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 1.17 2004/10/12 19:20:54 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 static MALLOC_DEFINE(M_FIFOINFO, "Fifo info", "Fifo info entries"); 131 132 /* 133 * fifo_vnoperate(struct vnodeop_desc *a_desc, ...) 134 */ 135 int 136 fifo_vnoperate(struct vop_generic_args *ap) 137 { 138 return (VOCALL(fifo_vnode_vops, ap)); 139 } 140 141 /* 142 * Trivial lookup routine that always fails. 143 * 144 * fifo_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 145 * struct componentname *a_cnp) 146 */ 147 /* ARGSUSED */ 148 static int 149 fifo_lookup(struct vop_lookup_args *ap) 150 { 151 *ap->a_vpp = NULL; 152 return (ENOTDIR); 153 } 154 155 /* 156 * Open called to set up a new instance of a fifo or 157 * to find an active instance of a fifo. 158 * 159 * fifo_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 160 * struct thread *a_td) 161 */ 162 /* ARGSUSED */ 163 static int 164 fifo_open(struct vop_open_args *ap) 165 { 166 struct vnode *vp = ap->a_vp; 167 struct fifoinfo *fip; 168 struct socket *rso, *wso; 169 int error; 170 171 if ((fip = vp->v_fifoinfo) == NULL) { 172 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_FIFOINFO, M_WAITOK); 173 vp->v_fifoinfo = fip; 174 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, ap->a_td); 175 if (error) { 176 free(fip, M_FIFOINFO); 177 vp->v_fifoinfo = NULL; 178 return (error); 179 } 180 fip->fi_readsock = rso; 181 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, ap->a_td); 182 if (error) { 183 (void)soclose(rso); 184 free(fip, M_FIFOINFO); 185 vp->v_fifoinfo = NULL; 186 return (error); 187 } 188 fip->fi_writesock = wso; 189 error = unp_connect2(wso, rso); 190 if (error) { 191 (void)soclose(wso); 192 (void)soclose(rso); 193 free(fip, M_FIFOINFO); 194 vp->v_fifoinfo = NULL; 195 return (error); 196 } 197 fip->fi_readers = fip->fi_writers = 0; 198 wso->so_snd.sb_lowat = PIPE_BUF; 199 rso->so_state |= SS_CANTRCVMORE; 200 } 201 if (ap->a_mode & FREAD) { 202 fip->fi_readers++; 203 if (fip->fi_readers == 1) { 204 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 205 if (fip->fi_writers > 0) { 206 wakeup((caddr_t)&fip->fi_writers); 207 sowwakeup(fip->fi_writesock); 208 } 209 } 210 } 211 if (ap->a_mode & FWRITE) { 212 fip->fi_writers++; 213 if (fip->fi_writers == 1) { 214 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 215 if (fip->fi_readers > 0) { 216 wakeup((caddr_t)&fip->fi_readers); 217 sorwakeup(fip->fi_writesock); 218 } 219 } 220 } 221 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) { 222 if (fip->fi_writers == 0) { 223 VOP_UNLOCK(vp, 0, ap->a_td); 224 error = tsleep((caddr_t)&fip->fi_readers, 225 PCATCH, "fifoor", 0); 226 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td); 227 if (error) 228 goto bad; 229 /* 230 * We must have got woken up because we had a writer. 231 * That (and not still having one) is the condition 232 * that we must wait for. 233 */ 234 } 235 } 236 if (ap->a_mode & FWRITE) { 237 if (ap->a_mode & O_NONBLOCK) { 238 if (fip->fi_readers == 0) { 239 error = ENXIO; 240 goto bad; 241 } 242 } else { 243 if (fip->fi_readers == 0) { 244 VOP_UNLOCK(vp, 0, ap->a_td); 245 error = tsleep((caddr_t)&fip->fi_writers, 246 PCATCH, "fifoow", 0); 247 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td); 248 if (error) 249 goto bad; 250 /* 251 * We must have got woken up because we had 252 * a reader. That (and not still having one) 253 * is the condition that we must wait for. 254 */ 255 } 256 } 257 } 258 return (0); 259 bad: 260 VOP_CLOSE(vp, ap->a_mode, ap->a_td); 261 return (error); 262 } 263 264 /* 265 * Vnode op for read 266 * 267 * fifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 268 * struct ucred *a_cred) 269 */ 270 /* ARGSUSED */ 271 static int 272 fifo_read(struct vop_read_args *ap) 273 { 274 struct uio *uio = ap->a_uio; 275 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 276 struct thread *td = uio->uio_td; 277 int error, startresid; 278 279 #ifdef DIAGNOSTIC 280 if (uio->uio_rw != UIO_READ) 281 panic("fifo_read mode"); 282 #endif 283 if (uio->uio_resid == 0) 284 return (0); 285 if (ap->a_ioflag & IO_NDELAY) 286 rso->so_state |= SS_NBIO; 287 startresid = uio->uio_resid; 288 VOP_UNLOCK(ap->a_vp, 0, td); 289 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0, 290 (struct mbuf **)0, (int *)0); 291 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 292 if (ap->a_ioflag & IO_NDELAY) 293 rso->so_state &= ~SS_NBIO; 294 return (error); 295 } 296 297 /* 298 * Vnode op for write 299 * 300 * fifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 301 * struct ucred *a_cred) 302 */ 303 /* ARGSUSED */ 304 static int 305 fifo_write(struct vop_write_args *ap) 306 { 307 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 308 struct thread *td = ap->a_uio->uio_td; 309 int error; 310 311 #ifdef DIAGNOSTIC 312 if (ap->a_uio->uio_rw != UIO_WRITE) 313 panic("fifo_write mode"); 314 #endif 315 if (ap->a_ioflag & IO_NDELAY) 316 wso->so_state |= SS_NBIO; 317 VOP_UNLOCK(ap->a_vp, 0, td); 318 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0, 319 (struct mbuf *)0, 0, td); 320 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 321 if (ap->a_ioflag & IO_NDELAY) 322 wso->so_state &= ~SS_NBIO; 323 return (error); 324 } 325 326 /* 327 * Device ioctl operation. 328 * 329 * fifo_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 330 * struct ucred *a_cred, struct thread *a_td) 331 */ 332 /* ARGSUSED */ 333 static int 334 fifo_ioctl(struct vop_ioctl_args *ap) 335 { 336 struct file filetmp; /* Local */ 337 int error; 338 339 if (ap->a_command == FIONBIO) 340 return (0); 341 if (ap->a_fflag & FREAD) { 342 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 343 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_td); 344 if (error) 345 return (error); 346 } 347 if (ap->a_fflag & FWRITE) { 348 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 349 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_td); 350 if (error) 351 return (error); 352 } 353 return (0); 354 } 355 356 /* 357 * fifo_kqfilter(struct vnode *a_vp, struct knote *a_kn) 358 */ 359 /* ARGSUSED */ 360 static int 361 fifo_kqfilter(struct vop_kqfilter_args *ap) 362 { 363 struct fifoinfo *fi = ap->a_vp->v_fifoinfo; 364 struct socket *so; 365 struct sockbuf *sb; 366 367 switch (ap->a_kn->kn_filter) { 368 case EVFILT_READ: 369 ap->a_kn->kn_fop = &fiforead_filtops; 370 so = fi->fi_readsock; 371 sb = &so->so_rcv; 372 break; 373 case EVFILT_WRITE: 374 ap->a_kn->kn_fop = &fifowrite_filtops; 375 so = fi->fi_writesock; 376 sb = &so->so_snd; 377 break; 378 default: 379 return (1); 380 } 381 382 ap->a_kn->kn_hook = (caddr_t)so; 383 384 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext); 385 sb->sb_flags |= SB_KNOTE; 386 387 return (0); 388 } 389 390 static void 391 filt_fifordetach(struct knote *kn) 392 { 393 struct socket *so = (struct socket *)kn->kn_hook; 394 395 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext); 396 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note)) 397 so->so_rcv.sb_flags &= ~SB_KNOTE; 398 } 399 400 static int 401 filt_fiforead(struct knote *kn, long hint) 402 { 403 struct socket *so = (struct socket *)kn->kn_hook; 404 405 kn->kn_data = so->so_rcv.sb_cc; 406 if (so->so_state & SS_CANTRCVMORE) { 407 kn->kn_flags |= EV_EOF; 408 return (1); 409 } 410 kn->kn_flags &= ~EV_EOF; 411 return (kn->kn_data > 0); 412 } 413 414 static void 415 filt_fifowdetach(struct knote *kn) 416 { 417 struct socket *so = (struct socket *)kn->kn_hook; 418 419 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext); 420 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note)) 421 so->so_snd.sb_flags &= ~SB_KNOTE; 422 } 423 424 static int 425 filt_fifowrite(struct knote *kn, long hint) 426 { 427 struct socket *so = (struct socket *)kn->kn_hook; 428 429 kn->kn_data = sbspace(&so->so_snd); 430 if (so->so_state & SS_CANTSENDMORE) { 431 kn->kn_flags |= EV_EOF; 432 return (1); 433 } 434 kn->kn_flags &= ~EV_EOF; 435 return (kn->kn_data >= so->so_snd.sb_lowat); 436 } 437 438 /* 439 * fifo_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred, 440 * struct thread *a_td) 441 */ 442 /* ARGSUSED */ 443 static int 444 fifo_poll(struct vop_poll_args *ap) 445 { 446 struct file filetmp; 447 int events, revents = 0; 448 449 events = ap->a_events & 450 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 451 if (events) { 452 /* 453 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 454 * not, then convert the first two to the last one. This 455 * tells the socket poll function to ignore EOF so that we 456 * block if there is no writer (and no data). Callers can 457 * set POLLINIGNEOF to get non-blocking behavior. 458 */ 459 if (events & (POLLIN | POLLRDNORM) && 460 !(events & POLLINIGNEOF)) { 461 events &= ~(POLLIN | POLLRDNORM); 462 events |= POLLINIGNEOF; 463 } 464 465 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 466 if (filetmp.f_data) 467 revents |= soo_poll(&filetmp, events, ap->a_cred, 468 ap->a_td); 469 470 /* Reverse the above conversion. */ 471 if ((revents & POLLINIGNEOF) && 472 !(ap->a_events & POLLINIGNEOF)) { 473 revents |= (ap->a_events & (POLLIN | POLLRDNORM)); 474 revents &= ~POLLINIGNEOF; 475 } 476 } 477 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND); 478 if (events) { 479 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 480 if (filetmp.f_data) 481 revents |= soo_poll(&filetmp, events, ap->a_cred, 482 ap->a_td); 483 } 484 return (revents); 485 } 486 487 /* 488 * fifo_inactive(struct vnode *a_vp, struct thread *a_td) 489 */ 490 static int 491 fifo_inactive(struct vop_inactive_args *ap) 492 { 493 return (0); 494 } 495 496 /* 497 * This is a noop, simply returning what one has been given. 498 * 499 * fifo_bmap(struct vnode *a_vp, daddr_t a_bn, struct vnode **a_vpp, 500 * daddr_t *a_bnp, int *a_runp, int *a_runb) 501 */ 502 static int 503 fifo_bmap(struct vop_bmap_args *ap) 504 { 505 if (ap->a_vpp != NULL) 506 *ap->a_vpp = ap->a_vp; 507 if (ap->a_bnp != NULL) 508 *ap->a_bnp = ap->a_bn; 509 if (ap->a_runp != NULL) 510 *ap->a_runp = 0; 511 if (ap->a_runb != NULL) 512 *ap->a_runb = 0; 513 return (0); 514 } 515 516 /* 517 * Device close routine 518 * 519 * fifo_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred, 520 * struct thread *a_td) 521 */ 522 /* ARGSUSED */ 523 static int 524 fifo_close(struct vop_close_args *ap) 525 { 526 struct vnode *vp = ap->a_vp; 527 struct fifoinfo *fip = vp->v_fifoinfo; 528 int error1, error2; 529 530 if (ap->a_fflag & FREAD) { 531 fip->fi_readers--; 532 if (fip->fi_readers == 0) 533 socantsendmore(fip->fi_writesock); 534 } 535 if (ap->a_fflag & FWRITE) { 536 fip->fi_writers--; 537 if (fip->fi_writers == 0) 538 socantrcvmore(fip->fi_readsock); 539 } 540 if (vp->v_usecount > 1) 541 return (0); 542 error1 = soclose(fip->fi_readsock); 543 error2 = soclose(fip->fi_writesock); 544 FREE(fip, M_FIFOINFO); 545 vp->v_fifoinfo = NULL; 546 if (error1) 547 return (error1); 548 return (error2); 549 } 550 551 552 /* 553 * Print out internal contents of a fifo vnode. 554 */ 555 int 556 fifo_printinfo(struct vnode *vp) 557 { 558 struct fifoinfo *fip = vp->v_fifoinfo; 559 560 printf(", fifo with %ld readers and %ld writers", 561 fip->fi_readers, fip->fi_writers); 562 return (0); 563 } 564 565 /* 566 * Print out the contents of a fifo vnode. 567 * 568 * fifo_print(struct vnode *a_vp) 569 */ 570 static int 571 fifo_print(struct vop_print_args *ap) 572 { 573 printf("tag VT_NON"); 574 fifo_printinfo(ap->a_vp); 575 printf("\n"); 576 return (0); 577 } 578 579 /* 580 * Return POSIX pathconf information applicable to fifo's. 581 * 582 * fifo_pathconf(struct vnode *a_vp, int a_name, int *a_retval) 583 */ 584 int 585 fifo_pathconf(struct vop_pathconf_args *ap) 586 { 587 switch (ap->a_name) { 588 case _PC_LINK_MAX: 589 *ap->a_retval = LINK_MAX; 590 return (0); 591 case _PC_PIPE_BUF: 592 *ap->a_retval = PIPE_BUF; 593 return (0); 594 case _PC_CHOWN_RESTRICTED: 595 *ap->a_retval = 1; 596 return (0); 597 default: 598 return (EINVAL); 599 } 600 /* NOTREACHED */ 601 } 602 603 /* 604 * Fifo advisory byte-level locks. 605 * 606 * fifo_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl, 607 * int a_flags) 608 */ 609 /* ARGSUSED */ 610 static int 611 fifo_advlock(struct vop_advlock_args *ap) 612 { 613 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 614 } 615 616 /* 617 * Fifo bad operation 618 */ 619 static int 620 fifo_badop(void) 621 { 622 panic("fifo_badop called"); 623 /* NOTREACHED */ 624 } 625