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 * $FreeBSD$ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/event.h> 39 #include <sys/filio.h> 40 #include <sys/fcntl.h> 41 #include <sys/file.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/malloc.h> 46 #include <sys/poll.h> 47 #include <sys/proc.h> /* XXXKSE */ 48 #include <sys/signalvar.h> 49 #include <sys/socket.h> 50 #include <sys/socketvar.h> 51 #include <sys/sx.h> 52 #include <sys/systm.h> 53 #include <sys/un.h> 54 #include <sys/unistd.h> 55 #include <sys/vnode.h> 56 #include <fs/fifofs/fifo.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 static int fifo_print(struct vop_print_args *); 70 static int fifo_lookup(struct vop_lookup_args *); 71 static int fifo_open(struct vop_open_args *); 72 static int fifo_close(struct vop_close_args *); 73 static int fifo_read(struct vop_read_args *); 74 static int fifo_write(struct vop_write_args *); 75 static int fifo_ioctl(struct vop_ioctl_args *); 76 static int fifo_poll(struct vop_poll_args *); 77 static int fifo_kqfilter(struct vop_kqfilter_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 vop_t **fifo_vnodeop_p; 92 static struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 93 { &vop_default_desc, (vop_t *) vop_defaultop }, 94 { &vop_access_desc, (vop_t *) vop_ebadf }, 95 { &vop_advlock_desc, (vop_t *) fifo_advlock }, 96 { &vop_close_desc, (vop_t *) fifo_close }, 97 { &vop_create_desc, (vop_t *) vop_panic }, 98 { &vop_getattr_desc, (vop_t *) vop_ebadf }, 99 { &vop_getwritemount_desc, (vop_t *) vop_stdgetwritemount }, 100 { &vop_ioctl_desc, (vop_t *) fifo_ioctl }, 101 { &vop_kqfilter_desc, (vop_t *) fifo_kqfilter }, 102 { &vop_lease_desc, (vop_t *) vop_null }, 103 { &vop_link_desc, (vop_t *) vop_panic }, 104 { &vop_lookup_desc, (vop_t *) fifo_lookup }, 105 { &vop_mkdir_desc, (vop_t *) vop_panic }, 106 { &vop_mknod_desc, (vop_t *) vop_panic }, 107 { &vop_open_desc, (vop_t *) fifo_open }, 108 { &vop_pathconf_desc, (vop_t *) fifo_pathconf }, 109 { &vop_poll_desc, (vop_t *) fifo_poll }, 110 { &vop_print_desc, (vop_t *) fifo_print }, 111 { &vop_read_desc, (vop_t *) fifo_read }, 112 { &vop_readdir_desc, (vop_t *) vop_panic }, 113 { &vop_readlink_desc, (vop_t *) vop_panic }, 114 { &vop_reallocblks_desc, (vop_t *) vop_panic }, 115 { &vop_reclaim_desc, (vop_t *) vop_null }, 116 { &vop_remove_desc, (vop_t *) vop_panic }, 117 { &vop_rename_desc, (vop_t *) vop_panic }, 118 { &vop_rmdir_desc, (vop_t *) vop_panic }, 119 { &vop_setattr_desc, (vop_t *) vop_ebadf }, 120 { &vop_symlink_desc, (vop_t *) vop_panic }, 121 { &vop_write_desc, (vop_t *) fifo_write }, 122 { NULL, NULL } 123 }; 124 static struct vnodeopv_desc fifo_vnodeop_opv_desc = 125 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 126 127 VNODEOP_SET(fifo_vnodeop_opv_desc); 128 129 int 130 fifo_vnoperate(ap) 131 struct vop_generic_args /* { 132 struct vnodeop_desc *a_desc; 133 <other random data follows, presumably> 134 } */ *ap; 135 { 136 return (VOCALL(fifo_vnodeop_p, ap->a_desc->vdesc_offset, ap)); 137 } 138 139 /* 140 * Trivial lookup routine that always fails. 141 */ 142 /* ARGSUSED */ 143 static int 144 fifo_lookup(ap) 145 struct vop_lookup_args /* { 146 struct vnode * a_dvp; 147 struct vnode ** a_vpp; 148 struct componentname * a_cnp; 149 } */ *ap; 150 { 151 152 *ap->a_vpp = NULL; 153 return (ENOTDIR); 154 } 155 156 /* 157 * Open called to set up a new instance of a fifo or 158 * to find an active instance of a fifo. 159 */ 160 /* ARGSUSED */ 161 static int 162 fifo_open(ap) 163 struct vop_open_args /* { 164 struct vnode *a_vp; 165 int a_mode; 166 struct ucred *a_cred; 167 struct thread *a_td; 168 } */ *ap; 169 { 170 struct vnode *vp = ap->a_vp; 171 struct fifoinfo *fip; 172 struct thread *td = ap->a_td; 173 struct socket *rso, *wso; 174 int error; 175 176 if ((fip = vp->v_fifoinfo) == NULL) { 177 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 178 vp->v_fifoinfo = fip; 179 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, 180 ap->a_td->td_ucred, ap->a_td); 181 if (error) { 182 free(fip, M_VNODE); 183 vp->v_fifoinfo = NULL; 184 return (error); 185 } 186 fip->fi_readsock = rso; 187 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, 188 ap->a_td->td_ucred, ap->a_td); 189 if (error) { 190 (void)soclose(rso); 191 free(fip, M_VNODE); 192 vp->v_fifoinfo = NULL; 193 return (error); 194 } 195 fip->fi_writesock = wso; 196 error = unp_connect2(wso, rso); 197 if (error) { 198 (void)soclose(wso); 199 (void)soclose(rso); 200 free(fip, M_VNODE); 201 vp->v_fifoinfo = NULL; 202 return (error); 203 } 204 fip->fi_readers = fip->fi_writers = 0; 205 wso->so_snd.sb_lowat = PIPE_BUF; 206 rso->so_state |= SS_CANTRCVMORE; 207 } 208 if (ap->a_mode & FREAD) { 209 fip->fi_readers++; 210 if (fip->fi_readers == 1) { 211 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 212 if (fip->fi_writers > 0) { 213 wakeup((caddr_t)&fip->fi_writers); 214 sowwakeup(fip->fi_writesock); 215 } 216 } 217 } 218 if (ap->a_mode & FWRITE) { 219 fip->fi_writers++; 220 if (fip->fi_writers == 1) { 221 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 222 if (fip->fi_readers > 0) { 223 wakeup((caddr_t)&fip->fi_readers); 224 sorwakeup(fip->fi_writesock); 225 } 226 } 227 } 228 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) { 229 while (fip->fi_writers == 0) { 230 VOP_UNLOCK(vp, 0, td); 231 error = tsleep((caddr_t)&fip->fi_readers, 232 PCATCH | PSOCK, "fifoor", 0); 233 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 234 if (error) 235 goto bad; 236 } 237 } 238 if (ap->a_mode & FWRITE) { 239 if (ap->a_mode & O_NONBLOCK) { 240 if (fip->fi_readers == 0) { 241 error = ENXIO; 242 goto bad; 243 } 244 } else { 245 while (fip->fi_readers == 0) { 246 VOP_UNLOCK(vp, 0, td); 247 error = tsleep((caddr_t)&fip->fi_writers, 248 PCATCH | PSOCK, "fifoow", 0); 249 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 250 if (error) 251 goto bad; 252 } 253 } 254 } 255 return (0); 256 bad: 257 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, td); 258 return (error); 259 } 260 261 /* 262 * Vnode op for read 263 */ 264 /* ARGSUSED */ 265 static int 266 fifo_read(ap) 267 struct vop_read_args /* { 268 struct vnode *a_vp; 269 struct uio *a_uio; 270 int a_ioflag; 271 struct ucred *a_cred; 272 } */ *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 /* ARGSUSED */ 301 static int 302 fifo_write(ap) 303 struct vop_write_args /* { 304 struct vnode *a_vp; 305 struct uio *a_uio; 306 int a_ioflag; 307 struct ucred *a_cred; 308 } */ *ap; 309 { 310 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 311 struct thread *td = ap->a_uio->uio_td; 312 int error; 313 314 #ifdef DIAGNOSTIC 315 if (ap->a_uio->uio_rw != UIO_WRITE) 316 panic("fifo_write mode"); 317 #endif 318 if (ap->a_ioflag & IO_NDELAY) 319 wso->so_state |= SS_NBIO; 320 VOP_UNLOCK(ap->a_vp, 0, td); 321 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0, 322 (struct mbuf *)0, 0, td); 323 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 324 if (ap->a_ioflag & IO_NDELAY) 325 wso->so_state &= ~SS_NBIO; 326 return (error); 327 } 328 329 /* 330 * Device ioctl operation. 331 */ 332 /* ARGSUSED */ 333 static int 334 fifo_ioctl(ap) 335 struct vop_ioctl_args /* { 336 struct vnode *a_vp; 337 u_long a_command; 338 caddr_t a_data; 339 int a_fflag; 340 struct ucred *a_cred; 341 struct thread *a_td; 342 } */ *ap; 343 { 344 struct file filetmp; /* Local, so need not be locked. */ 345 int error; 346 347 if (ap->a_command == FIONBIO) 348 return (0); 349 if (ap->a_fflag & FREAD) { 350 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 351 filetmp.f_cred = ap->a_cred; 352 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 353 ap->a_td->td_ucred, ap->a_td); 354 if (error) 355 return (error); 356 } 357 if (ap->a_fflag & FWRITE) { 358 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 359 filetmp.f_cred = ap->a_cred; 360 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 361 ap->a_td->td_ucred, ap->a_td); 362 if (error) 363 return (error); 364 } 365 return (0); 366 } 367 368 /* ARGSUSED */ 369 static int 370 fifo_kqfilter(ap) 371 struct vop_kqfilter_args /* { 372 struct vnode *a_vp; 373 struct knote *a_kn; 374 } */ *ap; 375 { 376 struct fifoinfo *fi = ap->a_vp->v_fifoinfo; 377 struct socket *so; 378 struct sockbuf *sb; 379 380 switch (ap->a_kn->kn_filter) { 381 case EVFILT_READ: 382 ap->a_kn->kn_fop = &fiforead_filtops; 383 so = fi->fi_readsock; 384 sb = &so->so_rcv; 385 break; 386 case EVFILT_WRITE: 387 ap->a_kn->kn_fop = &fifowrite_filtops; 388 so = fi->fi_writesock; 389 sb = &so->so_snd; 390 break; 391 default: 392 return (1); 393 } 394 395 ap->a_kn->kn_hook = (caddr_t)so; 396 397 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext); 398 sb->sb_flags |= SB_KNOTE; 399 400 return (0); 401 } 402 403 static void 404 filt_fifordetach(struct knote *kn) 405 { 406 struct socket *so = (struct socket *)kn->kn_hook; 407 408 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext); 409 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note)) 410 so->so_rcv.sb_flags &= ~SB_KNOTE; 411 } 412 413 static int 414 filt_fiforead(struct knote *kn, long hint) 415 { 416 struct socket *so = (struct socket *)kn->kn_hook; 417 418 kn->kn_data = so->so_rcv.sb_cc; 419 if (so->so_state & SS_CANTRCVMORE) { 420 kn->kn_flags |= EV_EOF; 421 return (1); 422 } 423 kn->kn_flags &= ~EV_EOF; 424 return (kn->kn_data > 0); 425 } 426 427 static void 428 filt_fifowdetach(struct knote *kn) 429 { 430 struct socket *so = (struct socket *)kn->kn_hook; 431 432 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext); 433 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note)) 434 so->so_snd.sb_flags &= ~SB_KNOTE; 435 } 436 437 static int 438 filt_fifowrite(struct knote *kn, long hint) 439 { 440 struct socket *so = (struct socket *)kn->kn_hook; 441 442 kn->kn_data = sbspace(&so->so_snd); 443 if (so->so_state & SS_CANTSENDMORE) { 444 kn->kn_flags |= EV_EOF; 445 return (1); 446 } 447 kn->kn_flags &= ~EV_EOF; 448 return (kn->kn_data >= so->so_snd.sb_lowat); 449 } 450 451 /* ARGSUSED */ 452 static int 453 fifo_poll(ap) 454 struct vop_poll_args /* { 455 struct vnode *a_vp; 456 int a_events; 457 struct ucred *a_cred; 458 struct thread *a_td; 459 } */ *ap; 460 { 461 struct file filetmp; 462 int events, revents = 0; 463 464 events = ap->a_events & 465 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 466 if (events) { 467 /* 468 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 469 * not, then convert the first two to the last one. This 470 * tells the socket poll function to ignore EOF so that we 471 * block if there is no writer (and no data). Callers can 472 * set POLLINIGNEOF to get non-blocking behavior. 473 */ 474 if (events & (POLLIN | POLLRDNORM) && 475 !(events & POLLINIGNEOF)) { 476 events &= ~(POLLIN | POLLRDNORM); 477 events |= POLLINIGNEOF; 478 } 479 480 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 481 filetmp.f_cred = ap->a_cred; 482 if (filetmp.f_data) 483 revents |= soo_poll(&filetmp, events, 484 ap->a_td->td_ucred, ap->a_td); 485 486 /* Reverse the above conversion. */ 487 if ((revents & POLLINIGNEOF) && 488 !(ap->a_events & POLLINIGNEOF)) { 489 revents |= (ap->a_events & (POLLIN | POLLRDNORM)); 490 revents &= ~POLLINIGNEOF; 491 } 492 } 493 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND); 494 if (events) { 495 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 496 filetmp.f_cred = ap->a_cred; 497 if (filetmp.f_data) 498 revents |= soo_poll(&filetmp, events, 499 ap->a_td->td_ucred, ap->a_td); 500 } 501 return (revents); 502 } 503 504 /* 505 * Device close routine 506 */ 507 /* ARGSUSED */ 508 static int 509 fifo_close(ap) 510 struct vop_close_args /* { 511 struct vnode *a_vp; 512 int a_fflag; 513 struct ucred *a_cred; 514 struct thread *a_td; 515 } */ *ap; 516 { 517 register struct vnode *vp = ap->a_vp; 518 register struct fifoinfo *fip = vp->v_fifoinfo; 519 int error1, error2; 520 521 if (ap->a_fflag & FREAD) { 522 fip->fi_readers--; 523 if (fip->fi_readers == 0) 524 socantsendmore(fip->fi_writesock); 525 } 526 if (ap->a_fflag & FWRITE) { 527 fip->fi_writers--; 528 if (fip->fi_writers == 0) 529 socantrcvmore(fip->fi_readsock); 530 } 531 if (vrefcnt(vp) > 1) 532 return (0); 533 error1 = soclose(fip->fi_readsock); 534 error2 = soclose(fip->fi_writesock); 535 FREE(fip, M_VNODE); 536 vp->v_fifoinfo = NULL; 537 if (error1) 538 return (error1); 539 return (error2); 540 } 541 542 543 /* 544 * Print out internal contents of a fifo vnode. 545 */ 546 int 547 fifo_printinfo(vp) 548 struct vnode *vp; 549 { 550 register struct fifoinfo *fip = vp->v_fifoinfo; 551 552 printf(", fifo with %ld readers and %ld writers", 553 fip->fi_readers, fip->fi_writers); 554 return (0); 555 } 556 557 /* 558 * Print out the contents of a fifo vnode. 559 */ 560 static int 561 fifo_print(ap) 562 struct vop_print_args /* { 563 struct vnode *a_vp; 564 } */ *ap; 565 { 566 fifo_printinfo(ap->a_vp); 567 printf("\n"); 568 return (0); 569 } 570 571 /* 572 * Return POSIX pathconf information applicable to fifo's. 573 */ 574 static int 575 fifo_pathconf(ap) 576 struct vop_pathconf_args /* { 577 struct vnode *a_vp; 578 int a_name; 579 int *a_retval; 580 } */ *ap; 581 { 582 583 switch (ap->a_name) { 584 case _PC_LINK_MAX: 585 *ap->a_retval = LINK_MAX; 586 return (0); 587 case _PC_PIPE_BUF: 588 *ap->a_retval = PIPE_BUF; 589 return (0); 590 case _PC_CHOWN_RESTRICTED: 591 *ap->a_retval = 1; 592 return (0); 593 default: 594 return (EINVAL); 595 } 596 /* NOTREACHED */ 597 } 598 599 /* 600 * Fifo advisory byte-level locks. 601 */ 602 /* ARGSUSED */ 603 static int 604 fifo_advlock(ap) 605 struct vop_advlock_args /* { 606 struct vnode *a_vp; 607 caddr_t a_id; 608 int a_op; 609 struct flock *a_fl; 610 int a_flags; 611 } */ *ap; 612 { 613 614 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 615 } 616