From a87089fd2dc08a69a4a4f1ef93db9a2871d819a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Fri, 8 Jul 2016 18:48:17 +0300
Subject: cmd, core, miner: add extradata validation to consensus rules

---
 core/block_validator.go | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

(limited to 'core/block_validator.go')

diff --git a/core/block_validator.go b/core/block_validator.go
index c3f959324..73d581328 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -17,6 +17,7 @@
 package core
 
 import (
+	"bytes"
 	"fmt"
 	"math/big"
 	"time"
@@ -247,6 +248,26 @@ func ValidateHeader(config *ChainConfig, pow pow.PoW, header *types.Header, pare
 			return &BlockNonceErr{header.Number, header.Hash(), header.Nonce.Uint64()}
 		}
 	}
+	// DAO hard-fork extension to the header validity: a) if the node is no-fork,
+	// do not accept blocks in the [fork, fork+10) range with the fork specific
+	// extra-data set; b) if the node is pro-fork, require blocks in the specific
+	// range to have the unique extra-data set.
+	if daoBlock := config.DAOForkBlock; daoBlock != nil {
+		// Check whether the block is among the fork extra-override range
+		limit := new(big.Int).Add(daoBlock, params.DAOForkExtraRange)
+		if daoBlock.Cmp(header.Number) <= 0 && header.Number.Cmp(limit) < 0 {
+			// Depending whether we support or oppose the fork, verrift the extra-data contents
+			if config.DAOForkSupport {
+				if bytes.Compare(header.Extra, params.DAOForkBlockExtra) != 0 {
+					return ValidationError("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
+				}
+			} else {
+				if bytes.Compare(header.Extra, params.DAOForkBlockExtra) == 0 {
+					return ValidationError("DAO no-fork bad block extra-data: 0x%x", header.Extra)
+				}
+			}
+		}
+	}
 	return nil
 }
 
-- 
cgit v1.2.3