src/yaz-proxy.cpp

   1 /*
   2  * Copyright (c) 1998-2000, Index Data.
   3  * See the file LICENSE for details.
   4  *
   5  * $Log: yaz-proxy.cpp,v $
   6  * Revision 1.18  2000-09-08 10:23:42  adam
   7  * Added skeleton of yaz-z-server.
   8  *
   9  * Revision 1.17  2000/09/05 13:57:28  adam
  10  * Fixed get_otherInfoAPDU to return otherInfo for extended services.
  11  *
  12  * Revision 1.16  2000/09/04 08:29:22  adam
  13  * Fixed memory leak(s). Added re-use of associations, rather than
  14  * re-init, when maximum number of targets are in use.
  15  *
  16  * Revision 1.15  2000/08/31 14:41:55  adam
  17  * Proxy no longer generates cookies (it's up to the client). Proxy
  18  * re-opens if target new op is started before previous operation finishes.
  19  *
  20  * Revision 1.14  2000/08/10 08:42:42  adam
  21  * Fixes for {set,get}_APDU_log.
  22  *
  23  * Revision 1.13  2000/08/07 14:19:59  adam
  24  * Fixed serious bug regarding timeouts. Improved logging for proxy.
  25  *
  26  * Revision 1.12  2000/07/04 13:48:49  adam
  27  * Implemented upper-limit on proxy-to-target sessions.
  28  *
  29  * Revision 1.11  1999/12/06 13:52:45  adam
  30  * Modified for new location of YAZ header files. Experimental threaded
  31  * operation.
  32  *
  33  * Revision 1.10  1999/11/10 10:02:34  adam
  34  * Work on proxy.
  35  *
  36  * Revision 1.9  1999/09/13 12:53:44  adam
  37  * Proxy removes OtherInfo Proxy Address and Session ID. Other
  38  * Otherinfo remains untouched.
  39  *
  40  * Revision 1.8  1999/05/04 10:53:00  adam
  41  * Changed the way the PROXY behaves when lost cookie is received.
  42  *
  43  * Revision 1.7  1999/04/28 13:31:17  adam
  44  * Better result set optimisation for proxy.
  45  *
  46  * Revision 1.6  1999/04/27 07:52:13  adam
  47  * Improved proxy; added query match for result set re-use.
  48  *
  49  * Revision 1.5  1999/04/21 12:09:01  adam
  50  * Many improvements. Modified to proxy server to work with "sessions"
  51  * based on cookies.
  52  *
  53  * Revision 1.4  1999/04/20 10:30:05  adam
  54  * Implemented various stuff for client and proxy. Updated calls
  55  * to ODR to reflect new name parameter.
  56  *
  57  * Revision 1.3  1999/04/09 11:46:57  adam
  58  * Added object Yaz_Z_Assoc. Much more functional client.
  59  *
  60  * Revision 1.2  1999/01/28 13:08:46  adam
  61  * Yaz_PDU_Assoc better encapsulated. Memory leak fix in
  62  * yaz-socket-manager.cc.
  63  *
  64  * Revision 1.1.1.1  1999/01/28 09:41:07  adam
  65  * First implementation of YAZ++.
  66  *
  67  */
  68
  69 #include <assert.h>
  70 #include <time.h>
  71
  72 #include <yaz/log.h>
  73 #include <yaz-proxy.h>
  74
  75 Yaz_Proxy::Yaz_Proxy(IYaz_PDU_Observable *the_PDU_Observable) :
  76     Yaz_Z_Assoc(the_PDU_Observable)
  77 {
  78     m_PDU_Observable = the_PDU_Observable;
  79     m_client = 0;
  80     m_parent = 0;
  81     m_clientPool = 0;
  82     m_seqno = 1;
  83     m_keepalive = 1;
  84     m_proxyTarget = 0;
  85     m_max_clients = 50;
  86     m_seed = time(0);
  87 }
  88
  89 Yaz_Proxy::~Yaz_Proxy()
  90 {
  91     xfree (m_proxyTarget);
  92 }
  93
  94 void Yaz_Proxy::set_proxyTarget(const char *target)
  95 {
  96     xfree (m_proxyTarget);
  97     m_proxyTarget = 0;
  98     if (target)
  99         m_proxyTarget = (char *) xstrdup (target);
 100 }
 101
 102 IYaz_PDU_Observer *Yaz_Proxy::clone(IYaz_PDU_Observable
 103                                     *the_PDU_Observable)
 104 {
 105     Yaz_Proxy *new_proxy = new Yaz_Proxy(the_PDU_Observable);
 106     new_proxy->m_parent = this;
 107     new_proxy->timeout(120);
 108     new_proxy->set_proxyTarget(m_proxyTarget);
 109     new_proxy->set_APDU_log(get_APDU_log());
 110     return new_proxy;
 111 }
 112
 113 char *Yaz_Proxy::get_cookie(Z_OtherInformation **otherInfo)
 114 {
 115     int oid[OID_SIZE];
 116     Z_OtherInformationUnit *oi;
 117     struct oident ent;
 118     ent.proto = PROTO_Z3950;
 119     ent.oclass = CLASS_USERINFO;
 120     ent.value = (oid_value) VAL_COOKIE;
 121     assert (oid_ent_to_oid (&ent, oid));
 122
 123     if (oid_ent_to_oid (&ent, oid) &&
 124         (oi = update_otherInformation(otherInfo, 0, oid, 1, 1)) &&
 125         oi->which == Z_OtherInfo_characterInfo)
 126         return oi->information.characterInfo;
 127     return 0;
 128 }
 129
 130 char *Yaz_Proxy::get_proxy(Z_OtherInformation **otherInfo)
 131 {
 132     int oid[OID_SIZE];
 133     Z_OtherInformationUnit *oi;
 134     struct oident ent;
 135     ent.proto = PROTO_Z3950;
 136     ent.oclass = CLASS_USERINFO;
 137     ent.value = (oid_value) VAL_PROXY;
 138     if (oid_ent_to_oid (&ent, oid) &&
 139         (oi = update_otherInformation(otherInfo, 0, oid, 1, 1)) &&
 140         oi->which == Z_OtherInfo_characterInfo)
 141         return oi->information.characterInfo;
 142     return 0;
 143 }
 144
 145 Yaz_ProxyClient *Yaz_Proxy::get_client(Z_APDU *apdu)
 146 {
 147     assert (m_parent);
 148     Yaz_Proxy *parent = m_parent;
 149     Z_OtherInformation **oi;
 150     Yaz_ProxyClient *c = m_client;
 151
 152     get_otherInfoAPDU(apdu, &oi);
 153     char *cookie = get_cookie(oi);
 154     logf (LOG_LOG, "Yaz_Proxy::get_client cookie=%s", cookie ? cookie :
 155           "null");
 156
 157     const char *proxy_host = get_proxy(oi);
 158     if (proxy_host)
 159         set_proxyTarget(proxy_host);
 160     logf (LOG_LOG, "proxy_host = %s", m_proxyTarget ? m_proxyTarget:"none");
 161
 162     // no target specified at all?
 163     if (!m_proxyTarget)
 164         return 0;
 165
 166     if (cookie)
 167     {
 168         logf (LOG_LOG, "lookup of clients cookie=%s target=%s",
 169               cookie, m_proxyTarget);
 170         Yaz_ProxyClient *cc = 0;
 171
 172         for (c = parent->m_clientPool; c; c = c->m_next)
 173         {
 174             logf (LOG_LOG, " found client cookie = %s target=%s seqno=%d",
 175                   c->m_cookie, c->get_hostname(), c->m_seqno);
 176             assert (c->m_prev);
 177             assert (*c->m_prev == c);
 178             if (!strcmp(cookie,c->m_cookie) &&
 179                 !strcmp(m_proxyTarget, c->get_hostname()))
 180             {
 181                 logf (LOG_LOG, "found!");
 182                 cc = c;
 183             }
 184         }
 185         if (cc)
 186         {
 187             // found it in cache
 188             c = cc;
 189             // The following handles "cancel"
 190             // If connection is busy (waiting for PDU) and
 191             // we have an initRequest we can safely do re-open
 192             if (c->m_waiting && apdu->which == Z_APDU_initRequest)
 193             {
 194                 logf (LOG_LOG, "reopen target=%s", c->get_hostname());
 195                 c->close();
 196                 c->client(m_proxyTarget);
 197                 c->m_init_flag = 0;
 198
 199                 delete c->m_last_query;
 200                 c->m_last_query = 0;
 201                 c->m_last_resultCount = 0;
 202                 c->m_sr_transform = 0;
 203                 c->m_waiting = 0;
 204                 c->timeout(600);
 205             }
 206             c->m_seqno = parent->m_seqno;
 207             (parent->m_seqno)++;
 208             return c;
 209         }
 210     }
 211     if (!m_client)
 212     {
 213         if (apdu->which != Z_APDU_initRequest)
 214         {
 215             logf (LOG_LOG, "no first INIT!");
 216             return 0;
 217         }
 218         logf (LOG_LOG, "got InitRequest");
 219
 220         // go through list of clients - and find the lowest/oldest one.
 221         Yaz_ProxyClient *c_min = 0;
 222         int min_seq = -1;
 223         int no_of_clients = 0;
 224         for (c = parent->m_clientPool; c; c = c->m_next)
 225         {
 226             no_of_clients++;
 227             if (min_seq < 0 || c->m_seqno < min_seq)
 228             {
 229                 min_seq = c->m_seqno;
 230                 c_min = c;
 231             }
 232         }
 233         if (no_of_clients >= parent->m_max_clients)
 234         {
 235             c = c_min;
 236             if (c->m_waiting || strcmp(m_proxyTarget, c->get_hostname()))
 237             {
 238                 logf (LOG_LOG, "Yaz_Proxy::get_client re-init session %d",
 239                       c->m_seqno);
 240                 if (c->m_server)
 241                     delete c->m_server;
 242                 c->m_server = 0;
 243             }
 244             else
 245             {
 246                 logf (LOG_LOG, "Yaz_Proxy::get_client re-use session %d to %d",
 247                       c->m_seqno, parent->m_seqno);
 248                 if (cookie)
 249                     strcpy (c->m_cookie, cookie);
 250                 else
 251                     c->m_cookie[0] = '\0';
 252                 c->m_seqno = parent->m_seqno;
 253                 (parent->m_seqno)++;
 254                 return c;
 255             }
 256         }
 257         else
 258         {
 259             logf (LOG_LOG, "Yaz_Proxy::get_client making session %d",
 260                   parent->m_seqno);
 261             c = new Yaz_ProxyClient(m_PDU_Observable->clone());
 262             c->m_next = parent->m_clientPool;
 263             if (c->m_next)
 264                 c->m_next->m_prev = &c->m_next;
 265             parent->m_clientPool = c;
 266             c->m_prev = &parent->m_clientPool;
 267         }
 268         if (cookie)
 269             strcpy (c->m_cookie, cookie);
 270         else
 271             c->m_cookie[0] = '\0';
 272         logf (LOG_LOG, "Yaz_Proxy::get_client connect to %s", m_proxyTarget);
 273         c->m_seqno = parent->m_seqno;
 274         c->client(m_proxyTarget);
 275         c->m_init_flag = 0;
 276
 277         delete c->m_last_query;
 278         c->m_last_query = 0;
 279         c->m_last_resultCount = 0;
 280         c->m_sr_transform = 0;
 281         c->m_waiting = 0;
 282         c->timeout(600);
 283
 284         (parent->m_seqno)++;
 285     }
 286     return c;
 287 }
 288
 289 Z_APDU *Yaz_Proxy::result_set_optimize(Z_APDU *apdu)
 290 {
 291     if (apdu->which != Z_APDU_searchRequest)
 292         return apdu;
 293     Z_SearchRequest *sr = apdu->u.searchRequest;
 294     Yaz_Z_Query *this_query = new Yaz_Z_Query;
 295
 296     this_query->set_Z_Query(sr->query);
 297
 298     if (m_client->m_last_query &&
 299         m_client->m_last_query->match(this_query))
 300     {
 301         delete this_query;
 302         if (m_client->m_last_resultCount > *sr->smallSetUpperBound &&
 303             m_client->m_last_resultCount < *sr->largeSetLowerBound)
 304         {
 305             // medium Set
 306             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize medium set");
 307             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
 308             Z_PresentRequest *pr = new_apdu->u.presentRequest;
 309             pr->referenceId = sr->referenceId;
 310             pr->resultSetId = sr->resultSetName;
 311             pr->preferredRecordSyntax = sr->preferredRecordSyntax;
 312             *pr->numberOfRecordsRequested = *sr->mediumSetPresentNumber;
 313             if (sr->mediumSetElementSetNames)
 314             {
 315                 pr->recordComposition = (Z_RecordComposition *)
 316                     odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
 317                 pr->recordComposition->which = Z_RecordComp_simple;
 318                 pr->recordComposition->u.simple = sr->mediumSetElementSetNames;
 319             }
 320             m_client->m_sr_transform = 1;
 321             return new_apdu;
 322         }
 323         else if (m_client->m_last_resultCount > *sr->largeSetLowerBound ||
 324             m_client->m_last_resultCount == 0)
 325         {
 326             // large set
 327             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize large set");
 328             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
 329             new_apdu->u.searchResponse->referenceId = sr->referenceId;
 330             new_apdu->u.searchResponse->resultCount =
 331                 &m_client->m_last_resultCount;
 332             send_Z_PDU(new_apdu);
 333             return 0;
 334         }
 335         else
 336         {
 337             // small set
 338             logf (LOG_LOG, "Yaz_Proxy::result_set_optimize small set");
 339             Z_APDU *new_apdu = create_Z_PDU(Z_APDU_presentRequest);
 340             Z_PresentRequest *pr = new_apdu->u.presentRequest;
 341             pr->referenceId = sr->referenceId;
 342             pr->resultSetId = sr->resultSetName;
 343             pr->preferredRecordSyntax = sr->preferredRecordSyntax;
 344             *pr->numberOfRecordsRequested = m_client->m_last_resultCount;
 345             if (sr->smallSetElementSetNames)
 346             {
 347                 pr->recordComposition = (Z_RecordComposition *)
 348                     odr_malloc(odr_encode(), sizeof(Z_RecordComposition));
 349                 pr->recordComposition->which = Z_RecordComp_simple;
 350                 pr->recordComposition->u.simple = sr->smallSetElementSetNames;
 351             }
 352             m_client->m_sr_transform = 1;
 353             return new_apdu;
 354         }
 355     }
 356     else
 357     {
 358         logf (LOG_LOG, "Yaz_Proxy::result_set_optimize new set");
 359         delete m_client->m_last_query;
 360         m_client->m_last_query = this_query;
 361     }
 362     return apdu;
 363 }
 364
 365 void Yaz_Proxy::recv_Z_PDU(Z_APDU *apdu)
 366 {
 367     logf (LOG_LOG, "Yaz_Proxy::recv_Z_PDU");
 368     // Determine our client.
 369     m_client = get_client(apdu);
 370     if (!m_client)
 371     {
 372         delete this;
 373         return;
 374     }
 375     m_client->m_server = this;
 376
 377     if (apdu->which == Z_APDU_initRequest)
 378     {
 379         if (m_client->m_init_flag)
 380         {
 381             Z_APDU *apdu = create_Z_PDU(Z_APDU_initResponse);
 382             if (m_client->m_cookie)
 383                 set_otherInformationString(apdu, VAL_COOKIE, 1,
 384                                            m_client->m_cookie);
 385             send_Z_PDU(apdu);
 386             return;
 387         }
 388         m_client->m_init_flag = 1;
 389     }
 390     apdu = result_set_optimize(apdu);
 391     if (!apdu)
 392         return;
 393
 394     logf (LOG_LOG, "Yaz_ProxyClient::send_Z_PDU %s", m_client->get_hostname());
 395
 396     // delete other info part from PDU before sending to target
 397     Z_OtherInformation **oi;
 398     get_otherInfoAPDU(apdu, &oi);
 399     if (oi)
 400         *oi = 0;
 401
 402     if (m_client->send_Z_PDU(apdu) < 0)
 403     {
 404         delete m_client;
 405         delete this;
 406     }
 407     else
 408         m_client->m_waiting = 1;
 409 }
 410
 411 void Yaz_Proxy::connectNotify()
 412 {
 413 }
 414
 415 void Yaz_Proxy::shutdown()
 416 {
 417     logf (LOG_LOG, "shutdown (client to proxy)");
 418     // only keep if keep_alive flag and cookie is set...
 419     if (m_keepalive && m_client && m_client->m_cookie[0])
 420     {
 421         // Tell client (if any) that no server connection is there..
 422         m_client->m_server = 0;
 423     }
 424     else
 425     {
 426         delete m_client;
 427     }
 428     delete this;
 429 }
 430
 431 void Yaz_ProxyClient::shutdown()
 432 {
 433     logf (LOG_LOG, "shutdown (proxy to server) %s", get_hostname());
 434     delete m_server;
 435     delete this;
 436 }
 437
 438 void Yaz_Proxy::failNotify()
 439 {
 440     logf (LOG_LOG, "connection closed by client");
 441     shutdown();
 442 }
 443
 444 void Yaz_ProxyClient::failNotify()
 445 {
 446     logf (LOG_LOG, "Yaz_ProxyClient connection closed by %s", get_hostname());
 447     shutdown();
 448 }
 449
 450 void Yaz_ProxyClient::connectNotify()
 451 {
 452     logf (LOG_LOG, "Yaz_ProxyClient connection accept by %s", get_hostname());
 453 }
 454
 455 IYaz_PDU_Observer *Yaz_ProxyClient::clone(IYaz_PDU_Observable
 456                                           *the_PDU_Observable)
 457 {
 458     return new Yaz_ProxyClient(the_PDU_Observable);
 459 }
 460
 461 Yaz_ProxyClient::~Yaz_ProxyClient()
 462 {
 463     if (m_prev)
 464     {
 465         *m_prev = m_next;
 466         if (m_next)
 467             m_next->m_prev = m_prev;
 468     }
 469     delete m_last_query;
 470 }
 471
 472 void Yaz_Proxy::timeoutNotify()
 473 {
 474     logf (LOG_LOG, "timeout (client to proxy)");
 475     shutdown();
 476 }
 477
 478 void Yaz_ProxyClient::timeoutNotify()
 479 {
 480     logf (LOG_LOG, "timeout (proxy to target) %s", get_hostname());
 481     shutdown();
 482 }
 483
 484 Yaz_ProxyClient::Yaz_ProxyClient(IYaz_PDU_Observable *the_PDU_Observable) :
 485     Yaz_Z_Assoc (the_PDU_Observable)
 486 {
 487     m_cookie[0] = 0;
 488     m_next = 0;
 489     m_prev = 0;
 490     m_init_flag = 0;
 491     m_last_query = 0;
 492     m_last_resultCount = 0;
 493     m_sr_transform = 0;
 494     m_waiting = 0;
 495 }
 496
 497 void Yaz_ProxyClient::recv_Z_PDU(Z_APDU *apdu)
 498 {
 499     m_waiting = 0;
 500     logf (LOG_LOG, "Yaz_ProxyClient::recv_Z_PDU %s", get_hostname());
 501     if (apdu->which == Z_APDU_searchResponse)
 502         m_last_resultCount = *apdu->u.searchResponse->resultCount;
 503     if (apdu->which == Z_APDU_presentResponse && m_sr_transform)
 504     {
 505         m_sr_transform = 0;
 506         Z_PresentResponse *pr = apdu->u.presentResponse;
 507         Z_APDU *new_apdu = create_Z_PDU(Z_APDU_searchResponse);
 508         Z_SearchResponse *sr = new_apdu->u.searchResponse;
 509         sr->referenceId = pr->referenceId;
 510         *sr->resultCount = m_last_resultCount;
 511         sr->records = pr->records;
 512         sr->nextResultSetPosition = pr->nextResultSetPosition;
 513         sr->numberOfRecordsReturned = pr->numberOfRecordsReturned;
 514         apdu = new_apdu;
 515     }
 516     if (m_cookie)
 517         set_otherInformationString (apdu, VAL_COOKIE, 1, m_cookie);
 518     if (m_server)
 519     {
 520         logf (LOG_LOG, "Yaz_Proxy::send_Z_PDU");
 521         m_server->send_Z_PDU(apdu);
 522     }
 523 }