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(&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(&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(&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 /* 248 * XXX: Some race I havn't located is solved 249 * by timing out after a sec. Race seen when 250 * sendmail hangs here during boot /phk 251 */ 252 error = tsleep(&fip->fi_writers, 253 PCATCH | PSOCK, "fifoow", hz); 254 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 255 if (error) 256 goto bad; 257 } 258 } 259 } 260 return (0); 261 bad: 262 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, td); 263 return (error); 264 } 265 266 /* 267 * Vnode op for read 268 */ 269 /* ARGSUSED */ 270 static int 271 fifo_read(ap) 272 struct vop_read_args /* { 273 struct vnode *a_vp; 274 struct uio *a_uio; 275 int a_ioflag; 276 struct ucred *a_cred; 277 } */ *ap; 278 { 279 struct uio *uio = ap->a_uio; 280 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 281 struct thread *td = uio->uio_td; 282 int error, startresid; 283 284 #ifdef DIAGNOSTIC 285 if (uio->uio_rw != UIO_READ) 286 panic("fifo_read mode"); 287 #endif 288 if (uio->uio_resid == 0) 289 return (0); 290 if (ap->a_ioflag & IO_NDELAY) 291 rso->so_state |= SS_NBIO; 292 startresid = uio->uio_resid; 293 VOP_UNLOCK(ap->a_vp, 0, td); 294 error = soreceive(rso, (struct sockaddr **)0, uio, (struct mbuf **)0, 295 (struct mbuf **)0, (int *)0); 296 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 297 if (ap->a_ioflag & IO_NDELAY) 298 rso->so_state &= ~SS_NBIO; 299 return (error); 300 } 301 302 /* 303 * Vnode op for write 304 */ 305 /* ARGSUSED */ 306 static int 307 fifo_write(ap) 308 struct vop_write_args /* { 309 struct vnode *a_vp; 310 struct uio *a_uio; 311 int a_ioflag; 312 struct ucred *a_cred; 313 } */ *ap; 314 { 315 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 316 struct thread *td = ap->a_uio->uio_td; 317 int error; 318 319 #ifdef DIAGNOSTIC 320 if (ap->a_uio->uio_rw != UIO_WRITE) 321 panic("fifo_write mode"); 322 #endif 323 if (ap->a_ioflag & IO_NDELAY) 324 wso->so_state |= SS_NBIO; 325 VOP_UNLOCK(ap->a_vp, 0, td); 326 error = sosend(wso, (struct sockaddr *)0, ap->a_uio, 0, 327 (struct mbuf *)0, 0, td); 328 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, td); 329 if (ap->a_ioflag & IO_NDELAY) 330 wso->so_state &= ~SS_NBIO; 331 return (error); 332 } 333 334 /* 335 * Device ioctl operation. 336 */ 337 /* ARGSUSED */ 338 static int 339 fifo_ioctl(ap) 340 struct vop_ioctl_args /* { 341 struct vnode *a_vp; 342 u_long a_command; 343 caddr_t a_data; 344 int a_fflag; 345 struct ucred *a_cred; 346 struct thread *a_td; 347 } */ *ap; 348 { 349 struct file filetmp; /* Local, so need not be locked. */ 350 int error; 351 352 if (ap->a_command == FIONBIO) 353 return (0); 354 if (ap->a_fflag & FREAD) { 355 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 356 filetmp.f_cred = ap->a_cred; 357 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 358 ap->a_td->td_ucred, ap->a_td); 359 if (error) 360 return (error); 361 } 362 if (ap->a_fflag & FWRITE) { 363 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 364 filetmp.f_cred = ap->a_cred; 365 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 366 ap->a_td->td_ucred, ap->a_td); 367 if (error) 368 return (error); 369 } 370 return (0); 371 } 372 373 /* ARGSUSED */ 374 static int 375 fifo_kqfilter(ap) 376 struct vop_kqfilter_args /* { 377 struct vnode *a_vp; 378 struct knote *a_kn; 379 } */ *ap; 380 { 381 struct fifoinfo *fi = ap->a_vp->v_fifoinfo; 382 struct socket *so; 383 struct sockbuf *sb; 384 385 switch (ap->a_kn->kn_filter) { 386 case EVFILT_READ: 387 ap->a_kn->kn_fop = &fiforead_filtops; 388 so = fi->fi_readsock; 389 sb = &so->so_rcv; 390 break; 391 case EVFILT_WRITE: 392 ap->a_kn->kn_fop = &fifowrite_filtops; 393 so = fi->fi_writesock; 394 sb = &so->so_snd; 395 break; 396 default: 397 return (1); 398 } 399 400 ap->a_kn->kn_hook = (caddr_t)so; 401 402 SLIST_INSERT_HEAD(&sb->sb_sel.si_note, ap->a_kn, kn_selnext); 403 sb->sb_flags |= SB_KNOTE; 404 405 return (0); 406 } 407 408 static void 409 filt_fifordetach(struct knote *kn) 410 { 411 struct socket *so = (struct socket *)kn->kn_hook; 412 413 SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext); 414 if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note)) 415 so->so_rcv.sb_flags &= ~SB_KNOTE; 416 } 417 418 static int 419 filt_fiforead(struct knote *kn, long hint) 420 { 421 struct socket *so = (struct socket *)kn->kn_hook; 422 423 kn->kn_data = so->so_rcv.sb_cc; 424 if (so->so_state & SS_CANTRCVMORE) { 425 kn->kn_flags |= EV_EOF; 426 return (1); 427 } 428 kn->kn_flags &= ~EV_EOF; 429 return (kn->kn_data > 0); 430 } 431 432 static void 433 filt_fifowdetach(struct knote *kn) 434 { 435 struct socket *so = (struct socket *)kn->kn_hook; 436 437 SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext); 438 if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note)) 439 so->so_snd.sb_flags &= ~SB_KNOTE; 440 } 441 442 static int 443 filt_fifowrite(struct knote *kn, long hint) 444 { 445 struct socket *so = (struct socket *)kn->kn_hook; 446 447 kn->kn_data = sbspace(&so->so_snd); 448 if (so->so_state & SS_CANTSENDMORE) { 449 kn->kn_flags |= EV_EOF; 450 return (1); 451 } 452 kn->kn_flags &= ~EV_EOF; 453 return (kn->kn_data >= so->so_snd.sb_lowat); 454 } 455 456 /* ARGSUSED */ 457 static int 458 fifo_poll(ap) 459 struct vop_poll_args /* { 460 struct vnode *a_vp; 461 int a_events; 462 struct ucred *a_cred; 463 struct thread *a_td; 464 } */ *ap; 465 { 466 struct file filetmp; 467 int events, revents = 0; 468 469 events = ap->a_events & 470 (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND); 471 if (events) { 472 /* 473 * If POLLIN or POLLRDNORM is requested and POLLINIGNEOF is 474 * not, then convert the first two to the last one. This 475 * tells the socket poll function to ignore EOF so that we 476 * block if there is no writer (and no data). Callers can 477 * set POLLINIGNEOF to get non-blocking behavior. 478 */ 479 if (events & (POLLIN | POLLRDNORM) && 480 !(events & POLLINIGNEOF)) { 481 events &= ~(POLLIN | POLLRDNORM); 482 events |= POLLINIGNEOF; 483 } 484 485 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 486 filetmp.f_cred = ap->a_cred; 487 if (filetmp.f_data) 488 revents |= soo_poll(&filetmp, events, 489 ap->a_td->td_ucred, ap->a_td); 490 491 /* Reverse the above conversion. */ 492 if ((revents & POLLINIGNEOF) && 493 !(ap->a_events & POLLINIGNEOF)) { 494 revents |= (ap->a_events & (POLLIN | POLLRDNORM)); 495 revents &= ~POLLINIGNEOF; 496 } 497 } 498 events = ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND); 499 if (events) { 500 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 501 filetmp.f_cred = ap->a_cred; 502 if (filetmp.f_data) { 503 revents |= soo_poll(&filetmp, events, 504 ap->a_td->td_ucred, ap->a_td); 505 } 506 } 507 return (revents); 508 } 509 510 /* 511 * Device close routine 512 */ 513 /* ARGSUSED */ 514 static int 515 fifo_close(ap) 516 struct vop_close_args /* { 517 struct vnode *a_vp; 518 int a_fflag; 519 struct ucred *a_cred; 520 struct thread *a_td; 521 } */ *ap; 522 { 523 register struct vnode *vp = ap->a_vp; 524 register struct fifoinfo *fip = vp->v_fifoinfo; 525 int error1, error2; 526 527 if (ap->a_fflag & FREAD) { 528 fip->fi_readers--; 529 if (fip->fi_readers == 0) 530 socantsendmore(fip->fi_writesock); 531 } 532 if (ap->a_fflag & FWRITE) { 533 fip->fi_writers--; 534 if (fip->fi_writers == 0) 535 socantrcvmore(fip->fi_readsock); 536 } 537 if (vrefcnt(vp) > 1) 538 return (0); 539 error1 = soclose(fip->fi_readsock); 540 error2 = soclose(fip->fi_writesock); 541 FREE(fip, M_VNODE); 542 vp->v_fifoinfo = NULL; 543 if (error1) 544 return (error1); 545 return (error2); 546 } 547 548 549 /* 550 * Print out internal contents of a fifo vnode. 551 */ 552 int 553 fifo_printinfo(vp) 554 struct vnode *vp; 555 { 556 register struct fifoinfo *fip = vp->v_fifoinfo; 557 558 printf(", fifo with %ld readers and %ld writers", 559 fip->fi_readers, fip->fi_writers); 560 return (0); 561 } 562 563 /* 564 * Print out the contents of a fifo vnode. 565 */ 566 static int 567 fifo_print(ap) 568 struct vop_print_args /* { 569 struct vnode *a_vp; 570 } */ *ap; 571 { 572 fifo_printinfo(ap->a_vp); 573 printf("\n"); 574 return (0); 575 } 576 577 /* 578 * Return POSIX pathconf information applicable to fifo's. 579 */ 580 static int 581 fifo_pathconf(ap) 582 struct vop_pathconf_args /* { 583 struct vnode *a_vp; 584 int a_name; 585 int *a_retval; 586 } */ *ap; 587 { 588 589 switch (ap->a_name) { 590 case _PC_LINK_MAX: 591 *ap->a_retval = LINK_MAX; 592 return (0); 593 case _PC_PIPE_BUF: 594 *ap->a_retval = PIPE_BUF; 595 return (0); 596 case _PC_CHOWN_RESTRICTED: 597 *ap->a_retval = 1; 598 return (0); 599 default: 600 return (EINVAL); 601 } 602 /* NOTREACHED */ 603 } 604 605 /* 606 * Fifo advisory byte-level locks. 607 */ 608 /* ARGSUSED */ 609 static int 610 fifo_advlock(ap) 611 struct vop_advlock_args /* { 612 struct vnode *a_vp; 613 caddr_t a_id; 614 int a_op; 615 struct flock *a_fl; 616 int a_flags; 617 } */ *ap; 618 { 619 620 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); 621 } 622