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