[Planetlab-users] a question about raw sockets (one more time)

[Michal S. <mi...@cs...>]

Andy,

> To monitor incoming and outgoing packets on a port, PlanetLab provides raw
> "sniffer" sockets.  Here is a bit of documentation:
>
>  http://www.planet-lab.org/raw_sockets/api_sniffer.html
>

I followed the instructions exactly, and:
- I can see incoming raw IP packets :-)
- I still cannot see any outgoing ones :-(
For example, during a TCP-handshake, I can see incoming SYN and ACK
packets, but I cannot see any SYNACK packet between them.

Here is a piece of my code:

#define PACKET_SIZE 1500

int m,on;
char packet[PACKET_SIZE];

if ((m=socket(PF_INET,SOCK_RAW,IPPROTO_TCP))==-1)
	fatal("monitor:socket");
on=1;if (setsockopt(m,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(int))==-1)
	fatal("monitor:reuseaddr");
on=1;if (setsockopt(m,0,SO_RAW_SNIFF,&on,sizeof(int))==-1)
	fatal("monitor:setrawsniff");
if (bind(m,(struct sockaddr*)&sa,sizeof(struct sockaddr_in))==-1)
	fatal("monitor:bind");

and then loop on recvfrom(m,packet,PACKET_SIZE,0,NULL,NULL);


Any ideas what may be wrong? BTW, thanks to everyone who tried to help me
the last time :-)

Kind regards,
M.
--
Michal Szymaniak | mailto:mi...@cs... | http://www.cs.vu.nl/~mszyman