1 /* $NetBSD: fifo_vnops.c,v 1.50 2004/07/17 20:53:01 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.50 2004/07/17 20:53:01 mycroft Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/proc.h> 40 #include <sys/time.h> 41 #include <sys/namei.h> 42 #include <sys/vnode.h> 43 #include <sys/socket.h> 44 #include <sys/protosw.h> 45 #include <sys/socketvar.h> 46 #include <sys/stat.h> 47 #include <sys/ioctl.h> 48 #include <sys/file.h> 49 #include <sys/errno.h> 50 #include <sys/malloc.h> 51 #include <sys/un.h> 52 #include <sys/poll.h> 53 #include <sys/event.h> 54 55 #include <miscfs/fifofs/fifo.h> 56 #include <miscfs/genfs/genfs.h> 57 58 /* 59 * This structure is associated with the FIFO vnode and stores 60 * the state associated with the FIFO. 61 */ 62 struct fifoinfo { 63 struct socket *fi_readsock; 64 struct socket *fi_writesock; 65 long fi_readers; 66 long fi_writers; 67 }; 68 69 int (**fifo_vnodeop_p) __P((void *)); 70 const struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 71 { &vop_default_desc, vn_default_error }, 72 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 73 { &vop_create_desc, fifo_create }, /* create */ 74 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 75 { &vop_open_desc, fifo_open }, /* open */ 76 { &vop_close_desc, fifo_close }, /* close */ 77 { &vop_access_desc, fifo_access }, /* access */ 78 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 79 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 80 { &vop_read_desc, fifo_read }, /* read */ 81 { &vop_write_desc, fifo_write }, /* write */ 82 { &vop_lease_desc, fifo_lease_check }, /* lease */ 83 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 84 { &vop_poll_desc, fifo_poll }, /* poll */ 85 { &vop_kqfilter_desc, fifo_kqfilter }, /* kqfilter */ 86 { &vop_revoke_desc, fifo_revoke }, /* revoke */ 87 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 88 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 89 { &vop_seek_desc, fifo_seek }, /* seek */ 90 { &vop_remove_desc, fifo_remove }, /* remove */ 91 { &vop_link_desc, fifo_link }, /* link */ 92 { &vop_rename_desc, fifo_rename }, /* rename */ 93 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 94 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 95 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 96 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 97 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 98 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 99 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 100 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 101 { &vop_lock_desc, fifo_lock }, /* lock */ 102 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 103 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 104 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 105 { &vop_print_desc, fifo_print }, /* print */ 106 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 107 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 108 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 109 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 110 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 111 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 112 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 113 { &vop_update_desc, fifo_update }, /* update */ 114 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 115 { &vop_putpages_desc, fifo_putpages }, /* putpages */ 116 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 117 }; 118 const struct vnodeopv_desc fifo_vnodeop_opv_desc = 119 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 120 121 /* 122 * Trivial lookup routine that always fails. 123 */ 124 /* ARGSUSED */ 125 int 126 fifo_lookup(void *v) 127 { 128 struct vop_lookup_args /* { 129 struct vnode *a_dvp; 130 struct vnode **a_vpp; 131 struct componentname *a_cnp; 132 } */ *ap = v; 133 134 *ap->a_vpp = NULL; 135 return (ENOTDIR); 136 } 137 138 /* 139 * Open called to set up a new instance of a fifo or 140 * to find an active instance of a fifo. 141 */ 142 /* ARGSUSED */ 143 int 144 fifo_open(void *v) 145 { 146 struct vop_open_args /* { 147 struct vnode *a_vp; 148 int a_mode; 149 struct ucred *a_cred; 150 struct proc *a_p; 151 } */ *ap = v; 152 struct vnode *vp; 153 struct fifoinfo *fip; 154 struct proc *p; 155 struct socket *rso, *wso; 156 int error; 157 158 vp = ap->a_vp; 159 p = ap->a_p; 160 161 if ((fip = vp->v_fifoinfo) == NULL) { 162 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 163 vp->v_fifoinfo = fip; 164 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, p); 165 if (error != 0) { 166 free(fip, M_VNODE); 167 vp->v_fifoinfo = NULL; 168 return (error); 169 } 170 fip->fi_readsock = rso; 171 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, p); 172 if (error != 0) { 173 (void)soclose(rso); 174 free(fip, M_VNODE); 175 vp->v_fifoinfo = NULL; 176 return (error); 177 } 178 fip->fi_writesock = wso; 179 if ((error = unp_connect2(wso, rso, PRU_CONNECT2)) != 0) { 180 (void)soclose(wso); 181 (void)soclose(rso); 182 free(fip, M_VNODE); 183 vp->v_fifoinfo = NULL; 184 return (error); 185 } 186 fip->fi_readers = fip->fi_writers = 0; 187 wso->so_state |= SS_CANTRCVMORE; 188 rso->so_state |= SS_CANTSENDMORE; 189 } 190 if (ap->a_mode & FREAD) { 191 if (fip->fi_readers++ == 0) { 192 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 193 if (fip->fi_writers > 0) 194 wakeup(&fip->fi_writers); 195 } 196 } 197 if (ap->a_mode & FWRITE) { 198 if (fip->fi_writers++ == 0) { 199 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 200 if (fip->fi_readers > 0) 201 wakeup(&fip->fi_readers); 202 } 203 } 204 if (ap->a_mode & FREAD) { 205 if (ap->a_mode & O_NONBLOCK) { 206 } else { 207 while (!soreadable(fip->fi_readsock) && fip->fi_writers == 0) { 208 VOP_UNLOCK(vp, 0); 209 error = tsleep(&fip->fi_readers, 210 PCATCH | PSOCK, "fifor", 0); 211 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 212 if (error) 213 goto bad; 214 } 215 } 216 } 217 if (ap->a_mode & FWRITE) { 218 if (ap->a_mode & O_NONBLOCK) { 219 if (fip->fi_readers == 0) { 220 error = ENXIO; 221 goto bad; 222 } 223 } else { 224 while (fip->fi_readers == 0) { 225 VOP_UNLOCK(vp, 0); 226 error = tsleep(&fip->fi_writers, 227 PCATCH | PSOCK, "fifow", 0); 228 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 229 if (error) 230 goto bad; 231 } 232 } 233 } 234 return (0); 235 bad: 236 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p); 237 return (error); 238 } 239 240 /* 241 * Vnode op for read 242 */ 243 /* ARGSUSED */ 244 int 245 fifo_read(void *v) 246 { 247 struct vop_read_args /* { 248 struct vnode *a_vp; 249 struct uio *a_uio; 250 int a_ioflag; 251 struct ucred *a_cred; 252 } */ *ap = v; 253 struct uio *uio; 254 struct socket *rso; 255 int error; 256 size_t startresid; 257 258 uio = ap->a_uio; 259 rso = ap->a_vp->v_fifoinfo->fi_readsock; 260 #ifdef DIAGNOSTIC 261 if (uio->uio_rw != UIO_READ) 262 panic("fifo_read mode"); 263 #endif 264 if (uio->uio_resid == 0) 265 return (0); 266 if (ap->a_ioflag & IO_NDELAY) 267 rso->so_state |= SS_NBIO; 268 startresid = uio->uio_resid; 269 VOP_UNLOCK(ap->a_vp, 0); 270 error = (*rso->so_receive)(rso, (struct mbuf **)0, uio, 271 (struct mbuf **)0, (struct mbuf **)0, (int *)0); 272 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 273 /* 274 * Clear EOF indication after first such return. 275 */ 276 if (uio->uio_resid == startresid) 277 rso->so_state &= ~SS_CANTRCVMORE; 278 if (ap->a_ioflag & IO_NDELAY) { 279 rso->so_state &= ~SS_NBIO; 280 if (error == EWOULDBLOCK && 281 ap->a_vp->v_fifoinfo->fi_writers == 0) 282 error = 0; 283 } 284 return (error); 285 } 286 287 /* 288 * Vnode op for write 289 */ 290 /* ARGSUSED */ 291 int 292 fifo_write(void *v) 293 { 294 struct vop_write_args /* { 295 struct vnode *a_vp; 296 struct uio *a_uio; 297 int a_ioflag; 298 struct ucred *a_cred; 299 } */ *ap = v; 300 struct socket *wso; 301 int error; 302 303 wso = ap->a_vp->v_fifoinfo->fi_writesock; 304 #ifdef DIAGNOSTIC 305 if (ap->a_uio->uio_rw != UIO_WRITE) 306 panic("fifo_write mode"); 307 #endif 308 if (ap->a_ioflag & IO_NDELAY) 309 wso->so_state |= SS_NBIO; 310 VOP_UNLOCK(ap->a_vp, 0); 311 error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0, 312 (struct mbuf *)0, 0, curproc /*XXX*/); 313 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 314 if (ap->a_ioflag & IO_NDELAY) 315 wso->so_state &= ~SS_NBIO; 316 return (error); 317 } 318 319 /* 320 * Device ioctl operation. 321 */ 322 /* ARGSUSED */ 323 int 324 fifo_ioctl(void *v) 325 { 326 struct vop_ioctl_args /* { 327 struct vnode *a_vp; 328 u_long a_command; 329 void *a_data; 330 int a_fflag; 331 struct ucred *a_cred; 332 struct proc *a_p; 333 } */ *ap = v; 334 struct file filetmp; 335 int error; 336 337 if (ap->a_command == FIONBIO) 338 return (0); 339 if (ap->a_fflag & FREAD) { 340 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 341 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 342 if (error) 343 return (error); 344 } 345 if (ap->a_fflag & FWRITE) { 346 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 347 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 348 if (error) 349 return (error); 350 } 351 return (0); 352 } 353 354 /* ARGSUSED */ 355 int 356 fifo_poll(void *v) 357 { 358 struct vop_poll_args /* { 359 struct vnode *a_vp; 360 int a_events; 361 struct proc *a_p; 362 } */ *ap = v; 363 struct file filetmp; 364 int revents; 365 366 revents = 0; 367 if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) { 368 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 369 if (filetmp.f_data) 370 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 371 } 372 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) { 373 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 374 if (filetmp.f_data) 375 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 376 } 377 378 return (revents); 379 } 380 381 int 382 fifo_inactive(void *v) 383 { 384 struct vop_inactive_args /* { 385 struct vnode *a_vp; 386 struct proc *a_p; 387 } */ *ap = v; 388 389 VOP_UNLOCK(ap->a_vp, 0); 390 return (0); 391 } 392 393 /* 394 * This is a noop, simply returning what one has been given. 395 */ 396 int 397 fifo_bmap(void *v) 398 { 399 struct vop_bmap_args /* { 400 struct vnode *a_vp; 401 daddr_t a_bn; 402 struct vnode **a_vpp; 403 daddr_t *a_bnp; 404 int *a_runp; 405 } */ *ap = v; 406 407 if (ap->a_vpp != NULL) 408 *ap->a_vpp = ap->a_vp; 409 if (ap->a_bnp != NULL) 410 *ap->a_bnp = ap->a_bn; 411 if (ap->a_runp != NULL) 412 *ap->a_runp = 0; 413 return (0); 414 } 415 416 /* 417 * Device close routine 418 */ 419 /* ARGSUSED */ 420 int 421 fifo_close(void *v) 422 { 423 struct vop_close_args /* { 424 struct vnode *a_vp; 425 int a_fflag; 426 struct ucred *a_cred; 427 struct proc *a_p; 428 } */ *ap = v; 429 struct vnode *vp; 430 struct fifoinfo *fip; 431 int isrevoke; 432 433 vp = ap->a_vp; 434 fip = vp->v_fifoinfo; 435 isrevoke = (ap->a_fflag & (FREAD | FWRITE | FNONBLOCK)) == FNONBLOCK; 436 if (isrevoke) { 437 if (fip->fi_readers != 0) { 438 fip->fi_readers = 0; 439 socantsendmore(fip->fi_writesock); 440 } 441 if (fip->fi_writers != 0) { 442 fip->fi_writers = 0; 443 socantrcvmore(fip->fi_readsock); 444 } 445 } else { 446 if ((ap->a_fflag & FREAD) && --fip->fi_readers == 0) 447 socantsendmore(fip->fi_writesock); 448 if ((ap->a_fflag & FWRITE) && --fip->fi_writers == 0) 449 socantrcvmore(fip->fi_readsock); 450 } 451 /* Shut down if all readers and writers are gone. */ 452 if ((fip->fi_readers + fip->fi_writers) == 0) { 453 (void) soclose(fip->fi_readsock); 454 (void) soclose(fip->fi_writesock); 455 FREE(fip, M_VNODE); 456 vp->v_fifoinfo = NULL; 457 } 458 return (0); 459 } 460 461 /* 462 * Print out the contents of a fifo vnode. 463 */ 464 int 465 fifo_print(void *v) 466 { 467 struct vop_print_args /* { 468 struct vnode *a_vp; 469 } */ *ap = v; 470 471 printf("tag VT_NON"); 472 fifo_printinfo(ap->a_vp); 473 printf("\n"); 474 return 0; 475 } 476 477 /* 478 * Print out internal contents of a fifo vnode. 479 */ 480 void 481 fifo_printinfo(struct vnode *vp) 482 { 483 struct fifoinfo *fip; 484 485 fip = vp->v_fifoinfo; 486 printf(", fifo with %ld readers and %ld writers", 487 fip->fi_readers, fip->fi_writers); 488 } 489 490 /* 491 * Return POSIX pathconf information applicable to fifo's. 492 */ 493 int 494 fifo_pathconf(void *v) 495 { 496 struct vop_pathconf_args /* { 497 struct vnode *a_vp; 498 int a_name; 499 register_t *a_retval; 500 } */ *ap = v; 501 502 switch (ap->a_name) { 503 case _PC_LINK_MAX: 504 *ap->a_retval = LINK_MAX; 505 return (0); 506 case _PC_PIPE_BUF: 507 *ap->a_retval = PIPE_BUF; 508 return (0); 509 case _PC_CHOWN_RESTRICTED: 510 *ap->a_retval = 1; 511 return (0); 512 case _PC_SYNC_IO: 513 *ap->a_retval = 1; 514 return (0); 515 default: 516 return (EINVAL); 517 } 518 /* NOTREACHED */ 519 } 520 521 static void 522 filt_fifordetach(struct knote *kn) 523 { 524 struct socket *so; 525 526 so = (struct socket *)kn->kn_hook; 527 SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext); 528 if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist)) 529 so->so_rcv.sb_flags &= ~SB_KNOTE; 530 } 531 532 static int 533 filt_fiforead(struct knote *kn, long hint) 534 { 535 struct socket *so; 536 537 so = (struct socket *)kn->kn_hook; 538 kn->kn_data = so->so_rcv.sb_cc; 539 if (so->so_state & SS_CANTRCVMORE) { 540 kn->kn_flags |= EV_EOF; 541 return (1); 542 } 543 kn->kn_flags &= ~EV_EOF; 544 return (kn->kn_data > 0); 545 } 546 547 static void 548 filt_fifowdetach(struct knote *kn) 549 { 550 struct socket *so; 551 552 so = (struct socket *)kn->kn_hook; 553 SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext); 554 if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist)) 555 so->so_snd.sb_flags &= ~SB_KNOTE; 556 } 557 558 static int 559 filt_fifowrite(struct knote *kn, long hint) 560 { 561 struct socket *so; 562 563 so = (struct socket *)kn->kn_hook; 564 kn->kn_data = sbspace(&so->so_snd); 565 if (so->so_state & SS_CANTSENDMORE) { 566 kn->kn_flags |= EV_EOF; 567 return (1); 568 } 569 kn->kn_flags &= ~EV_EOF; 570 return (kn->kn_data >= so->so_snd.sb_lowat); 571 } 572 573 static const struct filterops fiforead_filtops = 574 { 1, NULL, filt_fifordetach, filt_fiforead }; 575 static const struct filterops fifowrite_filtops = 576 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 577 578 /* ARGSUSED */ 579 int 580 fifo_kqfilter(void *v) 581 { 582 struct vop_kqfilter_args /* { 583 struct vnode *a_vp; 584 struct knote *a_kn; 585 } */ *ap = v; 586 struct socket *so; 587 struct sockbuf *sb; 588 589 so = (struct socket *)ap->a_vp->v_fifoinfo->fi_readsock; 590 switch (ap->a_kn->kn_filter) { 591 case EVFILT_READ: 592 ap->a_kn->kn_fop = &fiforead_filtops; 593 sb = &so->so_rcv; 594 break; 595 case EVFILT_WRITE: 596 ap->a_kn->kn_fop = &fifowrite_filtops; 597 sb = &so->so_snd; 598 break; 599 default: 600 return (1); 601 } 602 603 ap->a_kn->kn_hook = so; 604 605 SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, ap->a_kn, kn_selnext); 606 sb->sb_flags |= SB_KNOTE; 607 return (0); 608 } 609