Re: libnet doubt

You dont have to call libnet_clear_packet().

Just re-use the same l (context) and ptags, with different parameters
passed to the builder.

	Fred Raynal

On Tue, Jun 15, 2004 at 05:33:34PM +0530, [email protected] wrote:
> 
> 
> 
> 
> Hi,
> 
>  I tried doing this :
> 
>   after sending every UDP packet, I call, libnet_clear_packet(lh);, then in
> build_send_udp I set udp_ptag and ip_ptag to zero before calling
> libnet_build_udp or libnet_build_ipv4. But still, I am noe getting an error
> with libnet_write().
> 
> it says : write error : injection type not supported.
> 
> this is really wierd, is sending two consecutive udp packets so difficult,
> help section is not helping much since it is not very comlpete .. can
> someone point out as to what am I doing wrong, and give me a well defined
> wy of sending more than one packet(any protocol) on the same context(i.e
> without having to do a libnet_init and libnet_destroy every time I send a
> packet).
> 
> thanks
> Amit
> 
> 
> 
> 
> Amit Kumar Singh
> 06/15/2004 05:08 PM
> 
> To:    "Jee J.Z." <[email protected]>
> cc:
> 
> Subject:    libnet doubt
> 
> 
> ---------------------- Forwarded by Amit Kumar Singh/HSS on 06/15/2004
> 05:16 PM ---------------------------
> 
> 
> Amit Kumar Singh
> 06/15/2004 04:27 PM
> 
> To:    "Mustafa Abu Sedera" <[email protected]>
> cc:    [email protected]
> 
> Subject:    libnet doubt  (Document link: Amit Kumar Singh)
> 
> Hi,
> 
>  I am trying to do this :
> 
> libnet_t lh;
> libnet_ptag_t udp_ptag=0, ip_ptag=0;
> u_long dst_ip;
> 
> build_send_udp()
> {
> udp_ptag=0;
> udp_ptag=libnet_build_udp( ...... );
> if(udp_ptag==-1) {printf("we're goig to bad from here udptag");goto bad;}
> ip_ptag=libnet_autobuild_ipv4(....);
> if(ip_ptag==-1) {printf("\nwe're going to abd from iptag\n");goto bad;}
> 
> bad:
> destroy (lh);
> exit;
> }
> 
> main()
> {
> char * dst="192.x.x.x";
> lh=libnet_init(libnet_raw4 , NULL, err_buf);
> dst_ip=libnet_name2addr(lh, dst, DONT_RESOLVE);
> build_send_udp();
> build_send_udp();
> build_send_udp();
> libnet_destroy(lh);
> }
> 
> WHAT I AM TRYING TO DO :
> basically i am trying to send more than one udp packets from the same
> context. What I do is this :
> 1. first in main initialize using libnet_init, the handle is a global
> variable accessible to build_send_udp() too.
> 2. then send a udp packeteverytime build_send_udp is called.
> 3 finally after all 3 packets have been sent, destroy the context using
> libnet_destroy(lh);
> 
> PROBLEM :  On running the .out, the first packet goes out fine, but for the
> second, third (all after first ) I get the following error :
> 
> We're going to bad from iptag
> cannot build ip header : libnet_get_ipaddr4() : ioctl : no such device ....
> what is this can someone tell me how to send more than one packet from the
> same context.
> 
> i tried adding libnet_clear_packet(lh); after every call to
> build_send_udp(), but the same error persists.
> 
> Any clues ?
> 
> thanks
> Amit
> 
> 
> 
> 
>