/*
 * (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Heiko W.Rupp <hwr@pilhuhn.de>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * greconfig - frontend to set/query tunnel endpoints
 *
 * $NetBSD: greconfig.c,v 1.4 1999/01/26 21:32:40 hwr Exp $
 */

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/sockio.h>
#include <netdb.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>

/* from sys/sockio.h */
#define GRESADDRS       _IOW('i', 101, struct ifreq)
#define GRESADDRD       _IOW('i', 102, struct ifreq)   
#define GREGADDRS       _IOWR('i', 103, struct ifreq)
#define GREGADDRD       _IOWR('i', 104, struct ifreq)
#define GRESPROTO	_IOW('i' , 105, struct ifreq)
#define GREGPROTO	_IOWR('i', 106, struct ifreq)


void usage(void);
void name2sa(char *name,struct sockaddr **sa);
char* sa2name(struct sockaddr *sa);

int verbose;

int
main(int argc, char **argv)
{
	int i,s,err;
	char *dst,*src,*inf;
	struct ifreq ifr;
	struct sockaddr *sa;
	int pflag=0;
	u_char proto = 47;

	dst=src=inf=NULL;
	verbose=0;

	while ((i = getopt(argc, argv, "d:i:p:s:v")) != -1) 
		switch(i) {
			case 'd': dst=optarg; break;
			case 'i': inf=optarg; break;
			case 'p': proto=atoi(optarg); pflag++; break;
			case 's': src=optarg; break;
			case 'v': verbose++; break;
			default: usage(); exit(1); 
		}

	if (inf==NULL) {
		usage();
		exit(2);
	}

	if (strncmp("gre",inf,3)!=0) {
		usage();
		exit(3);
	}

	if((proto!=47) && (proto!=55)) {
		usage();
		exit(4);
	}

	s=socket(PF_INET,SOCK_DGRAM,0);
	if(s<0) {
		perror("Socket() failed: \n");
		exit(5);
	}
	if (pflag) {	/* IPPROTO_GRE is default in kernel */
		strncpy(ifr.ifr_name,inf,sizeof(ifr.ifr_name));
		ifr.ifr_flags =  proto;
		if (verbose)
			printf("Setting tunnel protocol to proto %d\n",proto);
		err=ioctl(s,GRESPROTO,(caddr_t)&ifr);
		if(err<0)
			perror("GRESPROTO");
	}
	if (src!=NULL) {
		strncpy(ifr.ifr_name,inf,sizeof(ifr.ifr_name));
		name2sa(src,&sa);
		ifr.ifr_addr=*sa;
		if(verbose)
			printf("Setting source address ...\n");
		err=ioctl(s,GRESADDRS,(caddr_t)&ifr);
		if(err<0)
			perror("GRESADDRS");
	}
	if (dst!=NULL) {
		strncpy(ifr.ifr_name,inf,sizeof(ifr.ifr_name));
		name2sa(dst,&sa);
		ifr.ifr_addr=*sa;
		if(verbose)
			printf("Setting destination address ...\n");
		err=ioctl(s,GRESADDRD,(caddr_t)&ifr);
		if(err<0)
			perror("GRESADDRD");
	}
	if (src==NULL && dst==NULL && !pflag) {
		strncpy(ifr.ifr_name,inf,sizeof(ifr.ifr_name));
		err=ioctl(s,GREGADDRS,(caddr_t)&ifr);
		if(err<0)
			perror("GREGADDRS");
		else 
			printf("%s -> ",sa2name(&ifr.ifr_addr));
		strncpy(ifr.ifr_name,inf,sizeof(ifr.ifr_name));
		err=ioctl(s,GREGADDRD,(caddr_t)&ifr);
		if(err<0)
			perror("GREGADDRD");
		else
			printf("%s, ",sa2name(&ifr.ifr_addr));
		err=ioctl(s,GREGPROTO,(caddr_t)&ifr);
		if(err<0)
			perror("GREGPROTO");
		else
			printf("running IP-Proto %d\n",ifr.ifr_flags);
	}
	close(s);

	exit(0);
}

void
usage(void)
{
	printf("greconfig -i unit [-d dst] [-s src] [-p proto] [-v]\n");
	printf("unit is gre<n>, proto either 47 or 55\n");
}

void name2sa(char *name,struct sockaddr **sa)
{
	struct hostent *hp;
	struct sockaddr_in *si;
	struct sockaddr_in s;

	hp=gethostbyname(name);

	bzero(&s,sizeof(struct sockaddr_in));
	s.sin_family=hp->h_addrtype;
	if(hp->h_addrtype != AF_INET) {
		printf("Only internet addresses allowed, not %s\n",name);
		exit(5);
	}
	bcopy(hp->h_addr,&s.sin_addr,hp->h_length);
	si=&s;

	*sa=(struct sockaddr *)si;
}
	
char* sa2name(struct sockaddr *sa)
{
	struct sockaddr_in *si;

	si=((struct sockaddr_in *)(sa));
	return(inet_ntoa(si->sin_addr));
}