/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.coyote.ajp;
import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.CharChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.res.StringManager;
/**
* A single packet for communication between the web server and the
* container. Designed to be reused many times with no creation of
* garbage. Understands the format of data types for these packets.
* Can be used (somewhat confusingly) for both incoming and outgoing
* packets.
*
* @author Henri Gomez
* @author Dan Milstein
* @author Keith Wannamaker
* @author Kevin Seguin
* @author Costin Manolache
*/
public class AjpMessage {
protected static org.apache.juli.logging.Log log =
org.apache.juli.logging.LogFactory.getLog(AjpMessage.class);
/**
* The string manager for this package.
*/
protected static StringManager sm =
StringManager.getManager(Constants.Package);
// ------------------------------------------------------------ Constructor
public AjpMessage(int packetSize) {
buf = new byte[packetSize];
}
// ----------------------------------------------------- Instance Variables
/**
* Fixed size buffer.
*/
protected byte buf[] = null;
/**
* The current read or write position in the buffer.
*/
protected int pos;
/**
* This actually means different things depending on whether the
* packet is read or write. For read, it's the length of the
* payload (excluding the header). For write, it's the length of
* the packet as a whole (counting the header). Oh, well.
*/
protected int len;
// --------------------------------------------------------- Public Methods
/**
* Prepare this packet for accumulating a message from the container to
* the web server. Set the write position to just after the header
* (but leave the length unwritten, because it is as yet unknown).
*/
public void reset() {
len = 4;
pos = 4;
}
/**
* For a packet to be sent to the web server, finish the process of
* accumulating data and write the length of the data payload into
* the header.
*/
public void end() {
len = pos;
int dLen = len - 4;
buf[0] = (byte) 0x41;
buf[1] = (byte) 0x42;
buf[2] = (byte) ((dLen>>>8) & 0xFF);
buf[3] = (byte) (dLen & 0xFF);
}
/**
* Return the underlying byte buffer.
*/
public byte[] getBuffer() {
return buf;
}
/**
* Return the current message length. For read, it's the length of the
* payload (excluding the header). For write, it's the length of
* the packet as a whole (counting the header).
*/
public int getLen() {
return len;
}
/**
* Add a short integer (2 bytes) to the message.
*/
public void appendInt(int val) {
buf[pos++] = (byte) ((val >>> 8) & 0xFF);
buf[pos++] = (byte) (val & 0xFF);
}
/**
* Append a byte (1 byte) to the message.
*/
public void appendByte(int val) {
buf[pos++] = (byte) val;
}
/**
* Append an int (4 bytes) to the message.
*/
public void appendLongInt(int val) {
buf[pos++] = (byte) ((val >>> 24) & 0xFF);
buf[pos++] = (byte) ((val >>> 16) & 0xFF);
buf[pos++] = (byte) ((val >>> 8) & 0xFF);
buf[pos++] = (byte) (val & 0xFF);
}
/**
* Write a MessageBytes out at the current write position.
* A null MessageBytes is encoded as a string with length 0.
*/
public void appendBytes(MessageBytes mb) {
if (mb == null) {
log.error(sm.getString("ajpmessage.null"),
new NullPointerException());
appendInt(0);
appendByte(0);
return;
}
if (mb.getType() == MessageBytes.T_BYTES) {
ByteChunk bc = mb.getByteChunk();
appendByteChunk(bc);
} else if (mb.getType() == MessageBytes.T_CHARS) {
CharChunk cc = mb.getCharChunk();
appendCharChunk(cc);
} else {
appendString(mb.toString());
}
}
/**
* Write a ByteChunk out at the current write position.
* A null ByteChunk is encoded as a string with length 0.
*/
public void appendByteChunk(ByteChunk bc) {
if (bc == null) {
log.error(sm.getString("ajpmessage.null"),
new NullPointerException());
appendInt(0);
appendByte(0);
return;
}
appendBytes(bc.getBytes(), bc.getStart(), bc.getLength());
}
/**
* Write a CharChunk out at the current write position.
* A null CharChunk is encoded as a string with length 0.
*/
public void appendCharChunk(CharChunk cc) {
if (cc == null) {
log.error(sm.getString("ajpmessage.null"),
new NullPointerException());
appendInt(0);
appendByte(0);
return;
}
int start = cc.getStart();
int end = cc.getEnd();
appendInt(end - start);
char[] cbuf = cc.getBuffer();
for (int i = start; i < end; i++) {
char c = cbuf[i];
// Note: This is clearly incorrect for many strings,
// but is the only consistent approach within the current
// servlet framework. It must suffice until servlet output
// streams properly encode their output.
if ((c <= 31) && (c != 9)) {
c = ' ';
} else if (c == 127) {
c = ' ';
}
appendByte(c);
}
appendByte(0);
}
/**
* Write a String out at the current write position. Strings are
* encoded with the length in two bytes first, then the string, and
* then a terminating \0 (which is <B>not</B> included in the
* encoded length). The terminator is for the convenience of the C
* code, where it saves a round of copying. A null string is
* encoded as a string with length 0.
*/
public void appendString(String str) {
if (str == null) {
log.error(sm.getString("ajpmessage.null"),
new NullPointerException());
appendInt(0);
appendByte(0);
return;
}
int len = str.length();
appendInt(len);
for (int i = 0; i < len; i++) {
char c = str.charAt (i);
// Note: This is clearly incorrect for many strings,
// but is the only consistent approach within the current
// servlet framework. It must suffice until servlet output
// streams properly encode their output.
if ((c <= 31) && (c != 9)) {
c = ' ';
} else if (c == 127) {
c = ' ';
}
appendByte(c);
}
appendByte(0);
}
/**
* Copy a chunk of bytes into the packet, starting at the current
* write position. The chunk of bytes is encoded with the length
* in two bytes first, then the data itself, and finally a
* terminating \0 (which is <B>not</B> included in the encoded
* length).
*
* @param b The array from which to copy bytes.
* @param off The offset into the array at which to start copying
* @param numBytes The number of bytes to copy.
*/
public void appendBytes(byte[] b, int off, int numBytes) {
if (pos + numBytes + 3 > buf.length) {
log.error(sm.getString("ajpmessage.overflow", "" + numBytes, "" + pos),
new ArrayIndexOutOfBoundsException());
if (log.isDebugEnabled()) {
dump("Overflow/coBytes");
}
return;
}
appendInt(numBytes);
System.arraycopy(b, off, buf, pos, numBytes);
pos += numBytes;
appendByte(0);
}
/**
* Read an integer from packet, and advance the read position past
* it. Integers are encoded as two unsigned bytes with the
* high-order byte first, and, as far as I can tell, in
* little-endian order within each byte.
*/
public int getInt() {
int b1 = buf[pos++] & 0xFF;
int b2 = buf[pos++] & 0xFF;
return (b1<<8) + b2;
}
public int peekInt() {
int b1 = buf[pos] & 0xFF;
int b2 = buf[pos+1] & 0xFF;
return (b1<<8) + b2;
}
public byte getByte() {
byte res = buf[pos++];
return res;
}
public byte peekByte() {
byte res = buf[pos];
return res;
}
public void getBytes(MessageBytes mb) {
int length = getInt();
if ((length == 0xFFFF) || (length == -1)) {
mb.recycle();
return;
}
mb.setBytes(buf, pos, length);
pos += length;
pos++; // Skip the terminating \0
}
/**
* Copy a chunk of bytes from the packet into an array and advance
* the read position past the chunk. See appendBytes() for details
* on the encoding.
*
* @return The number of bytes copied.
*/
public int getBytes(byte[] dest) {
int length = getInt();
if (pos + length > buf.length) {
log.error(sm.getString("ajpmessage.read", "" + length));
return 0;
}
if ((length == 0xFFFF) || (length == -1)) {
return 0;
}
System.arraycopy(buf, pos, dest, 0, length);
pos += length;
pos++; // Skip terminating \0
return length;
}
/**
* Read a 32 bits integer from packet, and advance the read position past
* it. Integers are encoded as four unsigned bytes with the
* high-order byte first, and, as far as I can tell, in
* little-endian order within each byte.
*/
public int getLongInt() {
int b1 = buf[pos++] & 0xFF; // No swap, Java order
b1 <<= 8;
b1 |= (buf[pos++] & 0xFF);
b1 <<= 8;
b1 |= (buf[pos++] & 0xFF);
b1 <<=8;
b1 |= (buf[pos++] & 0xFF);
return b1;
}
public int getHeaderLength() {
return 4;
}
public int getPacketSize() {
return buf.length;
}
public int processHeader() {
pos = 0;
int mark = getInt();
len = getInt();
// Verify message signature
if ((mark != 0x1234) && (mark != 0x4142)) {
log.error(sm.getString("ajpmessage.invalid", "" + mark));
if (log.isDebugEnabled()) {
dump("In: ");
}
return -1;
}
if (log.isDebugEnabled()) {
log.debug("Received " + len + " " + buf[0]);
}
return len;
}
/**
* Dump the contents of the message, prefixed with the given String.
*/
public void dump(String msg) {
if (log.isDebugEnabled()) {
log.debug(msg + ": " + buf + " " + pos +"/" + (len + 4));
}
int max = pos;
if (len + 4 > pos)
max = len+4;
if (max > 1000)
max = 1000;
if (log.isDebugEnabled()) {
for (int j = 0; j < max; j += 16) {
log.debug(hexLine(buf, j, len));
}
}
}
// ------------------------------------------------------ Protected Methods
protected static String hexLine(byte buf[], int start, int len) {
StringBuffer sb = new StringBuffer();
for (int i = start; i < start + 16 ; i++) {
if (i < len + 4) {
sb.append(hex(buf[i]) + " ");
} else {
sb.append(" ");
}
}
sb.append(" | ");
for (int i = start; i < start + 16 && i < len + 4; i++) {
if (!Character.isISOControl((char) buf[i])) {
sb.append(new Character((char) buf[i]));
} else {
sb.append(".");
}
}
return sb.toString();
}
protected static String hex(int x) {
String h = Integer.toHexString(x);
if (h.length() == 1) {
h = "0" + h;
}
return h.substring(h.length() - 2);
}
}
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