src/adaptation/icap/ModXact.cc

   1 /*
   2  * DEBUG: section 93    ICAP (RFC 3507) Client
   3  */
   4
   5 #include "squid.h"
   6 #include "comm.h"
   7 #include "HttpMsg.h"
   8 #include "HttpRequest.h"
   9 #include "HttpReply.h"
  10 #include "adaptation/Initiator.h"
  11 #include "adaptation/icap/ServiceRep.h"
  12 #include "adaptation/icap/Launcher.h"
  13 #include "adaptation/icap/ModXact.h"
  14 #include "adaptation/icap/Client.h"
  15 #include "ChunkedCodingParser.h"
  16 #include "TextException.h"
  17 #include "auth/UserRequest.h"
  18 #include "adaptation/icap/Config.h"
  19 #include "SquidTime.h"
  20 #include "AccessLogEntry.h"
  21 #include "adaptation/icap/History.h"
  22 #include "adaptation/History.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 extern Adaptation::Icap::Config Adaptation::Icap::TheConfig;
  36
  37
  38 Adaptation::Icap::ModXact::State::State()
  39 {
  40     memset(this, 0, sizeof(*this));
  41 }
  42
  43 Adaptation::Icap::ModXact::ModXact(Adaptation::Initiator *anInitiator, HttpMsg *virginHeader,
  44                                    HttpRequest *virginCause, Adaptation::Icap::ServiceRep::Pointer &aService):
  45         AsyncJob("Adaptation::Icap::ModXact"),
  46         Adaptation::Icap::Xaction("Adaptation::Icap::ModXact", anInitiator, aService),
  47         virginConsumed(0),
  48         bodyParser(NULL),
  49         canStartBypass(false), // too early
  50         protectGroupBypass(true),
  51         replyBodySize(0),
  52         adaptHistoryId(-1)
  53 {
  54     assert(virginHeader);
  55
  56     virgin.setHeader(virginHeader); // sets virgin.body_pipe if needed
  57     virgin.setCause(virginCause); // may be NULL
  58
  59     // adapted header and body are initialized when we parse them
  60
  61     // writing and reading ends are handled by Adaptation::Icap::Xaction
  62
  63     // encoding
  64     // nothing to do because we are using temporary buffers
  65
  66     // parsing; TODO: do not set until we parse, see ICAPOptXact
  67     icapReply = HTTPMSGLOCK(new HttpReply);
  68     icapReply->protoPrefix = "ICAP/"; // TODO: make an IcapReply class?
  69
  70     debugs(93,7, HERE << "initialized." << status());
  71 }
  72
  73 // initiator wants us to start
  74 void Adaptation::Icap::ModXact::start()
  75 {
  76     Adaptation::Icap::Xaction::start();
  77
  78     // reserve an adaptation history slot (attempts are known at this time)
  79     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
  80     if (ah != NULL)
  81         adaptHistoryId = ah->recordXactStart(service().cfg().key, icap_tr_start, attempts > 1);
  82
  83     estimateVirginBody(); // before virgin disappears!
  84
  85     canStartBypass = service().cfg().bypass;
  86
  87     // it is an ICAP violation to send request to a service w/o known OPTIONS
  88
  89     if (service().up())
  90         startWriting();
  91     else
  92         waitForService();
  93 }
  94
  95 void Adaptation::Icap::ModXact::waitForService()
  96 {
  97     Must(!state.serviceWaiting);
  98     debugs(93, 7, HERE << "will wait for the ICAP service" << status());
  99     state.serviceWaiting = true;
 100     AsyncCall::Pointer call = asyncCall(93,5, "Adaptation::Icap::ModXact::noteServiceReady",
 101                                         MemFun(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 start = act.offset();
 341     // absolute end of buffered data
 342     const uint64_t end = virginConsumed + virgin.body_pipe->buf().contentSize();
 343     Must(virginConsumed <= start && start <= end);
 344     return static_cast<size_t>(end - start);
 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 start = act.offset();
 352     Must(virginConsumed <= start);
 353     return virgin.body_pipe->buf().content() + static_cast<size_t>(start-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(connection >= 0);
 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 (connection >= 0) {
 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     default:
 733         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 734         handleUnknownScode();
 735         break;
 736     }
 737
 738     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 739     if (!request)
 740         request = &virginRequest();
 741
 742     // update the cross-transactional database if needed (all status codes!)
 743     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 744         Adaptation::History::Pointer ah = request->adaptHistory(true);
 745         if (ah != NULL) {
 746             const String val = icapReply->header.getByName(xxName);
 747             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 748                 ah->updateXxRecord(xxName, val);
 749         }
 750     }
 751
 752     // update the adaptation plan if needed (all status codes!)
 753     if (service().cfg().routing) {
 754         String services;
 755         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 756             Adaptation::History::Pointer ah = request->adaptHistory(true);
 757             if (ah != NULL)
 758                 ah->updateNextServices(services);
 759         }
 760     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 761
 762     // We need to store received ICAP headers for <icapLastHeader logformat option.
 763     // If we already have stored headers from previous ICAP transaction related to this
 764     // request, old headers will be replaced with the new one.
 765
 766     Adaptation::Icap::History::Pointer h = request->icapHistory();
 767     if (h != NULL) {
 768         h->mergeIcapHeaders(&icapReply->header);
 769         h->setIcapLastHeader(&icapReply->header);
 770     }
 771
 772     // handle100Continue() manages state.writing on its own.
 773     // Non-100 status means the server needs no postPreview data from us.
 774     if (state.writing == State::writingPaused)
 775         stopWriting(true);
 776 }
 777
 778 bool Adaptation::Icap::ModXact::validate200Ok()
 779 {
 780     if (ICAP::methodRespmod == service().cfg().method) {
 781         if (!gotEncapsulated("res-hdr"))
 782             return false;
 783
 784         return true;
 785     }
 786
 787     if (ICAP::methodReqmod == service().cfg().method) {
 788         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 789             return false;
 790
 791         return true;
 792     }
 793
 794     return false;
 795 }
 796
 797 void Adaptation::Icap::ModXact::handle100Continue()
 798 {
 799     Must(state.writing == State::writingPaused);
 800     // server must not respond before the end of preview: we may send ieof
 801     Must(preview.enabled() && preview.done() && !preview.ieof());
 802
 803     // 100 "Continue" cancels our preview commitment, not 204s outside preview
 804     if (!state.allowedPostview204)
 805         stopBackup();
 806
 807     state.parsing = State::psIcapHeader; // eventually
 808     icapReply->reset();
 809
 810     state.writing = State::writingPrime;
 811
 812     writeMore();
 813 }
 814
 815 void Adaptation::Icap::ModXact::handle200Ok()
 816 {
 817     state.parsing = State::psHttpHeader;
 818     state.sending = State::sendingAdapted;
 819     stopBackup();
 820     checkConsuming();
 821 }
 822
 823 void Adaptation::Icap::ModXact::handle204NoContent()
 824 {
 825     stopParsing();
 826     prepEchoing();
 827 }
 828
 829 // Called when we receive a 204 No Content response and
 830 // when we are trying to bypass a service failure.
 831 // We actually start sending (echoig or not) in startSending.
 832 void Adaptation::Icap::ModXact::prepEchoing()
 833 {
 834     disableRepeats("preparing to echo content");
 835     disableBypass("preparing to echo content", true);
 836     setOutcome(xoEcho);
 837
 838     // We want to clone the HTTP message, but we do not want
 839     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 840     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 841     // Instead, we simply write the HTTP message and "clone" it by parsing.
 842     // TODO: use HttpMsg::clone()!
 843
 844     HttpMsg *oldHead = virgin.header;
 845     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 846
 847     MemBuf httpBuf;
 848
 849     // write the virgin message into a memory buffer
 850     httpBuf.init();
 851     packHead(httpBuf, oldHead);
 852
 853     // allocate the adapted message and copy metainfo
 854     Must(!adapted.header);
 855     HttpMsg *newHead = NULL;
 856     if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 857         HttpRequest *newR = new HttpRequest;
 858         newR->canonical = oldR->canonical ?
 859                           xstrdup(oldR->canonical) : NULL; // parse() does not set it
 860         newHead = newR;
 861     } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 862         HttpReply *newRep = new HttpReply;
 863         newHead = newRep;
 864     }
 865     Must(newHead);
 866     newHead->inheritProperties(oldHead);
 867
 868     adapted.setHeader(newHead);
 869
 870     // parse the buffer back
 871     http_status error = HTTP_STATUS_NONE;
 872
 873     Must(newHead->parse(&httpBuf, true, &error));
 874
 875     Must(newHead->hdr_sz == httpBuf.contentSize()); // no leftovers
 876
 877     httpBuf.clean();
 878
 879     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 880            newHead);
 881
 882     // setup adapted body pipe if needed
 883     if (oldHead->body_pipe != NULL) {
 884         debugs(93, 7, HERE << "will echo virgin body from " <<
 885                oldHead->body_pipe);
 886         if (!virginBodySending.active())
 887             virginBodySending.plan(); // will throw if not possible
 888         state.sending = State::sendingVirgin;
 889         checkConsuming();
 890
 891         // TODO: optimize: is it possible to just use the oldHead pipe and
 892         // remove ICAP from the loop? This echoing is probably a common case!
 893         makeAdaptedBodyPipe("echoed virgin response");
 894         if (oldHead->body_pipe->bodySizeKnown())
 895             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 896         debugs(93, 7, HERE << "will echo virgin body to " <<
 897                adapted.body_pipe);
 898     } else {
 899         debugs(93, 7, HERE << "no virgin body to echo");
 900         stopSending(true);
 901     }
 902 }
 903
 904 void Adaptation::Icap::ModXact::handleUnknownScode()
 905 {
 906     stopParsing();
 907     stopBackup();
 908     // TODO: mark connection as "bad"
 909
 910     // Terminate the transaction; we do not know how to handle this response.
 911     throw TexcHere("Unsupported ICAP status code");
 912 }
 913
 914 void Adaptation::Icap::ModXact::parseHttpHead()
 915 {
 916     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
 917         maybeAllocateHttpMsg();
 918
 919         if (!parseHead(adapted.header))
 920             return; // need more header data
 921
 922         if (dynamic_cast<HttpRequest*>(adapted.header)) {
 923             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
 924             Must(oldR);
 925             // TODO: the adapted request did not really originate from the
 926             // client; give proxy admin an option to prevent copying of
 927             // sensitive client information here. See the following thread:
 928             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
 929         }
 930
 931         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
 932         if (adapted.header)
 933             adapted.header->inheritProperties(virgin.header);
 934     }
 935
 936     decideOnParsingBody();
 937 }
 938
 939 // parses both HTTP and ICAP headers
 940 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
 941 {
 942     Must(head);
 943     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
 944            "; state: " << state.parsing);
 945
 946     http_status error = HTTP_STATUS_NONE;
 947     const bool parsed = head->parse(&readBuf, commEof, &error);
 948     Must(parsed || !error); // success or need more data
 949
 950     if (!parsed) { // need more data
 951         debugs(93, 5, HERE << "parse failed, need more data, return false");
 952         head->reset();
 953         return false;
 954     }
 955
 956     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
 957         urlCanonical(r); // parse does not set HttpRequest::canonical
 958
 959     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
 960     readBuf.consume(head->hdr_sz);
 961     return true;
 962 }
 963
 964 void Adaptation::Icap::ModXact::decideOnParsingBody()
 965 {
 966     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
 967         debugs(93, 5, HERE << "expecting a body");
 968         state.parsing = State::psBody;
 969         bodyParser = new ChunkedCodingParser;
 970         makeAdaptedBodyPipe("adapted response from the ICAP server");
 971         Must(state.sending == State::sendingAdapted);
 972     } else {
 973         debugs(93, 5, HERE << "not expecting a body");
 974         stopParsing();
 975         stopSending(true);
 976     }
 977 }
 978
 979 void Adaptation::Icap::ModXact::parseBody()
 980 {
 981     Must(state.parsing == State::psBody);
 982     Must(bodyParser);
 983
 984     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
 985
 986     // the parser will throw on errors
 987     BodyPipeCheckout bpc(*adapted.body_pipe);
 988     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
 989     bpc.checkIn();
 990
 991     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
 992            "parse; parsed all: " << parsed);
 993     replyBodySize += adapted.body_pipe->buf().contentSize();
 994
 995     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
 996     // TODO: do we really need this if we disable when sending headers?
 997     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
 998         disableRepeats("sent adapted content");
 999         disableBypass("sent adapted content", true);
1000     }
1001
1002     if (parsed) {
1003         stopParsing();
1004         stopSending(true); // the parser succeeds only if all parsed data fits
1005         return;
1006     }
1007
1008     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1009
1010     if (bodyParser->needsMoreData()) {
1011         debugs(93,3,HERE << this);
1012         Must(mayReadMore());
1013         readMore();
1014     }
1015
1016     if (bodyParser->needsMoreSpace()) {
1017         Must(!doneSending()); // can hope for more space
1018         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1019         // TODO: there should be a timeout in case the sink is broken
1020         // or cannot consume partial content (while we need more space)
1021     }
1022 }
1023
1024 void Adaptation::Icap::ModXact::stopParsing()
1025 {
1026     if (state.parsing == State::psDone)
1027         return;
1028
1029     debugs(93, 7, HERE << "will no longer parse" << status());
1030
1031     delete bodyParser;
1032
1033     bodyParser = NULL;
1034
1035     state.parsing = State::psDone;
1036 }
1037
1038 // HTTP side added virgin body data
1039 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1040 {
1041     writeMore();
1042
1043     if (state.sending == State::sendingVirgin)
1044         echoMore();
1045 }
1046
1047 // HTTP side sent us all virgin info
1048 void Adaptation::Icap::ModXact::noteBodyProductionEnded(BodyPipe::Pointer)
1049 {
1050     Must(virgin.body_pipe->productionEnded());
1051
1052     // push writer and sender in case we were waiting for the last-chunk
1053     writeMore();
1054
1055     if (state.sending == State::sendingVirgin)
1056         echoMore();
1057 }
1058
1059 // body producer aborted, but the initiator may still want to know
1060 // the answer, even though the HTTP message has been truncated
1061 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1062 {
1063     Must(virgin.body_pipe->productionEnded());
1064
1065     // push writer and sender in case we were waiting for the last-chunk
1066     writeMore();
1067
1068     if (state.sending == State::sendingVirgin)
1069         echoMore();
1070 }
1071
1072 // adapted body consumer wants more adapted data and
1073 // possibly freed some buffer space
1074 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1075 {
1076     if (state.sending == State::sendingVirgin)
1077         echoMore();
1078     else if (state.sending == State::sendingAdapted)
1079         parseMore();
1080     else
1081         Must(state.sending == State::sendingUndecided);
1082 }
1083
1084 // adapted body consumer aborted
1085 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1086 {
1087     mustStop("adapted body consumer aborted");
1088 }
1089
1090 // internal cleanup
1091 void Adaptation::Icap::ModXact::swanSong()
1092 {
1093     debugs(93, 5, HERE << "swan sings" << status());
1094
1095     stopWriting(false);
1096     stopSending(false);
1097
1098     // update adaptation history if start was called and we reserved a slot
1099     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1100     if (ah != NULL && adaptHistoryId >= 0)
1101         ah->recordXactFinish(adaptHistoryId);
1102
1103     Adaptation::Icap::Xaction::swanSong();
1104 }
1105
1106 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1107
1108 void Adaptation::Icap::ModXact::finalizeLogInfo()
1109 {
1110     HttpRequest * request_ = NULL;
1111     HttpReply * reply_ = NULL;
1112     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1113         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1114         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1115     }
1116
1117     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1118     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1119     al.icp.opcode = ICP_INVALID;
1120     al.url = h->log_uri.termedBuf();
1121     const Adaptation::Icap::ServiceRep  &s = service();
1122     al.icap.reqMethod = s.cfg().method;
1123
1124     al.cache.caddr = request_->client_addr;
1125
1126     al.request = HTTPMSGLOCK(request_);
1127     if (reply_)
1128         al.reply = HTTPMSGLOCK(reply_);
1129     else
1130         al.reply = NULL;
1131
1132     if (h->rfc931.size())
1133         al.cache.rfc931 = h->rfc931.termedBuf();
1134
1135 #if USE_SSL
1136     if (h->ssluser.size())
1137         al.cache.ssluser = h->ssluser.termedBuf();
1138 #endif
1139     al.cache.code = h->logType;
1140     al.cache.requestSize = h->req_sz;
1141     if (reply_) {
1142         al.http.code = reply_->sline.status;
1143         al.http.content_type = reply_->content_type.termedBuf();
1144         al.cache.replySize = replyBodySize + reply_->hdr_sz;
1145         al.cache.highOffset = replyBodySize;
1146         //don't set al.cache.objectSize because it hasn't exist yet
1147
1148         Packer p;
1149         MemBuf mb;
1150
1151         mb.init();
1152         packerToMemInit(&p, &mb);
1153
1154         reply_->header.packInto(&p);
1155         al.headers.reply = xstrdup(mb.buf);
1156
1157         packerClean(&p);
1158         mb.clean();
1159     }
1160     prepareLogWithRequestDetails(request_, &al);
1161     Xaction::finalizeLogInfo();
1162 }
1163
1164
1165 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1166 {
1167     char ntoabuf[MAX_IPSTRLEN];
1168     /*
1169      * XXX These should use HttpHdr interfaces instead of Printfs
1170      */
1171     const Adaptation::ServiceConfig &s = service().cfg();
1172     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1173     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1174     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1175
1176     if (!TheConfig.reuse_connections)
1177         buf.Printf("Connection: close\r\n");
1178
1179     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1180     // as ICAP headers.
1181     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1182         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1183         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1184     }
1185
1186     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1187         String vh=virgin.header->header.getByName("Proxy-Authorization");
1188         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1189     }
1190
1191     const HttpRequest *request = &virginRequest();
1192
1193     // share the cross-transactional database records if needed
1194     if (Adaptation::Config::masterx_shared_name) {
1195         Adaptation::History::Pointer ah = request->adaptHistory(true);
1196         if (ah != NULL) {
1197             String name, value;
1198             if (ah->getXxRecord(name, value)) {
1199                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1200                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1201             }
1202         }
1203     }
1204
1205
1206     buf.Printf("Encapsulated: ");
1207
1208     MemBuf httpBuf;
1209
1210     httpBuf.init();
1211
1212     // build HTTP request header, if any
1213     ICAP::Method m = s.method;
1214
1215     // to simplify, we could assume that request is always available
1216
1217     String urlPath;
1218     if (request) {
1219         urlPath = request->urlpath;
1220         if (ICAP::methodRespmod == m)
1221             encapsulateHead(buf, "req-hdr", httpBuf, request);
1222         else if (ICAP::methodReqmod == m)
1223             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1224     }
1225
1226     if (ICAP::methodRespmod == m)
1227         if (const HttpMsg *prime = virgin.header)
1228             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1229
1230     if (!virginBody.expected())
1231         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1232     else if (ICAP::methodReqmod == m)
1233         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1234     else
1235         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1236
1237     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1238
1239     if (preview.enabled()) {
1240         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1241         if (virginBody.expected()) // there is a body to preview
1242             virginBodySending.plan();
1243         else
1244             finishNullOrEmptyBodyPreview(httpBuf);
1245     }
1246
1247     if (shouldAllow204()) {
1248         debugs(93,5, HERE << "will allow 204s outside of preview");
1249         state.allowedPostview204 = true;
1250         buf.Printf("Allow: 204\r\n");
1251         if (virginBody.expected()) // there is a body to echo
1252             virginBodySending.plan();
1253     }
1254
1255     if (TheConfig.send_client_ip && request)
1256         if (!request->client_addr.IsAnyAddr() && !request->client_addr.IsNoAddr())
1257             buf.Printf("X-Client-IP: %s\r\n", request->client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1258
1259     if (TheConfig.send_client_username && request)
1260         makeUsernameHeader(request, buf);
1261
1262     // fprintf(stderr, "%s\n", buf.content());
1263
1264     buf.append(ICAP::crlf, 2); // terminate ICAP header
1265
1266     // fill icapRequest for logging
1267     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1268
1269     // start ICAP request body with encapsulated HTTP headers
1270     buf.append(httpBuf.content(), httpBuf.contentSize());
1271
1272     httpBuf.clean();
1273 }
1274
1275 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1276 {
1277     if (const AuthUserRequest *auth = request->auth_user_request) {
1278         if (char const *name = auth->username()) {
1279             const char *value = TheConfig.client_username_encode ?
1280                                 base64_encode(name) : name;
1281             buf.Printf("%s: %s\r\n", TheConfig.client_username_header,
1282                        value);
1283         }
1284     }
1285 }
1286
1287 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1288 {
1289     // update ICAP header
1290     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1291
1292     // begin cloning
1293     HttpMsg *headClone = NULL;
1294
1295     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1296         HttpRequest* new_request = new HttpRequest;
1297         assert(old_request->canonical);
1298         urlParse(old_request->method, old_request->canonical, new_request);
1299         new_request->http_ver = old_request->http_ver;
1300         headClone = new_request;
1301     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1302         HttpReply* new_reply = new HttpReply;
1303         new_reply->sline = old_reply->sline;
1304         headClone = new_reply;
1305     }
1306
1307     Must(headClone);
1308     headClone->inheritProperties(head);
1309
1310     HttpHeaderPos pos = HttpHeaderInitPos;
1311     HttpHeaderEntry* p_head_entry = NULL;
1312     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1313         headClone->header.addEntry(p_head_entry->clone());
1314
1315     // end cloning
1316
1317     // remove all hop-by-hop headers from the clone
1318     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1319     headClone->header.removeHopByHopEntries();
1320
1321     // pack polished HTTP header
1322     packHead(httpBuf, headClone);
1323
1324     delete headClone;
1325 }
1326
1327 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1328 {
1329     Packer p;
1330     packerToMemInit(&p, &httpBuf);
1331     head->packInto(&p, true);
1332     packerClean(&p);
1333 }
1334
1335 // decides whether to offer a preview and calculates its size
1336 void Adaptation::Icap::ModXact::decideOnPreview()
1337 {
1338     if (!TheConfig.preview_enable) {
1339         debugs(93, 5, HERE << "preview disabled by squid.conf");
1340         return;
1341     }
1342
1343     const String urlPath = virginRequest().urlpath;
1344     size_t wantedSize;
1345     if (!service().wantsPreview(urlPath, wantedSize)) {
1346         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1347         return;
1348     }
1349
1350     // we decided to do preview, now compute its size
1351
1352     Must(wantedSize >= 0);
1353
1354     // cannot preview more than we can backup
1355     size_t ad = min(wantedSize, TheBackupLimit);
1356
1357     if (!virginBody.expected())
1358         ad = 0;
1359     else if (virginBody.knownSize())
1360         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1361
1362     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1363            "(service wanted " << wantedSize << ")");
1364
1365     preview.enable(ad);
1366     Must(preview.enabled());
1367 }
1368
1369 // decides whether to allow 204 responses
1370 bool Adaptation::Icap::ModXact::shouldAllow204()
1371 {
1372     if (!service().allows204())
1373         return false;
1374
1375     return canBackupEverything();
1376 }
1377
1378 // used by shouldAllow204 and decideOnRetries
1379 bool Adaptation::Icap::ModXact::canBackupEverything() const
1380 {
1381     if (!virginBody.expected())
1382         return true; // no body means no problems with backup
1383
1384     // if there is a body, check whether we can backup it all
1385
1386     if (!virginBody.knownSize())
1387         return false;
1388
1389     // or should we have a different backup limit?
1390     // note that '<' allows for 0-termination of the "full" backup buffer
1391     return virginBody.size() < TheBackupLimit;
1392 }
1393
1394 // Decide whether this transaction can be retried if pconn fails
1395 // Must be called after decideOnPreview and before openConnection()
1396 void Adaptation::Icap::ModXact::decideOnRetries()
1397 {
1398     if (!isRetriable)
1399         return; // no, already decided
1400
1401     if (preview.enabled())
1402         return; // yes, because preview provides enough guarantees
1403
1404     if (canBackupEverything())
1405         return; // yes, because we can back everything up
1406
1407     disableRetries(); // no, because we cannot back everything up
1408 }
1409
1410 // Normally, the body-writing code handles preview body. It can deal with
1411 // bodies of unexpected size, including those that turn out to be empty.
1412 // However, that code assumes that the body was expected and body control
1413 // structures were initialized. This is not the case when there is no body
1414 // or the body is known to be empty, because the virgin message will lack a
1415 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1416 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1417 {
1418     Must(!virginBodyWriting.active()); // one reason we handle it here
1419     Must(!virgin.body_pipe);          // another reason we handle it here
1420     Must(!preview.ad());
1421
1422     // do not add last-chunk because our Encapsulated header says null-body
1423     // addLastRequestChunk(buf);
1424     preview.wrote(0, true);
1425
1426     Must(preview.done());
1427     Must(preview.ieof());
1428 }
1429
1430 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1431 {
1432     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1433
1434     if (state.serviceWaiting)
1435         buf.append("U", 1);
1436
1437     if (virgin.body_pipe != NULL)
1438         buf.append("R", 1);
1439
1440     if (connection > 0 && !doneReading())
1441         buf.append("r", 1);
1442
1443     if (!state.doneWriting() && state.writing != State::writingInit)
1444         buf.Printf("w(%d)", state.writing);
1445
1446     if (preview.enabled()) {
1447         if (!preview.done())
1448             buf.Printf("P(%d)", (int) preview.debt());
1449     }
1450
1451     if (virginBodySending.active())
1452         buf.append("B", 1);
1453
1454     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1455         buf.Printf("p(%d)", state.parsing);
1456
1457     if (!doneSending() && state.sending != State::sendingUndecided)
1458         buf.Printf("S(%d)", state.sending);
1459
1460     if (canStartBypass)
1461         buf.append("Y", 1);
1462
1463     if (protectGroupBypass)
1464         buf.append("G", 1);
1465 }
1466
1467 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1468 {
1469     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1470
1471     if (!virgin.body_pipe)
1472         buf.append("R", 1);
1473
1474     if (state.doneWriting())
1475         buf.append("w", 1);
1476
1477     if (preview.enabled()) {
1478         if (preview.done())
1479             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1480     }
1481
1482     if (doneReading())
1483         buf.append("r", 1);
1484
1485     if (state.doneParsing())
1486         buf.append("p", 1);
1487
1488     if (doneSending())
1489         buf.append("S", 1);
1490 }
1491
1492 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1493 {
1494     return icapReply->header.getByNameListMember("Encapsulated",
1495             section, ',').size() > 0;
1496 }
1497
1498 // calculate whether there is a virgin HTTP body and
1499 // whether its expected size is known
1500 // TODO: rename because we do not just estimate
1501 void Adaptation::Icap::ModXact::estimateVirginBody()
1502 {
1503     // note: lack of size info may disable previews and 204s
1504
1505     HttpMsg *msg = virgin.header;
1506     Must(msg);
1507
1508     HttpRequestMethod method;
1509
1510     if (virgin.cause)
1511         method = virgin.cause->method;
1512     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1513         method = req->method;
1514     else
1515         method = METHOD_NONE;
1516
1517     int64_t size;
1518     // expectingBody returns true for zero-sized bodies, but we will not
1519     // get a pipe for that body, so we treat the message as bodyless
1520     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1521         debugs(93, 6, HERE << "expects virgin body from " <<
1522                virgin.body_pipe << "; size: " << size);
1523
1524         virginBody.expect(size);
1525         virginBodyWriting.plan();
1526
1527         // sign up as a body consumer
1528         Must(msg->body_pipe != NULL);
1529         Must(msg->body_pipe == virgin.body_pipe);
1530         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1531
1532         // make sure TheBackupLimit is in-sync with the buffer size
1533         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1534     } else {
1535         debugs(93, 6, HERE << "does not expect virgin body");
1536         Must(msg->body_pipe == NULL);
1537         checkConsuming();
1538     }
1539 }
1540
1541 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1542 {
1543     Must(!adapted.body_pipe);
1544     Must(!adapted.header->body_pipe);
1545     adapted.header->body_pipe = new BodyPipe(this);
1546     adapted.body_pipe = adapted.header->body_pipe;
1547     debugs(93, 7, HERE << "will supply " << what << " via " <<
1548            adapted.body_pipe << " pipe");
1549 }
1550
1551
1552 // TODO: Move SizedEstimate and Preview elsewhere
1553
1554 Adaptation::Icap::SizedEstimate::SizedEstimate()
1555         : theData(dtUnexpected)
1556 {}
1557
1558 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1559 {
1560     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1561 }
1562
1563 bool Adaptation::Icap::SizedEstimate::expected() const
1564 {
1565     return theData != dtUnexpected;
1566 }
1567
1568 bool Adaptation::Icap::SizedEstimate::knownSize() const
1569 {
1570     Must(expected());
1571     return theData != dtUnknown;
1572 }
1573
1574 uint64_t Adaptation::Icap::SizedEstimate::size() const
1575 {
1576     Must(knownSize());
1577     return static_cast<uint64_t>(theData);
1578 }
1579
1580
1581
1582 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1583 {}
1584
1585 void Adaptation::Icap::VirginBodyAct::plan()
1586 {
1587     Must(!disabled());
1588     Must(!theStart); // not started
1589     theState = stActive;
1590 }
1591
1592 void Adaptation::Icap::VirginBodyAct::disable()
1593 {
1594     theState = stDisabled;
1595 }
1596
1597 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1598 {
1599     Must(active());
1600     Must(size >= 0);
1601     theStart += static_cast<int64_t>(size);
1602 }
1603
1604 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1605 {
1606     Must(active());
1607     return static_cast<uint64_t>(theStart);
1608 }
1609
1610
1611 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1612 {}
1613
1614 void Adaptation::Icap::Preview::enable(size_t anAd)
1615 {
1616     // TODO: check for anAd not exceeding preview size limit
1617     Must(anAd >= 0);
1618     Must(!enabled());
1619     theAd = anAd;
1620     theState = stWriting;
1621 }
1622
1623 bool Adaptation::Icap::Preview::enabled() const
1624 {
1625     return theState != stDisabled;
1626 }
1627
1628 size_t Adaptation::Icap::Preview::ad() const
1629 {
1630     Must(enabled());
1631     return theAd;
1632 }
1633
1634 bool Adaptation::Icap::Preview::done() const
1635 {
1636     Must(enabled());
1637     return theState >= stIeof;
1638 }
1639
1640 bool Adaptation::Icap::Preview::ieof() const
1641 {
1642     Must(enabled());
1643     return theState == stIeof;
1644 }
1645
1646 size_t Adaptation::Icap::Preview::debt() const
1647 {
1648     Must(enabled());
1649     return done() ? 0 : (theAd - theWritten);
1650 }
1651
1652 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1653 {
1654     Must(enabled());
1655
1656     theWritten += size;
1657
1658     Must(theWritten <= theAd);
1659
1660     if (wroteEof)
1661         theState = stIeof; // written size is irrelevant
1662     else if (theWritten >= theAd)
1663         theState = stDone;
1664 }
1665
1666 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1667 {
1668     if (virgin.header == NULL)
1669         return false;
1670
1671     virgin.header->firstLineBuf(mb);
1672
1673     return true;
1674 }
1675
1676
1677 /* Adaptation::Icap::ModXactLauncher */
1678
1679 Adaptation::Icap::ModXactLauncher::ModXactLauncher(Adaptation::Initiator *anInitiator, HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1680         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1681         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", anInitiator, aService)
1682 {
1683     virgin.setHeader(virginHeader);
1684     virgin.setCause(virginCause);
1685     updateHistory(true);
1686 }
1687
1688 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1689 {
1690     Adaptation::Icap::ServiceRep::Pointer s =
1691         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1692     Must(s != NULL);
1693     return new Adaptation::Icap::ModXact(this, virgin.header, virgin.cause, s);
1694 }
1695
1696 void Adaptation::Icap::ModXactLauncher::swanSong()
1697 {
1698     debugs(93, 5, HERE << "swan sings");
1699     updateHistory(false);
1700     Adaptation::Icap::Launcher::swanSong();
1701 }
1702
1703 void Adaptation::Icap::ModXactLauncher::updateHistory(bool start)
1704 {
1705     HttpRequest *r = virgin.cause ?
1706                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1707
1708     // r should never be NULL but we play safe; TODO: add Should()
1709     if (r) {
1710         Adaptation::Icap::History::Pointer h = r->icapHistory();
1711         if (h != NULL) {
1712             if (start)
1713                 h->start("ICAPModXactLauncher");
1714             else
1715                 h->stop("ICAPModXactLauncher");
1716         }
1717     }
1718 }