diff options
| -rw-r--r-- | cmd/mybittorrent/client.go | 54 | ||||
| -rw-r--r-- | cmd/mybittorrent/main.go | 50 |
2 files changed, 87 insertions, 17 deletions
diff --git a/cmd/mybittorrent/client.go b/cmd/mybittorrent/client.go index f3988b6..ef3d860 100644 --- a/cmd/mybittorrent/client.go +++ b/cmd/mybittorrent/client.go @@ -1,9 +1,13 @@ package main import ( + "bytes" "encoding/binary" + "encoding/hex" "fmt" + "io" "log/slog" + "net" "net/http" "net/url" "os" @@ -30,6 +34,8 @@ type PeerResponse struct { Peers []string } +type HandshakeMessage []byte + func NewClient(peerId string, port int) *Client { return &Client{ PeerId: peerId, @@ -134,3 +140,51 @@ func (c *Client) GetPeers(filename string) (PeerResponse, error) { Peers: DecodePeers([]byte(resp.Peers)), }, err } + +func (m HandshakeMessage) PeerIdHex() string { + + return hex.EncodeToString(m[48:]) + +} + +func (c *Client) Handshake(filename, peerAddr string) (HandshakeMessage, error) { + ct, ok := c.Torrents[filename] + if !ok { + return nil, fmt.Errorf("missing torrent file: %s", filename) + } + + buf := new(bytes.Buffer) + buf.WriteByte(19) + buf.WriteString("BitTorrent protocol") + buf.Write([]byte{0, 0, 0, 0, 0, 0, 0, 0}) + + hash, err := ct.Meta.InfoHash() + if err != nil { + return nil, err + } + + buf.Write(hash) + buf.WriteString(c.PeerId) + + conn, err := net.Dial("tcp", peerAddr) + defer func(conn net.Conn) { + err := conn.Close() + if err != nil { + slog.Error("failed to close connection", "peerAddr", peerAddr) + } + }(conn) + + if err != nil { + return nil, err + } + + _, err = buf.WriteTo(conn) + if err != nil { + return nil, err + } + + respBuf := make([]byte, 68) + _, err = io.LimitReader(conn, 68).Read(respBuf) + + return respBuf, nil +} diff --git a/cmd/mybittorrent/main.go b/cmd/mybittorrent/main.go index c460c35..f000aa5 100644 --- a/cmd/mybittorrent/main.go +++ b/cmd/mybittorrent/main.go @@ -9,6 +9,18 @@ import ( bencode "github.com/jackpal/bencode-go" // Available if you need it! ) +func createClient() *Client { + fn := os.Args[2] + c := NewClient("00112233445566778899", 6881) + + _, err := c.AddTorrentFile(fn) + if err != nil { + panic(err) + } + + return c +} + func main() { command := os.Args[1] @@ -25,46 +37,50 @@ func main() { fmt.Println(string(jsonOutput)) case "info": - c := NewClient("00112233445566778899", 6881) - tf, err := c.AddTorrentFile(os.Args[2]) - if err != nil { - panic(err) - } + fn := os.Args[2] + c := createClient() + meta := c.Torrents[fn].Meta + fmt.Printf("Tracker URL: %s\n", meta.Announce) + fmt.Printf("Length: %d\n", meta.Info.Length) - fmt.Printf("Tracker URL: %s\n", tf.Meta.Announce) - fmt.Printf("Length: %d\n", tf.Meta.Info.Length) - - infoHash, err := tf.Meta.InfoHash() + infoHash, err := meta.InfoHash() if err != nil { panic(err) } fmt.Printf("Info Hash: %x", infoHash) - fmt.Printf("Piece Length: %d\n", tf.Meta.Info.PieceLength) + fmt.Printf("Piece Length: %d\n", meta.Info.PieceLength) fmt.Println("Piece Hashes:") - for _, h := range tf.Meta.PieceHashes() { + for _, h := range meta.PieceHashes() { fmt.Printf("%x\n", h) } case "peers": - c := NewClient("00112233445566778899", 6881) + fn := os.Args[2] + c := createClient() - _, err := c.AddTorrentFile(os.Args[2]) + pr, err := c.GetPeers(fn) if err != nil { panic(err) } - pr, err := c.GetPeers(os.Args[2]) + for _, peer := range pr.Peers { + fmt.Println(peer) + } + + case "handshake": + fn := os.Args[2] + c := createClient() + peerAddr := os.Args[3] + hs, err := c.Handshake(fn, peerAddr) if err != nil { panic(err) } - for _, peer := range pr.Peers { - fmt.Println(peer) - } + fmt.Printf("Peer ID: %s\n", hs.PeerIdHex()) default: fmt.Println("Unknown command: " + command) |