/**********************************************************************
 * 
 *  Copyright 2001, Lantronix 
 *
 *  All rights reserved, The contents of this file may not be used 
 *  and/or copied in any form or by any means without the written 
 *  permission of Lantronix.
 *
 *  Finds all CoBox / UDSs on the attached subnets.  For use with
 *  Linux and WIN32 systems.
 **********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <errno.h>

#ifdef linux
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
typedef struct ifreq LTX_INTERFACE_INFO;
typedef int LTX_SOCKET;
void closesocket(LTX_SOCKET);
#else
#include <winsock2.h>
#include <ws2tcpip.h>
typedef INTERFACE_INFO LTX_INTERFACE_INFO;
typedef SOCKET LTX_SOCKET;
#endif /* linux */

#define COBOX_UDP_PORT 0x77fe	/* CoBox UDP config port 30718 */
#define UDS_CONF_QUERY	0xf8	/* LTX code to get cobox setup record */
#define UDP_BUF_SIZE	512
#define MAX_INTERFACES	10

long interface_up(LTX_SOCKET, struct sockaddr_in *, LTX_INTERFACE_INFO *);

int main(int argc, char **argv)
{
//	static unsigned char	reqt[] = { 0x00,0x00,0x00,UDS_CONF_QUERY };
	unsigned char			reqt[18];
	unsigned char			buf[UDP_BUF_SIZE];
	int						i, len, n, timeout;
	unsigned long			br = 0;
	LTX_SOCKET				sock;
	LTX_INTERFACE_INFO		ifo[MAX_INTERFACES];
	struct sockaddr_in		peer;
	fd_set					rfds, efds;
	struct timeval			timev;

#ifdef linux
	struct ifconf 			if_conf;
#else
	WSADATA					info;
#endif /* linux */
	
	memset(reqt, 0, sizeof(reqt));
	reqt[3] = UDS_CONF_QUERY;
#ifdef WIN32
			/*  start up winsock */
	if ((i = WSAStartup(MAKEWORD(1,1), &info)) < 0 ) {
		fprintf(stderr, "Error on WSAStartup(), error (%d)\n", i);
		return(i);
	}
#endif /* WIN32 */

			/*  open a socket */
	if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
		fprintf(stderr, "Could not open socket\n");
		return(0);
	}
			/* It's a good idea to bind this socket to a local port number */
	peer.sin_family = AF_INET;
	peer.sin_addr.s_addr = INADDR_ANY;
	peer.sin_port = 0;
	if (bind(sock, (struct sockaddr *) &peer, sizeof(peer))) {
		fprintf(stderr, "Error binding socket\n");
		closesocket(sock);
		return(0);
	}
#ifdef linux
			/* Set socket to allow broadcasting */
	i = 1;
	if ((
	  setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (void *)&i, sizeof(i))) < 0) {
		fprintf(stderr, "Failure to set SO_BROADCAST.\n");
		closesocket(sock);
		return(0);
	}
#endif

			/* Grab all the network interfaces */
#ifdef WIN32
	memset(&ifo[0], 0, sizeof(ifo));
	if ((WSAIoctl(sock, SIO_GET_INTERFACE_LIST, NULL, 0, 
							&ifo[0], sizeof(ifo), &br, NULL, NULL)) != 0) {
		fprintf(stderr, "Get SIO_GET_INTERFACE_LIST error (%d)\n",
													(WSAGetLastError()));
		return(WSAGetLastError());
	}
#else
	if_conf.ifc_len = (sizeof (struct ifreq)) * MAX_INTERFACES;
	if_conf.ifc_buf = (char *) &ifo[0];
	if ((ioctl(sock, SIOCGIFCONF, &if_conf)) == -1) {
		fprintf(stderr, "Failure SIOCGIFCONF.\n");
		closesocket(sock);
		return(0);
    }
	br = if_conf.ifc_len;
#endif /* WIN32 */

			/* Query each network */
	for (i = 0; i < (int)(br / sizeof(LTX_INTERFACE_INFO)); i++) {
		if (interface_up(sock, &peer, &ifo[i])) {
//			fprintf(stderr, "sendto %s port 0x%x family 0x%x\n", 
//					inet_ntoa(peer.sin_addr), ntohs(peer.sin_port),
//					peer.sin_family);
			if ((n = sendto(sock, reqt, sizeof(reqt), 0, 
				(struct sockaddr *) &peer, sizeof(struct sockaddr_in))) <= 0) {
				fprintf(stderr, "sendto (%s) failed!\n", 
												 inet_ntoa(peer.sin_addr));
			}
		}
		else {
//			fprintf(stderr, "skipping interface %s\n", inet_ntoa(peer.sin_addr));
		}
	}

			/* We've sent the queries, now see if anyone responded */
	n = 0;
	while(1){
		FD_ZERO(&rfds);
		FD_ZERO(&efds);
		FD_SET(sock, &rfds);
		FD_SET(sock, &efds);
		timev.tv_sec = 3;	//three second timeout 
		timev.tv_usec = 0;
		timeout = select(FD_SETSIZE, &rfds, (fd_set *) NULL, &efds, &timev);
		if (timeout == -1) {
//			fprintf(stderr, "OS interrupt during select - ignore\n");
			continue;
		}
		else if (timeout == 0) {
//			fprintf(stderr, "Real timeout\n");
			break;
		}
		else if (FD_ISSET(sock, &efds)) {
			fprintf(stderr, "Bad news, exception on socket\n");
			break;
		}
		else if (FD_ISSET(sock, &rfds)) {
			memset(buf, 0, sizeof(buf));
			len = sizeof(struct sockaddr_in);
			if ( recvfrom(sock, buf, sizeof(buf), 0, 
								(struct sockaddr *) &peer, &len) > 0) {
				printf("cobox %02d: at %s\n", ++n, inet_ntoa(peer.sin_addr));
			}
		}
	}

	printf("\nDONE\n");
	closesocket(sock);
#ifdef WIN32
	WSACleanup();
#endif

	return 0;
}

long
interface_up(sock, peer, ifo)
LTX_SOCKET sock;
struct sockaddr_in *peer;
LTX_INTERFACE_INFO *ifo;
{
#ifdef WIN32
	peer->sin_addr.s_addr =	ifo->iiAddress.AddressIn.sin_addr.s_addr;
	if ( (ifo->iiAddress.AddressIn.sin_addr.S_un.S_addr != 0) &&
			((ifo->iiFlags & IFF_LOOPBACK) == 0) &&
			((ifo->iiFlags & (IFF_UP | IFF_BROADCAST)) ==
											 (IFF_UP | IFF_BROADCAST)) ) {
				/* The iiBroadcastAddress field is bogus, so do it manually */
		peer->sin_addr.s_addr =	ifo->iiAddress.AddressIn.sin_addr.s_addr &
								ifo->iiNetmask.AddressIn.sin_addr.s_addr;
		peer->sin_addr.s_addr |= ~(ifo->iiNetmask.AddressIn.sin_addr.s_addr);
		peer->sin_port = htons(COBOX_UDP_PORT);
		peer->sin_family = AF_INET;
		return(1);
	}
#else
	struct sockaddr_in *sptr;

	if ((ioctl(sock, SIOCGIFFLAGS, ifo)) != 0) {
		fprintf(stderr, "SIOCGIFFLAGS ioctl failed\n");
		closesocket(sock);
		return(0);
	}
	if ( ((ifo->ifr_flags & IFF_LOOPBACK) == 0) &&
		 ((ifo->ifr_flags & (IFF_UP | IFF_BROADCAST)) ==
											 (IFF_UP | IFF_BROADCAST)) ) {
		if ((ioctl(sock, SIOCGIFBRDADDR, ifo)) != 0) {
			fprintf(stderr, "SIOCGIFBRDADDR ioctl failed\n");
			closesocket(sock);
			return(0);
		}
		memcpy((void *) peer, (void *) &ifo->ifr_broadaddr,
										sizeof(struct sockaddr_in));
		peer->sin_port = htons(COBOX_UDP_PORT);
		peer->sin_family = AF_INET;
		return(1);
	}
#endif /* WIN32 */
	return(0);
}

#ifdef linux
void
closesocket(sock)
LTX_SOCKET sock;
{
		shutdown(sock, 2);
		close(sock);
}
#endif