From 61b9efd8b4cf35dce44ec2fefd26339d2d20cb3c Mon Sep 17 00:00:00 2001 From: Anders Svensson Date: Tue, 12 Feb 2013 17:46:38 +0100 Subject: Be less brutal in setting Result-Code/Failed-AVP When receiving a request for which errors have been detected during decode, diameter previously used the errors list in the decoded diameter_packet record to unconditionally set Result-Code and Failed-AVP in the outgoing answer. It wasn't particularly delicate in doing so however and would happily set a 5xxx Result-Code even if a handle_request callback returned an answer-message, leading to an encode error. This behaviour became even less endearing as of commit ac452e28, which made it possible to handle_request to take place even for protocol errors. (ie. When a callback typically should return an answer-message.) This commit fixes the behaviour by only setting a value that's appropriate for the answer in question, either a 3xxx or a 5xxx, depending on if the answer's an answer-message or not. It also allows handle_request to prevent diameter from setting anything by setting errors = false in a returned diameter_packet. Ideally it should have been errors = [] but the empty list is the default value for the errors field and changing the default (ideally there shouldn't have been one) would require recompilation of all modules including diameter.hrl: choose the less attractive 'false' to avoid such backwards incompatibility. The request reception is also refactored somewhat to shorten some call chains. --- lib/diameter/doc/src/diameter_app.xml | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) (limited to 'lib/diameter/doc/src') diff --git a/lib/diameter/doc/src/diameter_app.xml b/lib/diameter/doc/src/diameter_app.xml index f4db625c71..5c23c9d683 100644 --- a/lib/diameter/doc/src/diameter_app.xml +++ b/lib/diameter/doc/src/diameter_app.xml @@ -13,7 +13,7 @@
-20112012 +20112013 Ericsson AB. All Rights Reserved. @@ -509,14 +509,15 @@ Otherwise it contains the record representing the request as outlined in &dict;.

-The errors field specifies any Result-Code's identifying errors -that were encountered in decoding the request. -In this case diameter will set both Result-Code and -Failed-AVP AVP's in a returned -answer &message; before sending it to the peer: -the returned &message; need only set any other required AVP's. -Note that the errors detected by diameter are all of the 5xxx series -(Permanent Failures). +The errors field specifies any results codes identifying errors +found while decoding the request. +This is used to set Result-Code and/or Failed-AVP in a returned +answer unless the callback returns a #diameter_packet{} +whose errors field is set to either a non-empty list of its +own, in which case this list is used instead, or the atom false +to disable any setting of Result-Code and Failed-AVP. +Note that the errors detected by diameter are of the 3xxx +and 5xxx series, Protocol Errors and Permanent Failures respectively. The errors list is empty if the request has been received in the relay application.

@@ -558,8 +559,6 @@ where Avps sets the Origin-Host, Origin-Realm, the specified Result-Code and (if the request sent one) Session-Id AVP's.

-Note that &the_rfc; mandates that only answers with a 3xxx series -Result-Code (protocol errors) may set the E bit. Returning a non-3xxx value in a protocol_error tuple will cause the request process in question to fail.

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