From fac0300f168d5485e356770b65b0d0035a9cd6f9 Mon Sep 17 00:00:00 2001
From: Vlad <gluk256@gmail.com>
Date: Fri, 15 Dec 2017 10:27:00 +0200
Subject: [PATCH] whisper: powRequirementCode introduced

---
 whisper/whisperv6/doc.go     | 11 +++++++----
 whisper/whisperv6/peer.go    |  5 +++++
 whisper/whisperv6/whisper.go | 20 ++++++++++++++++++--
 3 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/whisper/whisperv6/doc.go b/whisper/whisperv6/doc.go
index 64925ba48b..2a4911d65a 100644
--- a/whisper/whisperv6/doc.go
+++ b/whisper/whisperv6/doc.go
@@ -40,10 +40,13 @@ const (
 	ProtocolVersionStr = "6.0"
 	ProtocolName       = "shh"
 
-	statusCode           = 0 // used by whisper protocol
-	messagesCode         = 1 // normal whisper message
-	p2pCode              = 2 // peer-to-peer message (to be consumed by the peer, but not forwarded any further)
-	p2pRequestCode       = 3 // peer-to-peer message, used by Dapp protocol
+	// whisper protocol message codes, according to EIP-627
+	statusCode           = 0   // used by whisper protocol
+	messagesCode         = 1   // normal whisper message
+	powRequirementCode   = 2   // PoW requirement
+	bloomFilterExCode    = 3   // bloom filter exchange
+	p2pRequestCode       = 126 // peer-to-peer message, used by Dapp protocol
+	p2pMessageCode       = 127 // peer-to-peer message (to be consumed by the peer, but not forwarded any further)
 	NumberOfMessageCodes = 128
 
 	paddingMask   = byte(3)
diff --git a/whisper/whisperv6/peer.go b/whisper/whisperv6/peer.go
index ac7b3b12b6..c104720b37 100644
--- a/whisper/whisperv6/peer.go
+++ b/whisper/whisperv6/peer.go
@@ -172,3 +172,8 @@ func (p *Peer) ID() []byte {
 	id := p.peer.ID()
 	return id[:]
 }
+
+func (p *Peer) notifyAboutPowRequirementChange(pow float64) error {
+	val := float32(pow)
+	return p2p.Send(p.ws, powRequirementCode, val)
+}
diff --git a/whisper/whisperv6/whisper.go b/whisper/whisperv6/whisper.go
index d09baab3fd..0aeba180f1 100644
--- a/whisper/whisperv6/whisper.go
+++ b/whisper/whisperv6/whisper.go
@@ -181,9 +181,25 @@ func (w *Whisper) SetMinimumPoW(val float64) error {
 		return fmt.Errorf("invalid PoW: %f", val)
 	}
 	w.settings.Store(minPowIdx, val)
+	w.notifyPeersAboutPowRequirementChange(val)
 	return nil
 }
 
+func (w *Whisper) notifyPeersAboutPowRequirementChange(pow float64) {
+	w.peerMu.Lock()
+	defer w.peerMu.Unlock()
+	for p := range w.peers {
+		err := p.notifyAboutPowRequirementChange(pow)
+		if err != nil {
+			// allow one retry
+			err = p.notifyAboutPowRequirementChange(pow)
+		}
+		if err != nil {
+			fmt.Errorf("Error sending PoW notification to peer [%x]: %s", p.ID(), err)
+		}
+	}
+}
+
 // getPeer retrieves peer by ID
 func (w *Whisper) getPeer(peerID []byte) (*Peer, error) {
 	w.peerMu.Lock()
@@ -233,7 +249,7 @@ func (w *Whisper) SendP2PMessage(peerID []byte, envelope *Envelope) error {
 
 // SendP2PDirect sends a peer-to-peer message to a specific peer.
 func (w *Whisper) SendP2PDirect(peer *Peer, envelope *Envelope) error {
-	return p2p.Send(peer.ws, p2pCode, envelope)
+	return p2p.Send(peer.ws, p2pMessageCode, envelope)
 }
 
 // NewKeyPair generates a new cryptographic identity for the client, and injects
@@ -528,7 +544,7 @@ func (wh *Whisper) runMessageLoop(p *Peer, rw p2p.MsgReadWriter) error {
 			if cached {
 				p.mark(&envelope)
 			}
-		case p2pCode:
+		case p2pMessageCode:
 			// peer-to-peer message, sent directly to peer bypassing PoW checks, etc.
 			// this message is not supposed to be forwarded to other peers, and
 			// therefore might not satisfy the PoW, expiry and other requirements.