/// <summary>
/// Process packet about this channel.
/// </summary>
/// <param name="packetType">a packet type (message number)</param>
/// <param name="packetFragment">a packet image except message number and recipient channel.</param>
public void ProcessPacket(SSH2PacketType packetType, DataFragment packetFragment)
{
if (_state == State.Closed) {
return; // ignore
}
DataFragment dataFragmentArg;
uint dataTypeCodeArg;
lock (_stateSync) {
switch (_state) {
case State.InitiatedByServer:
break;
case State.InitiatedByClient:
if (packetType == SSH2PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
RemoteChannel = reader.ReadUInt32();
_serverWindowSizeLeft = reader.ReadUInt32();
_serverMaxPacketSize = reader.ReadUInt32();
_state = State.Established;
Monitor.PulseAll(_stateSync); // notifies state change
dataFragmentArg = reader.GetRemainingDataView();
goto OnEstablished; // do it out of the lock block
}
if (packetType == SSH2PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE) {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
uint reasonCode = reader.ReadUInt32();
string description = reader.ReadUTF8String();
string lang = reader.ReadString();
goto RequestFailed; // do it out of the lock block
}
break;
case State.Closing:
if (packetType == SSH2PacketType.SSH_MSG_CHANNEL_CLOSE) {
goto SetStateClosedByClient; // do it out of the lock block
}
break;
case State.Established:
case State.Ready:
if (ProcessPacketSub(packetType, packetFragment) == SubPacketProcessResult.Consumed) {
return;
}
switch (packetType) {
case SSH2PacketType.SSH_MSG_CHANNEL_DATA: {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
int len = reader.ReadInt32();
dataFragmentArg = reader.GetRemainingDataView(len);
AdjustWindowSize(len);
}
goto OnData; // do it out of the lock block
case SSH2PacketType.SSH_MSG_CHANNEL_EXTENDED_DATA: {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
dataTypeCodeArg = reader.ReadUInt32();
int len = reader.ReadInt32();
dataFragmentArg = reader.GetRemainingDataView(len);
AdjustWindowSize(len);
}
goto OnExtendedData; // do it out of the lock block
case SSH2PacketType.SSH_MSG_CHANNEL_REQUEST: {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
string request = reader.ReadString();
bool wantReply = reader.ReadBool();
if (wantReply) { //we reject unknown requests including keep-alive check
Transmit(
0,
new SSH2Packet(SSH2PacketType.SSH_MSG_CHANNEL_FAILURE)
.WriteUInt32(RemoteChannel)
);
}
}
break;
case SSH2PacketType.SSH_MSG_CHANNEL_EOF:
goto OnEOF; // do it out of the lock block
case SSH2PacketType.SSH_MSG_CHANNEL_CLOSE:
Transmit(
0,
new SSH2Packet(SSH2PacketType.SSH_MSG_CHANNEL_CLOSE)
.WriteUInt32(RemoteChannel)
);
goto SetStateClosedByServer; // do it out of the lock block
case SSH2PacketType.SSH_MSG_CHANNEL_WINDOW_ADJUST: {
SSH2DataReader reader = new SSH2DataReader(packetFragment);
uint bytesToAdd = reader.ReadUInt32();
// some servers may not send SSH_MSG_CHANNEL_WINDOW_ADJUST.
// it is dangerous to wait this message in send procedure
_serverWindowSizeLeft += bytesToAdd;
}
goto OnWindowAdjust;
case SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS:
case SSH2PacketType.SSH_MSG_CHANNEL_FAILURE: {
_channelRequestResult.TrySet(packetType == SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS, 1000);
}
break;
default:
goto OnUnhandledPacket;
}
break; // case State.Ready
}
}
return;
OnEstablished:
_protocolEventManager.Trace(
"CH[{0}] remoteCH={1} remoteWindowSize={2} remoteMaxPacketSize={3}",
LocalChannel, RemoteChannel, _serverWindowSizeLeft, _serverMaxPacketSize);
_handler.OnEstablished(dataFragmentArg);
OnChannelEstablished();
return;
RequestFailed:
_protocolEventManager.Trace("CH[{0}] request failed", LocalChannel);
RequestFailed();
return;
SetStateClosedByClient:
_protocolEventManager.Trace("CH[{0}] closed completely", LocalChannel);
SetStateClosed(false);
return;
SetStateClosedByServer:
_protocolEventManager.Trace("CH[{0}] closed by server", LocalChannel);
SetStateClosed(true);
return;
OnData:
_handler.OnData(dataFragmentArg);
return;
OnExtendedData:
_handler.OnExtendedData(dataTypeCodeArg, dataFragmentArg);
return;
OnEOF:
_protocolEventManager.Trace("CH[{0}] caught EOF", LocalChannel);
_handler.OnEOF();
return;
OnWindowAdjust:
_protocolEventManager.Trace(
"CH[{0}] adjusted remote window size to {1}",
LocalChannel, _serverWindowSizeLeft);
return;
OnUnhandledPacket:
_handler.OnUnhandledPacket((byte)packetType, packetFragment);
return;
}
private AuthenticationResult ProcessAuthenticationResponse()
{
do {
SSH2DataReader response = new SSH2DataReader(ReceivePacket());
SSH2PacketType h = (SSH2PacketType) response.ReadByte();
if (h == SSH2PacketType.SSH_MSG_USERAUTH_FAILURE) {
string msg = response.ReadString();
TraceReceptionEvent(h, "user authentication failed:" + msg);
return AuthenticationResult.Failure;
}
else if (h == SSH2PacketType.SSH_MSG_USERAUTH_BANNER) {
TraceReceptionEvent(h, "");
}
else if (h == SSH2PacketType.SSH_MSG_USERAUTH_SUCCESS) {
TraceReceptionEvent(h, "user authentication succeeded");
_packetizer.SetInnerHandler(new CallbackSSH2PacketHandler(this));
return AuthenticationResult.Success; //successfully exit
}
else if (h == SSH2PacketType.SSH_MSG_USERAUTH_INFO_REQUEST) {
string name = response.ReadUTF8String();
string inst = response.ReadUTF8String();
string lang = response.ReadString();
int num = response.ReadInt32();
string[] prompts = new string[num];
for (int i = 0; i < num; i++) {
prompts[i] = response.ReadUTF8String();
bool echo = response.ReadBool();
}
_eventReceiver.OnAuthenticationPrompt(prompts);
_requiredResponseCount = num;
return AuthenticationResult.Prompt;
}
else
throw new SSHException("protocol error: unexpected packet type " + h);
} while (true);
}
private void OpenShellOrSubsystem(ISSHChannelEventReceiver receiver, SSH2PacketType pt, SSH2DataReader reader, string scheme)
{
if (_negotiationStatus == NegotiationStatus.WaitingChannelConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(new SSHException("opening channel failed; packet type=" + pt));
else {
int errcode = reader.ReadInt32();
string msg = reader.ReadUTF8String();
receiver.OnChannelError(new SSHException(msg));
}
// Close() shouldn't be called because remote channel number is not given yet.
// We just remove an event receiver from the collection of channels.
// FIXME: _negotiationStatus sould be set an error status ?
_connection.ChannelCollection.UnregisterChannelEventReceiver(_localID);
}
else {
_remoteID = reader.ReadInt32();
_allowedDataSize = reader.ReadUInt32();
_serverMaxPacketSize = reader.ReadInt32();
if (_type == ChannelType.Subsystem) {
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingSubsystemConfirmation;
}
else {
//open pty
SSHConnectionParameter param = _connection.Param;
Transmit(
0,
new SSH2Packet(SSH2PacketType.SSH_MSG_CHANNEL_REQUEST)
.WriteInt32(_remoteID)
.WriteString("pty-req")
.WriteBool(true)
.WriteString(param.TerminalName)
.WriteInt32(param.TerminalWidth)
.WriteInt32(param.TerminalHeight)
.WriteInt32(param.TerminalPixelWidth)
.WriteInt32(param.TerminalPixelHeight)
.WriteAsString(new byte[0])
);
if (_connection.IsEventTracerAvailable) {
_connection.TraceTransmissionEvent(
SSH2PacketType.SSH_MSG_CHANNEL_REQUEST, "pty-req", "terminal={0} width={1} height={2}",
param.TerminalName, param.TerminalWidth, param.TerminalHeight);
}
_negotiationStatus = NegotiationStatus.WaitingPtyReqConfirmation;
}
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingPtyReqConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("opening pty failed"));
Close();
}
else {
//agent request (optional)
if (_connection.Param.AgentForward != null) {
Transmit(
0,
new SSH2Packet(SSH2PacketType.SSH_MSG_CHANNEL_REQUEST)
.WriteInt32(_remoteID)
.WriteString("*****@*****.**")
.WriteBool(true)
);
_connection.TraceTransmissionEvent(SSH2PacketType.SSH_MSG_CHANNEL_REQUEST, "auth-agent-req", "");
_negotiationStatus = NegotiationStatus.WaitingAuthAgentReqConfirmation;
}
else {
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingShellConfirmation;
}
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingAuthAgentReqConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS && pt != SSH2PacketType.SSH_MSG_CHANNEL_FAILURE) {
receiver.OnChannelError(new SSHException("auth-agent-req error"));
Close();
}
else { //auth-agent-req is optional
_connection.SetAgentForwardConfirmed(pt == SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS);
_connection.TraceReceptionEvent(pt, "auth-agent-req");
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingShellConfirmation;
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingShellConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("Opening shell failed: packet type=" + pt.ToString()));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingSubsystemConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("Opening subsystem failed: packet type=" + pt.ToString()));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
}
private void ReceivePortForwardingResponse(ISSHChannelEventReceiver receiver, SSH2PacketType pt, SSH2DataReader reader)
{
if (_negotiationStatus == NegotiationStatus.WaitingChannelConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(new SSHException("opening channel failed; packet type=" + pt));
else {
int errcode = reader.ReadInt32();
string msg = reader.ReadUTF8String();
receiver.OnChannelError(new SSHException(msg));
}
Close();
}
else {
_remoteID = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
_negotiationStatus = NegotiationStatus.Ready;
receiver.OnChannelReady();
}
}
else
throw new SSHException("internal state error");
}
// sending "exec" service for SCP protocol.
private void ExecCommand(ISSHChannelEventReceiver receiver, SSH2PacketType pt, SSH2DataReader reader)
{
if (_negotiationStatus == NegotiationStatus.WaitingChannelConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(new SSHException("opening channel failed; packet type=" + pt));
else {
int errcode = reader.ReadInt32();
string msg = reader.ReadUTF8String();
receiver.OnChannelError(new SSHException(msg));
}
Close();
}
else {
_remoteID = reader.ReadInt32();
_allowedDataSize = reader.ReadUInt32();
_serverMaxPacketSize = reader.ReadInt32();
// exec command
SSHConnectionParameter param = _connection.Param;
Transmit(
0,
new SSH2Packet(SSH2PacketType.SSH_MSG_CHANNEL_REQUEST)
.WriteInt32(_remoteID)
.WriteString("exec") // "exec"
.WriteBool(false) // want confirm is disabled. (*)
.WriteString(_command)
);
if (_connection.IsEventTracerAvailable)
_connection.TraceTransmissionEvent("exec command", "cmd={0}", _command);
//confirmation is omitted
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingExecCmdConfirmation) {
if (pt != SSH2PacketType.SSH_MSG_CHANNEL_DATA) {
receiver.OnChannelError(new SSHException("exec command failed"));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else
throw new SSHException("internal state error");
}