public void requestSubSystem(Channel c, String subSystemName) throws IOException {
PacketSessionSubsystemRequest ssr;
synchronized (c) {
if (c.state != Channel.STATE_OPEN)
throw new IOException(
"Cannot request subsystem on this channel (" + c.getReasonClosed() + ")");
ssr = new PacketSessionSubsystemRequest(c.remoteID, true, subSystemName);
c.successCounter = c.failedCounter = 0;
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent)
throw new IOException(
"Cannot request subsystem on this channel (" + c.getReasonClosed() + ")");
tm.sendMessage(ssr.getPayload());
}
try {
waitForChannelSuccessOrFailure(c);
} catch (IOException e) {
throw (IOException) new IOException("The subsystem request failed.").initCause(e);
}
}
/**
* @param charsetName The charset used to convert between Java Unicode Strings and byte encodings
*/
public void requestExecCommand(Channel c, String cmd, String charsetName) throws IOException {
PacketSessionExecCommand sm;
synchronized (c) {
if (c.state != Channel.STATE_OPEN)
throw new IOException(
"Cannot execute command on this channel (" + c.getReasonClosed() + ")");
sm = new PacketSessionExecCommand(c.remoteID, true, cmd);
c.successCounter = c.failedCounter = 0;
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent)
throw new IOException(
"Cannot execute command on this channel (" + c.getReasonClosed() + ")");
tm.sendMessage(sm.getPayload(charsetName));
}
log.debug("Executing command (channel " + c.localID + ", '" + cmd + "')");
try {
waitForChannelSuccessOrFailure(c);
} catch (IOException e) {
throw (IOException) new IOException("The execute request failed.").initCause(e);
}
}
private void waitForChannelSuccessOrFailure(Channel c) throws IOException {
boolean wasInterrupted = false;
try {
synchronized (c) {
while ((c.successCounter == 0) && (c.failedCounter == 0)) {
if (c.state != Channel.STATE_OPEN) {
String detail = c.getReasonClosed();
if (detail == null) detail = "state: " + c.state;
throw new IOException("This SSH2 channel is not open (" + detail + ")");
}
try {
c.wait();
} catch (InterruptedException ignore) {
wasInterrupted = true;
}
}
if (c.failedCounter != 0) {
throw new IOException("The server denied the request.");
}
}
} finally {
if (wasInterrupted) Thread.currentThread().interrupt();
}
}
private void waitUntilChannelOpen(Channel c) throws IOException {
boolean wasInterrupted = false;
synchronized (c) {
while (c.state == Channel.STATE_OPENING) {
try {
c.wait();
} catch (InterruptedException ignore) {
wasInterrupted = true;
}
}
if (c.state != Channel.STATE_OPEN) {
removeChannel(c.localID);
String detail = c.getReasonClosed();
if (detail == null) detail = "state: " + c.state;
throw new IOException("Could not open channel (" + detail + ")");
}
}
if (wasInterrupted) Thread.currentThread().interrupt();
}
public void requestPTY(
Channel c,
String term,
int term_width_characters,
int term_height_characters,
int term_width_pixels,
int term_height_pixels,
byte[] terminal_modes)
throws IOException {
PacketSessionPtyRequest spr;
synchronized (c) {
if (c.state != Channel.STATE_OPEN)
throw new IOException("Cannot request PTY on this channel (" + c.getReasonClosed() + ")");
spr =
new PacketSessionPtyRequest(
c.remoteID,
true,
term,
term_width_characters,
term_height_characters,
term_width_pixels,
term_height_pixels,
terminal_modes);
c.successCounter = c.failedCounter = 0;
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent)
throw new IOException("Cannot request PTY on this channel (" + c.getReasonClosed() + ")");
tm.sendMessage(spr.getPayload());
}
try {
waitForChannelSuccessOrFailure(c);
} catch (IOException e) {
throw (IOException) new IOException("PTY request failed").initCause(e);
}
}
public void requestX11(
Channel c,
boolean singleConnection,
String x11AuthenticationProtocol,
String x11AuthenticationCookie,
int x11ScreenNumber)
throws IOException {
PacketSessionX11Request psr;
synchronized (c) {
if (c.state != Channel.STATE_OPEN)
throw new IOException("Cannot request X11 on this channel (" + c.getReasonClosed() + ")");
psr =
new PacketSessionX11Request(
c.remoteID,
true,
singleConnection,
x11AuthenticationProtocol,
x11AuthenticationCookie,
x11ScreenNumber);
c.successCounter = c.failedCounter = 0;
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent)
throw new IOException("Cannot request X11 on this channel (" + c.getReasonClosed() + ")");
tm.sendMessage(psr.getPayload());
}
log.debug("Requesting X11 forwarding (Channel " + c.localID + "/" + c.remoteID + ")");
try {
waitForChannelSuccessOrFailure(c);
} catch (IOException e) {
throw (IOException) new IOException("The X11 request failed.").initCause(e);
}
}
public void requestShell(Channel c) throws IOException {
PacketSessionStartShell sm;
synchronized (c) {
if (c.state != Channel.STATE_OPEN)
throw new IOException("Cannot start shell on this channel (" + c.getReasonClosed() + ")");
sm = new PacketSessionStartShell(c.remoteID, true);
c.successCounter = c.failedCounter = 0;
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent)
throw new IOException("Cannot start shell on this channel (" + c.getReasonClosed() + ")");
tm.sendMessage(sm.getPayload());
}
try {
waitForChannelSuccessOrFailure(c);
} catch (IOException e) {
throw (IOException) new IOException("The shell request failed.").initCause(e);
}
}
public void sendData(Channel c, byte[] buffer, int pos, int len) throws IOException {
boolean wasInterrupted = false;
try {
while (len > 0) {
int thislen = 0;
byte[] msg;
synchronized (c) {
while (true) {
if (c.state == Channel.STATE_CLOSED)
throw new ChannelClosedException(
"SSH channel is closed. (" + c.getReasonClosed() + ")");
if (c.state != Channel.STATE_OPEN)
throw new ChannelClosedException("SSH channel in strange state. (" + c.state + ")");
if (c.remoteWindow != 0) break;
try {
c.wait();
} catch (InterruptedException ignore) {
wasInterrupted = true;
}
}
/* len > 0, no sign extension can happen when comparing */
thislen = (c.remoteWindow >= len) ? len : (int) c.remoteWindow;
int estimatedMaxDataLen = c.remoteMaxPacketSize - (tm.getPacketOverheadEstimate() + 9);
/* The worst case scenario =) a true bottleneck */
if (estimatedMaxDataLen <= 0) {
estimatedMaxDataLen = 1;
}
if (thislen > estimatedMaxDataLen) thislen = estimatedMaxDataLen;
c.remoteWindow -= thislen;
msg = new byte[1 + 8 + thislen];
msg[0] = Packets.SSH_MSG_CHANNEL_DATA;
msg[1] = (byte) (c.remoteID >> 24);
msg[2] = (byte) (c.remoteID >> 16);
msg[3] = (byte) (c.remoteID >> 8);
msg[4] = (byte) (c.remoteID);
msg[5] = (byte) (thislen >> 24);
msg[6] = (byte) (thislen >> 16);
msg[7] = (byte) (thislen >> 8);
msg[8] = (byte) (thislen);
System.arraycopy(buffer, pos, msg, 9, thislen);
}
synchronized (c.channelSendLock) {
if (c.closeMessageSent == true)
throw new ChannelClosedException(
"SSH channel is closed. (" + c.getReasonClosed() + ")");
tm.sendMessage(msg);
}
pos += thislen;
len -= thislen;
}
} finally {
if (wasInterrupted) Thread.currentThread().interrupt();
}
}
