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 1.44  1995-08-17 12:45:25  quinn
   8  * Fixed minor problems with GRS-1. Added support in c&s.
   9  *
  10  * Revision 1.43  1995/08/15  12:00:31  quinn
  11  * Updated External
  12  *
  13  * Revision 1.42  1995/08/15  11:16:50  quinn
  14  * CV:e ----------------------------------------------------------------------
  15  * CV:e ----------------------------------------------------------------------
  16  *
  17  * Revision 1.41  1995/08/02  10:23:06  quinn
  18  * Smallish
  19  *
  20  * Revision 1.40  1995/07/31  14:34:26  quinn
  21  * Fixed bug in process_searchResponse (numberOfRecordsReturned).
  22  *
  23  * Revision 1.39  1995/06/27  13:21:00  quinn
  24  * SUTRS support
  25  *
  26  * Revision 1.38  1995/06/19  12:39:11  quinn
  27  * Fixed bug in timeout code. Added BER dumper.
  28  *
  29  * Revision 1.37  1995/06/16  13:16:14  quinn
  30  * Fixed Defaultdiagformat.
  31  *
  32  * Revision 1.36  1995/06/16  10:31:36  quinn
  33  * Added session timeout.
  34  *
  35  * Revision 1.35  1995/06/15  07:45:14  quinn
  36  * Moving to v3.
  37  *
  38  * Revision 1.34  1995/06/14  15:26:46  quinn
  39  * *** empty log message ***
  40  *
  41  * Revision 1.33  1995/06/06  14:57:05  quinn
  42  * Better diagnostics.
  43  *
  44  * Revision 1.32  1995/06/06  08:41:44  quinn
  45  * Better diagnostics.
  46  *
  47  * Revision 1.31  1995/06/06  08:15:37  quinn
  48  * Cosmetic.
  49  *
  50  * Revision 1.30  1995/06/05  10:53:32  quinn
  51  * Added a better SCAN.
  52  *
  53  * Revision 1.29  1995/06/01  11:25:03  quinn
  54  * Smallish.
  55  *
  56  * Revision 1.28  1995/06/01  11:21:01  quinn
  57  * Attempting to fix a bug in pack-records. replaced break with continue
  58  * for large records, according to standard.
  59  *
  60  * Revision 1.27  1995/05/29  08:12:06  quinn
  61  * Moved oid to util
  62  *
  63  * Revision 1.26  1995/05/18  13:02:12  quinn
  64  * Smallish.
  65  *
  66  * Revision 1.25  1995/05/17  08:42:26  quinn
  67  * Transfer auth info to backend. Allow backend to reject init gracefully.
  68  *
  69  * Revision 1.24  1995/05/16  08:51:04  quinn
  70  * License, documentation, and memory fixes
  71  *
  72  * Revision 1.23  1995/05/15  13:25:10  quinn
  73  * Fixed memory bug.
  74  *
  75  * Revision 1.22  1995/05/15  11:56:39  quinn
  76  * Asynchronous facilities. Restructuring of seshigh code.
  77  *
  78  * Revision 1.21  1995/05/02  08:53:19  quinn
  79  * Trying in vain to fix comm with ISODE
  80  *
  81  * Revision 1.20  1995/04/20  15:13:00  quinn
  82  * Cosmetic
  83  *
  84  * Revision 1.19  1995/04/18  08:15:34  quinn
  85  * Added dynamic memory allocation on encoding (whew). Code is now somewhat
  86  * neater. We'll make the same change for decoding one day.
  87  *
  88  * Revision 1.18  1995/04/17  11:28:25  quinn
  89  * Smallish
  90  *
  91  * Revision 1.17  1995/04/10  10:23:36  quinn
  92  * Some work to add scan and other things.
  93  *
  94  * Revision 1.16  1995/03/31  09:18:55  quinn
  95  * Added logging.
  96  *
  97  * Revision 1.15  1995/03/30  14:03:23  quinn
  98  * Added RFC1006 as separate library
  99  *
 100  * Revision 1.14  1995/03/30  12:18:17  quinn
 101  * Fixed bug.
 102  *
 103  * Revision 1.13  1995/03/30  09:09:24  quinn
 104  * Added state-handle and some support for asynchronous activities.
 105  *
 106  * Revision 1.12  1995/03/29  15:40:16  quinn
 107  * Ongoing work. Statserv is now dynamic by default
 108  *
 109  * Revision 1.11  1995/03/28  09:16:21  quinn
 110  * Added record packing to the search request
 111  *
 112  * Revision 1.10  1995/03/27  08:34:24  quinn
 113  * Added dynamic server functionality.
 114  * Released bindings to session.c (is now redundant)
 115  *
 116  * Revision 1.9  1995/03/22  15:01:26  quinn
 117  * Adjusting record packing.
 118  *
 119  * Revision 1.8  1995/03/22  10:13:21  quinn
 120  * Working on record packer
 121  *
 122  * Revision 1.7  1995/03/21  15:53:31  quinn
 123  * Little changes.
 124  *
 125  * Revision 1.6  1995/03/21  12:30:09  quinn
 126  * Beginning to add support for record packing.
 127  *
 128  * Revision 1.5  1995/03/17  10:44:13  quinn
 129  * Added catch of null-string in makediagrec
 130  *
 131  * Revision 1.4  1995/03/17  10:18:08  quinn
 132  * Added memory management.
 133  *
 134  * Revision 1.3  1995/03/16  17:42:39  quinn
 135  * Little changes
 136  *
 137  * Revision 1.2  1995/03/16  13:29:01  quinn
 138  * Partitioned server.
 139  *
 140  * Revision 1.1  1995/03/15  16:02:10  quinn
 141  * Modded session.c to seshigh.c
 142  *
 143  */
 144
 145 /*
 146  * Frontend server logic.
 147  *
 148  * This code receives incoming APDUs, and handles client requests by means
 149  * of the backend API.
 150  *
 151  * Some of the code is getting quite involved, compared to simpler servers -
 152  * primarily because it is asynchronous both in the communication with
 153  * the user and the backend. We think the complexity will pay off in
 154  * the form of greater flexibility when more asynchronous facilities
 155  * are implemented.
 156  *
 157  * Memory management has become somewhat involved. In the simple case, where
 158  * only one PDU is pending at a time, it will simply reuse the same memory,
 159  * once it has found its working size. When we enable multiple concurrent
 160  * operations, perhaps even with multiple parallel calls to the backend, it
 161  * will maintain a pool of buffers for encoding and decoding, trying to
 162  * minimize memory allocation/deallocation during normal operation.
 163  *
 164  * TODOs include (and will be done in order of public interest):
 165  *
 166  * Support for EXPLAIN - provide simple meta-database system.
 167  * Support for access control.
 168  * Support for resource control.
 169  * Support for extended services - primarily Item Order.
 170  * Rest of Z39.50-1994
 171  *
 172  */
 173
 174 #include <stdlib.h>
 175 #include <stdio.h>
 176 #include <unistd.h>
 177 #include <assert.h>
 178
 179 #include <dmalloc.h>
 180 #include <comstack.h>
 181 #include <eventl.h>
 182 #include <session.h>
 183 #include <proto.h>
 184 #include <oid.h>
 185 #include <log.h>
 186 #include <statserv.h>
 187
 188 #include <backend.h>
 189
 190 static int process_request(association *assoc);
 191 void backend_response(IOCHAN i, int event);
 192 static int process_response(association *assoc, request *req, Z_APDU *res);
 193 static Z_APDU *process_initRequest(association *assoc, request *reqb);
 194 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 195     int *fd);
 196 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 197     bend_searchresult *bsrt, int *fd);
 198 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 199     int *fd);
 200 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd);
 201
 202 static FILE *apduf = 0; /* for use in static mode */
 203 static statserv_options_block *control_block = 0;
 204
 205 /*
 206  * Create and initialize a new association-handle.
 207  *  channel  : iochannel for the current line.
 208  *  link     : communications channel.
 209  * Returns: 0 or a new association handle.
 210  */
 211 association *create_association(IOCHAN channel, COMSTACK link)
 212 {
 213     association *new;
 214
 215     if (!control_block)
 216         control_block = statserv_getcontrol();
 217     if (!(new = malloc(sizeof(*new))))
 218         return 0;
 219     new->client_chan = channel;
 220     new->client_link = link;
 221     if (!(new->decode = odr_createmem(ODR_DECODE)) ||
 222         !(new->encode = odr_createmem(ODR_ENCODE)))
 223         return 0;
 224     if (*control_block->apdufile)
 225     {
 226         char filename[256];
 227         FILE *f;
 228
 229         strcpy(filename, control_block->apdufile);
 230         if (!(new->print = odr_createmem(ODR_PRINT)))
 231             return 0;
 232         if (*control_block->apdufile != '-')
 233         {
 234             strcpy(filename, control_block->apdufile);
 235             if (!control_block->dynamic)
 236             {
 237                 if (!apduf)
 238                 {
 239                     if (!(apduf = fopen(filename, "w")))
 240                     {
 241                         logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 242                         return 0;
 243                     }
 244                     setvbuf(apduf, 0, _IONBF, 0);
 245                 }
 246                 f = apduf;
 247             }
 248             else
 249             {
 250                 sprintf(filename + strlen(filename), ".%d", getpid());
 251                 if (!(f = fopen(filename, "w")))
 252                 {
 253                     logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 254                     return 0;
 255                 }
 256                 setvbuf(f, 0, _IONBF, 0);
 257             }
 258             odr_setprint(new->print, f);
 259         }
 260     }
 261     else
 262         new->print = 0;
 263     new->input_buffer = 0;
 264     new->input_buffer_len = 0;
 265     new->backend = 0;
 266     new->rejected = 0;
 267     request_initq(&new->incoming);
 268     request_initq(&new->outgoing);
 269     new->proto = cs_getproto(link);
 270     return new;
 271 }
 272
 273 /*
 274  * Free association and release resources.
 275  */
 276 void destroy_association(association *h)
 277 {
 278     odr_destroy(h->decode);
 279     odr_destroy(h->encode);
 280     if (h->print)
 281         odr_destroy(h->print);
 282     if (h->input_buffer)
 283         free(h->input_buffer);
 284     if (h->backend)
 285         bend_close(h->backend);
 286     while (request_deq(&h->incoming));
 287     while (request_deq(&h->outgoing));
 288     free(h);
 289 }
 290
 291 /*
 292  * This is where PDUs from the client are read and the further
 293  * processing is initiated. Flow of control moves down through the
 294  * various process_* functions below, until the encoded result comes back up
 295  * to the output handler in here.
 296  *
 297  *  h     : the I/O channel that has an outstanding event.
 298  *  event : the current outstanding event.
 299  */
 300 void ir_session(IOCHAN h, int event)
 301 {
 302     int res;
 303     association *assoc = iochan_getdata(h);
 304     COMSTACK conn = assoc->client_link;
 305     request *req;
 306
 307     assert(h && conn && assoc);
 308     if (event == EVENT_TIMEOUT)
 309     {
 310         logf(LOG_LOG, "Timeout - closing connection.");
 311         cs_close(conn);
 312         destroy_association(assoc);
 313         iochan_destroy(h);
 314         return;
 315     }
 316     if (event & EVENT_INPUT || event & EVENT_WORK) /* input */
 317     {
 318         if (event & EVENT_INPUT)
 319         {
 320             logf(LOG_DEBUG, "ir_session (input)");
 321             assert(assoc && conn);
 322             /* We aren't speaking to this fellow */
 323             if (assoc->rejected)
 324             {
 325                 logf(LOG_LOG, "Closed connection after reject");
 326                 cs_close(conn);
 327                 destroy_association(assoc);
 328                 iochan_destroy(h);
 329                 return;
 330             }
 331             if ((res = cs_get(conn, &assoc->input_buffer,
 332                 &assoc->input_buffer_len)) <= 0)
 333             {
 334                 logf(LOG_LOG, "Connection closed by client");
 335                 cs_close(conn);
 336                 destroy_association(assoc);
 337                 iochan_destroy(h);
 338                 return;
 339             }
 340             else if (res == 1) /* incomplete read - wait for more  */
 341                 return;
 342             if (cs_more(conn)) /* more stuff - call us again later, please */
 343                 iochan_setevent(h, EVENT_INPUT);
 344
 345             /* we got a complete PDU. Let's decode it */
 346             logf(LOG_DEBUG, "Got PDU, %d bytes", res);
 347             req = request_get(); /* get a new request structure */
 348             odr_reset(assoc->decode);
 349             odr_setbuf(assoc->decode, assoc->input_buffer, res, 0);
 350             if (!z_APDU(assoc->decode, &req->request, 0))
 351             {
 352                 logf(LOG_LOG, "ODR error on incoming PDU: %s",
 353                     odr_errlist[odr_geterror(assoc->decode)]);
 354                 logf(LOG_LOG, "PDU dump:");
 355                 odr_dumpBER(log_file(), assoc->input_buffer, res);
 356                 cs_close(conn);
 357                 destroy_association(assoc);
 358                 iochan_destroy(h);
 359                 return;
 360             }
 361             req->request_mem = odr_extract_mem(assoc->decode);
 362             if (assoc->print && !z_APDU(assoc->print, &req->request, 0))
 363             {
 364                 logf(LOG_WARN, "ODR print error: %s",
 365                     odr_errlist[odr_geterror(assoc->print)]);
 366                 odr_reset(assoc->print);
 367             }
 368             request_enq(&assoc->incoming, req);
 369         }
 370
 371         /* can we do something yet? */
 372         req = request_head(&assoc->incoming);
 373         if (req->state == REQUEST_IDLE)
 374             if (process_request(assoc) < 0)
 375             {
 376                 cs_close(conn);
 377                 destroy_association(assoc);
 378                 iochan_destroy(h);
 379             }
 380     }
 381     if (event & EVENT_OUTPUT)
 382     {
 383         request *req = request_head(&assoc->outgoing);
 384
 385         logf(LOG_DEBUG, "ir_session (output)");
 386         req->state = REQUEST_PENDING;
 387         switch (res = cs_put(conn, req->response, req->len_response))
 388         {
 389             case -1:
 390                 logf(LOG_LOG, "Connection closed by client");
 391                 cs_close(conn);
 392                 destroy_association(assoc);
 393                 iochan_destroy(h);
 394                 break;
 395             case 0: /* all sent - release the request structure */
 396                 logf(LOG_DEBUG, "Wrote PDU, %d bytes", req->len_response);
 397                 odr_release_mem(req->request_mem);
 398                 request_deq(&assoc->outgoing);
 399                 request_release(req);
 400                 if (!request_head(&assoc->outgoing))
 401                     iochan_clearflag(h, EVENT_OUTPUT);
 402                 break;
 403             /* value of 1 -- partial send -- is simply ignored */
 404         }
 405     }
 406     if (event & EVENT_EXCEPT)
 407     {
 408         logf(LOG_DEBUG, "ir_session (exception)");
 409         cs_close(conn);
 410         destroy_association(assoc);
 411         iochan_destroy(h);
 412     }
 413 }
 414
 415 /*
 416  * Initiate request processing.
 417  */
 418 static int process_request(association *assoc)
 419 {
 420     request *req = request_head(&assoc->incoming);
 421     int fd = -1;
 422     Z_APDU *res;
 423
 424     logf(LOG_DEBUG, "process_request");
 425     assert(req && req->state == REQUEST_IDLE);
 426     switch (req->request->which)
 427     {
 428         case Z_APDU_initRequest:
 429             res = process_initRequest(assoc, req); break;
 430         case Z_APDU_searchRequest:
 431             res = process_searchRequest(assoc, req, &fd); break;
 432         case Z_APDU_presentRequest:
 433             res = process_presentRequest(assoc, req, &fd); break;
 434         case Z_APDU_scanRequest:
 435             res = process_scanRequest(assoc, req, &fd); break;
 436         default:
 437             logf(LOG_WARN, "Bad APDU received");
 438             return -1;
 439     }
 440     if (res)
 441     {
 442         logf(LOG_DEBUG, "  result immediately available");
 443         return process_response(assoc, req, res);
 444     }
 445     else if (fd < 0)
 446     {
 447         logf(LOG_WARN, "   bad result");
 448         return -1;
 449     }
 450     else /* no result yet - one will be provided later */
 451     {
 452         IOCHAN chan;
 453
 454         /* Set up an I/O handler for the fd supplied by the backend */
 455
 456         logf(LOG_DEBUG, "   establishing handler for result");
 457         req->state = REQUEST_PENDING;
 458         if (!(chan = iochan_create(fd, backend_response, EVENT_INPUT)))
 459             abort();
 460         iochan_setdata(chan, assoc);
 461         return 0;
 462     }
 463 }
 464
 465 /*
 466  * Handle message from the backend.
 467  */
 468 void backend_response(IOCHAN i, int event)
 469 {
 470     association *assoc = iochan_getdata(i);
 471     request *req = request_head(&assoc->incoming);
 472     Z_APDU *res;
 473     int fd;
 474
 475     logf(LOG_DEBUG, "backend_response");
 476     assert(assoc && req && req->state != REQUEST_IDLE);
 477     /* determine what it is we're waiting for */
 478     switch (req->request->which)
 479     {
 480         case Z_APDU_searchRequest:
 481             res = response_searchRequest(assoc, req, 0, &fd); break;
 482 #if 0
 483         case Z_APDU_presentRequest:
 484             res = response_presentRequest(assoc, req, 0, &fd); break;
 485         case Z_APDU_scanRequest:
 486             res = response_scanRequest(assoc, req, 0, &fd); break;
 487 #endif
 488         default:
 489             logf(LOG_WARN, "Serious programmer's lapse or bug");
 490             abort();
 491     }
 492     if ((res && process_response(assoc, req, res) < 0) || fd < 0)
 493     {
 494         logf(LOG_LOG, "Fatal error when talking to backend");
 495         cs_close(assoc->client_link);
 496         destroy_association(assoc);
 497         iochan_destroy(assoc->client_chan);
 498         iochan_destroy(i);
 499         return;
 500     }
 501     else if (!res) /* no result yet - try again later */
 502     {
 503         logf(LOG_DEBUG, "   no result yet");
 504         iochan_setfd(i, fd); /* in case fd has changed */
 505     }
 506 }
 507
 508 /*
 509  * Encode response, and transfer the request structure to the outgoing queue.
 510  */
 511 static int process_response(association *assoc, request *req, Z_APDU *res)
 512 {
 513     odr_setbuf(assoc->encode, req->response, req->size_response, 1);
 514     if (!z_APDU(assoc->encode, &res, 0))
 515     {
 516         logf(LOG_WARN, "ODR error when encoding response: %s",
 517             odr_errlist[odr_geterror(assoc->decode)]);
 518         return -1;
 519     }
 520     req->response = odr_getbuf(assoc->encode, &req->len_response,
 521         &req->size_response);
 522     odr_setbuf(assoc->encode, 0, 0, 0); /* don't free if we abort later */
 523     odr_reset(assoc->encode);
 524     if (assoc->print && !z_APDU(assoc->print, &res, 0))
 525     {
 526         logf(LOG_WARN, "ODR print error: %s",
 527             odr_errlist[odr_geterror(assoc->print)]);
 528         odr_reset(assoc->print);
 529     }
 530     /* change this when we make the backend reentrant */
 531     assert(req == request_head(&assoc->incoming));
 532     req->state = REQUEST_IDLE;
 533     request_deq(&assoc->incoming);
 534     request_enq(&assoc->outgoing, req);
 535     /* turn the work over to the ir_session handler */
 536     iochan_setflag(assoc->client_chan, EVENT_OUTPUT);
 537     /* Is there more work to be done? give that to the input handler too */
 538     if (request_head(&assoc->incoming))
 539         iochan_setevent(assoc->client_chan, EVENT_WORK);
 540     return 0;
 541 }
 542
 543 /*
 544  * Handle init request.
 545  * At the moment, we don't check the protocol version or the options
 546  * anywhere else in the code - we just try not to do anything that would
 547  * break a naive client. We'll toss 'em into the association block when
 548  * we need them there.
 549  */
 550 static Z_APDU *process_initRequest(association *assoc, request *reqb)
 551 {
 552     Z_InitRequest *req = reqb->request->u.initRequest;
 553     Z_APDU *apdu = zget_APDU(assoc->encode, Z_APDU_initResponse);
 554     Z_InitResponse *resp = apdu->u.initResponse;
 555     bend_initrequest binitreq;
 556     bend_initresult *binitres;
 557
 558     logf(LOG_LOG, "Got initRequest");
 559     if (req->implementationId)
 560         logf(LOG_LOG, "Id:        %s", req->implementationId);
 561     if (req->implementationName)
 562         logf(LOG_LOG, "Name:      %s", req->implementationName);
 563     if (req->implementationVersion)
 564         logf(LOG_LOG, "Version:   %s", req->implementationVersion);
 565
 566     binitreq.configname = "default-config";
 567     binitreq.auth = req->idAuthentication;
 568     if (!(binitres = bend_init(&binitreq)))
 569     {
 570         logf(LOG_WARN, "Bad response from backend.");
 571         return 0;
 572     }
 573
 574     assoc->backend = binitres->handle;
 575     resp->referenceId = req->referenceId;
 576     /* let's tell the client what we can do */
 577     if (ODR_MASK_GET(req->options, Z_Options_search))
 578         ODR_MASK_SET(resp->options, Z_Options_search);
 579     if (ODR_MASK_GET(req->options, Z_Options_present))
 580         ODR_MASK_SET(resp->options, Z_Options_present);
 581 #if 0
 582     if (ODR_MASK_GET(req->options, Z_Options_delSet))
 583         ODR_MASK_SET(&options, Z_Options_delSet);
 584 #endif
 585     if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 586         ODR_MASK_SET(resp->options, Z_Options_namedResultSets);
 587     if (ODR_MASK_GET(req->options, Z_Options_scan))
 588         ODR_MASK_SET(resp->options, Z_Options_scan);
 589     if (ODR_MASK_GET(req->options, Z_Options_concurrentOperations))
 590         ODR_MASK_SET(resp->options, Z_Options_concurrentOperations);
 591
 592     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_1))
 593         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_1);
 594     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_2))
 595         ODR_MASK_SET(resp->protocolVersion, Z_ProtocolVersion_2);
 596     assoc->maximumRecordSize = *req->maximumRecordSize;
 597     if (assoc->maximumRecordSize > control_block->maxrecordsize)
 598         assoc->maximumRecordSize = control_block->maxrecordsize;
 599     assoc->preferredMessageSize = *req->preferredMessageSize;
 600     if (assoc->preferredMessageSize > assoc->maximumRecordSize)
 601         assoc->preferredMessageSize = assoc->maximumRecordSize;
 602     resp->preferredMessageSize = &assoc->preferredMessageSize;
 603     resp->maximumRecordSize = &assoc->maximumRecordSize;
 604     resp->implementationName = "Index Data/YAZ Generic Frontend Server";
 605     if (binitres->errcode)
 606     {
 607         logf(LOG_LOG, "Connection rejected by backend.");
 608         *resp->result = 0;
 609         assoc->rejected = 1;
 610     }
 611     return apdu;
 612 }
 613
 614 /*
 615  * These functions should be merged.
 616  */
 617
 618 /*
 619  * nonsurrogate diagnostic record.
 620  */
 621 static Z_Records *diagrec(oid_proto proto, int error, char *addinfo)
 622 {
 623     static Z_Records rec;
 624     oident bib1;
 625     static int err;
 626 #ifdef Z_95
 627     static Z_DiagRec drec;
 628     static Z_DefaultDiagFormat dr;
 629 #else
 630     static Z_DiagRec dr;
 631 #endif
 632
 633     bib1.proto = proto;
 634     bib1.class = CLASS_DIAGSET;
 635     bib1.value = VAL_BIB1;
 636
 637     logf(LOG_DEBUG, "Diagnostic: %d -- %s", error, addinfo ? addinfo :
 638         "NULL");
 639     err = error;
 640     rec.which = Z_Records_NSD;
 641 #ifdef Z_95
 642     rec.u.nonSurrogateDiagnostic = &drec;
 643     drec.which = Z_DiagRec_defaultFormat;
 644     drec.u.defaultFormat = &dr;
 645 #else
 646     rec.u.nonSurrogateDiagnostic = &dr;
 647 #endif
 648     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 649     dr.condition = &err;
 650     dr.which = Z_DiagForm_v2AddInfo;
 651     dr.addinfo = addinfo ? addinfo : "";
 652     return &rec;
 653 }
 654
 655 /*
 656  * surrogate diagnostic.
 657  */
 658 static Z_NamePlusRecord *surrogatediagrec(oid_proto proto, char *dbname,
 659                                             int error, char *addinfo)
 660 {
 661     static Z_NamePlusRecord rec;
 662     static int err;
 663     oident bib1;
 664 #ifdef Z_95
 665     static Z_DiagRec drec;
 666     static Z_DefaultDiagFormat dr;
 667 #else
 668     static Z_DiagRec dr;
 669 #endif
 670
 671     bib1.proto = proto;
 672     bib1.class = CLASS_DIAGSET;
 673     bib1.value = VAL_BIB1;
 674
 675     logf(LOG_DEBUG, "SurrogateDiagnotic: %d -- %s", error, addinfo);
 676     err = error;
 677     rec.databaseName = dbname;
 678     rec.which = Z_NamePlusRecord_surrogateDiagnostic;
 679 #ifdef Z_95
 680     rec.u.surrogateDiagnostic = &drec;
 681     drec.which = Z_DiagRec_defaultFormat;
 682     drec.u.defaultFormat = &dr;
 683 #else
 684     rec.u.surrogateDiagnostic = &dr;
 685 #endif
 686     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 687     dr.condition = &err;
 688     dr.which = Z_DiagForm_v2AddInfo;
 689     dr.addinfo = addinfo ? addinfo : "";
 690     return &rec;
 691 }
 692
 693 /*
 694  * multiple nonsurrogate diagnostics.
 695  */
 696 static Z_DiagRecs *diagrecs(oid_proto proto, int error, char *addinfo)
 697 {
 698     static Z_DiagRecs recs;
 699     static int err;
 700     oident bib1;
 701 #ifdef Z_95
 702     static Z_DiagRec *recp[1], drec;
 703     static Z_DefaultDiagFormat rec;
 704 #else
 705     static Z_DiagRec *recp[1], rec;
 706 #endif
 707
 708     logf(LOG_DEBUG, "DiagRecs: %d -- %s", error, addinfo);
 709     bib1.proto = proto;
 710     bib1.class = CLASS_DIAGSET;
 711     bib1.value = VAL_BIB1;
 712
 713     err = error;
 714     recs.num_diagRecs = 1;
 715     recs.diagRecs = recp;
 716 #ifdef Z_95
 717     recp[0] = &drec;
 718     drec.which = Z_DiagRec_defaultFormat;
 719     drec.u.defaultFormat = &rec;
 720 #else
 721     recp[0] = &rec;
 722 #endif
 723     rec.diagnosticSetId = oid_getoidbyent(&bib1);
 724     rec.condition = &err;
 725     rec.which = Z_DiagForm_v2AddInfo;
 726     rec.addinfo = addinfo ? addinfo : "";
 727     return &recs;
 728 }
 729
 730 #define MAX_RECORDS 256
 731
 732 static Z_Records *pack_records(association *a, char *setname, int start,
 733                                 int *num, Z_ElementSetNames *esn,
 734                                 int *next, int *pres, oid_value format)
 735 {
 736     int recno, total_length = 0, toget = *num;
 737     static Z_Records records;
 738     static Z_NamePlusRecordList reclist;
 739     static Z_NamePlusRecord *list[MAX_RECORDS];
 740     oident recform;
 741
 742     records.which = Z_Records_DBOSD;
 743     records.u.databaseOrSurDiagnostics = &reclist;
 744     reclist.num_records = 0;
 745     reclist.records = list;
 746     *pres = Z_PRES_SUCCESS;
 747     *num = 0;
 748     *next = 0;
 749
 750     logf(LOG_DEBUG, "Request to pack %d+%d", start, toget);
 751     logf(LOG_DEBUG, "pms=%d, mrs=%d", a->preferredMessageSize,
 752         a->maximumRecordSize);
 753     for (recno = start; reclist.num_records < toget; recno++)
 754     {
 755         bend_fetchrequest freq;
 756         bend_fetchresult *fres;
 757         Z_NamePlusRecord *thisrec;
 758         Z_DatabaseRecord *thisext;
 759
 760         if (reclist.num_records == MAX_RECORDS - 1)
 761         {
 762             *pres = Z_PRES_PARTIAL_2;
 763             break;
 764         }
 765         freq.setname = setname;
 766         freq.number = recno;
 767         freq.format = format;
 768         freq.stream = a->encode;
 769         if (!(fres = bend_fetch(a->backend, &freq, 0)))
 770         {
 771             *pres = Z_PRES_FAILURE;
 772             return diagrec(a->proto, 2, "Backend interface problem");
 773         }
 774         /* backend should be able to signal whether error is system-wide
 775            or only pertaining to current record */
 776         if (fres->errcode)
 777         {
 778             *pres = Z_PRES_FAILURE;
 779             return diagrec(a->proto, fres->errcode, fres->errstring);
 780         }
 781         logf(LOG_DEBUG, "  fetched record, len=%d, total=%d",
 782             fres->len, total_length);
 783         if (fres->len + total_length > a->preferredMessageSize)
 784         {
 785             /* record is small enough, really */
 786             if (fres->len <= a->preferredMessageSize)
 787             {
 788                 logf(LOG_DEBUG, "  Dropped last normal-sized record");
 789                 *pres = Z_PRES_PARTIAL_2;
 790                 break;
 791             }
 792             /* record can only be fetched by itself */
 793             if (fres->len < a->maximumRecordSize)
 794             {
 795                 logf(LOG_DEBUG, "  Record > prefmsgsz");
 796                 if (toget > 1)
 797                 {
 798                     logf(LOG_DEBUG, "  Dropped it");
 799                     reclist.records[reclist.num_records] =
 800                          surrogatediagrec(a->proto, fres->basename, 16, 0);
 801                     reclist.num_records++;
 802                     total_length += 10; /* totally arbitrary */
 803                     continue;
 804                 }
 805             }
 806             else /* too big entirely */
 807             {
 808                 logf(LOG_DEBUG, "Record > maxrcdsz");
 809                 reclist.records[reclist.num_records] =
 810                     surrogatediagrec(a->proto, fres->basename, 17, 0);
 811                 reclist.num_records++;
 812                 total_length += 10; /* totally arbitrary */
 813                 continue;
 814             }
 815         }
 816         if (!(thisrec = odr_malloc(a->encode, sizeof(*thisrec))))
 817             return 0;
 818         if (!(thisrec->databaseName = odr_malloc(a->encode,
 819             strlen(fres->basename) + 1)))
 820             return 0;
 821         strcpy(thisrec->databaseName, fres->basename);
 822         thisrec->which = Z_NamePlusRecord_databaseRecord;
 823         if (!(thisrec->u.databaseRecord = thisext = odr_malloc(a->encode,
 824             sizeof(Z_DatabaseRecord))))
 825             return 0;
 826         recform.proto = a->proto;
 827         recform.class = CLASS_RECSYN;
 828         recform.value = fres->format;
 829         thisext->direct_reference = odr_oiddup(a->encode,
 830             oid_getoidbyent(&recform));
 831         thisext->indirect_reference = 0;
 832         thisext->descriptor = 0;
 833         if (fres->len < 0) /* Structured data */
 834         {
 835             switch (fres->format)
 836             {
 837                 case VAL_SUTRS: thisext->which = Z_External_sutrs; break;
 838                 case VAL_GRS1: thisext->which = Z_External_grs1; break;
 839                 case VAL_EXPLAIN: thisext->which = Z_External_explainRecord;
 840                     break;
 841
 842                 default:
 843                     logf(LOG_FATAL, "Unknown structured format from backend.");
 844                     return 0;
 845             }
 846
 847             /*
 848              * We cheat on the pointers here. Obviously, the record field
 849              * of the backend-fetch structure should have been a union for
 850              * correctness, but we're stuck with this for backwards
 851              * compatibility.
 852              */
 853             thisext->u.grs1 = (Z_GenericRecord*) fres->record;
 854         }
 855         else if (fres->format == VAL_SUTRS) /* SUTRS is a single-ASN.1-type */
 856         {
 857             Odr_oct *sutrs = odr_malloc(a->encode, sizeof(*sutrs));
 858
 859             thisext->which = Z_External_sutrs;
 860             thisext->u.sutrs = sutrs;
 861             sutrs->buf = odr_malloc(a->encode, fres->len);
 862             sutrs->len = sutrs->size = fres->len;
 863             memcpy(sutrs->buf, fres->record, fres->len);
 864         }
 865         else /* octet-aligned record. */
 866         {
 867             thisext->which = Z_External_octet;
 868             if (!(thisext->u.octet_aligned = odr_malloc(a->encode,
 869                 sizeof(Odr_oct))))
 870                 return 0;
 871             if (!(thisext->u.octet_aligned->buf = odr_malloc(a->encode,
 872                 fres->len)))
 873                 return 0;
 874             memcpy(thisext->u.octet_aligned->buf, fres->record, fres->len);
 875             thisext->u.octet_aligned->len = thisext->u.octet_aligned->size =
 876                 fres->len;
 877         }
 878         reclist.records[reclist.num_records] = thisrec;
 879         reclist.num_records++;
 880         total_length += fres->len;
 881         *next = fres->last_in_set ? 0 : recno + 1;
 882     }
 883     *num = reclist.num_records;
 884     return &records;
 885 }
 886
 887 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 888     int *fd)
 889 {
 890     Z_SearchRequest *req = reqb->request->u.searchRequest;
 891     bend_searchrequest bsrq;
 892     bend_searchresult *bsrt;
 893
 894     logf(LOG_LOG, "Got SearchRequest.");
 895
 896     bsrq.setname = req->resultSetName;
 897     bsrq.replace_set = *req->replaceIndicator;
 898     bsrq.num_bases = req->num_databaseNames;
 899     bsrq.basenames = req->databaseNames;
 900     bsrq.query = req->query;
 901
 902     if (!(bsrt = bend_search(assoc->backend, &bsrq, fd)))
 903         return 0;
 904     return response_searchRequest(assoc, reqb, bsrt, fd);
 905 }
 906
 907 bend_searchresult *bend_searchresponse(void *handle) {return 0;}
 908
 909 /*
 910  * Prepare a searchresponse based on the backend results. We probably want
 911  * to look at making the fetching of records nonblocking as well, but
 912  * so far, we'll keep things simple.
 913  * If bsrt is null, that means we're called in response to a communications
 914  * event, and we'll have to get the response for ourselves.
 915  */
 916 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 917     bend_searchresult *bsrt, int *fd)
 918 {
 919     Z_SearchRequest *req = reqb->request->u.searchRequest;
 920     static Z_APDU apdu;
 921     static Z_SearchResponse resp;
 922     static int nulint = 0;
 923     static bool_t sr = 1;
 924     static int next = 0;
 925     static int none = Z_RES_NONE;
 926
 927     apdu.which = Z_APDU_searchResponse;
 928     apdu.u.searchResponse = &resp;
 929     resp.referenceId = req->referenceId;
 930 #ifdef Z_95
 931     resp.additionalSearchInfo = 0;
 932     resp.otherInfo = 0;
 933 #endif
 934     *fd = -1;
 935     if (!bsrt && !(bsrt = bend_searchresponse(assoc->backend)))
 936     {
 937         logf(LOG_FATAL, "Bad result from backend");
 938         return 0;
 939     }
 940     else if (bsrt->errcode)
 941     {
 942         resp.records = diagrec(assoc->proto, bsrt->errcode,
 943             bsrt->errstring);
 944         resp.resultCount = &nulint;
 945         resp.numberOfRecordsReturned = &nulint;
 946         resp.nextResultSetPosition = &nulint;
 947         resp.searchStatus = &nulint;
 948         resp.resultSetStatus = &none;
 949         resp.presentStatus = 0;
 950     }
 951     else
 952     {
 953         static int toget;
 954         Z_ElementSetNames *setnames;
 955         static int presst = 0;
 956
 957         resp.records = 0;
 958         resp.resultCount = &bsrt->hits;
 959
 960         /* how many records does the user agent want, then? */
 961         if (bsrt->hits <= *req->smallSetUpperBound)
 962         {
 963             toget = bsrt->hits;
 964             setnames = req->smallSetElementSetNames;
 965         }
 966         else if (bsrt->hits < *req->largeSetLowerBound)
 967         {
 968             toget = *req->mediumSetPresentNumber;
 969             if (toget > bsrt->hits)
 970                 toget = bsrt->hits;
 971             setnames = req->mediumSetElementSetNames;
 972         }
 973         else
 974             toget = 0;
 975
 976         if (toget && !resp.records)
 977         {
 978             oident *prefformat;
 979             oid_value form;
 980
 981             if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
 982                 prefformat->class != CLASS_RECSYN)
 983                 form = VAL_NONE;
 984             else
 985                 form = prefformat->value;
 986             resp.records = pack_records(assoc, req->resultSetName, 1,
 987                 &toget, setnames, &next, &presst, form);
 988             if (!resp.records)
 989                 return 0;
 990             resp.numberOfRecordsReturned = &toget;
 991             resp.nextResultSetPosition = &next;
 992             resp.searchStatus = &sr;
 993             resp.resultSetStatus = 0;
 994             resp.presentStatus = &presst;
 995         }
 996         else
 997         {
 998             if (*resp.resultCount)
 999                 next = 1;
1000             resp.numberOfRecordsReturned = &nulint;
1001             resp.nextResultSetPosition = &next;
1002             resp.searchStatus = &sr;
1003             resp.resultSetStatus = 0;
1004             resp.presentStatus = 0;
1005         }
1006     }
1007     return &apdu;
1008 }
1009
1010 /*
1011  * Maybe we got a little over-friendly when we designed bend_fetch to
1012  * get only one record at a time. Some backends can optimise multiple-record
1013  * fetches, and at any rate, there is some overhead involved in
1014  * all that selecting and hopping around. Problem is, of course, that the
1015  * frontend can't know ahead of time how many records it'll need to
1016  * fill the negotiated PDU size. Annoying. Segmentation or not, Z/SR
1017  * is downright lousy as a bulk data transfer protocol.
1018  *
1019  * To start with, we'll do the fetching of records from the backend
1020  * in one operation: To save some trips in and out of the event-handler,
1021  * and to simplify the interface to pack_records. At any rate, asynch
1022  * operation is more fun in operations that have an unpredictable execution
1023  * speed - which is normally more true for search than for present.
1024  */
1025 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
1026     int *fd)
1027 {
1028     Z_PresentRequest *req = reqb->request->u.presentRequest;
1029     static Z_APDU apdu;
1030     static Z_PresentResponse resp;
1031     static int presst, next, num;
1032     oident *prefformat;
1033     oid_value form;
1034
1035
1036     logf(LOG_LOG, "Got PresentRequest.");
1037     apdu.which = Z_APDU_presentResponse;
1038     apdu.u.presentResponse = &resp;
1039     resp.referenceId = req->referenceId;
1040 #ifdef Z_95
1041     resp.otherInfo = 0;
1042 #endif
1043
1044     if (!(prefformat = oid_getentbyoid(req->preferredRecordSyntax)) ||
1045         prefformat->class != CLASS_RECSYN)
1046         form = VAL_NONE;
1047     else
1048         form = prefformat->value;
1049     num = *req->numberOfRecordsRequested;
1050     resp.records = pack_records(assoc, req->resultSetId,
1051         *req->resultSetStartPoint, &num, 0, &next, &presst, form);
1052     if (!resp.records)
1053         return 0;
1054     resp.numberOfRecordsReturned = &num;
1055     resp.presentStatus = &presst;
1056     resp.nextResultSetPosition = &next;
1057
1058     return &apdu;
1059 }
1060
1061 /*
1062  * Scan was implemented rather in a hurry, and with support for only the basic
1063  * elements of the service in the backend API. Suggestions are welcome.
1064  */
1065 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd)
1066 {
1067     Z_ScanRequest *req = reqb->request->u.scanRequest;
1068     static Z_APDU apdu;
1069     static Z_ScanResponse res;
1070     static int scanStatus = Z_Scan_failure;
1071     static int numberOfEntriesReturned = 0;
1072     oident *attent;
1073     static Z_ListEntries ents;
1074 #define SCAN_MAX_ENTRIES 200
1075     static Z_Entry *tab[SCAN_MAX_ENTRIES];
1076     bend_scanrequest srq;
1077     bend_scanresult *srs;
1078
1079     logf(LOG_LOG, "Got scanrequest");
1080     apdu.which = Z_APDU_scanResponse;
1081     apdu.u.scanResponse = &res;
1082     res.referenceId = req->referenceId;
1083     res.stepSize = 0;
1084     res.scanStatus = &scanStatus;
1085     res.numberOfEntriesReturned = &numberOfEntriesReturned;
1086     res.positionOfTerm = 0;
1087     res.entries = &ents;
1088     ents.which = Z_ListEntries_nonSurrogateDiagnostics;
1089     res.attributeSet = 0;
1090 #ifdef Z_95
1091     res.otherInfo = 0;
1092 #endif
1093
1094     if (req->attributeSet && (!(attent = oid_getentbyoid(req->attributeSet)) ||
1095         attent->class != CLASS_ATTSET || attent->value != VAL_BIB1))
1096         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 121, 0);
1097     else if (req->stepSize && *req->stepSize > 0)
1098         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 205, 0);
1099     else
1100     {
1101         if (req->termListAndStartPoint->term->which == Z_Term_general)
1102             logf(LOG_DEBUG, " term: '%.*s'",
1103                 req->termListAndStartPoint->term->u.general->len,
1104                 req->termListAndStartPoint->term->u.general->buf);
1105         srq.num_bases = req->num_databaseNames;
1106         srq.basenames = req->databaseNames;
1107         srq.num_entries = *req->numberOfTermsRequested;
1108         srq.term = req->termListAndStartPoint;
1109         srq.term_position = req->preferredPositionInResponse ?
1110             *req->preferredPositionInResponse : 1;
1111         if (!(srs = bend_scan(assoc->backend, &srq, 0)))
1112             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 2, 0);
1113         else if (srs->errcode)
1114             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto,
1115                 srs->errcode, srs->errstring);
1116         else
1117         {
1118             int i;
1119             static Z_Entries list;
1120
1121             if (srs->status == BEND_SCAN_PARTIAL)
1122                 scanStatus = Z_Scan_partial_5;
1123             else
1124                 scanStatus = Z_Scan_success;
1125             ents.which = Z_ListEntries_entries;
1126             ents.u.entries = &list;
1127             list.entries = tab;
1128             for (i = 0; i < srs->num_entries; i++)
1129             {
1130                 Z_Entry *e;
1131                 Z_TermInfo *t;
1132                 Odr_oct *o;
1133
1134                 if (i >= SCAN_MAX_ENTRIES)
1135                 {
1136                     scanStatus = Z_Scan_partial_4;
1137                     break;
1138                 }
1139                 list.entries[i] = e = odr_malloc(assoc->encode, sizeof(*e));
1140                 e->which = Z_Entry_termInfo;
1141                 e->u.termInfo = t = odr_malloc(assoc->encode, sizeof(*t));
1142                 t->suggestedAttributes = 0;
1143                 t->alternativeTerm = 0;
1144                 t->byAttributes = 0;
1145                 t->globalOccurrences = &srs->entries[i].occurrences;
1146                 t->term = odr_malloc(assoc->encode, sizeof(*t->term));
1147                 t->term->which = Z_Term_general;
1148                 t->term->u.general = o = odr_malloc(assoc->encode,
1149                     sizeof(Odr_oct));
1150                 o->buf = odr_malloc(assoc->encode, o->len = o->size =
1151                     strlen(srs->entries[i].term));
1152                 memcpy(o->buf, srs->entries[i].term, o->len);
1153                 logf(LOG_DEBUG, "  term #%d: '%s' (%d)", i,
1154                     srs->entries[i].term, srs->entries[i].occurrences);
1155             }
1156             list.num_entries = i;
1157             res.numberOfEntriesReturned = &list.num_entries;
1158             res.positionOfTerm = &srs->term_position;
1159         }
1160     }
1161
1162     return &apdu;
1163 }