workbench/devs/pipefs_handler.c

   1 /*
   2     Copyright © 1995-2006, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #define DEBUG 0
   7 #include <aros/debug.h>
   8
   9 #include <exec/errors.h>
  10 #include <exec/resident.h>
  11 #include <exec/memory.h>
  12 #include <exec/semaphores.h>
  13 #include <exec/lists.h>
  14 #include <exec/nodes.h>
  15 #include <proto/exec.h>
  16 #include <utility/tagitem.h>
  17 #include <dos/dosextens.h>
  18 #include <dos/filesystem.h>
  19 #include <proto/dos.h>
  20 #include <aros/symbolsets.h>
  21 #include <aros/asmcall.h>
  22 #if defined(__GNUC__) || defined(__INTEL_COMPILER)
  23 #include "pipefs_handler_gcc.h"
  24 #endif
  25
  26 #include LC_LIBDEFS_FILE
  27
  28 #include <string.h>
  29 #include <stddef.h>
  30
  31 AROS_UFP3(LONG, pipefsproc,
  32     AROS_UFPA(char *,argstr,A0),
  33     AROS_UFPA(ULONG,argsize,D0),
  34     AROS_UFPA(struct ExecBase *,SysBase,A6));
  35
  36 struct pipefsmessage
  37 {
  38     struct Message    msg;
  39     struct IOFileSys *iofs;
  40     LONG              curlen;
  41 };
  42
  43 struct dirnode
  44 {
  45     struct MinNode   node;
  46     struct dirnode  *parent;     /* Parent directory */
  47     STRPTR           name;
  48     LONG             type;
  49     struct DateStamp datestamp;
  50     ULONG            numusers;
  51     struct List      files;
  52 };
  53
  54 struct filenode
  55 {
  56     struct MinNode   node;
  57     struct dirnode  *parent;
  58     STRPTR           name;
  59     LONG             type;
  60     struct DateStamp datestamp;
  61     ULONG            numusers;           /* Number of actual users of this pipe */
  62     ULONG            numwriters;         /* Num of actual writers */
  63     ULONG            numreaders;         /* Num of actual readers */
  64     struct List      waitinglist;        /* List of files waiting for a reader or a writer to become available */
  65     struct List      pendingwrites;      /* List of pending write requestes */
  66     struct List      pendingreads;       /* List of pending read requestes */
  67     ULONG            flags;              /* See below */
  68 };
  69
  70 /* Flags for filenodes */
  71 #define FNF_DELETEONCLOSE 1               /* Specify this flag when you want a pipe to be deleted
  72                                              when it's closed. Useful for unnamed pipes */
  73 struct usernode
  74 {
  75     struct filenode *fn;
  76     ULONG            mode;
  77 };
  78
  79 static size_t           LenFirstPart (CONST_STRPTR path);
  80 static struct filenode *FindFile     (struct pipefsbase *pipefsbase, struct dirnode   **dn_ptr,      CONST_STRPTR path);
  81 static struct filenode *GetFile      (struct pipefsbase *pipefsbase, CONST_STRPTR filename, struct dirnode *dn, ULONG mode, ULONG *err);
  82 static ULONG            SendRequest  (struct pipefsbase *pipefsbase, struct IOFileSys *iofs, BOOL abort);
  83 static STRPTR           StrDup       (struct pipefsbase *pipefsbase, CONST_STRPTR str);
  84
  85
  86 static int GM_UNIQUENAME(Init)(LIBBASETYPEPTR pipefsbase)
  87 {
  88     DOSBase =  (struct DosLibrary *)OpenLibrary("dos.library",39);
  89
  90     if(DOSBase)
  91     {
  92         struct TagItem taglist[]=
  93         {
  94          {NP_Entry,              (IPTR)pipefsproc},
  95          {NP_Name, (IPTR)"pipefs.handler process"},
  96          {NP_UserData,           (IPTR)pipefsbase},
  97          {TAG_DONE,                           0}
  98         };
  99
 100         pipefsbase->proc = CreateNewProc(taglist);
 101
 102         if (pipefsbase->proc)
 103             return TRUE;
 104
 105         CloseLibrary((struct Library *)DOSBase);
 106     }
 107
 108     return FALSE;
 109 }
 110
 111 static int GM_UNIQUENAME(Open)
 112 (
 113     LIBBASETYPEPTR pipefsbase,
 114     struct IOFileSys *iofs,
 115     ULONG unitnum,
 116     ULONG flags
 117 )
 118 {
 119     struct usernode *un;
 120     struct dirnode  *dn;
 121
 122     /* Mark Message as recently used. */
 123     iofs->IOFS.io_Message.mn_Node.ln_Type=NT_REPLYMSG;
 124
 125     /* Build a fake usernode */
 126     un = AllocVec(sizeof(*un),MEMF_PUBLIC|MEMF_CLEAR);
 127     if(un)
 128     {
 129         dn = AllocVec(sizeof(*dn),MEMF_PUBLIC|MEMF_CLEAR);
 130         if (dn)
 131         {
 132             dn->type   = ST_ROOT;
 133             dn->name   = iofs->io_Union.io_OpenDevice.io_DosName;
 134             dn->parent = NULL;
 135
 136             NEWLIST(&dn->files);
 137             DateStamp(&dn->datestamp);
 138
 139             un->fn = (struct filenode *)dn;
 140             iofs->IOFS.io_Unit=(struct Unit *)un;
 141             iofs->IOFS.io_Device=&pipefsbase->device;
 142
 143             iofs->IOFS.io_Error=0;
 144
 145             return TRUE;
 146         }
 147
 148         FreeVec(un);
 149     }
 150
 151     iofs->io_DosError=ERROR_NO_FREE_STORE;
 152
 153     iofs->IOFS.io_Error=IOERR_OPENFAIL;
 154
 155     return FALSE;
 156 }
 157
 158 static int GM_UNIQUENAME(Close)
 159 (
 160     LIBBASETYPEPTR pipefsbase,
 161     struct IOFileSys *iofs
 162 )
 163 {
 164     struct usernode *un;
 165     struct dirnode  *dn;
 166
 167     un = (struct usernode *)iofs->IOFS.io_Unit;
 168     dn = (struct dirnode *)un->fn;
 169
 170     if(!IsListEmpty(&dn->files))
 171     {
 172         iofs->io_DosError=ERROR_OBJECT_IN_USE;
 173         return FALSE;
 174     }
 175
 176     FreeVec(dn);
 177     FreeVec(un);
 178
 179     iofs->io_DosError=0;
 180
 181     return TRUE;
 182 }
 183
 184 static int GM_UNIQUENAME(Expunge)(LIBBASETYPEPTR pipefsbase)
 185 {
 186     /*
 187         This function is single-threaded by exec by calling Forbid.
 188         Never break the Forbid() or strange things might happen.
 189     */
 190
 191     SendRequest(pipefsbase, NULL, TRUE);
 192
 193     /* Free all resources */
 194     CloseLibrary((struct Library *)pipefsbase->dosbase);
 195
 196     return TRUE;
 197 }
 198
 199 AROS_LH1(void, beginio,
 200  AROS_LHA(struct IOFileSys *, iofs, A1),
 201            struct pipefsbase *, pipefsbase, 5, Pipefs)
 202 {
 203     AROS_LIBFUNC_INIT
 204     LONG error=0;
 205     BOOL enqueued = FALSE;
 206
 207     D(bug("COMMAND %d\n", iofs->IOFS.io_Command));
 208     switch(iofs->IOFS.io_Command)
 209     {
 210         case FSA_OPEN:
 211         case FSA_OPEN_FILE:
 212         case FSA_PIPE:
 213         case FSA_EXAMINE:
 214         case FSA_EXAMINE_NEXT:
 215         case FSA_READ:
 216         case FSA_WRITE:
 217         case FSA_CLOSE:
 218         case FSA_CREATE_DIR:
 219         case FSA_DELETE_OBJECT:
 220         case FSA_FILE_MODE:
 221             error = SendRequest(pipefsbase, iofs, FALSE);
 222             enqueued = !error;
 223             break;
 224
 225         case FSA_SEEK:
 226             error = ERROR_SEEK_ERROR;
 227             break;
 228         case FSA_IS_FILESYSTEM:
 229             iofs->io_Union.io_IS_FILESYSTEM.io_IsFilesystem = TRUE;
 230             break;
 231         case FSA_SET_FILE_SIZE:
 232         case FSA_EXAMINE_ALL:
 233         case FSA_CREATE_HARDLINK:
 234         case FSA_CREATE_SOFTLINK:
 235         case FSA_RENAME:
 236             error = ERROR_NOT_IMPLEMENTED;
 237             break;
 238
 239         default:
 240             error = ERROR_ACTION_NOT_KNOWN;
 241             break;
 242     }
 243
 244     /* Set error code */
 245     iofs->io_DosError=error;
 246
 247     /* If the quick bit is not set and the request hasn't been redirected
 248        send the message to the port
 249     */
 250     if(!(iofs->IOFS.io_Flags&IOF_QUICK) && !enqueued)
 251         ReplyMsg(&iofs->IOFS.io_Message);
 252
 253     AROS_LIBFUNC_EXIT
 254 }
 255
 256 ADD2INITLIB(GM_UNIQUENAME(Init), 0)
 257 ADD2OPENDEV(GM_UNIQUENAME(Open), 0)
 258 ADD2CLOSEDEV(GM_UNIQUENAME(Close), 0)
 259 ADD2EXPUNGELIB(GM_UNIQUENAME(Expunge), 0)
 260
 261 AROS_LH1(LONG, abortio,
 262 AROS_LHA(struct IOFileSys *, iofs, A1),
 263 struct pipefsbase *, pipefsbase, 6, Pipefs)
 264 {
 265     AROS_LIBFUNC_INIT
 266
 267     return SendRequest(pipefsbase, iofs, TRUE);
 268
 269     AROS_LIBFUNC_EXIT
 270 }
 271
 272 static ULONG SendRequest(struct pipefsbase *pipefsbase, struct IOFileSys *iofs, BOOL abort)
 273 {
 274     struct pipefsmessage *msg = AllocVec(sizeof(*msg), MEMF_PUBLIC);
 275
 276     if (msg)
 277     {
 278         msg->msg.mn_Node.ln_Type = NT_MESSAGE;
 279         msg->msg.mn_Node.ln_Name = "PIPEFSMSG";
 280         msg->msg.mn_Length       = sizeof(struct pipefsmessage);
 281         msg->iofs                = iofs;
 282         msg->curlen              = abort;
 283
 284         if (iofs)
 285         {
 286             iofs->IOFS.io_Message.mn_Node.ln_Type = NT_MESSAGE;
 287             iofs->IOFS.io_Flags &= ~IOF_QUICK;
 288         }
 289
 290         PutMsg(&pipefsbase->proc->pr_MsgPort, (struct Message *)msg);
 291
 292         return 0;
 293     }
 294
 295     return ERROR_NO_FREE_STORE;
 296 }
 297
 298 /* The helper process */
 299
 300 #define SendBack(msg, err)                   \
 301 {                                            \
 302     msg->iofs->io_DosError = err;            \
 303     ReplyMsg(&(msg)->iofs->IOFS.io_Message); \
 304     FreeVec(msg);                            \
 305 }
 306
 307 static STRPTR StrDup(struct pipefsbase *pipefsbase, CONST_STRPTR str)
 308 {
 309     size_t len = strlen(str)+1;
 310     STRPTR ret = AllocVec(len, MEMF_ANY);
 311
 312     if (ret)
 313         CopyMem(str, ret, len);
 314
 315     return ret;
 316 }
 317
 318 /*
 319   Return the len of the first part in the path.
 320
 321   EXAMPLE
 322     LenFirstPart("yyy/xxx") would return 3
 323     LenFirstPart("xxxx") would return 4
 324 */
 325
 326 static size_t LenFirstPart(CONST_STRPTR path)
 327 {
 328     size_t len = 0;
 329
 330     for (; path[0] && path[0] != '/'; path++, len++);
 331
 332     return len;
 333 }
 334
 335 static struct filenode *FindFile(struct pipefsbase *pipefsbase, struct dirnode **dn_ptr, CONST_STRPTR path)
 336 {
 337     #define dn (*dn_ptr)
 338
 339     size_t len;
 340     CONST_STRPTR nextpart;
 341     struct filenode *fn;
 342
 343     while (path[0] == '/' && dn)
 344     {
 345         dn = dn->parent;
 346         path++;
 347     }
 348
 349     if (!dn) return NULL;
 350
 351     if (!path[0]) return (struct filenode *)dn;
 352
 353     if (dn->type <= 0)
 354     {
 355         D(bug("User wants %S to be a directory, but it's a file.\n", dn->name));
 356         dn = NULL;
 357         return NULL;
 358     }
 359
 360     len      = LenFirstPart(path);
 361     nextpart = &path[len];
 362     fn       = (struct filenode *)GetHead(&dn->files);
 363
 364     D(bug("Searching for %.*S.\n", len, path));
 365
 366     while (fn) {
 367         if (fn->name != NULL) {
 368             D(bug("Comparing %S with %.*S.\n", fn->name, len, path));
 369             if (strlen(fn->name) == len && strncasecmp(fn->name, path, len) == 0)
 370                 break;
 371         }
 372         fn = (struct filenode *)GetSucc((struct Node *)fn);
 373     }
 374
 375     if (fn)
 376     {
 377         if (nextpart[0] == '/') nextpart++;
 378
 379         dn = (struct dirnode *)fn;
 380         fn = FindFile(pipefsbase, &dn, nextpart);
 381     }
 382
 383     return fn;
 384
 385     #undef dn
 386 }
 387
 388 static struct filenode *NewFileNode(struct pipefsbase *pipefsbase, STRPTR filename, ULONG flags, struct dirnode *dn, ULONG *err)
 389 {
 390     struct filenode *fn;
 391
 392     fn = AllocVec(sizeof(*fn), MEMF_PUBLIC|MEMF_CLEAR);
 393     if (fn)
 394     {
 395         if (filename == NULL || (fn->name = StrDup(pipefsbase, filename)) != NULL) {
 396             fn->type = ST_PIPEFILE;
 397
 398             DateStamp(&fn->datestamp);
 399             NEWLIST(&fn->waitinglist);
 400             NEWLIST(&fn->pendingwrites);
 401             NEWLIST(&fn->pendingreads);
 402
 403             fn->parent = dn;
 404             fn->flags  = flags;
 405
 406             AddTail(&dn->files, (struct Node *)fn);
 407             D(bug("New file created and added to the list\n"));
 408
 409             return fn;
 410         }
 411
 412         FreeVec(fn);
 413     }
 414
 415     D(bug("AllocVec Failed. No more memory available\n"));
 416     *err = ERROR_NO_FREE_STORE;
 417     return NULL;
 418 }
 419
 420 static struct filenode *GetFile(struct pipefsbase *pipefsbase, CONST_STRPTR filename, struct dirnode *dn, ULONG mode, ULONG *err)
 421 {
 422     struct filenode *fn;
 423
 424     D(bug("User wants to open file %S.\n", filename));
 425     D(bug("Current directory is %S\n", dn->name));
 426
 427     if (dn && !dn->parent && strcmp(filename, "__UNNAMED__") == 0)
 428     {
 429         return NewFileNode(pipefsbase, "__UNNAMED__", FNF_DELETEONCLOSE, dn, err);
 430     }
 431
 432     fn = FindFile(pipefsbase, &dn, filename);
 433     if (!fn)
 434     {
 435         D(bug("The file couldn't be found.\n"));
 436
 437         if (dn && mode&FMF_CREATE)
 438         {
 439             D(bug("But the user wants it to be created.\n"));
 440
 441             return NewFileNode(pipefsbase, FilePart(filename), 0, dn, err);
 442         }
 443         else
 444         {
 445             *err = ERROR_OBJECT_NOT_FOUND;
 446         }
 447     }
 448
 449     if (fn && fn->type > 0 && mode&(FMF_WRITE|FMF_READ))
 450     {
 451         D(bug("The file is a directory, cannot be open for reading/writing\n"));
 452         *err = ERROR_OBJECT_WRONG_TYPE;
 453         return NULL;
 454     }
 455
 456     return fn;
 457 }
 458
 459 #undef SysBase
 460 #ifndef kprintf
 461      struct ExecBase *SysBase;
 462 #else
 463 #    define SysBase _SysBase
 464 #endif
 465
 466
 467 AROS_UFH3(LONG, pipefsproc,
 468     AROS_UFHA(char *,argstr,A0),
 469     AROS_UFHA(ULONG,argsize,D0),
 470     AROS_UFHA(struct ExecBase *,_SysBase,A6))
 471 {
 472     AROS_USERFUNC_INIT
 473
 474     struct Process       *me;
 475     struct pipefsbase    *pipefsbase;
 476     struct pipefsmessage *msg;
 477     struct usernode      *un;
 478     struct filenode      *fn;
 479     BOOL cont = TRUE;
 480
 481     SysBase = _SysBase;
 482
 483     me         = (struct Process *)FindTask(0);
 484     pipefsbase = me->pr_Task.tc_UserData;
 485
 486
 487     do
 488     {
 489         WaitPort(&(me->pr_MsgPort));
 490
 491         while
 492         (
 493             (msg =(struct pipefsmessage *)GetMsg(&(me->pr_MsgPort))) &&
 494             (cont = (msg->iofs != 0))
 495         )
 496         {
 497             D(bug("Message received.\n"));
 498
 499             un = (struct usernode *)msg->iofs->IOFS.io_Unit;
 500             fn = un->fn;
 501
 502             if (msg->curlen) /* This field is abused too see whethet the user wants to abort the request */
 503             {
 504                 struct pipefsmessage *msg2;
 505                 BOOL found = FALSE;
 506
 507                 D(bug("The user wants to abort this request.\n"));
 508
 509                 ForeachNode(&fn->waitinglist, msg2)
 510                 {
 511                     if (msg2->iofs == msg->iofs)
 512                     {
 513                         found = TRUE;
 514
 515                         fn->numusers--;
 516                         if (un->mode & FMF_WRITE)
 517                             fn->numwriters--;
 518                         if (un->mode & FMF_READ)
 519                             fn->numreaders--;
 520
 521                         FreeVec(un);
 522
 523                         break;
 524                     }
 525                 }
 526                 if (!found && (un->mode & FMF_WRITE))
 527                 {
 528                     ForeachNode(&fn->pendingwrites, msg2)
 529                     {
 530                         if (msg2->iofs == msg->iofs)
 531                         {
 532                             found = TRUE;
 533                             break;
 534                         }
 535                     }
 536                 }
 537                 if (!found && (un->mode & FMF_READ))
 538                 {
 539                     ForeachNode(&fn->pendingreads, msg2)
 540                     {
 541                         if (msg2->iofs == msg->iofs)
 542                         {
 543                             found = TRUE;
 544                             break;
 545                         }
 546                     }
 547                 }
 548
 549                 if (found)
 550                 {
 551                     D(bug("Aborting the request.\n"));
 552                     Remove((struct Node *)msg2);
 553                     msg2->iofs->IOFS.io_Error = IOERR_ABORTED;
 554                     SendBack(msg2, ERROR_INTERRUPTED);
 555                 }
 556                 else
 557                 {
 558                     D(bug("There was no I/O in process for this request.\n"));
 559                 }
 560
 561                 FreeVec(msg);
 562                 continue;
 563             }
 564
 565             switch (msg->iofs->IOFS.io_Command)
 566             {
 567                 case FSA_OPEN:
 568                     msg->iofs->io_Union.io_OPEN.io_FileMode &= ~(FMF_WRITE|FMF_READ);
 569                     /* Fall through */
 570                 case FSA_OPEN_FILE:
 571                 {
 572                     struct usernode *un;
 573                     BOOL             stillwaiting;
 574                     ULONG            err;
 575
 576                     D(bug("Command is OPEN\n"));
 577
 578                     /*
 579                        I would have liked to put this AFTER GetFile(),
 580                        but then it would have been really difficult to
 581                        undo what's done in GetFile() if the following AllocVec()
 582                        failed...
 583                     */
 584                     un = AllocVec(sizeof(*un), MEMF_PUBLIC);
 585                     if (!un)
 586                     {
 587                         SendBack(msg, ERROR_NO_FREE_STORE);
 588                         continue;
 589                     }
 590
 591                     un->mode = msg->iofs->io_Union.io_OPEN.io_FileMode;
 592
 593                     fn = GetFile(pipefsbase, msg->iofs->io_Union.io_OPEN.io_Filename, (struct dirnode *)fn, un->mode, &err);
 594                     if (!fn)
 595                     {
 596                         FreeVec(un);
 597                         SendBack(msg, err);
 598                         continue;
 599                     }
 600
 601                     D(bug("File requested found.\n"));
 602                     D(bug("The requested file is %s.\n",
 603                             fn->type <= 0  ?
 604                             "a pipe":
 605                             "a directory"));
 606
 607                     msg->iofs->IOFS.io_Unit = (struct Unit *)un;
 608                     fn->numusers++;
 609                     un->fn = fn;
 610
 611                     if (fn->type > 0)
 612                     {
 613                         SendBack(msg, 0);
 614                         continue;
 615                     }
 616
 617                     stillwaiting = !fn->numwriters || !fn->numreaders;
 618
 619                     if (un->mode == FMF_MODE_OLDFILE) un->mode &= ~FMF_WRITE;
 620                     if (un->mode == FMF_MODE_NEWFILE) un->mode &= ~FMF_READ;
 621
 622                     if (un->mode & FMF_READ)
 623                     {
 624                         D(bug("User wants to read. "));
 625                         fn->numreaders++;
 626                     }
 627                     if (un->mode & FMF_WRITE)
 628                     {
 629                         D(bug("User wants to write. "));
 630                         fn->numwriters++;
 631                     }
 632
 633                     D(bug("There are %d readers and %d writers at the moment\n", fn->numreaders, fn->numwriters));
 634
 635                     if (!fn->numwriters || !fn->numreaders)
 636                     {
 637                         if (un->mode&(FMF_WRITE|FMF_READ) && !(un->mode&FMF_NONBLOCK))
 638                         {
 639                             /*
 640                                If we're lacking of writers or readers
 641                                then add this message to a waiting list.
 642                             */
 643                             D(bug("There are no %s at the moment, so this %s must wait\n",
 644                                      fn->numwriters?"readers":"writers",
 645                                      fn->numwriters?"writer":"reader"));
 646
 647                             AddTail(&fn->waitinglist, (struct Node *)msg);
 648                         }
 649                         else
 650                             SendBack(msg, 0);
 651                     }
 652                     else
 653                     {
 654                         if (stillwaiting)
 655                         {
 656                             /*
 657                               Else wake up all the ones that were still waiting
 658                             */
 659                             struct pipefsmessage *msg;
 660
 661                             D(bug("Finally there are enough readers and writers! "
 662                                     "Wake up all of them\n"));
 663
 664                             while ((msg = (struct pipefsmessage *)RemHead(&fn->waitinglist)))
 665                                 SendBack(msg, 0);
 666                         }
 667                         SendBack(msg, 0);
 668                     }
 669
 670                     continue;
 671                 }
 672
 673                 case FSA_PIPE: {
 674                     struct usernode *reader, *writer;
 675                     LONG err;
 676
 677                     D(bug("Command is FSA_PIPE\n"));
 678
 679                     if ((reader = AllocVec(sizeof(struct usernode), MEMF_PUBLIC)) == NULL) {
 680                         SendBack(msg, ERROR_NO_FREE_STORE);
 681                         continue;
 682                     }
 683                     if ((writer = AllocVec(sizeof(struct usernode), MEMF_PUBLIC)) == NULL) {
 684                         SendBack(msg, ERROR_NO_FREE_STORE);
 685                         continue;
 686                     }
 687
 688                     fn = NewFileNode(pipefsbase, NULL, FNF_DELETEONCLOSE, (struct dirnode *) fn, &err);
 689                     if (fn == NULL) {
 690                         FreeVec(reader);
 691                         FreeVec(writer);
 692                         SendBack(msg, err);
 693                         continue;
 694                     }
 695
 696                     msg->iofs->IOFS.io_Unit = (struct Unit *) reader;
 697                     msg->iofs->io_Union.io_PIPE.io_Writer = (struct Unit *) writer;
 698
 699                     reader->fn = writer->fn = fn;
 700                     fn->numusers = 2;
 701
 702                     reader->mode = FMF_READ;
 703                     fn->numreaders++;
 704
 705                     writer->mode = FMF_WRITE;
 706                     fn->numwriters++;
 707
 708                     SendBack(msg, 0);
 709
 710                     continue;
 711                 }
 712
 713                 case FSA_CLOSE:
 714                     D(bug("Command is FSA_CLOSE\n"));
 715
 716                     if (un->mode & FMF_READ)
 717                     {
 718                         D(bug("User was a reader. "));
 719                         fn->numreaders--;
 720                         D(bug("There are %d readers at the moment\n", fn->numreaders));
 721                         if (!fn->numreaders)
 722                         {
 723                             struct pipefsmessage *msg;
 724
 725                             D(bug("There are no readers anymore. %s\n",
 726                                     IsListEmpty(&fn->pendingwrites) ?
 727                                     "There are no pending writes"   :
 728                                     "Reply to all the waiting writers"));
 729
 730                             while ((msg = (struct pipefsmessage *)RemHead(&fn->pendingwrites)))
 731                                 SendBack(msg, 0);
 732                         }
 733                     }
 734                     if (un->mode & FMF_WRITE)
 735                     {
 736                         D(bug("User was a writer. "));
 737                         fn->numwriters--;
 738                         D(bug("There are %d writers at the moment\n", fn->numwriters));
 739
 740                         if (!fn->numwriters)
 741                         {
 742                             struct pipefsmessage *msg;
 743
 744                             D(bug("There are no writers anymore. %s\n",
 745                                     IsListEmpty(&fn->pendingreads) ?
 746                                     "There are no pending reads"   :
 747                                     "Reply to all the waiting readers"));
 748                             while ((msg = (struct pipefsmessage *)RemHead(&fn->pendingreads)))
 749                             {
 750                                 msg->iofs->io_Union.io_READ_WRITE.io_Length =
 751                                 msg->iofs->io_Union.io_READ_WRITE.io_Length - msg->curlen;
 752                                 SendBack(msg, 0);
 753                             }
 754                         }
 755                     }
 756
 757                     un->fn->numusers--;
 758
 759                     if (!un->fn->numusers && un->fn->type <= 0 && (un->fn->flags & FNF_DELETEONCLOSE))
 760                     {
 761                         Remove((struct Node *)fn);
 762                         if (fn->name != NULL)
 763                             FreeVec(fn->name);
 764                         FreeVec(fn);
 765                     }
 766
 767                     FreeVec(un);
 768                     SendBack(msg, 0);
 769
 770                     continue;
 771                 case FSA_EXAMINE:
 772                 {
 773                     struct ExAllData  *ead        = msg->iofs->io_Union.io_EXAMINE.io_ead;
 774                     const ULONG        type       = msg->iofs->io_Union.io_EXAMINE.io_Mode;
 775                     const ULONG        size       = msg->iofs->io_Union.io_EXAMINE.io_Size;
 776                     STRPTR             next, end;
 777
 778                     static const ULONG sizes[]=
 779                     {
 780                         0,
 781                         offsetof(struct ExAllData,ed_Type),
 782                         offsetof(struct ExAllData,ed_Size),
 783                         offsetof(struct ExAllData,ed_Prot),
 784                         offsetof(struct ExAllData,ed_Days),
 785                         offsetof(struct ExAllData,ed_Comment),
 786                         offsetof(struct ExAllData,ed_OwnerUID),
 787                         sizeof(struct ExAllData)
 788                     };
 789
 790                     D(bug("Command is EXAMINE\n"));
 791
 792                     if (fn->name == NULL) {
 793                         SendBack(msg, ERROR_OBJECT_NOT_FOUND);
 794                         continue;
 795                     }
 796
 797                     D(bug("Examining file %S\n", fn->name));
 798
 799                     if (type > ED_OWNER)
 800                     {
 801                         D(bug("The user requested an invalid type\n"));
 802                         SendBack(msg, ERROR_BAD_NUMBER);
 803                         continue;
 804                     }
 805
 806                     next = (STRPTR)ead + sizes[type];
 807                     end  = (STRPTR)ead + size;
 808
 809                     if(next>end)  /* > is correct. Not >= */
 810                     {
 811                         SendBack(msg, ERROR_BUFFER_OVERFLOW);
 812                         continue;
 813                     }
 814
 815                     if (fn->type > 0)
 816                     {
 817                         msg->iofs->io_DirPos = (LONG)GetHead(&((struct dirnode *)fn)->files);
 818                     }
 819                     else
 820                     {
 821                         msg->iofs->io_DirPos = (LONG)fn;
 822                     }
 823
 824                     switch(type)
 825                     {
 826                         case ED_OWNER:
 827                         ead->ed_OwnerUID = 0;
 828                         ead->ed_OwnerGID = 0;
 829
 830                         /* Fall through */
 831                         case ED_COMMENT:
 832                             ead->ed_Comment = NULL;
 833
 834                         /* Fall through */
 835                         case ED_DATE:
 836                             ead->ed_Days  = fn->datestamp.ds_Days;
 837                             ead->ed_Mins  = fn->datestamp.ds_Minute;
 838                             ead->ed_Ticks = fn->datestamp.ds_Tick;
 839
 840                         /* Fall through */
 841                         case ED_PROTECTION:
 842                             ead->ed_Prot = 0;
 843
 844                         /* Fall through */
 845                         case ED_SIZE:
 846                             ead->ed_Size = 0;
 847
 848                         /* Fall through */
 849                         case ED_TYPE:
 850                             ead->ed_Type = fn->type;
 851
 852                         /* Fall through */
 853                         case ED_NAME:
 854                         {
 855                             STRPTR name = fn->name;
 856                             ead->ed_Name = next;
 857
 858                             for (;;)
 859                             {
 860                                 if (next >= end)
 861                                 {
 862                                     SendBack(msg, ERROR_BUFFER_OVERFLOW);
 863                                     continue;
 864                                 }
 865
 866                                 if (!(*next++ = *name++))
 867                                 {
 868                                     break;
 869                                 }
 870                             }
 871                         }
 872                     }
 873
 874                     ead->ed_Next = (struct ExAllData *)(((IPTR)next + AROS_PTRALIGN - 1) & ~(AROS_PTRALIGN - 1));
 875
 876                     SendBack(msg, 0);
 877                     continue;
 878                 }
 879                 case FSA_EXAMINE_NEXT:
 880                 {
 881                     struct FileInfoBlock *fib = msg->iofs->io_Union.io_EXAMINE_NEXT.io_fib;
 882                     struct filenode      *fn  = (struct filenode *)fib->fib_DiskKey;
 883
 884                     D(bug("Command is EXAMINE_NEXT\n"));
 885
 886                     if (!fn)
 887                     {
 888                         D(bug("There are no more entries in this directory\n"));
 889                         SendBack(msg, ERROR_NO_MORE_ENTRIES);
 890                         continue;
 891                     }
 892
 893                     if (fn->name == NULL) {
 894                         SendBack(msg, ERROR_OBJECT_NOT_FOUND);
 895                         continue;
 896                     }
 897
 898                     D(bug("Current directory is %S. Current file is %S\n", fn->parent->name, fn->name));
 899
 900                     fib->fib_OwnerUID       = 0;
 901                     fib->fib_OwnerGID       = 0;
 902                     fib->fib_Date.ds_Days   = fn->datestamp.ds_Days;
 903                     fib->fib_Date.ds_Minute = fn->datestamp.ds_Minute;
 904                     fib->fib_Date.ds_Tick   = fn->datestamp.ds_Tick;
 905                     fib->fib_Protection     = 0;
 906                     fib->fib_Size           = 0;
 907                     fib->fib_DirEntryType   = fn->type;
 908
 909                     strncpy(fib->fib_FileName, fn->name, MAXFILENAMELENGTH - 1);
 910                     fib->fib_Comment[0] = '\0';
 911
 912                     fib->fib_DiskKey = (IPTR)GetSucc(fn);
 913                     SendBack(msg, 0);
 914
 915                     continue;
 916                 }
 917                 case FSA_CREATE_DIR:
 918                 {
 919                     CONST_STRPTR filename  = msg->iofs->io_Union.io_CREATE_DIR.io_Filename;
 920                     struct dirnode *parent = (struct dirnode *)fn;
 921                     struct dirnode *dn;
 922
 923                     D(bug("Command is FSA_CREATE_DIR\n"));
 924                     D(bug("Current directory is %S\n", parent->name));
 925                     D(bug("User wants to create directory %S\n", filename));
 926
 927                     dn = (struct dirnode *)FindFile(pipefsbase, &parent, filename);
 928                     if (dn)
 929                     {
 930                         D(bug("The object %S already exists\n", filename));
 931                         SendBack(msg, ERROR_OBJECT_EXISTS);
 932                         continue;
 933                     }
 934                     else
 935                     if (!parent)
 936                     {
 937                         D(bug("The path is not valid.\n"));
 938                         SendBack(msg, ERROR_OBJECT_NOT_FOUND);
 939                         continue;
 940                     }
 941
 942                     if
 943                     (
 944                         !(un       = AllocVec(sizeof(*un), MEMF_PUBLIC)) ||
 945                         !(dn       = AllocVec(sizeof(*dn), MEMF_PUBLIC)) ||
 946                         !(dn->name = StrDup(pipefsbase, filename))
 947                     )
 948                     {
 949                         SendBack(msg, ERROR_NO_FREE_STORE);
 950                         continue;
 951                     }
 952
 953                     D(bug("Ok, there's room for this directory.\n"));
 954                     AddTail(&parent->files, (struct Node *)dn);
 955                     dn->parent   = parent;
 956                     dn->numusers = 0;
 957                     dn->type     = ST_USERDIR;
 958                     NEWLIST(&dn->files);
 959                     DateStamp(&dn->datestamp);
 960
 961                     un->fn   = (struct filenode *)dn;
 962                     un->mode = 0;
 963                     msg->iofs->IOFS.io_Unit = (struct Unit *)un;
 964
 965                     SendBack(msg, 0);
 966                     continue;
 967                 }
 968                 case FSA_FILE_MODE:
 969                     D(bug("Command is FSA_FILE_MODE\n"));
 970                     D(bug("Current mode is 0x%08x\n", un->mode));
 971
 972                     un->mode &= ~msg->iofs->io_Union.io_FILE_MODE.io_Mask;
 973                     un->mode |= msg->iofs->io_Union.io_FILE_MODE.io_FileMode;
 974
 975                     D(bug("New mode is 0x%08x\n", un->mode));
 976
 977                     SendBack(msg, 0);
 978                     continue;
 979                 case FSA_DELETE_OBJECT:
 980                 {
 981                     CONST_STRPTR filename = msg->iofs->io_Union.io_DELETE_OBJECT.io_Filename;
 982                     struct dirnode *dn = (struct dirnode *)fn;
 983
 984                     if (fn->name == NULL) {
 985                         SendBack(msg, ERROR_OBJECT_NOT_FOUND);
 986                         continue;
 987                     }
 988
 989                     D(bug("Command is FSA_DELETE_OBJECT\n"));
 990                     D(bug("Current directory is %S\n", fn->name));
 991                     D(bug("User wants to delete the object %S\n", filename));
 992
 993                     fn = FindFile(pipefsbase, &dn, filename);
 994                     if (!fn)
 995                     {
 996                         D(bug("The object doesn't exist\n"));
 997                         SendBack(msg, ERROR_OBJECT_NOT_FOUND);
 998                         continue;
 999                     }
1000                     if (fn->type == ST_ROOT)
1001                     {
1002                         D(bug("The object is the root directory. Cannot be deleted\n"));
1003                         SendBack(msg, ERROR_OBJECT_WRONG_TYPE);
1004                         continue;
1005                     }
1006                     if (fn->numusers)
1007                     {
1008                         D(bug("The object is in use, cannot be deleted\n"));
1009                         SendBack(msg, ERROR_OBJECT_IN_USE);
1010                         continue;
1011                     }
1012                     if (fn->type > 0 && !IsListEmpty(&((struct dirnode *)fn)->files))
1013                     {
1014                         D(bug("The object is a directory, but is not empty, thus cannot be deleted\n"));
1015                         SendBack(msg, ERROR_DIRECTORY_NOT_EMPTY);
1016                         continue;
1017                     }
1018
1019                     D(bug("Removing the object from it's parent directory\n"));
1020
1021                     Remove((struct Node *)fn);
1022                     FreeVec(fn->name);
1023                     FreeVec(fn);
1024
1025                     SendBack(msg, 0);
1026                     continue;
1027                 }
1028                 case FSA_WRITE:
1029                     D(bug("Command is FSA_WRITE. "));
1030                     if (!(un->mode & FMF_WRITE))
1031                     {
1032                         D(bug("User doesn't have permission to write.\n"));
1033                         SendBack(msg, ERROR_BAD_STREAM_NAME);
1034                         continue;
1035                     }
1036                     if (!fn->numreaders)
1037                     {
1038                         D(bug("There are no more readers: PIPE BROKEN.\n"));
1039                         SendBack(msg, ERROR_BROKEN_PIPE);
1040                         continue;
1041                     }
1042                     if (un->mode & FMF_NONBLOCK && IsListEmpty(&fn->pendingreads))
1043                     {
1044                         D(bug("There are no pending reads and the pipe is in nonblocking mode, so return EWOULDBLOCK\n"));
1045                         SendBack(msg, ERROR_WOULD_BLOCK);
1046                         continue;
1047                     }
1048
1049                     D(bug("Enqueing the message\n"));
1050                     msg->curlen = msg->iofs->io_Union.io_READ_WRITE.io_Length;
1051                     AddTail(&fn->pendingwrites, (struct Node *)msg);
1052                     break;
1053                 case FSA_READ:
1054                     D(bug("Command is FSA_READ. "));
1055                     if (!(un->mode & FMF_READ))
1056                     {
1057                         D(bug("User doesn't have permission to read.\n"));
1058                         SendBack(msg, ERROR_BAD_STREAM_NAME);
1059                         continue;
1060                     }
1061                     if (!fn->numwriters)
1062                     {
1063                         D(bug("There's no data to read: send EOF\n"));
1064                         msg->iofs->io_Union.io_READ_WRITE.io_Length = 0;
1065                         SendBack(msg, 0);
1066                         continue;
1067                     }
1068                     if (un->mode & FMF_NONBLOCK  && IsListEmpty(&fn->pendingwrites))
1069                     {
1070                         D(bug("There are no pending writes and the pipe is in nonblocking mode, so return EWOULDBLOCK\n"));
1071                         SendBack(msg, ERROR_WOULD_BLOCK);
1072                         continue;
1073                     }
1074
1075                     D(bug("Enqueing the message\n"));
1076                     msg->curlen = msg->iofs->io_Union.io_READ_WRITE.io_Length;
1077                     AddTail(&fn->pendingreads, (struct Node *)msg);
1078                     break;
1079             }
1080
1081             while (!IsListEmpty(&fn->pendingwrites) && !IsListEmpty(&fn->pendingreads))
1082             {
1083                 struct pipefsmessage *rmsg = (struct pipefsmessage *)RemHead(&fn->pendingreads);
1084                 struct pipefsmessage *wmsg = (struct pipefsmessage *)RemHead(&fn->pendingwrites);
1085
1086                 ULONG len = (rmsg->curlen > wmsg->curlen) ?
1087                              wmsg->curlen : rmsg->curlen;
1088
1089                 D(bug("Writer len = %d - Reader len = %d. Copying %d bytes\n",
1090                          wmsg->curlen, rmsg->curlen, len));
1091
1092                 CopyMem
1093                 (
1094                     wmsg->iofs->io_Union.io_READ_WRITE.io_Buffer +
1095                     wmsg->iofs->io_Union.io_READ_WRITE.io_Length -
1096                     wmsg->curlen,
1097
1098                     rmsg->iofs->io_Union.io_READ_WRITE.io_Buffer +
1099                     rmsg->iofs->io_Union.io_READ_WRITE.io_Length -
1100                     rmsg->curlen,
1101
1102                     len
1103                 );
1104
1105                 wmsg->curlen -= len;
1106                 rmsg->curlen -= len;
1107
1108                 D(bug("Writer curlen is now %d - Reader curlen is now %d\n",
1109                          wmsg->curlen, rmsg->curlen));
1110
1111                 if (!wmsg->curlen)
1112                 {
1113                     D(bug("Writer: finished its job.\n"));
1114                     SendBack(wmsg, 0);
1115                 }
1116                 else
1117                 {
1118                     D(bug("Writer: not finished yet. Enqueueing the request again.\n"));
1119                     AddTail(&fn->pendingwrites, (struct Node *)wmsg);
1120                 }
1121
1122                 if (!rmsg->curlen)
1123                 {
1124                     D(bug("Reader: finished its job.\n"));
1125                     SendBack(rmsg, 0);
1126                 }
1127                 else
1128                 if
1129                 (
1130                     ((struct usernode *)rmsg->iofs->IOFS.io_Unit)->mode & FMF_NONBLOCK &&
1131                     rmsg->iofs->io_Union.io_READ_WRITE.io_Length > wmsg->iofs->io_Union.io_READ_WRITE.io_Length
1132                 )
1133                 {
1134                     D(bug("Reader: wants to read more data than it's actually available, but since it's in nonblocking mode return anyway\n"));
1135                     rmsg->iofs->io_Union.io_READ_WRITE.io_Length = len;
1136                     SendBack(rmsg, 0);
1137                 }
1138                 else
1139                 {
1140                     D(bug("Reader: not finished yet. Enqueueing the request again.\n"));
1141                     AddTail(&fn->pendingreads, (struct Node *)rmsg);
1142                 }
1143             }
1144         }
1145         D(bug("Coming back to wait for a new message\n"));
1146
1147     } while (cont);
1148
1149     return 0;
1150
1151     AROS_USERFUNC_EXIT
1152 }