],"yoast_head":"\n