C++实现UDP协议通信，亲测有效

Question

如题所述

Answer 1

客户端

···

#include <stdio.h>

#include <string.h>

#include <errno.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#define DEST_PORT 6020

#define DSET_IP_ADDRESS  "192.168.1.92"

int main()

{

  /* socket锟侥硷拷锟斤拷锟斤拷锟斤拷 */

  int sock_fd;

  /* udp socket */

  sock_fd = socket(AF_INET, SOCK_DGRAM, 0);

  if(sock_fd < 0)

  {

    perror("socket");

    exit(1);

  }

  /* 锟斤拷锟斤拷address */

  struct sockaddr_in addr_serv;

  int len;

  memset(&addr_serv, 0, sizeof(addr_serv));

  addr_serv.sin_family = AF_INET;

  addr_serv.sin_addr.s_addr = inet_addr(DSET_IP_ADDRESS);

  addr_serv.sin_port = htons(DEST_PORT);

  len = sizeof(addr_serv);

  int send_num;

  int recv_num;

  char send_buf[100]={0};

send_buf[0]=0x23;

  send_buf[1]=0x23;

  send_buf[2]=0x23;

  send_buf[3]=0x23;

  send_buf[4]=0x4a;

  send_buf[5]=0;

  send_buf[6]=0;

  send_buf[7]=0;

  send_buf[8]=0x4a;

  send_buf[9]=0;

  send_buf[10]=0;

  send_buf[11]=0;

  send_buf[12]=0x01;

  send_buf[13]=0;

  send_buf[14]=0;

  send_buf[15]=0;

    send_buf[16]=0xFF;

    send_buf[17]=0xCC;

    send_buf[18]=0x0B;

    send_buf[19]=0x01;

    uint8_t mycheck;

    int i=0;

// char recv_buf[20];

while(1){

  send_buf[65]=0x01;

    for(i=0;i<71;i++)

  {

  mycheck ^= send_buf[i];

  }

  send_buf[71]= mycheck;

  send_buf[72]=0xEE;

  send_buf[73]=0xDD;

  //printf("client send: %s\n", send_buf);

sleep(1);

  send_num = sendto(sock_fd, send_buf, 74, 0, (struct sockaddr *)&addr_serv, len);

  if(send_num < 0)

  {

    perror("sendto error:");

    exit(1);

  }

/* recv_num = recvfrom(sock_fd, recv_buf, sizeof(recv_buf), 0, (struct sockaddr *)&addr_serv, (socklen_t *)&len);

  if(recv_num < 0)

  {

    perror("recvfrom error:");

    exit(1);

  }

  recv_buf[recv_num] = '\0';

  printf("client receive %d bytes: %s\n", recv_num, recv_buf);

}

  close(sock_fd);

  return 0;

*/

}}

···

服务器端

...

#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <unistd.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#define SERV_PORT  6020

int main()

{

  /* sock_fd --- socket文件描述符 创建udp套接字*/

  int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);

  if(sock_fd < 0)

  {

    perror("socket");

    exit(1);

  }

  /* 将套接字和IP、端口绑定 */

  struct sockaddr_in addr_serv;

  int len;

  memset(&addr_serv, 0, sizeof(struct sockaddr_in));  //每个字节都用0填充

  addr_serv.sin_family = AF_INET;  　　　　　　　　　　　 //使用IPV4地址

  addr_serv.sin_port = htons(SERV_PORT);  　　　　　　　 //端口

  /* INADDR_ANY表示不管是哪个网卡接收到数据，只要目的端口是SERV_PORT，就会被该应用程序接收到 */

  addr_serv.sin_addr.s_addr = htonl(INADDR_ANY);  //自动获取IP地址

  len = sizeof(addr_serv);

  /* 绑定socket */

  if(bind(sock_fd, (struct sockaddr *)&addr_serv, sizeof(addr_serv)) < 0)

  {

    perror("bind error:");

    exit(1);

  }

  int recv_num;

  int send_num;

  char send_buf[20] = "i am server!";

  char recv_buf[100];

  struct sockaddr_in addr_client;

  while(1)

  {

    printf("server wait:\n");

    recv_num = recvfrom(sock_fd, recv_buf, sizeof(recv_buf), 0, (struct sockaddr *)&addr_client, (socklen_t *)&len);

    if(recv_num < 0)

    {

      perror("recvfrom error:");

      exit(1);

    }

    recv_buf[recv_num] = '\0';

    printf("server receive %d bytes: %s\n", recv_num, recv_buf);

    send_num = sendto(sock_fd, send_buf, recv_num, 0, (struct sockaddr *)&addr_client, len);

    if(send_num < 0)

    {

      perror("sendto error:");

      exit(1);

    }

  }

  close(sock_fd);

  return 0;

}

...

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