Net之BroadCast极简编程

#include <stdio.h>   /* pritnf() */
#include <stdLib.h>  /* malloc() */
#include <sockLib.h> /* socket() */
#include <inetLib.h> /* struct sockaddr_in */

#define HOST_PORT 60000
#define MIN_SIZE  10
#define MIN_TIMES 10

void broadServer (int port, int size, int times)
{
    struct sockaddr_in localAddr;
    struct sockaddr_in peerAddr;
    int   addrSize = sizeof(struct sockaddr);
    int   opt = 1;
    int   fd;
    int   num;
    char *buffer;
    if(port  <= 2000) port  = HOST_PORT;
    if(size  <= 0)    size  = MIN_SIZE;
    if(times <= 0)    times = MIN_TIMES;
    printf (" broadServer: try to receive %d chars from port %d\n", size, port);
    
    /* 打开Socket */
    fd = socket (AF_INET, SOCK_DGRAM, 0);
    
    /* 指定本地地址信息 */
    localAddr.sin_family      = AF_INET;
    localAddr.sin_port        = htons (port);
    localAddr.sin_addr.s_addr = INADDR_ANY;
    bind (fd, (struct sockaddr *)&localAddr, sizeof(struct sockaddr));

    /* 加入广播 */
    setsockopt(fd, SOL_SOCKET, SO_BROADCAST, (char *)&opt, sizeof(int));

    buffer = (char *)malloc (size);
    while ((times--)>0)
        {
        /* 接收广播数据 */
        num = recvfrom (fd, buffer, size, 0, 
                       (struct sockaddr *)&peerAddr, &addrSize);
        if (num < 0) break;
        printf (" broadServer: recv %d chars from %s\n", 
                  num, inet_ntoa(peerAddr.sin_addr));
        }

    /* 关闭Socket */
    close (fd);
    free (buffer);
    printf (" broadServer: end\n");
    }

#include <stdio.h>   /* pritnf() */
#include <stdLib.h>  /* malloc() */
#include <sockLib.h> /* socket() */
#include <inetLib.h> /* struct sockaddr_in */

#define HOST_PORT 60000
#define MIN_SIZE  1
#define MIN_TIMES 1

void broadClient (int port, int size, int times)
{
    struct sockaddr_in serverAddr;
    int   opt = 1;
    int   fd;   
    char *buffer;
    int   num;    
    if(port <= 2000) port = HOST_PORT;
    if(size <= 0)    size = MIN_SIZE;
    if(times<= 0)    times= MIN_TIMES;
    buffer = (char *)malloc(size);
    for(num=0; num<size; num++) buffer[num] = (num%26)+'a';

    /* 服务器地址信息 */
    serverAddr.sin_family      = AF_INET;
    serverAddr.sin_port        = htons (port);
    serverAddr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
    printf (" broadClient: try to send %d chars %d times to %s:%d\n",
              size, times, inet_ntoa(serverAddr.sin_addr), port);

    /* 打开Socket */
    fd = socket (AF_INET, SOCK_DGRAM, 0);

    while ((times--)>0)
        {
        /* 发送数据到BroadCast Server */
        num = sendto(fd, buffer, size, 0, 
                    (struct sockaddr *)&serverAddr, sizeof(struct sockaddr));
        printf (" broadClient: send %d chars\n", num);
        }

    /* 关闭Socket */
    close (fd);
    free (buffer);
    printf (" broadClient: send finished\n");
    }