[BACK]Return to README CVS log [TXT][DIR] Up to [local] / src / lib / libpcap
File: [local] / src / lib / libpcap / README (download)

Revision 1.6, Wed Apr 26 21:25:52 2000 UTC (24 years, 1 month ago) by jakob
Branch: MAIN
CVS Tags: OPENBSD_5_5_BASE, OPENBSD_5_5, OPENBSD_5_4_BASE, OPENBSD_5_4, OPENBSD_5_3_BASE, OPENBSD_5_3, OPENBSD_5_2_BASE, OPENBSD_5_2, OPENBSD_5_1_BASE, OPENBSD_5_1, OPENBSD_5_0_BASE, OPENBSD_5_0, OPENBSD_4_9_BASE, OPENBSD_4_9, OPENBSD_4_8_BASE, OPENBSD_4_8, OPENBSD_4_7_BASE, OPENBSD_4_7, OPENBSD_4_6_BASE, OPENBSD_4_6, OPENBSD_4_5_BASE, OPENBSD_4_5, OPENBSD_4_4_BASE, OPENBSD_4_4, OPENBSD_4_3_BASE, OPENBSD_4_3, OPENBSD_4_2_BASE, OPENBSD_4_2, OPENBSD_4_1_BASE, OPENBSD_4_1, OPENBSD_4_0_BASE, OPENBSD_4_0, OPENBSD_3_9_BASE, OPENBSD_3_9, OPENBSD_3_8_BASE, OPENBSD_3_8, OPENBSD_3_7_BASE, OPENBSD_3_7, OPENBSD_3_6_BASE, OPENBSD_3_6, OPENBSD_3_5_BASE, OPENBSD_3_5, OPENBSD_3_4_BASE, OPENBSD_3_4, OPENBSD_3_3_BASE, OPENBSD_3_3, OPENBSD_3_2_BASE, OPENBSD_3_2, OPENBSD_3_1_BASE, OPENBSD_3_1, OPENBSD_3_0_BASE, OPENBSD_3_0, OPENBSD_2_9_BASE, OPENBSD_2_9, OPENBSD_2_8_BASE, OPENBSD_2_8, OPENBSD_2_7_BASE, OPENBSD_2_7
Changes since 1.5: +11 -11 lines 

sync with libpcap v0.5
add support for INET6 (kame)

$OpenBSD: README,v 1.6 2000/04/26 21:25:52 jakob Exp $
$NetBSD: README,v 1.2 1995/03/06 11:38:07 mycroft Exp $
@(#) $Header: /cvsrepo/anoncvs/cvs/src/lib/libpcap/README,v 1.6 2000/04/26 21:25:52 jakob Exp $ (LBL)

LIBPCAP 0.5
Now maintained by "The Tcpdump Group"
Send patches to patches@tcpdump.org
See 		www.tcpdump.org

formerly from 	Lawrence Berkeley National Laboratory
		Network Research Group <libpcap@ee.lbl.gov>
		ftp://ftp.ee.lbl.gov/libpcap.tar.Z (0.4)

This directory contains source code for libpcap, a system-independent
interface for user-level packet capture.  libpcap provides a portable
framework for low-level network monitoring.  Applications include
network statistics collection, security monitoring, network debugging,
etc.  Since almost every system vendor provides a different interface
for packet capture, and since we've developed several tools that
require this functionality, we've created this system-independent API
to ease in porting and to alleviate the need for several
system-dependent packet capture modules in each application.

Note well: this interface is new and is likely to change.

The libpcap interface supports a filtering mechanism based on the
architecture in the BSD packet filter.  BPF is described in the 1993
Winter Usenix paper ``The BSD Packet Filter: A New Architecture for
User-level Packet Capture''.  A compressed postscript version is in:

	ftp://ftp.ee.lbl.gov/papers/bpf-usenix93.ps.Z.

Although most packet capture interfaces support in-kernel filtering,
libpcap utilizes in-kernel filtering only for the BPF interface.
On systems that don't have BPF, all packets are read into user-space
and the BPF filters are evaluated in the libpcap library, incurring
added overhead (especially, for selective filters).  Ideally, libpcap
would translate BPF filters into a filter program that is compatible
with the underlying kernel subsystem, but this is not yet implemented.

BPF is standard in 4.4BSD, BSD/386, NetBSD, and FreeBSD.  DEC OSF/1
uses the packetfilter interface but has been extended to accept BPF
filters (which libpcap utilizes).  Also, you can add BPF filter support
to Ultrix using the kernel source and/or object patches available in:

	ftp://gatekeeper.dec.com/pub/DEC/net/bpfext42.tar.Z.

Problems, bugs, questions, desirable enhancements, source code
contributions, etc., should be sent to the email address
"patches@tcpdump.org".