From da2901a4fd0aa5ca055adbede1414d6692b8f5d8 Mon Sep 17 00:00:00 2001
From: "Owain G. Ainsworth" <oga@conformal.com>
Date: Tue, 29 Oct 2013 17:18:53 +0000
Subject: [PATCH] Add support for the addnode command

Currently this acts on the list of all peers, and not just the list of
permanent peers. this will be changed shortly.
---
 rpcserver.go | 25 ++++++++++++++++++++-
 server.go    | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/rpcserver.go b/rpcserver.go
index 9204000b..8d98ca28 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -311,6 +311,7 @@ func jsonRPCRead(w http.ResponseWriter, r *http.Request, s *rpcServer) {
 type commandHandler func(*rpcServer, btcjson.Cmd, chan []byte) (interface{}, error)
 
 var handlers = map[string]commandHandler{
+	"addnode":              handleAddNode,
 	"decoderawtransaction": handleDecodeRawTransaction,
 	"getbestblockhash":     handleGetBestBlockHash,
 	"getblock":             handleGetBlock,
@@ -328,6 +329,28 @@ var handlers = map[string]commandHandler{
 	"stop":                 handleStop,
 }
 
+// handleDecodeRawTransaction handles decoderawtransaction commands.
+func handleAddNode(s *rpcServer, cmd btcjson.Cmd,
+	walletNotification chan []byte) (interface{}, error) {
+	c := cmd.(*btcjson.AddNodeCmd)
+
+	addr := normalizePeerAddress(c.Addr)
+	var err error
+	switch c.SubCmd {
+	case "add":
+		err = s.server.AddAddr(addr, true)
+	case "remove":
+		err = s.server.RemoveAddr(addr)
+	case "onetry":
+		err = s.server.AddAddr(addr, false)
+	default:
+		err = errors.New("Invalid subcommand for addnode")
+	}
+
+	// no data returned unless an error.
+	return nil, err
+}
+
 // handleDecodeRawTransaction handles decoderawtransaction commands.
 func handleDecodeRawTransaction(s *rpcServer, cmd btcjson.Cmd,
 	walletNotification chan []byte) (interface{}, error) {
@@ -469,7 +492,7 @@ func handleGetHashesPerSec(s *rpcServer, cmd btcjson.Cmd, walletNotification cha
 
 // handleGetPeerInfo implements the getpeerinfo command.
 func handleGetPeerInfo(s *rpcServer, cmd btcjson.Cmd, walletNotification chan []byte) (interface{}, error) {
-	return	s.server.PeerInfo(), nil
+	return s.server.PeerInfo(), nil
 }
 
 // handleGetRawMempool implements the getrawmempool command.
diff --git a/server.go b/server.go
index 83aad7e3..df95f337 100644
--- a/server.go
+++ b/server.go
@@ -6,6 +6,7 @@ package main
 
 import (
 	"container/list"
+	"errors"
 	"fmt"
 	"github.com/conformal/btcdb"
 	"github.com/conformal/btcwire"
@@ -223,6 +224,16 @@ type getPeerInfoMsg struct {
 	reply chan []*PeerInfo
 }
 
+type addNodeMsg struct {
+	addr      string
+	permanent bool
+	reply     chan error
+}
+
+type delNodeMsg struct {
+	addr  string
+	reply chan error
+}
 
 func (s *server) handleQuery(querymsg interface{}, peers *list.List, bannedPeers map[string]time.Time) {
 	switch msg := querymsg.(type) {
@@ -265,6 +276,41 @@ func (s *server) handleQuery(querymsg interface{}, peers *list.List, bannedPeers
 			infos = append(infos, info)
 		}
 		msg.reply <- infos
+	case addNodeMsg:
+		// TODO(oga) really these checks only apply to permanent peers.
+		for e := peers.Front(); e != nil; e = e.Next() {
+			peer := e.Value.(*peer)
+			if peer.addr == msg.addr {
+				msg.reply <- errors.New("peer already connected")
+				return
+			}
+		}
+		// TODO(oga) if too many, nuke a non-perm peer.
+		if s.handleAddPeerMsg(peers, bannedPeers,
+			newOutboundPeer(s, msg.addr, msg.permanent)) {
+			msg.reply <- nil
+		} else {
+			msg.reply <- errors.New("failed to add peer")
+		}
+
+	case delNodeMsg:
+		found := false
+		// TODO(oga) really these checks only apply to permanent peers.
+		for e := peers.Front(); e != nil; e = e.Next() {
+			peer := e.Value.(*peer)
+			if peer.addr == msg.addr {
+				peer.persistent = false // XXX hack!
+				peer.Disconnect()
+				found = true
+				break
+			}
+		}
+
+		if found {
+			msg.reply <- nil
+		} else {
+			msg.reply <- errors.New("peer not found")
+		}
 	}
 }
 
@@ -545,6 +591,22 @@ func (s *server) PeerInfo() []*PeerInfo {
 	return <-replyChan
 }
 
+func (s *server) AddAddr(addr string, permanent bool) error {
+	replyChan := make(chan error)
+
+	s.query <- addNodeMsg{addr: addr, permanent: permanent, reply: replyChan}
+
+	return <-replyChan
+}
+
+func (s *server) RemoveAddr(addr string) error {
+	replyChan := make(chan error)
+
+	s.query <- delNodeMsg{addr: addr, reply: replyChan}
+
+	return <-replyChan
+}
+
 // Start begins accepting connections from peers.
 func (s *server) Start() {
 	// Already started?