Add autopeering over proxy

To use autopeering over a proxy, set the environment variable ALL_PROXY. For
example, ALL_PROXY=socks5://127.0.0.1:9150 ./yggdrasil -autopeer

src/autopeering/main.go

@@ -1,11 +1,13 @@
 package autopeering
 
 import (
+	"context"
 	"math/rand"
-	"net"
 	"sort"
 	"strings"
 	"time"
+
+	"golang.org/x/net/proxy"
 )
 
 const defaultTimeout time.Duration = time.Duration(3) * time.Second
@@ -48,7 +50,10 @@ func testPeer(pstring string, results chan Peer) {
 		return
 	}
 
-	conn, err := net.DialTimeout(network, peer_addr[1], defaultTimeout)
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
+	defer cancel()
+
+	conn, err := proxy.Dial(ctx, network, peer_addr[1])
 	if err == nil {
 		t1 := time.Now()
 		conn.Close()
@@ -101,3 +106,14 @@ func RandomPick(peerList []string, num int) []string {
 
 	return res
 }
+
+// Return tcp peers only since socks proxy can only work with those
+func GetTcpPeers() []string {
+	publicPeers := []string{}
+	for _, p := range PublicPeers {
+		if p[:3] == "tcp" {
+			publicPeers = append(publicPeers, p)
+		}
+	}
+	return publicPeers
+}

src/autopeering/module.go

@@ -1,6 +1,9 @@
 package autopeering
 
 import (
+	"fmt"
+	"net/url"
+	"os"
 	"time"
 
 	"github.com/gologme/log"
@@ -23,13 +26,29 @@ type AutoPeering struct {
 	log            *log.Logger
 	checkPeerTimer *time.Timer
 	hadPeers       time.Time
+	proxyURL       *url.URL
+	publicPeers    *[]string
 }
 
 func (ap *AutoPeering) Init(core *yggdrasil.Core, state *config.NodeState, popConfig *popura.PopuraConfig, log *log.Logger, options interface{}) error {
 	ap.core = core
 	ap.log = log
 
-	return nil
+	proxyEnv := os.Getenv("ALL_PROXY")
+	if proxyEnv == "" {
+		proxyEnv = os.Getenv("all_proxy")
+	}
+
+	if proxyEnv == "" {
+		ap.publicPeers = &PublicPeers
+	} else {
+		tcpPeers := GetTcpPeers()
+		ap.publicPeers = &tcpPeers
+	}
+
+	var err error
+	ap.proxyURL, err = url.Parse(proxyEnv)
+	return err
 }
 
 func (ap *AutoPeering) Start() error {
@@ -59,10 +78,12 @@ func (ap *AutoPeering) checkPeerLoop() {
 		ap.hadPeers = time.Now()
 	} else if time.Since(ap.hadPeers) > autopeerTimeout {
 		ap.hadPeers = time.Now()
-		peers := RandomPick(GetClosestPeers(PublicPeers, 10), 1)
+		peers := RandomPick(GetClosestPeers(*ap.publicPeers, 10), 1)
 		if len(peers) == 1 {
-			ap.log.Infoln("autopeering: adding new peer", peers[0])
-			if err := ap.core.AddPeer(peers[0], ""); err != nil {
+			peerUri := ap.getPeerUri(peers[0])
+
+			ap.log.Infoln("autopeering: adding new peer", peerUri)
+			if err := ap.core.AddPeer(peerUri, ""); err != nil {
 				ap.log.Infoln("autopeering: Failed to connect to peer:", err)
 			}
 		}
@@ -73,6 +94,14 @@ func (ap *AutoPeering) checkPeerLoop() {
 	})
 }
 
+// Return peer URI with respect to proxy environment settings
+func (ap *AutoPeering) getPeerUri(uri string) string {
+	if !ap.proxyURL.IsAbs() {
+		return uri
+	}
+	return fmt.Sprintf("socks://%s/%s", ap.proxyURL.Host, uri[6:len(uri)])
+}
+
 func (ap *AutoPeering) UpdateConfig(yggConfig *config.NodeConfig, popConfig *popura.PopuraConfig) {}
 func (ap *AutoPeering) SetupAdminHandlers(a *admin.AdminSocket)                                   {}
 func (ap *AutoPeering) IsStarted() bool                                                           { return false }