callback.c

#include "main.h"

/* callback function */
void packet_info (u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	int 			i, ipos=0;	// counters
	unsigned short 	        type;		// type field in ethernet frame
	double 			crnt_t;		// current time

	// set initial time
	if ( cpkNum == 0 )
		init_t = (double)h->ts.tv_sec + 0.000001*h->ts.tv_usec;

	if(user)
		pcap_dump(user, h, p);

	/* set color */
	if((type=p[12]<<8 | p[13]) == 0x0800)
	{
		if(p[23]==IP_PROTO_TCP)  setcolor(BLUE);
		else if(p[23]==IP_PROTO_UDP)  setcolor(PURPLE);
		else  setcolor(YELLO);
	}else
		setcolor(RED);

  //printf("(%4d) clen=%3d, len=%4d \r",cpkNum++,h->caplen,h->len);

	/* IP detection routine */
	checkIpAddress((unsigned char *)p, "168.126.63.1");

	/* Every 20 packets, close & reopen a log file for consistency */
	if((cpkNum%20) == 0 && (cpkNum != 0))
		LogIpDetection(NULL, NULL, 1);

	// current time compared to the initial time
	crnt_t = (double)h->ts.tv_sec + 0.000001*h->ts.tv_usec;
	printf("%9.4f: [",crnt_t-init_t);

	// source MAC address
	for ( i=0; i<6; i++)    printf("%02x%s",p[i+6],i==5 ? "->" : ":") ;

	// destination MAC address
	for ( i=0; i<6; i++)   printf("%02x%s",p[i],i==5? "]": ":");

	// IP datagram
	if ( (type=p[12]<<8 | p[13]) == 0x0800 )
	{
		printf("(");
		// source IP address
		for ( i=0; i<4; i++)
			printf("%02d%s",p[i+26], i==3?"->":".");

		// destination IP address
		for ( i=0; i<4; i++)
			printf("%02d%s",p[i+30], i==3?")":".");

		// upper layer protocol
		printf("%s", p[23]==IP_PROTO_TCP? "TCP":
			p[23]==IP_PROTO_UDP? "UDP":"OTH");
	}
	else
		printf("(Non-IP)");

	printf("\n");
	setcolor(RESET_BG);

	cpkNum++;

	if ( cpkNum == maxPkt )
	{
                setcolor(RESET_BG);
		// close all devices and files
		pcap_close(adhandle);
                if(user)
		{
                        pcap_dump_close((pcap_dumper_t *)user);
			makeStat();
		}
		exit(0);
	}
}