From eab5fd5bdd35f27e4134bec87f6518f823565fe8 Mon Sep 17 00:00:00 2001
From: AudriusButkevicius <audrius.butkevicius@gmail.com>
Date: Mon, 7 Sep 2015 09:21:23 +0100
Subject: [PATCH] Join relay pool by default

---
 main.go | 28 ++++++++++++++++++++++++-
 pool.go | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+), 1 deletion(-)
 create mode 100644 pool.go

diff --git a/main.go b/main.go
index c050c355d..4e7e9a137 100644
--- a/main.go
+++ b/main.go
@@ -5,9 +5,12 @@ package main
 import (
 	"crypto/tls"
 	"flag"
+	"fmt"
 	"log"
 	"net"
+	"net/url"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/juju/ratelimit"
@@ -32,7 +35,9 @@ var (
 	sessionLimiter  *ratelimit.Bucket
 	globalLimiter   *ratelimit.Bucket
 
-	statusAddr string
+	statusAddr       string
+	poolAddrs        string
+	defaultPoolAddrs string = "https://relays.syncthing.net"
 )
 
 func main() {
@@ -47,6 +52,7 @@ func main() {
 	flag.IntVar(&globalLimitBps, "global-rate", globalLimitBps, "Global rate limit, in bytes/s")
 	flag.BoolVar(&debug, "debug", false, "Enable debug output")
 	flag.StringVar(&statusAddr, "status-srv", ":22070", "Listen address for status service (blank to disable)")
+	flag.StringVar(&poolAddrs, "pools", defaultPoolAddrs, "Comma separated list of relau pool addresses to join")
 
 	flag.Parse()
 
@@ -101,5 +107,25 @@ func main() {
 		go statusService(statusAddr)
 	}
 
+	uri, err := url.Parse(fmt.Sprintf("relay://%s/?id=%s", extAddress, id))
+	if err != nil {
+		log.Fatalln("Failed to construct URI", err)
+	}
+
+	if poolAddrs == defaultPoolAddrs {
+		log.Println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")
+		log.Println("!!  Joining default relay pools, this relay will be available for public use. !!")
+		log.Println(`!!      Use the -pools="" command line option to make the relay private.      !!`)
+		log.Println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")
+	}
+
+	pools := strings.Split(poolAddrs, ",")
+	for _, pool := range pools {
+		pool = strings.TrimSpace(pool)
+		if len(pool) > 0 {
+			go poolHandler(pool, uri)
+		}
+	}
+
 	listener(listen, tlsCfg)
 }
diff --git a/pool.go b/pool.go
new file mode 100644
index 000000000..398b0c0a8
--- /dev/null
+++ b/pool.go
@@ -0,0 +1,63 @@
+// Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).
+
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+func poolHandler(pool string, uri *url.URL) {
+	for {
+		var b bytes.Buffer
+		json.NewEncoder(&b).Encode(struct {
+			URL string `json:"url"`
+		}{
+			uri.String(),
+		})
+
+		resp, err := http.Post(pool, "application/json", &b)
+		if err != nil {
+			if debug {
+				log.Println("Error joining pool", pool, err)
+			}
+		} else if resp.StatusCode == 500 {
+			if debug {
+				bs, err := ioutil.ReadAll(resp.Body)
+				if err != nil {
+					log.Println("Failed to read response body for", pool, err)
+				} else {
+					log.Println("Response for", pool, string(bs))
+				}
+				resp.Body.Close()
+			}
+		} else if resp.StatusCode == 429 {
+			if debug {
+				log.Println(pool, "under load, will retry in a minute")
+			}
+			time.Sleep(time.Minute)
+			continue
+		} else if resp.StatusCode == 200 {
+			var x struct {
+				EvictionIn time.Duration `json:"evictionIn"`
+			}
+			err := json.NewDecoder(resp.Body).Decode(&x)
+			if err == nil {
+				rejoin := x.EvictionIn - (x.EvictionIn / 5)
+				if debug {
+					log.Println("Joined", pool, "rejoining in", rejoin)
+				}
+				time.Sleep(rejoin)
+				continue
+			} else if debug {
+				log.Println("Failed to deserialize respnse", err)
+			}
+		}
+		time.Sleep(time.Hour)
+	}
+}