docs/102719: [patch] ng_bpf(4) example leads to unneeded promiscuos mode activation

[Eugene Grosbein]

>Number:         102719
>Category:       docs
>Synopsis:       [patch] ng_bpf(4) example leads to unneeded promiscuos mode activation
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Aug 31 06:10:12 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Eugene Grosbein
>Release:        FreeBSD 6.1-STABLE i386
>Organization:
Svyaz Service JSC
>Environment:
System: FreeBSD nkz.delikates-nk.ru 6.1-STABLE FreeBSD 6.1-STABLE #0: Wed Aug 16 20:09:18 KRAST 2006 sa at nkz.delikates-nk.ru:/home/obj/home/src/sys/NKZ i386

>Description:
	ng_bpf(4) teaches to use tcpdump(1) to generate raw BPF
        instructions. However, the exact command line does not
	include	'-p' option. This may activate promiscous mode on
	first ethernet interface, if any. This is not needed and
	should not happen.

>How-To-Repeat:
	Use example from bg_bpf(4) manual page and see pair of
	'promiscuous mode enabled/promiscuous mode disabled' messages
	in the kernel log.

>Fix:

--- src/share/man/man4/ng_bpf.4.orig	Sat Feb  5 18:31:31 2005
+++ src/share/man/man4/ng_bpf.4	Thu Aug 31 13:49:15 2006
@@ -170,7 +170,7 @@
 }
 xxENDxx
 
-BPFPROG=`tcpdump -s 8192 -ddd ${PATTERN} | awk -f /tmp/bpf.awk`
+BPFPROG=`tcpdump -s 8192 -i lo0 -p -ddd ${PATTERN} | awk -f /tmp/bpf.awk`
 
 ngctl msg ${NODEPATH} setprogram { thisHook=\\"${INHOOK}\\" \\
   ifMatch=\\"${MATCHHOOK}\\" \\


>Release-Note:
>Audit-Trail:
>Unformatted: