architecting peer

binary/byteslice.go

@@ -40,3 +40,11 @@ func ReadByteSlice(r io.Reader) ByteSlice {
     if err != nil { panic(err) }
     return ByteSlice(bytes)
 }
+
+func ReadByteSliceSafe(r io.Reader) (ByteSlice, error) {
+    length := int(ReadUInt32(r))
+    bytes := make([]byte, length)
+    _, err := io.ReadFull(r, bytes)
+    if err != nil { return nil, err }
+    return ByteSlice(bytes), nil
+}

binary/int.go

@@ -48,6 +48,13 @@ func ReadByte(r io.Reader) Byte {
     return Byte(buf[0])
 }
 
+func ReadByteSafe(r io.Reader) (Byte, error) {
+    buf := [1]byte{0}
+    _, err := io.ReadFull(r, buf[:])
+    if err != nil { return Byte(0), err }
+    return Byte(buf[0]), nil
+}
+
 
 // Int8
 

merkle/iavl_tree.go

@@ -0,0 +1,108 @@
+package merkle
+
+const HASH_BYTE_SIZE int = 4+32
+
+/*
+Immutable AVL Tree (wraps the Node root)
+
+This tree is not concurrency safe.
+You must wrap your calls with your own mutex.
+*/
+type IAVLTree struct {
+    db      Db
+    root    *IAVLNode
+}
+
+func NewIAVLTree(db Db) *IAVLTree {
+    return &IAVLTree{db:db, root:nil}
+}
+
+func NewIAVLTreeFromHash(db Db, hash ByteSlice) *IAVLTree {
+    root := &IAVLNode{
+        hash:   hash,
+        flags:  IAVLNODE_FLAG_PERSISTED | IAVLNODE_FLAG_PLACEHOLDER,
+    }
+    root.fill(db)
+    return &IAVLTree{db:db, root:root}
+}
+
+func (t *IAVLTree) Root() Node {
+    return t.root
+}
+
+func (t *IAVLTree) Size() uint64 {
+    if t.root == nil { return 0 }
+    return t.root.Size()
+}
+
+func (t *IAVLTree) Height() uint8 {
+    if t.root == nil { return 0 }
+    return t.root.Height()
+}
+
+func (t *IAVLTree) Has(key Key) bool {
+    if t.root == nil { return false }
+    return t.root.has(t.db, key)
+}
+
+func (t *IAVLTree) Put(key Key, value Value) (updated bool) {
+    if t.root == nil {
+        t.root = NewIAVLNode(key, value)
+        return false
+    }
+    t.root, updated = t.root.put(t.db, key, value)
+    return updated
+}
+
+func (t *IAVLTree) Hash() (ByteSlice, uint64) {
+    if t.root == nil { return nil, 0 }
+    return t.root.Hash()
+}
+
+func (t *IAVLTree) Save() {
+    if t.root == nil { return }
+    if t.root.hash == nil {
+        t.root.Hash()
+    }
+    t.root.Save(t.db)
+}
+
+func (t *IAVLTree) Get(key Key) (value Value) {
+    if t.root == nil { return nil }
+    return t.root.get(t.db, key)
+}
+
+func (t *IAVLTree) Remove(key Key) (value Value, err error) {
+    if t.root == nil { return nil, NotFound(key) }
+    newRoot, _, value, err := t.root.remove(t.db, key)
+    if err != nil {
+        return nil, err
+    }
+    t.root = newRoot
+    return value, nil
+}
+
+func (t *IAVLTree) Copy() Tree {
+    return &IAVLTree{db:t.db, root:t.root}
+}
+
+// Traverses all the nodes of the tree in prefix order.
+// return true from cb to halt iteration.
+// node.Height() == 0 if you just want a value node.
+func (t *IAVLTree) Traverse(cb func(Node) bool) {
+    if t.root == nil { return }
+    t.root.traverse(t.db, cb)
+}
+
+func (t *IAVLTree) Values() <-chan Value {
+    root := t.root
+    ch := make(chan Value)
+    go func() {
+        root.traverse(t.db, func(n Node) bool {
+            if n.Height() == 0 { ch <- n.Value() }
+            return true
+        })
+        close(ch)
+    }()
+    return ch
+}

peer/addrbook.go

@@ -36,9 +36,6 @@ type AddrBook struct {
     quit            chan struct{}
     nOld            int
     nNew            int
-
-    lamtx           sync.Mutex
-    localAddresses  map[string]*localAddress
 }
 
 const (
@@ -474,83 +471,6 @@ func (a *AddrBook) getOldBucket(addr *NetAddress) int {
 }
 
 
-/* Local Address */
-
-// addressPrio is an enum type used to describe the heirarchy of local address
-// discovery methods.
-type addressPrio int
-
-const (
-    InterfacePrio addressPrio = iota // address of local interface.
-    BoundPrio                        // Address explicitly bound to.
-    UpnpPrio                         // External IP discovered from UPnP
-    HttpPrio                         // Obtained from internet service.
-    ManualPrio                       // provided by --externalip.
-)
-
-type localAddress struct {
-    Addr    *NetAddress
-    Score   addressPrio
-}
-
-func (a *AddrBook) AddLocalAddress(addr *NetAddress, priority addressPrio) {
-	a.mtx.Lock(); defer a.mtx.Unlock()
-
-    // sanity check.
-    if !addr.Routable() {
-        log.Debugf("rejecting address %s:%d due to routability", addr.IP, addr.Port)
-        return
-    }
-    log.Debugf("adding address %s:%d", addr.IP, addr.Port)
-
-    key := addr.String()
-    la, ok := a.localAddresses[key]
-    if !ok || la.Score < priority {
-        if ok {
-            la.Score = priority + 1
-        } else {
-            a.localAddresses[key] = &localAddress{
-                Addr:   addr,
-                Score:  priority,
-            }
-        }
-    }
-}
-
-// Returns the most appropriate local address that we know
-// of to be contacted by rna (remote net address)
-func (a *AddrBook) GetBestLocalAddress(rna *NetAddress) *NetAddress {
-	a.mtx.Lock(); defer a.mtx.Unlock()
-
-    bestReach := 0
-    var bestScore addressPrio
-    var bestAddr *NetAddress
-    for _, la := range a.localAddresses {
-        reach := rna.ReachabilityTo(la.Addr)
-        if reach > bestReach ||
-            (reach == bestReach && la.Score > bestScore) {
-            bestReach = reach
-            bestScore = la.Score
-            bestAddr = la.Addr
-        }
-    }
-    if bestAddr != nil {
-        log.Debugf("Suggesting address %s:%d for %s:%d",
-            bestAddr.IP, bestAddr.Port, rna.IP, rna.Port)
-    } else {
-        log.Debugf("No worthy address for %s:%d",
-            rna.IP, rna.Port)
-        // Send something unroutable if nothing suitable.
-        bestAddr = &NetAddress{
-            IP:        net.IP([]byte{0, 0, 0, 0}),
-            Port:      0,
-        }
-    }
-
-    return bestAddr
-}
-
-
 // Return a string representing the network group of this address.
 // This is the /16 for IPv6, the /32 (/36 for he.net) for IPv6, the string
 // "local" for a local address and the string "unroutable for an unroutable

peer/client.go

@@ -3,153 +3,169 @@ package peer
 import (
     . "github.com/tendermint/tendermint/binary"
     "github.com/tendermint/tendermint/merkle"
+    "atomic"
     "sync"
     "io"
+    "errors"
 )
 
-/* Client */
+/*  Client
+
+    A client is half of a p2p system.
+    It can reach out to the network and establish connections with servers.
+    A client doesn't listen for incoming connections -- that's done by the server.
+
+    newPeerCb is a factory method for generating new peers from new *Connections.
+    newPeerCb(nil) must return a prototypical peer that represents the self "peer".
+
+    XXX what about peer disconnects?
+*/
 type Client struct {
-    listener        *Listener
     addrBook        AddrBook
-    strategies      map[String]*FilterStrategy
     targetNumPeers  int
+    newPeerCb       func(*Connection) *Peer
+    self            *Peer
+    inQueues        map[String]chan *InboundMsg
 
-    peersMtx        sync.Mutex
+    mtx             sync.Mutex
     peers           merkle.Tree // addr -> *Peer
-
-    filtersMtx      sync.Mutex
-    filters         merkle.Tree // channelName -> Filter (objects that I know of)
+    quit            chan struct{}
+    stopped         uint32
 }
 
-func NewClient(protocol string, laddr string) *Client {
-    // XXX set the handler
-    listener := NewListener(protocol, laddr, nil)
+var (
+    CLIENT_STOPPED_ERROR =          errors.New("Client already stopped")
+    CLIENT_DUPLICATE_PEER_ERROR =   errors.New("Duplicate peer")
+)
+
+func NewClient(newPeerCb func(*Connect) *Peer) *Client {
+    self := newPeerCb(nil)
+    if self == nil {
+        Panicf("newPeerCb(nil) must return a prototypical peer for self")
+    }
+
+    inQueues := make(map[String]chan *InboundMsg)
+    for chName, channel := peer.channels {
+        inQueues[chName] = make(chan *InboundMsg)
+    }
+
     c := &Client{
-        listener:   listener,
+        newPeerCb:  newPeerCb,
         peers:      merkle.NewIAVLTree(nil),
-        filters:    merkle.NewIAVLTree(nil),
+        self:       self,
+        inQueues:   inQueues,
     }
     return c
 }
 
-func (c *Client) Start() (<-chan *IncomingMsg) {
-    return nil
-}
-
 func (c *Client) Stop() {
-    c.listener.Close()
-}
-
-func (c *Client) LocalAddress() *NetAddress {
-    return c.listener.LocalAddress()
+    // lock
+    c.mtx.Lock()
+    if atomic.CompareAndSwapUint32(&c.stopped, 0, 1) {
+        close(c.quit)
+        // stop each peer.
+        for peerValue := range c.peers.Values() {
+            peer := peerValue.(*Peer)
+            peer.Stop()
+        }
+        // empty tree.
+        c.peers = merkle.NewIAVLTree(nil)
+    }
+    c.mtx.Unlock()
+    // unlock
 }
 
-func (c *Client) ConnectTo(addr *NetAddress) (*Peer, error) {
+func (c *Client) AddPeerWithConnection(conn *Connection, outgoing bool) (*Peer, error) {
+    if atomic.LoadUint32(&c.stopped) == 1 { return nil, CLIENT_STOPPED_ERROR }
 
-    conn, err := addr.Dial()
+    peer := c.newPeerCb(conn)
+    peer.outgoing = outgoing
+    err := c.addPeer(peer)
     if err != nil { return nil, err }
-    peer := NewPeer(conn)
 
-    // lock
-    c.peersMtx.Lock()
-    c.peers.Put(addr, peer)
-    c.peersMtx.Unlock()
-    // unlock
+    go peer.Start(c.inQueues)
 
     return peer, nil
 }
 
-func (c *Client) Broadcast(channel String, msg Binary) {
+func (c *Client) Broadcast(chName String, msg Msg) {
+    if atomic.LoadUint32(&c.stopped) == 1 { return }
+
     for v := range c.peersCopy().Values() {
-        peer, ok := v.(*Peer)
-        if !ok { panic("Expected peer but got something else") }
-        peer.Queue(channel, msg)
+        peer := v.(*Peer)
+        success := peer.TryQueueOut(chName , msg)
+        if !success {
+            // TODO: notify the peer
+        }
     }
 }
 
-// Updates the client's filter for a channel & broadcasts it.
-func (c *Client) UpdateFilter(channel String, filter Filter) {
-    c.filtersMtx.Lock()
-    c.filters.Put(channel, filter)
-    c.filtersMtx.Unlock()
-
-    c.Broadcast("", &NewFilterMsg{
-        Channel:    channel,
-        Filter:     filter,
-    })
-}
-
-func (c *Client) peersCopy() merkle.Tree {
-    c.peersMtx.Lock(); defer c.peersMtx.Unlock()
-    return c.peers.Copy()
-}
-
-
-/* Channel */
-type Channel struct {
-    Name            String
-    Filter          Filter
-    //Stats           Stats
-}
-
-
-/* Peer */
-type Peer struct {
-    Conn            *Connection
-    Channels        map[String]*Channel
-}
-
-func NewPeer(conn *Connection) *Peer {
-    return &Peer{
-        Conn:       conn,
-        Channels:   nil,
+func (c *Client) PopMessage(chName String) *InboundMsg {
+    if atomic.LoadUint32(&c.stopped) == 1 { return nil }
+
+    channel := c.Channel(chName)
+    q := c.inQueues[chName]
+    if q == nil { Panicf("Expected inQueues[%f], found none", chName) }
+
+    for {
+        select {
+        case <-quit:
+            return nil
+        case msg := <-q:
+            // skip if known.
+            if channel.Filter().Has(msg) {
+                continue
+            }
+            return msg
+        }
     }
 }
 
-// Must be quick and nonblocking.
-func (p *Peer) Queue(channel String, msg Binary) {}
-
-func (p *Peer) WriteTo(w io.Writer) (n int64, err error) {
-    return 0, nil // TODO
-}
+// Updates self's filter for a channel & broadcasts it.
+// TODO: maybe don't expose this
+func (c *Client) UpdateFilter(chName String, filter Filter) {
+    if atomic.LoadUint32(&c.stopped) == 1 { return }
 
+    c.self.Channel(chName).UpdateFilter(filter)
 
-/* IncomingMsg */
-type IncomingMsg struct {
-    SPeer           *Peer
-    SChan           *Channel
-
-    Time            Time
-
-    Msg             Binary
+    c.Broadcast("", &NewFilterMsg{
+        Channel:    chName,
+        Filter:     filter,
+    })
 }
 
+func (c *Client) StopPeer(peer *Peer) {
+    // lock
+    c.mtx.Lock()
+    p, _ := c.peers.Remove(peer.RemoteAddress())
+    c.mtx.Unlock()
+    // unlock
 
-/*  Filter
-
-    A Filter could be a bloom filter for lossy filtering, or could be a lossless filter.
-    Either way, it's used to keep track of what a peer knows of.
-*/
-type Filter interface {
-    Binary
-    Add(ByteSlice)
-    Has(ByteSlice) bool
+    if p != nil {
+        p.Stop()
+    }
 }
 
-/* FilterStrategy
+func (c *Client) addPeer(peer *Peer) error {
+    addr := peer.RemoteAddress()
 
-    Defines how filters are generated per peer, and whether they need to get refreshed occasionally.
-*/
-type FilterStrategy interface {
-    LoadFilter(ByteSlice) Filter
-}
-
-/* NewFilterMsg */
-type NewFilterMsg struct {
-    Channel         String
-    Filter          Filter
+    // lock & defer
+    c.mtx.Lock(); defer c.mtx.Unlock()
+    if c.stopped == 1 { return CLIENT_STOPPED_ERROR }
+    if !c.peers.Has(addr) {
+        c.peers.Put(addr, peer)
+        return nil
+    } else {
+        // ignore duplicate peer for addr.
+        log.Infof("Ignoring duplicate peer for addr %v", addr)
+        return CLIENT_DUPLICATE_PEER_ERROR
+    }
+    // unlock deferred
 }
 
-func (m *NewFilterMsg) WriteTo(w io.Writer) (int64, error) {
-    return 0, nil // TODO
+func (c *Client) peersCopy() merkle.Tree {
+    // lock & defer
+    c.mtx.Lock(); defer c.mtx.Unlock()
+    return c.peers.Copy()
+    // unlock deferred
 }

peer/connection.go

@@ -3,6 +3,7 @@ package peer
 import (
     . "github.com/tendermint/tendermint/common"
     . "github.com/tendermint/tendermint/binary"
+    "atomic"
     "sync"
     "net"
     "runtime"
@@ -20,12 +21,10 @@ const (
 type Connection struct {
     ioStats         IOStats
 
-    mtx             sync.Mutex
-    outQueue        chan ByteSlice
+    outQueue        chan ByteSlice // never closes.
     conn            net.Conn
     quit            chan struct{}
-    disconnected    bool
-
+    stopped         int32
     pingDebouncer   *Debouncer
     pong            chan struct{}
 }
@@ -46,13 +45,14 @@ func NewConnection(conn net.Conn) *Connection {
     }
 }
 
-func (c *Connection) QueueMessage(msg ByteSlice) bool {
-    c.mtx.Lock(); defer c.mtx.Unlock()
-    if c.disconnected { return false }
+// returns true if successfully queued,
+// returns false if connection was closed.
+// blocks.
+func (c *Connection) QueueOut(msg ByteSlice) bool {
     select {
     case c.outQueue <- msg:
         return true
-    default: // buffer full
+    case <-c.quit:
         return false
     }
 }
@@ -62,13 +62,25 @@ func (c *Connection) Start() {
     go c.inHandler()
 }
 
-func (c *Connection) Disconnect() {
-    c.mtx.Lock(); defer c.mtx.Unlock()
-    close(c.quit)
-    c.conn.Close()
-    c.pingDebouncer.Stop()
-    // do not close c.pong
-    c.disconnected = true
+func (c *Connection) Stop() {
+    if atomic.SwapAndCompare(&c.stopped, 0, 1) {
+        close(c.quit)
+        c.conn.Close()
+        c.pingDebouncer.Stop()
+        // We can't close pong safely here because
+        // inHandler may write to it after we've stopped.
+        // Though it doesn't need to get closed at all,
+        // we close it @ inHandler.
+        // close(c.pong)
+    }
+}
+
+func (c *Connection) LocalAddress() *NetAddress {
+    return NewNetAddress(c.conn.LocalAddr())
+}
+
+func (c *Connection) RemoteAddress() *NetAddress {
+    return NewNetAddress(c.conn.RemoteAddr())
 }
 
 func (c *Connection) flush() {
@@ -79,41 +91,42 @@ func (c *Connection) outHandler() {
 
     FOR_LOOP:
     for {
+        var err error
         select {
         case <-c.pingDebouncer.Ch:
-            PACKET_TYPE_PING.WriteTo(c.conn)
+            _, err = PACKET_TYPE_PING.WriteTo(c.conn)
         case outMsg := <-c.outQueue:
-            _, err := outMsg.WriteTo(c.conn)
-            if err != nil { Panicf("TODO: handle error %v", err) }
+            _, err = outMsg.WriteTo(c.conn)
         case <-c.pong:
-            PACKET_TYPE_PONG.WriteTo(c.conn)
+            _, err = PACKET_TYPE_PONG.WriteTo(c.conn)
         case <-c.quit:
             break FOR_LOOP
         }
+
+        if err != nil {
+            log.Infof("Connection %v failed @ outHandler:\n%v", c, err)
+            c.Stop()
+            break FOR_LOOP
+        }
+
         c.flush()
     }
 
-    // cleanup
-    for _ = range c.outQueue {
-        // do nothing but drain.
-    }
 }
 
 func (c *Connection) inHandler() {
-    defer func() {
-        if e := recover(); e != nil {
-            // Get stack trace
-            buf := make([]byte, 1<<16)
-            runtime.Stack(buf, false)
-            // TODO do proper logging
-            fmt.Printf("Disconnecting due to error:\n\n%v\n", string(buf))
-            c.Disconnect()
-        }
-    }()
 
-    //FOR_LOOP:
+    FOR_LOOP:
     for {
-        msgType := ReadUInt8(c.conn)
+        msgType, err := ReadUInt8Safe(c.conn)
+
+        if err != nil {
+            if atomic.LoadUint32(&c.stopped) != 1 {
+                log.Infof("Connection %v failed @ inHandler", c)
+                c.Stop()
+            }
+            break FOR_LOOP
+        }
 
         switch msgType {
         case PACKET_TYPE_PING:
@@ -121,12 +134,29 @@ func (c *Connection) inHandler() {
         case PACKET_TYPE_PONG:
             // do nothing
         case PACKET_TYPE_MSG:
-            ReadByteSlice(c.conn)
+            msg, err := ReadByteSliceSafe(c.conn)
+            if err != nil {
+                if atomic.LoadUint32(&c.stopped) != 1 {
+                    log.Infof("Connection %v failed @ inHandler", c)
+                    c.Stop()
+                }
+                break FOR_LOOP
+            }
+            // What to do?
+            // TODO
+            
         default:
             Panicf("Unknown message type %v", msgType)
         }
+
         c.pingDebouncer.Reset()
     }
+
+    // cleanup
+    close(c.pong)
+    for _ = range c.pong {
+        // drain
+    }
 }
 
 

peer/connection_test.go

@@ -2,15 +2,50 @@ package peer
 
 import (
     "testing"
+    "time"
 )
 
 func TestLocalConnection(t *testing.T) {
 
-    c1 := NewClient("tcp", ":8080")
-    c2 := NewClient("tcp", ":8081")
+    c1 := NewClient(func(conn *Connection) *Peer {
+        p := &Peer{conn: conn}
 
+        ch1 := NewChannel(String("ch1"),
+                nil,
+                // XXX these channels should be buffered.
+                make(chan ByteSlice),
+                make(chan ByteSlice),
+        )
+
+        ch2 := NewChannel(String("ch2"),
+                nil,
+                make(chan ByteSlice),
+                make(chan ByteSlice),
+        )
+
+        channels := make(map[String]*Channel)
+        channels[ch1.Name] = ch1
+        channels[ch2.Name] = ch2
+        p.channels = channels
+
+        return p
+    })
+
+    // XXX make c2 like c1.
+
+    c2 := NewClient(func(conn *Connection) *Peer {
+        return nil
+    })
+
+    // XXX clients don't have "local addresses"
     c1.ConnectTo(c2.LocalAddress())
 
+    // lets send a message from c1 to c2.
+    c1.Broadcast(String(""), String("message"))
+    time.Sleep(500 * time.Millisecond)
+
+    inMsg := c2.PopMessage()
+
     c1.Stop()
     c2.Stop()
 }

peer/filter.go

@@ -0,0 +1,16 @@
+package peer
+
+/*  Filter
+
+    A Filter could be a bloom filter for lossy filtering, or could be a lossless filter.
+    Either way, it's used to keep track of what a peer knows of.
+*/
+type Filter interface {
+    Binary
+    Add(Msg)
+    Has(Msg)    bool
+
+    // Loads a new filter.
+    // Convenience factory method
+    Load(ByteSlice) Filter
+}

peer/listener.go

@@ -1,60 +1,76 @@
 package peer
 
 import (
-    "sync"
+    "atomic"
     "net"
 )
 
 /* Listener */
 
-type Listener struct {
+type Listener interface {
+    Connections()   <-chan *Connection
+    LocalAddress()  *NetAddress
+    Stop()
+}
+
+
+/* DefaultListener */
+
+type DefaultListener struct {
     listener        net.Listener
-    handler         func(net.Conn)
-    mtx             sync.Mutex
-    closed          bool
+    connections     chan *Connection
+    stopped         uint32
 }
 
-func NewListener(protocol string, laddr string, handler func(net.Conn)) *Listener {
+const (
+    DEFAULT_BUFFERED_CONNECTIONS = 10
+)
+
+func NewListener(protocol string, laddr string) *Listener {
     ln, err := net.Listen(protocol, laddr)
     if err != nil { panic(err) }
 
     s := &Listener{
-        listener:   ln,
-        handler:    handler,
+        listener:       ln,
+        connections:    make(chan *Connection, DEFAULT_BUFFERED_CONNECTIONS),
     }
 
-    go s.listen()
+    go l.listenHandler()
 
     return s
 }
 
-func (s *Listener) listen() {
+func (l *Listener) listenHandler() {
     for {
-        conn, err := s.listener.Accept()
-        if err != nil {
-            // lock & defer
-            s.mtx.Lock(); defer s.mtx.Unlock()
-            if s.closed {
-                return
-            } else {
-                panic(err)
-            }
-            // unlock (deferred)
-        }
-
-        go s.handler(conn)
+        conn, err := l.listener.Accept()
+
+        if atomic.LoadUint32(&l.stopped) == 1 { return }
+
+        // listener wasn't stopped,
+        // yet we encountered an error.
+        if err != nil { panic(err) }
+
+        c := NewConnection(con)
+        l.connections <- c
+    }
+
+    // cleanup
+    close(l.connections)
+    for _ = range l.connections {
+        // drain
     }
 }
 
-func (s *Listener) LocalAddress() *NetAddress {
-    return NewNetAddress(s.listener.Addr())
+func (l *Listener) Connections() <-chan *Connection {
+    return l.connections
 }
 
-func (s *Listener) Close() {
-    // lock
-    s.mtx.Lock()
-    s.closed = true
-    s.mtx.Unlock()
-    // unlock
-    s.listener.Close()
+func (l *Listener) LocalAddress() *NetAddress {
+    return NewNetAddress(l.listener.Addr())
+}
+
+func (l *Listener) Stop() {
+    if atomic.CompareAndSwapUint32(&l.stopped, 0, 1) {
+        l.listener.Close()
+    }
 }

peer/msg.go

@@ -0,0 +1,30 @@
+package peer
+
+/* Msg */
+
+type Msg struct {
+    Bytes       ByteSlice
+    Hash        ByteSlice
+}
+
+
+/* InboundMsg */
+
+type InboundMsg struct {
+    Peer        *Peer
+    Channel     *Channel
+    Time        Time
+    Msg
+}
+
+
+/* NewFilterMsg */
+
+type NewFilterMsg struct {
+    ChName          String
+    Filter          Filter
+}
+
+func (m *NewFilterMsg) WriteTo(w io.Writer) (int64, error) {
+    return 0, nil // TODO
+}

peer/peer.go

@@ -1,715 +1,182 @@
 package peer
 
 import (
-    "bytes"
-    "container/list"
-    "fmt"
-    "github.com/davecgh/go-spew/spew"
-    "github.com/tendermint/btcwire"
-    "net"
-    "strconv"
+    "atomic"
     "sync"
-    "sync/atomic"
-    "time"
 )
 
-const (
-    // max protocol version the peer supports.
-    maxProtocolVersion = 70001
+/* Peer */
 
-    // number of elements the output channels use.
-    outputBufferSize = 50
+type Peer struct {
+    outgoing        bool
+    conn            *Connection
+    channels        map[String]*Channel
 
-    // number of seconds of inactivity before we timeout a peer
-    // that hasn't completed the initial version negotiation.
-    negotiateTimeoutSeconds = 30
-
-    // number of minutes of inactivity before we time out a peer.
-    idleTimeoutMinutes = 5
-
-    // number of minutes since we last sent a message
-    // requiring a reply before we will ping a host.
-    pingTimeoutMinutes = 2
-)
-
-var (
-    userAgentName = "tendermintd"
-    userAgentVersion = fmt.Sprintf("%d.%d.%d", appMajor, appMinor, appPatch)
-)
-
-// zeroHash is the zero value hash (all zeros).  It is defined as a convenience.
-var zeroHash btcwire.ShaHash
-
-// minUint32 is a helper function to return the minimum of two uint32s.
-// This avoids a math import and the need to cast to floats.
-func minUint32(a, b uint32) uint32 {
-    if a < b {
-        return a
-    }
-    return b
-}
-
-// TODO(davec): Rename and comment this
-type outMsg struct {
-    msg      btcwire.Message
-    doneChan chan bool
-}
-
-/*
-The overall data flow is split into 2 goroutines.
-
-Inbound messages are read via the inHandler goroutine and generally
-dispatched to their own handler.
-
-Outbound messages are queued via QueueMessage.
-*/
-type peer struct {
-    server              *server
-    addr                *NetAddress
-    inbound             bool
-    persistent          bool
-
-    started             bool        // atomic
-    quit                chan bool
-
-    conn                net.Conn
-    connMtx             sync.Mutex
-    disconnected        bool        // atomic && protected by connMtx
-    knownAddresses      map[string]bool
-    outputQueue         chan outMsg
-
-    statMtx             sync.Mutex  // protects all below here.
-    protocolVersion     uint32
-    timeConnected       time.Time
-    lastSend            time.Time
-    lastRecv            time.Time
-    bytesReceived       uint64
-    bytesSent           uint64
-    userAgent           string
-    lastPingNonce       uint64      // Set to nonce if we have a pending ping.
-    lastPingTime        time.Time   // Time we sent last ping.
-    lastPingMicros      int64       // Time for last ping to return.
-}
-
-// String returns the peer's address and directionality as a human-readable
-// string.
-func (p *peer) String() string {
-    return fmt.Sprintf("%s (%s)", p.addr.String(), directionString(p.inbound))
-}
-
-// VersionKnown returns the whether or not the version of a peer is known locally.
-// It is safe for concurrent access.
-func (p *peer) VersionKnown() bool {
-    p.statMtx.Lock(); defer p.statMtx.Unlock()
-
-    return p.protocolVersion != 0
-}
-
-// ProtocolVersion returns the peer protocol version in a manner that is safe
-// for concurrent access.
-func (p *peer) ProtocolVersion() uint32 {
-    p.statMtx.Lock(); defer p.statMtx.Unlock()
-
-    return p.protocolVersion
-}
-
-// pushVersionMsg sends a version message to the connected peer using the
-// current state.
-func (p *peer) pushVersionMsg() {
-    _, blockNum, err := p.server.db.NewestSha()
-    if err != nil { panic(err) }
-
-    // Version message.
-    // TODO: DisableListen -> send zero address
-    msg := btcwire.NewMsgVersion(
-        p.server.addrManager.getBestLocalAddress(p.addr), p.addr,
-        p.server.nonce, int32(blockNum))
-    msg.AddUserAgent(userAgentName, userAgentVersion)
-
-    // Advertise our max supported protocol version.
-    msg.ProtocolVersion = maxProtocolVersion
-
-    p.QueueMessage(msg, nil)
+    mtx             sync.Mutex
+    quit            chan struct{}
+    stopped         uint32
 }
 
-// handleVersionMsg is invoked when a peer receives a version bitcoin message
-// and is used to negotiate the protocol version details as well as kick start
-// the communications.
-func (p *peer) handleVersionMsg(msg *btcwire.MsgVersion) {
-    // Detect self connections.
-    if msg.Nonce == p.server.nonce {
-        peerLog.Debugf("Disconnecting peer connected to self %s", p)
-        p.Disconnect()
-        return
-    }
-
-    p.statMtx.Lock() // Updating a bunch of stats.
-    // Limit to one version message per peer.
-    if p.protocolVersion != 0 {
-        p.logError("Only one version message per peer is allowed %s.", p)
-        p.statMtx.Unlock()
-        p.Disconnect()
-        return
+func (p *Peer) Start(peerInQueues map[String]chan *InboundMsg ) {
+    for chName, _ := range p.channels {
+        go p.inHandler(chName, peerInQueues[chName])
+        go p.outHandler(chName)
     }
-
-    // Negotiate the protocol version.
-    p.protocolVersion = minUint32(p.protocolVersion, uint32(msg.ProtocolVersion))
-    peerLog.Debugf("Negotiated protocol version %d for peer %s", p.protocolVersion, p)
-
-    // Set the remote peer's user agent.
-    p.userAgent = msg.UserAgent
-
-    p.statMtx.Unlock()
-
-    // Inbound connections.
-    if p.inbound {
-        // Send version.
-        p.pushVersionMsg()
-    }
-
-    // Send verack.
-    p.QueueMessage(btcwire.NewMsgVerAck(), nil)
-
-    if p.inbound {
-        // A peer might not be advertising the same address that it
-        // actually connected from.  One example of why this can happen
-        // is with NAT.  Only add the address to the address manager if
-        // the addresses agree.
-        if msg.AddrMe.String() == p.addr.String() {
-            p.server.addrManager.AddAddress(p.addr, p.addr)
-        }
-    } else {
-        // Request known addresses from the remote peer.
-        if !cfg.SimNet && p.server.addrManager.NeedMoreAddresses() {
-            p.QueueMessage(btcwire.NewMsgGetAddr(), nil)
-        }
-    }
-
-    // Mark the address as a known good address.
-    p.server.addrManager.MarkGood(p.addr)
-
-    // Signal the block manager this peer is a new sync candidate.
-    p.server.blockManager.NewPeer(p)
-
-    // TODO: Relay alerts.
 }
 
-
-// handleGetAddrMsg is invoked when a peer receives a getaddr bitcoin message
-// and is used to provide the peer with known addresses from the address
-// manager.
-func (p *peer) handleGetAddrMsg(msg *btcwire.MsgGetAddr) {
-    // Don't return any addresses when running on the simulation test
-    // network.  This helps prevent the network from becoming another
-    // public test network since it will not be able to learn about other
-    // peers that have not specifically been provided.
-    if cfg.SimNet {
-        return
+func (p *Peer) Stop() {
+    // lock
+    p.mtx.Lock()
+    if atomic.CompareAndSwapUint32(&p.stopped, 0, 1) {
+        close(p.quit)
+        p.conn.Stop()
     }
-
-    // Get the current known addresses from the address manager.
-    addrCache := p.server.addrManager.AddressCache()
-
-    // Push the addresses.
-    p.pushAddrMsg(addrCache)
+    p.mtx.Unlock()
+    // unlock
 }
 
-// pushAddrMsg sends one, or more, addr message(s) to the connected peer using
-// the provided addresses.
-func (p *peer) pushAddrMsg(addresses []*NetAddress) {
-    // Nothing to send.
-    if len(addresses) == 0 { return }
-
-    numAdded := 0
-    msg := btcwire.NewMsgAddr()
-    for _, addr := range addresses {
-        // Filter addresses the peer already knows about.
-        if p.knownAddresses[addr.String()] {
-            continue
-        }
-
-        // Add the address to the message.
-        err := msg.AddAddress(addr)
-        if err != nil { panic(err) } // XXX remove error condition
-        numAdded++
-
-        // Split into multiple messages as needed.
-        if numAdded > 0 && numAdded%btcwire.MaxAddrPerMsg == 0 {
-            p.QueueMessage(msg, nil)
-
-            // NOTE: This needs to be a new address message and not
-            // simply call ClearAddresses since the message is a
-            // pointer and queueing it does not make a copy.
-            msg = btcwire.NewMsgAddr()
-        }
-    }
-
-    // Send message with remaining addresses if needed.
-    if numAdded%btcwire.MaxAddrPerMsg != 0 {
-        p.QueueMessage(msg, nil)
-    }
+func (p *Peer) LocalAddress() *NetAddress {
+    return p.conn.LocalAddress()
 }
 
-// handleAddrMsg is invoked when a peer receives an addr bitcoin message and
-// is used to notify the server about advertised addresses.
-func (p *peer) handleAddrMsg(msg *btcwire.MsgAddr) {
-    // Ignore addresses when running on the simulation test network.  This
-    // helps prevent the network from becoming another public test network
-    // since it will not be able to learn about other peers that have not
-    // specifically been provided.
-    if cfg.SimNet {
-        return
-    }
-
-    // A message that has no addresses is invalid.
-    if len(msg.AddrList) == 0 {
-        p.logError("Command [%s] from %s does not contain any addresses", msg.Command(), p)
-        p.Disconnect()
-        return
-    }
-
-    for _, addr := range msg.AddrList {
-        // Set the timestamp to 5 days ago if it's more than 24 hours
-        // in the future so this address is one of the first to be
-        // removed when space is needed.
-        now := time.Now()
-        if addr.Timestamp.After(now.Add(time.Minute * 10)) {
-            addr.Timestamp = now.Add(-1 * time.Hour * 24 * 5)
-        }
-
-        // Add address to known addresses for this peer.
-        p.knownAddresses[addr.String()] = true
-    }
-
-    // Add addresses to server address manager.  The address manager handles
-    // the details of things such as preventing duplicate addresses, max
-    // addresses, and last seen updates.
-    // XXX bitcoind gives a 2 hour time penalty here, do we want to do the
-    // same?
-    p.server.addrManager.AddAddresses(msg.AddrList, p.addr)
+func (p *Peer) RemoteAddress() *NetAddress {
+    return p.conn.RemoteAddress()
 }
 
-func (p *peer) handlePingMsg(msg *btcwire.MsgPing) {
-    // Include nonce from ping so pong can be identified.
-    p.QueueMessage(btcwire.NewMsgPong(msg.Nonce), nil)
+func (p *Peer) Channel(chName String) *Channel {
+    return p.channels[chName]
 }
 
-func (p *peer) handlePongMsg(msg *btcwire.MsgPong) {
-    p.statMtx.Lock(); defer p.statMtx.Unlock()
+// If msg isn't already in the peer's filter, then
+// queue the msg for output.
+// If the queue is full, just return false.
+func (p *Peer) TryQueueOut(chName String, msg Msg) bool {
+    channel := p.Channel(chName)
+    outQueue := channel.OutQueue()
 
-    // Arguably we could use a buffered channel here sending data
-    // in a fifo manner whenever we send a ping, or a list keeping track of
-    // the times of each ping. For now we just make a best effort and
-    // only record stats if it was for the last ping sent. Any preceding
-    // and overlapping pings will be ignored. It is unlikely to occur
-    // without large usage of the ping rpc call since we ping
-    // infrequently enough that if they overlap we would have timed out
-    // the peer.
-    if p.lastPingNonce != 0 && msg.Nonce == p.lastPingNonce {
-        p.lastPingMicros = time.Now().Sub(p.lastPingTime).Nanoseconds()
-        p.lastPingMicros /= 1000 // convert to usec.
-        p.lastPingNonce = 0
+    // just return if already in filter
+    if channel.Filter().Has(msg) {
+        return true
     }
-}
 
-// readMessage reads the next bitcoin message from the peer with logging.
-func (p *peer) readMessage() (btcwire.Message, []byte, error) {
-    n, msg, buf, err := btcwire.ReadMessageN(p.conn, p.ProtocolVersion())
-    p.statMtx.Lock()
-    p.bytesReceived += uint64(n)
-    p.statMtx.Unlock()
-    p.server.AddBytesReceived(uint64(n))
-    if err != nil {
-        return nil, nil, err
+    // lock & defer
+    p.mtx.Lock(); defer p.mtx.Unlock()
+    if p.stopped == 1 { return false }
+    select {
+    case outQueue <- msg:
+        return true
+    default: // buffer full
+        return false
     }
-
-    // Use closures to log expensive operations so they are only run when
-    // the logging level requires it.
-    peerLog.Debugf("%v", newLogClosure(func() string {
-        // Debug summary of message.
-        summary := messageSummary(msg)
-        if len(summary) > 0 {
-            summary = " (" + summary + ")"
-        }
-        return fmt.Sprintf("Received %v%s from %s", msg.Command(), summary, p)
-    }))
-    peerLog.Tracef("%v", newLogClosure(func() string {
-        return spew.Sdump(msg)
-    }))
-    peerLog.Tracef("%v", newLogClosure(func() string {
-        return spew.Sdump(buf)
-    }))
-
-    return msg, buf, nil
+    // unlock deferred
 }
 
-// writeMessage sends a bitcoin Message to the peer with logging.
-func (p *peer) writeMessage(msg btcwire.Message) {
-    if p.Disconnected() { return }
-
-    if !p.VersionKnown() {
-        switch msg.(type) {
-        case *btcwire.MsgVersion:
-            // This is OK.
-        default:
-            // We drop all messages other than version if we
-            // haven't done the handshake already.
-            return
-        }
-    }
-
-    // Use closures to log expensive operations so they are only run when
-    // the logging level requires it.
-    peerLog.Debugf("%v", newLogClosure(func() string {
-        // Debug summary of message.
-        summary := messageSummary(msg)
-        if len(summary) > 0 {
-            summary = " (" + summary + ")"
-        }
-        return fmt.Sprintf("Sending %v%s to %s", msg.Command(), summary, p)
-    }))
-    peerLog.Tracef("%v", newLogClosure(func() string {
-        return spew.Sdump(msg)
-    }))
-    peerLog.Tracef("%v", newLogClosure(func() string {
-        var buf bytes.Buffer
-        err := btcwire.WriteMessage(&buf, msg, p.ProtocolVersion())
-        if err != nil {
-            return err.Error()
-        }
-        return spew.Sdump(buf.Bytes())
-    }))
-
-    // Write the message to the peer.
-    n, err := btcwire.WriteMessageN(p.conn, msg, p.ProtocolVersion())
-    p.statMtx.Lock()
-    p.bytesSent += uint64(n)
-    p.statMtx.Unlock()
-    p.server.AddBytesSent(uint64(n))
-    if err != nil {
-        p.Disconnect()
-        p.logError("Can't send message to %s: %v", p, err)
-        return
-    }
+func (p *Peer) WriteTo(w io.Writer) (n int64, err error) {
+    return p.RemoteAddress().WriteTo(w)
 }
 
+func (p *Peer) inHandler(chName String, inboundMsgQueue chan<- *InboundMsg) {
+    channel := p.channels[chName]
+    inQueue := channel.InQueue()
 
-// inHandler handles all incoming messages for the peer.  It must be run as a
-// goroutine.
-func (p *peer) inHandler() {
-    // Peers must complete the initial version negotiation within a shorter
-    // timeframe than a general idle timeout.  The timer is then reset below
-    // to idleTimeoutMinutes for all future messages.
-    idleTimer := time.AfterFunc(negotiateTimeoutSeconds*time.Second, func() {
-        if p.VersionKnown() {
-            peerLog.Warnf("Peer %s no answer for %d minutes, disconnecting", p, idleTimeoutMinutes)
-        }
-        p.Disconnect()
-    })
-out:
-    for !p.Disconnected() {
-        rmsg, buf, err := p.readMessage()
-        // Stop the timer now, if we go around again we will reset it.
-        idleTimer.Stop()
-        if err != nil {
-            if !p.Disconnected() {
-                p.logError("Can't read message from %s: %v", p, err)
+    FOR_LOOP:
+    for {
+        select {
+        case <-quit:
+            break FOR_LOOP
+        case msg := <-inQueue:
+            // add to channel filter
+            channel.Filter().Add(msg)
+            // send to inboundMsgQueue
+            inboundMsg := &InboundMsg{
+                Peer:       p,
+                Channel:    channel,
+                Time:       Time(time.Now()),
+                Msg:        msg,
             }
-            break out
-        }
-        p.statMtx.Lock()
-        p.lastRecv = time.Now()
-        p.statMtx.Unlock()
-
-        // Ensure version message comes first.
-        if _, ok := rmsg.(*btcwire.MsgVersion); !ok && !p.VersionKnown() {
-            p.logError("A version message must precede all others")
-            break out
-        }
-
-        // Handle each supported message type.
-        markGood := false
-        switch msg := rmsg.(type) {
-        case *btcwire.MsgVersion:
-            p.handleVersionMsg(msg)
-
-        case *btcwire.MsgVerAck:
-            // Do nothing.
-
-        case *btcwire.MsgGetAddr:
-            p.handleGetAddrMsg(msg)
-
-        case *btcwire.MsgAddr:
-            p.handleAddrMsg(msg)
-            markGood = true
-
-        case *btcwire.MsgPing:
-            p.handlePingMsg(msg)
-            markGood = true
-
-        case *btcwire.MsgPong:
-            p.handlePongMsg(msg)
-
-        case *btcwire.MsgAlert:
-            p.server.BroadcastMessage(msg, p)
-
-        case *btcwire.MsgNotFound:
-            // TODO(davec): Ignore this for now, but ultimately
-            // it should probably be used to detect when something
-            // we requested needs to be re-requested from another
-            // peer.
-
-        default:
-            peerLog.Debugf("Received unhandled message of type %v: Fix Me", rmsg.Command())
-        }
-
-        // Mark the address as currently connected and working as of
-        // now if one of the messages that trigger it was processed.
-        if markGood && !p.Disconnected() {
-            if p.addr == nil {
-                peerLog.Warnf("we're getting stuff before we got a version message. that's bad")
+            select {
+            case <-quit:
+                break FOR_LOOP
+            case inboundMsgQueue <- inboundMsg:
                 continue
             }
-            p.server.addrManager.MarkGood(p.addr)
         }
-        // ok we got a message, reset the timer.
-        // timer just calls p.Disconnect() after logging.
-        idleTimer.Reset(idleTimeoutMinutes * time.Minute)
     }
 
-    idleTimer.Stop()
-
-    // Ensure connection is closed and notify the server that the peer is done.
-    p.Disconnect()
-    p.server.donePeers <- p
-
-    // Only tell block manager we are gone if we ever told it we existed.
-    if p.VersionKnown() {
-        p.server.blockManager.DonePeer(p)
-    }
-
-    peerLog.Tracef("Peer input handler done for %s", p)
+    // cleanup
+    // (none)
 }
 
-// outHandler handles all outgoing messages for the peer.  It must be run as a
-// goroutine.  It uses a buffered channel to serialize output messages while
-// allowing the sender to continue running asynchronously.
-func (p *peer) outHandler() {
-    pingTimer := time.AfterFunc(pingTimeoutMinutes*time.Minute, func() {
-        nonce, err := btcwire.RandomUint64()
-        if err != nil {
-            peerLog.Errorf("Not sending ping on timeout to %s: %v",
-                p, err)
-            return
-        }
-        p.QueueMessage(btcwire.NewMsgPing(nonce), nil)
-    })
-out:
+func (p *Peer) outHandler(chName String) {
+    outQueue := p.channels[chName].OutQueue()
+    FOR_LOOP:
     for {
         select {
-        case msg := <-p.outputQueue:
-            // If the message is one we should get a reply for
-            // then reset the timer, we only want to send pings
-            // when otherwise we would not receive a reply from
-            // the peer.
-            peerLog.Tracef("%s: received from outputQueue", p)
-            reset := true
-            switch m := msg.msg.(type) {
-            case *btcwire.MsgVersion:
-                // should get an ack
-            case *btcwire.MsgGetAddr:
-                // should get addresses
-            case *btcwire.MsgPing:
-                // expects pong
-                // Also set up statistics.
-                p.statMtx.Lock()
-                p.lastPingNonce = m.Nonce
-                p.lastPingTime = time.Now()
-                p.statMtx.Unlock()
-            default:
-                // Not one of the above, no sure reply.
-                // We want to ping if nothing else
-                // interesting happens.
-                reset = false
-            }
-            if reset {
-                pingTimer.Reset(pingTimeoutMinutes * time.Minute)
-            }
-            p.writeMessage(msg.msg)
-            p.statMtx.Lock()
-            p.lastSend = time.Now()
-            p.statMtx.Unlock()
-            if msg.doneChan != nil {
-                msg.doneChan <- true
-            }
-
-        case <-p.quit:
-            break out
+        case <-quit:
+            break FOR_LOOP
+        case msg := <-outQueue:
+            // blocks until the connection is Stop'd,
+            // which happens when this peer is Stop'd.
+            p.conn.QueueOut(msg.Bytes)
         }
     }
 
-    pingTimer.Stop()
-
-    // Drain outputQueue
-    for msg := range p.outputQueue {
-        if msg.doneChan != nil {
-            msg.doneChan <- false
-        }
-    }
-    peerLog.Tracef("Peer output handler done for %s", p)
+    // cleanup
+    // (none)
 }
 
-// QueueMessage adds the passed bitcoin message to the peer outputQueue.  It
-// uses a buffered channel to communicate with the output handler goroutine so
-// it is automatically rate limited and safe for concurrent access.
-func (p *peer) QueueMessage(msg btcwire.Message, doneChan chan bool) {
-    // Avoid risk of deadlock if goroutine already exited. The goroutine
-    // we will be sending to hangs around until it knows for a fact that
-    // it is marked as disconnected. *then* it drains the channels.
-    if p.Disconnected() {
-        // avoid deadlock...
-        if doneChan != nil {
-            go func() {
-                doneChan <- false
-            }()
-        }
-        return
-    }
-    p.outputQueue <- outMsg{msg: msg, doneChan: doneChan}
-}
 
-// True if is (or will become) disconnected.
-func (p *peer) Disconnected() bool {
-    return atomic.LoadInt32(&p.disconnected) == 1
-}
+/*  Channel */
 
-// Disconnects the peer by closing the connection.  It also sets
-// a flag so the impending shutdown can be detected.
-func (p *peer) Disconnect() {
-    p.connMtx.Lock(); defer p.connMtx.Unlock()
-    // did we win the race?
-    if atomic.AddInt32(&p.disconnected, 1) != 1 {
-        return
-    }
-    peerLog.Tracef("disconnecting %s", p)
-    close(p.quit)
-    if p.conn != nil {
-        p.conn.Close()
-    }
-}
-
-// Sets the connection & starts
-func (p *peer) StartWithConnection(conn *net.Conn) {
-    p.connMtx.Lock(); defer p.connMtx.Unlock()
-    if p.conn != nil { panic("Conn already set") }
-    if atomic.LoadInt32(&p.disconnected) == 1 { return }
-    peerLog.Debugf("Connected to %s", conn.RemoteAddr())
-    p.timeConnected = time.Now()
-    p.conn = conn
-    p.Start()
-}
+type Channel struct {
+    name            String
 
-// Start begins processing input and output messages.  It also sends the initial
-// version message for outbound connections to start the negotiation process.
-func (p *peer) Start() error {
-    // Already started?
-    if atomic.AddInt32(&p.started, 1) != 1 {
-        return nil
-    }
+    mtx             sync.Mutex
+    filter          Filter
 
-    peerLog.Tracef("Starting peer %s", p)
+    inQueue         chan Msg
+    outQueue        chan Msg
+    //stats           Stats
+}
 
-    // Send an initial version message if this is an outbound connection.
-    if !p.inbound {
-        p.pushVersionMsg()
+func NewChannel(name String, filter Filter, in, out chan Msg) *Channel {
+    return &Channel{
+        name:       name,
+        filter:     filter,
+        inQueue:    in,
+        outQueue:   out,
     }
-
-    // Start processing input and output.
-    go p.inHandler()
-    go p.outHandler()
-
-    return nil
 }
 
-// Shutdown gracefully shuts down the peer by disconnecting it.
-func (p *peer) Shutdown() {
-    peerLog.Tracef("Shutdown peer %s", p)
-    p.Disconnect()
+func (c *Channel) InQueue() <-chan Msg {
+    return c.inQueue
 }
 
-// newPeerBase returns a new base peer for the provided server and inbound flag.
-// This is used by the newInboundPeer and newOutboundPeer functions to perform
-// base setup needed by both types of peers.
-func newPeerBase(s *server, inbound bool) *peer {
-    p := peer{
-        server:          s,
-        protocolVersion: maxProtocolVersion,
-        inbound:         inbound,
-        knownAddresses:  make(map[string]bool),
-        outputQueue:     make(chan outMsg, outputBufferSize),
-        quit:            make(chan bool),
-    }
-    return &p
+func (c *Channel) OutQueue() chan<- Msg {
+    return c.outQueue
 }
 
-// newPeer returns a new inbound bitcoin peer for the provided server and
-// connection.  Use Start to begin processing incoming and outgoing messages.
-func newInboundPeer(s *server, conn net.Conn) *peer {
-    addr := NewNetAddress(conn.RemoteAddr())
-    // XXX What if p.addr doesn't match (to be) reported addr due to NAT?
-    s.addrManager.MarkAttempt(addr)
-
-    p := newPeerBase(s, true)
-    p.conn = conn
-    p.addr = addr
-    p.timeConnected = time.Now()
-    return p
+func (c *Channel) Add(msg Msg) {
+    c.Filter().Add(msg)
 }
 
-// newOutbountPeer returns a new outbound bitcoin peer for the provided server and
-// address and connects to it asynchronously. If the connection is successful
-// then the peer will also be started.
-func newOutboundPeer(s *server, addr *NetAddress, persistent bool) *peer {
-    p := newPeerBase(s, false)
-    p.addr = addr
-    p.persistent = persistent
+func (c *Channel) Has(msg Msg) bool {
+    return c.Filter().Has(msg)
+}
 
-    go func() {
-        // Mark this as one attempt, regardless of # of reconnects.
-        s.addrManager.MarkAttempt(p.addr)
-        retryCount := 0
-        // Attempt to connect to the peer.  If the connection fails and
-        // this is a persistent connection, retry after the retry
-        // interval.
-        for {
-            peerLog.Debugf("Attempting to connect to %s", addr)
-            conn, err := addr.Dial()
-            if err == nil {
-                p.StartWithConnection(conn)
-                return
-            } else {
-                retryCount++
-                peerLog.Debugf("Failed to connect to %s: %v", addr, err)
-                if !persistent {
-                    p.server.donePeers <- p
-                    return
-                }
-                scaledInterval := connectionRetryInterval.Nanoseconds() * retryCount / 2
-                scaledDuration := time.Duration(scaledInterval)
-                peerLog.Debugf("Retrying connection to %s in %s", addr, scaledDuration)
-                time.Sleep(scaledDuration)
-                continue
-            }
-        }
-    }()
-    return p
+// TODO: maybe don't expose this
+func (c *Channel) Filter() Filter {
+    // lock & defer
+    c.mtx.Lock(); defer c.mtx.Unlock()
+    return c.filter
+    // unlock deferred
 }
 
-// logError makes sure that we only log errors loudly on user peers.
-func (p *peer) logError(fmt string, args ...interface{}) {
-    if p.persistent {
-        peerLog.Errorf(fmt, args...)
-    } else {
-        peerLog.Debugf(fmt, args...)
-    }
+// TODO: maybe don't expose this
+func (c *Channel) UpdateFilter(filter Filter) {
+    // lock
+    c.mtx.Lock()
+    c.filter = filter
+    c.mtx.Unlock()
+    // unlock
 }

peer/server.go

@@ -0,0 +1,32 @@
+package peer
+
+import (
+)
+
+/* Server */
+
+type Server struct {
+    listener        Listener
+    client          *Client
+}
+
+func NewServer(l Listener, c *Client) *Server {
+    s := &Server{
+        listener:   l,
+        client:     c,
+    }
+    go s.IncomingConnectionsHandler()
+    return s
+}
+
+// meant to run in a goroutine
+func (s *Server) IncomingConnectionHandler() {
+    for conn := range s.listener.Connections() {
+        s.client.AddIncomingConnection(conn)
+    }
+}
+
+func (s *Server) Stop() {
+    s.listener.Stop()
+    s.client.Stop()
+}

peer/upnp.go

@@ -0,0 +1,368 @@
+// from taipei-torrent
+
+package peer
+
+// Just enough UPnP to be able to forward ports
+//
+
+import (
+    "bytes"
+    "encoding/xml"
+    "errors"
+    "io/ioutil"
+    "net"
+    "net/http"
+    "strconv"
+    "strings"
+    "time"
+)
+
+type upnpNAT struct {
+    serviceURL string
+    ourIP      string
+    urnDomain  string
+}
+
+func Discover() (nat NAT, err error) {
+    ssdp, err := net.ResolveUDPAddr("udp4", "239.255.255.250:1900")
+    if err != nil {
+        return
+    }
+    conn, err := net.ListenPacket("udp4", ":0")
+    if err != nil {
+        return
+    }
+    socket := conn.(*net.UDPConn)
+    defer socket.Close()
+
+    err = socket.SetDeadline(time.Now().Add(3 * time.Second))
+    if err != nil {
+        return
+    }
+
+    st := "InternetGatewayDevice:1"
+
+    buf := bytes.NewBufferString(
+        "M-SEARCH * HTTP/1.1\r\n" +
+            "HOST: 239.255.255.250:1900\r\n" +
+            "ST: ssdp:all\r\n" +
+            "MAN: \"ssdp:discover\"\r\n" +
+            "MX: 2\r\n\r\n")
+    message := buf.Bytes()
+    answerBytes := make([]byte, 1024)
+    for i := 0; i < 3; i++ {
+        _, err = socket.WriteToUDP(message, ssdp)
+        if err != nil {
+            return
+        }
+        var n int
+        n, _, err = socket.ReadFromUDP(answerBytes)
+        for {
+            n, _, err = socket.ReadFromUDP(answerBytes)
+            if err != nil {
+                break
+            }
+            answer := string(answerBytes[0:n])
+            if strings.Index(answer, st) < 0 {
+                continue
+            }
+            // HTTP header field names are case-insensitive.
+            // http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2
+            locString := "\r\nlocation:"
+            answer = strings.ToLower(answer)
+            locIndex := strings.Index(answer, locString)
+            if locIndex < 0 {
+                continue
+            }
+            loc := answer[locIndex+len(locString):]
+            endIndex := strings.Index(loc, "\r\n")
+            if endIndex < 0 {
+                continue
+            }
+            locURL := strings.TrimSpace(loc[0:endIndex])
+            var serviceURL, urnDomain string
+            serviceURL, urnDomain, err = getServiceURL(locURL)
+            if err != nil {
+                return
+            }
+            var ourIP net.IP
+            ourIP, err = localIPv4()
+            if err != nil {
+                return
+            }
+            nat = &upnpNAT{serviceURL: serviceURL, ourIP: ourIP.String(), urnDomain: urnDomain}
+            return
+        }
+    }
+    err = errors.New("UPnP port discovery failed.")
+    return
+}
+
+type Envelope struct {
+    XMLName xml.Name `xml:"http://schemas.xmlsoap.org/soap/envelope/ Envelope"`
+    Soap    *SoapBody
+}
+type SoapBody struct {
+    XMLName    xml.Name `xml:"http://schemas.xmlsoap.org/soap/envelope/ Body"`
+    ExternalIP *ExternalIPAddressResponse
+}
+
+type ExternalIPAddressResponse struct {
+    XMLName   xml.Name `xml:"GetExternalIPAddressResponse"`
+    IPAddress string   `xml:"NewExternalIPAddress"`
+}
+
+type ExternalIPAddress struct {
+    XMLName xml.Name `xml:"NewExternalIPAddress"`
+    IP      string
+}
+
+type Service struct {
+    ServiceType string `xml:"serviceType"`
+    ControlURL  string `xml:"controlURL"`
+}
+
+type DeviceList struct {
+    Device []Device `xml:"device"`
+}
+
+type ServiceList struct {
+    Service []Service `xml:"service"`
+}
+
+type Device struct {
+    XMLName     xml.Name    `xml:"device"`
+    DeviceType  string      `xml:"deviceType"`
+    DeviceList  DeviceList  `xml:"deviceList"`
+    ServiceList ServiceList `xml:"serviceList"`
+}
+
+type Root struct {
+    Device Device
+}
+
+func getChildDevice(d *Device, deviceType string) *Device {
+    dl := d.DeviceList.Device
+    for i := 0; i < len(dl); i++ {
+        if strings.Index(dl[i].DeviceType, deviceType) >= 0 {
+            return &dl[i]
+        }
+    }
+    return nil
+}
+
+func getChildService(d *Device, serviceType string) *Service {
+    sl := d.ServiceList.Service
+    for i := 0; i < len(sl); i++ {
+        if strings.Index(sl[i].ServiceType, serviceType) >= 0 {
+            return &sl[i]
+        }
+    }
+    return nil
+}
+
+func localIPv4() (net.IP, error) {
+    tt, err := net.Interfaces()
+    if err != nil {
+        return nil, err
+    }
+    for _, t := range tt {
+        aa, err := t.Addrs()
+        if err != nil {
+            return nil, err
+        }
+        for _, a := range aa {
+            ipnet, ok := a.(*net.IPNet)
+            if !ok {
+                continue
+            }
+            v4 := ipnet.IP.To4()
+            if v4 == nil || v4[0] == 127 { // loopback address
+                continue
+            }
+            return v4, nil
+        }
+    }
+    return nil, errors.New("cannot find local IP address")
+}
+
+func getServiceURL(rootURL string) (url, urnDomain string, err error) {
+    r, err := http.Get(rootURL)
+    if err != nil {
+        return
+    }
+    defer r.Body.Close()
+    if r.StatusCode >= 400 {
+        err = errors.New(string(r.StatusCode))
+        return
+    }
+    var root Root
+    err = xml.NewDecoder(r.Body).Decode(&root)
+    if err != nil {
+        return
+    }
+    a := &root.Device
+    if strings.Index(a.DeviceType, "InternetGatewayDevice:1") < 0 {
+        err = errors.New("No InternetGatewayDevice")
+        return
+    }
+    b := getChildDevice(a, "WANDevice:1")
+    if b == nil {
+        err = errors.New("No WANDevice")
+        return
+    }
+    c := getChildDevice(b, "WANConnectionDevice:1")
+    if c == nil {
+        err = errors.New("No WANConnectionDevice")
+        return
+    }
+    d := getChildService(c, "WANIPConnection:1")
+    if d == nil {
+        // Some routers don't follow the UPnP spec, and put WanIPConnection under WanDevice,
+        // instead of under WanConnectionDevice
+        d = getChildService(b, "WANIPConnection:1")
+
+        if d == nil {
+            err = errors.New("No WANIPConnection")
+            return
+        }
+    }
+    // Extract the domain name, which isn't always 'schemas-upnp-org'
+    urnDomain = strings.Split(d.ServiceType, ":")[1]
+    url = combineURL(rootURL, d.ControlURL)
+    return
+}
+
+func combineURL(rootURL, subURL string) string {
+    protocolEnd := "://"
+    protoEndIndex := strings.Index(rootURL, protocolEnd)
+    a := rootURL[protoEndIndex+len(protocolEnd):]
+    rootIndex := strings.Index(a, "/")
+    return rootURL[0:protoEndIndex+len(protocolEnd)+rootIndex] + subURL
+}
+
+func soapRequest(url, function, message, domain string) (r *http.Response, err error) {
+    fullMessage := "<?xml version=\"1.0\" ?>" +
+        "<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\" s:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\">\r\n" +
+        "<s:Body>" + message + "</s:Body></s:Envelope>"
+
+    req, err := http.NewRequest("POST", url, strings.NewReader(fullMessage))
+    if err != nil {
+        return nil, err
+    }
+    req.Header.Set("Content-Type", "text/xml ; charset=\"utf-8\"")
+    req.Header.Set("User-Agent", "Darwin/10.0.0, UPnP/1.0, MiniUPnPc/1.3")
+    //req.Header.Set("Transfer-Encoding", "chunked")
+    req.Header.Set("SOAPAction", "\"urn:"+domain+":service:WANIPConnection:1#"+function+"\"")
+    req.Header.Set("Connection", "Close")
+    req.Header.Set("Cache-Control", "no-cache")
+    req.Header.Set("Pragma", "no-cache")
+
+    // log.Stderr("soapRequest ", req)
+
+    r, err = http.DefaultClient.Do(req)
+    if err != nil {
+        return nil, err
+    }
+    /*if r.Body != nil {
+        defer r.Body.Close()
+    }*/
+
+    if r.StatusCode >= 400 {
+        // log.Stderr(function, r.StatusCode)
+        err = errors.New("Error " + strconv.Itoa(r.StatusCode) + " for " + function)
+        r = nil
+        return
+    }
+    return
+}
+
+type statusInfo struct {
+    externalIpAddress string
+}
+
+func (n *upnpNAT) getExternalIPAddress() (info statusInfo, err error) {
+
+    message := "<u:GetExternalIPAddress xmlns:u=\"urn:" + n.urnDomain + ":service:WANIPConnection:1\">\r\n" +
+        "</u:GetExternalIPAddress>"
+
+    var response *http.Response
+    response, err = soapRequest(n.serviceURL, "GetExternalIPAddress", message, n.urnDomain)
+    if response != nil {
+        defer response.Body.Close()
+    }
+    if err != nil {
+        return
+    }
+    var envelope Envelope
+    data, err := ioutil.ReadAll(response.Body)
+    reader := bytes.NewReader(data)
+    xml.NewDecoder(reader).Decode(&envelope)
+
+    info = statusInfo{envelope.Soap.ExternalIP.IPAddress}
+
+    if err != nil {
+        return
+    }
+
+    return
+}
+
+func (n *upnpNAT) GetExternalAddress() (addr net.IP, err error) {
+    info, err := n.getExternalIPAddress()
+    if err != nil {
+        return
+    }
+    addr = net.ParseIP(info.externalIpAddress)
+    return
+}
+
+func (n *upnpNAT) AddPortMapping(protocol string, externalPort, internalPort int, description string, timeout int) (mappedExternalPort int, err error) {
+    // A single concatenation would break ARM compilation.
+    message := "<u:AddPortMapping xmlns:u=\"urn:" + n.urnDomain + ":service:WANIPConnection:1\">\r\n" +
+        "<NewRemoteHost></NewRemoteHost><NewExternalPort>" + strconv.Itoa(externalPort)
+    message += "</NewExternalPort><NewProtocol>" + protocol + "</NewProtocol>"
+    message += "<NewInternalPort>" + strconv.Itoa(internalPort) + "</NewInternalPort>" +
+        "<NewInternalClient>" + n.ourIP + "</NewInternalClient>" +
+        "<NewEnabled>1</NewEnabled><NewPortMappingDescription>"
+    message += description +
+        "</NewPortMappingDescription><NewLeaseDuration>" + strconv.Itoa(timeout) +
+        "</NewLeaseDuration></u:AddPortMapping>"
+
+    var response *http.Response
+    response, err = soapRequest(n.serviceURL, "AddPortMapping", message, n.urnDomain)
+    if response != nil {
+        defer response.Body.Close()
+    }
+    if err != nil {
+        return
+    }
+
+    // TODO: check response to see if the port was forwarded
+    // log.Println(message, response)
+    mappedExternalPort = externalPort
+    _ = response
+    return
+}
+
+func (n *upnpNAT) DeletePortMapping(protocol string, externalPort, internalPort int) (err error) {
+
+    message := "<u:DeletePortMapping xmlns:u=\"urn:" + n.urnDomain + ":service:WANIPConnection:1\">\r\n" +
+        "<NewRemoteHost></NewRemoteHost><NewExternalPort>" + strconv.Itoa(externalPort) +
+        "</NewExternalPort><NewProtocol>" + protocol + "</NewProtocol>" +
+        "</u:DeletePortMapping>"
+
+    var response *http.Response
+    response, err = soapRequest(n.serviceURL, "DeletePortMapping", message, n.urnDomain)
+    if response != nil {
+        defer response.Body.Close()
+    }
+    if err != nil {
+        return
+    }
+
+    // TODO: check response to see if the port was deleted
+    // log.Println(message, response)
+    _ = response
+    return
+}