src/adaptation/icap/ModXact.cc

   1 /*
   2  * DEBUG: section 93    ICAP (RFC 3507) Client
   3  */
   4
   5 #include "squid.h"
   6 #include "AccessLogEntry.h"
   7 #include "adaptation/History.h"
   8 #include "adaptation/icap/Client.h"
   9 #include "adaptation/icap/Config.h"
  10 #include "adaptation/icap/History.h"
  11 #include "adaptation/icap/Launcher.h"
  12 #include "adaptation/icap/ModXact.h"
  13 #include "adaptation/icap/ServiceRep.h"
  14 #include "adaptation/Initiator.h"
  15 #include "auth/UserRequest.h"
  16 #include "base/TextException.h"
  17 #include "ChunkedCodingParser.h"
  18 #include "comm.h"
  19 #include "HttpMsg.h"
  20 #include "HttpRequest.h"
  21 #include "HttpReply.h"
  22 #include "SquidTime.h"
  23
  24 // flow and terminology:
  25 //     HTTP| --> receive --> encode --> write --> |network
  26 //     end | <-- send    <-- parse  <-- read  <-- |end
  27
  28 // TODO: replace gotEncapsulated() with something faster; we call it often
  29
  30 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXact);
  31 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXactLauncher);
  32
  33 static const size_t TheBackupLimit = BodyPipe::MaxCapacity;
  34
  35 Adaptation::Icap::ModXact::State::State()
  36 {
  37     memset(this, 0, sizeof(*this));
  38 }
  39
  40 Adaptation::Icap::ModXact::ModXact(Adaptation::Initiator *anInitiator, HttpMsg *virginHeader,
  41                                    HttpRequest *virginCause, Adaptation::Icap::ServiceRep::Pointer &aService):
  42         AsyncJob("Adaptation::Icap::ModXact"),
  43         Adaptation::Icap::Xaction("Adaptation::Icap::ModXact", anInitiator, aService),
  44         virginConsumed(0),
  45         bodyParser(NULL),
  46         canStartBypass(false), // too early
  47         protectGroupBypass(true),
  48         replyHttpHeaderSize(-1),
  49         replyHttpBodySize(-1),
  50         adaptHistoryId(-1)
  51 {
  52     assert(virginHeader);
  53
  54     virgin.setHeader(virginHeader); // sets virgin.body_pipe if needed
  55     virgin.setCause(virginCause); // may be NULL
  56
  57     // adapted header and body are initialized when we parse them
  58
  59     // writing and reading ends are handled by Adaptation::Icap::Xaction
  60
  61     // encoding
  62     // nothing to do because we are using temporary buffers
  63
  64     // parsing; TODO: do not set until we parse, see ICAPOptXact
  65     icapReply = HTTPMSGLOCK(new HttpReply);
  66     icapReply->protoPrefix = "ICAP/"; // TODO: make an IcapReply class?
  67
  68     debugs(93,7, HERE << "initialized." << status());
  69 }
  70
  71 // initiator wants us to start
  72 void Adaptation::Icap::ModXact::start()
  73 {
  74     Adaptation::Icap::Xaction::start();
  75
  76     // reserve an adaptation history slot (attempts are known at this time)
  77     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
  78     if (ah != NULL)
  79         adaptHistoryId = ah->recordXactStart(service().cfg().key, icap_tr_start, attempts > 1);
  80
  81     estimateVirginBody(); // before virgin disappears!
  82
  83     canStartBypass = service().cfg().bypass;
  84
  85     // it is an ICAP violation to send request to a service w/o known OPTIONS
  86
  87     if (service().up())
  88         startWriting();
  89     else
  90         waitForService();
  91 }
  92
  93 void Adaptation::Icap::ModXact::waitForService()
  94 {
  95     Must(!state.serviceWaiting);
  96     debugs(93, 7, HERE << "will wait for the ICAP service" << status());
  97     state.serviceWaiting = true;
  98     AsyncCall::Pointer call = asyncCall(93,5, "Adaptation::Icap::ModXact::noteServiceReady",
  99                                         MemFun(this, &Adaptation::Icap::ModXact::noteServiceReady));
 100     service().callWhenReady(call);
 101 }
 102
 103 void Adaptation::Icap::ModXact::noteServiceReady()
 104 {
 105     Must(state.serviceWaiting);
 106     state.serviceWaiting = false;
 107
 108     if (service().up()) {
 109         startWriting();
 110     } else {
 111         disableRetries();
 112         disableRepeats("ICAP service is unusable");
 113         throw TexcHere("ICAP service is unusable");
 114     }
 115 }
 116
 117 void Adaptation::Icap::ModXact::startWriting()
 118 {
 119     state.writing = State::writingConnect;
 120
 121     decideOnPreview(); // must be decided before we decideOnRetries
 122     decideOnRetries();
 123
 124     openConnection();
 125 }
 126
 127 // connection with the ICAP service established
 128 void Adaptation::Icap::ModXact::handleCommConnected()
 129 {
 130     Must(state.writing == State::writingConnect);
 131
 132     startReading(); // wait for early errors from the ICAP server
 133
 134     MemBuf requestBuf;
 135     requestBuf.init();
 136
 137     makeRequestHeaders(requestBuf);
 138     debugs(93, 9, HERE << "will write" << status() << ":\n" <<
 139            (requestBuf.terminate(), requestBuf.content()));
 140
 141     // write headers
 142     state.writing = State::writingHeaders;
 143     icap_tio_start = current_time;
 144     scheduleWrite(requestBuf);
 145 }
 146
 147 void Adaptation::Icap::ModXact::handleCommWrote(size_t sz)
 148 {
 149     debugs(93, 5, HERE << "Wrote " << sz << " bytes");
 150
 151     if (state.writing == State::writingHeaders)
 152         handleCommWroteHeaders();
 153     else
 154         handleCommWroteBody();
 155 }
 156
 157 void Adaptation::Icap::ModXact::handleCommWroteHeaders()
 158 {
 159     Must(state.writing == State::writingHeaders);
 160
 161     // determine next step
 162     if (preview.enabled())
 163         state.writing = preview.done() ? State::writingPaused : State::writingPreview;
 164     else if (virginBody.expected())
 165         state.writing = State::writingPrime;
 166     else {
 167         stopWriting(true);
 168         return;
 169     }
 170
 171     writeMore();
 172 }
 173
 174 void Adaptation::Icap::ModXact::writeMore()
 175 {
 176     debugs(93, 5, HERE << "checking whether to write more" << status());
 177
 178     if (writer != NULL) // already writing something
 179         return;
 180
 181     switch (state.writing) {
 182
 183     case State::writingInit:    // waiting for service OPTIONS
 184         Must(state.serviceWaiting);
 185
 186     case State::writingConnect: // waiting for the connection to establish
 187
 188     case State::writingHeaders: // waiting for the headers to be written
 189
 190     case State::writingPaused:  // waiting for the ICAP server response
 191
 192     case State::writingReallyDone: // nothing more to write
 193         return;
 194
 195     case State::writingAlmostDone: // was waiting for the last write
 196         stopWriting(false);
 197         return;
 198
 199     case State::writingPreview:
 200         writePreviewBody();
 201         return;
 202
 203     case State::writingPrime:
 204         writePrimeBody();
 205         return;
 206
 207     default:
 208         throw TexcHere("Adaptation::Icap::ModXact in bad writing state");
 209     }
 210 }
 211
 212 void Adaptation::Icap::ModXact::writePreviewBody()
 213 {
 214     debugs(93, 8, HERE << "will write Preview body from " <<
 215            virgin.body_pipe << status());
 216     Must(state.writing == State::writingPreview);
 217     Must(virgin.body_pipe != NULL);
 218
 219     const size_t sizeMax = (size_t)virgin.body_pipe->buf().contentSize();
 220     const size_t size = min(preview.debt(), sizeMax);
 221     writeSomeBody("preview body", size);
 222
 223     // change state once preview is written
 224
 225     if (preview.done()) {
 226         debugs(93, 7, HERE << "wrote entire Preview body" << status());
 227
 228         if (preview.ieof())
 229             stopWriting(true);
 230         else
 231             state.writing = State::writingPaused;
 232     }
 233 }
 234
 235 void Adaptation::Icap::ModXact::writePrimeBody()
 236 {
 237     Must(state.writing == State::writingPrime);
 238     Must(virginBodyWriting.active());
 239
 240     const size_t size = (size_t)virgin.body_pipe->buf().contentSize();
 241     writeSomeBody("prime virgin body", size);
 242
 243     if (virginBodyEndReached(virginBodyWriting)) {
 244         debugs(93, 5, HERE << "wrote entire body");
 245         stopWriting(true);
 246     }
 247 }
 248
 249 void Adaptation::Icap::ModXact::writeSomeBody(const char *label, size_t size)
 250 {
 251     Must(!writer && state.writing < state.writingAlmostDone);
 252     Must(virgin.body_pipe != NULL);
 253     debugs(93, 8, HERE << "will write up to " << size << " bytes of " <<
 254            label);
 255
 256     MemBuf writeBuf; // TODO: suggest a min size based on size and lastChunk
 257
 258     writeBuf.init(); // note: we assume that last-chunk will fit
 259
 260     const size_t writableSize = virginContentSize(virginBodyWriting);
 261     const size_t chunkSize = min(writableSize, size);
 262
 263     if (chunkSize) {
 264         debugs(93, 7, HERE << "will write " << chunkSize <<
 265                "-byte chunk of " << label);
 266
 267         openChunk(writeBuf, chunkSize, false);
 268         writeBuf.append(virginContentData(virginBodyWriting), chunkSize);
 269         closeChunk(writeBuf);
 270
 271         virginBodyWriting.progress(chunkSize);
 272         virginConsume();
 273     } else {
 274         debugs(93, 7, HERE << "has no writable " << label << " content");
 275     }
 276
 277     const bool wroteEof = virginBodyEndReached(virginBodyWriting);
 278     bool lastChunk = wroteEof;
 279     if (state.writing == State::writingPreview) {
 280         preview.wrote(chunkSize, wroteEof); // even if wrote nothing
 281         lastChunk = lastChunk || preview.done();
 282     }
 283
 284     if (lastChunk) {
 285         debugs(93, 8, HERE << "will write last-chunk of " << label);
 286         addLastRequestChunk(writeBuf);
 287     }
 288
 289     debugs(93, 7, HERE << "will write " << writeBuf.contentSize()
 290            << " raw bytes of " << label);
 291
 292     if (writeBuf.hasContent()) {
 293         scheduleWrite(writeBuf); // comm will free the chunk
 294     } else {
 295         writeBuf.clean();
 296     }
 297 }
 298
 299 void Adaptation::Icap::ModXact::addLastRequestChunk(MemBuf &buf)
 300 {
 301     const bool ieof = state.writing == State::writingPreview && preview.ieof();
 302     openChunk(buf, 0, ieof);
 303     closeChunk(buf);
 304 }
 305
 306 void Adaptation::Icap::ModXact::openChunk(MemBuf &buf, size_t chunkSize, bool ieof)
 307 {
 308     buf.Printf((ieof ? "%x; ieof\r\n" : "%x\r\n"), (int) chunkSize);
 309 }
 310
 311 void Adaptation::Icap::ModXact::closeChunk(MemBuf &buf)
 312 {
 313     buf.append(ICAP::crlf, 2); // chunk-terminating CRLF
 314 }
 315
 316 const HttpRequest &Adaptation::Icap::ModXact::virginRequest() const
 317 {
 318     const HttpRequest *request = virgin.cause ?
 319                                  virgin.cause : dynamic_cast<const HttpRequest*>(virgin.header);
 320     Must(request);
 321     return *request;
 322 }
 323
 324 // did the activity reached the end of the virgin body?
 325 bool Adaptation::Icap::ModXact::virginBodyEndReached(const Adaptation::Icap::VirginBodyAct &act) const
 326 {
 327     return
 328         !act.active() || // did all (assuming it was originally planned)
 329         !virgin.body_pipe->expectMoreAfter(act.offset()); // wont have more
 330 }
 331
 332 // the size of buffered virgin body data available for the specified activity
 333 // if this size is zero, we may be done or may be waiting for more data
 334 size_t Adaptation::Icap::ModXact::virginContentSize(const Adaptation::Icap::VirginBodyAct &act) const
 335 {
 336     Must(act.active());
 337     // asbolute start of unprocessed data
 338     const uint64_t dataStart = act.offset();
 339     // absolute end of buffered data
 340     const uint64_t dataEnd = virginConsumed + virgin.body_pipe->buf().contentSize();
 341     Must(virginConsumed <= dataStart && dataStart <= dataEnd);
 342     return static_cast<size_t>(dataEnd - dataStart);
 343 }
 344
 345 // pointer to buffered virgin body data available for the specified activity
 346 const char *Adaptation::Icap::ModXact::virginContentData(const Adaptation::Icap::VirginBodyAct &act) const
 347 {
 348     Must(act.active());
 349     const uint64_t dataStart = act.offset();
 350     Must(virginConsumed <= dataStart);
 351     return virgin.body_pipe->buf().content() + static_cast<size_t>(dataStart-virginConsumed);
 352 }
 353
 354 void Adaptation::Icap::ModXact::virginConsume()
 355 {
 356     debugs(93, 9, HERE << "consumption guards: " << !virgin.body_pipe << isRetriable <<
 357            isRepeatable << canStartBypass << protectGroupBypass);
 358
 359     if (!virgin.body_pipe)
 360         return; // nothing to consume
 361
 362     if (isRetriable)
 363         return; // do not consume if we may have to retry later
 364
 365     BodyPipe &bp = *virgin.body_pipe;
 366     const bool wantToPostpone = isRepeatable || canStartBypass || protectGroupBypass;
 367
 368     // Why > 2? HttpState does not use the last bytes in the buffer
 369     // because delayAwareRead() is arguably broken. See
 370     // HttpStateData::maybeReadVirginBody for more details.
 371     if (wantToPostpone && bp.buf().spaceSize() > 2) {
 372         // Postponing may increase memory footprint and slow the HTTP side
 373         // down. Not postponing may increase the number of ICAP errors
 374         // if the ICAP service fails. We may also use "potential" space to
 375         // postpone more aggressively. Should the trade-off be configurable?
 376         debugs(93, 8, HERE << "postponing consumption from " << bp.status());
 377         return;
 378     }
 379
 380     const size_t have = static_cast<size_t>(bp.buf().contentSize());
 381     const uint64_t end = virginConsumed + have;
 382     uint64_t offset = end;
 383
 384     debugs(93, 9, HERE << "max virgin consumption offset=" << offset <<
 385            " acts " << virginBodyWriting.active() << virginBodySending.active() <<
 386            " consumed=" << virginConsumed <<
 387            " from " << virgin.body_pipe->status());
 388
 389     if (virginBodyWriting.active())
 390         offset = min(virginBodyWriting.offset(), offset);
 391
 392     if (virginBodySending.active())
 393         offset = min(virginBodySending.offset(), offset);
 394
 395     Must(virginConsumed <= offset && offset <= end);
 396
 397     if (const size_t size = static_cast<size_t>(offset - virginConsumed)) {
 398         debugs(93, 8, HERE << "consuming " << size << " out of " << have <<
 399                " virgin body bytes");
 400         bp.consume(size);
 401         virginConsumed += size;
 402         Must(!isRetriable); // or we should not be consuming
 403         disableRepeats("consumed content");
 404         disableBypass("consumed content", true);
 405     }
 406 }
 407
 408 void Adaptation::Icap::ModXact::handleCommWroteBody()
 409 {
 410     writeMore();
 411 }
 412
 413 // Called when we do not expect to call comm_write anymore.
 414 // We may have a pending write though.
 415 // If stopping nicely, we will just wait for that pending write, if any.
 416 void Adaptation::Icap::ModXact::stopWriting(bool nicely)
 417 {
 418     if (state.writing == State::writingReallyDone)
 419         return;
 420
 421     if (writer != NULL) {
 422         if (nicely) {
 423             debugs(93, 7, HERE << "will wait for the last write" << status());
 424             state.writing = State::writingAlmostDone; // may already be set
 425             checkConsuming();
 426             return;
 427         }
 428         debugs(93, 3, HERE << "will NOT wait for the last write" << status());
 429
 430         // Comm does not have an interface to clear the writer callback nicely,
 431         // but without clearing the writer we cannot recycle the connection.
 432         // We prevent connection reuse and hope that we can handle a callback
 433         // call at any time, usually in the middle of the destruction sequence!
 434         // Somebody should add comm_remove_write_handler() to comm API.
 435         reuseConnection = false;
 436         ignoreLastWrite = true;
 437     }
 438
 439     debugs(93, 7, HERE << "will no longer write" << status());
 440     if (virginBodyWriting.active()) {
 441         virginBodyWriting.disable();
 442         virginConsume();
 443     }
 444     state.writing = State::writingReallyDone;
 445     checkConsuming();
 446 }
 447
 448 void Adaptation::Icap::ModXact::stopBackup()
 449 {
 450     if (!virginBodySending.active())
 451         return;
 452
 453     debugs(93, 7, HERE << "will no longer backup" << status());
 454     virginBodySending.disable();
 455     virginConsume();
 456 }
 457
 458 bool Adaptation::Icap::ModXact::doneAll() const
 459 {
 460     return Adaptation::Icap::Xaction::doneAll() && !state.serviceWaiting &&
 461            doneSending() &&
 462            doneReading() && state.doneWriting();
 463 }
 464
 465 void Adaptation::Icap::ModXact::startReading()
 466 {
 467     Must(connection >= 0);
 468     Must(!reader);
 469     Must(!adapted.header);
 470     Must(!adapted.body_pipe);
 471
 472     // we use the same buffer for headers and body and then consume headers
 473     readMore();
 474 }
 475
 476 void Adaptation::Icap::ModXact::readMore()
 477 {
 478     if (reader != NULL || doneReading()) {
 479         debugs(93,3,HERE << "returning from readMore because reader or doneReading()");
 480         return;
 481     }
 482
 483     // do not fill readBuf if we have no space to store the result
 484     if (adapted.body_pipe != NULL &&
 485             !adapted.body_pipe->buf().hasPotentialSpace()) {
 486         debugs(93,3,HERE << "not reading because ICAP reply pipe is full");
 487         return;
 488     }
 489
 490     if (readBuf.hasSpace())
 491         scheduleRead();
 492     else
 493         debugs(93,3,HERE << "nothing to do because !readBuf.hasSpace()");
 494 }
 495
 496 // comm module read a portion of the ICAP response for us
 497 void Adaptation::Icap::ModXact::handleCommRead(size_t)
 498 {
 499     Must(!state.doneParsing());
 500     icap_tio_finish = current_time;
 501     parseMore();
 502     readMore();
 503 }
 504
 505 void Adaptation::Icap::ModXact::echoMore()
 506 {
 507     Must(state.sending == State::sendingVirgin);
 508     Must(adapted.body_pipe != NULL);
 509     Must(virginBodySending.active());
 510
 511     const size_t sizeMax = virginContentSize(virginBodySending);
 512     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes from " <<
 513            virgin.body_pipe->status());
 514     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes to   " <<
 515            adapted.body_pipe->status());
 516
 517     if (sizeMax > 0) {
 518         const size_t size = adapted.body_pipe->putMoreData(virginContentData(virginBodySending), sizeMax);
 519         debugs(93,5, HERE << "echoed " << size << " out of " << sizeMax <<
 520                " bytes");
 521         virginBodySending.progress(size);
 522         disableRepeats("echoed content");
 523         disableBypass("echoed content", true);
 524         virginConsume();
 525     }
 526
 527     if (virginBodyEndReached(virginBodySending)) {
 528         debugs(93, 5, HERE << "echoed all" << status());
 529         stopSending(true);
 530     } else {
 531         debugs(93, 5, HERE << "has " <<
 532                virgin.body_pipe->buf().contentSize() << " bytes " <<
 533                "and expects more to echo" << status());
 534         // TODO: timeout if virgin or adapted pipes are broken
 535     }
 536 }
 537
 538 bool Adaptation::Icap::ModXact::doneSending() const
 539 {
 540     return state.sending == State::sendingDone;
 541 }
 542
 543 // stop (or do not start) sending adapted message body
 544 void Adaptation::Icap::ModXact::stopSending(bool nicely)
 545 {
 546     debugs(93, 7, HERE << "Enter stop sending ");
 547     if (doneSending())
 548         return;
 549     debugs(93, 7, HERE << "Proceed with stop sending ");
 550
 551     if (state.sending != State::sendingUndecided) {
 552         debugs(93, 7, HERE << "will no longer send" << status());
 553         if (adapted.body_pipe != NULL) {
 554             virginBodySending.disable();
 555             // we may leave debts if we were echoing and the virgin
 556             // body_pipe got exhausted before we echoed all planned bytes
 557             const bool leftDebts = adapted.body_pipe->needsMoreData();
 558             stopProducingFor(adapted.body_pipe, nicely && !leftDebts);
 559         }
 560     } else {
 561         debugs(93, 7, HERE << "will not start sending" << status());
 562         Must(!adapted.body_pipe);
 563     }
 564
 565     state.sending = State::sendingDone;
 566     checkConsuming();
 567 }
 568
 569 // should be called after certain state.writing or state.sending changes
 570 void Adaptation::Icap::ModXact::checkConsuming()
 571 {
 572     // quit if we already stopped or are still using the pipe
 573     if (!virgin.body_pipe || !state.doneConsumingVirgin())
 574         return;
 575
 576     debugs(93, 7, HERE << "will stop consuming" << status());
 577     stopConsumingFrom(virgin.body_pipe);
 578 }
 579
 580 void Adaptation::Icap::ModXact::parseMore()
 581 {
 582     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " bytes to parse" <<
 583            status());
 584     debugs(93, 5, HERE << "\n" << readBuf.content());
 585
 586     if (state.parsingHeaders())
 587         parseHeaders();
 588
 589     if (state.parsing == State::psBody)
 590         parseBody();
 591 }
 592
 593 void Adaptation::Icap::ModXact::callException(const std::exception &e)
 594 {
 595     if (!canStartBypass || isRetriable) {
 596         Adaptation::Icap::Xaction::callException(e);
 597         return;
 598     }
 599
 600     try {
 601         debugs(93, 3, HERE << "bypassing " << inCall << " exception: " <<
 602                e.what() << ' ' << status());
 603         bypassFailure();
 604     } catch (const std::exception &bypassE) {
 605         Adaptation::Icap::Xaction::callException(bypassE);
 606     }
 607 }
 608
 609 void Adaptation::Icap::ModXact::bypassFailure()
 610 {
 611     disableBypass("already started to bypass", false);
 612
 613     Must(!isRetriable); // or we should not be bypassing
 614     // TODO: should the same be enforced for isRepeatable? Check icap_repeat??
 615
 616     prepEchoing();
 617
 618     startSending();
 619
 620     // end all activities associated with the ICAP server
 621
 622     stopParsing();
 623
 624     stopWriting(true); // or should we force it?
 625     if (connection >= 0) {
 626         reuseConnection = false; // be conservative
 627         cancelRead(); // may not work; and we cannot stop connecting either
 628         if (!doneWithIo())
 629             debugs(93, 7, HERE << "Warning: bypass failed to stop I/O" << status());
 630     }
 631 }
 632
 633 void Adaptation::Icap::ModXact::disableBypass(const char *reason, bool includingGroupBypass)
 634 {
 635     if (canStartBypass) {
 636         debugs(93,7, HERE << "will never start bypass because " << reason);
 637         canStartBypass = false;
 638     }
 639     if (protectGroupBypass && includingGroupBypass) {
 640         debugs(93,7, HERE << "not protecting group bypass because " << reason);
 641         protectGroupBypass = false;
 642     }
 643 }
 644
 645
 646
 647 // note that allocation for echoing is done in handle204NoContent()
 648 void Adaptation::Icap::ModXact::maybeAllocateHttpMsg()
 649 {
 650     if (adapted.header) // already allocated
 651         return;
 652
 653     if (gotEncapsulated("res-hdr")) {
 654         adapted.setHeader(new HttpReply);
 655         setOutcome(service().cfg().method == ICAP::methodReqmod ?
 656                    xoSatisfied : xoModified);
 657     } else if (gotEncapsulated("req-hdr")) {
 658         adapted.setHeader(new HttpRequest);
 659         setOutcome(xoModified);
 660     } else
 661         throw TexcHere("Neither res-hdr nor req-hdr in maybeAllocateHttpMsg()");
 662 }
 663
 664 void Adaptation::Icap::ModXact::parseHeaders()
 665 {
 666     Must(state.parsingHeaders());
 667
 668     if (state.parsing == State::psIcapHeader) {
 669         debugs(93, 5, HERE << "parse ICAP headers");
 670         parseIcapHead();
 671     }
 672
 673     if (state.parsing == State::psHttpHeader) {
 674         debugs(93, 5, HERE << "parse HTTP headers");
 675         parseHttpHead();
 676     }
 677
 678     if (state.parsingHeaders()) { // need more data
 679         Must(mayReadMore());
 680         return;
 681     }
 682
 683     startSending();
 684 }
 685
 686 // called after parsing all headers or when bypassing an exception
 687 void Adaptation::Icap::ModXact::startSending()
 688 {
 689     disableRepeats("sent headers");
 690     disableBypass("sent headers", true);
 691     sendAnswer(adapted.header);
 692
 693     if (state.sending == State::sendingVirgin)
 694         echoMore();
 695 }
 696
 697 void Adaptation::Icap::ModXact::parseIcapHead()
 698 {
 699     Must(state.sending == State::sendingUndecided);
 700
 701     if (!parseHead(icapReply))
 702         return;
 703
 704     if (httpHeaderHasConnDir(&icapReply->header, "close")) {
 705         debugs(93, 5, HERE << "found connection close");
 706         reuseConnection = false;
 707     }
 708
 709     switch (icapReply->sline.status) {
 710
 711     case 100:
 712         handle100Continue();
 713         break;
 714
 715     case 200:
 716     case 201: // Symantec Scan Engine 5.0 and later when modifying HTTP msg
 717
 718         if (!validate200Ok()) {
 719             throw TexcHere("Invalid ICAP Response");
 720         } else {
 721             handle200Ok();
 722         }
 723
 724         break;
 725
 726     case 204:
 727         handle204NoContent();
 728         break;
 729
 730     case 206:
 731         handle206PartialContent();
 732         break;
 733
 734     default:
 735         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 736         handleUnknownScode();
 737         break;
 738     }
 739
 740     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 741     if (!request)
 742         request = &virginRequest();
 743
 744     // update the cross-transactional database if needed (all status codes!)
 745     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 746         Adaptation::History::Pointer ah = request->adaptHistory(true);
 747         if (ah != NULL) {
 748             const String val = icapReply->header.getByName(xxName);
 749             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 750                 ah->updateXxRecord(xxName, val);
 751         }
 752     }
 753
 754     // update the adaptation plan if needed (all status codes!)
 755     if (service().cfg().routing) {
 756         String services;
 757         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 758             Adaptation::History::Pointer ah = request->adaptHistory(true);
 759             if (ah != NULL)
 760                 ah->updateNextServices(services);
 761         }
 762     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 763
 764     // We need to store received ICAP headers for <icapLastHeader logformat option.
 765     // If we already have stored headers from previous ICAP transaction related to this
 766     // request, old headers will be replaced with the new one.
 767
 768     Adaptation::Icap::History::Pointer h = request->icapHistory();
 769     if (h != NULL) {
 770         h->mergeIcapHeaders(&icapReply->header);
 771         h->setIcapLastHeader(&icapReply->header);
 772     }
 773
 774     // handle100Continue() manages state.writing on its own.
 775     // Non-100 status means the server needs no postPreview data from us.
 776     if (state.writing == State::writingPaused)
 777         stopWriting(true);
 778 }
 779
 780 bool Adaptation::Icap::ModXact::validate200Ok()
 781 {
 782     if (ICAP::methodRespmod == service().cfg().method) {
 783         if (!gotEncapsulated("res-hdr"))
 784             return false;
 785
 786         return true;
 787     }
 788
 789     if (ICAP::methodReqmod == service().cfg().method) {
 790         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 791             return false;
 792
 793         return true;
 794     }
 795
 796     return false;
 797 }
 798
 799 void Adaptation::Icap::ModXact::handle100Continue()
 800 {
 801     Must(state.writing == State::writingPaused);
 802     // server must not respond before the end of preview: we may send ieof
 803     Must(preview.enabled() && preview.done() && !preview.ieof());
 804
 805     // 100 "Continue" cancels our Preview commitment,
 806     // but not commitment to handle 204 or 206 outside Preview
 807     if (!state.allowedPostview204 && !state.allowedPostview206)
 808         stopBackup();
 809
 810     state.parsing = State::psIcapHeader; // eventually
 811     icapReply->reset();
 812
 813     state.writing = State::writingPrime;
 814
 815     writeMore();
 816 }
 817
 818 void Adaptation::Icap::ModXact::handle200Ok()
 819 {
 820     state.parsing = State::psHttpHeader;
 821     state.sending = State::sendingAdapted;
 822     stopBackup();
 823     checkConsuming();
 824 }
 825
 826 void Adaptation::Icap::ModXact::handle204NoContent()
 827 {
 828     stopParsing();
 829     prepEchoing();
 830 }
 831
 832 void Adaptation::Icap::ModXact::handle206PartialContent()
 833 {
 834     if (state.writing == State::writingPaused) {
 835         Must(preview.enabled());
 836         Must(state.allowedPreview206);
 837         debugs(93, 7, HERE << "206 inside preview");
 838     } else {
 839         Must(state.writing > State::writingPaused);
 840         Must(state.allowedPostview206);
 841         debugs(93, 7, HERE << "206 outside preview");
 842     }
 843     state.parsing = State::psHttpHeader;
 844     state.sending = State::sendingAdapted;
 845     state.readyForUob = true;
 846     checkConsuming();
 847 }
 848
 849 // Called when we receive a 204 No Content response and
 850 // when we are trying to bypass a service failure.
 851 // We actually start sending (echoig or not) in startSending.
 852 void Adaptation::Icap::ModXact::prepEchoing()
 853 {
 854     disableRepeats("preparing to echo content");
 855     disableBypass("preparing to echo content", true);
 856     setOutcome(xoEcho);
 857
 858     // We want to clone the HTTP message, but we do not want
 859     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 860     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 861     // Instead, we simply write the HTTP message and "clone" it by parsing.
 862     // TODO: use HttpMsg::clone()!
 863
 864     HttpMsg *oldHead = virgin.header;
 865     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 866
 867     MemBuf httpBuf;
 868
 869     // write the virgin message into a memory buffer
 870     httpBuf.init();
 871     packHead(httpBuf, oldHead);
 872
 873     // allocate the adapted message and copy metainfo
 874     Must(!adapted.header);
 875     HttpMsg *newHead = NULL;
 876     if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 877         HttpRequest *newR = new HttpRequest;
 878         newR->canonical = oldR->canonical ?
 879                           xstrdup(oldR->canonical) : NULL; // parse() does not set it
 880         newHead = newR;
 881     } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 882         HttpReply *newRep = new HttpReply;
 883         newHead = newRep;
 884     }
 885     Must(newHead);
 886     newHead->inheritProperties(oldHead);
 887
 888     adapted.setHeader(newHead);
 889
 890     // parse the buffer back
 891     http_status error = HTTP_STATUS_NONE;
 892
 893     Must(newHead->parse(&httpBuf, true, &error));
 894
 895     Must(newHead->hdr_sz == httpBuf.contentSize()); // no leftovers
 896
 897     httpBuf.clean();
 898
 899     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 900            newHead);
 901
 902     // setup adapted body pipe if needed
 903     if (oldHead->body_pipe != NULL) {
 904         debugs(93, 7, HERE << "will echo virgin body from " <<
 905                oldHead->body_pipe);
 906         if (!virginBodySending.active())
 907             virginBodySending.plan(); // will throw if not possible
 908         state.sending = State::sendingVirgin;
 909         checkConsuming();
 910
 911         // TODO: optimize: is it possible to just use the oldHead pipe and
 912         // remove ICAP from the loop? This echoing is probably a common case!
 913         makeAdaptedBodyPipe("echoed virgin response");
 914         if (oldHead->body_pipe->bodySizeKnown())
 915             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 916         debugs(93, 7, HERE << "will echo virgin body to " <<
 917                adapted.body_pipe);
 918     } else {
 919         debugs(93, 7, HERE << "no virgin body to echo");
 920         stopSending(true);
 921     }
 922 }
 923
 924 /// Called when we received use-original-body chunk extension in 206 response.
 925 /// We actually start sending (echoing or not) in startSending().
 926 void Adaptation::Icap::ModXact::prepPartialBodyEchoing(uint64_t pos)
 927 {
 928     Must(virginBodySending.active());
 929     Must(virgin.header->body_pipe != NULL);
 930
 931     setOutcome(xoPartEcho);
 932
 933     debugs(93, 7, HERE << "will echo virgin body suffix from " <<
 934            virgin.header->body_pipe << " offset " << pos );
 935
 936     // check that use-original-body=N does not point beyond buffered data
 937     const uint64_t virginDataEnd = virginConsumed +
 938                                    virgin.body_pipe->buf().contentSize();
 939     Must(pos <= virginDataEnd);
 940     virginBodySending.progress(static_cast<size_t>(pos));
 941
 942     state.sending = State::sendingVirgin;
 943     checkConsuming();
 944
 945     if (virgin.header->body_pipe->bodySizeKnown())
 946         adapted.body_pipe->expectProductionEndAfter(virgin.header->body_pipe->bodySize() - pos);
 947
 948     debugs(93, 7, HERE << "will echo virgin body suffix to " <<
 949            adapted.body_pipe);
 950
 951     // Start echoing data
 952     echoMore();
 953 }
 954
 955 void Adaptation::Icap::ModXact::handleUnknownScode()
 956 {
 957     stopParsing();
 958     stopBackup();
 959     // TODO: mark connection as "bad"
 960
 961     // Terminate the transaction; we do not know how to handle this response.
 962     throw TexcHere("Unsupported ICAP status code");
 963 }
 964
 965 void Adaptation::Icap::ModXact::parseHttpHead()
 966 {
 967     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
 968         replyHttpHeaderSize = 0;
 969         maybeAllocateHttpMsg();
 970
 971         if (!parseHead(adapted.header))
 972             return; // need more header data
 973
 974         if (adapted.header)
 975             replyHttpHeaderSize = adapted.header->hdr_sz;
 976
 977         if (dynamic_cast<HttpRequest*>(adapted.header)) {
 978             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
 979             Must(oldR);
 980             // TODO: the adapted request did not really originate from the
 981             // client; give proxy admin an option to prevent copying of
 982             // sensitive client information here. See the following thread:
 983             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
 984         }
 985
 986         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
 987         if (adapted.header)
 988             adapted.header->inheritProperties(virgin.header);
 989     }
 990
 991     decideOnParsingBody();
 992 }
 993
 994 // parses both HTTP and ICAP headers
 995 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
 996 {
 997     Must(head);
 998     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
 999            "; state: " << state.parsing);
1000
1001     http_status error = HTTP_STATUS_NONE;
1002     const bool parsed = head->parse(&readBuf, commEof, &error);
1003     Must(parsed || !error); // success or need more data
1004
1005     if (!parsed) { // need more data
1006         debugs(93, 5, HERE << "parse failed, need more data, return false");
1007         head->reset();
1008         return false;
1009     }
1010
1011     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
1012         urlCanonical(r); // parse does not set HttpRequest::canonical
1013
1014     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
1015     readBuf.consume(head->hdr_sz);
1016     return true;
1017 }
1018
1019 void Adaptation::Icap::ModXact::decideOnParsingBody()
1020 {
1021     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
1022         debugs(93, 5, HERE << "expecting a body");
1023         state.parsing = State::psBody;
1024         replyHttpBodySize = 0;
1025         bodyParser = new ChunkedCodingParser;
1026         makeAdaptedBodyPipe("adapted response from the ICAP server");
1027         Must(state.sending == State::sendingAdapted);
1028     } else {
1029         debugs(93, 5, HERE << "not expecting a body");
1030         stopParsing();
1031         stopSending(true);
1032     }
1033 }
1034
1035 void Adaptation::Icap::ModXact::parseBody()
1036 {
1037     Must(state.parsing == State::psBody);
1038     Must(bodyParser);
1039
1040     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
1041
1042     // the parser will throw on errors
1043     BodyPipeCheckout bpc(*adapted.body_pipe);
1044     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
1045     bpc.checkIn();
1046
1047     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
1048            "parse; parsed all: " << parsed);
1049     replyHttpBodySize += adapted.body_pipe->buf().contentSize();
1050
1051     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
1052     // TODO: do we really need this if we disable when sending headers?
1053     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
1054         disableRepeats("sent adapted content");
1055         disableBypass("sent adapted content", true);
1056     }
1057
1058     if (parsed) {
1059         if (state.readyForUob && bodyParser->useOriginBody >= 0) {
1060             prepPartialBodyEchoing(
1061                 static_cast<uint64_t>(bodyParser->useOriginBody));
1062             stopParsing();
1063             return;
1064         }
1065
1066         stopParsing();
1067         stopSending(true); // the parser succeeds only if all parsed data fits
1068         return;
1069     }
1070
1071     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1072
1073     if (bodyParser->needsMoreData()) {
1074         debugs(93,3,HERE << this);
1075         Must(mayReadMore());
1076         readMore();
1077     }
1078
1079     if (bodyParser->needsMoreSpace()) {
1080         Must(!doneSending()); // can hope for more space
1081         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1082         // TODO: there should be a timeout in case the sink is broken
1083         // or cannot consume partial content (while we need more space)
1084     }
1085 }
1086
1087 void Adaptation::Icap::ModXact::stopParsing()
1088 {
1089     if (state.parsing == State::psDone)
1090         return;
1091
1092     debugs(93, 7, HERE << "will no longer parse" << status());
1093
1094     delete bodyParser;
1095
1096     bodyParser = NULL;
1097
1098     state.parsing = State::psDone;
1099 }
1100
1101 // HTTP side added virgin body data
1102 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1103 {
1104     writeMore();
1105
1106     if (state.sending == State::sendingVirgin)
1107         echoMore();
1108 }
1109
1110 // HTTP side sent us all virgin info
1111 void Adaptation::Icap::ModXact::noteBodyProductionEnded(BodyPipe::Pointer)
1112 {
1113     Must(virgin.body_pipe->productionEnded());
1114
1115     // push writer and sender in case we were waiting for the last-chunk
1116     writeMore();
1117
1118     if (state.sending == State::sendingVirgin)
1119         echoMore();
1120 }
1121
1122 // body producer aborted, but the initiator may still want to know
1123 // the answer, even though the HTTP message has been truncated
1124 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1125 {
1126     Must(virgin.body_pipe->productionEnded());
1127
1128     // push writer and sender in case we were waiting for the last-chunk
1129     writeMore();
1130
1131     if (state.sending == State::sendingVirgin)
1132         echoMore();
1133 }
1134
1135 // adapted body consumer wants more adapted data and
1136 // possibly freed some buffer space
1137 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1138 {
1139     if (state.sending == State::sendingVirgin)
1140         echoMore();
1141     else if (state.sending == State::sendingAdapted)
1142         parseMore();
1143     else
1144         Must(state.sending == State::sendingUndecided);
1145 }
1146
1147 // adapted body consumer aborted
1148 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1149 {
1150     mustStop("adapted body consumer aborted");
1151 }
1152
1153 // internal cleanup
1154 void Adaptation::Icap::ModXact::swanSong()
1155 {
1156     debugs(93, 5, HERE << "swan sings" << status());
1157
1158     stopWriting(false);
1159     stopSending(false);
1160
1161     // update adaptation history if start was called and we reserved a slot
1162     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1163     if (ah != NULL && adaptHistoryId >= 0)
1164         ah->recordXactFinish(adaptHistoryId);
1165
1166     Adaptation::Icap::Xaction::swanSong();
1167 }
1168
1169 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1170
1171 void Adaptation::Icap::ModXact::finalizeLogInfo()
1172 {
1173     HttpRequest * request_ = NULL;
1174     HttpReply * reply_ = NULL;
1175     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1176         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1177         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1178     }
1179
1180     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1181     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1182     al.icp.opcode = ICP_INVALID;
1183     al.url = h->log_uri.termedBuf();
1184     const Adaptation::Icap::ServiceRep  &s = service();
1185     al.icap.reqMethod = s.cfg().method;
1186
1187     al.cache.caddr = request_->client_addr;
1188
1189     al.request = HTTPMSGLOCK(request_);
1190     if (reply_)
1191         al.reply = HTTPMSGLOCK(reply_);
1192     else
1193         al.reply = NULL;
1194
1195     if (h->rfc931.size())
1196         al.cache.rfc931 = h->rfc931.termedBuf();
1197
1198 #if USE_SSL
1199     if (h->ssluser.size())
1200         al.cache.ssluser = h->ssluser.termedBuf();
1201 #endif
1202     al.cache.code = h->logType;
1203     al.cache.requestSize = h->req_sz;
1204
1205     // leave al.icap.bodyBytesRead negative if no body
1206     if (replyHttpHeaderSize >= 0 || replyHttpBodySize >= 0) {
1207         const int64_t zero = 0; // to make max() argument types the same
1208         al.icap.bodyBytesRead =
1209             max(zero, replyHttpHeaderSize) + max(zero, replyHttpBodySize);
1210     }
1211
1212     if (reply_) {
1213         al.http.code = reply_->sline.status;
1214         al.http.content_type = reply_->content_type.termedBuf();
1215         if (replyHttpBodySize >= 0) {
1216             al.cache.replySize = replyHttpBodySize + reply_->hdr_sz;
1217             al.cache.highOffset = replyHttpBodySize;
1218         }
1219         //don't set al.cache.objectSize because it hasn't exist yet
1220
1221         Packer p;
1222         MemBuf mb;
1223
1224         mb.init();
1225         packerToMemInit(&p, &mb);
1226
1227         reply_->header.packInto(&p);
1228         al.headers.reply = xstrdup(mb.buf);
1229
1230         packerClean(&p);
1231         mb.clean();
1232     }
1233     prepareLogWithRequestDetails(request_, &al);
1234     Xaction::finalizeLogInfo();
1235 }
1236
1237
1238 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1239 {
1240     char ntoabuf[MAX_IPSTRLEN];
1241     /*
1242      * XXX These should use HttpHdr interfaces instead of Printfs
1243      */
1244     const Adaptation::ServiceConfig &s = service().cfg();
1245     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1246     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1247     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1248
1249     if (!TheConfig.reuse_connections)
1250         buf.Printf("Connection: close\r\n");
1251
1252     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1253     // as ICAP headers.
1254     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1255         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1256         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1257     }
1258
1259     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1260         String vh=virgin.header->header.getByName("Proxy-Authorization");
1261         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1262     }
1263
1264     const HttpRequest *request = &virginRequest();
1265
1266     // share the cross-transactional database records if needed
1267     if (Adaptation::Config::masterx_shared_name) {
1268         Adaptation::History::Pointer ah = request->adaptHistory(true);
1269         if (ah != NULL) {
1270             String name, value;
1271             if (ah->getXxRecord(name, value)) {
1272                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1273                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1274             }
1275         }
1276     }
1277
1278
1279     buf.Printf("Encapsulated: ");
1280
1281     MemBuf httpBuf;
1282
1283     httpBuf.init();
1284
1285     // build HTTP request header, if any
1286     ICAP::Method m = s.method;
1287
1288     // to simplify, we could assume that request is always available
1289
1290     String urlPath;
1291     if (request) {
1292         urlPath = request->urlpath;
1293         if (ICAP::methodRespmod == m)
1294             encapsulateHead(buf, "req-hdr", httpBuf, request);
1295         else if (ICAP::methodReqmod == m)
1296             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1297     }
1298
1299     if (ICAP::methodRespmod == m)
1300         if (const HttpMsg *prime = virgin.header)
1301             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1302
1303     if (!virginBody.expected())
1304         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1305     else if (ICAP::methodReqmod == m)
1306         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1307     else
1308         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1309
1310     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1311
1312     if (preview.enabled()) {
1313         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1314         if (!virginBody.expected()) // there is no body to preview
1315             finishNullOrEmptyBodyPreview(httpBuf);
1316     }
1317
1318     makeAllowHeader(buf);
1319
1320     if (TheConfig.send_client_ip && request) {
1321         Ip::Address client_addr;
1322 #if FOLLOW_X_FORWARDED_FOR
1323         if (TheConfig.icap_uses_indirect_client) {
1324             client_addr = request->indirect_client_addr;
1325         } else
1326 #endif
1327             client_addr = request->client_addr;
1328         if (!client_addr.IsAnyAddr() && !client_addr.IsNoAddr())
1329             buf.Printf("X-Client-IP: %s\r\n", client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1330     }
1331
1332     if (TheConfig.send_client_username && request)
1333         makeUsernameHeader(request, buf);
1334
1335     // fprintf(stderr, "%s\n", buf.content());
1336
1337     buf.append(ICAP::crlf, 2); // terminate ICAP header
1338
1339     // fill icapRequest for logging
1340     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1341
1342     // start ICAP request body with encapsulated HTTP headers
1343     buf.append(httpBuf.content(), httpBuf.contentSize());
1344
1345     httpBuf.clean();
1346 }
1347
1348 // decides which Allow values to write and updates the request buffer
1349 void Adaptation::Icap::ModXact::makeAllowHeader(MemBuf &buf)
1350 {
1351     const bool allow204in = preview.enabled(); // TODO: add shouldAllow204in()
1352     const bool allow204out = state.allowedPostview204 = shouldAllow204();
1353     const bool allow206in = state.allowedPreview206 = shouldAllow206in();
1354     const bool allow206out = state.allowedPostview206 = shouldAllow206out();
1355
1356     debugs(93,9, HERE << "Allows: " << allow204in << allow204out <<
1357            allow206in << allow206out);
1358
1359     const bool allow204 = allow204in || allow204out;
1360     const bool allow206 = allow206in || allow206out;
1361
1362     if (!allow204 && !allow206)
1363         return; // nothing to do
1364
1365     if (virginBody.expected()) // if there is a virgin body, plan to send it
1366         virginBodySending.plan();
1367
1368     // writing Preview:...   means we will honor 204 inside preview
1369     // writing Allow/204     means we will honor 204 outside preview
1370     // writing Allow:206     means we will honor 206 inside preview
1371     // writing Allow:204,206 means we will honor 206 outside preview
1372     const char *allowHeader = NULL;
1373     if (allow204out && allow206)
1374         allowHeader = "Allow: 204, 206\r\n";
1375     else if (allow204out)
1376         allowHeader = "Allow: 204\r\n";
1377     else if (allow206)
1378         allowHeader = "Allow: 206\r\n";
1379
1380     if (allowHeader) { // may be nil if only allow204in is true
1381         buf.append(allowHeader, strlen(allowHeader));
1382         debugs(93,5, HERE << "Will write " << allowHeader);
1383     }
1384 }
1385
1386 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1387 {
1388     if (request->auth_user_request != NULL) {
1389         char const *name = request->auth_user_request->username();
1390         if (name) {
1391             const char *value = TheConfig.client_username_encode ? base64_encode(name) : name;
1392             buf.Printf("%s: %s\r\n", TheConfig.client_username_header, value);
1393         }
1394     }
1395 }
1396
1397 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1398 {
1399     // update ICAP header
1400     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1401
1402     // begin cloning
1403     HttpMsg *headClone = NULL;
1404
1405     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1406         HttpRequest* new_request = new HttpRequest;
1407         assert(old_request->canonical);
1408         urlParse(old_request->method, old_request->canonical, new_request);
1409         new_request->http_ver = old_request->http_ver;
1410         headClone = new_request;
1411     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1412         HttpReply* new_reply = new HttpReply;
1413         new_reply->sline = old_reply->sline;
1414         headClone = new_reply;
1415     }
1416
1417     Must(headClone);
1418     headClone->inheritProperties(head);
1419
1420     HttpHeaderPos pos = HttpHeaderInitPos;
1421     HttpHeaderEntry* p_head_entry = NULL;
1422     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1423         headClone->header.addEntry(p_head_entry->clone());
1424
1425     // end cloning
1426
1427     // remove all hop-by-hop headers from the clone
1428     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1429     headClone->header.removeHopByHopEntries();
1430
1431     // pack polished HTTP header
1432     packHead(httpBuf, headClone);
1433
1434     delete headClone;
1435 }
1436
1437 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1438 {
1439     Packer p;
1440     packerToMemInit(&p, &httpBuf);
1441     head->packInto(&p, true);
1442     packerClean(&p);
1443 }
1444
1445 // decides whether to offer a preview and calculates its size
1446 void Adaptation::Icap::ModXact::decideOnPreview()
1447 {
1448     if (!TheConfig.preview_enable) {
1449         debugs(93, 5, HERE << "preview disabled by squid.conf");
1450         return;
1451     }
1452
1453     const String urlPath = virginRequest().urlpath;
1454     size_t wantedSize;
1455     if (!service().wantsPreview(urlPath, wantedSize)) {
1456         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1457         return;
1458     }
1459
1460     // we decided to do preview, now compute its size
1461
1462     Must(wantedSize >= 0);
1463
1464     // cannot preview more than we can backup
1465     size_t ad = min(wantedSize, TheBackupLimit);
1466
1467     if (!virginBody.expected())
1468         ad = 0;
1469     else if (virginBody.knownSize())
1470         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1471
1472     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1473            "(service wanted " << wantedSize << ")");
1474
1475     preview.enable(ad);
1476     Must(preview.enabled());
1477 }
1478
1479 // decides whether to allow 204 responses
1480 bool Adaptation::Icap::ModXact::shouldAllow204()
1481 {
1482     if (!service().allows204())
1483         return false;
1484
1485     return canBackupEverything();
1486 }
1487
1488 // decides whether to allow 206 responses in some mode
1489 bool Adaptation::Icap::ModXact::shouldAllow206any()
1490 {
1491     return TheConfig.allow206_enable && service().allows206() &&
1492            virginBody.expected(); // no need for 206 without a body
1493 }
1494
1495 // decides whether to allow 206 responses in preview mode
1496 bool Adaptation::Icap::ModXact::shouldAllow206in()
1497 {
1498     return shouldAllow206any() && preview.enabled();
1499 }
1500
1501 // decides whether to allow 206 responses outside of preview
1502 bool Adaptation::Icap::ModXact::shouldAllow206out()
1503 {
1504     return shouldAllow206any() && canBackupEverything();
1505 }
1506
1507 // used by shouldAllow204 and decideOnRetries
1508 bool Adaptation::Icap::ModXact::canBackupEverything() const
1509 {
1510     if (!virginBody.expected())
1511         return true; // no body means no problems with backup
1512
1513     // if there is a body, check whether we can backup it all
1514
1515     if (!virginBody.knownSize())
1516         return false;
1517
1518     // or should we have a different backup limit?
1519     // note that '<' allows for 0-termination of the "full" backup buffer
1520     return virginBody.size() < TheBackupLimit;
1521 }
1522
1523 // Decide whether this transaction can be retried if pconn fails
1524 // Must be called after decideOnPreview and before openConnection()
1525 void Adaptation::Icap::ModXact::decideOnRetries()
1526 {
1527     if (!isRetriable)
1528         return; // no, already decided
1529
1530     if (preview.enabled())
1531         return; // yes, because preview provides enough guarantees
1532
1533     if (canBackupEverything())
1534         return; // yes, because we can back everything up
1535
1536     disableRetries(); // no, because we cannot back everything up
1537 }
1538
1539 // Normally, the body-writing code handles preview body. It can deal with
1540 // bodies of unexpected size, including those that turn out to be empty.
1541 // However, that code assumes that the body was expected and body control
1542 // structures were initialized. This is not the case when there is no body
1543 // or the body is known to be empty, because the virgin message will lack a
1544 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1545 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1546 {
1547     Must(!virginBodyWriting.active()); // one reason we handle it here
1548     Must(!virgin.body_pipe);          // another reason we handle it here
1549     Must(!preview.ad());
1550
1551     // do not add last-chunk because our Encapsulated header says null-body
1552     // addLastRequestChunk(buf);
1553     preview.wrote(0, true);
1554
1555     Must(preview.done());
1556     Must(preview.ieof());
1557 }
1558
1559 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1560 {
1561     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1562
1563     if (state.serviceWaiting)
1564         buf.append("U", 1);
1565
1566     if (virgin.body_pipe != NULL)
1567         buf.append("R", 1);
1568
1569     if (connection > 0 && !doneReading())
1570         buf.append("r", 1);
1571
1572     if (!state.doneWriting() && state.writing != State::writingInit)
1573         buf.Printf("w(%d)", state.writing);
1574
1575     if (preview.enabled()) {
1576         if (!preview.done())
1577             buf.Printf("P(%d)", (int) preview.debt());
1578     }
1579
1580     if (virginBodySending.active())
1581         buf.append("B", 1);
1582
1583     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1584         buf.Printf("p(%d)", state.parsing);
1585
1586     if (!doneSending() && state.sending != State::sendingUndecided)
1587         buf.Printf("S(%d)", state.sending);
1588
1589     if (state.readyForUob)
1590         buf.append("6", 1);
1591
1592     if (canStartBypass)
1593         buf.append("Y", 1);
1594
1595     if (protectGroupBypass)
1596         buf.append("G", 1);
1597 }
1598
1599 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1600 {
1601     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1602
1603     if (!virgin.body_pipe)
1604         buf.append("R", 1);
1605
1606     if (state.doneWriting())
1607         buf.append("w", 1);
1608
1609     if (preview.enabled()) {
1610         if (preview.done())
1611             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1612     }
1613
1614     if (doneReading())
1615         buf.append("r", 1);
1616
1617     if (state.doneParsing())
1618         buf.append("p", 1);
1619
1620     if (doneSending())
1621         buf.append("S", 1);
1622 }
1623
1624 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1625 {
1626     return icapReply->header.getByNameListMember("Encapsulated",
1627             section, ',').size() > 0;
1628 }
1629
1630 // calculate whether there is a virgin HTTP body and
1631 // whether its expected size is known
1632 // TODO: rename because we do not just estimate
1633 void Adaptation::Icap::ModXact::estimateVirginBody()
1634 {
1635     // note: lack of size info may disable previews and 204s
1636
1637     HttpMsg *msg = virgin.header;
1638     Must(msg);
1639
1640     HttpRequestMethod method;
1641
1642     if (virgin.cause)
1643         method = virgin.cause->method;
1644     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1645         method = req->method;
1646     else
1647         method = METHOD_NONE;
1648
1649     int64_t size;
1650     // expectingBody returns true for zero-sized bodies, but we will not
1651     // get a pipe for that body, so we treat the message as bodyless
1652     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1653         debugs(93, 6, HERE << "expects virgin body from " <<
1654                virgin.body_pipe << "; size: " << size);
1655
1656         virginBody.expect(size);
1657         virginBodyWriting.plan();
1658
1659         // sign up as a body consumer
1660         Must(msg->body_pipe != NULL);
1661         Must(msg->body_pipe == virgin.body_pipe);
1662         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1663
1664         // make sure TheBackupLimit is in-sync with the buffer size
1665         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1666     } else {
1667         debugs(93, 6, HERE << "does not expect virgin body");
1668         Must(msg->body_pipe == NULL);
1669         checkConsuming();
1670     }
1671 }
1672
1673 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1674 {
1675     Must(!adapted.body_pipe);
1676     Must(!adapted.header->body_pipe);
1677     adapted.header->body_pipe = new BodyPipe(this);
1678     adapted.body_pipe = adapted.header->body_pipe;
1679     debugs(93, 7, HERE << "will supply " << what << " via " <<
1680            adapted.body_pipe << " pipe");
1681 }
1682
1683
1684 // TODO: Move SizedEstimate and Preview elsewhere
1685
1686 Adaptation::Icap::SizedEstimate::SizedEstimate()
1687         : theData(dtUnexpected)
1688 {}
1689
1690 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1691 {
1692     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1693 }
1694
1695 bool Adaptation::Icap::SizedEstimate::expected() const
1696 {
1697     return theData != dtUnexpected;
1698 }
1699
1700 bool Adaptation::Icap::SizedEstimate::knownSize() const
1701 {
1702     Must(expected());
1703     return theData != dtUnknown;
1704 }
1705
1706 uint64_t Adaptation::Icap::SizedEstimate::size() const
1707 {
1708     Must(knownSize());
1709     return static_cast<uint64_t>(theData);
1710 }
1711
1712
1713
1714 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1715 {}
1716
1717 void Adaptation::Icap::VirginBodyAct::plan()
1718 {
1719     Must(!disabled());
1720     Must(!theStart); // not started
1721     theState = stActive;
1722 }
1723
1724 void Adaptation::Icap::VirginBodyAct::disable()
1725 {
1726     theState = stDisabled;
1727 }
1728
1729 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1730 {
1731     Must(active());
1732     Must(size >= 0);
1733     theStart += static_cast<int64_t>(size);
1734 }
1735
1736 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1737 {
1738     Must(active());
1739     return static_cast<uint64_t>(theStart);
1740 }
1741
1742
1743 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1744 {}
1745
1746 void Adaptation::Icap::Preview::enable(size_t anAd)
1747 {
1748     // TODO: check for anAd not exceeding preview size limit
1749     Must(anAd >= 0);
1750     Must(!enabled());
1751     theAd = anAd;
1752     theState = stWriting;
1753 }
1754
1755 bool Adaptation::Icap::Preview::enabled() const
1756 {
1757     return theState != stDisabled;
1758 }
1759
1760 size_t Adaptation::Icap::Preview::ad() const
1761 {
1762     Must(enabled());
1763     return theAd;
1764 }
1765
1766 bool Adaptation::Icap::Preview::done() const
1767 {
1768     Must(enabled());
1769     return theState >= stIeof;
1770 }
1771
1772 bool Adaptation::Icap::Preview::ieof() const
1773 {
1774     Must(enabled());
1775     return theState == stIeof;
1776 }
1777
1778 size_t Adaptation::Icap::Preview::debt() const
1779 {
1780     Must(enabled());
1781     return done() ? 0 : (theAd - theWritten);
1782 }
1783
1784 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1785 {
1786     Must(enabled());
1787
1788     theWritten += size;
1789
1790     Must(theWritten <= theAd);
1791
1792     if (wroteEof)
1793         theState = stIeof; // written size is irrelevant
1794     else if (theWritten >= theAd)
1795         theState = stDone;
1796 }
1797
1798 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1799 {
1800     if (virgin.header == NULL)
1801         return false;
1802
1803     virgin.header->firstLineBuf(mb);
1804
1805     return true;
1806 }
1807
1808
1809 /* Adaptation::Icap::ModXactLauncher */
1810
1811 Adaptation::Icap::ModXactLauncher::ModXactLauncher(Adaptation::Initiator *anInitiator, HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1812         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1813         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", anInitiator, aService)
1814 {
1815     virgin.setHeader(virginHeader);
1816     virgin.setCause(virginCause);
1817     updateHistory(true);
1818 }
1819
1820 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1821 {
1822     Adaptation::Icap::ServiceRep::Pointer s =
1823         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1824     Must(s != NULL);
1825     return new Adaptation::Icap::ModXact(this, virgin.header, virgin.cause, s);
1826 }
1827
1828 void Adaptation::Icap::ModXactLauncher::swanSong()
1829 {
1830     debugs(93, 5, HERE << "swan sings");
1831     updateHistory(false);
1832     Adaptation::Icap::Launcher::swanSong();
1833 }
1834
1835 void Adaptation::Icap::ModXactLauncher::updateHistory(bool doStart)
1836 {
1837     HttpRequest *r = virgin.cause ?
1838                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1839
1840     // r should never be NULL but we play safe; TODO: add Should()
1841     if (r) {
1842         Adaptation::Icap::History::Pointer h = r->icapHistory();
1843         if (h != NULL) {
1844             if (doStart)
1845                 h->start("ICAPModXactLauncher");
1846             else
1847                 h->stop("ICAPModXactLauncher");
1848         }
1849     }
1850 }