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