arp.c

* A ncurses user interface. * Network statistics to view the amount of packets and data in many

/*

  This file is part of sniffer, a packet capture utility and
  network moniter
  The author can be contacted at <[e-mail]>
  the lastest version is avilable from 
  http://stev.org

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "config.h"

#ifdef ARP

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include <fcntl.h>

#include <sys/stat.h>

#include "sniff.h"
#include "list.h"
#include "locks.h"
#include "in_ntoa.h"
#include "lookup.h"
#include "arp.h"
#include "arp_48bit.h"
#include "stat.h"
#include "log.h"

FILE *arp_log;

pthread_mutex_t arp_mutex =  PTHREAD_MUTEX_INITIALIZER;
unsigned long int inet_addr(const char *cp);
struct gen_stat arp_stat;


int arp_handle(struct sniff_pkt *pkt, void *data) {
	struct arphdr *in;
	void *pointer;
	int proto;

	pkt->func = "arp_handle";
	if (pkt->dataleft < sizeof(struct arphdr))
		return ERR_DATA;

	arp_stat.packets++;
	arp_stat.bytes += pkt->dataleft;

	in = (struct arphdr *) data;
	pointer = data + sizeof(struct arphdr);
	pkt->dataleft -= sizeof(struct arphdr);
	proto = ntohs(in->ar_hrd);


	switch(proto) {
#ifdef ARP_48BIT		
		case ARPHRD_ETHER:
			return arp_handle_48bit(pkt, in, pointer);
		case ARPHRD_IEEE802:
			return arp_handle_48bit(pkt, in, pointer);
#endif /* do we want ARP_48BIT ? */
		default:
		#ifdef DEBUG_ARP
			log_error("Arp_handle: unsupported protcol\n");
		#endif
			arp_stat.dropped++;
			return ERR_SUPP;
			break;
	}
	return -2;
}

/**************************************
****** arp_tidy() *********************
**************************************/

int arp_tidy() {
	if (arp_log)
		fflush(arp_log);
	return 0;
}


/**************************************
* let set up all the arp stuff
***************************************/

int arp_init() {

	/* open up a file for loggin */
#ifdef DEBUG
	arp_log = fopen("output/arp", "w");
#else
	arp_log = fopen("output/arp", "w+");
#endif
	if (!arp_log) {
		log_errno("fopen");
		return -1;
	}

	SLOCK(&arp_mutex);
	init_stat(&arp_stat, "ARP");

#ifdef ARP_48BIT
	if (arp_48bit_init() < 0) {
		SUNLOCK(&arp_mutex);
		return -2;
	}
#endif

	SUNLOCK(&arp_mutex);
	return 0;
}

#endif /* do we want arp ? */