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