Google Git
Sign in
android / platform / external / chromium_org / f0d22c2 / . / net / tools / balsa / balsa_frame.cc
blob: 463a678dead95cab698cda50771efa3307b861ec [file] [log] [blame]
// Copyright 2013 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.
#include "net/tools/balsa/balsa_frame.h"
#include <assert.h>
#if __SSE2__
#include <emmintrin.h>
#endif // __SSE2__
#include <limits>
#include <string>
#include <utility>
#include <vector>
#include "base/logging.h"
#include "base/port.h"
#include "base/strings/string_piece.h"
#include "net/tools/balsa/balsa_enums.h"
#include "net/tools/balsa/balsa_headers.h"
#include "net/tools/balsa/balsa_visitor_interface.h"
#include "net/tools/balsa/buffer_interface.h"
#include "net/tools/balsa/simple_buffer.h"
#include "net/tools/balsa/split.h"
#include "net/tools/balsa/string_piece_utils.h"
#if defined(COMPILER_MSVC)
#include <string.h>
#define strncasecmp _strnicmp
#else
#include <strings.h>
#endif
namespace net {
// Constants holding some header names for headers which can affect the way the
// HTTP message is framed, and so must be processed specially:
static const char kContentLength[] = "content-length";
static const size_t kContentLengthSize = sizeof(kContentLength) - 1;
static const char kTransferEncoding[] = "transfer-encoding";
static const size_t kTransferEncodingSize = sizeof(kTransferEncoding) - 1;
BalsaFrame::BalsaFrame()
: last_char_was_slash_r_(false),
saw_non_newline_char_(false),
start_was_space_(true),
chunk_length_character_extracted_(false),
is_request_(true),
request_was_head_(false),
max_header_length_(16 * 1024),
max_request_uri_length_(2048),
visitor_(&do_nothing_visitor_),
chunk_length_remaining_(0),
content_length_remaining_(0),
last_slash_n_loc_(NULL),
last_recorded_slash_n_loc_(NULL),
last_slash_n_idx_(0),
term_chars_(0),
parse_state_(BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE),
last_error_(BalsaFrameEnums::NO_ERROR),
headers_(NULL) {
}
BalsaFrame::~BalsaFrame() {}
void BalsaFrame::Reset() {
last_char_was_slash_r_ = false;
saw_non_newline_char_ = false;
start_was_space_ = true;
chunk_length_character_extracted_ = false;
// is_request_ = true; // not reset between messages.
// request_was_head_ = false; // not reset between messages.
// max_header_length_ = 4096; // not reset between messages.
// max_request_uri_length_ = 2048; // not reset between messages.
// visitor_ = &do_nothing_visitor_; // not reset between messages.
chunk_length_remaining_ = 0;
content_length_remaining_ = 0;
last_slash_n_loc_ = NULL;
last_recorded_slash_n_loc_ = NULL;
last_slash_n_idx_ = 0;
term_chars_ = 0;
parse_state_ = BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE;
last_error_ = BalsaFrameEnums::NO_ERROR;
lines_.clear();
if (headers_ != NULL) {
headers_->Clear();
}
}
const char* BalsaFrameEnums::ParseStateToString(
BalsaFrameEnums::ParseState error_code) {
switch (error_code) {
case PARSE_ERROR:
return "PARSE_ERROR";
case READING_HEADER_AND_FIRSTLINE:
return "READING_HEADER_AND_FIRSTLINE";
case READING_CHUNK_LENGTH:
return "READING_CHUNK_LENGTH";
case READING_CHUNK_EXTENSION:
return "READING_CHUNK_EXTENSION";
case READING_CHUNK_DATA:
return "READING_CHUNK_DATA";
case READING_CHUNK_TERM:
return "READING_CHUNK_TERM";
case READING_LAST_CHUNK_TERM:
return "READING_LAST_CHUNK_TERM";
case READING_TRAILER:
return "READING_TRAILER";
case READING_UNTIL_CLOSE:
return "READING_UNTIL_CLOSE";
case READING_CONTENT:
return "READING_CONTENT";
case MESSAGE_FULLY_READ:
return "MESSAGE_FULLY_READ";
case NUM_STATES:
return "UNKNOWN_STATE";
}
return "UNKNOWN_STATE";
}
const char* BalsaFrameEnums::ErrorCodeToString(
BalsaFrameEnums::ErrorCode error_code) {
switch (error_code) {
case NO_ERROR:
return "NO_ERROR";
case NO_STATUS_LINE_IN_RESPONSE:
return "NO_STATUS_LINE_IN_RESPONSE";
case NO_REQUEST_LINE_IN_REQUEST:
return "NO_REQUEST_LINE_IN_REQUEST";
case FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION:
return "FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION";
case FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD:
return "FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD";
case FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE:
return "FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE";
case FAILED_TO_FIND_WS_AFTER_REQUEST_REQUEST_URI:
return "FAILED_TO_FIND_WS_AFTER_REQUEST_REQUEST_URI";
case FAILED_TO_FIND_NL_AFTER_RESPONSE_REASON_PHRASE:
return "FAILED_TO_FIND_NL_AFTER_RESPONSE_REASON_PHRASE";
case FAILED_TO_FIND_NL_AFTER_REQUEST_HTTP_VERSION:
return "FAILED_TO_FIND_NL_AFTER_REQUEST_HTTP_VERSION";
case FAILED_CONVERTING_STATUS_CODE_TO_INT:
return "FAILED_CONVERTING_STATUS_CODE_TO_INT";
case REQUEST_URI_TOO_LONG:
return "REQUEST_URI_TOO_LONG";
case HEADERS_TOO_LONG:
return "HEADERS_TOO_LONG";
case UNPARSABLE_CONTENT_LENGTH:
return "UNPARSABLE_CONTENT_LENGTH";
case MAYBE_BODY_BUT_NO_CONTENT_LENGTH:
return "MAYBE_BODY_BUT_NO_CONTENT_LENGTH";
case REQUIRED_BODY_BUT_NO_CONTENT_LENGTH:
return "REQUIRED_BODY_BUT_NO_CONTENT_LENGTH";
case HEADER_MISSING_COLON:
return "HEADER_MISSING_COLON";
case INVALID_CHUNK_LENGTH:
return "INVALID_CHUNK_LENGTH";
case CHUNK_LENGTH_OVERFLOW:
return "CHUNK_LENGTH_OVERFLOW";
case CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO:
return "CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO";
case CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT:
return "CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT";
case MULTIPLE_CONTENT_LENGTH_KEYS:
return "MULTIPLE_CONTENT_LENGTH_KEYS";
case MULTIPLE_TRANSFER_ENCODING_KEYS:
return "MULTIPLE_TRANSFER_ENCODING_KEYS";
case UNKNOWN_TRANSFER_ENCODING:
return "UNKNOWN_TRANSFER_ENCODING";
case INVALID_HEADER_FORMAT:
return "INVALID_HEADER_FORMAT";
case INTERNAL_LOGIC_ERROR:
return "INTERNAL_LOGIC_ERROR";
case NUM_ERROR_CODES:
return "UNKNOWN_ERROR";
}
return "UNKNOWN_ERROR";
}
// Summary:
// Parses the first line of either a request or response.
// Note that in the case of a detected warning, error_code will be set
// but the function will not return false.
// Exactly zero or one warning or error (but not both) may be detected
// by this function.
// Note that this function will not write the data of the first-line
// into the header's buffer (that should already have been done elsewhere).
//
// Pre-conditions:
// begin != end
// *begin should be a character which is > ' '. This implies that there
// is at least one non-whitespace characters between [begin, end).
// headers is a valid pointer to a BalsaHeaders class.
// error_code is a valid pointer to a BalsaFrameEnums::ErrorCode value.
// Entire first line must exist between [begin, end)
// Exactly zero or one newlines -may- exist between [begin, end)
// [begin, end) should exist in the header's buffer.
//
// Side-effects:
// headers will be modified
// error_code may be modified if either a warning or error is detected
//
// Returns:
// True if no error (as opposed to warning) is detected.
// False if an error (as opposed to warning) is detected.
//
// If there is indeed non-whitespace in the line, then the following
// will take care of this for you:
// while (*begin <= ' ') ++begin;
// ProcessFirstLine(begin, end, is_request, &headers, &error_code);
//
bool ParseHTTPFirstLine(const char* begin,
const char* end,
bool is_request,
size_t max_request_uri_length,
BalsaHeaders* headers,
BalsaFrameEnums::ErrorCode* error_code) {
const char* current = begin;
// HTTP firstlines all have the following structure:
// LWS NONWS LWS NONWS LWS NONWS NOTCRLF CRLF
// [\t \r\n]+ [^\t ]+ [\t ]+ [^\t ]+ [\t ]+ [^\t ]+ [^\r\n]+ "\r\n"
// ws1 nws1 ws2 nws2 ws3 nws3 ws4
// | [-------) [-------) [----------------)
// REQ: method request_uri version
// RESP: version statuscode reason
//
// The first NONWS->LWS component we'll call firstline_a.
// The second firstline_b, and the third firstline_c.
//
// firstline_a goes from nws1 to (but not including) ws2
// firstline_b goes from nws2 to (but not including) ws3
// firstline_c goes from nws3 to (but not including) ws4
//
// In the code:
// ws1 == whitespace_1_idx_
// nws1 == non_whitespace_1_idx_
// ws2 == whitespace_2_idx_
// nws2 == non_whitespace_2_idx_
// ws3 == whitespace_3_idx_
// nws3 == non_whitespace_3_idx_
// ws4 == whitespace_4_idx_
// Kill all whitespace (including '\r\n') at the end of the line.
--end;
if (*end != '\n') {
*error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;
LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"
<< headers->OriginalHeadersForDebugging();
return false;
}
while (begin < end && *end <= ' ') {
--end;
}
DCHECK(*end != '\n');
if (*end == '\n') {
*error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;
LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"
<< headers->OriginalHeadersForDebugging();
return false;
}
++end;
// The two following statements should not be possible.
if (end == begin) {
*error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;
LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"
<< headers->OriginalHeadersForDebugging();
return false;
}
// whitespace_1_idx_
headers->whitespace_1_idx_ = current - begin;
// This loop is commented out as it is never used in current code. This is
// true only because we don't begin parsing the headers at all until we've
// encountered a non whitespace character at the beginning of the stream, at
// which point we begin our demarcation of header-start. If we did -not- do
// this (for instance, only looked for [\r\n] instead of (< ' ')), this loop
// would be necessary for the proper functioning of this parsing.
// This is left here as this function may (in the future) be refactored out
// of the BalsaFrame class so that it may be shared between code in
// BalsaFrame and BalsaHeaders (where it would be used in some variant of the
// set_first_line() function (at which point it would be necessary).
#if 0
while (*current <= ' ') {
++current;
}
#endif
// non_whitespace_1_idx_
headers->non_whitespace_1_idx_ = current - begin;
do {
// The first time through, we're guaranteed that the current character
// won't be a whitespace (else the loop above wouldn't have terminated).
// That implies that we're guaranteed to get at least one non-whitespace
// character if we get into this loop at all.
++current;
if (current == end) {
headers->whitespace_2_idx_ = current - begin;
headers->non_whitespace_2_idx_ = current - begin;
headers->whitespace_3_idx_ = current - begin;
headers->non_whitespace_3_idx_ = current - begin;
headers->whitespace_4_idx_ = current - begin;
// FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD for request
// FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION for response
*error_code =
static_cast<BalsaFrameEnums::ErrorCode>(
BalsaFrameEnums::FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION +
is_request);
if (!is_request) { // FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION
return false;
}
goto output_exhausted;
}
} while (*current > ' ');
// whitespace_2_idx_
headers->whitespace_2_idx_ = current - begin;
do {
++current;
// Note that due to the loop which consumes all of the whitespace
// at the end of the line, current can never == end while in this function.
} while (*current <= ' ');
// non_whitespace_2_idx_
headers->non_whitespace_2_idx_ = current - begin;
do {
++current;
if (current == end) {
headers->whitespace_3_idx_ = current - begin;
headers->non_whitespace_3_idx_ = current - begin;
headers->whitespace_4_idx_ = current - begin;
// FAILED_TO_FIND_START_OF_REQUEST_REQUEST_URI for request
// FAILED_TO_FIND_START_OF_RESPONSE_STATUSCODE for response
*error_code =
static_cast<BalsaFrameEnums::ErrorCode>(
BalsaFrameEnums::FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE
+ is_request);
goto output_exhausted;
}
} while (*current > ' ');
// whitespace_3_idx_
headers->whitespace_3_idx_ = current - begin;
do {
++current;
// Note that due to the loop which consumes all of the whitespace
// at the end of the line, current can never == end while in this function.
} while (*current <= ' ');
// non_whitespace_3_idx_
headers->non_whitespace_3_idx_ = current - begin;
headers->whitespace_4_idx_ = end - begin;
output_exhausted:
// Note that we don't fail the parse immediately when parsing of the
// firstline fails. Depending on the protocol type, we may want to accept
// a firstline with only one or two elements, e.g., for HTTP/0.9:
// GET\r\n
// or
// GET /\r\n
// should be parsed without issue (though the visitor should know that
// parsing the entire line was not exactly as it should be).
//
// Eventually, these errors may be removed alltogether, as the visitor can
// detect them on its own by examining the size of the various fields.
// headers->set_first_line(non_whitespace_1_idx_, current);
if (is_request) {
if ((headers->whitespace_3_idx_ - headers->non_whitespace_2_idx_) >
max_request_uri_length) {
// For requests, we need at least the method. We could assume that a
// blank URI means "/". If version isn't stated, it should be assumed
// to be HTTP/0.9 by the visitor.
*error_code = BalsaFrameEnums::REQUEST_URI_TOO_LONG;
return false;
}
} else {
headers->parsed_response_code_ = 0;
{
const char* parsed_response_code_current =
begin + headers->non_whitespace_2_idx_;
const char* parsed_response_code_end = begin + headers->whitespace_3_idx_;
const size_t kMaxDiv10 = std::numeric_limits<size_t>::max() / 10;
// Convert a string of [0-9]* into an int.
// Note that this allows for the conversion of response codes which
// are outside the bounds of normal HTTP response codes (no checking
// is done to ensure that these are valid-- they're merely parsed)!
while (parsed_response_code_current < parsed_response_code_end) {
if (*parsed_response_code_current < '0' ||
*parsed_response_code_current > '9') {
*error_code = BalsaFrameEnums::FAILED_CONVERTING_STATUS_CODE_TO_INT;
return false;
}
size_t status_code_x_10 = headers->parsed_response_code_ * 10;
uint8 c = *parsed_response_code_current - '0';
if ((headers->parsed_response_code_ > kMaxDiv10) ||
(std::numeric_limits<size_t>::max() - status_code_x_10) < c) {
// overflow.
*error_code = BalsaFrameEnums::FAILED_CONVERTING_STATUS_CODE_TO_INT;
return false;
}
headers->parsed_response_code_ = status_code_x_10 + c;
++parsed_response_code_current;
}
}
}
return true;
}
// begin - beginning of the firstline
// end - end of the firstline
//
// A precondition for this function is that there is non-whitespace between
// [begin, end). If this precondition is not met, the function will not perform
// as expected (and bad things may happen, and it will eat your first, second,
// and third unborn children!).
//
// Another precondition for this function is that [begin, end) includes
// at most one newline, which must be at the end of the line.
void BalsaFrame::ProcessFirstLine(const char* begin, const char* end) {
BalsaFrameEnums::ErrorCode previous_error = last_error_;
if (!ParseHTTPFirstLine(begin,
end,
is_request_,
max_request_uri_length_,
headers_,
&last_error_)) {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleHeaderError(this);
return;
}
if (previous_error != last_error_) {
visitor_->HandleHeaderWarning(this);
}
if (is_request_) {
size_t version_length =
headers_->whitespace_4_idx_ - headers_->non_whitespace_3_idx_;
visitor_->ProcessRequestFirstLine(
begin + headers_->non_whitespace_1_idx_,
headers_->whitespace_4_idx_ - headers_->non_whitespace_1_idx_,
begin + headers_->non_whitespace_1_idx_,
headers_->whitespace_2_idx_ - headers_->non_whitespace_1_idx_,
begin + headers_->non_whitespace_2_idx_,
headers_->whitespace_3_idx_ - headers_->non_whitespace_2_idx_,
begin + headers_->non_whitespace_3_idx_,
version_length);
if (version_length == 0)
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
} else {
visitor_->ProcessResponseFirstLine(
begin + headers_->non_whitespace_1_idx_,
headers_->whitespace_4_idx_ - headers_->non_whitespace_1_idx_,
begin + headers_->non_whitespace_1_idx_,
headers_->whitespace_2_idx_ - headers_->non_whitespace_1_idx_,
begin + headers_->non_whitespace_2_idx_,
headers_->whitespace_3_idx_ - headers_->non_whitespace_2_idx_,
begin + headers_->non_whitespace_3_idx_,
headers_->whitespace_4_idx_ - headers_->non_whitespace_3_idx_);
}
}
// 'stream_begin' points to the first character of the headers buffer.
// 'line_begin' points to the first character of the line.
// 'current' points to a char which is ':'.
// 'line_end' points to the position of '\n' + 1.
// 'line_begin' points to the position of first character of line.
void BalsaFrame::CleanUpKeyValueWhitespace(
const char* stream_begin,
const char* line_begin,
const char* current,
const char* line_end,
HeaderLineDescription* current_header_line) {
const char* colon_loc = current;
DCHECK_LT(colon_loc, line_end);
DCHECK_EQ(':', *colon_loc);
DCHECK_EQ(':', *current);
DCHECK_GE(' ', *line_end)
<< "\"" << std::string(line_begin, line_end) << "\"";
// TODO(fenix): Investigate whether or not the bounds tests in the
// while loops here are redundant, and if so, remove them.
--current;
while (current > line_begin && *current <= ' ') --current;
current += (current != colon_loc);
current_header_line->key_end_idx = current - stream_begin;
current = colon_loc;
DCHECK_EQ(':', *current);
++current;
while (current < line_end && *current <= ' ') ++current;
current_header_line->value_begin_idx = current - stream_begin;
DCHECK_GE(current_header_line->key_end_idx,
current_header_line->first_char_idx);
DCHECK_GE(current_header_line->value_begin_idx,
current_header_line->key_end_idx);
DCHECK_GE(current_header_line->last_char_idx,
current_header_line->value_begin_idx);
}
inline void BalsaFrame::FindColonsAndParseIntoKeyValue() {
DCHECK(!lines_.empty());
const char* stream_begin = headers_->OriginalHeaderStreamBegin();
// The last line is always just a newline (and is uninteresting).
const Lines::size_type lines_size_m1 = lines_.size() - 1;
#if __SSE2__
const __v16qi colons = { ':', ':', ':', ':', ':', ':', ':', ':',
':', ':', ':', ':', ':', ':', ':', ':'};
const char* header_lines_end_m16 = headers_->OriginalHeaderStreamEnd() - 16;
#endif // __SSE2__
const char* current = stream_begin + lines_[1].first;
// This code is a bit more subtle than it may appear at first glance.
// This code looks for a colon in the current line... but it also looks
// beyond the current line. If there is no colon in the current line, then
// for each subsequent line (until the colon which -has- been found is
// associated with a line), no searching for a colon will be performed. In
// this way, we minimize the amount of bytes we have scanned for a colon.
for (Lines::size_type i = 1; i < lines_size_m1;) {
const char* line_begin = stream_begin + lines_[i].first;
// Here we handle possible continuations. Note that we do not replace
// the '\n' in the line before a continuation (at least, as of now),
// which implies that any code which looks for a value must deal with
// "\r\n", etc -within- the line (and not just at the end of it).
for (++i; i < lines_size_m1; ++i) {
const char c = *(stream_begin + lines_[i].first);
if (c > ' ') {
// Not a continuation, so stop. Note that if the 'original' i = 1,
// and the next line is not a continuation, we'll end up with i = 2
// when we break. This handles the incrementing of i for the outer
// loop.
break;
}
}
const char* line_end = stream_begin + lines_[i - 1].second;
DCHECK_LT(line_begin - stream_begin, line_end - stream_begin);
// We cleanup the whitespace at the end of the line before doing anything
// else of interest as it allows us to do nothing when irregularly formatted
// headers are parsed (e.g. those with only keys, only values, or no colon).
//
// We're guaranteed to have *line_end > ' ' while line_end >= line_begin.
--line_end;
DCHECK_EQ('\n', *line_end)
<< "\"" << std::string(line_begin, line_end) << "\"";
while (*line_end <= ' ' && line_end > line_begin) {
--line_end;
}
++line_end;
DCHECK_GE(' ', *line_end);
DCHECK_LT(line_begin, line_end);
// We use '0' for the block idx, because we're always writing to the first
// block from the framer (we do this because the framer requires that the
// entire header sequence be in a contiguous buffer).
headers_->header_lines_.push_back(
HeaderLineDescription(line_begin - stream_begin,
line_end - stream_begin,
line_end - stream_begin,
line_end - stream_begin,
0));
if (current >= line_end) {
last_error_ = BalsaFrameEnums::HEADER_MISSING_COLON;
visitor_->HandleHeaderWarning(this);
// Then the next colon will not be found within this header line-- time
// to try again with another header-line.
continue;
} else if (current < line_begin) {
// When this condition is true, the last detected colon was part of a
// previous line. We reset to the beginning of the line as we don't care
// about the presence of any colon before the beginning of the current
// line.
current = line_begin;
}
#if __SSE2__
while (current < header_lines_end_m16) {
__m128i header_bytes =
_mm_loadu_si128(reinterpret_cast<const __m128i *>(current));
__m128i colon_cmp =
_mm_cmpeq_epi8(header_bytes, reinterpret_cast<__m128i>(colons));
int colon_msk = _mm_movemask_epi8(colon_cmp);
if (colon_msk == 0) {
current += 16;
continue;
}
current += (ffs(colon_msk) - 1);
if (current > line_end) {
break;
}
goto found_colon;
}
#endif // __SSE2__
for (; current < line_end; ++current) {
if (*current != ':') {
continue;
}
goto found_colon;
}
// If we've gotten to here, then there was no colon
// in the line. The arguments we passed into the construction
// for the HeaderLineDescription object should be OK-- it assumes
// that the entire content is 'key' by default (which is true, as
// there was no colon, there can be no value). Note that this is a
// construct which is technically not allowed by the spec.
last_error_ = BalsaFrameEnums::HEADER_MISSING_COLON;
visitor_->HandleHeaderWarning(this);
continue;
found_colon:
DCHECK_EQ(*current, ':');
DCHECK_LE(current - stream_begin, line_end - stream_begin);
DCHECK_LE(stream_begin - stream_begin, current - stream_begin);
HeaderLineDescription& current_header_line = headers_->header_lines_.back();
current_header_line.key_end_idx = current - stream_begin;
current_header_line.value_begin_idx = current_header_line.key_end_idx;
if (current < line_end) {
++current_header_line.key_end_idx;
CleanUpKeyValueWhitespace(stream_begin,
line_begin,
current,
line_end,
&current_header_line);
}
}
}
void BalsaFrame::ProcessContentLengthLine(
HeaderLines::size_type line_idx,
BalsaHeadersEnums::ContentLengthStatus* status,
size_t* length) {
const HeaderLineDescription& header_line = headers_->header_lines_[line_idx];
const char* stream_begin = headers_->OriginalHeaderStreamBegin();
const char* line_end = stream_begin + header_line.last_char_idx;
const char* value_begin = (stream_begin + header_line.value_begin_idx);
if (value_begin >= line_end) {
// There is no non-whitespace value data.
#if DEBUGFRAMER
LOG(INFO) << "invalid content-length -- no non-whitespace value data";
#endif
*status = BalsaHeadersEnums::INVALID_CONTENT_LENGTH;
return;
}
*length = 0;
while (value_begin < line_end) {
if (*value_begin < '0' || *value_begin > '9') {
// bad! content-length found, and couldn't parse all of it!
*status = BalsaHeadersEnums::INVALID_CONTENT_LENGTH;
#if DEBUGFRAMER
LOG(INFO) << "invalid content-length - non numeric character detected";
#endif // DEBUGFRAMER
return;
}
const size_t kMaxDiv10 = std::numeric_limits<size_t>::max() / 10;
size_t length_x_10 = *length * 10;
const unsigned char c = *value_begin - '0';
if (*length > kMaxDiv10 ||
(std::numeric_limits<size_t>::max() - length_x_10) < c) {
*status = BalsaHeadersEnums::CONTENT_LENGTH_OVERFLOW;
#if DEBUGFRAMER
LOG(INFO) << "content-length overflow";
#endif // DEBUGFRAMER
return;
}
*length = length_x_10 + c;
++value_begin;
}
#if DEBUGFRAMER
LOG(INFO) << "content_length parsed: " << *length;
#endif // DEBUGFRAMER
*status = BalsaHeadersEnums::VALID_CONTENT_LENGTH;
}
void BalsaFrame::ProcessTransferEncodingLine(HeaderLines::size_type line_idx) {
const HeaderLineDescription& header_line = headers_->header_lines_[line_idx];
const char* stream_begin = headers_->OriginalHeaderStreamBegin();
const char* line_end = stream_begin + header_line.last_char_idx;
const char* value_begin = stream_begin + header_line.value_begin_idx;
size_t value_length = line_end - value_begin;
if ((value_length == 7) &&
!strncasecmp(value_begin, "chunked", 7)) {
headers_->transfer_encoding_is_chunked_ = true;
} else if ((value_length == 8) &&
!strncasecmp(value_begin, "identity", 8)) {
headers_->transfer_encoding_is_chunked_ = false;
} else {
last_error_ = BalsaFrameEnums::UNKNOWN_TRANSFER_ENCODING;
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleHeaderError(this);
return;
}
}
namespace {
bool SplitStringPiece(base::StringPiece original, char delim,
base::StringPiece* before, base::StringPiece* after) {
const char* p = original.data();
const char* end = p + original.size();
while (p != end) {
if (*p == delim) {
++p;
} else {
const char* start = p;
while (++p != end && *p != delim) {
// Skip to the next occurence of the delimiter.
}
*before = base::StringPiece(start, p - start);
if (p != end)
*after = base::StringPiece(p + 1, end - (p + 1));
else
*after = base::StringPiece("");
StringPieceUtils::RemoveWhitespaceContext(before);
StringPieceUtils::RemoveWhitespaceContext(after);
return true;
}
}
*before = original;
*after = "";
return false;
}
// TODO(phython): Fix this function to properly deal with quoted values.
// E.g. ";;foo", "\";;\"", or \"aa;
// The last example, the semi-colon is a separator between extensions.
void ProcessChunkExtensionsManual(base::StringPiece all_extensions,
BalsaHeaders* extensions) {
base::StringPiece extension;
base::StringPiece remaining;
StringPieceUtils::RemoveWhitespaceContext(&all_extensions);
SplitStringPiece(all_extensions, ';', &extension, &remaining);
while (!extension.empty()) {
base::StringPiece key;
base::StringPiece value;
SplitStringPiece(extension, '=', &key, &value);
if (!value.empty()) {
// Strip quotation marks if they exist.
if (!value.empty() && value[0] == '"')
value.remove_prefix(1);
if (!value.empty() && value[value.length() - 1] == '"')
value.remove_suffix(1);
}
extensions->AppendHeader(key, value);
StringPieceUtils::RemoveWhitespaceContext(&remaining);
SplitStringPiece(remaining, ';', &extension, &remaining);
}
}
} // anonymous namespace
void BalsaFrame::ProcessChunkExtensions(const char* input, size_t size,
BalsaHeaders* extensions) {
ProcessChunkExtensionsManual(base::StringPiece(input, size), extensions);
}
void BalsaFrame::ProcessHeaderLines() {
HeaderLines::size_type content_length_idx = 0;
HeaderLines::size_type transfer_encoding_idx = 0;
DCHECK(!lines_.empty());
#if DEBUGFRAMER
LOG(INFO) << "******@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@**********\n";
#endif // DEBUGFRAMER
// There is no need to attempt to process headers if no header lines exist.
// There are at least two lines in the message which are not header lines.
// These two non-header lines are the first line of the message, and the
// last line of the message (which is an empty line).
// Thus, we test to see if we have more than two lines total before attempting
// to parse any header lines.
if (lines_.size() > 2) {
const char* stream_begin = headers_->OriginalHeaderStreamBegin();
// Then, for the rest of the header data, we parse these into key-value
// pairs.
FindColonsAndParseIntoKeyValue();
// At this point, we've parsed all of the headers. Time to look for those
// headers which we require for framing.
const HeaderLines::size_type
header_lines_size = headers_->header_lines_.size();
for (HeaderLines::size_type i = 0; i < header_lines_size; ++i) {
const HeaderLineDescription& current_header_line =
headers_->header_lines_[i];
const char* key_begin =
(stream_begin + current_header_line.first_char_idx);
const char* key_end = (stream_begin + current_header_line.key_end_idx);
const size_t key_len = key_end - key_begin;
const char c = *key_begin;
#if DEBUGFRAMER
LOG(INFO) << "[" << i << "]: " << std::string(key_begin, key_len)
<< " c: '" << c << "' key_len: " << key_len;
#endif // DEBUGFRAMER
// If a header begins with either lowercase or uppercase 'c' or 't', then
// the header may be one of content-length, connection, content-encoding
// or transfer-encoding. These headers are special, as they change the way
// that the message is framed, and so the framer is required to search
// for them.
if (c == 'c' || c == 'C') {
if ((key_len == kContentLengthSize) &&
0 == strncasecmp(key_begin, kContentLength, kContentLengthSize)) {
BalsaHeadersEnums::ContentLengthStatus content_length_status =
BalsaHeadersEnums::NO_CONTENT_LENGTH;
size_t length = 0;
ProcessContentLengthLine(i, &content_length_status, &length);
if (content_length_idx != 0) { // then we've already seen one!
if ((headers_->content_length_status_ != content_length_status) ||
((headers_->content_length_status_ ==
BalsaHeadersEnums::VALID_CONTENT_LENGTH) &&
length != headers_->content_length_)) {
last_error_ = BalsaFrameEnums::MULTIPLE_CONTENT_LENGTH_KEYS;
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleHeaderError(this);
return;
}
continue;
} else {
content_length_idx = i + 1;
headers_->content_length_status_ = content_length_status;
headers_->content_length_ = length;
content_length_remaining_ = length;
}
}
} else if (c == 't' || c == 'T') {
if ((key_len == kTransferEncodingSize) &&
0 == strncasecmp(key_begin, kTransferEncoding,
kTransferEncodingSize)) {
if (transfer_encoding_idx != 0) {
last_error_ = BalsaFrameEnums::MULTIPLE_TRANSFER_ENCODING_KEYS;
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleHeaderError(this);
return;
}
transfer_encoding_idx = i + 1;
}
} else if (i == 0 && (key_len == 0 || c == ' ')) {
last_error_ = BalsaFrameEnums::INVALID_HEADER_FORMAT;
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleHeaderError(this);
return;
}
}
if (headers_->transfer_encoding_is_chunked_) {
headers_->content_length_ = 0;
headers_->content_length_status_ = BalsaHeadersEnums::NO_CONTENT_LENGTH;
content_length_remaining_ = 0;
}
if (transfer_encoding_idx != 0) {
ProcessTransferEncodingLine(transfer_encoding_idx - 1);
}
}
}
void BalsaFrame::AssignParseStateAfterHeadersHaveBeenParsed() {
// For responses, can't have a body if the request was a HEAD, or if it is
// one of these response-codes. rfc2616 section 4.3
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
if (is_request_ ||
!(request_was_head_ ||
(headers_->parsed_response_code_ >= 100 &&
headers_->parsed_response_code_ < 200) ||
(headers_->parsed_response_code_ == 204) ||
(headers_->parsed_response_code_ == 304))) {
// Then we can have a body.
if (headers_->transfer_encoding_is_chunked_) {
// Note that
// if ( Transfer-Encoding: chunked && Content-length: )
// then Transfer-Encoding: chunked trumps.
// This is as specified in the spec.
// rfc2616 section 4.4.3
parse_state_ = BalsaFrameEnums::READING_CHUNK_LENGTH;
} else {
// Errors parsing content-length definitely can cause
// protocol errors/warnings
switch (headers_->content_length_status_) {
// If we have a content-length, and it is parsed
// properly, there are two options.
// 1) zero content, in which case the message is done, and
// 2) nonzero content, in which case we have to
// consume the body.
case BalsaHeadersEnums::VALID_CONTENT_LENGTH:
if (headers_->content_length_ == 0) {
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
} else {
parse_state_ = BalsaFrameEnums::READING_CONTENT;
}
break;
case BalsaHeadersEnums::CONTENT_LENGTH_OVERFLOW:
case BalsaHeadersEnums::INVALID_CONTENT_LENGTH:
// If there were characters left-over after parsing the
// content length, we should flag an error and stop.
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::UNPARSABLE_CONTENT_LENGTH;
visitor_->HandleHeaderError(this);
break;
// We can have: no transfer-encoding, no content length, and no
// connection: close...
// Unfortunately, this case doesn't seem to be covered in the spec.
// We'll assume that the safest thing to do here is what the google
// binaries before 2008 already do, which is to assume that
// everything until the connection is closed is body.
case BalsaHeadersEnums::NO_CONTENT_LENGTH:
if (is_request_) {
base::StringPiece method = headers_->request_method();
// POSTs and PUTs should have a detectable body length. If they
// do not we consider it an error.
if ((method.size() == 4 &&
strncmp(method.data(), "POST", 4) == 0) ||
(method.size() == 3 &&
strncmp(method.data(), "PUT", 3) == 0)) {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ =
BalsaFrameEnums::REQUIRED_BODY_BUT_NO_CONTENT_LENGTH;
visitor_->HandleHeaderError(this);
break;
}
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
} else {
parse_state_ = BalsaFrameEnums::READING_UNTIL_CLOSE;
last_error_ = BalsaFrameEnums::MAYBE_BODY_BUT_NO_CONTENT_LENGTH;
visitor_->HandleHeaderWarning(this);
}
break;
// The COV_NF_... statements here provide hints to the apparatus
// which computes coverage reports/ratios that this code is never
// intended to be executed, and should technically be impossible.
// COV_NF_START
default:
LOG(FATAL) << "Saw a content_length_status: "
<< headers_->content_length_status_ << " which is unknown.";
// COV_NF_END
}
}
}
}
size_t BalsaFrame::ProcessHeaders(const char* message_start,
size_t message_length) {
const char* const original_message_start = message_start;
const char* const message_end = message_start + message_length;
const char* message_current = message_start;
const char* checkpoint = message_start;
if (message_length == 0) {
goto bottom;
}
while (message_current < message_end) {
size_t base_idx = headers_->GetReadableBytesFromHeaderStream();
// Yes, we could use strchr (assuming null termination), or
// memchr, but as it turns out that is slower than this tight loop
// for the input that we see.
if (!saw_non_newline_char_) {
do {
const char c = *message_current;
if (c != '\r' && c != '\n') {
if (c <= ' ') {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::NO_REQUEST_LINE_IN_REQUEST;
visitor_->HandleHeaderError(this);
goto bottom;
} else {
saw_non_newline_char_ = true;
checkpoint = message_start = message_current;
goto read_real_message;
}
}
++message_current;
} while (message_current < message_end);
goto bottom; // this is necessary to skip 'last_char_was_slash_r' checks
} else {
read_real_message:
// Note that SSE2 can be enabled on certain piii platforms.
#if __SSE2__
{
const char* const message_end_m16 = message_end - 16;
__v16qi newlines = { '\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n',
'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n' };
while (message_current < message_end_m16) {
// What this does (using compiler intrinsics):
//
// Load 16 '\n's into an xmm register
// Load 16 bytes of currennt message into an xmm register
// Do byte-wise equals on those two xmm registers
// Take the first bit of each byte, and put that into the first
// 16 bits of a mask
// If the mask is zero, no '\n' found. increment by 16 and try again
// Else scan forward to find the first set bit.
// Increment current by the index of the first set bit
// (ffs returns index of first set bit + 1)
__m128i msg_bytes =
_mm_loadu_si128(const_cast<__m128i *>(
reinterpret_cast<const __m128i *>(message_current)));
__m128i newline_cmp =
_mm_cmpeq_epi8(msg_bytes, reinterpret_cast<__m128i>(newlines));
int newline_msk = _mm_movemask_epi8(newline_cmp);
if (newline_msk == 0) {
message_current += 16;
continue;
}
message_current += (ffs(newline_msk) - 1);
const size_t relative_idx = message_current - message_start;
const size_t message_current_idx = 1 + base_idx + relative_idx;
lines_.push_back(std::make_pair(last_slash_n_idx_,
message_current_idx));
if (lines_.size() == 1) {
headers_->WriteFromFramer(checkpoint,
1 + message_current - checkpoint);
checkpoint = message_current + 1;
const char* begin = headers_->OriginalHeaderStreamBegin();
#if DEBUGFRAMER
LOG(INFO) << "First line " << std::string(begin, lines_[0].second);
LOG(INFO) << "is_request_: " << is_request_;
#endif
ProcessFirstLine(begin, begin + lines_[0].second);
if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ)
goto process_lines;
else if (parse_state_ == BalsaFrameEnums::PARSE_ERROR)
goto bottom;
}
const size_t chars_since_last_slash_n = (message_current_idx -
last_slash_n_idx_);
last_slash_n_idx_ = message_current_idx;
if (chars_since_last_slash_n > 2) {
// We have a slash-n, but the last slash n was
// more than 2 characters away from this. Thus, we know
// that this cannot be an end-of-header.
++message_current;
continue;
}
if ((chars_since_last_slash_n == 1) ||
(((message_current > message_start) &&
(*(message_current - 1) == '\r')) ||
(last_char_was_slash_r_))) {
goto process_lines;
}
++message_current;
}
}
#endif // __SSE2__
while (message_current < message_end) {
if (*message_current != '\n') {
++message_current;
continue;
}
const size_t relative_idx = message_current - message_start;
const size_t message_current_idx = 1 + base_idx + relative_idx;
lines_.push_back(std::make_pair(last_slash_n_idx_,
message_current_idx));
if (lines_.size() == 1) {
headers_->WriteFromFramer(checkpoint,
1 + message_current - checkpoint);
checkpoint = message_current + 1;
const char* begin = headers_->OriginalHeaderStreamBegin();
#if DEBUGFRAMER
LOG(INFO) << "First line " << std::string(begin, lines_[0].second);
LOG(INFO) << "is_request_: " << is_request_;
#endif
ProcessFirstLine(begin, begin + lines_[0].second);
if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ)
goto process_lines;
else if (parse_state_ == BalsaFrameEnums::PARSE_ERROR)
goto bottom;
}
const size_t chars_since_last_slash_n = (message_current_idx -
last_slash_n_idx_);
last_slash_n_idx_ = message_current_idx;
if (chars_since_last_slash_n > 2) {
// false positive.
++message_current;
continue;
}
if ((chars_since_last_slash_n == 1) ||
(((message_current > message_start) &&
(*(message_current - 1) == '\r')) ||
(last_char_was_slash_r_))) {
goto process_lines;
}
++message_current;
}
}
continue;
process_lines:
++message_current;
DCHECK(message_current >= message_start);
if (message_current > message_start) {
headers_->WriteFromFramer(checkpoint, message_current - checkpoint);
}
// Check if we have exceeded maximum headers length
// Although we check for this limit before and after we call this function
// we check it here as well to make sure that in case the visitor changed
// the max_header_length_ (for example after processing the first line)
// we handle it gracefully.
if (headers_->GetReadableBytesFromHeaderStream() > max_header_length_) {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;
visitor_->HandleHeaderError(this);
goto bottom;
}
// Since we know that we won't be writing any more bytes of the header,
// we tell that to the headers object. The headers object may make
// more efficient allocation decisions when this is signaled.
headers_->DoneWritingFromFramer();
{
const char* readable_ptr = NULL;
size_t readable_size = 0;
headers_->GetReadablePtrFromHeaderStream(&readable_ptr, &readable_size);
visitor_->ProcessHeaderInput(readable_ptr, readable_size);
}
// Ok, now that we've written everything into our header buffer, it is
// time to process the header lines (extract proper values for headers
// which are important for framing).
ProcessHeaderLines();
if (parse_state_ == BalsaFrameEnums::PARSE_ERROR) {
goto bottom;
}
AssignParseStateAfterHeadersHaveBeenParsed();
if (parse_state_ == BalsaFrameEnums::PARSE_ERROR) {
goto bottom;
}
visitor_->ProcessHeaders(*headers_);
visitor_->HeaderDone();
if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ) {
visitor_->MessageDone();
}
goto bottom;
}
// If we've gotten to here, it means that we've consumed all of the
// available input. We need to record whether or not the last character we
// saw was a '\r' so that a subsequent call to ProcessInput correctly finds
// a header framing that is split across the two calls.
last_char_was_slash_r_ = (*(message_end - 1) == '\r');
DCHECK(message_current >= message_start);
if (message_current > message_start) {
headers_->WriteFromFramer(checkpoint, message_current - checkpoint);
}
bottom:
return message_current - original_message_start;
}
size_t BalsaFrame::BytesSafeToSplice() const {
switch (parse_state_) {
case BalsaFrameEnums::READING_CHUNK_DATA:
return chunk_length_remaining_;
case BalsaFrameEnums::READING_UNTIL_CLOSE:
return std::numeric_limits<size_t>::max();
case BalsaFrameEnums::READING_CONTENT:
return content_length_remaining_;
default:
return 0;
}
}
void BalsaFrame::BytesSpliced(size_t bytes_spliced) {
switch (parse_state_) {
case BalsaFrameEnums::READING_CHUNK_DATA:
if (chunk_length_remaining_ >= bytes_spliced) {
chunk_length_remaining_ -= bytes_spliced;
if (chunk_length_remaining_ == 0) {
parse_state_ = BalsaFrameEnums::READING_CHUNK_TERM;
}
return;
} else {
last_error_ =
BalsaFrameEnums::CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT;
goto error_exit;
}
case BalsaFrameEnums::READING_UNTIL_CLOSE:
return;
case BalsaFrameEnums::READING_CONTENT:
if (content_length_remaining_ >= bytes_spliced) {
content_length_remaining_ -= bytes_spliced;
if (content_length_remaining_ == 0) {
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
visitor_->MessageDone();
}
return;
} else {
last_error_ =
BalsaFrameEnums::CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT;
goto error_exit;
}
default:
last_error_ = BalsaFrameEnums::CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO;
goto error_exit;
}
error_exit:
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
visitor_->HandleBodyError(this);
};
// You may note that the state-machine contained within this function has both
// switch and goto labels for nearly the same thing. For instance, the
// following two labels refer to the same code block:
// label_reading_chunk_data:
// case BalsaFrameEnums::READING_CHUNK_DATA:
// The 'case' statement is required for the switch statement which occurs when
// ProcessInput is invoked. The goto label is required as the state-machine
// does not use a computed goto in any subsequent operations.
//
// Since several states exit the state machine for various reasons, there is
// also one label at the bottom of the function. When it is appropriate to
// return from the function, that part of the state machine instead issues a
// goto bottom; This results in less code duplication, and makes debugging
// easier (as you can add a statement to a section of code which is guaranteed
// to be invoked when the function is exiting.
size_t BalsaFrame::ProcessInput(const char* input, size_t size) {
const char* current = input;
const char* on_entry = current;
const char* end = current + size;
#if DEBUGFRAMER
LOG(INFO) << "\n=============="
<< BalsaFrameEnums::ParseStateToString(parse_state_)
<< "===============\n";
#endif // DEBUGFRAMER
DCHECK(headers_ != NULL);
if (headers_ == NULL) return 0;
if (parse_state_ == BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE) {
const size_t header_length = headers_->GetReadableBytesFromHeaderStream();
// Yes, we still have to check this here as the user can change the
// max_header_length amount!
// Also it is possible that we have reached the maximum allowed header size,
// and we have more to consume (remember we are still inside
// READING_HEADER_AND_FIRSTLINE) in which case we directly declare an error.
if (header_length > max_header_length_ ||
(header_length == max_header_length_ && size > 0)) {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;
visitor_->HandleHeaderError(this);
goto bottom;
}
size_t bytes_to_process = max_header_length_ - header_length;
if (bytes_to_process > size) {
bytes_to_process = size;
}
current += ProcessHeaders(input, bytes_to_process);
// If we are still reading headers check if we have crossed the headers
// limit. Note that we check for >= as opposed to >. This is because if
// header_length_after equals max_header_length_ and we are still in the
// parse_state_ BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE we know for
// sure that the headers limit will be crossed later on
if (parse_state_ == BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE) {
// Note that headers_ is valid only if we are still reading headers.
const size_t header_length_after =
headers_->GetReadableBytesFromHeaderStream();
if (header_length_after >= max_header_length_) {
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;
visitor_->HandleHeaderError(this);
}
}
goto bottom;
} else if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ ||
parse_state_ == BalsaFrameEnums::PARSE_ERROR) {
// Can do nothing more 'till we're reset.
goto bottom;
}
while (current < end) {
switch (parse_state_) {
label_reading_chunk_length:
case BalsaFrameEnums::READING_CHUNK_LENGTH:
// In this state we read the chunk length.
// Note that once we hit a character which is not in:
// [0-9;A-Fa-f\n], we transition to a different state.
//
{
// If we used strtol, etc, we'd have to buffer this line.
// This is more annoying than simply doing the conversion
// here. This code accounts for overflow.
static const signed char buf[] = {
// %0 %1 %2 %3 %4 %5 %6 %7 %8 \t \n %b %c \r %e %f
-1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1,
// %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
// ' ' %21 %22 %23 %24 %25 %26 %27 %28 %29 %2a %2b %2c %2d %2e %2f
-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
// %30 %31 %32 %33 %34 %35 %36 %37 %38 %39 %3a ';' %3c %3d %3e %3f
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -2, -1, -1, -1, -1,
// %40 'A' 'B' 'C' 'D' 'E' 'F' %47 %48 %49 %4a %4b %4c %4d %4e %4f
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
// %50 %51 %52 %53 %54 %55 %56 %57 %58 %59 %5a %5b %5c %5d %5e %5f
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
// %60 'a' 'b' 'c' 'd' 'e' 'f' %67 %68 %69 %6a %6b %6c %6d %6e %6f
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
// %70 %71 %72 %73 %74 %75 %76 %77 %78 %79 %7a %7b %7c %7d %7e %7f
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
// valid cases:
// "09123\n" // -> 09123
// "09123\r\n" // -> 09123
// "09123 \n" // -> 09123
// "09123 \r\n" // -> 09123
// "09123 12312\n" // -> 09123
// "09123 12312\r\n" // -> 09123
// "09123; foo=bar\n" // -> 09123
// "09123; foo=bar\r\n" // -> 09123
// "FFFFFFFFFFFFFFFF\r\n" // -> FFFFFFFFFFFFFFFF
// "FFFFFFFFFFFFFFFF 22\r\n" // -> FFFFFFFFFFFFFFFF
// invalid cases:
// "[ \t]+[^\n]*\n"
// "FFFFFFFFFFFFFFFFF\r\n" (would overflow)
// "\r\n"
// "\n"
while (current < end) {
const char c = *current;
++current;
const signed char addition = buf[static_cast<int>(c)];
if (addition >= 0) {
chunk_length_character_extracted_ = true;
size_t length_x_16 = chunk_length_remaining_ * 16;
const size_t kMaxDiv16 = std::numeric_limits<size_t>::max() / 16;
if ((chunk_length_remaining_ > kMaxDiv16) ||
((std::numeric_limits<size_t>::max() - length_x_16) <
static_cast<size_t>(addition))) {
// overflow -- asked for a chunk-length greater than 2^64 - 1!!
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::CHUNK_LENGTH_OVERFLOW;
visitor_->ProcessBodyInput(on_entry, current - on_entry);
visitor_->HandleChunkingError(this);
goto bottom;
}
chunk_length_remaining_ = length_x_16 + addition;
continue;
}
if (!chunk_length_character_extracted_ || addition == -1) {
// ^[0-9;A-Fa-f][ \t\n] -- was not matched, either because no
// characters were converted, or an unexpected character was
// seen.
parse_state_ = BalsaFrameEnums::PARSE_ERROR;
last_error_ = BalsaFrameEnums::INVALID_CHUNK_LENGTH;
visitor_->ProcessBodyInput(on_entry, current - on_entry);
visitor_->HandleChunkingError(this);
goto bottom;
}
--current;
parse_state_ = BalsaFrameEnums::READING_CHUNK_EXTENSION;
visitor_->ProcessChunkLength(chunk_length_remaining_);
goto label_reading_chunk_extension;
}
}
visitor_->ProcessBodyInput(on_entry, current - on_entry);
goto bottom; // case BalsaFrameEnums::READING_CHUNK_LENGTH
label_reading_chunk_extension:
case BalsaFrameEnums::READING_CHUNK_EXTENSION:
{
// TODO(phython): Convert this scanning to be 16 bytes at a time if
// there is data to be read.
const char* extensions_start = current;
size_t extensions_length = 0;
while (current < end) {
const char c = *current;
if (c == '\r' || c == '\n') {
extensions_length =
(extensions_start == current) ?
0 :
current - extensions_start - 1;
}
++current;
if (c == '\n') {
chunk_length_character_extracted_ = false;
visitor_->ProcessChunkExtensions(
extensions_start, extensions_length);
if (chunk_length_remaining_ != 0) {
parse_state_ = BalsaFrameEnums::READING_CHUNK_DATA;
goto label_reading_chunk_data;
}
HeaderFramingFound('\n');
parse_state_ = BalsaFrameEnums::READING_LAST_CHUNK_TERM;
goto label_reading_last_chunk_term;
}
}
visitor_->ProcessChunkExtensions(
extensions_start, extensions_length);
}
visitor_->ProcessBodyInput(on_entry, current - on_entry);
goto bottom; // case BalsaFrameEnums::READING_CHUNK_EXTENSION
label_reading_chunk_data:
case BalsaFrameEnums::READING_CHUNK_DATA:
while (current < end) {
if (chunk_length_remaining_ == 0) {
break;
}
// read in the chunk
size_t bytes_remaining = end - current;
size_t consumed_bytes = (chunk_length_remaining_ < bytes_remaining) ?
chunk_length_remaining_ : bytes_remaining;
const char* tmp_current = current + consumed_bytes;
visitor_->ProcessBodyInput(on_entry, tmp_current - on_entry);
visitor_->ProcessBodyData(current, consumed_bytes);
on_entry = current = tmp_current;
chunk_length_remaining_ -= consumed_bytes;
}
if (chunk_length_remaining_ == 0) {
parse_state_ = BalsaFrameEnums::READING_CHUNK_TERM;
goto label_reading_chunk_term;
}
visitor_->ProcessBodyInput(on_entry, current - on_entry);
goto bottom; // case BalsaFrameEnums::READING_CHUNK_DATA
label_reading_chunk_term:
case BalsaFrameEnums::READING_CHUNK_TERM:
while (current < end) {
const char c = *current;
++current;
if (c == '\n') {
parse_state_ = BalsaFrameEnums::READING_CHUNK_LENGTH;
goto label_reading_chunk_length;
}
}
visitor_->ProcessBodyInput(on_entry, current - on_entry);
goto bottom; // case BalsaFrameEnums::READING_CHUNK_TERM
label_reading_last_chunk_term:
case BalsaFrameEnums::READING_LAST_CHUNK_TERM:
while (current < end) {
const char c = *current;
if (!HeaderFramingFound(c)) {
// If not, however, since the spec only suggests that the
// client SHOULD indicate the presence of trailers, we get to
// *test* that they did or didn't.
// If all of the bytes we've seen since:
// OPTIONAL_WS 0 OPTIONAL_STUFF CRLF
// are either '\r', or '\n', then we can assume that we don't yet
// know if we need to parse headers, or if the next byte will make
// the HeaderFramingFound condition (above) true.
if (HeaderFramingMayBeFound()) {
// If true, then we have seen only characters '\r' or '\n'.
++current;
// Lets try again! There is no state change here.
continue;
} else {
// If (!HeaderFramingMayBeFound()), then we know that we must be
// reading the first non CRLF character of a trailer.
parse_state_ = BalsaFrameEnums::READING_TRAILER;
visitor_->ProcessBodyInput(on_entry, current - on_entry);
on_entry = current;
goto label_reading_trailer;
}
} else {
// If we've found a "\r\n\r\n", then the message
// is done.
++current;
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
visitor_->ProcessBodyInput(on_entry, current - on_entry);
visitor_->MessageDone();
goto bottom;
}
break; // from while loop
}
visitor_->ProcessBodyInput(on_entry, current - on_entry);
goto bottom; // case BalsaFrameEnums::READING_LAST_CHUNK_TERM
label_reading_trailer:
case BalsaFrameEnums::READING_TRAILER:
while (current < end) {
const char c = *current;
++current;
// TODO(fenix): If we ever care about trailers as part of framing,
// deal with them here (see below for part of the 'solution')
// if (LineFramingFound(c)) {
// trailer_lines_.push_back(make_pair(start_of_line_,
// trailer_length_ - 1));
// start_of_line_ = trailer_length_;
// }
if (HeaderFramingFound(c)) {
// ProcessTrailers(visitor_, &trailers_);
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
visitor_->ProcessTrailerInput(on_entry, current - on_entry);
visitor_->MessageDone();
goto bottom;
}
}
visitor_->ProcessTrailerInput(on_entry, current - on_entry);
break; // case BalsaFrameEnums::READING_TRAILER
// Note that there is no label:
// 'label_reading_until_close'
// here. This is because the state-machine exists immediately after
// reading the headers instead of transitioning here (as it would
// do if it was consuming all the data it could, all the time).
case BalsaFrameEnums::READING_UNTIL_CLOSE:
{
const size_t bytes_remaining = end - current;
if (bytes_remaining > 0) {
visitor_->ProcessBodyInput(current, bytes_remaining);
visitor_->ProcessBodyData(current, bytes_remaining);
current += bytes_remaining;
}
}
goto bottom; // case BalsaFrameEnums::READING_UNTIL_CLOSE
// label_reading_content:
case BalsaFrameEnums::READING_CONTENT:
#if DEBUGFRAMER
LOG(INFO) << "ReadingContent: " << content_length_remaining_;
#endif // DEBUGFRAMER
while (content_length_remaining_ && current < end) {
// read in the content
const size_t bytes_remaining = end - current;
const size_t consumed_bytes =
(content_length_remaining_ < bytes_remaining) ?
content_length_remaining_ : bytes_remaining;
visitor_->ProcessBodyInput(current, consumed_bytes);
visitor_->ProcessBodyData(current, consumed_bytes);
current += consumed_bytes;
content_length_remaining_ -= consumed_bytes;
}
if (content_length_remaining_ == 0) {
parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;
visitor_->MessageDone();
}
goto bottom; // case BalsaFrameEnums::READING_CONTENT
default:
// The state-machine should never be in a state that isn't handled
// above. This is a glaring logic error, and we should do something
// drastic to ensure that this gets looked-at and fixed.
LOG(FATAL) << "Unknown state: " << parse_state_ // COV_NF_LINE
<< " memory corruption?!"; // COV_NF_LINE
}
}
bottom:
#if DEBUGFRAMER
LOG(INFO) << "\n^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n"
<< std::string(input, current)
<< "\n$$$$$$$$$$$$$$"
<< BalsaFrameEnums::ParseStateToString(parse_state_)
<< "$$$$$$$$$$$$$$$"
<< " consumed: " << (current - input);
if (Error()) {
LOG(INFO) << BalsaFrameEnums::ErrorCodeToString(ErrorCode());
}
#endif // DEBUGFRAMER
return current - input;
}
} // namespace net