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 "comm/Connection.h"
  20 #include "HttpMsg.h"
  21 #include "HttpRequest.h"
  22 #include "HttpReply.h"
  23 #include "SquidTime.h"
  24
  25 // flow and terminology:
  26 //     HTTP| --> receive --> encode --> write --> |network
  27 //     end | <-- send    <-- parse  <-- read  <-- |end
  28
  29 // TODO: replace gotEncapsulated() with something faster; we call it often
  30
  31 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXact);
  32 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXactLauncher);
  33
  34 static const size_t TheBackupLimit = BodyPipe::MaxCapacity;
  35
  36 Adaptation::Icap::ModXact::State::State()
  37 {
  38     memset(this, 0, sizeof(*this));
  39 }
  40
  41 Adaptation::Icap::ModXact::ModXact(HttpMsg *virginHeader,
  42                                    HttpRequest *virginCause, Adaptation::Icap::ServiceRep::Pointer &aService):
  43         AsyncJob("Adaptation::Icap::ModXact"),
  44         Adaptation::Icap::Xaction("Adaptation::Icap::ModXact", aService),
  45         virginConsumed(0),
  46         bodyParser(NULL),
  47         canStartBypass(false), // too early
  48         protectGroupBypass(true),
  49         replyHttpHeaderSize(-1),
  50         replyHttpBodySize(-1),
  51         adaptHistoryId(-1)
  52 {
  53     assert(virginHeader);
  54
  55     virgin.setHeader(virginHeader); // sets virgin.body_pipe if needed
  56     virgin.setCause(virginCause); // may be NULL
  57
  58     // adapted header and body are initialized when we parse them
  59
  60     // writing and reading ends are handled by Adaptation::Icap::Xaction
  61
  62     // encoding
  63     // nothing to do because we are using temporary buffers
  64
  65     // parsing; TODO: do not set until we parse, see ICAPOptXact
  66     icapReply = HTTPMSGLOCK(new HttpReply);
  67     icapReply->protoPrefix = "ICAP/"; // TODO: make an IcapReply class?
  68
  69     debugs(93,7, HERE << "initialized." << status());
  70 }
  71
  72 // initiator wants us to start
  73 void Adaptation::Icap::ModXact::start()
  74 {
  75     Adaptation::Icap::Xaction::start();
  76
  77     // reserve an adaptation history slot (attempts are known at this time)
  78     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
  79     if (ah != NULL)
  80         adaptHistoryId = ah->recordXactStart(service().cfg().key, icap_tr_start, attempts > 1);
  81
  82     estimateVirginBody(); // before virgin disappears!
  83
  84     canStartBypass = service().cfg().bypass;
  85
  86     // it is an ICAP violation to send request to a service w/o known OPTIONS
  87
  88     if (service().up())
  89         startWriting();
  90     else
  91         waitForService();
  92 }
  93
  94 void Adaptation::Icap::ModXact::waitForService()
  95 {
  96     Must(!state.serviceWaiting);
  97     debugs(93, 7, HERE << "will wait for the ICAP service" << status());
  98     state.serviceWaiting = true;
  99     typedef NullaryMemFunT<ModXact> Dialer;
 100     AsyncCall::Pointer call = JobCallback(93,5,
 101                                           Dialer, this, Adaptation::Icap::ModXact::noteServiceReady);
 102     service().callWhenReady(call);
 103 }
 104
 105 void Adaptation::Icap::ModXact::noteServiceReady()
 106 {
 107     Must(state.serviceWaiting);
 108     state.serviceWaiting = false;
 109
 110     if (service().up()) {
 111         startWriting();
 112     } else {
 113         disableRetries();
 114         disableRepeats("ICAP service is unusable");
 115         throw TexcHere("ICAP service is unusable");
 116     }
 117 }
 118
 119 void Adaptation::Icap::ModXact::startWriting()
 120 {
 121     state.writing = State::writingConnect;
 122
 123     decideOnPreview(); // must be decided before we decideOnRetries
 124     decideOnRetries();
 125
 126     openConnection();
 127 }
 128
 129 // connection with the ICAP service established
 130 void Adaptation::Icap::ModXact::handleCommConnected()
 131 {
 132     Must(state.writing == State::writingConnect);
 133
 134     startReading(); // wait for early errors from the ICAP server
 135
 136     MemBuf requestBuf;
 137     requestBuf.init();
 138
 139     makeRequestHeaders(requestBuf);
 140     debugs(93, 9, HERE << "will write" << status() << ":\n" <<
 141            (requestBuf.terminate(), requestBuf.content()));
 142
 143     // write headers
 144     state.writing = State::writingHeaders;
 145     icap_tio_start = current_time;
 146     scheduleWrite(requestBuf);
 147 }
 148
 149 void Adaptation::Icap::ModXact::handleCommWrote(size_t sz)
 150 {
 151     debugs(93, 5, HERE << "Wrote " << sz << " bytes");
 152
 153     if (state.writing == State::writingHeaders)
 154         handleCommWroteHeaders();
 155     else
 156         handleCommWroteBody();
 157 }
 158
 159 void Adaptation::Icap::ModXact::handleCommWroteHeaders()
 160 {
 161     Must(state.writing == State::writingHeaders);
 162
 163     // determine next step
 164     if (preview.enabled())
 165         state.writing = preview.done() ? State::writingPaused : State::writingPreview;
 166     else if (virginBody.expected())
 167         state.writing = State::writingPrime;
 168     else {
 169         stopWriting(true);
 170         return;
 171     }
 172
 173     writeMore();
 174 }
 175
 176 void Adaptation::Icap::ModXact::writeMore()
 177 {
 178     debugs(93, 5, HERE << "checking whether to write more" << status());
 179
 180     if (writer != NULL) // already writing something
 181         return;
 182
 183     switch (state.writing) {
 184
 185     case State::writingInit:    // waiting for service OPTIONS
 186         Must(state.serviceWaiting);
 187
 188     case State::writingConnect: // waiting for the connection to establish
 189
 190     case State::writingHeaders: // waiting for the headers to be written
 191
 192     case State::writingPaused:  // waiting for the ICAP server response
 193
 194     case State::writingReallyDone: // nothing more to write
 195         return;
 196
 197     case State::writingAlmostDone: // was waiting for the last write
 198         stopWriting(false);
 199         return;
 200
 201     case State::writingPreview:
 202         writePreviewBody();
 203         return;
 204
 205     case State::writingPrime:
 206         writePrimeBody();
 207         return;
 208
 209     default:
 210         throw TexcHere("Adaptation::Icap::ModXact in bad writing state");
 211     }
 212 }
 213
 214 void Adaptation::Icap::ModXact::writePreviewBody()
 215 {
 216     debugs(93, 8, HERE << "will write Preview body from " <<
 217            virgin.body_pipe << status());
 218     Must(state.writing == State::writingPreview);
 219     Must(virgin.body_pipe != NULL);
 220
 221     const size_t sizeMax = (size_t)virgin.body_pipe->buf().contentSize();
 222     const size_t size = min(preview.debt(), sizeMax);
 223     writeSomeBody("preview body", size);
 224
 225     // change state once preview is written
 226
 227     if (preview.done()) {
 228         debugs(93, 7, HERE << "wrote entire Preview body" << status());
 229
 230         if (preview.ieof())
 231             stopWriting(true);
 232         else
 233             state.writing = State::writingPaused;
 234     }
 235 }
 236
 237 void Adaptation::Icap::ModXact::writePrimeBody()
 238 {
 239     Must(state.writing == State::writingPrime);
 240     Must(virginBodyWriting.active());
 241
 242     const size_t size = (size_t)virgin.body_pipe->buf().contentSize();
 243     writeSomeBody("prime virgin body", size);
 244
 245     if (virginBodyEndReached(virginBodyWriting)) {
 246         debugs(93, 5, HERE << "wrote entire body");
 247         stopWriting(true);
 248     }
 249 }
 250
 251 void Adaptation::Icap::ModXact::writeSomeBody(const char *label, size_t size)
 252 {
 253     Must(!writer && state.writing < state.writingAlmostDone);
 254     Must(virgin.body_pipe != NULL);
 255     debugs(93, 8, HERE << "will write up to " << size << " bytes of " <<
 256            label);
 257
 258     MemBuf writeBuf; // TODO: suggest a min size based on size and lastChunk
 259
 260     writeBuf.init(); // note: we assume that last-chunk will fit
 261
 262     const size_t writableSize = virginContentSize(virginBodyWriting);
 263     const size_t chunkSize = min(writableSize, size);
 264
 265     if (chunkSize) {
 266         debugs(93, 7, HERE << "will write " << chunkSize <<
 267                "-byte chunk of " << label);
 268
 269         openChunk(writeBuf, chunkSize, false);
 270         writeBuf.append(virginContentData(virginBodyWriting), chunkSize);
 271         closeChunk(writeBuf);
 272
 273         virginBodyWriting.progress(chunkSize);
 274         virginConsume();
 275     } else {
 276         debugs(93, 7, HERE << "has no writable " << label << " content");
 277     }
 278
 279     const bool wroteEof = virginBodyEndReached(virginBodyWriting);
 280     bool lastChunk = wroteEof;
 281     if (state.writing == State::writingPreview) {
 282         preview.wrote(chunkSize, wroteEof); // even if wrote nothing
 283         lastChunk = lastChunk || preview.done();
 284     }
 285
 286     if (lastChunk) {
 287         debugs(93, 8, HERE << "will write last-chunk of " << label);
 288         addLastRequestChunk(writeBuf);
 289     }
 290
 291     debugs(93, 7, HERE << "will write " << writeBuf.contentSize()
 292            << " raw bytes of " << label);
 293
 294     if (writeBuf.hasContent()) {
 295         scheduleWrite(writeBuf); // comm will free the chunk
 296     } else {
 297         writeBuf.clean();
 298     }
 299 }
 300
 301 void Adaptation::Icap::ModXact::addLastRequestChunk(MemBuf &buf)
 302 {
 303     const bool ieof = state.writing == State::writingPreview && preview.ieof();
 304     openChunk(buf, 0, ieof);
 305     closeChunk(buf);
 306 }
 307
 308 void Adaptation::Icap::ModXact::openChunk(MemBuf &buf, size_t chunkSize, bool ieof)
 309 {
 310     buf.Printf((ieof ? "%x; ieof\r\n" : "%x\r\n"), (int) chunkSize);
 311 }
 312
 313 void Adaptation::Icap::ModXact::closeChunk(MemBuf &buf)
 314 {
 315     buf.append(ICAP::crlf, 2); // chunk-terminating CRLF
 316 }
 317
 318 const HttpRequest &Adaptation::Icap::ModXact::virginRequest() const
 319 {
 320     const HttpRequest *request = virgin.cause ?
 321                                  virgin.cause : dynamic_cast<const HttpRequest*>(virgin.header);
 322     Must(request);
 323     return *request;
 324 }
 325
 326 // did the activity reached the end of the virgin body?
 327 bool Adaptation::Icap::ModXact::virginBodyEndReached(const Adaptation::Icap::VirginBodyAct &act) const
 328 {
 329     return
 330         !act.active() || // did all (assuming it was originally planned)
 331         !virgin.body_pipe->expectMoreAfter(act.offset()); // wont have more
 332 }
 333
 334 // the size of buffered virgin body data available for the specified activity
 335 // if this size is zero, we may be done or may be waiting for more data
 336 size_t Adaptation::Icap::ModXact::virginContentSize(const Adaptation::Icap::VirginBodyAct &act) const
 337 {
 338     Must(act.active());
 339     // asbolute start of unprocessed data
 340     const uint64_t dataStart = act.offset();
 341     // absolute end of buffered data
 342     const uint64_t dataEnd = virginConsumed + virgin.body_pipe->buf().contentSize();
 343     Must(virginConsumed <= dataStart && dataStart <= dataEnd);
 344     return static_cast<size_t>(dataEnd - dataStart);
 345 }
 346
 347 // pointer to buffered virgin body data available for the specified activity
 348 const char *Adaptation::Icap::ModXact::virginContentData(const Adaptation::Icap::VirginBodyAct &act) const
 349 {
 350     Must(act.active());
 351     const uint64_t dataStart = act.offset();
 352     Must(virginConsumed <= dataStart);
 353     return virgin.body_pipe->buf().content() + static_cast<size_t>(dataStart-virginConsumed);
 354 }
 355
 356 void Adaptation::Icap::ModXact::virginConsume()
 357 {
 358     debugs(93, 9, HERE << "consumption guards: " << !virgin.body_pipe << isRetriable <<
 359            isRepeatable << canStartBypass << protectGroupBypass);
 360
 361     if (!virgin.body_pipe)
 362         return; // nothing to consume
 363
 364     if (isRetriable)
 365         return; // do not consume if we may have to retry later
 366
 367     BodyPipe &bp = *virgin.body_pipe;
 368     const bool wantToPostpone = isRepeatable || canStartBypass || protectGroupBypass;
 369
 370     // Why > 2? HttpState does not use the last bytes in the buffer
 371     // because delayAwareRead() is arguably broken. See
 372     // HttpStateData::maybeReadVirginBody for more details.
 373     if (wantToPostpone && bp.buf().spaceSize() > 2) {
 374         // Postponing may increase memory footprint and slow the HTTP side
 375         // down. Not postponing may increase the number of ICAP errors
 376         // if the ICAP service fails. We may also use "potential" space to
 377         // postpone more aggressively. Should the trade-off be configurable?
 378         debugs(93, 8, HERE << "postponing consumption from " << bp.status());
 379         return;
 380     }
 381
 382     const size_t have = static_cast<size_t>(bp.buf().contentSize());
 383     const uint64_t end = virginConsumed + have;
 384     uint64_t offset = end;
 385
 386     debugs(93, 9, HERE << "max virgin consumption offset=" << offset <<
 387            " acts " << virginBodyWriting.active() << virginBodySending.active() <<
 388            " consumed=" << virginConsumed <<
 389            " from " << virgin.body_pipe->status());
 390
 391     if (virginBodyWriting.active())
 392         offset = min(virginBodyWriting.offset(), offset);
 393
 394     if (virginBodySending.active())
 395         offset = min(virginBodySending.offset(), offset);
 396
 397     Must(virginConsumed <= offset && offset <= end);
 398
 399     if (const size_t size = static_cast<size_t>(offset - virginConsumed)) {
 400         debugs(93, 8, HERE << "consuming " << size << " out of " << have <<
 401                " virgin body bytes");
 402         bp.consume(size);
 403         virginConsumed += size;
 404         Must(!isRetriable); // or we should not be consuming
 405         disableRepeats("consumed content");
 406         disableBypass("consumed content", true);
 407     }
 408 }
 409
 410 void Adaptation::Icap::ModXact::handleCommWroteBody()
 411 {
 412     writeMore();
 413 }
 414
 415 // Called when we do not expect to call comm_write anymore.
 416 // We may have a pending write though.
 417 // If stopping nicely, we will just wait for that pending write, if any.
 418 void Adaptation::Icap::ModXact::stopWriting(bool nicely)
 419 {
 420     if (state.writing == State::writingReallyDone)
 421         return;
 422
 423     if (writer != NULL) {
 424         if (nicely) {
 425             debugs(93, 7, HERE << "will wait for the last write" << status());
 426             state.writing = State::writingAlmostDone; // may already be set
 427             checkConsuming();
 428             return;
 429         }
 430         debugs(93, 3, HERE << "will NOT wait for the last write" << status());
 431
 432         // Comm does not have an interface to clear the writer callback nicely,
 433         // but without clearing the writer we cannot recycle the connection.
 434         // We prevent connection reuse and hope that we can handle a callback
 435         // call at any time, usually in the middle of the destruction sequence!
 436         // Somebody should add comm_remove_write_handler() to comm API.
 437         reuseConnection = false;
 438         ignoreLastWrite = true;
 439     }
 440
 441     debugs(93, 7, HERE << "will no longer write" << status());
 442     if (virginBodyWriting.active()) {
 443         virginBodyWriting.disable();
 444         virginConsume();
 445     }
 446     state.writing = State::writingReallyDone;
 447     checkConsuming();
 448 }
 449
 450 void Adaptation::Icap::ModXact::stopBackup()
 451 {
 452     if (!virginBodySending.active())
 453         return;
 454
 455     debugs(93, 7, HERE << "will no longer backup" << status());
 456     virginBodySending.disable();
 457     virginConsume();
 458 }
 459
 460 bool Adaptation::Icap::ModXact::doneAll() const
 461 {
 462     return Adaptation::Icap::Xaction::doneAll() && !state.serviceWaiting &&
 463            doneSending() &&
 464            doneReading() && state.doneWriting();
 465 }
 466
 467 void Adaptation::Icap::ModXact::startReading()
 468 {
 469     Must(haveConnection());
 470     Must(!reader);
 471     Must(!adapted.header);
 472     Must(!adapted.body_pipe);
 473
 474     // we use the same buffer for headers and body and then consume headers
 475     readMore();
 476 }
 477
 478 void Adaptation::Icap::ModXact::readMore()
 479 {
 480     if (reader != NULL || doneReading()) {
 481         debugs(93,3,HERE << "returning from readMore because reader or doneReading()");
 482         return;
 483     }
 484
 485     // do not fill readBuf if we have no space to store the result
 486     if (adapted.body_pipe != NULL &&
 487             !adapted.body_pipe->buf().hasPotentialSpace()) {
 488         debugs(93,3,HERE << "not reading because ICAP reply pipe is full");
 489         return;
 490     }
 491
 492     if (readBuf.hasSpace())
 493         scheduleRead();
 494     else
 495         debugs(93,3,HERE << "nothing to do because !readBuf.hasSpace()");
 496 }
 497
 498 // comm module read a portion of the ICAP response for us
 499 void Adaptation::Icap::ModXact::handleCommRead(size_t)
 500 {
 501     Must(!state.doneParsing());
 502     icap_tio_finish = current_time;
 503     parseMore();
 504     readMore();
 505 }
 506
 507 void Adaptation::Icap::ModXact::echoMore()
 508 {
 509     Must(state.sending == State::sendingVirgin);
 510     Must(adapted.body_pipe != NULL);
 511     Must(virginBodySending.active());
 512
 513     const size_t sizeMax = virginContentSize(virginBodySending);
 514     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes from " <<
 515            virgin.body_pipe->status());
 516     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes to   " <<
 517            adapted.body_pipe->status());
 518
 519     if (sizeMax > 0) {
 520         const size_t size = adapted.body_pipe->putMoreData(virginContentData(virginBodySending), sizeMax);
 521         debugs(93,5, HERE << "echoed " << size << " out of " << sizeMax <<
 522                " bytes");
 523         virginBodySending.progress(size);
 524         disableRepeats("echoed content");
 525         disableBypass("echoed content", true);
 526         virginConsume();
 527     }
 528
 529     if (virginBodyEndReached(virginBodySending)) {
 530         debugs(93, 5, HERE << "echoed all" << status());
 531         stopSending(true);
 532     } else {
 533         debugs(93, 5, HERE << "has " <<
 534                virgin.body_pipe->buf().contentSize() << " bytes " <<
 535                "and expects more to echo" << status());
 536         // TODO: timeout if virgin or adapted pipes are broken
 537     }
 538 }
 539
 540 bool Adaptation::Icap::ModXact::doneSending() const
 541 {
 542     return state.sending == State::sendingDone;
 543 }
 544
 545 // stop (or do not start) sending adapted message body
 546 void Adaptation::Icap::ModXact::stopSending(bool nicely)
 547 {
 548     debugs(93, 7, HERE << "Enter stop sending ");
 549     if (doneSending())
 550         return;
 551     debugs(93, 7, HERE << "Proceed with stop sending ");
 552
 553     if (state.sending != State::sendingUndecided) {
 554         debugs(93, 7, HERE << "will no longer send" << status());
 555         if (adapted.body_pipe != NULL) {
 556             virginBodySending.disable();
 557             // we may leave debts if we were echoing and the virgin
 558             // body_pipe got exhausted before we echoed all planned bytes
 559             const bool leftDebts = adapted.body_pipe->needsMoreData();
 560             stopProducingFor(adapted.body_pipe, nicely && !leftDebts);
 561         }
 562     } else {
 563         debugs(93, 7, HERE << "will not start sending" << status());
 564         Must(!adapted.body_pipe);
 565     }
 566
 567     state.sending = State::sendingDone;
 568     checkConsuming();
 569 }
 570
 571 // should be called after certain state.writing or state.sending changes
 572 void Adaptation::Icap::ModXact::checkConsuming()
 573 {
 574     // quit if we already stopped or are still using the pipe
 575     if (!virgin.body_pipe || !state.doneConsumingVirgin())
 576         return;
 577
 578     debugs(93, 7, HERE << "will stop consuming" << status());
 579     stopConsumingFrom(virgin.body_pipe);
 580 }
 581
 582 void Adaptation::Icap::ModXact::parseMore()
 583 {
 584     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " bytes to parse" <<
 585            status());
 586     debugs(93, 5, HERE << "\n" << readBuf.content());
 587
 588     if (state.parsingHeaders())
 589         parseHeaders();
 590
 591     if (state.parsing == State::psBody)
 592         parseBody();
 593 }
 594
 595 void Adaptation::Icap::ModXact::callException(const std::exception &e)
 596 {
 597     if (!canStartBypass || isRetriable) {
 598         Adaptation::Icap::Xaction::callException(e);
 599         return;
 600     }
 601
 602     try {
 603         debugs(93, 3, HERE << "bypassing " << inCall << " exception: " <<
 604                e.what() << ' ' << status());
 605         bypassFailure();
 606     } catch (const std::exception &bypassE) {
 607         Adaptation::Icap::Xaction::callException(bypassE);
 608     }
 609 }
 610
 611 void Adaptation::Icap::ModXact::bypassFailure()
 612 {
 613     disableBypass("already started to bypass", false);
 614
 615     Must(!isRetriable); // or we should not be bypassing
 616     // TODO: should the same be enforced for isRepeatable? Check icap_repeat??
 617
 618     prepEchoing();
 619
 620     startSending();
 621
 622     // end all activities associated with the ICAP server
 623
 624     stopParsing();
 625
 626     stopWriting(true); // or should we force it?
 627     if (haveConnection()) {
 628         reuseConnection = false; // be conservative
 629         cancelRead(); // may not work; and we cannot stop connecting either
 630         if (!doneWithIo())
 631             debugs(93, 7, HERE << "Warning: bypass failed to stop I/O" << status());
 632     }
 633 }
 634
 635 void Adaptation::Icap::ModXact::disableBypass(const char *reason, bool includingGroupBypass)
 636 {
 637     if (canStartBypass) {
 638         debugs(93,7, HERE << "will never start bypass because " << reason);
 639         canStartBypass = false;
 640     }
 641     if (protectGroupBypass && includingGroupBypass) {
 642         debugs(93,7, HERE << "not protecting group bypass because " << reason);
 643         protectGroupBypass = false;
 644     }
 645 }
 646
 647
 648
 649 // note that allocation for echoing is done in handle204NoContent()
 650 void Adaptation::Icap::ModXact::maybeAllocateHttpMsg()
 651 {
 652     if (adapted.header) // already allocated
 653         return;
 654
 655     if (gotEncapsulated("res-hdr")) {
 656         adapted.setHeader(new HttpReply);
 657         setOutcome(service().cfg().method == ICAP::methodReqmod ?
 658                    xoSatisfied : xoModified);
 659     } else if (gotEncapsulated("req-hdr")) {
 660         adapted.setHeader(new HttpRequest);
 661         setOutcome(xoModified);
 662     } else
 663         throw TexcHere("Neither res-hdr nor req-hdr in maybeAllocateHttpMsg()");
 664 }
 665
 666 void Adaptation::Icap::ModXact::parseHeaders()
 667 {
 668     Must(state.parsingHeaders());
 669
 670     if (state.parsing == State::psIcapHeader) {
 671         debugs(93, 5, HERE << "parse ICAP headers");
 672         parseIcapHead();
 673     }
 674
 675     if (state.parsing == State::psHttpHeader) {
 676         debugs(93, 5, HERE << "parse HTTP headers");
 677         parseHttpHead();
 678     }
 679
 680     if (state.parsingHeaders()) { // need more data
 681         Must(mayReadMore());
 682         return;
 683     }
 684
 685     startSending();
 686 }
 687
 688 // called after parsing all headers or when bypassing an exception
 689 void Adaptation::Icap::ModXact::startSending()
 690 {
 691     disableRepeats("sent headers");
 692     disableBypass("sent headers", true);
 693     sendAnswer(adapted.header);
 694
 695     if (state.sending == State::sendingVirgin)
 696         echoMore();
 697 }
 698
 699 void Adaptation::Icap::ModXact::parseIcapHead()
 700 {
 701     Must(state.sending == State::sendingUndecided);
 702
 703     if (!parseHead(icapReply))
 704         return;
 705
 706     if (httpHeaderHasConnDir(&icapReply->header, "close")) {
 707         debugs(93, 5, HERE << "found connection close");
 708         reuseConnection = false;
 709     }
 710
 711     switch (icapReply->sline.status) {
 712
 713     case 100:
 714         handle100Continue();
 715         break;
 716
 717     case 200:
 718     case 201: // Symantec Scan Engine 5.0 and later when modifying HTTP msg
 719
 720         if (!validate200Ok()) {
 721             throw TexcHere("Invalid ICAP Response");
 722         } else {
 723             handle200Ok();
 724         }
 725
 726         break;
 727
 728     case 204:
 729         handle204NoContent();
 730         break;
 731
 732     case 206:
 733         handle206PartialContent();
 734         break;
 735
 736     default:
 737         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 738         handleUnknownScode();
 739         break;
 740     }
 741
 742     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 743     if (!request)
 744         request = &virginRequest();
 745
 746     // update the cross-transactional database if needed (all status codes!)
 747     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 748         Adaptation::History::Pointer ah = request->adaptHistory(true);
 749         if (ah != NULL) {
 750             const String val = icapReply->header.getByName(xxName);
 751             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 752                 ah->updateXxRecord(xxName, val);
 753         }
 754     }
 755
 756     // update the adaptation plan if needed (all status codes!)
 757     if (service().cfg().routing) {
 758         String services;
 759         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 760             Adaptation::History::Pointer ah = request->adaptHistory(true);
 761             if (ah != NULL)
 762                 ah->updateNextServices(services);
 763         }
 764     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 765
 766     // We need to store received ICAP headers for <icapLastHeader logformat option.
 767     // If we already have stored headers from previous ICAP transaction related to this
 768     // request, old headers will be replaced with the new one.
 769
 770     Adaptation::Icap::History::Pointer h = request->icapHistory();
 771     if (h != NULL) {
 772         h->mergeIcapHeaders(&icapReply->header);
 773         h->setIcapLastHeader(&icapReply->header);
 774     }
 775
 776     // handle100Continue() manages state.writing on its own.
 777     // Non-100 status means the server needs no postPreview data from us.
 778     if (state.writing == State::writingPaused)
 779         stopWriting(true);
 780 }
 781
 782 bool Adaptation::Icap::ModXact::validate200Ok()
 783 {
 784     if (ICAP::methodRespmod == service().cfg().method) {
 785         if (!gotEncapsulated("res-hdr"))
 786             return false;
 787
 788         return true;
 789     }
 790
 791     if (ICAP::methodReqmod == service().cfg().method) {
 792         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 793             return false;
 794
 795         return true;
 796     }
 797
 798     return false;
 799 }
 800
 801 void Adaptation::Icap::ModXact::handle100Continue()
 802 {
 803     Must(state.writing == State::writingPaused);
 804     // server must not respond before the end of preview: we may send ieof
 805     Must(preview.enabled() && preview.done() && !preview.ieof());
 806
 807     // 100 "Continue" cancels our Preview commitment,
 808     // but not commitment to handle 204 or 206 outside Preview
 809     if (!state.allowedPostview204 && !state.allowedPostview206)
 810         stopBackup();
 811
 812     state.parsing = State::psIcapHeader; // eventually
 813     icapReply->reset();
 814
 815     state.writing = State::writingPrime;
 816
 817     writeMore();
 818 }
 819
 820 void Adaptation::Icap::ModXact::handle200Ok()
 821 {
 822     state.parsing = State::psHttpHeader;
 823     state.sending = State::sendingAdapted;
 824     stopBackup();
 825     checkConsuming();
 826 }
 827
 828 void Adaptation::Icap::ModXact::handle204NoContent()
 829 {
 830     stopParsing();
 831     prepEchoing();
 832 }
 833
 834 void Adaptation::Icap::ModXact::handle206PartialContent()
 835 {
 836     if (state.writing == State::writingPaused) {
 837         Must(preview.enabled());
 838         Must(state.allowedPreview206);
 839         debugs(93, 7, HERE << "206 inside preview");
 840     } else {
 841         Must(state.writing > State::writingPaused);
 842         Must(state.allowedPostview206);
 843         debugs(93, 7, HERE << "206 outside preview");
 844     }
 845     state.parsing = State::psHttpHeader;
 846     state.sending = State::sendingAdapted;
 847     state.readyForUob = true;
 848     checkConsuming();
 849 }
 850
 851 // Called when we receive a 204 No Content response and
 852 // when we are trying to bypass a service failure.
 853 // We actually start sending (echoig or not) in startSending.
 854 void Adaptation::Icap::ModXact::prepEchoing()
 855 {
 856     disableRepeats("preparing to echo content");
 857     disableBypass("preparing to echo content", true);
 858     setOutcome(xoEcho);
 859
 860     // We want to clone the HTTP message, but we do not want
 861     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 862     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 863     // Instead, we simply write the HTTP message and "clone" it by parsing.
 864     // TODO: use HttpMsg::clone()!
 865
 866     HttpMsg *oldHead = virgin.header;
 867     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 868
 869     MemBuf httpBuf;
 870
 871     // write the virgin message into a memory buffer
 872     httpBuf.init();
 873     packHead(httpBuf, oldHead);
 874
 875     // allocate the adapted message and copy metainfo
 876     Must(!adapted.header);
 877     HttpMsg *newHead = NULL;
 878     if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 879         HttpRequest *newR = new HttpRequest;
 880         newR->canonical = oldR->canonical ?
 881                           xstrdup(oldR->canonical) : NULL; // parse() does not set it
 882         newHead = newR;
 883     } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 884         HttpReply *newRep = new HttpReply;
 885         newHead = newRep;
 886     }
 887     Must(newHead);
 888     newHead->inheritProperties(oldHead);
 889
 890     adapted.setHeader(newHead);
 891
 892     // parse the buffer back
 893     http_status error = HTTP_STATUS_NONE;
 894
 895     Must(newHead->parse(&httpBuf, true, &error));
 896
 897     Must(newHead->hdr_sz == httpBuf.contentSize()); // no leftovers
 898
 899     httpBuf.clean();
 900
 901     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 902            newHead);
 903
 904     // setup adapted body pipe if needed
 905     if (oldHead->body_pipe != NULL) {
 906         debugs(93, 7, HERE << "will echo virgin body from " <<
 907                oldHead->body_pipe);
 908         if (!virginBodySending.active())
 909             virginBodySending.plan(); // will throw if not possible
 910         state.sending = State::sendingVirgin;
 911         checkConsuming();
 912
 913         // TODO: optimize: is it possible to just use the oldHead pipe and
 914         // remove ICAP from the loop? This echoing is probably a common case!
 915         makeAdaptedBodyPipe("echoed virgin response");
 916         if (oldHead->body_pipe->bodySizeKnown())
 917             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 918         debugs(93, 7, HERE << "will echo virgin body to " <<
 919                adapted.body_pipe);
 920     } else {
 921         debugs(93, 7, HERE << "no virgin body to echo");
 922         stopSending(true);
 923     }
 924 }
 925
 926 /// Called when we received use-original-body chunk extension in 206 response.
 927 /// We actually start sending (echoing or not) in startSending().
 928 void Adaptation::Icap::ModXact::prepPartialBodyEchoing(uint64_t pos)
 929 {
 930     Must(virginBodySending.active());
 931     Must(virgin.header->body_pipe != NULL);
 932
 933     setOutcome(xoPartEcho);
 934
 935     debugs(93, 7, HERE << "will echo virgin body suffix from " <<
 936            virgin.header->body_pipe << " offset " << pos );
 937
 938     // check that use-original-body=N does not point beyond buffered data
 939     const uint64_t virginDataEnd = virginConsumed +
 940                                    virgin.body_pipe->buf().contentSize();
 941     Must(pos <= virginDataEnd);
 942     virginBodySending.progress(static_cast<size_t>(pos));
 943
 944     state.sending = State::sendingVirgin;
 945     checkConsuming();
 946
 947     if (virgin.header->body_pipe->bodySizeKnown())
 948         adapted.body_pipe->expectProductionEndAfter(virgin.header->body_pipe->bodySize() - pos);
 949
 950     debugs(93, 7, HERE << "will echo virgin body suffix to " <<
 951            adapted.body_pipe);
 952
 953     // Start echoing data
 954     echoMore();
 955 }
 956
 957 void Adaptation::Icap::ModXact::handleUnknownScode()
 958 {
 959     stopParsing();
 960     stopBackup();
 961     // TODO: mark connection as "bad"
 962
 963     // Terminate the transaction; we do not know how to handle this response.
 964     throw TexcHere("Unsupported ICAP status code");
 965 }
 966
 967 void Adaptation::Icap::ModXact::parseHttpHead()
 968 {
 969     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
 970         replyHttpHeaderSize = 0;
 971         maybeAllocateHttpMsg();
 972
 973         if (!parseHead(adapted.header))
 974             return; // need more header data
 975
 976         if (adapted.header)
 977             replyHttpHeaderSize = adapted.header->hdr_sz;
 978
 979         if (dynamic_cast<HttpRequest*>(adapted.header)) {
 980             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
 981             Must(oldR);
 982             // TODO: the adapted request did not really originate from the
 983             // client; give proxy admin an option to prevent copying of
 984             // sensitive client information here. See the following thread:
 985             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
 986         }
 987
 988         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
 989         if (adapted.header)
 990             adapted.header->inheritProperties(virgin.header);
 991     }
 992
 993     decideOnParsingBody();
 994 }
 995
 996 // parses both HTTP and ICAP headers
 997 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
 998 {
 999     Must(head);
1000     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
1001            "; state: " << state.parsing);
1002
1003     http_status error = HTTP_STATUS_NONE;
1004     const bool parsed = head->parse(&readBuf, commEof, &error);
1005     Must(parsed || !error); // success or need more data
1006
1007     if (!parsed) { // need more data
1008         debugs(93, 5, HERE << "parse failed, need more data, return false");
1009         head->reset();
1010         return false;
1011     }
1012
1013     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
1014         urlCanonical(r); // parse does not set HttpRequest::canonical
1015
1016     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
1017     readBuf.consume(head->hdr_sz);
1018     return true;
1019 }
1020
1021 void Adaptation::Icap::ModXact::decideOnParsingBody()
1022 {
1023     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
1024         debugs(93, 5, HERE << "expecting a body");
1025         state.parsing = State::psBody;
1026         replyHttpBodySize = 0;
1027         bodyParser = new ChunkedCodingParser;
1028         makeAdaptedBodyPipe("adapted response from the ICAP server");
1029         Must(state.sending == State::sendingAdapted);
1030     } else {
1031         debugs(93, 5, HERE << "not expecting a body");
1032         stopParsing();
1033         stopSending(true);
1034     }
1035 }
1036
1037 void Adaptation::Icap::ModXact::parseBody()
1038 {
1039     Must(state.parsing == State::psBody);
1040     Must(bodyParser);
1041
1042     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
1043
1044     // the parser will throw on errors
1045     BodyPipeCheckout bpc(*adapted.body_pipe);
1046     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
1047     bpc.checkIn();
1048
1049     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
1050            "parse; parsed all: " << parsed);
1051     replyHttpBodySize += adapted.body_pipe->buf().contentSize();
1052
1053     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
1054     // TODO: do we really need this if we disable when sending headers?
1055     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
1056         disableRepeats("sent adapted content");
1057         disableBypass("sent adapted content", true);
1058     }
1059
1060     if (parsed) {
1061         if (state.readyForUob && bodyParser->useOriginBody >= 0) {
1062             prepPartialBodyEchoing(
1063                 static_cast<uint64_t>(bodyParser->useOriginBody));
1064             stopParsing();
1065             return;
1066         }
1067
1068         stopParsing();
1069         stopSending(true); // the parser succeeds only if all parsed data fits
1070         return;
1071     }
1072
1073     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1074
1075     if (bodyParser->needsMoreData()) {
1076         debugs(93,3,HERE << this);
1077         Must(mayReadMore());
1078         readMore();
1079     }
1080
1081     if (bodyParser->needsMoreSpace()) {
1082         Must(!doneSending()); // can hope for more space
1083         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1084         // TODO: there should be a timeout in case the sink is broken
1085         // or cannot consume partial content (while we need more space)
1086     }
1087 }
1088
1089 void Adaptation::Icap::ModXact::stopParsing()
1090 {
1091     if (state.parsing == State::psDone)
1092         return;
1093
1094     debugs(93, 7, HERE << "will no longer parse" << status());
1095
1096     delete bodyParser;
1097
1098     bodyParser = NULL;
1099
1100     state.parsing = State::psDone;
1101 }
1102
1103 // HTTP side added virgin body data
1104 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1105 {
1106     writeMore();
1107
1108     if (state.sending == State::sendingVirgin)
1109         echoMore();
1110 }
1111
1112 // HTTP side sent us all virgin info
1113 void Adaptation::Icap::ModXact::noteBodyProductionEnded(BodyPipe::Pointer)
1114 {
1115     Must(virgin.body_pipe->productionEnded());
1116
1117     // push writer and sender in case we were waiting for the last-chunk
1118     writeMore();
1119
1120     if (state.sending == State::sendingVirgin)
1121         echoMore();
1122 }
1123
1124 // body producer aborted, but the initiator may still want to know
1125 // the answer, even though the HTTP message has been truncated
1126 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1127 {
1128     Must(virgin.body_pipe->productionEnded());
1129
1130     // push writer and sender in case we were waiting for the last-chunk
1131     writeMore();
1132
1133     if (state.sending == State::sendingVirgin)
1134         echoMore();
1135 }
1136
1137 // adapted body consumer wants more adapted data and
1138 // possibly freed some buffer space
1139 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1140 {
1141     if (state.sending == State::sendingVirgin)
1142         echoMore();
1143     else if (state.sending == State::sendingAdapted)
1144         parseMore();
1145     else
1146         Must(state.sending == State::sendingUndecided);
1147 }
1148
1149 // adapted body consumer aborted
1150 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1151 {
1152     mustStop("adapted body consumer aborted");
1153 }
1154
1155 // internal cleanup
1156 void Adaptation::Icap::ModXact::swanSong()
1157 {
1158     debugs(93, 5, HERE << "swan sings" << status());
1159
1160     stopWriting(false);
1161     stopSending(false);
1162
1163     // update adaptation history if start was called and we reserved a slot
1164     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1165     if (ah != NULL && adaptHistoryId >= 0)
1166         ah->recordXactFinish(adaptHistoryId);
1167
1168     Adaptation::Icap::Xaction::swanSong();
1169 }
1170
1171 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1172
1173 void Adaptation::Icap::ModXact::finalizeLogInfo()
1174 {
1175     HttpRequest * request_ = NULL;
1176     HttpReply * reply_ = NULL;
1177     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1178         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1179         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1180     }
1181
1182     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1183     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1184     al.icp.opcode = ICP_INVALID;
1185     al.url = h->log_uri.termedBuf();
1186     const Adaptation::Icap::ServiceRep  &s = service();
1187     al.icap.reqMethod = s.cfg().method;
1188
1189     al.cache.caddr = request_->client_addr;
1190
1191     al.request = HTTPMSGLOCK(request_);
1192     if (reply_)
1193         al.reply = HTTPMSGLOCK(reply_);
1194     else
1195         al.reply = NULL;
1196
1197     if (h->rfc931.size())
1198         al.cache.rfc931 = h->rfc931.termedBuf();
1199
1200 #if USE_SSL
1201     if (h->ssluser.size())
1202         al.cache.ssluser = h->ssluser.termedBuf();
1203 #endif
1204     al.cache.code = h->logType;
1205     al.cache.requestSize = h->req_sz;
1206
1207     // leave al.icap.bodyBytesRead negative if no body
1208     if (replyHttpHeaderSize >= 0 || replyHttpBodySize >= 0) {
1209         const int64_t zero = 0; // to make max() argument types the same
1210         al.icap.bodyBytesRead =
1211             max(zero, replyHttpHeaderSize) + max(zero, replyHttpBodySize);
1212     }
1213
1214     if (reply_) {
1215         al.http.code = reply_->sline.status;
1216         al.http.content_type = reply_->content_type.termedBuf();
1217         if (replyHttpBodySize >= 0) {
1218             al.cache.replySize = replyHttpBodySize + reply_->hdr_sz;
1219             al.cache.highOffset = replyHttpBodySize;
1220         }
1221         //don't set al.cache.objectSize because it hasn't exist yet
1222
1223         Packer p;
1224         MemBuf mb;
1225
1226         mb.init();
1227         packerToMemInit(&p, &mb);
1228
1229         reply_->header.packInto(&p);
1230         al.headers.reply = xstrdup(mb.buf);
1231
1232         packerClean(&p);
1233         mb.clean();
1234     }
1235     prepareLogWithRequestDetails(request_, &al);
1236     Xaction::finalizeLogInfo();
1237 }
1238
1239
1240 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1241 {
1242     char ntoabuf[MAX_IPSTRLEN];
1243     /*
1244      * XXX These should use HttpHdr interfaces instead of Printfs
1245      */
1246     const Adaptation::ServiceConfig &s = service().cfg();
1247     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1248     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1249     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1250
1251     if (!TheConfig.reuse_connections)
1252         buf.Printf("Connection: close\r\n");
1253
1254     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1255     // as ICAP headers.
1256     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1257         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1258         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1259     }
1260
1261     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1262         String vh=virgin.header->header.getByName("Proxy-Authorization");
1263         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1264     }
1265
1266     const HttpRequest *request = &virginRequest();
1267
1268     // share the cross-transactional database records if needed
1269     if (Adaptation::Config::masterx_shared_name) {
1270         Adaptation::History::Pointer ah = request->adaptHistory(true);
1271         if (ah != NULL) {
1272             String name, value;
1273             if (ah->getXxRecord(name, value)) {
1274                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1275                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1276             }
1277         }
1278     }
1279
1280
1281     buf.Printf("Encapsulated: ");
1282
1283     MemBuf httpBuf;
1284
1285     httpBuf.init();
1286
1287     // build HTTP request header, if any
1288     ICAP::Method m = s.method;
1289
1290     // to simplify, we could assume that request is always available
1291
1292     String urlPath;
1293     if (request) {
1294         urlPath = request->urlpath;
1295         if (ICAP::methodRespmod == m)
1296             encapsulateHead(buf, "req-hdr", httpBuf, request);
1297         else if (ICAP::methodReqmod == m)
1298             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1299     }
1300
1301     if (ICAP::methodRespmod == m)
1302         if (const HttpMsg *prime = virgin.header)
1303             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1304
1305     if (!virginBody.expected())
1306         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1307     else if (ICAP::methodReqmod == m)
1308         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1309     else
1310         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1311
1312     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1313
1314     if (preview.enabled()) {
1315         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1316         if (!virginBody.expected()) // there is no body to preview
1317             finishNullOrEmptyBodyPreview(httpBuf);
1318     }
1319
1320     makeAllowHeader(buf);
1321
1322     if (TheConfig.send_client_ip && request) {
1323         Ip::Address client_addr;
1324 #if FOLLOW_X_FORWARDED_FOR
1325         if (TheConfig.icap_uses_indirect_client) {
1326             client_addr = request->indirect_client_addr;
1327         } else
1328 #endif
1329             client_addr = request->client_addr;
1330         if (!client_addr.IsAnyAddr() && !client_addr.IsNoAddr())
1331             buf.Printf("X-Client-IP: %s\r\n", client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1332     }
1333
1334     if (TheConfig.send_client_username && request)
1335         makeUsernameHeader(request, buf);
1336
1337     // fprintf(stderr, "%s\n", buf.content());
1338
1339     buf.append(ICAP::crlf, 2); // terminate ICAP header
1340
1341     // fill icapRequest for logging
1342     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1343
1344     // start ICAP request body with encapsulated HTTP headers
1345     buf.append(httpBuf.content(), httpBuf.contentSize());
1346
1347     httpBuf.clean();
1348 }
1349
1350 // decides which Allow values to write and updates the request buffer
1351 void Adaptation::Icap::ModXact::makeAllowHeader(MemBuf &buf)
1352 {
1353     const bool allow204in = preview.enabled(); // TODO: add shouldAllow204in()
1354     const bool allow204out = state.allowedPostview204 = shouldAllow204();
1355     const bool allow206in = state.allowedPreview206 = shouldAllow206in();
1356     const bool allow206out = state.allowedPostview206 = shouldAllow206out();
1357
1358     debugs(93,9, HERE << "Allows: " << allow204in << allow204out <<
1359            allow206in << allow206out);
1360
1361     const bool allow204 = allow204in || allow204out;
1362     const bool allow206 = allow206in || allow206out;
1363
1364     if (!allow204 && !allow206)
1365         return; // nothing to do
1366
1367     if (virginBody.expected()) // if there is a virgin body, plan to send it
1368         virginBodySending.plan();
1369
1370     // writing Preview:...   means we will honor 204 inside preview
1371     // writing Allow/204     means we will honor 204 outside preview
1372     // writing Allow:206     means we will honor 206 inside preview
1373     // writing Allow:204,206 means we will honor 206 outside preview
1374     const char *allowHeader = NULL;
1375     if (allow204out && allow206)
1376         allowHeader = "Allow: 204, 206\r\n";
1377     else if (allow204out)
1378         allowHeader = "Allow: 204\r\n";
1379     else if (allow206)
1380         allowHeader = "Allow: 206\r\n";
1381
1382     if (allowHeader) { // may be nil if only allow204in is true
1383         buf.append(allowHeader, strlen(allowHeader));
1384         debugs(93,5, HERE << "Will write " << allowHeader);
1385     }
1386 }
1387
1388 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1389 {
1390     if (request->auth_user_request != NULL) {
1391         char const *name = request->auth_user_request->username();
1392         if (name) {
1393             const char *value = TheConfig.client_username_encode ? base64_encode(name) : name;
1394             buf.Printf("%s: %s\r\n", TheConfig.client_username_header, value);
1395         }
1396     }
1397 }
1398
1399 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1400 {
1401     // update ICAP header
1402     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1403
1404     // begin cloning
1405     HttpMsg *headClone = NULL;
1406
1407     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1408         HttpRequest* new_request = new HttpRequest;
1409         assert(old_request->canonical);
1410         urlParse(old_request->method, old_request->canonical, new_request);
1411         new_request->http_ver = old_request->http_ver;
1412         headClone = new_request;
1413     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1414         HttpReply* new_reply = new HttpReply;
1415         new_reply->sline = old_reply->sline;
1416         headClone = new_reply;
1417     }
1418
1419     Must(headClone);
1420     headClone->inheritProperties(head);
1421
1422     HttpHeaderPos pos = HttpHeaderInitPos;
1423     HttpHeaderEntry* p_head_entry = NULL;
1424     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1425         headClone->header.addEntry(p_head_entry->clone());
1426
1427     // end cloning
1428
1429     // remove all hop-by-hop headers from the clone
1430     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1431     headClone->header.removeHopByHopEntries();
1432
1433     // pack polished HTTP header
1434     packHead(httpBuf, headClone);
1435
1436     delete headClone;
1437 }
1438
1439 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1440 {
1441     Packer p;
1442     packerToMemInit(&p, &httpBuf);
1443     head->packInto(&p, true);
1444     packerClean(&p);
1445 }
1446
1447 // decides whether to offer a preview and calculates its size
1448 void Adaptation::Icap::ModXact::decideOnPreview()
1449 {
1450     if (!TheConfig.preview_enable) {
1451         debugs(93, 5, HERE << "preview disabled by squid.conf");
1452         return;
1453     }
1454
1455     const String urlPath = virginRequest().urlpath;
1456     size_t wantedSize;
1457     if (!service().wantsPreview(urlPath, wantedSize)) {
1458         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1459         return;
1460     }
1461
1462     // we decided to do preview, now compute its size
1463
1464     Must(wantedSize >= 0);
1465
1466     // cannot preview more than we can backup
1467     size_t ad = min(wantedSize, TheBackupLimit);
1468
1469     if (!virginBody.expected())
1470         ad = 0;
1471     else if (virginBody.knownSize())
1472         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1473
1474     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1475            "(service wanted " << wantedSize << ")");
1476
1477     preview.enable(ad);
1478     Must(preview.enabled());
1479 }
1480
1481 // decides whether to allow 204 responses
1482 bool Adaptation::Icap::ModXact::shouldAllow204()
1483 {
1484     if (!service().allows204())
1485         return false;
1486
1487     return canBackupEverything();
1488 }
1489
1490 // decides whether to allow 206 responses in some mode
1491 bool Adaptation::Icap::ModXact::shouldAllow206any()
1492 {
1493     return TheConfig.allow206_enable && service().allows206() &&
1494            virginBody.expected(); // no need for 206 without a body
1495 }
1496
1497 // decides whether to allow 206 responses in preview mode
1498 bool Adaptation::Icap::ModXact::shouldAllow206in()
1499 {
1500     return shouldAllow206any() && preview.enabled();
1501 }
1502
1503 // decides whether to allow 206 responses outside of preview
1504 bool Adaptation::Icap::ModXact::shouldAllow206out()
1505 {
1506     return shouldAllow206any() && canBackupEverything();
1507 }
1508
1509 // used by shouldAllow204 and decideOnRetries
1510 bool Adaptation::Icap::ModXact::canBackupEverything() const
1511 {
1512     if (!virginBody.expected())
1513         return true; // no body means no problems with backup
1514
1515     // if there is a body, check whether we can backup it all
1516
1517     if (!virginBody.knownSize())
1518         return false;
1519
1520     // or should we have a different backup limit?
1521     // note that '<' allows for 0-termination of the "full" backup buffer
1522     return virginBody.size() < TheBackupLimit;
1523 }
1524
1525 // Decide whether this transaction can be retried if pconn fails
1526 // Must be called after decideOnPreview and before openConnection()
1527 void Adaptation::Icap::ModXact::decideOnRetries()
1528 {
1529     if (!isRetriable)
1530         return; // no, already decided
1531
1532     if (preview.enabled())
1533         return; // yes, because preview provides enough guarantees
1534
1535     if (canBackupEverything())
1536         return; // yes, because we can back everything up
1537
1538     disableRetries(); // no, because we cannot back everything up
1539 }
1540
1541 // Normally, the body-writing code handles preview body. It can deal with
1542 // bodies of unexpected size, including those that turn out to be empty.
1543 // However, that code assumes that the body was expected and body control
1544 // structures were initialized. This is not the case when there is no body
1545 // or the body is known to be empty, because the virgin message will lack a
1546 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1547 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1548 {
1549     Must(!virginBodyWriting.active()); // one reason we handle it here
1550     Must(!virgin.body_pipe);          // another reason we handle it here
1551     Must(!preview.ad());
1552
1553     // do not add last-chunk because our Encapsulated header says null-body
1554     // addLastRequestChunk(buf);
1555     preview.wrote(0, true);
1556
1557     Must(preview.done());
1558     Must(preview.ieof());
1559 }
1560
1561 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1562 {
1563     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1564
1565     if (state.serviceWaiting)
1566         buf.append("U", 1);
1567
1568     if (virgin.body_pipe != NULL)
1569         buf.append("R", 1);
1570
1571     if (haveConnection() && !doneReading())
1572         buf.append("r", 1);
1573
1574     if (!state.doneWriting() && state.writing != State::writingInit)
1575         buf.Printf("w(%d)", state.writing);
1576
1577     if (preview.enabled()) {
1578         if (!preview.done())
1579             buf.Printf("P(%d)", (int) preview.debt());
1580     }
1581
1582     if (virginBodySending.active())
1583         buf.append("B", 1);
1584
1585     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1586         buf.Printf("p(%d)", state.parsing);
1587
1588     if (!doneSending() && state.sending != State::sendingUndecided)
1589         buf.Printf("S(%d)", state.sending);
1590
1591     if (state.readyForUob)
1592         buf.append("6", 1);
1593
1594     if (canStartBypass)
1595         buf.append("Y", 1);
1596
1597     if (protectGroupBypass)
1598         buf.append("G", 1);
1599 }
1600
1601 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1602 {
1603     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1604
1605     if (!virgin.body_pipe)
1606         buf.append("R", 1);
1607
1608     if (state.doneWriting())
1609         buf.append("w", 1);
1610
1611     if (preview.enabled()) {
1612         if (preview.done())
1613             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1614     }
1615
1616     if (doneReading())
1617         buf.append("r", 1);
1618
1619     if (state.doneParsing())
1620         buf.append("p", 1);
1621
1622     if (doneSending())
1623         buf.append("S", 1);
1624 }
1625
1626 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1627 {
1628     return icapReply->header.getByNameListMember("Encapsulated",
1629             section, ',').size() > 0;
1630 }
1631
1632 // calculate whether there is a virgin HTTP body and
1633 // whether its expected size is known
1634 // TODO: rename because we do not just estimate
1635 void Adaptation::Icap::ModXact::estimateVirginBody()
1636 {
1637     // note: lack of size info may disable previews and 204s
1638
1639     HttpMsg *msg = virgin.header;
1640     Must(msg);
1641
1642     HttpRequestMethod method;
1643
1644     if (virgin.cause)
1645         method = virgin.cause->method;
1646     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1647         method = req->method;
1648     else
1649         method = METHOD_NONE;
1650
1651     int64_t size;
1652     // expectingBody returns true for zero-sized bodies, but we will not
1653     // get a pipe for that body, so we treat the message as bodyless
1654     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1655         debugs(93, 6, HERE << "expects virgin body from " <<
1656                virgin.body_pipe << "; size: " << size);
1657
1658         virginBody.expect(size);
1659         virginBodyWriting.plan();
1660
1661         // sign up as a body consumer
1662         Must(msg->body_pipe != NULL);
1663         Must(msg->body_pipe == virgin.body_pipe);
1664         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1665
1666         // make sure TheBackupLimit is in-sync with the buffer size
1667         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1668     } else {
1669         debugs(93, 6, HERE << "does not expect virgin body");
1670         Must(msg->body_pipe == NULL);
1671         checkConsuming();
1672     }
1673 }
1674
1675 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1676 {
1677     Must(!adapted.body_pipe);
1678     Must(!adapted.header->body_pipe);
1679     adapted.header->body_pipe = new BodyPipe(this);
1680     adapted.body_pipe = adapted.header->body_pipe;
1681     debugs(93, 7, HERE << "will supply " << what << " via " <<
1682            adapted.body_pipe << " pipe");
1683 }
1684
1685
1686 // TODO: Move SizedEstimate and Preview elsewhere
1687
1688 Adaptation::Icap::SizedEstimate::SizedEstimate()
1689         : theData(dtUnexpected)
1690 {}
1691
1692 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1693 {
1694     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1695 }
1696
1697 bool Adaptation::Icap::SizedEstimate::expected() const
1698 {
1699     return theData != dtUnexpected;
1700 }
1701
1702 bool Adaptation::Icap::SizedEstimate::knownSize() const
1703 {
1704     Must(expected());
1705     return theData != dtUnknown;
1706 }
1707
1708 uint64_t Adaptation::Icap::SizedEstimate::size() const
1709 {
1710     Must(knownSize());
1711     return static_cast<uint64_t>(theData);
1712 }
1713
1714
1715
1716 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1717 {}
1718
1719 void Adaptation::Icap::VirginBodyAct::plan()
1720 {
1721     Must(!disabled());
1722     Must(!theStart); // not started
1723     theState = stActive;
1724 }
1725
1726 void Adaptation::Icap::VirginBodyAct::disable()
1727 {
1728     theState = stDisabled;
1729 }
1730
1731 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1732 {
1733     Must(active());
1734     Must(size >= 0);
1735     theStart += static_cast<int64_t>(size);
1736 }
1737
1738 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1739 {
1740     Must(active());
1741     return static_cast<uint64_t>(theStart);
1742 }
1743
1744
1745 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1746 {}
1747
1748 void Adaptation::Icap::Preview::enable(size_t anAd)
1749 {
1750     // TODO: check for anAd not exceeding preview size limit
1751     Must(anAd >= 0);
1752     Must(!enabled());
1753     theAd = anAd;
1754     theState = stWriting;
1755 }
1756
1757 bool Adaptation::Icap::Preview::enabled() const
1758 {
1759     return theState != stDisabled;
1760 }
1761
1762 size_t Adaptation::Icap::Preview::ad() const
1763 {
1764     Must(enabled());
1765     return theAd;
1766 }
1767
1768 bool Adaptation::Icap::Preview::done() const
1769 {
1770     Must(enabled());
1771     return theState >= stIeof;
1772 }
1773
1774 bool Adaptation::Icap::Preview::ieof() const
1775 {
1776     Must(enabled());
1777     return theState == stIeof;
1778 }
1779
1780 size_t Adaptation::Icap::Preview::debt() const
1781 {
1782     Must(enabled());
1783     return done() ? 0 : (theAd - theWritten);
1784 }
1785
1786 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1787 {
1788     Must(enabled());
1789
1790     theWritten += size;
1791
1792     Must(theWritten <= theAd);
1793
1794     if (wroteEof)
1795         theState = stIeof; // written size is irrelevant
1796     else if (theWritten >= theAd)
1797         theState = stDone;
1798 }
1799
1800 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1801 {
1802     if (virgin.header == NULL)
1803         return false;
1804
1805     virgin.header->firstLineBuf(mb);
1806
1807     return true;
1808 }
1809
1810
1811 /* Adaptation::Icap::ModXactLauncher */
1812
1813 Adaptation::Icap::ModXactLauncher::ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1814         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1815         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", aService)
1816 {
1817     virgin.setHeader(virginHeader);
1818     virgin.setCause(virginCause);
1819     updateHistory(true);
1820 }
1821
1822 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1823 {
1824     Adaptation::Icap::ServiceRep::Pointer s =
1825         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1826     Must(s != NULL);
1827     return new Adaptation::Icap::ModXact(virgin.header, virgin.cause, s);
1828 }
1829
1830 void Adaptation::Icap::ModXactLauncher::swanSong()
1831 {
1832     debugs(93, 5, HERE << "swan sings");
1833     updateHistory(false);
1834     Adaptation::Icap::Launcher::swanSong();
1835 }
1836
1837 void Adaptation::Icap::ModXactLauncher::updateHistory(bool doStart)
1838 {
1839     HttpRequest *r = virgin.cause ?
1840                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1841
1842     // r should never be NULL but we play safe; TODO: add Should()
1843     if (r) {
1844         Adaptation::Icap::History::Pointer h = r->icapHistory();
1845         if (h != NULL) {
1846             if (doStart)
1847                 h->start("ICAPModXactLauncher");
1848             else
1849                 h->stop("ICAPModXactLauncher");
1850         }
1851     }
1852 }