params: check fork ordering when initializing new genesis, fixes #20136 (#20169)

prevent users from misconfiguring their nodes so that fork ordering is not preserved.

params/config.go

@@ -415,6 +415,42 @@ func (c *ChainConfig) CheckCompatible(newcfg *ChainConfig, height uint64) *Confi
 	return lasterr
 }
 
+// CheckConfigForkOrder checks that we don't "skip" any forks, geth isn't pluggable enough
+// to guarantee that forks
+func (c *ChainConfig) CheckConfigForkOrder() error {
+	type fork struct {
+		name  string
+		block *big.Int
+	}
+	var lastFork fork
+	for _, cur := range []fork{
+		{"homesteadBlock", c.HomesteadBlock},
+		{"eip150Block", c.EIP150Block},
+		{"eip155Block", c.EIP155Block},
+		{"eip158Block", c.EIP158Block},
+		{"byzantiumBlock", c.ByzantiumBlock},
+		{"constantinopleBlock", c.ConstantinopleBlock},
+		{"petersburgBlock", c.PetersburgBlock},
+		{"istanbulBlock", c.IstanbulBlock},
+	} {
+		if lastFork.name != "" {
+			// Next one must be higher number
+			if lastFork.block == nil && cur.block != nil {
+				return fmt.Errorf("unsupported fork ordering: %v not enabled, but %v enabled at %v",
+					lastFork.name, cur.name, cur.block)
+			}
+			if lastFork.block != nil && cur.block != nil {
+				if lastFork.block.Cmp(cur.block) > 0 {
+					return fmt.Errorf("unsupported fork ordering: %v enabled at %v, but %v enabled at %v",
+						lastFork.name, lastFork.block, cur.name, cur.block)
+				}
+			}
+		}
+		lastFork = cur
+	}
+	return nil
+}
+
 func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *ConfigCompatError {
 	if isForkIncompatible(c.HomesteadBlock, newcfg.HomesteadBlock, head) {
 		return newCompatError("Homestead fork block", c.HomesteadBlock, newcfg.HomesteadBlock)