1 /* $NetBSD: fifo_vnops.c,v 1.31 2001/09/22 22:35:18 sommerfeld 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)fifo_vnops.c 8.10 (Berkeley) 5/27/95 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/proc.h> 41 #include <sys/time.h> 42 #include <sys/namei.h> 43 #include <sys/vnode.h> 44 #include <sys/socket.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 54 #include <miscfs/fifofs/fifo.h> 55 #include <miscfs/genfs/genfs.h> 56 57 /* 58 * This structure is associated with the FIFO vnode and stores 59 * the state associated with the FIFO. 60 */ 61 struct fifoinfo { 62 struct socket *fi_readsock; 63 struct socket *fi_writesock; 64 long fi_readers; 65 long fi_writers; 66 }; 67 68 int (**fifo_vnodeop_p) __P((void *)); 69 const struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 70 { &vop_default_desc, vn_default_error }, 71 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 72 { &vop_create_desc, fifo_create }, /* create */ 73 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 74 { &vop_open_desc, fifo_open }, /* open */ 75 { &vop_close_desc, fifo_close }, /* close */ 76 { &vop_access_desc, fifo_access }, /* access */ 77 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 78 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 79 { &vop_read_desc, fifo_read }, /* read */ 80 { &vop_write_desc, fifo_write }, /* write */ 81 { &vop_lease_desc, fifo_lease_check }, /* lease */ 82 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 83 { &vop_poll_desc, fifo_poll }, /* poll */ 84 { &vop_revoke_desc, fifo_revoke }, /* revoke */ 85 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 86 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 87 { &vop_seek_desc, fifo_seek }, /* seek */ 88 { &vop_remove_desc, fifo_remove }, /* remove */ 89 { &vop_link_desc, fifo_link }, /* link */ 90 { &vop_rename_desc, fifo_rename }, /* rename */ 91 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 92 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 93 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 94 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 95 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 96 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 97 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 98 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 99 { &vop_lock_desc, fifo_lock }, /* lock */ 100 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 101 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 102 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 103 { &vop_print_desc, fifo_print }, /* print */ 104 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 105 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 106 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 107 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 108 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 109 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 110 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 111 { &vop_update_desc, fifo_update }, /* update */ 112 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 113 { &vop_putpages_desc, fifo_putpages }, /* putpages */ 114 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 115 }; 116 const struct vnodeopv_desc fifo_vnodeop_opv_desc = 117 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 118 119 /* 120 * Trivial lookup routine that always fails. 121 */ 122 /* ARGSUSED */ 123 int 124 fifo_lookup(void *v) 125 { 126 struct vop_lookup_args /* { 127 struct vnode *a_dvp; 128 struct vnode **a_vpp; 129 struct componentname *a_cnp; 130 } */ *ap = v; 131 132 *ap->a_vpp = NULL; 133 return (ENOTDIR); 134 } 135 136 /* 137 * Open called to set up a new instance of a fifo or 138 * to find an active instance of a fifo. 139 */ 140 /* ARGSUSED */ 141 int 142 fifo_open(void *v) 143 { 144 struct vop_open_args /* { 145 struct vnode *a_vp; 146 int a_mode; 147 struct ucred *a_cred; 148 struct proc *a_p; 149 } */ *ap = v; 150 struct vnode *vp; 151 struct fifoinfo *fip; 152 struct proc *p; 153 struct socket *rso, *wso; 154 int error; 155 static const char openstr[] = "fifo"; 156 157 vp = ap->a_vp; 158 p = ap->a_p; 159 160 if ((fip = vp->v_fifoinfo) == NULL) { 161 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 162 vp->v_fifoinfo = fip; 163 if ((error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) != 0) { 164 free(fip, M_VNODE); 165 vp->v_fifoinfo = NULL; 166 return (error); 167 } 168 fip->fi_readsock = rso; 169 if ((error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) != 0) { 170 (void)soclose(rso); 171 free(fip, M_VNODE); 172 vp->v_fifoinfo = NULL; 173 return (error); 174 } 175 fip->fi_writesock = wso; 176 if ((error = unp_connect2(wso, rso)) != 0) { 177 (void)soclose(wso); 178 (void)soclose(rso); 179 free(fip, M_VNODE); 180 vp->v_fifoinfo = NULL; 181 return (error); 182 } 183 fip->fi_readers = fip->fi_writers = 0; 184 wso->so_state |= SS_CANTRCVMORE; 185 rso->so_state |= SS_CANTSENDMORE; 186 } 187 if (ap->a_mode & FREAD) { 188 if (fip->fi_readers++ == 0) { 189 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 190 if (fip->fi_writers > 0) 191 wakeup((caddr_t)&fip->fi_writers); 192 } 193 } 194 if (ap->a_mode & FWRITE) { 195 if (fip->fi_writers++ == 0) { 196 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 197 if (fip->fi_readers > 0) 198 wakeup((caddr_t)&fip->fi_readers); 199 } 200 } 201 if (ap->a_mode & FREAD) { 202 if (ap->a_mode & O_NONBLOCK) { 203 } else { 204 while (fip->fi_writers == 0) { 205 VOP_UNLOCK(vp, 0); 206 error = tsleep((caddr_t)&fip->fi_readers, 207 PCATCH | PSOCK, openstr, 0); 208 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 209 if (error) 210 goto bad; 211 } 212 } 213 } 214 if (ap->a_mode & FWRITE) { 215 if (ap->a_mode & O_NONBLOCK) { 216 if (fip->fi_readers == 0) { 217 error = ENXIO; 218 goto bad; 219 } 220 } else { 221 while (fip->fi_readers == 0) { 222 VOP_UNLOCK(vp, 0); 223 error = tsleep((caddr_t)&fip->fi_writers, 224 PCATCH | PSOCK, openstr, 0); 225 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 226 if (error) 227 goto bad; 228 } 229 } 230 } 231 return (0); 232 bad: 233 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p); 234 return (error); 235 } 236 237 /* 238 * Vnode op for read 239 */ 240 /* ARGSUSED */ 241 int 242 fifo_read(void *v) 243 { 244 struct vop_read_args /* { 245 struct vnode *a_vp; 246 struct uio *a_uio; 247 int a_ioflag; 248 struct ucred *a_cred; 249 } */ *ap = v; 250 struct uio *uio; 251 struct socket *rso; 252 int error, startresid; 253 254 uio = ap->a_uio; 255 rso = ap->a_vp->v_fifoinfo->fi_readsock; 256 #ifdef DIAGNOSTIC 257 if (uio->uio_rw != UIO_READ) 258 panic("fifo_read mode"); 259 #endif 260 if (uio->uio_resid == 0) 261 return (0); 262 if (ap->a_ioflag & IO_NDELAY) 263 rso->so_state |= SS_NBIO; 264 startresid = uio->uio_resid; 265 VOP_UNLOCK(ap->a_vp, 0); 266 error = (*rso->so_receive)(rso, (struct mbuf **)0, uio, 267 (struct mbuf **)0, (struct mbuf **)0, (int *)0); 268 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 269 /* 270 * Clear EOF indication after first such return. 271 */ 272 if (uio->uio_resid == startresid) 273 rso->so_state &= ~SS_CANTRCVMORE; 274 if (ap->a_ioflag & IO_NDELAY) { 275 rso->so_state &= ~SS_NBIO; 276 if (error == EWOULDBLOCK && 277 ap->a_vp->v_fifoinfo->fi_writers == 0) 278 error = 0; 279 } 280 return (error); 281 } 282 283 /* 284 * Vnode op for write 285 */ 286 /* ARGSUSED */ 287 int 288 fifo_write(void *v) 289 { 290 struct vop_write_args /* { 291 struct vnode *a_vp; 292 struct uio *a_uio; 293 int a_ioflag; 294 struct ucred *a_cred; 295 } */ *ap = v; 296 struct socket *wso; 297 int error; 298 299 wso = ap->a_vp->v_fifoinfo->fi_writesock; 300 #ifdef DIAGNOSTIC 301 if (ap->a_uio->uio_rw != UIO_WRITE) 302 panic("fifo_write mode"); 303 #endif 304 if (ap->a_ioflag & IO_NDELAY) 305 wso->so_state |= SS_NBIO; 306 VOP_UNLOCK(ap->a_vp, 0); 307 error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0, 308 (struct mbuf *)0, 0); 309 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 310 if (ap->a_ioflag & IO_NDELAY) 311 wso->so_state &= ~SS_NBIO; 312 return (error); 313 } 314 315 /* 316 * Device ioctl operation. 317 */ 318 /* ARGSUSED */ 319 int 320 fifo_ioctl(void *v) 321 { 322 struct vop_ioctl_args /* { 323 struct vnode *a_vp; 324 u_long a_command; 325 caddr_t a_data; 326 int a_fflag; 327 struct ucred *a_cred; 328 struct proc *a_p; 329 } */ *ap = v; 330 struct file filetmp; 331 int error; 332 333 if (ap->a_command == FIONBIO) 334 return (0); 335 if (ap->a_fflag & FREAD) { 336 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 337 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 338 if (error) 339 return (error); 340 } 341 if (ap->a_fflag & FWRITE) { 342 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 343 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 344 if (error) 345 return (error); 346 } 347 return (0); 348 } 349 350 /* ARGSUSED */ 351 int 352 fifo_poll(void *v) 353 { 354 struct vop_poll_args /* { 355 struct vnode *a_vp; 356 int a_events; 357 struct proc *a_p; 358 } */ *ap = v; 359 struct file filetmp; 360 int revents; 361 362 revents = 0; 363 if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) { 364 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 365 if (filetmp.f_data) 366 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 367 } 368 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) { 369 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 370 if (filetmp.f_data) 371 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 372 } 373 374 return (revents); 375 } 376 377 int 378 fifo_inactive(void *v) 379 { 380 struct vop_inactive_args /* { 381 struct vnode *a_vp; 382 struct proc *a_p; 383 } */ *ap = v; 384 385 VOP_UNLOCK(ap->a_vp, 0); 386 return (0); 387 } 388 389 /* 390 * This is a noop, simply returning what one has been given. 391 */ 392 int 393 fifo_bmap(void *v) 394 { 395 struct vop_bmap_args /* { 396 struct vnode *a_vp; 397 daddr_t a_bn; 398 struct vnode **a_vpp; 399 daddr_t *a_bnp; 400 int *a_runp; 401 } */ *ap = v; 402 403 if (ap->a_vpp != NULL) 404 *ap->a_vpp = ap->a_vp; 405 if (ap->a_bnp != NULL) 406 *ap->a_bnp = ap->a_bn; 407 if (ap->a_runp != NULL) 408 *ap->a_runp = 0; 409 return (0); 410 } 411 412 /* 413 * Device close routine 414 */ 415 /* ARGSUSED */ 416 int 417 fifo_close(void *v) 418 { 419 struct vop_close_args /* { 420 struct vnode *a_vp; 421 int a_fflag; 422 struct ucred *a_cred; 423 struct proc *a_p; 424 } */ *ap = v; 425 struct vnode *vp; 426 struct fifoinfo *fip; 427 int error1, error2; 428 429 vp = ap->a_vp; 430 fip = vp->v_fifoinfo; 431 if (ap->a_fflag & FREAD) { 432 if (--fip->fi_readers == 0) 433 socantsendmore(fip->fi_writesock); 434 } 435 if (ap->a_fflag & FWRITE) { 436 if (--fip->fi_writers == 0) 437 socantrcvmore(fip->fi_readsock); 438 } 439 if (vp->v_usecount > 1) 440 return (0); 441 error1 = soclose(fip->fi_readsock); 442 error2 = soclose(fip->fi_writesock); 443 FREE(fip, M_VNODE); 444 vp->v_fifoinfo = NULL; 445 if (error1) 446 return (error1); 447 return (error2); 448 } 449 450 /* 451 * Print out the contents of a fifo vnode. 452 */ 453 int 454 fifo_print(void *v) 455 { 456 struct vop_print_args /* { 457 struct vnode *a_vp; 458 } */ *ap = v; 459 460 printf("tag VT_NON"); 461 fifo_printinfo(ap->a_vp); 462 printf("\n"); 463 return 0; 464 } 465 466 /* 467 * Print out internal contents of a fifo vnode. 468 */ 469 void 470 fifo_printinfo(struct vnode *vp) 471 { 472 struct fifoinfo *fip; 473 474 fip = vp->v_fifoinfo; 475 printf(", fifo with %ld readers and %ld writers", 476 fip->fi_readers, fip->fi_writers); 477 } 478 479 /* 480 * Return POSIX pathconf information applicable to fifo's. 481 */ 482 int 483 fifo_pathconf(void *v) 484 { 485 struct vop_pathconf_args /* { 486 struct vnode *a_vp; 487 int a_name; 488 register_t *a_retval; 489 } */ *ap = v; 490 491 switch (ap->a_name) { 492 case _PC_LINK_MAX: 493 *ap->a_retval = LINK_MAX; 494 return (0); 495 case _PC_PIPE_BUF: 496 *ap->a_retval = PIPE_BUF; 497 return (0); 498 case _PC_CHOWN_RESTRICTED: 499 *ap->a_retval = 1; 500 return (0); 501 case _PC_SYNC_IO: 502 *ap->a_retval = 1; 503 return (0); 504 default: 505 return (EINVAL); 506 } 507 /* NOTREACHED */ 508 } 509 510 /* 511 * Dummy putpages routine. 512 */ 513 514 int 515 fifo_putpages(void *v) 516 { 517 struct vop_putpages_args /* { 518 struct vnode *a_vp; 519 voff_t a_offlo; 520 voff_t a_offhi; 521 int a_flags; 522 } */ *ap = v; 523 struct vnode *vp = ap->a_vp; 524 struct uvm_object *uobj = &vp->v_uobj; 525 526 KASSERT(uobj->uo_npages == 0); 527 simple_unlock(&uobj->vmobjlock); 528 return (0); 529 } 530