1 /* $NetBSD: fifo_vnops.c,v 1.59 2007/12/05 17:19:59 pooka 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 1.59 2007/12/05 17:19:59 pooka 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)(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_bwrite_desc, fifo_bwrite }, /* bwrite */ 110 { &vop_putpages_desc, fifo_putpages }, /* putpages */ 111 { (struct vnodeop_desc*)NULL, (int(*)(void *))NULL } 112 }; 113 const struct vnodeopv_desc fifo_vnodeop_opv_desc = 114 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 115 116 /* 117 * Trivial lookup routine that always fails. 118 */ 119 /* ARGSUSED */ 120 int 121 fifo_lookup(void *v) 122 { 123 struct vop_lookup_args /* { 124 struct vnode *a_dvp; 125 struct vnode **a_vpp; 126 struct componentname *a_cnp; 127 } */ *ap = v; 128 129 *ap->a_vpp = NULL; 130 return (ENOTDIR); 131 } 132 133 /* 134 * Open called to set up a new instance of a fifo or 135 * to find an active instance of a fifo. 136 */ 137 /* ARGSUSED */ 138 int 139 fifo_open(void *v) 140 { 141 struct vop_open_args /* { 142 struct vnode *a_vp; 143 int a_mode; 144 kauth_cred_t a_cred; 145 } */ *ap = v; 146 struct lwp *l = curlwp; 147 struct vnode *vp; 148 struct fifoinfo *fip; 149 struct proc *p; 150 struct socket *rso, *wso; 151 int error; 152 153 vp = ap->a_vp; 154 p = l->l_proc; 155 156 if ((fip = vp->v_fifoinfo) == NULL) { 157 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 158 vp->v_fifoinfo = fip; 159 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, l); 160 if (error != 0) { 161 free(fip, M_VNODE); 162 vp->v_fifoinfo = NULL; 163 return (error); 164 } 165 fip->fi_readsock = rso; 166 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, l); 167 if (error != 0) { 168 (void)soclose(rso); 169 free(fip, M_VNODE); 170 vp->v_fifoinfo = NULL; 171 return (error); 172 } 173 fip->fi_writesock = wso; 174 if ((error = unp_connect2(wso, rso, PRU_CONNECT2)) != 0) { 175 (void)soclose(wso); 176 (void)soclose(rso); 177 free(fip, M_VNODE); 178 vp->v_fifoinfo = NULL; 179 return (error); 180 } 181 fip->fi_readers = fip->fi_writers = 0; 182 wso->so_state |= SS_CANTRCVMORE; 183 rso->so_state |= SS_CANTSENDMORE; 184 } 185 if (ap->a_mode & FREAD) { 186 if (fip->fi_readers++ == 0) { 187 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 188 if (fip->fi_writers > 0) 189 wakeup(&fip->fi_writers); 190 } 191 } 192 if (ap->a_mode & FWRITE) { 193 if (fip->fi_writers++ == 0) { 194 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 195 if (fip->fi_readers > 0) 196 wakeup(&fip->fi_readers); 197 } 198 } 199 if (ap->a_mode & FREAD) { 200 if (ap->a_mode & O_NONBLOCK) { 201 } else { 202 while (!soreadable(fip->fi_readsock) && fip->fi_writers == 0) { 203 VOP_UNLOCK(vp, 0); 204 error = tsleep(&fip->fi_readers, 205 PCATCH | PSOCK, "fifor", 0); 206 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 207 if (error) 208 goto bad; 209 } 210 } 211 } 212 if (ap->a_mode & FWRITE) { 213 if (ap->a_mode & O_NONBLOCK) { 214 if (fip->fi_readers == 0) { 215 error = ENXIO; 216 goto bad; 217 } 218 } else { 219 while (fip->fi_readers == 0) { 220 VOP_UNLOCK(vp, 0); 221 error = tsleep(&fip->fi_writers, 222 PCATCH | PSOCK, "fifow", 0); 223 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 224 if (error) 225 goto bad; 226 } 227 } 228 } 229 return (0); 230 bad: 231 VOP_CLOSE(vp, ap->a_mode, ap->a_cred); 232 return (error); 233 } 234 235 /* 236 * Vnode op for read 237 */ 238 /* ARGSUSED */ 239 int 240 fifo_read(void *v) 241 { 242 struct vop_read_args /* { 243 struct vnode *a_vp; 244 struct uio *a_uio; 245 int a_ioflag; 246 kauth_cred_t a_cred; 247 } */ *ap = v; 248 struct uio *uio; 249 struct socket *rso; 250 int error; 251 size_t startresid; 252 253 uio = ap->a_uio; 254 rso = ap->a_vp->v_fifoinfo->fi_readsock; 255 #ifdef DIAGNOSTIC 256 if (uio->uio_rw != UIO_READ) 257 panic("fifo_read mode"); 258 #endif 259 if (uio->uio_resid == 0) 260 return (0); 261 if (ap->a_ioflag & IO_NDELAY) 262 rso->so_state |= SS_NBIO; 263 startresid = uio->uio_resid; 264 VOP_UNLOCK(ap->a_vp, 0); 265 error = (*rso->so_receive)(rso, (struct mbuf **)0, uio, 266 (struct mbuf **)0, (struct mbuf **)0, (int *)0); 267 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 268 /* 269 * Clear EOF indication after first such return. 270 */ 271 if (uio->uio_resid == startresid) 272 rso->so_state &= ~SS_CANTRCVMORE; 273 if (ap->a_ioflag & IO_NDELAY) { 274 rso->so_state &= ~SS_NBIO; 275 if (error == EWOULDBLOCK && 276 ap->a_vp->v_fifoinfo->fi_writers == 0) 277 error = 0; 278 } 279 return (error); 280 } 281 282 /* 283 * Vnode op for write 284 */ 285 /* ARGSUSED */ 286 int 287 fifo_write(void *v) 288 { 289 struct vop_write_args /* { 290 struct vnode *a_vp; 291 struct uio *a_uio; 292 int a_ioflag; 293 kauth_cred_t a_cred; 294 } */ *ap = v; 295 struct socket *wso; 296 int error; 297 298 wso = ap->a_vp->v_fifoinfo->fi_writesock; 299 #ifdef DIAGNOSTIC 300 if (ap->a_uio->uio_rw != UIO_WRITE) 301 panic("fifo_write mode"); 302 #endif 303 if (ap->a_ioflag & IO_NDELAY) 304 wso->so_state |= SS_NBIO; 305 VOP_UNLOCK(ap->a_vp, 0); 306 error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0, 307 (struct mbuf *)0, 0, curlwp /*XXX*/); 308 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 309 if (ap->a_ioflag & IO_NDELAY) 310 wso->so_state &= ~SS_NBIO; 311 return (error); 312 } 313 314 /* 315 * Device ioctl operation. 316 */ 317 /* ARGSUSED */ 318 int 319 fifo_ioctl(void *v) 320 { 321 struct vop_ioctl_args /* { 322 struct vnode *a_vp; 323 u_long a_command; 324 void *a_data; 325 int a_fflag; 326 kauth_cred_t a_cred; 327 struct lwp *a_l; 328 } */ *ap = v; 329 struct file filetmp; 330 int error; 331 332 if (ap->a_command == FIONBIO) 333 return (0); 334 if (ap->a_fflag & FREAD) { 335 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 336 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, curlwp); 337 if (error) 338 return (error); 339 } 340 if (ap->a_fflag & FWRITE) { 341 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 342 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, curlwp); 343 if (error) 344 return (error); 345 } 346 return (0); 347 } 348 349 /* ARGSUSED */ 350 int 351 fifo_poll(void *v) 352 { 353 struct vop_poll_args /* { 354 struct vnode *a_vp; 355 int a_events; 356 struct lwp *a_l; 357 } */ *ap = v; 358 struct file filetmp; 359 int revents; 360 361 revents = 0; 362 if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) { 363 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_readsock; 364 if (filetmp.f_data) 365 revents |= soo_poll(&filetmp, ap->a_events, curlwp); 366 } 367 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) { 368 filetmp.f_data = ap->a_vp->v_fifoinfo->fi_writesock; 369 if (filetmp.f_data) 370 revents |= soo_poll(&filetmp, ap->a_events, curlwp); 371 } 372 373 return (revents); 374 } 375 376 int 377 fifo_inactive(void *v) 378 { 379 struct vop_inactive_args /* { 380 struct vnode *a_vp; 381 struct lwp *a_l; 382 } */ *ap = v; 383 384 VOP_UNLOCK(ap->a_vp, 0); 385 return (0); 386 } 387 388 /* 389 * This is a noop, simply returning what one has been given. 390 */ 391 int 392 fifo_bmap(void *v) 393 { 394 struct vop_bmap_args /* { 395 struct vnode *a_vp; 396 daddr_t a_bn; 397 struct vnode **a_vpp; 398 daddr_t *a_bnp; 399 int *a_runp; 400 } */ *ap = v; 401 402 if (ap->a_vpp != NULL) 403 *ap->a_vpp = ap->a_vp; 404 if (ap->a_bnp != NULL) 405 *ap->a_bnp = ap->a_bn; 406 if (ap->a_runp != NULL) 407 *ap->a_runp = 0; 408 return (0); 409 } 410 411 /* 412 * Device close routine 413 */ 414 /* ARGSUSED */ 415 int 416 fifo_close(void *v) 417 { 418 struct vop_close_args /* { 419 struct vnode *a_vp; 420 int a_fflag; 421 kauth_cred_t a_cred; 422 struct lwp *a_l; 423 } */ *ap = v; 424 struct vnode *vp; 425 struct fifoinfo *fip; 426 int isrevoke; 427 428 vp = ap->a_vp; 429 fip = vp->v_fifoinfo; 430 isrevoke = (ap->a_fflag & (FREAD | FWRITE | FNONBLOCK)) == FNONBLOCK; 431 if (isrevoke) { 432 if (fip->fi_readers != 0) { 433 fip->fi_readers = 0; 434 socantsendmore(fip->fi_writesock); 435 } 436 if (fip->fi_writers != 0) { 437 fip->fi_writers = 0; 438 socantrcvmore(fip->fi_readsock); 439 } 440 } else { 441 if ((ap->a_fflag & FREAD) && --fip->fi_readers == 0) 442 socantsendmore(fip->fi_writesock); 443 if ((ap->a_fflag & FWRITE) && --fip->fi_writers == 0) 444 socantrcvmore(fip->fi_readsock); 445 } 446 /* Shut down if all readers and writers are gone. */ 447 if ((fip->fi_readers + fip->fi_writers) == 0) { 448 (void) soclose(fip->fi_readsock); 449 (void) soclose(fip->fi_writesock); 450 FREE(fip, M_VNODE); 451 vp->v_fifoinfo = NULL; 452 } 453 return (0); 454 } 455 456 /* 457 * Print out the contents of a fifo vnode. 458 */ 459 int 460 fifo_print(void *v) 461 { 462 struct vop_print_args /* { 463 struct vnode *a_vp; 464 } */ *ap = v; 465 466 printf("tag VT_NON"); 467 fifo_printinfo(ap->a_vp); 468 printf("\n"); 469 return 0; 470 } 471 472 /* 473 * Print out internal contents of a fifo vnode. 474 */ 475 void 476 fifo_printinfo(struct vnode *vp) 477 { 478 struct fifoinfo *fip; 479 480 fip = vp->v_fifoinfo; 481 printf(", fifo with %ld readers and %ld writers", 482 fip->fi_readers, fip->fi_writers); 483 } 484 485 /* 486 * Return POSIX pathconf information applicable to fifo's. 487 */ 488 int 489 fifo_pathconf(void *v) 490 { 491 struct vop_pathconf_args /* { 492 struct vnode *a_vp; 493 int a_name; 494 register_t *a_retval; 495 } */ *ap = v; 496 497 switch (ap->a_name) { 498 case _PC_LINK_MAX: 499 *ap->a_retval = LINK_MAX; 500 return (0); 501 case _PC_PIPE_BUF: 502 *ap->a_retval = PIPE_BUF; 503 return (0); 504 case _PC_CHOWN_RESTRICTED: 505 *ap->a_retval = 1; 506 return (0); 507 case _PC_SYNC_IO: 508 *ap->a_retval = 1; 509 return (0); 510 default: 511 return (EINVAL); 512 } 513 /* NOTREACHED */ 514 } 515 516 static void 517 filt_fifordetach(struct knote *kn) 518 { 519 struct socket *so; 520 521 so = (struct socket *)kn->kn_hook; 522 SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext); 523 if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist)) 524 so->so_rcv.sb_flags &= ~SB_KNOTE; 525 } 526 527 static int 528 filt_fiforead(struct knote *kn, long hint) 529 { 530 struct socket *so; 531 532 so = (struct socket *)kn->kn_hook; 533 kn->kn_data = so->so_rcv.sb_cc; 534 if (so->so_state & SS_CANTRCVMORE) { 535 kn->kn_flags |= EV_EOF; 536 return (1); 537 } 538 kn->kn_flags &= ~EV_EOF; 539 return (kn->kn_data > 0); 540 } 541 542 static void 543 filt_fifowdetach(struct knote *kn) 544 { 545 struct socket *so; 546 547 so = (struct socket *)kn->kn_hook; 548 SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext); 549 if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist)) 550 so->so_snd.sb_flags &= ~SB_KNOTE; 551 } 552 553 static int 554 filt_fifowrite(struct knote *kn, long hint) 555 { 556 struct socket *so; 557 558 so = (struct socket *)kn->kn_hook; 559 kn->kn_data = sbspace(&so->so_snd); 560 if (so->so_state & SS_CANTSENDMORE) { 561 kn->kn_flags |= EV_EOF; 562 return (1); 563 } 564 kn->kn_flags &= ~EV_EOF; 565 return (kn->kn_data >= so->so_snd.sb_lowat); 566 } 567 568 static const struct filterops fiforead_filtops = 569 { 1, NULL, filt_fifordetach, filt_fiforead }; 570 static const struct filterops fifowrite_filtops = 571 { 1, NULL, filt_fifowdetach, filt_fifowrite }; 572 573 /* ARGSUSED */ 574 int 575 fifo_kqfilter(void *v) 576 { 577 struct vop_kqfilter_args /* { 578 struct vnode *a_vp; 579 struct knote *a_kn; 580 } */ *ap = v; 581 struct socket *so; 582 struct sockbuf *sb; 583 584 so = (struct socket *)ap->a_vp->v_fifoinfo->fi_readsock; 585 switch (ap->a_kn->kn_filter) { 586 case EVFILT_READ: 587 ap->a_kn->kn_fop = &fiforead_filtops; 588 sb = &so->so_rcv; 589 break; 590 case EVFILT_WRITE: 591 ap->a_kn->kn_fop = &fifowrite_filtops; 592 sb = &so->so_snd; 593 break; 594 default: 595 return (EINVAL); 596 } 597 598 ap->a_kn->kn_hook = so; 599 600 SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, ap->a_kn, kn_selnext); 601 sb->sb_flags |= SB_KNOTE; 602 return (0); 603 } 604