GoLint and GoVet warnings (#143)

This patch removes GoLint and GoVet warnings.

cookie.go

@@ -9,6 +9,7 @@ import (
 	"reflect"
 )
 
+// CookieJar manages storage and use of cookies in OpenFlow requests.
 type CookieJar interface {
 	SetCookies(uint64)
 	Cookies() uint64
@@ -55,7 +56,7 @@ func NewCookieMatcher(j CookieJar) *CookieMatcher {
 	cookiesLow := rand.Uint32()
 	cookiesHigh := rand.Uint32()
 
-	cookies = uint64(cookiesHigh<<32) | uint64(cookiesLow)
+	cookies = (uint64(cookiesHigh) << 32) | uint64(cookiesLow)
 
 	// Set the generated cookies to the given cookie jar and also
 	// put this value to the matcher.

header.go

@@ -9,57 +9,154 @@ import (
 )
 
 const (
-	// Immutable messages.
+	// TypeHello is used by either controller or switch during connection
+	// setup. It is used for version negotiation. When the connection
+	// is established, each side must immediately send a Hello message
+	// with the version field set to the highest version supported by
+	// the sender. If the version negotiation fails, an Error message
+	// is sent with type HelloFailed and code Incompatible.
 	TypeHello Type = iota
+
+	// TypeError can be sent by either the switch or the controller and
+	// indicates the failure of an operation. The simplest failure pertain
+	// to malformed messages or failed version negotiation, while more
+	// complex scenarios desbie some failure in state change at the switch.
 	TypeError
+
+	// TypeEchoRequest is used to exchange information about latency,
+	// bandwidth and liveness. Echo request timeout indicates disconnection.
 	TypeEchoRequest
+
+	// TypeEchoReply is used to exchange information about latency,
+	// bandwidth and liveness. Echo reply is sent as a response to Echo
+	// request.
 	TypeEchoReply
+
+	// TypeExperiment is a mechanism for proprietary messages within the
+	// protocol.
 	TypeExperiment
 
-	// Switch configuration messages.
+	// TypeFeaturesRequest is used when a transport channel (TCP, SCTP,
+	// TLS) is established between the switch and controller, the first
+	// activity is feature determination. The controller will send a
+	// feature request to the switch over the transport channel.
 	TypeFeaturesRequest
+
+	// TypeFeaturesReply is the switch's reply to the controller
+	// enumerating its abilities.
 	TypeFeaturesReply
+
+	// TypeGetConfigRequest sequence is used to query and set the
+	// fragmentation handling properties of the packet processing pipeline.
 	TypeGetConfigRequest
+
+	// TypeGetConfigReply is the switch's reply to the controller
+	// that acknowledges configuration requests.
 	TypeGetConfigReply
+
+	// TypeSetConfig is used by the controller to alter the switch's
+	// configuration. This message is unacknowledged.
 	TypeSetConfig
 
-	// Asynchronous messages.
+	// TypePacketIn message is a way for the switch to send a captured
+	// packet to the controller.
 	TypePacketIn
+
+	// TypeFlowRemoved is sent to the controller by the switch when a
+	// flow entry in a flow table is removed. It happens when a timeout
+	// occurs, either due to inactivity or hard timeout. An idle timeout
+	// happens when no packets are matched in a period of time. A hard
+	// timeout happens when a certain period of time elapses, regardless
+	// of the number of matching packets. Whether the switch sends a
+	// TypeFlowRemoved message after a timeout is specified by the
+	// TypeFlowMod. Flow entry removal with a TypeFlowMod message from
+	// the controller can also lead to a TypeFlowRemoved message.
 	TypeFlowRemoved
+
+	// TypePortStatus messages are asynchronous events sent from the
+	// switch to the controller indicating a change of status for the
+	// indicated port.
 	TypePortStatus
 
-	// Controller command messages.
+	// TypePacketOut is used by the controller to inject packets into the
+	// data plane of a particular switch. Such message can either carry a
+	// raw packet to inject into the switch, or indicate a local buffer
+	// on the switch containing a raw packet to release. Packets injected
+	// into the data plane of a switch using this method are not treated
+	// the same as packets that arrive on standard ports. The packet jumps
+	// to the action set application stage in the standard packet processing
+	// pipeline. If the action set indicates table processing is necessary
+	// then the input port id is used as the arrival port of the raw packet.
 	TypePacketOut
+
+	// TypeFlowMod is one of the main messages, it allows the controller
+	// to modify the state of switch.
 	TypeFlowMod
+
+	// TypeGroupMod is used by controller to modify group tables.
 	TypeGroupMod
+
+	// TypePortMod is used by the controller to modify the state of port.
 	TypePortMod
+
+	// TypeTableMod is used to determine a packet's fate when it misses
+	// in the table. It can be forwarded to the controller, dropped, or
+	// sent to the next table.
 	TypeTableMod
 
-	// Multipart messages
+	// TypeMultipartRequest is used by the controller to request the
+	// state of the datapath.
 	TypeMultipartRequest
+
+	// TypeMultipartReply are the replies from the switch to controller
+	// on TypeMultipartRequest messages.
 	TypeMultipartReply
 
-	// Barrier messages
+	// TypeBarrierRequest can be used by the controller to set a
+	// synchronization point, ensuring that all previous state messages
+	// are completed before the barrier response is sent back to the
+	// controller.
 	TypeBarrierRequest
+
+	// TypeBarrierReply is a response from the switch to controller
+	// on TypeBarrierRequest messages.
 	TypeBarrierReply
 
-	// Queue configuration messages.
+	// TypeQueueGetConfigRequest can be used by the controller to
+	// query the state of queues associated with various ports on switch.
 	TypeQueueGetConfigRequest
+
+	// TypeQueueGetConfigReply is a response from the switch to controller
+	// on TypeQueueGetConfigReply messages.
 	TypeQueueGetConfigReply
 
-	// Controller role change request messages.
+	// TypeRoleRequest is the message used by the controller to
+	// modify its role among multiple controllers on a switch.
 	TypeRoleRequest
+
+	// TypeRoleReply is a response from the switch to controller on
+	// TypeRoleRequest.
 	TypeRoleReply
 
-	// Asynchronous message configuration.
-	TypeAsynchRequest
-	TypeAsyncReply
+	// TypeGetAsyncRequest is used by the controller to request the switch
+	// which asynchronous events are enabled on the switch for the
+	// communication channel.
+	TypeGetAsyncRequest
+
+	// TypeGetAsyncReply is used by the switch as response to controller
+	// on TypeAsyncRequest messages.
+	TypeGetAsyncReply
+
+	// TypeSetAsync is used by the controller to set which asynchronous
+	// messages it should send, as well as to query the switch for which
+	// asynchronous messages it will send.
 	TypeSetAsync
 
-	// Meters and rate limiters configuration messages.
+	// TypeMeterMod used by the controller to modify the meter.
 	TypeMeterMod
 )
 
+// Type is an OpenFlow message type.
 type Type uint8
 
 func (t Type) String() string {
@@ -98,8 +195,8 @@ var typeText = map[Type]string{
 	TypeQueueGetConfigReply:   "TypeQueueGetConfigReply",
 	TypeRoleRequest:           "TypeRoleRequest",
 	TypeRoleReply:             "TypeRoleReply",
-	TypeAsynchRequest:         "TypeAsynchRequest",
-	TypeAsyncReply:            "TypeAsyncReply",
+	TypeGetAsyncRequest:       "TypeGetAsyncRequest",
+	TypeGetAsyncReply:         "TypeGetAsyncReply",
 	TypeSetAsync:              "TypeSetAsync",
 	TypeMeterMod:              "TypeMeterMod",
 }
@@ -122,11 +219,12 @@ type Header struct {
 	Transaction uint32
 }
 
+// Copy returns a copy of the request header.
 func (h *Header) Copy() *Header {
 	return &Header{h.Version, h.Type, h.Length, h.Transaction}
 }
 
-// Length of the packet payload including header.
+// Len of the packet payload including header.
 func (h *Header) Len() int {
 	return int(h.Length)
 }

internal/encoding/encoding.go

@@ -175,8 +175,6 @@ func ReadFunc(r io.Reader, rm ReaderMaker, fn func(r io.ReaderFrom)) (int64, err
 
 		fn(reader)
 	}
-
-	return n, nil
 }
 
 // ReaderMaker defines factory types, used to created new exemplars
@@ -204,7 +202,7 @@ func (fn ReaderMakerFunc) MakeReader() (io.ReaderFrom, error) {
 }
 
 func ScanFrom(r io.Reader, v interface{}, rm ReaderMaker) (int64, error) {
-	// Retrieve the size of the instruction type, that preceeds
+	// Retrieve the size of the instruction type, that precedes
 	// every instruction body.
 	valType := reflect.TypeOf(v)
 	typeLen := int(valType.Elem().Size())
@@ -244,8 +242,6 @@ func ScanFrom(r io.Reader, v interface{}, rm ReaderMaker) (int64, error) {
 			return n, SkipEOF(err)
 		}
 	}
-
-	return n, nil
 }
 
 // SkipEOF returns nil of the given error caused by the

mux.go

@@ -31,7 +31,7 @@ func (t TypeMatcher) Match(r *Request) bool {
 }
 
 // MultiMatcher creates a new Matcher instance that matches the request
-// by all specified criterias.
+// by all specified criteria.
 func MultiMatcher(m ...Matcher) Matcher {
 	fn := func(r *Request) bool {
 		for _, matcher := range m {
@@ -97,7 +97,7 @@ func (mux *ServeMux) Handle(m Matcher, h Handler) {
 	mux.handle(&muxEntry{m, h, false})
 }
 
-// Handle registers disposable handler for the given pattern.
+// HandleOnce registers disposable handler for the given pattern.
 //
 // It is not guaranteed that handler will process the first message
 // exemplar of the matching message.
@@ -110,7 +110,7 @@ func (mux *ServeMux) HandleFunc(m Matcher, h HandlerFunc) {
 	mux.Handle(m, h)
 }
 
-// HandleFunc registers handler function for the given message type.
+// Handler returns a handler of the specified request.
 func (mux *ServeMux) Handler(r *Request) Handler {
 	var matcher Matcher
 	var entry *muxEntry
@@ -175,6 +175,7 @@ type TypeMux struct {
 	mux *ServeMux
 }
 
+// NewTypeMux creates and returns a new TypeMux.
 func NewTypeMux() *TypeMux {
 	return &TypeMux{NewServeMux()}
 }
@@ -194,7 +195,7 @@ func (mux *TypeMux) HandleFunc(t Type, f HandlerFunc) {
 	mux.Handle(t, f)
 }
 
-// Handle returns a Handler instance for the given OpenFlow request.
+// Handler returns a Handler instance for the given OpenFlow request.
 func (mux *TypeMux) Handler(r *Request) Handler {
 	return mux.mux.Handler(r)
 }

net.go

@@ -9,16 +9,40 @@ import (
 	"time"
 )
 
+// A ConnState represents the state of a client connection to a server. It's
+// used by the optional Server.ConnState hook.
 type ConnState int
 
 const (
+	// StateNew represents a new connection that is expected to
+	// send a request immediately. Connections begin at this
+	// state and the transition to either StateHandshake or
+	// StateClosed.
 	StateNew ConnState = iota
+
+	// StateHandshake represents a connection that has initiated
+	// OpenFlow handshake routine. After the request is handled,
+	// the state transitions to one of: StateHandshake, StateActive,
+	// StateIdle or StateClosed.
 	StateHandshake
+
+	// StateActive represents a connection that has read 1 or more
+	// bytes of the request. The Server.ConnState hook for StateActive
+	// fires before the request has been handled.
 	StateActive
+
+	// StateIdle represents a connection that has finished
+	// handling a request and is in the keep-alive state, waiting
+	// for a new request. Connections transition from StateIdle
+	// to StateHandshake, StateActive or StateClosed
 	StateIdle
+
+	// StateClosed represents a closed connection. This is a
+	// terminal state.
 	StateClosed
 )
 
+// String returns the string presentation of the ConnState.
 func (c ConnState) String() string {
 	text, ok := connStateText[c]
 	if !ok {

ofp/action.go

@@ -229,7 +229,7 @@ type ActionOutput struct {
 	MaxLen uint16
 }
 
-// Type retuns the type of the action.
+// Type returns the type of the action.
 func (a *ActionOutput) Type() ActionType {
 	return ActionTypeOutput
 }

ofp/action_test.go

@@ -10,7 +10,7 @@ func TestActionCopyTTLInOut(t *testing.T) {
 	tests := []encodingtest.MU{
 		{ReadWriter: &ActionCopyTTLOut{}, Bytes: []byte{
 			0x00, 0xb, // Action type.
-			0x00, 0x08, // Action lenght.
+			0x00, 0x08, // Action length.
 			0x00, 0x00, 0x00, 0x00, // 4-byte padding.
 		}},
 		{ReadWriter: &ActionCopyTTLIn{}, Bytes: []byte{

ofp/instruction_test.go

@@ -27,7 +27,7 @@ func TestIntructionWriteMetadata(t *testing.T) {
 			MetadataMask: 0x3ec894d841073494,
 		}, Bytes: []byte{
 			0x00, 0x02, // Instruction type.
-			0x00, 0x18, // Intruction length.
+			0x00, 0x18, // Instruction length.
 			0x00, 0x00, 0x00, 0x00, // 4-byte padding.
 			0x50, 0x91, 0xae, 0xdc, 0x96, 0x97, 0x44, 0x5e, // Metadata.
 			0x3e, 0xc8, 0x94, 0xd8, 0x41, 0x07, 0x34, 0x94, // Metadata mask.
@@ -51,10 +51,10 @@ func TestInstructionApplyActions(t *testing.T) {
 
 			// Actions.
 			0x00, 0x16, // Action group.
-			0x00, 0x08, // Action lenght.
+			0x00, 0x08, // Action length.
 			0xff, 0xff, 0xff, 0xfc,
 			0x00, 0xb, // Action type.
-			0x00, 0x08, // Action lenght.
+			0x00, 0x08, // Action length.
 			0x00, 0x00, 0x00, 0x00, // 4-byte padding.
 		}},
 	}

ofp/match.go

@@ -282,7 +282,7 @@ const (
 )
 
 const (
-	// xmlen defines the length of the extention match header, it does
+	// xmlen defines the length of the extension match header, it does
 	// not include the value and mask.
 	xmlen = 4
 )

ofp/queue.go

@@ -90,7 +90,7 @@ func (q QueueProps) ReadFrom(r io.Reader) (int64, error) {
 // packetQueueLen defines the length of the packet queue header.
 const packetQueueLen = 16
 
-// PacketQueue decribes the packet processing queue.
+// PacketQueue describes the packet processing queue.
 //
 // An OpenFlow switch provides limited Quality-of-Service support (QoS)
 // through a simple queuing mechanism. One (or more) queues can attach