func (s *Server) handleQuery(source Addr, m krpc.Msg) {
node := s.getNode(source, m.SenderID())
node.lastGotQuery = time.Now()
if s.config.OnQuery != nil {
propagate := s.config.OnQuery(&m, source.UDPAddr())
if !propagate {
return
}
}
// Don't respond.
if s.config.Passive {
return
}
args := m.A
switch m.Q {
case "ping":
s.reply(source, m.T, krpc.Return{})
case "get_peers": // TODO: Extract common behaviour with find_node.
targetID := args.InfoHash
if len(targetID) != 20 {
break
}
var rNodes []krpc.NodeInfo
// TODO: Reply with "values" list if we have peers instead.
for _, node := range s.closestGoodNodes(8, targetID) {
rNodes = append(rNodes, node.NodeInfo())
}
s.reply(source, m.T, krpc.Return{
Nodes: rNodes,
// TODO: Generate this dynamically, and store it for the source.
Token: "hi",
})
case "find_node": // TODO: Extract common behaviour with get_peers.
targetID := args.Target
if len(targetID) != 20 {
log.Printf("bad DHT query: %v", m)
return
}
var rNodes []krpc.NodeInfo
if node := s.nodeByID(targetID); node != nil {
rNodes = append(rNodes, node.NodeInfo())
} else {
// This will probably cause a crash for IPv6, but meh.
for _, node := range s.closestGoodNodes(8, targetID) {
rNodes = append(rNodes, node.NodeInfo())
}
}
s.reply(source, m.T, krpc.Return{
Nodes: rNodes,
})
case "announce_peer":
// TODO(anacrolix): Implement this lolz.
// log.Print(m)
case "vote":
// TODO(anacrolix): Or reject, I don't think I want this.
default:
log.Printf("%s: not handling received query: q=%s", s, m.Q)
return
}
}
func (s *Server) processPacket(b []byte, addr Addr) {
if len(b) < 2 || b[0] != 'd' || b[len(b)-1] != 'e' {
// KRPC messages are bencoded dicts.
readNotKRPCDict.Add(1)
return
}
var d krpc.Msg
err := bencode.Unmarshal(b, &d)
if err != nil {
readUnmarshalError.Add(1)
func() {
if se, ok := err.(*bencode.SyntaxError); ok {
// The message was truncated.
if int(se.Offset) == len(b) {
return
}
// Some messages seem to drop to nul chars abrubtly.
if int(se.Offset) < len(b) && b[se.Offset] == 0 {
return
}
// The message isn't bencode from the first.
if se.Offset == 0 {
return
}
}
// if missinggo.CryHeard() {
// log.Printf("%s: received bad krpc message from %s: %s: %+q", s, addr, err, b)
// }
}()
return
}
s.mu.Lock()
defer s.mu.Unlock()
if s.closed.IsSet() {
return
}
if d.Y == "q" {
readQuery.Add(1)
s.handleQuery(addr, d)
return
}
t := s.findResponseTransaction(d.T, addr)
if t == nil {
//log.Printf("unexpected message: %#v", d)
return
}
node := s.getNode(addr, d.SenderID())
node.lastGotResponse = time.Now()
// TODO: Update node ID as this is an authoritative packet.
go t.handleResponse(d)
s.deleteTransaction(t)
}