Date: Wed, 9 Jun 2010 22:16:51 +0300 From: Kostik Belousov <kostikbel@gmail.com> To: Jung-uk Kim <jkim@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: [RFC] BPF timestamping Message-ID: <20100609191651.GR83316@deviant.kiev.zoral.com.ua> In-Reply-To: <201006091444.50560.jkim@FreeBSD.org> References: <201006091444.50560.jkim@FreeBSD.org>
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[-- Attachment #1 --] On Wed, Jun 09, 2010 at 02:44:47PM -0400, Jung-uk Kim wrote: > bpf(4) can only timestamp packets with microtime(9). I want to expand > it to be able to use different format and resolution. The patch is > here: > > http://people.freebsd.org/~jkim/bpf_tstamp.diff > > With this patch, we can select different format and resolution of the > timestamps. It is done via ioctl(2) with BIOCSTSTAMP command. > Similarly, you can get the current format and resolution with > BIOCGTSTAMP command. Currently, the following functions are > available: > > BPF_T_MICROTIME microtime(9) > BPF_T_NANOTIME nanotime(9) > BPF_T_BINTIME bintime(9) > BPF_T_MICROTIME_FAST getmicrotime(9) > BPF_T_NANOTIME_FAST getnanotime(9) > BPF_T_BINTIME_FAST getbintime(9) > BPF_T_NONE ignore time stamps > > (Note: Additionally, there is an experimental machanism to tag packets > with timestamps in struct bintime format via mbuf_tags(9) from lower > layer, e.g., device driver. However, I didn't test it because I > wasn't sure whether this is the right thing to do.) > > While I was here, I moved the bogus SIZEOF_BPF_HDR macro into bpf.c > and tried to make it little bit more correct. For example, the > 32-bit shim should be able to handle alignment more properly for > non-Ethernet DLTs. I tried my best not to break ABI/API (especially > for 32-bit platforms) and relevant places are all marked with > BURN_BRIDGES. Putting COMPAT_FREEBSD32 under BURN_BRIDGES feels somewhat strange. [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkwP6KMACgkQC3+MBN1Mb4gMUgCggfGPETcl7pZMIGgEO2aQwiU1 vjEAoLBJwH1ZOgNDulSWZ1q1/umWXi71 =iYaM -----END PGP SIGNATURE-----
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