1 /* $NetBSD: fifo_vnops.c,v 1.33 2001/12/06 04:27:41 chs 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/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: fifo_vnops.c,v 1.33 2001/12/06 04:27:41 chs Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/proc.h> 44 #include <sys/time.h> 45 #include <sys/namei.h> 46 #include <sys/vnode.h> 47 #include <sys/socket.h> 48 #include <sys/socketvar.h> 49 #include <sys/stat.h> 50 #include <sys/ioctl.h> 51 #include <sys/file.h> 52 #include <sys/errno.h> 53 #include <sys/malloc.h> 54 #include <sys/un.h> 55 #include <sys/poll.h> 56 57 #include <miscfs/fifofs/fifo.h> 58 #include <miscfs/genfs/genfs.h> 59 60 /* 61 * This structure is associated with the FIFO vnode and stores 62 * the state associated with the FIFO. 63 */ 64 struct fifoinfo { 65 struct socket *fi_readsock; 66 struct socket *fi_writesock; 67 long fi_readers; 68 long fi_writers; 69 }; 70 71 int (**fifo_vnodeop_p) __P((void *)); 72 const struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 73 { &vop_default_desc, vn_default_error }, 74 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 75 { &vop_create_desc, fifo_create }, /* create */ 76 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 77 { &vop_open_desc, fifo_open }, /* open */ 78 { &vop_close_desc, fifo_close }, /* close */ 79 { &vop_access_desc, fifo_access }, /* access */ 80 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 81 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 82 { &vop_read_desc, fifo_read }, /* read */ 83 { &vop_write_desc, fifo_write }, /* write */ 84 { &vop_lease_desc, fifo_lease_check }, /* lease */ 85 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 86 { &vop_poll_desc, fifo_poll }, /* poll */ 87 { &vop_revoke_desc, fifo_revoke }, /* revoke */ 88 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 89 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 90 { &vop_seek_desc, fifo_seek }, /* seek */ 91 { &vop_remove_desc, fifo_remove }, /* remove */ 92 { &vop_link_desc, fifo_link }, /* link */ 93 { &vop_rename_desc, fifo_rename }, /* rename */ 94 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 95 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 96 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 97 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 98 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 99 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 100 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 101 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 102 { &vop_lock_desc, fifo_lock }, /* lock */ 103 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 104 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 105 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 106 { &vop_print_desc, fifo_print }, /* print */ 107 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 108 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 109 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 110 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 111 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 112 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 113 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 114 { &vop_update_desc, fifo_update }, /* update */ 115 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 116 { &vop_putpages_desc, fifo_putpages }, /* putpages */ 117 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 118 }; 119 const struct vnodeopv_desc fifo_vnodeop_opv_desc = 120 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 121 122 /* 123 * Trivial lookup routine that always fails. 124 */ 125 /* ARGSUSED */ 126 int 127 fifo_lookup(void *v) 128 { 129 struct vop_lookup_args /* { 130 struct vnode *a_dvp; 131 struct vnode **a_vpp; 132 struct componentname *a_cnp; 133 } */ *ap = v; 134 135 *ap->a_vpp = NULL; 136 return (ENOTDIR); 137 } 138 139 /* 140 * Open called to set up a new instance of a fifo or 141 * to find an active instance of a fifo. 142 */ 143 /* ARGSUSED */ 144 int 145 fifo_open(void *v) 146 { 147 struct vop_open_args /* { 148 struct vnode *a_vp; 149 int a_mode; 150 struct ucred *a_cred; 151 struct proc *a_p; 152 } */ *ap = v; 153 struct vnode *vp; 154 struct fifoinfo *fip; 155 struct proc *p; 156 struct socket *rso, *wso; 157 int error; 158 static const char openstr[] = "fifo"; 159 160 vp = ap->a_vp; 161 p = ap->a_p; 162 163 if ((fip = vp->v_fifoinfo) == NULL) { 164 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 165 vp->v_fifoinfo = fip; 166 if ((error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) != 0) { 167 free(fip, M_VNODE); 168 vp->v_fifoinfo = NULL; 169 return (error); 170 } 171 fip->fi_readsock = rso; 172 if ((error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) != 0) { 173 (void)soclose(rso); 174 free(fip, M_VNODE); 175 vp->v_fifoinfo = NULL; 176 return (error); 177 } 178 fip->fi_writesock = wso; 179 if ((error = unp_connect2(wso, rso)) != 0) { 180 (void)soclose(wso); 181 (void)soclose(rso); 182 free(fip, M_VNODE); 183 vp->v_fifoinfo = NULL; 184 return (error); 185 } 186 fip->fi_readers = fip->fi_writers = 0; 187 wso->so_state |= SS_CANTRCVMORE; 188 rso->so_state |= SS_CANTSENDMORE; 189 } 190 if (ap->a_mode & FREAD) { 191 if (fip->fi_readers++ == 0) { 192 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 193 if (fip->fi_writers > 0) 194 wakeup((caddr_t)&fip->fi_writers); 195 } 196 } 197 if (ap->a_mode & FWRITE) { 198 if (fip->fi_writers++ == 0) { 199 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 200 if (fip->fi_readers > 0) 201 wakeup((caddr_t)&fip->fi_readers); 202 } 203 } 204 if (ap->a_mode & FREAD) { 205 if (ap->a_mode & O_NONBLOCK) { 206 } else { 207 while (fip->fi_writers == 0) { 208 VOP_UNLOCK(vp, 0); 209 error = tsleep((caddr_t)&fip->fi_readers, 210 PCATCH | PSOCK, openstr, 0); 211 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 212 if (error) 213 goto bad; 214 } 215 } 216 } 217 if (ap->a_mode & FWRITE) { 218 if (ap->a_mode & O_NONBLOCK) { 219 if (fip->fi_readers == 0) { 220 error = ENXIO; 221 goto bad; 222 } 223 } else { 224 while (fip->fi_readers == 0) { 225 VOP_UNLOCK(vp, 0); 226 error = tsleep((caddr_t)&fip->fi_writers, 227 PCATCH | PSOCK, openstr, 0); 228 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 229 if (error) 230 goto bad; 231 } 232 } 233 } 234 return (0); 235 bad: 236 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p); 237 return (error); 238 } 239 240 /* 241 * Vnode op for read 242 */ 243 /* ARGSUSED */ 244 int 245 fifo_read(void *v) 246 { 247 struct vop_read_args /* { 248 struct vnode *a_vp; 249 struct uio *a_uio; 250 int a_ioflag; 251 struct ucred *a_cred; 252 } */ *ap = v; 253 struct uio *uio; 254 struct socket *rso; 255 int error, startresid; 256 257 uio = ap->a_uio; 258 rso = ap->a_vp->v_fifoinfo->fi_readsock; 259 #ifdef DIAGNOSTIC 260 if (uio->uio_rw != UIO_READ) 261 panic("fifo_read mode"); 262 #endif 263 if (uio->uio_resid == 0) 264 return (0); 265 if (ap->a_ioflag & IO_NDELAY) 266 rso->so_state |= SS_NBIO; 267 startresid = uio->uio_resid; 268 VOP_UNLOCK(ap->a_vp, 0); 269 error = (*rso->so_receive)(rso, (struct mbuf **)0, uio, 270 (struct mbuf **)0, (struct mbuf **)0, (int *)0); 271 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 272 /* 273 * Clear EOF indication after first such return. 274 */ 275 if (uio->uio_resid == startresid) 276 rso->so_state &= ~SS_CANTRCVMORE; 277 if (ap->a_ioflag & IO_NDELAY) { 278 rso->so_state &= ~SS_NBIO; 279 if (error == EWOULDBLOCK && 280 ap->a_vp->v_fifoinfo->fi_writers == 0) 281 error = 0; 282 } 283 return (error); 284 } 285 286 /* 287 * Vnode op for write 288 */ 289 /* ARGSUSED */ 290 int 291 fifo_write(void *v) 292 { 293 struct vop_write_args /* { 294 struct vnode *a_vp; 295 struct uio *a_uio; 296 int a_ioflag; 297 struct ucred *a_cred; 298 } */ *ap = v; 299 struct socket *wso; 300 int error; 301 302 wso = ap->a_vp->v_fifoinfo->fi_writesock; 303 #ifdef DIAGNOSTIC 304 if (ap->a_uio->uio_rw != UIO_WRITE) 305 panic("fifo_write mode"); 306 #endif 307 if (ap->a_ioflag & IO_NDELAY) 308 wso->so_state |= SS_NBIO; 309 VOP_UNLOCK(ap->a_vp, 0); 310 error = (*wso->so_send)(wso, (struct mbuf *)0, ap->a_uio, 0, 311 (struct mbuf *)0, 0); 312 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY); 313 if (ap->a_ioflag & IO_NDELAY) 314 wso->so_state &= ~SS_NBIO; 315 return (error); 316 } 317 318 /* 319 * Device ioctl operation. 320 */ 321 /* ARGSUSED */ 322 int 323 fifo_ioctl(void *v) 324 { 325 struct vop_ioctl_args /* { 326 struct vnode *a_vp; 327 u_long a_command; 328 caddr_t a_data; 329 int a_fflag; 330 struct ucred *a_cred; 331 struct proc *a_p; 332 } */ *ap = v; 333 struct file filetmp; 334 int error; 335 336 if (ap->a_command == FIONBIO) 337 return (0); 338 if (ap->a_fflag & FREAD) { 339 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 340 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 341 if (error) 342 return (error); 343 } 344 if (ap->a_fflag & FWRITE) { 345 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 346 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 347 if (error) 348 return (error); 349 } 350 return (0); 351 } 352 353 /* ARGSUSED */ 354 int 355 fifo_poll(void *v) 356 { 357 struct vop_poll_args /* { 358 struct vnode *a_vp; 359 int a_events; 360 struct proc *a_p; 361 } */ *ap = v; 362 struct file filetmp; 363 int revents; 364 365 revents = 0; 366 if (ap->a_events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) { 367 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 368 if (filetmp.f_data) 369 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 370 } 371 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) { 372 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 373 if (filetmp.f_data) 374 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 375 } 376 377 return (revents); 378 } 379 380 int 381 fifo_inactive(void *v) 382 { 383 struct vop_inactive_args /* { 384 struct vnode *a_vp; 385 struct proc *a_p; 386 } */ *ap = v; 387 388 VOP_UNLOCK(ap->a_vp, 0); 389 return (0); 390 } 391 392 /* 393 * This is a noop, simply returning what one has been given. 394 */ 395 int 396 fifo_bmap(void *v) 397 { 398 struct vop_bmap_args /* { 399 struct vnode *a_vp; 400 daddr_t a_bn; 401 struct vnode **a_vpp; 402 daddr_t *a_bnp; 403 int *a_runp; 404 } */ *ap = v; 405 406 if (ap->a_vpp != NULL) 407 *ap->a_vpp = ap->a_vp; 408 if (ap->a_bnp != NULL) 409 *ap->a_bnp = ap->a_bn; 410 if (ap->a_runp != NULL) 411 *ap->a_runp = 0; 412 return (0); 413 } 414 415 /* 416 * Device close routine 417 */ 418 /* ARGSUSED */ 419 int 420 fifo_close(void *v) 421 { 422 struct vop_close_args /* { 423 struct vnode *a_vp; 424 int a_fflag; 425 struct ucred *a_cred; 426 struct proc *a_p; 427 } */ *ap = v; 428 struct vnode *vp; 429 struct fifoinfo *fip; 430 int error1, error2; 431 432 vp = ap->a_vp; 433 fip = vp->v_fifoinfo; 434 if (ap->a_fflag & FREAD) { 435 if (--fip->fi_readers == 0) 436 socantsendmore(fip->fi_writesock); 437 } 438 if (ap->a_fflag & FWRITE) { 439 if (--fip->fi_writers == 0) 440 socantrcvmore(fip->fi_readsock); 441 } 442 if (vp->v_usecount > 1) 443 return (0); 444 error1 = soclose(fip->fi_readsock); 445 error2 = soclose(fip->fi_writesock); 446 FREE(fip, M_VNODE); 447 vp->v_fifoinfo = NULL; 448 if (error1) 449 return (error1); 450 return (error2); 451 } 452 453 /* 454 * Print out the contents of a fifo vnode. 455 */ 456 int 457 fifo_print(void *v) 458 { 459 struct vop_print_args /* { 460 struct vnode *a_vp; 461 } */ *ap = v; 462 463 printf("tag VT_NON"); 464 fifo_printinfo(ap->a_vp); 465 printf("\n"); 466 return 0; 467 } 468 469 /* 470 * Print out internal contents of a fifo vnode. 471 */ 472 void 473 fifo_printinfo(struct vnode *vp) 474 { 475 struct fifoinfo *fip; 476 477 fip = vp->v_fifoinfo; 478 printf(", fifo with %ld readers and %ld writers", 479 fip->fi_readers, fip->fi_writers); 480 } 481 482 /* 483 * Return POSIX pathconf information applicable to fifo's. 484 */ 485 int 486 fifo_pathconf(void *v) 487 { 488 struct vop_pathconf_args /* { 489 struct vnode *a_vp; 490 int a_name; 491 register_t *a_retval; 492 } */ *ap = v; 493 494 switch (ap->a_name) { 495 case _PC_LINK_MAX: 496 *ap->a_retval = LINK_MAX; 497 return (0); 498 case _PC_PIPE_BUF: 499 *ap->a_retval = PIPE_BUF; 500 return (0); 501 case _PC_CHOWN_RESTRICTED: 502 *ap->a_retval = 1; 503 return (0); 504 case _PC_SYNC_IO: 505 *ap->a_retval = 1; 506 return (0); 507 default: 508 return (EINVAL); 509 } 510 /* NOTREACHED */ 511 } 512