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 "base64.h"
  18 #include "ChunkedCodingParser.h"
  19 #include "comm.h"
  20 #include "comm/Connection.h"
  21 #include "HttpMsg.h"
  22 #include "HttpRequest.h"
  23 #include "HttpReply.h"
  24 #include "SquidTime.h"
  25 #include "err_detail_type.h"
  26
  27 // flow and terminology:
  28 //     HTTP| --> receive --> encode --> write --> |network
  29 //     end | <-- send    <-- parse  <-- read  <-- |end
  30
  31 // TODO: replace gotEncapsulated() with something faster; we call it often
  32
  33 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXact);
  34 CBDATA_NAMESPACED_CLASS_INIT(Adaptation::Icap, ModXactLauncher);
  35
  36 static const size_t TheBackupLimit = BodyPipe::MaxCapacity;
  37
  38 Adaptation::Icap::ModXact::State::State()
  39 {
  40     memset(this, 0, sizeof(*this));
  41 }
  42
  43 Adaptation::Icap::ModXact::ModXact(HttpMsg *virginHeader,
  44                                    HttpRequest *virginCause, Adaptation::Icap::ServiceRep::Pointer &aService):
  45         AsyncJob("Adaptation::Icap::ModXact"),
  46         Adaptation::Icap::Xaction("Adaptation::Icap::ModXact", aService),
  47         virginConsumed(0),
  48         bodyParser(NULL),
  49         canStartBypass(false), // too early
  50         protectGroupBypass(true),
  51         replyHttpHeaderSize(-1),
  52         replyHttpBodySize(-1),
  53         adaptHistoryId(-1)
  54 {
  55     assert(virginHeader);
  56
  57     virgin.setHeader(virginHeader); // sets virgin.body_pipe if needed
  58     virgin.setCause(virginCause); // may be NULL
  59
  60     // adapted header and body are initialized when we parse them
  61
  62     // writing and reading ends are handled by Adaptation::Icap::Xaction
  63
  64     // encoding
  65     // nothing to do because we are using temporary buffers
  66
  67     // parsing; TODO: do not set until we parse, see ICAPOptXact
  68     icapReply = new HttpReply;
  69     icapReply->protoPrefix = "ICAP/"; // TODO: make an IcapReply class?
  70
  71     debugs(93,7, HERE << "initialized." << status());
  72 }
  73
  74 // initiator wants us to start
  75 void Adaptation::Icap::ModXact::start()
  76 {
  77     Adaptation::Icap::Xaction::start();
  78
  79     // reserve an adaptation history slot (attempts are known at this time)
  80     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
  81     if (ah != NULL)
  82         adaptHistoryId = ah->recordXactStart(service().cfg().key, icap_tr_start, attempts > 1);
  83
  84     estimateVirginBody(); // before virgin disappears!
  85
  86     canStartBypass = service().cfg().bypass;
  87
  88     // it is an ICAP violation to send request to a service w/o known OPTIONS
  89
  90     if (service().up())
  91         startWriting();
  92     else
  93         waitForService();
  94 }
  95
  96 void Adaptation::Icap::ModXact::waitForService()
  97 {
  98     Must(!state.serviceWaiting);
  99     debugs(93, 7, HERE << "will wait for the ICAP service" << status());
 100     typedef NullaryMemFunT<ModXact> Dialer;
 101     AsyncCall::Pointer call = JobCallback(93,5,
 102                                           Dialer, this, Adaptation::Icap::ModXact::noteServiceReady);
 103     service().callWhenReady(call);
 104     state.serviceWaiting = true; // after callWhenReady() which may throw
 105 }
 106
 107 void Adaptation::Icap::ModXact::noteServiceReady()
 108 {
 109     Must(state.serviceWaiting);
 110     state.serviceWaiting = false;
 111
 112     if (service().up()) {
 113         startWriting();
 114     } else {
 115         disableRetries();
 116         disableRepeats("ICAP service is unusable");
 117         throw TexcHere("ICAP service is unusable");
 118     }
 119 }
 120
 121 void Adaptation::Icap::ModXact::startWriting()
 122 {
 123     state.writing = State::writingConnect;
 124
 125     decideOnPreview(); // must be decided before we decideOnRetries
 126     decideOnRetries();
 127
 128     openConnection();
 129 }
 130
 131 // connection with the ICAP service established
 132 void Adaptation::Icap::ModXact::handleCommConnected()
 133 {
 134     Must(state.writing == State::writingConnect);
 135
 136     startReading(); // wait for early errors from the ICAP server
 137
 138     MemBuf requestBuf;
 139     requestBuf.init();
 140
 141     makeRequestHeaders(requestBuf);
 142     debugs(93, 9, HERE << "will write" << status() << ":\n" <<
 143            (requestBuf.terminate(), requestBuf.content()));
 144
 145     // write headers
 146     state.writing = State::writingHeaders;
 147     icap_tio_start = current_time;
 148     scheduleWrite(requestBuf);
 149 }
 150
 151 void Adaptation::Icap::ModXact::handleCommWrote(size_t sz)
 152 {
 153     debugs(93, 5, HERE << "Wrote " << sz << " bytes");
 154
 155     if (state.writing == State::writingHeaders)
 156         handleCommWroteHeaders();
 157     else
 158         handleCommWroteBody();
 159 }
 160
 161 void Adaptation::Icap::ModXact::handleCommWroteHeaders()
 162 {
 163     Must(state.writing == State::writingHeaders);
 164
 165     // determine next step
 166     if (preview.enabled()) {
 167         if (preview.done())
 168             decideWritingAfterPreview("zero-size");
 169         else
 170             state.writing = State::writingPreview;
 171     } else if (virginBody.expected()) {
 172         state.writing = State::writingPrime;
 173     } else {
 174         stopWriting(true);
 175         return;
 176     }
 177
 178     writeMore();
 179 }
 180
 181 void Adaptation::Icap::ModXact::writeMore()
 182 {
 183     debugs(93, 5, HERE << "checking whether to write more" << status());
 184
 185     if (writer != NULL) // already writing something
 186         return;
 187
 188     switch (state.writing) {
 189
 190     case State::writingInit:    // waiting for service OPTIONS
 191         Must(state.serviceWaiting);
 192
 193     case State::writingConnect: // waiting for the connection to establish
 194
 195     case State::writingHeaders: // waiting for the headers to be written
 196
 197     case State::writingPaused:  // waiting for the ICAP server response
 198
 199     case State::writingReallyDone: // nothing more to write
 200         return;
 201
 202     case State::writingAlmostDone: // was waiting for the last write
 203         stopWriting(false);
 204         return;
 205
 206     case State::writingPreview:
 207         writePreviewBody();
 208         return;
 209
 210     case State::writingPrime:
 211         writePrimeBody();
 212         return;
 213
 214     default:
 215         throw TexcHere("Adaptation::Icap::ModXact in bad writing state");
 216     }
 217 }
 218
 219 void Adaptation::Icap::ModXact::writePreviewBody()
 220 {
 221     debugs(93, 8, HERE << "will write Preview body from " <<
 222            virgin.body_pipe << status());
 223     Must(state.writing == State::writingPreview);
 224     Must(virgin.body_pipe != NULL);
 225
 226     const size_t sizeMax = (size_t)virgin.body_pipe->buf().contentSize();
 227     const size_t size = min(preview.debt(), sizeMax);
 228     writeSomeBody("preview body", size);
 229
 230     // change state once preview is written
 231
 232     if (preview.done())
 233         decideWritingAfterPreview("body");
 234 }
 235
 236 /// determine state.writing after we wrote the entire preview
 237 void Adaptation::Icap::ModXact::decideWritingAfterPreview(const char *kind)
 238 {
 239     if (preview.ieof()) // nothing more to write
 240         stopWriting(true);
 241     else if (state.parsing == State::psIcapHeader) // did not get a reply yet
 242         state.writing = State::writingPaused; // wait for the ICAP server reply
 243     else
 244         stopWriting(true); // ICAP server reply implies no post-preview writing
 245
 246     debugs(93, 6, HERE << "decided on writing after " << kind << " preview" <<
 247            status());
 248 }
 249
 250 void Adaptation::Icap::ModXact::writePrimeBody()
 251 {
 252     Must(state.writing == State::writingPrime);
 253     Must(virginBodyWriting.active());
 254
 255     const size_t size = (size_t)virgin.body_pipe->buf().contentSize();
 256     writeSomeBody("prime virgin body", size);
 257
 258     if (virginBodyEndReached(virginBodyWriting)) {
 259         debugs(93, 5, HERE << "wrote entire body");
 260         stopWriting(true);
 261     }
 262 }
 263
 264 void Adaptation::Icap::ModXact::writeSomeBody(const char *label, size_t size)
 265 {
 266     Must(!writer && state.writing < state.writingAlmostDone);
 267     Must(virgin.body_pipe != NULL);
 268     debugs(93, 8, HERE << "will write up to " << size << " bytes of " <<
 269            label);
 270
 271     MemBuf writeBuf; // TODO: suggest a min size based on size and lastChunk
 272
 273     writeBuf.init(); // note: we assume that last-chunk will fit
 274
 275     const size_t writableSize = virginContentSize(virginBodyWriting);
 276     const size_t chunkSize = min(writableSize, size);
 277
 278     if (chunkSize) {
 279         debugs(93, 7, HERE << "will write " << chunkSize <<
 280                "-byte chunk of " << label);
 281
 282         openChunk(writeBuf, chunkSize, false);
 283         writeBuf.append(virginContentData(virginBodyWriting), chunkSize);
 284         closeChunk(writeBuf);
 285
 286         virginBodyWriting.progress(chunkSize);
 287         virginConsume();
 288     } else {
 289         debugs(93, 7, HERE << "has no writable " << label << " content");
 290     }
 291
 292     const bool wroteEof = virginBodyEndReached(virginBodyWriting);
 293     bool lastChunk = wroteEof;
 294     if (state.writing == State::writingPreview) {
 295         preview.wrote(chunkSize, wroteEof); // even if wrote nothing
 296         lastChunk = lastChunk || preview.done();
 297     }
 298
 299     if (lastChunk) {
 300         debugs(93, 8, HERE << "will write last-chunk of " << label);
 301         addLastRequestChunk(writeBuf);
 302     }
 303
 304     debugs(93, 7, HERE << "will write " << writeBuf.contentSize()
 305            << " raw bytes of " << label);
 306
 307     if (writeBuf.hasContent()) {
 308         scheduleWrite(writeBuf); // comm will free the chunk
 309     } else {
 310         writeBuf.clean();
 311     }
 312 }
 313
 314 void Adaptation::Icap::ModXact::addLastRequestChunk(MemBuf &buf)
 315 {
 316     const bool ieof = state.writing == State::writingPreview && preview.ieof();
 317     openChunk(buf, 0, ieof);
 318     closeChunk(buf);
 319 }
 320
 321 void Adaptation::Icap::ModXact::openChunk(MemBuf &buf, size_t chunkSize, bool ieof)
 322 {
 323     buf.Printf((ieof ? "%x; ieof\r\n" : "%x\r\n"), (int) chunkSize);
 324 }
 325
 326 void Adaptation::Icap::ModXact::closeChunk(MemBuf &buf)
 327 {
 328     buf.append(ICAP::crlf, 2); // chunk-terminating CRLF
 329 }
 330
 331 const HttpRequest &Adaptation::Icap::ModXact::virginRequest() const
 332 {
 333     const HttpRequest *request = virgin.cause ?
 334                                  virgin.cause : dynamic_cast<const HttpRequest*>(virgin.header);
 335     Must(request);
 336     return *request;
 337 }
 338
 339 // did the activity reached the end of the virgin body?
 340 bool Adaptation::Icap::ModXact::virginBodyEndReached(const Adaptation::Icap::VirginBodyAct &act) const
 341 {
 342     return
 343         !act.active() || // did all (assuming it was originally planned)
 344         !virgin.body_pipe->expectMoreAfter(act.offset()); // wont have more
 345 }
 346
 347 // the size of buffered virgin body data available for the specified activity
 348 // if this size is zero, we may be done or may be waiting for more data
 349 size_t Adaptation::Icap::ModXact::virginContentSize(const Adaptation::Icap::VirginBodyAct &act) const
 350 {
 351     Must(act.active());
 352     // asbolute start of unprocessed data
 353     const uint64_t dataStart = act.offset();
 354     // absolute end of buffered data
 355     const uint64_t dataEnd = virginConsumed + virgin.body_pipe->buf().contentSize();
 356     Must(virginConsumed <= dataStart && dataStart <= dataEnd);
 357     return static_cast<size_t>(dataEnd - dataStart);
 358 }
 359
 360 // pointer to buffered virgin body data available for the specified activity
 361 const char *Adaptation::Icap::ModXact::virginContentData(const Adaptation::Icap::VirginBodyAct &act) const
 362 {
 363     Must(act.active());
 364     const uint64_t dataStart = act.offset();
 365     Must(virginConsumed <= dataStart);
 366     return virgin.body_pipe->buf().content() + static_cast<size_t>(dataStart-virginConsumed);
 367 }
 368
 369 void Adaptation::Icap::ModXact::virginConsume()
 370 {
 371     debugs(93, 9, HERE << "consumption guards: " << !virgin.body_pipe << isRetriable <<
 372            isRepeatable << canStartBypass << protectGroupBypass);
 373
 374     if (!virgin.body_pipe)
 375         return; // nothing to consume
 376
 377     if (isRetriable)
 378         return; // do not consume if we may have to retry later
 379
 380     BodyPipe &bp = *virgin.body_pipe;
 381     const bool wantToPostpone = isRepeatable || canStartBypass || protectGroupBypass;
 382
 383     // Why > 2? HttpState does not use the last bytes in the buffer
 384     // because delayAwareRead() is arguably broken. See
 385     // HttpStateData::maybeReadVirginBody for more details.
 386     if (wantToPostpone && bp.buf().spaceSize() > 2) {
 387         // Postponing may increase memory footprint and slow the HTTP side
 388         // down. Not postponing may increase the number of ICAP errors
 389         // if the ICAP service fails. We may also use "potential" space to
 390         // postpone more aggressively. Should the trade-off be configurable?
 391         debugs(93, 8, HERE << "postponing consumption from " << bp.status());
 392         return;
 393     }
 394
 395     const size_t have = static_cast<size_t>(bp.buf().contentSize());
 396     const uint64_t end = virginConsumed + have;
 397     uint64_t offset = end;
 398
 399     debugs(93, 9, HERE << "max virgin consumption offset=" << offset <<
 400            " acts " << virginBodyWriting.active() << virginBodySending.active() <<
 401            " consumed=" << virginConsumed <<
 402            " from " << virgin.body_pipe->status());
 403
 404     if (virginBodyWriting.active())
 405         offset = min(virginBodyWriting.offset(), offset);
 406
 407     if (virginBodySending.active())
 408         offset = min(virginBodySending.offset(), offset);
 409
 410     Must(virginConsumed <= offset && offset <= end);
 411
 412     if (const size_t size = static_cast<size_t>(offset - virginConsumed)) {
 413         debugs(93, 8, HERE << "consuming " << size << " out of " << have <<
 414                " virgin body bytes");
 415         bp.consume(size);
 416         virginConsumed += size;
 417         Must(!isRetriable); // or we should not be consuming
 418         disableRepeats("consumed content");
 419         disableBypass("consumed content", true);
 420     }
 421 }
 422
 423 void Adaptation::Icap::ModXact::handleCommWroteBody()
 424 {
 425     writeMore();
 426 }
 427
 428 // Called when we do not expect to call comm_write anymore.
 429 // We may have a pending write though.
 430 // If stopping nicely, we will just wait for that pending write, if any.
 431 void Adaptation::Icap::ModXact::stopWriting(bool nicely)
 432 {
 433     if (state.writing == State::writingReallyDone)
 434         return;
 435
 436     if (writer != NULL) {
 437         if (nicely) {
 438             debugs(93, 7, HERE << "will wait for the last write" << status());
 439             state.writing = State::writingAlmostDone; // may already be set
 440             checkConsuming();
 441             return;
 442         }
 443         debugs(93, 3, HERE << "will NOT wait for the last write" << status());
 444
 445         // Comm does not have an interface to clear the writer callback nicely,
 446         // but without clearing the writer we cannot recycle the connection.
 447         // We prevent connection reuse and hope that we can handle a callback
 448         // call at any time, usually in the middle of the destruction sequence!
 449         // Somebody should add comm_remove_write_handler() to comm API.
 450         reuseConnection = false;
 451         ignoreLastWrite = true;
 452     }
 453
 454     debugs(93, 7, HERE << "will no longer write" << status());
 455     if (virginBodyWriting.active()) {
 456         virginBodyWriting.disable();
 457         virginConsume();
 458     }
 459     state.writing = State::writingReallyDone;
 460     checkConsuming();
 461 }
 462
 463 void Adaptation::Icap::ModXact::stopBackup()
 464 {
 465     if (!virginBodySending.active())
 466         return;
 467
 468     debugs(93, 7, HERE << "will no longer backup" << status());
 469     virginBodySending.disable();
 470     virginConsume();
 471 }
 472
 473 bool Adaptation::Icap::ModXact::doneAll() const
 474 {
 475     return Adaptation::Icap::Xaction::doneAll() && !state.serviceWaiting &&
 476            doneSending() &&
 477            doneReading() && state.doneWriting();
 478 }
 479
 480 void Adaptation::Icap::ModXact::startReading()
 481 {
 482     Must(haveConnection());
 483     Must(!reader);
 484     Must(!adapted.header);
 485     Must(!adapted.body_pipe);
 486
 487     // we use the same buffer for headers and body and then consume headers
 488     readMore();
 489 }
 490
 491 void Adaptation::Icap::ModXact::readMore()
 492 {
 493     if (reader != NULL || doneReading()) {
 494         debugs(93,3,HERE << "returning from readMore because reader or doneReading()");
 495         return;
 496     }
 497
 498     // do not fill readBuf if we have no space to store the result
 499     if (adapted.body_pipe != NULL &&
 500             !adapted.body_pipe->buf().hasPotentialSpace()) {
 501         debugs(93,3,HERE << "not reading because ICAP reply pipe is full");
 502         return;
 503     }
 504
 505     if (readBuf.hasSpace())
 506         scheduleRead();
 507     else
 508         debugs(93,3,HERE << "nothing to do because !readBuf.hasSpace()");
 509 }
 510
 511 // comm module read a portion of the ICAP response for us
 512 void Adaptation::Icap::ModXact::handleCommRead(size_t)
 513 {
 514     Must(!state.doneParsing());
 515     icap_tio_finish = current_time;
 516     parseMore();
 517     readMore();
 518 }
 519
 520 void Adaptation::Icap::ModXact::echoMore()
 521 {
 522     Must(state.sending == State::sendingVirgin);
 523     Must(adapted.body_pipe != NULL);
 524     Must(virginBodySending.active());
 525
 526     const size_t sizeMax = virginContentSize(virginBodySending);
 527     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes from " <<
 528            virgin.body_pipe->status());
 529     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes to   " <<
 530            adapted.body_pipe->status());
 531
 532     if (sizeMax > 0) {
 533         const size_t size = adapted.body_pipe->putMoreData(virginContentData(virginBodySending), sizeMax);
 534         debugs(93,5, HERE << "echoed " << size << " out of " << sizeMax <<
 535                " bytes");
 536         virginBodySending.progress(size);
 537         disableRepeats("echoed content");
 538         disableBypass("echoed content", true);
 539         virginConsume();
 540     }
 541
 542     if (virginBodyEndReached(virginBodySending)) {
 543         debugs(93, 5, HERE << "echoed all" << status());
 544         stopSending(true);
 545     } else {
 546         debugs(93, 5, HERE << "has " <<
 547                virgin.body_pipe->buf().contentSize() << " bytes " <<
 548                "and expects more to echo" << status());
 549         // TODO: timeout if virgin or adapted pipes are broken
 550     }
 551 }
 552
 553 bool Adaptation::Icap::ModXact::doneSending() const
 554 {
 555     return state.sending == State::sendingDone;
 556 }
 557
 558 // stop (or do not start) sending adapted message body
 559 void Adaptation::Icap::ModXact::stopSending(bool nicely)
 560 {
 561     debugs(93, 7, HERE << "Enter stop sending ");
 562     if (doneSending())
 563         return;
 564     debugs(93, 7, HERE << "Proceed with stop sending ");
 565
 566     if (state.sending != State::sendingUndecided) {
 567         debugs(93, 7, HERE << "will no longer send" << status());
 568         if (adapted.body_pipe != NULL) {
 569             virginBodySending.disable();
 570             // we may leave debts if we were echoing and the virgin
 571             // body_pipe got exhausted before we echoed all planned bytes
 572             const bool leftDebts = adapted.body_pipe->needsMoreData();
 573             stopProducingFor(adapted.body_pipe, nicely && !leftDebts);
 574         }
 575     } else {
 576         debugs(93, 7, HERE << "will not start sending" << status());
 577         Must(!adapted.body_pipe);
 578     }
 579
 580     state.sending = State::sendingDone;
 581     checkConsuming();
 582 }
 583
 584 // should be called after certain state.writing or state.sending changes
 585 void Adaptation::Icap::ModXact::checkConsuming()
 586 {
 587     // quit if we already stopped or are still using the pipe
 588     if (!virgin.body_pipe || !state.doneConsumingVirgin())
 589         return;
 590
 591     debugs(93, 7, HERE << "will stop consuming" << status());
 592     stopConsumingFrom(virgin.body_pipe);
 593 }
 594
 595 void Adaptation::Icap::ModXact::parseMore()
 596 {
 597     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " bytes to parse" <<
 598            status());
 599     debugs(93, 5, HERE << "\n" << readBuf.content());
 600
 601     if (state.parsingHeaders())
 602         parseHeaders();
 603
 604     if (state.parsing == State::psBody)
 605         parseBody();
 606 }
 607
 608 void Adaptation::Icap::ModXact::callException(const std::exception &e)
 609 {
 610     if (!canStartBypass || isRetriable) {
 611         if (!isRetriable) {
 612             if (const TextException *te = dynamic_cast<const TextException *>(&e))
 613                 detailError(ERR_DETAIL_EXCEPTION_START + te->id());
 614             else
 615                 detailError(ERR_DETAIL_EXCEPTION_OTHER);
 616         }
 617         Adaptation::Icap::Xaction::callException(e);
 618         return;
 619     }
 620
 621     try {
 622         debugs(93, 3, HERE << "bypassing " << inCall << " exception: " <<
 623                e.what() << ' ' << status());
 624         bypassFailure();
 625     } catch (const TextException &bypassTe) {
 626         detailError(ERR_DETAIL_EXCEPTION_START + bypassTe.id());
 627         Adaptation::Icap::Xaction::callException(bypassTe);
 628     } catch (const std::exception &bypassE) {
 629         detailError(ERR_DETAIL_EXCEPTION_OTHER);
 630         Adaptation::Icap::Xaction::callException(bypassE);
 631     }
 632 }
 633
 634 void Adaptation::Icap::ModXact::bypassFailure()
 635 {
 636     disableBypass("already started to bypass", false);
 637
 638     Must(!isRetriable); // or we should not be bypassing
 639     // TODO: should the same be enforced for isRepeatable? Check icap_repeat??
 640
 641     prepEchoing();
 642
 643     startSending();
 644
 645     // end all activities associated with the ICAP server
 646
 647     stopParsing();
 648
 649     stopWriting(true); // or should we force it?
 650     if (haveConnection()) {
 651         reuseConnection = false; // be conservative
 652         cancelRead(); // may not work; and we cannot stop connecting either
 653         if (!doneWithIo())
 654             debugs(93, 7, HERE << "Warning: bypass failed to stop I/O" << status());
 655     }
 656 }
 657
 658 void Adaptation::Icap::ModXact::disableBypass(const char *reason, bool includingGroupBypass)
 659 {
 660     if (canStartBypass) {
 661         debugs(93,7, HERE << "will never start bypass because " << reason);
 662         canStartBypass = false;
 663     }
 664     if (protectGroupBypass && includingGroupBypass) {
 665         debugs(93,7, HERE << "not protecting group bypass because " << reason);
 666         protectGroupBypass = false;
 667     }
 668 }
 669
 670
 671
 672 // note that allocation for echoing is done in handle204NoContent()
 673 void Adaptation::Icap::ModXact::maybeAllocateHttpMsg()
 674 {
 675     if (adapted.header) // already allocated
 676         return;
 677
 678     if (gotEncapsulated("res-hdr")) {
 679         adapted.setHeader(new HttpReply);
 680         setOutcome(service().cfg().method == ICAP::methodReqmod ?
 681                    xoSatisfied : xoModified);
 682     } else if (gotEncapsulated("req-hdr")) {
 683         adapted.setHeader(new HttpRequest);
 684         setOutcome(xoModified);
 685     } else
 686         throw TexcHere("Neither res-hdr nor req-hdr in maybeAllocateHttpMsg()");
 687 }
 688
 689 void Adaptation::Icap::ModXact::parseHeaders()
 690 {
 691     Must(state.parsingHeaders());
 692
 693     if (state.parsing == State::psIcapHeader) {
 694         debugs(93, 5, HERE << "parse ICAP headers");
 695         parseIcapHead();
 696     }
 697
 698     if (state.parsing == State::psHttpHeader) {
 699         debugs(93, 5, HERE << "parse HTTP headers");
 700         parseHttpHead();
 701     }
 702
 703     if (state.parsingHeaders()) { // need more data
 704         Must(mayReadMore());
 705         return;
 706     }
 707
 708     startSending();
 709 }
 710
 711 // called after parsing all headers or when bypassing an exception
 712 void Adaptation::Icap::ModXact::startSending()
 713 {
 714     disableRepeats("sent headers");
 715     disableBypass("sent headers", true);
 716     sendAnswer(adapted.header);
 717
 718     if (state.sending == State::sendingVirgin)
 719         echoMore();
 720 }
 721
 722 void Adaptation::Icap::ModXact::parseIcapHead()
 723 {
 724     Must(state.sending == State::sendingUndecided);
 725
 726     if (!parseHead(icapReply))
 727         return;
 728
 729     if (httpHeaderHasConnDir(&icapReply->header, "close")) {
 730         debugs(93, 5, HERE << "found connection close");
 731         reuseConnection = false;
 732     }
 733
 734     switch (icapReply->sline.status) {
 735
 736     case 100:
 737         handle100Continue();
 738         break;
 739
 740     case 200:
 741     case 201: // Symantec Scan Engine 5.0 and later when modifying HTTP msg
 742
 743         if (!validate200Ok()) {
 744             throw TexcHere("Invalid ICAP Response");
 745         } else {
 746             handle200Ok();
 747         }
 748
 749         break;
 750
 751     case 204:
 752         handle204NoContent();
 753         break;
 754
 755     case 206:
 756         handle206PartialContent();
 757         break;
 758
 759     default:
 760         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 761         handleUnknownScode();
 762         break;
 763     }
 764
 765     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 766     if (!request)
 767         request = &virginRequest();
 768
 769     // update the cross-transactional database if needed (all status codes!)
 770     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 771         Adaptation::History::Pointer ah = request->adaptHistory(true);
 772         if (ah != NULL) {
 773             const String val = icapReply->header.getByName(xxName);
 774             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 775                 ah->updateXxRecord(xxName, val);
 776         }
 777     }
 778
 779     // update the adaptation plan if needed (all status codes!)
 780     if (service().cfg().routing) {
 781         String services;
 782         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 783             Adaptation::History::Pointer ah = request->adaptHistory(true);
 784             if (ah != NULL)
 785                 ah->updateNextServices(services);
 786         }
 787     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 788
 789     // We need to store received ICAP headers for <icapLastHeader logformat option.
 790     // If we already have stored headers from previous ICAP transaction related to this
 791     // request, old headers will be replaced with the new one.
 792
 793     Adaptation::Icap::History::Pointer h = request->icapHistory();
 794     if (h != NULL) {
 795         h->mergeIcapHeaders(&icapReply->header);
 796         h->setIcapLastHeader(&icapReply->header);
 797     }
 798
 799     // handle100Continue() manages state.writing on its own.
 800     // Non-100 status means the server needs no postPreview data from us.
 801     if (state.writing == State::writingPaused)
 802         stopWriting(true);
 803 }
 804
 805 bool Adaptation::Icap::ModXact::validate200Ok()
 806 {
 807     if (ICAP::methodRespmod == service().cfg().method) {
 808         if (!gotEncapsulated("res-hdr"))
 809             return false;
 810
 811         return true;
 812     }
 813
 814     if (ICAP::methodReqmod == service().cfg().method) {
 815         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 816             return false;
 817
 818         return true;
 819     }
 820
 821     return false;
 822 }
 823
 824 void Adaptation::Icap::ModXact::handle100Continue()
 825 {
 826     Must(state.writing == State::writingPaused);
 827     // server must not respond before the end of preview: we may send ieof
 828     Must(preview.enabled() && preview.done() && !preview.ieof());
 829
 830     // 100 "Continue" cancels our Preview commitment,
 831     // but not commitment to handle 204 or 206 outside Preview
 832     if (!state.allowedPostview204 && !state.allowedPostview206)
 833         stopBackup();
 834
 835     state.parsing = State::psIcapHeader; // eventually
 836     icapReply->reset();
 837
 838     state.writing = State::writingPrime;
 839
 840     writeMore();
 841 }
 842
 843 void Adaptation::Icap::ModXact::handle200Ok()
 844 {
 845     state.parsing = State::psHttpHeader;
 846     state.sending = State::sendingAdapted;
 847     stopBackup();
 848     checkConsuming();
 849 }
 850
 851 void Adaptation::Icap::ModXact::handle204NoContent()
 852 {
 853     stopParsing();
 854     prepEchoing();
 855 }
 856
 857 void Adaptation::Icap::ModXact::handle206PartialContent()
 858 {
 859     if (state.writing == State::writingPaused) {
 860         Must(preview.enabled());
 861         Must(state.allowedPreview206);
 862         debugs(93, 7, HERE << "206 inside preview");
 863     } else {
 864         Must(state.writing > State::writingPaused);
 865         Must(state.allowedPostview206);
 866         debugs(93, 7, HERE << "206 outside preview");
 867     }
 868     state.parsing = State::psHttpHeader;
 869     state.sending = State::sendingAdapted;
 870     state.readyForUob = true;
 871     checkConsuming();
 872 }
 873
 874 // Called when we receive a 204 No Content response and
 875 // when we are trying to bypass a service failure.
 876 // We actually start sending (echoig or not) in startSending.
 877 void Adaptation::Icap::ModXact::prepEchoing()
 878 {
 879     disableRepeats("preparing to echo content");
 880     disableBypass("preparing to echo content", true);
 881     setOutcome(xoEcho);
 882
 883     // We want to clone the HTTP message, but we do not want
 884     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 885     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 886     // Instead, we simply write the HTTP message and "clone" it by parsing.
 887     // TODO: use HttpMsg::clone()!
 888
 889     HttpMsg *oldHead = virgin.header;
 890     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 891
 892     MemBuf httpBuf;
 893
 894     // write the virgin message into a memory buffer
 895     httpBuf.init();
 896     packHead(httpBuf, oldHead);
 897
 898     // allocate the adapted message and copy metainfo
 899     Must(!adapted.header);
 900     {
 901         HttpMsg::Pointer newHead;
 902         if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 903             HttpRequest::Pointer newR(new HttpRequest);
 904             newR->canonical = oldR->canonical ?
 905                               xstrdup(oldR->canonical) : NULL; // parse() does not set it
 906             newHead = newR;
 907         } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 908             newHead = new HttpReply;
 909         }
 910         Must(newHead != NULL);
 911
 912         newHead->inheritProperties(oldHead);
 913
 914         adapted.setHeader(newHead);
 915     }
 916
 917     // parse the buffer back
 918     http_status error = HTTP_STATUS_NONE;
 919
 920     Must(adapted.header->parse(&httpBuf, true, &error));
 921
 922     Must(adapted.header->hdr_sz == httpBuf.contentSize()); // no leftovers
 923
 924     httpBuf.clean();
 925
 926     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 927            adapted.header);
 928
 929     // setup adapted body pipe if needed
 930     if (oldHead->body_pipe != NULL) {
 931         debugs(93, 7, HERE << "will echo virgin body from " <<
 932                oldHead->body_pipe);
 933         if (!virginBodySending.active())
 934             virginBodySending.plan(); // will throw if not possible
 935         state.sending = State::sendingVirgin;
 936         checkConsuming();
 937
 938         // TODO: optimize: is it possible to just use the oldHead pipe and
 939         // remove ICAP from the loop? This echoing is probably a common case!
 940         makeAdaptedBodyPipe("echoed virgin response");
 941         if (oldHead->body_pipe->bodySizeKnown())
 942             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 943         debugs(93, 7, HERE << "will echo virgin body to " <<
 944                adapted.body_pipe);
 945     } else {
 946         debugs(93, 7, HERE << "no virgin body to echo");
 947         stopSending(true);
 948     }
 949 }
 950
 951 /// Called when we received use-original-body chunk extension in 206 response.
 952 /// We actually start sending (echoing or not) in startSending().
 953 void Adaptation::Icap::ModXact::prepPartialBodyEchoing(uint64_t pos)
 954 {
 955     Must(virginBodySending.active());
 956     Must(virgin.header->body_pipe != NULL);
 957
 958     setOutcome(xoPartEcho);
 959
 960     debugs(93, 7, HERE << "will echo virgin body suffix from " <<
 961            virgin.header->body_pipe << " offset " << pos );
 962
 963     // check that use-original-body=N does not point beyond buffered data
 964     const uint64_t virginDataEnd = virginConsumed +
 965                                    virgin.body_pipe->buf().contentSize();
 966     Must(pos <= virginDataEnd);
 967     virginBodySending.progress(static_cast<size_t>(pos));
 968
 969     state.sending = State::sendingVirgin;
 970     checkConsuming();
 971
 972     if (virgin.header->body_pipe->bodySizeKnown())
 973         adapted.body_pipe->expectProductionEndAfter(virgin.header->body_pipe->bodySize() - pos);
 974
 975     debugs(93, 7, HERE << "will echo virgin body suffix to " <<
 976            adapted.body_pipe);
 977
 978     // Start echoing data
 979     echoMore();
 980 }
 981
 982 void Adaptation::Icap::ModXact::handleUnknownScode()
 983 {
 984     stopParsing();
 985     stopBackup();
 986     // TODO: mark connection as "bad"
 987
 988     // Terminate the transaction; we do not know how to handle this response.
 989     throw TexcHere("Unsupported ICAP status code");
 990 }
 991
 992 void Adaptation::Icap::ModXact::parseHttpHead()
 993 {
 994     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
 995         replyHttpHeaderSize = 0;
 996         maybeAllocateHttpMsg();
 997
 998         if (!parseHead(adapted.header))
 999             return; // need more header data
1000
1001         if (adapted.header)
1002             replyHttpHeaderSize = adapted.header->hdr_sz;
1003
1004         if (dynamic_cast<HttpRequest*>(adapted.header)) {
1005             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
1006             Must(oldR);
1007             // TODO: the adapted request did not really originate from the
1008             // client; give proxy admin an option to prevent copying of
1009             // sensitive client information here. See the following thread:
1010             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
1011         }
1012
1013         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
1014         if (adapted.header)
1015             adapted.header->inheritProperties(virgin.header);
1016     }
1017
1018     decideOnParsingBody();
1019 }
1020
1021 // parses both HTTP and ICAP headers
1022 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
1023 {
1024     Must(head);
1025     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
1026            "; state: " << state.parsing);
1027
1028     http_status error = HTTP_STATUS_NONE;
1029     const bool parsed = head->parse(&readBuf, commEof, &error);
1030     Must(parsed || !error); // success or need more data
1031
1032     if (!parsed) { // need more data
1033         debugs(93, 5, HERE << "parse failed, need more data, return false");
1034         head->reset();
1035         return false;
1036     }
1037
1038     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
1039         urlCanonical(r); // parse does not set HttpRequest::canonical
1040
1041     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
1042     readBuf.consume(head->hdr_sz);
1043     return true;
1044 }
1045
1046 void Adaptation::Icap::ModXact::decideOnParsingBody()
1047 {
1048     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
1049         debugs(93, 5, HERE << "expecting a body");
1050         state.parsing = State::psBody;
1051         replyHttpBodySize = 0;
1052         bodyParser = new ChunkedCodingParser;
1053         makeAdaptedBodyPipe("adapted response from the ICAP server");
1054         Must(state.sending == State::sendingAdapted);
1055     } else {
1056         debugs(93, 5, HERE << "not expecting a body");
1057         stopParsing();
1058         stopSending(true);
1059     }
1060 }
1061
1062 void Adaptation::Icap::ModXact::parseBody()
1063 {
1064     Must(state.parsing == State::psBody);
1065     Must(bodyParser);
1066
1067     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
1068
1069     // the parser will throw on errors
1070     BodyPipeCheckout bpc(*adapted.body_pipe);
1071     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
1072     bpc.checkIn();
1073
1074     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
1075            "parse; parsed all: " << parsed);
1076     replyHttpBodySize += adapted.body_pipe->buf().contentSize();
1077
1078     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
1079     // TODO: do we really need this if we disable when sending headers?
1080     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
1081         disableRepeats("sent adapted content");
1082         disableBypass("sent adapted content", true);
1083     }
1084
1085     if (parsed) {
1086         if (state.readyForUob && bodyParser->useOriginBody >= 0) {
1087             prepPartialBodyEchoing(
1088                 static_cast<uint64_t>(bodyParser->useOriginBody));
1089             stopParsing();
1090             return;
1091         }
1092
1093         stopParsing();
1094         stopSending(true); // the parser succeeds only if all parsed data fits
1095         return;
1096     }
1097
1098     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1099
1100     if (bodyParser->needsMoreData()) {
1101         debugs(93,3,HERE << this);
1102         Must(mayReadMore());
1103         readMore();
1104     }
1105
1106     if (bodyParser->needsMoreSpace()) {
1107         Must(!doneSending()); // can hope for more space
1108         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1109         // TODO: there should be a timeout in case the sink is broken
1110         // or cannot consume partial content (while we need more space)
1111     }
1112 }
1113
1114 void Adaptation::Icap::ModXact::stopParsing()
1115 {
1116     if (state.parsing == State::psDone)
1117         return;
1118
1119     debugs(93, 7, HERE << "will no longer parse" << status());
1120
1121     delete bodyParser;
1122
1123     bodyParser = NULL;
1124
1125     state.parsing = State::psDone;
1126 }
1127
1128 // HTTP side added virgin body data
1129 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1130 {
1131     writeMore();
1132
1133     if (state.sending == State::sendingVirgin)
1134         echoMore();
1135 }
1136
1137 // HTTP side sent us all virgin info
1138 void Adaptation::Icap::ModXact::noteBodyProductionEnded(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 // body producer aborted, but the initiator may still want to know
1150 // the answer, even though the HTTP message has been truncated
1151 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1152 {
1153     Must(virgin.body_pipe->productionEnded());
1154
1155     // push writer and sender in case we were waiting for the last-chunk
1156     writeMore();
1157
1158     if (state.sending == State::sendingVirgin)
1159         echoMore();
1160 }
1161
1162 // adapted body consumer wants more adapted data and
1163 // possibly freed some buffer space
1164 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1165 {
1166     if (state.sending == State::sendingVirgin)
1167         echoMore();
1168     else if (state.sending == State::sendingAdapted)
1169         parseMore();
1170     else
1171         Must(state.sending == State::sendingUndecided);
1172 }
1173
1174 // adapted body consumer aborted
1175 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1176 {
1177     detailError(ERR_DETAIL_ICAP_XACT_BODY_CONSUMER_ABORT);
1178     mustStop("adapted body consumer aborted");
1179 }
1180
1181 Adaptation::Icap::ModXact::~ModXact()
1182 {
1183     delete bodyParser;
1184 }
1185
1186 // internal cleanup
1187 void Adaptation::Icap::ModXact::swanSong()
1188 {
1189     debugs(93, 5, HERE << "swan sings" << status());
1190
1191     stopWriting(false);
1192     stopSending(false);
1193
1194     if (theInitiator.set()) // we have not sent the answer to the initiator
1195         detailError(ERR_DETAIL_ICAP_XACT_OTHER);
1196
1197     // update adaptation history if start was called and we reserved a slot
1198     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1199     if (ah != NULL && adaptHistoryId >= 0)
1200         ah->recordXactFinish(adaptHistoryId);
1201
1202     Adaptation::Icap::Xaction::swanSong();
1203 }
1204
1205 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1206
1207 void Adaptation::Icap::ModXact::finalizeLogInfo()
1208 {
1209     HttpRequest * request_ = NULL;
1210     HttpReply * reply_ = NULL;
1211     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1212         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1213         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1214     }
1215
1216     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1217     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1218     al.icp.opcode = ICP_INVALID;
1219     al.url = h->log_uri.termedBuf();
1220     const Adaptation::Icap::ServiceRep  &s = service();
1221     al.icap.reqMethod = s.cfg().method;
1222
1223     al.cache.caddr = request_->client_addr;
1224
1225     al.request = HTTPMSGLOCK(request_);
1226     if (reply_)
1227         al.reply = HTTPMSGLOCK(reply_);
1228     else
1229         al.reply = NULL;
1230
1231     if (h->rfc931.size())
1232         al.cache.rfc931 = h->rfc931.termedBuf();
1233
1234 #if USE_SSL
1235     if (h->ssluser.size())
1236         al.cache.ssluser = h->ssluser.termedBuf();
1237 #endif
1238     al.cache.code = h->logType;
1239     al.cache.requestSize = h->req_sz;
1240
1241     // leave al.icap.bodyBytesRead negative if no body
1242     if (replyHttpHeaderSize >= 0 || replyHttpBodySize >= 0) {
1243         const int64_t zero = 0; // to make max() argument types the same
1244         al.icap.bodyBytesRead =
1245             max(zero, replyHttpHeaderSize) + max(zero, replyHttpBodySize);
1246     }
1247
1248     if (reply_) {
1249         al.http.code = reply_->sline.status;
1250         al.http.content_type = reply_->content_type.termedBuf();
1251         if (replyHttpBodySize >= 0) {
1252             al.cache.replySize = replyHttpBodySize + reply_->hdr_sz;
1253             al.cache.highOffset = replyHttpBodySize;
1254         }
1255         //don't set al.cache.objectSize because it hasn't exist yet
1256
1257         Packer p;
1258         MemBuf mb;
1259
1260         mb.init();
1261         packerToMemInit(&p, &mb);
1262
1263         reply_->header.packInto(&p);
1264         al.headers.reply = xstrdup(mb.buf);
1265
1266         packerClean(&p);
1267         mb.clean();
1268     }
1269     prepareLogWithRequestDetails(request_, &al);
1270     Xaction::finalizeLogInfo();
1271 }
1272
1273
1274 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1275 {
1276     char ntoabuf[MAX_IPSTRLEN];
1277     /*
1278      * XXX These should use HttpHdr interfaces instead of Printfs
1279      */
1280     const Adaptation::ServiceConfig &s = service().cfg();
1281     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1282     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1283     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1284
1285     if (!TheConfig.reuse_connections)
1286         buf.Printf("Connection: close\r\n");
1287
1288     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1289     // as ICAP headers.
1290     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1291         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1292         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1293     }
1294
1295     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1296         String vh=virgin.header->header.getByName("Proxy-Authorization");
1297         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1298     }
1299
1300     const HttpRequest *request = &virginRequest();
1301
1302     // share the cross-transactional database records if needed
1303     if (Adaptation::Config::masterx_shared_name) {
1304         Adaptation::History::Pointer ah = request->adaptHistory(true);
1305         if (ah != NULL) {
1306             String name, value;
1307             if (ah->getXxRecord(name, value)) {
1308                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1309                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1310             }
1311         }
1312     }
1313
1314
1315     buf.Printf("Encapsulated: ");
1316
1317     MemBuf httpBuf;
1318
1319     httpBuf.init();
1320
1321     // build HTTP request header, if any
1322     ICAP::Method m = s.method;
1323
1324     // to simplify, we could assume that request is always available
1325
1326     String urlPath;
1327     if (request) {
1328         urlPath = request->urlpath;
1329         if (ICAP::methodRespmod == m)
1330             encapsulateHead(buf, "req-hdr", httpBuf, request);
1331         else if (ICAP::methodReqmod == m)
1332             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1333     }
1334
1335     if (ICAP::methodRespmod == m)
1336         if (const HttpMsg *prime = virgin.header)
1337             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1338
1339     if (!virginBody.expected())
1340         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1341     else if (ICAP::methodReqmod == m)
1342         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1343     else
1344         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1345
1346     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1347
1348     if (preview.enabled()) {
1349         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1350         if (!virginBody.expected()) // there is no body to preview
1351             finishNullOrEmptyBodyPreview(httpBuf);
1352     }
1353
1354     makeAllowHeader(buf);
1355
1356     if (TheConfig.send_client_ip && request) {
1357         Ip::Address client_addr;
1358 #if FOLLOW_X_FORWARDED_FOR
1359         if (TheConfig.icap_uses_indirect_client) {
1360             client_addr = request->indirect_client_addr;
1361         } else
1362 #endif
1363             client_addr = request->client_addr;
1364         if (!client_addr.IsAnyAddr() && !client_addr.IsNoAddr())
1365             buf.Printf("X-Client-IP: %s\r\n", client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1366     }
1367
1368     if (TheConfig.send_client_username && request)
1369         makeUsernameHeader(request, buf);
1370
1371     // fprintf(stderr, "%s\n", buf.content());
1372
1373     buf.append(ICAP::crlf, 2); // terminate ICAP header
1374
1375     // fill icapRequest for logging
1376     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1377
1378     // start ICAP request body with encapsulated HTTP headers
1379     buf.append(httpBuf.content(), httpBuf.contentSize());
1380
1381     httpBuf.clean();
1382 }
1383
1384 // decides which Allow values to write and updates the request buffer
1385 void Adaptation::Icap::ModXact::makeAllowHeader(MemBuf &buf)
1386 {
1387     const bool allow204in = preview.enabled(); // TODO: add shouldAllow204in()
1388     const bool allow204out = state.allowedPostview204 = shouldAllow204();
1389     const bool allow206in = state.allowedPreview206 = shouldAllow206in();
1390     const bool allow206out = state.allowedPostview206 = shouldAllow206out();
1391
1392     debugs(93,9, HERE << "Allows: " << allow204in << allow204out <<
1393            allow206in << allow206out);
1394
1395     const bool allow204 = allow204in || allow204out;
1396     const bool allow206 = allow206in || allow206out;
1397
1398     if (!allow204 && !allow206)
1399         return; // nothing to do
1400
1401     if (virginBody.expected()) // if there is a virgin body, plan to send it
1402         virginBodySending.plan();
1403
1404     // writing Preview:...   means we will honor 204 inside preview
1405     // writing Allow/204     means we will honor 204 outside preview
1406     // writing Allow:206     means we will honor 206 inside preview
1407     // writing Allow:204,206 means we will honor 206 outside preview
1408     const char *allowHeader = NULL;
1409     if (allow204out && allow206)
1410         allowHeader = "Allow: 204, 206\r\n";
1411     else if (allow204out)
1412         allowHeader = "Allow: 204\r\n";
1413     else if (allow206)
1414         allowHeader = "Allow: 206\r\n";
1415
1416     if (allowHeader) { // may be nil if only allow204in is true
1417         buf.append(allowHeader, strlen(allowHeader));
1418         debugs(93,5, HERE << "Will write " << allowHeader);
1419     }
1420 }
1421
1422 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1423 {
1424     if (request->auth_user_request != NULL) {
1425         char const *name = request->auth_user_request->username();
1426         if (name) {
1427             const char *value = TheConfig.client_username_encode ? base64_encode(name) : name;
1428             buf.Printf("%s: %s\r\n", TheConfig.client_username_header, value);
1429         }
1430     }
1431 }
1432
1433 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1434 {
1435     // update ICAP header
1436     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1437
1438     // begin cloning
1439     HttpMsg::Pointer headClone;
1440
1441     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1442         HttpRequest::Pointer new_request(new HttpRequest);
1443         Must(old_request->canonical);
1444         urlParse(old_request->method, old_request->canonical, new_request);
1445         new_request->http_ver = old_request->http_ver;
1446         headClone = new_request;
1447     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1448         HttpReply::Pointer new_reply(new HttpReply);
1449         new_reply->sline = old_reply->sline;
1450         headClone = new_reply;
1451     }
1452     Must(headClone != NULL);
1453     headClone->inheritProperties(head);
1454
1455     HttpHeaderPos pos = HttpHeaderInitPos;
1456     HttpHeaderEntry* p_head_entry = NULL;
1457     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1458         headClone->header.addEntry(p_head_entry->clone());
1459
1460     // end cloning
1461
1462     // remove all hop-by-hop headers from the clone
1463     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1464     headClone->header.removeHopByHopEntries();
1465
1466     // pack polished HTTP header
1467     packHead(httpBuf, headClone);
1468
1469     // headClone unlocks and, hence, deletes the message we packed
1470 }
1471
1472 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1473 {
1474     Packer p;
1475     packerToMemInit(&p, &httpBuf);
1476     head->packInto(&p, true);
1477     packerClean(&p);
1478 }
1479
1480 // decides whether to offer a preview and calculates its size
1481 void Adaptation::Icap::ModXact::decideOnPreview()
1482 {
1483     if (!TheConfig.preview_enable) {
1484         debugs(93, 5, HERE << "preview disabled by squid.conf");
1485         return;
1486     }
1487
1488     const String urlPath = virginRequest().urlpath;
1489     size_t wantedSize;
1490     if (!service().wantsPreview(urlPath, wantedSize)) {
1491         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1492         return;
1493     }
1494
1495     // we decided to do preview, now compute its size
1496
1497     Must(wantedSize >= 0);
1498
1499     // cannot preview more than we can backup
1500     size_t ad = min(wantedSize, TheBackupLimit);
1501
1502     if (!virginBody.expected())
1503         ad = 0;
1504     else if (virginBody.knownSize())
1505         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1506
1507     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1508            "(service wanted " << wantedSize << ")");
1509
1510     preview.enable(ad);
1511     Must(preview.enabled());
1512 }
1513
1514 // decides whether to allow 204 responses
1515 bool Adaptation::Icap::ModXact::shouldAllow204()
1516 {
1517     if (!service().allows204())
1518         return false;
1519
1520     return canBackupEverything();
1521 }
1522
1523 // decides whether to allow 206 responses in some mode
1524 bool Adaptation::Icap::ModXact::shouldAllow206any()
1525 {
1526     return TheConfig.allow206_enable && service().allows206() &&
1527            virginBody.expected(); // no need for 206 without a body
1528 }
1529
1530 // decides whether to allow 206 responses in preview mode
1531 bool Adaptation::Icap::ModXact::shouldAllow206in()
1532 {
1533     return shouldAllow206any() && preview.enabled();
1534 }
1535
1536 // decides whether to allow 206 responses outside of preview
1537 bool Adaptation::Icap::ModXact::shouldAllow206out()
1538 {
1539     return shouldAllow206any() && canBackupEverything();
1540 }
1541
1542 // used by shouldAllow204 and decideOnRetries
1543 bool Adaptation::Icap::ModXact::canBackupEverything() const
1544 {
1545     if (!virginBody.expected())
1546         return true; // no body means no problems with backup
1547
1548     // if there is a body, check whether we can backup it all
1549
1550     if (!virginBody.knownSize())
1551         return false;
1552
1553     // or should we have a different backup limit?
1554     // note that '<' allows for 0-termination of the "full" backup buffer
1555     return virginBody.size() < TheBackupLimit;
1556 }
1557
1558 // Decide whether this transaction can be retried if pconn fails
1559 // Must be called after decideOnPreview and before openConnection()
1560 void Adaptation::Icap::ModXact::decideOnRetries()
1561 {
1562     if (!isRetriable)
1563         return; // no, already decided
1564
1565     if (preview.enabled())
1566         return; // yes, because preview provides enough guarantees
1567
1568     if (canBackupEverything())
1569         return; // yes, because we can back everything up
1570
1571     disableRetries(); // no, because we cannot back everything up
1572 }
1573
1574 // Normally, the body-writing code handles preview body. It can deal with
1575 // bodies of unexpected size, including those that turn out to be empty.
1576 // However, that code assumes that the body was expected and body control
1577 // structures were initialized. This is not the case when there is no body
1578 // or the body is known to be empty, because the virgin message will lack a
1579 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1580 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1581 {
1582     Must(!virginBodyWriting.active()); // one reason we handle it here
1583     Must(!virgin.body_pipe);          // another reason we handle it here
1584     Must(!preview.ad());
1585
1586     // do not add last-chunk because our Encapsulated header says null-body
1587     // addLastRequestChunk(buf);
1588     preview.wrote(0, true);
1589
1590     Must(preview.done());
1591     Must(preview.ieof());
1592 }
1593
1594 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1595 {
1596     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1597
1598     if (state.serviceWaiting)
1599         buf.append("U", 1);
1600
1601     if (virgin.body_pipe != NULL)
1602         buf.append("R", 1);
1603
1604     if (haveConnection() && !doneReading())
1605         buf.append("r", 1);
1606
1607     if (!state.doneWriting() && state.writing != State::writingInit)
1608         buf.Printf("w(%d)", state.writing);
1609
1610     if (preview.enabled()) {
1611         if (!preview.done())
1612             buf.Printf("P(%d)", (int) preview.debt());
1613     }
1614
1615     if (virginBodySending.active())
1616         buf.append("B", 1);
1617
1618     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1619         buf.Printf("p(%d)", state.parsing);
1620
1621     if (!doneSending() && state.sending != State::sendingUndecided)
1622         buf.Printf("S(%d)", state.sending);
1623
1624     if (state.readyForUob)
1625         buf.append("6", 1);
1626
1627     if (canStartBypass)
1628         buf.append("Y", 1);
1629
1630     if (protectGroupBypass)
1631         buf.append("G", 1);
1632 }
1633
1634 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1635 {
1636     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1637
1638     if (!virgin.body_pipe)
1639         buf.append("R", 1);
1640
1641     if (state.doneWriting())
1642         buf.append("w", 1);
1643
1644     if (preview.enabled()) {
1645         if (preview.done())
1646             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1647     }
1648
1649     if (doneReading())
1650         buf.append("r", 1);
1651
1652     if (state.doneParsing())
1653         buf.append("p", 1);
1654
1655     if (doneSending())
1656         buf.append("S", 1);
1657 }
1658
1659 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1660 {
1661     return icapReply->header.getByNameListMember("Encapsulated",
1662             section, ',').size() > 0;
1663 }
1664
1665 // calculate whether there is a virgin HTTP body and
1666 // whether its expected size is known
1667 // TODO: rename because we do not just estimate
1668 void Adaptation::Icap::ModXact::estimateVirginBody()
1669 {
1670     // note: lack of size info may disable previews and 204s
1671
1672     HttpMsg *msg = virgin.header;
1673     Must(msg);
1674
1675     HttpRequestMethod method;
1676
1677     if (virgin.cause)
1678         method = virgin.cause->method;
1679     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1680         method = req->method;
1681     else
1682         method = METHOD_NONE;
1683
1684     int64_t size;
1685     // expectingBody returns true for zero-sized bodies, but we will not
1686     // get a pipe for that body, so we treat the message as bodyless
1687     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1688         debugs(93, 6, HERE << "expects virgin body from " <<
1689                virgin.body_pipe << "; size: " << size);
1690
1691         virginBody.expect(size);
1692         virginBodyWriting.plan();
1693
1694         // sign up as a body consumer
1695         Must(msg->body_pipe != NULL);
1696         Must(msg->body_pipe == virgin.body_pipe);
1697         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1698
1699         // make sure TheBackupLimit is in-sync with the buffer size
1700         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1701     } else {
1702         debugs(93, 6, HERE << "does not expect virgin body");
1703         Must(msg->body_pipe == NULL);
1704         checkConsuming();
1705     }
1706 }
1707
1708 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1709 {
1710     Must(!adapted.body_pipe);
1711     Must(!adapted.header->body_pipe);
1712     adapted.header->body_pipe = new BodyPipe(this);
1713     adapted.body_pipe = adapted.header->body_pipe;
1714     debugs(93, 7, HERE << "will supply " << what << " via " <<
1715            adapted.body_pipe << " pipe");
1716 }
1717
1718
1719 // TODO: Move SizedEstimate and Preview elsewhere
1720
1721 Adaptation::Icap::SizedEstimate::SizedEstimate()
1722         : theData(dtUnexpected)
1723 {}
1724
1725 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1726 {
1727     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1728 }
1729
1730 bool Adaptation::Icap::SizedEstimate::expected() const
1731 {
1732     return theData != dtUnexpected;
1733 }
1734
1735 bool Adaptation::Icap::SizedEstimate::knownSize() const
1736 {
1737     Must(expected());
1738     return theData != dtUnknown;
1739 }
1740
1741 uint64_t Adaptation::Icap::SizedEstimate::size() const
1742 {
1743     Must(knownSize());
1744     return static_cast<uint64_t>(theData);
1745 }
1746
1747
1748
1749 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1750 {}
1751
1752 void Adaptation::Icap::VirginBodyAct::plan()
1753 {
1754     Must(!disabled());
1755     Must(!theStart); // not started
1756     theState = stActive;
1757 }
1758
1759 void Adaptation::Icap::VirginBodyAct::disable()
1760 {
1761     theState = stDisabled;
1762 }
1763
1764 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1765 {
1766     Must(active());
1767     Must(size >= 0);
1768     theStart += static_cast<int64_t>(size);
1769 }
1770
1771 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1772 {
1773     Must(active());
1774     return static_cast<uint64_t>(theStart);
1775 }
1776
1777
1778 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1779 {}
1780
1781 void Adaptation::Icap::Preview::enable(size_t anAd)
1782 {
1783     // TODO: check for anAd not exceeding preview size limit
1784     Must(anAd >= 0);
1785     Must(!enabled());
1786     theAd = anAd;
1787     theState = stWriting;
1788 }
1789
1790 bool Adaptation::Icap::Preview::enabled() const
1791 {
1792     return theState != stDisabled;
1793 }
1794
1795 size_t Adaptation::Icap::Preview::ad() const
1796 {
1797     Must(enabled());
1798     return theAd;
1799 }
1800
1801 bool Adaptation::Icap::Preview::done() const
1802 {
1803     Must(enabled());
1804     return theState >= stIeof;
1805 }
1806
1807 bool Adaptation::Icap::Preview::ieof() const
1808 {
1809     Must(enabled());
1810     return theState == stIeof;
1811 }
1812
1813 size_t Adaptation::Icap::Preview::debt() const
1814 {
1815     Must(enabled());
1816     return done() ? 0 : (theAd - theWritten);
1817 }
1818
1819 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1820 {
1821     Must(enabled());
1822
1823     theWritten += size;
1824
1825     Must(theWritten <= theAd);
1826
1827     if (wroteEof)
1828         theState = stIeof; // written size is irrelevant
1829     else if (theWritten >= theAd)
1830         theState = stDone;
1831 }
1832
1833 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1834 {
1835     if (virgin.header == NULL)
1836         return false;
1837
1838     virgin.header->firstLineBuf(mb);
1839
1840     return true;
1841 }
1842
1843 void Adaptation::Icap::ModXact::detailError(int errDetail)
1844 {
1845     if (HttpRequest *request = virgin.cause ?
1846                                virgin.cause : dynamic_cast<HttpRequest*>(virgin.header)) {
1847         request->detailError(ERR_ICAP_FAILURE, errDetail);
1848     }
1849 }
1850
1851 /* Adaptation::Icap::ModXactLauncher */
1852
1853 Adaptation::Icap::ModXactLauncher::ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1854         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1855         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", aService)
1856 {
1857     virgin.setHeader(virginHeader);
1858     virgin.setCause(virginCause);
1859     updateHistory(true);
1860 }
1861
1862 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1863 {
1864     Adaptation::Icap::ServiceRep::Pointer s =
1865         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1866     Must(s != NULL);
1867     return new Adaptation::Icap::ModXact(virgin.header, virgin.cause, s);
1868 }
1869
1870 void Adaptation::Icap::ModXactLauncher::swanSong()
1871 {
1872     debugs(93, 5, HERE << "swan sings");
1873     updateHistory(false);
1874     Adaptation::Icap::Launcher::swanSong();
1875 }
1876
1877 void Adaptation::Icap::ModXactLauncher::updateHistory(bool doStart)
1878 {
1879     HttpRequest *r = virgin.cause ?
1880                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1881
1882     // r should never be NULL but we play safe; TODO: add Should()
1883     if (r) {
1884         Adaptation::Icap::History::Pointer h = r->icapHistory();
1885         if (h != NULL) {
1886             if (doStart)
1887                 h->start("ICAPModXactLauncher");
1888             else
1889                 h->stop("ICAPModXactLauncher");
1890         }
1891     }
1892 }