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 1.42  1995-08-15 11:16:50  quinn
   8  * CV:e ----------------------------------------------------------------------
   9  * CV:e ----------------------------------------------------------------------
  10  *
  11  * Revision 1.41  1995/08/02  10:23:06  quinn
  12  * Smallish
  13  *
  14  * Revision 1.40  1995/07/31  14:34:26  quinn
  15  * Fixed bug in process_searchResponse (numberOfRecordsReturned).
  16  *
  17  * Revision 1.39  1995/06/27  13:21:00  quinn
  18  * SUTRS support
  19  *
  20  * Revision 1.38  1995/06/19  12:39:11  quinn
  21  * Fixed bug in timeout code. Added BER dumper.
  22  *
  23  * Revision 1.37  1995/06/16  13:16:14  quinn
  24  * Fixed Defaultdiagformat.
  25  *
  26  * Revision 1.36  1995/06/16  10:31:36  quinn
  27  * Added session timeout.
  28  *
  29  * Revision 1.35  1995/06/15  07:45:14  quinn
  30  * Moving to v3.
  31  *
  32  * Revision 1.34  1995/06/14  15:26:46  quinn
  33  * *** empty log message ***
  34  *
  35  * Revision 1.33  1995/06/06  14:57:05  quinn
  36  * Better diagnostics.
  37  *
  38  * Revision 1.32  1995/06/06  08:41:44  quinn
  39  * Better diagnostics.
  40  *
  41  * Revision 1.31  1995/06/06  08:15:37  quinn
  42  * Cosmetic.
  43  *
  44  * Revision 1.30  1995/06/05  10:53:32  quinn
  45  * Added a better SCAN.
  46  *
  47  * Revision 1.29  1995/06/01  11:25:03  quinn
  48  * Smallish.
  49  *
  50  * Revision 1.28  1995/06/01  11:21:01  quinn
  51  * Attempting to fix a bug in pack-records. replaced break with continue
  52  * for large records, according to standard.
  53  *
  54  * Revision 1.27  1995/05/29  08:12:06  quinn
  55  * Moved oid to util
  56  *
  57  * Revision 1.26  1995/05/18  13:02:12  quinn
  58  * Smallish.
  59  *
  60  * Revision 1.25  1995/05/17  08:42:26  quinn
  61  * Transfer auth info to backend. Allow backend to reject init gracefully.
  62  *
  63  * Revision 1.24  1995/05/16  08:51:04  quinn
  64  * License, documentation, and memory fixes
  65  *
  66  * Revision 1.23  1995/05/15  13:25:10  quinn
  67  * Fixed memory bug.
  68  *
  69  * Revision 1.22  1995/05/15  11:56:39  quinn
  70  * Asynchronous facilities. Restructuring of seshigh code.
  71  *
  72  * Revision 1.21  1995/05/02  08:53:19  quinn
  73  * Trying in vain to fix comm with ISODE
  74  *
  75  * Revision 1.20  1995/04/20  15:13:00  quinn
  76  * Cosmetic
  77  *
  78  * Revision 1.19  1995/04/18  08:15:34  quinn
  79  * Added dynamic memory allocation on encoding (whew). Code is now somewhat
  80  * neater. We'll make the same change for decoding one day.
  81  *
  82  * Revision 1.18  1995/04/17  11:28:25  quinn
  83  * Smallish
  84  *
  85  * Revision 1.17  1995/04/10  10:23:36  quinn
  86  * Some work to add scan and other things.
  87  *
  88  * Revision 1.16  1995/03/31  09:18:55  quinn
  89  * Added logging.
  90  *
  91  * Revision 1.15  1995/03/30  14:03:23  quinn
  92  * Added RFC1006 as separate library
  93  *
  94  * Revision 1.14  1995/03/30  12:18:17  quinn
  95  * Fixed bug.
  96  *
  97  * Revision 1.13  1995/03/30  09:09:24  quinn
  98  * Added state-handle and some support for asynchronous activities.
  99  *
 100  * Revision 1.12  1995/03/29  15:40:16  quinn
 101  * Ongoing work. Statserv is now dynamic by default
 102  *
 103  * Revision 1.11  1995/03/28  09:16:21  quinn
 104  * Added record packing to the search request
 105  *
 106  * Revision 1.10  1995/03/27  08:34:24  quinn
 107  * Added dynamic server functionality.
 108  * Released bindings to session.c (is now redundant)
 109  *
 110  * Revision 1.9  1995/03/22  15:01:26  quinn
 111  * Adjusting record packing.
 112  *
 113  * Revision 1.8  1995/03/22  10:13:21  quinn
 114  * Working on record packer
 115  *
 116  * Revision 1.7  1995/03/21  15:53:31  quinn
 117  * Little changes.
 118  *
 119  * Revision 1.6  1995/03/21  12:30:09  quinn
 120  * Beginning to add support for record packing.
 121  *
 122  * Revision 1.5  1995/03/17  10:44:13  quinn
 123  * Added catch of null-string in makediagrec
 124  *
 125  * Revision 1.4  1995/03/17  10:18:08  quinn
 126  * Added memory management.
 127  *
 128  * Revision 1.3  1995/03/16  17:42:39  quinn
 129  * Little changes
 130  *
 131  * Revision 1.2  1995/03/16  13:29:01  quinn
 132  * Partitioned server.
 133  *
 134  * Revision 1.1  1995/03/15  16:02:10  quinn
 135  * Modded session.c to seshigh.c
 136  *
 137  */
 138
 139 /*
 140  * Frontend server logic.
 141  *
 142  * This code receives incoming APDUs, and handles client requests by means
 143  * of the backend API.
 144  *
 145  * Some of the code is getting quite involved, compared to simpler servers -
 146  * primarily because it is asynchronous both in the communication with
 147  * the user and the backend. We think the complexity will pay off in
 148  * the form of greater flexibility when more asynchronous facilities
 149  * are implemented.
 150  *
 151  * Memory management has become somewhat involved. In the simple case, where
 152  * only one PDU is pending at a time, it will simply reuse the same memory,
 153  * once it has found its working size. When we enable multiple concurrent
 154  * operations, perhaps even with multiple parallel calls to the backend, it
 155  * will maintain a pool of buffers for encoding and decoding, trying to
 156  * minimize memory allocation/deallocation during normal operation.
 157  *
 158  * TODOs include (and will be done in order of public interest):
 159  *
 160  * Support for EXPLAIN - provide simple meta-database system.
 161  * Support for access control.
 162  * Support for resource control.
 163  * Support for extended services - primarily Item Order.
 164  * Rest of Z39.50-1994
 165  *
 166  */
 167
 168 #include <stdlib.h>
 169 #include <stdio.h>
 170 #include <unistd.h>
 171 #include <assert.h>
 172
 173 #include <dmalloc.h>
 174 #include <comstack.h>
 175 #include <eventl.h>
 176 #include <session.h>
 177 #include <proto.h>
 178 #include <oid.h>
 179 #include <log.h>
 180 #include <statserv.h>
 181
 182 #include <backend.h>
 183
 184 static int process_request(association *assoc);
 185 void backend_response(IOCHAN i, int event);
 186 static int process_response(association *assoc, request *req, Z_APDU *res);
 187 static Z_APDU *process_initRequest(association *assoc, request *reqb);
 188 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 189     int *fd);
 190 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 191     bend_searchresult *bsrt, int *fd);
 192 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 193     int *fd);
 194 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd);
 195
 196 static FILE *apduf = 0; /* for use in static mode */
 197 static statserv_options_block *control_block = 0;
 198
 199 /*
 200  * Create and initialize a new association-handle.
 201  *  channel  : iochannel for the current line.
 202  *  link     : communications channel.
 203  * Returns: 0 or a new association handle.
 204  */
 205 association *create_association(IOCHAN channel, COMSTACK link)
 206 {
 207     association *new;
 208
 209     if (!control_block)
 210         control_block = statserv_getcontrol();
 211     if (!(new = malloc(sizeof(*new))))
 212         return 0;
 213     new->client_chan = channel;
 214     new->client_link = link;
 215     if (!(new->decode = odr_createmem(ODR_DECODE)) ||
 216         !(new->encode = odr_createmem(ODR_ENCODE)))
 217         return 0;
 218     if (*control_block->apdufile)
 219     {
 220         char filename[256];
 221         FILE *f;
 222
 223         strcpy(filename, control_block->apdufile);
 224         if (!(new->print = odr_createmem(ODR_PRINT)))
 225             return 0;
 226         if (*control_block->apdufile != '-')
 227         {
 228             strcpy(filename, control_block->apdufile);
 229             if (!control_block->dynamic)
 230             {
 231                 if (!apduf)
 232                 {
 233                     if (!(apduf = fopen(filename, "w")))
 234                     {
 235                         logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 236                         return 0;
 237                     }
 238                     setvbuf(apduf, 0, _IONBF, 0);
 239                 }
 240                 f = apduf;
 241             }
 242             else
 243             {
 244                 sprintf(filename + strlen(filename), ".%d", getpid());
 245                 if (!(f = fopen(filename, "w")))
 246                 {
 247                     logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 248                     return 0;
 249                 }
 250                 setvbuf(f, 0, _IONBF, 0);
 251             }
 252             odr_setprint(new->print, f);
 253         }
 254     }
 255     else
 256         new->print = 0;
 257     new->input_buffer = 0;
 258     new->input_buffer_len = 0;
 259     new->backend = 0;
 260     new->rejected = 0;
 261     request_initq(&new->incoming);
 262     request_initq(&new->outgoing);
 263     new->proto = cs_getproto(link);
 264     return new;
 265 }
 266
 267 /*
 268  * Free association and release resources.
 269  */
 270 void destroy_association(association *h)
 271 {
 272     odr_destroy(h->decode);
 273     odr_destroy(h->encode);
 274     if (h->print)
 275         odr_destroy(h->print);
 276     if (h->input_buffer)
 277         free(h->input_buffer);
 278     if (h->backend)
 279         bend_close(h->backend);
 280     while (request_deq(&h->incoming));
 281     while (request_deq(&h->outgoing));
 282     free(h);
 283 }
 284
 285 /*
 286  * This is where PDUs from the client are read and the further
 287  * processing is initiated. Flow of control moves down through the
 288  * various process_* functions below, until the encoded result comes back up
 289  * to the output handler in here.
 290  *
 291  *  h     : the I/O channel that has an outstanding event.
 292  *  event : the current outstanding event.
 293  */
 294 void ir_session(IOCHAN h, int event)
 295 {
 296     int res;
 297     association *assoc = iochan_getdata(h);
 298     COMSTACK conn = assoc->client_link;
 299     request *req;
 300
 301     assert(h && conn && assoc);
 302     if (event == EVENT_TIMEOUT)
 303     {
 304         logf(LOG_LOG, "Timeout - closing connection.");
 305         cs_close(conn);
 306         destroy_association(assoc);
 307         iochan_destroy(h);
 308         return;
 309     }
 310     if (event & EVENT_INPUT || event & EVENT_WORK) /* input */
 311     {
 312         if (event & EVENT_INPUT)
 313         {
 314             logf(LOG_DEBUG, "ir_session (input)");
 315             assert(assoc && conn);
 316             /* We aren't speaking to this fellow */
 317             if (assoc->rejected)
 318             {
 319                 logf(LOG_LOG, "Closed connection after reject");
 320                 cs_close(conn);
 321                 destroy_association(assoc);
 322                 iochan_destroy(h);
 323                 return;
 324             }
 325             if ((res = cs_get(conn, &assoc->input_buffer,
 326                 &assoc->input_buffer_len)) <= 0)
 327             {
 328                 logf(LOG_LOG, "Connection closed by client");
 329                 cs_close(conn);
 330                 destroy_association(assoc);
 331                 iochan_destroy(h);
 332                 return;
 333             }
 334             else if (res == 1) /* incomplete read - wait for more  */
 335                 return;
 336             if (cs_more(conn)) /* more stuff - call us again later, please */
 337                 iochan_setevent(h, EVENT_INPUT);
 338
 339             /* we got a complete PDU. Let's decode it */
 340             logf(LOG_DEBUG, "Got PDU, %d bytes", res);
 341             req = request_get(); /* get a new request structure */
 342             odr_reset(assoc->decode);
 343             odr_setbuf(assoc->decode, assoc->input_buffer, res, 0);
 344             if (!z_APDU(assoc->decode, &req->request, 0))
 345             {
 346                 logf(LOG_LOG, "ODR error on incoming PDU: %s",
 347                     odr_errlist[odr_geterror(assoc->decode)]);
 348                 logf(LOG_LOG, "PDU dump:");
 349                 odr_dumpBER(log_file(), assoc->input_buffer, res);
 350                 cs_close(conn);
 351                 destroy_association(assoc);
 352                 iochan_destroy(h);
 353                 return;
 354             }
 355             req->request_mem = odr_extract_mem(assoc->decode);
 356             if (assoc->print && !z_APDU(assoc->print, &req->request, 0))
 357             {
 358                 logf(LOG_WARN, "ODR print error: %s",
 359                     odr_errlist[odr_geterror(assoc->print)]);
 360                 odr_reset(assoc->print);
 361             }
 362             request_enq(&assoc->incoming, req);
 363         }
 364
 365         /* can we do something yet? */
 366         req = request_head(&assoc->incoming);
 367         if (req->state == REQUEST_IDLE)
 368             if (process_request(assoc) < 0)
 369             {
 370                 cs_close(conn);
 371                 destroy_association(assoc);
 372                 iochan_destroy(h);
 373             }
 374     }
 375     if (event & EVENT_OUTPUT)
 376     {
 377         request *req = request_head(&assoc->outgoing);
 378
 379         logf(LOG_DEBUG, "ir_session (output)");
 380         req->state = REQUEST_PENDING;
 381         switch (res = cs_put(conn, req->response, req->len_response))
 382         {
 383             case -1:
 384                 logf(LOG_LOG, "Connection closed by client");
 385                 cs_close(conn);
 386                 destroy_association(assoc);
 387                 iochan_destroy(h);
 388                 break;
 389             case 0: /* all sent - release the request structure */
 390                 logf(LOG_DEBUG, "Wrote PDU, %d bytes", req->len_response);
 391                 odr_release_mem(req->request_mem);
 392                 request_deq(&assoc->outgoing);
 393                 request_release(req);
 394                 if (!request_head(&assoc->outgoing))
 395                     iochan_clearflag(h, EVENT_OUTPUT);
 396                 break;
 397             /* value of 1 -- partial send -- is simply ignored */
 398         }
 399     }
 400     if (event & EVENT_EXCEPT)
 401     {
 402         logf(LOG_DEBUG, "ir_session (exception)");
 403         cs_close(conn);
 404         destroy_association(assoc);
 405         iochan_destroy(h);
 406     }
 407 }
 408
 409 /*
 410  * Initiate request processing.
 411  */
 412 static int process_request(association *assoc)
 413 {
 414     request *req = request_head(&assoc->incoming);
 415     int fd = -1;
 416     Z_APDU *res;
 417
 418     logf(LOG_DEBUG, "process_request");
 419     assert(req && req->state == REQUEST_IDLE);
 420     switch (req->request->which)
 421     {
 422         case Z_APDU_initRequest:
 423             res = process_initRequest(assoc, req); break;
 424         case Z_APDU_searchRequest:
 425             res = process_searchRequest(assoc, req, &fd); break;
 426         case Z_APDU_presentRequest:
 427             res = process_presentRequest(assoc, req, &fd); break;
 428         case Z_APDU_scanRequest:
 429             res = process_scanRequest(assoc, req, &fd); break;
 430         default:
 431             logf(LOG_WARN, "Bad APDU received");
 432             return -1;
 433     }
 434     if (res)
 435     {
 436         logf(LOG_DEBUG, "  result immediately available");
 437         return process_response(assoc, req, res);
 438     }
 439     else if (fd < 0)
 440     {
 441         logf(LOG_WARN, "   bad result");
 442         return -1;
 443     }
 444     else /* no result yet - one will be provided later */
 445     {
 446         IOCHAN chan;
 447
 448         /* Set up an I/O handler for the fd supplied by the backend */
 449
 450         logf(LOG_DEBUG, "   establishing handler for result");
 451         req->state = REQUEST_PENDING;
 452         if (!(chan = iochan_create(fd, backend_response, EVENT_INPUT)))
 453             abort();
 454         iochan_setdata(chan, assoc);
 455         return 0;
 456     }
 457 }
 458
 459 /*
 460  * Handle message from the backend.
 461  */
 462 void backend_response(IOCHAN i, int event)
 463 {
 464     association *assoc = iochan_getdata(i);
 465     request *req = request_head(&assoc->incoming);
 466     Z_APDU *res;
 467     int fd;
 468
 469     logf(LOG_DEBUG, "backend_response");
 470     assert(assoc && req && req->state != REQUEST_IDLE);
 471     /* determine what it is we're waiting for */
 472     switch (req->request->which)
 473     {
 474         case Z_APDU_searchRequest:
 475             res = response_searchRequest(assoc, req, 0, &fd); break;
 476 #if 0
 477         case Z_APDU_presentRequest:
 478             res = response_presentRequest(assoc, req, 0, &fd); break;
 479         case Z_APDU_scanRequest:
 480             res = response_scanRequest(assoc, req, 0, &fd); break;
 481 #endif
 482         default:
 483             logf(LOG_WARN, "Serious programmer's lapse or bug");
 484             abort();
 485     }
 486     if ((res && process_response(assoc, req, res) < 0) || fd < 0)
 487     {
 488         logf(LOG_LOG, "Fatal error when talking to backend");
 489         cs_close(assoc->client_link);
 490         destroy_association(assoc);
 491         iochan_destroy(assoc->client_chan);
 492         iochan_destroy(i);
 493         return;
 494     }
 495     else if (!res) /* no result yet - try again later */
 496     {
 497         logf(LOG_DEBUG, "   no result yet");
 498         iochan_setfd(i, fd); /* in case fd has changed */
 499     }
 500 }
 501
 502 /*
 503  * Encode response, and transfer the request structure to the outgoing queue.
 504  */
 505 static int process_response(association *assoc, request *req, Z_APDU *res)
 506 {
 507     odr_setbuf(assoc->encode, req->response, req->size_response, 1);
 508     if (!z_APDU(assoc->encode, &res, 0))
 509     {
 510         logf(LOG_WARN, "ODR error when encoding response: %s",
 511             odr_errlist[odr_geterror(assoc->decode)]);
 512         return -1;
 513     }
 514     req->response = odr_getbuf(assoc->encode, &req->len_response,
 515         &req->size_response);
 516     odr_setbuf(assoc->encode, 0, 0, 0); /* don't free if we abort later */
 517     odr_reset(assoc->encode);
 518     if (assoc->print && !z_APDU(assoc->print, &res, 0))
 519     {
 520         logf(LOG_WARN, "ODR print error: %s",
 521             odr_errlist[odr_geterror(assoc->print)]);
 522         odr_reset(assoc->print);
 523     }
 524     /* change this when we make the backend reentrant */
 525     assert(req == request_head(&assoc->incoming));
 526     req->state = REQUEST_IDLE;
 527     request_deq(&assoc->incoming);
 528     request_enq(&assoc->outgoing, req);
 529     /* turn the work over to the ir_session handler */
 530     iochan_setflag(assoc->client_chan, EVENT_OUTPUT);
 531     /* Is there more work to be done? give that to the input handler too */
 532     if (request_head(&assoc->incoming))
 533         iochan_setevent(assoc->client_chan, EVENT_WORK);
 534     return 0;
 535 }
 536
 537 /*
 538  * Handle init request.
 539  * At the moment, we don't check the protocol version or the options
 540  * anywhere else in the code - we just try not to do anything that would
 541  * break a naive client. We'll toss 'em into the association block when
 542  * we need them there.
 543  */
 544 static Z_APDU *process_initRequest(association *assoc, request *reqb)
 545 {
 546     Z_InitRequest *req = reqb->request->u.initRequest;
 547     Z_APDU *apdu = zget_APDU(assoc->encode, Z_APDU_initResponse);
 548     Z_InitResponse *resp = apdu->u.initResponse;
 549     bend_initrequest binitreq;
 550     bend_initresult *binitres;
 551
 552     logf(LOG_LOG, "Got initRequest");
 553     if (req->implementationId)
 554         logf(LOG_LOG, "Id:        %s", req->implementationId);
 555     if (req->implementationName)
 556         logf(LOG_LOG, "Name:      %s", req->implementationName);
 557     if (req->implementationVersion)
 558         logf(LOG_LOG, "Version:   %s", req->implementationVersion);
 559
 560     binitreq.configname = "default-config";
 561     binitreq.auth = req->idAuthentication;
 562     if (!(binitres = bend_init(&binitreq)))
 563     {
 564         logf(LOG_WARN, "Bad response from backend.");
 565         return 0;
 566     }
 567
 568     assoc->backend = binitres->handle;
 569     resp->referenceId = req->referenceId;
 570     /* let's tell the client what we can do */
 571     if (ODR_MASK_GET(req->options, Z_Options_search))
 572         ODR_MASK_SET(resp->options, Z_Options_search);
 573     if (ODR_MASK_GET(req->options, Z_Options_present))
 574         ODR_MASK_SET(resp->options, Z_Options_present);
 575 #if 0
 576     if (ODR_MASK_GET(req->options, Z_Options_delSet))
 577         ODR_MASK_SET(&options, Z_Options_delSet);
 578 #endif
 579     if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 580         ODR_MASK_SET(resp->options, Z_Options_namedResultSets);
 581     if (ODR_MASK_GET(req->options, Z_Options_scan))
 582         ODR_MASK_SET(resp->options, Z_Options_scan);
 583     if (ODR_MASK_GET(req->options, Z_Options_concurrentOperations))
 584         ODR_MASK_SET(resp->options, Z_Options_concurrentOperations);
 585
 586     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_1))
 587         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_1);
 588     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_2))
 589         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_2);
 590     assoc->maximumRecordSize = *req->maximumRecordSize;
 591     if (assoc->maximumRecordSize > control_block->maxrecordsize)
 592         assoc->maximumRecordSize = control_block->maxrecordsize;
 593     assoc->preferredMessageSize = *req->preferredMessageSize;
 594     if (assoc->preferredMessageSize > assoc->maximumRecordSize)
 595         assoc->preferredMessageSize = assoc->maximumRecordSize;
 596     resp->preferredMessageSize = &assoc->preferredMessageSize;
 597     resp->maximumRecordSize = &assoc->maximumRecordSize;
 598     resp->implementationName = "Index Data/YAZ Generic Frontend Server";
 599     if (binitres->errcode)
 600     {
 601         logf(LOG_LOG, "Connection rejected by backend.");
 602         *resp->result = 0;
 603         assoc->rejected = 1;
 604     }
 605     return apdu;
 606 }
 607
 608 /*
 609  * These functions should be merged.
 610  */
 611
 612 /*
 613  * nonsurrogate diagnostic record.
 614  */
 615 static Z_Records *diagrec(oid_proto proto, int error, char *addinfo)
 616 {
 617     static Z_Records rec;
 618     oident bib1;
 619     static int err;
 620 #ifdef Z_95
 621     static Z_DiagRec drec;
 622     static Z_DefaultDiagFormat dr;
 623 #else
 624     static Z_DiagRec dr;
 625 #endif
 626
 627     bib1.proto = proto;
 628     bib1.class = CLASS_DIAGSET;
 629     bib1.value = VAL_BIB1;
 630
 631     logf(LOG_DEBUG, "Diagnostic: %d -- %s", error, addinfo ? addinfo :
 632         "NULL");
 633     err = error;
 634     rec.which = Z_Records_NSD;
 635 #ifdef Z_95
 636     rec.u.nonSurrogateDiagnostic = &drec;
 637     drec.which = Z_DiagRec_defaultFormat;
 638     drec.u.defaultFormat = &dr;
 639 #else
 640     rec.u.nonSurrogateDiagnostic = &dr;
 641 #endif
 642     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 643     dr.condition = &err;
 644     dr.which = Z_DiagForm_v2AddInfo;
 645     dr.addinfo = addinfo ? addinfo : "";
 646     return &rec;
 647 }
 648
 649 /*
 650  * surrogate diagnostic.
 651  */
 652 static Z_NamePlusRecord *surrogatediagrec(oid_proto proto, char *dbname,
 653                                             int error, char *addinfo)
 654 {
 655     static Z_NamePlusRecord rec;
 656     static int err;
 657     oident bib1;
 658 #ifdef Z_95
 659     static Z_DiagRec drec;
 660     static Z_DefaultDiagFormat dr;
 661 #else
 662     static Z_DiagRec dr;
 663 #endif
 664
 665     bib1.proto = proto;
 666     bib1.class = CLASS_DIAGSET;
 667     bib1.value = VAL_BIB1;
 668
 669     logf(LOG_DEBUG, "SurrogateDiagnotic: %d -- %s", error, addinfo);
 670     err = error;
 671     rec.databaseName = dbname;
 672     rec.which = Z_NamePlusRecord_surrogateDiagnostic;
 673 #ifdef Z_95
 674     rec.u.surrogateDiagnostic = &drec;
 675     drec.which = Z_DiagRec_defaultFormat;
 676     drec.u.defaultFormat = &dr;
 677 #else
 678     rec.u.surrogateDiagnostic = &dr;
 679 #endif
 680     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 681     dr.condition = &err;
 682     dr.which = Z_DiagForm_v2AddInfo;
 683     dr.addinfo = addinfo ? addinfo : "";
 684     return &rec;
 685 }
 686
 687 /*
 688  * multiple nonsurrogate diagnostics.
 689  */
 690 static Z_DiagRecs *diagrecs(oid_proto proto, int error, char *addinfo)
 691 {
 692     static Z_DiagRecs recs;
 693     static int err;
 694     oident bib1;
 695 #ifdef Z_95
 696     static Z_DiagRec *recp[1], drec;
 697     static Z_DefaultDiagFormat rec;
 698 #else
 699     static Z_DiagRec *recp[1], rec;
 700 #endif
 701
 702     logf(LOG_DEBUG, "DiagRecs: %d -- %s", error, addinfo);
 703     bib1.proto = proto;
 704     bib1.class = CLASS_DIAGSET;
 705     bib1.value = VAL_BIB1;
 706
 707     err = error;
 708     recs.num_diagRecs = 1;
 709     recs.diagRecs = recp;
 710 #ifdef Z_95
 711     recp[0] = &drec;
 712     drec.which = Z_DiagRec_defaultFormat;
 713     drec.u.defaultFormat = &rec;
 714 #else
 715     recp[0] = &rec;
 716 #endif
 717     rec.diagnosticSetId = oid_getoidbyent(&bib1);
 718     rec.condition = &err;
 719     rec.which = Z_DiagForm_v2AddInfo;
 720     rec.addinfo = addinfo ? addinfo : "";
 721     return &recs;
 722 }
 723
 724 #define MAX_RECORDS 256
 725
 726 static Z_Records *pack_records(association *a, char *setname, int start,
 727                                 int *num, Z_ElementSetNames *esn,
 728                                 int *next, int *pres, oid_value format)
 729 {
 730     int recno, total_length = 0, toget = *num;
 731     static Z_Records records;
 732     static Z_NamePlusRecordList reclist;
 733     static Z_NamePlusRecord *list[MAX_RECORDS];
 734     oident recform;
 735
 736     records.which = Z_Records_DBOSD;
 737     records.u.databaseOrSurDiagnostics = &reclist;
 738     reclist.num_records = 0;
 739     reclist.records = list;
 740     *pres = Z_PRES_SUCCESS;
 741     *num = 0;
 742     *next = 0;
 743
 744     logf(LOG_DEBUG, "Request to pack %d+%d", start, toget);
 745     logf(LOG_DEBUG, "pms=%d, mrs=%d", a->preferredMessageSize,
 746         a->maximumRecordSize);
 747     for (recno = start; reclist.num_records < toget; recno++)
 748     {
 749         bend_fetchrequest freq;
 750         bend_fetchresult *fres;
 751         Z_NamePlusRecord *thisrec;
 752         Z_DatabaseRecord *thisext;
 753
 754         if (reclist.num_records == MAX_RECORDS - 1)
 755         {
 756             *pres = Z_PRES_PARTIAL_2;
 757             break;
 758         }
 759         freq.setname = setname;
 760         freq.number = recno;
 761         freq.format = format;
 762         if (!(fres = bend_fetch(a->backend, &freq, 0)))
 763         {
 764             *pres = Z_PRES_FAILURE;
 765             return diagrec(a->proto, 2, "Backend interface problem");
 766         }
 767         /* backend should be able to signal whether error is system-wide
 768            or only pertaining to current record */
 769         if (fres->errcode)
 770         {
 771             *pres = Z_PRES_FAILURE;
 772             return diagrec(a->proto, fres->errcode, fres->errstring);
 773         }
 774         logf(LOG_DEBUG, "  fetched record, len=%d, total=%d",
 775             fres->len, total_length);
 776         if (fres->len + total_length > a->preferredMessageSize)
 777         {
 778             /* record is small enough, really */
 779             if (fres->len <= a->preferredMessageSize)
 780             {
 781                 logf(LOG_DEBUG, "  Dropped last normal-sized record");
 782                 *pres = Z_PRES_PARTIAL_2;
 783                 break;
 784             }
 785             /* record can only be fetched by itself */
 786             if (fres->len < a->maximumRecordSize)
 787             {
 788                 logf(LOG_DEBUG, "  Record > prefmsgsz");
 789                 if (toget > 1)
 790                 {
 791                     logf(LOG_DEBUG, "  Dropped it");
 792                     reclist.records[reclist.num_records] =
 793                          surrogatediagrec(a->proto, fres->basename, 16, 0);
 794                     reclist.num_records++;
 795                     total_length += 10; /* totally arbitrary */
 796                     continue;
 797                 }
 798             }
 799             else /* too big entirely */
 800             {
 801                 logf(LOG_DEBUG, "Record > maxrcdsz");
 802                 reclist.records[reclist.num_records] =
 803                     surrogatediagrec(a->proto, fres->basename, 17, 0);
 804                 reclist.num_records++;
 805                 total_length += 10; /* totally arbitrary */
 806                 continue;
 807             }
 808         }
 809         if (!(thisrec = odr_malloc(a->encode, sizeof(*thisrec))))
 810             return 0;
 811         if (!(thisrec->databaseName = odr_malloc(a->encode,
 812             strlen(fres->basename) + 1)))
 813             return 0;
 814         strcpy(thisrec->databaseName, fres->basename);
 815         thisrec->which = Z_NamePlusRecord_databaseRecord;
 816         if (!(thisrec->u.databaseRecord = thisext = odr_malloc(a->encode,
 817             sizeof(Z_DatabaseRecord))))
 818             return 0;
 819         recform.proto = a->proto;
 820         recform.class = CLASS_RECSYN;
 821         recform.value = fres->format;
 822         thisext->direct_reference = odr_oiddup(a->encode,
 823             oid_getoidbyent(&recform));
 824         thisext->indirect_reference = 0;
 825         thisext->descriptor = 0;
 826         if (fres->format == VAL_SUTRS) /* SUTRS ios a single-ASN.1-type */
 827         {
 828             Odr_oct sutrs_asn;
 829             Odr_oct *sp = &sutrs_asn;
 830             Odr_any *single = odr_malloc(a->encode, sizeof(*single));
 831             char *buf, *remember;
 832             int len, s_remember;
 833
 834             sutrs_asn.buf = (unsigned char*) fres->record;
 835             sutrs_asn.len = sutrs_asn.size = fres->len;
 836             /*
 837              * we borrow the encoding stream for preparing the buffer. This
 838              * is not the most elegant solution - a better way might have been
 839              * to reserve a different stream, or to devise a better system
 840              * for handling externals in general.
 841              */
 842             remember = odr_getbuf(a->encode, &len, &s_remember);
 843             buf = odr_malloc(a->encode, fres->len + 10); /* buf for encoding */
 844             odr_setbuf(a->encode, buf, fres->len + 10, 0); /* can_grow==0 */
 845             if (!z_SUTRS(a->encode, &sp, 0))
 846             {
 847                 logf(LOG_LOG, "ODR error encoding SUTRS: %s",
 848                     odr_errlist[odr_geterror(a->encode)]);
 849                 return 0;
 850             }
 851             thisext->which = ODR_EXTERNAL_single;
 852             thisext->u.single_ASN1_type = single;
 853             single->buf = (unsigned char*)odr_getbuf(a->encode, &single->len,
 854                 &single->size);
 855             /* Now restore the encoding stream */
 856             odr_setbuf(a->encode, remember, s_remember, 1);
 857             logf(LOG_DEBUG, "   Format is SUTRS. len %d, encoded len %d",
 858                 fres->len, single->len);
 859         }
 860         else /* octet-aligned record. Easy as pie */
 861         {
 862             thisext->which = ODR_EXTERNAL_octet;
 863             if (!(thisext->u.octet_aligned = odr_malloc(a->encode,
 864                 sizeof(Odr_oct))))
 865                 return 0;
 866             if (!(thisext->u.octet_aligned->buf = odr_malloc(a->encode,
 867                 fres->len)))
 868                 return 0;
 869             memcpy(thisext->u.octet_aligned->buf, fres->record, fres->len);
 870             thisext->u.octet_aligned->len = thisext->u.octet_aligned->size =
 871                 fres->len;
 872         }
 873         reclist.records[reclist.num_records] = thisrec;
 874         reclist.num_records++;
 875         total_length += fres->len;
 876         *next = fres->last_in_set ? 0 : recno + 1;
 877     }
 878     *num = reclist.num_records;
 879     return &records;
 880 }
 881
 882 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 883     int *fd)
 884 {
 885     Z_SearchRequest *req = reqb->request->u.searchRequest;
 886     bend_searchrequest bsrq;
 887     bend_searchresult *bsrt;
 888
 889     logf(LOG_LOG, "Got SearchRequest.");
 890
 891     bsrq.setname = req->resultSetName;
 892     bsrq.replace_set = *req->replaceIndicator;
 893     bsrq.num_bases = req->num_databaseNames;
 894     bsrq.basenames = req->databaseNames;
 895     bsrq.query = req->query;
 896
 897     if (!(bsrt = bend_search(assoc->backend, &bsrq, fd)))
 898         return 0;
 899     return response_searchRequest(assoc, reqb, bsrt, fd);
 900 }
 901
 902 bend_searchresult *bend_searchresponse(void *handle) {return 0;}
 903
 904 /*
 905  * Prepare a searchresponse based on the backend results. We probably want
 906  * to look at making the fetching of records nonblocking as well, but
 907  * so far, we'll keep things simple.
 908  * If bsrt is null, that means we're called in response to a communications
 909  * event, and we'll have to get the response for ourselves.
 910  */
 911 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 912     bend_searchresult *bsrt, int *fd)
 913 {
 914     Z_SearchRequest *req = reqb->request->u.searchRequest;
 915     static Z_APDU apdu;
 916     static Z_SearchResponse resp;
 917     static int nulint = 0;
 918     static bool_t sr = 1;
 919     static int next = 0;
 920     static int none = Z_RES_NONE;
 921
 922     apdu.which = Z_APDU_searchResponse;
 923     apdu.u.searchResponse = &resp;
 924     resp.referenceId = req->referenceId;
 925 #ifdef Z_95
 926     resp.additionalSearchInfo = 0;
 927     resp.otherInfo = 0;
 928 #endif
 929     *fd = -1;
 930     if (!bsrt && !(bsrt = bend_searchresponse(assoc->backend)))
 931     {
 932         logf(LOG_FATAL, "Bad result from backend");
 933         return 0;
 934     }
 935     else if (bsrt->errcode)
 936     {
 937         resp.records = diagrec(assoc->proto, bsrt->errcode,
 938             bsrt->errstring);
 939         resp.resultCount = &nulint;
 940         resp.numberOfRecordsReturned = &nulint;
 941         resp.nextResultSetPosition = &nulint;
 942         resp.searchStatus = &nulint;
 943         resp.resultSetStatus = &none;
 944         resp.presentStatus = 0;
 945     }
 946     else
 947     {
 948         static int toget;
 949         Z_ElementSetNames *setnames;
 950         static int presst = 0;
 951
 952         resp.records = 0;
 953         resp.resultCount = &bsrt->hits;
 954
 955         /* how many records does the user agent want, then? */
 956         if (bsrt->hits <= *req->smallSetUpperBound)
 957         {
 958             toget = bsrt->hits;
 959             setnames = req->smallSetElementSetNames;
 960         }
 961         else if (bsrt->hits < *req->largeSetLowerBound)
 962         {
 963             toget = *req->mediumSetPresentNumber;
 964             if (toget > bsrt->hits)
 965                 toget = bsrt->hits;
 966             setnames = req->mediumSetElementSetNames;
 967         }
 968         else
 969             toget = 0;
 970
 971         if (toget && !resp.records)
 972         {
 973             oident *prefformat;
 974             oid_value form;
 975
 976             if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
 977                 prefformat->class != CLASS_RECSYN)
 978                 form = VAL_NONE;
 979             else
 980                 form = prefformat->value;
 981             resp.records = pack_records(assoc, req->resultSetName, 1,
 982                 &toget, setnames, &next, &presst, form);
 983             if (!resp.records)
 984                 return 0;
 985             resp.numberOfRecordsReturned = &toget;
 986             resp.nextResultSetPosition = &next;
 987             resp.searchStatus = &sr;
 988             resp.resultSetStatus = 0;
 989             resp.presentStatus = &presst;
 990         }
 991         else
 992         {
 993             resp.numberOfRecordsReturned = &nulint;
 994             resp.nextResultSetPosition = &next;
 995             resp.searchStatus = &sr;
 996             resp.resultSetStatus = 0;
 997             resp.presentStatus = 0;
 998         }
 999     }
1000     return &apdu;
1001 }
1002
1003 /*
1004  * Maybe we got a little over-friendly when we designed bend_fetch to
1005  * get only one record at a time. Some backends can optimise multiple-record
1006  * fetches, and at any rate, there is some overhead involved in
1007  * all that selecting and hopping around. Problem is, of course, that the
1008  * frontend can't know ahead of time how many records it'll need to
1009  * fill the negotiated PDU size. Annoying. Segmentation or not, Z/SR
1010  * is downright lousy as a bulk data transfer protocol.
1011  *
1012  * To start with, we'll do the fetching of records from the backend
1013  * in one operation: To save some trips in and out of the event-handler,
1014  * and to simplify the interface to pack_records. At any rate, asynch
1015  * operation is more fun in operations that have an unpredictable execution
1016  * speed - which is normally more true for search than for present.
1017  */
1018 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
1019     int *fd)
1020 {
1021     Z_PresentRequest *req = reqb->request->u.presentRequest;
1022     static Z_APDU apdu;
1023     static Z_PresentResponse resp;
1024     static int presst, next, num;
1025     oident *prefformat;
1026     oid_value form;
1027
1028
1029     logf(LOG_LOG, "Got PresentRequest.");
1030     apdu.which = Z_APDU_presentResponse;
1031     apdu.u.presentResponse = &resp;
1032     resp.referenceId = req->referenceId;
1033 #ifdef Z_95
1034     resp.otherInfo = 0;
1035 #endif
1036
1037     if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
1038         prefformat->class != CLASS_RECSYN)
1039         form = VAL_NONE;
1040     else
1041         form = prefformat->value;
1042     num = *req->numberOfRecordsRequested;
1043     resp.records = pack_records(assoc, req->resultSetId,
1044         *req->resultSetStartPoint, &num, 0, &next, &presst, form);
1045     if (!resp.records)
1046         return 0;
1047     resp.numberOfRecordsReturned = &num;
1048     resp.presentStatus = &presst;
1049     resp.nextResultSetPosition = &next;
1050
1051     return &apdu;
1052 }
1053
1054 /*
1055  * Scan was implemented rather in a hurry, and with support for only the basic
1056  * elements of the service in the backend API. Suggestions are welcome.
1057  */
1058 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd)
1059 {
1060     Z_ScanRequest *req = reqb->request->u.scanRequest;
1061     static Z_APDU apdu;
1062     static Z_ScanResponse res;
1063     static int scanStatus = Z_Scan_failure;
1064     static int numberOfEntriesReturned = 0;
1065     oident *attent;
1066     static Z_ListEntries ents;
1067 #define SCAN_MAX_ENTRIES 200
1068     static Z_Entry *tab[SCAN_MAX_ENTRIES];
1069     bend_scanrequest srq;
1070     bend_scanresult *srs;
1071
1072     logf(LOG_LOG, "Got scanrequest");
1073     apdu.which = Z_APDU_scanResponse;
1074     apdu.u.scanResponse = &res;
1075     res.referenceId = req->referenceId;
1076     res.stepSize = 0;
1077     res.scanStatus = &scanStatus;
1078     res.numberOfEntriesReturned = &numberOfEntriesReturned;
1079     res.positionOfTerm = 0;
1080     res.entries = &ents;
1081     ents.which = Z_ListEntries_nonSurrogateDiagnostics;
1082     res.attributeSet = 0;
1083 #ifdef Z_95
1084     res.otherInfo = 0;
1085 #endif
1086
1087     if (req->attributeSet && (!(attent = oid_getentbyoid(req->attributeSet)) ||
1088         attent->class != CLASS_ATTSET || attent->value != VAL_BIB1))
1089         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 121, 0);
1090     else if (req->stepSize && *req->stepSize > 0)
1091         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 205, 0);
1092     else
1093     {
1094         if (req->termListAndStartPoint->term->which == Z_Term_general)
1095             logf(LOG_DEBUG, " term: '%.*s'",
1096                 req->termListAndStartPoint->term->u.general->len,
1097                 req->termListAndStartPoint->term->u.general->buf);
1098         srq.num_bases = req->num_databaseNames;
1099         srq.basenames = req->databaseNames;
1100         srq.num_entries = *req->numberOfTermsRequested;
1101         srq.term = req->termListAndStartPoint;
1102         srq.term_position = req->preferredPositionInResponse ?
1103             *req->preferredPositionInResponse : 1;
1104         if (!(srs = bend_scan(assoc->backend, &srq, 0)))
1105             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 2, 0);
1106         else if (srs->errcode)
1107             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto,
1108                 srs->errcode, srs->errstring);
1109         else
1110         {
1111             int i;
1112             static Z_Entries list;
1113
1114             if (srs->status == BEND_SCAN_PARTIAL)
1115                 scanStatus = Z_Scan_partial_5;
1116             else
1117                 scanStatus = Z_Scan_success;
1118             ents.which = Z_ListEntries_entries;
1119             ents.u.entries = &list;
1120             list.entries = tab;
1121             for (i = 0; i < srs->num_entries; i++)
1122             {
1123                 Z_Entry *e;
1124                 Z_TermInfo *t;
1125                 Odr_oct *o;
1126
1127                 if (i >= SCAN_MAX_ENTRIES)
1128                 {
1129                     scanStatus = Z_Scan_partial_4;
1130                     break;
1131                 }
1132                 list.entries[i] = e = odr_malloc(assoc->encode, sizeof(*e));
1133                 e->which = Z_Entry_termInfo;
1134                 e->u.termInfo = t = odr_malloc(assoc->encode, sizeof(*t));
1135                 t->suggestedAttributes = 0;
1136                 t->alternativeTerm = 0;
1137                 t->byAttributes = 0;
1138                 t->globalOccurrences = &srs->entries[i].occurrences;
1139                 t->term = odr_malloc(assoc->encode, sizeof(*t->term));
1140                 t->term->which = Z_Term_general;
1141                 t->term->u.general = o = odr_malloc(assoc->encode,
1142                     sizeof(Odr_oct));
1143                 o->buf = odr_malloc(assoc->encode, o->len = o->size =
1144                     strlen(srs->entries[i].term));
1145                 memcpy(o->buf, srs->entries[i].term, o->len);
1146                 logf(LOG_DEBUG, "  term #%d: '%s' (%d)", i,
1147                     srs->entries[i].term, srs->entries[i].occurrences);
1148             }
1149             list.num_entries = i;
1150             res.numberOfEntriesReturned = &list.num_entries;
1151             res.positionOfTerm = &srs->term_position;
1152         }
1153     }
1154
1155     return &apdu;
1156 }