From 0e80059e79de3b1e27a5255f4f64d590ddcfc0f4 Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Wed, 22 Apr 2015 13:50:37 -0700
Subject: [PATCH] versioning

---
 node/node.go  |  1 +
 p2p/peer.go   |  6 ------
 p2p/switch.go |  5 +++--
 types/node.go | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/node/node.go b/node/node.go
index 415796367..52e2d26fd 100644
--- a/node/node.go
+++ b/node/node.go
@@ -188,6 +188,7 @@ func makeNodeInfo(sw *p2p.Switch) *types.NodeInfo {
 	nodeInfo := &types.NodeInfo{
 		Moniker: config.App().GetString("Moniker"),
 		Network: config.App().GetString("Network"),
+		Version: "0.0.1",
 	}
 	if !sw.IsListening() {
 		return nodeInfo
diff --git a/p2p/peer.go b/p2p/peer.go
index 1a63b52e8..549200e24 100644
--- a/p2p/peer.go
+++ b/p2p/peer.go
@@ -12,12 +12,6 @@ import (
 	"github.com/tendermint/tendermint/types"
 )
 
-type nodeInfo struct {
-	Host    string
-	RPCPort uint16
-	P2PPort uint16
-}
-
 type Peer struct {
 	outbound bool
 	mconn    *MConnection
diff --git a/p2p/switch.go b/p2p/switch.go
index c873874af..00d48c0e7 100644
--- a/p2p/switch.go
+++ b/p2p/switch.go
@@ -161,9 +161,10 @@ func (sw *Switch) AddPeerWithConnection(conn net.Conn, outbound bool) (*Peer, er
 	if err != nil {
 		return nil, err
 	}
-	if peerNodeInfo.Network != sw.nodeInfo.Network {
-		return nil, fmt.Errorf("Peer is on different network %v", peerNodeInfo.Network)
+	if err := sw.nodeInfo.CompatibleWith(peerNodeInfo); err != nil {
+		return nil, err
 	}
+
 	peer := newPeer(conn, peerNodeInfo, outbound, sw.reactorsByCh, sw.chDescs, sw.StopPeerForError)
 
 	// Add the peer to .peers
diff --git a/types/node.go b/types/node.go
index 7a3c41a73..0498e33e9 100644
--- a/types/node.go
+++ b/types/node.go
@@ -1,9 +1,56 @@
 package types
 
+import (
+	"fmt"
+	"strings"
+)
+
 type NodeInfo struct {
 	Moniker string
 	Network string
+	Version string
+
 	Host    string
 	P2PPort uint16
 	RPCPort uint16
 }
+
+func (ni *NodeInfo) CompatibleWith(no *NodeInfo) error {
+	iM, im, _, ie := splitVersion(ni.Version)
+	oM, om, _, oe := splitVersion(no.Version)
+
+	// if our own version number is not formatted right, we messed up
+	if ie != nil {
+		return ie
+	}
+
+	// version number must be formatted correctly ("x.x.x")
+	if oe != nil {
+		return oe
+	}
+
+	// major version must match
+	if iM != oM {
+		return fmt.Errorf("Peer is on a different major version. Got %v, expected %v", oM, iM)
+	}
+
+	// minor version must match
+	if im != om {
+		return fmt.Errorf("Peer is on a different minor version. Got %v, expected %v", om, im)
+	}
+
+	// nodes must be on the same network
+	if ni.Network != no.Network {
+		return fmt.Errorf("Peer is on a different network. Got %v, expected %v", no.Network, ni.Network)
+	}
+
+	return nil
+}
+
+func splitVersion(version string) (string, string, string, error) {
+	spl := strings.Split(version, ".")
+	if len(spl) != 3 {
+		return "", "", "", fmt.Errorf("Invalid version format %v", version)
+	}
+	return spl[0], spl[1], spl[2], nil
+}