lib/connections, vendor: Change KCP mux to SMUX

Closes #4032

lib/connections/config.go

@@ -7,10 +7,9 @@
 package connections
 
 import (
-	"io/ioutil"
 	"time"
 
-	"github.com/hashicorp/yamux"
+	"github.com/xtaci/smux"
 )
 
 const (
@@ -25,12 +24,10 @@ const (
 )
 
 var (
-	yamuxConfig = &yamux.Config{
-		AcceptBacklog:          256,
-		EnableKeepAlive:        true,
-		KeepAliveInterval:      30 * time.Second,
-		ConnectionWriteTimeout: 10 * time.Second,
-		MaxStreamWindowSize:    256 * 1024,
-		LogOutput:              ioutil.Discard,
+	smuxConfig = &smux.Config{
+		KeepAliveInterval: 10 * time.Second,
+		KeepAliveTimeout:  30 * time.Second,
+		MaxFrameSize:      4096,
+		MaxReceiveBuffer:  4 * 1024 * 1024,
 	}
 )

lib/connections/kcp_dial.go

@@ -11,10 +11,10 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/hashicorp/yamux"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/xtaci/kcp-go"
+	"github.com/xtaci/smux"
 )
 
 func init() {
@@ -56,7 +56,7 @@ func (d *kcpDialer) Dial(id protocol.DeviceID, uri *url.URL) (internalConn, erro
 	conn.SetWindowSize(opts.KCPSendWindowSize, opts.KCPReceiveWindowSize)
 	conn.SetNoDelay(boolInt(opts.KCPNoDelay), opts.KCPUpdateIntervalMs, boolInt(opts.KCPFastResend), boolInt(!opts.KCPCongestionControl))
 
-	ses, err := yamux.Client(conn, yamuxConfig)
+	ses, err := smux.Client(conn, smuxConfig)
 	if err != nil {
 		conn.Close()
 		return internalConn{}, err

lib/connections/kcp_listen.go

@@ -16,10 +16,10 @@ import (
 
 	"github.com/AudriusButkevicius/pfilter"
 	"github.com/ccding/go-stun/stun"
-	"github.com/hashicorp/yamux"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/nat"
 	"github.com/xtaci/kcp-go"
+	"github.com/xtaci/smux"
 )
 
 func init() {
@@ -116,16 +116,16 @@ func (t *kcpListener) Serve() {
 
 		l.Debugln("connect from", conn.RemoteAddr())
 
-		ses, err := yamux.Server(conn, yamuxConfig)
+		ses, err := smux.Server(conn, smuxConfig)
 		if err != nil {
-			l.Debugln("yamux server:", err)
+			l.Debugln("smux server:", err)
 			conn.Close()
 			continue
 		}
 
 		stream, err := ses.AcceptStream()
 		if err != nil {
-			l.Debugln("yamux accept:", err)
+			l.Debugln("smux accept:", err)
 			ses.Close()
 			continue
 		}

lib/connections/kcp_misc.go

@@ -16,7 +16,7 @@ import (
 	"time"
 
 	"github.com/AudriusButkevicius/pfilter"
-	"github.com/hashicorp/yamux"
+	"github.com/xtaci/smux"
 )
 
 var (
@@ -162,8 +162,8 @@ func (f *stunFilter) reap() {
 }
 
 type sessionClosingStream struct {
-	*yamux.Stream
-	session *yamux.Session
+	*smux.Stream
+	session *smux.Session
 }
 
 func (w *sessionClosingStream) Close() error {

vendor/github.com/hashicorp/yamux/LICENSE

@@ -1,362 +0,0 @@
-Mozilla Public License, version 2.0
-
-1. Definitions
-
-1.1. "Contributor"
-
-     means each individual or legal entity that creates, contributes to the
-     creation of, or owns Covered Software.
-
-1.2. "Contributor Version"
-
-     means the combination of the Contributions of others (if any) used by a
-     Contributor and that particular Contributor's Contribution.
-
-1.3. "Contribution"
-
-     means Covered Software of a particular Contributor.
-
-1.4. "Covered Software"
-
-     means Source Code Form to which the initial Contributor has attached the
-     notice in Exhibit A, the Executable Form of such Source Code Form, and
-     Modifications of such Source Code Form, in each case including portions
-     thereof.
-
-1.5. "Incompatible With Secondary Licenses"
-     means
-
-     a. that the initial Contributor has attached the notice described in
-        Exhibit B to the Covered Software; or
-
-     b. that the Covered Software was made available under the terms of
-        version 1.1 or earlier of the License, but not also under the terms of
-        a Secondary License.
-
-1.6. "Executable Form"
-
-     means any form of the work other than Source Code Form.
-
-1.7. "Larger Work"
-
-     means a work that combines Covered Software with other material, in a
-     separate file or files, that is not Covered Software.
-
-1.8. "License"
-
-     means this document.
-
-1.9. "Licensable"
-
-     means having the right to grant, to the maximum extent possible, whether
-     at the time of the initial grant or subsequently, any and all of the
-     rights conveyed by this License.
-
-1.10. "Modifications"
-
-     means any of the following:
-
-     a. any file in Source Code Form that results from an addition to,
-        deletion from, or modification of the contents of Covered Software; or
-
-     b. any new file in Source Code Form that contains any Covered Software.
-
-1.11. "Patent Claims" of a Contributor
-
-      means any patent claim(s), including without limitation, method,
-      process, and apparatus claims, in any patent Licensable by such
-      Contributor that would be infringed, but for the grant of the License,
-      by the making, using, selling, offering for sale, having made, import,
-      or transfer of either its Contributions or its Contributor Version.
-
-1.12. "Secondary License"
-
-      means either the GNU General Public License, Version 2.0, the GNU Lesser
-      General Public License, Version 2.1, the GNU Affero General Public
-      License, Version 3.0, or any later versions of those licenses.
-
-1.13. "Source Code Form"
-
-      means the form of the work preferred for making modifications.
-
-1.14. "You" (or "Your")
-
-      means an individual or a legal entity exercising rights under this
-      License. For legal entities, "You" includes any entity that controls, is
-      controlled by, or is under common control with You. For purposes of this
-      definition, "control" means (a) the power, direct or indirect, to cause
-      the direction or management of such entity, whether by contract or
-      otherwise, or (b) ownership of more than fifty percent (50%) of the
-      outstanding shares or beneficial ownership of such entity.
-
-
-2. License Grants and Conditions
-
-2.1. Grants
-
-     Each Contributor hereby grants You a world-wide, royalty-free,
-     non-exclusive license:
-
-     a. under intellectual property rights (other than patent or trademark)
-        Licensable by such Contributor to use, reproduce, make available,
-        modify, display, perform, distribute, and otherwise exploit its
-        Contributions, either on an unmodified basis, with Modifications, or
-        as part of a Larger Work; and
-
-     b. under Patent Claims of such Contributor to make, use, sell, offer for
-        sale, have made, import, and otherwise transfer either its
-        Contributions or its Contributor Version.
-
-2.2. Effective Date
-
-     The licenses granted in Section 2.1 with respect to any Contribution
-     become effective for each Contribution on the date the Contributor first
-     distributes such Contribution.
-
-2.3. Limitations on Grant Scope
-
-     The licenses granted in this Section 2 are the only rights granted under
-     this License. No additional rights or licenses will be implied from the
-     distribution or licensing of Covered Software under this License.
-     Notwithstanding Section 2.1(b) above, no patent license is granted by a
-     Contributor:
-
-     a. for any code that a Contributor has removed from Covered Software; or
-
-     b. for infringements caused by: (i) Your and any other third party's
-        modifications of Covered Software, or (ii) the combination of its
-        Contributions with other software (except as part of its Contributor
-        Version); or
-
-     c. under Patent Claims infringed by Covered Software in the absence of
-        its Contributions.
-
-     This License does not grant any rights in the trademarks, service marks,
-     or logos of any Contributor (except as may be necessary to comply with
-     the notice requirements in Section 3.4).
-
-2.4. Subsequent Licenses
-
-     No Contributor makes additional grants as a result of Your choice to
-     distribute the Covered Software under a subsequent version of this
-     License (see Section 10.2) or under the terms of a Secondary License (if
-     permitted under the terms of Section 3.3).
-
-2.5. Representation
-
-     Each Contributor represents that the Contributor believes its
-     Contributions are its original creation(s) or it has sufficient rights to
-     grant the rights to its Contributions conveyed by this License.
-
-2.6. Fair Use
-
-     This License is not intended to limit any rights You have under
-     applicable copyright doctrines of fair use, fair dealing, or other
-     equivalents.
-
-2.7. Conditions
-
-     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
-     Section 2.1.
-
-
-3. Responsibilities
-
-3.1. Distribution of Source Form
-
-     All distribution of Covered Software in Source Code Form, including any
-     Modifications that You create or to which You contribute, must be under
-     the terms of this License. You must inform recipients that the Source
-     Code Form of the Covered Software is governed by the terms of this
-     License, and how they can obtain a copy of this License. You may not
-     attempt to alter or restrict the recipients' rights in the Source Code
-     Form.
-
-3.2. Distribution of Executable Form
-
-     If You distribute Covered Software in Executable Form then:
-
-     a. such Covered Software must also be made available in Source Code Form,
-        as described in Section 3.1, and You must inform recipients of the
-        Executable Form how they can obtain a copy of such Source Code Form by
-        reasonable means in a timely manner, at a charge no more than the cost
-        of distribution to the recipient; and
-
-     b. You may distribute such Executable Form under the terms of this
-        License, or sublicense it under different terms, provided that the
-        license for the Executable Form does not attempt to limit or alter the
-        recipients' rights in the Source Code Form under this License.
-
-3.3. Distribution of a Larger Work
-
-     You may create and distribute a Larger Work under terms of Your choice,
-     provided that You also comply with the requirements of this License for
-     the Covered Software. If the Larger Work is a combination of Covered
-     Software with a work governed by one or more Secondary Licenses, and the
-     Covered Software is not Incompatible With Secondary Licenses, this
-     License permits You to additionally distribute such Covered Software
-     under the terms of such Secondary License(s), so that the recipient of
-     the Larger Work may, at their option, further distribute the Covered
-     Software under the terms of either this License or such Secondary
-     License(s).
-
-3.4. Notices
-
-     You may not remove or alter the substance of any license notices
-     (including copyright notices, patent notices, disclaimers of warranty, or
-     limitations of liability) contained within the Source Code Form of the
-     Covered Software, except that You may alter any license notices to the
-     extent required to remedy known factual inaccuracies.
-
-3.5. Application of Additional Terms
-
-     You may choose to offer, and to charge a fee for, warranty, support,
-     indemnity or liability obligations to one or more recipients of Covered
-     Software. However, You may do so only on Your own behalf, and not on
-     behalf of any Contributor. You must make it absolutely clear that any
-     such warranty, support, indemnity, or liability obligation is offered by
-     You alone, and You hereby agree to indemnify every Contributor for any
-     liability incurred by such Contributor as a result of warranty, support,
-     indemnity or liability terms You offer. You may include additional
-     disclaimers of warranty and limitations of liability specific to any
-     jurisdiction.
-
-4. Inability to Comply Due to Statute or Regulation
-
-   If it is impossible for You to comply with any of the terms of this License
-   with respect to some or all of the Covered Software due to statute,
-   judicial order, or regulation then You must: (a) comply with the terms of
-   this License to the maximum extent possible; and (b) describe the
-   limitations and the code they affect. Such description must be placed in a
-   text file included with all distributions of the Covered Software under
-   this License. Except to the extent prohibited by statute or regulation,
-   such description must be sufficiently detailed for a recipient of ordinary
-   skill to be able to understand it.
-
-5. Termination
-
-5.1. The rights granted under this License will terminate automatically if You
-     fail to comply with any of its terms. However, if You become compliant,
-     then the rights granted under this License from a particular Contributor
-     are reinstated (a) provisionally, unless and until such Contributor
-     explicitly and finally terminates Your grants, and (b) on an ongoing
-     basis, if such Contributor fails to notify You of the non-compliance by
-     some reasonable means prior to 60 days after You have come back into
-     compliance. Moreover, Your grants from a particular Contributor are
-     reinstated on an ongoing basis if such Contributor notifies You of the
-     non-compliance by some reasonable means, this is the first time You have
-     received notice of non-compliance with this License from such
-     Contributor, and You become compliant prior to 30 days after Your receipt
-     of the notice.
-
-5.2. If You initiate litigation against any entity by asserting a patent
-     infringement claim (excluding declaratory judgment actions,
-     counter-claims, and cross-claims) alleging that a Contributor Version
-     directly or indirectly infringes any patent, then the rights granted to
-     You by any and all Contributors for the Covered Software under Section
-     2.1 of this License shall terminate.
-
-5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
-     license agreements (excluding distributors and resellers) which have been
-     validly granted by You or Your distributors under this License prior to
-     termination shall survive termination.
-
-6. Disclaimer of Warranty
-
-   Covered Software is provided under this License on an "as is" basis,
-   without warranty of any kind, either expressed, implied, or statutory,
-   including, without limitation, warranties that the Covered Software is free
-   of defects, merchantable, fit for a particular purpose or non-infringing.
-   The entire risk as to the quality and performance of the Covered Software
-   is with You. Should any Covered Software prove defective in any respect,
-   You (not any Contributor) assume the cost of any necessary servicing,
-   repair, or correction. This disclaimer of warranty constitutes an essential
-   part of this License. No use of  any Covered Software is authorized under
-   this License except under this disclaimer.
-
-7. Limitation of Liability
-
-   Under no circumstances and under no legal theory, whether tort (including
-   negligence), contract, or otherwise, shall any Contributor, or anyone who
-   distributes Covered Software as permitted above, be liable to You for any
-   direct, indirect, special, incidental, or consequential damages of any
-   character including, without limitation, damages for lost profits, loss of
-   goodwill, work stoppage, computer failure or malfunction, or any and all
-   other commercial damages or losses, even if such party shall have been
-   informed of the possibility of such damages. This limitation of liability
-   shall not apply to liability for death or personal injury resulting from
-   such party's negligence to the extent applicable law prohibits such
-   limitation. Some jurisdictions do not allow the exclusion or limitation of
-   incidental or consequential damages, so this exclusion and limitation may
-   not apply to You.
-
-8. Litigation
-
-   Any litigation relating to this License may be brought only in the courts
-   of a jurisdiction where the defendant maintains its principal place of
-   business and such litigation shall be governed by laws of that
-   jurisdiction, without reference to its conflict-of-law provisions. Nothing
-   in this Section shall prevent a party's ability to bring cross-claims or
-   counter-claims.
-
-9. Miscellaneous
-
-   This License represents the complete agreement concerning the subject
-   matter hereof. If any provision of this License is held to be
-   unenforceable, such provision shall be reformed only to the extent
-   necessary to make it enforceable. Any law or regulation which provides that
-   the language of a contract shall be construed against the drafter shall not
-   be used to construe this License against a Contributor.
-
-
-10. Versions of the License
-
-10.1. New Versions
-
-      Mozilla Foundation is the license steward. Except as provided in Section
-      10.3, no one other than the license steward has the right to modify or
-      publish new versions of this License. Each version will be given a
-      distinguishing version number.
-
-10.2. Effect of New Versions
-
-      You may distribute the Covered Software under the terms of the version
-      of the License under which You originally received the Covered Software,
-      or under the terms of any subsequent version published by the license
-      steward.
-
-10.3. Modified Versions
-
-      If you create software not governed by this License, and you want to
-      create a new license for such software, you may create and use a
-      modified version of this License if you rename the license and remove
-      any references to the name of the license steward (except to note that
-      such modified license differs from this License).
-
-10.4. Distributing Source Code Form that is Incompatible With Secondary
-      Licenses If You choose to distribute Source Code Form that is
-      Incompatible With Secondary Licenses under the terms of this version of
-      the License, the notice described in Exhibit B of this License must be
-      attached.
-
-Exhibit A - Source Code Form License Notice
-
-      This Source Code Form is subject to the
-      terms of the Mozilla Public License, v.
-      2.0. If a copy of the MPL was not
-      distributed with this file, You can
-      obtain one at
-      http://mozilla.org/MPL/2.0/.
-
-If it is not possible or desirable to put the notice in a particular file,
-then You may include the notice in a location (such as a LICENSE file in a
-relevant directory) where a recipient would be likely to look for such a
-notice.
-
-You may add additional accurate notices of copyright ownership.
-
-Exhibit B - "Incompatible With Secondary Licenses" Notice
-
-      This Source Code Form is "Incompatible
-      With Secondary Licenses", as defined by
-      the Mozilla Public License, v. 2.0.

vendor/github.com/hashicorp/yamux/addr.go

@@ -1,60 +0,0 @@
-package yamux
-
-import (
-	"fmt"
-	"net"
-)
-
-// hasAddr is used to get the address from the underlying connection
-type hasAddr interface {
-	LocalAddr() net.Addr
-	RemoteAddr() net.Addr
-}
-
-// yamuxAddr is used when we cannot get the underlying address
-type yamuxAddr struct {
-	Addr string
-}
-
-func (*yamuxAddr) Network() string {
-	return "yamux"
-}
-
-func (y *yamuxAddr) String() string {
-	return fmt.Sprintf("yamux:%s", y.Addr)
-}
-
-// Addr is used to get the address of the listener.
-func (s *Session) Addr() net.Addr {
-	return s.LocalAddr()
-}
-
-// LocalAddr is used to get the local address of the
-// underlying connection.
-func (s *Session) LocalAddr() net.Addr {
-	addr, ok := s.conn.(hasAddr)
-	if !ok {
-		return &yamuxAddr{"local"}
-	}
-	return addr.LocalAddr()
-}
-
-// RemoteAddr is used to get the address of remote end
-// of the underlying connection
-func (s *Session) RemoteAddr() net.Addr {
-	addr, ok := s.conn.(hasAddr)
-	if !ok {
-		return &yamuxAddr{"remote"}
-	}
-	return addr.RemoteAddr()
-}
-
-// LocalAddr returns the local address
-func (s *Stream) LocalAddr() net.Addr {
-	return s.session.LocalAddr()
-}
-
-// LocalAddr returns the remote address
-func (s *Stream) RemoteAddr() net.Addr {
-	return s.session.RemoteAddr()
-}

vendor/github.com/hashicorp/yamux/const.go

@@ -1,157 +0,0 @@
-package yamux
-
-import (
-	"encoding/binary"
-	"fmt"
-)
-
-var (
-	// ErrInvalidVersion means we received a frame with an
-	// invalid version
-	ErrInvalidVersion = fmt.Errorf("invalid protocol version")
-
-	// ErrInvalidMsgType means we received a frame with an
-	// invalid message type
-	ErrInvalidMsgType = fmt.Errorf("invalid msg type")
-
-	// ErrSessionShutdown is used if there is a shutdown during
-	// an operation
-	ErrSessionShutdown = fmt.Errorf("session shutdown")
-
-	// ErrStreamsExhausted is returned if we have no more
-	// stream ids to issue
-	ErrStreamsExhausted = fmt.Errorf("streams exhausted")
-
-	// ErrDuplicateStream is used if a duplicate stream is
-	// opened inbound
-	ErrDuplicateStream = fmt.Errorf("duplicate stream initiated")
-
-	// ErrReceiveWindowExceeded indicates the window was exceeded
-	ErrRecvWindowExceeded = fmt.Errorf("recv window exceeded")
-
-	// ErrTimeout is used when we reach an IO deadline
-	ErrTimeout = fmt.Errorf("i/o deadline reached")
-
-	// ErrStreamClosed is returned when using a closed stream
-	ErrStreamClosed = fmt.Errorf("stream closed")
-
-	// ErrUnexpectedFlag is set when we get an unexpected flag
-	ErrUnexpectedFlag = fmt.Errorf("unexpected flag")
-
-	// ErrRemoteGoAway is used when we get a go away from the other side
-	ErrRemoteGoAway = fmt.Errorf("remote end is not accepting connections")
-
-	// ErrConnectionReset is sent if a stream is reset. This can happen
-	// if the backlog is exceeded, or if there was a remote GoAway.
-	ErrConnectionReset = fmt.Errorf("connection reset")
-
-	// ErrConnectionWriteTimeout indicates that we hit the "safety valve"
-	// timeout writing to the underlying stream connection.
-	ErrConnectionWriteTimeout = fmt.Errorf("connection write timeout")
-
-	// ErrKeepAliveTimeout is sent if a missed keepalive caused the stream close
-	ErrKeepAliveTimeout = fmt.Errorf("keepalive timeout")
-)
-
-const (
-	// protoVersion is the only version we support
-	protoVersion uint8 = 0
-)
-
-const (
-	// Data is used for data frames. They are followed
-	// by length bytes worth of payload.
-	typeData uint8 = iota
-
-	// WindowUpdate is used to change the window of
-	// a given stream. The length indicates the delta
-	// update to the window.
-	typeWindowUpdate
-
-	// Ping is sent as a keep-alive or to measure
-	// the RTT. The StreamID and Length value are echoed
-	// back in the response.
-	typePing
-
-	// GoAway is sent to terminate a session. The StreamID
-	// should be 0 and the length is an error code.
-	typeGoAway
-)
-
-const (
-	// SYN is sent to signal a new stream. May
-	// be sent with a data payload
-	flagSYN uint16 = 1 << iota
-
-	// ACK is sent to acknowledge a new stream. May
-	// be sent with a data payload
-	flagACK
-
-	// FIN is sent to half-close the given stream.
-	// May be sent with a data payload.
-	flagFIN
-
-	// RST is used to hard close a given stream.
-	flagRST
-)
-
-const (
-	// initialStreamWindow is the initial stream window size
-	initialStreamWindow uint32 = 256 * 1024
-)
-
-const (
-	// goAwayNormal is sent on a normal termination
-	goAwayNormal uint32 = iota
-
-	// goAwayProtoErr sent on a protocol error
-	goAwayProtoErr
-
-	// goAwayInternalErr sent on an internal error
-	goAwayInternalErr
-)
-
-const (
-	sizeOfVersion  = 1
-	sizeOfType     = 1
-	sizeOfFlags    = 2
-	sizeOfStreamID = 4
-	sizeOfLength   = 4
-	headerSize     = sizeOfVersion + sizeOfType + sizeOfFlags +
-		sizeOfStreamID + sizeOfLength
-)
-
-type header []byte
-
-func (h header) Version() uint8 {
-	return h[0]
-}
-
-func (h header) MsgType() uint8 {
-	return h[1]
-}
-
-func (h header) Flags() uint16 {
-	return binary.BigEndian.Uint16(h[2:4])
-}
-
-func (h header) StreamID() uint32 {
-	return binary.BigEndian.Uint32(h[4:8])
-}
-
-func (h header) Length() uint32 {
-	return binary.BigEndian.Uint32(h[8:12])
-}
-
-func (h header) String() string {
-	return fmt.Sprintf("Vsn:%d Type:%d Flags:%d StreamID:%d Length:%d",
-		h.Version(), h.MsgType(), h.Flags(), h.StreamID(), h.Length())
-}
-
-func (h header) encode(msgType uint8, flags uint16, streamID uint32, length uint32) {
-	h[0] = protoVersion
-	h[1] = msgType
-	binary.BigEndian.PutUint16(h[2:4], flags)
-	binary.BigEndian.PutUint32(h[4:8], streamID)
-	binary.BigEndian.PutUint32(h[8:12], length)
-}

vendor/github.com/hashicorp/yamux/mux.go

@@ -1,87 +0,0 @@
-package yamux
-
-import (
-	"fmt"
-	"io"
-	"os"
-	"time"
-)
-
-// Config is used to tune the Yamux session
-type Config struct {
-	// AcceptBacklog is used to limit how many streams may be
-	// waiting an accept.
-	AcceptBacklog int
-
-	// EnableKeepalive is used to do a period keep alive
-	// messages using a ping.
-	EnableKeepAlive bool
-
-	// KeepAliveInterval is how often to perform the keep alive
-	KeepAliveInterval time.Duration
-
-	// ConnectionWriteTimeout is meant to be a "safety valve" timeout after
-	// we which will suspect a problem with the underlying connection and
-	// close it. This is only applied to writes, where's there's generally
-	// an expectation that things will move along quickly.
-	ConnectionWriteTimeout time.Duration
-
-	// MaxStreamWindowSize is used to control the maximum
-	// window size that we allow for a stream.
-	MaxStreamWindowSize uint32
-
-	// LogOutput is used to control the log destination
-	LogOutput io.Writer
-}
-
-// DefaultConfig is used to return a default configuration
-func DefaultConfig() *Config {
-	return &Config{
-		AcceptBacklog:          256,
-		EnableKeepAlive:        true,
-		KeepAliveInterval:      30 * time.Second,
-		ConnectionWriteTimeout: 10 * time.Second,
-		MaxStreamWindowSize:    initialStreamWindow,
-		LogOutput:              os.Stderr,
-	}
-}
-
-// VerifyConfig is used to verify the sanity of configuration
-func VerifyConfig(config *Config) error {
-	if config.AcceptBacklog <= 0 {
-		return fmt.Errorf("backlog must be positive")
-	}
-	if config.KeepAliveInterval == 0 {
-		return fmt.Errorf("keep-alive interval must be positive")
-	}
-	if config.MaxStreamWindowSize < initialStreamWindow {
-		return fmt.Errorf("MaxStreamWindowSize must be larger than %d", initialStreamWindow)
-	}
-	return nil
-}
-
-// Server is used to initialize a new server-side connection.
-// There must be at most one server-side connection. If a nil config is
-// provided, the DefaultConfiguration will be used.
-func Server(conn io.ReadWriteCloser, config *Config) (*Session, error) {
-	if config == nil {
-		config = DefaultConfig()
-	}
-	if err := VerifyConfig(config); err != nil {
-		return nil, err
-	}
-	return newSession(config, conn, false), nil
-}
-
-// Client is used to initialize a new client-side connection.
-// There must be at most one client-side connection.
-func Client(conn io.ReadWriteCloser, config *Config) (*Session, error) {
-	if config == nil {
-		config = DefaultConfig()
-	}
-
-	if err := VerifyConfig(config); err != nil {
-		return nil, err
-	}
-	return newSession(config, conn, true), nil
-}

vendor/github.com/hashicorp/yamux/session.go

@@ -1,623 +0,0 @@
-package yamux
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"log"
-	"math"
-	"net"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
-)
-
-// Session is used to wrap a reliable ordered connection and to
-// multiplex it into multiple streams.
-type Session struct {
-	// remoteGoAway indicates the remote side does
-	// not want futher connections. Must be first for alignment.
-	remoteGoAway int32
-
-	// localGoAway indicates that we should stop
-	// accepting futher connections. Must be first for alignment.
-	localGoAway int32
-
-	// nextStreamID is the next stream we should
-	// send. This depends if we are a client/server.
-	nextStreamID uint32
-
-	// config holds our configuration
-	config *Config
-
-	// logger is used for our logs
-	logger *log.Logger
-
-	// conn is the underlying connection
-	conn io.ReadWriteCloser
-
-	// bufRead is a buffered reader
-	bufRead *bufio.Reader
-
-	// pings is used to track inflight pings
-	pings    map[uint32]chan struct{}
-	pingID   uint32
-	pingLock sync.Mutex
-
-	// streams maps a stream id to a stream, and inflight has an entry
-	// for any outgoing stream that has not yet been established. Both are
-	// protected by streamLock.
-	streams    map[uint32]*Stream
-	inflight   map[uint32]struct{}
-	streamLock sync.Mutex
-
-	// synCh acts like a semaphore. It is sized to the AcceptBacklog which
-	// is assumed to be symmetric between the client and server. This allows
-	// the client to avoid exceeding the backlog and instead blocks the open.
-	synCh chan struct{}
-
-	// acceptCh is used to pass ready streams to the client
-	acceptCh chan *Stream
-
-	// sendCh is used to mark a stream as ready to send,
-	// or to send a header out directly.
-	sendCh chan sendReady
-
-	// recvDoneCh is closed when recv() exits to avoid a race
-	// between stream registration and stream shutdown
-	recvDoneCh chan struct{}
-
-	// shutdown is used to safely close a session
-	shutdown     bool
-	shutdownErr  error
-	shutdownCh   chan struct{}
-	shutdownLock sync.Mutex
-}
-
-// sendReady is used to either mark a stream as ready
-// or to directly send a header
-type sendReady struct {
-	Hdr  []byte
-	Body io.Reader
-	Err  chan error
-}
-
-// newSession is used to construct a new session
-func newSession(config *Config, conn io.ReadWriteCloser, client bool) *Session {
-	s := &Session{
-		config:     config,
-		logger:     log.New(config.LogOutput, "", log.LstdFlags),
-		conn:       conn,
-		bufRead:    bufio.NewReader(conn),
-		pings:      make(map[uint32]chan struct{}),
-		streams:    make(map[uint32]*Stream),
-		inflight:   make(map[uint32]struct{}),
-		synCh:      make(chan struct{}, config.AcceptBacklog),
-		acceptCh:   make(chan *Stream, config.AcceptBacklog),
-		sendCh:     make(chan sendReady, 64),
-		recvDoneCh: make(chan struct{}),
-		shutdownCh: make(chan struct{}),
-	}
-	if client {
-		s.nextStreamID = 1
-	} else {
-		s.nextStreamID = 2
-	}
-	go s.recv()
-	go s.send()
-	if config.EnableKeepAlive {
-		go s.keepalive()
-	}
-	return s
-}
-
-// IsClosed does a safe check to see if we have shutdown
-func (s *Session) IsClosed() bool {
-	select {
-	case <-s.shutdownCh:
-		return true
-	default:
-		return false
-	}
-}
-
-// NumStreams returns the number of currently open streams
-func (s *Session) NumStreams() int {
-	s.streamLock.Lock()
-	num := len(s.streams)
-	s.streamLock.Unlock()
-	return num
-}
-
-// Open is used to create a new stream as a net.Conn
-func (s *Session) Open() (net.Conn, error) {
-	conn, err := s.OpenStream()
-	if err != nil {
-		return nil, err
-	}
-	return conn, nil
-}
-
-// OpenStream is used to create a new stream
-func (s *Session) OpenStream() (*Stream, error) {
-	if s.IsClosed() {
-		return nil, ErrSessionShutdown
-	}
-	if atomic.LoadInt32(&s.remoteGoAway) == 1 {
-		return nil, ErrRemoteGoAway
-	}
-
-	// Block if we have too many inflight SYNs
-	select {
-	case s.synCh <- struct{}{}:
-	case <-s.shutdownCh:
-		return nil, ErrSessionShutdown
-	}
-
-GET_ID:
-	// Get an ID, and check for stream exhaustion
-	id := atomic.LoadUint32(&s.nextStreamID)
-	if id >= math.MaxUint32-1 {
-		return nil, ErrStreamsExhausted
-	}
-	if !atomic.CompareAndSwapUint32(&s.nextStreamID, id, id+2) {
-		goto GET_ID
-	}
-
-	// Register the stream
-	stream := newStream(s, id, streamInit)
-	s.streamLock.Lock()
-	s.streams[id] = stream
-	s.inflight[id] = struct{}{}
-	s.streamLock.Unlock()
-
-	// Send the window update to create
-	if err := stream.sendWindowUpdate(); err != nil {
-		select {
-		case <-s.synCh:
-		default:
-			s.logger.Printf("[ERR] yamux: aborted stream open without inflight syn semaphore")
-		}
-		return nil, err
-	}
-	return stream, nil
-}
-
-// Accept is used to block until the next available stream
-// is ready to be accepted.
-func (s *Session) Accept() (net.Conn, error) {
-	conn, err := s.AcceptStream()
-	if err != nil {
-		return nil, err
-	}
-	return conn, err
-}
-
-// AcceptStream is used to block until the next available stream
-// is ready to be accepted.
-func (s *Session) AcceptStream() (*Stream, error) {
-	select {
-	case stream := <-s.acceptCh:
-		if err := stream.sendWindowUpdate(); err != nil {
-			return nil, err
-		}
-		return stream, nil
-	case <-s.shutdownCh:
-		return nil, s.shutdownErr
-	}
-}
-
-// Close is used to close the session and all streams.
-// Attempts to send a GoAway before closing the connection.
-func (s *Session) Close() error {
-	s.shutdownLock.Lock()
-	defer s.shutdownLock.Unlock()
-
-	if s.shutdown {
-		return nil
-	}
-	s.shutdown = true
-	if s.shutdownErr == nil {
-		s.shutdownErr = ErrSessionShutdown
-	}
-	close(s.shutdownCh)
-	s.conn.Close()
-	<-s.recvDoneCh
-
-	s.streamLock.Lock()
-	defer s.streamLock.Unlock()
-	for _, stream := range s.streams {
-		stream.forceClose()
-	}
-	return nil
-}
-
-// exitErr is used to handle an error that is causing the
-// session to terminate.
-func (s *Session) exitErr(err error) {
-	s.shutdownLock.Lock()
-	if s.shutdownErr == nil {
-		s.shutdownErr = err
-	}
-	s.shutdownLock.Unlock()
-	s.Close()
-}
-
-// GoAway can be used to prevent accepting further
-// connections. It does not close the underlying conn.
-func (s *Session) GoAway() error {
-	return s.waitForSend(s.goAway(goAwayNormal), nil)
-}
-
-// goAway is used to send a goAway message
-func (s *Session) goAway(reason uint32) header {
-	atomic.SwapInt32(&s.localGoAway, 1)
-	hdr := header(make([]byte, headerSize))
-	hdr.encode(typeGoAway, 0, 0, reason)
-	return hdr
-}
-
-// Ping is used to measure the RTT response time
-func (s *Session) Ping() (time.Duration, error) {
-	// Get a channel for the ping
-	ch := make(chan struct{})
-
-	// Get a new ping id, mark as pending
-	s.pingLock.Lock()
-	id := s.pingID
-	s.pingID++
-	s.pings[id] = ch
-	s.pingLock.Unlock()
-
-	// Send the ping request
-	hdr := header(make([]byte, headerSize))
-	hdr.encode(typePing, flagSYN, 0, id)
-	if err := s.waitForSend(hdr, nil); err != nil {
-		return 0, err
-	}
-
-	// Wait for a response
-	start := time.Now()
-	select {
-	case <-ch:
-	case <-time.After(s.config.ConnectionWriteTimeout):
-		s.pingLock.Lock()
-		delete(s.pings, id) // Ignore it if a response comes later.
-		s.pingLock.Unlock()
-		return 0, ErrTimeout
-	case <-s.shutdownCh:
-		return 0, ErrSessionShutdown
-	}
-
-	// Compute the RTT
-	return time.Now().Sub(start), nil
-}
-
-// keepalive is a long running goroutine that periodically does
-// a ping to keep the connection alive.
-func (s *Session) keepalive() {
-	for {
-		select {
-		case <-time.After(s.config.KeepAliveInterval):
-			_, err := s.Ping()
-			if err != nil {
-				s.logger.Printf("[ERR] yamux: keepalive failed: %v", err)
-				s.exitErr(ErrKeepAliveTimeout)
-				return
-			}
-		case <-s.shutdownCh:
-			return
-		}
-	}
-}
-
-// waitForSendErr waits to send a header, checking for a potential shutdown
-func (s *Session) waitForSend(hdr header, body io.Reader) error {
-	errCh := make(chan error, 1)
-	return s.waitForSendErr(hdr, body, errCh)
-}
-
-// waitForSendErr waits to send a header with optional data, checking for a
-// potential shutdown. Since there's the expectation that sends can happen
-// in a timely manner, we enforce the connection write timeout here.
-func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
-
-	ready := sendReady{Hdr: hdr, Body: body, Err: errCh}
-	select {
-	case s.sendCh <- ready:
-	case <-s.shutdownCh:
-		return ErrSessionShutdown
-	case <-timer.C:
-		return ErrConnectionWriteTimeout
-	}
-
-	select {
-	case err := <-errCh:
-		return err
-	case <-s.shutdownCh:
-		return ErrSessionShutdown
-	case <-timer.C:
-		return ErrConnectionWriteTimeout
-	}
-}
-
-// sendNoWait does a send without waiting. Since there's the expectation that
-// the send happens right here, we enforce the connection write timeout if we
-// can't queue the header to be sent.
-func (s *Session) sendNoWait(hdr header) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
-
-	select {
-	case s.sendCh <- sendReady{Hdr: hdr}:
-		return nil
-	case <-s.shutdownCh:
-		return ErrSessionShutdown
-	case <-timer.C:
-		return ErrConnectionWriteTimeout
-	}
-}
-
-// send is a long running goroutine that sends data
-func (s *Session) send() {
-	for {
-		select {
-		case ready := <-s.sendCh:
-			// Send a header if ready
-			if ready.Hdr != nil {
-				sent := 0
-				for sent < len(ready.Hdr) {
-					n, err := s.conn.Write(ready.Hdr[sent:])
-					if err != nil {
-						s.logger.Printf("[ERR] yamux: Failed to write header: %v", err)
-						asyncSendErr(ready.Err, err)
-						s.exitErr(err)
-						return
-					}
-					sent += n
-				}
-			}
-
-			// Send data from a body if given
-			if ready.Body != nil {
-				_, err := io.Copy(s.conn, ready.Body)
-				if err != nil {
-					s.logger.Printf("[ERR] yamux: Failed to write body: %v", err)
-					asyncSendErr(ready.Err, err)
-					s.exitErr(err)
-					return
-				}
-			}
-
-			// No error, successful send
-			asyncSendErr(ready.Err, nil)
-		case <-s.shutdownCh:
-			return
-		}
-	}
-}
-
-// recv is a long running goroutine that accepts new data
-func (s *Session) recv() {
-	if err := s.recvLoop(); err != nil {
-		s.exitErr(err)
-	}
-}
-
-// recvLoop continues to receive data until a fatal error is encountered
-func (s *Session) recvLoop() error {
-	defer close(s.recvDoneCh)
-	hdr := header(make([]byte, headerSize))
-	var handler func(header) error
-	for {
-		// Read the header
-		if _, err := io.ReadFull(s.bufRead, hdr); err != nil {
-			if err != io.EOF && !strings.Contains(err.Error(), "closed") && !strings.Contains(err.Error(), "reset by peer") {
-				s.logger.Printf("[ERR] yamux: Failed to read header: %v", err)
-			}
-			return err
-		}
-
-		// Verify the version
-		if hdr.Version() != protoVersion {
-			s.logger.Printf("[ERR] yamux: Invalid protocol version: %d", hdr.Version())
-			return ErrInvalidVersion
-		}
-
-		// Switch on the type
-		switch hdr.MsgType() {
-		case typeData:
-			handler = s.handleStreamMessage
-		case typeWindowUpdate:
-			handler = s.handleStreamMessage
-		case typeGoAway:
-			handler = s.handleGoAway
-		case typePing:
-			handler = s.handlePing
-		default:
-			return ErrInvalidMsgType
-		}
-
-		// Invoke the handler
-		if err := handler(hdr); err != nil {
-			return err
-		}
-	}
-}
-
-// handleStreamMessage handles either a data or window update frame
-func (s *Session) handleStreamMessage(hdr header) error {
-	// Check for a new stream creation
-	id := hdr.StreamID()
-	flags := hdr.Flags()
-	if flags&flagSYN == flagSYN {
-		if err := s.incomingStream(id); err != nil {
-			return err
-		}
-	}
-
-	// Get the stream
-	s.streamLock.Lock()
-	stream := s.streams[id]
-	s.streamLock.Unlock()
-
-	// If we do not have a stream, likely we sent a RST
-	if stream == nil {
-		// Drain any data on the wire
-		if hdr.MsgType() == typeData && hdr.Length() > 0 {
-			s.logger.Printf("[WARN] yamux: Discarding data for stream: %d", id)
-			if _, err := io.CopyN(ioutil.Discard, s.bufRead, int64(hdr.Length())); err != nil {
-				s.logger.Printf("[ERR] yamux: Failed to discard data: %v", err)
-				return nil
-			}
-		} else {
-			s.logger.Printf("[WARN] yamux: frame for missing stream: %v", hdr)
-		}
-		return nil
-	}
-
-	// Check if this is a window update
-	if hdr.MsgType() == typeWindowUpdate {
-		if err := stream.incrSendWindow(hdr, flags); err != nil {
-			if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
-				s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
-			}
-			return err
-		}
-		return nil
-	}
-
-	// Read the new data
-	if err := stream.readData(hdr, flags, s.bufRead); err != nil {
-		if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
-			s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
-		}
-		return err
-	}
-	return nil
-}
-
-// handlePing is invokde for a typePing frame
-func (s *Session) handlePing(hdr header) error {
-	flags := hdr.Flags()
-	pingID := hdr.Length()
-
-	// Check if this is a query, respond back in a separate context so we
-	// don't interfere with the receiving thread blocking for the write.
-	if flags&flagSYN == flagSYN {
-		go func() {
-			hdr := header(make([]byte, headerSize))
-			hdr.encode(typePing, flagACK, 0, pingID)
-			if err := s.sendNoWait(hdr); err != nil {
-				s.logger.Printf("[WARN] yamux: failed to send ping reply: %v", err)
-			}
-		}()
-		return nil
-	}
-
-	// Handle a response
-	s.pingLock.Lock()
-	ch := s.pings[pingID]
-	if ch != nil {
-		delete(s.pings, pingID)
-		close(ch)
-	}
-	s.pingLock.Unlock()
-	return nil
-}
-
-// handleGoAway is invokde for a typeGoAway frame
-func (s *Session) handleGoAway(hdr header) error {
-	code := hdr.Length()
-	switch code {
-	case goAwayNormal:
-		atomic.SwapInt32(&s.remoteGoAway, 1)
-	case goAwayProtoErr:
-		s.logger.Printf("[ERR] yamux: received protocol error go away")
-		return fmt.Errorf("yamux protocol error")
-	case goAwayInternalErr:
-		s.logger.Printf("[ERR] yamux: received internal error go away")
-		return fmt.Errorf("remote yamux internal error")
-	default:
-		s.logger.Printf("[ERR] yamux: received unexpected go away")
-		return fmt.Errorf("unexpected go away received")
-	}
-	return nil
-}
-
-// incomingStream is used to create a new incoming stream
-func (s *Session) incomingStream(id uint32) error {
-	// Reject immediately if we are doing a go away
-	if atomic.LoadInt32(&s.localGoAway) == 1 {
-		hdr := header(make([]byte, headerSize))
-		hdr.encode(typeWindowUpdate, flagRST, id, 0)
-		return s.sendNoWait(hdr)
-	}
-
-	// Allocate a new stream
-	stream := newStream(s, id, streamSYNReceived)
-
-	s.streamLock.Lock()
-	defer s.streamLock.Unlock()
-
-	// Check if stream already exists
-	if _, ok := s.streams[id]; ok {
-		s.logger.Printf("[ERR] yamux: duplicate stream declared")
-		if sendErr := s.sendNoWait(s.goAway(goAwayProtoErr)); sendErr != nil {
-			s.logger.Printf("[WARN] yamux: failed to send go away: %v", sendErr)
-		}
-		return ErrDuplicateStream
-	}
-
-	// Register the stream
-	s.streams[id] = stream
-
-	// Check if we've exceeded the backlog
-	select {
-	case s.acceptCh <- stream:
-		return nil
-	default:
-		// Backlog exceeded! RST the stream
-		s.logger.Printf("[WARN] yamux: backlog exceeded, forcing connection reset")
-		delete(s.streams, id)
-		stream.sendHdr.encode(typeWindowUpdate, flagRST, id, 0)
-		return s.sendNoWait(stream.sendHdr)
-	}
-}
-
-// closeStream is used to close a stream once both sides have
-// issued a close. If there was an in-flight SYN and the stream
-// was not yet established, then this will give the credit back.
-func (s *Session) closeStream(id uint32) {
-	s.streamLock.Lock()
-	if _, ok := s.inflight[id]; ok {
-		select {
-		case <-s.synCh:
-		default:
-			s.logger.Printf("[ERR] yamux: SYN tracking out of sync")
-		}
-	}
-	delete(s.streams, id)
-	s.streamLock.Unlock()
-}
-
-// establishStream is used to mark a stream that was in the
-// SYN Sent state as established.
-func (s *Session) establishStream(id uint32) {
-	s.streamLock.Lock()
-	if _, ok := s.inflight[id]; ok {
-		delete(s.inflight, id)
-	} else {
-		s.logger.Printf("[ERR] yamux: established stream without inflight SYN (no tracking entry)")
-	}
-	select {
-	case <-s.synCh:
-	default:
-		s.logger.Printf("[ERR] yamux: established stream without inflight SYN (didn't have semaphore)")
-	}
-	s.streamLock.Unlock()
-}

vendor/github.com/hashicorp/yamux/stream.go

@@ -1,457 +0,0 @@
-package yamux
-
-import (
-	"bytes"
-	"io"
-	"sync"
-	"sync/atomic"
-	"time"
-)
-
-type streamState int
-
-const (
-	streamInit streamState = iota
-	streamSYNSent
-	streamSYNReceived
-	streamEstablished
-	streamLocalClose
-	streamRemoteClose
-	streamClosed
-	streamReset
-)
-
-// Stream is used to represent a logical stream
-// within a session.
-type Stream struct {
-	recvWindow uint32
-	sendWindow uint32
-
-	id      uint32
-	session *Session
-
-	state     streamState
-	stateLock sync.Mutex
-
-	recvBuf  *bytes.Buffer
-	recvLock sync.Mutex
-
-	controlHdr     header
-	controlErr     chan error
-	controlHdrLock sync.Mutex
-
-	sendHdr  header
-	sendErr  chan error
-	sendLock sync.Mutex
-
-	recvNotifyCh chan struct{}
-	sendNotifyCh chan struct{}
-
-	readDeadline  time.Time
-	writeDeadline time.Time
-}
-
-// newStream is used to construct a new stream within
-// a given session for an ID
-func newStream(session *Session, id uint32, state streamState) *Stream {
-	s := &Stream{
-		id:           id,
-		session:      session,
-		state:        state,
-		controlHdr:   header(make([]byte, headerSize)),
-		controlErr:   make(chan error, 1),
-		sendHdr:      header(make([]byte, headerSize)),
-		sendErr:      make(chan error, 1),
-		recvWindow:   initialStreamWindow,
-		sendWindow:   initialStreamWindow,
-		recvNotifyCh: make(chan struct{}, 1),
-		sendNotifyCh: make(chan struct{}, 1),
-	}
-	return s
-}
-
-// Session returns the associated stream session
-func (s *Stream) Session() *Session {
-	return s.session
-}
-
-// StreamID returns the ID of this stream
-func (s *Stream) StreamID() uint32 {
-	return s.id
-}
-
-// Read is used to read from the stream
-func (s *Stream) Read(b []byte) (n int, err error) {
-	defer asyncNotify(s.recvNotifyCh)
-START:
-	s.stateLock.Lock()
-	switch s.state {
-	case streamLocalClose:
-		fallthrough
-	case streamRemoteClose:
-		fallthrough
-	case streamClosed:
-		s.recvLock.Lock()
-		if s.recvBuf == nil || s.recvBuf.Len() == 0 {
-			s.recvLock.Unlock()
-			s.stateLock.Unlock()
-			return 0, io.EOF
-		}
-		s.recvLock.Unlock()
-	case streamReset:
-		s.stateLock.Unlock()
-		return 0, ErrConnectionReset
-	}
-	s.stateLock.Unlock()
-
-	// If there is no data available, block
-	s.recvLock.Lock()
-	if s.recvBuf == nil || s.recvBuf.Len() == 0 {
-		s.recvLock.Unlock()
-		goto WAIT
-	}
-
-	// Read any bytes
-	n, _ = s.recvBuf.Read(b)
-	s.recvLock.Unlock()
-
-	// Send a window update potentially
-	err = s.sendWindowUpdate()
-	return n, err
-
-WAIT:
-	var timeout <-chan time.Time
-	var timer *time.Timer
-	if !s.readDeadline.IsZero() {
-		delay := s.readDeadline.Sub(time.Now())
-		timer = time.NewTimer(delay)
-		timeout = timer.C
-	}
-	select {
-	case <-s.recvNotifyCh:
-		if timer != nil {
-			timer.Stop()
-		}
-		goto START
-	case <-timeout:
-		return 0, ErrTimeout
-	}
-}
-
-// Write is used to write to the stream
-func (s *Stream) Write(b []byte) (n int, err error) {
-	s.sendLock.Lock()
-	defer s.sendLock.Unlock()
-	total := 0
-	for total < len(b) {
-		n, err := s.write(b[total:])
-		total += n
-		if err != nil {
-			return total, err
-		}
-	}
-	return total, nil
-}
-
-// write is used to write to the stream, may return on
-// a short write.
-func (s *Stream) write(b []byte) (n int, err error) {
-	var flags uint16
-	var max uint32
-	var body io.Reader
-START:
-	s.stateLock.Lock()
-	switch s.state {
-	case streamLocalClose:
-		fallthrough
-	case streamClosed:
-		s.stateLock.Unlock()
-		return 0, ErrStreamClosed
-	case streamReset:
-		s.stateLock.Unlock()
-		return 0, ErrConnectionReset
-	}
-	s.stateLock.Unlock()
-
-	// If there is no data available, block
-	window := atomic.LoadUint32(&s.sendWindow)
-	if window == 0 {
-		goto WAIT
-	}
-
-	// Determine the flags if any
-	flags = s.sendFlags()
-
-	// Send up to our send window
-	max = min(window, uint32(len(b)))
-	body = bytes.NewReader(b[:max])
-
-	// Send the header
-	s.sendHdr.encode(typeData, flags, s.id, max)
-	if err := s.session.waitForSendErr(s.sendHdr, body, s.sendErr); err != nil {
-		return 0, err
-	}
-
-	// Reduce our send window
-	atomic.AddUint32(&s.sendWindow, ^uint32(max-1))
-
-	// Unlock
-	return int(max), err
-
-WAIT:
-	var timeout <-chan time.Time
-	if !s.writeDeadline.IsZero() {
-		delay := s.writeDeadline.Sub(time.Now())
-		timeout = time.After(delay)
-	}
-	select {
-	case <-s.sendNotifyCh:
-		goto START
-	case <-timeout:
-		return 0, ErrTimeout
-	}
-	return 0, nil
-}
-
-// sendFlags determines any flags that are appropriate
-// based on the current stream state
-func (s *Stream) sendFlags() uint16 {
-	s.stateLock.Lock()
-	defer s.stateLock.Unlock()
-	var flags uint16
-	switch s.state {
-	case streamInit:
-		flags |= flagSYN
-		s.state = streamSYNSent
-	case streamSYNReceived:
-		flags |= flagACK
-		s.state = streamEstablished
-	}
-	return flags
-}
-
-// sendWindowUpdate potentially sends a window update enabling
-// further writes to take place. Must be invoked with the lock.
-func (s *Stream) sendWindowUpdate() error {
-	s.controlHdrLock.Lock()
-	defer s.controlHdrLock.Unlock()
-
-	// Determine the delta update
-	max := s.session.config.MaxStreamWindowSize
-	delta := max - atomic.LoadUint32(&s.recvWindow)
-
-	// Determine the flags if any
-	flags := s.sendFlags()
-
-	// Check if we can omit the update
-	if delta < (max/2) && flags == 0 {
-		return nil
-	}
-
-	// Update our window
-	atomic.AddUint32(&s.recvWindow, delta)
-
-	// Send the header
-	s.controlHdr.encode(typeWindowUpdate, flags, s.id, delta)
-	if err := s.session.waitForSendErr(s.controlHdr, nil, s.controlErr); err != nil {
-		return err
-	}
-	return nil
-}
-
-// sendClose is used to send a FIN
-func (s *Stream) sendClose() error {
-	s.controlHdrLock.Lock()
-	defer s.controlHdrLock.Unlock()
-
-	flags := s.sendFlags()
-	flags |= flagFIN
-	s.controlHdr.encode(typeWindowUpdate, flags, s.id, 0)
-	if err := s.session.waitForSendErr(s.controlHdr, nil, s.controlErr); err != nil {
-		return err
-	}
-	return nil
-}
-
-// Close is used to close the stream
-func (s *Stream) Close() error {
-	closeStream := false
-	s.stateLock.Lock()
-	switch s.state {
-	// Opened means we need to signal a close
-	case streamSYNSent:
-		fallthrough
-	case streamSYNReceived:
-		fallthrough
-	case streamEstablished:
-		s.state = streamLocalClose
-		goto SEND_CLOSE
-
-	case streamLocalClose:
-	case streamRemoteClose:
-		s.state = streamClosed
-		closeStream = true
-		goto SEND_CLOSE
-
-	case streamClosed:
-	case streamReset:
-	default:
-		panic("unhandled state")
-	}
-	s.stateLock.Unlock()
-	return nil
-SEND_CLOSE:
-	s.stateLock.Unlock()
-	s.sendClose()
-	s.notifyWaiting()
-	if closeStream {
-		s.session.closeStream(s.id)
-	}
-	return nil
-}
-
-// forceClose is used for when the session is exiting
-func (s *Stream) forceClose() {
-	s.stateLock.Lock()
-	s.state = streamClosed
-	s.stateLock.Unlock()
-	s.notifyWaiting()
-}
-
-// processFlags is used to update the state of the stream
-// based on set flags, if any. Lock must be held
-func (s *Stream) processFlags(flags uint16) error {
-	// Close the stream without holding the state lock
-	closeStream := false
-	defer func() {
-		if closeStream {
-			s.session.closeStream(s.id)
-		}
-	}()
-
-	s.stateLock.Lock()
-	defer s.stateLock.Unlock()
-	if flags&flagACK == flagACK {
-		if s.state == streamSYNSent {
-			s.state = streamEstablished
-		}
-		s.session.establishStream(s.id)
-	}
-	if flags&flagFIN == flagFIN {
-		switch s.state {
-		case streamSYNSent:
-			fallthrough
-		case streamSYNReceived:
-			fallthrough
-		case streamEstablished:
-			s.state = streamRemoteClose
-			s.notifyWaiting()
-		case streamLocalClose:
-			s.state = streamClosed
-			closeStream = true
-			s.notifyWaiting()
-		default:
-			s.session.logger.Printf("[ERR] yamux: unexpected FIN flag in state %d", s.state)
-			return ErrUnexpectedFlag
-		}
-	}
-	if flags&flagRST == flagRST {
-		s.state = streamReset
-		closeStream = true
-		s.notifyWaiting()
-	}
-	return nil
-}
-
-// notifyWaiting notifies all the waiting channels
-func (s *Stream) notifyWaiting() {
-	asyncNotify(s.recvNotifyCh)
-	asyncNotify(s.sendNotifyCh)
-}
-
-// incrSendWindow updates the size of our send window
-func (s *Stream) incrSendWindow(hdr header, flags uint16) error {
-	if err := s.processFlags(flags); err != nil {
-		return err
-	}
-
-	// Increase window, unblock a sender
-	atomic.AddUint32(&s.sendWindow, hdr.Length())
-	asyncNotify(s.sendNotifyCh)
-	return nil
-}
-
-// readData is used to handle a data frame
-func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
-	if err := s.processFlags(flags); err != nil {
-		return err
-	}
-
-	// Check that our recv window is not exceeded
-	length := hdr.Length()
-	if length == 0 {
-		return nil
-	}
-	if remain := atomic.LoadUint32(&s.recvWindow); length > remain {
-		s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, remain, length)
-		return ErrRecvWindowExceeded
-	}
-
-	// Wrap in a limited reader
-	conn = &io.LimitedReader{R: conn, N: int64(length)}
-
-	// Copy into buffer
-	s.recvLock.Lock()
-	if s.recvBuf == nil {
-		// Allocate the receive buffer just-in-time to fit the full data frame.
-		// This way we can read in the whole packet without further allocations.
-		s.recvBuf = bytes.NewBuffer(make([]byte, 0, length))
-	}
-	if _, err := io.Copy(s.recvBuf, conn); err != nil {
-		s.session.logger.Printf("[ERR] yamux: Failed to read stream data: %v", err)
-		s.recvLock.Unlock()
-		return err
-	}
-
-	// Decrement the receive window
-	atomic.AddUint32(&s.recvWindow, ^uint32(length-1))
-	s.recvLock.Unlock()
-
-	// Unblock any readers
-	asyncNotify(s.recvNotifyCh)
-	return nil
-}
-
-// SetDeadline sets the read and write deadlines
-func (s *Stream) SetDeadline(t time.Time) error {
-	if err := s.SetReadDeadline(t); err != nil {
-		return err
-	}
-	if err := s.SetWriteDeadline(t); err != nil {
-		return err
-	}
-	return nil
-}
-
-// SetReadDeadline sets the deadline for future Read calls.
-func (s *Stream) SetReadDeadline(t time.Time) error {
-	s.readDeadline = t
-	return nil
-}
-
-// SetWriteDeadline sets the deadline for future Write calls
-func (s *Stream) SetWriteDeadline(t time.Time) error {
-	s.writeDeadline = t
-	return nil
-}
-
-// Shrink is used to compact the amount of buffers utilized
-// This is useful when using Yamux in a connection pool to reduce
-// the idle memory utilization.
-func (s *Stream) Shrink() {
-	s.recvLock.Lock()
-	if s.recvBuf != nil && s.recvBuf.Len() == 0 {
-		s.recvBuf = nil
-	}
-	s.recvLock.Unlock()
-}

vendor/github.com/hashicorp/yamux/util.go

@@ -1,28 +0,0 @@
-package yamux
-
-// asyncSendErr is used to try an async send of an error
-func asyncSendErr(ch chan error, err error) {
-	if ch == nil {
-		return
-	}
-	select {
-	case ch <- err:
-	default:
-	}
-}
-
-// asyncNotify is used to signal a waiting goroutine
-func asyncNotify(ch chan struct{}) {
-	select {
-	case ch <- struct{}{}:
-	default:
-	}
-}
-
-// min computes the minimum of two values
-func min(a, b uint32) uint32 {
-	if a < b {
-		return a
-	}
-	return b
-}

vendor/github.com/xtaci/kcp-go/emitter.go

@@ -7,17 +7,17 @@ import (
 
 var defaultEmitter Emitter
 
-const emitQueue = 8192
-
 func init() {
 	defaultEmitter.init()
 }
 
 type (
+	// packet emit request
 	emitPacket struct {
-		conn    net.PacketConn
-		to      net.Addr
-		data    []byte
+		conn net.PacketConn
+		to   net.Addr
+		data []byte
+		// mark this packet should recycle to global xmitBuf
 		recycle bool
 	}
 
@@ -28,7 +28,7 @@ type (
 )
 
 func (e *Emitter) init() {
-	e.ch = make(chan emitPacket, emitQueue)
+	e.ch = make(chan emitPacket)
 	go e.emitTask()
 }
 
@@ -36,7 +36,7 @@ func (e *Emitter) init() {
 func (e *Emitter) emitTask() {
 	for p := range e.ch {
 		if n, err := p.conn.WriteTo(p.data, p.to); err == nil {
-			atomic.AddUint64(&DefaultSnmp.OutSegs, 1)
+			atomic.AddUint64(&DefaultSnmp.OutPkts, 1)
 			atomic.AddUint64(&DefaultSnmp.OutBytes, uint64(n))
 		}
 		if p.recycle {

vendor/github.com/xtaci/kcp-go/kcp.go

@@ -117,6 +117,7 @@ func (seg *Segment) encode(ptr []byte) []byte {
 	ptr = ikcp_encode32u(ptr, seg.sn)
 	ptr = ikcp_encode32u(ptr, seg.una)
 	ptr = ikcp_encode32u(ptr, uint32(len(seg.data)))
+	atomic.AddUint64(&DefaultSnmp.OutSegs, 1)
 	return ptr
 }
 
@@ -484,9 +485,10 @@ func (kcp *KCP) Input(data []byte, regular, ackNoDelay bool) int {
 	}
 
 	var maxack uint32
+	var lastackts uint32
 	var flag int
+	var inSegs uint64
 
-	current := currentMs()
 	for {
 		var ts, sn, length, una, conv uint32
 		var wnd uint16
@@ -525,10 +527,6 @@ func (kcp *KCP) Input(data []byte, regular, ackNoDelay bool) int {
 		kcp.shrink_buf()
 
 		if cmd == IKCP_CMD_ACK {
-			if _itimediff(current, ts) >= 0 {
-				kcp.update_ack(_itimediff(current, ts))
-			}
-
 			kcp.parse_ack(sn)
 			kcp.shrink_buf()
 			if flag == 0 {
@@ -537,6 +535,7 @@ func (kcp *KCP) Input(data []byte, regular, ackNoDelay bool) int {
 			} else if _itimediff(sn, maxack) > 0 {
 				maxack = sn
 			}
+			lastackts = ts
 		} else if cmd == IKCP_CMD_PUSH {
 			if _itimediff(sn, kcp.rcv_nxt+kcp.rcv_wnd) < 0 {
 				kcp.ack_push(sn, ts)
@@ -567,11 +566,17 @@ func (kcp *KCP) Input(data []byte, regular, ackNoDelay bool) int {
 			return -3
 		}
 
+		inSegs++
 		data = data[length:]
 	}
+	atomic.AddUint64(&DefaultSnmp.InSegs, inSegs)
 
 	if flag != 0 && regular {
 		kcp.parse_fastack(maxack)
+		current := currentMs()
+		if _itimediff(current, lastackts) >= 0 {
+			kcp.update_ack(_itimediff(current, lastackts))
+		}
 	}
 
 	if _itimediff(kcp.snd_una, una) > 0 {
@@ -660,9 +665,9 @@ func (kcp *KCP) flush(ackOnly bool) {
 		return
 	}
 
-	current := currentMs()
 	// probe window size (if remote window size equals zero)
 	if kcp.rmt_wnd == 0 {
+		current := currentMs()
 		if kcp.probe_wait == 0 {
 			kcp.probe_wait = IKCP_PROBE_INIT
 			kcp.ts_probe = current + kcp.probe_wait
@@ -742,6 +747,7 @@ func (kcp *KCP) flush(ackOnly bool) {
 
 	// send new segments
 	for k := len(kcp.snd_buf) - newSegsCount; k < len(kcp.snd_buf); k++ {
+		current := currentMs()
 		segment := &kcp.snd_buf[k]
 		segment.xmit++
 		segment.rto = kcp.rx_rto
@@ -765,6 +771,7 @@ func (kcp *KCP) flush(ackOnly bool) {
 
 	// check for retransmissions
 	for k := 0; k < len(kcp.snd_buf)-newSegsCount; k++ {
+		current := currentMs()
 		segment := &kcp.snd_buf[k]
 		needsend := false
 		if _itimediff(current, segment.resendts) >= 0 { // RTO

vendor/github.com/xtaci/kcp-go/sess.go

@@ -23,13 +23,23 @@ func (errTimeout) Temporary() bool { return true }
 func (errTimeout) Error() string   { return "i/o timeout" }
 
 const (
-	defaultWndSize  = 128 // default window size, in packet
-	nonceSize       = 16  // magic number
-	crcSize         = 4   // 4bytes packet checksum
+	// 16-bytes magic number for each packet
+	nonceSize = 16
+
+	// 4-bytes packet checksum
+	crcSize = 4
+
+	// overall crypto header size
 	cryptHeaderSize = nonceSize + crcSize
-	mtuLimit        = 2048
-	rxQueueLimit    = 8192
-	rxFECMulti      = 3 // FEC keeps rxFECMulti* (dataShard+parityShard) ordered packets in memory
+
+	// maximum packet size
+	mtuLimit = 2048
+
+	// packet receiving channel limit
+	rxQueueLimit = 2048
+
+	// FEC keeps rxFECMulti* (dataShard+parityShard) ordered packets in memory
+	rxFECMulti = 3
 )
 
 const (
@@ -38,8 +48,12 @@ const (
 )
 
 var (
+	// global packet buffer
+	// shared among sending/receiving/FEC
 	xmitBuf sync.Pool
-	sid     uint32
+
+	// monotonic session id
+	sid uint32
 )
 
 func init() {
@@ -51,36 +65,39 @@ func init() {
 type (
 	// UDPSession defines a KCP session implemented by UDP
 	UDPSession struct {
-		// core
-		sid      uint32
-		conn     net.PacketConn // the underlying packet socket
-		kcp      *KCP           // the core ARQ
-		l        *Listener      // point to server listener if it's a server socket
-		block    BlockCrypt     // encryption
-		sockbuff []byte         // kcp receiving is based on packet, I turn it into stream
-
-		// forward error correction
-		fec              *FEC
-		fecDataShards    [][]byte
-		fecHeaderOffset  int
-		fecPayloadOffset int
-		fecCnt           int // count datashard
-		fecMaxSize       int // record maximum data length in datashard
+		sid   uint32         // session id(monotonic)
+		conn  net.PacketConn // the underlying packet connection
+		kcp   *KCP           // KCP ARQ protocol
+		l     *Listener      // point to the Listener if it's accepted by Listener
+		block BlockCrypt     // block encryption
+
+		// kcp receiving is based on packets
+		// sockbuff turns packets into stream
+		sockbuff []byte
+
+		fec           *FEC     // forward error correction
+		fecDataShards [][]byte // data shards cache
+		fecShardCount int      // count the number of datashards collected
+		fecMaxSize    int      // record maximum data length in datashard
+
+		fecHeaderOffset  int // FEC header offset in packet
+		fecPayloadOffset int // FEC payload offset in packet
 
 		// settings
-		remote         net.Addr
+		remote         net.Addr  // remote peer address
 		rd             time.Time // read deadline
 		wd             time.Time // write deadline
-		headerSize     int
-		updateInterval int32
-		ackNoDelay     bool
+		headerSize     int       // the overall header size added before KCP frame
+		updateInterval int32     // interval in seconds to call kcp.flush()
+		ackNoDelay     bool      // send ack immediately for each incoming packet
 
 		// notifications
-		die          chan struct{}
-		chReadEvent  chan struct{}
-		chWriteEvent chan struct{}
-		isClosed     bool
-		mu           sync.Mutex
+		die          chan struct{} // notify session has Closed
+		chReadEvent  chan struct{} // notify Read() can be called without blocking
+		chWriteEvent chan struct{} // notify Write() can be called without blocking
+
+		isClosed bool // flag the session has Closed
+		mu       sync.Mutex
 	}
 
 	setReadBuffer interface {
@@ -132,7 +149,6 @@ func newUDPSession(conv uint32, dataShards, parityShards int, l *Listener, conn
 			sess.output(buf[:size])
 		}
 	})
-	sess.kcp.WndSize(defaultWndSize, defaultWndSize)
 	sess.kcp.SetMtu(IKCP_MTU_DEF - sess.headerSize)
 	sess.kcp.setFEC(dataShards, parityShards)
 
@@ -324,11 +340,16 @@ func (s *UDPSession) SetWindowSize(sndwnd, rcvwnd int) {
 	s.kcp.WndSize(sndwnd, rcvwnd)
 }
 
-// SetMtu sets the maximum transmission unit
-func (s *UDPSession) SetMtu(mtu int) {
+// SetMtu sets the maximum transmission unit(not including UDP header)
+func (s *UDPSession) SetMtu(mtu int) bool {
+	if mtu > mtuLimit {
+		return false
+	}
+
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.kcp.SetMtu(mtu - s.headerSize)
+	return true
 }
 
 // SetStreamMode toggles the stream mode on/off
@@ -416,9 +437,9 @@ func (s *UDPSession) output(buf []byte) {
 
 		// copy data to fec datashards
 		sz := len(ext)
-		s.fecDataShards[s.fecCnt] = s.fecDataShards[s.fecCnt][:sz]
-		copy(s.fecDataShards[s.fecCnt], ext)
-		s.fecCnt++
+		s.fecDataShards[s.fecShardCount] = s.fecDataShards[s.fecShardCount][:sz]
+		copy(s.fecDataShards[s.fecShardCount], ext)
+		s.fecShardCount++
 
 		// record max datashard length
 		if sz > s.fecMaxSize {
@@ -426,7 +447,7 @@ func (s *UDPSession) output(buf []byte) {
 		}
 
 		//  calculate Reed-Solomon Erasure Code
-		if s.fecCnt == s.fec.dataShards {
+		if s.fecShardCount == s.fec.dataShards {
 			// bzero each datashard's tail
 			for i := 0; i < s.fec.dataShards; i++ {
 				shard := s.fecDataShards[i]
@@ -442,7 +463,7 @@ func (s *UDPSession) output(buf []byte) {
 			}
 
 			// reset counters to zero
-			s.fecCnt = 0
+			s.fecShardCount = 0
 			s.fecMaxSize = 0
 		}
 	}
@@ -557,7 +578,7 @@ func (s *UDPSession) kcpInput(data []byte) {
 		s.mu.Unlock()
 	}
 
-	atomic.AddUint64(&DefaultSnmp.InSegs, 1)
+	atomic.AddUint64(&DefaultSnmp.InPkts, 1)
 	atomic.AddUint64(&DefaultSnmp.InBytes, uint64(len(data)))
 	if fecParityShards > 0 {
 		atomic.AddUint64(&DefaultSnmp.FECParityShards, fecParityShards)
@@ -626,21 +647,23 @@ func (s *UDPSession) readLoop() {
 type (
 	// Listener defines a server listening for connections
 	Listener struct {
-		block                    BlockCrypt
-		dataShards, parityShards int
-		fec                      *FEC // for fec init test
-		conn                     net.PacketConn
-		sessions                 map[string]*UDPSession
-		chAccepts                chan *UDPSession
-		chDeadlinks              chan net.Addr
-		headerSize               int
-		die                      chan struct{}
-		rxbuf                    sync.Pool
-		rd                       atomic.Value
-		wd                       atomic.Value
-	}
-
-	packet struct {
+		block        BlockCrypt     // block encryption
+		dataShards   int            // FEC data shard
+		parityShards int            // FEC parity shard
+		fec          *FEC           // FEC mock initialization
+		conn         net.PacketConn // the underlying packet connection
+
+		sessions    map[string]*UDPSession // all sessions accepted by this Listener
+		chAccepts   chan *UDPSession       // Listen() backlog
+		chDeadlinks chan net.Addr          // session close queue
+		headerSize  int                    // the overall header size added before KCP frame
+		die         chan struct{}          // notify the listener has closed
+		rd          atomic.Value           // read deadline for Accept()
+		wd          atomic.Value
+	}
+
+	// incoming packet
+	inPacket struct {
 		from net.Addr
 		data []byte
 	}
@@ -648,7 +671,7 @@ type (
 
 // monitor incoming data for all connections of server
 func (l *Listener) monitor() {
-	chPacket := make(chan packet, rxQueueLimit)
+	chPacket := make(chan inPacket, rxQueueLimit)
 	go l.receiver(chPacket)
 	for {
 		select {
@@ -699,7 +722,7 @@ func (l *Listener) monitor() {
 				}
 			}
 
-			l.rxbuf.Put(raw)
+			xmitBuf.Put(raw)
 		case deadlink := <-l.chDeadlinks:
 			delete(l.sessions, deadlink.String())
 		case <-l.die:
@@ -708,11 +731,11 @@ func (l *Listener) monitor() {
 	}
 }
 
-func (l *Listener) receiver(ch chan packet) {
+func (l *Listener) receiver(ch chan inPacket) {
 	for {
-		data := l.rxbuf.Get().([]byte)[:mtuLimit]
+		data := xmitBuf.Get().([]byte)[:mtuLimit]
 		if n, from, err := l.conn.ReadFrom(data); err == nil && n >= l.headerSize+IKCP_OVERHEAD {
-			ch <- packet{from, data[:n]}
+			ch <- inPacket{from, data[:n]}
 		} else if err != nil {
 			return
 		} else {
@@ -829,9 +852,6 @@ func ServeConn(block BlockCrypt, dataShards, parityShards int, conn net.PacketCo
 	l.parityShards = parityShards
 	l.block = block
 	l.fec = newFEC(rxFECMulti*(dataShards+parityShards), dataShards, parityShards)
-	l.rxbuf.New = func() interface{} {
-		return make([]byte, mtuLimit)
-	}
 
 	// calculate header size
 	if l.block != nil {

vendor/github.com/xtaci/kcp-go/snmp.go

@@ -7,22 +7,24 @@ import (
 
 // Snmp defines network statistics indicator
 type Snmp struct {
-	BytesSent        uint64 // raw bytes sent
-	BytesReceived    uint64
-	MaxConn          uint64
-	ActiveOpens      uint64
-	PassiveOpens     uint64
-	CurrEstab        uint64 // count of connections for now
-	InErrs           uint64 // udp read errors
+	BytesSent        uint64 // bytes sent from upper level
+	BytesReceived    uint64 // bytes received to upper level
+	MaxConn          uint64 // max number of connections ever reached
+	ActiveOpens      uint64 // accumulated active open connections
+	PassiveOpens     uint64 // accumulated passive open connections
+	CurrEstab        uint64 // current number of established connections
+	InErrs           uint64 // UDP read errors reported from net.PacketConn
 	InCsumErrors     uint64 // checksum errors from CRC32
-	KCPInErrors      uint64 // packet iput errors from kcp
-	InSegs           uint64
-	OutSegs          uint64
-	InBytes          uint64 // udp bytes received
-	OutBytes         uint64 // udp bytes sent
-	RetransSegs      uint64
-	FastRetransSegs  uint64
-	EarlyRetransSegs uint64
+	KCPInErrors      uint64 // packet iput errors reported from KCP
+	InPkts           uint64 // incoming packets count
+	OutPkts          uint64 // outgoing packets count
+	InSegs           uint64 // incoming KCP segments
+	OutSegs          uint64 // outgoing KCP segments
+	InBytes          uint64 // UDP bytes received
+	OutBytes         uint64 // UDP bytes sent
+	RetransSegs      uint64 // accmulated retransmited segments
+	FastRetransSegs  uint64 // accmulated fast retransmitted segments
+	EarlyRetransSegs uint64 // accmulated early retransmitted segments
 	LostSegs         uint64 // number of segs infered as lost
 	RepeatSegs       uint64 // number of segs duplicated
 	FECRecovered     uint64 // correct packets recovered from FEC
@@ -47,6 +49,8 @@ func (s *Snmp) Header() []string {
 		"InErrs",
 		"InCsumErrors",
 		"KCPInErrors",
+		"InPkts",
+		"OutPkts",
 		"InSegs",
 		"OutSegs",
 		"InBytes",
@@ -76,6 +80,8 @@ func (s *Snmp) ToSlice() []string {
 		fmt.Sprint(snmp.InErrs),
 		fmt.Sprint(snmp.InCsumErrors),
 		fmt.Sprint(snmp.KCPInErrors),
+		fmt.Sprint(snmp.InPkts),
+		fmt.Sprint(snmp.OutPkts),
 		fmt.Sprint(snmp.InSegs),
 		fmt.Sprint(snmp.OutSegs),
 		fmt.Sprint(snmp.InBytes),
@@ -104,6 +110,8 @@ func (s *Snmp) Copy() *Snmp {
 	d.InErrs = atomic.LoadUint64(&s.InErrs)
 	d.InCsumErrors = atomic.LoadUint64(&s.InCsumErrors)
 	d.KCPInErrors = atomic.LoadUint64(&s.KCPInErrors)
+	d.InPkts = atomic.LoadUint64(&s.InPkts)
+	d.OutPkts = atomic.LoadUint64(&s.OutPkts)
 	d.InSegs = atomic.LoadUint64(&s.InSegs)
 	d.OutSegs = atomic.LoadUint64(&s.OutSegs)
 	d.InBytes = atomic.LoadUint64(&s.InBytes)
@@ -131,6 +139,8 @@ func (s *Snmp) Reset() {
 	atomic.StoreUint64(&s.InErrs, 0)
 	atomic.StoreUint64(&s.InCsumErrors, 0)
 	atomic.StoreUint64(&s.KCPInErrors, 0)
+	atomic.StoreUint64(&s.InPkts, 0)
+	atomic.StoreUint64(&s.OutPkts, 0)
 	atomic.StoreUint64(&s.InSegs, 0)
 	atomic.StoreUint64(&s.OutSegs, 0)
 	atomic.StoreUint64(&s.InBytes, 0)

vendor/github.com/xtaci/kcp-go/updater.go

@@ -13,12 +13,14 @@ func init() {
 	go updater.updateTask()
 }
 
+// entry contains a session update info
 type entry struct {
 	sid uint32
 	ts  time.Time
 	s   *UDPSession
 }
 
+// a global heap managed kcp.flush() caller
 type updateHeap struct {
 	entries  []entry
 	indices  map[uint32]int

vendor/github.com/xtaci/smux/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2016-2017 Daniel Fu
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/xtaci/smux/frame.go

@@ -0,0 +1,60 @@
+package smux
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	version = 1
+)
+
+const ( // cmds
+	cmdSYN byte = iota // stream open
+	cmdFIN             // stream close, a.k.a EOF mark
+	cmdPSH             // data push
+	cmdNOP             // no operation
+)
+
+const (
+	sizeOfVer    = 1
+	sizeOfCmd    = 1
+	sizeOfLength = 2
+	sizeOfSid    = 4
+	headerSize   = sizeOfVer + sizeOfCmd + sizeOfSid + sizeOfLength
+)
+
+// Frame defines a packet from or to be multiplexed into a single connection
+type Frame struct {
+	ver  byte
+	cmd  byte
+	sid  uint32
+	data []byte
+}
+
+func newFrame(cmd byte, sid uint32) Frame {
+	return Frame{ver: version, cmd: cmd, sid: sid}
+}
+
+type rawHeader []byte
+
+func (h rawHeader) Version() byte {
+	return h[0]
+}
+
+func (h rawHeader) Cmd() byte {
+	return h[1]
+}
+
+func (h rawHeader) Length() uint16 {
+	return binary.LittleEndian.Uint16(h[2:])
+}
+
+func (h rawHeader) StreamID() uint32 {
+	return binary.LittleEndian.Uint32(h[4:])
+}
+
+func (h rawHeader) String() string {
+	return fmt.Sprintf("Version:%d Cmd:%d StreamID:%d Length:%d",
+		h.Version(), h.Cmd(), h.StreamID(), h.Length())
+}

vendor/github.com/xtaci/smux/mux.go

@@ -0,0 +1,80 @@
+package smux
+
+import (
+	"fmt"
+	"io"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// Config is used to tune the Smux session
+type Config struct {
+	// KeepAliveInterval is how often to send a NOP command to the remote
+	KeepAliveInterval time.Duration
+
+	// KeepAliveTimeout is how long the session
+	// will be closed if no data has arrived
+	KeepAliveTimeout time.Duration
+
+	// MaxFrameSize is used to control the maximum
+	// frame size to sent to the remote
+	MaxFrameSize int
+
+	// MaxReceiveBuffer is used to control the maximum
+	// number of data in the buffer pool
+	MaxReceiveBuffer int
+}
+
+// DefaultConfig is used to return a default configuration
+func DefaultConfig() *Config {
+	return &Config{
+		KeepAliveInterval: 10 * time.Second,
+		KeepAliveTimeout:  30 * time.Second,
+		MaxFrameSize:      4096,
+		MaxReceiveBuffer:  4194304,
+	}
+}
+
+// VerifyConfig is used to verify the sanity of configuration
+func VerifyConfig(config *Config) error {
+	if config.KeepAliveInterval == 0 {
+		return errors.New("keep-alive interval must be positive")
+	}
+	if config.KeepAliveTimeout < config.KeepAliveInterval {
+		return fmt.Errorf("keep-alive timeout must be larger than keep-alive interval")
+	}
+	if config.MaxFrameSize <= 0 {
+		return errors.New("max frame size must be positive")
+	}
+	if config.MaxFrameSize > 65535 {
+		return errors.New("max frame size must not be larger than 65535")
+	}
+	if config.MaxReceiveBuffer <= 0 {
+		return errors.New("max receive buffer must be positive")
+	}
+	return nil
+}
+
+// Server is used to initialize a new server-side connection.
+func Server(conn io.ReadWriteCloser, config *Config) (*Session, error) {
+	if config == nil {
+		config = DefaultConfig()
+	}
+	if err := VerifyConfig(config); err != nil {
+		return nil, err
+	}
+	return newSession(config, conn, false), nil
+}
+
+// Client is used to initialize a new client-side connection.
+func Client(conn io.ReadWriteCloser, config *Config) (*Session, error) {
+	if config == nil {
+		config = DefaultConfig()
+	}
+
+	if err := VerifyConfig(config); err != nil {
+		return nil, err
+	}
+	return newSession(config, conn, true), nil
+}

vendor/github.com/xtaci/smux/session.go

@@ -0,0 +1,335 @@
+package smux
+
+import (
+	"encoding/binary"
+	"io"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	defaultAcceptBacklog = 1024
+)
+
+const (
+	errBrokenPipe      = "broken pipe"
+	errInvalidProtocol = "invalid protocol version"
+)
+
+type writeRequest struct {
+	frame  Frame
+	result chan writeResult
+}
+
+type writeResult struct {
+	n   int
+	err error
+}
+
+// Session defines a multiplexed connection for streams
+type Session struct {
+	conn io.ReadWriteCloser
+
+	config       *Config
+	nextStreamID uint32 // next stream identifier
+
+	bucket     int32      // token bucket
+	bucketCond *sync.Cond // used for waiting for tokens
+
+	streams    map[uint32]*Stream // all streams in this session
+	streamLock sync.Mutex         // locks streams
+
+	die       chan struct{} // flag session has died
+	dieLock   sync.Mutex
+	chAccepts chan *Stream
+
+	dataReady int32 // flag data has arrived
+
+	deadline atomic.Value
+
+	writes chan writeRequest
+}
+
+func newSession(config *Config, conn io.ReadWriteCloser, client bool) *Session {
+	s := new(Session)
+	s.die = make(chan struct{})
+	s.conn = conn
+	s.config = config
+	s.streams = make(map[uint32]*Stream)
+	s.chAccepts = make(chan *Stream, defaultAcceptBacklog)
+	s.bucket = int32(config.MaxReceiveBuffer)
+	s.bucketCond = sync.NewCond(&sync.Mutex{})
+	s.writes = make(chan writeRequest)
+
+	if client {
+		s.nextStreamID = 1
+	} else {
+		s.nextStreamID = 2
+	}
+	go s.recvLoop()
+	go s.sendLoop()
+	go s.keepalive()
+	return s
+}
+
+// OpenStream is used to create a new stream
+func (s *Session) OpenStream() (*Stream, error) {
+	if s.IsClosed() {
+		return nil, errors.New(errBrokenPipe)
+	}
+
+	sid := atomic.AddUint32(&s.nextStreamID, 2)
+	stream := newStream(sid, s.config.MaxFrameSize, s)
+
+	if _, err := s.writeFrame(newFrame(cmdSYN, sid)); err != nil {
+		return nil, errors.Wrap(err, "writeFrame")
+	}
+
+	s.streamLock.Lock()
+	s.streams[sid] = stream
+	s.streamLock.Unlock()
+	return stream, nil
+}
+
+// AcceptStream is used to block until the next available stream
+// is ready to be accepted.
+func (s *Session) AcceptStream() (*Stream, error) {
+	var deadline <-chan time.Time
+	if d, ok := s.deadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+	select {
+	case stream := <-s.chAccepts:
+		return stream, nil
+	case <-deadline:
+		return nil, errTimeout
+	case <-s.die:
+		return nil, errors.New(errBrokenPipe)
+	}
+}
+
+// Close is used to close the session and all streams.
+func (s *Session) Close() (err error) {
+	s.dieLock.Lock()
+
+	select {
+	case <-s.die:
+		s.dieLock.Unlock()
+		return errors.New(errBrokenPipe)
+	default:
+		close(s.die)
+		s.dieLock.Unlock()
+		s.streamLock.Lock()
+		for k := range s.streams {
+			s.streams[k].sessionClose()
+		}
+		s.streamLock.Unlock()
+		s.bucketCond.Signal()
+		return s.conn.Close()
+	}
+}
+
+// IsClosed does a safe check to see if we have shutdown
+func (s *Session) IsClosed() bool {
+	select {
+	case <-s.die:
+		return true
+	default:
+		return false
+	}
+}
+
+// NumStreams returns the number of currently open streams
+func (s *Session) NumStreams() int {
+	if s.IsClosed() {
+		return 0
+	}
+	s.streamLock.Lock()
+	defer s.streamLock.Unlock()
+	return len(s.streams)
+}
+
+// SetDeadline sets a deadline used by Accept* calls.
+// A zero time value disables the deadline.
+func (s *Session) SetDeadline(t time.Time) error {
+	s.deadline.Store(t)
+	return nil
+}
+
+// notify the session that a stream has closed
+func (s *Session) streamClosed(sid uint32) {
+	s.streamLock.Lock()
+	if n := s.streams[sid].recycleTokens(); n > 0 { // return remaining tokens to the bucket
+		if atomic.AddInt32(&s.bucket, int32(n)) > 0 {
+			s.bucketCond.Signal()
+		}
+	}
+	delete(s.streams, sid)
+	s.streamLock.Unlock()
+}
+
+// returnTokens is called by stream to return token after read
+func (s *Session) returnTokens(n int) {
+	oldvalue := atomic.LoadInt32(&s.bucket)
+	newvalue := atomic.AddInt32(&s.bucket, int32(n))
+	if oldvalue <= 0 && newvalue > 0 {
+		s.bucketCond.Signal()
+	}
+
+}
+
+// session read a frame from underlying connection
+// it's data is pointed to the input buffer
+func (s *Session) readFrame(buffer []byte) (f Frame, err error) {
+	if _, err := io.ReadFull(s.conn, buffer[:headerSize]); err != nil {
+		return f, errors.Wrap(err, "readFrame")
+	}
+
+	dec := rawHeader(buffer)
+	if dec.Version() != version {
+		return f, errors.New(errInvalidProtocol)
+	}
+
+	f.ver = dec.Version()
+	f.cmd = dec.Cmd()
+	f.sid = dec.StreamID()
+	if length := dec.Length(); length > 0 {
+		if _, err := io.ReadFull(s.conn, buffer[headerSize:headerSize+length]); err != nil {
+			return f, errors.Wrap(err, "readFrame")
+		}
+		f.data = buffer[headerSize : headerSize+length]
+	}
+	return f, nil
+}
+
+// recvLoop keeps on reading from underlying connection if tokens are available
+func (s *Session) recvLoop() {
+	buffer := make([]byte, (1<<16)+headerSize)
+	for {
+		s.bucketCond.L.Lock()
+		for atomic.LoadInt32(&s.bucket) <= 0 && !s.IsClosed() {
+			s.bucketCond.Wait()
+		}
+		s.bucketCond.L.Unlock()
+
+		if s.IsClosed() {
+			return
+		}
+
+		if f, err := s.readFrame(buffer); err == nil {
+			atomic.StoreInt32(&s.dataReady, 1)
+
+			switch f.cmd {
+			case cmdNOP:
+			case cmdSYN:
+				s.streamLock.Lock()
+				if _, ok := s.streams[f.sid]; !ok {
+					stream := newStream(f.sid, s.config.MaxFrameSize, s)
+					s.streams[f.sid] = stream
+					select {
+					case s.chAccepts <- stream:
+					case <-s.die:
+					}
+				}
+				s.streamLock.Unlock()
+			case cmdFIN:
+				s.streamLock.Lock()
+				if stream, ok := s.streams[f.sid]; ok {
+					stream.markRST()
+					stream.notifyReadEvent()
+				}
+				s.streamLock.Unlock()
+			case cmdPSH:
+				s.streamLock.Lock()
+				if stream, ok := s.streams[f.sid]; ok {
+					atomic.AddInt32(&s.bucket, -int32(len(f.data)))
+					stream.pushBytes(f.data)
+					stream.notifyReadEvent()
+				}
+				s.streamLock.Unlock()
+			default:
+				s.Close()
+				return
+			}
+		} else {
+			s.Close()
+			return
+		}
+	}
+}
+
+func (s *Session) keepalive() {
+	tickerPing := time.NewTicker(s.config.KeepAliveInterval)
+	tickerTimeout := time.NewTicker(s.config.KeepAliveTimeout)
+	defer tickerPing.Stop()
+	defer tickerTimeout.Stop()
+	for {
+		select {
+		case <-tickerPing.C:
+			s.writeFrame(newFrame(cmdNOP, 0))
+			s.bucketCond.Signal() // force a signal to the recvLoop
+		case <-tickerTimeout.C:
+			if !atomic.CompareAndSwapInt32(&s.dataReady, 1, 0) {
+				s.Close()
+				return
+			}
+		case <-s.die:
+			return
+		}
+	}
+}
+
+func (s *Session) sendLoop() {
+	buf := make([]byte, (1<<16)+headerSize)
+	for {
+		select {
+		case <-s.die:
+			return
+		case request, ok := <-s.writes:
+			if !ok {
+				continue
+			}
+			buf[0] = request.frame.ver
+			buf[1] = request.frame.cmd
+			binary.LittleEndian.PutUint16(buf[2:], uint16(len(request.frame.data)))
+			binary.LittleEndian.PutUint32(buf[4:], request.frame.sid)
+			copy(buf[headerSize:], request.frame.data)
+			n, err := s.conn.Write(buf[:headerSize+len(request.frame.data)])
+
+			n -= headerSize
+			if n < 0 {
+				n = 0
+			}
+
+			result := writeResult{
+				n:   n,
+				err: err,
+			}
+
+			request.result <- result
+			close(request.result)
+		}
+	}
+}
+
+// writeFrame writes the frame to the underlying connection
+// and returns the number of bytes written if successful
+func (s *Session) writeFrame(f Frame) (n int, err error) {
+	req := writeRequest{
+		frame:  f,
+		result: make(chan writeResult, 1),
+	}
+	select {
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	case s.writes <- req:
+	}
+
+	result := <-req.result
+	return result.n, result.err
+}

vendor/github.com/xtaci/smux/stream.go

@@ -0,0 +1,261 @@
+package smux
+
+import (
+	"bytes"
+	"io"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// Stream implements net.Conn
+type Stream struct {
+	id            uint32
+	rstflag       int32
+	sess          *Session
+	buffer        bytes.Buffer
+	bufferLock    sync.Mutex
+	frameSize     int
+	chReadEvent   chan struct{} // notify a read event
+	die           chan struct{} // flag the stream has closed
+	dieLock       sync.Mutex
+	readDeadline  atomic.Value
+	writeDeadline atomic.Value
+}
+
+// newStream initiates a Stream struct
+func newStream(id uint32, frameSize int, sess *Session) *Stream {
+	s := new(Stream)
+	s.id = id
+	s.chReadEvent = make(chan struct{}, 1)
+	s.frameSize = frameSize
+	s.sess = sess
+	s.die = make(chan struct{})
+	return s
+}
+
+// ID returns the unique stream ID.
+func (s *Stream) ID() uint32 {
+	return s.id
+}
+
+// Read implements net.Conn
+func (s *Stream) Read(b []byte) (n int, err error) {
+	var deadline <-chan time.Time
+	if d, ok := s.readDeadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+
+READ:
+	select {
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	case <-deadline:
+		return n, errTimeout
+	default:
+	}
+
+	s.bufferLock.Lock()
+	n, err = s.buffer.Read(b)
+	s.bufferLock.Unlock()
+
+	if n > 0 {
+		s.sess.returnTokens(n)
+		return n, nil
+	} else if atomic.LoadInt32(&s.rstflag) == 1 {
+		_ = s.Close()
+		return 0, io.EOF
+	}
+
+	select {
+	case <-s.chReadEvent:
+		goto READ
+	case <-deadline:
+		return n, errTimeout
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	}
+}
+
+// Write implements net.Conn
+func (s *Stream) Write(b []byte) (n int, err error) {
+	var deadline <-chan time.Time
+	if d, ok := s.writeDeadline.Load().(time.Time); ok && !d.IsZero() {
+		timer := time.NewTimer(d.Sub(time.Now()))
+		defer timer.Stop()
+		deadline = timer.C
+	}
+
+	select {
+	case <-s.die:
+		return 0, errors.New(errBrokenPipe)
+	default:
+	}
+
+	frames := s.split(b, cmdPSH, s.id)
+	sent := 0
+	for k := range frames {
+		req := writeRequest{
+			frame:  frames[k],
+			result: make(chan writeResult, 1),
+		}
+
+		select {
+		case s.sess.writes <- req:
+		case <-s.die:
+			return sent, errors.New(errBrokenPipe)
+		case <-deadline:
+			return sent, errTimeout
+		}
+
+		select {
+		case result := <-req.result:
+			sent += result.n
+			if result.err != nil {
+				return sent, result.err
+			}
+		case <-s.die:
+			return sent, errors.New(errBrokenPipe)
+		case <-deadline:
+			return sent, errTimeout
+		}
+	}
+	return sent, nil
+}
+
+// Close implements net.Conn
+func (s *Stream) Close() error {
+	s.dieLock.Lock()
+
+	select {
+	case <-s.die:
+		s.dieLock.Unlock()
+		return errors.New(errBrokenPipe)
+	default:
+		close(s.die)
+		s.dieLock.Unlock()
+		s.sess.streamClosed(s.id)
+		_, err := s.sess.writeFrame(newFrame(cmdFIN, s.id))
+		return err
+	}
+}
+
+// SetReadDeadline sets the read deadline as defined by
+// net.Conn.SetReadDeadline.
+// A zero time value disables the deadline.
+func (s *Stream) SetReadDeadline(t time.Time) error {
+	s.readDeadline.Store(t)
+	return nil
+}
+
+// SetWriteDeadline sets the write deadline as defined by
+// net.Conn.SetWriteDeadline.
+// A zero time value disables the deadline.
+func (s *Stream) SetWriteDeadline(t time.Time) error {
+	s.writeDeadline.Store(t)
+	return nil
+}
+
+// SetDeadline sets both read and write deadlines as defined by
+// net.Conn.SetDeadline.
+// A zero time value disables the deadlines.
+func (s *Stream) SetDeadline(t time.Time) error {
+	if err := s.SetReadDeadline(t); err != nil {
+		return err
+	}
+	if err := s.SetWriteDeadline(t); err != nil {
+		return err
+	}
+	return nil
+}
+
+// session closes the stream
+func (s *Stream) sessionClose() {
+	s.dieLock.Lock()
+	defer s.dieLock.Unlock()
+
+	select {
+	case <-s.die:
+	default:
+		close(s.die)
+	}
+}
+
+// LocalAddr satisfies net.Conn interface
+func (s *Stream) LocalAddr() net.Addr {
+	if ts, ok := s.sess.conn.(interface {
+		LocalAddr() net.Addr
+	}); ok {
+		return ts.LocalAddr()
+	}
+	return nil
+}
+
+// RemoteAddr satisfies net.Conn interface
+func (s *Stream) RemoteAddr() net.Addr {
+	if ts, ok := s.sess.conn.(interface {
+		RemoteAddr() net.Addr
+	}); ok {
+		return ts.RemoteAddr()
+	}
+	return nil
+}
+
+// pushBytes a slice into buffer
+func (s *Stream) pushBytes(p []byte) {
+	s.bufferLock.Lock()
+	s.buffer.Write(p)
+	s.bufferLock.Unlock()
+}
+
+// recycleTokens transform remaining bytes to tokens(will truncate buffer)
+func (s *Stream) recycleTokens() (n int) {
+	s.bufferLock.Lock()
+	n = s.buffer.Len()
+	s.buffer.Reset()
+	s.bufferLock.Unlock()
+	return
+}
+
+// split large byte buffer into smaller frames, reference only
+func (s *Stream) split(bts []byte, cmd byte, sid uint32) []Frame {
+	var frames []Frame
+	for len(bts) > s.frameSize {
+		frame := newFrame(cmd, sid)
+		frame.data = bts[:s.frameSize]
+		bts = bts[s.frameSize:]
+		frames = append(frames, frame)
+	}
+	if len(bts) > 0 {
+		frame := newFrame(cmd, sid)
+		frame.data = bts
+		frames = append(frames, frame)
+	}
+	return frames
+}
+
+// notify read event
+func (s *Stream) notifyReadEvent() {
+	select {
+	case s.chReadEvent <- struct{}{}:
+	default:
+	}
+}
+
+// mark this stream has been reset
+func (s *Stream) markRST() {
+	atomic.StoreInt32(&s.rstflag, 1)
+}
+
+var errTimeout error = &timeoutError{}
+
+type timeoutError struct{}
+
+func (e *timeoutError) Error() string   { return "i/o timeout" }
+func (e *timeoutError) Timeout() bool   { return true }
+func (e *timeoutError) Temporary() bool { return true }

vendor/manifest

@@ -199,14 +199,6 @@
 			"revision": "5f1c01d9f64b941dd9582c638279d046eda6ca31",
 			"branch": "master"
 		},
-		{
-			"importpath": "github.com/hashicorp/yamux",
-			"repository": "https://github.com/hashicorp/yamux",
-			"vcs": "git",
-			"revision": "d1caa6c97c9fc1cc9e83bbe34d0603f9ff0ce8bd",
-			"branch": "master",
-			"notests": true
-		},
 		{
 			"importpath": "github.com/jackpal/gateway",
 			"repository": "https://github.com/jackpal/gateway",
@@ -354,7 +346,15 @@
 			"importpath": "github.com/xtaci/kcp-go",
 			"repository": "https://github.com/xtaci/kcp-go",
 			"vcs": "git",
-			"revision": "0ca962cb10f29ee0735ff7dec69ec7283af47f65",
+			"revision": "f918e6d43cb5e8398d91e1767ec61bed7b7b4d49",
+			"branch": "master",
+			"notests": true
+		},
+		{
+			"importpath": "github.com/xtaci/smux",
+			"repository": "https://github.com/xtaci/smux",
+			"vcs": "git",
+			"revision": "bfc89bc3f7f7791e35a10b24496cc7454a9b4a64",
 			"branch": "master",
 			"notests": true
 		},