Move some things around a bit, delete session workers

src/yggdrasil/conn.go

@@ -0,0 +1,150 @@
+package yggdrasil
+
+import (
+	"encoding/hex"
+	"errors"
+	"time"
+
+	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
+	"github.com/yggdrasil-network/yggdrasil-go/src/util"
+)
+
+type Conn struct {
+	core          *Core
+	nodeID        *crypto.NodeID
+	nodeMask      *crypto.NodeID
+	session       *sessionInfo
+	readDeadline  time.Time
+	writeDeadline time.Time
+}
+
+// This method should only be called from the router goroutine
+func (c *Conn) startSearch() {
+	searchCompleted := func(sinfo *sessionInfo, err error) {
+		if err != nil {
+			c.core.log.Debugln("DHT search failed:", err)
+			return
+		}
+		if sinfo != nil {
+			c.session = sinfo
+			c.core.log.Println("Search from API found", hex.EncodeToString(sinfo.theirPermPub[:]))
+		}
+	}
+	// Try and search for the node on the network
+	doSearch := func() {
+		sinfo, isIn := c.core.searches.searches[*c.nodeID]
+		if !isIn {
+			c.core.log.Debugln("Starting search for", hex.EncodeToString(c.nodeID[:]))
+			sinfo = c.core.searches.newIterSearch(c.nodeID, c.nodeMask, searchCompleted)
+		}
+		c.core.searches.continueSearch(sinfo)
+	}
+	var sinfo *sessionInfo
+	var isIn bool
+	switch {
+	case !isIn || !sinfo.init:
+		// No or unintiialized session, so we need to search first
+		doSearch()
+	case time.Since(sinfo.time) > 6*time.Second:
+		if sinfo.time.Before(sinfo.pingTime) && time.Since(sinfo.pingTime) > 6*time.Second {
+			// We haven't heard from the dest in a while
+			// We tried pinging but didn't get a response
+			// They may have changed coords
+			// Try searching to discover new coords
+			// Note that search spam is throttled internally
+			doSearch()
+		} else {
+			// We haven't heard about the dest in a while
+			now := time.Now()
+			if !sinfo.time.Before(sinfo.pingTime) {
+				// Update pingTime to start the clock for searches (above)
+				sinfo.pingTime = now
+			}
+			if time.Since(sinfo.pingSend) > time.Second {
+				// Send at most 1 ping per second
+				sinfo.pingSend = now
+				c.core.sessions.sendPingPong(sinfo, false)
+			}
+		}
+	}
+}
+
+func (c *Conn) Read(b []byte) (int, error) {
+	if c.session == nil {
+		return 0, errors.New("session not open")
+	}
+	p := <-c.session.recv
+	defer util.PutBytes(p.Payload)
+	if !c.session.nonceIsOK(&p.Nonce) {
+		return 0, errors.New("packet dropped due to invalid nonce")
+	}
+	bs, isOK := crypto.BoxOpen(&c.session.sharedSesKey, p.Payload, &p.Nonce)
+	if !isOK {
+		util.PutBytes(bs)
+		return 0, errors.New("packet dropped due to decryption failure")
+	}
+	b = b[:0]
+	b = append(b, bs...)
+	c.session.updateNonce(&p.Nonce)
+	c.session.time = time.Now()
+	c.session.bytesRecvd += uint64(len(bs))
+	return len(b), nil
+}
+
+func (c *Conn) Write(b []byte) (int, error) {
+	if c.session == nil {
+		c.core.router.doAdmin(func() {
+			c.startSearch()
+		})
+		return 0, errors.New("session not open")
+	}
+	defer util.PutBytes(b)
+	if !c.session.init {
+		// To prevent using empty session keys
+		return 0, errors.New("session not initialised")
+	}
+	// code isn't multithreaded so appending to this is safe
+	coords := c.session.coords
+	// Prepare the payload
+	payload, nonce := crypto.BoxSeal(&c.session.sharedSesKey, b, &c.session.myNonce)
+	defer util.PutBytes(payload)
+	p := wire_trafficPacket{
+		Coords:  coords,
+		Handle:  c.session.theirHandle,
+		Nonce:   *nonce,
+		Payload: payload,
+	}
+	packet := p.encode()
+	c.session.bytesSent += uint64(len(b))
+	c.session.send <- packet
+	c.session.core.router.out(packet)
+	return len(b), nil
+}
+
+func (c *Conn) Close() error {
+	return nil
+}
+
+func (c *Conn) LocalAddr() crypto.NodeID {
+	return *crypto.GetNodeID(&c.session.core.boxPub)
+}
+
+func (c *Conn) RemoteAddr() crypto.NodeID {
+	return *crypto.GetNodeID(&c.session.theirPermPub)
+}
+
+func (c *Conn) SetDeadline(t time.Time) error {
+	c.SetReadDeadline(t)
+	c.SetWriteDeadline(t)
+	return nil
+}
+
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	c.readDeadline = t
+	return nil
+}
+
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	c.writeDeadline = t
+	return nil
+}