Libnet
 

Hey pals
Here we meet again

I wanted to do a program which does some packet injection such as arp requests etc.

So I heard there is a library for that called libnet (http://www.packetfactory.net/libnet/)

But nfortunately the man pages written with it are very short and miss many details, so does any one know a documentation or a detailed tutorial or howto to help me understand how to use this library

Also If anyone knows a better library please tell me

Check the sources for these tools:
http://www.citi.umich.edu/u/provos/h...rpd-0.2.tar.gz
http://www.packetfactory.net/projects/packit/
ftp://ftp.dementia.org/pub/net-tools/

Thanks a lot HKO

Now I have one more question

I wrote a program to send arp

--------------------START OF CODE-------------------------------------------------------------------

#include <libnet.h>

int main(int argc,char** argv){

u_long ip_src;
u_char ip_dst[4] = {0x0a,0x00,0x00,0x04};
u_char enet_src[6] = {0x00,0x01,0x02,0x03,0x04,0x05};
u_char enet_dst[6] = {0xff,0xff,0xff,0xff,0xff,0xff};

libnet_t* l;
libnet_ptag_t t;
char* device;
char errorBuffer[LIBNET_ERRBUF_SIZE];

if(argc>=2) device=argv[1];

l = libnet_init(LIBNET_LINK_ADV,device,errorBuffer);
if(l==NULL){
fprintf(stderr,"\nError in libnet_init(): %s",errorBuffer);
return -1;
}

ip_src = libnet_get_ipaddr4(l);

t = libnet_build_arp(ARPHRD_ETHER,ETHERTYPE_IP,6,4,ARPOP_REPLY,enet_src,(u_char*)&ip_src,enet_dst,ip_dst ,NULL,0,l,0);
if(t==-1){
fprintf(stderr,"\nError in libnet_build_arp(): %s",libnet_geterror(l));
libnet_destroy(l);
return -1;
}

t = libnet_autobuild_ethernet(enet_dst,ETHERTYPE_ARP,l);
if(t==-1){
fprintf(stderr,"\nError in libnet_autobuild_ethernet(): %s",libnet_geterror(l));
libnet_destroy(l);
return -1;
}

int x=libnet_write(l);
if(x==-1){
fprintf(stderr,"\nError in libnet_write(): %s \n",libnet_geterror(l));
libnet_destroy(l);
return -1;
}

libnet_destroy(l);
}

--------------------------END OF CODE-------------------------------------------

And whenever I run it the computer hangs !!

So does anyone know what's wrong with it ??