HOWTO: pcap in 'background' thread

[Steve Hyatt <shyatt () bigbangwidth com>]

Hi all.

I am maintaining a piece of software which uses the pcap library to monitor packets being sent from a given machine and 
then categorizing this packets based on the destination IP grabbed from the packet's headers.  The software uses 
pthreads to separate the recording of the packets (through call to pcap_open_live, pcap_loop, and a callback funtion) 
in one thread from the processing of this data in another pthread thread.  The implemented use of pthreads and mutex's 
are giving me problems which I would like to resolve by removing pthreads.

I am not sure however how this can be done.  What i'd like to be able to do is something like the following pseudo-code:

  while (!done) {
    use pcap to count packets and bytes for next 200 ms;
    evaluate last 200ms worth of data and process;
  }

The idea is only have one thread which does both things.  This only would work however if there is a way to ask the 
pcap library to 'watch packets for X MS'.  How can I do this?  

I think I can do this by using fork to have a child process do the capturing and using the callback to 'pipe' the data 
back to the parent process, and have the wile loop in the parent process.  However one of the platforms that I need a 
solution for does not have the fork method (its an MMU-less platform).

Any help would be greatly appreciated.

Steve
shyatt () bigbangwidth com

-
This is the TCPDUMP workers list. It is archived at
http://www.tcpdump.org/lists/workers/index.html
To unsubscribe use mailto:tcpdump-workers-request () tcpdump org?body=unsubscribe