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 1.25  1995-05-17 08:42:26  quinn
   8  * Transfer auth info to backend. Allow backend to reject init gracefully.
   9  *
  10  * Revision 1.24  1995/05/16  08:51:04  quinn
  11  * License, documentation, and memory fixes
  12  *
  13  * Revision 1.23  1995/05/15  13:25:10  quinn
  14  * Fixed memory bug.
  15  *
  16  * Revision 1.22  1995/05/15  11:56:39  quinn
  17  * Asynchronous facilities. Restructuring of seshigh code.
  18  *
  19  * Revision 1.21  1995/05/02  08:53:19  quinn
  20  * Trying in vain to fix comm with ISODE
  21  *
  22  * Revision 1.20  1995/04/20  15:13:00  quinn
  23  * Cosmetic
  24  *
  25  * Revision 1.19  1995/04/18  08:15:34  quinn
  26  * Added dynamic memory allocation on encoding (whew). Code is now somewhat
  27  * neater. We'll make the same change for decoding one day.
  28  *
  29  * Revision 1.18  1995/04/17  11:28:25  quinn
  30  * Smallish
  31  *
  32  * Revision 1.17  1995/04/10  10:23:36  quinn
  33  * Some work to add scan and other things.
  34  *
  35  * Revision 1.16  1995/03/31  09:18:55  quinn
  36  * Added logging.
  37  *
  38  * Revision 1.15  1995/03/30  14:03:23  quinn
  39  * Added RFC1006 as separate library
  40  *
  41  * Revision 1.14  1995/03/30  12:18:17  quinn
  42  * Fixed bug.
  43  *
  44  * Revision 1.13  1995/03/30  09:09:24  quinn
  45  * Added state-handle and some support for asynchronous activities.
  46  *
  47  * Revision 1.12  1995/03/29  15:40:16  quinn
  48  * Ongoing work. Statserv is now dynamic by default
  49  *
  50  * Revision 1.11  1995/03/28  09:16:21  quinn
  51  * Added record packing to the search request
  52  *
  53  * Revision 1.10  1995/03/27  08:34:24  quinn
  54  * Added dynamic server functionality.
  55  * Released bindings to session.c (is now redundant)
  56  *
  57  * Revision 1.9  1995/03/22  15:01:26  quinn
  58  * Adjusting record packing.
  59  *
  60  * Revision 1.8  1995/03/22  10:13:21  quinn
  61  * Working on record packer
  62  *
  63  * Revision 1.7  1995/03/21  15:53:31  quinn
  64  * Little changes.
  65  *
  66  * Revision 1.6  1995/03/21  12:30:09  quinn
  67  * Beginning to add support for record packing.
  68  *
  69  * Revision 1.5  1995/03/17  10:44:13  quinn
  70  * Added catch of null-string in makediagrec
  71  *
  72  * Revision 1.4  1995/03/17  10:18:08  quinn
  73  * Added memory management.
  74  *
  75  * Revision 1.3  1995/03/16  17:42:39  quinn
  76  * Little changes
  77  *
  78  * Revision 1.2  1995/03/16  13:29:01  quinn
  79  * Partitioned server.
  80  *
  81  * Revision 1.1  1995/03/15  16:02:10  quinn
  82  * Modded session.c to seshigh.c
  83  *
  84  */
  85
  86 /*
  87  * Frontend server logic.
  88  *
  89  * This code receives incoming APDUs, and handles client requests by means
  90  * of the backend API.
  91  *
  92  * Some of the code is getting quite involved, compared to simpler servers -
  93  * primarily because it is asynchronous both in the communication with
  94  * the user and the backend. We think the complexity will pay off in
  95  * the form of greater flexibility when more asynchronous facilities
  96  * are implemented.
  97  *
  98  * Memory management has become somewhat involved. In the simple case, where
  99  * only one PDU is pending at a time, it will simply reuse the same memory,
 100  * once it has found its working size. When we enable multiple concurrent
 101  * operations, perhaps even with multiple parallel calls to the backend, it
 102  * will maintain a pool of buffers for encoding and decoding, trying to
 103  * minimize memory allocation/deallocation during normal operation.
 104  *
 105  * TODOs include (and will be done in order of public interest):
 106  *
 107  * Support for EXPLAIN - provide simple meta-database system.
 108  * Support for access control.
 109  * Support for resource control.
 110  * Support for extended services - primarily Item Order.
 111  * Rest of Z39.50-1994
 112  *
 113  */
 114
 115 #include <stdlib.h>
 116 #include <stdio.h>
 117 #include <unistd.h>
 118 #include <assert.h>
 119
 120 #include <dmalloc.h>
 121 #include <comstack.h>
 122 #include <eventl.h>
 123 #include <session.h>
 124 #include <proto.h>
 125 #include <oid.h>
 126 #include <log.h>
 127 #include <statserv.h>
 128 #include "../version.h"
 129
 130 #include <backend.h>
 131
 132 static int process_request(association *assoc);
 133 void backend_response(IOCHAN i, int event);
 134 static int process_response(association *assoc, request *req, Z_APDU *res);
 135 static Z_APDU *process_initRequest(association *assoc, request *reqb);
 136 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 137     int *fd);
 138 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 139     bend_searchresult *bsrt, int *fd);
 140 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 141     int *fd);
 142 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd);
 143
 144 static FILE *apduf = 0; /* for use in static mode */
 145 static statserv_options_block *control_block = 0;
 146
 147 /*
 148  * Create and initialize a new association-handle.
 149  *  channel  : iochannel for the current line.
 150  *  link     : communications channel.
 151  * Returns: 0 or a new association handle.
 152  */
 153 association *create_association(IOCHAN channel, COMSTACK link)
 154 {
 155     association *new;
 156
 157     if (!control_block)
 158         control_block = statserv_getcontrol();
 159     if (!(new = malloc(sizeof(*new))))
 160         return 0;
 161     new->client_chan = channel;
 162     new->client_link = link;
 163     if (!(new->decode = odr_createmem(ODR_DECODE)) ||
 164         !(new->encode = odr_createmem(ODR_ENCODE)))
 165         return 0;
 166     if (*control_block->apdufile)
 167     {
 168         char filename[256];
 169         FILE *f;
 170
 171         strcpy(filename, control_block->apdufile);
 172         if (!(new->print = odr_createmem(ODR_PRINT)))
 173             return 0;
 174         if (*control_block->apdufile != '-')
 175         {
 176             strcpy(filename, control_block->apdufile);
 177             if (!control_block->dynamic)
 178             {
 179                 if (!apduf)
 180                 {
 181                     if (!(apduf = fopen(filename, "w")))
 182                     {
 183                         logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 184                         return 0;
 185                     }
 186                     setvbuf(apduf, 0, _IONBF, 0);
 187                 }
 188                 f = apduf;
 189             }
 190             else
 191             {
 192                 sprintf(filename + strlen(filename), ".%d", getpid());
 193                 if (!(f = fopen(filename, "w")))
 194                 {
 195                     logf(LOG_WARN|LOG_ERRNO, "%s", filename);
 196                     return 0;
 197                 }
 198                 setvbuf(f, 0, _IONBF, 0);
 199             }
 200             odr_setprint(new->print, f);
 201         }
 202     }
 203     else
 204         new->print = 0;
 205     new->input_buffer = 0;
 206     new->input_buffer_len = 0;
 207     new->backend = 0;
 208     new->rejected = 0;
 209     request_initq(&new->incoming);
 210     request_initq(&new->outgoing);
 211     if (cs_getproto(link) == CS_Z3950)
 212         new->proto = PROTO_Z3950;
 213     else
 214         new->proto = PROTO_SR;
 215     return new;
 216 }
 217
 218 /*
 219  * Free association and release resources.
 220  */
 221 void destroy_association(association *h)
 222 {
 223     odr_destroy(h->decode);
 224     odr_destroy(h->encode);
 225     if (h->print)
 226         odr_destroy(h->print);
 227     if (h->input_buffer)
 228         free(h->input_buffer);
 229     if (h->backend)
 230         bend_close(h->backend);
 231     while (request_deq(&h->incoming));
 232     while (request_deq(&h->outgoing));
 233     free(h);
 234 }
 235
 236 /*
 237  * This is where PDUs from the client are read and the further
 238  * processing is initiated. Flow of control moves down through the
 239  * various process_* functions below, until the encoded result comes back up
 240  * to the output handler in here.
 241  *
 242  *  h     : the I/O channel that has an outstanding event.
 243  *  event : the current outstanding event.
 244  */
 245 void ir_session(IOCHAN h, int event)
 246 {
 247     int res;
 248     association *assoc = iochan_getdata(h);
 249     COMSTACK conn = assoc->client_link;
 250     request *req;
 251
 252     assert(h && conn && assoc);
 253     if (event & EVENT_INPUT || event & EVENT_WORK) /* input */
 254     {
 255         if (event & EVENT_INPUT)
 256         {
 257             logf(LOG_DEBUG, "ir_session (input)");
 258             assert(assoc && conn);
 259             if (assoc->rejected)
 260             {
 261                 logf(LOG_LOG, "Closed connection after reject");
 262                 cs_close(conn);
 263                 destroy_association(assoc);
 264                 iochan_destroy(h);
 265                 return;
 266             }
 267             if ((res = cs_get(conn, &assoc->input_buffer,
 268                 &assoc->input_buffer_len)) <= 0)
 269             {
 270                 logf(LOG_LOG, "Connection closed by client");
 271                 cs_close(conn);
 272                 destroy_association(assoc);
 273                 iochan_destroy(h);
 274                 return;
 275             }
 276             else if (res == 1) /* incomplete read - wait for more  */
 277                 return;
 278             if (cs_more(conn)) /* more stuff - call us again later, please */
 279                 iochan_setevent(h, EVENT_INPUT);
 280
 281             /* we got a complete PDU. Let's decode it */
 282             req = request_get(); /* get a new request structure */
 283             odr_reset(assoc->decode);
 284             odr_setbuf(assoc->decode, assoc->input_buffer, res, 0);
 285             if (!z_APDU(assoc->decode, &req->request, 0))
 286             {
 287                 logf(LOG_WARN, "ODR error: %s",
 288                     odr_errlist[odr_geterror(assoc->decode)]);
 289                 cs_close(conn);
 290                 destroy_association(assoc);
 291                 iochan_destroy(h);
 292                 return;
 293             }
 294             req->request_mem = odr_extract_mem(assoc->decode);
 295             if (assoc->print && !z_APDU(assoc->print, &req->request, 0))
 296             {
 297                 logf(LOG_WARN, "ODR print error: %s",
 298                     odr_errlist[odr_geterror(assoc->print)]);
 299                 odr_reset(assoc->print);
 300             }
 301             request_enq(&assoc->incoming, req);
 302         }
 303
 304         /* can we do something yet? */
 305         req = request_head(&assoc->incoming);
 306         if (req->state == REQUEST_IDLE)
 307             if (process_request(assoc) < 0)
 308             {
 309                 cs_close(conn);
 310                 destroy_association(assoc);
 311                 iochan_destroy(h);
 312             }
 313     }
 314     if (event & EVENT_OUTPUT)
 315     {
 316         request *req = request_head(&assoc->outgoing);
 317
 318         logf(LOG_DEBUG, "ir_session (output)");
 319         req->state = REQUEST_PENDING;
 320         switch (res = cs_put(conn, req->response, req->len_response))
 321         {
 322             case -1:
 323                 logf(LOG_LOG, "Connection closed by client");
 324                 cs_close(conn);
 325                 destroy_association(assoc);
 326                 iochan_destroy(h);
 327                 break;
 328             case 0: /* all sent - release the request structure */
 329                 odr_release_mem(req->request_mem);
 330                 request_deq(&assoc->outgoing);
 331                 request_release(req);
 332                 if (!request_head(&assoc->outgoing))
 333                     iochan_clearflag(h, EVENT_OUTPUT);
 334                 break;
 335             /* value of 1 -- partial send -- is simply ignored */
 336         }
 337     }
 338     if (event & EVENT_EXCEPT)
 339     {
 340         logf(LOG_DEBUG, "ir_session (exception)");
 341         cs_close(conn);
 342         destroy_association(assoc);
 343         iochan_destroy(h);
 344     }
 345 }
 346
 347 /*
 348  * Initiate request processing.
 349  */
 350 static int process_request(association *assoc)
 351 {
 352     request *req = request_head(&assoc->incoming);
 353     int fd = -1;
 354     Z_APDU *res;
 355
 356     logf(LOG_DEBUG, "process_request");
 357     assert(req && req->state == REQUEST_IDLE);
 358     switch (req->request->which)
 359     {
 360         case Z_APDU_initRequest:
 361             res = process_initRequest(assoc, req); break;
 362         case Z_APDU_searchRequest:
 363             res = process_searchRequest(assoc, req, &fd); break;
 364         case Z_APDU_presentRequest:
 365             res = process_presentRequest(assoc, req, &fd); break;
 366         case Z_APDU_scanRequest:
 367             res = process_scanRequest(assoc, req, &fd); break;
 368         default:
 369             logf(LOG_WARN, "Bad APDU");
 370             return -1;
 371     }
 372     if (res)
 373     {
 374         logf(LOG_DEBUG, "  result immediately available");
 375         return process_response(assoc, req, res);
 376     }
 377     else if (fd < 0)
 378     {
 379         logf(LOG_WARN, "   bad result");
 380         return -1;
 381     }
 382     else /* no result yet - one will be provided later */
 383     {
 384         IOCHAN chan;
 385
 386         /* Set up an I/O handler for the fd supplied by the backend */
 387
 388         logf(LOG_DEBUG, "   establishing handler for result");
 389         req->state = REQUEST_PENDING;
 390         if (!(chan = iochan_create(fd, backend_response, EVENT_INPUT)))
 391             abort();
 392         iochan_setdata(chan, assoc);
 393         return 0;
 394     }
 395 }
 396
 397 /*
 398  * Handle message from the backend.
 399  */
 400 void backend_response(IOCHAN i, int event)
 401 {
 402     association *assoc = iochan_getdata(i);
 403     request *req = request_head(&assoc->incoming);
 404     Z_APDU *res;
 405     int fd;
 406
 407     logf(LOG_DEBUG, "backend_response");
 408     assert(assoc && req && req->state != REQUEST_IDLE);
 409     /* determine what it is we're waiting for */
 410     switch (req->request->which)
 411     {
 412         case Z_APDU_searchRequest:
 413             res = response_searchRequest(assoc, req, 0, &fd); break;
 414 #if 0
 415         case Z_APDU_presentRequest:
 416             res = response_presentRequest(assoc, req, 0, &fd); break;
 417         case Z_APDU_scanRequest:
 418             res = response_scanRequest(assoc, req, 0, &fd); break;
 419 #endif
 420         default:
 421             logf(LOG_WARN, "Serious programmer's lapse or bug");
 422             abort();
 423     }
 424     if ((res && process_response(assoc, req, res) < 0) || fd < 0)
 425     {
 426         logf(LOG_LOG, "Fatal error when talking to backend");
 427         cs_close(assoc->client_link);
 428         destroy_association(assoc);
 429         iochan_destroy(assoc->client_chan);
 430         iochan_destroy(i);
 431         return;
 432     }
 433     else if (!res) /* no result yet - try again later */
 434     {
 435         logf(LOG_DEBUG, "   no result yet");
 436         iochan_setfd(i, fd); /* in case fd has changed */
 437     }
 438 }
 439
 440 /*
 441  * Encode response, and transfer the request structure to the outgoing queue.
 442  */
 443 static int process_response(association *assoc, request *req, Z_APDU *res)
 444 {
 445     odr_setbuf(assoc->encode, req->response, req->size_response, 1);
 446     if (!z_APDU(assoc->encode, &res, 0))
 447     {
 448         logf(LOG_WARN, "ODR error when encoding response: %s",
 449             odr_errlist[odr_geterror(assoc->decode)]);
 450         return -1;
 451     }
 452     req->response = odr_getbuf(assoc->encode, &req->len_response,
 453         &req->size_response);
 454     odr_setbuf(assoc->encode, 0, 0, 0); /* don't free if we have to quit */
 455     odr_reset(assoc->encode);
 456     if (assoc->print && !z_APDU(assoc->print, &res, 0))
 457     {
 458         logf(LOG_WARN, "ODR print error: %s",
 459             odr_errlist[odr_geterror(assoc->print)]);
 460         odr_reset(assoc->print);
 461     }
 462     /* change this when we make the backend reentrant */
 463     assert(req == request_head(&assoc->incoming));
 464     req->state = REQUEST_IDLE;
 465     request_deq(&assoc->incoming);
 466     request_enq(&assoc->outgoing, req);
 467     /* turn the work over to the ir_session handler */
 468     iochan_setflag(assoc->client_chan, EVENT_OUTPUT);
 469     /* Is there more work to be done? */
 470     if (request_head(&assoc->incoming))
 471         iochan_setevent(assoc->client_chan, EVENT_WORK);
 472     return 0;
 473 }
 474
 475 static Z_APDU *process_initRequest(association *assoc, request *reqb)
 476 {
 477     Z_InitRequest *req = reqb->request->u.initRequest;
 478     static Z_APDU apdu;
 479     static Z_InitResponse resp;
 480     static bool_t result = 1;
 481     static Odr_bitmask options, protocolVersion;
 482     bend_initrequest binitreq;
 483     bend_initresult *binitres;
 484
 485     logf(LOG_LOG, "Got initRequest");
 486     if (req->implementationId)
 487         logf(LOG_LOG, "Id:        %s", req->implementationId);
 488     if (req->implementationName)
 489         logf(LOG_LOG, "Name:      %s", req->implementationName);
 490     if (req->implementationVersion)
 491         logf(LOG_LOG, "Version:   %s", req->implementationVersion);
 492
 493     binitreq.configname = "default-config";
 494     binitreq.auth = req->idAuthentication;
 495     if (!(binitres = bend_init(&binitreq)))
 496     {
 497         logf(LOG_WARN, "Bad response from backend.");
 498         return 0;
 499     }
 500
 501     assoc->backend = binitres->handle;
 502     apdu.which = Z_APDU_initResponse;
 503     apdu.u.initResponse = &resp;
 504     resp.referenceId = req->referenceId;
 505     /* let's tell the client what we can do */
 506     ODR_MASK_ZERO(&options);
 507     if (ODR_MASK_GET(req->options, Z_Options_search))
 508         ODR_MASK_SET(&options, Z_Options_search);
 509     if (ODR_MASK_GET(req->options, Z_Options_present))
 510         ODR_MASK_SET(&options, Z_Options_present);
 511 #if 0
 512     if (ODR_MASK_GET(req->options, Z_Options_delSet))
 513         ODR_MASK_SET(&options, Z_Options_delSet);
 514 #endif
 515     if (ODR_MASK_GET(req->options, Z_Options_namedResultSets))
 516         ODR_MASK_SET(&options, Z_Options_namedResultSets);
 517     if (ODR_MASK_GET(req->options, Z_Options_scan))
 518         ODR_MASK_SET(&options, Z_Options_scan);
 519     if (ODR_MASK_GET(req->options, Z_Options_concurrentOperations))
 520         ODR_MASK_SET(&options, Z_Options_concurrentOperations);
 521     resp.options = &options;
 522
 523     ODR_MASK_ZERO(&protocolVersion);
 524     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_1))
 525         ODR_MASK_SET(&protocolVersion, Z_ProtocolVersion_1);
 526     if (ODR_MASK_GET(req->protocolVersion, Z_ProtocolVersion_2))
 527         ODR_MASK_SET(&protocolVersion, Z_ProtocolVersion_2);
 528     resp.protocolVersion = &protocolVersion;
 529     assoc->maximumRecordSize = *req->maximumRecordSize;
 530     if (assoc->maximumRecordSize > control_block->maxrecordsize)
 531         assoc->maximumRecordSize = control_block->maxrecordsize;
 532     assoc->preferredMessageSize = *req->preferredMessageSize;
 533     if (assoc->preferredMessageSize > assoc->maximumRecordSize)
 534         assoc->preferredMessageSize = assoc->maximumRecordSize;
 535     resp.preferredMessageSize = &assoc->preferredMessageSize;
 536     resp.maximumRecordSize = &assoc->maximumRecordSize;
 537     resp.result = &result;
 538     resp.implementationId = "YAZ";
 539     resp.implementationName = "Index Data/YAZ Generic Frontend Server";
 540     resp.implementationVersion = YAZ_VERSION;
 541     resp.userInformationField = 0;
 542     if (binitres->errcode)
 543     {
 544         logf(LOG_LOG, "Connection rejected by backend.");
 545         result = 0;
 546         assoc->rejected = 1;
 547     }
 548     return &apdu;
 549 }
 550
 551 static Z_Records *diagrec(oid_proto proto, int error, char *addinfo)
 552 {
 553     static Z_Records rec;
 554     oident bib1;
 555     static Z_DiagRec dr;
 556     static int err;
 557
 558     bib1.proto = proto;
 559     bib1.class = CLASS_DIAGSET;
 560     bib1.value = VAL_BIB1;
 561
 562     logf(LOG_DEBUG, "Diagnostic: %d -- %s", error, addinfo ? addinfo :
 563         "NULL");
 564     err = error;
 565     rec.which = Z_Records_NSD;
 566     rec.u.nonSurrogateDiagnostic = &dr;
 567     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 568     dr.condition = &err;
 569     dr.addinfo = addinfo ? addinfo : "";
 570     return &rec;
 571 }
 572
 573 static Z_NamePlusRecord *surrogatediagrec(oid_proto proto, char *dbname,
 574                                             int error, char *addinfo)
 575 {
 576     static Z_NamePlusRecord rec;
 577     static Z_DiagRec dr;
 578     static int err;
 579     oident bib1;
 580
 581     bib1.proto = proto;
 582     bib1.class = CLASS_DIAGSET;
 583     bib1.value = VAL_BIB1;
 584
 585     logf(LOG_DEBUG, "SurrogateDiagnotic: %d -- %s", error, addinfo);
 586     err = error;
 587     rec.databaseName = dbname;
 588     rec.which = Z_NamePlusRecord_surrogateDiagnostic;
 589     rec.u.surrogateDiagnostic = &dr;
 590     dr.diagnosticSetId = oid_getoidbyent(&bib1);
 591     dr.condition = &err;
 592     dr.addinfo = addinfo ? addinfo : "";
 593     return &rec;
 594 }
 595
 596 static Z_DiagRecs *diagrecs(oid_proto proto, int error, char *addinfo)
 597 {
 598     static Z_DiagRecs recs;
 599     static Z_DiagRec *recp[1], rec;
 600     static int err;
 601     oident bib1;
 602
 603     logf(LOG_DEBUG, "DiagRecs: %d -- %s", error, addinfo);
 604     bib1.proto = proto;
 605     bib1.class = CLASS_DIAGSET;
 606     bib1.value = VAL_BIB1;
 607
 608     err = error;
 609     recs.num_diagRecs = 1;
 610     recs.diagRecs = recp;
 611     recp[0] = &rec;
 612     rec.diagnosticSetId = oid_getoidbyent(&bib1);
 613     rec.condition = &err;
 614     rec.addinfo = addinfo ? addinfo : "";
 615     return &recs;
 616 }
 617
 618 #define MAX_RECORDS 256
 619
 620 static Z_Records *pack_records(association *a, char *setname, int start,
 621                                 int *num, Z_ElementSetNames *esn,
 622                                 int *next, int *pres)
 623 {
 624     int recno, total_length = 0, toget = *num;
 625     static Z_Records records;
 626     static Z_NamePlusRecordList reclist;
 627     static Z_NamePlusRecord *list[MAX_RECORDS];
 628     oident recform;
 629     Odr_oid *oid;
 630
 631     records.which = Z_Records_DBOSD;
 632     records.u.databaseOrSurDiagnostics = &reclist;
 633     reclist.num_records = 0;
 634     reclist.records = list;
 635     *pres = Z_PRES_SUCCESS;
 636     *num = 0;
 637     *next = 0;
 638
 639     recform.proto = a->proto;
 640     recform.class = CLASS_RECSYN;
 641     recform.value = VAL_USMARC;
 642     if (!(oid = odr_oiddup(a->encode, oid_getoidbyent(&recform))))
 643         return 0;
 644
 645     logf(LOG_DEBUG, "Request to pack %d+%d", start, toget);
 646     logf(LOG_DEBUG, "pms=%d, mrs=%d", a->preferredMessageSize,
 647         a->maximumRecordSize);
 648     for (recno = start; reclist.num_records < toget; recno++)
 649     {
 650         bend_fetchrequest freq;
 651         bend_fetchresult *fres;
 652         Z_NamePlusRecord *thisrec;
 653         Z_DatabaseRecord *thisext;
 654
 655         if (reclist.num_records == MAX_RECORDS - 1)
 656         {
 657             *pres = Z_PRES_PARTIAL_2;
 658             break;
 659         }
 660         freq.setname = setname;
 661         freq.number = recno;
 662         if (!(fres = bend_fetch(a->backend, &freq, 0)))
 663         {
 664             *pres = Z_PRES_FAILURE;
 665             return diagrec(a->proto, 2, "Backend interface problem");
 666         }
 667         /* backend should be able to signal whether error is system-wide
 668            or only pertaining to current record */
 669         if (fres->errcode)
 670         {
 671             *pres = Z_PRES_FAILURE;
 672             return diagrec(a->proto, fres->errcode, fres->errstring);
 673         }
 674         logf(LOG_DEBUG, "  fetched record, len=%d, total=%d",
 675             fres->len, total_length);
 676         if (fres->len + total_length > a->preferredMessageSize)
 677         {
 678             /* record is small enough, really */
 679             if (fres->len <= a->preferredMessageSize)
 680             {
 681                 logf(LOG_DEBUG, "  Dropped last normal-sized record");
 682                 *pres = Z_PRES_PARTIAL_2;
 683                 break;
 684             }
 685             /* record can only be fetched by itself */
 686             if (fres->len < a->maximumRecordSize)
 687             {
 688                 logf(LOG_DEBUG, "  Record > prefmsgsz");
 689                 if (toget > 1)
 690                 {
 691                     logf(LOG_DEBUG, "  Dropped it");
 692                     reclist.records[reclist.num_records] =
 693                          surrogatediagrec(a->proto, fres->basename, 16, 0);
 694                     reclist.num_records++;
 695                     *pres = Z_PRES_PARTIAL_2;
 696                     break;
 697                 }
 698             }
 699             else /* too big entirely */
 700             {
 701                 logf(LOG_DEBUG, "Record > maxrcdsz");
 702                 reclist.records[reclist.num_records] =
 703                     surrogatediagrec(a->proto, fres->basename, 17, 0);
 704                 reclist.num_records++;
 705                 *pres = Z_PRES_PARTIAL_2;
 706                 break;
 707             }
 708         }
 709         if (!(thisrec = odr_malloc(a->encode, sizeof(*thisrec))))
 710             return 0;
 711         if (!(thisrec->databaseName = odr_malloc(a->encode,
 712             strlen(fres->basename) + 1)))
 713             return 0;
 714         strcpy(thisrec->databaseName, fres->basename);
 715         thisrec->which = Z_NamePlusRecord_databaseRecord;
 716         if (!(thisrec->u.databaseRecord = thisext = odr_malloc(a->encode,
 717             sizeof(Z_DatabaseRecord))))
 718             return 0;
 719         thisext->direct_reference = oid; /* should be OID for current MARC */
 720         thisext->indirect_reference = 0;
 721         thisext->descriptor = 0;
 722         thisext->which = ODR_EXTERNAL_octet;
 723         if (!(thisext->u.octet_aligned = odr_malloc(a->encode,
 724             sizeof(Odr_oct))))
 725             return 0;
 726         if (!(thisext->u.octet_aligned->buf = odr_malloc(a->encode, fres->len)))
 727             return 0;
 728         memcpy(thisext->u.octet_aligned->buf, fres->record, fres->len);
 729         thisext->u.octet_aligned->len = thisext->u.octet_aligned->size =
 730             fres->len;
 731         reclist.records[reclist.num_records] = thisrec;
 732         reclist.num_records++;
 733         total_length += fres->len;
 734         (*num)++;
 735         *next = fres->last_in_set ? 0 : recno + 1;
 736     }
 737     return &records;
 738 }
 739
 740 static Z_APDU *process_searchRequest(association *assoc, request *reqb,
 741     int *fd)
 742 {
 743     Z_SearchRequest *req = reqb->request->u.searchRequest;
 744     bend_searchrequest bsrq;
 745     bend_searchresult *bsrt;
 746
 747     logf(LOG_LOG, "Got SearchRequest.");
 748
 749     bsrq.setname = req->resultSetName;
 750     bsrq.replace_set = *req->replaceIndicator;
 751     bsrq.num_bases = req->num_databaseNames;
 752     bsrq.basenames = req->databaseNames;
 753     bsrq.query = req->query;
 754
 755     if (!(bsrt = bend_search(assoc->backend, &bsrq, fd)))
 756         return 0;
 757     return response_searchRequest(assoc, reqb, bsrt, fd);
 758 }
 759
 760 bend_searchresult *bend_searchresponse(void *handle) {return 0;}
 761
 762 /*
 763  * Prepare a searchresponse based on the backend results. We probably want
 764  * to look at making the fetching of records nonblocking as well, but
 765  * so far, we'll keep things simple.
 766  * If bsrt is null, that means we're called in response to a communications
 767  * event, and we'll have to get the response for ourselves.
 768  */
 769 static Z_APDU *response_searchRequest(association *assoc, request *reqb,
 770     bend_searchresult *bsrt, int *fd)
 771 {
 772     Z_SearchRequest *req = reqb->request->u.searchRequest;
 773     static Z_APDU apdu;
 774     static Z_SearchResponse resp;
 775     static int nulint = 0;
 776     static bool_t sr = 1;
 777     static int next = 0;
 778     static int none = Z_RES_NONE;
 779
 780     apdu.which = Z_APDU_searchResponse;
 781     apdu.u.searchResponse = &resp;
 782     resp.referenceId = req->referenceId;
 783     *fd = -1;
 784     if (!bsrt && !(bsrt = bend_searchresponse(assoc->backend)))
 785     {
 786         logf(LOG_FATAL, "Bad result from backend");
 787         return 0;
 788     }
 789     else if (bsrt->errcode)
 790     {
 791         resp.records = diagrec(assoc->proto, bsrt->errcode,
 792             bsrt->errstring);
 793         resp.resultCount = &nulint;
 794         resp.numberOfRecordsReturned = &nulint;
 795         resp.nextResultSetPosition = &nulint;
 796         resp.searchStatus = &nulint;
 797         resp.resultSetStatus = &none;
 798         resp.presentStatus = 0;
 799     }
 800     else
 801     {
 802         int toget;
 803         Z_ElementSetNames *setnames;
 804         int presst = 0;
 805
 806         resp.records = 0;
 807         resp.resultCount = &bsrt->hits;
 808
 809         /* how many records does the user agent want, then? */
 810         if (bsrt->hits <= *req->smallSetUpperBound)
 811         {
 812             toget = bsrt->hits;
 813             setnames = req->smallSetElementSetNames;
 814         }
 815         else if (bsrt->hits < *req->largeSetLowerBound)
 816         {
 817             toget = *req->mediumSetPresentNumber;
 818             if (toget > bsrt->hits)
 819                 toget = bsrt->hits;
 820             setnames = req->mediumSetElementSetNames;
 821         }
 822         else
 823             toget = 0;
 824
 825         if (toget && !resp.records)
 826         {
 827             resp.records = pack_records(assoc, req->resultSetName, 1,
 828                 &toget, setnames, &next, &presst);
 829             if (!resp.records)
 830                 return 0;
 831             resp.numberOfRecordsReturned = &toget;
 832             resp.nextResultSetPosition = &next;
 833             resp.searchStatus = &sr;
 834             resp.resultSetStatus = 0;
 835             resp.presentStatus = &presst;
 836         }
 837         else
 838         {
 839             resp.numberOfRecordsReturned = &nulint;
 840             resp.nextResultSetPosition = &next;
 841             resp.searchStatus = &sr;
 842             resp.resultSetStatus = 0;
 843             resp.presentStatus = 0;
 844         }
 845     }
 846     return &apdu;
 847 }
 848
 849 /*
 850  * Maybe we got a little over-friendly when we designed bend_fetch to
 851  * get only one record at a time. Some backends can optimise multiple-record
 852  * fetches, and at any rate, there is some overhead involved in
 853  * all that selecting and hopping around. Problem is, of course, that the
 854  * frontend can't know ahead of time how many records it'll need to
 855  * fill the negotiated PDU size. Annoying. Segmentation or not, Z/SR
 856  * is downright lousy as a bulk data transfer protocol.
 857  *
 858  * To start with, we'll do the fetching of records from the backend
 859  * in one operation: To save some trips in and out of the event-handler,
 860  * and to simplify the interface to pack_records. At any rate, asynch
 861  * operation is more fun in operations that have an unpredictable execution
 862  * speed - which is normally more true for search than for present.
 863  */
 864 static Z_APDU *process_presentRequest(association *assoc, request *reqb,
 865     int *fd)
 866 {
 867     Z_PresentRequest *req = reqb->request->u.presentRequest;
 868     static Z_APDU apdu;
 869     static Z_PresentResponse resp;
 870     static int presst, next, num;
 871
 872     logf(LOG_LOG, "Got PresentRequest.");
 873     apdu.which = Z_APDU_presentResponse;
 874     apdu.u.presentResponse = &resp;
 875     resp.referenceId = req->referenceId;
 876
 877     num = *req->numberOfRecordsRequested;
 878     resp.records = pack_records(assoc, req->resultSetId,
 879         *req->resultSetStartPoint, &num, req->elementSetNames, &next, &presst);
 880     if (!resp.records)
 881         return 0;
 882     resp.numberOfRecordsReturned = &num;
 883     resp.presentStatus = &presst;
 884     resp.nextResultSetPosition = &next;
 885
 886     return &apdu;
 887 }
 888
 889 /*
 890  * Scan was implemented rather in a hurry, and with support for only the basic
 891  * elements of the service in the backend API. Suggestions are welcome.
 892  */
 893 static Z_APDU *process_scanRequest(association *assoc, request *reqb, int *fd)
 894 {
 895     Z_ScanRequest *req = reqb->request->u.scanRequest;
 896     static Z_APDU apdu;
 897     static Z_ScanResponse res;
 898     static int scanStatus = Z_Scan_failure;
 899     static int numberOfEntriesReturned = 0;
 900     oident *attent;
 901     static Z_ListEntries ents;
 902 #define SCAN_MAX_ENTRIES 200
 903     static Z_Entry *tab[SCAN_MAX_ENTRIES];
 904     bend_scanrequest srq;
 905     bend_scanresult *srs;
 906
 907     apdu.which = Z_APDU_scanResponse;
 908     apdu.u.scanResponse = &res;
 909     res.referenceId = req->referenceId;
 910     res.stepSize = 0;
 911     res.scanStatus = &scanStatus;
 912     res.numberOfEntriesReturned = &numberOfEntriesReturned;
 913     res.positionOfTerm = 0;
 914     res.entries = &ents;
 915     ents.which = Z_ListEntries_nonSurrogateDiagnostics;
 916     res.attributeSet = 0;
 917
 918     if (req->attributeSet && (!(attent = oid_getentbyoid(req->attributeSet)) ||
 919         attent->class != CLASS_ATTSET || attent->value != VAL_BIB1))
 920         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 121, 0);
 921     else if (req->stepSize && *req->stepSize > 0)
 922         ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 205, 0);
 923     else
 924     {
 925         srq.num_bases = req->num_databaseNames;
 926         srq.basenames = req->databaseNames;
 927         srq.num_entries = *req->numberOfTermsRequested;
 928         srq.term = req->termListAndStartPoint;
 929         srq.term_position = req->preferredPositionInResponse ?
 930             *req->preferredPositionInResponse : 1;
 931         if (!(srs = bend_scan(assoc->backend, &srq, 0)))
 932             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto, 2, 0);
 933         else if (srs->errcode)
 934             ents.u.nonSurrogateDiagnostics = diagrecs(assoc->proto,
 935                 srs->errcode, srs->errstring);
 936         else
 937         {
 938             int i;
 939             static Z_Entries list;
 940
 941             if (srs->status == BEND_SCAN_PARTIAL)
 942                 scanStatus = Z_Scan_partial_5;
 943             else
 944                 scanStatus = Z_Scan_success;
 945             ents.which = Z_ListEntries_entries;
 946             ents.u.entries = &list;
 947             list.entries = tab;
 948             for (i = 0; i < srs->num_entries; i++)
 949             {
 950                 Z_Entry *e;
 951                 Z_TermInfo *t;
 952                 Odr_oct *o;
 953
 954                 if (i >= SCAN_MAX_ENTRIES)
 955                 {
 956                     scanStatus = Z_Scan_partial_4;
 957                     break;
 958                 }
 959                 list.entries[i] = e = odr_malloc(assoc->encode, sizeof(*e));
 960                 e->which = Z_Entry_termInfo;
 961                 e->u.termInfo = t = odr_malloc(assoc->encode, sizeof(*t));
 962                 t->suggestedAttributes = 0;
 963                 t->alternativeTerm = 0;
 964                 t->byAttributes = 0;
 965                 t->globalOccurrences = &srs->entries[i].occurrences;
 966                 t->term = odr_malloc(assoc->encode, sizeof(*t->term));
 967                 t->term->which = Z_Term_general;
 968                 t->term->u.general = o = odr_malloc(assoc->encode,
 969                     sizeof(Odr_oct));
 970                 o->buf = odr_malloc(assoc->encode, o->len = o->size =
 971                     strlen(srs->entries[i].term));
 972                 memcpy(o->buf, srs->entries[i].term, o->len);
 973             }
 974             list.num_entries = i;
 975             res.numberOfEntriesReturned = &list.num_entries;
 976             res.positionOfTerm = &srs->term_position;
 977         }
 978     }
 979
 980     return &apdu;
 981 }