add new pex messages (#312)

proto/p2p/pex.proto

@@ -17,9 +17,21 @@ message PexResponse {
   repeated PexAddress addresses = 1 [(gogoproto.nullable) = false];
 }
 
+message PexAddressV2 {
+  string url = 1 [(gogoproto.customname) = "URL"];
+}
+
+message PexRequestV2 {}
+
+message PexResponseV2 {
+  repeated PexAddressV2 addresses = 1 [(gogoproto.nullable) = false];
+}
+
 message PexMessage {
   oneof sum {
-    PexRequest  pex_request  = 1;
-    PexResponse pex_response = 2;
+    PexRequest    pex_request     = 1;
+    PexResponse   pex_response    = 2;
+    PexRequestV2  pex_request_v2  = 3;
+    PexResponseV2 pex_response_v2 = 4;
   }
 }

spec/p2p/messages/pex.md

@@ -14,6 +14,9 @@ Pex has one channel. The channel identifier is listed below.
 
 ## Message Types
 
+The current PEX service has two versions. The first uses IP/port pair but since the p2p stack is moving towards a transport agnostic approach, 
+node endpoints require a `Protocol` and `Path` hence the V2 version uses a [url](https://golang.org/pkg/net/url/#URL) instead.
+
 ### PexRequest
 
 PexRequest is an empty message requesting a list of peers.
@@ -26,7 +29,7 @@ PexResponse is an list of net addresses provided to a peer to dial.
 
 | Name  | Type                               | Description                              | Field Number |
 |-------|------------------------------------|------------------------------------------|--------------|
-| addresses | repeated [PexAddress](#Pexaddress) | List of peer addresses available to dial | 1            |
+| addresses | repeated [PexAddress](#PexAddress) | List of peer addresses available to dial | 1            |
 
 ### PexAddress
 
@@ -38,11 +41,36 @@ PexAddress provides needed information for a node to dial a peer.
 | ip   | string | The IP of a node | 2            |
 | port | port   | Port of a peer   | 3            |
 
+
+### PexRequestV2
+
+PexRequest is an empty message requesting a list of peers.
+
+> EmptyRequest
+
+### PexResponseV2
+
+PexResponse is an list of net addresses provided to a peer to dial.
+
+| Name  | Type                               | Description                              | Field Number |
+|-------|------------------------------------|------------------------------------------|--------------|
+| addresses | repeated [PexAddressV2](#PexAddressV2) | List of peer addresses available to dial | 1            |
+
+### PexAddressV2
+
+PexAddress provides needed information for a node to dial a peer.
+
+| Name | Type   | Description      | Field Number |
+|------|--------|------------------|--------------|
+| url   | string | See [golang url](https://golang.org/pkg/net/url/#URL) | 1            |
+
 ### Message
 
 Message is a [`oneof` protobuf type](https://developers.google.com/protocol-buffers/docs/proto#oneof). The one of consists of two messages.
 
 | Name         | Type                      | Description                                          | Field Number |
 |--------------|---------------------------|------------------------------------------------------|--------------|
-| pex_request  | [PexRequest](#pexrequest) | Empty request asking for a list of addresses to dial | 1            |
-| pex_response | [PexResponse]                | List of addresses to dial                            | 2            |
+| pex_request  | [PexRequest](#PexRequest) | Empty request asking for a list of addresses to dial | 1            |
+| pex_response | [PexResponse](#PexResponse)  | List of addresses to dial                            | 2            |
+| pex_request_v2 | [PexRequestV2](#PexRequestV2) | Empty request asking for a list of addresses to dial | 3         |
+| pex_response_v2 | [PexRespinseV2](#PexResponseV2) | List of addresses to dial | 4 |