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/Answer.h"
   8 #include "adaptation/History.h"
   9 #include "adaptation/icap/Client.h"
  10 #include "adaptation/icap/Config.h"
  11 #include "adaptation/icap/History.h"
  12 #include "adaptation/icap/Launcher.h"
  13 #include "adaptation/icap/ModXact.h"
  14 #include "adaptation/icap/ServiceRep.h"
  15 #include "adaptation/Initiator.h"
  16 #include "auth/UserRequest.h"
  17 #include "base/TextException.h"
  18 #include "base64.h"
  19 #include "ChunkedCodingParser.h"
  20 #include "comm.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     // and the service may is too busy for us: honor Max-Connections and such
  90     if (service().up() && service().availableForNew())
  91         startWriting();
  92     else
  93         waitForService();
  94 }
  95
  96 void Adaptation::Icap::ModXact::waitForService()
  97 {
  98     const char *comment;
  99     Must(!state.serviceWaiting);
 100
 101     if (!service().up()) {
 102         AsyncCall::Pointer call = JobCallback(93,5,
 103                                               ConnWaiterDialer, this, Adaptation::Icap::ModXact::noteServiceReady);
 104
 105         service().callWhenReady(call);
 106         comment = "to be up";
 107     } else {
 108         //The service is unavailable because of max-connection or other reason
 109
 110         if (service().cfg().onOverload != srvWait) {
 111             // The service is overloaded, but waiting to be available prohibited by
 112             // user configuration (onOverload is set to "block" or "bypass")
 113             if (service().cfg().onOverload == srvBlock)
 114                 disableBypass("not available", true);
 115             else //if (service().cfg().onOverload == srvBypass)
 116                 canStartBypass = true;
 117
 118             disableRetries();
 119             disableRepeats("ICAP service is not available");
 120
 121             debugs(93, 7, HERE << "will not wait for the service to be available" <<
 122                    status());
 123
 124             throw TexcHere("ICAP service is not available");
 125         }
 126
 127         AsyncCall::Pointer call = JobCallback(93,5,
 128                                               ConnWaiterDialer, this, Adaptation::Icap::ModXact::noteServiceAvailable);
 129         service().callWhenAvailable(call, state.waitedForService);
 130         comment = "to be available";
 131     }
 132
 133     debugs(93, 7, HERE << "will wait for the service " << comment <<  status());
 134     state.serviceWaiting = true; // after callWhenReady() which may throw
 135     state.waitedForService = true;
 136 }
 137
 138 void Adaptation::Icap::ModXact::noteServiceReady()
 139 {
 140     Must(state.serviceWaiting);
 141     state.serviceWaiting = false;
 142
 143     if (!service().up()) {
 144         disableRetries();
 145         disableRepeats("ICAP service is unusable");
 146         throw TexcHere("ICAP service is unusable");
 147     }
 148
 149     if (service().availableForOld())
 150         startWriting();
 151     else
 152         waitForService();
 153 }
 154
 155 void Adaptation::Icap::ModXact::noteServiceAvailable()
 156 {
 157     Must(state.serviceWaiting);
 158     state.serviceWaiting = false;
 159
 160     if (service().up() && service().availableForOld())
 161         startWriting();
 162     else
 163         waitForService();
 164 }
 165
 166 void Adaptation::Icap::ModXact::startWriting()
 167 {
 168     state.writing = State::writingConnect;
 169
 170     decideOnPreview(); // must be decided before we decideOnRetries
 171     decideOnRetries();
 172
 173     openConnection();
 174 }
 175
 176 // connection with the ICAP service established
 177 void Adaptation::Icap::ModXact::handleCommConnected()
 178 {
 179     Must(state.writing == State::writingConnect);
 180
 181     startReading(); // wait for early errors from the ICAP server
 182
 183     MemBuf requestBuf;
 184     requestBuf.init();
 185
 186     makeRequestHeaders(requestBuf);
 187     debugs(93, 9, HERE << "will write" << status() << ":\n" <<
 188            (requestBuf.terminate(), requestBuf.content()));
 189
 190     // write headers
 191     state.writing = State::writingHeaders;
 192     icap_tio_start = current_time;
 193     scheduleWrite(requestBuf);
 194 }
 195
 196 void Adaptation::Icap::ModXact::handleCommWrote(size_t sz)
 197 {
 198     debugs(93, 5, HERE << "Wrote " << sz << " bytes");
 199
 200     if (state.writing == State::writingHeaders)
 201         handleCommWroteHeaders();
 202     else
 203         handleCommWroteBody();
 204 }
 205
 206 void Adaptation::Icap::ModXact::handleCommWroteHeaders()
 207 {
 208     Must(state.writing == State::writingHeaders);
 209
 210     // determine next step
 211     if (preview.enabled()) {
 212         if (preview.done())
 213             decideWritingAfterPreview("zero-size");
 214         else
 215             state.writing = State::writingPreview;
 216     } else if (virginBody.expected()) {
 217         state.writing = State::writingPrime;
 218     } else {
 219         stopWriting(true);
 220         return;
 221     }
 222
 223     writeMore();
 224 }
 225
 226 void Adaptation::Icap::ModXact::writeMore()
 227 {
 228     debugs(93, 5, HERE << "checking whether to write more" << status());
 229
 230     if (writer != NULL) // already writing something
 231         return;
 232
 233     switch (state.writing) {
 234
 235     case State::writingInit:    // waiting for service OPTIONS
 236         Must(state.serviceWaiting);
 237
 238     case State::writingConnect: // waiting for the connection to establish
 239
 240     case State::writingHeaders: // waiting for the headers to be written
 241
 242     case State::writingPaused:  // waiting for the ICAP server response
 243
 244     case State::writingReallyDone: // nothing more to write
 245         return;
 246
 247     case State::writingAlmostDone: // was waiting for the last write
 248         stopWriting(false);
 249         return;
 250
 251     case State::writingPreview:
 252         writePreviewBody();
 253         return;
 254
 255     case State::writingPrime:
 256         writePrimeBody();
 257         return;
 258
 259     default:
 260         throw TexcHere("Adaptation::Icap::ModXact in bad writing state");
 261     }
 262 }
 263
 264 void Adaptation::Icap::ModXact::writePreviewBody()
 265 {
 266     debugs(93, 8, HERE << "will write Preview body from " <<
 267            virgin.body_pipe << status());
 268     Must(state.writing == State::writingPreview);
 269     Must(virgin.body_pipe != NULL);
 270
 271     const size_t sizeMax = (size_t)virgin.body_pipe->buf().contentSize();
 272     const size_t size = min(preview.debt(), sizeMax);
 273     writeSomeBody("preview body", size);
 274
 275     // change state once preview is written
 276
 277     if (preview.done())
 278         decideWritingAfterPreview("body");
 279 }
 280
 281 /// determine state.writing after we wrote the entire preview
 282 void Adaptation::Icap::ModXact::decideWritingAfterPreview(const char *kind)
 283 {
 284     if (preview.ieof()) // nothing more to write
 285         stopWriting(true);
 286     else if (state.parsing == State::psIcapHeader) // did not get a reply yet
 287         state.writing = State::writingPaused; // wait for the ICAP server reply
 288     else
 289         stopWriting(true); // ICAP server reply implies no post-preview writing
 290
 291     debugs(93, 6, HERE << "decided on writing after " << kind << " preview" <<
 292            status());
 293 }
 294
 295 void Adaptation::Icap::ModXact::writePrimeBody()
 296 {
 297     Must(state.writing == State::writingPrime);
 298     Must(virginBodyWriting.active());
 299
 300     const size_t size = (size_t)virgin.body_pipe->buf().contentSize();
 301     writeSomeBody("prime virgin body", size);
 302
 303     if (virginBodyEndReached(virginBodyWriting)) {
 304         debugs(93, 5, HERE << "wrote entire body");
 305         stopWriting(true);
 306     }
 307 }
 308
 309 void Adaptation::Icap::ModXact::writeSomeBody(const char *label, size_t size)
 310 {
 311     Must(!writer && state.writing < state.writingAlmostDone);
 312     Must(virgin.body_pipe != NULL);
 313     debugs(93, 8, HERE << "will write up to " << size << " bytes of " <<
 314            label);
 315
 316     MemBuf writeBuf; // TODO: suggest a min size based on size and lastChunk
 317
 318     writeBuf.init(); // note: we assume that last-chunk will fit
 319
 320     const size_t writableSize = virginContentSize(virginBodyWriting);
 321     const size_t chunkSize = min(writableSize, size);
 322
 323     if (chunkSize) {
 324         debugs(93, 7, HERE << "will write " << chunkSize <<
 325                "-byte chunk of " << label);
 326
 327         openChunk(writeBuf, chunkSize, false);
 328         writeBuf.append(virginContentData(virginBodyWriting), chunkSize);
 329         closeChunk(writeBuf);
 330
 331         virginBodyWriting.progress(chunkSize);
 332         virginConsume();
 333     } else {
 334         debugs(93, 7, HERE << "has no writable " << label << " content");
 335     }
 336
 337     const bool wroteEof = virginBodyEndReached(virginBodyWriting);
 338     bool lastChunk = wroteEof;
 339     if (state.writing == State::writingPreview) {
 340         preview.wrote(chunkSize, wroteEof); // even if wrote nothing
 341         lastChunk = lastChunk || preview.done();
 342     }
 343
 344     if (lastChunk) {
 345         debugs(93, 8, HERE << "will write last-chunk of " << label);
 346         addLastRequestChunk(writeBuf);
 347     }
 348
 349     debugs(93, 7, HERE << "will write " << writeBuf.contentSize()
 350            << " raw bytes of " << label);
 351
 352     if (writeBuf.hasContent()) {
 353         scheduleWrite(writeBuf); // comm will free the chunk
 354     } else {
 355         writeBuf.clean();
 356     }
 357 }
 358
 359 void Adaptation::Icap::ModXact::addLastRequestChunk(MemBuf &buf)
 360 {
 361     const bool ieof = state.writing == State::writingPreview && preview.ieof();
 362     openChunk(buf, 0, ieof);
 363     closeChunk(buf);
 364 }
 365
 366 void Adaptation::Icap::ModXact::openChunk(MemBuf &buf, size_t chunkSize, bool ieof)
 367 {
 368     buf.Printf((ieof ? "%x; ieof\r\n" : "%x\r\n"), (int) chunkSize);
 369 }
 370
 371 void Adaptation::Icap::ModXact::closeChunk(MemBuf &buf)
 372 {
 373     buf.append(ICAP::crlf, 2); // chunk-terminating CRLF
 374 }
 375
 376 const HttpRequest &Adaptation::Icap::ModXact::virginRequest() const
 377 {
 378     const HttpRequest *request = virgin.cause ?
 379                                  virgin.cause : dynamic_cast<const HttpRequest*>(virgin.header);
 380     Must(request);
 381     return *request;
 382 }
 383
 384 // did the activity reached the end of the virgin body?
 385 bool Adaptation::Icap::ModXact::virginBodyEndReached(const Adaptation::Icap::VirginBodyAct &act) const
 386 {
 387     return
 388         !act.active() || // did all (assuming it was originally planned)
 389         !virgin.body_pipe->expectMoreAfter(act.offset()); // wont have more
 390 }
 391
 392 // the size of buffered virgin body data available for the specified activity
 393 // if this size is zero, we may be done or may be waiting for more data
 394 size_t Adaptation::Icap::ModXact::virginContentSize(const Adaptation::Icap::VirginBodyAct &act) const
 395 {
 396     Must(act.active());
 397     // asbolute start of unprocessed data
 398     const uint64_t dataStart = act.offset();
 399     // absolute end of buffered data
 400     const uint64_t dataEnd = virginConsumed + virgin.body_pipe->buf().contentSize();
 401     Must(virginConsumed <= dataStart && dataStart <= dataEnd);
 402     return static_cast<size_t>(dataEnd - dataStart);
 403 }
 404
 405 // pointer to buffered virgin body data available for the specified activity
 406 const char *Adaptation::Icap::ModXact::virginContentData(const Adaptation::Icap::VirginBodyAct &act) const
 407 {
 408     Must(act.active());
 409     const uint64_t dataStart = act.offset();
 410     Must(virginConsumed <= dataStart);
 411     return virgin.body_pipe->buf().content() + static_cast<size_t>(dataStart-virginConsumed);
 412 }
 413
 414 void Adaptation::Icap::ModXact::virginConsume()
 415 {
 416     debugs(93, 9, HERE << "consumption guards: " << !virgin.body_pipe << isRetriable <<
 417            isRepeatable << canStartBypass << protectGroupBypass);
 418
 419     if (!virgin.body_pipe)
 420         return; // nothing to consume
 421
 422     if (isRetriable)
 423         return; // do not consume if we may have to retry later
 424
 425     BodyPipe &bp = *virgin.body_pipe;
 426     const bool wantToPostpone = isRepeatable || canStartBypass || protectGroupBypass;
 427
 428     // Why > 2? HttpState does not use the last bytes in the buffer
 429     // because delayAwareRead() is arguably broken. See
 430     // HttpStateData::maybeReadVirginBody for more details.
 431     if (wantToPostpone && bp.buf().spaceSize() > 2) {
 432         // Postponing may increase memory footprint and slow the HTTP side
 433         // down. Not postponing may increase the number of ICAP errors
 434         // if the ICAP service fails. We may also use "potential" space to
 435         // postpone more aggressively. Should the trade-off be configurable?
 436         debugs(93, 8, HERE << "postponing consumption from " << bp.status());
 437         return;
 438     }
 439
 440     const size_t have = static_cast<size_t>(bp.buf().contentSize());
 441     const uint64_t end = virginConsumed + have;
 442     uint64_t offset = end;
 443
 444     debugs(93, 9, HERE << "max virgin consumption offset=" << offset <<
 445            " acts " << virginBodyWriting.active() << virginBodySending.active() <<
 446            " consumed=" << virginConsumed <<
 447            " from " << virgin.body_pipe->status());
 448
 449     if (virginBodyWriting.active())
 450         offset = min(virginBodyWriting.offset(), offset);
 451
 452     if (virginBodySending.active())
 453         offset = min(virginBodySending.offset(), offset);
 454
 455     Must(virginConsumed <= offset && offset <= end);
 456
 457     if (const size_t size = static_cast<size_t>(offset - virginConsumed)) {
 458         debugs(93, 8, HERE << "consuming " << size << " out of " << have <<
 459                " virgin body bytes");
 460         bp.consume(size);
 461         virginConsumed += size;
 462         Must(!isRetriable); // or we should not be consuming
 463         disableRepeats("consumed content");
 464         disableBypass("consumed content", true);
 465     }
 466 }
 467
 468 void Adaptation::Icap::ModXact::handleCommWroteBody()
 469 {
 470     writeMore();
 471 }
 472
 473 // Called when we do not expect to call comm_write anymore.
 474 // We may have a pending write though.
 475 // If stopping nicely, we will just wait for that pending write, if any.
 476 void Adaptation::Icap::ModXact::stopWriting(bool nicely)
 477 {
 478     if (state.writing == State::writingReallyDone)
 479         return;
 480
 481     if (writer != NULL) {
 482         if (nicely) {
 483             debugs(93, 7, HERE << "will wait for the last write" << status());
 484             state.writing = State::writingAlmostDone; // may already be set
 485             checkConsuming();
 486             return;
 487         }
 488         debugs(93, 3, HERE << "will NOT wait for the last write" << status());
 489
 490         // Comm does not have an interface to clear the writer callback nicely,
 491         // but without clearing the writer we cannot recycle the connection.
 492         // We prevent connection reuse and hope that we can handle a callback
 493         // call at any time, usually in the middle of the destruction sequence!
 494         // Somebody should add comm_remove_write_handler() to comm API.
 495         reuseConnection = false;
 496         ignoreLastWrite = true;
 497     }
 498
 499     debugs(93, 7, HERE << "will no longer write" << status());
 500     if (virginBodyWriting.active()) {
 501         virginBodyWriting.disable();
 502         virginConsume();
 503     }
 504     state.writing = State::writingReallyDone;
 505     checkConsuming();
 506 }
 507
 508 void Adaptation::Icap::ModXact::stopBackup()
 509 {
 510     if (!virginBodySending.active())
 511         return;
 512
 513     debugs(93, 7, HERE << "will no longer backup" << status());
 514     virginBodySending.disable();
 515     virginConsume();
 516 }
 517
 518 bool Adaptation::Icap::ModXact::doneAll() const
 519 {
 520     return Adaptation::Icap::Xaction::doneAll() && !state.serviceWaiting &&
 521            doneSending() &&
 522            doneReading() && state.doneWriting();
 523 }
 524
 525 void Adaptation::Icap::ModXact::startReading()
 526 {
 527     Must(connection >= 0);
 528     Must(!reader);
 529     Must(!adapted.header);
 530     Must(!adapted.body_pipe);
 531
 532     // we use the same buffer for headers and body and then consume headers
 533     readMore();
 534 }
 535
 536 void Adaptation::Icap::ModXact::readMore()
 537 {
 538     if (reader != NULL || doneReading()) {
 539         debugs(93,3,HERE << "returning from readMore because reader or doneReading()");
 540         return;
 541     }
 542
 543     // do not fill readBuf if we have no space to store the result
 544     if (adapted.body_pipe != NULL &&
 545             !adapted.body_pipe->buf().hasPotentialSpace()) {
 546         debugs(93,3,HERE << "not reading because ICAP reply pipe is full");
 547         return;
 548     }
 549
 550     if (readBuf.hasSpace())
 551         scheduleRead();
 552     else
 553         debugs(93,3,HERE << "nothing to do because !readBuf.hasSpace()");
 554 }
 555
 556 // comm module read a portion of the ICAP response for us
 557 void Adaptation::Icap::ModXact::handleCommRead(size_t)
 558 {
 559     Must(!state.doneParsing());
 560     icap_tio_finish = current_time;
 561     parseMore();
 562     readMore();
 563 }
 564
 565 void Adaptation::Icap::ModXact::echoMore()
 566 {
 567     Must(state.sending == State::sendingVirgin);
 568     Must(adapted.body_pipe != NULL);
 569     Must(virginBodySending.active());
 570
 571     const size_t sizeMax = virginContentSize(virginBodySending);
 572     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes from " <<
 573            virgin.body_pipe->status());
 574     debugs(93,5, HERE << "will echo up to " << sizeMax << " bytes to   " <<
 575            adapted.body_pipe->status());
 576
 577     if (sizeMax > 0) {
 578         const size_t size = adapted.body_pipe->putMoreData(virginContentData(virginBodySending), sizeMax);
 579         debugs(93,5, HERE << "echoed " << size << " out of " << sizeMax <<
 580                " bytes");
 581         virginBodySending.progress(size);
 582         disableRepeats("echoed content");
 583         disableBypass("echoed content", true);
 584         virginConsume();
 585     }
 586
 587     if (virginBodyEndReached(virginBodySending)) {
 588         debugs(93, 5, HERE << "echoed all" << status());
 589         stopSending(true);
 590     } else {
 591         debugs(93, 5, HERE << "has " <<
 592                virgin.body_pipe->buf().contentSize() << " bytes " <<
 593                "and expects more to echo" << status());
 594         // TODO: timeout if virgin or adapted pipes are broken
 595     }
 596 }
 597
 598 bool Adaptation::Icap::ModXact::doneSending() const
 599 {
 600     return state.sending == State::sendingDone;
 601 }
 602
 603 // stop (or do not start) sending adapted message body
 604 void Adaptation::Icap::ModXact::stopSending(bool nicely)
 605 {
 606     debugs(93, 7, HERE << "Enter stop sending ");
 607     if (doneSending())
 608         return;
 609     debugs(93, 7, HERE << "Proceed with stop sending ");
 610
 611     if (state.sending != State::sendingUndecided) {
 612         debugs(93, 7, HERE << "will no longer send" << status());
 613         if (adapted.body_pipe != NULL) {
 614             virginBodySending.disable();
 615             // we may leave debts if we were echoing and the virgin
 616             // body_pipe got exhausted before we echoed all planned bytes
 617             const bool leftDebts = adapted.body_pipe->needsMoreData();
 618             stopProducingFor(adapted.body_pipe, nicely && !leftDebts);
 619         }
 620     } else {
 621         debugs(93, 7, HERE << "will not start sending" << status());
 622         Must(!adapted.body_pipe);
 623     }
 624
 625     state.sending = State::sendingDone;
 626     checkConsuming();
 627 }
 628
 629 // should be called after certain state.writing or state.sending changes
 630 void Adaptation::Icap::ModXact::checkConsuming()
 631 {
 632     // quit if we already stopped or are still using the pipe
 633     if (!virgin.body_pipe || !state.doneConsumingVirgin())
 634         return;
 635
 636     debugs(93, 7, HERE << "will stop consuming" << status());
 637     stopConsumingFrom(virgin.body_pipe);
 638 }
 639
 640 void Adaptation::Icap::ModXact::parseMore()
 641 {
 642     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " bytes to parse" <<
 643            status());
 644     debugs(93, 5, HERE << "\n" << readBuf.content());
 645
 646     if (state.parsingHeaders())
 647         parseHeaders();
 648
 649     if (state.parsing == State::psBody)
 650         parseBody();
 651 }
 652
 653 void Adaptation::Icap::ModXact::callException(const std::exception &e)
 654 {
 655     if (!canStartBypass || isRetriable) {
 656         if (!isRetriable) {
 657             if (const TextException *te = dynamic_cast<const TextException *>(&e))
 658                 detailError(ERR_DETAIL_EXCEPTION_START + te->id());
 659             else
 660                 detailError(ERR_DETAIL_EXCEPTION_OTHER);
 661         }
 662         Adaptation::Icap::Xaction::callException(e);
 663         return;
 664     }
 665
 666     try {
 667         debugs(93, 3, HERE << "bypassing " << inCall << " exception: " <<
 668                e.what() << ' ' << status());
 669         bypassFailure();
 670     } catch (const TextException &bypassTe) {
 671         detailError(ERR_DETAIL_EXCEPTION_START + bypassTe.id());
 672         Adaptation::Icap::Xaction::callException(bypassTe);
 673     } catch (const std::exception &bypassE) {
 674         detailError(ERR_DETAIL_EXCEPTION_OTHER);
 675         Adaptation::Icap::Xaction::callException(bypassE);
 676     }
 677 }
 678
 679 void Adaptation::Icap::ModXact::bypassFailure()
 680 {
 681     disableBypass("already started to bypass", false);
 682
 683     Must(!isRetriable); // or we should not be bypassing
 684     // TODO: should the same be enforced for isRepeatable? Check icap_repeat??
 685
 686     prepEchoing();
 687
 688     startSending();
 689
 690     // end all activities associated with the ICAP server
 691
 692     stopParsing();
 693
 694     stopWriting(true); // or should we force it?
 695     if (connection >= 0) {
 696         reuseConnection = false; // be conservative
 697         cancelRead(); // may not work; and we cannot stop connecting either
 698         if (!doneWithIo())
 699             debugs(93, 7, HERE << "Warning: bypass failed to stop I/O" << status());
 700     }
 701
 702     service().noteFailure(); // we are bypassing, but this is still a failure
 703 }
 704
 705 void Adaptation::Icap::ModXact::disableBypass(const char *reason, bool includingGroupBypass)
 706 {
 707     if (canStartBypass) {
 708         debugs(93,7, HERE << "will never start bypass because " << reason);
 709         canStartBypass = false;
 710     }
 711     if (protectGroupBypass && includingGroupBypass) {
 712         debugs(93,7, HERE << "not protecting group bypass because " << reason);
 713         protectGroupBypass = false;
 714     }
 715 }
 716
 717
 718
 719 // note that allocation for echoing is done in handle204NoContent()
 720 void Adaptation::Icap::ModXact::maybeAllocateHttpMsg()
 721 {
 722     if (adapted.header) // already allocated
 723         return;
 724
 725     if (gotEncapsulated("res-hdr")) {
 726         adapted.setHeader(new HttpReply);
 727         setOutcome(service().cfg().method == ICAP::methodReqmod ?
 728                    xoSatisfied : xoModified);
 729     } else if (gotEncapsulated("req-hdr")) {
 730         adapted.setHeader(new HttpRequest);
 731         setOutcome(xoModified);
 732     } else
 733         throw TexcHere("Neither res-hdr nor req-hdr in maybeAllocateHttpMsg()");
 734 }
 735
 736 void Adaptation::Icap::ModXact::parseHeaders()
 737 {
 738     Must(state.parsingHeaders());
 739
 740     if (state.parsing == State::psIcapHeader) {
 741         debugs(93, 5, HERE << "parse ICAP headers");
 742         parseIcapHead();
 743     }
 744
 745     if (state.parsing == State::psHttpHeader) {
 746         debugs(93, 5, HERE << "parse HTTP headers");
 747         parseHttpHead();
 748     }
 749
 750     if (state.parsingHeaders()) { // need more data
 751         Must(mayReadMore());
 752         return;
 753     }
 754
 755     startSending();
 756 }
 757
 758 // called after parsing all headers or when bypassing an exception
 759 void Adaptation::Icap::ModXact::startSending()
 760 {
 761     disableRepeats("sent headers");
 762     disableBypass("sent headers", true);
 763     sendAnswer(Answer::Forward(adapted.header));
 764
 765     if (state.sending == State::sendingVirgin)
 766         echoMore();
 767 }
 768
 769 void Adaptation::Icap::ModXact::parseIcapHead()
 770 {
 771     Must(state.sending == State::sendingUndecided);
 772
 773     if (!parseHead(icapReply))
 774         return;
 775
 776     if (httpHeaderHasConnDir(&icapReply->header, "close")) {
 777         debugs(93, 5, HERE << "found connection close");
 778         reuseConnection = false;
 779     }
 780
 781     switch (icapReply->sline.status) {
 782
 783     case 100:
 784         handle100Continue();
 785         break;
 786
 787     case 200:
 788     case 201: // Symantec Scan Engine 5.0 and later when modifying HTTP msg
 789
 790         if (!validate200Ok()) {
 791             throw TexcHere("Invalid ICAP Response");
 792         } else {
 793             handle200Ok();
 794         }
 795
 796         break;
 797
 798     case 204:
 799         handle204NoContent();
 800         break;
 801
 802     case 206:
 803         handle206PartialContent();
 804         break;
 805
 806     default:
 807         debugs(93, 5, HERE << "ICAP status " << icapReply->sline.status);
 808         handleUnknownScode();
 809         break;
 810     }
 811
 812     const HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
 813     if (!request)
 814         request = &virginRequest();
 815
 816     // update the cross-transactional database if needed (all status codes!)
 817     if (const char *xxName = Adaptation::Config::masterx_shared_name) {
 818         Adaptation::History::Pointer ah = request->adaptHistory(true);
 819         if (ah != NULL) { // TODO: reorder checks to avoid creating history
 820             const String val = icapReply->header.getByName(xxName);
 821             if (val.size() > 0) // XXX: HttpHeader lacks empty value detection
 822                 ah->updateXxRecord(xxName, val);
 823         }
 824     }
 825
 826     // update the adaptation plan if needed (all status codes!)
 827     if (service().cfg().routing) {
 828         String services;
 829         if (icapReply->header.getList(HDR_X_NEXT_SERVICES, &services)) {
 830             Adaptation::History::Pointer ah = request->adaptHistory(true);
 831             if (ah != NULL)
 832                 ah->updateNextServices(services);
 833         }
 834     } // TODO: else warn (occasionally!) if we got HDR_X_NEXT_SERVICES
 835
 836     // We need to store received ICAP headers for <icapLastHeader logformat option.
 837     // If we already have stored headers from previous ICAP transaction related to this
 838     // request, old headers will be replaced with the new one.
 839
 840     Adaptation::History::Pointer ah = request->adaptLogHistory();
 841     if (ah != NULL)
 842         ah->recordMeta(&icapReply->header);
 843
 844     // handle100Continue() manages state.writing on its own.
 845     // Non-100 status means the server needs no postPreview data from us.
 846     if (state.writing == State::writingPaused)
 847         stopWriting(true);
 848 }
 849
 850 bool Adaptation::Icap::ModXact::validate200Ok()
 851 {
 852     if (ICAP::methodRespmod == service().cfg().method) {
 853         if (!gotEncapsulated("res-hdr"))
 854             return false;
 855
 856         return true;
 857     }
 858
 859     if (ICAP::methodReqmod == service().cfg().method) {
 860         if (!gotEncapsulated("res-hdr") && !gotEncapsulated("req-hdr"))
 861             return false;
 862
 863         return true;
 864     }
 865
 866     return false;
 867 }
 868
 869 void Adaptation::Icap::ModXact::handle100Continue()
 870 {
 871     Must(state.writing == State::writingPaused);
 872     // server must not respond before the end of preview: we may send ieof
 873     Must(preview.enabled() && preview.done() && !preview.ieof());
 874
 875     // 100 "Continue" cancels our Preview commitment,
 876     // but not commitment to handle 204 or 206 outside Preview
 877     if (!state.allowedPostview204 && !state.allowedPostview206)
 878         stopBackup();
 879
 880     state.parsing = State::psIcapHeader; // eventually
 881     icapReply->reset();
 882
 883     state.writing = State::writingPrime;
 884
 885     writeMore();
 886 }
 887
 888 void Adaptation::Icap::ModXact::handle200Ok()
 889 {
 890     state.parsing = State::psHttpHeader;
 891     state.sending = State::sendingAdapted;
 892     stopBackup();
 893     checkConsuming();
 894 }
 895
 896 void Adaptation::Icap::ModXact::handle204NoContent()
 897 {
 898     stopParsing();
 899     prepEchoing();
 900 }
 901
 902 void Adaptation::Icap::ModXact::handle206PartialContent()
 903 {
 904     if (state.writing == State::writingPaused) {
 905         Must(preview.enabled());
 906         Must(state.allowedPreview206);
 907         debugs(93, 7, HERE << "206 inside preview");
 908     } else {
 909         Must(state.writing > State::writingPaused);
 910         Must(state.allowedPostview206);
 911         debugs(93, 7, HERE << "206 outside preview");
 912     }
 913     state.parsing = State::psHttpHeader;
 914     state.sending = State::sendingAdapted;
 915     state.readyForUob = true;
 916     checkConsuming();
 917 }
 918
 919 // Called when we receive a 204 No Content response and
 920 // when we are trying to bypass a service failure.
 921 // We actually start sending (echoig or not) in startSending.
 922 void Adaptation::Icap::ModXact::prepEchoing()
 923 {
 924     disableRepeats("preparing to echo content");
 925     disableBypass("preparing to echo content", true);
 926     setOutcome(xoEcho);
 927
 928     // We want to clone the HTTP message, but we do not want
 929     // to copy some non-HTTP state parts that HttpMsg kids carry in them.
 930     // Thus, we cannot use a smart pointer, copy constructor, or equivalent.
 931     // Instead, we simply write the HTTP message and "clone" it by parsing.
 932     // TODO: use HttpMsg::clone()!
 933
 934     HttpMsg *oldHead = virgin.header;
 935     debugs(93, 7, HERE << "cloning virgin message " << oldHead);
 936
 937     MemBuf httpBuf;
 938
 939     // write the virgin message into a memory buffer
 940     httpBuf.init();
 941     packHead(httpBuf, oldHead);
 942
 943     // allocate the adapted message and copy metainfo
 944     Must(!adapted.header);
 945     {
 946         HttpMsg::Pointer newHead;
 947         if (const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(oldHead)) {
 948             HttpRequest::Pointer newR(new HttpRequest);
 949             newR->canonical = oldR->canonical ?
 950                               xstrdup(oldR->canonical) : NULL; // parse() does not set it
 951             newHead = newR;
 952         } else if (dynamic_cast<const HttpReply*>(oldHead)) {
 953             newHead = new HttpReply;
 954         }
 955         Must(newHead != NULL);
 956
 957         newHead->inheritProperties(oldHead);
 958
 959         adapted.setHeader(newHead);
 960     }
 961
 962     // parse the buffer back
 963     http_status error = HTTP_STATUS_NONE;
 964
 965     Must(adapted.header->parse(&httpBuf, true, &error));
 966
 967     Must(adapted.header->hdr_sz == httpBuf.contentSize()); // no leftovers
 968
 969     httpBuf.clean();
 970
 971     debugs(93, 7, HERE << "cloned virgin message " << oldHead << " to " <<
 972            adapted.header);
 973
 974     // setup adapted body pipe if needed
 975     if (oldHead->body_pipe != NULL) {
 976         debugs(93, 7, HERE << "will echo virgin body from " <<
 977                oldHead->body_pipe);
 978         if (!virginBodySending.active())
 979             virginBodySending.plan(); // will throw if not possible
 980         state.sending = State::sendingVirgin;
 981         checkConsuming();
 982
 983         // TODO: optimize: is it possible to just use the oldHead pipe and
 984         // remove ICAP from the loop? This echoing is probably a common case!
 985         makeAdaptedBodyPipe("echoed virgin response");
 986         if (oldHead->body_pipe->bodySizeKnown())
 987             adapted.body_pipe->setBodySize(oldHead->body_pipe->bodySize());
 988         debugs(93, 7, HERE << "will echo virgin body to " <<
 989                adapted.body_pipe);
 990     } else {
 991         debugs(93, 7, HERE << "no virgin body to echo");
 992         stopSending(true);
 993     }
 994 }
 995
 996 /// Called when we received use-original-body chunk extension in 206 response.
 997 /// We actually start sending (echoing or not) in startSending().
 998 void Adaptation::Icap::ModXact::prepPartialBodyEchoing(uint64_t pos)
 999 {
1000     Must(virginBodySending.active());
1001     Must(virgin.header->body_pipe != NULL);
1002
1003     setOutcome(xoPartEcho);
1004
1005     debugs(93, 7, HERE << "will echo virgin body suffix from " <<
1006            virgin.header->body_pipe << " offset " << pos );
1007
1008     // check that use-original-body=N does not point beyond buffered data
1009     const uint64_t virginDataEnd = virginConsumed +
1010                                    virgin.body_pipe->buf().contentSize();
1011     Must(pos <= virginDataEnd);
1012     virginBodySending.progress(static_cast<size_t>(pos));
1013
1014     state.sending = State::sendingVirgin;
1015     checkConsuming();
1016
1017     if (virgin.header->body_pipe->bodySizeKnown())
1018         adapted.body_pipe->expectProductionEndAfter(virgin.header->body_pipe->bodySize() - pos);
1019
1020     debugs(93, 7, HERE << "will echo virgin body suffix to " <<
1021            adapted.body_pipe);
1022
1023     // Start echoing data
1024     echoMore();
1025 }
1026
1027 void Adaptation::Icap::ModXact::handleUnknownScode()
1028 {
1029     stopParsing();
1030     stopBackup();
1031     // TODO: mark connection as "bad"
1032
1033     // Terminate the transaction; we do not know how to handle this response.
1034     throw TexcHere("Unsupported ICAP status code");
1035 }
1036
1037 void Adaptation::Icap::ModXact::parseHttpHead()
1038 {
1039     if (gotEncapsulated("res-hdr") || gotEncapsulated("req-hdr")) {
1040         replyHttpHeaderSize = 0;
1041         maybeAllocateHttpMsg();
1042
1043         if (!parseHead(adapted.header))
1044             return; // need more header data
1045
1046         if (adapted.header)
1047             replyHttpHeaderSize = adapted.header->hdr_sz;
1048
1049         if (dynamic_cast<HttpRequest*>(adapted.header)) {
1050             const HttpRequest *oldR = dynamic_cast<const HttpRequest*>(virgin.header);
1051             Must(oldR);
1052             // TODO: the adapted request did not really originate from the
1053             // client; give proxy admin an option to prevent copying of
1054             // sensitive client information here. See the following thread:
1055             // http://www.squid-cache.org/mail-archive/squid-dev/200703/0040.html
1056         }
1057
1058         // Maybe adapted.header==NULL if HttpReply and have Http 0.9 ....
1059         if (adapted.header)
1060             adapted.header->inheritProperties(virgin.header);
1061     }
1062
1063     decideOnParsingBody();
1064 }
1065
1066 // parses both HTTP and ICAP headers
1067 bool Adaptation::Icap::ModXact::parseHead(HttpMsg *head)
1068 {
1069     Must(head);
1070     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " head bytes to parse" <<
1071            "; state: " << state.parsing);
1072
1073     http_status error = HTTP_STATUS_NONE;
1074     const bool parsed = head->parse(&readBuf, commEof, &error);
1075     Must(parsed || !error); // success or need more data
1076
1077     if (!parsed) { // need more data
1078         debugs(93, 5, HERE << "parse failed, need more data, return false");
1079         head->reset();
1080         return false;
1081     }
1082
1083     if (HttpRequest *r = dynamic_cast<HttpRequest*>(head))
1084         urlCanonical(r); // parse does not set HttpRequest::canonical
1085
1086     debugs(93, 5, HERE << "parse success, consume " << head->hdr_sz << " bytes, return true");
1087     readBuf.consume(head->hdr_sz);
1088     return true;
1089 }
1090
1091 void Adaptation::Icap::ModXact::decideOnParsingBody()
1092 {
1093     if (gotEncapsulated("res-body") || gotEncapsulated("req-body")) {
1094         debugs(93, 5, HERE << "expecting a body");
1095         state.parsing = State::psBody;
1096         replyHttpBodySize = 0;
1097         bodyParser = new ChunkedCodingParser;
1098         makeAdaptedBodyPipe("adapted response from the ICAP server");
1099         Must(state.sending == State::sendingAdapted);
1100     } else {
1101         debugs(93, 5, HERE << "not expecting a body");
1102         stopParsing();
1103         stopSending(true);
1104     }
1105 }
1106
1107 void Adaptation::Icap::ModXact::parseBody()
1108 {
1109     Must(state.parsing == State::psBody);
1110     Must(bodyParser);
1111
1112     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes to parse");
1113
1114     // the parser will throw on errors
1115     BodyPipeCheckout bpc(*adapted.body_pipe);
1116     const bool parsed = bodyParser->parse(&readBuf, &bpc.buf);
1117     bpc.checkIn();
1118
1119     debugs(93, 5, HERE << "have " << readBuf.contentSize() << " body bytes after " <<
1120            "parse; parsed all: " << parsed);
1121     replyHttpBodySize += adapted.body_pipe->buf().contentSize();
1122
1123     // TODO: expose BodyPipe::putSize() to make this check simpler and clearer
1124     // TODO: do we really need this if we disable when sending headers?
1125     if (adapted.body_pipe->buf().contentSize() > 0) { // parsed something sometime
1126         disableRepeats("sent adapted content");
1127         disableBypass("sent adapted content", true);
1128     }
1129
1130     if (parsed) {
1131         if (state.readyForUob && bodyParser->useOriginBody >= 0) {
1132             prepPartialBodyEchoing(
1133                 static_cast<uint64_t>(bodyParser->useOriginBody));
1134             stopParsing();
1135             return;
1136         }
1137
1138         stopParsing();
1139         stopSending(true); // the parser succeeds only if all parsed data fits
1140         return;
1141     }
1142
1143     debugs(93,3,HERE << this << " needsMoreData = " << bodyParser->needsMoreData());
1144
1145     if (bodyParser->needsMoreData()) {
1146         debugs(93,3,HERE << this);
1147         Must(mayReadMore());
1148         readMore();
1149     }
1150
1151     if (bodyParser->needsMoreSpace()) {
1152         Must(!doneSending()); // can hope for more space
1153         Must(adapted.body_pipe->buf().contentSize() > 0); // paranoid
1154         // TODO: there should be a timeout in case the sink is broken
1155         // or cannot consume partial content (while we need more space)
1156     }
1157 }
1158
1159 void Adaptation::Icap::ModXact::stopParsing()
1160 {
1161     if (state.parsing == State::psDone)
1162         return;
1163
1164     debugs(93, 7, HERE << "will no longer parse" << status());
1165
1166     delete bodyParser;
1167
1168     bodyParser = NULL;
1169
1170     state.parsing = State::psDone;
1171 }
1172
1173 // HTTP side added virgin body data
1174 void Adaptation::Icap::ModXact::noteMoreBodyDataAvailable(BodyPipe::Pointer)
1175 {
1176     writeMore();
1177
1178     if (state.sending == State::sendingVirgin)
1179         echoMore();
1180 }
1181
1182 // HTTP side sent us all virgin info
1183 void Adaptation::Icap::ModXact::noteBodyProductionEnded(BodyPipe::Pointer)
1184 {
1185     Must(virgin.body_pipe->productionEnded());
1186
1187     // push writer and sender in case we were waiting for the last-chunk
1188     writeMore();
1189
1190     if (state.sending == State::sendingVirgin)
1191         echoMore();
1192 }
1193
1194 // body producer aborted, but the initiator may still want to know
1195 // the answer, even though the HTTP message has been truncated
1196 void Adaptation::Icap::ModXact::noteBodyProducerAborted(BodyPipe::Pointer)
1197 {
1198     Must(virgin.body_pipe->productionEnded());
1199
1200     // push writer and sender in case we were waiting for the last-chunk
1201     writeMore();
1202
1203     if (state.sending == State::sendingVirgin)
1204         echoMore();
1205 }
1206
1207 // adapted body consumer wants more adapted data and
1208 // possibly freed some buffer space
1209 void Adaptation::Icap::ModXact::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
1210 {
1211     if (state.sending == State::sendingVirgin)
1212         echoMore();
1213     else if (state.sending == State::sendingAdapted)
1214         parseMore();
1215     else
1216         Must(state.sending == State::sendingUndecided);
1217 }
1218
1219 // adapted body consumer aborted
1220 void Adaptation::Icap::ModXact::noteBodyConsumerAborted(BodyPipe::Pointer)
1221 {
1222     detailError(ERR_DETAIL_ICAP_XACT_BODY_CONSUMER_ABORT);
1223     mustStop("adapted body consumer aborted");
1224 }
1225
1226 Adaptation::Icap::ModXact::~ModXact()
1227 {
1228     delete bodyParser;
1229 }
1230
1231 // internal cleanup
1232 void Adaptation::Icap::ModXact::swanSong()
1233 {
1234     debugs(93, 5, HERE << "swan sings" << status());
1235
1236     stopWriting(false);
1237     stopSending(false);
1238
1239     if (theInitiator.set()) // we have not sent the answer to the initiator
1240         detailError(ERR_DETAIL_ICAP_XACT_OTHER);
1241
1242     // update adaptation history if start was called and we reserved a slot
1243     Adaptation::History::Pointer ah = virginRequest().adaptLogHistory();
1244     if (ah != NULL && adaptHistoryId >= 0)
1245         ah->recordXactFinish(adaptHistoryId);
1246
1247     Adaptation::Icap::Xaction::swanSong();
1248 }
1249
1250 void prepareLogWithRequestDetails(HttpRequest *, AccessLogEntry *);
1251
1252 void Adaptation::Icap::ModXact::finalizeLogInfo()
1253 {
1254     HttpRequest * request_ = NULL;
1255     HttpReply * reply_ = NULL;
1256     if (!(request_ = dynamic_cast<HttpRequest*>(adapted.header))) {
1257         request_ = (virgin.cause? virgin.cause: dynamic_cast<HttpRequest*>(virgin.header));
1258         reply_ = dynamic_cast<HttpReply*>(adapted.header);
1259     }
1260
1261     Adaptation::Icap::History::Pointer h = request_->icapHistory();
1262     Must(h != NULL); // ICAPXaction::maybeLog calls only if there is a log
1263     al.icp.opcode = ICP_INVALID;
1264     al.url = h->log_uri.termedBuf();
1265     const Adaptation::Icap::ServiceRep  &s = service();
1266     al.icap.reqMethod = s.cfg().method;
1267
1268     al.cache.caddr = request_->client_addr;
1269
1270     al.request = HTTPMSGLOCK(request_);
1271     if (reply_)
1272         al.reply = HTTPMSGLOCK(reply_);
1273     else
1274         al.reply = NULL;
1275
1276     if (h->rfc931.size())
1277         al.cache.rfc931 = h->rfc931.termedBuf();
1278
1279 #if USE_SSL
1280     if (h->ssluser.size())
1281         al.cache.ssluser = h->ssluser.termedBuf();
1282 #endif
1283     al.cache.code = h->logType;
1284     al.cache.requestSize = h->req_sz;
1285
1286     // leave al.icap.bodyBytesRead negative if no body
1287     if (replyHttpHeaderSize >= 0 || replyHttpBodySize >= 0) {
1288         const int64_t zero = 0; // to make max() argument types the same
1289         al.icap.bodyBytesRead =
1290             max(zero, replyHttpHeaderSize) + max(zero, replyHttpBodySize);
1291     }
1292
1293     if (reply_) {
1294         al.http.code = reply_->sline.status;
1295         al.http.content_type = reply_->content_type.termedBuf();
1296         if (replyHttpBodySize >= 0) {
1297             al.cache.replySize = replyHttpBodySize + reply_->hdr_sz;
1298             al.cache.highOffset = replyHttpBodySize;
1299         }
1300         //don't set al.cache.objectSize because it hasn't exist yet
1301
1302         Packer p;
1303         MemBuf mb;
1304
1305         mb.init();
1306         packerToMemInit(&p, &mb);
1307
1308         reply_->header.packInto(&p);
1309         al.headers.reply = xstrdup(mb.buf);
1310
1311         packerClean(&p);
1312         mb.clean();
1313     }
1314     prepareLogWithRequestDetails(request_, &al);
1315     Xaction::finalizeLogInfo();
1316 }
1317
1318
1319 void Adaptation::Icap::ModXact::makeRequestHeaders(MemBuf &buf)
1320 {
1321     char ntoabuf[MAX_IPSTRLEN];
1322     /*
1323      * XXX These should use HttpHdr interfaces instead of Printfs
1324      */
1325     const Adaptation::ServiceConfig &s = service().cfg();
1326     buf.Printf("%s " SQUIDSTRINGPH " ICAP/1.0\r\n", s.methodStr(), SQUIDSTRINGPRINT(s.uri));
1327     buf.Printf("Host: " SQUIDSTRINGPH ":%d\r\n", SQUIDSTRINGPRINT(s.host), s.port);
1328     buf.Printf("Date: %s\r\n", mkrfc1123(squid_curtime));
1329
1330     if (!TheConfig.reuse_connections)
1331         buf.Printf("Connection: close\r\n");
1332
1333     // we must forward "Proxy-Authenticate" and "Proxy-Authorization"
1334     // as ICAP headers.
1335     if (virgin.header->header.has(HDR_PROXY_AUTHENTICATE)) {
1336         String vh=virgin.header->header.getByName("Proxy-Authenticate");
1337         buf.Printf("Proxy-Authenticate: " SQUIDSTRINGPH "\r\n",SQUIDSTRINGPRINT(vh));
1338     }
1339
1340     if (virgin.header->header.has(HDR_PROXY_AUTHORIZATION)) {
1341         String vh=virgin.header->header.getByName("Proxy-Authorization");
1342         buf.Printf("Proxy-Authorization: " SQUIDSTRINGPH "\r\n", SQUIDSTRINGPRINT(vh));
1343     }
1344
1345     const HttpRequest *request = &virginRequest();
1346
1347     // share the cross-transactional database records if needed
1348     if (Adaptation::Config::masterx_shared_name) {
1349         Adaptation::History::Pointer ah = request->adaptHistory(false);
1350         if (ah != NULL) {
1351             String name, value;
1352             if (ah->getXxRecord(name, value)) {
1353                 buf.Printf(SQUIDSTRINGPH ": " SQUIDSTRINGPH "\r\n",
1354                            SQUIDSTRINGPRINT(name), SQUIDSTRINGPRINT(value));
1355             }
1356         }
1357     }
1358
1359
1360     buf.Printf("Encapsulated: ");
1361
1362     MemBuf httpBuf;
1363
1364     httpBuf.init();
1365
1366     // build HTTP request header, if any
1367     ICAP::Method m = s.method;
1368
1369     // to simplify, we could assume that request is always available
1370
1371     String urlPath;
1372     if (request) {
1373         urlPath = request->urlpath;
1374         if (ICAP::methodRespmod == m)
1375             encapsulateHead(buf, "req-hdr", httpBuf, request);
1376         else if (ICAP::methodReqmod == m)
1377             encapsulateHead(buf, "req-hdr", httpBuf, virgin.header);
1378     }
1379
1380     if (ICAP::methodRespmod == m)
1381         if (const HttpMsg *prime = virgin.header)
1382             encapsulateHead(buf, "res-hdr", httpBuf, prime);
1383
1384     if (!virginBody.expected())
1385         buf.Printf("null-body=%d", (int) httpBuf.contentSize());
1386     else if (ICAP::methodReqmod == m)
1387         buf.Printf("req-body=%d", (int) httpBuf.contentSize());
1388     else
1389         buf.Printf("res-body=%d", (int) httpBuf.contentSize());
1390
1391     buf.append(ICAP::crlf, 2); // terminate Encapsulated line
1392
1393     if (preview.enabled()) {
1394         buf.Printf("Preview: %d\r\n", (int)preview.ad());
1395         if (!virginBody.expected()) // there is no body to preview
1396             finishNullOrEmptyBodyPreview(httpBuf);
1397     }
1398
1399     makeAllowHeader(buf);
1400
1401     if (TheConfig.send_client_ip && request) {
1402         Ip::Address client_addr;
1403 #if FOLLOW_X_FORWARDED_FOR
1404         if (TheConfig.use_indirect_client) {
1405             client_addr = request->indirect_client_addr;
1406         } else
1407 #endif
1408             client_addr = request->client_addr;
1409         if (!client_addr.IsAnyAddr() && !client_addr.IsNoAddr())
1410             buf.Printf("X-Client-IP: %s\r\n", client_addr.NtoA(ntoabuf,MAX_IPSTRLEN));
1411     }
1412
1413     if (TheConfig.send_username && request)
1414         makeUsernameHeader(request, buf);
1415
1416     // fprintf(stderr, "%s\n", buf.content());
1417
1418     buf.append(ICAP::crlf, 2); // terminate ICAP header
1419
1420     // fill icapRequest for logging
1421     Must(icapRequest->parseCharBuf(buf.content(), buf.contentSize()));
1422
1423     // start ICAP request body with encapsulated HTTP headers
1424     buf.append(httpBuf.content(), httpBuf.contentSize());
1425
1426     httpBuf.clean();
1427 }
1428
1429 // decides which Allow values to write and updates the request buffer
1430 void Adaptation::Icap::ModXact::makeAllowHeader(MemBuf &buf)
1431 {
1432     const bool allow204in = preview.enabled(); // TODO: add shouldAllow204in()
1433     const bool allow204out = state.allowedPostview204 = shouldAllow204();
1434     const bool allow206in = state.allowedPreview206 = shouldAllow206in();
1435     const bool allow206out = state.allowedPostview206 = shouldAllow206out();
1436
1437     debugs(93,9, HERE << "Allows: " << allow204in << allow204out <<
1438            allow206in << allow206out);
1439
1440     const bool allow204 = allow204in || allow204out;
1441     const bool allow206 = allow206in || allow206out;
1442
1443     if (!allow204 && !allow206)
1444         return; // nothing to do
1445
1446     if (virginBody.expected()) // if there is a virgin body, plan to send it
1447         virginBodySending.plan();
1448
1449     // writing Preview:...   means we will honor 204 inside preview
1450     // writing Allow/204     means we will honor 204 outside preview
1451     // writing Allow:206     means we will honor 206 inside preview
1452     // writing Allow:204,206 means we will honor 206 outside preview
1453     const char *allowHeader = NULL;
1454     if (allow204out && allow206)
1455         allowHeader = "Allow: 204, 206\r\n";
1456     else if (allow204out)
1457         allowHeader = "Allow: 204\r\n";
1458     else if (allow206)
1459         allowHeader = "Allow: 206\r\n";
1460
1461     if (allowHeader) { // may be nil if only allow204in is true
1462         buf.append(allowHeader, strlen(allowHeader));
1463         debugs(93,5, HERE << "Will write " << allowHeader);
1464     }
1465 }
1466
1467 void Adaptation::Icap::ModXact::makeUsernameHeader(const HttpRequest *request, MemBuf &buf)
1468 {
1469 #if USE_AUTH
1470     if (request->auth_user_request != NULL) {
1471         char const *name = request->auth_user_request->username();
1472         if (name) {
1473             const char *value = TheConfig.client_username_encode ? old_base64_encode(name) : name;
1474             buf.Printf("%s: %s\r\n", TheConfig.client_username_header, value);
1475         }
1476     }
1477 #endif
1478 }
1479
1480 void Adaptation::Icap::ModXact::encapsulateHead(MemBuf &icapBuf, const char *section, MemBuf &httpBuf, const HttpMsg *head)
1481 {
1482     // update ICAP header
1483     icapBuf.Printf("%s=%d, ", section, (int) httpBuf.contentSize());
1484
1485     // begin cloning
1486     HttpMsg::Pointer headClone;
1487
1488     if (const HttpRequest* old_request = dynamic_cast<const HttpRequest*>(head)) {
1489         HttpRequest::Pointer new_request(new HttpRequest);
1490         Must(old_request->canonical);
1491         urlParse(old_request->method, old_request->canonical, new_request);
1492         new_request->http_ver = old_request->http_ver;
1493         headClone = new_request;
1494     } else if (const HttpReply *old_reply = dynamic_cast<const HttpReply*>(head)) {
1495         HttpReply::Pointer new_reply(new HttpReply);
1496         new_reply->sline = old_reply->sline;
1497         headClone = new_reply;
1498     }
1499     Must(headClone != NULL);
1500     headClone->inheritProperties(head);
1501
1502     HttpHeaderPos pos = HttpHeaderInitPos;
1503     HttpHeaderEntry* p_head_entry = NULL;
1504     while (NULL != (p_head_entry = head->header.getEntry(&pos)) )
1505         headClone->header.addEntry(p_head_entry->clone());
1506
1507     // end cloning
1508
1509     // remove all hop-by-hop headers from the clone
1510     headClone->header.delById(HDR_PROXY_AUTHENTICATE);
1511     headClone->header.removeHopByHopEntries();
1512
1513     // pack polished HTTP header
1514     packHead(httpBuf, headClone);
1515
1516     // headClone unlocks and, hence, deletes the message we packed
1517 }
1518
1519 void Adaptation::Icap::ModXact::packHead(MemBuf &httpBuf, const HttpMsg *head)
1520 {
1521     Packer p;
1522     packerToMemInit(&p, &httpBuf);
1523     head->packInto(&p, true);
1524     packerClean(&p);
1525 }
1526
1527 // decides whether to offer a preview and calculates its size
1528 void Adaptation::Icap::ModXact::decideOnPreview()
1529 {
1530     if (!TheConfig.preview_enable) {
1531         debugs(93, 5, HERE << "preview disabled by squid.conf");
1532         return;
1533     }
1534
1535     const String urlPath = virginRequest().urlpath;
1536     size_t wantedSize;
1537     if (!service().wantsPreview(urlPath, wantedSize)) {
1538         debugs(93, 5, HERE << "should not offer preview for " << urlPath);
1539         return;
1540     }
1541
1542     // we decided to do preview, now compute its size
1543
1544     // cannot preview more than we can backup
1545     size_t ad = min(wantedSize, TheBackupLimit);
1546
1547     if (!virginBody.expected())
1548         ad = 0;
1549     else if (virginBody.knownSize())
1550         ad = min(static_cast<uint64_t>(ad), virginBody.size()); // not more than we have
1551
1552     debugs(93, 5, HERE << "should offer " << ad << "-byte preview " <<
1553            "(service wanted " << wantedSize << ")");
1554
1555     preview.enable(ad);
1556     Must(preview.enabled());
1557 }
1558
1559 // decides whether to allow 204 responses
1560 bool Adaptation::Icap::ModXact::shouldAllow204()
1561 {
1562     if (!service().allows204())
1563         return false;
1564
1565     return canBackupEverything();
1566 }
1567
1568 // decides whether to allow 206 responses in some mode
1569 bool Adaptation::Icap::ModXact::shouldAllow206any()
1570 {
1571     return TheConfig.allow206_enable && service().allows206() &&
1572            virginBody.expected(); // no need for 206 without a body
1573 }
1574
1575 // decides whether to allow 206 responses in preview mode
1576 bool Adaptation::Icap::ModXact::shouldAllow206in()
1577 {
1578     return shouldAllow206any() && preview.enabled();
1579 }
1580
1581 // decides whether to allow 206 responses outside of preview
1582 bool Adaptation::Icap::ModXact::shouldAllow206out()
1583 {
1584     return shouldAllow206any() && canBackupEverything();
1585 }
1586
1587 // used by shouldAllow204 and decideOnRetries
1588 bool Adaptation::Icap::ModXact::canBackupEverything() const
1589 {
1590     if (!virginBody.expected())
1591         return true; // no body means no problems with backup
1592
1593     // if there is a body, check whether we can backup it all
1594
1595     if (!virginBody.knownSize())
1596         return false;
1597
1598     // or should we have a different backup limit?
1599     // note that '<' allows for 0-termination of the "full" backup buffer
1600     return virginBody.size() < TheBackupLimit;
1601 }
1602
1603 // Decide whether this transaction can be retried if pconn fails
1604 // Must be called after decideOnPreview and before openConnection()
1605 void Adaptation::Icap::ModXact::decideOnRetries()
1606 {
1607     if (!isRetriable)
1608         return; // no, already decided
1609
1610     if (preview.enabled())
1611         return; // yes, because preview provides enough guarantees
1612
1613     if (canBackupEverything())
1614         return; // yes, because we can back everything up
1615
1616     disableRetries(); // no, because we cannot back everything up
1617 }
1618
1619 // Normally, the body-writing code handles preview body. It can deal with
1620 // bodies of unexpected size, including those that turn out to be empty.
1621 // However, that code assumes that the body was expected and body control
1622 // structures were initialized. This is not the case when there is no body
1623 // or the body is known to be empty, because the virgin message will lack a
1624 // body_pipe. So we handle preview of null-body and zero-size bodies here.
1625 void Adaptation::Icap::ModXact::finishNullOrEmptyBodyPreview(MemBuf &buf)
1626 {
1627     Must(!virginBodyWriting.active()); // one reason we handle it here
1628     Must(!virgin.body_pipe);          // another reason we handle it here
1629     Must(!preview.ad());
1630
1631     // do not add last-chunk because our Encapsulated header says null-body
1632     // addLastRequestChunk(buf);
1633     preview.wrote(0, true);
1634
1635     Must(preview.done());
1636     Must(preview.ieof());
1637 }
1638
1639 void Adaptation::Icap::ModXact::fillPendingStatus(MemBuf &buf) const
1640 {
1641     Adaptation::Icap::Xaction::fillPendingStatus(buf);
1642
1643     if (state.serviceWaiting)
1644         buf.append("U", 1);
1645
1646     if (virgin.body_pipe != NULL)
1647         buf.append("R", 1);
1648
1649     if (connection > 0 && !doneReading())
1650         buf.append("r", 1);
1651
1652     if (!state.doneWriting() && state.writing != State::writingInit)
1653         buf.Printf("w(%d)", state.writing);
1654
1655     if (preview.enabled()) {
1656         if (!preview.done())
1657             buf.Printf("P(%d)", (int) preview.debt());
1658     }
1659
1660     if (virginBodySending.active())
1661         buf.append("B", 1);
1662
1663     if (!state.doneParsing() && state.parsing != State::psIcapHeader)
1664         buf.Printf("p(%d)", state.parsing);
1665
1666     if (!doneSending() && state.sending != State::sendingUndecided)
1667         buf.Printf("S(%d)", state.sending);
1668
1669     if (state.readyForUob)
1670         buf.append("6", 1);
1671
1672     if (canStartBypass)
1673         buf.append("Y", 1);
1674
1675     if (protectGroupBypass)
1676         buf.append("G", 1);
1677 }
1678
1679 void Adaptation::Icap::ModXact::fillDoneStatus(MemBuf &buf) const
1680 {
1681     Adaptation::Icap::Xaction::fillDoneStatus(buf);
1682
1683     if (!virgin.body_pipe)
1684         buf.append("R", 1);
1685
1686     if (state.doneWriting())
1687         buf.append("w", 1);
1688
1689     if (preview.enabled()) {
1690         if (preview.done())
1691             buf.Printf("P%s", preview.ieof() ? "(ieof)" : "");
1692     }
1693
1694     if (doneReading())
1695         buf.append("r", 1);
1696
1697     if (state.doneParsing())
1698         buf.append("p", 1);
1699
1700     if (doneSending())
1701         buf.append("S", 1);
1702 }
1703
1704 bool Adaptation::Icap::ModXact::gotEncapsulated(const char *section) const
1705 {
1706     return icapReply->header.getByNameListMember("Encapsulated",
1707             section, ',').size() > 0;
1708 }
1709
1710 // calculate whether there is a virgin HTTP body and
1711 // whether its expected size is known
1712 // TODO: rename because we do not just estimate
1713 void Adaptation::Icap::ModXact::estimateVirginBody()
1714 {
1715     // note: lack of size info may disable previews and 204s
1716
1717     HttpMsg *msg = virgin.header;
1718     Must(msg);
1719
1720     HttpRequestMethod method;
1721
1722     if (virgin.cause)
1723         method = virgin.cause->method;
1724     else if (HttpRequest *req = dynamic_cast<HttpRequest*>(msg))
1725         method = req->method;
1726     else
1727         method = METHOD_NONE;
1728
1729     int64_t size;
1730     // expectingBody returns true for zero-sized bodies, but we will not
1731     // get a pipe for that body, so we treat the message as bodyless
1732     if (method != METHOD_NONE && msg->expectingBody(method, size) && size) {
1733         debugs(93, 6, HERE << "expects virgin body from " <<
1734                virgin.body_pipe << "; size: " << size);
1735
1736         virginBody.expect(size);
1737         virginBodyWriting.plan();
1738
1739         // sign up as a body consumer
1740         Must(msg->body_pipe != NULL);
1741         Must(msg->body_pipe == virgin.body_pipe);
1742         Must(virgin.body_pipe->setConsumerIfNotLate(this));
1743
1744         // make sure TheBackupLimit is in-sync with the buffer size
1745         Must(TheBackupLimit <= static_cast<size_t>(msg->body_pipe->buf().max_capacity));
1746     } else {
1747         debugs(93, 6, HERE << "does not expect virgin body");
1748         Must(msg->body_pipe == NULL);
1749         checkConsuming();
1750     }
1751 }
1752
1753 void Adaptation::Icap::ModXact::makeAdaptedBodyPipe(const char *what)
1754 {
1755     Must(!adapted.body_pipe);
1756     Must(!adapted.header->body_pipe);
1757     adapted.header->body_pipe = new BodyPipe(this);
1758     adapted.body_pipe = adapted.header->body_pipe;
1759     debugs(93, 7, HERE << "will supply " << what << " via " <<
1760            adapted.body_pipe << " pipe");
1761 }
1762
1763
1764 // TODO: Move SizedEstimate and Preview elsewhere
1765
1766 Adaptation::Icap::SizedEstimate::SizedEstimate()
1767         : theData(dtUnexpected)
1768 {}
1769
1770 void Adaptation::Icap::SizedEstimate::expect(int64_t aSize)
1771 {
1772     theData = (aSize >= 0) ? aSize : (int64_t)dtUnknown;
1773 }
1774
1775 bool Adaptation::Icap::SizedEstimate::expected() const
1776 {
1777     return theData != dtUnexpected;
1778 }
1779
1780 bool Adaptation::Icap::SizedEstimate::knownSize() const
1781 {
1782     Must(expected());
1783     return theData != dtUnknown;
1784 }
1785
1786 uint64_t Adaptation::Icap::SizedEstimate::size() const
1787 {
1788     Must(knownSize());
1789     return static_cast<uint64_t>(theData);
1790 }
1791
1792
1793
1794 Adaptation::Icap::VirginBodyAct::VirginBodyAct(): theStart(0), theState(stUndecided)
1795 {}
1796
1797 void Adaptation::Icap::VirginBodyAct::plan()
1798 {
1799     Must(!disabled());
1800     Must(!theStart); // not started
1801     theState = stActive;
1802 }
1803
1804 void Adaptation::Icap::VirginBodyAct::disable()
1805 {
1806     theState = stDisabled;
1807 }
1808
1809 void Adaptation::Icap::VirginBodyAct::progress(size_t size)
1810 {
1811     Must(active());
1812 #if SIZEOF_SIZE_T > 4
1813     /* always true for smaller size_t's */
1814     Must(static_cast<int64_t>(size) >= 0);
1815 #endif
1816     theStart += static_cast<int64_t>(size);
1817 }
1818
1819 uint64_t Adaptation::Icap::VirginBodyAct::offset() const
1820 {
1821     Must(active());
1822     return static_cast<uint64_t>(theStart);
1823 }
1824
1825
1826 Adaptation::Icap::Preview::Preview(): theWritten(0), theAd(0), theState(stDisabled)
1827 {}
1828
1829 void Adaptation::Icap::Preview::enable(size_t anAd)
1830 {
1831     // TODO: check for anAd not exceeding preview size limit
1832     Must(!enabled());
1833     theAd = anAd;
1834     theState = stWriting;
1835 }
1836
1837 bool Adaptation::Icap::Preview::enabled() const
1838 {
1839     return theState != stDisabled;
1840 }
1841
1842 size_t Adaptation::Icap::Preview::ad() const
1843 {
1844     Must(enabled());
1845     return theAd;
1846 }
1847
1848 bool Adaptation::Icap::Preview::done() const
1849 {
1850     Must(enabled());
1851     return theState >= stIeof;
1852 }
1853
1854 bool Adaptation::Icap::Preview::ieof() const
1855 {
1856     Must(enabled());
1857     return theState == stIeof;
1858 }
1859
1860 size_t Adaptation::Icap::Preview::debt() const
1861 {
1862     Must(enabled());
1863     return done() ? 0 : (theAd - theWritten);
1864 }
1865
1866 void Adaptation::Icap::Preview::wrote(size_t size, bool wroteEof)
1867 {
1868     Must(enabled());
1869
1870     theWritten += size;
1871
1872     Must(theWritten <= theAd);
1873
1874     if (wroteEof)
1875         theState = stIeof; // written size is irrelevant
1876     else if (theWritten >= theAd)
1877         theState = stDone;
1878 }
1879
1880 bool Adaptation::Icap::ModXact::fillVirginHttpHeader(MemBuf &mb) const
1881 {
1882     if (virgin.header == NULL)
1883         return false;
1884
1885     virgin.header->firstLineBuf(mb);
1886
1887     return true;
1888 }
1889
1890 void Adaptation::Icap::ModXact::detailError(int errDetail)
1891 {
1892     HttpRequest *request = dynamic_cast<HttpRequest*>(adapted.header);
1893     // if no adapted request, update virgin (and inherit its properties later)
1894     // TODO: make this and HttpRequest::detailError constant, like adaptHistory
1895     if (!request)
1896         request = const_cast<HttpRequest*>(&virginRequest());
1897
1898     if (request)
1899         request->detailError(ERR_ICAP_FAILURE, errDetail);
1900 }
1901
1902 /* Adaptation::Icap::ModXactLauncher */
1903
1904 Adaptation::Icap::ModXactLauncher::ModXactLauncher(HttpMsg *virginHeader, HttpRequest *virginCause, Adaptation::ServicePointer aService):
1905         AsyncJob("Adaptation::Icap::ModXactLauncher"),
1906         Adaptation::Icap::Launcher("Adaptation::Icap::ModXactLauncher", aService)
1907 {
1908     virgin.setHeader(virginHeader);
1909     virgin.setCause(virginCause);
1910     updateHistory(true);
1911 }
1912
1913 Adaptation::Icap::Xaction *Adaptation::Icap::ModXactLauncher::createXaction()
1914 {
1915     Adaptation::Icap::ServiceRep::Pointer s =
1916         dynamic_cast<Adaptation::Icap::ServiceRep*>(theService.getRaw());
1917     Must(s != NULL);
1918     return new Adaptation::Icap::ModXact(virgin.header, virgin.cause, s);
1919 }
1920
1921 void Adaptation::Icap::ModXactLauncher::swanSong()
1922 {
1923     debugs(93, 5, HERE << "swan sings");
1924     updateHistory(false);
1925     Adaptation::Icap::Launcher::swanSong();
1926 }
1927
1928 void Adaptation::Icap::ModXactLauncher::updateHistory(bool doStart)
1929 {
1930     HttpRequest *r = virgin.cause ?
1931                      virgin.cause : dynamic_cast<HttpRequest*>(virgin.header);
1932
1933     // r should never be NULL but we play safe; TODO: add Should()
1934     if (r) {
1935         Adaptation::Icap::History::Pointer h = r->icapHistory();
1936         if (h != NULL) {
1937             if (doStart)
1938                 h->start("ICAPModXactLauncher");
1939             else
1940                 h->stop("ICAPModXactLauncher");
1941         }
1942     }
1943 }