catch.c~

在linux下的网络嗅探器 使用的是GTK2.0+GLADE做的前台 具体的后台是ANSI C 编译器 GCC

/*
 *autor:tianyongzhen
 *filename:catch.c
 *object:get raw packets from your ethernet with your net broadcast
 *use:libpcap
 *notice:no use raw socket,for libpcap could give us some rules to fltier packets with bpfs
 */
#include <gtk/gtk.h>
#include <glade/glade.h>
#include <stdio.h>
#include <string.h>
#include <pcap.h>

#include "catch.h"

GtkWidget * textview2 ;
char filter_app[1024] ;

void
insert_time_to_textview2 ()
{
   GtkTextBuffer *buffer;
   GtkTextIter end;
   time_t start ;
   char data[30]={0} ;
   time(&start) ;
   sprintf(data, "%s", ctime(&start));
   buffer=gtk_text_view_get_buffer(GTK_TEXT_VIEW(textview2)); //textview2是一个gtktextview控件
   gtk_text_buffer_get_end_iter(buffer,&end);
   gtk_text_buffer_insert(buffer, &end, "\n", -1);
   gtk_text_buffer_get_end_iter(buffer,&end);
   gtk_text_buffer_insert(buffer, &end, data, -1);
}

void
insert_text_to_textview2 (gchar * data)
{
   GtkTextBuffer *buffer;
   GtkTextIter end;
   buffer=gtk_text_view_get_buffer(GTK_TEXT_VIEW(textview2)); //textview2是一个gtktextview控件
   gtk_text_buffer_get_end_iter(buffer,&end);
   gtk_text_buffer_insert(buffer, &end, data, -1);
   gtk_text_buffer_get_end_iter(buffer,&end);
   gtk_text_buffer_insert(buffer, &end, "\n", -1);
}

void catch_packets(void)
{
#ifdef JUSTFORFUN	
	for(;;)
		printf("catch packets\n") ;

	char *dev ;
	char errbuf[PCAP_ERRBUF_SIZE] ;
	pcap_t *descr ;
	
	bpf_u_int32 mask ;
	bpf_u_int32 net ;

	struct bpf_program fp ;
#else

	;//do nothing
	char *dev ;
	char errbuf[PCAP_ERRBUF_SIZE] ;
	const unsigned char *data = NULL;
	int ret ;
	pcap_t *descr ;
	
	bpf_u_int32 mask ;
	bpf_u_int32 net ;

	struct bpf_program filter ;
	struct pcap_pkthdr pkthdr ;
	
	descr = pcap_open_live ( "eth0", 4096, 1, 
                          512, errbuf );
	if(descr == NULL)
		perror("open eth0 error!") ;
	ret = pcap_lookupnet ( "eth0",&net,&mask, errbuf );
	if(ret == -1)
		perror("look up net error!") ;

	char net_info[500] ;
	sprintf(net_info, "Interface: eth0 Net_IP: %s Mask: %s", inet_ntoa(net),inet_ntoa(mask)) ;

	read_rules_from_file() ;
	set_filter_app() ;
	//compile the rules
	pcap_compile(descr,&filter,filter_app,1,mask) ;	
	//pcap_compile(descr,&filter,"",1,mask) ;	
	pcap_setfilter(descr,&filter) ;
	while(1)
	{
		data = pcap_next(descr,&pkthdr) ;
		if(data == NULL){
			perror("catch packet error!") ;
			exit(0) ;
		}
		insert_time_to_textview2 () ;
		insert_text_to_textview2((gchar *)net_info) ;
		//analysis
		
	}
#endif
}