src/yaz-proxy.cpp

   1 /*
   2  * Copyright (c) 1998-2000, Index Data.
   3  * See the file LICENSE for details.
   4  * Sebastian Hammer, Adam Dickmeiss
   5  *
   6  * $Log: yaz-proxy.cpp,v $
   7  * Revision 1.16  2000-09-04 08:29:22  adam
   8  * Fixed memory leak(s). Added re-use of associations, rather than
   9  * re-init, when maximum number of targets are in use.
  10  *
  11  * Revision 1.15  2000/08/31 14:41:55  adam
  12  * Proxy no longer generates cookies (it's up to the client). Proxy
  13  * re-opens if target new op is started before previous operation finishes.
  14  *
  15  * Revision 1.14  2000/08/10 08:42:42  adam
  16  * Fixes for {set,get}_APDU_log.
  17  *
  18  * Revision 1.13  2000/08/07 14:19:59  adam
  19  * Fixed serious bug regarding timeouts. Improved logging for proxy.
  20  *
  21  * Revision 1.12  2000/07/04 13:48:49  adam
  22  * Implemented upper-limit on proxy-to-target sessions.
  23  *
  24  * Revision 1.11  1999/12/06 13:52:45  adam
  25  * Modified for new location of YAZ header files. Experimental threaded
  26  * operation.
  27  *
  28  * Revision 1.10  1999/11/10 10:02:34  adam
  29  * Work on proxy.
  30  *
  31  * Revision 1.9  1999/09/13 12:53:44  adam
  32  * Proxy removes OtherInfo Proxy Address and Session ID. Other
  33  * Otherinfo remains untouched.
  34  *
  35  * Revision 1.8  1999/05/04 10:53:00  adam
  36  * Changed the way the PROXY behaves when lost cookie is received.
  37  *
  38  * Revision 1.7  1999/04/28 13:31:17  adam
  39  * Better result set optimisation for proxy.
  40  *
  41  * Revision 1.6  1999/04/27 07:52:13  adam
  42  * Improved proxy; added query match for result set re-use.
  43  *
  44  * Revision 1.5  1999/04/21 12:09:01  adam
  45  * Many improvements. Modified to proxy server to work with "sessions"
  46  * based on cookies.
  47  *
  48  * Revision 1.4  1999/04/20 10:30:05  adam
  49  * Implemented various stuff for client and proxy. Updated calls
  50  * to ODR to reflect new name parameter.
  51  *
  52  * Revision 1.3  1999/04/09 11:46:57  adam
  53  * Added object Yaz_Z_Assoc. Much more functional client.
  54  *
  55  * Revision 1.2  1999/01/28 13:08:46  adam
  56  * Yaz_PDU_Assoc better encapsulated. Memory leak fix in
  57  * yaz-socket-manager.cc.
  58  *
  59  * Revision 1.1.1.1  1999/01/28 09:41:07  adam
  60  * First implementation of YAZ++.
  61  *
  62  */
  63
  64 #include <assert.h>
  65 #include <time.h>
  66
  67 #include <yaz/log.h>
  68 #include <yaz-proxy.h>
  69
  70 Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable) :
  71     Yaz_Z_Assoc(the_PDU_Observable)
  72 {
  73     m_PDU_Observable = the_PDU_Observable;
  74     m_client = 0;
  75     m_parent = 0;
  76     m_clientPool = 0;
  77     m_seqno = 1;
  78     m_keepalive = 1;
  79     m_proxyTarget = 0;
  80     m_max_clients = 50;
  81     m_seed = time(0);
  82 }
  83
  84 Yaz_Proxy::~Yaz_Proxy()
  85 {
  86     xfree (m_proxyTarget);
  87 }
  88
  89 void Yaz_Proxy::set_proxyTarget(const char *target)
  90 {
  91     xfree (m_proxyTarget);
  92     m_proxyTarget = 0;
  93     if (target)
  94         m_proxyTarget = (char *) xstrdup (target);
  95 }
  96
  97 IYaz_PDU_Observer *Yaz_Proxy::clone(IYaz_PDU_Observable
  98                                     *the_PDU_Observable)
  99 {
 100     Yaz_Proxy *new_proxy = new Yaz_Proxy(the_PDU_Observable);
 101     new_proxy->m_parent = this;
 102     new_proxy->timeout(120);
 103     new_proxy->set_proxyTarget(m_proxyTarget);
 104     new_proxy->set_APDU_log(get_APDU_log());
 105     return new_proxy;
 106 }
 107
 108 char *Yaz_Proxy::get_cookie(Z_OtherInformation **otherInfo)
 109 {
 110     int oid[OID_SIZE];
 111     Z_OtherInformationUnit *oi;
 112     struct oident ent;
 113     ent.proto = PROTO_Z3950;
 114     ent.oclass = CLASS_USERINFO;
 115     ent.value = (oid_value) VAL_COOKIE;
 116     assert (oid_ent_to_oid (&ent, oid));
 117
 118     if (oid_ent_to_oid (&ent, oid) &&
 119         (oi = update_otherInformation(otherInfo, 0, oid, 1, 1)) &&
 120         oi->which == Z_OtherInfo_characterInfo)
 121         return oi->information.characterInfo;
 122     return 0;
 123 }
 124
 125 char *Yaz_Proxy::get_proxy(Z_OtherInformation **otherInfo)
 126 {
 127     int oid[OID_SIZE];
 128     Z_OtherInformationUnit *oi;
 129     struct oident ent;
 130     ent.proto = PROTO_Z3950;
 131     ent.oclass = CLASS_USERINFO;
 132     ent.value = (oid_value) VAL_PROXY;
 133     if (oid_ent_to_oid (&ent, oid) &&
 134         (oi = update_otherInformation(otherInfo, 0, oid, 1, 1)) &&
 135         oi->which == Z_OtherInfo_characterInfo)
 136         return oi->information.characterInfo;
 137     return 0;
 138 }
 139
 140 Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
 141 {
 142     assert (m_parent);
 143     Yaz_Proxy *parent = m_parent;
 144     Z_OtherInformation **oi;
 145     Yaz_ProxyClient *c = m_client;
 146
 147     get_otherInfoAPDU(apdu, &oi);
 148     char *cookie = get_cookie(oi);
 149     logf (LOG_LOG, "Yaz_Proxy::get_client cookie=%s", cookie ? cookie :
 150           "null");
 151
 152     const char *proxy_host = get_proxy(oi);
 153     if (proxy_host)
 154         set_proxyTarget(proxy_host);
 155     logf (LOG_LOG, "proxy_host = %s", m_proxyTarget ? m_proxyTarget:"none");
 156
 157     // no target specified at all?
 158     if (!m_proxyTarget)
 159         return 0;
 160
 161     if (cookie)
 162     {
 163         logf (LOG_LOG, "lookup of clients cookie=%s target=%s",
 164               cookie, m_proxyTarget);
 165         Yaz_ProxyClient *cc = 0;
 166
 167         for (c = parent->m_clientPool; c; c = c->m_next)
 168         {
 169             logf (LOG_LOG, " found client cookie = %s target=%s seqno=%d",
 170                   c->m_cookie, c->get_hostname(), c->m_seqno);
 171             assert (c->m_prev);
 172             assert (*c->m_prev == c);
 173             if (!strcmp(cookie,c->m_cookie) &&
 174                 !strcmp(m_proxyTarget, c->get_hostname()))
 175             {
 176                 logf (LOG_LOG, "found!");
 177                 cc = c;
 178             }
 179         }
 180         if (cc)
 181         {
 182             // found it in cache
 183             c = cc;
 184             // The following handles "cancel"
 185             // If connection is busy (waiting for PDU) and
 186             // we have an initRequest we can safely do re-open
 187             if (c->m_waiting && apdu->which == Z_APDU_initRequest)
 188             {
 189                 logf (LOG_LOG, "reopen target=%s", c->get_hostname());
 190                 c->close();
 191                 c->client(m_proxyTarget);
 192                 c->m_init_flag = 0;
 193
 194                 delete c->m_last_query;
 195                 c->m_last_query = 0;
 196                 c->m_last_resultCount = 0;
 197                 c->m_sr_transform = 0;
 198                 c->m_waiting = 0;
 199                 c->timeout(600);
 200             }
 201             c->m_seqno = parent->m_seqno;
 202             (parent->m_seqno)++;
 203             return c;
 204         }
 205     }
 206     if (!m_client)
 207     {
 208         if (apdu->which != Z_APDU_initRequest)
 209         {
 210             logf (LOG_LOG, "no first INIT!");
 211             return 0;
 212         }
 213         logf (LOG_LOG, "got InitRequest");
 214
 215         // go through list of clients - and find the lowest/oldest one.
 216         Yaz_ProxyClient *c_min = 0;
 217         int min_seq = -1;
 218         int no_of_clients = 0;
 219         for (c = parent->m_clientPool; c; c = c->m_next)
 220         {
 221             no_of_clients++;
 222             if (min_seq < 0 || c->m_seqno < min_seq)
 223             {
 224                 min_seq = c->m_seqno;
 225                 c_min = c;
 226             }
 227         }
 228         if (no_of_clients >= parent->m_max_clients)
 229         {
 230             c = c_min;
 231             if (c->m_waiting || strcmp(m_proxyTarget, c->get_hostname()))
 232             {
 233                 logf (LOG_LOG, "Yaz_Proxy::get_client re-init session %d",
 234                       c->m_seqno);
 235                 if (c->m_server)
 236                     delete c->m_server;
 237                 c->m_server = 0;
 238             }
 239             else
 240             {
 241                 logf (LOG_LOG, "Yaz_Proxy::get_client re-use session %d to %d",
 242                       c->m_seqno, parent->m_seqno);
 243                 if (cookie)
 244                     strcpy (c->m_cookie, cookie);
 245                 else
 246                     c->m_cookie[0] = '\0';
 247                 c->m_seqno = parent->m_seqno;
 248                 (parent->m_seqno)++;
 249                 return c;
 250             }
 251         }
 252         else
 253         {
 254             logf (LOG_LOG, "Yaz_Proxy::get_client making session %d",
 255                   parent->m_seqno);
 256             c = new Yaz_ProxyClient(m_PDU_Observable->clone());
 257             c->m_next = parent->m_clientPool;
 258             if (c->m_next)
 259                 c->m_next->m_prev = &c->m_next;
 260             parent->m_clientPool = c;
 261             c->m_prev = &parent->m_clientPool;
 262         }
 263         if (cookie)
 264             strcpy (c->m_cookie, cookie);
 265         else
 266             c->m_cookie[0] = '\0';
 267         logf (LOG_LOG, "Yaz_Proxy::get_client connect to %s", m_proxyTarget);
 268         c->m_seqno = parent->m_seqno;
 269         c->client(m_proxyTarget);
 270         c->m_init_flag = 0;
 271
 272         delete c->m_last_query;
 273         c->m_last_query = 0;
 274         c->m_last_resultCount = 0;
 275         c->m_sr_transform = 0;
 276         c->m_waiting = 0;
 277         c->timeout(600);
 278
 279         (parent->m_seqno)++;
 280     }
 281     return c;
 282 }
 283
 284 Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
 285 {
 286     if (apdu->which != Z_APDU_searchRequest)
 287         return apdu;
 288     Z_SearchRequest *sr = apdu->u.searchRequest;
 289     Yaz_Z_Query *this_query = new Yaz_Z_Query;
 290
 291     this_query->set_Z_Query(sr->query);
 292
 293     if (m_client->m_last_query &&
 294         m_client->m_last_query->match(this_query))
 295     {
 296         delete this_query;
 297         if (m_client->m_last_resultCount > *sr->smallSetUpperBound &&
 298             m_client->m_last_resultCount < *sr->largeSetLowerBound)
 299         {
 300             // medium Set
 301             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize medium set");
 302             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
 303             Z_PresentRequest *pr = new_apdu->u.presentRequest;
 304             pr->referenceId = sr->referenceId;
 305             pr->resultSetId = sr->resultSetName;
 306             pr->preferredRecordSyntax = sr->preferredRecordSyntax;
 307             *pr->numberOfRecordsRequested = *sr->mediumSetPresentNumber;
 308             if (sr->mediumSetElementSetNames)
 309             {
 310                 pr->recordComposition = (Z_RecordComposition *)
 311                     odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
 312                 pr->recordComposition->which = Z_RecordComp_simple;
 313                 pr->recordComposition->u.simple = sr->mediumSetElementSetNames;
 314             }
 315             m_client->m_sr_transform = 1;
 316             return new_apdu;
 317         }
 318         else if (m_client->m_last_resultCount > *sr->largeSetLowerBound ||
 319             m_client->m_last_resultCount == 0)
 320         {
 321             // large set
 322             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize large set");
 323             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
 324             new_apdu->u.searchResponse->referenceId = sr->referenceId;
 325             new_apdu->u.searchResponse->resultCount =
 326                 &m_client->m_last_resultCount;
 327             send_Z_PDU(new_apdu);
 328             return 0;
 329         }
 330         else
 331         {
 332             // small set
 333             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize small set");
 334             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
 335             Z_PresentRequest *pr = new_apdu->u.presentRequest;
 336             pr->referenceId = sr->referenceId;
 337             pr->resultSetId = sr->resultSetName;
 338             pr->preferredRecordSyntax = sr->preferredRecordSyntax;
 339             *pr->numberOfRecordsRequested = m_client->m_last_resultCount;
 340             if (sr->smallSetElementSetNames)
 341             {
 342                 pr->recordComposition = (Z_RecordComposition *)
 343                     odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
 344                 pr->recordComposition->which = Z_RecordComp_simple;
 345                 pr->recordComposition->u.simple = sr->smallSetElementSetNames;
 346             }
 347             m_client->m_sr_transform = 1;
 348             return new_apdu;
 349         }
 350     }
 351     else
 352     {
 353         logf (LOG_LOG, "Yaz_Proxy::result_set_optimize new set");
 354         delete m_client->m_last_query;
 355         m_client->m_last_query = this_query;
 356     }
 357     return apdu;
 358 }
 359
 360 void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
 361 {
 362     logf (LOG_LOG, "Yaz_Proxy::recv_Z_PDU");
 363     // Determine our client.
 364     m_client = get_client(apdu);
 365     if (!m_client)
 366     {
 367         delete this;
 368         return;
 369     }
 370     m_client->m_server = this;
 371
 372     if (apdu->which == Z_APDU_initRequest)
 373     {
 374         if (m_client->m_init_flag)
 375         {
 376             Z_APDU *apdu = create_Z_PDU(Z_APDU_initResponse);
 377             if (m_client->m_cookie)
 378                 set_otherInformationString(apdu, VAL_COOKIE, 1,
 379                                            m_client->m_cookie);
 380             send_Z_PDU(apdu);
 381             return;
 382         }
 383         m_client->m_init_flag = 1;
 384     }
 385     apdu = result_set_optimize(apdu);
 386     if (!apdu)
 387         return;
 388
 389     logf (LOG_LOG, "Yaz_ProxyClient::send_Z_PDU %s", m_client->get_hostname());
 390
 391     // delete other info part from PDU before sending to target
 392     Z_OtherInformation **oi;
 393     get_otherInfoAPDU(apdu, &oi);
 394     *oi = 0;
 395
 396     if (m_client->send_Z_PDU(apdu) < 0)
 397     {
 398         delete m_client;
 399         delete this;
 400     }
 401     else
 402         m_client->m_waiting = 1;
 403 }
 404
 405 void Yaz_Proxy::connectNotify()
 406 {
 407 }
 408
 409 void Yaz_Proxy::shutdown()
 410 {
 411     logf (LOG_LOG, "shutdown (client to proxy)");
 412     // only keep if keep_alive flag and cookie is set...
 413     if (m_keepalive && m_client && m_client->m_cookie[0])
 414     {
 415         // Tell client (if any) that no server connection is there..
 416         m_client->m_server = 0;
 417     }
 418     else
 419     {
 420         delete m_client;
 421     }
 422     delete this;
 423 }
 424
 425 void Yaz_ProxyClient::shutdown()
 426 {
 427     logf (LOG_LOG, "shutdown (proxy to server) %s", get_hostname());
 428     delete m_server;
 429     delete this;
 430 }
 431
 432 void Yaz_Proxy::failNotify()
 433 {
 434     logf (LOG_LOG, "connection closed by client");
 435     shutdown();
 436 }
 437
 438 void Yaz_ProxyClient::failNotify()
 439 {
 440     logf (LOG_LOG, "Yaz_ProxyClient connection closed by %s", get_hostname());
 441     shutdown();
 442 }
 443
 444 void Yaz_ProxyClient::connectNotify()
 445 {
 446     logf (LOG_LOG, "Yaz_ProxyClient connection accept by %s", get_hostname());
 447 }
 448
 449 IYaz_PDU_Observer *Yaz_ProxyClient::clone(IYaz_PDU_Observable
 450                                           *the_PDU_Observable)
 451 {
 452     return new Yaz_ProxyClient(the_PDU_Observable);
 453 }
 454
 455 Yaz_ProxyClient::~Yaz_ProxyClient()
 456 {
 457     if (m_prev)
 458     {
 459         *m_prev = m_next;
 460         if (m_next)
 461             m_next->m_prev = m_prev;
 462     }
 463     delete m_last_query;
 464 }
 465
 466 void Yaz_Proxy::timeoutNotify()
 467 {
 468     logf (LOG_LOG, "timeout (client to proxy)");
 469     shutdown();
 470 }
 471
 472 void Yaz_ProxyClient::timeoutNotify()
 473 {
 474     logf (LOG_LOG, "timeout (proxy to target) %s", get_hostname());
 475     shutdown();
 476 }
 477
 478 Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable) :
 479     Yaz_Z_Assoc (the_PDU_Observable)
 480 {
 481     m_cookie[0] = 0;
 482     m_next = 0;
 483     m_prev = 0;
 484     m_init_flag = 0;
 485     m_last_query = 0;
 486     m_last_resultCount = 0;
 487     m_sr_transform = 0;
 488     m_waiting = 0;
 489 }
 490
 491 void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
 492 {
 493     m_waiting = 0;
 494     logf (LOG_LOG, "Yaz_ProxyClient::recv_Z_PDU %s", get_hostname());
 495     if (apdu->which == Z_APDU_searchResponse)
 496         m_last_resultCount = *apdu->u.searchResponse->resultCount;
 497     if (apdu->which == Z_APDU_presentResponse && m_sr_transform)
 498     {
 499         m_sr_transform = 0;
 500         Z_PresentResponse *pr = apdu->u.presentResponse;
 501         Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
 502         Z_SearchResponse *sr = new_apdu->u.searchResponse;
 503         sr->referenceId = pr->referenceId;
 504         *sr->resultCount = m_last_resultCount;
 505         sr->records = pr->records;
 506         sr->nextResultSetPosition = pr->nextResultSetPosition;
 507         sr->numberOfRecordsReturned = pr->numberOfRecordsReturned;
 508         apdu = new_apdu;
 509     }
 510     if (m_cookie)
 511         set_otherInformationString (apdu, VAL_COOKIE, 1, m_cookie);
 512     if (m_server)
 513     {
 514         logf (LOG_LOG, "Yaz_Proxy::send_Z_PDU");
 515         m_server->send_Z_PDU(apdu);
 516     }
 517 }