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