%% -*- erlang -*- %% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2010-2011. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in %% compliance with the License. You should have received a copy of the %% Erlang Public License along with this software. If not, it can be %% retrieved online at http://www.erlang.org/. %% %% Software distributed under the License is distributed on an "AS IS" %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See %% the License for the specific language governing rights and limitations %% under the License. %% %% %CopyrightEnd% %% %% %% A grammar for dictionary specification. %% Nonterminals application_id avp avp_code avp_def avp_defs avp_flags avp_header avp_header_tok avp_name avp_names avp_ref avp_spec avp_type avp_vendor avps bit bits command_def command_id diameter_name dictionary enum_def enum_defs group_def group_defs header header_tok ident idents message_defs module qual section sections. Terminals avp_types avp_vendor_id codecs custom_types define enum grouped id inherits messages name prefix vendor number word '{' '}' '<' '>' '[' ']' '*' '::=' ':' ',' '-' code 'answer-message' 'AVP' 'AVP-Header' 'Diameter' 'Diameter-Header' 'Header' 'REQ' 'PXY' 'ERR'. Rootsymbol dictionary. Endsymbol '$end'. %% =========================================================================== dictionary -> sections : '$1'. sections -> '$empty' : []. sections -> section sections : ['$1' | '$2']. section -> name ident : ['$1', '$2']. section -> prefix ident : ['$1', '$2']. section -> id number : ['$1', '$2']. section -> vendor number ident : ['$1', '$2', '$3']. section -> inherits module avp_names : ['$1', '$2' | '$3']. section -> avp_types avp_defs : ['$1' | '$2']. section -> avp_vendor_id number avp_names : ['$1', '$2' | '$3']. section -> custom_types module avp_names : ['$1', '$2' | '$3']. section -> codecs module avp_names : ['$1', '$2' | '$3']. section -> messages message_defs : ['$1' | '$2']. section -> grouped group_defs : ['$1' | '$2']. section -> enum ident enum_defs : ['$1', '$2' | '$3']. section -> define ident enum_defs : ['$1', '$2' | '$3']. %% ===================================== module -> ident : '$1'. avp_names -> idents : '$1'. %% Note: not 'AVP' avp_defs -> '$empty' : []. avp_defs -> avp_def avp_defs : ['$1' | '$2']. avp_def -> ident number avp_type avp_flags : ['$1', '$2', '$3', '$4']. avp_type -> ident : '$1'. idents -> '$empty' : []. idents -> ident idents : ['$1' | '$2']. avp_flags -> '-' : {_, Lineno} = '$1', {word, Lineno, ""}. avp_flags -> ident : '$1'. %% Could support lowercase here if there's a use for distinguishing %% between Must and Should in the future in deciding whether or not %% to set a flag. ident -> word : '$1'. %% Don't bother mapping reserved words to make these usable in this %% context. That an AVP can't be named Diameter-Header is probably no %% great loss, and that it can't be named AVP may even save someone %% from themselves. (Temporarily at least.) group_defs -> '$empty' : []. group_defs -> group_def group_defs : ['$1' | '$2']. message_defs -> '$empty' : []. message_defs -> command_def message_defs : ['$1' | '$2']. enum_defs -> '$empty' : []. enum_defs -> enum_def enum_defs : ['$1' | '$2']. enum_def -> ident number : ['$1', '$2']. %% ===================================== %% 3.2. Command Code ABNF specification %% %% Every Command Code defined MUST include a corresponding ABNF %% specification, which is used to define the AVPs that MUST or MAY be %% present when sending the message. The following format is used in %% the definition: %% command-def = <command-name> "::=" diameter-message %% %% command-name = diameter-name %% %% diameter-name = ALPHA *(ALPHA / DIGIT / "-") %% %% diameter-message = header [ *fixed] [ *required] [ *optional] %% answer-message is a special case. command_def -> 'answer-message' '::=' '<' header_tok ':' code ',' 'ERR' '[' 'PXY' ']' '>' avps : ['$1', false | '$13']. command_def -> diameter_name '::=' header avps : ['$1', '$3' | '$4']. %% Ensure the order fixed/required/optional by semantic checks rather %% than grammatically since the latter requires more lookahead: don't %% know until after a leading qual which of the three it is that's %% being parsed. diameter_name -> ident : '$1'. %% header = "<" "Diameter Header:" command-id %% [r-bit] [p-bit] [e-bit] [application-id] ">" %% %% command-id = 1*DIGIT %% ; The Command Code assigned to the command %% %% r-bit = ", REQ" %% ; If present, the 'R' bit in the Command %% ; Flags is set, indicating that the message %% ; is a request, as opposed to an answer. %% %% p-bit = ", PXY" %% ; If present, the 'P' bit in the Command %% ; Flags is set, indicating that the message %% ; is proxiable. %% %% e-bit = ", ERR" %% ; If present, the 'E' bit in the Command %% ; Flags is set, indicating that the answer %% ; message contains a Result-Code AVP in %% ; the "protocol error" class. %% %% application-id = 1*DIGIT header -> '<' header_tok ':' command_id bits application_id '>' : ['$4', '$5', '$6']. command_id -> number : '$1'. %% Accept both the form of the base definition and the typo (fixed in %% 3588bis) of the grammar. header_tok -> 'Diameter' 'Header'. header_tok -> 'Diameter-Header'. bits -> '$empty' : []. bits -> ',' bit bits : ['$2' | '$3']. %% ERR only makes sense for answer-message so don't allow it here %% (despite 3588). bit -> 'REQ' : '$1'. bit -> 'PXY' : '$1'. application_id -> '$empty' : false. application_id -> number : '$1'. %% fixed = [qual] "<" avp-spec ">" %% ; Defines the fixed position of an AVP %% %% required = [qual] "{" avp-spec "}" %% ; The AVP MUST be present and can appear %% ; anywhere in the message. %% %% optional = [qual] "[" avp-name "]" %% ; The avp-name in the 'optional' rule cannot %% ; evaluate to any AVP Name which is included %% ; in a fixed or required rule. The AVP can %% ; appear anywhere in the message. %% ; %% ; NOTE: "[" and "]" have a slightly different %% ; meaning than in ABNF (RFC 5234]). These braces %% ; cannot be used to express optional fixed rules %% ; (such as an optional ICV at the end). To do this, %% ; the convention is '0*1fixed'. avps -> '$empty' : []. avps -> avp avps : ['$1' | '$2']. avp -> avp_ref : [false | '$1']. avp -> qual avp_ref : ['$1' | '$2']. avp_ref -> '<' avp_spec '>' : [$<, '$2']. avp_ref -> '{' avp_name '}' : [${, '$2']. avp_ref -> '[' avp_name ']' : [$[, '$2']. %% Note that required can be an avp_name, not just avp_spec. 'AVP' %% is specified as required by Failed-AVP for example. %% qual = [min] "*" [max] %% ; See ABNF conventions, RFC 5234 Section 4. %% ; The absence of any qualifiers depends on %% ; whether it precedes a fixed, required, or %% ; optional rule. If a fixed or required rule has %% ; no qualifier, then exactly one such AVP MUST %% ; be present. If an optional rule has no %% ; qualifier, then 0 or 1 such AVP may be %% ; present. If an optional rule has a qualifier, %% ; then the value of min MUST be 0 if present. %% %% min = 1*DIGIT %% ; The minimum number of times the element may %% ; be present. If absent, the default value is zero %% ; for fixed and optional rules and one for required %% ; rules. The value MUST be at least one for for %% ; required rules. %% %% max = 1*DIGIT %% ; The maximum number of times the element may %% ; be present. If absent, the default value is %% ; infinity. A value of zero implies the AVP MUST %% ; NOT be present. qual -> number '*' number : {'$1', '$3'}. qual -> number '*' : {'$1', true}. qual -> '*' number : {true, '$2'}. qual -> '*' : true. %% avp-spec = diameter-name %% ; The avp-spec has to be an AVP Name, defined %% ; in the base or extended Diameter %% ; specifications. avp_spec -> diameter_name : '$1'. %% avp-name = avp-spec / "AVP" %% ; The string "AVP" stands for *any* arbitrary AVP %% ; Name, not otherwise listed in that command code %% ; definition. Addition this AVP is recommended for %% ; all command ABNFs to allow for extensibility. avp_name -> 'AVP' : '$1'. avp_name -> avp_spec : '$1'. %% The following is a definition of a fictitious command code: %% %% Example-Request ::= < Diameter Header: 9999999, REQ, PXY > %% { User-Name } %% * { Origin-Host } %% * [ AVP ] %% ===================================== %% 4.4. Grouped AVP Values %% %% The Diameter protocol allows AVP values of type 'Grouped'. This %% implies that the Data field is actually a sequence of AVPs. It is %% possible to include an AVP with a Grouped type within a Grouped type, %% that is, to nest them. AVPs within an AVP of type Grouped have the %% same padding requirements as non-Grouped AVPs, as defined in Section %% 4. %% %% The AVP Code numbering space of all AVPs included in a Grouped AVP is %% the same as for non-grouped AVPs. Receivers of a Grouped AVP that %% does not have the 'M' (mandatory) bit set and one or more of the %% encapsulated AVPs within the group has the 'M' (mandatory) bit set %% MAY simply be ignored if the Grouped AVP itself is unrecognized. The %% rule applies even if the encapsulated AVP with its 'M' (mandatory) %% bit set is further encapsulated within other sub-groups; i.e. other %% Grouped AVPs embedded within the Grouped AVP. %% %% Every Grouped AVP defined MUST include a corresponding grammar, using %% ABNF [RFC5234] (with modifications), as defined below. %% grouped-avp-def = <name> "::=" avp %% %% name-fmt = ALPHA *(ALPHA / DIGIT / "-") %% %% name = name-fmt %% ; The name has to be the name of an AVP, %% ; defined in the base or extended Diameter %% ; specifications. %% %% avp = header [ *fixed] [ *required] [ *optional] group_def -> ident '::=' avp_header avps : ['$1', '$3' | '$4']. %% header = "<" "AVP-Header:" avpcode [vendor] ">" %% %% avpcode = 1*DIGIT %% ; The AVP Code assigned to the Grouped AVP %% %% vendor = 1*DIGIT %% ; The Vendor-ID assigned to the Grouped AVP. %% ; If absent, the default value of zero is %% ; used. avp_header -> '<' avp_header_tok ':' avp_code avp_vendor '>' : ['$4', '$5']. avp_header_tok -> 'AVP-Header'. avp_header_tok -> 'AVP' 'Header'. avp_code -> number : '$1'. avp_vendor -> '$empty' : false. avp_vendor -> number : '$1'.