/*
 * (C)opyright 1993,1994,1995 by Darren Reed.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and due credit is given
 * to the original author and the contributors.
 */

/*
                                            icmp type
 lnth proto         source     destination   src port   dst port

etherfind -n

   60  tcp   128.250.20.20  128.250.133.13       2419     telnet

etherfind -n -t

 0.32    91   04    131.170.1.10  128.250.133.13
 0.33   566  udp  128.250.37.155   128.250.133.3        901        901
*/
#include <stdio.h>
#include <string.h>
#if !defined(__SVR4) && !defined(__GNUC__)
#include <strings.h>
#endif
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip_var.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#include <netinet/tcpip.h>
#include <net/if.h>
#include <netdb.h>
#include "ip_fil.h"
#include "ipf.h"
#include "ipt.h"

#ifndef lint
static char sccsid[] = "@(#)ipft_ef.c	1.6 2/4/96 (C)1995 Darren Reed";
static	char	rcsid[] = "$Id: ipft_ef.c,v 1.4 1996/07/18 04:59:22 dm Exp $";
#endif

static	int	etherf_open(), etherf_close(), etherf_readip();

struct	ipread	etherf = { etherf_open, etherf_close, etherf_readip };

static	FILE	*efp = NULL;
static	int	efd = -1;

#ifdef	NEED_INET_ATON
extern	u_long	inet_aton();
#else
#include <arpa/inet.h>
#endif

static	int	etherf_open(fname)
char	*fname;
{
	if (efd != -1)
		return efd;

	if (!strcmp(fname, "-")) {
		efd = 0;
		efp = stdin;
	} else {
		efd = open(fname, O_RDONLY);
		efp = fdopen(efd, "r");
	}
	return efd;
}


static	int	etherf_close()
{
	return close(efd);
}


static	int	etherf_readip(buf, cnt, ifn, dir)
char	*buf, **ifn;
int	cnt, *dir;
{
	struct	tcpiphdr pkt;
	struct	ip	*ip = (struct ip *)&pkt;
	struct	protoent *p = NULL;
	char	src[16], dst[16], sprt[16], dprt[16];
	char	lbuf[128], len[8], prot[8], time[8], *s;
	int	slen, extra = 0, i, n;

	if (!fgets(lbuf, sizeof(lbuf) - 1, efp))
		return 0;

	if ((s = strchr(lbuf, '\n')))
		*s = '\0';
	lbuf[sizeof(lbuf)-1] = '\0';

	bzero(&pkt, sizeof(pkt));

	if ((n = sscanf(lbuf, "%s %s %s %s %s %s", len, prot, src, dst,
			sprt, dprt)) != 6)
		if ((n = sscanf(lbuf, "%s %s %s %s %s %s %s", time,
				len, prot, src, dst, sprt, dprt)) != 7)
			return -1;

	ip->ip_p = atoi(prot);
	if (ip->ip_p == 0) {
		if (!(p = getprotobyname(prot)))
			return -1;
		ip->ip_p = p->p_proto;
	}

	switch (ip->ip_p) {
	case IPPROTO_TCP :
	case IPPROTO_UDP :
		s = strtok(NULL, " :");
		ip->ip_len += atoi(s);
		if (p->p_proto == IPPROTO_TCP)
			extra = sizeof(struct tcphdr);
		else if (p->p_proto == IPPROTO_UDP)
			extra = sizeof(struct udphdr);
		break;
#ifdef	IGMP
	case IPPROTO_IGMP :
		extra = sizeof(struct igmp);
		break;
#endif
	case IPPROTO_ICMP :
		extra = sizeof(struct icmp);
		break;
	default :
		break;
	}

	(void) inet_aton(src, &ip->ip_src);
	(void) inet_aton(dst, &ip->ip_dst);
	ip->ip_len = atoi(len);
	ip->ip_hl = sizeof(struct ip);

	slen = ip->ip_hl + extra;
	i = MIN(cnt, slen);
	bcopy((char *)&pkt, buf, i);
	return i;
}