chaincfg+integration: add BIP0009 deployment parameters for segwit

This commit adds set of BIP0009 (Version Bits) deployment parameters
for all networks detailing the activation parameters for the segwit
soft-fork.

Additionally, the BIP0009 integration test has been updated to test for
the proper transitioning of version bits state for the segwit soft
fork. Finally, the `getblockchaininfo` test has also been updated to
properly display the state of segwit.

chaincfg/params.go

@@ -91,6 +91,11 @@ const (
 	// 68, 112, and 113.
 	DeploymentCSV
 
+	// DeploymentSegwit defines the rule change deployment ID for the
+	// Segragated Witness (segwit) soft-fork package. The segwit package
+	// includes the deployment of BIPS 141, 142, 144, 145, 147 and 173.
+	DeploymentSegwit
+
 	// NOTE: DefinedDeployments must always come last since it is used to
 	// determine how many defined deployments there currently are.
 
@@ -286,6 +291,11 @@ var MainNetParams = Params{
 			StartTime:  1462060800, // May 1st, 2016
 			ExpireTime: 1493596800, // May 1st, 2017
 		},
+		DeploymentSegwit: {
+			BitNumber:  1,
+			StartTime:  1479168000, // November 15, 2016 UTC
+			ExpireTime: 1510704000, // November 15, 2017 UTC.
+		},
 	},
 
 	// Mempool parameters
@@ -357,6 +367,11 @@ var RegressionNetParams = Params{
 			StartTime:  0,             // Always available for vote
 			ExpireTime: math.MaxInt64, // Never expires
 		},
+		DeploymentSegwit: {
+			BitNumber:  1,
+			StartTime:  0,             // Always available for vote
+			ExpireTime: math.MaxInt64, // Never expires.
+		},
 	},
 
 	// Mempool parameters
@@ -443,6 +458,11 @@ var TestNet3Params = Params{
 			StartTime:  1456790400, // March 1st, 2016
 			ExpireTime: 1493596800, // May 1st, 2017
 		},
+		DeploymentSegwit: {
+			BitNumber:  1,
+			StartTime:  1462060800, // May 1, 2016 UTC
+			ExpireTime: 1493596800, // May 1, 2017 UTC.
+		},
 	},
 
 	// Mempool parameters
@@ -518,6 +538,11 @@ var SimNetParams = Params{
 			StartTime:  0,             // Always available for vote
 			ExpireTime: math.MaxInt64, // Never expires
 		},
+		DeploymentSegwit: {
+			BitNumber:  1,
+			StartTime:  0,             // Always available for vote
+			ExpireTime: math.MaxInt64, // Never expires.
+		},
 	},
 
 	// Mempool parameters

integration/bip0009_test.go

@@ -299,6 +299,7 @@ func TestBIP0009(t *testing.T) {
 	t.Parallel()
 
 	testBIP0009(t, "dummy", chaincfg.DeploymentTestDummy)
+	testBIP0009(t, "segwit", chaincfg.DeploymentSegwit)
 }
 
 // TestBIP0009Mining ensures blocks built via btcd's CPU miner follow the rules

rpcserver.go

@@ -1207,8 +1207,13 @@ func handleGetBlockChainInfo(s *rpcServer, cmd interface{}, closeChan <-chan str
 		switch deployment {
 		case chaincfg.DeploymentTestDummy:
 			forkName = "dummy"
+
 		case chaincfg.DeploymentCSV:
 			forkName = "csv"
+
+		case chaincfg.DeploymentSegwit:
+			forkName = "segwit"
+
 		default:
 			return nil, &btcjson.RPCError{
 				Code: btcjson.ErrRPCInternal.Code,