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