Tonight,I downloaded and installed libpcap on Ubuntu8.04 .
I followed those steps:
1. Add a web link to my source.list .
vim /etc/apt/sources.list
1 vim /etc/apt/sources.list
then add "deb http://fr.archive.ubuntu.com/ubuntu degy main" to sources.list
2. Execute "apt-cache search" command.
1 root@houcy-desktop:/# apt-cache search libpcap
2 libnet1 - library for the construction and handling of network packets
3 libnet1-dev - development files for libnet
4 libpcap-dev - Development library for libpcap (transitional package)
5 libpcap0.7 - System interface for user-level packet capture
6 libpcap0.7-dev - Development library and header files for libpcap 0.7
7 sing - A fully programmable ping replacement
8 libpcap0.8 - System interface for user-level packet capture
9 libpcap0.8-dev - Development library and header files for libpcap 0.8
then, "apt-get install libpcap0.8-dev"
3.Where is the package installed?
1 root@houcy-desktop:/# whereis libpcap
2 libpcap: /usr/lib/libpcap.a /usr/lib/libpcap.so
3 root@houcy-desktop:/# whereis pcap
4 pcap: /usr/include/pcap.h /usr/share/man/man3/pcap.3.gz
4.Write an example program to test and sniffer the packets.
//whenever there is packet appears on net ,then print("find data")
//This is a simple program.
1 #include <stdio.h>
2 #include <sys/types.h>
3 #include <sys/time.h>
4 #include <sys/socket.h>
5 #include <netinet/in.h>
6 #include <netinet/in_systm.h>
7 #include <netinet/ip.h>
8 #include <netinet/if_ether.h>
9 #include <pcap.h> //this is a new header file
10
11 #define DEFAULT_SNAPLEN 68
12
13 void packet_print(u_char *user,const struct pcap_pkthdr * h,const u_char *p)
14 {
15 printf("Finde data\n");
16 }
17
18 int main(int argc,char * argv[])
19 {
20 char ebuf[PCAP_ERRBUF_SIZE];
21 pcap_t * pd;
22
23 if(argc<=1)
24 {
25 printf("usage:%s <network interface>\n",argv[0]);
26 exit(0);
27 }
28
29 if((pd=pcap_open_live(argv[1],DEFAULT_SNAPLEN,1,1000,ebuf))==NULL)
30 {
31 (void)packet_print(stderr,"%s",ebuf);
32 exit(1);
33 }
34
35 if(pcap_loop(pd,-1,packet_print,NULL)<0)
36 {
37 (void)fprintf(stderr,"pcap_loop:%s\n",pcap_geterr(pd));
38 exit(1);
39 }
40
41 pcap_close(pd);
42 exit(0);
43 }
then,compile it:
1 root@houcy-desktop:/# gcc eth_txt.c -L/usr/lib -lpcap -o ext_txt
5.Run and see.
1 root@houcy-desktop:/home/houcy# ./ext_txt eth0
2 Finde data
3 Finde data
4 Finde data
5 Finde data
6 Finde data
7 Finde data
8 
Okay, we have seen all the process, from the beginning of installing to writing a test program.Next day,we`ll add some feature to this simple program and make it more powerful!
Good night!^_^