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