bsd/miscfs/fifofs/fifo_vnops.c

   1 /*
   2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1990, 1993, 1995
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)fifo_vnops.c        8.4 (Berkeley) 8/10/94
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/proc.h>
  66 #include <sys/time.h>
  67 #include <sys/namei.h>
  68 #include <sys/vnode_internal.h>
  69 #include <sys/socket.h>
  70 #include <sys/socketvar.h>
  71 #include <sys/stat.h>
  72 #include <sys/systm.h>
  73 #include <sys/ioctl.h>
  74 #include <sys/file_internal.h>
  75 #include <sys/errno.h>
  76 #include <sys/malloc.h>
  77 #include <miscfs/fifofs/fifo.h>
  78 #include <vfs/vfs_support.h>
  79
  80 #define VOPFUNC int (*)(void *)
  81
  82 extern int      soo_ioctl(struct fileproc *fp, u_long cmd, caddr_t data, vfs_context_t ctx);
  83 extern int      soo_select(struct fileproc *fp, int which, void * wql, vfs_context_t ctx);
  84
  85 int (**fifo_vnodeop_p)(void *);
  86 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
  87         { &vnop_default_desc, (VOPFUNC)vn_default_error },
  88         { &vnop_lookup_desc, (VOPFUNC)fifo_lookup },            /* lookup */
  89         { &vnop_create_desc, (VOPFUNC)err_create },             /* create */
  90         { &vnop_mknod_desc, (VOPFUNC)err_mknod },               /* mknod */
  91         { &vnop_open_desc, (VOPFUNC)fifo_open },                        /* open */
  92         { &vnop_close_desc, (VOPFUNC)fifo_close },              /* close */
  93         { &vnop_access_desc, (VOPFUNC)fifo_access },            /* access */
  94         { &vnop_getattr_desc, (VOPFUNC)fifo_getattr },          /* getattr */
  95         { &vnop_setattr_desc, (VOPFUNC)fifo_setattr },          /* setattr */
  96         { &vnop_read_desc, (VOPFUNC)fifo_read },                        /* read */
  97         { &vnop_write_desc, (VOPFUNC)fifo_write },              /* write */
  98         { &vnop_ioctl_desc, (VOPFUNC)fifo_ioctl },              /* ioctl */
  99         { &vnop_select_desc, (VOPFUNC)fifo_select },            /* select */
 100         { &vnop_revoke_desc, (VOPFUNC)fifo_revoke },            /* revoke */
 101         { &vnop_mmap_desc, (VOPFUNC)err_mmap },                 /* mmap */
 102         { &vnop_fsync_desc, (VOPFUNC)fifo_fsync },              /* fsync */
 103         { &vnop_remove_desc, (VOPFUNC)err_remove },             /* remove */
 104         { &vnop_link_desc, (VOPFUNC)err_link },                 /* link */
 105         { &vnop_rename_desc, (VOPFUNC)err_rename },             /* rename */
 106         { &vnop_mkdir_desc, (VOPFUNC)err_mkdir },               /* mkdir */
 107         { &vnop_rmdir_desc, (VOPFUNC)err_rmdir },               /* rmdir */
 108         { &vnop_symlink_desc, (VOPFUNC)err_symlink },           /* symlink */
 109         { &vnop_readdir_desc, (VOPFUNC)err_readdir },           /* readdir */
 110         { &vnop_readlink_desc, (VOPFUNC)err_readlink },         /* readlink */
 111         { &vnop_inactive_desc, (VOPFUNC)fifo_inactive },                /* inactive */
 112         { &vnop_reclaim_desc, (VOPFUNC)fifo_reclaim },          /* reclaim */
 113         { &vnop_strategy_desc, (VOPFUNC)err_strategy },         /* strategy */
 114         { &vnop_pathconf_desc, (VOPFUNC)fifo_pathconf },                /* pathconf */
 115         { &vnop_advlock_desc, (VOPFUNC)fifo_advlock },          /* advlock */
 116         { &vnop_bwrite_desc, (VOPFUNC)fifo_bwrite },            /* bwrite */
 117         { &vnop_pagein_desc, (VOPFUNC)err_pagein },             /* Pagein */
 118         { &vnop_pageout_desc, (VOPFUNC)err_pageout },           /* Pageout */
 119         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile },         /* Copyfile */
 120         { &vnop_blktooff_desc, (VOPFUNC)err_blktooff },         /* blktooff */
 121         { &vnop_offtoblk_desc, (VOPFUNC)err_offtoblk },         /* offtoblk */
 122         { &vnop_blockmap_desc, (VOPFUNC)err_blockmap },                 /* blockmap */
 123         { (struct vnodeop_desc*)NULL, (int(*)())NULL }
 124 };
 125 struct vnodeopv_desc fifo_vnodeop_opv_desc =
 126         { &fifo_vnodeop_p, fifo_vnodeop_entries };
 127
 128 /*
 129  * Trivial lookup routine that always fails.
 130  */
 131 /* ARGSUSED */
 132 int
 133 fifo_lookup(struct vnop_lookup_args *ap)
 134 {
 135
 136         *ap->a_vpp = NULL;
 137         return (ENOTDIR);
 138 }
 139
 140 /*
 141  * Open called to set up a new instance of a fifo or
 142  * to find an active instance of a fifo.
 143  */
 144 /* ARGSUSED */
 145 int
 146 fifo_open(struct vnop_open_args *ap)
 147 {
 148         struct vnode *vp = ap->a_vp;
 149         struct fifoinfo *fip;
 150         struct socket *rso, *wso;
 151         int error;
 152
 153         vnode_lock(vp);
 154
 155 retry:
 156
 157         fip = vp->v_fifoinfo;
 158
 159         if (fip == (struct fifoinfo *)0)
 160                 panic("fifo_open with no fifoinfo");
 161
 162         if ((fip->fi_flags & FIFO_CREATED) == 0) {
 163                 if (fip->fi_flags & FIFO_INCREATE) {
 164                         fip->fi_flags |= FIFO_CREATEWAIT;
 165                         error = msleep(&fip->fi_flags, &vp->v_lock, PRIBIO | PCATCH, "fifocreatewait", NULL);
 166                         if (error) {
 167                                 vnode_unlock(vp);
 168                                 return(error);
 169                         }
 170                         goto retry;
 171                 } else {
 172                         fip->fi_flags |= FIFO_INCREATE;
 173                         vnode_unlock(vp);
 174                         if ( (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) ) {
 175                                 goto bad1;
 176                         }
 177                         fip->fi_readsock = rso;
 178
 179                         if ( (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) ) {
 180                                 (void)soclose(rso);
 181                                 goto bad1;
 182                         }
 183                         fip->fi_writesock = wso;
 184
 185                         if ( (error = soconnect2(wso, rso)) ) {
 186                                 (void)soclose(wso);
 187                                 (void)soclose(rso);
 188                                 goto bad1;
 189                         }
 190                         fip->fi_readers = fip->fi_writers = 0;
 191
 192                 socket_lock(wso, 1);
 193                         wso->so_state |= SS_CANTRCVMORE;
 194                         wso->so_snd.sb_lowat = PIPE_BUF;
 195 #if 0
 196                         /* Because all the unp is protected by single mutex
 197                          * doing it in two step may actually cause problems
 198                          * as it opens up window between the drop and acquire
 199                          */
 200                 socket_unlock(wso, 1);
 201
 202                 socket_lock(rso, 1);
 203 #endif
 204                         rso->so_state |= SS_CANTSENDMORE;
 205                 socket_unlock(wso, 1);
 206
 207                         vnode_lock(vp);
 208                         fip->fi_flags |= FIFO_CREATED;
 209                         fip->fi_flags &= ~FIFO_INCREATE;
 210
 211                         if ((fip->fi_flags & FIFO_CREATEWAIT)) {
 212                                 fip->fi_flags &= ~FIFO_CREATEWAIT;
 213                                 wakeup(&fip->fi_flags);
 214                         }
 215                         /* vnode lock is held  to process further */
 216                 }
 217         }
 218
 219         /* vnode is locked at this point */
 220         /* fifo in created already */
 221         if (ap->a_mode & FREAD) {
 222                 fip->fi_readers++;
 223                 if (fip->fi_readers == 1) {
 224                         socket_lock(fip->fi_writesock, 1);
 225                         fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
 226                         socket_unlock(fip->fi_writesock, 1);
 227
 228                         if (fip->fi_writers > 0)
 229                                 wakeup((caddr_t)&fip->fi_writers);
 230                 }
 231         }
 232         if (ap->a_mode & FWRITE) {
 233                 fip->fi_writers++;
 234                 if (fip->fi_writers == 1) {
 235                         socket_lock(fip->fi_readsock, 1);
 236                         fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
 237                         socket_unlock(fip->fi_readsock, 1);
 238
 239                         if (fip->fi_readers > 0)
 240                                 wakeup((caddr_t)&fip->fi_readers);
 241                 }
 242         }
 243         if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) {
 244                 if (fip->fi_writers == 0) {
 245                         error = msleep((caddr_t)&fip->fi_readers, &vp->v_lock,
 246                                         PCATCH | PSOCK, "fifoor", NULL);
 247                         if (error)
 248                                 goto bad;
 249                         if (fip->fi_readers == 1) {
 250                                 if (fip->fi_writers > 0)
 251                                         wakeup((caddr_t)&fip->fi_writers);
 252                         }
 253                 }
 254         }
 255         if (ap->a_mode & FWRITE) {
 256                 if (ap->a_mode & O_NONBLOCK) {
 257                         if (fip->fi_readers == 0) {
 258                                         error = ENXIO;
 259                                         goto bad;
 260                         }
 261                 } else {
 262                         if (fip->fi_readers == 0) {
 263                                 error = msleep((caddr_t)&fip->fi_writers,&vp->v_lock,
 264                                                 PCATCH | PSOCK, "fifoow", NULL);
 265                                 if (error)
 266                                         goto bad;
 267                                 if (fip->fi_writers == 1) {
 268                                         if (fip->fi_readers > 0)
 269                                                 wakeup((caddr_t)&fip->fi_readers);
 270                                 }
 271                         }
 272                 }
 273         }
 274
 275         vnode_unlock(vp);
 276         return (0);
 277 bad:
 278         fifo_close_internal(vp, ap->a_mode, ap->a_context, 1);
 279
 280         vnode_unlock(vp);
 281         return (error);
 282 bad1:
 283         vnode_lock(vp);
 284
 285         fip->fi_flags &= ~FIFO_INCREATE;
 286
 287         if ((fip->fi_flags & FIFO_CREATEWAIT)) {
 288                 fip->fi_flags &= ~FIFO_CREATEWAIT;
 289                 wakeup(&fip->fi_flags);
 290         }
 291         vnode_unlock(vp);
 292
 293         return (error);
 294 }
 295
 296 /*
 297  * Vnode op for read
 298  */
 299 int
 300 fifo_read(struct vnop_read_args *ap)
 301 {
 302         struct uio *uio = ap->a_uio;
 303         struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
 304         int error, startresid;
 305         int rflags;
 306
 307 #if DIAGNOSTIC
 308         if (uio->uio_rw != UIO_READ)
 309                 panic("fifo_read mode");
 310 #endif
 311         if (uio_resid(uio) == 0)
 312                 return (0);
 313
 314         rflags = (ap->a_ioflag & IO_NDELAY) ? MSG_NBIO : 0;
 315
 316         // LP64todo - fix this!
 317         startresid = uio_resid(uio);
 318
 319         /* fifo conformance - if we have a reader open on the fifo but no
 320          * writers then we need to make sure we do not block.  We do that by
 321          * checking the receive buffer and if empty set error to EWOULDBLOCK.
 322          * If error is set to EWOULDBLOCK we skip the call into soreceive
 323          */
 324         error = 0;
 325         if (ap->a_vp->v_fifoinfo->fi_writers < 1) {
 326                 socket_lock(rso, 1);
 327                 error = (rso->so_rcv.sb_cc == 0) ? EWOULDBLOCK : 0;
 328                 socket_unlock(rso, 1);
 329         }
 330
 331         /* skip soreceive to avoid blocking when we have no writers */
 332         if (error != EWOULDBLOCK) {
 333                 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0,
 334                                                 (struct mbuf **)0, &rflags);
 335         }
 336         else {
 337                 /* clear EWOULDBLOCK and return EOF (zero) */
 338                 error = 0;
 339         }
 340         /*
 341          * Clear EOF indication after first such return.
 342          */
 343         if (uio_resid(uio) == startresid) {
 344                 socket_lock(rso, 1);
 345                 rso->so_state &= ~SS_CANTRCVMORE;
 346                 socket_unlock(rso, 1);
 347         }
 348         return (error);
 349 }
 350
 351 /*
 352  * Vnode op for write
 353  */
 354 int
 355 fifo_write(struct vnop_write_args *ap)
 356 {
 357         struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
 358         int error;
 359
 360 #if DIAGNOSTIC
 361         if (ap->a_uio->uio_rw != UIO_WRITE)
 362                 panic("fifo_write mode");
 363 #endif
 364         error = sosend(wso, (struct sockaddr *)0, ap->a_uio, NULL,
 365                        (struct mbuf *)0, (ap->a_ioflag & IO_NDELAY) ? MSG_NBIO : 0);
 366
 367         return (error);
 368 }
 369
 370 /*
 371  * Device ioctl operation.
 372  */
 373 int
 374 fifo_ioctl(struct vnop_ioctl_args *ap)
 375 {
 376         struct fileproc filetmp;
 377         struct fileglob filefg;
 378         int error;
 379
 380         if (ap->a_command == FIONBIO)
 381                 return (0);
 382         bzero(&filetmp, sizeof(struct fileproc));
 383         filetmp.f_fglob = &filefg;
 384         if (ap->a_fflag & FREAD) {
 385                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
 386                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_context);
 387                 if (error)
 388                         return (error);
 389         }
 390         if (ap->a_fflag & FWRITE) {
 391                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
 392                 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_context);
 393                 if (error)
 394                         return (error);
 395         }
 396         return (0);
 397 }
 398
 399 int
 400 fifo_select(struct vnop_select_args *ap)
 401 {
 402         struct fileproc filetmp;
 403         struct fileglob filefg;
 404         int ready;
 405
 406         bzero(&filetmp, sizeof(struct fileproc));
 407         filetmp.f_fglob = &filefg;
 408         if (ap->a_which & FREAD) {
 409                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
 410                 ready = soo_select(&filetmp, ap->a_which, ap->a_wql, ap->a_context);
 411                 if (ready)
 412                         return (ready);
 413         }
 414         if (ap->a_which & FWRITE) {
 415                 filetmp.f_fglob->fg_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
 416                 ready = soo_select(&filetmp, ap->a_which, ap->a_wql, ap->a_context);
 417                 if (ready)
 418                         return (ready);
 419         }
 420         return (0);
 421 }
 422
 423 int
 424 fifo_inactive(__unused struct vnop_inactive_args *ap)
 425 {
 426         return (0);
 427 }
 428
 429
 430 /*
 431  * Device close routine
 432  */
 433 int
 434 fifo_close(struct vnop_close_args *ap)
 435 {
 436         return fifo_close_internal(ap->a_vp, ap->a_fflag, ap->a_context, 0);
 437 }
 438
 439 int
 440 fifo_close_internal(vnode_t vp, int fflag, __unused vfs_context_t context, int locked)
 441 {
 442         struct fifoinfo *fip = vp->v_fifoinfo;
 443         int error1, error2;
 444         struct socket *rso;
 445         struct socket *wso;
 446
 447         if (!locked)
 448                 vnode_lock(vp);
 449
 450         if ((fip->fi_flags & FIFO_CREATED) == 0) {
 451                 if (!locked)
 452                         vnode_unlock(vp);
 453                 return(0);
 454
 455         }
 456
 457         if (fflag & FREAD) {
 458                 fip->fi_readers--;
 459                 if (fip->fi_readers == 0){
 460                         socket_lock(fip->fi_writesock, 1);
 461                         socantsendmore(fip->fi_writesock);
 462                         socket_unlock(fip->fi_writesock, 1);
 463                 }
 464         }
 465
 466         if (fflag & FWRITE) {
 467                 fip->fi_writers--;
 468                 if (fip->fi_writers == 0) {
 469                         socket_lock(fip->fi_readsock, 1);
 470                         socantrcvmore(fip->fi_readsock);
 471                         socket_unlock(fip->fi_readsock, 1);
 472                 }
 473         }
 474 #if 0
 475         if (vnode_isinuse_locked(vp, 0, 1)) {
 476                 if (!locked)
 477                         vnode_unlock(vp);
 478                 return (0);
 479         }
 480 #endif
 481
 482         if (fip->fi_writers || fip->fi_readers) {
 483                 if (!locked)
 484                         vnode_unlock(vp);
 485                 return (0);
 486         }
 487
 488         wso = fip->fi_writesock;
 489         rso = fip->fi_readsock;
 490         fip->fi_readsock = NULL;
 491         fip->fi_writesock = NULL;
 492         fip->fi_flags &= ~FIFO_CREATED;
 493         if (!locked)
 494                 vnode_unlock(vp);
 495         error1 = soclose(rso);
 496         error2 = soclose(wso);
 497
 498         if (error1)
 499                 return (error1);
 500         return (error2);
 501 }
 502
 503 #if !CONFIG_NO_PRINTF_STRINGS
 504 /*
 505  * Print out internal contents of a fifo vnode.
 506  */
 507 void
 508 fifo_printinfo(struct vnode *vp)
 509 {
 510         struct fifoinfo *fip = vp->v_fifoinfo;
 511
 512         printf(", fifo with %ld readers and %ld writers",
 513                 fip->fi_readers, fip->fi_writers);
 514 }
 515 #endif /* !CONFIG_NO_PRINTF_STRINGS */
 516
 517 /*
 518  * Return POSIX pathconf information applicable to fifo's.
 519  */
 520 int
 521 fifo_pathconf(struct vnop_pathconf_args *ap)
 522 {
 523         switch (ap->a_name) {
 524         case _PC_LINK_MAX:
 525                 *ap->a_retval = LINK_MAX;
 526                 return (0);
 527         case _PC_PIPE_BUF:
 528                 *ap->a_retval = PIPE_BUF;
 529                 return (0);
 530         case _PC_CHOWN_RESTRICTED:
 531                 *ap->a_retval = 200112;         /* _POSIX_CHOWN_RESTRICTED */
 532                 return (0);
 533         default:
 534                 return (EINVAL);
 535         }
 536         /* NOTREACHED */
 537 }
 538
 539 /*
 540  * Fifo failed operation
 541  */
 542 int
 543 fifo_ebadf(__unused void *dummy)
 544 {
 545
 546         return (EBADF);
 547 }
 548
 549 /*
 550  * Fifo advisory byte-level locks.
 551  */
 552 int
 553 fifo_advlock(__unused struct vnop_advlock_args *ap)
 554 {
 555
 556         return (ENOTSUP);
 557 }
 558