tcpdump mailing list archives
Re: "final" radiotap patch for tcpdump
From: David Young <dyoung () pobox com>
Date: Fri, 24 Sep 2004 21:37:26 -0500
On Sun, Sep 19, 2004 at 02:02:05PM -0700, Guy Harris wrote:
"pcap_is_swapped(p)" returns "true" if the capture file you've opened was captured on a machine with a different byte order, based on the byte order of the magic number - if that matches the byte order of the radiotap values, that'd be sufficient. (It always returns "false" for live captures.)
"Oh." Have we got the stomach for radiotap v2? If big-endian kernels no longer have to convert fields to little-endian, I think that puts the second-to-last performance issue to rest. [The "last" performance issue is that libpcap & tcpdump don't grok variable-length headers, so radiotap headers are padded to a whopping 64 bytes. A roadmap: v2 pads to just 48 or 32 bytes (maybe not...); v3 eliminates the need for padding. Thoughts?] I'm getting WAY ahead of myself. First thing is to wrap up importing tcpdump into NetBSD. Next is to find more free time for 802.11 hacking. Dave
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Current thread:
- "final" radiotap patch for tcpdump David Young (Sep 19)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 19)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 19)
- Re: "final" radiotap patch for tcpdump Bruce M Simpson (Sep 22)
- Re: "final" radiotap patch for tcpdump Michael Richardson (Sep 23)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 23)
- Re: "final" radiotap patch for tcpdump Michael Richardson (Sep 23)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 23)
- Re: x.9 branch Hannes Gredler (Sep 24)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 19)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 19)
- Re: "final" radiotap patch for tcpdump David Young (Sep 24)
- Re: "final" radiotap patch for tcpdump Guy Harris (Sep 25)