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