1 /* 2 * Copyright (c) 1990, 1993 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 8.2 (Berkeley) 1/4/94 34 * $Id$ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/proc.h> 39 #include <sys/time.h> 40 #include <sys/namei.h> 41 #include <sys/vnode.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 #include <sys/stat.h> 45 #include <sys/systm.h> 46 #include <sys/ioctl.h> 47 #include <sys/file.h> 48 #include <sys/errno.h> 49 #include <sys/malloc.h> 50 #include <miscfs/fifofs/fifo.h> 51 52 /* 53 * This structure is associated with the FIFO vnode and stores 54 * the state associated with the FIFO. 55 */ 56 struct fifoinfo { 57 struct socket *fi_readsock; 58 struct socket *fi_writesock; 59 long fi_readers; 60 long fi_writers; 61 }; 62 63 int (**fifo_vnodeop_p)(); 64 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 65 { &vop_default_desc, vn_default_error }, 66 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 67 { &vop_create_desc, fifo_create }, /* create */ 68 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 69 { &vop_open_desc, fifo_open }, /* open */ 70 { &vop_close_desc, fifo_close }, /* close */ 71 { &vop_access_desc, fifo_access }, /* access */ 72 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 73 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 74 { &vop_read_desc, fifo_read }, /* read */ 75 { &vop_write_desc, fifo_write }, /* write */ 76 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 77 { &vop_select_desc, fifo_select }, /* select */ 78 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 79 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 80 { &vop_seek_desc, fifo_seek }, /* seek */ 81 { &vop_remove_desc, fifo_remove }, /* remove */ 82 { &vop_link_desc, fifo_link }, /* link */ 83 { &vop_rename_desc, fifo_rename }, /* rename */ 84 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 85 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 86 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 87 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 88 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 89 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 90 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 91 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 92 { &vop_lock_desc, fifo_lock }, /* lock */ 93 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 94 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 95 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 96 { &vop_print_desc, fifo_print }, /* print */ 97 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 98 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 99 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 100 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 101 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 102 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 103 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 104 { &vop_update_desc, fifo_update }, /* update */ 105 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 106 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 107 }; 108 struct vnodeopv_desc fifo_vnodeop_opv_desc = 109 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 110 111 /* 112 * Trivial lookup routine that always fails. 113 */ 114 /* ARGSUSED */ 115 int 116 fifo_lookup(ap) 117 struct vop_lookup_args /* { 118 struct vnode * a_dvp; 119 struct vnode ** a_vpp; 120 struct componentname * a_cnp; 121 } */ *ap; 122 { 123 124 *ap->a_vpp = NULL; 125 return (ENOTDIR); 126 } 127 128 /* 129 * Open called to set up a new instance of a fifo or 130 * to find an active instance of a fifo. 131 */ 132 /* ARGSUSED */ 133 int 134 fifo_open(ap) 135 struct vop_open_args /* { 136 struct vnode *a_vp; 137 int a_mode; 138 struct ucred *a_cred; 139 struct proc *a_p; 140 } */ *ap; 141 { 142 register struct vnode *vp = ap->a_vp; 143 register struct fifoinfo *fip; 144 struct socket *rso, *wso; 145 int error; 146 static char openstr[] = "fifo"; 147 148 if ((ap->a_mode & (FREAD|FWRITE)) == (FREAD|FWRITE)) 149 return (EINVAL); 150 if ((fip = vp->v_fifoinfo) == NULL) { 151 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 152 vp->v_fifoinfo = fip; 153 if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) { 154 free(fip, M_VNODE); 155 vp->v_fifoinfo = NULL; 156 return (error); 157 } 158 fip->fi_readsock = rso; 159 if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) { 160 (void)soclose(rso); 161 free(fip, M_VNODE); 162 vp->v_fifoinfo = NULL; 163 return (error); 164 } 165 fip->fi_writesock = wso; 166 if (error = unp_connect2(wso, rso)) { 167 (void)soclose(wso); 168 (void)soclose(rso); 169 free(fip, M_VNODE); 170 vp->v_fifoinfo = NULL; 171 return (error); 172 } 173 fip->fi_readers = fip->fi_writers = 0; 174 wso->so_state |= SS_CANTRCVMORE; 175 rso->so_state |= SS_CANTSENDMORE; 176 } 177 error = 0; 178 if (ap->a_mode & FREAD) { 179 fip->fi_readers++; 180 if (fip->fi_readers == 1) { 181 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 182 if (fip->fi_writers > 0) 183 wakeup((caddr_t)&fip->fi_writers); 184 } 185 if (ap->a_mode & O_NONBLOCK) 186 return (0); 187 while (fip->fi_writers == 0) { 188 VOP_UNLOCK(vp); 189 error = tsleep((caddr_t)&fip->fi_readers, 190 PCATCH | PSOCK, openstr, 0); 191 VOP_LOCK(vp); 192 if (error) 193 break; 194 } 195 } else { 196 fip->fi_writers++; 197 if (fip->fi_readers == 0 && (ap->a_mode & O_NONBLOCK)) { 198 error = ENXIO; 199 } else { 200 if (fip->fi_writers == 1) { 201 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 202 if (fip->fi_readers > 0) 203 wakeup((caddr_t)&fip->fi_readers); 204 } 205 while (fip->fi_readers == 0) { 206 VOP_UNLOCK(vp); 207 error = tsleep((caddr_t)&fip->fi_writers, 208 PCATCH | PSOCK, openstr, 0); 209 VOP_LOCK(vp); 210 if (error) 211 break; 212 } 213 } 214 } 215 if (error) 216 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, ap->a_p); 217 return (error); 218 } 219 220 /* 221 * Vnode op for read 222 */ 223 /* ARGSUSED */ 224 int 225 fifo_read(ap) 226 struct vop_read_args /* { 227 struct vnode *a_vp; 228 struct uio *a_uio; 229 int a_ioflag; 230 struct ucred *a_cred; 231 } */ *ap; 232 { 233 register struct uio *uio = ap->a_uio; 234 register struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 235 int error, startresid; 236 237 #ifdef DIAGNOSTIC 238 if (uio->uio_rw != UIO_READ) 239 panic("fifo_read mode"); 240 #endif 241 if (uio->uio_resid == 0) 242 return (0); 243 if (ap->a_ioflag & IO_NDELAY) 244 rso->so_state |= SS_NBIO; 245 startresid = uio->uio_resid; 246 VOP_UNLOCK(ap->a_vp); 247 error = soreceive(rso, (struct mbuf **)0, uio, (int *)0, 248 (struct mbuf **)0, (struct mbuf **)0); 249 VOP_LOCK(ap->a_vp); 250 /* 251 * Clear EOF indication after first such return. 252 */ 253 if (uio->uio_resid == startresid) 254 rso->so_state &= ~SS_CANTRCVMORE; 255 if (ap->a_ioflag & IO_NDELAY) 256 rso->so_state &= ~SS_NBIO; 257 return (error); 258 } 259 260 /* 261 * Vnode op for write 262 */ 263 /* ARGSUSED */ 264 int 265 fifo_write(ap) 266 struct vop_write_args /* { 267 struct vnode *a_vp; 268 struct uio *a_uio; 269 int a_ioflag; 270 struct ucred *a_cred; 271 } */ *ap; 272 { 273 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 274 int error; 275 276 #ifdef DIAGNOSTIC 277 if (ap->a_uio->uio_rw != UIO_WRITE) 278 panic("fifo_write mode"); 279 #endif 280 if (ap->a_ioflag & IO_NDELAY) 281 wso->so_state |= SS_NBIO; 282 VOP_UNLOCK(ap->a_vp); 283 error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0); 284 VOP_LOCK(ap->a_vp); 285 if (ap->a_ioflag & IO_NDELAY) 286 wso->so_state &= ~SS_NBIO; 287 return (error); 288 } 289 290 /* 291 * Device ioctl operation. 292 */ 293 /* ARGSUSED */ 294 int 295 fifo_ioctl(ap) 296 struct vop_ioctl_args /* { 297 struct vnode *a_vp; 298 int a_command; 299 caddr_t a_data; 300 int a_fflag; 301 struct ucred *a_cred; 302 struct proc *a_p; 303 } */ *ap; 304 { 305 struct file filetmp; 306 307 if (ap->a_command == FIONBIO) 308 return (0); 309 if (ap->a_fflag & FREAD) 310 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 311 else 312 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 313 return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p)); 314 } 315 316 /* ARGSUSED */ 317 int 318 fifo_select(ap) 319 struct vop_select_args /* { 320 struct vnode *a_vp; 321 int a_which; 322 int a_fflags; 323 struct ucred *a_cred; 324 struct proc *a_p; 325 } */ *ap; 326 { 327 struct file filetmp; 328 329 if (ap->a_fflags & FREAD) 330 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 331 else 332 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 333 return (soo_select(&filetmp, ap->a_which, ap->a_p)); 334 } 335 336 /* 337 * This is a noop, simply returning what one has been given. 338 */ 339 int 340 fifo_bmap(ap) 341 struct vop_bmap_args /* { 342 struct vnode *a_vp; 343 daddr_t a_bn; 344 struct vnode **a_vpp; 345 daddr_t *a_bnp; 346 } */ *ap; 347 { 348 349 if (ap->a_vpp != NULL) 350 *ap->a_vpp = ap->a_vp; 351 if (ap->a_bnp != NULL) 352 *ap->a_bnp = ap->a_bn; 353 return (0); 354 } 355 356 /* 357 * At the moment we do not do any locking. 358 */ 359 /* ARGSUSED */ 360 int 361 fifo_lock(ap) 362 struct vop_lock_args /* { 363 struct vnode *a_vp; 364 } */ *ap; 365 { 366 367 return (0); 368 } 369 370 /* ARGSUSED */ 371 int 372 fifo_unlock(ap) 373 struct vop_unlock_args /* { 374 struct vnode *a_vp; 375 } */ *ap; 376 { 377 378 return (0); 379 } 380 381 /* 382 * Device close routine 383 */ 384 /* ARGSUSED */ 385 int 386 fifo_close(ap) 387 struct vop_close_args /* { 388 struct vnode *a_vp; 389 int a_fflag; 390 struct ucred *a_cred; 391 struct proc *a_p; 392 } */ *ap; 393 { 394 register struct vnode *vp = ap->a_vp; 395 register struct fifoinfo *fip = vp->v_fifoinfo; 396 int error1, error2; 397 398 if (ap->a_fflag & FWRITE) { 399 fip->fi_writers--; 400 if (fip->fi_writers == 0) 401 socantrcvmore(fip->fi_readsock); 402 } else { 403 fip->fi_readers--; 404 if (fip->fi_readers == 0) 405 socantsendmore(fip->fi_writesock); 406 } 407 if (vp->v_usecount > 1) 408 return (0); 409 error1 = soclose(fip->fi_readsock); 410 error2 = soclose(fip->fi_writesock); 411 FREE(fip, M_VNODE); 412 vp->v_fifoinfo = NULL; 413 if (error1) 414 return (error1); 415 return (error2); 416 } 417 418 /* 419 * Print out the contents of a fifo vnode. 420 */ 421 int 422 fifo_print(ap) 423 struct vop_print_args /* { 424 struct vnode *a_vp; 425 } */ *ap; 426 { 427 428 printf("tag VT_NON"); 429 fifo_printinfo(ap->a_vp); 430 printf("\n"); 431 return (0); 432 } 433 434 /* 435 * Print out internal contents of a fifo vnode. 436 */ 437 int 438 fifo_printinfo(vp) 439 struct vnode *vp; 440 { 441 register struct fifoinfo *fip = vp->v_fifoinfo; 442 443 printf(", fifo with %d readers and %d writers", 444 fip->fi_readers, fip->fi_writers); 445 return (0); 446 } 447 448 /* 449 * Return POSIX pathconf information applicable to fifo's. 450 */ 451 int 452 fifo_pathconf(ap) 453 struct vop_pathconf_args /* { 454 struct vnode *a_vp; 455 int a_name; 456 int *a_retval; 457 } */ *ap; 458 { 459 460 switch (ap->a_name) { 461 case _PC_LINK_MAX: 462 *ap->a_retval = LINK_MAX; 463 return (0); 464 case _PC_PIPE_BUF: 465 *ap->a_retval = PIPE_BUF; 466 return (0); 467 case _PC_CHOWN_RESTRICTED: 468 *ap->a_retval = 1; 469 return (0); 470 default: 471 return (EINVAL); 472 } 473 /* NOTREACHED */ 474 } 475 476 /* 477 * Fifo failed operation 478 */ 479 int 480 fifo_ebadf() 481 { 482 483 return (EBADF); 484 } 485 486 /* 487 * Fifo advisory byte-level locks. 488 */ 489 /* ARGSUSED */ 490 int 491 fifo_advlock(ap) 492 struct vop_advlock_args /* { 493 struct vnode *a_vp; 494 caddr_t a_id; 495 int a_op; 496 struct flock *a_fl; 497 int a_flags; 498 } */ *ap; 499 { 500 501 return (EOPNOTSUPP); 502 } 503 504 /* 505 * Fifo bad operation 506 */ 507 int 508 fifo_badop() 509 { 510 511 panic("fifo_badop called"); 512 /* NOTREACHED */ 513 } 514