src/adaptation/icap/ModXact.cc

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