/
krpc-msgs.go
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/
krpc-msgs.go
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package dht
import (
"bytes"
"encoding/binary"
"fmt"
"github.com/hlandau/dht/krpc"
"github.com/hlandauf/bencode"
"net"
"strings"
)
func init() {
krpc.RegisterQuery("ping", krPing{})
krpc.RegisterResponse("ping", krPing{})
krpc.RegisterQuery("find_node", krFindNodeReq{})
krpc.RegisterResponse("find_node", krFindNodeRes{})
krpc.RegisterQuery("get_peers", krGetPeersReq{})
krpc.RegisterResponse("get_peers", krGetPeersRes{})
krpc.RegisterQuery("announce_peer", krAnnouncePeerReq{})
krpc.RegisterResponse("announce_peer", krAnnouncePeerRes{})
krpc.RegisterQuery("get", krGetReq{})
krpc.RegisterResponse("get", krGetRes{})
krpc.RegisterQuery("put", krPutReq{})
krpc.RegisterResponse("put", krPutRes{})
}
func getNodeID(msg *krpc.Message) NodeID {
r := msg.Response
if msg.Type == "q" {
r = msg.Args
}
hni, ok := r.(interface {
GetNodeID() NodeID
})
if !ok {
log.Errorf("warning: %T doesn't support GetNodeID", msg.Response)
return ""
}
return hni.GetNodeID()
}
// KRPC "ping" request/response.
type krPing struct {
ID NodeID `bencode:"id"`
}
func (m *krPing) String() string {
return fmt.Sprintf("ping(%v)", m.ID.ShortString())
}
func (m *krPing) GetNodeID() NodeID {
return m.ID
}
// KRPC "find_node" request.
type krFindNodeReq struct {
ID NodeID `bencode:"id"`
Target NodeID `bencode:"target"`
Want []string `bencode:"want,omitempty"` // "n4", "n6"
}
func (m *krFindNodeReq) String() string {
return fmt.Sprintf("findNode?(%v ->%v %v)", m.ID.ShortString(), m.Target.ShortString(), m.Want)
}
func (m *krFindNodeReq) GetNodeID() NodeID {
return m.ID
}
// KRPC "find_node" response.
type krFindNodeRes struct {
ID NodeID `bencode:"id"`
Nodes krNodesIPv4 `bencode:"nodes,omitempty"`
Nodes6 krNodesIPv6 `bencode:"nodes6,omitempty"`
}
func (m *krFindNodeRes) String() string {
return fmt.Sprintf("findNode.(%v %v %v)", m.ID.ShortString(), m.Nodes, m.Nodes6)
}
func (m *krFindNodeRes) GetNodeID() NodeID {
return m.ID
}
// KRPC "get_peers" request.
type krGetPeersReq struct {
ID NodeID `bencode:"id"`
InfoHash InfoHash `bencode:"info_hash"`
Want []string `bencode:"want,omitempty"` // "n4", "n6"
}
func (m *krGetPeersReq) String() string {
return fmt.Sprintf("getPeers?(%v ->%v %v)", m.ID.ShortString(), m.InfoHash.ShortString(), m.Want)
}
func (m *krGetPeersReq) GetNodeID() NodeID {
return m.ID
}
// KRPC "get_peers" response.
type krGetPeersRes struct {
ID NodeID `bencode:"id"`
Token []byte `bencode:"token"`
Nodes krNodesIPv4 `bencode:"nodes,omitempty"`
Nodes6 krNodesIPv6 `bencode:"nodes6,omitempty"`
Endpoints []krpc.Endpoint `bencode:"values"`
}
func (m *krGetPeersRes) String() string {
return fmt.Sprintf("getPeers.(%v tok=%x %v %v %v)", m.ID.ShortString(), string(m.Token), m.Nodes, m.Nodes6, m.Endpoints)
}
func (m *krGetPeersRes) GetNodeID() NodeID {
return m.ID
}
// KRPC "announce_peer" request.
type krAnnouncePeerReq struct {
ID NodeID `bencode:"id"`
ImpliedPort int `bencode:"implied_port"`
InfoHash InfoHash `bencode:"info_hash"`
Port int `bencode:"port"`
Token []byte `bencode:"token"`
}
func (m *krAnnouncePeerReq) String() string {
port := "implied"
if m.ImpliedPort == 0 {
port = fmt.Sprintf("%d", m.Port)
}
return fmt.Sprintf("announcePeer?(%v ->%v %v tok=%x)", m.ID.ShortString(), m.InfoHash.ShortString(), port, m.Token)
}
func (m *krAnnouncePeerReq) GetNodeID() NodeID {
return m.ID
}
// KRPC "announce_peer" response.
type krAnnouncePeerRes struct {
ID NodeID `bencode:"id"`
}
func (m *krAnnouncePeerRes) String() string {
return fmt.Sprintf("announcePeer.(%v)", m.ID.ShortString())
}
func (m *krAnnouncePeerRes) GetNodeID() NodeID {
return m.ID
}
// KRPC "get" request.
type krGetReq struct {
ID NodeID `bencode:"id"`
Target InfoHash `bencode:"target"`
Seq *uint64 `bencode:"seq,omitempty"` // mutable values only
}
func (m *krGetReq) GetNodeID() NodeID {
return m.ID
}
// KRPC "get" response.
type krGetRes struct {
ID NodeID `bencode:"id"`
Nodes krNodesIPv4 `bencode:"nodes,omitempty"`
Nodes6 krNodesIPv6 `bencode:"nodes6,omitempty"`
Token []byte `bencode:"token"`
Value string `bencode:"v"`
// For mutable values only.
Key krPublicKey `bencode:"k,omitempty"` // 32 bytes
Signature krSignature `bencode:"sig,omitempty"` // 64 byte Ed25519 signature
SequenceNo *uint64 `bencode:"seq,omitempty"`
}
func (m *krGetRes) GetNodeID() NodeID {
return m.ID
}
// KRPC "put" request.
type krPutReq struct {
ID NodeID `bencode:"id"`
Token []byte `bencode:"token"`
Value string `bencode:"v"`
// For mutable values only.
Key krPublicKey `bencode:"k,omitempty"` // 32-byte Ed25519 public key
Signature krSignature `bencode:"sig,omitempty"` // 64 byte Ed25519 signature
Salt []byte `bencode:"salt,omitempty"` // Optional salt
SequenceNo *uint64 `bencode:"seq,omitempty"`
CAS *uint64 `bencode:"cas,omitempty"` // Optional compare-and-set sequence number
}
func (m *krPutReq) GetNodeID() NodeID {
return m.ID
}
// KRPC "put" response.
type krPutRes struct {
ID NodeID `bencode:"id"`
}
func (m *krPutRes) GetNodeID() NodeID {
return m.ID
}
// A NodeLocator provides the NodeID and UDP address of a node.
type NodeLocator struct {
NodeID NodeID // Node ID
Addr net.UDPAddr // DHT Node UDP IP:Port
}
func (nl *NodeLocator) String() string {
return fmt.Sprintf("%v@%s", nl.NodeID.ShortString(), &nl.Addr)
}
func isValidAddress(addr net.UDPAddr) bool {
return !addr.IP.IsUnspecified() && addr.Port != 0
}
// An IPv4 node list is a string which is the concatenation of 26-byte
// node descriptors (NodeID, IPv4 Address, Port).
type krNodesIPv4 []NodeLocator
func (n krNodesIPv4) String() string {
var s []string
for _, x := range n {
s = append(s, x.String())
}
return fmt.Sprintf("n4(%v)", strings.Join(s, "; "))
}
func (n krNodesIPv4) MarshalBencode() ([]byte, error) {
b := bytes.Buffer{}
var bb [26]byte
for i := range n {
v4 := n[i].Addr.IP.To4()
if v4 == nil {
return nil, fmt.Errorf("IPv6 address in IPv4 nodes list")
}
copy(bb[:], n[i].NodeID)
copy(bb[20:], v4)
binary.BigEndian.PutUint16(bb[24:26], uint16(n[i].Addr.Port))
_, err := b.Write(bb[:])
if err != nil {
return nil, err
}
}
return bencode.EncodeBytes(b.Bytes())
}
func (n *krNodesIPv4) UnmarshalBencode(b []byte) error {
var bb []byte
err := bencode.DecodeBytes(b, &bb)
if err != nil {
return err
}
if len(bb)%26 != 0 {
return fmt.Errorf("not divisible by 26")
}
*n = nil
for len(bb) > 0 {
nodeID := NodeID(bb[0:20])
ip := net.IP(bb[20:24])
port := binary.BigEndian.Uint16(bb[24:26])
*n = append(*n, NodeLocator{
NodeID: nodeID,
Addr: net.UDPAddr{
IP: ip,
Port: int(port),
},
})
bb = bb[26:]
}
return nil
}
// An IPv6 node list is a string which is the concatenation of 38-byte
// node descriptors (NodeID, IPv6 Address, Port).
type krNodesIPv6 []NodeLocator
func (n krNodesIPv6) String() string {
var s []string
for _, x := range n {
s = append(s, x.String())
}
return fmt.Sprintf("n6(%v)", strings.Join(s, "; "))
}
func (n krNodesIPv6) MarshalBencode() ([]byte, error) {
b := bytes.Buffer{}
var bb [38]byte
for i := range n {
v4 := n[i].Addr.IP.To4()
if v4 != nil {
return nil, fmt.Errorf("IPv4 address in IPv6 nodes list")
}
copy(bb[:], n[i].NodeID)
copy(bb[20:], n[i].Addr.IP.To16())
binary.BigEndian.PutUint16(bb[36:38], uint16(n[i].Addr.Port))
_, err := b.Write(bb[:])
if err != nil {
return nil, err
}
}
return bencode.EncodeBytes(b.Bytes())
}
func (n *krNodesIPv6) UnmarshalBencode(b []byte) error {
var bb []byte
err := bencode.DecodeBytes(b, &bb)
if err != nil {
return err
}
if len(bb)%38 != 0 {
return fmt.Errorf("not divisible by 38")
}
*n = nil
for len(bb) > 0 {
nodeID := NodeID(bb[0:20])
ip := net.IP(bb[20:36])
port := binary.BigEndian.Uint16(bb[36:38])
*n = append(*n, NodeLocator{
NodeID: nodeID,
Addr: net.UDPAddr{
IP: ip,
Port: int(port),
},
})
bb = bb[38:]
}
return nil
}
// Ed25519 public key.
type krPublicKey string
// Is the key a well-formatted Ed25519 public key?
func (k krPublicKey) IsWellFormed() bool {
return len(k) == 32
}
// Ed25519 signature.
type krSignature string
// Is the key a well-formatted (i.e. 64-byte) signature?
func (k krSignature) IsWellFormed() bool {
return len(k) == 64
}
// An endpoint is encoded as a 6-byte string (IPv4 IP:port) or 18 byte string
// (IPv6 IP:port). The length is used to disambiguate.
type xkrEndpoint net.UDPAddr
/*
func (n krEndpoint) MarshalBencode() ([]byte, error) {
var b [18]byte
v4 := n.IP.To4()
if v4 != nil {
copy(b[:], v4)
binary.BigEndian.PutUint16(b[4:6], uint16(n.Port))
return b[0:6], nil
}
copy(b[0:16], n.IP.To16())
binary.BigEndian.PutUint16(b[16:18], uint16(n.Port))
return b[:], nil
}
func (n *krEndpoint) UnmarshalBencode(b []byte) error {
var bb []byte
err := bencode.DecodeBytes(b, &bb)
if err != nil {
return err
}
if len(bb) != 6 && len(bb) != 18 {
return fmt.Errorf("endpoint not 6 or 18 bytes in length")
}
ip := net.IP(bb[0 : len(bb)-2])
port := binary.BigEndian.Uint16(bb[len(bb)-2:])
*n = krEndpoint{
IP: ip,
Port: int(port),
}
return nil
}*/