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