HardenedBSD/contrib/libpcap
Archie Cobbs dceab8ea63 When pcap_compile() detects an error, it longjmp()'s out of the
scanner/parser. FreeBSD recently made 'flex' its default implementation
of 'lex'. One of the incompatibilities of 'flex' vs. 'lex' is that
if you longjmp() out of the scanner, you must call yyrestart()
before doing another scan (as documented in flex(1)). So add an
invocation to yyrestart() in lex_init(). This change should be
backwards compatible with the original 'lex'.

PR:	bin/24116
2001-01-07 00:26:32 +00:00
..
bpf/net Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
lbl
acsite.m4
bpf_image.c
CHANGES
config.guess
config.sub
configure
configure.in
CREDITS
etherent.c
ethertype.h
FILES
FREEBSD-upgrade
gencode.c Merge updated file for 0.5 release: handle "ip host foo" and 2000-03-04 23:57:39 +00:00
gencode.h Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
grammar.y Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
inet.c Import rev 1.26 of tcpdump.org's inet.c -- don't free 2000-07-20 21:26:45 +00:00
INSTALL
install-sh
Makefile.in
mkdep
nametoaddr.c Fix make world breakage. 2000-07-19 16:03:34 +00:00
nlpid.h
optimize.c
pcap-bpf.c
pcap-dlpi.c
pcap-enet.c
pcap-int.h Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
pcap-linux.c
pcap-namedb.h Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
pcap-nit.c
pcap-nit.h
pcap-null.c
pcap-pf.c
pcap-pf.h
pcap-snit.c
pcap-snoop.c
pcap.3 Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
pcap.c
pcap.h Merge libpcap 0.5 2000-01-30 00:43:38 +00:00
ppp.h
README
savefile.c
scanner.l When pcap_compile() detects an error, it longjmp()'s out of the 2001-01-07 00:26:32 +00:00
VERSION

@(#) $Header: /tcpdump/master/libpcap/README,v 1.18.1.1 1999/10/07 23:46:40 mcr Exp $ (LBL)

LIBPCAP 0.4
Lawrence Berkeley National Laboratory
Network Research Group
libpcap@ee.lbl.gov
ftp://ftp.ee.lbl.gov/libpcap.tar.Z

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
"libpcap@ee.lbl.gov".

 - Steve McCanne
   Craig Leres
   Van Jacobson