From aa2917b1a0412d5cd5eb4acef71d643072d5a67e Mon Sep 17 00:00:00 2001
From: Martin/Geno <geno+dev@fireorbit.de>
Date: Mon, 3 Jun 2019 15:38:46 +0200
Subject: [PATCH] Add backend pinger

---
 data/ping_result.go |   6 +++
 main.go             |   6 +++
 runtime/ping.go     | 104 ++++++++++++++++++++++++++++++++++++++++++++
 websocket/send.go   |   5 ++-
 4 files changed, 119 insertions(+), 2 deletions(-)
 create mode 100644 data/ping_result.go
 create mode 100644 runtime/ping.go

diff --git a/data/ping_result.go b/data/ping_result.go
new file mode 100644
index 0000000..b6225d2
--- /dev/null
+++ b/data/ping_result.go
@@ -0,0 +1,6 @@
+package data
+
+type PingResult struct {
+    True  []string `json:"true"`
+    False []string `json:"false"`
+}
\ No newline at end of file
diff --git a/main.go b/main.go
index 25f1af0..0d9b30d 100644
--- a/main.go
+++ b/main.go
@@ -56,6 +56,12 @@ func main() {
 	ws := websocket.NewWebsocketServer(config.Secret, config.SSHIPAddressPrefix, db, config.BlacklistFor.Duration, nodesYanic)
 
 	yanic := runtime.NewYanicDB(db, sshmanager, config.BlacklistFor.Duration, ws.SendNode, ws.SendStats, config.SSHIPAddressPrefix)
+	
+	pinger, err := runtime.NewPinger(db, config.BlacklistFor.Duration, ws.SendPing)
+	if err != nil {
+		log.Panic(err)
+	}
+	go pinger.Start()
 
 	if config.YanicEnable {
 		if duration := config.YanicSynchronize.Duration; duration > 0 {
diff --git a/runtime/ping.go b/runtime/ping.go
new file mode 100644
index 0000000..16dd48c
--- /dev/null
+++ b/runtime/ping.go
@@ -0,0 +1,104 @@
+package runtime
+
+import (
+    "net"
+    "time"
+    "sync"
+
+    log "github.com/sirupsen/logrus"
+    "github.com/digineo/go-ping"
+    "github.com/jinzhu/gorm"
+
+    "github.com/FreifunkBremen/freifunkmanager/data"
+)
+
+type Pinger struct {
+	db           *gorm.DB
+    blacklistFor time.Duration
+	sendResult   func(*data.PingResult)
+
+    stop bool
+    wg   sync.WaitGroup
+
+    p           *ping.Pinger
+    pingTimeout time.Duration
+    pingCount   int
+}
+
+func NewPinger(db *gorm.DB, blacklistFor time.Duration, sendResult func(*data.PingResult)) (*Pinger, error) {
+    ping, err := ping.New("", "::")
+    if err != nil {
+        return nil, err
+    }
+    
+	return &Pinger{
+		db:           db,
+        blacklistFor: blacklistFor,
+		sendResult:   sendResult,
+
+        stop: false,
+
+        p:           ping,
+        pingTimeout: time.Duration(time.Second),
+        pingCount:   2,
+	}, nil
+}
+
+func (pinger *Pinger) Start() {
+    pinger.wg.Add(1)
+    for !pinger.stop {
+        pinger.run()
+    }
+    pinger.wg.Done()
+}
+
+func (pinger *Pinger) Stop() {
+    pinger.stop = true
+    pinger.wg.Wait()
+}
+
+func (pinger *Pinger) run() {
+    result := &data.PingResult{}
+    now := time.Now()
+
+    count := 0
+    var nodes []*Node
+
+    pinger.db.Find(&nodes).Count(&count)
+
+    wg := sync.WaitGroup{}
+    wg.Add(count)
+
+    for _, node := range nodes {
+		go func(n *Node) {
+            defer wg.Done()
+            if n.Blacklist.After(now.Add(-pinger.blacklistFor)) {
+                return
+            }
+
+            addr, err := net.ResolveIPAddr("ip6", n.Address)
+            if  err != nil {
+                return
+            }
+
+            _, err = pinger.p.PingAttempts(addr, pinger.pingTimeout, pinger.pingCount)
+
+            if  err == nil {
+                result.True = append(result.True, n.NodeID)
+            } else {
+                result.False = append(result.False, n.NodeID)
+            }
+
+        }(node)
+    }
+    wg.Wait()
+
+    log.WithFields(map[string]interface{}{
+        "count":         count,
+        "count_skipped": count - (len(result.True) + len(result.False)),
+        "count_false":   len(result.False),
+        "count_true":    len(result.True),
+    }).Debug("pinger complete")
+
+    pinger.sendResult(result)
+}
\ No newline at end of file
diff --git a/websocket/send.go b/websocket/send.go
index 65f694e..bf36245 100644
--- a/websocket/send.go
+++ b/websocket/send.go
@@ -6,6 +6,7 @@ import (
 	yanicRuntime "github.com/FreifunkBremen/yanic/runtime"
 
 	"github.com/FreifunkBremen/freifunkmanager/runtime"
+	"github.com/FreifunkBremen/freifunkmanager/data"
 )
 
 func (ws *WebsocketServer) SendNode(node *runtime.Node) {
@@ -15,9 +16,9 @@ func (ws *WebsocketServer) SendNode(node *runtime.Node) {
 func (ws *WebsocketServer) SendStats(data *yanicRuntime.GlobalStats) {
 	ws.ws.SendAll(&wsLib.Message{Subject: MessageTypeStats, Body: data})
 }
-func (ws *WebsocketServer) SendPing(data interface{}) {
+func (ws *WebsocketServer) SendPing(pResult *data.PingResult) {
 	var sessions []*Session
-	msg := &wsLib.Message{Subject: MessageTypePing, Body: data}
+	msg := &wsLib.Message{Subject: MessageTypePing, Body: pResult}
 
 	ws.db.Find(&sessions)
 	for _, session := range sessions {