/*
 * Copyright (c) 1999
 * 	RISS-Telecom Networking Center. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>

#if __STDC__
struct mbuf;
struct rtentry;
#endif
#include <net/if.h>

#include <netinet/in.h>
#include <net/ethernet.h>
#include <net/ppp_defs.h>
#include <net/slip.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>

#include <stdio.h>
#include <pcap.h>

#include "ethertype.h"
#include "interface.h"
#include "addrtoname.h"

const u_char *packetp;
const u_char *snapend;


struct printer {
		pcap_handler f;
		int type;
};

static struct printer printers[] = {
		{ ether_if_print,       DLT_EN10MB },
		{ sl_if_print,          DLT_SLIP },
		{ sl_bsdos_if_print,    DLT_SLIP_BSDOS },
		{ ppp_if_print,         DLT_PPP },
		{ ppp_bsdos_if_print,   DLT_PPP_BSDOS },
		{ null_if_print,        DLT_NULL },
		{ raw_if_print,         DLT_RAW },
		{ NULL,                 0 },
};

pcap_handler
lookup_printer(int type)
{
		struct printer *p;

		for (p = printers; p->f; p++)
				if (type == p->type)
						return p->f;

		error("unknown data link type 0x%x", type);
		/* NOREACHED */
}

/*
 * This is the top level routine of the printer.  'p' is the points
 * to the ether header of the packet, 'tvp' is the timestamp,
 * 'length' is the length of the packet off the wire, and 'caplen'
 * is the number of bytes actually captured.
 */
void
ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	u_int caplen = h->caplen;
	u_int length = h->len;
	struct ether_header *ep;

	if (caplen < sizeof(struct ether_header)) 
		return;

	packetp = p;
	snapend = p + caplen;

	length -= sizeof(struct ether_header);
	caplen -= sizeof(struct ether_header);
	ep = (struct ether_header *)p;
	p += sizeof(struct ether_header);

	if(ntohs(ep->ether_type) == ETHERTYPE_IP)
			processing_ip(p, length);
}

/*
 * The DLT_NULL packet header is 4 bytes long. It contains a network
 * order 32 bit integer that specifies the family, e.g. AF_INET
 */
#define	NULL_HDRLEN 4

void
null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	u_int family;
	u_int length = h->len;
	u_int caplen = h->caplen;

	memcpy((char *)&family, (char *)p, sizeof(family));

	packetp = p;
	snapend = p + caplen;

	length -= NULL_HDRLEN;

	if (family == AF_INET)
			processing_ip(p + NULL_HDRLEN, length);
}

void
ppp_if_print(u_char *user, const struct pcap_pkthdr *h,
	     register const u_char *p)
{
	register u_int length = h->len;
	register u_int caplen = h->caplen;


	if (caplen < PPP_HDRLEN) {
			return;
	}

	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;

	length -= PPP_HDRLEN;

	if(PPP_PROTOCOL(p) == PPP_IP || PPP_PROTOCOL(p) == ETHERTYPE_IP) {
		processing_ip((const u_char *)(p + PPP_HDRLEN), length);
	}
}

#define PPP_BSDI_HDRLEN 24
#define PPP_BSDI_ADDRESS	0xff
#define PPP_BSDI_CONTROL	0x03

/* BSD/OS specific PPP printer */
void
ppp_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h,
	     register const u_char *p)
{
	register u_int length = h->len;
	register u_int caplen = h->caplen;
	register int hdrlength;
	u_short ptype;

	if (caplen < PPP_BSDI_HDRLEN) {
			return;
	}

	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;
	hdrlength = 0;

	if (p[0] == PPP_BSDI_ADDRESS && p[1] == PPP_BSDI_CONTROL) {
		p += 2;
		hdrlength = 2;
	}

	/* Retrieve the protocol type */
	if (*p & 01) {
		/* Compressed protocol field */
		ptype = *p++;
		hdrlength++;
	} else {
		/* Un-compressed protocol field */
		ptype = ntohs(*(u_short *)p);
		p += 2;
		hdrlength += 2;
	}
  
	length -= hdrlength;

	if (ptype == PPP_IP)
		processing_ip(p, length);
}

/*
 * The DLT_RAW packet has no header. It contains a raw IP packet.
 */

void
raw_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	u_int length = h->len;
	u_int caplen = h->caplen;

	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;

	processing_ip(p, length);
}

/* XXX BSD/OS 2.1 compatibility */
#if !defined(SLIP_HDRLEN) && defined(SLC_BPFHDR)
#define SLIP_HDRLEN SLC_BPFHDR
#define SLX_DIR 0
#define SLX_CHDR (SLC_BPFHDRLEN - 1)
#define CHDR_LEN (SLC_BPFHDR - SLC_BPFHDRLEN)
#endif

/* XXX needs more hacking to work right */

void
sl_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	register u_int caplen = h->caplen;
	register u_int length = h->len;

	if (caplen < SLIP_HDRLEN) {
			return;
	}
	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;

	length -= SLIP_HDRLEN;

	processing_ip((p + SLIP_HDRLEN), length);

}


void
sl_bsdos_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	register u_int caplen = h->caplen;
	register u_int length = h->len;

	if (caplen < SLIP_HDRLEN) {
			return;
	}
	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;

	length -= SLIP_HDRLEN;

	processing_ip(p + SLIP_HDRLEN, length);

}