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 1.24  1995-05-16 08:51:04  quinn
   8  * License, documentation, and memory fixes
   9  *
  10  * Revision 1.23  1995/05/15  13:25:10  quinn
  11  * Fixed memory bug.
  12  *
  13  * Revision 1.22  1995/05/15  11:56:39  quinn
  14  * Asynchronous facilities. Restructuring of seshigh code.
  15  *
  16  * Revision 1.21  1995/05/02  08:53:19  quinn
  17  * Trying in vain to fix comm with ISODE
  18  *
  19  * Revision 1.20  1995/04/20  15:13:00  quinn
  20  * Cosmetic
  21  *
  22  * Revision 1.19  1995/04/18  08:15:34  quinn
  23  * Added dynamic memory allocation on encoding (whew). Code is now somewhat
  24  * neater. We'll make the same change for decoding one day.
  25  *
  26  * Revision 1.18  1995/04/17  11:28:25  quinn
  27  * Smallish
  28  *
  29  * Revision 1.17  1995/04/10  10:23:36  quinn
  30  * Some work to add scan and other things.
  31  *
  32  * Revision 1.16  1995/03/31  09:18:55  quinn
  33  * Added logging.
  34  *
  35  * Revision 1.15  1995/03/30  14:03:23  quinn
  36  * Added RFC1006 as separate library
  37  *
  38  * Revision 1.14  1995/03/30  12:18:17  quinn
  39  * Fixed bug.
  40  *
  41  * Revision 1.13  1995/03/30  09:09:24  quinn
  42  * Added state-handle and some support for asynchronous activities.
  43  *
  44  * Revision 1.12  1995/03/29  15:40:16  quinn
  45  * Ongoing work. Statserv is now dynamic by default
  46  *
  47  * Revision 1.11  1995/03/28  09:16:21  quinn
  48  * Added record packing to the search request
  49  *
  50  * Revision 1.10  1995/03/27  08:34:24  quinn
  51  * Added dynamic server functionality.
  52  * Released bindings to session.c (is now redundant)
  53  *
  54  * Revision 1.9  1995/03/22  15:01:26  quinn
  55  * Adjusting record packing.
  56  *
  57  * Revision 1.8  1995/03/22  10:13:21  quinn
  58  * Working on record packer
  59  *
  60  * Revision 1.7  1995/03/21  15:53:31  quinn
  61  * Little changes.
  62  *
  63  * Revision 1.6  1995/03/21  12:30:09  quinn
  64  * Beginning to add support for record packing.
  65  *
  66  * Revision 1.5  1995/03/17  10:44:13  quinn
  67  * Added catch of null-string in makediagrec
  68  *
  69  * Revision 1.4  1995/03/17  10:18:08  quinn
  70  * Added memory management.
  71  *
  72  * Revision 1.3  1995/03/16  17:42:39  quinn
  73  * Little changes
  74  *
  75  * Revision 1.2  1995/03/16  13:29:01  quinn
  76  * Partitioned server.
  77  *
  78  * Revision 1.1  1995/03/15  16:02:10  quinn
  79  * Modded session.c to seshigh.c
  80  *
  81  */
  82
  83 /*
  84  * Frontend server logic.
  85  *
  86  * This code receives incoming APDUs, and handles client requests by means
  87  * of the backend API.
  88  *
  89  * Some of the code is getting quite involved, compared to simpler servers -
  90  * primarily because it is asynchronous both in the communication with
  91  * the user and the backend. We think the complexity will pay off in
  92  * the form of greater flexibility when more asynchronous facilities
  93  * are implemented.
  94  *
  95  * Memory management has become somewhat involved. In the simple case, where
  96  * only one PDU is pending at a time, it will simply reuse the same memory,
  97  * once it has found its working size. When we enable multiple concurrent
  98  * operations, perhaps even with multiple parallel calls to the backend, it
  99  * will maintain a pool of buffers for encoding and decoding, trying to
 100  * minimize memory allocation/deallocation during normal operation.
 101  *
 102  * TODOs include (and will be done in order of public interest):
 103  *
 104  * Support for EXPLAIN - provide simple meta-database system.
 105  * Support for access control.
 106  * Support for resource control.
 107  * Support for extended services - primarily Item Order.
 108  * Rest of Z39.50-1994
 109  *
 110  */
 111
 112 #include <stdlib.h>
 113 #include <stdio.h>
 114 #include <unistd.h>
 115 #include <assert.h>
 116
 117 #include <dmalloc.h>
 118 #include <comstack.h>
 119 #include <eventl.h>
 120 #include <session.h>
 121 #include <proto.h>
 122 #include <oid.h>
 123 #include <log.h>
 124 #include <statserv.h>
 125 #include "../version.h"
 126
 127 #include <backend.h>
 128
 129 static int process_request(association *assoc);
 130 void backend_response(IOCHAN i, int event);
 131 static int process_response(association *assoc, request *req, Z_APDU *res);
 132 static Z_APDU *process_initRequest(association *assoc, request *reqb);
 133 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 134     int *fd);
 135 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 136     bend_searchresult *bsrt, int *fd);
 137 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 138     int *fd);
 139 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd);
 140
 141 static FILE *apduf = 0; /* for use in static mode */
 142 static statserv_options_block *control_block = 0;
 143
 144 /*
 145  * Create and initialize a new association-handle.
 146  *  channel  : iochannel for the current line.
 147  *  link     : communications channel.
 148  * Returns: 0 or a new association handle.
 149  */
 150 association *create_association(IOCHAN channel, COMSTACK link)
 151 {
 152     association *new;
 153
 154     if (!control_block)
 155         control_block = statserv_getcontrol();
 156     if (!(new = malloc(sizeof(*new))))
 157         return 0;
 158     new->client_chan = channel;
 159     new->client_link = link;
 160     if (!(new->decode = odr_createmem(ODR_DECODE)) ||
 161         !(new->encode = odr_createmem(ODR_ENCODE)))
 162         return 0;
 163     if (*control_block->apdufile)
 164     {
 165         char filename[256];
 166         FILE *f;
 167
 168         strcpy(filename, control_block->apdufile);
 169         if (!(new->print = odr_createmem(ODR_PRINT)))
 170             return 0;
 171         if (*control_block->apdufile != '-')
 172         {
 173             strcpy(filename, control_block->apdufile);
 174             if (!control_block->dynamic)
 175             {
 176                 if (!apduf)
 177                 {
 178                     if (!(apduf = fopen(filename, "w")))
 179                     {
 180                         logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 181                         return 0;
 182                     }
 183                     setvbuf(apduf, 0, _IONBF, 0);
 184                 }
 185                 f = apduf;
 186             }
 187             else
 188             {
 189                 sprintf(filename + strlen(filename), ".%d", getpid());
 190                 if (!(f = fopen(filename, "w")))
 191                 {
 192                     logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 193                     return 0;
 194                 }
 195                 setvbuf(f, 0, _IONBF, 0);
 196             }
 197             odr_setprint(new->print, f);
 198         }
 199     }
 200     else
 201         new->print = 0;
 202     new->input_buffer = 0;
 203     new->input_buffer_len = 0;
 204     new->backend = 0;
 205     request_initq(&new->incoming);
 206     request_initq(&new->outgoing);
 207     if (cs_getproto(link) == CS_Z3950)
 208         new->proto = PROTO_Z3950;
 209     else
 210         new->proto = PROTO_SR;
 211     return new;
 212 }
 213
 214 /*
 215  * Free association and release resources.
 216  */
 217 void destroy_association(association *h)
 218 {
 219     odr_destroy(h->decode);
 220     odr_destroy(h->encode);
 221     if (h->print)
 222         odr_destroy(h->print);
 223     if (h->input_buffer)
 224         free(h->input_buffer);
 225     if (h->backend)
 226         bend_close(h->backend);
 227     while (request_deq(&h->incoming));
 228     while (request_deq(&h->outgoing));
 229     free(h);
 230 }
 231
 232 /*
 233  * This is where PDUs from the client are read and the further
 234  * processing is initiated. Flow of control moves down through the
 235  * various process_* functions below, until the encoded result comes back up
 236  * to the output handler in here.
 237  *
 238  *  h     : the I/O channel that has an outstanding event.
 239  *  event : the current outstanding event.
 240  */
 241 void ir_session(IOCHAN h, int event)
 242 {
 243     int res;
 244     association *assoc = iochan_getdata(h);
 245     COMSTACK conn = assoc->client_link;
 246     request *req;
 247
 248     assert(h && conn && assoc);
 249     if (event & EVENT_INPUT || event & EVENT_WORK) /* input */
 250     {
 251         if (event & EVENT_INPUT)
 252         {
 253             logf(LOG_DEBUG, "ir_session (input)");
 254             assert(assoc && conn);
 255             if ((res = cs_get(conn, &assoc->input_buffer,
 256                 &assoc->input_buffer_len)) <= 0)
 257             {
 258                 logf(LOG_LOG, "Connection closed by client");
 259                 cs_close(conn);
 260                 destroy_association(assoc);
 261                 iochan_destroy(h);
 262                 return;
 263             }
 264             else if (res == 1) /* incomplete read - wait for more  */
 265                 return;
 266             if (cs_more(conn)) /* more stuff - call us again later, please */
 267                 iochan_setevent(h, EVENT_INPUT);
 268
 269             /* we got a complete PDU. Let's decode it */
 270             req = request_get(); /* get a new request structure */
 271             odr_reset(assoc->decode);
 272             odr_setbuf(assoc->decode, assoc->input_buffer, res, 0);
 273             if (!z_APDU(assoc->decode, &req->request, 0))
 274             {
 275                 logf(LOG_WARN, "ODR error: %s",
 276                     odr_errlist[odr_geterror(assoc->decode)]);
 277                 cs_close(conn);
 278                 destroy_association(assoc);
 279                 iochan_destroy(h);
 280                 return;
 281             }
 282             req->request_mem = odr_extract_mem(assoc->decode);
 283             if (assoc->print && !z_APDU(assoc->print, &req->request, 0))
 284             {
 285                 logf(LOG_WARN, "ODR print error: %s",
 286                     odr_errlist[odr_geterror(assoc->print)]);
 287                 odr_reset(assoc->print);
 288             }
 289             request_enq(&assoc->incoming, req);
 290         }
 291
 292         /* can we do something yet? */
 293         req = request_head(&assoc->incoming);
 294         if (req->state == REQUEST_IDLE)
 295             if (process_request(assoc) < 0)
 296             {
 297                 cs_close(conn);
 298                 destroy_association(assoc);
 299                 iochan_destroy(h);
 300             }
 301     }
 302     if (event & EVENT_OUTPUT)
 303     {
 304         request *req = request_head(&assoc->outgoing);
 305
 306         logf(LOG_DEBUG, "ir_session (output)");
 307         req->state = REQUEST_PENDING;
 308         switch (res = cs_put(conn, req->response, req->len_response))
 309         {
 310             case -1:
 311                 logf(LOG_LOG, "Connection closed by client");
 312                 cs_close(conn);
 313                 destroy_association(assoc);
 314                 iochan_destroy(h);
 315                 break;
 316             case 0: /* all sent - release the request structure */
 317                 odr_release_mem(req->request_mem);
 318                 request_deq(&assoc->outgoing);
 319                 request_release(req);
 320                 if (!request_head(&assoc->outgoing))
 321                     iochan_clearflag(h, EVENT_OUTPUT);
 322                 break;
 323             /* value of 1 -- partial send -- is simply ignored */
 324         }
 325     }
 326     if (event & EVENT_EXCEPT)
 327     {
 328         logf(LOG_DEBUG, "ir_session (exception)");
 329         cs_close(conn);
 330         destroy_association(assoc);
 331         iochan_destroy(h);
 332     }
 333 }
 334
 335 /*
 336  * Initiate request processing.
 337  */
 338 static int process_request(association *assoc)
 339 {
 340     request *req = request_head(&assoc->incoming);
 341     int fd = -1;
 342     Z_APDU *res;
 343
 344     logf(LOG_DEBUG, "process_request");
 345     assert(req && req->state == REQUEST_IDLE);
 346     switch (req->request->which)
 347     {
 348         case Z_APDU_initRequest:
 349             res = process_initRequest(assoc, req); break;
 350         case Z_APDU_searchRequest:
 351             res = process_searchRequest(assoc, req, &fd); break;
 352         case Z_APDU_presentRequest:
 353             res = process_presentRequest(assoc, req, &fd); break;
 354         case Z_APDU_scanRequest:
 355             res = process_scanRequest(assoc, req, &fd); break;
 356         default:
 357             logf(LOG_WARN, "Bad APDU");
 358             return -1;
 359     }
 360     if (res)
 361     {
 362         logf(LOG_DEBUG, "  result immediately available");
 363         return process_response(assoc, req, res);
 364     }
 365     else if (fd < 0)
 366     {
 367         logf(LOG_WARN, "   bad result");
 368         return -1;
 369     }
 370     else /* no result yet - one will be provided later */
 371     {
 372         IOCHAN chan;
 373
 374         /* Set up an I/O handler for the fd supplied by the backend */
 375
 376         logf(LOG_DEBUG, "   establishing handler for result");
 377         req->state = REQUEST_PENDING;
 378         if (!(chan = iochan_create(fd, backend_response, EVENT_INPUT)))
 379             abort();
 380         iochan_setdata(chan, assoc);
 381         return 0;
 382     }
 383 }
 384
 385 /*
 386  * Handle message from the backend.
 387  */
 388 void backend_response(IOCHAN i, int event)
 389 {
 390     association *assoc = iochan_getdata(i);
 391     request *req = request_head(&assoc->incoming);
 392     Z_APDU *res;
 393     int fd;
 394
 395     logf(LOG_DEBUG, "backend_response");
 396     assert(assoc && req && req->state != REQUEST_IDLE);
 397     /* determine what it is we're waiting for */
 398     switch (req->request->which)
 399     {
 400         case Z_APDU_searchRequest:
 401             res = response_searchRequest(assoc, req, 0, &fd); break;
 402 #if 0
 403         case Z_APDU_presentRequest:
 404             res = response_presentRequest(assoc, req, 0, &fd); break;
 405         case Z_APDU_scanRequest:
 406             res = response_scanRequest(assoc, req, 0, &fd); break;
 407 #endif
 408         default:
 409             logf(LOG_WARN, "Serious programmer's lapse or bug");
 410             abort();
 411     }
 412     if ((res && process_response(assoc, req, res) < 0) || fd < 0)
 413     {
 414         logf(LOG_LOG, "Fatal error when talking to backend");
 415         cs_close(assoc->client_link);
 416         destroy_association(assoc);
 417         iochan_destroy(assoc->client_chan);
 418         iochan_destroy(i);
 419         return;
 420     }
 421     else if (!res) /* no result yet - try again later */
 422     {
 423         logf(LOG_DEBUG, "   no result yet");
 424         iochan_setfd(i, fd); /* in case fd has changed */
 425     }
 426 }
 427
 428 /*
 429  * Encode response, and transfer the request structure to the outgoing queue.
 430  */
 431 static int process_response(association *assoc, request *req, Z_APDU *res)
 432 {
 433     odr_setbuf(assoc->encode, req->response, req->size_response, 1);
 434     if (!z_APDU(assoc->encode, &res, 0))
 435     {
 436         logf(LOG_WARN, "ODR error when encoding response: %s",
 437             odr_errlist[odr_geterror(assoc->decode)]);
 438         return -1;
 439     }
 440     req->response = odr_getbuf(assoc->encode, &req->len_response,
 441         &req->size_response);
 442     odr_setbuf(assoc->encode, 0, 0, 0); /* don't free if we have to quit */
 443     odr_reset(assoc->encode);
 444     if (assoc->print && !z_APDU(assoc->print, &res, 0))
 445     {
 446         logf(LOG_WARN, "ODR print error: %s",
 447             odr_errlist[odr_geterror(assoc->print)]);
 448         odr_reset(assoc->print);
 449     }
 450     /* change this when we make the backend reentrant */
 451     assert(req == request_head(&assoc->incoming));
 452     req->state = REQUEST_IDLE;
 453     request_deq(&assoc->incoming);
 454     request_enq(&assoc->outgoing, req);
 455     /* turn the work over to the ir_session handler */
 456     iochan_setflag(assoc->client_chan, EVENT_OUTPUT);
 457     /* Is there more work to be done? */
 458     if (request_head(&assoc->incoming))
 459         iochan_setevent(assoc->client_chan, EVENT_WORK);
 460     return 0;
 461 }
 462
 463 static Z_APDU *process_initRequest(association *assoc, request *reqb)
 464 {
 465     Z_InitRequest *req = reqb->request->u.initRequest;
 466     static Z_APDU apdu;
 467     static Z_InitResponse resp;
 468     static bool_t result = 1;
 469     static Odr_bitmask options, protocolVersion;
 470     bend_initrequest binitreq;
 471     bend_initresult *binitres;
 472
 473     logf(LOG_LOG, "Got initRequest");
 474     if (req->implementationId)
 475         logf(LOG_LOG, "Id:        %s", req->implementationId);
 476     if (req->implementationName)
 477         logf(LOG_LOG, "Name:      %s", req->implementationName);
 478     if (req->implementationVersion)
 479         logf(LOG_LOG, "Version:   %s", req->implementationVersion);
 480
 481     binitreq.configname = "default-config";
 482     if (!(binitres = bend_init(&binitreq)) || binitres->errcode)
 483     {
 484         logf(LOG_WARN, "Negative response from backend");
 485         return 0;
 486     }
 487
 488     assoc->backend = binitres->handle;
 489     apdu.which = Z_APDU_initResponse;
 490     apdu.u.initResponse = &resp;
 491     resp.referenceId = req->referenceId;
 492     /* let's tell the client what we can do */
 493     ODR_MASK_ZERO(&options);
 494     if (ODR_MASK_GET(req->options, Z_Options_search))
 495         ODR_MASK_SET(&options, Z_Options_search);
 496     if (ODR_MASK_GET(req->options, Z_Options_present))
 497         ODR_MASK_SET(&options, Z_Options_present);
 498 #if 0
 499     if (ODR_MASK_GET(req->options, Z_Options_delSet))
 500         ODR_MASK_SET(&options, Z_Options_delSet);
 501 #endif
 502     if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 503         ODR_MASK_SET(&options, Z_Options_namedResultSets);
 504     if (ODR_MASK_GET(req->options, Z_Options_scan))
 505         ODR_MASK_SET(&options, Z_Options_scan);
 506     if (ODR_MASK_GET(req->options, Z_Options_concurrentOperations))
 507         ODR_MASK_SET(&options, Z_Options_concurrentOperations);
 508     resp.options = &options;
 509
 510     ODR_MASK_ZERO(&protocolVersion);
 511     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_1))
 512         ODR_MASK_SET(&protocolVersion, Z_ProtocolVersion_1);
 513     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_2))
 514         ODR_MASK_SET(&protocolVersion, Z_ProtocolVersion_2);
 515     resp.protocolVersion = &protocolVersion;
 516     assoc->maximumRecordSize = *req->maximumRecordSize;
 517     if (assoc->maximumRecordSize > control_block->maxrecordsize)
 518         assoc->maximumRecordSize = control_block->maxrecordsize;
 519     assoc->preferredMessageSize = *req->preferredMessageSize;
 520     if (assoc->preferredMessageSize > assoc->maximumRecordSize)
 521         assoc->preferredMessageSize = assoc->maximumRecordSize;
 522     resp.preferredMessageSize = &assoc->preferredMessageSize;
 523     resp.maximumRecordSize = &assoc->maximumRecordSize;
 524     resp.result = &result;
 525     resp.implementationId = "YAZ";
 526     resp.implementationName = "Index Data/YAZ Generic Frontend Server";
 527     resp.implementationVersion = YAZ_VERSION;
 528     resp.userInformationField = 0;
 529     return &apdu;
 530 }
 531
 532 static Z_Records *diagrec(oid_proto proto, int error, char *addinfo)
 533 {
 534     static Z_Records rec;
 535     oident bib1;
 536     static Z_DiagRec dr;
 537     static int err;
 538
 539     bib1.proto = proto;
 540     bib1.class = CLASS_DIAGSET;
 541     bib1.value = VAL_BIB1;
 542
 543     logf(LOG_DEBUG, "Diagnostic: %d -- %s", error, addinfo ? addinfo :
 544         "NULL");
 545     err = error;
 546     rec.which = Z_Records_NSD;
 547     rec.u.nonSurrogateDiagnostic = &dr;
 548     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 549     dr.condition = &err;
 550     dr.addinfo = addinfo ? addinfo : "";
 551     return &rec;
 552 }
 553
 554 static Z_NamePlusRecord *surrogatediagrec(oid_proto proto, char *dbname,
 555                                             int error, char *addinfo)
 556 {
 557     static Z_NamePlusRecord rec;
 558     static Z_DiagRec dr;
 559     static int err;
 560     oident bib1;
 561
 562     bib1.proto = proto;
 563     bib1.class = CLASS_DIAGSET;
 564     bib1.value = VAL_BIB1;
 565
 566     logf(LOG_DEBUG, "SurrogateDiagnotic: %d -- %s", error, addinfo);
 567     err = error;
 568     rec.databaseName = dbname;
 569     rec.which = Z_NamePlusRecord_surrogateDiagnostic;
 570     rec.u.surrogateDiagnostic = &dr;
 571     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 572     dr.condition = &err;
 573     dr.addinfo = addinfo ? addinfo : "";
 574     return &rec;
 575 }
 576
 577 static Z_DiagRecs *diagrecs(oid_proto proto, int error, char *addinfo)
 578 {
 579     static Z_DiagRecs recs;
 580     static Z_DiagRec *recp[1], rec;
 581     static int err;
 582     oident bib1;
 583
 584     logf(LOG_DEBUG, "DiagRecs: %d -- %s", error, addinfo);
 585     bib1.proto = proto;
 586     bib1.class = CLASS_DIAGSET;
 587     bib1.value = VAL_BIB1;
 588
 589     err = error;
 590     recs.num_diagRecs = 1;
 591     recs.diagRecs = recp;
 592     recp[0] = &rec;
 593     rec.diagnosticSetId = oid_getoidbyent(&bib1);
 594     rec.condition = &err;
 595     rec.addinfo = addinfo ? addinfo : "";
 596     return &recs;
 597 }
 598
 599 #define MAX_RECORDS 256
 600
 601 static Z_Records *pack_records(association *a, char *setname, int start,
 602                                 int *num, Z_ElementSetNames *esn,
 603                                 int *next, int *pres)
 604 {
 605     int recno, total_length = 0, toget = *num;
 606     static Z_Records records;
 607     static Z_NamePlusRecordList reclist;
 608     static Z_NamePlusRecord *list[MAX_RECORDS];
 609     oident recform;
 610     Odr_oid *oid;
 611
 612     records.which = Z_Records_DBOSD;
 613     records.u.databaseOrSurDiagnostics = &reclist;
 614     reclist.num_records = 0;
 615     reclist.records = list;
 616     *pres = Z_PRES_SUCCESS;
 617     *num = 0;
 618     *next = 0;
 619
 620     recform.proto = a->proto;
 621     recform.class = CLASS_RECSYN;
 622     recform.value = VAL_USMARC;
 623     if (!(oid = odr_oiddup(a->encode, oid_getoidbyent(&recform))))
 624         return 0;
 625
 626     logf(LOG_DEBUG, "Request to pack %d+%d", start, toget);
 627     logf(LOG_DEBUG, "pms=%d, mrs=%d", a->preferredMessageSize,
 628         a->maximumRecordSize);
 629     for (recno = start; reclist.num_records < toget; recno++)
 630     {
 631         bend_fetchrequest freq;
 632         bend_fetchresult *fres;
 633         Z_NamePlusRecord *thisrec;
 634         Z_DatabaseRecord *thisext;
 635
 636         if (reclist.num_records == MAX_RECORDS - 1)
 637         {
 638             *pres = Z_PRES_PARTIAL_2;
 639             break;
 640         }
 641         freq.setname = setname;
 642         freq.number = recno;
 643         if (!(fres = bend_fetch(a->backend, &freq, 0)))
 644         {
 645             *pres = Z_PRES_FAILURE;
 646             return diagrec(a->proto, 2, "Backend interface problem");
 647         }
 648         /* backend should be able to signal whether error is system-wide
 649            or only pertaining to current record */
 650         if (fres->errcode)
 651         {
 652             *pres = Z_PRES_FAILURE;
 653             return diagrec(a->proto, fres->errcode, fres->errstring);
 654         }
 655         logf(LOG_DEBUG, "  fetched record, len=%d, total=%d",
 656             fres->len, total_length);
 657         if (fres->len + total_length > a->preferredMessageSize)
 658         {
 659             /* record is small enough, really */
 660             if (fres->len <= a->preferredMessageSize)
 661             {
 662                 logf(LOG_DEBUG, "  Dropped last normal-sized record");
 663                 *pres = Z_PRES_PARTIAL_2;
 664                 break;
 665             }
 666             /* record can only be fetched by itself */
 667             if (fres->len < a->maximumRecordSize)
 668             {
 669                 logf(LOG_DEBUG, "  Record > prefmsgsz");
 670                 if (toget > 1)
 671                 {
 672                     logf(LOG_DEBUG, "  Dropped it");
 673                     reclist.records[reclist.num_records] =
 674                          surrogatediagrec(a->proto, fres->basename, 16, 0);
 675                     reclist.num_records++;
 676                     *pres = Z_PRES_PARTIAL_2;
 677                     break;
 678                 }
 679             }
 680             else /* too big entirely */
 681             {
 682                 logf(LOG_DEBUG, "Record > maxrcdsz");
 683                 reclist.records[reclist.num_records] =
 684                     surrogatediagrec(a->proto, fres->basename, 17, 0);
 685                 reclist.num_records++;
 686                 *pres = Z_PRES_PARTIAL_2;
 687                 break;
 688             }
 689         }
 690         if (!(thisrec = odr_malloc(a->encode, sizeof(*thisrec))))
 691             return 0;
 692         if (!(thisrec->databaseName = odr_malloc(a->encode,
 693             strlen(fres->basename) + 1)))
 694             return 0;
 695         strcpy(thisrec->databaseName, fres->basename);
 696         thisrec->which = Z_NamePlusRecord_databaseRecord;
 697         if (!(thisrec->u.databaseRecord = thisext = odr_malloc(a->encode,
 698             sizeof(Z_DatabaseRecord))))
 699             return 0;
 700         thisext->direct_reference = oid; /* should be OID for current MARC */
 701         thisext->indirect_reference = 0;
 702         thisext->descriptor = 0;
 703         thisext->which = ODR_EXTERNAL_octet;
 704         if (!(thisext->u.octet_aligned = odr_malloc(a->encode,
 705             sizeof(Odr_oct))))
 706             return 0;
 707         if (!(thisext->u.octet_aligned->buf = odr_malloc(a->encode, fres->len)))
 708             return 0;
 709         memcpy(thisext->u.octet_aligned->buf, fres->record, fres->len);
 710         thisext->u.octet_aligned->len = thisext->u.octet_aligned->size =
 711             fres->len;
 712         reclist.records[reclist.num_records] = thisrec;
 713         reclist.num_records++;
 714         total_length += fres->len;
 715         (*num)++;
 716         *next = fres->last_in_set ? 0 : recno + 1;
 717     }
 718     return &records;
 719 }
 720
 721 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 722     int *fd)
 723 {
 724     Z_SearchRequest *req = reqb->request->u.searchRequest;
 725     bend_searchrequest bsrq;
 726     bend_searchresult *bsrt;
 727
 728     logf(LOG_LOG, "Got SearchRequest.");
 729
 730     bsrq.setname = req->resultSetName;
 731     bsrq.replace_set = *req->replaceIndicator;
 732     bsrq.num_bases = req->num_databaseNames;
 733     bsrq.basenames = req->databaseNames;
 734     bsrq.query = req->query;
 735
 736     if (!(bsrt = bend_search(assoc->backend, &bsrq, fd)))
 737         return 0;
 738     return response_searchRequest(assoc, reqb, bsrt, fd);
 739 }
 740
 741 bend_searchresult *bend_searchresponse(void *handle) {return 0;}
 742
 743 /*
 744  * Prepare a searchresponse based on the backend results. We probably want
 745  * to look at making the fetching of records nonblocking as well, but
 746  * so far, we'll keep things simple.
 747  * If bsrt is null, that means we're called in response to a communications
 748  * event, and we'll have to get the response for ourselves.
 749  */
 750 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 751     bend_searchresult *bsrt, int *fd)
 752 {
 753     Z_SearchRequest *req = reqb->request->u.searchRequest;
 754     static Z_APDU apdu;
 755     static Z_SearchResponse resp;
 756     static int nulint = 0;
 757     static bool_t sr = 1;
 758     static int next = 0;
 759     static int none = Z_RES_NONE;
 760
 761     apdu.which = Z_APDU_searchResponse;
 762     apdu.u.searchResponse = &resp;
 763     resp.referenceId = req->referenceId;
 764     *fd = -1;
 765     if (!bsrt && !(bsrt = bend_searchresponse(assoc->backend)))
 766     {
 767         logf(LOG_FATAL, "Bad result from backend");
 768         return 0;
 769     }
 770     else if (bsrt->errcode)
 771     {
 772         resp.records = diagrec(assoc->proto, bsrt->errcode,
 773             bsrt->errstring);
 774         resp.resultCount = &nulint;
 775         resp.numberOfRecordsReturned = &nulint;
 776         resp.nextResultSetPosition = &nulint;
 777         resp.searchStatus = &nulint;
 778         resp.resultSetStatus = &none;
 779         resp.presentStatus = 0;
 780     }
 781     else
 782     {
 783         int toget;
 784         Z_ElementSetNames *setnames;
 785         int presst = 0;
 786
 787         resp.records = 0;
 788         resp.resultCount = &bsrt->hits;
 789
 790         /* how many records does the user agent want, then? */
 791         if (bsrt->hits <= *req->smallSetUpperBound)
 792         {
 793             toget = bsrt->hits;
 794             setnames = req->smallSetElementSetNames;
 795         }
 796         else if (bsrt->hits < *req->largeSetLowerBound)
 797         {
 798             toget = *req->mediumSetPresentNumber;
 799             if (toget > bsrt->hits)
 800                 toget = bsrt->hits;
 801             setnames = req->mediumSetElementSetNames;
 802         }
 803         else
 804             toget = 0;
 805
 806         if (toget && !resp.records)
 807         {
 808             resp.records = pack_records(assoc, req->resultSetName, 1,
 809                 &toget, setnames, &next, &presst);
 810             if (!resp.records)
 811                 return 0;
 812             resp.numberOfRecordsReturned = &toget;
 813             resp.nextResultSetPosition = &next;
 814             resp.searchStatus = &sr;
 815             resp.resultSetStatus = 0;
 816             resp.presentStatus = &presst;
 817         }
 818         else
 819         {
 820             resp.numberOfRecordsReturned = &nulint;
 821             resp.nextResultSetPosition = &next;
 822             resp.searchStatus = &sr;
 823             resp.resultSetStatus = 0;
 824             resp.presentStatus = 0;
 825         }
 826     }
 827     return &apdu;
 828 }
 829
 830 /*
 831  * Maybe we got a little over-friendly when we designed bend_fetch to
 832  * get only one record at a time. Some backends can optimise multiple-record
 833  * fetches, and at any rate, there is some overhead involved in
 834  * all that selecting and hopping around. Problem is, of course, that the
 835  * frontend can't know ahead of time how many records it'll need to
 836  * fill the negotiated PDU size. Annoying. Segmentation or not, Z/SR
 837  * is downright lousy as a bulk data transfer protocol.
 838  *
 839  * To start with, we'll do the fetching of records from the backend
 840  * in one operation: To save some trips in and out of the event-handler,
 841  * and to simplify the interface to pack_records. At any rate, asynch
 842  * operation is more fun in operations that have an unpredictable execution
 843  * speed - which is normally more true for search than for present.
 844  */
 845 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 846     int *fd)
 847 {
 848     Z_PresentRequest *req = reqb->request->u.presentRequest;
 849     static Z_APDU apdu;
 850     static Z_PresentResponse resp;
 851     static int presst, next, num;
 852
 853     logf(LOG_LOG, "Got PresentRequest.");
 854     apdu.which = Z_APDU_presentResponse;
 855     apdu.u.presentResponse = &resp;
 856     resp.referenceId = req->referenceId;
 857
 858     num = *req->numberOfRecordsRequested;
 859     resp.records = pack_records(assoc, req->resultSetId,
 860         *req->resultSetStartPoint, &num, req->elementSetNames, &next, &presst);
 861     if (!resp.records)
 862         return 0;
 863     resp.numberOfRecordsReturned = &num;
 864     resp.presentStatus = &presst;
 865     resp.nextResultSetPosition = &next;
 866
 867     return &apdu;
 868 }
 869
 870 /*
 871  * Scan was implemented rather in a hurry, and with support for only the basic
 872  * elements of the service in the backend API. Suggestions are welcome.
 873  */
 874 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd)
 875 {
 876     Z_ScanRequest *req = reqb->request->u.scanRequest;
 877     static Z_APDU apdu;
 878     static Z_ScanResponse res;
 879     static int scanStatus = Z_Scan_failure;
 880     static int numberOfEntriesReturned = 0;
 881     oident *attent;
 882     static Z_ListEntries ents;
 883 #define SCAN_MAX_ENTRIES 200
 884     static Z_Entry *tab[SCAN_MAX_ENTRIES];
 885     bend_scanrequest srq;
 886     bend_scanresult *srs;
 887
 888     apdu.which = Z_APDU_scanResponse;
 889     apdu.u.scanResponse = &res;
 890     res.referenceId = req->referenceId;
 891     res.stepSize = 0;
 892     res.scanStatus = &scanStatus;
 893     res.numberOfEntriesReturned = &numberOfEntriesReturned;
 894     res.positionOfTerm = 0;
 895     res.entries = &ents;
 896     ents.which = Z_ListEntries_nonSurrogateDiagnostics;
 897     res.attributeSet = 0;
 898
 899     if (req->attributeSet && (!(attent = oid_getentbyoid(req->attributeSet)) ||
 900         attent->class != CLASS_ATTSET || attent->value != VAL_BIB1))
 901         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 121, 0);
 902     else if (req->stepSize && *req->stepSize > 0)
 903         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 205, 0);
 904     else
 905     {
 906         srq.num_bases = req->num_databaseNames;
 907         srq.basenames = req->databaseNames;
 908         srq.num_entries = *req->numberOfTermsRequested;
 909         srq.term = req->termListAndStartPoint;
 910         srq.term_position = req->preferredPositionInResponse ?
 911             *req->preferredPositionInResponse : 1;
 912         if (!(srs = bend_scan(assoc->backend, &srq, 0)))
 913             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 2, 0);
 914         else if (srs->errcode)
 915             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto,
 916                 srs->errcode, srs->errstring);
 917         else
 918         {
 919             int i;
 920             static Z_Entries list;
 921
 922             if (srs->status == BEND_SCAN_PARTIAL)
 923                 scanStatus = Z_Scan_partial_5;
 924             else
 925                 scanStatus = Z_Scan_success;
 926             ents.which = Z_ListEntries_entries;
 927             ents.u.entries = &list;
 928             list.entries = tab;
 929             for (i = 0; i < srs->num_entries; i++)
 930             {
 931                 Z_Entry *e;
 932                 Z_TermInfo *t;
 933                 Odr_oct *o;
 934
 935                 if (i >= SCAN_MAX_ENTRIES)
 936                 {
 937                     scanStatus = Z_Scan_partial_4;
 938                     break;
 939                 }
 940                 list.entries[i] = e = odr_malloc(assoc->encode, sizeof(*e));
 941                 e->which = Z_Entry_termInfo;
 942                 e->u.termInfo = t = odr_malloc(assoc->encode, sizeof(*t));
 943                 t->suggestedAttributes = 0;
 944                 t->alternativeTerm = 0;
 945                 t->byAttributes = 0;
 946                 t->globalOccurrences = &srs->entries[i].occurrences;
 947                 t->term = odr_malloc(assoc->encode, sizeof(*t->term));
 948                 t->term->which = Z_Term_general;
 949                 t->term->u.general = o = odr_malloc(assoc->encode,
 950                     sizeof(Odr_oct));
 951                 o->buf = odr_malloc(assoc->encode, o->len = o->size =
 952                     strlen(srs->entries[i].term));
 953                 memcpy(o->buf, srs->entries[i].term, o->len);
 954             }
 955             list.num_entries = i;
 956             res.numberOfEntriesReturned = &list.num_entries;
 957             res.positionOfTerm = &srs->term_position;
 958         }
 959     }
 960
 961     return &apdu;
 962 }