amf-sim, gnb-cu-up, and ASN.1 CHOICE extensions (#186)

* amf-sim executable
* GNB-CU-UP executable
* Terminate pending requests when connection dies
* Add connection retry
* Add BearerContextSetupProcedure and BearerContextModificationRequest 
* Add StateStore
* Supply cell ID on UeContextSetupRequest
* Fill in Drbs to setup item
* Allow use of XXAP choice extensions
* Form CuToDuRrcInformation correctly
* BearerContextModificationRequest and CellGroupConfig

Cargo.toml

@@ -2,6 +2,7 @@
 
 members = [
     "asn1-per",
+    "amf-sim",
     "common",
     "sctp",
     "net",
@@ -12,6 +13,7 @@ members = [
     "rrc",
     "pdcp",
     "gnb-cu-cp",
+    "gnb-cu-up",
     "connection-api",
     "coordination-api",
     "gnb-cu-cp-coordinator",

README.md

@@ -7,20 +7,32 @@ The gNodeB is the component that manages the radio access of 5G User Equipment (
 This project is currently a proof of concept and not yet a fully functional gNB-CU.
 
 ## Current support
-
 - UE registration demo against free5GC.
 - Session setup (TS 23.502, figure 4.3.2.2.1-1).
 - UE state in Redis datastore.
 - ASN.1 libraries for NGAP, E1AP, F1AP and RRC.
 - Connection management stack 
 - Scale-out of GNB-CU-CP workers using multiple TNLAs.
-- Procedures: NG Setup, RAN Configuration Update, F1 Setup, E1 Setup, Initial Access, Uplink NAS, Downlink NAS, Initial Context Setup, Pdu Session Resource Setup, AMF Status Indication, GNB CU Configuration Update, GNB DU Configuration Update, GNB CU CP Configuration Update.
 - [Triangular redirection](documentation/design/triangular-redirection.md)
 - Rust ASN.1 autogenerator (written in Python).
 
-The gNB-CU-UP does not exist yet.
-
+The gNB-CU-UP is currently a simple stub that replies to E1AP requests but does not process userplane packets.
 Generally only the success cases are covered, and there are a lot of 'To Dos'.  
+### Procedure support
+-  NG Setup
+-  RAN Configuration Update
+-  F1 Setup
+-  E1 Setup
+-  Initial Access
+-  Uplink NAS
+-  Downlink NAS
+-  Initial Context Setup
+-  Pdu Session Resource Setup (Bearer Context Setup)
+-  AMF Status Indication
+-  GNB CU Configuration Update
+-  GNB DU Configuration Update
+-  GNB CU CP Configuration Update.
+
 
 ## What's different about Alsoran?
 

amf-sim/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "amf-sim"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+mocks = { path = "../mocks" }
+slog = "2.7.0"
+anyhow = "1.0.52"
+async-std = { version = "1.10.0", features = ["attributes"] }
+common = { path = "../common" }
+hex = "0.4.3"

amf-sim/src/main.rs

@@ -0,0 +1,65 @@
+// main - acts as an AMF for testing with O-RAN O-DU
+
+use anyhow::Result;
+use mocks::MockAmf;
+use slog::info;
+
+// The purpose of this code is to cause Alsoran GNB-CU to produce the same message sequence as the O-RAN-SC O-DU Cu Stub.
+// The required call flow is documented in full at `documentation/odu.md`.
+#[async_std::main]
+async fn main() -> Result<()> {
+    let logger = common::logging::init();
+    let mut amf = MockAmf::new(&logger).await;
+    amf.disable_receive_timeouts();
+
+    // Wait for connection and do NG Setup.
+    amf.add_endpoint("127.0.0.1").await?;
+    amf.expect_connection_established().await;
+    amf.handle_ng_setup().await?;
+
+    // Receive Ngap InitialUeMessage + Nas Registration Request
+    let ue = amf.receive_initial_ue_message(1).await?;
+    info!(&logger, ">> Registration request");
+
+    // Send Nas Authentication Request
+    info!(&logger, "<< Nas Authentication request");
+    let nas = hex::decode(
+        "7e005602020000217ac1c891b8aba0b2646e9cad34f4a0192010037859caf5e58000d58e09fc227bbf19",
+    )?;
+    amf.send_downlink_nas_transport(&ue, nas).await?;
+
+    // Receive Nas Authentication Response
+    let _nas = amf.receive_uplink_nas_transport(&ue).await?;
+    info!(&logger, ">> Nas Authentication Response");
+
+    // Send Nas Security Mode Command
+    info!(&logger, "<< Nas Security Mode Comamnd");
+    let nas = hex::decode("7e03e8e277e4007e005d010204f070f070e1360102")?;
+    amf.send_downlink_nas_transport(&ue, nas).await?;
+
+    // Receive Nas Security Mode Complete
+    let _nas = amf.receive_uplink_nas_transport(&ue).await?;
+    info!(&logger, ">> Nas Security Mode Complete");
+
+    // Send Ngap InitialContextSetupRequest + Nas Registration Accept
+    let nas = hex::decode("7e00420101")?;
+    amf.send_initial_context_setup_request(&ue, nas).await?;
+
+    // Receive Ngap InitialContextSetupResponse
+    amf.receive_initial_context_setup_response(&ue).await?;
+
+    // Send Nas Registration Accept
+    //info!(&logger, "<< Nas Registration Accept");
+    //amf.send_downlink_nas_transport(&ue, nas).await?;
+
+    // Receive Nas Registration Complete
+    let _nas = amf.receive_uplink_nas_transport(&ue).await?;
+    info!(&logger, ">> Nas Registration complete");
+
+    amf.send_pdu_session_resource_setup(&ue).await?;
+    amf.receive_pdu_session_resource_setup_response(&ue).await?;
+
+    amf.terminate().await;
+
+    Ok(())
+}

asn1-generator/asn1/f1ap/F1AP-PDU-Contents.asn

@@ -1999,7 +1999,7 @@ InitialULRRCMessageTransferIEs F1AP-PROTOCOL-IES ::= {
 	{ ID id-RRCContainer						CRITICALITY reject	TYPE RRCContainer							PRESENCE mandatory } |
 	{ ID id-DUtoCURRCContainer					CRITICALITY reject	TYPE DUtoCURRCContainer						PRESENCE optional } |
 	{ ID id-SULAccessIndication					CRITICALITY ignore	TYPE SULAccessIndication					PRESENCE optional } |
-	-- To work around bug in O-RAN ODU, we have transaction ID is set to optional here when it is actually mandatory
+	-- To work with rel 15 peers such as O-RAN-SC O-DU, transaction ID is set to optional here when it is actually defined as mandatory
 	{ ID id-TransactionID						CRITICALITY ignore	TYPE TransactionID							PRESENCE optional --mandatory-- } |
 	{ ID id-RANUEID								CRITICALITY ignore	TYPE RANUEID								PRESENCE optional } |
 	{ ID id-RRCContainer-RRCSetupComplete		CRITICALITY ignore	TYPE RRCContainer-RRCSetupComplete 		PRESENCE optional } ,

asn1-generator/src/grammar.lark

@@ -17,6 +17,12 @@ _OID:                   /{[^}]+}/
 //_OBJECT_CLASS:          /\w+/
 _IMPORTS:                /[^;]+;/
 extension_marker:       "..." [","]
+_size:                  "(" "SIZE" "(" _constraints ")" ")"
+_constraints:           _range_options+
+_range_options:         _range["|" _range] * [","]
+_range:                 extension_marker | (BOUND [".." BOUND])        
+named_values:           _nested_braces
+_nested_braces:         "{" (_nested_braces|/[^\{\}]+/) * "}"
 
 // For testability, we make the parts before and after the definitions optional
 // This means we can just run small fragments through the grammar.
@@ -26,8 +32,8 @@ _fragment:              _definitions
 module_name:            IDENTIFIER
 _begin:                 "DEFINITIONS AUTOMATIC TAGS ::=" "BEGIN" 
 
-_definitions:           ( tuple_struct 
-                        | struct 
+_definitions:           ( primitive_def 
+                        | sequence_def 
                         | enum_def 
                         | choice_def 
                         | generic_choice_def
@@ -38,8 +44,8 @@ _definitions:           ( tuple_struct
                         | top_level_enum_def
                         | class_instance)+
 ?assign:                IDENTIFIER "::="
-tuple_struct:           assign _primitive
-struct:                 assign sequence
+primitive_def:           assign _primitive
+sequence_def:           assign sequence
 enum_def:               assign enumerated
 choice_def:             assign choice
 generic_choice_def:     IDENTIFIER type_parameter "::=" choice
@@ -54,17 +60,19 @@ _bracketed_group{x}:    ("[[" _comma_separated{x} "]]") | x
 
 sequence_of:            "SEQUENCE" [_size] "OF" (_field_type | single_ie_container)
 sequence:               "SEQUENCE" _items{_sequence_item}
-_sequence_item:         optional_field | field | extension_container | private_ie_container | ie_container | single_ie_container | (empty_sequence "OPTIONAL")
+_sequence_item:         optional_field | field | extension_container_field | private_ie_container_field | protocol_ies_field | single_ie_container | (empty_sequence_field "OPTIONAL")
 optional_field.2:       _identifier _field_type ("OPTIONAL" | "DEFAULT" _identifier)
 field.1:                _identifier _field_type
 
+_empty_sequence.3:       "SEQUENCE" "{}"
+empty_sequence_field.1:  _identifier _empty_sequence
+
 enumerated.1:             "ENUMERATED" _items{enum_field}
 enum_field:              _identifier
 
 choice:                 "CHOICE" _items{_choice_item}
-_choice_item:            choice_field | choice_ie_container | choice_extension_container
+_choice_item:            choice_field | choice_field_ie_container | choice_field_ie_extension | empty_sequence_field
 choice_field:           _identifier _field_type
-empty_sequence.3:       _identifier "SEQUENCE" "{}"
 
 integer:                "INTEGER" named_values? ["(" _constraints ")"]
 printable_string:       "PrintableString" [_size]
@@ -92,26 +100,24 @@ _field_type:            _primitive | enumerated | sequence | choice
 type_parameter:         "{" _identifier "}"
 type_parameterized_identifier: _identifier type_parameter
 
-ie_container.1:         "protocolIEs" "ProtocolIE-Container" "{" "{" _identifier "}" "}"
-choice_ie_container:    _identifier "ProtocolIE-Container" "{" "{" _identifier "}" "}"
+// XXAP IE and protocol containers
+_protocol_ie_container: "ProtocolIE-Container" "{" "{" _identifier "}" "}"
 single_ie_container.1:  "ProtocolIE-SingleContainer" "{" "{" _identifier "}" "}"
+_private_ie_container:  "PrivateIE-Container" "{" "{" _identifier "}" "}" "OPTIONAL"? ","?
+_extension_container:   "ProtocolExtensionContainer" "{" "{" _identifier "}" "}" "OPTIONAL"? ","?
+
+extension_container_field.0:             _IDENTIFIER _extension_container
+choice_field_ie_extension:               _identifier single_ie_container
+choice_field_ie_container:               _identifier _protocol_ie_container
+private_ie_container_field.0:            _identifier _private_ie_container
+protocol_ies_field.1:                    "protocolIEs" _protocol_ie_container
+
 ies:                    "{" (ie | optional_ie)* [","] extension_marker? "}"
 _ie{p}:                 "{" "ID" _identifier "CRITICALITY" _identifier  ("TYPE" | "EXTENSION") _field_type+ "PRESENCE" p "}" ["|" | ","]
 optional_ie:            _ie{"optional"} | _ie{"conditional"}
 ie:                      _ie{"mandatory"}
 
-extension_container.0:  _IDENTIFIER "ProtocolExtensionContainer" "{" "{" _identifier "}" "}" "OPTIONAL"? ","?
-private_ie_container.0: _identifier "PrivateIE-Container" "{" "{" _identifier "}" "}" "OPTIONAL"? ","?
-choice_extension_container: _identifier single_ie_container | empty_sequence
-
-_size:                  "(" "SIZE" "(" _constraints ")" ")"
-_constraints:           _range_options+
-_range_options:         _range["|" _range] * [","]
-_range:                 extension_marker | (BOUND [".." BOUND])        
-
-named_values:           _nested_braces
-_nested_braces:         "{" (_nested_braces|/[^\{\}]+/) * "}"
-
+// XXAP procedures
 family:                 /\w*-ELEMENTARY-PROCEDURE/
 procedure_def.2:        procedure_name family "::=" "{" initiating successful? unsuccessful? procedure_code criticality "}"
 procedure_name:         IDENTIFIER