UDP广播之socket bad address 错误被解决，舒服

在编写UDP广播程序编写完后，一编译，提示socket bad address.后面查资料得知在读取socket缓冲的时候,发送端sendto返回值正常，接收端recvfrom却读不到信息，是因为指针指向了无法访问的空间。
发送端代码：client.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main(void){
    int ret;
    int serverfd;

    serverfd = socket(AF_INET, SOCK_DGRAM, 0);
    if(serverfd == -1){
        perror("socket fail\n");
        close(serverfd);
        return -1;
    }

    struct sockaddr_in serveraddr, clientaddr;

    memset(&serveraddr, 0, sizeof(serveraddr));
    memset(&clientaddr, 0, sizeof(clientaddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_port = htons(8000);
    serveraddr.sin_addr.s_addr = INADDR_ANY;


    ret = bind(serverfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
    if(ret == -1){
        perror("bind error\n");
        close(serverfd);
        return -1;
    }

    char buf[128];
    int sin_size = sizeof(clientaddr);
    while(1){
        memset(buf, 128, 0);
        recvfrom(serverfd, buf, 128, 0, (struct sockaddr *)&clientaddr, &sin_size);
        printf("Recv msg from client: %s\n", buf);
    }

    return 0;
}

接收端代码:server.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main(void){
    int ret;
    int clientfd;

    clientfd = socket(AF_INET, SOCK_DGRAM, 0);
    if(clientfd ==  -1){
        perror("socket fail\n");
        close(clientfd);
        return -1;
    }

    struct sockaddr_in serveraddr;

    memset(&serveraddr, 0, sizeof(serveraddr));
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_port = htons(8000);
    serveraddr.sin_addr.s_addr = inet_addr("192.168.5.255");

    int on = 1;
    ret = setsockopt(clientfd, SOL_SOCKET, SO_BROADCAST, (void *)&on, sizeof(on));
    //ret = setsockopt(clientfd, SOL_SOCKET, SO_BROADCAST, (void *)on, sizeof(on));
    //注意on与上一条语句的&on,少了一个取址符，
    //on的值此时为1（及地址值为1）,因此指向了无法访问的空间
    if(ret == -1){
        perror("setsockopt fail\n");
        close(clientfd);
        return -1;
    }

    char buf[128];
    while(1){
        memset(buf, 0, 128);
        printf("Client send msg: ");
        fgets(buf, 128, stdin);
        sendto(clientfd, buf, strlen(buf), 0, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
    }

    close(clientfd);

    return 0;
}

为了突出重点（指针指向了无法访问的空间），就省略了其它注释了，见谅~