setbroadmsg.c

使用udp的broadcast方式写的c程序

#include <string.h> 
#include <sys/types.h> 
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <stdlib.h>
 
#include <sys/ioctl.h> 
#include <net/if.h> 
#include <net/if_arp.h> 
#include <net/ethernet.h> 
#include <netinet/ip.h> 

#include "msgstruct.h"

broadcasttype *setbroadmsg() 
{ 
	#if 0
	struct  in_addr myip, mymask; 
	int     fd_arp;              /* socket fd for receive packets */ 
	struct  ifreq   ifr;            /* ifr structure  in if.h header */ 	
	
	char	device[32];  /* ethernet device name */ 
	int	fromlen; 
	struct sockaddr_in	*sin_ptr; 
	u_char	*ptr; 
	int  n, i=0; 
	broadcasttype *broadmsg;
	static broadcasttype init;
	broadmsg = (broadcasttype *)&init;
	bzero(broadmsg,sizeof(broadcasttype));
	
	strcpy(device, "eth0"); 
 
	if ((fd_arp = socket(AF_INET, SOCK_PACKET, 0/*htons(0x0806)*/)) < 0) { 
		perror( "arp socket error"); 
		return NULL;
	} 
 
	strcpy(ifr.ifr_name, device); 
	/*ifr.ifr_addr.sa_family = AF_INET;*/
 
	/* get ip address of my interface */ 
	if (ioctl(fd_arp, SIOCGIFADDR, &ifr) < 0) { 
		perror("ioctl SIOCGIFADDR error"); 
		return NULL; 
	} 
	sin_ptr = (struct sockaddr_in *)&ifr.ifr_addr; 
	myip  = sin_ptr->sin_addr; 

 	sprintf( broadmsg->ipaddress, "%s", inet_ntoa(myip));
 	
 	/*Device type*/
	strcpy(broadmsg->message,"IP Camera");
	close(fd_arp);
	
	return broadmsg;
	#else

    signed int nSockFd;
    struct ifreq sIfr;
    struct sockaddr_in *pSockAddr;
    signed   char* pTmp="0.0.0.0";
    signed   char cRet=0;
	unsigned char * pIfName = "eth0";
	static broadcasttype init;

    nSockFd = socket ( AF_INET, SOCK_DGRAM, 0 );
    if ( nSockFd == -1 ){
        printf ( "get_ip_addr: creat socket error\n" );
    }
    strcpy ( sIfr.ifr_name, pIfName);
    sIfr.ifr_addr.sa_family=AF_INET;
    if ( ioctl ( nSockFd, SIOCGIFADDR, &sIfr ) < 0 )
    {
        printf( "get_ip_addr: ioctl \n" );
        cRet=-2;
    }
    else{
        pSockAddr= ( struct sockaddr_in * ) &sIfr.ifr_addr;
        pTmp = inet_ntoa ( pSockAddr->sin_addr );
    }
    memcpy(init.ipaddress,pTmp,sizeof(init));
	memcpy(init.message,"IP Camera",strlen("IP Camera"));
    close(nSockFd);
	
    return (&init);
  	#endif
}  /* end of main */