cURL / Mailing Lists / curl-library / Single Mail


Post size 1024 with Continue 100

From: Chris Brown <>
Date: Fri, 29 Aug 2008 17:54:31 +1200


I am running libcurl version on 7.18.2 on embedded Linux using the libcurl easy interface. I am using http to post SOAP messages to a .Net web service running on IIS 7 with digest authentication. For the most part this is working well.

I have encountered an issue with posts exceeding 1024 bytes in size with the 'Expect: continue-100' header. Running with CURLOPT_VERBOSE and using Wireshark I can see the server returning the 'HTTP/1.1 100 Continue' message but libcurl does not appear to transmit the "post data"- instead reporting error 28 (CURLE_OPERATION_TIMEOUTED). If I add an "Expect:" header to prevent libcurl adding it automatically the post still times out as if it is still waiting for the Continue 100 message from the server.

The other odd thing is that in the application protocol I am using the first request is always quite large (3000 bytes) compared to the rest. This will always work whether the "Expect:" header has been disabled or not but the problem is occuring with any subsequent posts in the same session exceeding 1024 bytes. This is odd but seems to at least suggest that my server is handling the 'Expect" header correctly. What I can't understand is why it would work on the first post and then fail on the second post.

I have read numerous posts relating to this issue (or something similar) on the forum but most were reported some time ago in much older versions.

Any help or suggestions would be appreciated.

Received on 2008-08-29