From 8668abf48117d4e2fb729313bf13b26e6cfb593b Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Sat, 22 May 2021 19:54:52 -0500
Subject: [PATCH] WIP adding crawling debug packets

---
 src/tuntap/debug.go | 122 ++++++++++++++++++++++++++++++++++++++++++++
 src/tuntap/iface.go |   5 ++
 src/tuntap/tun.go   |   2 +
 src/tuntap/types.go |   1 +
 4 files changed, 130 insertions(+)
 create mode 100644 src/tuntap/debug.go

diff --git a/src/tuntap/debug.go b/src/tuntap/debug.go
new file mode 100644
index 00000000..ee19d3f0
--- /dev/null
+++ b/src/tuntap/debug.go
@@ -0,0 +1,122 @@
+package tuntap
+
+import (
+	"time"
+
+	iwt "github.com/Arceliar/ironwood/types"
+	"github.com/Arceliar/phony"
+)
+
+const (
+	typeDebugDummy = iota
+	typeDebugGetSelfRequest
+	typeDebugGetSelfResponse
+	typeDebugGetPeersRequest
+	typeDebugGetPeersResponse
+	typeDebugGetDHTRequest
+	typeDebugGetDHTResponse
+)
+
+type reqInfo struct {
+	ch    chan []byte
+	timer time.Timer // time.AfterFunc cleanup
+}
+
+type debugHandler struct {
+	phony.Inbox
+	tun   *TunAdapter
+	sreqs struct{} // TODO
+	preqs map[keyArray]*reqInfo
+	dreqs map[keyArray]*reqInfo
+}
+
+func (d *debugHandler) init(tun *TunAdapter) {
+	d.tun = tun
+	d.preqs = make(map[keyArray]*reqInfo)
+	d.dreqs = make(map[keyArray]*reqInfo)
+}
+
+func (d *debugHandler) handleDebug(from phony.Actor, key keyArray, bs []byte) {
+	d.Act(from, func() {
+		d._handleDebug(key, bs)
+	})
+}
+
+func (d *debugHandler) _handleDebug(key keyArray, bs []byte) {
+	if len(bs) == 0 {
+		return
+	}
+	switch bs[0] {
+	case typeDebugDummy:
+	case typeDebugGetSelfRequest:
+		d._handleGetSelfRequest(key)
+	case typeDebugGetSelfResponse:
+		d._handleGetSelfResponse(key, bs[1:])
+	case typeDebugGetPeersRequest:
+		d._handleGetPeersRequest(key)
+	case typeDebugGetPeersResponse:
+		d._handleGetPeersResponse(key, bs[1:])
+	case typeDebugGetDHTRequest:
+		d._handleGetDHTRequest(key)
+	case typeDebugGetDHTResponse:
+		d._handleGetDHTResponse(key, bs[1:])
+	default:
+	}
+}
+
+func (d *debugHandler) _handleGetSelfRequest(key keyArray) {
+	// TODO
+}
+
+func (d *debugHandler) _handleGetSelfResponse(key keyArray, bs []byte) {
+	// TODO
+}
+
+func (d *debugHandler) _handleGetPeersRequest(key keyArray) {
+	peers := d.tun.core.GetPeers()
+	var bs []byte
+	for _, p := range peers {
+		tmp := append(bs, p.Key[:]...)
+		const responseOverhead = 1
+		if uint64(len(tmp))+1 > d.tun.maxSessionMTU() {
+			break
+		}
+		bs = tmp
+	}
+	d._sendDebug(key, typeDebugGetPeersResponse, bs)
+}
+
+func (d *debugHandler) _handleGetPeersResponse(key keyArray, bs []byte) {
+	if info := d.preqs[key]; info != nil {
+		info.timer.Stop()
+		info.ch <- bs
+		delete(d.preqs, key)
+	}
+}
+
+func (d *debugHandler) _handleGetDHTRequest(key keyArray) {
+	dinfos := d.tun.core.GetDHT()
+	var bs []byte
+	for _, dinfo := range dinfos {
+		tmp := append(bs, dinfo.Key[:]...)
+		const responseOverhead = 1
+		if uint64(len(tmp))+1 > d.tun.maxSessionMTU() {
+			break
+		}
+		bs = tmp
+	}
+	d._sendDebug(key, typeDebugGetDHTResponse, bs)
+}
+
+func (d *debugHandler) _handleGetDHTResponse(key keyArray, bs []byte) {
+	if info := d.dreqs[key]; info != nil {
+		info.timer.Stop()
+		info.ch <- bs
+		delete(d.dreqs, key)
+	}
+}
+
+func (d *debugHandler) _sendDebug(key keyArray, dType uint8, data []byte) {
+	bs := append([]byte{typeSessionDebug, dType}, data...)
+	d.tun.core.WriteTo(bs, iwt.Addr(key[:]))
+}
diff --git a/src/tuntap/iface.go b/src/tuntap/iface.go
index a3275436..20720db4 100644
--- a/src/tuntap/iface.go
+++ b/src/tuntap/iface.go
@@ -88,6 +88,11 @@ func (tun *TunAdapter) write() {
 			res := append([]byte(nil), bs[1:n]...)
 			tun.nodeinfo.handleRes(nil, key, res)
 			continue
+		case typeSessionDebug:
+			var key keyArray
+			copy(key[:], from.(iwt.Addr))
+			data := append([]byte(nil), bs[1:n]...)
+			tun.debug.handleDebug(nil, key, data)
 		default:
 			continue
 		}
diff --git a/src/tuntap/tun.go b/src/tuntap/tun.go
index 53546c32..36736719 100644
--- a/src/tuntap/tun.go
+++ b/src/tuntap/tun.go
@@ -47,6 +47,7 @@ type TunAdapter struct {
 	isEnabled  bool // Used by the writer to drop sessionTraffic if not enabled
 	gatekeeper func(pubkey ed25519.PublicKey, initiator bool) bool
 	nodeinfo   nodeinfo
+	debug      debugHandler
 }
 
 func (tun *TunAdapter) SetSessionGatekeeper(gatekeeper func(pubkey ed25519.PublicKey, initiator bool) bool) {
@@ -113,6 +114,7 @@ func (tun *TunAdapter) Init(core *yggdrasil.Core, config *config.NodeState, log
 	if err := tun.core.SetOutOfBandHandler(tun.oobHandler); err != nil {
 		return fmt.Errorf("tun.core.SetOutOfBandHander: %w", err)
 	}
+	tun.debug.init(tun)
 	return nil
 }
 
diff --git a/src/tuntap/types.go b/src/tuntap/types.go
index f1267a92..102e03f0 100644
--- a/src/tuntap/types.go
+++ b/src/tuntap/types.go
@@ -13,4 +13,5 @@ const (
 	typeSessionTraffic
 	typeSessionNodeInfoRequest
 	typeSessionNodeInfoResponse
+	typeSessionDebug // Debug messages, intended to be removed at some point
 )