exp/ssh: messages now contain remote channel's id instead of local id

According to http://www.ietf.org/rfc/rfc4254.txt most channel messages contain the channel id of the recipient channel, not the sender id. This allows the recipient connection multiplexer to route the message to the correct channel.

This changeset fixes several messages that incorrectly send the local channel id instead of the remote channel's id.

While sessions were being created and closed in sequence channels in the channel pool were freed and reused on the server side of the connection at the same rate as was done on the client, so the channel local and remote channel ids always corresponded. As soon as I had concurrent sessions on the same clientConn the server started to complain of 'uknown channel id N' where N is the local channel id, which is actually paired with server channel id K.

R=golang-dev, dave, rsc, agl
CC=golang-dev
https://golang.org/cl/5433063

diff --git a/src/pkg/exp/ssh/client.go b/src/pkg/exp/ssh/client.go
index 9721723488bbbcc7d08a25ee6c68e0d53397f5b0..5e7b846b4079f39b0fb1eef98c81b0e24edf4fbf 100644 (file)
--- a/src/pkg/exp/ssh/client.go
+++ b/src/pkg/exp/ssh/client.go
@@ -338,7 +338,7 @@ func newClientChan(t *transport, id uint32) *clientChan {
 // Close closes the channel. This does not close the underlying connection.
 func (c *clientChan) Close() error {
        return c.writePacket(marshal(msgChannelClose, channelCloseMsg{
-               PeersId: c.id,
+               PeersId: c.peersId,
        }))
 }
 
@@ -384,7 +384,7 @@ func (c *chanlist) remove(id uint32) {
 // A chanWriter represents the stdin of a remote process.
 type chanWriter struct {
        win          chan int // receives window adjustments
-       id           uint32   // this channel's id
+       peersId      uint32   // the peers id
        rwin         int      // current rwin size
        packetWriter          // for sending channelDataMsg
 }
@@ -403,7 +403,7 @@ func (w *chanWriter) Write(data []byte) (n int, err error) {
                n = len(data)
                packet := make([]byte, 0, 9+n)
                packet = append(packet, msgChannelData,
-                       byte(w.id)>>24, byte(w.id)>>16, byte(w.id)>>8, byte(w.id),
+                       byte(w.peersId)>>24, byte(w.peersId)>>16, byte(w.peersId)>>8, byte(w.peersId),
                        byte(n)>>24, byte(n)>>16, byte(n)>>8, byte(n))
                err = w.writePacket(append(packet, data...))
                w.rwin -= n
@@ -413,7 +413,7 @@ func (w *chanWriter) Write(data []byte) (n int, err error) {
 }
 
 func (w *chanWriter) Close() error {
-       return w.writePacket(marshal(msgChannelEOF, channelEOFMsg{w.id}))
+       return w.writePacket(marshal(msgChannelEOF, channelEOFMsg{w.peersId}))
 }
 
 // A chanReader represents stdout or stderr of a remote process.
@@ -422,8 +422,8 @@ type chanReader struct {
        // If writes to this channel block, they will block mainLoop, making
        // it unable to receive new messages from the remote side.
        data         chan []byte // receives data from remote
-       id           uint32
-       packetWriter // for sending windowAdjustMsg
+       peersId      uint32      // the peers id
+       packetWriter             // for sending windowAdjustMsg
        buf          []byte
 }
 
@@ -435,7 +435,7 @@ func (r *chanReader) Read(data []byte) (int, error) {
                        n := copy(data, r.buf)
                        r.buf = r.buf[n:]
                        msg := windowAdjustMsg{
-                               PeersId:         r.id,
+                               PeersId:         r.peersId,
                                AdditionalBytes: uint32(n),
                        }
                        return n, r.writePacket(marshal(msgChannelWindowAdjust, msg))
@@ -447,7 +447,3 @@ func (r *chanReader) Read(data []byte) (int, error) {
        }
        panic("unreachable")
 }
-
-func (r *chanReader) Close() error {
-       return r.writePacket(marshal(msgChannelEOF, channelEOFMsg{r.id}))
-}

diff --git a/src/pkg/exp/ssh/session.go b/src/pkg/exp/ssh/session.go
index 181a89688396ec6f48626300ec95946c00ead890..ade61757b8f99ba58f3888da033f7382d9987657 100644 (file)
--- a/src/pkg/exp/ssh/session.go
+++ b/src/pkg/exp/ssh/session.go
@@ -53,7 +53,7 @@ type setenvRequest struct {
 // command executed by Shell or Exec.
 func (s *Session) Setenv(name, value string) error {
        req := setenvRequest{
-               PeersId:   s.id,
+               PeersId:   s.peersId,
                Request:   "env",
                WantReply: true,
                Name:      name,
@@ -84,7 +84,7 @@ type ptyRequestMsg struct {
 // RequestPty requests the association of a pty with the session on the remote host.
 func (s *Session) RequestPty(term string, h, w int) error {
        req := ptyRequestMsg{
-               PeersId:   s.id,
+               PeersId:   s.peersId,
                Request:   "pty-req",
                WantReply: true,
                Term:      term,
@@ -116,7 +116,7 @@ func (s *Session) Exec(cmd string) error {
                return errors.New("ssh: session already started")
        }
        req := execMsg{
-               PeersId:   s.id,
+               PeersId:   s.peersId,
                Request:   "exec",
                WantReply: true,
                Command:   cmd,
@@ -140,7 +140,7 @@ func (s *Session) Shell() error {
                return errors.New("ssh: session already started")
        }
        req := channelRequestMsg{
-               PeersId:   s.id,
+               PeersId:   s.peersId,
                Request:   "shell",
                WantReply: true,
        }
@@ -237,7 +237,7 @@ func (s *Session) stdin() error {
        s.copyFuncs = append(s.copyFuncs, func() error {
                _, err := io.Copy(&chanWriter{
                        packetWriter: s,
-                       id:           s.id,
+                       peersId:      s.peersId,
                        win:          s.win,
                }, s.Stdin)
                return err
@@ -252,7 +252,7 @@ func (s *Session) stdout() error {
        s.copyFuncs = append(s.copyFuncs, func() error {
                _, err := io.Copy(s.Stdout, &chanReader{
                        packetWriter: s,
-                       id:           s.id,
+                       peersId:      s.peersId,
                        data:         s.data,
                })
                return err
@@ -267,7 +267,7 @@ func (s *Session) stderr() error {
        s.copyFuncs = append(s.copyFuncs, func() error {
                _, err := io.Copy(s.Stderr, &chanReader{
                        packetWriter: s,
-                       id:           s.id,
+                       peersId:      s.peersId,
                        data:         s.dataExt,
                })
                return err

diff --git a/src/pkg/exp/ssh/tcpip.go b/src/pkg/exp/ssh/tcpip.go
index 859dedc93b3e2d166ca47fff4a80702d490de4cf..f3bbac5d19e1071a07b8e86029692b96b0bfb13b 100644 (file)
--- a/src/pkg/exp/ssh/tcpip.go
+++ b/src/pkg/exp/ssh/tcpip.go
@@ -86,12 +86,12 @@ func (c *ClientConn) dial(laddr string, lport int, raddr string, rport int) (*tc
                clientChan: ch,
                Reader: &chanReader{
                        packetWriter: ch,
-                       id:           ch.id,
+                       peersId:      ch.peersId,
                        data:         ch.data,
                },
                Writer: &chanWriter{
                        packetWriter: ch,
-                       id:           ch.id,
+                       peersId:      ch.peersId,
                        win:          ch.win,
                },
        }, nil