Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.sys.apple2.programmer > #1548

Re: Resolved!, was Re: Uthernet receive error: bytes swapped

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From D Finnigan <dog_cow@macgui.com>
Newsgroups comp.sys.apple2.programmer
Subject Re: Resolved!, was Re: Uthernet receive error: bytes swapped
Date Fri, 6 Mar 2015 00:30:23 +0000 (UTC)
Organization Mac GUI
Lines 23
Message-ID <dog_cow-1425601864@macgui.com> (permalink)
References <dog_cow-1425155060@macgui.com> <dog_cow-1425329291@macgui.com> <27094031-e746-4e9d-a0a4-e81ef6f82c44@googlegroups.com>
Mime-Version 1.0
Content-Type text/plain; charset=UTF-8
Content-Transfer-Encoding 8bit
Injection-Date Fri, 6 Mar 2015 00:30:23 +0000 (UTC)
Injection-Info mx02.eternal-september.org; posting-host="ac9e0e4d7dd3957fb97803ee6801bab8"; logging-data="31354"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18AEwulaxapPQgi56Fr2kiO"
User-Agent Mac GUI Usenet
In-Reply-To <27094031-e746-4e9d-a0a4-e81ef6f82c44@googlegroups.com>
Cancel-Lock sha1:WxGM1djUgIb2TowCToqpBMKGizs=
Xref csiph.com comp.sys.apple2.programmer:1548

Show key headers only | View raw


gids.rs wrote:
>> What's incredible is how the checksum routine still managed to give
>> correct
>> results in so many cases. That's definitely one of those tricky bugs.
>> 
> 
> 
> Maybe not so incredible.  Wouldn't 10 bytes of code followed by 10 bytes
> of
> 0's give the same checksum?

I don't know. This IP checksum routine was supposed to only cover the 20
byte IP header. If it was running twice as long, it was either checksumming
a bit of the data payload, or something else. I'm not really interested in
looking into exactly what it was doing, just surprised that it was giving
correct results in its broken state.

-- 
]DF$
Apple II Book: http://macgui.com/newa2guide/
Usenet: http://macgui.com/usenet/  <-- get posts by email!
Apple II Web & Blog hosting: http://a2hq.com/

Back to comp.sys.apple2.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-02-28 20:23 +0000
  Re: Uthernet receive error: bytes swapped David Schmenk <dschmenk@gmail.com> - 2015-02-28 12:58 -0800
  Re: Uthernet receive error: bytes swapped a2retrosystems@gmail.com - 2015-02-28 16:20 -0800
    Re: Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-03-01 00:34 +0000
      Re: Uthernet receive error: bytes swapped a2retrosystems@gmail.com - 2015-02-28 17:17 -0800
      Re: Uthernet receive error: bytes swapped David Schmidt <schmidtd@my-deja.com> - 2015-02-28 21:58 -0500
  Re: Uthernet receive error: bytes swapped ol.sc@web.de (Oliver Schmidt) - 2015-03-01 14:33 +0000
    Re: Uthernet receive error: bytes swapped David Schmenk <dschmenk@gmail.com> - 2015-03-01 12:15 -0800
  Resolved!, was Re: Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-03-02 20:47 +0000
    Re: Resolved!, was Re: Uthernet receive error: bytes swapped gids.rs@sasktel.net - 2015-03-02 16:14 -0800
      Re: Resolved!, was Re: Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-03-06 00:30 +0000
        Re: Resolved!, was Re: Uthernet receive error: bytes swapped David Schmidt <schmidtd@my-deja.com> - 2015-03-05 20:53 -0500
          Re: Resolved!, was Re: Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-03-07 17:37 +0000
        Re: Resolved!, was Re: Uthernet receive error: bytes swapped David Schmenk <dschmenk@gmail.com> - 2015-03-06 07:21 -0800
          Re: Resolved!, was Re: Uthernet receive error: bytes swapped D Finnigan <dog_cow@macgui.com> - 2015-03-07 17:31 +0000

csiph-web