[Monotone-devel] Regular HMAC problems

[Richard Levitte - VMS Whacker]

Hi,

I've regular HMAC problems, looks reproducible, and would like to know
if anyone else has hit this.

The two machines involved run Debian GNU/Linux.  On the server side,
it's the "testing" distribution, on the client side it's "unstable".
For both of them, I've built a monotone package locally using
"dpkg-buildpackage -rfakeroot -b -uc" and installed it locally.

The error never shows itself for small payloads, it looks to me like
the it's getting trigger at some random point after 700 Ki bytes out.


  mtn: accepted new client connection from 82.183.134.65 : 33922
  mtn: allowed 'address@hidden' read permission for 'richard.levitte.org:*' 
excluding ''
  mtn: allowed 'address@hidden' write permission for 'richard.levitte.org:*' 
excluding ''
  mtn: finding items to synchronize:
  mtn: ticks: c="certificates"/256, k="keys"/1, r="revisions"/64
  mtn: ckrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
  mtn: rrrrrrrrrrrcccccccccccccccccccccccccccccccccccccccccccccccccccccccc
  mtn: ckkkkkkkkkkkkkkkkkkkkkkkk
  mtn: warning: protocol error while processing peer 82.183.134.65:33922: 'bad 
HMAC checksum (got 92bcc8f2787f64782aa16e8133613aceefd7f468, wanted 
15ba58804cc34dbb67361a743dd5873ee19053a9)
  mtn: warning: this suggests data was corrupted in transit
  mtn: warning: ', disconnecting

It starts by being unusually still for quite some time (half an hour?
Haven't made any exact measurements) at some point:

 On the client side:

  : ; LANG=C sh RL-push.sh
  mtn: connecting to guardian.lp.se
  mtn: finding items to synchronize:
  mtn: certificates | keys | revisions
  mtn:        13820 |   24 |      4573
  mtn: bytes in | bytes out | certs out | revs out
  mtn:  363.6 k |   636.0 k |     74/74 |    24/24

 On the server side:

  mtn: accepted new client connection from 82.183.134.65 : 32880
  mtn: allowed 'address@hidden' read permission for 'richard.levitte.org:*' 
excluding ''
  mtn: allowed 'address@hidden' write permission for 'richard.levitte.org:*' 
excluding ''
  mtn: finding items to synchronize:
  mtn: ticks: c="certificates"/256, k="keys"/1, r="revisions"/64
  mtn: 
  
and then, the rest of the bytes start pouring out, and it goes BAM...

 On the client side:

  : ; LANG=C sh RL-push.sh
  mtn: connecting to guardian.lp.se
  mtn: finding items to synchronize:
  mtn: certificates | keys | revisions
  mtn:        13820 |   24 |      4573
  mtn: bytes in | bytes out | certs out | revs out
  mtn:  363.6 k |  1012.2 k |     74/74 |    24/24
  mtn: error: I/O failure while talking to peer guardian.lp.se, disconnecting
  
 On the server side:

  mtn: warning: protocol error while processing peer 82.183.134.65:32880: 'bad 
HMAC checksum (got e4771c8e1014e7006a33e3ca0ce98416b05dbf3c, wanted 
6fff6f6647fbdc91af37fb7bfbe2f340831f4438)
  mtn: warning: this suggests data was corrupted in transit
  mtn: warning: ', disconnecting
  
On both machines, the monotone used is revision
cc6f65e51edf922fcf632839c98114cae27c8ec1, which is a combination
(through propagation to a private branch) of the following:

  4c0a91d8d4dff25ccf52de071fd5af2f10465ab2 (nvm)
  383fd4172141eb91e2487010dee78e14fa493c7f (nvm.debian)
  7bbd6c5dd6d5f5fbf6f4afc24e085d8189b6bd16 (nvm.levitte.select-heads-of)

Has anyone else hit this at all?

My next try will be to take the regular mtn head (nvm) and see if that
makes a difference.

Cheers,
Richard

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-- 
Richard Levitte                         address@hidden
                                        http://richard.levitte.org/

"When I became a man I put away childish things, including
 the fear of childishness and the desire to be very grown up."
                                                -- C.S. Lewis