1 /* $NetBSD: fifo_vnops.c,v 1.30 2001/02/27 19:52:21 lukem 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 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 114 }; 115 const struct vnodeopv_desc fifo_vnodeop_opv_desc = 116 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 117 118 /* 119 * Trivial lookup routine that always fails. 120 */ 121 /* ARGSUSED */ 122 int 123 fifo_lookup(void *v) 124 { 125 struct vop_lookup_args /* { 126 struct vnode *a_dvp; 127 struct vnode **a_vpp; 128 struct componentname *a_cnp; 129 } */ *ap = v; 130 131 *ap->a_vpp = NULL; 132 return (ENOTDIR); 133 } 134 135 /* 136 * Open called to set up a new instance of a fifo or 137 * to find an active instance of a fifo. 138 */ 139 /* ARGSUSED */ 140 int 141 fifo_open(void *v) 142 { 143 struct vop_open_args /* { 144 struct vnode *a_vp; 145 int a_mode; 146 struct ucred *a_cred; 147 struct proc *a_p; 148 } */ *ap = v; 149 struct vnode *vp; 150 struct fifoinfo *fip; 151 struct proc *p; 152 struct socket *rso, *wso; 153 int error; 154 static const char openstr[] = "fifo"; 155 156 vp = ap->a_vp; 157 p = ap->a_p; 158 159 if ((fip = vp->v_fifoinfo) == NULL) { 160 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 161 vp->v_fifoinfo = fip; 162 if ((error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) != 0) { 163 free(fip, M_VNODE); 164 vp->v_fifoinfo = NULL; 165 return (error); 166 } 167 fip->fi_readsock = rso; 168 if ((error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) != 0) { 169 (void)soclose(rso); 170 free(fip, M_VNODE); 171 vp->v_fifoinfo = NULL; 172 return (error); 173 } 174 fip->fi_writesock = wso; 175 if ((error = unp_connect2(wso, rso)) != 0) { 176 (void)soclose(wso); 177 (void)soclose(rso); 178 free(fip, M_VNODE); 179 vp->v_fifoinfo = NULL; 180 return (error); 181 } 182 fip->fi_readers = fip->fi_writers = 0; 183 wso->so_state |= SS_CANTRCVMORE; 184 rso->so_state |= SS_CANTSENDMORE; 185 } 186 if (ap->a_mode & FREAD) { 187 if (fip->fi_readers++ == 0) { 188 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 189 if (fip->fi_writers > 0) 190 wakeup((caddr_t)&fip->fi_writers); 191 } 192 } 193 if (ap->a_mode & FWRITE) { 194 if (fip->fi_writers++ == 0) { 195 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 196 if (fip->fi_readers > 0) 197 wakeup((caddr_t)&fip->fi_readers); 198 } 199 } 200 if (ap->a_mode & FREAD) { 201 if (ap->a_mode & O_NONBLOCK) { 202 } else { 203 while (fip->fi_writers == 0) { 204 VOP_UNLOCK(vp, 0); 205 error = tsleep((caddr_t)&fip->fi_readers, 206 PCATCH | PSOCK, openstr, 0); 207 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 208 if (error) 209 goto bad; 210 } 211 } 212 } 213 if (ap->a_mode & FWRITE) { 214 if (ap->a_mode & O_NONBLOCK) { 215 if (fip->fi_readers == 0) { 216 error = ENXIO; 217 goto bad; 218 } 219 } else { 220 while (fip->fi_readers == 0) { 221 VOP_UNLOCK(vp, 0); 222 error = tsleep((caddr_t)&fip->fi_writers, 223 PCATCH | PSOCK, openstr, 0); 224 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 225 if (error) 226 goto bad; 227 } 228 } 229 } 230 return (0); 231 bad: 232 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p); 233 return (error); 234 } 235 236 /* 237 * Vnode op for read 238 */ 239 /* ARGSUSED */ 240 int 241 fifo_read(void *v) 242 { 243 struct vop_read_args /* { 244 struct vnode *a_vp; 245 struct uio *a_uio; 246 int a_ioflag; 247 struct ucred *a_cred; 248 } */ *ap = v; 249 struct uio *uio; 250 struct socket *rso; 251 int error, 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 struct ucred *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); 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 caddr_t a_data; 325 int a_fflag; 326 struct ucred *a_cred; 327 struct proc *a_p; 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 = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 336 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 337 if (error) 338 return (error); 339 } 340 if (ap->a_fflag & FWRITE) { 341 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 342 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p); 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 proc *a_p; 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 = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 364 if (filetmp.f_data) 365 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 366 } 367 if (ap->a_events & (POLLOUT | POLLWRNORM | POLLWRBAND)) { 368 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 369 if (filetmp.f_data) 370 revents |= soo_poll(&filetmp, ap->a_events, ap->a_p); 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 proc *a_p; 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 struct ucred *a_cred; 422 struct proc *a_p; 423 } */ *ap = v; 424 struct vnode *vp; 425 struct fifoinfo *fip; 426 int error1, error2; 427 428 vp = ap->a_vp; 429 fip = vp->v_fifoinfo; 430 if (ap->a_fflag & FREAD) { 431 if (--fip->fi_readers == 0) 432 socantsendmore(fip->fi_writesock); 433 } 434 if (ap->a_fflag & FWRITE) { 435 if (--fip->fi_writers == 0) 436 socantrcvmore(fip->fi_readsock); 437 } 438 if (vp->v_usecount > 1) 439 return (0); 440 error1 = soclose(fip->fi_readsock); 441 error2 = soclose(fip->fi_writesock); 442 FREE(fip, M_VNODE); 443 vp->v_fifoinfo = NULL; 444 if (error1) 445 return (error1); 446 return (error2); 447 } 448 449 /* 450 * Print out the contents of a fifo vnode. 451 */ 452 int 453 fifo_print(void *v) 454 { 455 struct vop_print_args /* { 456 struct vnode *a_vp; 457 } */ *ap = v; 458 459 printf("tag VT_NON"); 460 fifo_printinfo(ap->a_vp); 461 printf("\n"); 462 return 0; 463 } 464 465 /* 466 * Print out internal contents of a fifo vnode. 467 */ 468 void 469 fifo_printinfo(struct vnode *vp) 470 { 471 struct fifoinfo *fip; 472 473 fip = vp->v_fifoinfo; 474 printf(", fifo with %ld readers and %ld writers", 475 fip->fi_readers, fip->fi_writers); 476 } 477 478 /* 479 * Return POSIX pathconf information applicable to fifo's. 480 */ 481 int 482 fifo_pathconf(void *v) 483 { 484 struct vop_pathconf_args /* { 485 struct vnode *a_vp; 486 int a_name; 487 register_t *a_retval; 488 } */ *ap = v; 489 490 switch (ap->a_name) { 491 case _PC_LINK_MAX: 492 *ap->a_retval = LINK_MAX; 493 return (0); 494 case _PC_PIPE_BUF: 495 *ap->a_retval = PIPE_BUF; 496 return (0); 497 case _PC_CHOWN_RESTRICTED: 498 *ap->a_retval = 1; 499 return (0); 500 case _PC_SYNC_IO: 501 *ap->a_retval = 1; 502 return (0); 503 default: 504 return (EINVAL); 505 } 506 /* NOTREACHED */ 507 } 508