1 /* 2 * Copyright (c) 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 34 * $FreeBSD: src/sys/miscfs/fifofs/fifo_vnops.c,v 1.45.2.4 2003/04/22 10:11:24 bde Exp $ 35 * $DragonFly: src/sys/vfs/fifofs/fifo_vnops.c,v 1.16 2004/08/17 18:57:33 dillon Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/unistd.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/vnode.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/filio.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/event.h> 51 #include <sys/poll.h> 52 #include <sys/un.h> 53 #include "fifo.h" 54 55 /* 56 * This structure is associated with the FIFO vnode and stores 57 * the state associated with the FIFO. 58 */ 59 struct fifoinfo { 60 struct socket *fi_readsock; 61 struct socket *fi_writesock; 62 long fi_readers; 63 long fi_writers; 64 }; 65 66 static int fifo_badop (void); 67 static int fifo_print (struct vop_print_args *); 68 static int fifo_lookup (struct vop_lookup_args *); 69 static int fifo_open (struct vop_open_args *); 70 static int fifo_close (struct vop_close_args *); 71 static int fifo_read (struct vop_read_args *); 72 static int fifo_write (struct vop_write_args *); 73 static int fifo_ioctl (struct vop_ioctl_args *); 74 static int fifo_poll (struct vop_poll_args *); 75 static int fifo_kqfilter (struct vop_kqfilter_args *); 76 static int fifo_inactive (struct vop_inactive_args *); 77 static int fifo_bmap (struct vop_bmap_args *); 78 static int fifo_pathconf (struct vop_pathconf_args *); 79 static int fifo_advlock (struct vop_advlock_args *); 80 81 static void filt_fifordetach(struct knote *kn); 82 static int filt_fiforead(struct knote *kn, long hint); 83 static void filt_fifowdetach(struct knote *kn); 84 static int filt_fifowrite(struct knote *kn, long hint); 85 86 static struct filterops fiforead_filtops = 87 { 1, NULL, filt_fifordetach, filt_fiforead }; 88 static struct filterops fifowrite_filtops = 89 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 90 91 struct vop_ops *fifo_vnode_vops; 92 static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 93 { &vop_default_desc, (void *) vop_defaultop }, 94 { &vop_access_desc, (void *) vop_ebadf }, 95 { &vop_advlock_desc, (void *) fifo_advlock }, 96 { &vop_bmap_desc, (void *) fifo_bmap }, 97 { &vop_close_desc, (void *) fifo_close }, 98 { &vop_create_desc, (void *) fifo_badop }, 99 { &vop_getattr_desc, (void *) vop_ebadf }, 100 { &vop_inactive_desc, (void *) fifo_inactive }, 101 { &vop_ioctl_desc, (void *) fifo_ioctl }, 102 { &vop_kqfilter_desc, (void *) fifo_kqfilter }, 103 { &vop_lease_desc, (void *) vop_null }, 104 { &vop_link_desc, (void *) fifo_badop }, 105 { &vop_lookup_desc, (void *) fifo_lookup }, 106 { &vop_mkdir_desc, (void *) fifo_badop }, 107 { &vop_mknod_desc, (void *) fifo_badop }, 108 { &vop_open_desc, (void *) fifo_open }, 109 { &vop_pathconf_desc, (void *) fifo_pathconf }, 110 { &vop_poll_desc, (void *) fifo_poll }, 111 { &vop_print_desc, (void *) fifo_print }, 112 { &vop_read_desc, (void *) fifo_read }, 113 { &vop_readdir_desc, (void *) fifo_badop }, 114 { &vop_readlink_desc, (void *) fifo_badop }, 115 { &vop_reallocblks_desc, (void *) fifo_badop }, 116 { &vop_reclaim_desc, (void *) vop_null }, 117 { &vop_remove_desc, (void *) fifo_badop }, 118 { &vop_rename_desc, (void *) fifo_badop }, 119 { &vop_rmdir_desc, (void *) fifo_badop }, 120 { &vop_setattr_desc, (void *) vop_ebadf }, 121 { &vop_symlink_desc, (void *) fifo_badop }, 122 { &vop_write_desc, (void *) fifo_write }, 123 { NULL, NULL } 124 }; 125 static struct vnodeopv_desc fifo_vnodeop_opv_desc = 126 { &fifo_vnode_vops, fifo_vnodeop_entries }; 127 128 VNODEOP_SET(fifo_vnodeop_opv_desc); 129 130 /* 131 * fifo_vnoperate(struct vnodeop_desc *a_desc, ...) 132 */ 133 int 134 fifo_vnoperate(struct vop_generic_args *ap) 135 { 136 return (VOCALL(fifo_vnode_vops, ap)); 137 } 138 139 /* 140 * Trivial lookup routine that always fails. 141 * 142 * fifo_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 143 * struct componentname *a_cnp) 144 */ 145 /* ARGSUSED */ 146 static int 147 fifo_lookup(struct vop_lookup_args *ap) 148 { 149 *ap->a_vpp = NULL; 150 return (ENOTDIR); 151 } 152 153 /* 154 * Open called to set up a new instance of a fifo or 155 * to find an active instance of a fifo. 156 * 157 * fifo_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 158 * struct thread *a_td) 159 */ 160 /* ARGSUSED */ 161 static int 162 fifo_open(struct vop_open_args *ap) 163 { 164 struct vnode *vp = ap->a_vp; 165 struct fifoinfo *fip; 166 struct socket *rso, *wso; 167 int error; 168 169 if ((fip = vp->v_fifoinfo) == NULL) { 170 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 171 vp->v_fifoinfo = fip; 172 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, ap->a_td); 173 if (error) { 174 free(fip, M_VNODE); 175 vp->v_fifoinfo = NULL; 176 return (error); 177 } 178 fip->fi_readsock = rso; 179 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, ap->a_td); 180 if (error) { 181 (void)soclose(rso); 182 free(fip, M_VNODE); 183 vp->v_fifoinfo = NULL; 184 return (error); 185 } 186 fip->fi_writesock = wso; 187 error = unp_connect2(wso, rso); 188 if (error) { 189 (void)soclose(wso); 190 (void)soclose(rso); 191 free(fip, M_VNODE); 192 vp->v_fifoinfo = NULL; 193 return (error); 194 } 195 fip->fi_readers = fip->fi_writers = 0; 196 wso->so_snd.sb_lowat = PIPE_BUF; 197 rso->so_state |= SS_CANTRCVMORE; 198 } 199 if (ap->a_mode & FREAD) { 200 fip->fi_readers++; 201 if (fip->fi_readers == 1) { 202 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 203 if (fip->fi_writers > 0) { 204 wakeup((caddr_t)&fip->fi_writers); 205 sowwakeup(fip->fi_writesock); 206 } 207 } 208 } 209 if (ap->a_mode & FWRITE) { 210 fip->fi_writers++; 211 if (fip->fi_writers == 1) { 212 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 213 if (fip->fi_readers > 0) { 214 wakeup((caddr_t)&fip->fi_readers); 215 sorwakeup(fip->fi_writesock); 216 } 217 } 218 } 219 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) { 220 if (fip->fi_writers == 0) { 221 VOP_UNLOCK(vp, NULL, 0, ap->a_td); 222 error = tsleep((caddr_t)&fip->fi_readers, 223 PCATCH, "fifoor", 0); 224 vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, ap->a_td); 225 if (error) 226 goto bad; 227 /* 228 * We must have got woken up because we had a writer. 229 * That (and not still having one) is the condition 230 * that we must wait for. 231 */ 232 } 233 } 234 if (ap->a_mode & FWRITE) { 235 if (ap->a_mode & O_NONBLOCK) { 236 if (fip->fi_readers == 0) { 237 error = ENXIO; 238 goto bad; 239 } 240 } else { 241 if (fip->fi_readers == 0) { 242 VOP_UNLOCK(vp, NULL, 0, ap->a_td); 243 error = tsleep((caddr_t)&fip->fi_writers, 244 PCATCH, "fifoow", 0); 245 vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, ap->a_td); 246 if (error) 247 goto bad; 248 /* 249 * We must have got woken up because we had 250 * a reader. That (and not still having one) 251 * is the condition that we must wait for. 252 */ 253 } 254 } 255 } 256 return (0); 257 bad: 258 VOP_CLOSE(vp, ap->a_mode, ap->a_td); 259 return (error); 260 } 261 262 /* 263 * Vnode op for read 264 * 265 * fifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 266 * struct ucred *a_cred) 267 */ 268 /* ARGSUSED */ 269 static int 270 fifo_read(struct vop_read_args *ap) 271 { 272 struct uio *uio = ap->a_uio; 273 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 274 struct thread *td = uio->uio_td; 275 int error, startresid; 276 277 #ifdef DIAGNOSTIC 278 if (uio->uio_rw != UIO_READ) 279 panic("fifo_read mode"); 280 #endif 281 if (uio->uio_resid == 0) 282 return (0); 283 if (ap->a_ioflag & IO_NDELAY) 284 rso->so_state |= SS_NBIO; 285 startresid = uio->uio_resid; 286 VOP_UNLOCK(ap->a_vp, NULL, 0, td); 287 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0, 288 (struct mbuf **)0, (int *)0); 289 vn_lock(ap->a_vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 290 if (ap->a_ioflag & IO_NDELAY) 291 rso->so_state &= ~SS_NBIO; 292 return (error); 293 } 294 295 /* 296 * Vnode op for write 297 * 298 * fifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 299 * struct ucred *a_cred) 300 */ 301 /* ARGSUSED */ 302 static int 303 fifo_write(struct vop_write_args *ap) 304 { 305 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 306 struct thread *td = ap->a_uio->uio_td; 307 int error; 308 309 #ifdef DIAGNOSTIC 310 if (ap->a_uio->uio_rw != UIO_WRITE) 311 panic("fifo_write mode"); 312 #endif 313 if (ap->a_ioflag & IO_NDELAY) 314 wso->so_state |= SS_NBIO; 315 VOP_UNLOCK(ap->a_vp, NULL, 0, td); 316 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0, 317 (struct mbuf *)0, 0, td); 318 vn_lock(ap->a_vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 319 if (ap->a_ioflag & IO_NDELAY) 320 wso->so_state &= ~SS_NBIO; 321 return (error); 322 } 323 324 /* 325 * Device ioctl operation. 326 * 327 * fifo_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 328 * struct ucred *a_cred, struct thread *a_td) 329 */ 330 /* ARGSUSED */ 331 static int 332 fifo_ioctl(struct vop_ioctl_args *ap) 333 { 334 struct file filetmp; /* Local */ 335 int error; 336 337 if (ap->a_command == FIONBIO) 338 return (0); 339 if (ap->a_fflag & FREAD) { 340 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 341 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_td); 342 if (error) 343 return (error); 344 } 345 if (ap->a_fflag & FWRITE) { 346 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 347 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_td); 348 if (error) 349 return (error); 350 } 351 return (0); 352 } 353 354 /* 355 * fifo_kqfilter(struct vnode *a_vp, struct knote *a_kn) 356 */ 357 /* ARGSUSED */ 358 static int 359 fifo_kqfilter(struct vop_kqfilter_args *ap) 360 { 361 struct fifoinfo *fi = ap->a_vp->v_fifoinfo; 362 struct socket *so; 363 struct sockbuf *sb; 364 365 switch (ap->a_kn->kn_filter) { 366 case EVFILT_READ: 367 ap->a_kn->kn_fop = &fiforead_filtops; 368 so = fi->fi_readsock; 369 sb = &so->so_rcv; 370 break; 371 case EVFILT_WRITE: 372 ap->a_kn->kn_fop = &fifowrite_filtops; 373 so = fi->fi_writesock; 374 sb = &so->so_snd; 375 break; 376 default: 377 return (1); 378 } 379 380 ap->a_kn->kn_hook = (caddr_t)so; 381 382 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext); 383 sb->sb_flags |= SB_KNOTE; 384 385 return (0); 386 } 387 388 static void 389 filt_fifordetach(struct knote *kn) 390 { 391 struct socket *so = (struct socket *)kn->kn_hook; 392 393 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext); 394 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note)) 395 so->so_rcv.sb_flags &= ~SB_KNOTE; 396 } 397 398 static int 399 filt_fiforead(struct knote *kn, long hint) 400 { 401 struct socket *so = (struct socket *)kn->kn_hook; 402 403 kn->kn_data = so->so_rcv.sb_cc; 404 if (so->so_state & SS_CANTRCVMORE) { 405 kn->kn_flags |= EV_EOF; 406 return (1); 407 } 408 kn->kn_flags &= ~EV_EOF; 409 return (kn->kn_data > 0); 410 } 411 412 static void 413 filt_fifowdetach(struct knote *kn) 414 { 415 struct socket *so = (struct socket *)kn->kn_hook; 416 417 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext); 418 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note)) 419 so->so_snd.sb_flags &= ~SB_KNOTE; 420 } 421 422 static int 423 filt_fifowrite(struct knote *kn, long hint) 424 { 425 struct socket *so = (struct socket *)kn->kn_hook; 426 427 kn->kn_data = sbspace(&so->so_snd); 428 if (so->so_state & SS_CANTSENDMORE) { 429 kn->kn_flags |= EV_EOF; 430 return (1); 431 } 432 kn->kn_flags &= ~EV_EOF; 433 return (kn->kn_data >= so->so_snd.sb_lowat); 434 } 435 436 /* 437 * fifo_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred, 438 * struct thread *a_td) 439 */ 440 /* ARGSUSED */ 441 static int 442 fifo_poll(struct vop_poll_args *ap) 443 { 444 struct file filetmp; 445 int events, revents = 0; 446 447 events = ap->a_events & 448 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 449 if (events) { 450 /* 451 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 452 * not, then convert the first two to the last one. This 453 * tells the socket poll function to ignore EOF so that we 454 * block if there is no writer (and no data). Callers can 455 * set POLLINIGNEOF to get non-blocking behavior. 456 */ 457 if (events & (POLLIN | POLLRDNORM) && 458 !(events & POLLINIGNEOF)) { 459 events &= ~(POLLIN | POLLRDNORM); 460 events |= POLLINIGNEOF; 461 } 462 463 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 464 if (filetmp.f_data) 465 revents |= soo_poll(&filetmp, events, ap->a_cred, 466 ap->a_td); 467 468 /* Reverse the above conversion. */ 469 if ((revents & POLLINIGNEOF) && 470 !(ap->a_events & POLLINIGNEOF)) { 471 revents |= (ap->a_events & (POLLIN | POLLRDNORM)); 472 revents &= ~POLLINIGNEOF; 473 } 474 } 475 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND); 476 if (events) { 477 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 478 if (filetmp.f_data) 479 revents |= soo_poll(&filetmp, events, ap->a_cred, 480 ap->a_td); 481 } 482 return (revents); 483 } 484 485 /* 486 * fifo_inactive(struct vnode *a_vp, struct thread *a_td) 487 */ 488 static int 489 fifo_inactive(struct vop_inactive_args *ap) 490 { 491 VOP_UNLOCK(ap->a_vp, NULL, 0, ap->a_td); 492 return (0); 493 } 494 495 /* 496 * This is a noop, simply returning what one has been given. 497 * 498 * fifo_bmap(struct vnode *a_vp, daddr_t a_bn, struct vnode **a_vpp, 499 * daddr_t *a_bnp, int *a_runp, int *a_runb) 500 */ 501 static int 502 fifo_bmap(struct vop_bmap_args *ap) 503 { 504 if (ap->a_vpp != NULL) 505 *ap->a_vpp = ap->a_vp; 506 if (ap->a_bnp != NULL) 507 *ap->a_bnp = ap->a_bn; 508 if (ap->a_runp != NULL) 509 *ap->a_runp = 0; 510 if (ap->a_runb != NULL) 511 *ap->a_runb = 0; 512 return (0); 513 } 514 515 /* 516 * Device close routine 517 * 518 * fifo_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred, 519 * struct thread *a_td) 520 */ 521 /* ARGSUSED */ 522 static int 523 fifo_close(struct vop_close_args *ap) 524 { 525 struct vnode *vp = ap->a_vp; 526 struct fifoinfo *fip = vp->v_fifoinfo; 527 int error1, error2; 528 529 if (ap->a_fflag & FREAD) { 530 fip->fi_readers--; 531 if (fip->fi_readers == 0) 532 socantsendmore(fip->fi_writesock); 533 } 534 if (ap->a_fflag & FWRITE) { 535 fip->fi_writers--; 536 if (fip->fi_writers == 0) 537 socantrcvmore(fip->fi_readsock); 538 } 539 if (vp->v_usecount > 1) 540 return (0); 541 error1 = soclose(fip->fi_readsock); 542 error2 = soclose(fip->fi_writesock); 543 FREE(fip, M_VNODE); 544 vp->v_fifoinfo = NULL; 545 if (error1) 546 return (error1); 547 return (error2); 548 } 549 550 551 /* 552 * Print out internal contents of a fifo vnode. 553 */ 554 int 555 fifo_printinfo(struct vnode *vp) 556 { 557 struct fifoinfo *fip = vp->v_fifoinfo; 558 559 printf(", fifo with %ld readers and %ld writers", 560 fip->fi_readers, fip->fi_writers); 561 return (0); 562 } 563 564 /* 565 * Print out the contents of a fifo vnode. 566 * 567 * fifo_print(struct vnode *a_vp) 568 */ 569 static int 570 fifo_print(struct vop_print_args *ap) 571 { 572 printf("tag VT_NON"); 573 fifo_printinfo(ap->a_vp); 574 printf("\n"); 575 return (0); 576 } 577 578 /* 579 * Return POSIX pathconf information applicable to fifo's. 580 * 581 * fifo_pathconf(struct vnode *a_vp, int a_name, int *a_retval) 582 */ 583 int 584 fifo_pathconf(struct vop_pathconf_args *ap) 585 { 586 switch (ap->a_name) { 587 case _PC_LINK_MAX: 588 *ap->a_retval = LINK_MAX; 589 return (0); 590 case _PC_PIPE_BUF: 591 *ap->a_retval = PIPE_BUF; 592 return (0); 593 case _PC_CHOWN_RESTRICTED: 594 *ap->a_retval = 1; 595 return (0); 596 default: 597 return (EINVAL); 598 } 599 /* NOTREACHED */ 600 } 601 602 /* 603 * Fifo advisory byte-level locks. 604 * 605 * fifo_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl, 606 * int a_flags) 607 */ 608 /* ARGSUSED */ 609 static int 610 fifo_advlock(struct vop_advlock_args *ap) 611 { 612 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 613 } 614 615 /* 616 * Fifo bad operation 617 */ 618 static int 619 fifo_badop(void) 620 { 621 panic("fifo_badop called"); 622 /* NOTREACHED */ 623 } 624