Date: Fri, 30 Jan 2009 19:33:04 +0000 (UTC) From: Giorgos Keramidas <keramida@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r187935 - head/share/man/man4 Message-ID: <200901301933.n0UJX4wC001282@svn.freebsd.org>
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Author: keramida (doc committer) Date: Fri Jan 30 19:33:04 2009 New Revision: 187935 URL: http://svn.freebsd.org/changeset/base/187935 Log: Sometimes, depending on the bpf filter rules used in $PATTERN, the example script of the manpage feeds awk(1) with values larger than UINT32_MAX. Then awk prints a negative value, and this messes up $BPFPROG. Trying to load the resulting bpf byte codes with ngctl then fails. For example, the output for PATTERN="udp and dst net 255.255.0.0/16" should be (all in one line): bpf_prog_len=10 bpf_prog=[ { code=40 jt=0 jf=0 k=12 } { code=21 jt=7 jf=0 k=34525 } { code=21 jt=0 jf=6 k=2048 } { code=48 jt=0 jf=0 k=23 } { code=21 jt=0 jf=4 k=17 } { code=32 jt=0 jf=0 k=30 } { code=84 jt=0 jf=0 k=4294901760 } { code=21 jt=0 jf=1 k=4294901760 } { code=6 jt=0 jf=0 k=8192 } { code=6 jt=0 jf=0 k=0 } ] The two k=4294901760 values are displayed as k=-2147483648 by awk. Replace the awk script of the manpage example with a slower but safer version, that doesn't really attempt to convert the byte code printed by tcpdump from string to number and back. PR: docs/123255 Submitted by: Eugenio Maffione, eugenio.maffione at telecomitalia.it MFC after: 3 days Modified: head/share/man/man4/ng_bpf.4 Modified: head/share/man/man4/ng_bpf.4 ============================================================================== --- head/share/man/man4/ng_bpf.4 Fri Jan 30 18:34:54 2009 (r187934) +++ head/share/man/man4/ng_bpf.4 Fri Jan 30 19:33:04 2009 (r187935) @@ -156,21 +156,14 @@ INHOOK="hook1" MATCHHOOK="hook2" NOTMATCHHOOK="hook3" -cat > /tmp/bpf.awk << xxENDxx -{ - if (!init) { - printf "bpf_prog_len=%d bpf_prog=[", \\$1; - init=1; - } else { - printf " { code=%d jt=%d jf=%d k=%d }", \\$1, \\$2, \\$3, \\$4; - } -} -END { - print " ]" -} -xxENDxx - -BPFPROG=`tcpdump -s 8192 -ddd ${PATTERN} | awk -f /tmp/bpf.awk` +BPFPROG=$( tcpdump -s 8192 -ddd ${PATTERN} | \\ + ( read len ; \\ + echo -n "bpf_prog_len=$len" ; \\ + echo -n "bpf_prog=[" ; \\ + while read code jt jf k ; do \\ + echo -n " { code=$code jt=$jt jf=$jf k=$k }" ; \\ + done ; \\ + echo " ]" ) ) ngctl msg ${NODEPATH} setprogram { thisHook=\\"${INHOOK}\\" \\ ifMatch=\\"${MATCHHOOK}\\" \\
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