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(HttpMsg *virginHeader,
  41                                    HttpRequest *virginCause, Adaptation::Icap::ServiceRep::Pointer &aService):
  42         AsyncJob("Adaptation::Icap::ModXact"),
  43         Adaptation::Icap::Xaction("Adaptation::Icap::ModXact", aService),
  44         virginConsumed(0),
  45         bodyParser(NULL),
  46         canStartBypass(false), // too early
  47         protectGroupBypass(true),
  48         replyHttpHeaderSize(-1),
  49         replyHttpBodySize(-1),
  50         adaptHistoryId(-1)
  51 {
  52     assert(virginHeader);
  53
  54     virgin.setHeader(virginHeader); // sets virgin.body_pipe if needed
  55     virgin.setCause(virginCause); // may be NULL
  56
  57     // adapted header and body are initialized when we parse them
  58
  59     // writing and reading ends are handled by Adaptation::Icap::Xaction
  60
  61     // encoding
  62     // nothing to do because we are using temporary buffers
  63
  64     // parsing; TODO: do not set until we parse, see ICAPOptXact
  65     icapReply = new HttpReply;
  66     icapReply->protoPrefix = "ICAP/"; // TODO: make an IcapReply class?
  67
  68     debugs(93,7, HERE << "initialized." << status());
  69 }
  70
  71 // initiator wants us to start
  72 void Adaptation::Icap::ModXact::start()
  73 {
  74     Adaptation::Icap::Xaction::start();
  75
  76     // reserve an adaptation history slot (attempts are known at this time)
  77     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
  78     if (ah != NULL)
  79         adaptHistoryId = ah->recordXactStart(service().cfg().key, icap_tr_start, attempts > 1);
  80
  81     estimateVirginBody(); // before virgin disappears!
  82
  83     canStartBypass = service().cfg().bypass;
  84
  85     // it is an ICAP violation to send request to a service w/o known OPTIONS
  86
  87     if (service().up())
  88         startWriting();
  89     else
  90         waitForService();
  91 }
  92
  93 void Adaptation::Icap::ModXact::waitForService()
  94 {
  95     Must(!state.serviceWaiting);
  96     debugs(93, 7, HERE << "will wait for the ICAP service" << status());
  97     typedef NullaryMemFunT<ModXact> Dialer;
  98     AsyncCall::Pointer call = JobCallback(93,5,
  99                                           Dialer, this, Adaptation::Icap::ModXact::noteServiceReady);
 100     service().callWhenReady(call);
 101     state.serviceWaiting = true; // after callWhenReady() which may throw
 102 }
 103
 104 void Adaptation::Icap::ModXact::noteServiceReady()
 105 {
 106     Must(state.serviceWaiting);
 107     state.serviceWaiting = false;
 108
 109     if (service().up()) {
 110         startWriting();
 111     } else {
 112         disableRetries();
 113         disableRepeats("ICAP service is unusable");
 114         throw TexcHere("ICAP service is unusable");
 115     }
 116 }
 117
 118 void Adaptation::Icap::ModXact::startWriting()
 119 {
 120     state.writing = State::writingConnect;
 121
 122     decideOnPreview(); // must be decided before we decideOnRetries
 123     decideOnRetries();
 124
 125     openConnection();
 126 }
 127
 128 // connection with the ICAP service established
 129 void Adaptation::Icap::ModXact::handleCommConnected()
 130 {
 131     Must(state.writing == State::writingConnect);
 132
 133     startReading(); // wait for early errors from the ICAP server
 134
 135     MemBuf requestBuf;
 136     requestBuf.init();
 137
 138     makeRequestHeaders(requestBuf);
 139     debugs(93, 9, HERE << "will write" << status() << ":\n" <<
 140            (requestBuf.terminate(), requestBuf.content()));
 141
 142     // write headers
 143     state.writing = State::writingHeaders;
 144     icap_tio_start = current_time;
 145     scheduleWrite(requestBuf);
 146 }
 147
 148 void Adaptation::Icap::ModXact::handleCommWrote(size_t sz)
 149 {
 150     debugs(93, 5, HERE << "Wrote " << sz << " bytes");
 151
 152     if (state.writing == State::writingHeaders)
 153         handleCommWroteHeaders();
 154     else
 155         handleCommWroteBody();
 156 }
 157
 158 void Adaptation::Icap::ModXact::handleCommWroteHeaders()
 159 {
 160     Must(state.writing == State::writingHeaders);
 161
 162     // determine next step
 163     if (preview.enabled()) {
 164         if (preview.done())
 165             decideWritingAfterPreview("zero-size");
 166         else
 167             state.writing = State::writingPreview;
 168     } else if (virginBody.expected()) {
 169         state.writing = State::writingPrime;
 170     } else {
 171         stopWriting(true);
 172         return;
 173     }
 174
 175     writeMore();
 176 }
 177
 178 void Adaptation::Icap::ModXact::writeMore()
 179 {
 180     debugs(93, 5, HERE << "checking whether to write more" << status());
 181
 182     if (writer != NULL) // already writing something
 183         return;
 184
 185     switch (state.writing) {
 186
 187     case State::writingInit:    // waiting for service OPTIONS
 188         Must(state.serviceWaiting);
 189
 190     case State::writingConnect: // waiting for the connection to establish
 191
 192     case State::writingHeaders: // waiting for the headers to be written
 193
 194     case State::writingPaused:  // waiting for the ICAP server response
 195
 196     case State::writingReallyDone: // nothing more to write
 197         return;
 198
 199     case State::writingAlmostDone: // was waiting for the last write
 200         stopWriting(false);
 201         return;
 202
 203     case State::writingPreview:
 204         writePreviewBody();
 205         return;
 206
 207     case State::writingPrime:
 208         writePrimeBody();
 209         return;
 210
 211     default:
 212         throw TexcHere("Adaptation::Icap::ModXact in bad writing state");
 213     }
 214 }
 215
 216 void Adaptation::Icap::ModXact::writePreviewBody()
 217 {
 218     debugs(93, 8, HERE << "will write Preview body from " <<
 219            virgin.body_pipe << status());
 220     Must(state.writing == State::writingPreview);
 221     Must(virgin.body_pipe != NULL);
 222
 223     const size_t sizeMax = (size_t)virgin.body_pipe->buf().contentSize();
 224     const size_t size = min(preview.debt(), sizeMax);
 225     writeSomeBody("preview body", size);
 226
 227     // change state once preview is written
 228
 229     if (preview.done())
 230         decideWritingAfterPreview("body");
 231 }
 232
 233 /// determine state.writing after we wrote the entire preview
 234 void Adaptation::Icap::ModXact::decideWritingAfterPreview(const char *kind)
 235 {
 236     if (preview.ieof()) // nothing more to write
 237         stopWriting(true);
 238     else if (state.parsing == State::psIcapHeader) // did not get a reply yet
 239         state.writing = State::writingPaused; // wait for the ICAP server reply
 240     else
 241         stopWriting(true); // ICAP server reply implies no post-preview writing
 242
 243     debugs(93, 6, HERE << "decided on writing after " << kind << " preview" <<
 244            status());
 245 }
 246
 247 void Adaptation::Icap::ModXact::writePrimeBody()
 248 {
 249     Must(state.writing == State::writingPrime);
 250     Must(virginBodyWriting.active());
 251
 252     const size_t size = (size_t)virgin.body_pipe->buf().contentSize();
 253     writeSomeBody("prime virgin body", size);
 254
 255     if (virginBodyEndReached(virginBodyWriting)) {
 256         debugs(93, 5, HERE << "wrote entire body");
 257         stopWriting(true);
 258     }
 259 }
 260
 261 void Adaptation::Icap::ModXact::writeSomeBody(const char *label, size_t size)
 262 {
 263     Must(!writer && state.writing < state.writingAlmostDone);
 264     Must(virgin.body_pipe != NULL);
 265     debugs(93, 8, HERE << "will write up to " << size << " bytes of " <<
 266            label);
 267
 268     MemBuf writeBuf; // TODO: suggest a min size based on size and lastChunk
 269
 270     writeBuf.init(); // note: we assume that last-chunk will fit
 271
 272     const size_t writableSize = virginContentSize(virginBodyWriting);
 273     const size_t chunkSize = min(writableSize, size);
 274
 275     if (chunkSize) {
 276         debugs(93, 7, HERE << "will write " << chunkSize <<
 277                "-byte chunk of " << label);
 278
 279         openChunk(writeBuf, chunkSize, false);
 280         writeBuf.append(virginContentData(virginBodyWriting), chunkSize);
 281         closeChunk(writeBuf);
 282
 283         virginBodyWriting.progress(chunkSize);
 284         virginConsume();
 285     } else {
 286         debugs(93, 7, HERE << "has no writable " << label << " content");
 287     }
 288
 289     const bool wroteEof = virginBodyEndReached(virginBodyWriting);
 290     bool lastChunk = wroteEof;
 291     if (state.writing == State::writingPreview) {
 292         preview.wrote(chunkSize, wroteEof); // even if wrote nothing
 293         lastChunk = lastChunk || preview.done();
 294     }
 295
 296     if (lastChunk) {
 297         debugs(93, 8, HERE << "will write last-chunk of " << label);
 298         addLastRequestChunk(writeBuf);
 299     }
 300
 301     debugs(93, 7, HERE << "will write " << writeBuf.contentSize()
 302            << " raw bytes of " << label);
 303
 304     if (writeBuf.hasContent()) {
 305         scheduleWrite(writeBuf); // comm will free the chunk
 306     } else {
 307         writeBuf.clean();
 308     }
 309 }
 310
 311 void Adaptation::Icap::ModXact::addLastRequestChunk(MemBuf &buf)
 312 {
 313     const bool ieof = state.writing == State::writingPreview && preview.ieof();
 314     openChunk(buf, 0, ieof);
 315     closeChunk(buf);
 316 }
 317
 318 void Adaptation::Icap::ModXact::openChunk(MemBuf &buf, size_t chunkSize, bool ieof)
 319 {
 320     buf.Printf((ieof ? "%x; ieof\r\n" : "%x\r\n"), (int) chunkSize);
 321 }
 322
 323 void Adaptation::Icap::ModXact::closeChunk(MemBuf &buf)
 324 {
 325     buf.append(ICAP::crlf, 2); // chunk-terminating CRLF
 326 }
 327
 328 const HttpRequest &Adaptation::Icap::ModXact::virginRequest() const
 329 {
 330     const HttpRequest *request = virgin.cause ?
 331                                  virgin.cause : dynamic_cast<const HttpRequest*>(virgin.header);
 332     Must(request);
 333     return *request;
 334 }
 335
 336 // did the activity reached the end of the virgin body?
 337 bool Adaptation::Icap::ModXact::virginBodyEndReached(const Adaptation::Icap::VirginBodyAct &act) const
 338 {
 339     return
 340         !act.active() || // did all (assuming it was originally planned)
 341         !virgin.body_pipe->expectMoreAfter(act.offset()); // wont have more
 342 }
 343
 344 // the size of buffered virgin body data available for the specified activity
 345 // if this size is zero, we may be done or may be waiting for more data
 346 size_t Adaptation::Icap::ModXact::virginContentSize(const Adaptation::Icap::VirginBodyAct &act) const
 347 {
 348     Must(act.active());
 349     // asbolute start of unprocessed data
 350     const uint64_t dataStart = act.offset();
 351     // absolute end of buffered data
 352     const uint64_t dataEnd = virginConsumed + virgin.body_pipe->buf().contentSize();
 353     Must(virginConsumed <= dataStart && dataStart <= dataEnd);
 354     return static_cast<size_t>(dataEnd - dataStart);
 355 }
 356
 357 // pointer to buffered virgin body data available for the specified activity
 358 const char *Adaptation::Icap::ModXact::virginContentData(const Adaptation::Icap::VirginBodyAct &act) const
 359 {
 360     Must(act.active());
 361     const uint64_t dataStart = act.offset();
 362     Must(virginConsumed <= dataStart);
 363     return virgin.body_pipe->buf().content() + static_cast<size_t>(dataStart-virginConsumed);
 364 }
 365
 366 void Adaptation::Icap::ModXact::virginConsume()
 367 {
 368     debugs(93, 9, HERE << "consumption guards: " << !virgin.body_pipe << isRetriable <<
 369            isRepeatable << canStartBypass << protectGroupBypass);
 370
 371     if (!virgin.body_pipe)
 372         return; // nothing to consume
 373
 374     if (isRetriable)
 375         return; // do not consume if we may have to retry later
 376
 377     BodyPipe &bp = *virgin.body_pipe;
 378     const bool wantToPostpone = isRepeatable || canStartBypass || protectGroupBypass;
 379
 380     // Why > 2? HttpState does not use the last bytes in the buffer
 381     // because delayAwareRead() is arguably broken. See
 382     // HttpStateData::maybeReadVirginBody for more details.
 383     if (wantToPostpone && bp.buf().spaceSize() > 2) {
 384         // Postponing may increase memory footprint and slow the HTTP side
 385         // down. Not postponing may increase the number of ICAP errors
 386         // if the ICAP service fails. We may also use "potential" space to
 387         // postpone more aggressively. Should the trade-off be configurable?
 388         debugs(93, 8, HERE << "postponing consumption from " << bp.status());
 389         return;
 390     }
 391
 392     const size_t have = static_cast<size_t>(bp.buf().contentSize());
 393     const uint64_t end = virginConsumed + have;
 394     uint64_t offset = end;
 395
 396     debugs(93, 9, HERE << "max virgin consumption offset=" << offset <<
 397            " acts " << virginBodyWriting.active() << virginBodySending.active() <<
 398            " consumed=" << virginConsumed <<
 399            " from " << virgin.body_pipe->status());
 400
 401     if (virginBodyWriting.active())
 402         offset = min(virginBodyWriting.offset(), offset);
 403
 404     if (virginBodySending.active())
 405         offset = min(virginBodySending.offset(), offset);
 406
 407     Must(virginConsumed <= offset && offset <= end);
 408
 409     if (const size_t size = static_cast<size_t>(offset - virginConsumed)) {
 410         debugs(93, 8, HERE << "consuming " << size << " out of " << have <<
 411                " virgin body bytes");
 412         bp.consume(size);
 413         virginConsumed += size;
 414         Must(!isRetriable); // or we should not be consuming
 415         disableRepeats("consumed content");
 416         disableBypass("consumed content", true);
 417     }
 418 }
 419
 420 void Adaptation::Icap::ModXact::handleCommWroteBody()
 421 {
 422     writeMore();
 423 }
 424
 425 // Called when we do not expect to call comm_write anymore.
 426 // We may have a pending write though.
 427 // If stopping nicely, we will just wait for that pending write, if any.
 428 void Adaptation::Icap::ModXact::stopWriting(bool nicely)
 429 {
 430     if (state.writing == State::writingReallyDone)
 431         return;
 432
 433     if (writer != NULL) {
 434         if (nicely) {
 435             debugs(93, 7, HERE << "will wait for the last write" << status());
 436             state.writing = State::writingAlmostDone; // may already be set
 437             checkConsuming();
 438             return;
 439         }
 440         debugs(93, 3, HERE << "will NOT wait for the last write" << status());
 441
 442         // Comm does not have an interface to clear the writer callback nicely,
 443         // but without clearing the writer we cannot recycle the connection.
 444         // We prevent connection reuse and hope that we can handle a callback
 445         // call at any time, usually in the middle of the destruction sequence!
 446         // Somebody should add comm_remove_write_handler() to comm API.
 447         reuseConnection = false;
 448         ignoreLastWrite = true;
 449     }
 450
 451     debugs(93, 7, HERE << "will no longer write" << status());
 452     if (virginBodyWriting.active()) {
 453         virginBodyWriting.disable();
 454         virginConsume();
 455     }
 456     state.writing = State::writingReallyDone;
 457     checkConsuming();
 458 }
 459
 460 void Adaptation::Icap::ModXact::stopBackup()
 461 {
 462     if (!virginBodySending.active())
 463         return;
 464
 465     debugs(93, 7, HERE << "will no longer backup" << status());
 466     virginBodySending.disable();
 467     virginConsume();
 468 }
 469
 470 bool Adaptation::Icap::ModXact::doneAll() const
 471 {
 472     return Adaptation::Icap::Xaction::doneAll() && !state.serviceWaiting &&
 473            doneSending() &&
 474            doneReading() && state.doneWriting();
 475 }
 476
 477 void Adaptation::Icap::ModXact::startReading()
 478 {
 479     Must(connection >= 0);
 480     Must(!reader);
 481     Must(!adapted.header);
 482     Must(!adapted.body_pipe);
 483
 484     // we use the same buffer for headers and body and then consume headers
 485     readMore();
 486 }
 487
 488 void Adaptation::Icap::ModXact::readMore()
 489 {
 490     if (reader != NULL || doneReading()) {
 491         debugs(93,3,HERE << "returning from readMore because reader or doneReading()");
 492         return;
 493     }
 494
 495     // do not fill readBuf if we have no space to store the result
 496     if (adapted.body_pipe != NULL &&
 497             !adapted.body_pipe->buf().hasPotentialSpace()) {
 498         debugs(93,3,HERE << "not reading because ICAP reply pipe is full");
 499         return;
 500     }
 501
 502     if (readBuf.hasSpace())
 503         scheduleRead();
 504     else
 505         debugs(93,3,HERE << "nothing to do because !readBuf.hasSpace()");
 506 }
 507
 508 // comm module read a portion of the ICAP response for us
 509 void Adaptation::Icap::ModXact::handleCommRead(size_t)
 510 {
 511     Must(!state.doneParsing());
 512     icap_tio_finish = current_time;
 513     parseMore();
 514     readMore();
 515 }
 516
 517 void Adaptation::Icap::ModXact::echoMore()
 518 {
 519     Must(state.sending == State::sendingVirgin);
 520     Must(adapted.body_pipe != NULL);
 521     Must(virginBodySending.active());
 522
 523     const size_t sizeMax = virginContentSize(virginBodySending);
 524     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes from " <<
 525            virgin.body_pipe->status());
 526     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes to   " <<
 527            adapted.body_pipe->status());
 528
 529     if (sizeMax > 0) {
 530         const size_t size = adapted.body_pipe->putMoreData(virginContentData(virginBodySending), sizeMax);
 531         debugs(93,5, HERE << "echoed " << size << " out of " << sizeMax <<
 532                " bytes");
 533         virginBodySending.progress(size);
 534         disableRepeats("echoed content");
 535         disableBypass("echoed content", true);
 536         virginConsume();
 537     }
 538
 539     if (virginBodyEndReached(virginBodySending)) {
 540         debugs(93, 5, HERE << "echoed all" << status());
 541         stopSending(true);
 542     } else {
 543         debugs(93, 5, HERE << "has " <<
 544                virgin.body_pipe->buf().contentSize() << " bytes " <<
 545                "and expects more to echo" << status());
 546         // TODO: timeout if virgin or adapted pipes are broken
 547     }
 548 }
 549
 550 bool Adaptation::Icap::ModXact::doneSending() const
 551 {
 552     return state.sending == State::sendingDone;
 553 }
 554
 555 // stop (or do not start) sending adapted message body
 556 void Adaptation::Icap::ModXact::stopSending(bool nicely)
 557 {
 558     debugs(93, 7, HERE << "Enter stop sending ");
 559     if (doneSending())
 560         return;
 561     debugs(93, 7, HERE << "Proceed with stop sending ");
 562
 563     if (state.sending != State::sendingUndecided) {
 564         debugs(93, 7, HERE << "will no longer send" << status());
 565         if (adapted.body_pipe != NULL) {
 566             virginBodySending.disable();
 567             // we may leave debts if we were echoing and the virgin
 568             // body_pipe got exhausted before we echoed all planned bytes
 569             const bool leftDebts = adapted.body_pipe->needsMoreData();
 570             stopProducingFor(adapted.body_pipe, nicely && !leftDebts);
 571         }
 572     } else {
 573         debugs(93, 7, HERE << "will not start sending" << status());
 574         Must(!adapted.body_pipe);
 575     }
 576
 577     state.sending = State::sendingDone;
 578     checkConsuming();
 579 }
 580
 581 // should be called after certain state.writing or state.sending changes
 582 void Adaptation::Icap::ModXact::checkConsuming()
 583 {
 584     // quit if we already stopped or are still using the pipe
 585     if (!virgin.body_pipe || !state.doneConsumingVirgin())
 586         return;
 587
 588     debugs(93, 7, HERE << "will stop consuming" << status());
 589     stopConsumingFrom(virgin.body_pipe);
 590 }
 591
 592 void Adaptation::Icap::ModXact::parseMore()
 593 {
 594     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " bytes to parse" <<
 595            status());
 596     debugs(93, 5, HERE << "\n" << readBuf.content());
 597
 598     if (state.parsingHeaders())
 599         parseHeaders();
 600
 601     if (state.parsing == State::psBody)
 602         parseBody();
 603 }
 604
 605 void Adaptation::Icap::ModXact::callException(const std::exception &e)
 606 {
 607     if (!canStartBypass || isRetriable) {
 608         Adaptation::Icap::Xaction::callException(e);
 609         return;
 610     }
 611
 612     try {
 613         debugs(93, 3, HERE << "bypassing " << inCall << " exception: " <<
 614                e.what() << ' ' << status());
 615         bypassFailure();
 616     } catch (const std::exception &bypassE) {
 617         Adaptation::Icap::Xaction::callException(bypassE);
 618     }
 619 }
 620
 621 void Adaptation::Icap::ModXact::bypassFailure()
 622 {
 623     disableBypass("already started to bypass", false);
 624
 625     Must(!isRetriable); // or we should not be bypassing
 626     // TODO: should the same be enforced for isRepeatable? Check icap_repeat??
 627
 628     prepEchoing();
 629
 630     startSending();
 631
 632     // end all activities associated with the ICAP server
 633
 634     stopParsing();
 635
 636     stopWriting(true); // or should we force it?
 637     if (connection >= 0) {
 638         reuseConnection = false; // be conservative
 639         cancelRead(); // may not work; and we cannot stop connecting either
 640         if (!doneWithIo())
 641             debugs(93, 7, HERE << "Warning: bypass failed to stop I/O" << status());
 642     }
 643 }
 644
 645 void Adaptation::Icap::ModXact::disableBypass(const char *reason, bool includingGroupBypass)
 646 {
 647     if (canStartBypass) {
 648         debugs(93,7, HERE << "will never start bypass because " << reason);
 649         canStartBypass = false;
 650     }
 651     if (protectGroupBypass && includingGroupBypass) {
 652         debugs(93,7, HERE << "not protecting group bypass because " << reason);
 653         protectGroupBypass = false;
 654     }
 655 }
 656
 657
 658
 659 // note that allocation for echoing is done in handle204NoContent()
 660 void Adaptation::Icap::ModXact::maybeAllocateHttpMsg()
 661 {
 662     if (adapted.header) // already allocated
 663         return;
 664
 665     if (gotEncapsulated("res-hdr")) {
 666         adapted.setHeader(new HttpReply);
 667         setOutcome(service().cfg().method == ICAP::methodReqmod ?
 668                    xoSatisfied : xoModified);
 669     } else if (gotEncapsulated("req-hdr")) {
 670         adapted.setHeader(new HttpRequest);
 671         setOutcome(xoModified);
 672     } else
 673         throw TexcHere("Neither res-hdr nor req-hdr in maybeAllocateHttpMsg()");
 674 }
 675
 676 void Adaptation::Icap::ModXact::parseHeaders()
 677 {
 678     Must(state.parsingHeaders());
 679
 680     if (state.parsing == State::psIcapHeader) {
 681         debugs(93, 5, HERE << "parse ICAP headers");
 682         parseIcapHead();
 683     }
 684
 685     if (state.parsing == State::psHttpHeader) {
 686         debugs(93, 5, HERE << "parse HTTP headers");
 687         parseHttpHead();
 688     }
 689
 690     if (state.parsingHeaders()) { // need more data
 691         Must(mayReadMore());
 692         return;
 693     }
 694
 695     startSending();
 696 }
 697
 698 // called after parsing all headers or when bypassing an exception
 699 void Adaptation::Icap::ModXact::startSending()
 700 {
 701     disableRepeats("sent headers");
 702     disableBypass("sent headers", true);
 703     sendAnswer(adapted.header);
 704
 705     if (state.sending == State::sendingVirgin)
 706         echoMore();
 707 }
 708
 709 void Adaptation::Icap::ModXact::parseIcapHead()
 710 {
 711     Must(state.sending == State::sendingUndecided);
 712
 713     if (!parseHead(icapReply))
 714         return;
 715
 716     if (httpHeaderHasConnDir(&icapReply->header, "close")) {
 717         debugs(93, 5, HERE << "found connection close");
 718         reuseConnection = false;
 719     }
 720
 721     switch (icapReply->sline.status) {
 722
 723     case 100:
 724         handle100Continue();
 725         break;
 726
 727     case 200:
 728     case 201: // Symantec Scan Engine 5.0 and later when modifying HTTP msg
 729
 730         if (!validate200Ok()) {
 731             throw TexcHere("Invalid ICAP Response");
 732         } else {
 733             handle200Ok();
 734         }
 735
 736         break;
 737
 738     case 204:
 739         handle204NoContent();
 740         break;
 741
 742     case 206:
 743         handle206PartialContent();
 744         break;
 745
 746     default:
 747         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 748         handleUnknownScode();
 749         break;
 750     }
 751
 752     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 753     if (!request)
 754         request = &virginRequest();
 755
 756     // update the cross-transactional database if needed (all status codes!)
 757     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 758         Adaptation::History::Pointer ah = request->adaptHistory(true);
 759         if (ah != NULL) {
 760             const String val = icapReply->header.getByName(xxName);
 761             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 762                 ah->updateXxRecord(xxName, val);
 763         }
 764     }
 765
 766     // update the adaptation plan if needed (all status codes!)
 767     if (service().cfg().routing) {
 768         String services;
 769         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 770             Adaptation::History::Pointer ah = request->adaptHistory(true);
 771             if (ah != NULL)
 772                 ah->updateNextServices(services);
 773         }
 774     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 775
 776     // We need to store received ICAP headers for <icapLastHeader logformat option.
 777     // If we already have stored headers from previous ICAP transaction related to this
 778     // request, old headers will be replaced with the new one.
 779
 780     Adaptation::Icap::History::Pointer h = request->icapHistory();
 781     if (h != NULL) {
 782         h->mergeIcapHeaders(&icapReply->header);
 783         h->setIcapLastHeader(&icapReply->header);
 784     }
 785
 786     // handle100Continue() manages state.writing on its own.
 787     // Non-100 status means the server needs no postPreview data from us.
 788     if (state.writing == State::writingPaused)
 789         stopWriting(true);
 790 }
 791
 792 bool Adaptation::Icap::ModXact::validate200Ok()
 793 {
 794     if (ICAP::methodRespmod == service().cfg().method) {
 795         if (!gotEncapsulated("res-hdr"))
 796             return false;
 797
 798         return true;
 799     }
 800
 801     if (ICAP::methodReqmod == service().cfg().method) {
 802         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 803             return false;
 804
 805         return true;
 806     }
 807
 808     return false;
 809 }
 810
 811 void Adaptation::Icap::ModXact::handle100Continue()
 812 {
 813     Must(state.writing == State::writingPaused);
 814     // server must not respond before the end of preview: we may send ieof
 815     Must(preview.enabled() && preview.done() && !preview.ieof());
 816
 817     // 100 "Continue" cancels our Preview commitment,
 818     // but not commitment to handle 204 or 206 outside Preview
 819     if (!state.allowedPostview204 && !state.allowedPostview206)
 820         stopBackup();
 821
 822     state.parsing = State::psIcapHeader; // eventually
 823     icapReply->reset();
 824
 825     state.writing = State::writingPrime;
 826
 827     writeMore();
 828 }
 829
 830 void Adaptation::Icap::ModXact::handle200Ok()
 831 {
 832     state.parsing = State::psHttpHeader;
 833     state.sending = State::sendingAdapted;
 834     stopBackup();
 835     checkConsuming();
 836 }
 837
 838 void Adaptation::Icap::ModXact::handle204NoContent()
 839 {
 840     stopParsing();
 841     prepEchoing();
 842 }
 843
 844 void Adaptation::Icap::ModXact::handle206PartialContent()
 845 {
 846     if (state.writing == State::writingPaused) {
 847         Must(preview.enabled());
 848         Must(state.allowedPreview206);
 849         debugs(93, 7, HERE << "206 inside preview");
 850     } else {
 851         Must(state.writing > State::writingPaused);
 852         Must(state.allowedPostview206);
 853         debugs(93, 7, HERE << "206 outside preview");
 854     }
 855     state.parsing = State::psHttpHeader;
 856     state.sending = State::sendingAdapted;
 857     state.readyForUob = true;
 858     checkConsuming();
 859 }
 860
 861 // Called when we receive a 204 No Content response and
 862 // when we are trying to bypass a service failure.
 863 // We actually start sending (echoig or not) in startSending.
 864 void Adaptation::Icap::ModXact::prepEchoing()
 865 {
 866     disableRepeats("preparing to echo content");
 867     disableBypass("preparing to echo content", true);
 868     setOutcome(xoEcho);
 869
 870     // We want to clone the HTTP message, but we do not want
 871     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 872     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 873     // Instead, we simply write the HTTP message and "clone" it by parsing.
 874     // TODO: use HttpMsg::clone()!
 875
 876     HttpMsg *oldHead = virgin.header;
 877     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 878
 879     MemBuf httpBuf;
 880
 881     // write the virgin message into a memory buffer
 882     httpBuf.init();
 883     packHead(httpBuf, oldHead);
 884
 885     // allocate the adapted message and copy metainfo
 886     Must(!adapted.header);
 887     {
 888         HttpMsg::Pointer newHead;
 889         if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 890             HttpRequest::Pointer newR(new HttpRequest);
 891             newR->canonical = oldR->canonical ?
 892                               xstrdup(oldR->canonical) : NULL; // parse() does not set it
 893             newHead = newR;
 894         } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 895             newHead = new HttpReply;
 896         }
 897         Must(newHead != NULL);
 898
 899         newHead->inheritProperties(oldHead);
 900
 901         adapted.setHeader(newHead);
 902     }
 903
 904     // parse the buffer back
 905     http_status error = HTTP_STATUS_NONE;
 906
 907     Must(adapted.header->parse(&httpBuf, true, &error));
 908
 909     Must(adapted.header->hdr_sz == httpBuf.contentSize()); // no leftovers
 910
 911     httpBuf.clean();
 912
 913     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 914            adapted.header);
 915
 916     // setup adapted body pipe if needed
 917     if (oldHead->body_pipe != NULL) {
 918         debugs(93, 7, HERE << "will echo virgin body from " <<
 919                oldHead->body_pipe);
 920         if (!virginBodySending.active())
 921             virginBodySending.plan(); // will throw if not possible
 922         state.sending = State::sendingVirgin;
 923         checkConsuming();
 924
 925         // TODO: optimize: is it possible to just use the oldHead pipe and
 926         // remove ICAP from the loop? This echoing is probably a common case!
 927         makeAdaptedBodyPipe("echoed virgin response");
 928         if (oldHead->body_pipe->bodySizeKnown())
 929             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 930         debugs(93, 7, HERE << "will echo virgin body to " <<
 931                adapted.body_pipe);
 932     } else {
 933         debugs(93, 7, HERE << "no virgin body to echo");
 934         stopSending(true);
 935     }
 936 }
 937
 938 /// Called when we received use-original-body chunk extension in 206 response.
 939 /// We actually start sending (echoing or not) in startSending().
 940 void Adaptation::Icap::ModXact::prepPartialBodyEchoing(uint64_t pos)
 941 {
 942     Must(virginBodySending.active());
 943     Must(virgin.header->body_pipe != NULL);
 944
 945     setOutcome(xoPartEcho);
 946
 947     debugs(93, 7, HERE << "will echo virgin body suffix from " <<
 948            virgin.header->body_pipe << " offset " << pos );
 949
 950     // check that use-original-body=N does not point beyond buffered data
 951     const uint64_t virginDataEnd = virginConsumed +
 952                                    virgin.body_pipe->buf().contentSize();
 953     Must(pos <= virginDataEnd);
 954     virginBodySending.progress(static_cast<size_t>(pos));
 955
 956     state.sending = State::sendingVirgin;
 957     checkConsuming();
 958
 959     if (virgin.header->body_pipe->bodySizeKnown())
 960         adapted.body_pipe->expectProductionEndAfter(virgin.header->body_pipe->bodySize() - pos);
 961
 962     debugs(93, 7, HERE << "will echo virgin body suffix to " <<
 963            adapted.body_pipe);
 964
 965     // Start echoing data
 966     echoMore();
 967 }
 968
 969 void Adaptation::Icap::ModXact::handleUnknownScode()
 970 {
 971     stopParsing();
 972     stopBackup();
 973     // TODO: mark connection as "bad"
 974
 975     // Terminate the transaction; we do not know how to handle this response.
 976     throw TexcHere("Unsupported ICAP status code");
 977 }
 978
 979 void Adaptation::Icap::ModXact::parseHttpHead()
 980 {
 981     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
 982         replyHttpHeaderSize = 0;
 983         maybeAllocateHttpMsg();
 984
 985         if (!parseHead(adapted.header))
 986             return; // need more header data
 987
 988         if (adapted.header)
 989             replyHttpHeaderSize = adapted.header->hdr_sz;
 990
 991         if (dynamic_cast<HttpRequest*>(adapted.header)) {
 992             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
 993             Must(oldR);
 994             // TODO: the adapted request did not really originate from the
 995             // client; give proxy admin an option to prevent copying of
 996             // sensitive client information here. See the following thread:
 997             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
 998         }
 999
1000         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
1001         if (adapted.header)
1002             adapted.header->inheritProperties(virgin.header);
1003     }
1004
1005     decideOnParsingBody();
1006 }
1007
1008 // parses both HTTP and ICAP headers
1009 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
1010 {
1011     Must(head);
1012     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
1013            "; state: " << state.parsing);
1014
1015     http_status error = HTTP_STATUS_NONE;
1016     const bool parsed = head->parse(&readBuf, commEof, &error);
1017     Must(parsed || !error); // success or need more data
1018
1019     if (!parsed) { // need more data
1020         debugs(93, 5, HERE << "parse failed, need more data, return false");
1021         head->reset();
1022         return false;
1023     }
1024
1025     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
1026         urlCanonical(r); // parse does not set HttpRequest::canonical
1027
1028     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
1029     readBuf.consume(head->hdr_sz);
1030     return true;
1031 }
1032
1033 void Adaptation::Icap::ModXact::decideOnParsingBody()
1034 {
1035     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
1036         debugs(93, 5, HERE << "expecting a body");
1037         state.parsing = State::psBody;
1038         replyHttpBodySize = 0;
1039         bodyParser = new ChunkedCodingParser;
1040         makeAdaptedBodyPipe("adapted response from the ICAP server");
1041         Must(state.sending == State::sendingAdapted);
1042     } else {
1043         debugs(93, 5, HERE << "not expecting a body");
1044         stopParsing();
1045         stopSending(true);
1046     }
1047 }
1048
1049 void Adaptation::Icap::ModXact::parseBody()
1050 {
1051     Must(state.parsing == State::psBody);
1052     Must(bodyParser);
1053
1054     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
1055
1056     // the parser will throw on errors
1057     BodyPipeCheckout bpc(*adapted.body_pipe);
1058     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
1059     bpc.checkIn();
1060
1061     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
1062            "parse; parsed all: " << parsed);
1063     replyHttpBodySize += adapted.body_pipe->buf().contentSize();
1064
1065     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
1066     // TODO: do we really need this if we disable when sending headers?
1067     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
1068         disableRepeats("sent adapted content");
1069         disableBypass("sent adapted content", true);
1070     }
1071
1072     if (parsed) {
1073         if (state.readyForUob && bodyParser->useOriginBody >= 0) {
1074             prepPartialBodyEchoing(
1075                 static_cast<uint64_t>(bodyParser->useOriginBody));
1076             stopParsing();
1077             return;
1078         }
1079
1080         stopParsing();
1081         stopSending(true); // the parser succeeds only if all parsed data fits
1082         return;
1083     }
1084
1085     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1086
1087     if (bodyParser->needsMoreData()) {
1088         debugs(93,3,HERE << this);
1089         Must(mayReadMore());
1090         readMore();
1091     }
1092
1093     if (bodyParser->needsMoreSpace()) {
1094         Must(!doneSending()); // can hope for more space
1095         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1096         // TODO: there should be a timeout in case the sink is broken
1097         // or cannot consume partial content (while we need more space)
1098     }
1099 }
1100
1101 void Adaptation::Icap::ModXact::stopParsing()
1102 {
1103     if (state.parsing == State::psDone)
1104         return;
1105
1106     debugs(93, 7, HERE << "will no longer parse" << status());
1107
1108     delete bodyParser;
1109
1110     bodyParser = NULL;
1111
1112     state.parsing = State::psDone;
1113 }
1114
1115 // HTTP side added virgin body data
1116 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1117 {
1118     writeMore();
1119
1120     if (state.sending == State::sendingVirgin)
1121         echoMore();
1122 }
1123
1124 // HTTP side sent us all virgin info
1125 void Adaptation::Icap::ModXact::noteBodyProductionEnded(BodyPipe::Pointer)
1126 {
1127     Must(virgin.body_pipe->productionEnded());
1128
1129     // push writer and sender in case we were waiting for the last-chunk
1130     writeMore();
1131
1132     if (state.sending == State::sendingVirgin)
1133         echoMore();
1134 }
1135
1136 // body producer aborted, but the initiator may still want to know
1137 // the answer, even though the HTTP message has been truncated
1138 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1139 {
1140     Must(virgin.body_pipe->productionEnded());
1141
1142     // push writer and sender in case we were waiting for the last-chunk
1143     writeMore();
1144
1145     if (state.sending == State::sendingVirgin)
1146         echoMore();
1147 }
1148
1149 // adapted body consumer wants more adapted data and
1150 // possibly freed some buffer space
1151 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1152 {
1153     if (state.sending == State::sendingVirgin)
1154         echoMore();
1155     else if (state.sending == State::sendingAdapted)
1156         parseMore();
1157     else
1158         Must(state.sending == State::sendingUndecided);
1159 }
1160
1161 // adapted body consumer aborted
1162 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1163 {
1164     mustStop("adapted body consumer aborted");
1165 }
1166
1167 Adaptation::Icap::ModXact::~ModXact()
1168 {
1169     delete bodyParser;
1170 }
1171
1172 // internal cleanup
1173 void Adaptation::Icap::ModXact::swanSong()
1174 {
1175     debugs(93, 5, HERE << "swan sings" << status());
1176
1177     stopWriting(false);
1178     stopSending(false);
1179
1180     // update adaptation history if start was called and we reserved a slot
1181     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1182     if (ah != NULL && adaptHistoryId >= 0)
1183         ah->recordXactFinish(adaptHistoryId);
1184
1185     Adaptation::Icap::Xaction::swanSong();
1186 }
1187
1188 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1189
1190 void Adaptation::Icap::ModXact::finalizeLogInfo()
1191 {
1192     HttpRequest * request_ = NULL;
1193     HttpReply * reply_ = NULL;
1194     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1195         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1196         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1197     }
1198
1199     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1200     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1201     al.icp.opcode = ICP_INVALID;
1202     al.url = h->log_uri.termedBuf();
1203     const Adaptation::Icap::ServiceRep  &s = service();
1204     al.icap.reqMethod = s.cfg().method;
1205
1206     al.cache.caddr = request_->client_addr;
1207
1208     al.request = HTTPMSGLOCK(request_);
1209     if (reply_)
1210         al.reply = HTTPMSGLOCK(reply_);
1211     else
1212         al.reply = NULL;
1213
1214     if (h->rfc931.size())
1215         al.cache.rfc931 = h->rfc931.termedBuf();
1216
1217 #if USE_SSL
1218     if (h->ssluser.size())
1219         al.cache.ssluser = h->ssluser.termedBuf();
1220 #endif
1221     al.cache.code = h->logType;
1222     al.cache.requestSize = h->req_sz;
1223
1224     // leave al.icap.bodyBytesRead negative if no body
1225     if (replyHttpHeaderSize >= 0 || replyHttpBodySize >= 0) {
1226         const int64_t zero = 0; // to make max() argument types the same
1227         al.icap.bodyBytesRead =
1228             max(zero, replyHttpHeaderSize) + max(zero, replyHttpBodySize);
1229     }
1230
1231     if (reply_) {
1232         al.http.code = reply_->sline.status;
1233         al.http.content_type = reply_->content_type.termedBuf();
1234         if (replyHttpBodySize >= 0) {
1235             al.cache.replySize = replyHttpBodySize + reply_->hdr_sz;
1236             al.cache.highOffset = replyHttpBodySize;
1237         }
1238         //don't set al.cache.objectSize because it hasn't exist yet
1239
1240         Packer p;
1241         MemBuf mb;
1242
1243         mb.init();
1244         packerToMemInit(&p, &mb);
1245
1246         reply_->header.packInto(&p);
1247         al.headers.reply = xstrdup(mb.buf);
1248
1249         packerClean(&p);
1250         mb.clean();
1251     }
1252     prepareLogWithRequestDetails(request_, &al);
1253     Xaction::finalizeLogInfo();
1254 }
1255
1256
1257 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1258 {
1259     char ntoabuf[MAX_IPSTRLEN];
1260     /*
1261      * XXX These should use HttpHdr interfaces instead of Printfs
1262      */
1263     const Adaptation::ServiceConfig &s = service().cfg();
1264     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1265     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1266     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1267
1268     if (!TheConfig.reuse_connections)
1269         buf.Printf("Connection: close\r\n");
1270
1271     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1272     // as ICAP headers.
1273     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1274         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1275         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1276     }
1277
1278     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1279         String vh=virgin.header->header.getByName("Proxy-Authorization");
1280         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1281     }
1282
1283     const HttpRequest *request = &virginRequest();
1284
1285     // share the cross-transactional database records if needed
1286     if (Adaptation::Config::masterx_shared_name) {
1287         Adaptation::History::Pointer ah = request->adaptHistory(true);
1288         if (ah != NULL) {
1289             String name, value;
1290             if (ah->getXxRecord(name, value)) {
1291                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1292                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1293             }
1294         }
1295     }
1296
1297
1298     buf.Printf("Encapsulated: ");
1299
1300     MemBuf httpBuf;
1301
1302     httpBuf.init();
1303
1304     // build HTTP request header, if any
1305     ICAP::Method m = s.method;
1306
1307     // to simplify, we could assume that request is always available
1308
1309     String urlPath;
1310     if (request) {
1311         urlPath = request->urlpath;
1312         if (ICAP::methodRespmod == m)
1313             encapsulateHead(buf, "req-hdr", httpBuf, request);
1314         else if (ICAP::methodReqmod == m)
1315             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1316     }
1317
1318     if (ICAP::methodRespmod == m)
1319         if (const HttpMsg *prime = virgin.header)
1320             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1321
1322     if (!virginBody.expected())
1323         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1324     else if (ICAP::methodReqmod == m)
1325         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1326     else
1327         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1328
1329     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1330
1331     if (preview.enabled()) {
1332         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1333         if (!virginBody.expected()) // there is no body to preview
1334             finishNullOrEmptyBodyPreview(httpBuf);
1335     }
1336
1337     makeAllowHeader(buf);
1338
1339     if (TheConfig.send_client_ip && request) {
1340         Ip::Address client_addr;
1341 #if FOLLOW_X_FORWARDED_FOR
1342         if (TheConfig.icap_uses_indirect_client) {
1343             client_addr = request->indirect_client_addr;
1344         } else
1345 #endif
1346             client_addr = request->client_addr;
1347         if (!client_addr.IsAnyAddr() && !client_addr.IsNoAddr())
1348             buf.Printf("X-Client-IP: %s\r\n", client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1349     }
1350
1351     if (TheConfig.send_client_username && request)
1352         makeUsernameHeader(request, buf);
1353
1354     // fprintf(stderr, "%s\n", buf.content());
1355
1356     buf.append(ICAP::crlf, 2); // terminate ICAP header
1357
1358     // fill icapRequest for logging
1359     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1360
1361     // start ICAP request body with encapsulated HTTP headers
1362     buf.append(httpBuf.content(), httpBuf.contentSize());
1363
1364     httpBuf.clean();
1365 }
1366
1367 // decides which Allow values to write and updates the request buffer
1368 void Adaptation::Icap::ModXact::makeAllowHeader(MemBuf &buf)
1369 {
1370     const bool allow204in = preview.enabled(); // TODO: add shouldAllow204in()
1371     const bool allow204out = state.allowedPostview204 = shouldAllow204();
1372     const bool allow206in = state.allowedPreview206 = shouldAllow206in();
1373     const bool allow206out = state.allowedPostview206 = shouldAllow206out();
1374
1375     debugs(93,9, HERE << "Allows: " << allow204in << allow204out <<
1376            allow206in << allow206out);
1377
1378     const bool allow204 = allow204in || allow204out;
1379     const bool allow206 = allow206in || allow206out;
1380
1381     if (!allow204 && !allow206)
1382         return; // nothing to do
1383
1384     if (virginBody.expected()) // if there is a virgin body, plan to send it
1385         virginBodySending.plan();
1386
1387     // writing Preview:...   means we will honor 204 inside preview
1388     // writing Allow/204     means we will honor 204 outside preview
1389     // writing Allow:206     means we will honor 206 inside preview
1390     // writing Allow:204,206 means we will honor 206 outside preview
1391     const char *allowHeader = NULL;
1392     if (allow204out && allow206)
1393         allowHeader = "Allow: 204, 206\r\n";
1394     else if (allow204out)
1395         allowHeader = "Allow: 204\r\n";
1396     else if (allow206)
1397         allowHeader = "Allow: 206\r\n";
1398
1399     if (allowHeader) { // may be nil if only allow204in is true
1400         buf.append(allowHeader, strlen(allowHeader));
1401         debugs(93,5, HERE << "Will write " << allowHeader);
1402     }
1403 }
1404
1405 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1406 {
1407     if (request->auth_user_request != NULL) {
1408         char const *name = request->auth_user_request->username();
1409         if (name) {
1410             const char *value = TheConfig.client_username_encode ? base64_encode(name) : name;
1411             buf.Printf("%s: %s\r\n", TheConfig.client_username_header, value);
1412         }
1413     }
1414 }
1415
1416 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1417 {
1418     // update ICAP header
1419     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1420
1421     // begin cloning
1422     HttpMsg::Pointer headClone;
1423
1424     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1425         HttpRequest::Pointer new_request(new HttpRequest);
1426         Must(old_request->canonical);
1427         urlParse(old_request->method, old_request->canonical, new_request);
1428         new_request->http_ver = old_request->http_ver;
1429         headClone = new_request;
1430     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1431         HttpReply::Pointer new_reply(new HttpReply);
1432         new_reply->sline = old_reply->sline;
1433         headClone = new_reply;
1434     }
1435     Must(headClone != NULL);
1436     headClone->inheritProperties(head);
1437
1438     HttpHeaderPos pos = HttpHeaderInitPos;
1439     HttpHeaderEntry* p_head_entry = NULL;
1440     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1441         headClone->header.addEntry(p_head_entry->clone());
1442
1443     // end cloning
1444
1445     // remove all hop-by-hop headers from the clone
1446     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1447     headClone->header.removeHopByHopEntries();
1448
1449     // pack polished HTTP header
1450     packHead(httpBuf, headClone);
1451
1452     // headClone unlocks and, hence, deletes the message we packed
1453 }
1454
1455 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1456 {
1457     Packer p;
1458     packerToMemInit(&p, &httpBuf);
1459     head->packInto(&p, true);
1460     packerClean(&p);
1461 }
1462
1463 // decides whether to offer a preview and calculates its size
1464 void Adaptation::Icap::ModXact::decideOnPreview()
1465 {
1466     if (!TheConfig.preview_enable) {
1467         debugs(93, 5, HERE << "preview disabled by squid.conf");
1468         return;
1469     }
1470
1471     const String urlPath = virginRequest().urlpath;
1472     size_t wantedSize;
1473     if (!service().wantsPreview(urlPath, wantedSize)) {
1474         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1475         return;
1476     }
1477
1478     // we decided to do preview, now compute its size
1479
1480     Must(wantedSize >= 0);
1481
1482     // cannot preview more than we can backup
1483     size_t ad = min(wantedSize, TheBackupLimit);
1484
1485     if (!virginBody.expected())
1486         ad = 0;
1487     else if (virginBody.knownSize())
1488         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1489
1490     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1491            "(service wanted " << wantedSize << ")");
1492
1493     preview.enable(ad);
1494     Must(preview.enabled());
1495 }
1496
1497 // decides whether to allow 204 responses
1498 bool Adaptation::Icap::ModXact::shouldAllow204()
1499 {
1500     if (!service().allows204())
1501         return false;
1502
1503     return canBackupEverything();
1504 }
1505
1506 // decides whether to allow 206 responses in some mode
1507 bool Adaptation::Icap::ModXact::shouldAllow206any()
1508 {
1509     return TheConfig.allow206_enable && service().allows206() &&
1510            virginBody.expected(); // no need for 206 without a body
1511 }
1512
1513 // decides whether to allow 206 responses in preview mode
1514 bool Adaptation::Icap::ModXact::shouldAllow206in()
1515 {
1516     return shouldAllow206any() && preview.enabled();
1517 }
1518
1519 // decides whether to allow 206 responses outside of preview
1520 bool Adaptation::Icap::ModXact::shouldAllow206out()
1521 {
1522     return shouldAllow206any() && canBackupEverything();
1523 }
1524
1525 // used by shouldAllow204 and decideOnRetries
1526 bool Adaptation::Icap::ModXact::canBackupEverything() const
1527 {
1528     if (!virginBody.expected())
1529         return true; // no body means no problems with backup
1530
1531     // if there is a body, check whether we can backup it all
1532
1533     if (!virginBody.knownSize())
1534         return false;
1535
1536     // or should we have a different backup limit?
1537     // note that '<' allows for 0-termination of the "full" backup buffer
1538     return virginBody.size() < TheBackupLimit;
1539 }
1540
1541 // Decide whether this transaction can be retried if pconn fails
1542 // Must be called after decideOnPreview and before openConnection()
1543 void Adaptation::Icap::ModXact::decideOnRetries()
1544 {
1545     if (!isRetriable)
1546         return; // no, already decided
1547
1548     if (preview.enabled())
1549         return; // yes, because preview provides enough guarantees
1550
1551     if (canBackupEverything())
1552         return; // yes, because we can back everything up
1553
1554     disableRetries(); // no, because we cannot back everything up
1555 }
1556
1557 // Normally, the body-writing code handles preview body. It can deal with
1558 // bodies of unexpected size, including those that turn out to be empty.
1559 // However, that code assumes that the body was expected and body control
1560 // structures were initialized. This is not the case when there is no body
1561 // or the body is known to be empty, because the virgin message will lack a
1562 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1563 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1564 {
1565     Must(!virginBodyWriting.active()); // one reason we handle it here
1566     Must(!virgin.body_pipe);          // another reason we handle it here
1567     Must(!preview.ad());
1568
1569     // do not add last-chunk because our Encapsulated header says null-body
1570     // addLastRequestChunk(buf);
1571     preview.wrote(0, true);
1572
1573     Must(preview.done());
1574     Must(preview.ieof());
1575 }
1576
1577 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1578 {
1579     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1580
1581     if (state.serviceWaiting)
1582         buf.append("U", 1);
1583
1584     if (virgin.body_pipe != NULL)
1585         buf.append("R", 1);
1586
1587     if (connection > 0 && !doneReading())
1588         buf.append("r", 1);
1589
1590     if (!state.doneWriting() && state.writing != State::writingInit)
1591         buf.Printf("w(%d)", state.writing);
1592
1593     if (preview.enabled()) {
1594         if (!preview.done())
1595             buf.Printf("P(%d)", (int) preview.debt());
1596     }
1597
1598     if (virginBodySending.active())
1599         buf.append("B", 1);
1600
1601     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1602         buf.Printf("p(%d)", state.parsing);
1603
1604     if (!doneSending() && state.sending != State::sendingUndecided)
1605         buf.Printf("S(%d)", state.sending);
1606
1607     if (state.readyForUob)
1608         buf.append("6", 1);
1609
1610     if (canStartBypass)
1611         buf.append("Y", 1);
1612
1613     if (protectGroupBypass)
1614         buf.append("G", 1);
1615 }
1616
1617 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1618 {
1619     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1620
1621     if (!virgin.body_pipe)
1622         buf.append("R", 1);
1623
1624     if (state.doneWriting())
1625         buf.append("w", 1);
1626
1627     if (preview.enabled()) {
1628         if (preview.done())
1629             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1630     }
1631
1632     if (doneReading())
1633         buf.append("r", 1);
1634
1635     if (state.doneParsing())
1636         buf.append("p", 1);
1637
1638     if (doneSending())
1639         buf.append("S", 1);
1640 }
1641
1642 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1643 {
1644     return icapReply->header.getByNameListMember("Encapsulated",
1645             section, ',').size() > 0;
1646 }
1647
1648 // calculate whether there is a virgin HTTP body and
1649 // whether its expected size is known
1650 // TODO: rename because we do not just estimate
1651 void Adaptation::Icap::ModXact::estimateVirginBody()
1652 {
1653     // note: lack of size info may disable previews and 204s
1654
1655     HttpMsg *msg = virgin.header;
1656     Must(msg);
1657
1658     HttpRequestMethod method;
1659
1660     if (virgin.cause)
1661         method = virgin.cause->method;
1662     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1663         method = req->method;
1664     else
1665         method = METHOD_NONE;
1666
1667     int64_t size;
1668     // expectingBody returns true for zero-sized bodies, but we will not
1669     // get a pipe for that body, so we treat the message as bodyless
1670     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1671         debugs(93, 6, HERE << "expects virgin body from " <<
1672                virgin.body_pipe << "; size: " << size);
1673
1674         virginBody.expect(size);
1675         virginBodyWriting.plan();
1676
1677         // sign up as a body consumer
1678         Must(msg->body_pipe != NULL);
1679         Must(msg->body_pipe == virgin.body_pipe);
1680         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1681
1682         // make sure TheBackupLimit is in-sync with the buffer size
1683         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1684     } else {
1685         debugs(93, 6, HERE << "does not expect virgin body");
1686         Must(msg->body_pipe == NULL);
1687         checkConsuming();
1688     }
1689 }
1690
1691 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1692 {
1693     Must(!adapted.body_pipe);
1694     Must(!adapted.header->body_pipe);
1695     adapted.header->body_pipe = new BodyPipe(this);
1696     adapted.body_pipe = adapted.header->body_pipe;
1697     debugs(93, 7, HERE << "will supply " << what << " via " <<
1698            adapted.body_pipe << " pipe");
1699 }
1700
1701
1702 // TODO: Move SizedEstimate and Preview elsewhere
1703
1704 Adaptation::Icap::SizedEstimate::SizedEstimate()
1705         : theData(dtUnexpected)
1706 {}
1707
1708 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1709 {
1710     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1711 }
1712
1713 bool Adaptation::Icap::SizedEstimate::expected() const
1714 {
1715     return theData != dtUnexpected;
1716 }
1717
1718 bool Adaptation::Icap::SizedEstimate::knownSize() const
1719 {
1720     Must(expected());
1721     return theData != dtUnknown;
1722 }
1723
1724 uint64_t Adaptation::Icap::SizedEstimate::size() const
1725 {
1726     Must(knownSize());
1727     return static_cast<uint64_t>(theData);
1728 }
1729
1730
1731
1732 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1733 {}
1734
1735 void Adaptation::Icap::VirginBodyAct::plan()
1736 {
1737     Must(!disabled());
1738     Must(!theStart); // not started
1739     theState = stActive;
1740 }
1741
1742 void Adaptation::Icap::VirginBodyAct::disable()
1743 {
1744     theState = stDisabled;
1745 }
1746
1747 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1748 {
1749     Must(active());
1750     Must(size >= 0);
1751     theStart += static_cast<int64_t>(size);
1752 }
1753
1754 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1755 {
1756     Must(active());
1757     return static_cast<uint64_t>(theStart);
1758 }
1759
1760
1761 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1762 {}
1763
1764 void Adaptation::Icap::Preview::enable(size_t anAd)
1765 {
1766     // TODO: check for anAd not exceeding preview size limit
1767     Must(anAd >= 0);
1768     Must(!enabled());
1769     theAd = anAd;
1770     theState = stWriting;
1771 }
1772
1773 bool Adaptation::Icap::Preview::enabled() const
1774 {
1775     return theState != stDisabled;
1776 }
1777
1778 size_t Adaptation::Icap::Preview::ad() const
1779 {
1780     Must(enabled());
1781     return theAd;
1782 }
1783
1784 bool Adaptation::Icap::Preview::done() const
1785 {
1786     Must(enabled());
1787     return theState >= stIeof;
1788 }
1789
1790 bool Adaptation::Icap::Preview::ieof() const
1791 {
1792     Must(enabled());
1793     return theState == stIeof;
1794 }
1795
1796 size_t Adaptation::Icap::Preview::debt() const
1797 {
1798     Must(enabled());
1799     return done() ? 0 : (theAd - theWritten);
1800 }
1801
1802 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1803 {
1804     Must(enabled());
1805
1806     theWritten += size;
1807
1808     Must(theWritten <= theAd);
1809
1810     if (wroteEof)
1811         theState = stIeof; // written size is irrelevant
1812     else if (theWritten >= theAd)
1813         theState = stDone;
1814 }
1815
1816 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1817 {
1818     if (virgin.header == NULL)
1819         return false;
1820
1821     virgin.header->firstLineBuf(mb);
1822
1823     return true;
1824 }
1825
1826
1827 /* Adaptation::Icap::ModXactLauncher */
1828
1829 Adaptation::Icap::ModXactLauncher::ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1830         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1831         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", aService)
1832 {
1833     virgin.setHeader(virginHeader);
1834     virgin.setCause(virginCause);
1835     updateHistory(true);
1836 }
1837
1838 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1839 {
1840     Adaptation::Icap::ServiceRep::Pointer s =
1841         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1842     Must(s != NULL);
1843     return new Adaptation::Icap::ModXact(virgin.header, virgin.cause, s);
1844 }
1845
1846 void Adaptation::Icap::ModXactLauncher::swanSong()
1847 {
1848     debugs(93, 5, HERE << "swan sings");
1849     updateHistory(false);
1850     Adaptation::Icap::Launcher::swanSong();
1851 }
1852
1853 void Adaptation::Icap::ModXactLauncher::updateHistory(bool doStart)
1854 {
1855     HttpRequest *r = virgin.cause ?
1856                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1857
1858     // r should never be NULL but we play safe; TODO: add Should()
1859     if (r) {
1860         Adaptation::Icap::History::Pointer h = r->icapHistory();
1861         if (h != NULL) {
1862             if (doStart)
1863                 h->start("ICAPModXactLauncher");
1864             else
1865                 h->stop("ICAPModXactLauncher");
1866         }
1867     }
1868 }