I'm using a webdav server based on IIS 7.5. Some files cannot be copied/read from the server, instead the server reports 404 not found.

After some investigation, it appears that this is because some IIS servers (depending on the configuration) will report 404 if the file name has an unknown extension and the GET request does not have a "Translate: f" header.

For more information about this special header proposed by Microsoft, you can refer to:
http://msdn.microsoft.com/en-us/library/cc250216%28v=prot.10%29.aspx
http://msdn.microsoft.com/en-us/library/cc250234%28v=prot.10%29.aspx
http://blogs.msdn.com/b/david.wang/archive/2008/09/29/webdav-source-and-read-permissions-on-iis.aspx

The man page of davfs also mentions it (at the "add_header" option):
http://linux.die.net/man/5/davfs2.conf

Basically, it's supposed to be a feature to allow either downloading the output of a script of the script source. However, it seems that in some default configurations the webdav server considers any file with an unknown extension (content type of application/octet-stream) as following this rule too. As they can be executed, 404 is returned.

As in the case of a webdav filesystem it's unlikely that the user would like the output of a script, a rather straightforward fix is to always add "Translate: f" as header of a request. It seems to be what the webdav mount in Windows does. According to the HTTP specification, unknown headers should be ignored by the server, so it shouldn't cause problems with other servers, however for safety, you might want to only add this header to servers which report being Microsoft-IIS.


Here are two traces using wget to demonstrate the behaviour of the server I have to use.

Example of failing request (with wget):
GET /blabla.SPE HTTP/1.0
User-Agent: Wget/1.12 (linux-gnu)
Accept: */*
Host: webdata.tudelft.nl
Connection: Keep-Alive
Authorization: Basic c3ZkZW5ob2VkdDpIaWtnMXZEZQ==

---response begin---
HTTP/1.1 404 Not Found
Content-Type: text/html
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
Date: Fri, 13 Apr 2012 08:16:59 GMT
Connection: keep-alive
Content-Length: 1245



Example of working request (with wget --header "Translate: f"):
GET /blabla.SPE HTTP/1.0
User-Agent: Wget/1.12 (linux-gnu)
Accept: */*
Host: webdata.tudelft.nl
Connection: Keep-Alive
Translate: f
Authorization: Basic c3ZkZW5ob2VkdDpIaWtnMXZEZQ==

---response begin---
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Last-Modified: Thu, 02 Feb 2012 13:58:07 GMT
Accept-Ranges: bytes
ETag: "20e1db1b2e1cc1:0"
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
Date: Fri, 13 Apr 2012 08:15:01 GMT
Connection: keep-alive
Content-Length: 135172