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