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