X-Git-Url: http://git.nikiroo.be/?a=blobdiff_plain;f=src%2Fjexer%2Fnet%2FTelnetInputStream.java;h=be3ab507976b72e81d6763b2773b27a6d97d9a34;hb=12b90437b5f22c2ae6e9b9b14c3b62b60f6143e5;hp=f409b7a6d17084fe021a9cbeb4920f1a087f6d4e;hpb=005ec49709aab8590ee9571f17a67440969c6248;p=fanfix.git diff --git a/src/jexer/net/TelnetInputStream.java b/src/jexer/net/TelnetInputStream.java index f409b7a..be3ab50 100644 --- a/src/jexer/net/TelnetInputStream.java +++ b/src/jexer/net/TelnetInputStream.java @@ -1,29 +1,27 @@ -/** +/* * Jexer - Java Text User Interface * - * License: LGPLv3 or later - * - * This module is licensed under the GNU Lesser General Public License - * Version 3. Please see the file "COPYING" in this directory for more - * information about the GNU Lesser General Public License Version 3. + * The MIT License (MIT) * - * Copyright (C) 2015 Kevin Lamonte + * Copyright (C) 2019 Kevin Lamonte * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public License - * as published by the Free Software Foundation; either version 3 of - * the License, or (at your option) any later version. + * 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: * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. * - * You should have received a copy of the GNU Lesser General Public - * License along with this program; if not, see - * http://www.gnu.org/licenses/, or write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA - * 02110-1301 USA + * 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. * * @author Kevin Lamonte [kevin.lamonte@gmail.com] * @version 1 @@ -32,16 +30,25 @@ package jexer.net; import java.io.InputStream; import java.io.IOException; +import java.util.ArrayList; import java.util.Map; import java.util.TreeMap; -import jexer.session.SessionInfo; +import jexer.backend.SessionInfo; import static jexer.net.TelnetSocket.*; /** * TelnetInputStream works with TelnetSocket to perform the telnet protocol. */ -public final class TelnetInputStream extends InputStream implements SessionInfo { +public class TelnetInputStream extends InputStream implements SessionInfo { + + // ------------------------------------------------------------------------ + // Constants -------------------------------------------------------------- + // ------------------------------------------------------------------------ + + // ------------------------------------------------------------------------ + // Variables -------------------------------------------------------------- + // ------------------------------------------------------------------------ /** * The root TelnetSocket that has my telnet protocol state. @@ -76,6 +83,61 @@ public final class TelnetInputStream extends InputStream implements SessionInfo */ private int readBufferStart; + /** + * User name. + */ + private String username = ""; + + /** + * Language. + */ + private String language = "en_US"; + + /** + * Text window width. + */ + private int windowWidth = 80; + + /** + * Text window height. + */ + private int windowHeight = 24; + + /** + * When true, the last read byte from the remote side was IAC. + */ + private boolean iac = false; + + /** + * When true, we are in the middle of a DO/DONT/WILL/WONT negotiation. + */ + private boolean dowill = false; + + /** + * The telnet option being negotiated. + */ + private int dowillType = 0; + + /** + * When true, we are waiting to see the end of the sub-negotiation + * sequence. + */ + private boolean subnegEnd = false; + + /** + * When true, the last byte read from the remote side was CR. + */ + private boolean readCR = false; + + /** + * The subnegotiation buffer. + */ + private ArrayList subnegBuffer; + + // ------------------------------------------------------------------------ + // Constructors ----------------------------------------------------------- + // ------------------------------------------------------------------------ + /** * Package private constructor. * @@ -94,29 +156,12 @@ public final class TelnetInputStream extends InputStream implements SessionInfo readBuffer = new byte[1024]; readBufferStart = 0; readBufferEnd = 0; + subnegBuffer = new ArrayList(); } - // SessionInfo interface -------------------------------------------------- - - /** - * User name. - */ - private String username = ""; - - /** - * Language. - */ - private String language = "en_US"; - - /** - * Text window width. - */ - private int windowWidth = 80; - - /** - * Text window height. - */ - private int windowHeight = 24; + // ------------------------------------------------------------------------ + // SessionInfo ------------------------------------------------------------ + // ------------------------------------------------------------------------ /** * Username getter. @@ -154,6 +199,15 @@ public final class TelnetInputStream extends InputStream implements SessionInfo this.language = language; } + /** + * Get the terminal type as reported by the telnet Terminal Type option. + * + * @return the terminal type + */ + public String getTerminalType() { + return master.terminalType; + } + /** * Text window width getter. * @@ -179,13 +233,19 @@ public final class TelnetInputStream extends InputStream implements SessionInfo // NOP } - // InputStream interface -------------------------------------------------- + // ------------------------------------------------------------------------ + // InputStream ------------------------------------------------------------ + // ------------------------------------------------------------------------ /** * Returns an estimate of the number of bytes that can be read (or * skipped over) from this input stream without blocking by the next * invocation of a method for this input stream. * + * @return an estimate of the number of bytes that can be read (or + * skipped over) from this input stream without blocking or 0 when it + * reaches the end of the input stream. + * @throws IOException if an I/O error occurs */ @Override public int available() throws IOException { @@ -201,6 +261,8 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Closes this input stream and releases any system resources associated * with the stream. + * + * @throws IOException if an I/O error occurs */ @Override public void close() throws IOException { @@ -212,14 +274,20 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Marks the current position in this input stream. + * + * @param readLimit the maximum limit of bytes that can be read before + * the mark position becomes invalid */ @Override - public void mark(int readlimit) { + public void mark(final int readLimit) { // Do nothing } /** * Tests if this input stream supports the mark and reset methods. + * + * @return true if this stream instance supports the mark and reset + * methods; false otherwise */ @Override public boolean markSupported() { @@ -228,6 +296,10 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Reads the next byte of data from the input stream. + * + * @return the next byte of data, or -1 if there is no more data because + * the end of the stream has been reached. + * @throws IOException if an I/O error occurs */ @Override public int read() throws IOException { @@ -248,6 +320,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo // If we got something, return it. if (rc > 0) { + readBufferEnd += rc; readBufferStart++; return readBuffer[readBufferStart - 1]; } @@ -261,18 +334,32 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Reads some number of bytes from the input stream and stores them into * the buffer array b. + * + * @param b the buffer into which the data is read. + * @return the total number of bytes read into the buffer, or -1 if there + * is no more data because the end of the stream has been reached. + * @throws IOException if an I/O error occurs */ @Override - public int read(byte[] b) throws IOException { + public int read(final byte[] b) throws IOException { return read(b, 0, b.length); } /** * Reads up to len bytes of data from the input stream into an array of * bytes. + * + * @param b the buffer into which the data is read. + * @param off the start offset in array b at which the data is written. + * @param len the maximum number of bytes to read. + * @return the total number of bytes read into the buffer, or -1 if there + * is no more data because the end of the stream has been reached. + * @throws IOException if an I/O error occurs */ @Override - public int read(byte[] b, int off, int len) throws IOException { + public int read(final byte[] b, final int off, + final int len) throws IOException { + // The only time we can return 0 is if len is 0, as per the // InputStream contract. if (len == 0) { @@ -300,7 +387,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo // If we got something, return it. if (rc > 0) { - System.arraycopy(readBuffer, 0, b, off, len); + System.arraycopy(readBuffer, 0, b, off, rc); return rc; } // If we read 0, I screwed up big time. @@ -312,7 +399,10 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Repositions this stream to the position at the time the mark method - * was last called on this input stream. + * was last called on this input stream. This is not supported by + * TelnetInputStream, so IOException is always thrown. + * + * @throws IOException if this function is used */ @Override public void reset() throws IOException { @@ -321,9 +411,13 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Skips over and discards n bytes of data from this input stream. + * + * @param n the number of bytes to be skipped + * @return the actual number of bytes skipped + * @throws IOException if an I/O error occurs */ @Override - public long skip(long n) throws IOException { + public long skip(final long n) throws IOException { if (n < 0) { return 0; } @@ -333,19 +427,18 @@ public final class TelnetInputStream extends InputStream implements SessionInfo return n; } - // Telnet protocol -------------------------------------------------------- - - /** - * The subnegotiation buffer. - */ - private byte [] subnegBuffer; + // ------------------------------------------------------------------------ + // TelnetInputStream ------------------------------------------------------ + // ------------------------------------------------------------------------ /** * For debugging, return a descriptive string for this telnet option. * These are pulled from: http://www.iana.org/assignments/telnet-options * + * @param option the telnet option byte * @return a string describing the telnet option code */ + @SuppressWarnings("unused") private String optionString(final int option) { switch (option) { case 0: return "Binary Transmission"; @@ -415,14 +508,15 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * * @param response a TELNET_DO/DONT/WILL/WONT byte * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void respond(final int response, final int option) throws IOException { byte [] buffer = new byte[3]; - buffer[0] = (byte)TELNET_IAC; - buffer[1] = (byte)response; - buffer[2] = (byte)option; + buffer[0] = (byte) TELNET_IAC; + buffer[1] = (byte) response; + buffer[2] = (byte) option; output.rawWrite(buffer); } @@ -431,6 +525,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * Tell the remote side we WILL support an option. * * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void WILL(final int option) throws IOException { respond(TELNET_WILL, option); @@ -440,6 +535,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * Tell the remote side we WON'T support an option. * * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void WONT(final int option) throws IOException { respond(TELNET_WONT, option); @@ -449,6 +545,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * Tell the remote side we DO support an option. * * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void DO(final int option) throws IOException { respond(TELNET_DO, option); @@ -458,6 +555,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * Tell the remote side we DON'T support an option. * * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void DONT(final int option) throws IOException { respond(TELNET_DONT, option); @@ -468,6 +566,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * * @param remoteQuery a TELNET_DO/DONT/WILL/WONT byte * @param option telnet option byte (binary mode, term type, etc.) + * @throws IOException if an I/O error occurs */ private void refuse(final int remoteQuery, final int option) throws IOException { @@ -480,26 +579,29 @@ public final class TelnetInputStream extends InputStream implements SessionInfo } /** - * Build sub-negotiation packet (RFC 855) + * Build sub-negotiation packet (RFC 855). * * @param option telnet option * @param response output buffer of response bytes + * @throws IOException if an I/O error occurs */ private void telnetSendSubnegResponse(final int option, final byte [] response) throws IOException { byte [] buffer = new byte[response.length + 5]; - buffer[0] = (byte)TELNET_IAC; - buffer[1] = (byte)TELNET_SB; - buffer[2] = (byte)option; + buffer[0] = (byte) TELNET_IAC; + buffer[1] = (byte) TELNET_SB; + buffer[2] = (byte) option; System.arraycopy(response, 0, buffer, 3, response.length); - buffer[response.length + 3] = (byte)TELNET_IAC; - buffer[response.length + 4] = (byte)TELNET_SE; + buffer[response.length + 3] = (byte) TELNET_IAC; + buffer[response.length + 4] = (byte) TELNET_SE; output.rawWrite(buffer); } /** * Telnet option: Terminal Speed (RFC 1079). Client side. + * + * @throws IOException if an I/O error occurs */ private void telnetSendTerminalSpeed() throws IOException { byte [] response = {0, '3', '8', '4', '0', '0', ',', @@ -509,6 +611,8 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Telnet option: Terminal Type (RFC 1091). Client side. + * + * @throws IOException if an I/O error occurs */ private void telnetSendTerminalType() throws IOException { byte [] response = {0, 'v', 't', '1', '0', '0' }; @@ -517,6 +621,8 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Telnet option: Terminal Type (RFC 1091). Server side. + * + * @throws IOException if an I/O error occurs */ private void requestTerminalType() throws IOException { byte [] response = new byte[1]; @@ -526,6 +632,8 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Telnet option: Terminal Speed (RFC 1079). Server side. + * + * @throws IOException if an I/O error occurs */ private void requestTerminalSpeed() throws IOException { byte [] response = new byte[1]; @@ -535,6 +643,8 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Telnet option: New Environment (RFC 1572). Server side. + * + * @throws IOException if an I/O error occurs */ private void requestEnvironment() throws IOException { byte [] response = new byte[1]; @@ -543,7 +653,12 @@ public final class TelnetInputStream extends InputStream implements SessionInfo } /** - * Send the options we want to negotiate on: + * Send the options we want to negotiate on. + * + *

The options we use are: + * + *

+ * 

      *     Binary Transmission           RFC 856
      *     Suppress Go Ahead             RFC 858
      *     Negotiate About Window Size   RFC 1073
@@ -552,70 +667,75 @@ public final class TelnetInputStream extends InputStream implements SessionInfo
      *     New Environment               RFC 1572
      *
      * When run as a server:
-     *     Echo
+     *     Echo                          RFC 857
+     *
+ * + * @throws IOException if an I/O error occurs */ void telnetSendOptions() throws IOException { - if (master.nvt.binaryMode == false) { + if (master.binaryMode == false) { // Binary Transmission: must ask both do and will DO(0); WILL(0); } - if (master.nvt.goAhead == true) { + if (master.goAhead == true) { // Suppress Go Ahead DO(3); WILL(3); } // Server only options - if (master.nvt.isServer == true) { + if (master.isServer == true) { // Enable Echo - I echo to them, they do not echo back to me. DONT(1); WILL(1); - if (master.nvt.doTermType == true) { + if (master.doTermType == true) { // Terminal type - request it DO(24); } - if (master.nvt.doTermSpeed == true) { + if (master.doTermSpeed == true) { // Terminal speed - request it DO(32); } - if (master.nvt.doNAWS == true) { + if (master.doNAWS == true) { // NAWS - request it DO(31); } - if (master.nvt.doEnvironment == true) { + if (master.doEnvironment == true) { // Environment - request it DO(39); } } else { - if (master.nvt.doTermType == true) { + if (master.doTermType == true) { // Terminal type - request it WILL(24); } - if (master.nvt.doTermSpeed == true) { + if (master.doTermSpeed == true) { // Terminal speed - request it WILL(32); } - if (master.nvt.doNAWS == true) { + if (master.doNAWS == true) { // NAWS - request it WILL(31); } - if (master.nvt.doEnvironment == true) { + if (master.doEnvironment == true) { // Environment - request it WILL(39); } - } + + // Push it all out + output.flush(); } /** @@ -633,13 +753,23 @@ public final class TelnetInputStream extends InputStream implements SessionInfo * fails to handle ESC as defined in RFC 1572. */ private void handleNewEnvironment() { - Map newEnv = new TreeMap(); + Map newEnv = new TreeMap(); + EnvState state = EnvState.INIT; StringBuilder name = new StringBuilder(); StringBuilder value = new StringBuilder(); - for (int i = 0; i < subnegBuffer.length; i++) { - byte b = subnegBuffer[i]; + /* + System.err.printf("handleNewEnvironment() %d bytes\n", + subnegBuffer.size()); + */ + + for (int i = 1; i < subnegBuffer.size(); i++) { + Byte b = subnegBuffer.get(i); + /* + System.err.printf(" b: %c %d 0x%02x\n", (char)b.byteValue(), + b, b); + */ switch (state) { @@ -677,7 +807,7 @@ public final class TelnetInputStream extends InputStream implements SessionInfo value = new StringBuilder(); } else { // Take it as an environment variable name/key byte - name.append((char)b); + name.append((char)b.byteValue()); } break; @@ -688,117 +818,159 @@ public final class TelnetInputStream extends InputStream implements SessionInfo // VAR state = EnvState.NAME; if (value.length() > 0) { - newEnv.put(name, value); + /* + System.err.printf("NAME: '%s' VALUE: '%s'\n", + name, value); + */ + newEnv.put(name.toString(), value.toString()); } name = new StringBuilder(); } else if (b == 3) { // USERVAR state = EnvState.NAME; if (value.length() > 0) { - newEnv.put(name, value); + /* + System.err.printf("NAME: '%s' VALUE: '%s'\n", + name, value); + */ + newEnv.put(name.toString(), value.toString()); } name = new StringBuilder(); } else { // Take it as an environment variable value byte - value.append((char)b); + value.append((char)b.byteValue()); } break; + + default: + throw new RuntimeException("Invalid state: " + state); + } } if ((name.length() > 0) && (value.length() > 0)) { - newEnv.put(name, value); + /* + System.err.printf("NAME: '%s' VALUE: '%s'\n", name, value); + */ + newEnv.put(name.toString(), value.toString()); } - for (StringBuilder key: newEnv.keySet()) { + for (String key: newEnv.keySet()) { if (key.equals("LANG")) { - language = newEnv.get(key).toString(); + language = newEnv.get(key); } if (key.equals("LOGNAME")) { - username = newEnv.get(key).toString(); + username = newEnv.get(key); } if (key.equals("USER")) { - username = newEnv.get(key).toString(); + username = newEnv.get(key); } } } /** * Handle an option sub-negotiation. + * + * @throws IOException if an I/O error occurs */ private void handleSubneg() throws IOException { - byte option; + Byte option; // Sanity check: there must be at least 1 byte in subnegBuffer - if (subnegBuffer.length < 1) { + if (subnegBuffer.size() < 1) { // Buffer too small: the other side is a broken telnetd, it did // not send the right sub-negotiation data. Bail out now. return; } - option = subnegBuffer[0]; + option = subnegBuffer.get(0); switch (option) { case 24: // Terminal Type - if ((subnegBuffer.length > 1) && (subnegBuffer[1] == 1)) { + if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { // Server sent "SEND", we say "IS" telnetSendTerminalType(); } - if ((subnegBuffer.length > 1) && (subnegBuffer[1] == 0)) { + if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { // Client sent "IS", record it StringBuilder terminalString = new StringBuilder(); - for (int i = 2; i < subnegBuffer.length; i++) { - terminalString.append((char)subnegBuffer[i]); + for (int i = 2; i < subnegBuffer.size(); i++) { + terminalString.append((char)subnegBuffer. + get(i).byteValue()); } - master.nvt.terminal = terminalString.toString(); + master.terminalType = terminalString.toString(); + /* + System.err.printf("terminal type: '%s'\n", + master.terminalType); + */ } break; case 32: // Terminal Speed - if ((subnegBuffer.length > 1) && (subnegBuffer[1] == 1)) { + if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { // Server sent "SEND", we say "IS" telnetSendTerminalSpeed(); } - if ((subnegBuffer.length > 1) && (subnegBuffer[1] == 0)) { + if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { // Client sent "IS", record it StringBuilder speedString = new StringBuilder(); - for (int i = 2; i < subnegBuffer.length; i++) { - speedString.append((char)subnegBuffer[i]); + for (int i = 2; i < subnegBuffer.size(); i++) { + speedString.append((char)subnegBuffer.get(i).byteValue()); } - String termSpeed = speedString.toString(); + master.terminalSpeed = speedString.toString(); + /* + System.err.printf("terminal speed: '%s'\n", + master.terminalSpeed); + */ } break; case 31: // NAWS - if (subnegBuffer.length >= 5) { + if (subnegBuffer.size() >= 5) { int i = 0; i++; - if (subnegBuffer[i] == TELNET_IAC) { + if (subnegBuffer.get(i) == (byte) TELNET_IAC) { i++; } - windowWidth = subnegBuffer[i] * 256; + int width = subnegBuffer.get(i); + if (width < 0) { + width += 256; + } + windowWidth = width * 256; i++; - if (subnegBuffer[i] == TELNET_IAC) { + if (subnegBuffer.get(i) == (byte) TELNET_IAC) { i++; } - windowWidth += subnegBuffer[i]; + width = subnegBuffer.get(i); + windowWidth += width; + if (width < 0) { + windowWidth += 256; + } i++; - if (subnegBuffer[i] == TELNET_IAC) { + if (subnegBuffer.get(i) == (byte) TELNET_IAC) { i++; } - windowHeight = subnegBuffer[i] * 256; + int height = subnegBuffer.get(i); + if (height < 0) { + height += 256; + } + windowHeight = height * 256; i++; - if (subnegBuffer[i] == TELNET_IAC) { + if (subnegBuffer.get(i) == (byte) TELNET_IAC) { i++; } - windowHeight += subnegBuffer[i]; + height = subnegBuffer.get(i); + windowHeight += height; + if (height < 0) { + windowHeight += 256; + } } break; @@ -816,12 +988,412 @@ public final class TelnetInputStream extends InputStream implements SessionInfo /** * Reads up to len bytes of data from the input stream into an array of * bytes. + * + * @param buf the buffer into which the data is read. + * @param off the start offset in array b at which the data is written. + * @param len the maximum number of bytes to read. + * @return the total number of bytes read into the buffer, or -1 if there + * is no more data because the end of the stream has been reached. + * @throws IOException if an I/O error occurs */ - private int readImpl(byte[] b, int off, int len) throws IOException { + private int readImpl(final byte[] buf, final int off, + final int len) throws IOException { + assert (len > 0); - // TODO - return -1; - } + // The current writing position in buf. + int bufN = off; + + // We will keep trying to read() until we have something to return. + do { + + byte [] buffer = null; + if (master.binaryMode) { + // Binary mode: read up to len bytes. There will never be + // more bytes to pass upstream than there are bytes on the + // wire. + buffer = new byte[len]; + } else { + // ASCII mode: read up to len - 2 bytes. There may have been + // some combination of IAC, CR, and NUL from a previous + // readImpl() that could result in more bytes to pass up than + // are on the wire. + buffer = new byte[len - 2]; + } + + int bufferN = 0; + + // Read some data from the other end + int rc = input.read(buffer); + + // Check for EOF or error + if (rc > 0) { + // More data came in + bufferN = rc; + } else { + // EOF, just return it. + return rc; + } + + // Loop through the read bytes + for (int i = 0; i < bufferN; i++) { + byte b = buffer[i]; + + if (subnegEnd == true) { + // Looking for IAC SE to end this subnegotiation + if (b == (byte) TELNET_SE) { + if (iac == true) { + iac = false; + subnegEnd = false; + handleSubneg(); + } + } else if (b == (byte) TELNET_IAC) { + if (iac == true) { + // An argument to the subnegotiation option + subnegBuffer.add((byte) TELNET_IAC); + } else { + iac = true; + } + } else { + // An argument to the subnegotiation option + subnegBuffer.add(b); + } + continue; + } + + // Look for DO/DON'T/WILL/WON'T option + if (dowill == true) { + + // Look for option/ + switch (b) { + + case 0: + // Binary Transmission + if (dowillType == (byte) TELNET_WILL) { + // Server will use binary transmission, yay. + master.binaryMode = true; + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for binary transmission. + WILL(b); + master.binaryMode = true; + } else if (dowillType == (byte) TELNET_WONT) { + // We're screwed, server won't do binary + // transmission. + master.binaryMode = false; + } else { + // Server demands NVT ASCII mode. + master.binaryMode = false; + } + break; + + case 1: + // Echo + if (dowillType == (byte) TELNET_WILL) { + // Server will use echo, yay. + master.echoMode = true; + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for echo. + WILL(b); + master.echoMode = true; + } else if (dowillType == (byte) TELNET_WONT) { + // We're screwed, server won't do echo. + master.echoMode = false; + } else { + // Server demands no echo. + master.echoMode = false; + } + break; + + case 3: + // Suppress Go Ahead + if (dowillType == (byte) TELNET_WILL) { + // Server will use suppress go-ahead, yay. + master.goAhead = false; + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for suppress go-ahead. + WILL(b); + master.goAhead = false; + } else if (dowillType == (byte) TELNET_WONT) { + // We're screwed, server won't do suppress + // go-ahead. + master.goAhead = true; + } else { + // Server demands Go-Ahead mode. + master.goAhead = true; + } + break; + + case 24: + // Terminal Type - send what's in TERM + if (dowillType == (byte) TELNET_WILL) { + // Server will use terminal type, yay. + if (master.isServer + && master.doTermType + ) { + requestTerminalType(); + master.doTermType = false; + } else if (!master.isServer) { + master.doTermType = true; + } + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for terminal type. + WILL(b); + master.doTermType = true; + } else if (dowillType == (byte) TELNET_WONT) { + // We're screwed, server won't do terminal type. + master.doTermType = false; + } else { + // Server will not listen to terminal type. + master.doTermType = false; + } + break; + + case 31: + // NAWS + if (dowillType == (byte) TELNET_WILL) { + // Server will use NAWS, yay. + master.doNAWS = true; + // NAWS cannot be requested by the server, it is + // only sent by the client. + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for NAWS. + WILL(b); + master.doNAWS = true; + } else if (dowillType == (byte) TELNET_WONT) { + // Server won't do NAWS. + master.doNAWS = false; + } else { + // Server will not listen to NAWS. + master.doNAWS = false; + } + break; + + case 32: + // Terminal Speed + if (dowillType == (byte) TELNET_WILL) { + // Server will use terminal speed, yay. + if (master.isServer + && master.doTermSpeed + ) { + requestTerminalSpeed(); + master.doTermSpeed = false; + } else if (!master.isServer) { + master.doTermSpeed = true; + } + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for terminal speed. + WILL(b); + master.doTermSpeed = true; + } else if (dowillType == (byte) TELNET_WONT) { + // We're screwed, server won't do terminal speed. + master.doTermSpeed = false; + } else { + // Server will not listen to terminal speed. + master.doTermSpeed = false; + } + break; + + case 39: + // New Environment + if (dowillType == (byte) TELNET_WILL) { + // Server will use NewEnvironment, yay. + if (master.isServer + && master.doEnvironment + ) { + requestEnvironment(); + master.doEnvironment = false; + } else if (!master.isServer) { + master.doEnvironment = true; + } + } else if (dowillType == (byte) TELNET_DO) { + // Server asks for NewEnvironment. + WILL(b); + master.doEnvironment = true; + } else if (dowillType == (byte) TELNET_WONT) { + // Server won't do NewEnvironment. + master.doEnvironment = false; + } else { + // Server will not listen to New Environment. + master.doEnvironment = false; + } + break; + + + default: + // Other side asked for something we don't + // understand. Tell them we will not do this option. + refuse(dowillType, b); + break; + } + + dowill = false; + continue; + } // if (dowill == true) + + // Perform read processing + if (b == (byte) TELNET_IAC) { + + // Telnet command + if (iac == true) { + // IAC IAC -> IAC + buf[bufN++] = (byte) TELNET_IAC; + iac = false; + } else { + iac = true; + } + continue; + } else { + if (iac == true) { + + switch (b) { + + case (byte) TELNET_SE: + // END Sub-Negotiation + break; + case (byte) TELNET_NOP: + // NOP + break; + case (byte) TELNET_DM: + // Data Mark + break; + case (byte) TELNET_BRK: + // Break + break; + case (byte) TELNET_IP: + // Interrupt Process + break; + case (byte) TELNET_AO: + // Abort Output + break; + case (byte) TELNET_AYT: + // Are You There? + break; + case (byte) TELNET_EC: + // Erase Character + break; + case (byte) TELNET_EL: + // Erase Line + break; + case (byte) TELNET_GA: + // Go Ahead + break; + case (byte) TELNET_SB: + // START Sub-Negotiation + // From here we wait for the IAC SE + subnegEnd = true; + subnegBuffer.clear(); + break; + case (byte) TELNET_WILL: + // WILL + dowill = true; + dowillType = b; + break; + case (byte) TELNET_WONT: + // WON'T + dowill = true; + dowillType = b; + break; + case (byte) TELNET_DO: + // DO + dowill = true; + dowillType = b; + break; + case (byte) TELNET_DONT: + // DON'T + dowill = true; + dowillType = b; + break; + default: + // This should be equivalent to IAC NOP + break; + } + iac = false; + continue; + + } // if (iac == true) + + /* + * All of the regular IAC processing is completed at this + * point. Now we need to handle the CR and CR LF cases. + * + * According to RFC 854, in NVT ASCII mode: + * Bare CR -> CR NUL + * CR LF -> CR LF + * + */ + if (master.binaryMode == false) { + + if (b == C_LF) { + if (readCR == true) { + // This is CR LF. Send CR LF and turn the cr + // flag off. + buf[bufN++] = C_CR; + buf[bufN++] = C_LF; + readCR = false; + continue; + } + // This is bare LF. Send LF. + buf[bufN++] = C_LF; + continue; + } + + if (b == C_NUL) { + if (readCR == true) { + // This is CR NUL. Send CR and turn the cr + // flag off. + buf[bufN++] = C_CR; + readCR = false; + continue; + } + // This is bare NUL. Send NUL. + buf[bufN++] = C_NUL; + continue; + } + + if (b == C_CR) { + if (readCR == true) { + // This is CR CR. Send a CR NUL and leave + // the cr flag on. + buf[bufN++] = C_CR; + buf[bufN++] = C_NUL; + continue; + } + // This is the first CR. Set the cr flag. + readCR = true; + continue; + } + + if (readCR == true) { + // This was a bare CR in the stream. + buf[bufN++] = C_CR; + readCR = false; + } + + // This is a regular character. Pass it on. + buf[bufN++] = b; + continue; + } + + /* + * This is the case for any of: + * + * 1) A NVT ASCII character that isn't CR, LF, or + * NUL. + * + * 2) A NVT binary character. + * + * For all of these cases, we just pass the character on. + */ + buf[bufN++] = b; + + } // if (b == TELNET_IAC) + + } // for (int i = 0; i < bufferN; i++) + + } while (bufN == 0); + + // Return bytes read + return bufN; + } }