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