bin/105334: Error in output of tcpdump

[Oliver Fromme]

The following reply was made to PR bin/105334; it has been noted by GNATS.

From: Oliver Fromme <olli at lurza.secnetix.de>
To: rnsanchez at wait4.org (Ricardo Nabinger Sanchez)
Cc: olli at secnetix.de (Oliver Fromme), FreeBSD-gnats-submit at FreeBSD.org
Subject: Re: bin/105334: Error in output of tcpdump
Date: Thu, 9 Nov 2006 18:35:44 +0100 (CET)

 Ricardo Nabinger Sanchez wrote:
  > Oliver Fromme wrote:
  > 
  > > 	While trying to debug a problem with NFS mounts via TCP,
  > > 	I used the following tcpdump(1) command to watch traffic
  > > 	on lo0.  Note that some (but not all) of the port numbers
  > > 	are wrong:
  > > 
  > > 		127.0.0.1.2714894848 > 127.0.0.1.2049
  > > 		127.0.0.1.2049       > 127.0.0.1.3251765760
  > 
  > Not sure if it makes sense, but 2714894848 & 65535 == 1024.  Any
  > chances that this port was indeed used during your capture (perhaps
  > cross-checking with netstat)?
 
 No, the actual port was 982, which seems to be completely
 unrelated to the numbers printed by tcpdump.  I converted
 the "suspicios" numbers to hex:
 
 2714894848 == 0xa1d20200
 3251765760 == 0xc1d20200
 652476928  == 0x26e40200
 1054278144 == 0x3ed70200
 98828800   == 0x05e40200
 
 The only common patter is 0x0200 (decimal 1024) in the
 lower 16 bits.
 
 Could this be a subtle compiler bug?  I've compiled the
 system without any special compiler settings.  make.conf
 is empty.
 
  > In contrib/tcpdump/addrtoname.c:621:638 (-CURRENT):
  > [...]
 
 The source you quoted looks OK to me.  I can't see anything
 that could explain the symptom.
 
  > Are you running i386 binary on an AMD64/EMT64 (or another
  > 64 bits variant)?
 
 It's all i386 32bit (both kernel + userland).  I don't even
 know if the machine supports 64bit, it's a Xeon 3.2 GHz.
 The dmesg says "AMD Features=0x20000000<LM>", does that
 mean "long mode", i.e. 64bit?  Anyway, I'm running 32bit,
 and going to 64bit is not an option.
 
 Best regards
    Oliver
 
 -- 
 Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
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