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- // Copyright (c) 2011 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- // Derived from:
- // mozilla/netwerk/protocol/http/src/nsHttpChunkedDecoder.cpp
- // The license block is:
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications.
- * Portions created by the Initial Developer are Copyright (C) 2001
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Darin Fisher <darin@netscape.com> (original author)
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- #include "net/http/http_chunked_decoder.h"
- #include <algorithm>
- #include "base/logging.h"
- #include "base/strings/string_number_conversions.h"
- #include "base/strings/string_piece.h"
- #include "base/strings/string_util.h"
- #include "net/base/net_errors.h"
- namespace net {
- // Absurdly long size to avoid imposing a constraint on chunked encoding
- // extensions.
- const size_t HttpChunkedDecoder::kMaxLineBufLen = 16384;
- HttpChunkedDecoder::HttpChunkedDecoder() = default;
- int HttpChunkedDecoder::FilterBuf(char* buf, int buf_len) {
- int result = 0;
- while (buf_len > 0) {
- if (chunk_remaining_ > 0) {
- // Since |chunk_remaining_| is positive and |buf_len| an int, the minimum
- // of the two must be an int.
- int num = static_cast<int>(
- std::min(chunk_remaining_, static_cast<int64_t>(buf_len)));
- buf_len -= num;
- chunk_remaining_ -= num;
- result += num;
- buf += num;
- // After each chunk's data there should be a CRLF.
- if (chunk_remaining_ == 0)
- chunk_terminator_remaining_ = true;
- continue;
- } else if (reached_eof_) {
- bytes_after_eof_ += buf_len;
- break; // Done!
- }
- int bytes_consumed = ScanForChunkRemaining(buf, buf_len);
- if (bytes_consumed < 0)
- return bytes_consumed; // Error
- buf_len -= bytes_consumed;
- if (buf_len > 0)
- memmove(buf, buf + bytes_consumed, buf_len);
- }
- return result;
- }
- int HttpChunkedDecoder::ScanForChunkRemaining(const char* buf, int buf_len) {
- DCHECK_EQ(0, chunk_remaining_);
- DCHECK_GT(buf_len, 0);
- int bytes_consumed = 0;
- size_t index_of_lf = base::StringPiece(buf, buf_len).find('\n');
- if (index_of_lf != base::StringPiece::npos) {
- buf_len = static_cast<int>(index_of_lf);
- if (buf_len && buf[buf_len - 1] == '\r') // Eliminate a preceding CR.
- buf_len--;
- bytes_consumed = static_cast<int>(index_of_lf) + 1;
- // Make buf point to the full line buffer to parse.
- if (!line_buf_.empty()) {
- line_buf_.append(buf, buf_len);
- buf = line_buf_.data();
- buf_len = static_cast<int>(line_buf_.size());
- }
- if (reached_last_chunk_) {
- if (buf_len > 0)
- DVLOG(1) << "ignoring http trailer";
- else
- reached_eof_ = true;
- } else if (chunk_terminator_remaining_) {
- if (buf_len > 0) {
- DLOG(ERROR) << "chunk data not terminated properly";
- return ERR_INVALID_CHUNKED_ENCODING;
- }
- chunk_terminator_remaining_ = false;
- } else if (buf_len > 0) {
- // Ignore any chunk-extensions.
- size_t index_of_semicolon = base::StringPiece(buf, buf_len).find(';');
- if (index_of_semicolon != base::StringPiece::npos)
- buf_len = static_cast<int>(index_of_semicolon);
- if (!ParseChunkSize(buf, buf_len, &chunk_remaining_)) {
- DLOG(ERROR) << "Failed parsing HEX from: " <<
- std::string(buf, buf_len);
- return ERR_INVALID_CHUNKED_ENCODING;
- }
- if (chunk_remaining_ == 0)
- reached_last_chunk_ = true;
- } else {
- DLOG(ERROR) << "missing chunk-size";
- return ERR_INVALID_CHUNKED_ENCODING;
- }
- line_buf_.clear();
- } else {
- // Save the partial line; wait for more data.
- bytes_consumed = buf_len;
- // Ignore a trailing CR
- if (buf[buf_len - 1] == '\r')
- buf_len--;
- if (line_buf_.length() + buf_len > kMaxLineBufLen) {
- DLOG(ERROR) << "Chunked line length too long";
- return ERR_INVALID_CHUNKED_ENCODING;
- }
- line_buf_.append(buf, buf_len);
- }
- return bytes_consumed;
- }
- // While the HTTP 1.1 specification defines chunk-size as 1*HEX
- // some sites rely on more lenient parsing.
- // http://www.yahoo.com/, for example, pads chunk-size with trailing spaces
- // (0x20) to be 7 characters long, such as "819b ".
- //
- // A comparison of browsers running on WindowsXP shows that
- // they will parse the following inputs (egrep syntax):
- //
- // Let \X be the character class for a hex digit: [0-9a-fA-F]
- //
- // RFC 7230: ^\X+$
- // IE7: ^\X+[^\X]*$
- // Safari 3.1: ^[\t\r ]*\X+[\t ]*$
- // Firefox 3: ^[\t\f\v\r ]*[+]?(0x)?\X+[^\X]*$
- // Opera 9.51: ^[\t\f\v ]*[+]?(0x)?\X+[^\X]*$
- //
- // Our strategy is to be as strict as possible, while not breaking
- // known sites.
- //
- // Us: ^\X+[ ]*$
- bool HttpChunkedDecoder::ParseChunkSize(const char* start,
- int len,
- int64_t* out) {
- DCHECK_GE(len, 0);
- // Strip trailing spaces
- while (len > 0 && start[len - 1] == ' ')
- len--;
- // Be more restrictive than HexStringToInt64;
- // don't allow inputs with leading "-", "+", "0x", "0X"
- base::StringPiece chunk_size(start, len);
- if (chunk_size.find_first_not_of("0123456789abcdefABCDEF")
- != base::StringPiece::npos) {
- return false;
- }
- int64_t parsed_number;
- bool ok = base::HexStringToInt64(chunk_size, &parsed_number);
- if (ok && parsed_number >= 0) {
- *out = parsed_number;
- return true;
- }
- return false;
- }
- } // namespace net
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