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Re: svn commit: r1495419 - in /subversion/trunk/subversion/libsvn_ra_serf: options.c ra_serf.h serf.c util.c

From: Greg Stein <gstein_at_gmail.com>
Date: Fri, 21 Jun 2013 09:28:06 -0400

This has been quoted before, but I'll repeat it again. RFC 2145, Section 2:

"One consequence of these rules is that an HTTP/1.1 message sent to an
 HTTP/1.0 recipient (or a recipient whose version is unknown) MUST be
 constructed so that it remains a valid HTTP/1.0 message when all
 headers not defined in the HTTP/1.0 specification [1] are removed."

Removing the Transfer-Coding: chunked header completely alters the
message. Thus, it cannot be sent to a 1.0 server. This is why you
cannot rely on any particular behavior or response status.

-g

On Fri, Jun 21, 2013 at 9:19 AM, Greg Stein <gstein_at_gmail.com> wrote:
> Please revert this. You *cannot* rely on a 411 response.
>
> You are also not allowed to send a 1.1 request to a server for which
> you don't know if they support 1.0 vs 1.1.
>
> Sigh. Seriously, man. This is completely counter to the work that was
> done. We *start* with 1.0, and then we upgrade to 1.1 only when the
> server identifies that it can handle it. Not to mention the
> complications of intervening proxies. You're making a mess of that
> work.
>
> -g
>
> On Fri, Jun 21, 2013 at 8:47 AM, <ivan_at_apache.org> wrote:
>> Author: ivan
>> Date: Fri Jun 21 12:47:46 2013
>> New Revision: 1495419
>>
>> URL: http://svn.apache.org/r1495419
>> Log:
>> Rework server chunked transfer encoding support detection in ra_serf. Use
>> HTTP/1.1 chunked transfer encoding for first OPTIONS request and then
>> fallback to HTTP/1.0 requests if HTTP 411 status code or HTTP/1.0 response
>> received.
>>
>> Discussion and report: http://svn.haxx.se/dev/archive-2013-06/0408.shtml
>>
>> * subversion/libsvn_ra_serf/ra_serf.h
>> (svn_ra_serf__session_t): Remove HTTP10 and add USE_CHUNKED_ENCODING.
>> * subversion/libsvn_ra_serf/options.c
>> (svn_ra_serf__exchange_capabilities): Retry OPTIONS request without using
>> chunked transfer encoding if HTTP 411 status code or HTTP/1.0 response
>> received for chunked request.
>> * subversion/libsvn_ra_serf/serf.c
>> (svn_ra_serf__open): Initialize USE_CHUNKED_ENCODING to TRUE.
>> * subversion/libsvn_ra_serf/util.c
>> (setup_serf_req): Use USE_CHUNKED_ENCODING member instead of removed
>> HTTP10. Always send 'Connection: keep-alive' header.
>>
>> Modified:
>> subversion/trunk/subversion/libsvn_ra_serf/options.c
>> subversion/trunk/subversion/libsvn_ra_serf/ra_serf.h
>> subversion/trunk/subversion/libsvn_ra_serf/serf.c
>> subversion/trunk/subversion/libsvn_ra_serf/util.c
>>
>> Modified: subversion/trunk/subversion/libsvn_ra_serf/options.c
>> URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_ra_serf/options.c?rev=1495419&r1=1495418&r2=1495419&view=diff
>> ==============================================================================
>> --- subversion/trunk/subversion/libsvn_ra_serf/options.c (original)
>> +++ subversion/trunk/subversion/libsvn_ra_serf/options.c Fri Jun 21 12:47:46 2013
>> @@ -488,6 +488,22 @@ svn_ra_serf__exchange_capabilities(svn_r
>>
>> err = svn_ra_serf__context_run_one(opt_ctx->handler, pool);
>>
>> + /* Retry request if HTTP/1.1 411 Length Required or we got HTTP/1.0 response. */
>> + if (serf_sess->use_chunked_encoding &&
>> + (opt_ctx->handler->sline.code == 411 ||
>> + opt_ctx->handler->sline.version == SERF_HTTP_10))
>> + {
>> + /* Ignore any errors and retry request using HTTP/1.0 with
>> + Content-Length.*/
>> + svn_error_clear(err);
>> +
>> + serf_sess->use_chunked_encoding = FALSE;
>> +
>> + SVN_ERR(create_options_req(&opt_ctx, serf_sess, serf_sess->conns[0], pool));
>> +
>> + err = svn_ra_serf__context_run_one(opt_ctx->handler, pool);
>> + }
>> +
>> /* If our caller cares about server redirections, and our response
>> carries such a thing, report as much. We'll disregard ERR --
>> it's most likely just a complaint about the response body not
>>
>> Modified: subversion/trunk/subversion/libsvn_ra_serf/ra_serf.h
>> URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_ra_serf/ra_serf.h?rev=1495419&r1=1495418&r2=1495419&view=diff
>> ==============================================================================
>> --- subversion/trunk/subversion/libsvn_ra_serf/ra_serf.h (original)
>> +++ subversion/trunk/subversion/libsvn_ra_serf/ra_serf.h Fri Jun 21 12:47:46 2013
>> @@ -140,9 +140,8 @@ struct svn_ra_serf__session_t {
>> apr_uri_t repos_root;
>> const char *repos_root_str;
>>
>> - /* The server is not Apache/mod_dav_svn (directly) and only supports
>> - HTTP/1.0. Thus, we cannot send chunked requests. */
>> - svn_boolean_t http10;
>> + /* The server supports chunked request bodies. */
>> + svn_boolean_t use_chunked_encoding;
>>
>> /* Our Version-Controlled-Configuration; may be NULL until we know it. */
>> const char *vcc_url;
>>
>> Modified: subversion/trunk/subversion/libsvn_ra_serf/serf.c
>> URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_ra_serf/serf.c?rev=1495419&r1=1495418&r2=1495419&view=diff
>> ==============================================================================
>> --- subversion/trunk/subversion/libsvn_ra_serf/serf.c (original)
>> +++ subversion/trunk/subversion/libsvn_ra_serf/serf.c Fri Jun 21 12:47:46 2013
>> @@ -437,9 +437,10 @@ svn_ra_serf__open(svn_ra_session_t *sess
>>
>> serf_sess->capabilities = apr_hash_make(serf_sess->pool);
>>
>> - /* We have to assume that the server only supports HTTP/1.0. Once it's clear
>> - HTTP/1.1 is supported, we can upgrade. */
>> - serf_sess->http10 = TRUE;
>> + /* Assume HTTP/1.1 server and use chunked transfer encoding. We fallback
>> + * to HTTP/1.0 requests in svn_ra_serf__exchange_capabilities() if server
>> + * doesn't support chunked encoding. */
>> + serf_sess->use_chunked_encoding = FALSE;
>>
>> SVN_ERR(load_config(serf_sess, config, serf_sess->pool));
>>
>>
>> Modified: subversion/trunk/subversion/libsvn_ra_serf/util.c
>> URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_ra_serf/util.c?rev=1495419&r1=1495418&r2=1495419&view=diff
>> ==============================================================================
>> --- subversion/trunk/subversion/libsvn_ra_serf/util.c (original)
>> +++ subversion/trunk/subversion/libsvn_ra_serf/util.c Fri Jun 21 12:47:46 2013
>> @@ -642,7 +642,7 @@ setup_serf_req(serf_request_t *request,
>>
>> svn_spillbuf_t *buf;
>>
>> - if (session->http10 && body_bkt != NULL)
>> + if (!session->use_chunked_encoding && body_bkt != NULL)
>> {
>> /* Ugh. Use HTTP/1.0 to talk to the server because we don't know if
>> it speaks HTTP/1.1 (and thus, chunked requests), or because the
>> @@ -670,7 +670,7 @@ setup_serf_req(serf_request_t *request,
>>
>> /* Set the Content-Length value. This will also trigger an HTTP/1.0
>> request (rather than the default chunked request). */
>> - if (session->http10)
>> + if (!session->use_chunked_encoding)
>> {
>> if (body_bkt == NULL)
>> serf_bucket_request_set_CL(*req_bkt, 0);
>> @@ -690,10 +690,9 @@ setup_serf_req(serf_request_t *request,
>> serf_bucket_headers_setn(*hdrs_bkt, "Content-Type", content_type);
>> }
>>
>> - if (session->http10)
>> - {
>> - serf_bucket_headers_setn(*hdrs_bkt, "Connection", "keep-alive");
>> - }
>> + /* Always set Connection: keep-alive because we don't know if server
>> + * is HTTP/1.1 aware. */
>> + serf_bucket_headers_setn(*hdrs_bkt, "Connection", "keep-alive");
>>
>> if (accept_encoding)
>> {
>> @@ -1861,10 +1860,6 @@ handle_response(serf_request_t *request,
>>
>> handler->sline = sl;
>> handler->sline.reason = apr_pstrdup(handler->handler_pool, sl.reason);
>> -
>> - /* HTTP/1.1? (or later) */
>> - if (sl.version != SERF_HTTP_10)
>> - handler->session->http10 = FALSE;
>> }
>>
>> /* Keep reading from the network until we've read all the headers. */
>>
>>
Received on 2013-06-21 15:28:38 CEST

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