[Mono-list] mod_mono/XSP HEAD (source) + Mono 1.0.5 (source)+ Apache 2 (binary) + Debian Sarge

[Winfried Harbecke]

Hi,

  I don't know if someone else has figured this out before,
  but I could not find any evidence to that so far ...

  My findings provide an explanation why some
  people fare better with apache installed from source
  when setting up mod_mono, and they also explain why
  some people have symptoms that point to a version
  inconsistency betweeen mod_mono.so and mod_mono_server
  although they promise they don't have any inconsistecy
  at all. I'll also post what I did to provide some
  help with debugging mod_mono - to help improving future
  bug reports and support requests    :-).

  Skimming recent postings on the Mono list, I noticed that
  there are a few bugs that were only fixed in the 1.0.5 version
  of the mod_mono/XSP packages. Thus, a combination of Mono 1.0.5
  with an up-to-date version of mod_mono/XSP seemed like the
  most promising combination. I installed Debian Sarge onto a
  new partition, pulled in the prerequisites and compiled
  Mono 1.0.5 from the released tarballs. I also obtained
  the HEAD versions of mod_mono and XSP and compiled them - after
  getting the apache development package from Debian testing.

  Starting mod-mono-server from command line to see the output,  I got 

               In ModMonoWorker.Run: Abnormal string size.

  and a 500 Internal Server Error in Apache.

  I added a couple DEBUG_PRINT's and some hex output to mod_mono.c,
  and found

  [Sat Jan 29 12:29:01 2005] [warn] write_string_to_buffer (8:134217728)
  [Sat Jan 29 12:29:01 2005] [warn]    length prefix 00 00 00 08
  [Sat Jan 29 12:29:01 2005] [warn] write_data (44) bytes
  [Sat Jan 29 12:29:01 2005] [warn]    01 00 00 00 03 47 45 54  .....GET
  [Sat Jan 29 12:29:01 2005] [warn]    00 00 00 10 2f 64 65 6d  ..../dem
  [Sat Jan 29 12:29:01 2005] [warn]    6f 2f 69 6e 64 65 78 2e  o/index.
  [Sat Jan 29 12:29:01 2005] [warn]    61 73 70 78 00 00 00 00  aspx....
  [Sat Jan 29 12:29:01 2005] [warn]    00 00 00 08 48 54 54 50  ....HTTP
  [Sat Jan 29 12:29:01 2005] [warn]    2f 31 2e 31              /1.1....

  in /var/log/apache2/error.log. Running cpp against mod_mono.c
  like the Makefile does (just replacing "-c" with "-E") gives

         lel = ((unsigned int) \
  ( (((unsigned int) (l) & (unsigned int) 0x000000ffU) << 24) \
  | (((unsigned int) (l) & (unsigned int) 0x0000ff00U) << 8) \
  | (((unsigned int) (l) & (unsigned int) 0x00ff0000U) >> 8) \
  | (((unsigned int) (l) & (unsigned int) 0xff000000U) >> 24)));

  At this point, I noticed that /usr/include/apache2/ap_config_auto.h
  (in the Apache 2 development package) has
   #define WORDS_BIGENDIAN 1

  which really messes things up, at least on an Intel machine    :-).

  After changing that to 
   #undef WORDS_BIGENDIAN
  I finally got to look at the first ASP.

  I could post a bug report for apache-debian, but I would not
  expect anybody running into these symptoms to check that bug list    :-)
 
  Gonzalo, I can provide patches for the hex output (it's
  boilerplate stuff, though); I could also write up a few lines
  to add to the FAQ. What I am really curious about is the
  more fundamental question:

  Why is mod_mono_server implemented as a standalone server
  instead of baseing it on an embedded Mono runtime, which would
  also be much closer to the Apache plug-in architecture? Licensing
  issues?
  
Greetings
Winfried