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