blob: 2224e4b8716971efef2a71c5c902ae7004f49bed [file] [log] [blame]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// Global constants.
class _Const {
// Bytes for "HTTP".
static const HTTP = const [72, 84, 84, 80];
// Bytes for "HTTP/1.".
static const HTTP1DOT = const [72, 84, 84, 80, 47, 49, 46];
// Bytes for "HTTP/1.0".
static const HTTP10 = const [72, 84, 84, 80, 47, 49, 46, 48];
// Bytes for "HTTP/1.1".
static const HTTP11 = const [72, 84, 84, 80, 47, 49, 46, 49];
static const END_CHUNKED = const [0x30, 13, 10, 13, 10];
// Bytes for '()<>@,;:\\"/[]?={} \t'.
static const SEPARATORS = const [40, 41, 60, 62, 64, 44, 59, 58, 92, 34, 47,
91, 93, 63, 61, 123, 125, 32, 9];
// Bytes for '()<>@,;:\\"/[]?={} \t\r\n'.
static const SEPARATORS_AND_CR_LF = const [40, 41, 60, 62, 64, 44, 59, 58, 92,
34, 47, 91, 93, 63, 61, 123, 125,
32, 9, 13, 10];
}
// Frequently used character codes.
class _CharCode {
static const int HT = 9;
static const int LF = 10;
static const int CR = 13;
static const int SP = 32;
static const int COMMA = 44;
static const int DASH = 45;
static const int SLASH = 47;
static const int ZERO = 48;
static const int ONE = 49;
static const int COLON = 58;
static const int SEMI_COLON = 59;
}
// States of the HTTP parser state machine.
class _State {
static const int START = 0;
static const int METHOD_OR_RESPONSE_HTTP_VERSION = 1;
static const int RESPONSE_HTTP_VERSION = 2;
static const int REQUEST_LINE_METHOD = 3;
static const int REQUEST_LINE_URI = 4;
static const int REQUEST_LINE_HTTP_VERSION = 5;
static const int REQUEST_LINE_ENDING = 6;
static const int RESPONSE_LINE_STATUS_CODE = 7;
static const int RESPONSE_LINE_REASON_PHRASE = 8;
static const int RESPONSE_LINE_ENDING = 9;
static const int HEADER_START = 10;
static const int HEADER_FIELD = 11;
static const int HEADER_VALUE_START = 12;
static const int HEADER_VALUE = 13;
static const int HEADER_VALUE_FOLDING_OR_ENDING = 14;
static const int HEADER_VALUE_FOLD_OR_END = 15;
static const int HEADER_ENDING = 16;
static const int CHUNK_SIZE_STARTING_CR = 17;
static const int CHUNK_SIZE_STARTING_LF = 18;
static const int CHUNK_SIZE = 19;
static const int CHUNK_SIZE_EXTENSION = 20;
static const int CHUNK_SIZE_ENDING = 21;
static const int CHUNKED_BODY_DONE_CR = 22;
static const int CHUNKED_BODY_DONE_LF = 23;
static const int BODY = 24;
static const int CLOSED = 25;
static const int UPGRADED = 26;
static const int FAILURE = 27;
static const int FIRST_BODY_STATE = CHUNK_SIZE_STARTING_CR;
}
// HTTP version of the request or response being parsed.
class _HttpVersion {
static const int UNDETERMINED = 0;
static const int HTTP10 = 1;
static const int HTTP11 = 2;
}
// States of the HTTP parser state machine.
class _MessageType {
static const int UNDETERMINED = 0;
static const int REQUEST = 1;
static const int RESPONSE = 0;
}
/**
* HTTP parser which parses the HTTP stream as data is supplied
* through the [:writeList:] and [:connectionClosed:] methods. As the
* data is parsed the following callbacks are called:
*
* [:requestStart:]
* [:responseStart:]
* [:headerReceived:]
* [:headersComplete:]
* [:dataReceived:]
* [:dataEnd:]
* [:error:]
*
* If an HTTP parser error occours it is possible to get an exception
* thrown from the [:writeList:] and [:connectionClosed:] methods if
* the error callback is not set.
*
* The connection upgrades (e.g. switching from HTTP/1.1 to the
* WebSocket protocol) is handled in a special way. If connection
* upgrade is specified in the headers, then on the callback to
* [:headersComplete:] the [:upgrade:] property on the [:HttpParser:]
* object will be [:true:] indicating that from now on the protocol is
* not HTTP anymore and no more callbacks will happen, that is
* [:dataReceived:] and [:dataEnd:] are not called in this case as
* there is no more HTTP data. After the upgrade the call to
* [:writeList:] causing the upgrade will return with the number of
* bytes parsed as HTTP. Any unparsed bytes is part of the protocol
* the connection is upgrading to and should be handled according to
* that protocol.
*/
class _HttpParser {
_HttpParser() {
_reset();
}
// From RFC 2616.
// generic-message = start-line
// *(message-header CRLF)
// CRLF
// [ message-body ]
// start-line = Request-Line | Status-Line
// Request-Line = Method SP Request-URI SP HTTP-Version CRLF
// Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF
// message-header = field-name ":" [ field-value ]
int writeList(List<int> buffer, int offset, int count) {
int index = offset;
int lastIndex = offset + count;
try {
if (_state == _State.CLOSED) {
throw new HttpParserException("Data on closed connection");
}
if (_state == _State.UPGRADED) {
throw new HttpParserException("Data on upgraded connection");
}
if (_state == _State.FAILURE) {
throw new HttpParserException("Data on failed connection");
}
while ((index < lastIndex) &&
_state != _State.FAILURE &&
_state != _State.UPGRADED) {
int byte = buffer[index];
switch (_state) {
case _State.START:
if (byte == _Const.HTTP[0]) {
// Start parsing method or HTTP version.
_httpVersionIndex = 1;
_state = _State.METHOD_OR_RESPONSE_HTTP_VERSION;
} else {
// Start parsing method.
if (!_isTokenChar(byte)) {
throw new HttpParserException("Invalid request method");
}
_method_or_status_code.addCharCode(byte);
_state = _State.REQUEST_LINE_METHOD;
}
break;
case _State.METHOD_OR_RESPONSE_HTTP_VERSION:
if (_httpVersionIndex < _Const.HTTP.length &&
byte == _Const.HTTP[_httpVersionIndex]) {
// Continue parsing HTTP version.
_httpVersionIndex++;
} else if (_httpVersionIndex == _Const.HTTP.length &&
byte == _CharCode.SLASH) {
// HTTP/ parsed. As method is a token this cannot be a
// method anymore.
_httpVersionIndex++;
_state = _State.RESPONSE_HTTP_VERSION;
} else {
// Did not parse HTTP version. Expect method instead.
for (int i = 0; i < _httpVersionIndex; i++) {
_method_or_status_code.addCharCode(_Const.HTTP[i]);
}
if (byte == _CharCode.SP) {
_state = _State.REQUEST_LINE_URI;
} else {
_method_or_status_code.addCharCode(byte);
_httpVersion = _HttpVersion.UNDETERMINED;
_state = _State.REQUEST_LINE_METHOD;
}
}
break;
case _State.RESPONSE_HTTP_VERSION:
if (_httpVersionIndex < _Const.HTTP1DOT.length) {
// Continue parsing HTTP version.
_expect(byte, _Const.HTTP1DOT[_httpVersionIndex]);
_httpVersionIndex++;
} else if (_httpVersionIndex == _Const.HTTP1DOT.length &&
byte == _CharCode.ONE) {
// HTTP/1.1 parsed.
_httpVersion = _HttpVersion.HTTP11;
_persistentConnection = true;
_httpVersionIndex++;
} else if (_httpVersionIndex == _Const.HTTP1DOT.length &&
byte == _CharCode.ZERO) {
// HTTP/1.0 parsed.
_httpVersion = _HttpVersion.HTTP10;
_persistentConnection = false;
_httpVersionIndex++;
} else if (_httpVersionIndex == _Const.HTTP1DOT.length + 1) {
_expect(byte, _CharCode.SP);
// HTTP version parsed.
_state = _State.RESPONSE_LINE_STATUS_CODE;
} else {
throw new HttpParserException("Invalid response line");
}
break;
case _State.REQUEST_LINE_METHOD:
if (byte == _CharCode.SP) {
_state = _State.REQUEST_LINE_URI;
} else {
if (_Const.SEPARATORS_AND_CR_LF.indexOf(byte) != -1) {
throw new HttpParserException("Invalid request method");
}
_method_or_status_code.addCharCode(byte);
}
break;
case _State.REQUEST_LINE_URI:
if (byte == _CharCode.SP) {
_state = _State.REQUEST_LINE_HTTP_VERSION;
_httpVersionIndex = 0;
} else {
if (byte == _CharCode.CR || byte == _CharCode.LF) {
throw new HttpParserException("Invalid request URI");
}
_uri_or_reason_phrase.addCharCode(byte);
}
break;
case _State.REQUEST_LINE_HTTP_VERSION:
if (_httpVersionIndex < _Const.HTTP1DOT.length) {
_expect(byte, _Const.HTTP11[_httpVersionIndex]);
_httpVersionIndex++;
} else if (_httpVersionIndex == _Const.HTTP1DOT.length) {
if (byte == _CharCode.ONE) {
// HTTP/1.1 parsed.
_httpVersion = _HttpVersion.HTTP11;
_persistentConnection = true;
_httpVersionIndex++;
} else if (byte == _CharCode.ZERO) {
// HTTP/1.0 parsed.
_httpVersion = _HttpVersion.HTTP10;
_persistentConnection = false;
_httpVersionIndex++;
} else {
throw new HttpParserException("Invalid response line");
}
} else {
_expect(byte, _CharCode.CR);
_state = _State.REQUEST_LINE_ENDING;
}
break;
case _State.REQUEST_LINE_ENDING:
_expect(byte, _CharCode.LF);
_messageType = _MessageType.REQUEST;
if (requestStart != null) {
requestStart(_method_or_status_code.toString(),
_uri_or_reason_phrase.toString(),
version);
}
_method_or_status_code.clear();
_uri_or_reason_phrase.clear();
_state = _State.HEADER_START;
break;
case _State.RESPONSE_LINE_STATUS_CODE:
if (byte == _CharCode.SP) {
if (_method_or_status_code.length != 3) {
throw new HttpParserException("Invalid response status code");
}
_state = _State.RESPONSE_LINE_REASON_PHRASE;
} else {
if (byte < 0x30 && 0x39 < byte) {
throw new HttpParserException("Invalid response status code");
} else {
_method_or_status_code.addCharCode(byte);
}
}
break;
case _State.RESPONSE_LINE_REASON_PHRASE:
if (byte == _CharCode.CR) {
if (_uri_or_reason_phrase.length == 0) {
throw new HttpParserException("Invalid response reason phrase");
}
_state = _State.RESPONSE_LINE_ENDING;
} else {
if (byte == _CharCode.CR || byte == _CharCode.LF) {
throw new HttpParserException("Invalid response reason phrase");
}
_uri_or_reason_phrase.addCharCode(byte);
}
break;
case _State.RESPONSE_LINE_ENDING:
_expect(byte, _CharCode.LF);
_messageType == _MessageType.RESPONSE;
int statusCode = parseInt(_method_or_status_code.toString());
if (statusCode < 100 || statusCode > 599) {
throw new HttpParserException("Invalid response status code");
} else {
// Check whether this response will never have a body.
_noMessageBody =
statusCode <= 199 || statusCode == 204 || statusCode == 304;
}
if (responseStart != null) {
responseStart(statusCode, _uri_or_reason_phrase.toString(), version);
}
_method_or_status_code.clear();
_uri_or_reason_phrase.clear();
_state = _State.HEADER_START;
break;
case _State.HEADER_START:
if (byte == _CharCode.CR) {
_state = _State.HEADER_ENDING;
} else {
// Start of new header field.
_headerField.addCharCode(_toLowerCase(byte));
_state = _State.HEADER_FIELD;
}
break;
case _State.HEADER_FIELD:
if (byte == _CharCode.COLON) {
_state = _State.HEADER_VALUE_START;
} else {
if (!_isTokenChar(byte)) {
throw new HttpParserException("Invalid header field name");
}
_headerField.addCharCode(_toLowerCase(byte));
}
break;
case _State.HEADER_VALUE_START:
if (byte == _CharCode.CR) {
_state = _State.HEADER_VALUE_FOLDING_OR_ENDING;
} else if (byte != _CharCode.SP && byte != _CharCode.HT) {
// Start of new header value.
_headerValue.addCharCode(byte);
_state = _State.HEADER_VALUE;
}
break;
case _State.HEADER_VALUE:
if (byte == _CharCode.CR) {
_state = _State.HEADER_VALUE_FOLDING_OR_ENDING;
} else {
_headerValue.addCharCode(byte);
}
break;
case _State.HEADER_VALUE_FOLDING_OR_ENDING:
_expect(byte, _CharCode.LF);
_state = _State.HEADER_VALUE_FOLD_OR_END;
break;
case _State.HEADER_VALUE_FOLD_OR_END:
if (byte == _CharCode.SP || byte == _CharCode.HT) {
_state = _State.HEADER_VALUE_START;
} else {
String headerField = _headerField.toString();
String headerValue =_headerValue.toString();
bool reportHeader = true;
if (headerField == "content-length" && !_chunked) {
// Ignore the Content-Length header if Transfer-Encoding
// is chunked (RFC 2616 section 4.4)
_contentLength = parseInt(headerValue);
} else if (headerField == "connection") {
List<String> tokens = _tokenizeFieldValue(headerValue);
for (int i = 0; i < tokens.length; i++) {
String token = tokens[i].toLowerCase();
if (token == "keep-alive") {
_persistentConnection = true;
} else if (token == "close") {
_persistentConnection = false;
} else if (token == "upgrade") {
_connectionUpgrade = true;
}
if (headerReceived != null) {
headerReceived(headerField, token);
}
}
reportHeader = false;
} else if (headerField == "transfer-encoding" &&
headerValue.toLowerCase() == "chunked") {
// Ignore the Content-Length header if Transfer-Encoding
// is chunked (RFC 2616 section 4.4)
_chunked = true;
_contentLength = -1;
}
if (reportHeader && headerReceived != null) {
headerReceived(headerField, headerValue);
}
_headerField.clear();
_headerValue.clear();
if (byte == _CharCode.CR) {
_state = _State.HEADER_ENDING;
} else {
// Start of new header field.
_headerField.addCharCode(_toLowerCase(byte));
_state = _State.HEADER_FIELD;
}
}
break;
case _State.HEADER_ENDING:
_expect(byte, _CharCode.LF);
if (_connectionUpgrade) {
_state = _State.UPGRADED;
_unparsedData =
buffer.getRange(index + 1, count - (index + 1 - offset));
if (headersComplete != null) headersComplete();
} else {
if (headersComplete != null) headersComplete();
if (_chunked) {
_state = _State.CHUNK_SIZE;
_remainingContent = 0;
} else if (_contentLength == 0 ||
(_messageType == _MessageType.REQUEST &&
_contentLength == -1) ||
(_messageType == _MessageType.RESPONSE &&
(_noMessageBody || _responseToMethod == "HEAD"))) {
// If there is no message body get ready to process the
// next request.
_bodyEnd();
_reset();
} else if (_contentLength > 0) {
_remainingContent = _contentLength;
_state = _State.BODY;
} else {
// Neither chunked nor content length. End of body
// indicated by close.
_state = _State.BODY;
}
}
break;
case _State.CHUNK_SIZE_STARTING_CR:
_expect(byte, _CharCode.CR);
_state = _State.CHUNK_SIZE_STARTING_LF;
break;
case _State.CHUNK_SIZE_STARTING_LF:
_expect(byte, _CharCode.LF);
_state = _State.CHUNK_SIZE;
break;
case _State.CHUNK_SIZE:
if (byte == _CharCode.CR) {
_state = _State.CHUNK_SIZE_ENDING;
} else if (byte == _CharCode.SEMI_COLON) {
_state = _State.CHUNK_SIZE_EXTENSION;
} else {
int value = _expectHexDigit(byte);
_remainingContent = _remainingContent * 16 + value;
}
break;
case _State.CHUNK_SIZE_EXTENSION:
if (byte == _CharCode.CR) {
_state = _State.CHUNK_SIZE_ENDING;
}
break;
case _State.CHUNK_SIZE_ENDING:
_expect(byte, _CharCode.LF);
if (_remainingContent > 0) {
_state = _State.BODY;
} else {
_state = _State.CHUNKED_BODY_DONE_CR;
}
break;
case _State.CHUNKED_BODY_DONE_CR:
_expect(byte, _CharCode.CR);
_state = _State.CHUNKED_BODY_DONE_LF;
break;
case _State.CHUNKED_BODY_DONE_LF:
_expect(byte, _CharCode.LF);
_bodyEnd();
_reset();
break;
case _State.BODY:
// The body is not handled one byte at a time but in blocks.
int dataAvailable = lastIndex - index;
List<int> data;
if (_remainingContent == null ||
dataAvailable <= _remainingContent) {
data = new Uint8List(dataAvailable);
data.setRange(0, dataAvailable, buffer, index);
} else {
data = new Uint8List(_remainingContent);
data.setRange(0, _remainingContent, buffer, index);
}
if (dataReceived != null) dataReceived(data);
if (_remainingContent != null) {
_remainingContent -= data.length;
}
index += data.length;
if (_remainingContent == 0) {
if (!_chunked) {
_bodyEnd();
_reset();
} else {
_state = _State.CHUNK_SIZE_STARTING_CR;
}
}
// Hack - as we always do index++ below.
index--;
break;
case _State.FAILURE:
// Should be unreachable.
assert(false);
break;
default:
// Should be unreachable.
assert(false);
break;
}
// Move to the next byte.
index++;
}
} catch (e) {
// Report the error through the error callback if any. Otherwise
// throw the error.
if (error != null) {
error(e);
_state = _State.FAILURE;
} else {
throw e;
}
}
// Return the number of bytes parsed.
return index - offset;
}
void connectionClosed() {
if (_state < _State.FIRST_BODY_STATE) {
_state = _State.FAILURE;
// Report the error through the error callback if any. Otherwise
// throw the error.
var e = new HttpParserException(
"Connection closed before full header was received");
if (error != null) {
error(e);
return;
}
throw e;
}
if (!_chunked && _contentLength == -1) {
if (_state != _State.START) {
if (dataEnd != null) dataEnd(true);
}
_state = _State.CLOSED;
} else {
_state = _State.FAILURE;
// Report the error through the error callback if any. Otherwise
// throw the error.
var e = new HttpParserException(
"Connection closed before full body was received");
if (error != null) {
error(e);
return;
}
throw e;
}
}
String get version {
switch (_httpVersion) {
case _HttpVersion.HTTP10:
return "1.0";
case _HttpVersion.HTTP11:
return "1.1";
}
return null;
}
int get messageType => _messageType;
int get contentLength => _contentLength;
bool get upgrade => _connectionUpgrade && _state == _State.UPGRADED;
bool get persistentConnection => _persistentConnection;
void set responseToMethod(String method) { _responseToMethod = method; }
bool get isIdle => _state == _State.START;
List<int> get unparsedData => _unparsedData;
void _bodyEnd() {
if (dataEnd != null) {
dataEnd(_messageType == _MessageType.RESPONSE && !_persistentConnection);
}
}
_reset() {
_state = _State.START;
_messageType = _MessageType.UNDETERMINED;
_headerField = new StringBuffer();
_headerValue = new StringBuffer();
_method_or_status_code = new StringBuffer();
_uri_or_reason_phrase = new StringBuffer();
_httpVersion = _HttpVersion.UNDETERMINED;
_contentLength = -1;
_persistentConnection = false;
_connectionUpgrade = false;
_chunked = false;
_noMessageBody = false;
_responseToMethod = null;
_remainingContent = null;
}
bool _isTokenChar(int byte) {
return byte > 31 && byte < 128 && _Const.SEPARATORS.indexOf(byte) == -1;
}
List<String> _tokenizeFieldValue(String headerValue) {
List<String> tokens = new List<String>();
int start = 0;
int index = 0;
while (index < headerValue.length) {
if (headerValue[index] == ",") {
tokens.add(headerValue.substring(start, index));
start = index + 1;
} else if (headerValue[index] == " " || headerValue[index] == "\t") {
start++;
}
index++;
}
tokens.add(headerValue.substring(start, index));
return tokens;
}
int _toLowerCase(int byte) {
final int aCode = "A".charCodeAt(0);
final int zCode = "Z".charCodeAt(0);
final int delta = "a".charCodeAt(0) - aCode;
return (aCode <= byte && byte <= zCode) ? byte + delta : byte;
}
int _expect(int val1, int val2) {
if (val1 != val2) {
throw new HttpParserException("Failed to parse HTTP");
}
}
int _expectHexDigit(int byte) {
if (0x30 <= byte && byte <= 0x39) {
return byte - 0x30; // 0 - 9
} else if (0x41 <= byte && byte <= 0x46) {
return byte - 0x41 + 10; // A - F
} else if (0x61 <= byte && byte <= 0x66) {
return byte - 0x61 + 10; // a - f
} else {
throw new HttpParserException("Failed to parse HTTP");
}
}
int _state;
int _httpVersionIndex;
int _messageType;
StringBuffer _method_or_status_code;
StringBuffer _uri_or_reason_phrase;
StringBuffer _headerField;
StringBuffer _headerValue;
int _httpVersion;
int _contentLength;
bool _persistentConnection;
bool _connectionUpgrade;
bool _chunked;
bool _noMessageBody;
String _responseToMethod; // Indicates the method used for the request.
int _remainingContent;
List<int> _unparsedData; // Unparsed data after connection upgrade.
// Callbacks.
Function requestStart;
Function responseStart;
Function headerReceived;
Function headersComplete;
Function dataReceived;
Function dataEnd;
Function error;
}
class HttpParserException implements Exception {
const HttpParserException([String this.message = ""]);
String toString() => "HttpParserException: $message";
final String message;
}