From 8c5aaee7935f5ddd912920d5992648b99afd96c7 Mon Sep 17 00:00:00 2001
From: Callan Bryant <callan.bryant@gmail.com>
Date: Thu, 5 Mar 2020 22:05:47 +0000
Subject: [PATCH] compute peer status (incomplete)

---
 configtypes.go |  3 +--
 const.go       |  8 +++++++-
 reporttypes.go | 33 +++++++++++++++++++++++----------
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/configtypes.go b/configtypes.go
index 370f740..3cbf728 100644
--- a/configtypes.go
+++ b/configtypes.go
@@ -5,7 +5,6 @@ import (
 	"io/ioutil"
 	"net"
 	"os"
-	"time"
 
 	"github.com/go-playground/validator/v10"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
@@ -180,7 +179,7 @@ func (conf DsnetConfig) MustAllocateIP() net.IP {
 func (conf DsnetConfig) GetWgPeerConfigs() []wgtypes.PeerConfig {
 	wgPeers := make([]wgtypes.PeerConfig, 0, len(conf.Peers))
 
-	interval := time.Second * KEEPALIVE_SECONDS
+	interval := KEEPALIVE
 
 	for _, peer := range conf.Peers {
 		wgPeers = append(wgPeers, wgtypes.PeerConfig{
diff --git a/const.go b/const.go
index a95972b..2e53a4a 100644
--- a/const.go
+++ b/const.go
@@ -1,5 +1,9 @@
 package dsnet
 
+import (
+	"time"
+)
+
 const (
 	// could be overridden in future via env
 	CONFIG_FILE = "/etc/dsnetconfig.json"
@@ -11,7 +15,9 @@ const (
 
 	// keepalive always configured for everything. Set to a value likely to
 	// stop most NATs from dropping the connection.
-	KEEPALIVE_SECONDS = 21
+	KEEPALIVE = 21 * time.Second
+	// allow missing a single keepalive + margin. Received data resets timeout, too.
+	TIMEOUT = 50 * time.Second
 
 	// when is a peer considered gone forever? (could remove)
 	EXPIRY_DAYS = 28
diff --git a/reporttypes.go b/reporttypes.go
index 4535ec0..f1ae33b 100644
--- a/reporttypes.go
+++ b/reporttypes.go
@@ -12,27 +12,28 @@ import (
 type Status int
 
 const (
+	StatusUnknown = iota
 	// Host has not been loaded into wireguard yet
-	Pending = iota
+	StatusSyncRequired
 	// Host has not transferred anything (not even a keepalive) for 30 seconds
-	Offline
+	StatusOffline
 	// Host has transferred something in the last 30 seconds, keepalive counts
-	Online
+	StatusOnline
 	// Host has not connected for 28 days and may be removed
-	Expired
+	StatusExpired
 )
 
 // TODO pending/unknown
 
 func (s Status) String() string {
 	switch s {
-	case Pending:
-		return "pending"
-	case Offline:
+	case StatusSyncRequired:
+		return "syncrequired"
+	case StatusOffline:
 		return "offline"
-	case Online:
+	case StatusOnline:
 		return "online"
-	case Expired:
+	case StatusExpired:
 		return "expired"
 	default:
 		return "unknown"
@@ -70,12 +71,24 @@ func GenerateReport(dev *wgtypes.Device, conf *DsnetConfig) DsnetReport {
 	for i, peer := range conf.Peers {
 		wgPeer, known := wgPeerIndex[peer.PublicKey.Key]
 
+		status := Status(StatusUnknown)
+
+		if !known {
+			status = StatusSyncRequired
+		} else if wgPeer.LastHandshakeTime.After(time.Now().Add(-TIMEOUT)) {
+			status = StatusOnline
+			// TODO same test but with rx byte data from last report (otherwise
+			// peer can fake online status by disabling handshake)
+		} else {
+			status = StatusOffline
+		}
+
 		peerReports[i] = PeerReport{
 			Hostname: peer.Hostname,
 			Owner: peer.Owner,
 			Description: peer.Description,
 			IP: peer.IP,
-			// TODO Status
+			Status: status,
 			Networks: peer.Networks,
 			LastHandshakeTime: wgPeer.LastHandshakeTime,
 			ReceiveBytes: wgPeer.ReceiveBytes,