Add support for the x.pe magnet link parameter

client.go

@@ -1164,6 +1164,13 @@ func (cl *Client) AddTorrentSpec(spec *TorrentSpec) (t *Torrent, new bool, err e
 	return
 }
 
+type stringAddr string
+
+var _ net.Addr = stringAddr("")
+
+func (stringAddr) Network() string   { return "" }
+func (me stringAddr) String() string { return string(me) }
+
 // The trackers will be merged with the existing ones. If the Info isn't yet known, it will be set.
 // spec.DisallowDataDownload/Upload will be read and applied
 // The display name is replaced if the new spec provides one. Note that any `Storage` is ignored.
@@ -1185,6 +1192,13 @@ func (t *Torrent) MergeSpec(spec *TorrentSpec) error {
 	for _, url := range spec.Webseeds {
 		t.addWebSeed(url)
 	}
+	for _, peerAddr := range spec.PeerAddrs {
+		t.addPeer(PeerInfo{
+			Addr:    stringAddr(peerAddr),
+			Source:  PeerSourceDirect,
+			Trusted: true,
+		})
+	}
 	if spec.ChunkSize != 0 {
 		t.setChunkSize(pp.Integer(spec.ChunkSize))
 	}

peerconn.go

@@ -34,6 +34,8 @@ const (
 	PeerSourceDhtGetPeers     = "Hg" // Peers we found by searching a DHT.
 	PeerSourceDhtAnnouncePeer = "Ha" // Peers that were announced to us by a DHT.
 	PeerSourcePex             = "X"
+	// The peer was given directly, such as through a magnet link.
+	PeerSourceDirect = "M"
 )
 
 type peer struct {

spec.go

@@ -16,6 +16,7 @@ type TorrentSpec struct {
 	DisplayName string
 	Webseeds    []string
 	DhtNodes    []string
+	PeerAddrs   []string
 	// The combination of the "xs" and "as" fields in magnet links, for now.
 	Sources []string
 
@@ -39,7 +40,8 @@ func TorrentSpecFromMagnetUri(uri string) (spec *TorrentSpec, err error) {
 		InfoHash:    m.InfoHash,
 		Webseeds:    m.Params["ws"],
 		Sources:     append(m.Params["xs"], m.Params["as"]...),
-		// TODO: What's the parameter for DHT nodes or bootstrap peers in a magnet link?
+		PeerAddrs:   m.Params["x.pe"], // BEP 9
+		// TODO: What's the parameter for DHT nodes?
 	}
 	return
 }