ports/127313: [patch] security/knockd: use less CPU

[Duane Wessels]

>Number:         127313
>Category:       ports
>Synopsis:       [patch] security/knockd: use less CPU
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 12 06:40:00 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Duane Wessels
>Release:        6.3-STABLE
>Organization:
>Environment:
FreeBSD ipsec.life-gone-hazy.com 6.3-STABLE FreeBSD 6.3-STABLE #1: Sun Aug 17 23:23:58 PDT 2008     root at life-gone-hazy.com:/usr/obj/usr/src/sys/SOEKRIS  i386

>Description:
knockd uses too much CPU, especially on systems with slower or low-power
CPUS (such as the Soekris net4501).

The timeout argument to pcap_open_live (1 ms) seems unreasonably small.  On a
soekris box it uses 15% of CPU.  Setting the timeout to 1 second reduces it to
"0.00%".
>How-To-Repeat:
Install and configure on a system with ~133 MHz CPU.  Check process CPU
usage with 'top'.

>Fix:


Patch attached with submission follows:

--- src/knockd.c.orig	2008-09-11 23:24:37.000000000 -0700
+++ src/knockd.c	2008-09-11 23:24:49.000000000 -0700
@@ -200,7 +200,7 @@
 	}
 
 #if defined(__FreeBSD__) || defined(__APPLE__)
-	cap = pcap_open_live(o_int, 65535, 0, 1, pcapErr);
+	cap = pcap_open_live(o_int, 65535, 0, 1000, pcapErr);
 #else
 	cap = pcap_open_live(o_int, 65535, 0, 0, pcapErr);
 #endif	


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