WebDAV CGI: Troubleshooting Guide

Content of this site:

Client issues
Setup/Configuration issues
Common issues

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Client issues

Speedy is supported since v0.5.3 but if you get "Out of memory" messages in your Apache error log you must set "MaxRuns", e.g. #!/usr/bin/speedy -- -r20
Windows Web Folder tries to read folders without a trailing '/' and Apache responses with a redirect (Workaround: use Apache rewrite rule instead of direct folder access)
Windows 7 does not support SSL with Web Folders (yet) and has some trouble with HTTP Basic authentication (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WebClient\Parameters\BasicAuthLevel should be 2(DWORD))
Amaya upload does not work yet in some configurations (works only with rewrites not with error handler)
DAVExplorer has some trouble with XML parsing (PROPFIND) ... sometimes.
nautilus cannot copy folders via clipboard
more: see Client issues

Finder (MacOS X 10.x):

... is really slow because the MacOS X Finder generates a lot of requests to get Apple doubleheaders and to put .DS_Store files.
a solution is to use CyberDuck instead of Finder
or speed up the Finder a little bit: disable Finder previews and prevent .DS_Store file creation.

iCal:

You must specifiy the server port, e.g. cal.example.org:80

Addressbook (MacOS X 10.6.x):

WebDAV CGI must run in a root context (WebDAV CGI must handle the root of your (virtual) server)
You must specify the server port, e.g. abook.example.org:80

iPhone/iPad:

you must change the Account-URL to work with WebDAV CGI: it should be the same as your CalDAV folder URL or principal URL:
1. Settings > Other > Add CalDAV Account
2. Setup Server (e.g. https://www.example.org:443/webdav/caldav/), Username and Password
3. Next > Advanced Settings > Account URL (e.g. https://www.example.org:443/webdav/caldav/)

Windows Vista/7:

Slow response working with WebDAV resources on Windows Vista or Windows 7: see http://support.microsoft.com/kb/2445570 OR http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol

Setup/Configuration issues

Timeout

Maybe it helps to increase the Timeout value in your Apache configuration (300 is a good minimum value).
If a larger Timeout value does not fix the problem perhaps the Apache mod_reqtimeout is loaded. You should disable this module (Debian/Ubuntu: a2dismod reqtimeout; /etc/init.d/apache2 restart) or configure it with larger values.

Apache error log: `Request exceeded the limit of X internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.`

This is a typical rewrite misconfiguration. A common mistake is to take the .htaccess rewrite rule example for the Apache configuration. A rule like RewriteRule .* ... in the Apache configuration runs into a 'endless' recursion only stopped by the Apache limit (LimitInternalRecursion). Please use a rule like RewriteRule ^/ ... to fix this problem. In a .htaccess makes the pattern ^/ no sense because this pattern will never match. Rewite rule patterns in a .htaccess have to be relative to the current path therefore .* works fine.
If this does not help put the following to your Apache configuration:

RewriteLogLevel 3
RewriteLog /var/log/apache2/rewrite.log

and analyze the rewrite.log after a single access to your WebDAV area and don't forget to set the RewriteLogLevel back to 0 after your debug session.

404 File Not Found / 500 Internal Server Error / 'Premature end of script headers'

Please check the following:

Apache error log - Apache writes sometimes helpful things into logs
read and execute file permissions of webdavwrapper and webdav.pl and fix it if necessary (owner/group too):
```
chmod a+rx webdav.pl
chmod a+rx,ug+s webdavwrapper
chown root:root webdavwrapper
```
shebang of webdav.pl: path to the Perl interpreter have to be correct

/etc/webdav.conf syntax (maybe a broken config):

#> perl -c /etc/webdav.conf
webdav.conf syntax OK

check your /etc/webdav.conf: wrong $VIRTUAL_BASE or $DOCUMENT_ROOT values are cause for a 404 File Not Found

webdav.pl syntax (maybe a broken config or a missing Perl module):

#> perl -I/etc/webdavcgi/lib/perl -c webdav.pl
webdav.pl syntax OK

#> bash /etc/webdavcgi/checkenv 
+++ Checking perl:
  perl /usr/bin/perl
++++ Checking required modules:
  CGI installed
  DBI installed
  POSIX installed
  File::Temp installed
  Date::Parse installed
  UUID::Tiny installed
  XML::Simple installed
  Quota installed
  Archive::Zip installed
  IO::Compress::Gzip installed
  IO::Compress::Deflate installed
  Digest::MD5 installed
  Module::Load installed
++++ Checking optional modules:
  DBD::SQLite installed
  DBD::mysql installed
  DBD::Pg installed
++++ Checking required modules for FS backend:
  File::Spec::Link installed
++++ Checking required modules for AFS backend:
  File::Spec::Link already checked
++++ Checking required modules for GFS backend:
  File::Spec::Link already checked
++++ Checking required modules for SMB backend:
  Filesys::SmbClient installed
++++ Checking required modules for RCS backend:
  Rcs installed
++++ Checking optional binaries:
  smbclient /usr/bin/smbclient
#### Summary:
All modules found.
All binaries found.

Check your database setup ($DBI_SRC, $DBI_USER, $DBI_PASS).

Call webdav.pl from a shell:

#> env WEBDAVCONF=/etc/webdav.conf perl -I/etc/webdavcgi/lib/perl webdav.pl 
DAV: 1, 2, 3, <http://apache.org/dav/propset/fs/1>, extended-mkcol, access-control, calendar-access, calendarserver-private-comments, calendar-auto-schedule, addressbook, bind
MS-Author-Via: DAV
Status: 404 Not Found
Date: Mon, 14 Mar 2011 12:51:35 GMT
Etag: "d41d8cd98f00b204e9800998ecf8427e"
Content-length: 0
Content-Type: text/plain; charset=utf-8

Call webdavwrapper from a shell:

#> ./webdavwrapper
Status: 404 Not Found
Content-Type: text/plain

404 Not Found - your wrapper

Contact the author

FreeBSD/OpenBSD: all LOCK requests result in a segmentation fault error (signal 11)

In some installations OSSP::uuid module lets Perl crashing with a segmentation fault. A solution is to replace OSSP::uuid with UUID::Tiny (thx Tony Wijnhard):

install UUID::Tiny: perl -MCPAN -e 'install UUID::Tiny'

replace use OSSP:uuid; with use UUID::Tiny;:

sed -i -e 's@use OSSP::uuid;@use UUID::Tiny;@g' webdav.pl

replace sub getuuid { with sub _unused_getuuid {:

sed -i -e 's@^sub getuuid@sub _unused_getuuid@g' webdav.pl

add a new getuuid routine to webdav.pl:

cat - >>webdav.pl <<'EOF'
sub getuuid {
        my ($fn) = @_;
        my $uuid_ns = create_UUID(UUID_V1, "opaquelocktoken:$fn");
        my $uuid = create_UUID(UUID_V3, $uuid_ns, "$fn".time());
        debug("_LOCK after uuid made in method:");
        return UUID_to_string($uuid);
}
EOF

Web interface: Copy/Cut/Paste and bookmarks do not work as expected.

WebDAV CGI uses the 'secure' flag for cookies. If you access the Web interface without encryption (http instead of https) all cookie based actions do not work.

Web interface: missing stylesheets, locales, and/or icons

Check your $INSTALL_BASE variable in your /etc/webdav.conf (maybe you forget the trailing slash?)
Check /etc/webdav.conf syntax: perl -c /etc/webdav.conf
Check your Apache rewrite rule: the path to your webdav.conf must be correct: E=WEBDAVCONF:/etc/webdav.conf

Web interface: wrong date/time/number formatting for a language

WebDAV CGI uses language specific formattings for date/time/numbers. Check your locales

#> locale -a
de_DE.utf8
en_US.utf8
fr_FR.utf8
hu_HU.utf8
it_IT.utf8

and install missing locales for the language with a wrong date/time/number formatting, e.g. Ubuntu:

# add new locale entry to the list:
echo fr_FR.UTF-8 UTF-8 >> /var/lib/locales/supported.d/local
# or add all supported locales (! slows down package installation/updates):
### cp /usr/share/i18n/SUPPORTED /var/lib/locales/supported.d/local

# and don't forget to compile locale definition files:
locale-gen

Slow response working with WebDAV resources on Windows Vista or Windows 7

see http://support.microsoft.com/kb/2445570

OR: see http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol

RedHat/Fedora/CentOS: Graphics::Magick does not compile

see https://bugzilla.redhat.com/show_bug.cgi?id=527143#c2

Apache error log: Permission denied: exec of '.../webdavwrapper' failed

Check all file and folder permissions (Apache runs with user permissions)
SELinux users should define a policy to allow the execution of webdavwrapper.

Speedy problems with different WebDAV CGI instances on a single server

If you run multiple WebDAV CGI instances on a single server with different setups and databases you have to separate the Speedy instances. This can be done with a additional rewrite option: E=SPEEDY_TMPBASE:myprojecttmpbase (replace myprojecttmpbase with a unique name for a WebDAV CGI instances, e.g. E=SPEEDY_TMPBASE:/tmp/project2)

Common issues

Wide character in print at ... warning

You can ignore this warning.