rgw: make compatability deconfliction optional.

Per request from Yehuda, the deconfliction for having both
HTTP_CONTENT_LENGTH and CONTENT_LENGTH set is now optional, and
controlled by new configuration boolean, which defaults to false.
rgw content length compat

X-URL: #4436 (comment)
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
(cherry picked from commit 79d17af)

doc/radosgw/config-ref.rst

@@ -316,6 +316,12 @@ Ceph configuration file, the default value will be set automatically.
 :Default: ``admin``
 
 
+``rgw content length compat``
+
+:Description: Enable compatability handling of FCGI requests with both CONTENT_LENGTH AND HTTP_CONTENT_LENGTH set.
+:Type: Boolean
+:Default: ``false``
+
 Regions
 =======
 

src/common/config_opts.h

@@ -938,6 +938,7 @@ OPTION(rgw_socket_path, OPT_STR, "")   // path to unix domain socket, if not spe
 OPTION(rgw_host, OPT_STR, "")  // host for radosgw, can be an IP, default is 0.0.0.0
 OPTION(rgw_port, OPT_STR, "")  // port to listen, format as "8080" "5000", if not specified, rgw will not run external fcgi
 OPTION(rgw_dns_name, OPT_STR, "")
+OPTION(rgw_content_length_compat, OPT_BOOL, false) // Check both HTTP_CONTENT_LENGTH and CONTENT_LENGTH in fcgi env
 OPTION(rgw_script_uri, OPT_STR, "") // alternative value for SCRIPT_URI if not set in request
 OPTION(rgw_request_uri, OPT_STR,  "") // alternative value for REQUEST_URI if not set in request
 OPTION(rgw_swift_url, OPT_STR, "")             // the swift url, being published by the internal swift auth

src/rgw/rgw_rest.cc

@@ -1370,7 +1370,7 @@ int RGWREST::preprocess(struct req_state *s, RGWClientIO *cio)
     /* Easy case #1: CONTENT_LENGTH is missing or empty */
     s_contentlength = s_httpcontentlength;
     s_httpcontentlength = NULL;
-  } else if (s_contentlength && s_httpcontentlength) {
+  } else if (s->cct->_conf->rgw_content_length_compat && s_contentlength && s_httpcontentlength) {
     /* Hard case: Both are set, we have to disambiguate */
     int64_t i_contentlength = -1, i_httpcontentlength = -1;
     // Test CONTENT_LENGTH
@@ -1411,7 +1411,7 @@ int RGWREST::preprocess(struct req_state *s, RGWClientIO *cio)
 	s_httpcontentlength = NULL;
       }
     }
-
+    // End of: else if (s->cct->_conf->rgw_content_length_compat && s_contentlength && s_httpcontentlength) {
   } else {
     // By implication, httpcontentlength is NULL here
     /* Easy case #2: HTTP_CONTENT_LENGTH is not set */