PeerID is now honoured, -MC- is our prefix!

Makefile

@@ -3,12 +3,13 @@
 all: test magneticod magneticow
 
 magneticod:
-	go install --tags fts5 "-ldflags=-s -w" github.com/boramalper/magnetico/cmd/magneticod
+	go install --tags fts5 "-ldflags=-s -w -X main.compiledOn=`date -u +%Y-%m-%dT%H:%M:%SZ`" github.com/boramalper/magnetico/cmd/magneticod
 
 magneticow:
 	# TODO: minify files!
+	# https://github.com/kevinburke/go-bindata
 	go-bindata -o="cmd/magneticow/bindata.go" -prefix="cmd/magneticow/data/" cmd/magneticow/data/...
-	go install --tags fts5 "-ldflags=-s -w" github.com/boramalper/magnetico/cmd/magneticow
+	go install --tags fts5 "-ldflags=-s -w -X main.compiledOn=`date -u +%Y-%m-%dT%H:%M:%SZ`" github.com/boramalper/magnetico/cmd/magneticow
 
 image-magneticod:
 	docker build -t magneticod -f Dockerfile.magneticod .

cmd/magneticod/bittorrent/metadata/leech_test.go

@@ -2,9 +2,8 @@ package metadata
 
 import (
 	"bytes"
-	"testing"
-
 	"github.com/anacrolix/torrent/bencode"
+	"testing"
 )
 
 var operationsTest_instances = []struct {

cmd/magneticod/bittorrent/metadata/sink.go

@@ -1,7 +1,7 @@
 package metadata
 
 import (
-	"crypto/rand"
+	"math/rand"
 	"sync"
 	"time"
 
@@ -24,7 +24,7 @@ type Metadata struct {
 }
 
 type Sink struct {
-	clientID             []byte
+	PeerID               []byte
 	deadline             time.Duration
 	drain                chan Metadata
 	incomingInfoHashes   map[[20]byte]struct{}
@@ -33,18 +33,49 @@ type Sink struct {
 	termination          chan interface{}
 }
 
+func randomID() []byte {
+	/* > The peer_id is exactly 20 bytes (characters) long.
+	 * >
+	 * > There are mainly two conventions how to encode client and client version information into the peer_id,
+	 * > Azureus-style and Shadow's-style.
+	 * >
+	 * > Azureus-style uses the following encoding: '-', two characters for client id, four ascii digits for version
+	 * > number, '-', followed by random numbers.
+	 * >
+	 * > For example: '-AZ2060-'...
+	 *
+	 * https://wiki.theory.org/index.php/BitTorrentSpecification
+	 *
+	 * We encode the version number as:
+	 *  - First two digits for the major version number
+	 *  - Last two digits for the minor version number
+	 *  - Patch version number is not encoded.
+	 */
+	prefix := []byte("-MC0007-")
+
+	var rando []byte
+	for i := 20 - len(prefix); i >= 0; i-- {
+		rando = append(rando, randomDigit())
+	}
+
+	return append(prefix, rando...)
+}
+
+func randomDigit() byte {
+	var max, min int
+	max, min = '9', '0'
+	return byte(rand.Intn(max-min) + min)
+}
+
 func NewSink(deadline time.Duration) *Sink {
 	ms := new(Sink)
 
-	ms.clientID = make([]byte, 20)
-	_, err := rand.Read(ms.clientID)
-	if err != nil {
-		zap.L().Panic("sinkMetadata couldn't read 20 random bytes for client ID!", zap.Error(err))
-	}
+	ms.PeerID = randomID()
 	ms.deadline = deadline
 	ms.drain = make(chan Metadata)
 	ms.incomingInfoHashes = make(map[[20]byte]struct{})
 	ms.termination = make(chan interface{})
+
 	return ms
 }
 
@@ -66,7 +97,7 @@ func (ms *Sink) Sink(res mainline.TrawlingResult) {
 
 	zap.L().Info("Sunk!", zap.Int("leeches", len(ms.incomingInfoHashes)), util.HexField("infoHash", res.InfoHash[:]))
 
-	go NewLeech(res.InfoHash, res.PeerAddr, LeechEventHandlers{
+	go NewLeech(res.InfoHash, res.PeerAddr, ms.PeerID, LeechEventHandlers{
 		OnSuccess: ms.flush,
 		OnError:   ms.onLeechError,
 	}).Do(time.Now().Add(ms.deadline))
@@ -88,7 +119,10 @@ func (ms *Sink) Terminate() {
 }
 
 func (ms *Sink) flush(result Metadata) {
-	if !ms.terminated {
+	if ms.terminated {
+		return
+	}
+
 	ms.drain <- result
 	// Delete the infoHash from ms.incomingInfoHashes ONLY AFTER once we've flushed the
 	// metadata!
@@ -97,7 +131,6 @@ func (ms *Sink) flush(result Metadata) {
 	ms.incomingInfoHashesMx.Lock()
 	delete(ms.incomingInfoHashes, infoHash)
 	ms.incomingInfoHashesMx.Unlock()
-	}
 }
 
 func (ms *Sink) onLeechError(infoHash [20]byte, err error) {