net/tools/flip_server/balsa_frame.cc - Issue 25085002: Break out balsa and epoll_server from net/tools/flip_server.

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Issue 25085002: Break out balsa and epoll_server from net/tools/flip_server. (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src

Patch Set: Rebase Created 7 years, 2 months ago

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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.

2 // Use of this source code is governed by a BSD-style license that can be

3 // found in the LICENSE file.

4

5 #include "net/tools/flip_server/balsa_frame.h"

6

7 #include <assert.h>

8 #if __SSE2__

9 #include <emmintrin.h>

10 #endif // __SSE2__

11 #include <strings.h>

12

13 #include <limits>

14 #include <string>

15 #include <utility>

16 #include <vector>

17

18 #include "base/logging.h"

19 #include "base/port.h"

20 #include "base/strings/string_piece.h"

21 #include "net/tools/flip_server/balsa_enums.h"

22 #include "net/tools/flip_server/balsa_headers.h"

23 #include "net/tools/flip_server/balsa_visitor_interface.h"

24 #include "net/tools/flip_server/buffer_interface.h"

25 #include "net/tools/flip_server/simple_buffer.h"

26 #include "net/tools/flip_server/split.h"

27 #include "net/tools/flip_server/string_piece_utils.h"

28

29 namespace net {

30

31 // Constants holding some header names for headers which can affect the way the

32 // HTTP message is framed, and so must be processed specially:

33 static const char kContentLength[] = "content-length";

34 static const size_t kContentLengthSize = sizeof(kContentLength) - 1;

35 static const char kTransferEncoding[] = "transfer-encoding";

36 static const size_t kTransferEncodingSize = sizeof(kTransferEncoding) - 1;

37

38 BalsaFrame::BalsaFrame()

39 : last_char_was_slash_r_(false),

40 saw_non_newline_char_(false),

41 start_was_space_(true),

42 chunk_length_character_extracted_(false),

43 is_request_(true),

44 request_was_head_(false),

45 max_header_length_(16 * 1024),

46 max_request_uri_length_(2048),

47 visitor_(&do_nothing_visitor_),

48 chunk_length_remaining_(0),

49 content_length_remaining_(0),

50 last_slash_n_loc_(NULL),

51 last_recorded_slash_n_loc_(NULL),

52 last_slash_n_idx_(0),

53 term_chars_(0),

54 parse_state_(BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE),

55 last_error_(BalsaFrameEnums::NO_ERROR),

56 headers_(NULL) {

57 }

58

59 BalsaFrame::~BalsaFrame() {}

60

61 void BalsaFrame::Reset() {

62 last_char_was_slash_r_ = false;

63 saw_non_newline_char_ = false;

64 start_was_space_ = true;

65 chunk_length_character_extracted_ = false;

66 // is_request_ = true; // not reset between messages.

67 // request_was_head_ = false; // not reset between messages.

68 // max_header_length_ = 4096; // not reset between messages.

69 // max_request_uri_length_ = 2048; // not reset between messages.

70 // visitor_ = &do_nothing_visitor_; // not reset between messages.

71 chunk_length_remaining_ = 0;

72 content_length_remaining_ = 0;

73 last_slash_n_loc_ = NULL;

74 last_recorded_slash_n_loc_ = NULL;

75 last_slash_n_idx_ = 0;

76 term_chars_ = 0;

77 parse_state_ = BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE;

78 last_error_ = BalsaFrameEnums::NO_ERROR;

79 lines_.clear();

80 if (headers_ != NULL) {

81 headers_->Clear();

82 }

83 }

84

85 const char* BalsaFrameEnums::ParseStateToString(

86 BalsaFrameEnums::ParseState error_code) {

87 switch (error_code) {

88 case PARSE_ERROR:

89 return "PARSE_ERROR";

90 case READING_HEADER_AND_FIRSTLINE:

91 return "READING_HEADER_AND_FIRSTLINE";

92 case READING_CHUNK_LENGTH:

93 return "READING_CHUNK_LENGTH";

94 case READING_CHUNK_EXTENSION:

95 return "READING_CHUNK_EXTENSION";

96 case READING_CHUNK_DATA:

97 return "READING_CHUNK_DATA";

98 case READING_CHUNK_TERM:

99 return "READING_CHUNK_TERM";

100 case READING_LAST_CHUNK_TERM:

101 return "READING_LAST_CHUNK_TERM";

102 case READING_TRAILER:

103 return "READING_TRAILER";

104 case READING_UNTIL_CLOSE:

105 return "READING_UNTIL_CLOSE";

106 case READING_CONTENT:

107 return "READING_CONTENT";

108 case MESSAGE_FULLY_READ:

109 return "MESSAGE_FULLY_READ";

110 case NUM_STATES:

111 return "UNKNOWN_STATE";

112 }

113 return "UNKNOWN_STATE";

114 }

115

116 const char* BalsaFrameEnums::ErrorCodeToString(

117 BalsaFrameEnums::ErrorCode error_code) {

118 switch (error_code) {

119 case NO_ERROR:

120 return "NO_ERROR";

121 case NO_STATUS_LINE_IN_RESPONSE:

122 return "NO_STATUS_LINE_IN_RESPONSE";

123 case NO_REQUEST_LINE_IN_REQUEST:

124 return "NO_REQUEST_LINE_IN_REQUEST";

125 case FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION:

126 return "FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION";

127 case FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD:

128 return "FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD";

129 case FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE:

130 return "FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE";

131 case FAILED_TO_FIND_WS_AFTER_REQUEST_REQUEST_URI:

132 return "FAILED_TO_FIND_WS_AFTER_REQUEST_REQUEST_URI";

133 case FAILED_TO_FIND_NL_AFTER_RESPONSE_REASON_PHRASE:

134 return "FAILED_TO_FIND_NL_AFTER_RESPONSE_REASON_PHRASE";

135 case FAILED_TO_FIND_NL_AFTER_REQUEST_HTTP_VERSION:

136 return "FAILED_TO_FIND_NL_AFTER_REQUEST_HTTP_VERSION";

137 case FAILED_CONVERTING_STATUS_CODE_TO_INT:

138 return "FAILED_CONVERTING_STATUS_CODE_TO_INT";

139 case REQUEST_URI_TOO_LONG:

140 return "REQUEST_URI_TOO_LONG";

141 case HEADERS_TOO_LONG:

142 return "HEADERS_TOO_LONG";

143 case UNPARSABLE_CONTENT_LENGTH:

144 return "UNPARSABLE_CONTENT_LENGTH";

145 case MAYBE_BODY_BUT_NO_CONTENT_LENGTH:

146 return "MAYBE_BODY_BUT_NO_CONTENT_LENGTH";

147 case REQUIRED_BODY_BUT_NO_CONTENT_LENGTH:

148 return "REQUIRED_BODY_BUT_NO_CONTENT_LENGTH";

149 case HEADER_MISSING_COLON:

150 return "HEADER_MISSING_COLON";

151 case INVALID_CHUNK_LENGTH:

152 return "INVALID_CHUNK_LENGTH";

153 case CHUNK_LENGTH_OVERFLOW:

154 return "CHUNK_LENGTH_OVERFLOW";

155 case CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO:

156 return "CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO";

157 case CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT:

158 return "CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT";

159 case MULTIPLE_CONTENT_LENGTH_KEYS:

160 return "MULTIPLE_CONTENT_LENGTH_KEYS";

161 case MULTIPLE_TRANSFER_ENCODING_KEYS:

162 return "MULTIPLE_TRANSFER_ENCODING_KEYS";

163 case UNKNOWN_TRANSFER_ENCODING:

164 return "UNKNOWN_TRANSFER_ENCODING";

165 case INVALID_HEADER_FORMAT:

166 return "INVALID_HEADER_FORMAT";

167 case INTERNAL_LOGIC_ERROR:

168 return "INTERNAL_LOGIC_ERROR";

169 case NUM_ERROR_CODES:

170 return "UNKNOWN_ERROR";

171 }

172 return "UNKNOWN_ERROR";

173 }

174

175 // Summary:

176 // Parses the first line of either a request or response.

177 // Note that in the case of a detected warning, error_code will be set

178 // but the function will not return false.

179 // Exactly zero or one warning or error (but not both) may be detected

180 // by this function.

181 // Note that this function will not write the data of the first-line

182 // into the header's buffer (that should already have been done elsewhere).

183 //

184 // Pre-conditions:

185 // begin != end

186 // *begin should be a character which is > ' '. This implies that there

187 // is at least one non-whitespace characters between [begin, end).

188 // headers is a valid pointer to a BalsaHeaders class.

189 // error_code is a valid pointer to a BalsaFrameEnums::ErrorCode value.

190 // Entire first line must exist between [begin, end)

191 // Exactly zero or one newlines -may- exist between [begin, end)

192 // [begin, end) should exist in the header's buffer.

193 //

194 // Side-effects:

195 // headers will be modified

196 // error_code may be modified if either a warning or error is detected

197 //

198 // Returns:

199 // True if no error (as opposed to warning) is detected.

200 // False if an error (as opposed to warning) is detected.

201

202 //

203 // If there is indeed non-whitespace in the line, then the following

204 // will take care of this for you:

205 // while (*begin <= ' ') ++begin;

206 // ProcessFirstLine(begin, end, is_request, &headers, &error_code);

207 //

208 bool ParseHTTPFirstLine(const char* begin,

209 const char* end,

210 bool is_request,

211 size_t max_request_uri_length,

212 BalsaHeaders* headers,

213 BalsaFrameEnums::ErrorCode* error_code) {

214 const char* current = begin;

215 // HTTP firstlines all have the following structure:

216 // LWS NONWS LWS NONWS LWS NONWS NOTCRLF CRLF

217 // [\t \r\n]+ [^\t ]+ [\t ]+ [^\t ]+ [\t ]+ [^\t ]+ [^\r\n]+ "\r\n"

218 // ws1 nws1 ws2 nws2 ws3 nws3 ws4

219 // \| [-------) [-------) [----------------)

220 // REQ: method request_uri version

221 // RESP: version statuscode reason

222 //

223 // The first NONWS->LWS component we'll call firstline_a.

224 // The second firstline_b, and the third firstline_c.

225 //

226 // firstline_a goes from nws1 to (but not including) ws2

227 // firstline_b goes from nws2 to (but not including) ws3

228 // firstline_c goes from nws3 to (but not including) ws4

229 //

230 // In the code:

231 // ws1 == whitespace_1_idx_

232 // nws1 == non_whitespace_1_idx_

233 // ws2 == whitespace_2_idx_

234 // nws2 == non_whitespace_2_idx_

235 // ws3 == whitespace_3_idx_

236 // nws3 == non_whitespace_3_idx_

237 // ws4 == whitespace_4_idx_

238

239 // Kill all whitespace (including '\r\n') at the end of the line.

240 --end;

241 if (*end != '\n') {

242 *error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;

243 LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"

244 << headers->OriginalHeadersForDebugging();

245 return false;

246 }

247 while (begin < end && *end <= ' ') {

248 --end;

249 }

250 DCHECK(*end != '\n');

251 if (*end == '\n') {

252 *error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;

253 LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"

254 << headers->OriginalHeadersForDebugging();

255 return false;

256 }

257 ++end;

258

259 // The two following statements should not be possible.

260 if (end == begin) {

261 *error_code = BalsaFrameEnums::INTERNAL_LOGIC_ERROR;

262 LOG(DFATAL) << "INTERNAL_LOGIC_ERROR Headers: \n"

263 << headers->OriginalHeadersForDebugging();

264 return false;

265 }

266

267 // whitespace_1_idx_

268 headers->whitespace_1_idx_ = current - begin;

269 // This loop is commented out as it is never used in current code. This is

270 // true only because we don't begin parsing the headers at all until we've

271 // encountered a non whitespace character at the beginning of the stream, at

272 // which point we begin our demarcation of header-start. If we did -not- do

273 // this (for instance, only looked for [\r\n] instead of (< ' ')), this loop

274 // would be necessary for the proper functioning of this parsing.

275 // This is left here as this function may (in the future) be refactored out

276 // of the BalsaFrame class so that it may be shared between code in

277 // BalsaFrame and BalsaHeaders (where it would be used in some variant of the

278 // set_first_line() function (at which point it would be necessary).

279 #if 0

280 while (*current <= ' ') {

281 ++current;

282 }

283 #endif

284 // non_whitespace_1_idx_

285 headers->non_whitespace_1_idx_ = current - begin;

286 do {

287 // The first time through, we're guaranteed that the current character

288 // won't be a whitespace (else the loop above wouldn't have terminated).

289 // That implies that we're guaranteed to get at least one non-whitespace

290 // character if we get into this loop at all.

291 ++current;

292 if (current == end) {

293 headers->whitespace_2_idx_ = current - begin;

294 headers->non_whitespace_2_idx_ = current - begin;

295 headers->whitespace_3_idx_ = current - begin;

296 headers->non_whitespace_3_idx_ = current - begin;

297 headers->whitespace_4_idx_ = current - begin;

298 // FAILED_TO_FIND_WS_AFTER_REQUEST_METHOD for request

299 // FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION for response

300 *error_code =

301 static_cast<BalsaFrameEnums::ErrorCode>(

302 BalsaFrameEnums::FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION +

303 is_request);

304 if (!is_request) { // FAILED_TO_FIND_WS_AFTER_RESPONSE_VERSION

305 return false;

306 }

307 goto output_exhausted;

308 }

309 } while (*current > ' ');

310 // whitespace_2_idx_

311 headers->whitespace_2_idx_ = current - begin;

312 do {

313 ++current;

314 // Note that due to the loop which consumes all of the whitespace

315 // at the end of the line, current can never == end while in this function.

316 } while (*current <= ' ');

317 // non_whitespace_2_idx_

318 headers->non_whitespace_2_idx_ = current - begin;

319 do {

320 ++current;

321 if (current == end) {

322 headers->whitespace_3_idx_ = current - begin;

323 headers->non_whitespace_3_idx_ = current - begin;

324 headers->whitespace_4_idx_ = current - begin;

325 // FAILED_TO_FIND_START_OF_REQUEST_REQUEST_URI for request

326 // FAILED_TO_FIND_START_OF_RESPONSE_STATUSCODE for response

327 *error_code =

328 static_cast<BalsaFrameEnums::ErrorCode>(

329 BalsaFrameEnums::FAILED_TO_FIND_WS_AFTER_RESPONSE_STATUSCODE

330 + is_request);

331 goto output_exhausted;

332 }

333 } while (*current > ' ');

334 // whitespace_3_idx_

335 headers->whitespace_3_idx_ = current - begin;

336 do {

337 ++current;

338 // Note that due to the loop which consumes all of the whitespace

339 // at the end of the line, current can never == end while in this function.

340 } while (*current <= ' ');

341 // non_whitespace_3_idx_

342 headers->non_whitespace_3_idx_ = current - begin;

343 headers->whitespace_4_idx_ = end - begin;

344

345 output_exhausted:

346 // Note that we don't fail the parse immediately when parsing of the

347 // firstline fails. Depending on the protocol type, we may want to accept

348 // a firstline with only one or two elements, e.g., for HTTP/0.9:

349 // GET\r\n

350 // or

351 // GET /\r\n

352 // should be parsed without issue (though the visitor should know that

353 // parsing the entire line was not exactly as it should be).

354 //

355 // Eventually, these errors may be removed alltogether, as the visitor can

356 // detect them on its own by examining the size of the various fields.

357 // headers->set_first_line(non_whitespace_1_idx_, current);

358

359 if (is_request) {

360 if ((headers->whitespace_3_idx_ - headers->non_whitespace_2_idx_) >

361 max_request_uri_length) {

362 // For requests, we need at least the method. We could assume that a

363 // blank URI means "/". If version isn't stated, it should be assumed

364 // to be HTTP/0.9 by the visitor.

365 *error_code = BalsaFrameEnums::REQUEST_URI_TOO_LONG;

366 return false;

367 }

368 } else {

369 headers->parsed_response_code_ = 0;

370 {

371 const char* parsed_response_code_current =

372 begin + headers->non_whitespace_2_idx_;

373 const char* parsed_response_code_end = begin + headers->whitespace_3_idx_;

374 const size_t kMaxDiv10 = std::numeric_limits<size_t>::max() / 10;

375

376 // Convert a string of [0-9]* into an int.

377 // Note that this allows for the conversion of response codes which

378 // are outside the bounds of normal HTTP response codes (no checking

379 // is done to ensure that these are valid-- they're merely parsed)!

380 while (parsed_response_code_current < parsed_response_code_end) {

381 if (*parsed_response_code_current < '0' \|\|

382 *parsed_response_code_current > '9') {

383 *error_code = BalsaFrameEnums::FAILED_CONVERTING_STATUS_CODE_TO_INT;

384 return false;

385 }

386 size_t status_code_x_10 = headers->parsed_response_code_ * 10;

387 uint8 c = *parsed_response_code_current - '0';

388 if ((headers->parsed_response_code_ > kMaxDiv10) \|\|

389 (std::numeric_limits<size_t>::max() - status_code_x_10) < c) {

390 // overflow.

391 *error_code = BalsaFrameEnums::FAILED_CONVERTING_STATUS_CODE_TO_INT;

392 return false;

393 }

394 headers->parsed_response_code_ = status_code_x_10 + c;

395 ++parsed_response_code_current;

396 }

397 }

398 }

399 return true;

400 }

401

402 // begin - beginning of the firstline

403 // end - end of the firstline

404 //

405 // A precondition for this function is that there is non-whitespace between

406 // [begin, end). If this precondition is not met, the function will not perform

407 // as expected (and bad things may happen, and it will eat your first, second,

408 // and third unborn children!).

409 //

410 // Another precondition for this function is that [begin, end) includes

411 // at most one newline, which must be at the end of the line.

412 void BalsaFrame::ProcessFirstLine(const char* begin, const char* end) {

413 BalsaFrameEnums::ErrorCode previous_error = last_error_;

414 if (!ParseHTTPFirstLine(begin,

415 end,

416 is_request_,

417 max_request_uri_length_,

418 headers_,

419 &last_error_)) {

420 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

421 visitor_->HandleHeaderError(this);

422 return;

423 }

424 if (previous_error != last_error_) {

425 visitor_->HandleHeaderWarning(this);

426 }

427

428 if (is_request_) {

429 int version_length =

430 headers_->whitespace_4_idx_ - headers_->non_whitespace_3_idx_;

431 visitor_->ProcessRequestFirstLine(

432 begin + headers_->non_whitespace_1_idx_,

433 headers_->whitespace_4_idx_ - headers_->non_whitespace_1_idx_,

434 begin + headers_->non_whitespace_1_idx_,

435 headers_->whitespace_2_idx_ - headers_->non_whitespace_1_idx_,

436 begin + headers_->non_whitespace_2_idx_,

437 headers_->whitespace_3_idx_ - headers_->non_whitespace_2_idx_,

438 begin + headers_->non_whitespace_3_idx_,

439 version_length);

440 if (version_length == 0)

441 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

442 } else {

443 visitor_->ProcessResponseFirstLine(

444 begin + headers_->non_whitespace_1_idx_,

445 headers_->whitespace_4_idx_ - headers_->non_whitespace_1_idx_,

446 begin + headers_->non_whitespace_1_idx_,

447 headers_->whitespace_2_idx_ - headers_->non_whitespace_1_idx_,

448 begin + headers_->non_whitespace_2_idx_,

449 headers_->whitespace_3_idx_ - headers_->non_whitespace_2_idx_,

450 begin + headers_->non_whitespace_3_idx_,

451 headers_->whitespace_4_idx_ - headers_->non_whitespace_3_idx_);

452 }

453 }

454

455 // 'stream_begin' points to the first character of the headers buffer.

456 // 'line_begin' points to the first character of the line.

457 // 'current' points to a char which is ':'.

458 // 'line_end' points to the position of '\n' + 1.

459 // 'line_begin' points to the position of first character of line.

460 void BalsaFrame::CleanUpKeyValueWhitespace(

461 const char* stream_begin,

462 const char* line_begin,

463 const char* current,

464 const char* line_end,

465 HeaderLineDescription* current_header_line) {

466 const char* colon_loc = current;

467 DCHECK_LT(colon_loc, line_end);

468 DCHECK_EQ(':', *colon_loc);

469 DCHECK_EQ(':', *current);

470 DCHECK_GE(' ', *line_end)

471 << "\"" << std::string(line_begin, line_end) << "\"";

472

473 // TODO(fenix): Investigate whether or not the bounds tests in the

474 // while loops here are redundant, and if so, remove them.

475 --current;

476 while (current > line_begin && *current <= ' ') --current;

477 current += (current != colon_loc);

478 current_header_line->key_end_idx = current - stream_begin;

479

480 current = colon_loc;

481 DCHECK_EQ(':', *current);

482 ++current;

483 while (current < line_end && *current <= ' ') ++current;

484 current_header_line->value_begin_idx = current - stream_begin;

485

486 DCHECK_GE(current_header_line->key_end_idx,

487 current_header_line->first_char_idx);

488 DCHECK_GE(current_header_line->value_begin_idx,

489 current_header_line->key_end_idx);

490 DCHECK_GE(current_header_line->last_char_idx,

491 current_header_line->value_begin_idx);

492 }

493

494 inline void BalsaFrame::FindColonsAndParseIntoKeyValue() {

495 DCHECK(!lines_.empty());

496 const char* stream_begin = headers_->OriginalHeaderStreamBegin();

497 // The last line is always just a newline (and is uninteresting).

498 const Lines::size_type lines_size_m1 = lines_.size() - 1;

499 #if __SSE2__

500 const __v16qi colons = { ':', ':', ':', ':', ':', ':', ':', ':',

501 ':', ':', ':', ':', ':', ':', ':', ':'};

502 const char* header_lines_end_m16 = headers_->OriginalHeaderStreamEnd() - 16;

503 #endif // __SSE2__

504 const char* current = stream_begin + lines_[1].first;

505 // This code is a bit more subtle than it may appear at first glance.

506 // This code looks for a colon in the current line... but it also looks

507 // beyond the current line. If there is no colon in the current line, then

508 // for each subsequent line (until the colon which -has- been found is

509 // associated with a line), no searching for a colon will be performed. In

510 // this way, we minimize the amount of bytes we have scanned for a colon.

511 for (Lines::size_type i = 1; i < lines_size_m1;) {

512 const char* line_begin = stream_begin + lines_[i].first;

513

514 // Here we handle possible continuations. Note that we do not replace

515 // the '\n' in the line before a continuation (at least, as of now),

516 // which implies that any code which looks for a value must deal with

517 // "\r\n", etc -within- the line (and not just at the end of it).

518 for (++i; i < lines_size_m1; ++i) {

519 const char c = *(stream_begin + lines_[i].first);

520 if (c > ' ') {

521 // Not a continuation, so stop. Note that if the 'original' i = 1,

522 // and the next line is not a continuation, we'll end up with i = 2

523 // when we break. This handles the incrementing of i for the outer

524 // loop.

525 break;

526 }

527 }

528 const char* line_end = stream_begin + lines_[i - 1].second;

529 DCHECK_LT(line_begin - stream_begin, line_end - stream_begin);

530

531 // We cleanup the whitespace at the end of the line before doing anything

532 // else of interest as it allows us to do nothing when irregularly formatted

533 // headers are parsed (e.g. those with only keys, only values, or no colon).

534 //

535 // We're guaranteed to have *line_end > ' ' while line_end >= line_begin.

536 --line_end;

537 DCHECK_EQ('\n', *line_end)

538 << "\"" << std::string(line_begin, line_end) << "\"";

539 while (*line_end <= ' ' && line_end > line_begin) {

540 --line_end;

541 }

542 ++line_end;

543 DCHECK_GE(' ', *line_end);

544 DCHECK_LT(line_begin, line_end);

545

546 // We use '0' for the block idx, because we're always writing to the first

547 // block from the framer (we do this because the framer requires that the

548 // entire header sequence be in a contiguous buffer).

549 headers_->header_lines_.push_back(

550 HeaderLineDescription(line_begin - stream_begin,

551 line_end - stream_begin,

552 line_end - stream_begin,

553 line_end - stream_begin,

554 0));

555 if (current >= line_end) {

556 last_error_ = BalsaFrameEnums::HEADER_MISSING_COLON;

557 visitor_->HandleHeaderWarning(this);

558 // Then the next colon will not be found within this header line-- time

559 // to try again with another header-line.

560 continue;

561 } else if (current < line_begin) {

562 // When this condition is true, the last detected colon was part of a

563 // previous line. We reset to the beginning of the line as we don't care

564 // about the presence of any colon before the beginning of the current

565 // line.

566 current = line_begin;

567 }

568 #if __SSE2__

569 while (current < header_lines_end_m16) {

570 __m128i header_bytes =

571 _mm_loadu_si128(reinterpret_cast<const __m128i *>(current));

572 __m128i colon_cmp =

573 _mm_cmpeq_epi8(header_bytes, reinterpret_cast<__m128i>(colons));

574 int colon_msk = _mm_movemask_epi8(colon_cmp);

575 if (colon_msk == 0) {

576 current += 16;

577 continue;

578 }

579 current += (ffs(colon_msk) - 1);

580 if (current > line_end) {

581 break;

582 }

583 goto found_colon;

584 }

585 #endif // __SSE2__

586 for (; current < line_end; ++current) {

587 if (*current != ':') {

588 continue;

589 }

590 goto found_colon;

591 }

592 // If we've gotten to here, then there was no colon

593 // in the line. The arguments we passed into the construction

594 // for the HeaderLineDescription object should be OK-- it assumes

595 // that the entire content is 'key' by default (which is true, as

596 // there was no colon, there can be no value). Note that this is a

597 // construct which is technically not allowed by the spec.

598 last_error_ = BalsaFrameEnums::HEADER_MISSING_COLON;

599 visitor_->HandleHeaderWarning(this);

600 continue;

601 found_colon:

602 DCHECK_EQ(*current, ':');

603 DCHECK_LE(current - stream_begin, line_end - stream_begin);

604 DCHECK_LE(stream_begin - stream_begin, current - stream_begin);

605

606 HeaderLineDescription& current_header_line = headers_->header_lines_.back();

607 current_header_line.key_end_idx = current - stream_begin;

608 current_header_line.value_begin_idx = current_header_line.key_end_idx;

609 if (current < line_end) {

610 ++current_header_line.key_end_idx;

611

612 CleanUpKeyValueWhitespace(stream_begin,

613 line_begin,

614 current,

615 line_end,

616 &current_header_line);

617 }

618 }

619 }

620

621 void BalsaFrame::ProcessContentLengthLine(

622 HeaderLines::size_type line_idx,

623 BalsaHeadersEnums::ContentLengthStatus* status,

624 size_t* length) {

625 const HeaderLineDescription& header_line = headers_->header_lines_[line_idx];

626 const char* stream_begin = headers_->OriginalHeaderStreamBegin();

627 const char* line_end = stream_begin + header_line.last_char_idx;

628 const char* value_begin = (stream_begin + header_line.value_begin_idx);

629

630 if (value_begin >= line_end) {

631 // There is no non-whitespace value data.

632 #if DEBUGFRAMER

633 LOG(INFO) << "invalid content-length -- no non-whitespace value data";

634 #endif

635 *status = BalsaHeadersEnums::INVALID_CONTENT_LENGTH;

636 return;

637 }

638

639 *length = 0;

640 while (value_begin < line_end) {

641 if (value_begin < '0' \|\| value_begin > '9') {

642 // bad! content-length found, and couldn't parse all of it!

643 *status = BalsaHeadersEnums::INVALID_CONTENT_LENGTH;

644 #if DEBUGFRAMER

645 LOG(INFO) << "invalid content-length - non numeric character detected";

646 #endif // DEBUGFRAMER

647 return;

648 }

649 const size_t kMaxDiv10 = std::numeric_limits<size_t>::max() / 10;

650 size_t length_x_10 = length 10;

651 const unsigned char c = *value_begin - '0';

652 if (*length > kMaxDiv10 \|\|

653 (std::numeric_limits<size_t>::max() - length_x_10) < c) {

654 *status = BalsaHeadersEnums::CONTENT_LENGTH_OVERFLOW;

655 #if DEBUGFRAMER

656 LOG(INFO) << "content-length overflow";

657 #endif // DEBUGFRAMER

658 return;

659 }

660 *length = length_x_10 + c;

661 ++value_begin;

662 }

663 #if DEBUGFRAMER

664 LOG(INFO) << "content_length parsed: " << *length;

665 #endif // DEBUGFRAMER

666 *status = BalsaHeadersEnums::VALID_CONTENT_LENGTH;

667 }

668

669 void BalsaFrame::ProcessTransferEncodingLine(HeaderLines::size_type line_idx) {

670 const HeaderLineDescription& header_line = headers_->header_lines_[line_idx];

671 const char* stream_begin = headers_->OriginalHeaderStreamBegin();

672 const char* line_end = stream_begin + header_line.last_char_idx;

673 const char* value_begin = stream_begin + header_line.value_begin_idx;

674 size_t value_length = line_end - value_begin;

675

676 if ((value_length == 7) &&

677 !strncasecmp(value_begin, "chunked", 7)) {

678 headers_->transfer_encoding_is_chunked_ = true;

679 } else if ((value_length == 8) &&

680 !strncasecmp(value_begin, "identity", 8)) {

681 headers_->transfer_encoding_is_chunked_ = false;

682 } else {

683 last_error_ = BalsaFrameEnums::UNKNOWN_TRANSFER_ENCODING;

684 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

685 visitor_->HandleHeaderError(this);

686 return;

687 }

688 }

689

690 namespace {

691 bool SplitStringPiece(base::StringPiece original, char delim,

692 base::StringPiece* before, base::StringPiece* after) {

693 const char* p = original.data();

694 const char* end = p + original.size();

695

696 while (p != end) {

697 if (*p == delim) {

698 ++p;

699 } else {

700 const char* start = p;

701 while (++p != end && *p != delim) {

702 // Skip to the next occurence of the delimiter.

703 }

704 *before = base::StringPiece(start, p - start);

705 if (p != end)

706 *after = base::StringPiece(p + 1, end - (p + 1));

707 else

708 *after = base::StringPiece("");

709 StringPieceUtils::RemoveWhitespaceContext(before);

710 StringPieceUtils::RemoveWhitespaceContext(after);

711 return true;

712 }

713 }

714

715 *before = original;

716 *after = "";

717 return false;

718 }

719

720 // TODO(phython): Fix this function to properly deal with quoted values.

721 // E.g. ";;foo", "\";;\"", or \"aa;

722 // The last example, the semi-colon is a separator between extensions.

723 void ProcessChunkExtensionsManual(base::StringPiece all_extensions,

724 BalsaHeaders* extensions) {

725 base::StringPiece extension;

726 base::StringPiece remaining;

727 StringPieceUtils::RemoveWhitespaceContext(&all_extensions);

728 SplitStringPiece(all_extensions, ';', &extension, &remaining);

729 while (!extension.empty()) {

730 base::StringPiece key;

731 base::StringPiece value;

732 SplitStringPiece(extension, '=', &key, &value);

733 if (!value.empty()) {

734 // Strip quotation marks if they exist.

735 if (!value.empty() && value[0] == '"')

736 value.remove_prefix(1);

737 if (!value.empty() && value[value.length() - 1] == '"')

738 value.remove_suffix(1);

739 }

740

741 extensions->AppendHeader(key, value);

742

743 StringPieceUtils::RemoveWhitespaceContext(&remaining);

744 SplitStringPiece(remaining, ';', &extension, &remaining);

745 }

746 }

747

748 // TODO(phython): Fix this function to properly deal with quoted values.

749 // E.g. ";;foo", "\";;\"", or \"aa;

750 // The last example, the semi-colon is a separator between extensions.

751 void ProcessChunkExtensionsGoogle3(const char* input, size_t size,

752 BalsaHeaders* extensions) {

753 std::vector<base::StringPiece> key_values;

754 SplitStringPieceToVector(base::StringPiece(input, size), ";",

755 &key_values, true);

756 for (unsigned int i = 0; i < key_values.size(); ++i) {

757 base::StringPiece key = key_values[i].substr(0, key_values[i].find('='));

758 base::StringPiece value;

759 if (key.length() < key_values[i].length()) {

760 value = key_values[i].substr(key.length() + 1);

761 // Remove any leading and trailing whitespace.

762 StringPieceUtils::RemoveWhitespaceContext(&value);

763

764 // Strip quotation marks if they exist.

765 if (!value.empty() && value[0] == '"')

766 value.remove_prefix(1);

767 if (!value.empty() && value[value.length() - 1] == '"')

768 value.remove_suffix(1);

769 }

770

771 // Strip the key whitespace after checking that there is a value.

772 StringPieceUtils::RemoveWhitespaceContext(&key);

773 extensions->AppendHeader(key, value);

774 }

775 }

776

777 } // anonymous namespace

778

779 void BalsaFrame::ProcessChunkExtensions(const char* input, size_t size,

780 BalsaHeaders* extensions) {

781 #if 0

782 ProcessChunkExtensionsGoogle3(input, size, extensions);

783 #else

784 ProcessChunkExtensionsManual(base::StringPiece(input, size), extensions);

785 #endif

786 }

787

788 void BalsaFrame::ProcessHeaderLines() {

789 HeaderLines::size_type content_length_idx = 0;

790 HeaderLines::size_type transfer_encoding_idx = 0;

791

792 DCHECK(!lines_.empty());

793 #if DEBUGFRAMER

794 LOG(INFO) << "****@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@********\n";

795 #endif // DEBUGFRAMER

796

797 // There is no need to attempt to process headers if no header lines exist.

798 // There are at least two lines in the message which are not header lines.

799 // These two non-header lines are the first line of the message, and the

800 // last line of the message (which is an empty line).

801 // Thus, we test to see if we have more than two lines total before attempting

802 // to parse any header lines.

803 if (lines_.size() > 2) {

804 const char* stream_begin = headers_->OriginalHeaderStreamBegin();

805

806 // Then, for the rest of the header data, we parse these into key-value

807 // pairs.

808 FindColonsAndParseIntoKeyValue();

809 // At this point, we've parsed all of the headers. Time to look for those

810 // headers which we require for framing.

811 const HeaderLines::size_type

812 header_lines_size = headers_->header_lines_.size();

813 for (HeaderLines::size_type i = 0; i < header_lines_size; ++i) {

814 const HeaderLineDescription& current_header_line =

815 headers_->header_lines_[i];

816 const char* key_begin =

817 (stream_begin + current_header_line.first_char_idx);

818 const char* key_end = (stream_begin + current_header_line.key_end_idx);

819 const size_t key_len = key_end - key_begin;

820 const char c = *key_begin;

821 #if DEBUGFRAMER

822 LOG(INFO) << "[" << i << "]: " << std::string(key_begin, key_len)

823 << " c: '" << c << "' key_len: " << key_len;

824 #endif // DEBUGFRAMER

825 // If a header begins with either lowercase or uppercase 'c' or 't', then

826 // the header may be one of content-length, connection, content-encoding

827 // or transfer-encoding. These headers are special, as they change the way

828 // that the message is framed, and so the framer is required to search

829 // for them.

830

831

832 if (c == 'c' \|\| c == 'C') {

833 if ((key_len == kContentLengthSize) &&

834 0 == strncasecmp(key_begin, kContentLength, kContentLengthSize)) {

835 BalsaHeadersEnums::ContentLengthStatus content_length_status =

836 BalsaHeadersEnums::NO_CONTENT_LENGTH;

837 size_t length = 0;

838 ProcessContentLengthLine(i, &content_length_status, &length);

839 if (content_length_idx != 0) { // then we've already seen one!

840 if ((headers_->content_length_status_ != content_length_status) \|\|

841 ((headers_->content_length_status_ ==

842 BalsaHeadersEnums::VALID_CONTENT_LENGTH) &&

843 length != headers_->content_length_)) {

844 last_error_ = BalsaFrameEnums::MULTIPLE_CONTENT_LENGTH_KEYS;

845 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

846 visitor_->HandleHeaderError(this);

847 return;

848 }

849 continue;

850 } else {

851 content_length_idx = i + 1;

852 headers_->content_length_status_ = content_length_status;

853 headers_->content_length_ = length;

854 content_length_remaining_ = length;

855 }

856

857 }

858 } else if (c == 't' \|\| c == 'T') {

859 if ((key_len == kTransferEncodingSize) &&

860 0 == strncasecmp(key_begin, kTransferEncoding,

861 kTransferEncodingSize)) {

862 if (transfer_encoding_idx != 0) {

863 last_error_ = BalsaFrameEnums::MULTIPLE_TRANSFER_ENCODING_KEYS;

864 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

865 visitor_->HandleHeaderError(this);

866 return;

867 }

868 transfer_encoding_idx = i + 1;

869 }

870 } else if (i == 0 && (key_len == 0 \|\| c == ' ')) {

871 last_error_ = BalsaFrameEnums::INVALID_HEADER_FORMAT;

872 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

873 visitor_->HandleHeaderError(this);

874 return;

875 }

876 }

877 if (headers_->transfer_encoding_is_chunked_) {

878 headers_->content_length_ = 0;

879 headers_->content_length_status_ = BalsaHeadersEnums::NO_CONTENT_LENGTH;

880 content_length_remaining_ = 0;

881 }

882 if (transfer_encoding_idx != 0) {

883 ProcessTransferEncodingLine(transfer_encoding_idx - 1);

884 }

885 }

886 }

887

888 void BalsaFrame::AssignParseStateAfterHeadersHaveBeenParsed() {

889 // For responses, can't have a body if the request was a HEAD, or if it is

890 // one of these response-codes. rfc2616 section 4.3

891 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

892 if (is_request_ \|\|

893 !(request_was_head_ \|\|

894 (headers_->parsed_response_code_ >= 100 &&

895 headers_->parsed_response_code_ < 200) \|\|

896 (headers_->parsed_response_code_ == 204) \|\|

897 (headers_->parsed_response_code_ == 304))) {

898 // Then we can have a body.

899 if (headers_->transfer_encoding_is_chunked_) {

900 // Note that

901 // if ( Transfer-Encoding: chunked && Content-length: )

902 // then Transfer-Encoding: chunked trumps.

903 // This is as specified in the spec.

904 // rfc2616 section 4.4.3

905 parse_state_ = BalsaFrameEnums::READING_CHUNK_LENGTH;

906 } else {

907 // Errors parsing content-length definitely can cause

908 // protocol errors/warnings

909 switch (headers_->content_length_status_) {

910 // If we have a content-length, and it is parsed

911 // properly, there are two options.

912 // 1) zero content, in which case the message is done, and

913 // 2) nonzero content, in which case we have to

914 // consume the body.

915 case BalsaHeadersEnums::VALID_CONTENT_LENGTH:

916 if (headers_->content_length_ == 0) {

917 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

918 } else {

919 parse_state_ = BalsaFrameEnums::READING_CONTENT;

920 }

921 break;

922 case BalsaHeadersEnums::CONTENT_LENGTH_OVERFLOW:

923 case BalsaHeadersEnums::INVALID_CONTENT_LENGTH:

924 // If there were characters left-over after parsing the

925 // content length, we should flag an error and stop.

926 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

927 last_error_ = BalsaFrameEnums::UNPARSABLE_CONTENT_LENGTH;

928 visitor_->HandleHeaderError(this);

929 break;

930 // We can have: no transfer-encoding, no content length, and no

931 // connection: close...

932 // Unfortunately, this case doesn't seem to be covered in the spec.

933 // We'll assume that the safest thing to do here is what the google

934 // binaries before 2008 already do, which is to assume that

935 // everything until the connection is closed is body.

936 case BalsaHeadersEnums::NO_CONTENT_LENGTH:

937 if (is_request_) {

938 base::StringPiece method = headers_->request_method();

939 // POSTs and PUTs should have a detectable body length. If they

940 // do not we consider it an error.

941 if ((method.size() == 4 &&

942 strncmp(method.data(), "POST", 4) == 0) \|\|

943 (method.size() == 3 &&

944 strncmp(method.data(), "PUT", 3) == 0)) {

945 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

946 last_error_ =

947 BalsaFrameEnums::REQUIRED_BODY_BUT_NO_CONTENT_LENGTH;

948 visitor_->HandleHeaderError(this);

949 break;

950 }

951 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

952 } else {

953 parse_state_ = BalsaFrameEnums::READING_UNTIL_CLOSE;

954 last_error_ = BalsaFrameEnums::MAYBE_BODY_BUT_NO_CONTENT_LENGTH;

955 visitor_->HandleHeaderWarning(this);

956 }

957 break;

958 // The COV_NF_... statements here provide hints to the apparatus

959 // which computes coverage reports/ratios that this code is never

960 // intended to be executed, and should technically be impossible.

961 // COV_NF_START

962 default:

963 LOG(FATAL) << "Saw a content_length_status: "

964 << headers_->content_length_status_ << " which is unknown.";

965 // COV_NF_END

966 }

967 }

968 }

969 }

970

971 size_t BalsaFrame::ProcessHeaders(const char* message_start,

972 size_t message_length) {

973 const char* const original_message_start = message_start;

974 const char* const message_end = message_start + message_length;

975 const char* message_current = message_start;

976 const char* checkpoint = message_start;

977

978 if (message_length == 0) {

979 goto bottom;

980 }

981

982 while (message_current < message_end) {

983 size_t base_idx = headers_->GetReadableBytesFromHeaderStream();

984

985 // Yes, we could use strchr (assuming null termination), or

986 // memchr, but as it turns out that is slower than this tight loop

987 // for the input that we see.

988 if (!saw_non_newline_char_) {

989 do {

990 const char c = *message_current;

991 if (c != '\r' && c != '\n') {

992 if (c <= ' ') {

993 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

994 last_error_ = BalsaFrameEnums::NO_REQUEST_LINE_IN_REQUEST;

995 visitor_->HandleHeaderError(this);

996 goto bottom;

997 } else {

998 saw_non_newline_char_ = true;

999 checkpoint = message_start = message_current;

1000 goto read_real_message;

1001 }

1002 }

1003 ++message_current;

1004 } while (message_current < message_end);

1005 goto bottom; // this is necessary to skip 'last_char_was_slash_r' checks

1006 } else {

1007 read_real_message:

1008 // Note that SSE2 can be enabled on certain piii platforms.

1009 #if __SSE2__

1010 {

1011 const char* const message_end_m16 = message_end - 16;

1012 __v16qi newlines = { '\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n',

1013 '\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n' };

1014 while (message_current < message_end_m16) {

1015 // What this does (using compiler intrinsics):

1016 //

1017 // Load 16 '\n's into an xmm register

1018 // Load 16 bytes of currennt message into an xmm register

1019 // Do byte-wise equals on those two xmm registers

1020 // Take the first bit of each byte, and put that into the first

1021 // 16 bits of a mask

1022 // If the mask is zero, no '\n' found. increment by 16 and try again

1023 // Else scan forward to find the first set bit.

1024 // Increment current by the index of the first set bit

1025 // (ffs returns index of first set bit + 1)

1026 __m128i msg_bytes =

1027 _mm_loadu_si128(const_cast<__m128i *>(

1028 reinterpret_cast<const __m128i *>(message_current)));

1029 __m128i newline_cmp =

1030 _mm_cmpeq_epi8(msg_bytes, reinterpret_cast<__m128i>(newlines));

1031 int newline_msk = _mm_movemask_epi8(newline_cmp);

1032 if (newline_msk == 0) {

1033 message_current += 16;

1034 continue;

1035 }

1036 message_current += (ffs(newline_msk) - 1);

1037 const size_t relative_idx = message_current - message_start;

1038 const size_t message_current_idx = 1 + base_idx + relative_idx;

1039 lines_.push_back(std::make_pair(last_slash_n_idx_,

1040 message_current_idx));

1041 if (lines_.size() == 1) {

1042 headers_->WriteFromFramer(checkpoint,

1043 1 + message_current - checkpoint);

1044 checkpoint = message_current + 1;

1045 const char* begin = headers_->OriginalHeaderStreamBegin();

1046 #if DEBUGFRAMER

1047 LOG(INFO) << "First line " << std::string(begin, lines_[0].second);

1048 LOG(INFO) << "is_request_: " << is_request_;

1049 #endif

1050 ProcessFirstLine(begin, begin + lines_[0].second);

1051 if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ)

1052 goto process_lines;

1053 else if (parse_state_ == BalsaFrameEnums::PARSE_ERROR)

1054 goto bottom;

1055 }

1056 const size_t chars_since_last_slash_n = (message_current_idx -

1057 last_slash_n_idx_);

1058 last_slash_n_idx_ = message_current_idx;

1059 if (chars_since_last_slash_n > 2) {

1060 // We have a slash-n, but the last slash n was

1061 // more than 2 characters away from this. Thus, we know

1062 // that this cannot be an end-of-header.

1063 ++message_current;

1064 continue;

1065 }

1066 if ((chars_since_last_slash_n == 1) \|\|

1067 (((message_current > message_start) &&

1068 (*(message_current - 1) == '\r')) \|\|

1069 (last_char_was_slash_r_))) {

1070 goto process_lines;

1071 }

1072 ++message_current;

1073 }

1074 }

1075 #endif // __SSE2__

1076 while (message_current < message_end) {

1077 if (*message_current != '\n') {

1078 ++message_current;

1079 continue;

1080 }

1081 const size_t relative_idx = message_current - message_start;

1082 const size_t message_current_idx = 1 + base_idx + relative_idx;

1083 lines_.push_back(std::make_pair(last_slash_n_idx_,

1084 message_current_idx));

1085 if (lines_.size() == 1) {

1086 headers_->WriteFromFramer(checkpoint,

1087 1 + message_current - checkpoint);

1088 checkpoint = message_current + 1;

1089 const char* begin = headers_->OriginalHeaderStreamBegin();

1090 #if DEBUGFRAMER

1091 LOG(INFO) << "First line " << std::string(begin, lines_[0].second);

1092 LOG(INFO) << "is_request_: " << is_request_;

1093 #endif

1094 ProcessFirstLine(begin, begin + lines_[0].second);

1095 if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ)

1096 goto process_lines;

1097 else if (parse_state_ == BalsaFrameEnums::PARSE_ERROR)

1098 goto bottom;

1099 }

1100 const size_t chars_since_last_slash_n = (message_current_idx -

1101 last_slash_n_idx_);

1102 last_slash_n_idx_ = message_current_idx;

1103 if (chars_since_last_slash_n > 2) {

1104 // false positive.

1105 ++message_current;

1106 continue;

1107 }

1108 if ((chars_since_last_slash_n == 1) \|\|

1109 (((message_current > message_start) &&

1110 (*(message_current - 1) == '\r')) \|\|

1111 (last_char_was_slash_r_))) {

1112 goto process_lines;

1113 }

1114 ++message_current;

1115 }

1116 }

1117 continue;

1118 process_lines:

1119 ++message_current;

1120 DCHECK(message_current >= message_start);

1121 if (message_current > message_start) {

1122 headers_->WriteFromFramer(checkpoint, message_current - checkpoint);

1123 }

1124

1125 // Check if we have exceeded maximum headers length

1126 // Although we check for this limit before and after we call this function

1127 // we check it here as well to make sure that in case the visitor changed

1128 // the max_header_length_ (for example after processing the first line)

1129 // we handle it gracefully.

1130 if (headers_->GetReadableBytesFromHeaderStream() > max_header_length_) {

1131 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1132 last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;

1133 visitor_->HandleHeaderError(this);

1134 goto bottom;

1135 }

1136

1137 // Since we know that we won't be writing any more bytes of the header,

1138 // we tell that to the headers object. The headers object may make

1139 // more efficient allocation decisions when this is signaled.

1140 headers_->DoneWritingFromFramer();

1141 {

1142 const char* readable_ptr = NULL;

1143 size_t readable_size = 0;

1144 headers_->GetReadablePtrFromHeaderStream(&readable_ptr, &readable_size);

1145 visitor_->ProcessHeaderInput(readable_ptr, readable_size);

1146 }

1147

1148 // Ok, now that we've written everything into our header buffer, it is

1149 // time to process the header lines (extract proper values for headers

1150 // which are important for framing).

1151 ProcessHeaderLines();

1152 if (parse_state_ == BalsaFrameEnums::PARSE_ERROR) {

1153 goto bottom;

1154 }

1155 AssignParseStateAfterHeadersHaveBeenParsed();

1156 if (parse_state_ == BalsaFrameEnums::PARSE_ERROR) {

1157 goto bottom;

1158 }

1159 visitor_->ProcessHeaders(*headers_);

1160 visitor_->HeaderDone();

1161 if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ) {

1162 visitor_->MessageDone();

1163 }

1164 goto bottom;

1165 }

1166 // If we've gotten to here, it means that we've consumed all of the

1167 // available input. We need to record whether or not the last character we

1168 // saw was a '\r' so that a subsequent call to ProcessInput correctly finds

1169 // a header framing that is split across the two calls.

1170 last_char_was_slash_r_ = (*(message_end - 1) == '\r');

1171 DCHECK(message_current >= message_start);

1172 if (message_current > message_start) {

1173 headers_->WriteFromFramer(checkpoint, message_current - checkpoint);

1174 }

1175 bottom:

1176 return message_current - original_message_start;

1177 }

1178

1179

1180 size_t BalsaFrame::BytesSafeToSplice() const {

1181 switch (parse_state_) {

1182 case BalsaFrameEnums::READING_CHUNK_DATA:

1183 return chunk_length_remaining_;

1184 case BalsaFrameEnums::READING_UNTIL_CLOSE:

1185 return std::numeric_limits<size_t>::max();

1186 case BalsaFrameEnums::READING_CONTENT:

1187 return content_length_remaining_;

1188 default:

1189 return 0;

1190 }

1191 }

1192

1193 void BalsaFrame::BytesSpliced(size_t bytes_spliced) {

1194 switch (parse_state_) {

1195 case BalsaFrameEnums::READING_CHUNK_DATA:

1196 if (chunk_length_remaining_ >= bytes_spliced) {

1197 chunk_length_remaining_ -= bytes_spliced;

1198 if (chunk_length_remaining_ == 0) {

1199 parse_state_ = BalsaFrameEnums::READING_CHUNK_TERM;

1200 }

1201 return;

1202 } else {

1203 last_error_ =

1204 BalsaFrameEnums::CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT;

1205 goto error_exit;

1206 }

1207

1208 case BalsaFrameEnums::READING_UNTIL_CLOSE:

1209 return;

1210

1211 case BalsaFrameEnums::READING_CONTENT:

1212 if (content_length_remaining_ >= bytes_spliced) {

1213 content_length_remaining_ -= bytes_spliced;

1214 if (content_length_remaining_ == 0) {

1215 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

1216 visitor_->MessageDone();

1217 }

1218 return;

1219 } else {

1220 last_error_ =

1221 BalsaFrameEnums::CALLED_BYTES_SPLICED_AND_EXCEEDED_SAFE_SPLICE_AMOUNT;

1222 goto error_exit;

1223 }

1224

1225 default:

1226 last_error_ = BalsaFrameEnums::CALLED_BYTES_SPLICED_WHEN_UNSAFE_TO_DO_SO;

1227 goto error_exit;

1228 }

1229

1230 error_exit:

1231 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1232 visitor_->HandleBodyError(this);

1233 };

1234

1235 // You may note that the state-machine contained within this function has both

1236 // switch and goto labels for nearly the same thing. For instance, the

1237 // following two labels refer to the same code block:

1238 // label_reading_chunk_data:

1239 // case BalsaFrameEnums::READING_CHUNK_DATA:

1240 // The 'case' statement is required for the switch statement which occurs when

1241 // ProcessInput is invoked. The goto label is required as the state-machine

1242 // does not use a computed goto in any subsequent operations.

1243 //

1244 // Since several states exit the state machine for various reasons, there is

1245 // also one label at the bottom of the function. When it is appropriate to

1246 // return from the function, that part of the state machine instead issues a

1247 // goto bottom; This results in less code duplication, and makes debugging

1248 // easier (as you can add a statement to a section of code which is guaranteed

1249 // to be invoked when the function is exiting.

1250 size_t BalsaFrame::ProcessInput(const char* input, size_t size) {

1251 const char* current = input;

1252 const char* on_entry = current;

1253 const char* end = current + size;

1254 #if DEBUGFRAMER

1255 LOG(INFO) << "\n=============="

1256 << BalsaFrameEnums::ParseStateToString(parse_state_)

1257 << "===============\n";

1258 #endif // DEBUGFRAMER

1259

1260 DCHECK(headers_ != NULL);

1261 if (headers_ == NULL) return 0;

1262

1263 if (parse_state_ == BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE) {

1264 const size_t header_length = headers_->GetReadableBytesFromHeaderStream();

1265 // Yes, we still have to check this here as the user can change the

1266 // max_header_length amount!

1267 // Also it is possible that we have reached the maximum allowed header size,

1268 // and we have more to consume (remember we are still inside

1269 // READING_HEADER_AND_FIRSTLINE) in which case we directly declare an error.

1270 if (header_length > max_header_length_ \|\|

1271 (header_length == max_header_length_ && size > 0)) {

1272 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1273 last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;

1274 visitor_->HandleHeaderError(this);

1275 goto bottom;

1276 }

1277 size_t bytes_to_process = max_header_length_ - header_length;

1278 if (bytes_to_process > size) {

1279 bytes_to_process = size;

1280 }

1281 current += ProcessHeaders(input, bytes_to_process);

1282 // If we are still reading headers check if we have crossed the headers

1283 // limit. Note that we check for >= as opposed to >. This is because if

1284 // header_length_after equals max_header_length_ and we are still in the

1285 // parse_state_ BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE we know for

1286 // sure that the headers limit will be crossed later on

1287 if (parse_state_ == BalsaFrameEnums::READING_HEADER_AND_FIRSTLINE) {

1288 // Note that headers_ is valid only if we are still reading headers.

1289 const size_t header_length_after =

1290 headers_->GetReadableBytesFromHeaderStream();

1291 if (header_length_after >= max_header_length_) {

1292 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1293 last_error_ = BalsaFrameEnums::HEADERS_TOO_LONG;

1294 visitor_->HandleHeaderError(this);

1295 }

1296 }

1297 goto bottom;

1298 } else if (parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ \|\|

1299 parse_state_ == BalsaFrameEnums::PARSE_ERROR) {

1300 // Can do nothing more 'till we're reset.

1301 goto bottom;

1302 }

1303

1304 while (current < end) {

1305 switch (parse_state_) {

1306 label_reading_chunk_length:

1307 case BalsaFrameEnums::READING_CHUNK_LENGTH:

1308 // In this state we read the chunk length.

1309 // Note that once we hit a character which is not in:

1310 // [0-9;A-Fa-f\n], we transition to a different state.

1311 //

1312 {

1313 // If we used strtol, etc, we'd have to buffer this line.

1314 // This is more annoying than simply doing the conversion

1315 // here. This code accounts for overflow.

1316 static const signed char buf[] = {

1317 // %0 %1 %2 %3 %4 %5 %6 %7 %8 \t \n %b %c \r %e %f

1318 -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1,

1319 // %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %1a %1b %1c %1d %1e %1f

1320 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1321 // ' ' %21 %22 %23 %24 %25 %26 %27 %28 %29 %2a %2b %2c %2d %2e %2f

1322 -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1323 // %30 %31 %32 %33 %34 %35 %36 %37 %38 %39 %3a ';' %3c %3d %3e %3f

1324 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -2, -1, -1, -1, -1,

1325 // %40 'A' 'B' 'C' 'D' 'E' 'F' %47 %48 %49 %4a %4b %4c %4d %4e %4f

1326 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1327 // %50 %51 %52 %53 %54 %55 %56 %57 %58 %59 %5a %5b %5c %5d %5e %5f

1328 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1329 // %60 'a' 'b' 'c' 'd' 'e' 'f' %67 %68 %69 %6a %6b %6c %6d %6e %6f

1330 -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1331 // %70 %71 %72 %73 %74 %75 %76 %77 %78 %79 %7a %7b %7c %7d %7e %7f

1332 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

1333 };

1334 // valid cases:

1335 // "09123\n" // -> 09123

1336 // "09123\r\n" // -> 09123

1337 // "09123 \n" // -> 09123

1338 // "09123 \r\n" // -> 09123

1339 // "09123 12312\n" // -> 09123

1340 // "09123 12312\r\n" // -> 09123

1341 // "09123; foo=bar\n" // -> 09123

1342 // "09123; foo=bar\r\n" // -> 09123

1343 // "FFFFFFFFFFFFFFFF\r\n" // -> FFFFFFFFFFFFFFFF

1344 // "FFFFFFFFFFFFFFFF 22\r\n" // -> FFFFFFFFFFFFFFFF

1345 // invalid cases:

1346 // "[ \t]+[^\n]*\n"

1347 // "FFFFFFFFFFFFFFFFF\r\n" (would overflow)

1348 // "\r\n"

1349 // "\n"

1350 while (current < end) {

1351 const char c = *current;

1352 ++current;

1353 const signed char addition = buf[static_cast<int>(c)];

1354 if (addition >= 0) {

1355 chunk_length_character_extracted_ = true;

1356 size_t length_x_16 = chunk_length_remaining_ * 16;

1357 const size_t kMaxDiv16 = std::numeric_limits<size_t>::max() / 16;

1358 if ((chunk_length_remaining_ > kMaxDiv16) \|\|

1359 ((std::numeric_limits<size_t>::max() - length_x_16) <

1360 static_cast<size_t>(addition))) {

1361 // overflow -- asked for a chunk-length greater than 2^64 - 1!!

1362 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1363 last_error_ = BalsaFrameEnums::CHUNK_LENGTH_OVERFLOW;

1364 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1365 visitor_->HandleChunkingError(this);

1366 goto bottom;

1367 }

1368 chunk_length_remaining_ = length_x_16 + addition;

1369 continue;

1370 }

1371

1372 if (!chunk_length_character_extracted_ \|\| addition == -1) {

1373 // ^[0-9;A-Fa-f][ \t\n] -- was not matched, either because no

1374 // characters were converted, or an unexpected character was

1375 // seen.

1376 parse_state_ = BalsaFrameEnums::PARSE_ERROR;

1377 last_error_ = BalsaFrameEnums::INVALID_CHUNK_LENGTH;

1378 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1379 visitor_->HandleChunkingError(this);

1380 goto bottom;

1381 }

1382

1383 --current;

1384 parse_state_ = BalsaFrameEnums::READING_CHUNK_EXTENSION;

1385 visitor_->ProcessChunkLength(chunk_length_remaining_);

1386 goto label_reading_chunk_extension;

1387 }

1388 }

1389 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1390 goto bottom; // case BalsaFrameEnums::READING_CHUNK_LENGTH

1391

1392 label_reading_chunk_extension:

1393 case BalsaFrameEnums::READING_CHUNK_EXTENSION:

1394 {

1395 // TODO(phython): Convert this scanning to be 16 bytes at a time if

1396 // there is data to be read.

1397 const char* extensions_start = current;

1398 size_t extensions_length = 0;

1399 while (current < end) {

1400 const char c = *current;

1401 if (c == '\r' \|\| c == '\n') {

1402 extensions_length =

1403 (extensions_start == current) ?

1404 0 :

1405 current - extensions_start - 1;

1406 }

1407

1408 ++current;

1409 if (c == '\n') {

1410 chunk_length_character_extracted_ = false;

1411 visitor_->ProcessChunkExtensions(

1412 extensions_start, extensions_length);

1413 if (chunk_length_remaining_ != 0) {

1414 parse_state_ = BalsaFrameEnums::READING_CHUNK_DATA;

1415 goto label_reading_chunk_data;

1416 }

1417 HeaderFramingFound('\n');

1418 parse_state_ = BalsaFrameEnums::READING_LAST_CHUNK_TERM;

1419 goto label_reading_last_chunk_term;

1420 }

1421 }

1422 visitor_->ProcessChunkExtensions(

1423 extensions_start, extensions_length);

1424 }

1425

1426 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1427 goto bottom; // case BalsaFrameEnums::READING_CHUNK_EXTENSION

1428

1429 label_reading_chunk_data:

1430 case BalsaFrameEnums::READING_CHUNK_DATA:

1431 while (current < end) {

1432 if (chunk_length_remaining_ == 0) {

1433 break;

1434 }

1435 // read in the chunk

1436 size_t bytes_remaining = end - current;

1437 size_t consumed_bytes = (chunk_length_remaining_ < bytes_remaining) ?

1438 chunk_length_remaining_ : bytes_remaining;

1439 const char* tmp_current = current + consumed_bytes;

1440 visitor_->ProcessBodyInput(on_entry, tmp_current - on_entry);

1441 visitor_->ProcessBodyData(current, consumed_bytes);

1442 on_entry = current = tmp_current;

1443 chunk_length_remaining_ -= consumed_bytes;

1444 }

1445 if (chunk_length_remaining_ == 0) {

1446 parse_state_ = BalsaFrameEnums::READING_CHUNK_TERM;

1447 goto label_reading_chunk_term;

1448 }

1449 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1450 goto bottom; // case BalsaFrameEnums::READING_CHUNK_DATA

1451

1452 label_reading_chunk_term:

1453 case BalsaFrameEnums::READING_CHUNK_TERM:

1454 while (current < end) {

1455 const char c = *current;

1456 ++current;

1457

1458 if (c == '\n') {

1459 parse_state_ = BalsaFrameEnums::READING_CHUNK_LENGTH;

1460 goto label_reading_chunk_length;

1461 }

1462 }

1463 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1464 goto bottom; // case BalsaFrameEnums::READING_CHUNK_TERM

1465

1466 label_reading_last_chunk_term:

1467 case BalsaFrameEnums::READING_LAST_CHUNK_TERM:

1468 while (current < end) {

1469 const char c = *current;

1470

1471 if (!HeaderFramingFound(c)) {

1472 // If not, however, since the spec only suggests that the

1473 // client SHOULD indicate the presence of trailers, we get to

1474 // test that they did or didn't.

1475 // If all of the bytes we've seen since:

1476 // OPTIONAL_WS 0 OPTIONAL_STUFF CRLF

1477 // are either '\r', or '\n', then we can assume that we don't yet

1478 // know if we need to parse headers, or if the next byte will make

1479 // the HeaderFramingFound condition (above) true.

1480 if (HeaderFramingMayBeFound()) {

1481 // If true, then we have seen only characters '\r' or '\n'.

1482 ++current;

1483

1484 // Lets try again! There is no state change here.

1485 continue;

1486 } else {

1487 // If (!HeaderFramingMayBeFound()), then we know that we must be

1488 // reading the first non CRLF character of a trailer.

1489 parse_state_ = BalsaFrameEnums::READING_TRAILER;

1490 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1491 on_entry = current;

1492 goto label_reading_trailer;

1493 }

1494 } else {

1495 // If we've found a "\r\n\r\n", then the message

1496 // is done.

1497 ++current;

1498 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

1499 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1500 visitor_->MessageDone();

1501 goto bottom;

1502 }

1503 break; // from while loop

1504 }

1505 visitor_->ProcessBodyInput(on_entry, current - on_entry);

1506 goto bottom; // case BalsaFrameEnums::READING_LAST_CHUNK_TERM

1507

1508 label_reading_trailer:

1509 case BalsaFrameEnums::READING_TRAILER:

1510 while (current < end) {

1511 const char c = *current;

1512 ++current;

1513 // TODO(fenix): If we ever care about trailers as part of framing,

1514 // deal with them here (see below for part of the 'solution')

1515 // if (LineFramingFound(c)) {

1516 // trailer_lines_.push_back(make_pair(start_of_line_,

1517 // trailer_length_ - 1));

1518 // start_of_line_ = trailer_length_;

1519 // }

1520 if (HeaderFramingFound(c)) {

1521 // ProcessTrailers(visitor_, &trailers_);

1522 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

1523 visitor_->ProcessTrailerInput(on_entry, current - on_entry);

1524 visitor_->MessageDone();

1525 goto bottom;

1526 }

1527 }

1528 visitor_->ProcessTrailerInput(on_entry, current - on_entry);

1529 break; // case BalsaFrameEnums::READING_TRAILER

1530

1531 // Note that there is no label:

1532 // 'label_reading_until_close'

1533 // here. This is because the state-machine exists immediately after

1534 // reading the headers instead of transitioning here (as it would

1535 // do if it was consuming all the data it could, all the time).

1536 case BalsaFrameEnums::READING_UNTIL_CLOSE:

1537 {

1538 const size_t bytes_remaining = end - current;

1539 if (bytes_remaining > 0) {

1540 visitor_->ProcessBodyInput(current, bytes_remaining);

1541 visitor_->ProcessBodyData(current, bytes_remaining);

1542 current += bytes_remaining;

1543 }

1544 }

1545 goto bottom; // case BalsaFrameEnums::READING_UNTIL_CLOSE

1546

1547 // label_reading_content:

1548 case BalsaFrameEnums::READING_CONTENT:

1549 #if DEBUGFRAMER

1550 LOG(INFO) << "ReadingContent: " << content_length_remaining_;

1551 #endif // DEBUGFRAMER

1552 while (content_length_remaining_ && current < end) {

1553 // read in the content

1554 const size_t bytes_remaining = end - current;

1555 const size_t consumed_bytes =

1556 (content_length_remaining_ < bytes_remaining) ?

1557 content_length_remaining_ : bytes_remaining;

1558 visitor_->ProcessBodyInput(current, consumed_bytes);

1559 visitor_->ProcessBodyData(current, consumed_bytes);

1560 current += consumed_bytes;

1561 content_length_remaining_ -= consumed_bytes;

1562 }

1563 if (content_length_remaining_ == 0) {

1564 parse_state_ = BalsaFrameEnums::MESSAGE_FULLY_READ;

1565 visitor_->MessageDone();

1566 }

1567 goto bottom; // case BalsaFrameEnums::READING_CONTENT

1568

1569 default:

1570 // The state-machine should never be in a state that isn't handled

1571 // above. This is a glaring logic error, and we should do something

1572 // drastic to ensure that this gets looked-at and fixed.

1573 LOG(FATAL) << "Unknown state: " << parse_state_ // COV_NF_LINE

1574 << " memory corruption?!"; // COV_NF_LINE

1575 }

1576 }

1577 bottom:

1578 #if DEBUGFRAMER

1579 LOG(INFO) << "\n^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n"

1580 << std::string(input, current)

1581 << "\n$$$$$$$$$$$$$$"

1582 << BalsaFrameEnums::ParseStateToString(parse_state_)

1583 << "$$$$$$$$$$$$$$$"

1584 << " consumed: " << (current - input);

1585 if (Error()) {

1586 LOG(INFO) << BalsaFrameEnums::ErrorCodeToString(ErrorCode());

1587 }

1588 #endif // DEBUGFRAMER

1589 return current - input;

1590 }

1591

1592 const uint32 BalsaFrame::kValidTerm1;

1593 const uint32 BalsaFrame::kValidTerm1Mask;

1594 const uint32 BalsaFrame::kValidTerm2;

1595 const uint32 BalsaFrame::kValidTerm2Mask;

1596

1597 } // namespace net

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