src/filter_virt_db.cpp

   1 /* This file is part of Metaproxy.
   2    Copyright (C) 2005-2011 Index Data
   3
   4 Metaproxy is free software; you can redistribute it and/or modify it under
   5 the terms of the GNU General Public License as published by the Free
   6 Software Foundation; either version 2, or (at your option) any later
   7 version.
   8
   9 Metaproxy is distributed in the hope that it will be useful, but WITHOUT ANY
  10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18
  19 #include "config.hpp"
  20
  21 #include "filter_virt_db.hpp"
  22 #include <metaproxy/package.hpp>
  23
  24 #include <boost/thread/mutex.hpp>
  25 #include <boost/thread/condition.hpp>
  26 #include <boost/shared_ptr.hpp>
  27
  28 #include <metaproxy/util.hpp>
  29
  30 #include <yaz/zgdu.h>
  31 #include <yaz/otherinfo.h>
  32 #include <yaz/diagbib1.h>
  33 #include <yaz/match_glob.h>
  34 #include <yaz/log.h>
  35
  36 #include <map>
  37 #include <iostream>
  38
  39 namespace mp = metaproxy_1;
  40 namespace yf = mp::filter;
  41
  42 namespace metaproxy_1 {
  43     namespace filter {
  44
  45         struct VirtualDB::Set {
  46             Set(BackendPtr b, std::string setname);
  47             Set();
  48             ~Set();
  49
  50             BackendPtr m_backend;
  51             std::string m_setname;
  52         };
  53         struct VirtualDB::Map {
  54             Map(std::string database, std::list<std::string> targets, std::string route);
  55             Map();
  56             bool match(const std::string db) const;
  57             std::string m_dbpattern;
  58             std::list<std::string> m_targets;
  59             std::string m_route;
  60         };
  61         struct VirtualDB::Backend {
  62             mp::Session m_backend_session;
  63             std::list<std::string> m_frontend_databases;
  64             std::list<std::string> m_targets;
  65             std::string m_route;
  66             bool m_named_result_sets;
  67             int m_number_of_sets;
  68         };
  69         struct VirtualDB::Frontend {
  70             Frontend(Rep *rep);
  71             ~Frontend();
  72             mp::Session m_session;
  73             bool m_is_virtual;
  74             bool m_in_use;
  75             yazpp_1::GDU m_init_gdu;
  76             std::list<BackendPtr> m_backend_list;
  77             std::map<std::string,VirtualDB::Set> m_sets;
  78
  79             void search(Package &package, Z_APDU *apdu);
  80             void present(Package &package, Z_APDU *apdu);
  81             void scan(Package &package, Z_APDU *apdu);
  82             int relay_apdu(Package &package, Z_APDU *apdu);
  83
  84             void close(Package &package);
  85             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
  86
  87             void fixup_package(Package &p, BackendPtr b);
  88             void fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
  89                                   BackendPtr b);
  90             void fixup_npr_records(ODR odr, Z_Records *records,
  91                                    BackendPtr b);
  92
  93             BackendPtr lookup_backend_from_databases(
  94                 std::list<std::string> databases);
  95             BackendPtr create_backend_from_databases(
  96                 std::list<std::string> databases,
  97                 int &error_code,
  98                 std::string &failing_database);
  99
 100             BackendPtr init_backend(std::list<std::string> database,
 101                                     Package &package,
 102                                     int &error_code, std::string &addinfo);
 103             Rep *m_p;
 104         };
 105         class VirtualDB::Rep {
 106             friend class VirtualDB;
 107             friend struct Frontend;
 108
 109             FrontendPtr get_frontend(Package &package);
 110             void release_frontend(Package &package);
 111         private:
 112             std::list<VirtualDB::Map>m_maps;
 113             typedef std::map<std::string,VirtualDB::Set>::iterator Sets_it;
 114             boost::mutex m_mutex;
 115             boost::condition m_cond_session_ready;
 116             std::map<mp::Session, FrontendPtr> m_clients;
 117             bool pass_vhosts;
 118         };
 119     }
 120 }
 121
 122 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::lookup_backend_from_databases(
 123     std::list<std::string> databases)
 124 {
 125     std::list<BackendPtr>::const_iterator map_it;
 126     map_it = m_backend_list.begin();
 127     for (; map_it != m_backend_list.end(); map_it++)
 128         if ((*map_it)->m_frontend_databases == databases)
 129             return *map_it;
 130     BackendPtr null;
 131     return null;
 132 }
 133
 134 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::create_backend_from_databases(
 135     std::list<std::string> databases, int &error_code, std::string &addinfo)
 136 {
 137     BackendPtr b(new Backend);
 138     std::list<std::string>::const_iterator db_it = databases.begin();
 139
 140     b->m_number_of_sets = 0;
 141     b->m_frontend_databases = databases;
 142     b->m_named_result_sets = false;
 143
 144     bool first_route = true;
 145
 146     std::map<std::string,bool> targets_dedup;
 147     for (; db_it != databases.end(); db_it++)
 148     {
 149         std::list<VirtualDB::Map>::const_iterator map_it;
 150         map_it = m_p->m_maps.begin();
 151         while (map_it != m_p->m_maps.end())
 152         {
 153             if (map_it->match(*db_it))
 154                 break;
 155             map_it++;
 156         }
 157
 158         if (map_it == m_p->m_maps.end())  // database not found
 159         {
 160             error_code = YAZ_BIB1_DATABASE_DOES_NOT_EXIST;
 161             addinfo = *db_it;
 162             BackendPtr ptr;
 163             return ptr;
 164         }
 165         std::list<std::string>::const_iterator t_it =
 166             map_it->m_targets.begin();
 167         for (; t_it != map_it->m_targets.end(); t_it++) {
 168             if (!targets_dedup[*t_it])
 169             {
 170                 targets_dedup[*t_it] = true;
 171                 b->m_targets.push_back(*t_it);
 172             }
 173         }
 174
 175         // see if we have a route conflict.
 176         if (!first_route && b->m_route != map_it->m_route)
 177         {
 178             // we have a conflict..
 179             error_code =  YAZ_BIB1_COMBI_OF_SPECIFIED_DATABASES_UNSUPP;
 180             BackendPtr ptr;
 181             return ptr;
 182         }
 183         b->m_route = map_it->m_route;
 184         first_route = false;
 185     }
 186     return b;
 187 }
 188
 189 yf::VirtualDB::BackendPtr yf::VirtualDB::Frontend::init_backend(
 190     std::list<std::string> databases, mp::Package &package,
 191     int &error_code, std::string &addinfo)
 192 {
 193     BackendPtr b = create_backend_from_databases(databases, error_code,
 194                                                  addinfo);
 195     if (!b)
 196         return b;
 197     Package init_package(b->m_backend_session, package.origin());
 198     init_package.copy_filter(package);
 199
 200     mp::odr odr;
 201
 202     Z_APDU *init_apdu = zget_APDU(odr, Z_APDU_initRequest);
 203
 204     mp::util::set_vhost_otherinfo(&init_apdu->u.initRequest->otherInfo, odr,
 205                                    b->m_targets);
 206     Z_InitRequest *req = init_apdu->u.initRequest;
 207
 208     // copy stuff from Frontend Init Request
 209     Z_GDU *org_gdu = m_init_gdu.get();
 210     Z_InitRequest *org_init = org_gdu->u.z3950->u.initRequest;
 211
 212     req->idAuthentication = org_init->idAuthentication;
 213     req->implementationId = org_init->implementationId;
 214     req->implementationName = org_init->implementationName;
 215     req->implementationVersion = org_init->implementationVersion;
 216     *req->preferredMessageSize = *org_init->preferredMessageSize;
 217     *req->maximumRecordSize = *org_init->maximumRecordSize;
 218
 219     ODR_MASK_SET(req->options, Z_Options_search);
 220     ODR_MASK_SET(req->options, Z_Options_present);
 221     ODR_MASK_SET(req->options, Z_Options_namedResultSets);
 222     ODR_MASK_SET(req->options, Z_Options_scan);
 223
 224     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_1);
 225     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_2);
 226     ODR_MASK_SET(req->protocolVersion, Z_ProtocolVersion_3);
 227
 228     init_package.request() = init_apdu;
 229
 230     init_package.move(b->m_route);  // sending init
 231
 232     Z_GDU *gdu = init_package.response().get();
 233     // we hope to get an init response
 234     error_code = YAZ_BIB1_DATABASE_UNAVAILABLE;
 235     if (gdu && gdu->which == Z_GDU_Z3950
 236         && gdu->u.z3950->which == Z_APDU_initResponse
 237         && *gdu->u.z3950->u.initResponse->result)
 238     {
 239         Z_InitResponse *res = gdu->u.z3950->u.initResponse;
 240         if (ODR_MASK_GET(res->options, Z_Options_namedResultSets))
 241         {
 242             b->m_named_result_sets = true;
 243         }
 244         if (*res->result && !init_package.session().is_closed())
 245         {
 246             m_backend_list.push_back(b);
 247             return b;
 248         }
 249         mp::util::get_init_diagnostics(res, error_code, addinfo);
 250     }
 251     if (!init_package.session().is_closed())
 252     {
 253         Package close_package(b->m_backend_session, package.origin());
 254         close_package.copy_filter(package);
 255         close_package.session().close();
 256         close_package.move(b->m_route);  // closing it
 257     }
 258     BackendPtr null;
 259     return null;
 260 }
 261
 262 void yf::VirtualDB::Frontend::search(mp::Package &package, Z_APDU *apdu_req)
 263 {
 264     Z_SearchRequest *req = apdu_req->u.searchRequest;
 265     std::string vhost;
 266     std::string resultSetId = req->resultSetName;
 267     mp::odr odr;
 268
 269     std::list<std::string> databases;
 270     int i;
 271     for (i = 0; i<req->num_databaseNames; i++)
 272         databases.push_back(req->databaseNames[i]);
 273
 274     Sets_it sets_it = m_sets.find(req->resultSetName);
 275     if (sets_it != m_sets.end())
 276     {
 277         // result set already exist
 278         // if replace indicator is off: we return diagnostic if
 279         // result set already exist.
 280         if (*req->replaceIndicator == 0)
 281         {
 282             Z_APDU *apdu =
 283                 odr.create_searchResponse(
 284                     apdu_req,
 285                     YAZ_BIB1_RESULT_SET_EXISTS_AND_REPLACE_INDICATOR_OFF,
 286                     0);
 287             package.response() = apdu;
 288
 289             return;
 290         }
 291         sets_it->second.m_backend->m_number_of_sets--;
 292     }
 293     // pick up any existing database with named result sets ..
 294     // or one which has no result sets.. yet.
 295     BackendPtr b; // null for now
 296     std::list<BackendPtr>::const_iterator map_it;
 297     map_it = m_backend_list.begin();
 298     for (; map_it != m_backend_list.end(); map_it++)
 299     {
 300         BackendPtr tmp = *map_it;
 301         if (tmp->m_frontend_databases == databases &&
 302             (tmp->m_named_result_sets ||
 303              tmp->m_number_of_sets == 0))
 304         {
 305             b = *map_it;
 306             break;
 307         }
 308     }
 309     if (!b)  // no backend yet. Must create a new one
 310     {
 311         int error_code;
 312         std::string addinfo;
 313         b = init_backend(databases, package, error_code, addinfo);
 314         if (!b)
 315         {
 316             // did not get a backend (unavailable somehow?)
 317
 318             Z_APDU *apdu =
 319                 odr.create_searchResponse(
 320                     apdu_req, error_code, addinfo.c_str());
 321             package.response() = apdu;
 322             return;
 323         }
 324     }
 325     m_sets.erase(req->resultSetName);
 326     // sending search to backend
 327     Package search_package(b->m_backend_session, package.origin());
 328
 329     search_package.copy_filter(package);
 330
 331     std::string backend_setname;
 332     if (b->m_named_result_sets)
 333     {
 334         backend_setname = std::string(req->resultSetName);
 335     }
 336     else
 337     {
 338         backend_setname = "default";
 339         req->resultSetName = odr_strdup(odr, backend_setname.c_str());
 340     }
 341
 342     // pick first targets spec and move the databases from it ..
 343     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 344     if (t_it != b->m_targets.end())
 345     {
 346         mp::util::set_databases_from_zurl(odr, *t_it,
 347                                                 &req->num_databaseNames,
 348                                                 &req->databaseNames);
 349     }
 350
 351     *req->replaceIndicator = 1;
 352
 353     search_package.request() = yazpp_1::GDU(apdu_req);
 354
 355     search_package.move(b->m_route);
 356
 357     if (search_package.session().is_closed())
 358     {
 359         package.response() = search_package.response();
 360         package.session().close();
 361         return;
 362     }
 363     b->m_number_of_sets++;
 364
 365     m_sets[resultSetId] = VirtualDB::Set(b, backend_setname);
 366     fixup_package(search_package, b);
 367     package.response() = search_package.response();
 368 }
 369
 370 yf::VirtualDB::Frontend::Frontend(Rep *rep)
 371 {
 372     m_p = rep;
 373     m_is_virtual = false;
 374 }
 375
 376 void yf::VirtualDB::Frontend::close(mp::Package &package)
 377 {
 378     std::list<BackendPtr>::const_iterator b_it;
 379
 380     for (b_it = m_backend_list.begin(); b_it != m_backend_list.end(); b_it++)
 381     {
 382         (*b_it)->m_backend_session.close();
 383         Package close_package((*b_it)->m_backend_session, package.origin());
 384         close_package.copy_filter(package);
 385         close_package.move((*b_it)->m_route);
 386     }
 387     m_backend_list.clear();
 388 }
 389
 390 yf::VirtualDB::Frontend::~Frontend()
 391 {
 392 }
 393
 394 yf::VirtualDB::FrontendPtr yf::VirtualDB::Rep::get_frontend(mp::Package &package)
 395 {
 396     boost::mutex::scoped_lock lock(m_mutex);
 397
 398     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 399
 400     while(true)
 401     {
 402         it = m_clients.find(package.session());
 403         if (it == m_clients.end())
 404             break;
 405
 406         if (!it->second->m_in_use)
 407         {
 408             it->second->m_in_use = true;
 409             return it->second;
 410         }
 411         m_cond_session_ready.wait(lock);
 412     }
 413     FrontendPtr f(new Frontend(this));
 414     m_clients[package.session()] = f;
 415     f->m_in_use = true;
 416     return f;
 417 }
 418
 419 void yf::VirtualDB::Rep::release_frontend(mp::Package &package)
 420 {
 421     boost::mutex::scoped_lock lock(m_mutex);
 422     std::map<mp::Session,yf::VirtualDB::FrontendPtr>::iterator it;
 423
 424     it = m_clients.find(package.session());
 425     if (it != m_clients.end())
 426     {
 427         if (package.session().is_closed())
 428         {
 429             it->second->close(package);
 430             m_clients.erase(it);
 431         }
 432         else
 433         {
 434             it->second->m_in_use = false;
 435         }
 436         m_cond_session_ready.notify_all();
 437     }
 438 }
 439
 440 yf::VirtualDB::Set::Set(BackendPtr b, std::string setname)
 441     :  m_backend(b), m_setname(setname)
 442 {
 443 }
 444
 445
 446 yf::VirtualDB::Set::Set()
 447 {
 448 }
 449
 450
 451 yf::VirtualDB::Set::~Set()
 452 {
 453 }
 454
 455 yf::VirtualDB::Map::Map(std::string database,
 456                         std::list<std::string> targets, std::string route)
 457     : m_dbpattern(database), m_targets(targets), m_route(route)
 458 {
 459 }
 460
 461 yf::VirtualDB::Map::Map()
 462 {
 463 }
 464
 465 bool yf::VirtualDB::Map::match(const std::string db) const
 466 {
 467     std::string norm_db = mp::util::database_name_normalize(db);
 468     if (yaz_match_glob(m_dbpattern.c_str(), norm_db.c_str()))
 469         return true;
 470     return false;
 471 }
 472
 473 yf::VirtualDB::VirtualDB() : m_p(new VirtualDB::Rep)
 474 {
 475     m_p->pass_vhosts = false;
 476 }
 477
 478 yf::VirtualDB::~VirtualDB() {
 479 }
 480
 481 void yf::VirtualDB::Frontend::fixup_npr_record(ODR odr, Z_NamePlusRecord *npr,
 482                                              BackendPtr b)
 483 {
 484     if (npr->databaseName)
 485     {
 486         std::string b_database = std::string(npr->databaseName);
 487
 488         // consider each of the frontend databases..
 489         std::list<std::string>::const_iterator db_it;
 490         for (db_it = b->m_frontend_databases.begin();
 491              db_it != b->m_frontend_databases.end(); db_it++)
 492         {
 493             // see which target it corresponds to.. (if any)
 494             std::list<VirtualDB::Map>::const_iterator map_it =
 495                 m_p->m_maps.begin();
 496             while (map_it != m_p->m_maps.end())
 497             {
 498                 if (map_it->match(*db_it))
 499                     break;
 500                 map_it++;
 501             }
 502             if (map_it != m_p->m_maps.end())
 503             {
 504                 std::list<std::string>::const_iterator t
 505                     = map_it->m_targets.begin();
 506                 while (t != map_it->m_targets.end())
 507                 {
 508                     if (*t == b_database)
 509                     {
 510                         npr->databaseName = odr_strdup(odr, (*db_it).c_str());
 511                         return;
 512                     }
 513                     t++;
 514                 }
 515             }
 516
 517         }
 518         db_it = b->m_frontend_databases.begin();
 519         if (db_it != b->m_frontend_databases.end())
 520         {
 521             std::string database = *db_it;
 522             npr->databaseName = odr_strdup(odr, database.c_str());
 523         }
 524     }
 525 }
 526
 527 void yf::VirtualDB::Frontend::fixup_npr_records(ODR odr, Z_Records *records,
 528                                               BackendPtr b)
 529 {
 530     if (records && records->which == Z_Records_DBOSD)
 531     {
 532         Z_NamePlusRecordList *nprlist = records->u.databaseOrSurDiagnostics;
 533         int i;
 534         for (i = 0; i < nprlist->num_records; i++)
 535         {
 536             fixup_npr_record(odr, nprlist->records[i], b);
 537         }
 538     }
 539 }
 540
 541 void yf::VirtualDB::Frontend::fixup_package(mp::Package &p, BackendPtr b)
 542 {
 543     Z_GDU *gdu = p.response().get();
 544     mp::odr odr;
 545
 546     if (gdu && gdu->which == Z_GDU_Z3950)
 547     {
 548         Z_APDU *apdu = gdu->u.z3950;
 549         if (apdu->which == Z_APDU_presentResponse)
 550         {
 551             fixup_npr_records(odr, apdu->u.presentResponse->records, b);
 552             p.response() = gdu;
 553         }
 554         else if (apdu->which == Z_APDU_searchResponse)
 555         {
 556             fixup_npr_records(odr,  apdu->u.searchResponse->records, b);
 557             p.response() = gdu;
 558         }
 559     }
 560 }
 561
 562 void yf::VirtualDB::Frontend::present(mp::Package &package, Z_APDU *apdu_req)
 563 {
 564     Z_PresentRequest *req = apdu_req->u.presentRequest;
 565     std::string resultSetId = req->resultSetId;
 566     mp::odr odr;
 567
 568     Sets_it sets_it = m_sets.find(resultSetId);
 569     if (sets_it == m_sets.end())
 570     {
 571         Z_APDU *apdu =
 572             odr.create_presentResponse(
 573                 apdu_req,
 574                 YAZ_BIB1_SPECIFIED_RESULT_SET_DOES_NOT_EXIST,
 575                 resultSetId.c_str());
 576         package.response() = apdu;
 577         return;
 578     }
 579     Session *id =
 580         new mp::Session(sets_it->second.m_backend->m_backend_session);
 581
 582     // sending present to backend
 583     Package present_package(*id, package.origin());
 584     present_package.copy_filter(package);
 585
 586     req->resultSetId = odr_strdup(odr, sets_it->second.m_setname.c_str());
 587
 588     present_package.request() = yazpp_1::GDU(apdu_req);
 589
 590     present_package.move(sets_it->second.m_backend->m_route);
 591
 592     fixup_package(present_package, sets_it->second.m_backend);
 593
 594     if (present_package.session().is_closed())
 595     {
 596         package.response() = present_package.response();
 597         package.session().close();
 598         return;
 599     }
 600     else
 601     {
 602         package.response() = present_package.response();
 603     }
 604     delete id;
 605 }
 606
 607 int yf::VirtualDB::Frontend::relay_apdu(mp::Package &package, Z_APDU *apdu_req)
 608 {
 609     int no = 0;
 610     std::list<BackendPtr>::const_iterator map_it;
 611     map_it = m_backend_list.begin();
 612     for (; map_it != m_backend_list.end(); map_it++)
 613     {
 614         BackendPtr b = *map_it;
 615
 616         Package relay_package(b->m_backend_session, package.origin());
 617         relay_package.copy_filter(package);
 618
 619         relay_package.request() = yazpp_1::GDU(apdu_req);
 620
 621         relay_package.move(b->m_route);
 622         package.response() = relay_package.response();
 623         no++;
 624     }
 625     return no;
 626 }
 627
 628 void yf::VirtualDB::Frontend::scan(mp::Package &package, Z_APDU *apdu_req)
 629 {
 630     Z_ScanRequest *req = apdu_req->u.scanRequest;
 631     std::string vhost;
 632     mp::odr odr;
 633
 634     std::list<std::string> databases;
 635     int i;
 636     for (i = 0; i<req->num_databaseNames; i++)
 637         databases.push_back(req->databaseNames[i]);
 638
 639     BackendPtr b;
 640     // pick up any existing backend with a database match
 641     std::list<BackendPtr>::const_iterator map_it;
 642     map_it = m_backend_list.begin();
 643     for (; map_it != m_backend_list.end(); map_it++)
 644     {
 645         BackendPtr tmp = *map_it;
 646         if (tmp->m_frontend_databases == databases)
 647             break;
 648     }
 649     if (map_it != m_backend_list.end())
 650         b = *map_it;
 651     if (!b)  // no backend yet. Must create a new one
 652     {
 653         int error_code;
 654         std::string addinfo;
 655         b = init_backend(databases, package, error_code, addinfo);
 656         if (!b)
 657         {
 658             // did not get a backend (unavailable somehow?)
 659             Z_APDU *apdu =
 660                 odr.create_scanResponse(
 661                     apdu_req, error_code, addinfo.c_str());
 662             package.response() = apdu;
 663
 664             return;
 665         }
 666     }
 667     // sending scan to backend
 668     Package scan_package(b->m_backend_session, package.origin());
 669
 670     scan_package.copy_filter(package);
 671
 672     // pick first targets spec and move the databases from it ..
 673     std::list<std::string>::const_iterator t_it = b->m_targets.begin();
 674     if (t_it != b->m_targets.end())
 675     {
 676         mp::util::set_databases_from_zurl(odr, *t_it,
 677                                                 &req->num_databaseNames,
 678                                                 &req->databaseNames);
 679     }
 680     scan_package.request() = yazpp_1::GDU(apdu_req);
 681
 682     scan_package.move(b->m_route);
 683
 684     if (scan_package.session().is_closed())
 685     {
 686         package.response() = scan_package.response();
 687         package.session().close();
 688         return;
 689     }
 690     package.response() = scan_package.response();
 691 }
 692
 693
 694 void yf::VirtualDB::add_map_db2targets(std::string db,
 695                                      std::list<std::string> targets,
 696                                      std::string route)
 697 {
 698     m_p->m_maps.push_back(
 699         VirtualDB::Map(mp::util::database_name_normalize(db), targets, route));
 700 }
 701
 702
 703 void yf::VirtualDB::add_map_db2target(std::string db,
 704                                     std::string target,
 705                                     std::string route)
 706 {
 707     std::list<std::string> targets;
 708     targets.push_back(target);
 709
 710     add_map_db2targets(db, targets, route);
 711 }
 712
 713 void yf::VirtualDB::process(mp::Package &package) const
 714 {
 715     FrontendPtr f = m_p->get_frontend(package);
 716
 717     Z_GDU *gdu = package.request().get();
 718
 719     if (gdu && gdu->which == Z_GDU_Z3950 && gdu->u.z3950->which ==
 720         Z_APDU_initRequest && !f->m_is_virtual)
 721     {
 722         Z_InitRequest *req = gdu->u.z3950->u.initRequest;
 723
 724         std::list<std::string> vhosts;
 725         mp::util::get_vhost_otherinfo(req->otherInfo, vhosts);
 726
 727         if (vhosts.size() > 0 && m_p->pass_vhosts)
 728         {
 729             package.move();
 730         }
 731         else
 732         {
 733             f->m_init_gdu = gdu;
 734
 735             mp::odr odr;
 736             Z_APDU *apdu = odr.create_initResponse(gdu->u.z3950, 0, 0);
 737             Z_InitResponse *resp = apdu->u.initResponse;
 738
 739             int i;
 740             static const int masks[] = {
 741                 Z_Options_search,
 742                 Z_Options_present,
 743                 Z_Options_namedResultSets,
 744                 Z_Options_scan,
 745                 -1
 746             };
 747             for (i = 0; masks[i] != -1; i++)
 748                 if (ODR_MASK_GET(req->options, masks[i]))
 749                     ODR_MASK_SET(resp->options, masks[i]);
 750
 751             static const int versions[] = {
 752                 Z_ProtocolVersion_1,
 753                 Z_ProtocolVersion_2,
 754                 Z_ProtocolVersion_3,
 755                 -1
 756             };
 757             for (i = 0; versions[i] != -1; i++)
 758                 if (ODR_MASK_GET(req->protocolVersion, versions[i]))
 759                     ODR_MASK_SET(resp->protocolVersion, versions[i]);
 760                 else
 761                     break;
 762
 763             *resp->preferredMessageSize = *req->preferredMessageSize;
 764             *resp->maximumRecordSize = *req->maximumRecordSize;
 765
 766             package.response() = apdu;
 767             f->m_is_virtual = true;
 768         }
 769     }
 770     else if (!f->m_is_virtual)
 771         package.move();
 772     else if (gdu && gdu->which == Z_GDU_Z3950)
 773     {
 774         Z_APDU *apdu = gdu->u.z3950;
 775         if (apdu->which == Z_APDU_initRequest)
 776         {
 777             mp::odr odr;
 778
 779             package.response() = odr.create_close(
 780                 apdu,
 781                 Z_Close_protocolError,
 782                 "double init");
 783
 784             package.session().close();
 785         }
 786         else if (apdu->which == Z_APDU_searchRequest)
 787         {
 788             f->search(package, apdu);
 789         }
 790         else if (apdu->which == Z_APDU_presentRequest)
 791         {
 792             f->present(package, apdu);
 793         }
 794         else if (apdu->which == Z_APDU_scanRequest)
 795         {
 796             f->scan(package, apdu);
 797         }
 798         else if (apdu->which == Z_APDU_close)
 799         {
 800             if (f->relay_apdu(package, apdu) == 0)
 801             {
 802                 mp::odr odr;
 803
 804                 package.response() = odr.create_close(
 805                     apdu, Z_Close_finished, "virt_db");
 806
 807                 package.session().close();
 808             }
 809         }
 810         else
 811         {
 812             mp::odr odr;
 813
 814             package.response() = odr.create_close(
 815                 apdu, Z_Close_protocolError,
 816                 "unsupported APDU in filter_virt_db");
 817
 818             package.session().close();
 819         }
 820     }
 821     m_p->release_frontend(package);
 822 }
 823
 824
 825 void mp::filter::VirtualDB::configure(const xmlNode * ptr, bool test_only)
 826 {
 827     for (ptr = ptr->children; ptr; ptr = ptr->next)
 828     {
 829         if (ptr->type != XML_ELEMENT_NODE)
 830             continue;
 831         if (!strcmp((const char *) ptr->name, "pass-vhosts"))
 832         {
 833             m_p->pass_vhosts = mp::xml::get_bool(ptr->children, false);
 834         }
 835         else if (!strcmp((const char *) ptr->name, "virtual"))
 836         {
 837             std::string database;
 838             std::list<std::string> targets;
 839             xmlNode *v_node = ptr->children;
 840             for (; v_node; v_node = v_node->next)
 841             {
 842                 if (v_node->type != XML_ELEMENT_NODE)
 843                     continue;
 844
 845                 if (mp::xml::is_element_mp(v_node, "database"))
 846                     database = mp::xml::get_text(v_node);
 847                 else if (mp::xml::is_element_mp(v_node, "target"))
 848                     targets.push_back(mp::xml::get_text(v_node));
 849                 else
 850                     throw mp::filter::FilterException
 851                         ("Bad element "
 852                          + std::string((const char *) v_node->name)
 853                          + " in virtual section"
 854                             );
 855             }
 856             std::string route = mp::xml::get_route(ptr);
 857             add_map_db2targets(database, targets, route);
 858         }
 859         else
 860         {
 861             throw mp::filter::FilterException
 862                 ("Bad element "
 863                  + std::string((const char *) ptr->name)
 864                  + " in virt_db filter");
 865         }
 866     }
 867 }
 868
 869 static mp::filter::Base* filter_creator()
 870 {
 871     return new mp::filter::VirtualDB;
 872 }
 873
 874 extern "C" {
 875     struct metaproxy_1_filter_struct metaproxy_1_filter_virt_db = {
 876         0,
 877         "virt_db",
 878         filter_creator
 879     };
 880 }
 881
 882
 883 /*
 884  * Local variables:
 885  * c-basic-offset: 4
 886  * c-file-style: "Stroustrup"
 887  * indent-tabs-mode: nil
 888  * End:
 889  * vim: shiftwidth=4 tabstop=8 expandtab
 890  */
 891