大家好，我在BF533下运行我写的UDPCLIENT出现如下错误提示：

socket: Function not implemented

我的代码：

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <errno.h>

#define MYPORT 4950 /* the port users will be sending to */

int main(int argc, char *argv[])
{
int sockfd;
struct sockaddr_in their_addr; /* connector's address information */
struct hostent *he;
int numbytes;
if(argc != 3)
{
   fprintf(stderr,"usage: talker hostname message\n");
   exit (1);
}

if((he=gethostbyname(argv[1])) == NULL)
{ /* get the host info */
   herror("get host by name" );
   exit(1);
}

if((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
{
   perror("socket");
   exit( 1 );
}

their_addr.sin_family = AF_INET; /* host byte order */
their_addr.sin_port = htons(MYPORT); /* short, network byte order */
their_addr.sin_addr = *((struct in_addr *)he->h_addr);
bzero(&(their_addr.sin_zero), 8); /* zero the rest of the struct */

if((numbytes=sendto(sockfd, argv[2], strlen(argv[2]), 0, (struct sockaddr *)&their_addr, sizeof(struct sockaddr))) == -1)
{
   perror("send to" );
   exit(1);
}

printf("sent %d bytes to %s\n",numbytes,inet_ntoa(their_addr.sin_addr));
close(sockfd);

return 0;
}

编译方法：

bfin-uclinux-gcc -Wl,-elf2flt udpclient.c -o udpclient

请问是什么问题？