From owner-freebsd-hackers Wed Jan 13 14:09:01 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA10257 for freebsd-hackers-outgoing; Wed, 13 Jan 1999 14:09:01 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from guppy.pond.net (guppy.pond.net [205.240.25.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA10245 for ; Wed, 13 Jan 1999 14:08:54 -0800 (PST) (envelope-from dwhite@pond.net) Received: from localhost (dwhite@localhost) by guppy.pond.net (8.8.8/8.8.7) with SMTP id OAA11635; Wed, 13 Jan 1999 14:03:49 -0800 (PST) Date: Wed, 13 Jan 1999 14:03:49 -0800 (PST) From: Doug White To: Bill Fenner cc: hackers@FreeBSD.ORG Subject: Re: using raw sockets In-Reply-To: <199901130039.QAA06354@mango.parc.xerox.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, 12 Jan 1999, Bill Fenner wrote: > In message you write: > >I'm assuming the timestamps are generated by tcpdump, > >or are they the real packet timestamps? > > The timestamp that tcpdump prints is the timestamp that bpf attaches > (i.e. when the driver calls bpf_[m]tap() ). Hm, I'll have to look at that. It might be a peculiarity with the ep driver. I want to try a de card and see what I get. > Can you compare that timestamp against gettimeofday(), to see if it > looks like the latency is in the bpf buffer? > >From a brief inspection of the bpf code, it looks like bpf won't > wake up a selecting process until the buffer is almost full. Have > you tried using the BIOCIMMEDIATE ioctl? Assuming I did the ioctl right, it is set. Doug White | Pacific Crest Networks Internet: dwhite@pond.net | http://www.pond.net/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message