/*
* Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package jdk.internal.net.http;
import java.net.ProtocolException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.net.http.HttpHeaders;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
class Http1HeaderParser {
private static final char CR = '\r';
private static final char LF = '\n';
private static final char HT = '\t';
private static final char SP = ' ';
private StringBuilder sb = new StringBuilder();
private String statusLine;
private int responseCode;
private HttpHeaders headers;
private Map<String,List<String>> privateMap = new HashMap<>();
enum State { STATUS_LINE,
STATUS_LINE_FOUND_CR,
STATUS_LINE_END,
STATUS_LINE_END_CR,
HEADER,
HEADER_FOUND_CR,
HEADER_FOUND_LF,
HEADER_FOUND_CR_LF,
HEADER_FOUND_CR_LF_CR,
FINISHED }
private State state = State.STATUS_LINE;
/** Returns the status-line. */
String statusLine() { return statusLine; }
/** Returns the response code. */
int responseCode() { return responseCode; }
/** Returns the headers, possibly empty. */
HttpHeaders headers() { assert state == State.FINISHED; return headers; }
/**
* Parses HTTP/1.X status-line and headers from the given bytes. Must be
* called successive times, with additional data, until returns true.
*
* All given ByteBuffers will be consumed, until ( possibly ) the last one
* ( when true is returned ), which may not be fully consumed.
*
* @param input the ( partial ) header data
* @return true iff the end of the headers block has been reached
*/
boolean parse(ByteBuffer input) throws ProtocolException {
requireNonNull(input, "null input");
while (input.hasRemaining() && state != State.FINISHED) {
switch (state) {
case STATUS_LINE:
readResumeStatusLine(input);
break;
case STATUS_LINE_FOUND_CR:
readStatusLineFeed(input);
break;
case STATUS_LINE_END:
maybeStartHeaders(input);
break;
case STATUS_LINE_END_CR:
maybeEndHeaders(input);
break;
case HEADER:
readResumeHeader(input);
break;
// fallthrough
case HEADER_FOUND_CR:
case HEADER_FOUND_LF:
resumeOrLF(input);
break;
case HEADER_FOUND_CR_LF:
resumeOrSecondCR(input);
break;
case HEADER_FOUND_CR_LF_CR:
resumeOrEndHeaders(input);
break;
default:
throw new InternalError(
"Unexpected state: " + String.valueOf(state));
}
}
return state == State.FINISHED;
}
private void readResumeStatusLine(ByteBuffer input) {
char c = 0;
while (input.hasRemaining() && (c =(char)input.get()) != CR) {
sb.append(c);
}
if (c == CR) {
state = State.STATUS_LINE_FOUND_CR;
}
}
private void readStatusLineFeed(ByteBuffer input) throws ProtocolException {
char c = (char)input.get();
if (c != LF) {
throw protocolException("Bad trailing char, \"%s\", when parsing status-line, \"%s\"",
c, sb.toString());
}
statusLine = sb.toString();
sb = new StringBuilder();
if (!statusLine.startsWith("HTTP/1.")) {
throw protocolException("Invalid status line: \"%s\"", statusLine);
}
if (statusLine.length() < 12) {
throw protocolException("Invalid status line: \"%s\"", statusLine);
}
responseCode = Integer.parseInt(statusLine.substring(9, 12));
state = State.STATUS_LINE_END;
}
private void maybeStartHeaders(ByteBuffer input) {
assert state == State.STATUS_LINE_END;
assert sb.length() == 0;
char c = (char)input.get();
if (c == CR) {
state = State.STATUS_LINE_END_CR;
} else {
sb.append(c);
state = State.HEADER;
}
}
private void maybeEndHeaders(ByteBuffer input) throws ProtocolException {
assert state == State.STATUS_LINE_END_CR;
assert sb.length() == 0;
char c = (char)input.get();
if (c == LF) {
headers = ImmutableHeaders.of(privateMap);
privateMap = null;
state = State.FINISHED; // no headers
} else {
throw protocolException("Unexpected \"%s\", after status-line CR", c);
}
}
private void readResumeHeader(ByteBuffer input) {
assert state == State.HEADER;
assert input.hasRemaining();
while (input.hasRemaining()) {
char c = (char)input.get();
if (c == CR) {
state = State.HEADER_FOUND_CR;
break;
} else if (c == LF) {
state = State.HEADER_FOUND_LF;
break;
}
if (c == HT)
c = SP;
sb.append(c);
}
}
private void addHeaderFromString(String headerString) {
assert sb.length() == 0;
int idx = headerString.indexOf(':');
if (idx == -1)
return;
String name = headerString.substring(0, idx).trim();
if (name.isEmpty())
return;
String value = headerString.substring(idx + 1, headerString.length()).trim();
privateMap.computeIfAbsent(name.toLowerCase(Locale.US),
k -> new ArrayList<>()).add(value);
}
private void resumeOrLF(ByteBuffer input) {
assert state == State.HEADER_FOUND_CR || state == State.HEADER_FOUND_LF;
char c = (char)input.get();
if (c == LF && state == State.HEADER_FOUND_CR) {
// header value will be flushed by
// resumeOrSecondCR if next line does not
// begin by SP or HT
state = State.HEADER_FOUND_CR_LF;
} else if (c == SP || c == HT) {
sb.append(SP); // parity with MessageHeaders
state = State.HEADER;
} else {
sb = new StringBuilder();
sb.append(c);
state = State.HEADER;
}
}
private void resumeOrSecondCR(ByteBuffer input) {
assert state == State.HEADER_FOUND_CR_LF;
char c = (char)input.get();
if (c == CR) {
if (sb.length() > 0) {
// no continuation line - flush
// previous header value.
String headerString = sb.toString();
sb = new StringBuilder();
addHeaderFromString(headerString);
}
state = State.HEADER_FOUND_CR_LF_CR;
} else if (c == SP || c == HT) {
assert sb.length() != 0;
sb.append(SP); // continuation line
state = State.HEADER;
} else {
if (sb.length() > 0) {
// no continuation line - flush
// previous header value.
String headerString = sb.toString();
sb = new StringBuilder();
addHeaderFromString(headerString);
}
sb.append(c);
state = State.HEADER;
}
}
private void resumeOrEndHeaders(ByteBuffer input) throws ProtocolException {
assert state == State.HEADER_FOUND_CR_LF_CR;
char c = (char)input.get();
if (c == LF) {
state = State.FINISHED;
headers = ImmutableHeaders.of(privateMap);
privateMap = null;
} else {
throw protocolException("Unexpected \"%s\", after CR LF CR", c);
}
}
private ProtocolException protocolException(String format, Object... args) {
return new ProtocolException(format(format, args));
}
}