server/seshigh.c

   1 /*
   2  * Copyright (c) 1995, Index Data
   3  * See the file LICENSE for details.
   4  * Sebastian Hammer, Adam Dickmeiss
   5  *
   6  * $Log: seshigh.c,v $
   7  * Revision 1.46  1995-08-29 11:17:58  quinn
   8  * Added code to receive close
   9  *
  10  * Revision 1.45  1995/08/21  09:11:00  quinn
  11  * Smallish fixes to suppport new formats.
  12  *
  13  * Revision 1.44  1995/08/17  12:45:25  quinn
  14  * Fixed minor problems with GRS-1. Added support in c&s.
  15  *
  16  * Revision 1.43  1995/08/15  12:00:31  quinn
  17  * Updated External
  18  *
  19  * Revision 1.42  1995/08/15  11:16:50  quinn
  20  * CV:e ----------------------------------------------------------------------
  21  * CV:e ----------------------------------------------------------------------
  22  *
  23  * Revision 1.41  1995/08/02  10:23:06  quinn
  24  * Smallish
  25  *
  26  * Revision 1.40  1995/07/31  14:34:26  quinn
  27  * Fixed bug in process_searchResponse (numberOfRecordsReturned).
  28  *
  29  * Revision 1.39  1995/06/27  13:21:00  quinn
  30  * SUTRS support
  31  *
  32  * Revision 1.38  1995/06/19  12:39:11  quinn
  33  * Fixed bug in timeout code. Added BER dumper.
  34  *
  35  * Revision 1.37  1995/06/16  13:16:14  quinn
  36  * Fixed Defaultdiagformat.
  37  *
  38  * Revision 1.36  1995/06/16  10:31:36  quinn
  39  * Added session timeout.
  40  *
  41  * Revision 1.35  1995/06/15  07:45:14  quinn
  42  * Moving to v3.
  43  *
  44  * Revision 1.34  1995/06/14  15:26:46  quinn
  45  * *** empty log message ***
  46  *
  47  * Revision 1.33  1995/06/06  14:57:05  quinn
  48  * Better diagnostics.
  49  *
  50  * Revision 1.32  1995/06/06  08:41:44  quinn
  51  * Better diagnostics.
  52  *
  53  * Revision 1.31  1995/06/06  08:15:37  quinn
  54  * Cosmetic.
  55  *
  56  * Revision 1.30  1995/06/05  10:53:32  quinn
  57  * Added a better SCAN.
  58  *
  59  * Revision 1.29  1995/06/01  11:25:03  quinn
  60  * Smallish.
  61  *
  62  * Revision 1.28  1995/06/01  11:21:01  quinn
  63  * Attempting to fix a bug in pack-records. replaced break with continue
  64  * for large records, according to standard.
  65  *
  66  * Revision 1.27  1995/05/29  08:12:06  quinn
  67  * Moved oid to util
  68  *
  69  * Revision 1.26  1995/05/18  13:02:12  quinn
  70  * Smallish.
  71  *
  72  * Revision 1.25  1995/05/17  08:42:26  quinn
  73  * Transfer auth info to backend. Allow backend to reject init gracefully.
  74  *
  75  * Revision 1.24  1995/05/16  08:51:04  quinn
  76  * License, documentation, and memory fixes
  77  *
  78  * Revision 1.23  1995/05/15  13:25:10  quinn
  79  * Fixed memory bug.
  80  *
  81  * Revision 1.22  1995/05/15  11:56:39  quinn
  82  * Asynchronous facilities. Restructuring of seshigh code.
  83  *
  84  * Revision 1.21  1995/05/02  08:53:19  quinn
  85  * Trying in vain to fix comm with ISODE
  86  *
  87  * Revision 1.20  1995/04/20  15:13:00  quinn
  88  * Cosmetic
  89  *
  90  * Revision 1.19  1995/04/18  08:15:34  quinn
  91  * Added dynamic memory allocation on encoding (whew). Code is now somewhat
  92  * neater. We'll make the same change for decoding one day.
  93  *
  94  * Revision 1.18  1995/04/17  11:28:25  quinn
  95  * Smallish
  96  *
  97  * Revision 1.17  1995/04/10  10:23:36  quinn
  98  * Some work to add scan and other things.
  99  *
 100  * Revision 1.16  1995/03/31  09:18:55  quinn
 101  * Added logging.
 102  *
 103  * Revision 1.15  1995/03/30  14:03:23  quinn
 104  * Added RFC1006 as separate library
 105  *
 106  * Revision 1.14  1995/03/30  12:18:17  quinn
 107  * Fixed bug.
 108  *
 109  * Revision 1.13  1995/03/30  09:09:24  quinn
 110  * Added state-handle and some support for asynchronous activities.
 111  *
 112  * Revision 1.12  1995/03/29  15:40:16  quinn
 113  * Ongoing work. Statserv is now dynamic by default
 114  *
 115  * Revision 1.11  1995/03/28  09:16:21  quinn
 116  * Added record packing to the search request
 117  *
 118  * Revision 1.10  1995/03/27  08:34:24  quinn
 119  * Added dynamic server functionality.
 120  * Released bindings to session.c (is now redundant)
 121  *
 122  * Revision 1.9  1995/03/22  15:01:26  quinn
 123  * Adjusting record packing.
 124  *
 125  * Revision 1.8  1995/03/22  10:13:21  quinn
 126  * Working on record packer
 127  *
 128  * Revision 1.7  1995/03/21  15:53:31  quinn
 129  * Little changes.
 130  *
 131  * Revision 1.6  1995/03/21  12:30:09  quinn
 132  * Beginning to add support for record packing.
 133  *
 134  * Revision 1.5  1995/03/17  10:44:13  quinn
 135  * Added catch of null-string in makediagrec
 136  *
 137  * Revision 1.4  1995/03/17  10:18:08  quinn
 138  * Added memory management.
 139  *
 140  * Revision 1.3  1995/03/16  17:42:39  quinn
 141  * Little changes
 142  *
 143  * Revision 1.2  1995/03/16  13:29:01  quinn
 144  * Partitioned server.
 145  *
 146  * Revision 1.1  1995/03/15  16:02:10  quinn
 147  * Modded session.c to seshigh.c
 148  *
 149  */
 150
 151 /*
 152  * Frontend server logic.
 153  *
 154  * This code receives incoming APDUs, and handles client requests by means
 155  * of the backend API.
 156  *
 157  * Some of the code is getting quite involved, compared to simpler servers -
 158  * primarily because it is asynchronous both in the communication with
 159  * the user and the backend. We think the complexity will pay off in
 160  * the form of greater flexibility when more asynchronous facilities
 161  * are implemented.
 162  *
 163  * Memory management has become somewhat involved. In the simple case, where
 164  * only one PDU is pending at a time, it will simply reuse the same memory,
 165  * once it has found its working size. When we enable multiple concurrent
 166  * operations, perhaps even with multiple parallel calls to the backend, it
 167  * will maintain a pool of buffers for encoding and decoding, trying to
 168  * minimize memory allocation/deallocation during normal operation.
 169  *
 170  * TODOs include (and will be done in order of public interest):
 171  *
 172  * Support for EXPLAIN - provide simple meta-database system.
 173  * Support for access control.
 174  * Support for resource control.
 175  * Support for extended services - primarily Item Order.
 176  * Rest of Z39.50-1994
 177  *
 178  */
 179
 180 #include <stdlib.h>
 181 #include <stdio.h>
 182 #include <unistd.h>
 183 #include <assert.h>
 184 #include <sys/time.h>
 185
 186 #include <dmalloc.h>
 187 #include <comstack.h>
 188 #include <eventl.h>
 189 #include <session.h>
 190 #include <proto.h>
 191 #include <oid.h>
 192 #include <log.h>
 193 #include <statserv.h>
 194
 195 #include <backend.h>
 196
 197 static int process_request(association *assoc);
 198 void backend_response(IOCHAN i, int event);
 199 static int process_response(association *assoc, request *req, Z_APDU *res);
 200 static Z_APDU *process_initRequest(association *assoc, request *reqb);
 201 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 202     int *fd);
 203 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 204     bend_searchresult *bsrt, int *fd);
 205 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 206     int *fd);
 207 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd);
 208
 209 static FILE *apduf = 0; /* for use in static mode */
 210 static statserv_options_block *control_block = 0;
 211
 212 /*
 213  * Create and initialize a new association-handle.
 214  *  channel  : iochannel for the current line.
 215  *  link     : communications channel.
 216  * Returns: 0 or a new association handle.
 217  */
 218 association *create_association(IOCHAN channel, COMSTACK link)
 219 {
 220     association *new;
 221
 222     if (!control_block)
 223         control_block = statserv_getcontrol();
 224     if (!(new = malloc(sizeof(*new))))
 225         return 0;
 226     new->client_chan = channel;
 227     new->client_link = link;
 228     if (!(new->decode = odr_createmem(ODR_DECODE)) ||
 229         !(new->encode = odr_createmem(ODR_ENCODE)))
 230         return 0;
 231     if (*control_block->apdufile)
 232     {
 233         char filename[256];
 234         FILE *f;
 235
 236         strcpy(filename, control_block->apdufile);
 237         if (!(new->print = odr_createmem(ODR_PRINT)))
 238             return 0;
 239         if (*control_block->apdufile != '-')
 240         {
 241             strcpy(filename, control_block->apdufile);
 242             if (!control_block->dynamic)
 243             {
 244                 if (!apduf)
 245                 {
 246                     if (!(apduf = fopen(filename, "w")))
 247                     {
 248                         logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 249                         return 0;
 250                     }
 251                     setvbuf(apduf, 0, _IONBF, 0);
 252                 }
 253                 f = apduf;
 254             }
 255             else
 256             {
 257                 sprintf(filename + strlen(filename), ".%d", getpid());
 258                 if (!(f = fopen(filename, "w")))
 259                 {
 260                     logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 261                     return 0;
 262                 }
 263                 setvbuf(f, 0, _IONBF, 0);
 264             }
 265             odr_setprint(new->print, f);
 266         }
 267     }
 268     else
 269         new->print = 0;
 270     new->input_buffer = 0;
 271     new->input_buffer_len = 0;
 272     new->backend = 0;
 273     new->state = ASSOC_NEW;
 274     request_initq(&new->incoming);
 275     request_initq(&new->outgoing);
 276     new->proto = cs_getproto(link);
 277     return new;
 278 }
 279
 280 /*
 281  * Free association and release resources.
 282  */
 283 void destroy_association(association *h)
 284 {
 285     odr_destroy(h->decode);
 286     odr_destroy(h->encode);
 287     if (h->print)
 288         odr_destroy(h->print);
 289     if (h->input_buffer)
 290         free(h->input_buffer);
 291     if (h->backend)
 292         bend_close(h->backend);
 293     while (request_deq(&h->incoming));
 294     while (request_deq(&h->outgoing));
 295     free(h);
 296 }
 297
 298 static void do_close(association *a, int reason, char *message)
 299 {
 300     Z_APDU apdu;
 301     Z_Close *cls = zget_Close(a->encode);
 302     request *req = request_get();
 303
 304     /* Purge request queue */
 305     while (request_deq(&a->incoming));
 306     while (request_deq(&a->outgoing));
 307     if (a->version >= 3)
 308     {
 309         logf(LOG_DEBUG, "Generating Close PDU");
 310         apdu.which = Z_APDU_close;
 311         apdu.u.close = cls;
 312         *cls->closeReason = reason;
 313         cls->diagnosticInformation = message;
 314         process_response(a, req, &apdu);
 315         iochan_settimeout(a->client_chan, 60);
 316     }
 317     else
 318     {
 319         logf(LOG_DEBUG, "v2 client. No Close PDU");
 320         iochan_setevent(a->client_chan, EVENT_TIMEOUT); /* force imm close */
 321     }
 322     a->state = ASSOC_DEAD;
 323 }
 324
 325 /*
 326  * This is where PDUs from the client are read and the further
 327  * processing is initiated. Flow of control moves down through the
 328  * various process_* functions below, until the encoded result comes back up
 329  * to the output handler in here.
 330  *
 331  *  h     : the I/O channel that has an outstanding event.
 332  *  event : the current outstanding event.
 333  */
 334 void ir_session(IOCHAN h, int event)
 335 {
 336     int res;
 337     association *assoc = iochan_getdata(h);
 338     COMSTACK conn = assoc->client_link;
 339     request *req;
 340
 341     assert(h && conn && assoc);
 342     if (event == EVENT_TIMEOUT)
 343     {
 344         if (assoc->state != ASSOC_UP)
 345         {
 346             logf(LOG_LOG, "Final timeout - closing connection.");
 347             cs_close(conn);
 348             destroy_association(assoc);
 349             iochan_destroy(h);
 350         }
 351         else
 352         {
 353             logf(LOG_LOG, "Session idle too long. Sending close.");
 354             do_close(assoc, Z_Close_lackOfActivity, 0);
 355         }
 356         return;
 357     }
 358     if (event & EVENT_INPUT || event & EVENT_WORK) /* input */
 359     {
 360         if (event & EVENT_INPUT)
 361         {
 362             logf(LOG_DEBUG, "ir_session (input)");
 363             assert(assoc && conn);
 364             /* We aren't speaking to this fellow */
 365             if (assoc->state == ASSOC_DEAD)
 366             {
 367                 logf(LOG_LOG, "Closed connection after reject");
 368                 cs_close(conn);
 369                 destroy_association(assoc);
 370                 iochan_destroy(h);
 371                 return;
 372             }
 373             if ((res = cs_get(conn, &assoc->input_buffer,
 374                 &assoc->input_buffer_len)) <= 0)
 375             {
 376                 logf(LOG_LOG, "Connection closed by client");
 377                 cs_close(conn);
 378                 destroy_association(assoc);
 379                 iochan_destroy(h);
 380                 return;
 381             }
 382             else if (res == 1) /* incomplete read - wait for more  */
 383                 return;
 384             if (cs_more(conn)) /* more stuff - call us again later, please */
 385                 iochan_setevent(h, EVENT_INPUT);
 386
 387             /* we got a complete PDU. Let's decode it */
 388             logf(LOG_DEBUG, "Got PDU, %d bytes", res);
 389             req = request_get(); /* get a new request structure */
 390             odr_reset(assoc->decode);
 391             odr_setbuf(assoc->decode, assoc->input_buffer, res, 0);
 392             if (!z_APDU(assoc->decode, &req->request, 0))
 393             {
 394                 logf(LOG_LOG, "ODR error on incoming PDU: %s",
 395                     odr_errlist[odr_geterror(assoc->decode)]);
 396                 logf(LOG_LOG, "PDU dump:");
 397                 odr_dumpBER(log_file(), assoc->input_buffer, res);
 398                 do_close(assoc, Z_Close_protocolError, "Malformed package");
 399                 return;
 400             }
 401             req->request_mem = odr_extract_mem(assoc->decode);
 402             if (assoc->print && !z_APDU(assoc->print, &req->request, 0))
 403             {
 404                 logf(LOG_WARN, "ODR print error: %s",
 405                     odr_errlist[odr_geterror(assoc->print)]);
 406                 odr_reset(assoc->print);
 407             }
 408             request_enq(&assoc->incoming, req);
 409         }
 410
 411         /* can we do something yet? */
 412         req = request_head(&assoc->incoming);
 413         if (req->state == REQUEST_IDLE)
 414             if (process_request(assoc) < 0)
 415                 do_close(assoc, Z_Close_systemProblem, "Unknown error");
 416     }
 417     if (event & EVENT_OUTPUT)
 418     {
 419         request *req = request_head(&assoc->outgoing);
 420
 421         logf(LOG_DEBUG, "ir_session (output)");
 422         req->state = REQUEST_PENDING;
 423         switch (res = cs_put(conn, req->response, req->len_response))
 424         {
 425             case -1:
 426                 logf(LOG_LOG, "Connection closed by client");
 427                 cs_close(conn);
 428                 destroy_association(assoc);
 429                 iochan_destroy(h);
 430                 break;
 431             case 0: /* all sent - release the request structure */
 432                 logf(LOG_DEBUG, "Wrote PDU, %d bytes", req->len_response);
 433                 odr_release_mem(req->request_mem);
 434                 request_deq(&assoc->outgoing);
 435                 request_release(req);
 436                 if (!request_head(&assoc->outgoing))
 437                     iochan_clearflag(h, EVENT_OUTPUT);
 438                 break;
 439             /* value of 1 -- partial send -- is simply ignored */
 440         }
 441     }
 442     if (event & EVENT_EXCEPT)
 443     {
 444         logf(LOG_DEBUG, "ir_session (exception)");
 445         cs_close(conn);
 446         destroy_association(assoc);
 447         iochan_destroy(h);
 448     }
 449 }
 450
 451 /*
 452  * Initiate request processing.
 453  */
 454 static int process_request(association *assoc)
 455 {
 456     request *req = request_head(&assoc->incoming);
 457     int fd = -1;
 458     Z_APDU *res;
 459
 460     logf(LOG_DEBUG, "process_request");
 461     assert(req && req->state == REQUEST_IDLE);
 462     switch (req->request->which)
 463     {
 464         case Z_APDU_initRequest:
 465             res = process_initRequest(assoc, req); break;
 466         case Z_APDU_searchRequest:
 467             res = process_searchRequest(assoc, req, &fd); break;
 468         case Z_APDU_presentRequest:
 469             res = process_presentRequest(assoc, req, &fd); break;
 470         case Z_APDU_scanRequest:
 471             res = process_scanRequest(assoc, req, &fd); break;
 472         default:
 473             logf(LOG_WARN, "Bad APDU received");
 474             return -1;
 475     }
 476     if (res)
 477     {
 478         logf(LOG_DEBUG, "  result immediately available");
 479         return process_response(assoc, req, res);
 480     }
 481     else if (fd < 0)
 482     {
 483         logf(LOG_WARN, "   bad result");
 484         return -1;
 485     }
 486     else /* no result yet - one will be provided later */
 487     {
 488         IOCHAN chan;
 489
 490         /* Set up an I/O handler for the fd supplied by the backend */
 491
 492         logf(LOG_DEBUG, "   establishing handler for result");
 493         req->state = REQUEST_PENDING;
 494         if (!(chan = iochan_create(fd, backend_response, EVENT_INPUT)))
 495             abort();
 496         iochan_setdata(chan, assoc);
 497         return 0;
 498     }
 499 }
 500
 501 /*
 502  * Handle message from the backend.
 503  */
 504 void backend_response(IOCHAN i, int event)
 505 {
 506     association *assoc = iochan_getdata(i);
 507     request *req = request_head(&assoc->incoming);
 508     Z_APDU *res;
 509     int fd;
 510
 511     logf(LOG_DEBUG, "backend_response");
 512     assert(assoc && req && req->state != REQUEST_IDLE);
 513     /* determine what it is we're waiting for */
 514     switch (req->request->which)
 515     {
 516         case Z_APDU_searchRequest:
 517             res = response_searchRequest(assoc, req, 0, &fd); break;
 518 #if 0
 519         case Z_APDU_presentRequest:
 520             res = response_presentRequest(assoc, req, 0, &fd); break;
 521         case Z_APDU_scanRequest:
 522             res = response_scanRequest(assoc, req, 0, &fd); break;
 523 #endif
 524         default:
 525             logf(LOG_WARN, "Serious programmer's lapse or bug");
 526             abort();
 527     }
 528     if ((res && process_response(assoc, req, res) < 0) || fd < 0)
 529     {
 530         logf(LOG_LOG, "Fatal error when talking to backend");
 531         do_close(assoc, Z_Close_systemProblem, 0);
 532         iochan_destroy(i);
 533         return;
 534     }
 535     else if (!res) /* no result yet - try again later */
 536     {
 537         logf(LOG_DEBUG, "   no result yet");
 538         iochan_setfd(i, fd); /* in case fd has changed */
 539     }
 540 }
 541
 542 /*
 543  * Encode response, and transfer the request structure to the outgoing queue.
 544  */
 545 static int process_response(association *assoc, request *req, Z_APDU *res)
 546 {
 547     odr_setbuf(assoc->encode, req->response, req->size_response, 1);
 548     if (!z_APDU(assoc->encode, &res, 0))
 549     {
 550         logf(LOG_WARN, "ODR error when encoding response: %s",
 551             odr_errlist[odr_geterror(assoc->decode)]);
 552         return -1;
 553     }
 554     req->response = odr_getbuf(assoc->encode, &req->len_response,
 555         &req->size_response);
 556     odr_setbuf(assoc->encode, 0, 0, 0); /* don't free if we abort later */
 557     odr_reset(assoc->encode);
 558     if (assoc->print && !z_APDU(assoc->print, &res, 0))
 559     {
 560         logf(LOG_WARN, "ODR print error: %s",
 561             odr_errlist[odr_geterror(assoc->print)]);
 562         odr_reset(assoc->print);
 563     }
 564     /* change this when we make the backend reentrant */
 565     if (req == request_head(&assoc->incoming))
 566     {
 567         req->state = REQUEST_IDLE;
 568         request_deq(&assoc->incoming);
 569     }
 570     request_enq(&assoc->outgoing, req);
 571     /* turn the work over to the ir_session handler */
 572     iochan_setflag(assoc->client_chan, EVENT_OUTPUT);
 573     /* Is there more work to be done? give that to the input handler too */
 574     if (request_head(&assoc->incoming))
 575         iochan_setevent(assoc->client_chan, EVENT_WORK);
 576     return 0;
 577 }
 578
 579 /*
 580  * Handle init request.
 581  * At the moment, we don't check the protocol version or the options
 582  * anywhere else in the code - we just try not to do anything that would
 583  * break a naive client. We'll toss 'em into the association block when
 584  * we need them there.
 585  */
 586 static Z_APDU *process_initRequest(association *assoc, request *reqb)
 587 {
 588     Z_InitRequest *req = reqb->request->u.initRequest;
 589     Z_APDU *apdu = zget_APDU(assoc->encode, Z_APDU_initResponse);
 590     Z_InitResponse *resp = apdu->u.initResponse;
 591     bend_initrequest binitreq;
 592     bend_initresult *binitres;
 593     char options[100];
 594
 595     logf(LOG_LOG, "Got initRequest");
 596     if (req->implementationId)
 597         logf(LOG_LOG, "Id:        %s", req->implementationId);
 598     if (req->implementationName)
 599         logf(LOG_LOG, "Name:      %s", req->implementationName);
 600     if (req->implementationVersion)
 601         logf(LOG_LOG, "Version:   %s", req->implementationVersion);
 602
 603     binitreq.configname = "default-config";
 604     binitreq.auth = req->idAuthentication;
 605     if (!(binitres = bend_init(&binitreq)))
 606     {
 607         logf(LOG_WARN, "Bad response from backend.");
 608         return 0;
 609     }
 610
 611     assoc->backend = binitres->handle;
 612     resp->referenceId = req->referenceId;
 613     *options = '\0';
 614     /* let's tell the client what we can do */
 615     if (ODR_MASK_GET(req->options, Z_Options_search))
 616     {
 617         ODR_MASK_SET(resp->options, Z_Options_search);
 618         strcat(options, "srch");
 619     }
 620     if (ODR_MASK_GET(req->options, Z_Options_present))
 621     {
 622         ODR_MASK_SET(resp->options, Z_Options_present);
 623         strcat(options, " prst");
 624     }
 625 #if 0
 626     if (ODR_MASK_GET(req->options, Z_Options_delSet))
 627     {
 628         ODR_MASK_SET(&options, Z_Options_delSet);
 629         strcat(options, " del");
 630     }
 631 #endif
 632     if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 633     {
 634         ODR_MASK_SET(resp->options, Z_Options_namedResultSets);
 635         strcat(options, " namedresults");
 636     }
 637     if (ODR_MASK_GET(req->options, Z_Options_scan))
 638     {
 639         ODR_MASK_SET(resp->options, Z_Options_scan);
 640         strcat(options, " scan");
 641     }
 642     if (ODR_MASK_GET(req->options, Z_Options_concurrentOperations))
 643     {
 644         ODR_MASK_SET(resp->options, Z_Options_concurrentOperations);
 645         strcat(options, " concurop");
 646     }
 647
 648     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_1))
 649     {
 650         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_1);
 651         assoc->version = 2; /* 1 & 2 are equivalent */
 652     }
 653     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_2))
 654     {
 655         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_2);
 656         assoc->version = 2;
 657     }
 658     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_3))
 659     {
 660         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_3);
 661         assoc->version = 3;
 662     }
 663     logf(LOG_LOG, "Negotiated to v%d: %s", assoc->version, options);
 664     assoc->maximumRecordSize = *req->maximumRecordSize;
 665     if (assoc->maximumRecordSize > control_block->maxrecordsize)
 666         assoc->maximumRecordSize = control_block->maxrecordsize;
 667     assoc->preferredMessageSize = *req->preferredMessageSize;
 668     if (assoc->preferredMessageSize > assoc->maximumRecordSize)
 669         assoc->preferredMessageSize = assoc->maximumRecordSize;
 670     resp->preferredMessageSize = &assoc->preferredMessageSize;
 671     resp->maximumRecordSize = &assoc->maximumRecordSize;
 672     resp->implementationName = "Index Data/YAZ Generic Frontend Server";
 673     if (binitres->errcode)
 674     {
 675         logf(LOG_LOG, "Connection rejected by backend.");
 676         *resp->result = 0;
 677         assoc->state = ASSOC_DEAD;
 678     }
 679     else
 680         assoc->state = ASSOC_UP;
 681     return apdu;
 682 }
 683
 684 /*
 685  * These functions should be merged.
 686  */
 687
 688 /*
 689  * nonsurrogate diagnostic record.
 690  */
 691 static Z_Records *diagrec(oid_proto proto, int error, char *addinfo)
 692 {
 693     static Z_Records rec;
 694     oident bib1;
 695     static int err;
 696 #ifdef Z_95
 697     static Z_DiagRec drec;
 698     static Z_DefaultDiagFormat dr;
 699 #else
 700     static Z_DiagRec dr;
 701 #endif
 702
 703     bib1.proto = proto;
 704     bib1.class = CLASS_DIAGSET;
 705     bib1.value = VAL_BIB1;
 706
 707     logf(LOG_DEBUG, "Diagnostic: %d -- %s", error, addinfo ? addinfo :
 708         "NULL");
 709     err = error;
 710     rec.which = Z_Records_NSD;
 711 #ifdef Z_95
 712     rec.u.nonSurrogateDiagnostic = &drec;
 713     drec.which = Z_DiagRec_defaultFormat;
 714     drec.u.defaultFormat = &dr;
 715 #else
 716     rec.u.nonSurrogateDiagnostic = &dr;
 717 #endif
 718     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 719     dr.condition = &err;
 720     dr.which = Z_DiagForm_v2AddInfo;
 721     dr.addinfo = addinfo ? addinfo : "";
 722     return &rec;
 723 }
 724
 725 /*
 726  * surrogate diagnostic.
 727  */
 728 static Z_NamePlusRecord *surrogatediagrec(oid_proto proto, char *dbname,
 729                                             int error, char *addinfo)
 730 {
 731     static Z_NamePlusRecord rec;
 732     static int err;
 733     oident bib1;
 734 #ifdef Z_95
 735     static Z_DiagRec drec;
 736     static Z_DefaultDiagFormat dr;
 737 #else
 738     static Z_DiagRec dr;
 739 #endif
 740
 741     bib1.proto = proto;
 742     bib1.class = CLASS_DIAGSET;
 743     bib1.value = VAL_BIB1;
 744
 745     logf(LOG_DEBUG, "SurrogateDiagnotic: %d -- %s", error, addinfo);
 746     err = error;
 747     rec.databaseName = dbname;
 748     rec.which = Z_NamePlusRecord_surrogateDiagnostic;
 749 #ifdef Z_95
 750     rec.u.surrogateDiagnostic = &drec;
 751     drec.which = Z_DiagRec_defaultFormat;
 752     drec.u.defaultFormat = &dr;
 753 #else
 754     rec.u.surrogateDiagnostic = &dr;
 755 #endif
 756     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 757     dr.condition = &err;
 758     dr.which = Z_DiagForm_v2AddInfo;
 759     dr.addinfo = addinfo ? addinfo : "";
 760     return &rec;
 761 }
 762
 763 /*
 764  * multiple nonsurrogate diagnostics.
 765  */
 766 static Z_DiagRecs *diagrecs(oid_proto proto, int error, char *addinfo)
 767 {
 768     static Z_DiagRecs recs;
 769     static int err;
 770     oident bib1;
 771 #ifdef Z_95
 772     static Z_DiagRec *recp[1], drec;
 773     static Z_DefaultDiagFormat rec;
 774 #else
 775     static Z_DiagRec *recp[1], rec;
 776 #endif
 777
 778     logf(LOG_DEBUG, "DiagRecs: %d -- %s", error, addinfo);
 779     bib1.proto = proto;
 780     bib1.class = CLASS_DIAGSET;
 781     bib1.value = VAL_BIB1;
 782
 783     err = error;
 784     recs.num_diagRecs = 1;
 785     recs.diagRecs = recp;
 786 #ifdef Z_95
 787     recp[0] = &drec;
 788     drec.which = Z_DiagRec_defaultFormat;
 789     drec.u.defaultFormat = &rec;
 790 #else
 791     recp[0] = &rec;
 792 #endif
 793     rec.diagnosticSetId = oid_getoidbyent(&bib1);
 794     rec.condition = &err;
 795     rec.which = Z_DiagForm_v2AddInfo;
 796     rec.addinfo = addinfo ? addinfo : "";
 797     return &recs;
 798 }
 799
 800 #define MAX_RECORDS 256
 801
 802 static Z_Records *pack_records(association *a, char *setname, int start,
 803                                 int *num, Z_ElementSetNames *esn,
 804                                 int *next, int *pres, oid_value format)
 805 {
 806     int recno, total_length = 0, toget = *num;
 807     static Z_Records records;
 808     static Z_NamePlusRecordList reclist;
 809     static Z_NamePlusRecord *list[MAX_RECORDS];
 810     oident recform;
 811
 812     records.which = Z_Records_DBOSD;
 813     records.u.databaseOrSurDiagnostics = &reclist;
 814     reclist.num_records = 0;
 815     reclist.records = list;
 816     *pres = Z_PRES_SUCCESS;
 817     *num = 0;
 818     *next = 0;
 819
 820     logf(LOG_DEBUG, "Request to pack %d+%d", start, toget);
 821     logf(LOG_DEBUG, "pms=%d, mrs=%d", a->preferredMessageSize,
 822         a->maximumRecordSize);
 823     for (recno = start; reclist.num_records < toget; recno++)
 824     {
 825         bend_fetchrequest freq;
 826         bend_fetchresult *fres;
 827         Z_NamePlusRecord *thisrec;
 828         Z_DatabaseRecord *thisext;
 829         int this_length;
 830
 831         /*
 832          * we get the number of bytes allocated on the stream before any
 833          * allocation done by the backend - this should give us a reasonable
 834          * idea of the total size of the data so far.
 835          */
 836         total_length = odr_total(a->encode);
 837         if (reclist.num_records == MAX_RECORDS - 1)
 838         {
 839             *pres = Z_PRES_PARTIAL_2;
 840             break;
 841         }
 842         freq.setname = setname;
 843         freq.number = recno;
 844         freq.format = format;
 845         freq.stream = a->encode;
 846         if (!(fres = bend_fetch(a->backend, &freq, 0)))
 847         {
 848             *pres = Z_PRES_FAILURE;
 849             return diagrec(a->proto, 2, "Backend interface problem");
 850         }
 851         /* backend should be able to signal whether error is system-wide
 852            or only pertaining to current record */
 853         if (fres->errcode)
 854         {
 855             *pres = Z_PRES_FAILURE;
 856             return diagrec(a->proto, fres->errcode, fres->errstring);
 857         }
 858         if (fres->len >= 0)
 859             this_length = fres->len;
 860         else
 861             this_length = odr_total(a->encode) - total_length;
 862         logf(LOG_DEBUG, "  fetched record, len=%d, total=%d",
 863             this_length, total_length);
 864         if (this_length + total_length > a->preferredMessageSize)
 865         {
 866             /* record is small enough, really */
 867             if (this_length <= a->preferredMessageSize)
 868             {
 869                 logf(LOG_DEBUG, "  Dropped last normal-sized record");
 870                 *pres = Z_PRES_PARTIAL_2;
 871                 break;
 872             }
 873             /* record can only be fetched by itself */
 874             if (this_length < a->maximumRecordSize)
 875             {
 876                 logf(LOG_DEBUG, "  Record > prefmsgsz");
 877                 if (toget > 1)
 878                 {
 879                     logf(LOG_DEBUG, "  Dropped it");
 880                     reclist.records[reclist.num_records] =
 881                          surrogatediagrec(a->proto, fres->basename, 16, 0);
 882                     reclist.num_records++;
 883                     continue;
 884                 }
 885             }
 886             else /* too big entirely */
 887             {
 888                 logf(LOG_DEBUG, "Record > maxrcdsz");
 889                 reclist.records[reclist.num_records] =
 890                     surrogatediagrec(a->proto, fres->basename, 17, 0);
 891                 reclist.num_records++;
 892                 continue;
 893             }
 894         }
 895         if (!(thisrec = odr_malloc(a->encode, sizeof(*thisrec))))
 896             return 0;
 897         if (!(thisrec->databaseName = odr_malloc(a->encode,
 898             strlen(fres->basename) + 1)))
 899             return 0;
 900         strcpy(thisrec->databaseName, fres->basename);
 901         thisrec->which = Z_NamePlusRecord_databaseRecord;
 902         if (!(thisrec->u.databaseRecord = thisext = odr_malloc(a->encode,
 903             sizeof(Z_DatabaseRecord))))
 904             return 0;
 905         recform.proto = a->proto;
 906         recform.class = CLASS_RECSYN;
 907         recform.value = fres->format;
 908         thisext->direct_reference = odr_oiddup(a->encode,
 909             oid_getoidbyent(&recform));
 910         thisext->indirect_reference = 0;
 911         thisext->descriptor = 0;
 912         if (fres->len < 0) /* Structured data */
 913         {
 914             switch (fres->format)
 915             {
 916                 case VAL_SUTRS: thisext->which = Z_External_sutrs; break;
 917                 case VAL_GRS1: thisext->which = Z_External_grs1; break;
 918                 case VAL_EXPLAIN: thisext->which = Z_External_explainRecord;
 919                     break;
 920
 921                 default:
 922                     logf(LOG_FATAL, "Unknown structured format from backend.");
 923                     return 0;
 924             }
 925
 926             /*
 927              * We cheat on the pointers here. Obviously, the record field
 928              * of the backend-fetch structure should have been a union for
 929              * correctness, but we're stuck with this for backwards
 930              * compatibility.
 931              */
 932             thisext->u.grs1 = (Z_GenericRecord*) fres->record;
 933         }
 934         else if (fres->format == VAL_SUTRS) /* SUTRS is a single-ASN.1-type */
 935         {
 936             Odr_oct *sutrs = odr_malloc(a->encode, sizeof(*sutrs));
 937
 938             thisext->which = Z_External_sutrs;
 939             thisext->u.sutrs = sutrs;
 940             sutrs->buf = odr_malloc(a->encode, fres->len);
 941             sutrs->len = sutrs->size = fres->len;
 942             memcpy(sutrs->buf, fres->record, fres->len);
 943         }
 944         else /* octet-aligned record. */
 945         {
 946             thisext->which = Z_External_octet;
 947             if (!(thisext->u.octet_aligned = odr_malloc(a->encode,
 948                 sizeof(Odr_oct))))
 949                 return 0;
 950             if (!(thisext->u.octet_aligned->buf = odr_malloc(a->encode,
 951                 fres->len)))
 952                 return 0;
 953             memcpy(thisext->u.octet_aligned->buf, fres->record, fres->len);
 954             thisext->u.octet_aligned->len = thisext->u.octet_aligned->size =
 955                 fres->len;
 956         }
 957         reclist.records[reclist.num_records] = thisrec;
 958         reclist.num_records++;
 959         *next = fres->last_in_set ? 0 : recno + 1;
 960     }
 961     *num = reclist.num_records;
 962     return &records;
 963 }
 964
 965 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 966     int *fd)
 967 {
 968     Z_SearchRequest *req = reqb->request->u.searchRequest;
 969     bend_searchrequest bsrq;
 970     bend_searchresult *bsrt;
 971
 972     logf(LOG_LOG, "Got SearchRequest.");
 973
 974     bsrq.setname = req->resultSetName;
 975     bsrq.replace_set = *req->replaceIndicator;
 976     bsrq.num_bases = req->num_databaseNames;
 977     bsrq.basenames = req->databaseNames;
 978     bsrq.query = req->query;
 979
 980     if (!(bsrt = bend_search(assoc->backend, &bsrq, fd)))
 981         return 0;
 982     return response_searchRequest(assoc, reqb, bsrt, fd);
 983 }
 984
 985 bend_searchresult *bend_searchresponse(void *handle) {return 0;}
 986
 987 /*
 988  * Prepare a searchresponse based on the backend results. We probably want
 989  * to look at making the fetching of records nonblocking as well, but
 990  * so far, we'll keep things simple.
 991  * If bsrt is null, that means we're called in response to a communications
 992  * event, and we'll have to get the response for ourselves.
 993  */
 994 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 995     bend_searchresult *bsrt, int *fd)
 996 {
 997     Z_SearchRequest *req = reqb->request->u.searchRequest;
 998     static Z_APDU apdu;
 999     static Z_SearchResponse resp;
1000     static int nulint = 0;
1001     static bool_t sr = 1;
1002     static int next = 0;
1003     static int none = Z_RES_NONE;
1004
1005     apdu.which = Z_APDU_searchResponse;
1006     apdu.u.searchResponse = &resp;
1007     resp.referenceId = req->referenceId;
1008 #ifdef Z_95
1009     resp.additionalSearchInfo = 0;
1010     resp.otherInfo = 0;
1011 #endif
1012     *fd = -1;
1013     if (!bsrt && !(bsrt = bend_searchresponse(assoc->backend)))
1014     {
1015         logf(LOG_FATAL, "Bad result from backend");
1016         return 0;
1017     }
1018     else if (bsrt->errcode)
1019     {
1020         resp.records = diagrec(assoc->proto, bsrt->errcode,
1021             bsrt->errstring);
1022         resp.resultCount = &nulint;
1023         resp.numberOfRecordsReturned = &nulint;
1024         resp.nextResultSetPosition = &nulint;
1025         resp.searchStatus = &nulint;
1026         resp.resultSetStatus = &none;
1027         resp.presentStatus = 0;
1028     }
1029     else
1030     {
1031         static int toget;
1032         Z_ElementSetNames *setnames;
1033         static int presst = 0;
1034
1035         resp.records = 0;
1036         resp.resultCount = &bsrt->hits;
1037
1038         /* how many records does the user agent want, then? */
1039         if (bsrt->hits <= *req->smallSetUpperBound)
1040         {
1041             toget = bsrt->hits;
1042             setnames = req->smallSetElementSetNames;
1043         }
1044         else if (bsrt->hits < *req->largeSetLowerBound)
1045         {
1046             toget = *req->mediumSetPresentNumber;
1047             if (toget > bsrt->hits)
1048                 toget = bsrt->hits;
1049             setnames = req->mediumSetElementSetNames;
1050         }
1051         else
1052             toget = 0;
1053
1054         if (toget && !resp.records)
1055         {
1056             oident *prefformat;
1057             oid_value form;
1058
1059             if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
1060                 prefformat->class != CLASS_RECSYN)
1061                 form = VAL_NONE;
1062             else
1063                 form = prefformat->value;
1064             resp.records = pack_records(assoc, req->resultSetName, 1,
1065                 &toget, setnames, &next, &presst, form);
1066             if (!resp.records)
1067                 return 0;
1068             resp.numberOfRecordsReturned = &toget;
1069             resp.nextResultSetPosition = &next;
1070             resp.searchStatus = &sr;
1071             resp.resultSetStatus = 0;
1072             resp.presentStatus = &presst;
1073         }
1074         else
1075         {
1076             if (*resp.resultCount)
1077                 next = 1;
1078             resp.numberOfRecordsReturned = &nulint;
1079             resp.nextResultSetPosition = &next;
1080             resp.searchStatus = &sr;
1081             resp.resultSetStatus = 0;
1082             resp.presentStatus = 0;
1083         }
1084     }
1085     return &apdu;
1086 }
1087
1088 /*
1089  * Maybe we got a little over-friendly when we designed bend_fetch to
1090  * get only one record at a time. Some backends can optimise multiple-record
1091  * fetches, and at any rate, there is some overhead involved in
1092  * all that selecting and hopping around. Problem is, of course, that the
1093  * frontend can't know ahead of time how many records it'll need to
1094  * fill the negotiated PDU size. Annoying. Segmentation or not, Z/SR
1095  * is downright lousy as a bulk data transfer protocol.
1096  *
1097  * To start with, we'll do the fetching of records from the backend
1098  * in one operation: To save some trips in and out of the event-handler,
1099  * and to simplify the interface to pack_records. At any rate, asynch
1100  * operation is more fun in operations that have an unpredictable execution
1101  * speed - which is normally more true for search than for present.
1102  */
1103 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
1104     int *fd)
1105 {
1106     Z_PresentRequest *req = reqb->request->u.presentRequest;
1107     static Z_APDU apdu;
1108     static Z_PresentResponse resp;
1109     static int presst, next, num;
1110     oident *prefformat;
1111     oid_value form;
1112
1113
1114     logf(LOG_LOG, "Got PresentRequest.");
1115     apdu.which = Z_APDU_presentResponse;
1116     apdu.u.presentResponse = &resp;
1117     resp.referenceId = req->referenceId;
1118 #ifdef Z_95
1119     resp.otherInfo = 0;
1120 #endif
1121
1122     if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
1123         prefformat->class != CLASS_RECSYN)
1124         form = VAL_NONE;
1125     else
1126         form = prefformat->value;
1127     num = *req->numberOfRecordsRequested;
1128     resp.records = pack_records(assoc, req->resultSetId,
1129         *req->resultSetStartPoint, &num, 0, &next, &presst, form);
1130     if (!resp.records)
1131         return 0;
1132     resp.numberOfRecordsReturned = &num;
1133     resp.presentStatus = &presst;
1134     resp.nextResultSetPosition = &next;
1135
1136     return &apdu;
1137 }
1138
1139 /*
1140  * Scan was implemented rather in a hurry, and with support for only the basic
1141  * elements of the service in the backend API. Suggestions are welcome.
1142  */
1143 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd)
1144 {
1145     Z_ScanRequest *req = reqb->request->u.scanRequest;
1146     static Z_APDU apdu;
1147     static Z_ScanResponse res;
1148     static int scanStatus = Z_Scan_failure;
1149     static int numberOfEntriesReturned = 0;
1150     oident *attent;
1151     static Z_ListEntries ents;
1152 #define SCAN_MAX_ENTRIES 200
1153     static Z_Entry *tab[SCAN_MAX_ENTRIES];
1154     bend_scanrequest srq;
1155     bend_scanresult *srs;
1156
1157     logf(LOG_LOG, "Got scanrequest");
1158     apdu.which = Z_APDU_scanResponse;
1159     apdu.u.scanResponse = &res;
1160     res.referenceId = req->referenceId;
1161     res.stepSize = 0;
1162     res.scanStatus = &scanStatus;
1163     res.numberOfEntriesReturned = &numberOfEntriesReturned;
1164     res.positionOfTerm = 0;
1165     res.entries = &ents;
1166     ents.which = Z_ListEntries_nonSurrogateDiagnostics;
1167     res.attributeSet = 0;
1168 #ifdef Z_95
1169     res.otherInfo = 0;
1170 #endif
1171
1172     if (req->attributeSet && (!(attent = oid_getentbyoid(req->attributeSet)) ||
1173         attent->class != CLASS_ATTSET || attent->value != VAL_BIB1))
1174         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 121, 0);
1175     else if (req->stepSize && *req->stepSize > 0)
1176         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 205, 0);
1177     else
1178     {
1179         if (req->termListAndStartPoint->term->which == Z_Term_general)
1180             logf(LOG_DEBUG, " term: '%.*s'",
1181                 req->termListAndStartPoint->term->u.general->len,
1182                 req->termListAndStartPoint->term->u.general->buf);
1183         srq.num_bases = req->num_databaseNames;
1184         srq.basenames = req->databaseNames;
1185         srq.num_entries = *req->numberOfTermsRequested;
1186         srq.term = req->termListAndStartPoint;
1187         srq.term_position = req->preferredPositionInResponse ?
1188             *req->preferredPositionInResponse : 1;
1189         if (!(srs = bend_scan(assoc->backend, &srq, 0)))
1190             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 2, 0);
1191         else if (srs->errcode)
1192             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto,
1193                 srs->errcode, srs->errstring);
1194         else
1195         {
1196             int i;
1197             static Z_Entries list;
1198
1199             if (srs->status == BEND_SCAN_PARTIAL)
1200                 scanStatus = Z_Scan_partial_5;
1201             else
1202                 scanStatus = Z_Scan_success;
1203             ents.which = Z_ListEntries_entries;
1204             ents.u.entries = &list;
1205             list.entries = tab;
1206             for (i = 0; i < srs->num_entries; i++)
1207             {
1208                 Z_Entry *e;
1209                 Z_TermInfo *t;
1210                 Odr_oct *o;
1211
1212                 if (i >= SCAN_MAX_ENTRIES)
1213                 {
1214                     scanStatus = Z_Scan_partial_4;
1215                     break;
1216                 }
1217                 list.entries[i] = e = odr_malloc(assoc->encode, sizeof(*e));
1218                 e->which = Z_Entry_termInfo;
1219                 e->u.termInfo = t = odr_malloc(assoc->encode, sizeof(*t));
1220                 t->suggestedAttributes = 0;
1221                 t->alternativeTerm = 0;
1222                 t->byAttributes = 0;
1223                 t->globalOccurrences = &srs->entries[i].occurrences;
1224                 t->term = odr_malloc(assoc->encode, sizeof(*t->term));
1225                 t->term->which = Z_Term_general;
1226                 t->term->u.general = o = odr_malloc(assoc->encode,
1227                     sizeof(Odr_oct));
1228                 o->buf = odr_malloc(assoc->encode, o->len = o->size =
1229                     strlen(srs->entries[i].term));
1230                 memcpy(o->buf, srs->entries[i].term, o->len);
1231                 logf(LOG_DEBUG, "  term #%d: '%s' (%d)", i,
1232                     srs->entries[i].term, srs->entries[i].occurrences);
1233             }
1234             list.num_entries = i;
1235             res.numberOfEntriesReturned = &list.num_entries;
1236             res.positionOfTerm = &srs->term_position;
1237         }
1238     }
1239
1240     return &apdu;
1241 }