tcpdump mailing list archives
Re: adding new devices to libpcap
From: Stephen Donnelly <stephen () endace com>
Date: Tue, 14 Jan 2003 17:02:17 +1300
Michael Richardson wrote:
"Sean" == Sean Irvine <sairvin () xtra co nz> writes:Sean> We have pieces of hardware capable of monitoring various Sean> kinds of network links. This hardware is not configured Sean> as a network device (i.e. it is not ifconfig friendly), Sean> but we do have Linux drivers to talk to the hardware. I do not think that you need to be ifconfig'ed to talk to the packet capture mechanisms on Linux. Just go read netif_rx() and netif_receive_skb() in net/core/dev.c. So long as you can call with an skb, you are probably set. I'm not sure exactly what it means to be ifconfig-unfriendly - but as long as you can pretend to be a network device in some fashion, and produce SKB's, I think you should use the stock interfaces.
Our hardware is actually not a network device at all, but registers as a char device and provides mmapped IO for performance reasons. Hence packets avoid kernel memory management and the Linux packet-socket for efficiency.
Preferably we'd like to be able to compile a single libpcap which could operate in Linux on both 'traditional' network devices and on our hardware transparently.
This would be better I think than having a pcap-XYZ implementation that operated only on our hardware and not regular interfaces, requiring the compilation of applications twice against different libpcap libraries on a single system.
Looking at libpcap, could we add some small state items to the end of "struct pcap_md", if they were suitably ifdef'd? The eventual goal is to contribute any changes made back upstream, so indications on what is and isn't likely to be accepted would be useful.
Stephen. -- ----------------------------------------------------------------------- Stephen Donnelly BCMS PhD email: sfd () endace com Endace Technology Ltd phone: +64 7 839 0540 Hamilton, New Zealand cell: +64 21 1104378 ----------------------------------------------------------------------- - 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
Current thread:
- adding new devices to libpcap Sean Irvine (Jan 13)
- Re: adding new devices to libpcap Guy Harris (Jan 13)
- Re: adding new devices to libpcap Guy Harris (Jan 13)
- Re: adding new devices to libpcap Michael Richardson (Jan 13)
- Re: adding new devices to libpcap Guy Harris (Jan 13)
- Re: adding new devices to libpcap Stephen Donnelly (Jan 13)
- Re: adding new devices to libpcap Guy Harris (Jan 13)