src/servers/FtpServer.cc

   1 /*
   2  * Copyright (C) 1996-2018 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 33    Transfer protocol servers */
  10
  11 #include "squid.h"
  12 #include "acl/FilledChecklist.h"
  13 #include "base/CharacterSet.h"
  14 #include "base/RefCount.h"
  15 #include "base/Subscription.h"
  16 #include "client_side_reply.h"
  17 #include "client_side_request.h"
  18 #include "clientStream.h"
  19 #include "comm/ConnOpener.h"
  20 #include "comm/Read.h"
  21 #include "comm/TcpAcceptor.h"
  22 #include "comm/Write.h"
  23 #include "errorpage.h"
  24 #include "fd.h"
  25 #include "ftp/Elements.h"
  26 #include "ftp/Parsing.h"
  27 #include "globals.h"
  28 #include "http/one/RequestParser.h"
  29 #include "http/Stream.h"
  30 #include "HttpHdrCc.h"
  31 #include "ip/tools.h"
  32 #include "ipc/FdNotes.h"
  33 #include "parser/Tokenizer.h"
  34 #include "servers/forward.h"
  35 #include "servers/FtpServer.h"
  36 #include "SquidConfig.h"
  37 #include "StatCounters.h"
  38 #include "tools.h"
  39
  40 #include <set>
  41 #include <map>
  42
  43 CBDATA_NAMESPACED_CLASS_INIT(Ftp, Server);
  44
  45 namespace Ftp
  46 {
  47 static void PrintReply(MemBuf &mb, const HttpReply *reply, const char *const prefix = "");
  48 static bool SupportedCommand(const SBuf &name);
  49 static bool CommandHasPathParameter(const SBuf &cmd);
  50 };
  51
  52 Ftp::Server::Server(const MasterXaction::Pointer &xact):
  53     AsyncJob("Ftp::Server"),
  54     ConnStateData(xact),
  55     master(new MasterState),
  56     uri(),
  57     host(),
  58     gotEpsvAll(false),
  59     onDataAcceptCall(),
  60     dataListenConn(),
  61     dataConn(),
  62     uploadAvailSize(0),
  63     listener(),
  64     connector(),
  65     reader(),
  66     waitingForOrigin(false),
  67     originDataDownloadAbortedOnError(false)
  68 {
  69     flags.readMore = false; // we need to announce ourselves first
  70     *uploadBuf = 0;
  71 }
  72
  73 Ftp::Server::~Server()
  74 {
  75     closeDataConnection();
  76 }
  77
  78 int
  79 Ftp::Server::pipelinePrefetchMax() const
  80 {
  81     return 0; // no support for concurrent FTP requests
  82 }
  83
  84 time_t
  85 Ftp::Server::idleTimeout() const
  86 {
  87     return Config.Timeout.ftpClientIdle;
  88 }
  89
  90 void
  91 Ftp::Server::start()
  92 {
  93     ConnStateData::start();
  94
  95     if (transparent()) {
  96         char buf[MAX_IPSTRLEN];
  97         clientConnection->local.toUrl(buf, MAX_IPSTRLEN);
  98         host = buf;
  99         calcUri(NULL);
 100         debugs(33, 5, "FTP transparent URL: " << uri);
 101     }
 102
 103     writeEarlyReply(220, "Service ready");
 104 }
 105
 106 /// schedules another data connection read if needed
 107 void
 108 Ftp::Server::maybeReadUploadData()
 109 {
 110     if (reader != NULL)
 111         return;
 112
 113     const size_t availSpace = sizeof(uploadBuf) - uploadAvailSize;
 114     if (availSpace <= 0)
 115         return;
 116
 117     debugs(33, 4, dataConn << ": reading FTP data...");
 118
 119     typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
 120     reader = JobCallback(33, 5, Dialer, this, Ftp::Server::readUploadData);
 121     comm_read(dataConn, uploadBuf + uploadAvailSize, availSpace,
 122               reader);
 123 }
 124
 125 /// react to the freshly parsed request
 126 void
 127 Ftp::Server::doProcessRequest()
 128 {
 129     // zero pipelinePrefetchMax() ensures that there is only parsed request
 130     Must(pipeline.count() == 1);
 131     Http::StreamPointer context = pipeline.front();
 132     Must(context != nullptr);
 133
 134     ClientHttpRequest *const http = context->http;
 135     assert(http != NULL);
 136
 137     HttpRequest *const request = http->request;
 138     Must(http->storeEntry() || request);
 139     const bool mayForward = !http->storeEntry() && handleRequest(request);
 140
 141     if (http->storeEntry() != NULL) {
 142         debugs(33, 4, "got an immediate response");
 143         clientSetKeepaliveFlag(http);
 144         context->pullData();
 145     } else if (mayForward) {
 146         debugs(33, 4, "forwarding request to server side");
 147         assert(http->storeEntry() == NULL);
 148         clientProcessRequest(this, Http1::RequestParserPointer(), context.getRaw());
 149     } else {
 150         debugs(33, 4, "will resume processing later");
 151     }
 152 }
 153
 154 void
 155 Ftp::Server::processParsedRequest(Http::StreamPointer &)
 156 {
 157     Must(pipeline.count() == 1);
 158
 159     // Process FTP request asynchronously to make sure FTP
 160     // data connection accept callback is fired first.
 161     CallJobHere(33, 4, CbcPointer<Server>(this),
 162                 Ftp::Server, doProcessRequest);
 163 }
 164
 165 /// imports more upload data from the data connection
 166 void
 167 Ftp::Server::readUploadData(const CommIoCbParams &io)
 168 {
 169     debugs(33, 5, io.conn << " size " << io.size);
 170     Must(reader != NULL);
 171     reader = NULL;
 172
 173     assert(Comm::IsConnOpen(dataConn));
 174     assert(io.conn->fd == dataConn->fd);
 175
 176     if (io.flag == Comm::OK && bodyPipe != NULL) {
 177         if (io.size > 0) {
 178             statCounter.client_http.kbytes_in += io.size;
 179
 180             char *const current_buf = uploadBuf + uploadAvailSize;
 181             if (io.buf != current_buf)
 182                 memmove(current_buf, io.buf, io.size);
 183             uploadAvailSize += io.size;
 184             shovelUploadData();
 185         } else if (io.size == 0) {
 186             debugs(33, 5, io.conn << " closed");
 187             closeDataConnection();
 188             if (uploadAvailSize <= 0)
 189                 finishDechunkingRequest(true);
 190         }
 191     } else { // not Comm::Flags::OK or unexpected read
 192         debugs(33, 5, io.conn << " closed");
 193         closeDataConnection();
 194         finishDechunkingRequest(false);
 195     }
 196
 197 }
 198
 199 /// shovel upload data from the internal buffer to the body pipe if possible
 200 void
 201 Ftp::Server::shovelUploadData()
 202 {
 203     assert(bodyPipe != NULL);
 204
 205     debugs(33, 5, "handling FTP request data for " << clientConnection);
 206     const size_t putSize = bodyPipe->putMoreData(uploadBuf,
 207                            uploadAvailSize);
 208     if (putSize > 0) {
 209         uploadAvailSize -= putSize;
 210         if (uploadAvailSize > 0)
 211             memmove(uploadBuf, uploadBuf + putSize, uploadAvailSize);
 212     }
 213
 214     if (Comm::IsConnOpen(dataConn))
 215         maybeReadUploadData();
 216     else if (uploadAvailSize <= 0)
 217         finishDechunkingRequest(true);
 218 }
 219
 220 void
 221 Ftp::Server::noteMoreBodySpaceAvailable(BodyPipe::Pointer)
 222 {
 223     if (!isOpen()) // if we are closing, nothing to do
 224         return;
 225
 226     shovelUploadData();
 227 }
 228
 229 void
 230 Ftp::Server::noteBodyConsumerAborted(BodyPipe::Pointer ptr)
 231 {
 232     if (!isOpen()) // if we are closing, nothing to do
 233         return;
 234
 235     ConnStateData::noteBodyConsumerAborted(ptr);
 236     closeDataConnection();
 237 }
 238
 239 /// accept a new FTP control connection and hand it to a dedicated Server
 240 void
 241 Ftp::Server::AcceptCtrlConnection(const CommAcceptCbParams &params)
 242 {
 243     MasterXaction::Pointer xact = params.xaction;
 244     AnyP::PortCfgPointer s = xact->squidPort;
 245
 246     // NP: it is possible the port was reconfigured when the call or accept() was queued.
 247
 248     if (params.flag != Comm::OK) {
 249         // Its possible the call was still queued when the client disconnected
 250         debugs(33, 2, s->listenConn << ": FTP accept failure: " << xstrerr(params.xerrno));
 251         return;
 252     }
 253
 254     debugs(33, 4, params.conn << ": accepted");
 255     fd_note(params.conn->fd, "client ftp connect");
 256
 257     if (s->tcp_keepalive.enabled)
 258         commSetTcpKeepalive(params.conn->fd, s->tcp_keepalive.idle, s->tcp_keepalive.interval, s->tcp_keepalive.timeout);
 259
 260     ++incoming_sockets_accepted;
 261
 262     AsyncJob::Start(new Server(xact));
 263 }
 264
 265 void
 266 Ftp::StartListening()
 267 {
 268     for (AnyP::PortCfgPointer s = FtpPortList; s != NULL; s = s->next) {
 269         if (MAXTCPLISTENPORTS == NHttpSockets) {
 270             debugs(1, DBG_IMPORTANT, "Ignoring ftp_port lines exceeding the" <<
 271                    " limit of " << MAXTCPLISTENPORTS << " ports.");
 272             break;
 273         }
 274
 275         // direct new connections accepted by listenConn to Accept()
 276         typedef CommCbFunPtrCallT<CommAcceptCbPtrFun> AcceptCall;
 277         RefCount<AcceptCall> subCall = commCbCall(5, 5, "Ftp::Server::AcceptCtrlConnection",
 278                                        CommAcceptCbPtrFun(Ftp::Server::AcceptCtrlConnection,
 279                                                CommAcceptCbParams(NULL)));
 280         clientStartListeningOn(s, subCall, Ipc::fdnFtpSocket);
 281     }
 282 }
 283
 284 void
 285 Ftp::StopListening()
 286 {
 287     for (AnyP::PortCfgPointer s = FtpPortList; s != NULL; s = s->next) {
 288         if (s->listenConn != NULL) {
 289             debugs(1, DBG_IMPORTANT, "Closing FTP port " << s->listenConn->local);
 290             s->listenConn->close();
 291             s->listenConn = NULL;
 292         }
 293     }
 294 }
 295
 296 void
 297 Ftp::Server::notePeerConnection(Comm::ConnectionPointer conn)
 298 {
 299     // find request
 300     Http::StreamPointer context = pipeline.front();
 301     Must(context != nullptr);
 302     ClientHttpRequest *const http = context->http;
 303     Must(http != NULL);
 304     HttpRequest *const request = http->request;
 305     Must(request != NULL);
 306     // make FTP peer connection exclusive to our request
 307     pinBusyConnection(conn, request);
 308 }
 309
 310 void
 311 Ftp::Server::clientPinnedConnectionClosed(const CommCloseCbParams &io)
 312 {
 313     ConnStateData::clientPinnedConnectionClosed(io);
 314
 315     // TODO: Keep the control connection open after fixing the reset
 316     // problem below
 317     if (Comm::IsConnOpen(clientConnection))
 318         clientConnection->close();
 319
 320     // TODO: If the server control connection is gone, reset state to login
 321     // again. Reseting login alone is not enough: FtpRelay::sendCommand() will
 322     // not re-login because FtpRelay::serverState() is not going to be
 323     // fssConnected. Calling resetLogin() alone is also harmful because
 324     // it does not reset correctly the client-to-squid control connection (eg
 325     // respond if required with an error code, in all cases)
 326     // resetLogin("control connection closure");
 327 }
 328
 329 /// clear client and server login-related state after the old login is gone
 330 void
 331 Ftp::Server::resetLogin(const char *reason)
 332 {
 333     debugs(33, 5, "will need to re-login due to " << reason);
 334     master->clientReadGreeting = false;
 335     changeState(fssBegin, reason);
 336 }
 337
 338 /// computes uri member from host and, if tracked, working dir with file name
 339 void
 340 Ftp::Server::calcUri(const SBuf *file)
 341 {
 342     // TODO: fill a class URL instead of string
 343     uri = "ftp://";
 344     uri.append(host);
 345     if (port->ftp_track_dirs && master->workingDir.length()) {
 346         if (master->workingDir[0] != '/')
 347             uri.append("/", 1);
 348         uri.append(master->workingDir);
 349     }
 350
 351     if (uri[uri.length() - 1] != '/')
 352         uri.append("/", 1);
 353
 354     if (port->ftp_track_dirs && file) {
 355         static const CharacterSet Slash("/", "/");
 356         Parser::Tokenizer tok(*file);
 357         tok.skipAll(Slash);
 358         uri.append(tok.remaining());
 359     }
 360 }
 361
 362 /// Starts waiting for a data connection. Returns listening port.
 363 /// On errors, responds with an error and returns zero.
 364 unsigned int
 365 Ftp::Server::listenForDataConnection()
 366 {
 367     closeDataConnection();
 368
 369     Comm::ConnectionPointer conn = new Comm::Connection;
 370     conn->flags = COMM_NONBLOCKING;
 371     conn->local = transparent() ? port->s : clientConnection->local;
 372     conn->local.port(0);
 373     const char *const note = uri.c_str();
 374     comm_open_listener(SOCK_STREAM, IPPROTO_TCP, conn, note);
 375     if (!Comm::IsConnOpen(conn)) {
 376         debugs(5, DBG_CRITICAL, "comm_open_listener failed for FTP data: " <<
 377                conn->local << " error: " << errno);
 378         writeCustomReply(451, "Internal error");
 379         return 0;
 380     }
 381
 382     typedef CommCbMemFunT<Server, CommAcceptCbParams> AcceptDialer;
 383     typedef AsyncCallT<AcceptDialer> AcceptCall;
 384     RefCount<AcceptCall> call = static_cast<AcceptCall*>(JobCallback(5, 5, AcceptDialer, this, Ftp::Server::acceptDataConnection));
 385     Subscription::Pointer sub = new CallSubscription<AcceptCall>(call);
 386     listener = call.getRaw();
 387     dataListenConn = conn;
 388     AsyncJob::Start(new Comm::TcpAcceptor(conn, note, sub));
 389
 390     const unsigned int listeningPort = comm_local_port(conn->fd);
 391     conn->local.port(listeningPort);
 392     return listeningPort;
 393 }
 394
 395 void
 396 Ftp::Server::acceptDataConnection(const CommAcceptCbParams &params)
 397 {
 398     if (params.flag != Comm::OK) {
 399         // Its possible the call was still queued when the client disconnected
 400         debugs(33, 2, dataListenConn << ": accept "
 401                "failure: " << xstrerr(params.xerrno));
 402         return;
 403     }
 404
 405     debugs(33, 4, "accepted " << params.conn);
 406     fd_note(params.conn->fd, "passive client ftp data");
 407     ++incoming_sockets_accepted;
 408
 409     if (!clientConnection) {
 410         debugs(33, 5, "late data connection?");
 411         closeDataConnection(); // in case we are still listening
 412         params.conn->close();
 413     } else if (params.conn->remote != clientConnection->remote) {
 414         debugs(33, 2, "rogue data conn? ctrl: " << clientConnection->remote);
 415         params.conn->close();
 416         // Some FTP servers close control connection here, but it may make
 417         // things worse from DoS p.o.v. and no better from data stealing p.o.v.
 418     } else {
 419         closeDataConnection();
 420         dataConn = params.conn;
 421         uploadAvailSize = 0;
 422         debugs(33, 7, "ready for data");
 423         if (onDataAcceptCall != NULL) {
 424             AsyncCall::Pointer call = onDataAcceptCall;
 425             onDataAcceptCall = NULL;
 426             // If we got an upload request, start reading data from the client.
 427             if (master->serverState == fssHandleUploadRequest)
 428                 maybeReadUploadData();
 429             else
 430                 Must(master->serverState == fssHandleDataRequest);
 431             MemBuf mb;
 432             mb.init();
 433             mb.appendf("150 Data connection opened.\r\n");
 434             Comm::Write(clientConnection, &mb, call);
 435         }
 436     }
 437 }
 438
 439 void
 440 Ftp::Server::closeDataConnection()
 441 {
 442     if (listener != NULL) {
 443         listener->cancel("no longer needed");
 444         listener = NULL;
 445     }
 446
 447     if (Comm::IsConnOpen(dataListenConn)) {
 448         debugs(33, 5, "FTP closing client data listen socket: " <<
 449                *dataListenConn);
 450         dataListenConn->close();
 451     }
 452     dataListenConn = NULL;
 453
 454     if (reader != NULL) {
 455         // Comm::ReadCancel can deal with negative FDs
 456         Comm::ReadCancel(dataConn->fd, reader);
 457         reader = NULL;
 458     }
 459
 460     if (Comm::IsConnOpen(dataConn)) {
 461         debugs(33, 5, "FTP closing client data connection: " <<
 462                *dataConn);
 463         dataConn->close();
 464     }
 465     dataConn = NULL;
 466 }
 467
 468 /// Writes FTP [error] response before we fully parsed the FTP request and
 469 /// created the corresponding HTTP request wrapper for that FTP request.
 470 void
 471 Ftp::Server::writeEarlyReply(const int code, const char *msg)
 472 {
 473     debugs(33, 7, code << ' ' << msg);
 474     assert(99 < code && code < 1000);
 475
 476     MemBuf mb;
 477     mb.init();
 478     mb.appendf("%i %s\r\n", code, msg);
 479
 480     typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
 481     AsyncCall::Pointer call = JobCallback(33, 5, Dialer, this, Ftp::Server::wroteEarlyReply);
 482     Comm::Write(clientConnection, &mb, call);
 483
 484     flags.readMore = false;
 485
 486     // TODO: Create master transaction. Log it in wroteEarlyReply().
 487 }
 488
 489 void
 490 Ftp::Server::writeReply(MemBuf &mb)
 491 {
 492     debugs(9, 2, "FTP Client " << clientConnection);
 493     debugs(9, 2, "FTP Client REPLY:\n---------\n" << mb.buf <<
 494            "\n----------");
 495
 496     typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
 497     AsyncCall::Pointer call = JobCallback(33, 5, Dialer, this, Ftp::Server::wroteReply);
 498     Comm::Write(clientConnection, &mb, call);
 499 }
 500
 501 void
 502 Ftp::Server::writeCustomReply(const int code, const char *msg, const HttpReply *reply)
 503 {
 504     debugs(33, 7, code << ' ' << msg);
 505     assert(99 < code && code < 1000);
 506
 507     const bool sendDetails = reply != NULL &&
 508                              reply->header.has(Http::HdrType::FTP_STATUS) && reply->header.has(Http::HdrType::FTP_REASON);
 509
 510     MemBuf mb;
 511     mb.init();
 512     if (sendDetails) {
 513         mb.appendf("%i-%s\r\n", code, msg);
 514         mb.appendf(" Server reply:\r\n");
 515         Ftp::PrintReply(mb, reply, " ");
 516         mb.appendf("%i \r\n", code);
 517     } else
 518         mb.appendf("%i %s\r\n", code, msg);
 519
 520     writeReply(mb);
 521 }
 522
 523 void
 524 Ftp::Server::changeState(const ServerState newState, const char *reason)
 525 {
 526     if (master->serverState == newState) {
 527         debugs(33, 3, "client state unchanged at " << master->serverState <<
 528                " because " << reason);
 529         master->serverState = newState;
 530     } else {
 531         debugs(33, 3, "client state was " << master->serverState <<
 532                ", now " << newState << " because " << reason);
 533         master->serverState = newState;
 534     }
 535 }
 536
 537 /// whether the given FTP command has a pathname parameter
 538 static bool
 539 Ftp::CommandHasPathParameter(const SBuf &cmd)
 540 {
 541     static std::set<SBuf> PathedCommands;
 542     if (!PathedCommands.size()) {
 543         PathedCommands.insert(cmdMlst());
 544         PathedCommands.insert(cmdMlsd());
 545         PathedCommands.insert(cmdStat());
 546         PathedCommands.insert(cmdNlst());
 547         PathedCommands.insert(cmdList());
 548         PathedCommands.insert(cmdMkd());
 549         PathedCommands.insert(cmdRmd());
 550         PathedCommands.insert(cmdDele());
 551         PathedCommands.insert(cmdRnto());
 552         PathedCommands.insert(cmdRnfr());
 553         PathedCommands.insert(cmdAppe());
 554         PathedCommands.insert(cmdStor());
 555         PathedCommands.insert(cmdRetr());
 556         PathedCommands.insert(cmdSmnt());
 557         PathedCommands.insert(cmdCwd());
 558     }
 559
 560     return PathedCommands.find(cmd) != PathedCommands.end();
 561 }
 562
 563 /// creates a context filled with an error message for a given early error
 564 Http::Stream *
 565 Ftp::Server::earlyError(const EarlyErrorKind eek)
 566 {
 567     /* Default values, to be updated by the switch statement below */
 568     int scode = 421;
 569     const char *reason = "Internal error";
 570     const char *errUri = "error:ftp-internal-early-error";
 571
 572     switch (eek) {
 573     case EarlyErrorKind::HugeRequest:
 574         scode = 421;
 575         reason = "Huge request";
 576         errUri = "error:ftp-huge-request";
 577         break;
 578
 579     case EarlyErrorKind::MissingLogin:
 580         scode = 530;
 581         reason = "Must login first";
 582         errUri = "error:ftp-must-login-first";
 583         break;
 584
 585     case EarlyErrorKind::MissingUsername:
 586         scode = 501;
 587         reason = "Missing username";
 588         errUri = "error:ftp-missing-username";
 589         break;
 590
 591     case EarlyErrorKind::MissingHost:
 592         scode = 501;
 593         reason = "Missing host";
 594         errUri = "error:ftp-missing-host";
 595         break;
 596
 597     case EarlyErrorKind::UnsupportedCommand:
 598         scode = 502;
 599         reason = "Unknown or unsupported command";
 600         errUri = "error:ftp-unsupported-command";
 601         break;
 602
 603     case EarlyErrorKind::InvalidUri:
 604         scode = 501;
 605         reason = "Invalid URI";
 606         errUri = "error:ftp-invalid-uri";
 607         break;
 608
 609     case EarlyErrorKind::MalformedCommand:
 610         scode = 421;
 611         reason = "Malformed command";
 612         errUri = "error:ftp-malformed-command";
 613         break;
 614
 615         // no default so that a compiler can check that we have covered all cases
 616     }
 617
 618     Http::Stream *context = abortRequestParsing(errUri);
 619     clientStreamNode *node = context->getClientReplyContext();
 620     Must(node);
 621     clientReplyContext *repContext = dynamic_cast<clientReplyContext *>(node->data.getRaw());
 622     Must(repContext);
 623
 624     // We cannot relay FTP scode/reason via HTTP-specific ErrorState.
 625     // TODO: When/if ErrorState can handle native FTP errors, use it instead.
 626     HttpReply *reply = Ftp::HttpReplyWrapper(scode, reason, Http::scBadRequest, -1);
 627     repContext->setReplyToReply(reply);
 628     return context;
 629 }
 630
 631 /// Parses a single FTP request on the control connection.
 632 /// Returns a new Http::Stream on valid requests and all errors.
 633 /// Returns NULL on incomplete requests that may still succeed given more data.
 634 Http::Stream *
 635 Ftp::Server::parseOneRequest()
 636 {
 637     flags.readMore = false; // common for all but one case below
 638
 639     // OWS <command> [ RWS <parameter> ] OWS LF
 640
 641     // InlineSpaceChars are isspace(3) or RFC 959 Section 3.1.1.5.2, except
 642     // for the LF character that we must exclude here (but see FullWhiteSpace).
 643     static const char * const InlineSpaceChars = " \f\r\t\v";
 644     static const CharacterSet InlineSpace = CharacterSet("Ftp::Inline", InlineSpaceChars);
 645     static const CharacterSet FullWhiteSpace = (InlineSpace + CharacterSet::LF).rename("Ftp::FWS");
 646     static const CharacterSet CommandChars = FullWhiteSpace.complement("Ftp::Command");
 647     static const CharacterSet TailChars = CharacterSet::LF.complement("Ftp::Tail");
 648
 649     // This set is used to ignore empty commands without allowing an attacker
 650     // to keep us endlessly busy by feeding us whitespace or empty commands.
 651     static const CharacterSet &LeadingSpace = FullWhiteSpace;
 652
 653     SBuf cmd;
 654     SBuf params;
 655
 656     Parser::Tokenizer tok(inBuf);
 657
 658     (void)tok.skipAll(LeadingSpace); // leading OWS and empty commands
 659     const bool parsed = tok.prefix(cmd, CommandChars); // required command
 660
 661     // note that the condition below will eat either RWS or trailing OWS
 662     if (parsed && tok.skipAll(InlineSpace) && tok.prefix(params, TailChars)) {
 663         // now params may include trailing OWS
 664         // TODO: Support right-trimming using CharacterSet in Tokenizer instead
 665         static const SBuf bufWhiteSpace(InlineSpaceChars);
 666         params.trim(bufWhiteSpace, false, true);
 667     }
 668
 669     // Why limit command line and parameters size? Did not we just parse them?
 670     // XXX: Our good old String cannot handle very long strings.
 671     const SBuf::size_type tokenMax = min(
 672                                          static_cast<SBuf::size_type>(32*1024), // conservative
 673                                          static_cast<SBuf::size_type>(Config.maxRequestHeaderSize));
 674     if (cmd.length() > tokenMax || params.length() > tokenMax) {
 675         changeState(fssError, "huge req token");
 676         quitAfterError(NULL);
 677         return earlyError(EarlyErrorKind::HugeRequest);
 678     }
 679
 680     // technically, we may skip multiple NLs below, but that is OK
 681     if (!parsed || !tok.skipAll(CharacterSet::LF)) { // did not find terminating LF yet
 682         // we need more data, but can we buffer more?
 683         if (inBuf.length() >= Config.maxRequestHeaderSize) {
 684             changeState(fssError, "huge req");
 685             quitAfterError(NULL);
 686             return earlyError(EarlyErrorKind::HugeRequest);
 687         } else {
 688             flags.readMore = true;
 689             debugs(33, 5, "Waiting for more, up to " <<
 690                    (Config.maxRequestHeaderSize - inBuf.length()));
 691             return NULL;
 692         }
 693     }
 694
 695     Must(parsed && cmd.length());
 696     consumeInput(tok.parsedSize()); // TODO: Would delaying optimize copying?
 697
 698     debugs(33, 2, ">>ftp " << cmd << (params.isEmpty() ? "" : " ") << params);
 699
 700     cmd.toUpper(); // this should speed up and simplify future comparisons
 701
 702     // interception cases do not need USER to calculate the uri
 703     if (!transparent()) {
 704         if (!master->clientReadGreeting) {
 705             // the first command must be USER
 706             if (!pinning.pinned && cmd != cmdUser())
 707                 return earlyError(EarlyErrorKind::MissingLogin);
 708         }
 709
 710         // process USER request now because it sets FTP peer host name
 711         if (cmd == cmdUser()) {
 712             if (Http::Stream *errCtx = handleUserRequest(cmd, params))
 713                 return errCtx;
 714         }
 715     }
 716
 717     if (!Ftp::SupportedCommand(cmd))
 718         return earlyError(EarlyErrorKind::UnsupportedCommand);
 719
 720     const HttpRequestMethod method =
 721         cmd == cmdAppe() || cmd == cmdStor() || cmd == cmdStou() ?
 722         Http::METHOD_PUT : Http::METHOD_GET;
 723
 724     const SBuf *path = (params.length() && CommandHasPathParameter(cmd)) ?
 725                        &params : NULL;
 726     calcUri(path);
 727     MasterXaction::Pointer mx = new MasterXaction(XactionInitiator::initClient);
 728     mx->tcpClient = clientConnection;
 729     HttpRequest *const request = HttpRequest::FromUrl(uri.c_str(), mx, method);
 730     if (!request) {
 731         debugs(33, 5, "Invalid FTP URL: " << uri);
 732         uri.clear();
 733         return earlyError(EarlyErrorKind::InvalidUri);
 734     }
 735     char *newUri = xstrdup(uri.c_str());
 736
 737     request->flags.ftpNative = true;
 738     request->http_ver = Http::ProtocolVersion(Ftp::ProtocolVersion().major, Ftp::ProtocolVersion().minor);
 739
 740     // Our fake Request-URIs are not distinctive enough for caching to work
 741     request->flags.cachable = false; // XXX: reset later by maybeCacheable()
 742     request->flags.noCache = true;
 743
 744     request->header.putStr(Http::HdrType::FTP_COMMAND, cmd.c_str());
 745     request->header.putStr(Http::HdrType::FTP_ARGUMENTS, params.c_str()); // may be ""
 746     if (method == Http::METHOD_PUT) {
 747         request->header.putStr(Http::HdrType::EXPECT, "100-continue");
 748         request->header.putStr(Http::HdrType::TRANSFER_ENCODING, "chunked");
 749     }
 750
 751     ClientHttpRequest *const http = new ClientHttpRequest(this);
 752     http->request = request;
 753     HTTPMSGLOCK(http->request);
 754     http->req_sz = tok.parsedSize();
 755     http->uri = newUri;
 756
 757     Http::Stream *const result =
 758         new Http::Stream(clientConnection, http);
 759
 760     StoreIOBuffer tempBuffer;
 761     tempBuffer.data = result->reqbuf;
 762     tempBuffer.length = HTTP_REQBUF_SZ;
 763
 764     ClientStreamData newServer = new clientReplyContext(http);
 765     ClientStreamData newClient = result;
 766     clientStreamInit(&http->client_stream, clientGetMoreData, clientReplyDetach,
 767                      clientReplyStatus, newServer, clientSocketRecipient,
 768                      clientSocketDetach, newClient, tempBuffer);
 769
 770     result->flags.parsed_ok = 1;
 771     return result;
 772 }
 773
 774 void
 775 Ftp::Server::handleReply(HttpReply *reply, StoreIOBuffer data)
 776 {
 777     // the caller guarantees that we are dealing with the current context only
 778     Http::StreamPointer context = pipeline.front();
 779     assert(context != nullptr);
 780
 781     if (context->http && context->http->al != NULL &&
 782             !context->http->al->reply && reply) {
 783         context->http->al->reply = reply;
 784         HTTPMSGLOCK(context->http->al->reply);
 785     }
 786
 787     static ReplyHandler handlers[] = {
 788         NULL, // fssBegin
 789         NULL, // fssConnected
 790         &Ftp::Server::handleFeatReply, // fssHandleFeat
 791         &Ftp::Server::handlePasvReply, // fssHandlePasv
 792         &Ftp::Server::handlePortReply, // fssHandlePort
 793         &Ftp::Server::handleDataReply, // fssHandleDataRequest
 794         &Ftp::Server::handleUploadReply, // fssHandleUploadRequest
 795         &Ftp::Server::handleEprtReply,// fssHandleEprt
 796         &Ftp::Server::handleEpsvReply,// fssHandleEpsv
 797         NULL, // fssHandleCwd
 798         NULL, // fssHandlePass
 799         NULL, // fssHandleCdup
 800         &Ftp::Server::handleErrorReply // fssError
 801     };
 802     try {
 803         const Server &server = dynamic_cast<const Ftp::Server&>(*context->getConn());
 804         if (const ReplyHandler handler = handlers[server.master->serverState])
 805             (this->*handler)(reply, data);
 806         else
 807             writeForwardedReply(reply);
 808     } catch (const std::exception &e) {
 809         callException(e);
 810         throw TexcHere(e.what());
 811     }
 812 }
 813
 814 void
 815 Ftp::Server::handleFeatReply(const HttpReply *reply, StoreIOBuffer)
 816 {
 817     if (pipeline.front()->http->request->errType != ERR_NONE) {
 818         writeCustomReply(502, "Server does not support FEAT", reply);
 819         return;
 820     }
 821
 822     Must(reply);
 823     HttpReply::Pointer featReply = Ftp::HttpReplyWrapper(211, "End", Http::scNoContent, 0);
 824     HttpHeader const &serverReplyHeader = reply->header;
 825
 826     HttpHeaderPos pos = HttpHeaderInitPos;
 827     bool hasEPRT = false;
 828     bool hasEPSV = false;
 829     int prependSpaces = 1;
 830
 831     featReply->header.putStr(Http::HdrType::FTP_PRE, "\"211-Features:\"");
 832     const int scode = serverReplyHeader.getInt(Http::HdrType::FTP_STATUS);
 833     if (scode == 211) {
 834         while (const HttpHeaderEntry *e = serverReplyHeader.getEntry(&pos)) {
 835             if (e->id == Http::HdrType::FTP_PRE) {
 836                 // assume RFC 2389 FEAT response format, quoted by Squid:
 837                 // <"> SP NAME [SP PARAMS] <">
 838                 // but accommodate MS servers sending four SPs before NAME
 839
 840                 // command name ends with (SP parameter) or quote
 841                 static const CharacterSet AfterFeatNameChars("AfterFeatName", " \"");
 842                 static const CharacterSet FeatNameChars = AfterFeatNameChars.complement("FeatName");
 843
 844                 Parser::Tokenizer tok(SBuf(e->value.termedBuf()));
 845                 if (!tok.skip('"') || !tok.skip(' '))
 846                     continue;
 847
 848                 // optional spaces; remember their number to accomodate MS servers
 849                 prependSpaces = 1 + tok.skipAll(CharacterSet::SP);
 850
 851                 SBuf cmd;
 852                 if (!tok.prefix(cmd, FeatNameChars))
 853                     continue;
 854                 cmd.toUpper();
 855
 856                 if (Ftp::SupportedCommand(cmd)) {
 857                     featReply->header.addEntry(e->clone());
 858                 }
 859
 860                 if (cmd == cmdEprt())
 861                     hasEPRT = true;
 862                 else if (cmd == cmdEpsv())
 863                     hasEPSV = true;
 864             }
 865         }
 866     } // else we got a FEAT error and will only report Squid-supported features
 867
 868     char buf[256];
 869     if (!hasEPRT) {
 870         snprintf(buf, sizeof(buf), "\"%*s\"", prependSpaces + 4, "EPRT");
 871         featReply->header.putStr(Http::HdrType::FTP_PRE, buf);
 872     }
 873     if (!hasEPSV) {
 874         snprintf(buf, sizeof(buf), "\"%*s\"", prependSpaces + 4, "EPSV");
 875         featReply->header.putStr(Http::HdrType::FTP_PRE, buf);
 876     }
 877
 878     featReply->header.refreshMask();
 879
 880     writeForwardedReply(featReply.getRaw());
 881 }
 882
 883 void
 884 Ftp::Server::handlePasvReply(const HttpReply *reply, StoreIOBuffer)
 885 {
 886     const Http::StreamPointer context(pipeline.front());
 887     assert(context != nullptr);
 888
 889     if (context->http->request->errType != ERR_NONE) {
 890         writeCustomReply(502, "Server does not support PASV", reply);
 891         return;
 892     }
 893
 894     const unsigned short localPort = listenForDataConnection();
 895     if (!localPort)
 896         return;
 897
 898     char addr[MAX_IPSTRLEN];
 899     // remote server in interception setups and local address otherwise
 900     const Ip::Address &server = transparent() ?
 901                                 clientConnection->local : dataListenConn->local;
 902     server.toStr(addr, MAX_IPSTRLEN, AF_INET);
 903     addr[MAX_IPSTRLEN - 1] = '\0';
 904     for (char *c = addr; *c != '\0'; ++c) {
 905         if (*c == '.')
 906             *c = ',';
 907     }
 908
 909     // In interception setups, we combine remote server address with a
 910     // local port number and hope that traffic will be redirected to us.
 911     // Do not use "227 =a,b,c,d,p1,p2" format or omit parens: some nf_ct_ftp
 912     // versions block responses that use those alternative syntax rules!
 913     MemBuf mb;
 914     mb.init();
 915     mb.appendf("227 Entering Passive Mode (%s,%i,%i).\r\n",
 916                addr,
 917                static_cast<int>(localPort / 256),
 918                static_cast<int>(localPort % 256));
 919     debugs(9, 3, Raw("writing", mb.buf, mb.size));
 920     writeReply(mb);
 921 }
 922
 923 void
 924 Ftp::Server::handlePortReply(const HttpReply *reply, StoreIOBuffer)
 925 {
 926     if (pipeline.front()->http->request->errType != ERR_NONE) {
 927         writeCustomReply(502, "Server does not support PASV (converted from PORT)", reply);
 928         return;
 929     }
 930
 931     writeCustomReply(200, "PORT successfully converted to PASV.");
 932
 933     // and wait for RETR
 934 }
 935
 936 void
 937 Ftp::Server::handleErrorReply(const HttpReply *reply, StoreIOBuffer)
 938 {
 939     if (!pinning.pinned) // we failed to connect to server
 940         uri.clear();
 941     // 421: we will close due to fssError
 942     writeErrorReply(reply, 421);
 943 }
 944
 945 void
 946 Ftp::Server::handleDataReply(const HttpReply *reply, StoreIOBuffer data)
 947 {
 948     if (reply != NULL && reply->sline.status() != Http::scOkay) {
 949         writeForwardedReply(reply);
 950         if (Comm::IsConnOpen(dataConn)) {
 951             debugs(33, 3, "closing " << dataConn << " on KO reply");
 952             closeDataConnection();
 953         }
 954         return;
 955     }
 956
 957     if (!dataConn) {
 958         // We got STREAM_COMPLETE (or error) and closed the client data conn.
 959         debugs(33, 3, "ignoring FTP srv data response after clt data closure");
 960         return;
 961     }
 962
 963     if (!checkDataConnPost()) {
 964         writeCustomReply(425, "Data connection is not established.");
 965         closeDataConnection();
 966         return;
 967     }
 968
 969     debugs(33, 7, data.length);
 970
 971     if (data.length <= 0) {
 972         replyDataWritingCheckpoint(); // skip the actual write call
 973         return;
 974     }
 975
 976     MemBuf mb;
 977     mb.init(data.length + 1, data.length + 1);
 978     mb.append(data.data, data.length);
 979
 980     typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
 981     AsyncCall::Pointer call = JobCallback(33, 5, Dialer, this, Ftp::Server::wroteReplyData);
 982     Comm::Write(dataConn, &mb, call);
 983
 984     pipeline.front()->noteSentBodyBytes(data.length);
 985 }
 986
 987 /// called when we are done writing a chunk of the response data
 988 void
 989 Ftp::Server::wroteReplyData(const CommIoCbParams &io)
 990 {
 991     if (io.flag == Comm::ERR_CLOSING)
 992         return;
 993
 994     if (io.flag != Comm::OK) {
 995         debugs(33, 3, "FTP reply data writing failed: " << xstrerr(io.xerrno));
 996         userDataCompletionCheckpoint(426);
 997         return;
 998     }
 999
1000     assert(pipeline.front()->http);
1001     pipeline.front()->http->out.size += io.size;
1002     replyDataWritingCheckpoint();
1003 }
1004
1005 /// ClientStream checks after (actual or skipped) reply data writing
1006 void
1007 Ftp::Server::replyDataWritingCheckpoint()
1008 {
1009     switch (pipeline.front()->socketState()) {
1010     case STREAM_NONE:
1011         debugs(33, 3, "Keep going");
1012         pipeline.front()->pullData();
1013         return;
1014     case STREAM_COMPLETE:
1015         debugs(33, 3, "FTP reply data transfer successfully complete");
1016         userDataCompletionCheckpoint(226);
1017         break;
1018     case STREAM_UNPLANNED_COMPLETE:
1019         debugs(33, 3, "FTP reply data transfer failed: STREAM_UNPLANNED_COMPLETE");
1020         userDataCompletionCheckpoint(451);
1021         break;
1022     case STREAM_FAILED:
1023         userDataCompletionCheckpoint(451);
1024         debugs(33, 3, "FTP reply data transfer failed: STREAM_FAILED");
1025         break;
1026     default:
1027         fatal("unreachable code");
1028     }
1029 }
1030
1031 void
1032 Ftp::Server::handleUploadReply(const HttpReply *reply, StoreIOBuffer)
1033 {
1034     writeForwardedReply(reply);
1035     // note that the client data connection may already be closed by now
1036 }
1037
1038 void
1039 Ftp::Server::writeForwardedReply(const HttpReply *reply)
1040 {
1041     Must(reply);
1042
1043     if (waitingForOrigin) {
1044         Must(delayedReply == NULL);
1045         delayedReply = reply;
1046         return;
1047     }
1048
1049     const HttpHeader &header = reply->header;
1050     // adaptation and forwarding errors lack Http::HdrType::FTP_STATUS
1051     if (!header.has(Http::HdrType::FTP_STATUS)) {
1052         writeForwardedForeign(reply); // will get to Ftp::Server::wroteReply
1053         return;
1054     }
1055
1056     typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
1057     AsyncCall::Pointer call = JobCallback(33, 5, Dialer, this, Ftp::Server::wroteReply);
1058     writeForwardedReplyAndCall(reply, call);
1059 }
1060
1061 void
1062 Ftp::Server::handleEprtReply(const HttpReply *reply, StoreIOBuffer)
1063 {
1064     if (pipeline.front()->http->request->errType != ERR_NONE) {
1065         writeCustomReply(502, "Server does not support PASV (converted from EPRT)", reply);
1066         return;
1067     }
1068
1069     writeCustomReply(200, "EPRT successfully converted to PASV.");
1070
1071     // and wait for RETR
1072 }
1073
1074 void
1075 Ftp::Server::handleEpsvReply(const HttpReply *reply, StoreIOBuffer)
1076 {
1077     if (pipeline.front()->http->request->errType != ERR_NONE) {
1078         writeCustomReply(502, "Cannot connect to server", reply);
1079         return;
1080     }
1081
1082     const unsigned short localPort = listenForDataConnection();
1083     if (!localPort)
1084         return;
1085
1086     // In interception setups, we use a local port number and hope that data
1087     // traffic will be redirected to us.
1088     MemBuf mb;
1089     mb.init();
1090     mb.appendf("229 Entering Extended Passive Mode (|||%u|)\r\n", localPort);
1091
1092     debugs(9, 3, Raw("writing", mb.buf, mb.size));
1093     writeReply(mb);
1094 }
1095
1096 /// writes FTP error response with given status and reply-derived error details
1097 void
1098 Ftp::Server::writeErrorReply(const HttpReply *reply, const int scode)
1099 {
1100     const HttpRequest *request = pipeline.front()->http->request;
1101     assert(request);
1102
1103     MemBuf mb;
1104     mb.init();
1105
1106     if (request->errType != ERR_NONE)
1107         mb.appendf("%i-%s\r\n", scode, errorPageName(request->errType));
1108
1109     if (request->errDetail > 0) {
1110         // XXX: > 0 may not always mean that this is an errno
1111         mb.appendf("%i-Error: (%d) %s\r\n", scode,
1112                    request->errDetail,
1113                    strerror(request->errDetail));
1114     }
1115
1116 #if USE_ADAPTATION
1117     // XXX: Remove hard coded names. Use an error page template instead.
1118     const Adaptation::History::Pointer ah = request->adaptHistory();
1119     if (ah != NULL) { // XXX: add adapt::<all_h but use lastMeta here
1120         const String info = ah->allMeta.getByName("X-Response-Info");
1121         const String desc = ah->allMeta.getByName("X-Response-Desc");
1122         if (info.size())
1123             mb.appendf("%i-Information: %s\r\n", scode, info.termedBuf());
1124         if (desc.size())
1125             mb.appendf("%i-Description: %s\r\n", scode, desc.termedBuf());
1126     }
1127 #endif
1128
1129     const char *reason = "Lost Error";
1130     if (reply) {
1131         reason = reply->header.has(Http::HdrType::FTP_REASON) ?
1132                  reply->header.getStr(Http::HdrType::FTP_REASON):
1133                  reply->sline.reason();
1134     }
1135
1136     mb.appendf("%i %s\r\n", scode, reason); // error terminating line
1137
1138     // TODO: errorpage.cc should detect FTP client and use
1139     // configurable FTP-friendly error templates which we should
1140     // write to the client "as is" instead of hiding most of the info
1141
1142     writeReply(mb);
1143 }
1144
1145 /// writes FTP response based on HTTP reply that is not an FTP-response wrapper
1146 /// for example, internally-generated Squid "errorpages" end up here (for now)
1147 void
1148 Ftp::Server::writeForwardedForeign(const HttpReply *reply)
1149 {
1150     changeState(fssConnected, "foreign reply");
1151     closeDataConnection();
1152     // 451: We intend to keep the control connection open.
1153     writeErrorReply(reply, 451);
1154 }
1155
1156 bool
1157 Ftp::Server::writeControlMsgAndCall(HttpReply *reply, AsyncCall::Pointer &call)
1158 {
1159     // the caller guarantees that we are dealing with the current context only
1160     // the caller should also make sure reply->header.has(Http::HdrType::FTP_STATUS)
1161     writeForwardedReplyAndCall(reply, call);
1162     return true;
1163 }
1164
1165 void
1166 Ftp::Server::writeForwardedReplyAndCall(const HttpReply *reply, AsyncCall::Pointer &call)
1167 {
1168     assert(reply != NULL);
1169     const HttpHeader &header = reply->header;
1170
1171     // without status, the caller must use the writeForwardedForeign() path
1172     Must(header.has(Http::HdrType::FTP_STATUS));
1173     Must(header.has(Http::HdrType::FTP_REASON));
1174     const int scode = header.getInt(Http::HdrType::FTP_STATUS);
1175     debugs(33, 7, "scode: " << scode);
1176
1177     // Status 125 or 150 implies upload or data request, but we still check
1178     // the state in case the server is buggy.
1179     if ((scode == 125 || scode == 150) &&
1180             (master->serverState == fssHandleUploadRequest ||
1181              master->serverState == fssHandleDataRequest)) {
1182         if (checkDataConnPost()) {
1183             // If the data connection is ready, start reading data (here)
1184             // and forward the response to client (further below).
1185             debugs(33, 7, "data connection established, start data transfer");
1186             if (master->serverState == fssHandleUploadRequest)
1187                 maybeReadUploadData();
1188         } else {
1189             // If we are waiting to accept the data connection, keep waiting.
1190             if (Comm::IsConnOpen(dataListenConn)) {
1191                 debugs(33, 7, "wait for the client to establish a data connection");
1192                 onDataAcceptCall = call;
1193                 // TODO: Add connect timeout for passive connections listener?
1194                 // TODO: Remember server response so that we can forward it?
1195             } else {
1196                 // Either the connection was establised and closed after the
1197                 // data was transferred OR we failed to establish an active
1198                 // data connection and already sent the error to the client.
1199                 // In either case, there is nothing more to do.
1200                 debugs(33, 7, "done with data OR active connection failed");
1201             }
1202             return;
1203         }
1204     }
1205
1206     MemBuf mb;
1207     mb.init();
1208     Ftp::PrintReply(mb, reply);
1209
1210     debugs(9, 2, "FTP Client " << clientConnection);
1211     debugs(9, 2, "FTP Client REPLY:\n---------\n" << mb.buf <<
1212            "\n----------");
1213
1214     Comm::Write(clientConnection, &mb, call);
1215 }
1216
1217 static void
1218 Ftp::PrintReply(MemBuf &mb, const HttpReply *reply, const char *const)
1219 {
1220     const HttpHeader &header = reply->header;
1221
1222     HttpHeaderPos pos = HttpHeaderInitPos;
1223     while (const HttpHeaderEntry *e = header.getEntry(&pos)) {
1224         if (e->id == Http::HdrType::FTP_PRE) {
1225             String raw;
1226             if (httpHeaderParseQuotedString(e->value.rawBuf(), e->value.size(), &raw))
1227                 mb.appendf("%s\r\n", raw.termedBuf());
1228         }
1229     }
1230
1231     if (header.has(Http::HdrType::FTP_STATUS)) {
1232         const char *reason = header.getStr(Http::HdrType::FTP_REASON);
1233         mb.appendf("%i %s\r\n", header.getInt(Http::HdrType::FTP_STATUS),
1234                    (reason ? reason : 0));
1235     }
1236 }
1237
1238 void
1239 Ftp::Server::wroteEarlyReply(const CommIoCbParams &io)
1240 {
1241     if (io.flag == Comm::ERR_CLOSING)
1242         return;
1243
1244     if (io.flag != Comm::OK) {
1245         debugs(33, 3, "FTP reply writing failed: " << xstrerr(io.xerrno));
1246         io.conn->close();
1247         return;
1248     }
1249
1250     Http::StreamPointer context = pipeline.front();
1251     if (context != nullptr && context->http) {
1252         context->http->out.size += io.size;
1253         context->http->out.headers_sz += io.size;
1254     }
1255
1256     flags.readMore = true;
1257     readSomeData();
1258 }
1259
1260 void
1261 Ftp::Server::wroteReply(const CommIoCbParams &io)
1262 {
1263     if (io.flag == Comm::ERR_CLOSING)
1264         return;
1265
1266     if (io.flag != Comm::OK) {
1267         debugs(33, 3, "FTP reply writing failed: " << xstrerr(io.xerrno));
1268         io.conn->close();
1269         return;
1270     }
1271
1272     Http::StreamPointer context = pipeline.front();
1273     assert(context->http);
1274     context->http->out.size += io.size;
1275     context->http->out.headers_sz += io.size;
1276
1277     if (master->serverState == fssError) {
1278         debugs(33, 5, "closing on FTP server error");
1279         io.conn->close();
1280         return;
1281     }
1282
1283     const clientStream_status_t socketState = context->socketState();
1284     debugs(33, 5, "FTP client stream state " << socketState);
1285     switch (socketState) {
1286     case STREAM_UNPLANNED_COMPLETE:
1287     case STREAM_FAILED:
1288         io.conn->close();
1289         return;
1290
1291     case STREAM_NONE:
1292     case STREAM_COMPLETE:
1293         flags.readMore = true;
1294         changeState(fssConnected, "Ftp::Server::wroteReply");
1295         if (bodyParser)
1296             finishDechunkingRequest(false);
1297         context->finished();
1298         kick();
1299         return;
1300     }
1301 }
1302
1303 bool
1304 Ftp::Server::handleRequest(HttpRequest *request)
1305 {
1306     debugs(33, 9, request);
1307     Must(request);
1308
1309     HttpHeader &header = request->header;
1310     Must(header.has(Http::HdrType::FTP_COMMAND));
1311     String &cmd = header.findEntry(Http::HdrType::FTP_COMMAND)->value;
1312     Must(header.has(Http::HdrType::FTP_ARGUMENTS));
1313     String &params = header.findEntry(Http::HdrType::FTP_ARGUMENTS)->value;
1314
1315     if (Debug::Enabled(9, 2)) {
1316         MemBuf mb;
1317         mb.init();
1318         request->pack(&mb);
1319
1320         debugs(9, 2, "FTP Client " << clientConnection);
1321         debugs(9, 2, "FTP Client REQUEST:\n---------\n" << mb.buf <<
1322                "\n----------");
1323     }
1324
1325     // TODO: When HttpHeader uses SBuf, change keys to SBuf
1326     typedef std::map<const std::string, RequestHandler> RequestHandlers;
1327     static RequestHandlers handlers;
1328     if (!handlers.size()) {
1329         handlers["LIST"] = &Ftp::Server::handleDataRequest;
1330         handlers["NLST"] = &Ftp::Server::handleDataRequest;
1331         handlers["MLSD"] = &Ftp::Server::handleDataRequest;
1332         handlers["FEAT"] = &Ftp::Server::handleFeatRequest;
1333         handlers["PASV"] = &Ftp::Server::handlePasvRequest;
1334         handlers["PORT"] = &Ftp::Server::handlePortRequest;
1335         handlers["RETR"] = &Ftp::Server::handleDataRequest;
1336         handlers["EPRT"] = &Ftp::Server::handleEprtRequest;
1337         handlers["EPSV"] = &Ftp::Server::handleEpsvRequest;
1338         handlers["CWD"] = &Ftp::Server::handleCwdRequest;
1339         handlers["PASS"] = &Ftp::Server::handlePassRequest;
1340         handlers["CDUP"] = &Ftp::Server::handleCdupRequest;
1341     }
1342
1343     RequestHandler handler = NULL;
1344     if (request->method == Http::METHOD_PUT)
1345         handler = &Ftp::Server::handleUploadRequest;
1346     else {
1347         const RequestHandlers::const_iterator hi = handlers.find(cmd.termedBuf());
1348         if (hi != handlers.end())
1349             handler = hi->second;
1350     }
1351
1352     if (!handler) {
1353         debugs(9, 7, "forwarding " << cmd << " as is, no post-processing");
1354         return true;
1355     }
1356
1357     return (this->*handler)(cmd, params);
1358 }
1359
1360 /// Called to parse USER command, which is required to create an HTTP request
1361 /// wrapper. W/o request, the errors are handled by returning earlyError().
1362 Http::Stream *
1363 Ftp::Server::handleUserRequest(const SBuf &, SBuf &params)
1364 {
1365     if (params.isEmpty())
1366         return earlyError(EarlyErrorKind::MissingUsername);
1367
1368     // find the [end of] user name
1369     const SBuf::size_type eou = params.rfind('@');
1370     if (eou == SBuf::npos || eou + 1 >= params.length())
1371         return earlyError(EarlyErrorKind::MissingHost);
1372
1373     // Determine the intended destination.
1374     host = params.substr(eou + 1, params.length());
1375     // If we can parse it as raw IPv6 address, then surround with "[]".
1376     // Otherwise (domain, IPv4, [bracketed] IPv6, garbage, etc), use as is.
1377     if (host.find(':') != SBuf::npos) {
1378         const Ip::Address ipa(host.c_str());
1379         if (!ipa.isAnyAddr()) {
1380             char ipBuf[MAX_IPSTRLEN];
1381             ipa.toHostStr(ipBuf, MAX_IPSTRLEN);
1382             host = ipBuf;
1383         }
1384     }
1385
1386     // const SBuf login = params.substr(0, eou);
1387     params.chop(0, eou); // leave just the login part for the peer
1388
1389     SBuf oldUri;
1390     if (master->clientReadGreeting)
1391         oldUri = uri;
1392
1393     master->workingDir.clear();
1394     calcUri(NULL);
1395
1396     if (!master->clientReadGreeting) {
1397         debugs(9, 3, "set URI to " << uri);
1398     } else if (oldUri.caseCmp(uri) == 0) {
1399         debugs(9, 5, "kept URI as " << oldUri);
1400     } else {
1401         debugs(9, 3, "reset URI from " << oldUri << " to " << uri);
1402         closeDataConnection();
1403         unpinConnection(true); // close control connection to peer
1404         resetLogin("URI reset");
1405     }
1406
1407     return NULL; // no early errors
1408 }
1409
1410 bool
1411 Ftp::Server::handleFeatRequest(String &, String &)
1412 {
1413     changeState(fssHandleFeat, "handleFeatRequest");
1414     return true;
1415 }
1416
1417 bool
1418 Ftp::Server::handlePasvRequest(String &, String &params)
1419 {
1420     if (gotEpsvAll) {
1421         setReply(500, "Bad PASV command");
1422         return false;
1423     }
1424
1425     if (params.size() > 0) {
1426         setReply(501, "Unexpected parameter");
1427         return false;
1428     }
1429
1430     changeState(fssHandlePasv, "handlePasvRequest");
1431     // no need to fake PASV request via setDataCommand() in true PASV case
1432     return true;
1433 }
1434
1435 /// [Re]initializes dataConn for active data transfers. Does not connect.
1436 bool
1437 Ftp::Server::createDataConnection(Ip::Address cltAddr)
1438 {
1439     assert(clientConnection != NULL);
1440     assert(!clientConnection->remote.isAnyAddr());
1441
1442     if (cltAddr != clientConnection->remote) {
1443         debugs(33, 2, "rogue PORT " << cltAddr << " request? ctrl: " << clientConnection->remote);
1444         // Closing the control connection would not help with attacks because
1445         // the client is evidently able to connect to us. Besides, closing
1446         // makes retrials easier for the client and more damaging to us.
1447         setReply(501, "Prohibited parameter value");
1448         return false;
1449     }
1450
1451     closeDataConnection();
1452
1453     Comm::ConnectionPointer conn = new Comm::Connection();
1454     conn->flags |= COMM_DOBIND;
1455
1456     if (clientConnection->flags & COMM_INTERCEPTION) {
1457         // In the case of NAT interception conn->local value is not set
1458         // because the TCP stack will automatically pick correct source
1459         // address for the data connection. We must only ensure that IP
1460         // version matches client's address.
1461         conn->local.setAnyAddr();
1462
1463         if (cltAddr.isIPv4())
1464             conn->local.setIPv4();
1465
1466         conn->remote = cltAddr;
1467     } else {
1468         // In the case of explicit-proxy the local IP of the control connection
1469         // is the Squid IP the client is knowingly talking to.
1470         //
1471         // In the case of TPROXY the IP address of the control connection is
1472         // server IP the client is connecting to, it can be spoofed by Squid.
1473         //
1474         // In both cases some clients may refuse to accept data connections if
1475         // these control connectin local-IP's are not used.
1476         conn->setAddrs(clientConnection->local, cltAddr);
1477
1478         // Using non-local addresses in TPROXY mode requires appropriate socket option.
1479         if (clientConnection->flags & COMM_TRANSPARENT)
1480             conn->flags |= COMM_TRANSPARENT;
1481     }
1482
1483     // RFC 959 requires active FTP connections to originate from port 20
1484     // but that would preclude us from supporting concurrent transfers! (XXX?)
1485     conn->local.port(0);
1486
1487     debugs(9, 3, "will actively connect from " << conn->local << " to " <<
1488            conn->remote);
1489
1490     dataConn = conn;
1491     uploadAvailSize = 0;
1492     return true;
1493 }
1494
1495 bool
1496 Ftp::Server::handlePortRequest(String &, String &params)
1497 {
1498     // TODO: Should PORT errors trigger closeDataConnection() cleanup?
1499
1500     if (gotEpsvAll) {
1501         setReply(500, "Rejecting PORT after EPSV ALL");
1502         return false;
1503     }
1504
1505     if (!params.size()) {
1506         setReply(501, "Missing parameter");
1507         return false;
1508     }
1509
1510     Ip::Address cltAddr;
1511     if (!Ftp::ParseIpPort(params.termedBuf(), NULL, cltAddr)) {
1512         setReply(501, "Invalid parameter");
1513         return false;
1514     }
1515
1516     if (!createDataConnection(cltAddr))
1517         return false;
1518
1519     changeState(fssHandlePort, "handlePortRequest");
1520     setDataCommand();
1521     return true; // forward our fake PASV request
1522 }
1523
1524 bool
1525 Ftp::Server::handleDataRequest(String &, String &)
1526 {
1527     if (!checkDataConnPre())
1528         return false;
1529
1530     master->userDataDone = 0;
1531     originDataDownloadAbortedOnError = false;
1532
1533     changeState(fssHandleDataRequest, "handleDataRequest");
1534
1535     return true;
1536 }
1537
1538 bool
1539 Ftp::Server::handleUploadRequest(String &, String &)
1540 {
1541     if (!checkDataConnPre())
1542         return false;
1543
1544     if (Config.accessList.forceRequestBodyContinuation) {
1545         ClientHttpRequest *http = pipeline.front()->http;
1546         HttpRequest *request = http->request;
1547         ACLFilledChecklist bodyContinuationCheck(Config.accessList.forceRequestBodyContinuation, request, NULL);
1548         if (bodyContinuationCheck.fastCheck().allowed()) {
1549             request->forcedBodyContinuation = true;
1550             if (checkDataConnPost()) {
1551                 // Write control Msg
1552                 writeEarlyReply(150, "Data connection opened");
1553                 maybeReadUploadData();
1554             } else {
1555                 // wait for acceptDataConnection but tell it to call wroteEarlyReply
1556                 // after writing "150 Data connection opened"
1557                 typedef CommCbMemFunT<Server, CommIoCbParams> Dialer;
1558                 AsyncCall::Pointer call = JobCallback(33, 5, Dialer, this, Ftp::Server::wroteEarlyReply);
1559                 onDataAcceptCall = call;
1560             }
1561         }
1562     }
1563
1564     changeState(fssHandleUploadRequest, "handleDataRequest");
1565
1566     return true;
1567 }
1568
1569 bool
1570 Ftp::Server::handleEprtRequest(String &, String &params)
1571 {
1572     debugs(9, 3, "Process an EPRT " << params);
1573
1574     if (gotEpsvAll) {
1575         setReply(500, "Rejecting EPRT after EPSV ALL");
1576         return false;
1577     }
1578
1579     if (!params.size()) {
1580         setReply(501, "Missing parameter");
1581         return false;
1582     }
1583
1584     Ip::Address cltAddr;
1585     if (!Ftp::ParseProtoIpPort(params.termedBuf(), cltAddr)) {
1586         setReply(501, "Invalid parameter");
1587         return false;
1588     }
1589
1590     if (!createDataConnection(cltAddr))
1591         return false;
1592
1593     changeState(fssHandleEprt, "handleEprtRequest");
1594     setDataCommand();
1595     return true; // forward our fake PASV request
1596 }
1597
1598 bool
1599 Ftp::Server::handleEpsvRequest(String &, String &params)
1600 {
1601     debugs(9, 3, "Process an EPSV command with params: " << params);
1602     if (params.size() <= 0) {
1603         // treat parameterless EPSV as "use the protocol of the ctrl conn"
1604     } else if (params.caseCmp("ALL") == 0) {
1605         setReply(200, "EPSV ALL ok");
1606         gotEpsvAll = true;
1607         return false;
1608     } else if (params.cmp("2") == 0) {
1609         if (!Ip::EnableIpv6) {
1610             setReply(522, "Network protocol not supported, use (1)");
1611             return false;
1612         }
1613     } else if (params.cmp("1") != 0) {
1614         setReply(501, "Unsupported EPSV parameter");
1615         return false;
1616     }
1617
1618     changeState(fssHandleEpsv, "handleEpsvRequest");
1619     setDataCommand();
1620     return true; // forward our fake PASV request
1621 }
1622
1623 bool
1624 Ftp::Server::handleCwdRequest(String &, String &)
1625 {
1626     changeState(fssHandleCwd, "handleCwdRequest");
1627     return true;
1628 }
1629
1630 bool
1631 Ftp::Server::handlePassRequest(String &, String &)
1632 {
1633     changeState(fssHandlePass, "handlePassRequest");
1634     return true;
1635 }
1636
1637 bool
1638 Ftp::Server::handleCdupRequest(String &, String &)
1639 {
1640     changeState(fssHandleCdup, "handleCdupRequest");
1641     return true;
1642 }
1643
1644 // Convert user PORT, EPRT, PASV, or EPSV data command to Squid PASV command.
1645 // Squid FTP client decides what data command to use with peers.
1646 void
1647 Ftp::Server::setDataCommand()
1648 {
1649     ClientHttpRequest *const http = pipeline.front()->http;
1650     assert(http != NULL);
1651     HttpRequest *const request = http->request;
1652     assert(request != NULL);
1653     HttpHeader &header = request->header;
1654     header.delById(Http::HdrType::FTP_COMMAND);
1655     header.putStr(Http::HdrType::FTP_COMMAND, "PASV");
1656     header.delById(Http::HdrType::FTP_ARGUMENTS);
1657     header.putStr(Http::HdrType::FTP_ARGUMENTS, "");
1658     debugs(9, 5, "client data command converted to fake PASV");
1659 }
1660
1661 /// check that client data connection is ready for future I/O or at least
1662 /// has a chance of becoming ready soon.
1663 bool
1664 Ftp::Server::checkDataConnPre()
1665 {
1666     if (Comm::IsConnOpen(dataConn))
1667         return true;
1668
1669     if (Comm::IsConnOpen(dataListenConn)) {
1670         // We are still waiting for a client to connect to us after PASV.
1671         // Perhaps client's data conn handshake has not reached us yet.
1672         // After we talk to the server, checkDataConnPost() will recheck.
1673         debugs(33, 3, "expecting clt data conn " << dataListenConn);
1674         return true;
1675     }
1676
1677     if (!dataConn || dataConn->remote.isAnyAddr()) {
1678         debugs(33, 5, "missing " << dataConn);
1679         // TODO: use client address and default port instead.
1680         setReply(425, "Use PORT or PASV first");
1681         return false;
1682     }
1683
1684     // active transfer: open a data connection from Squid to client
1685     typedef CommCbMemFunT<Server, CommConnectCbParams> Dialer;
1686     connector = JobCallback(17, 3, Dialer, this, Ftp::Server::connectedForData);
1687     Comm::ConnOpener *cs = new Comm::ConnOpener(dataConn, connector,
1688             Config.Timeout.connect);
1689     AsyncJob::Start(cs);
1690     return false; // ConnStateData::processFtpRequest waits handleConnectDone
1691 }
1692
1693 /// Check that client data connection is ready for immediate I/O.
1694 bool
1695 Ftp::Server::checkDataConnPost() const
1696 {
1697     if (!Comm::IsConnOpen(dataConn)) {
1698         debugs(33, 3, "missing client data conn: " << dataConn);
1699         return false;
1700     }
1701     return true;
1702 }
1703
1704 /// Done establishing a data connection to the user.
1705 void
1706 Ftp::Server::connectedForData(const CommConnectCbParams &params)
1707 {
1708     connector = NULL;
1709
1710     if (params.flag != Comm::OK) {
1711         /* it might have been a timeout with a partially open link */
1712         if (params.conn != NULL)
1713             params.conn->close();
1714         setReply(425, "Cannot open data connection.");
1715         Http::StreamPointer context = pipeline.front();
1716         Must(context->http);
1717         Must(context->http->storeEntry() != NULL);
1718     } else {
1719         Must(dataConn == params.conn);
1720         Must(Comm::IsConnOpen(params.conn));
1721         fd_note(params.conn->fd, "active client ftp data");
1722     }
1723
1724     doProcessRequest();
1725 }
1726
1727 void
1728 Ftp::Server::setReply(const int code, const char *msg)
1729 {
1730     Http::StreamPointer context = pipeline.front();
1731     ClientHttpRequest *const http = context->http;
1732     assert(http != NULL);
1733     assert(http->storeEntry() == NULL);
1734
1735     HttpReply *const reply = Ftp::HttpReplyWrapper(code, msg, Http::scNoContent, 0);
1736
1737     setLogUri(http, urlCanonicalClean(http->request));
1738
1739     clientStreamNode *const node = context->getClientReplyContext();
1740     clientReplyContext *const repContext =
1741         dynamic_cast<clientReplyContext *>(node->data.getRaw());
1742     assert(repContext != NULL);
1743
1744     RequestFlags reqFlags;
1745     reqFlags.cachable = false; // force releaseRequest() in storeCreateEntry()
1746     reqFlags.noCache = true;
1747     repContext->createStoreEntry(http->request->method, reqFlags);
1748     http->storeEntry()->replaceHttpReply(reply);
1749 }
1750
1751 void
1752 Ftp::Server::callException(const std::exception &e)
1753 {
1754     debugs(33, 2, "FTP::Server job caught: " << e.what());
1755     closeDataConnection();
1756     unpinConnection(true);
1757     if (Comm::IsConnOpen(clientConnection))
1758         clientConnection->close();
1759     AsyncJob::callException(e);
1760 }
1761
1762 void
1763 Ftp::Server::startWaitingForOrigin()
1764 {
1765     if (!isOpen()) // if we are closing, nothing to do
1766         return;
1767
1768     debugs(33, 5, "waiting for Ftp::Client data transfer to end");
1769     waitingForOrigin = true;
1770 }
1771
1772 void
1773 Ftp::Server::stopWaitingForOrigin(int originStatus)
1774 {
1775     Must(waitingForOrigin);
1776     waitingForOrigin = false;
1777
1778     if (!isOpen()) // if we are closing, nothing to do
1779         return;
1780
1781     // if we have already decided how to respond, respond now
1782     if (delayedReply) {
1783         HttpReply::Pointer reply = delayedReply;
1784         delayedReply = nullptr;
1785         writeForwardedReply(reply.getRaw());
1786         return; // do not completeDataDownload() after an earlier response
1787     }
1788
1789     if (master->serverState != fssHandleDataRequest)
1790         return;
1791
1792     // completeDataDownload() could be waitingForOrigin in fssHandleDataRequest
1793     // Depending on which side has finished downloading first, either trust
1794     // master->userDataDone status or set originDataDownloadAbortedOnError:
1795     if (master->userDataDone) {
1796         // We finished downloading before Ftp::Client. Most likely, the
1797         // adaptation shortened the origin response or we hit an error.
1798         // Our status (stored in master->userDataDone) is more informative.
1799         // Use master->userDataDone; avoid originDataDownloadAbortedOnError.
1800         completeDataDownload();
1801     } else {
1802         debugs(33, 5, "too early to write the response");
1803         // Ftp::Client naturally finished downloading before us. Set
1804         // originDataDownloadAbortedOnError to overwrite future
1805         // master->userDataDone and relay Ftp::Client error, if there was
1806         // any, to the user.
1807         originDataDownloadAbortedOnError = (originStatus >= 400);
1808     }
1809 }
1810
1811 void Ftp::Server::userDataCompletionCheckpoint(int finalStatusCode)
1812 {
1813     Must(!master->userDataDone);
1814     master->userDataDone = finalStatusCode;
1815
1816     if (bodyParser)
1817         finishDechunkingRequest(false);
1818
1819     if (waitingForOrigin) {
1820         // The completeDataDownload() is not called here unconditionally
1821         // because we want to signal the FTP user that we are not fully
1822         // done processing its data stream, even though all data bytes
1823         // have been sent or received already.
1824         debugs(33, 5, "Transfering from FTP server is not complete");
1825         return;
1826     }
1827
1828     // Adjust our reply if the server aborted with an error before we are done.
1829     if (master->userDataDone == 226 && originDataDownloadAbortedOnError) {
1830         debugs(33, 5, "Transfering from FTP server terminated with an error, adjust status code");
1831         master->userDataDone = 451;
1832     }
1833     completeDataDownload();
1834 }
1835
1836 void Ftp::Server::completeDataDownload()
1837 {
1838     writeCustomReply(master->userDataDone, master->userDataDone == 226 ? "Transfer complete" : "Server error; transfer aborted");
1839     closeDataConnection();
1840 }
1841
1842 /// Whether Squid FTP Relay supports a named feature (e.g., a command).
1843 static bool
1844 Ftp::SupportedCommand(const SBuf &name)
1845 {
1846     static std::set<SBuf> BlackList;
1847     if (BlackList.empty()) {
1848         /* Add FTP commands that Squid cannot relay correctly. */
1849
1850         // We probably do not support AUTH TLS.* and AUTH SSL,
1851         // but let's disclaim all AUTH support to KISS, for now.
1852         BlackList.insert(cmdAuth());
1853     }
1854
1855     // we claim support for all commands that we do not know about
1856     return BlackList.find(name) == BlackList.end();
1857 }
1858