fifo_vnops.c revision 1.13
1 /* $NetBSD: fifo_vnops.c,v 1.13 1994/12/13 20:14:39 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1993 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 8.4 (Berkeley) 8/10/94 36 */ 37 38 #include <sys/param.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/socketvar.h> 45 #include <sys/stat.h> 46 #include <sys/systm.h> 47 #include <sys/ioctl.h> 48 #include <sys/file.h> 49 #include <sys/errno.h> 50 #include <sys/malloc.h> 51 #include <miscfs/fifofs/fifo.h> 52 53 /* 54 * This structure is associated with the FIFO vnode and stores 55 * the state associated with the FIFO. 56 */ 57 struct fifoinfo { 58 struct socket *fi_readsock; 59 struct socket *fi_writesock; 60 long fi_readers; 61 long fi_writers; 62 }; 63 64 int (**fifo_vnodeop_p)(); 65 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 66 { &vop_default_desc, vn_default_error }, 67 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 68 { &vop_create_desc, fifo_create }, /* create */ 69 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 70 { &vop_open_desc, fifo_open }, /* open */ 71 { &vop_close_desc, fifo_close }, /* close */ 72 { &vop_access_desc, fifo_access }, /* access */ 73 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 74 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 75 { &vop_read_desc, fifo_read }, /* read */ 76 { &vop_write_desc, fifo_write }, /* write */ 77 { &vop_lease_desc, fifo_lease_check }, /* lease */ 78 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 79 { &vop_select_desc, fifo_select }, /* select */ 80 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 81 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 82 { &vop_seek_desc, fifo_seek }, /* seek */ 83 { &vop_remove_desc, fifo_remove }, /* remove */ 84 { &vop_link_desc, fifo_link }, /* link */ 85 { &vop_rename_desc, fifo_rename }, /* rename */ 86 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 87 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 88 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 89 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 90 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 91 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 92 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 93 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 94 { &vop_lock_desc, fifo_lock }, /* lock */ 95 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 96 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 97 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 98 { &vop_print_desc, fifo_print }, /* print */ 99 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 100 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 101 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 102 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 103 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 104 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 105 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 106 { &vop_update_desc, fifo_update }, /* update */ 107 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 108 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 109 }; 110 struct vnodeopv_desc fifo_vnodeop_opv_desc = 111 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 112 113 /* 114 * Trivial lookup routine that always fails. 115 */ 116 /* ARGSUSED */ 117 fifo_lookup(ap) 118 struct vop_lookup_args /* { 119 struct vnode * a_dvp; 120 struct vnode ** a_vpp; 121 struct componentname * a_cnp; 122 } */ *ap; 123 { 124 125 *ap->a_vpp = NULL; 126 return (ENOTDIR); 127 } 128 129 /* 130 * Open called to set up a new instance of a fifo or 131 * to find an active instance of a fifo. 132 */ 133 /* ARGSUSED */ 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 struct file *a_fp; 141 } */ *ap; 142 { 143 register struct vnode *vp = ap->a_vp; 144 register struct fifoinfo *fip; 145 struct socket *rso, *wso; 146 int error; 147 static char openstr[] = "fifo"; 148 149 if ((ap->a_mode & (FREAD|FWRITE)) == (FREAD|FWRITE)) 150 return (EINVAL); 151 if ((fip = vp->v_fifoinfo) == NULL) { 152 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 153 vp->v_fifoinfo = fip; 154 if (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) { 155 free(fip, M_VNODE); 156 vp->v_fifoinfo = NULL; 157 return (error); 158 } 159 fip->fi_readsock = rso; 160 if (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) { 161 (void)soclose(rso); 162 free(fip, M_VNODE); 163 vp->v_fifoinfo = NULL; 164 return (error); 165 } 166 fip->fi_writesock = wso; 167 if (error = unp_connect2(wso, rso)) { 168 (void)soclose(wso); 169 (void)soclose(rso); 170 free(fip, M_VNODE); 171 vp->v_fifoinfo = NULL; 172 return (error); 173 } 174 fip->fi_readers = fip->fi_writers = 0; 175 wso->so_state |= SS_CANTRCVMORE; 176 rso->so_state |= SS_CANTSENDMORE; 177 } 178 error = 0; 179 if (ap->a_mode & FREAD) { 180 fip->fi_readers++; 181 if (fip->fi_readers == 1) { 182 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 183 if (fip->fi_writers > 0) 184 wakeup((caddr_t)&fip->fi_writers); 185 } 186 if (ap->a_mode & O_NONBLOCK) 187 return (0); 188 while (fip->fi_writers == 0) { 189 VOP_UNLOCK(vp); 190 error = tsleep((caddr_t)&fip->fi_readers, 191 PCATCH | PSOCK, openstr, 0); 192 VOP_LOCK(vp); 193 if (error) 194 break; 195 } 196 } else { 197 fip->fi_writers++; 198 if (fip->fi_readers == 0 && (ap->a_mode & O_NONBLOCK)) { 199 error = ENXIO; 200 } else { 201 if (fip->fi_writers == 1) { 202 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 203 if (fip->fi_readers > 0) 204 wakeup((caddr_t)&fip->fi_readers); 205 } 206 while (fip->fi_readers == 0) { 207 VOP_UNLOCK(vp); 208 error = tsleep((caddr_t)&fip->fi_writers, 209 PCATCH | PSOCK, openstr, 0); 210 VOP_LOCK(vp); 211 if (error) 212 break; 213 } 214 } 215 } 216 if (error) 217 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, ap->a_p); 218 return (error); 219 } 220 221 /* 222 * Vnode op for read 223 */ 224 /* ARGSUSED */ 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, (struct mbuf **)0, 248 (struct mbuf **)0, (int *)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 fifo_write(ap) 265 struct vop_write_args /* { 266 struct vnode *a_vp; 267 struct uio *a_uio; 268 int a_ioflag; 269 struct ucred *a_cred; 270 } */ *ap; 271 { 272 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 273 int error; 274 275 #ifdef DIAGNOSTIC 276 if (ap->a_uio->uio_rw != UIO_WRITE) 277 panic("fifo_write mode"); 278 #endif 279 if (ap->a_ioflag & IO_NDELAY) 280 wso->so_state |= SS_NBIO; 281 VOP_UNLOCK(ap->a_vp); 282 error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0); 283 VOP_LOCK(ap->a_vp); 284 if (ap->a_ioflag & IO_NDELAY) 285 wso->so_state &= ~SS_NBIO; 286 return (error); 287 } 288 289 /* 290 * Device ioctl operation. 291 */ 292 /* ARGSUSED */ 293 fifo_ioctl(ap) 294 struct vop_ioctl_args /* { 295 struct vnode *a_vp; 296 u_long a_command; 297 caddr_t a_data; 298 int a_fflag; 299 struct ucred *a_cred; 300 struct proc *a_p; 301 } */ *ap; 302 { 303 struct file filetmp; 304 305 if (ap->a_command == FIONBIO) 306 return (0); 307 if (ap->a_fflag & FREAD) 308 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 309 else 310 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 311 return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p)); 312 } 313 314 /* ARGSUSED */ 315 fifo_select(ap) 316 struct vop_select_args /* { 317 struct vnode *a_vp; 318 int a_which; 319 int a_fflags; 320 struct ucred *a_cred; 321 struct proc *a_p; 322 } */ *ap; 323 { 324 struct file filetmp; 325 326 if (ap->a_fflags & FREAD) 327 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 328 else 329 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 330 return (soo_select(&filetmp, ap->a_which, ap->a_p)); 331 } 332 333 /* 334 * This is a noop, simply returning what one has been given. 335 */ 336 fifo_bmap(ap) 337 struct vop_bmap_args /* { 338 struct vnode *a_vp; 339 daddr_t a_bn; 340 struct vnode **a_vpp; 341 daddr_t *a_bnp; 342 } */ *ap; 343 { 344 345 if (ap->a_vpp != NULL) 346 *ap->a_vpp = ap->a_vp; 347 if (ap->a_bnp != NULL) 348 *ap->a_bnp = ap->a_bn; 349 return (0); 350 } 351 352 /* 353 * At the moment we do not do any locking. 354 */ 355 /* ARGSUSED */ 356 fifo_lock(ap) 357 struct vop_lock_args /* { 358 struct vnode *a_vp; 359 } */ *ap; 360 { 361 362 return (0); 363 } 364 365 /* ARGSUSED */ 366 fifo_unlock(ap) 367 struct vop_unlock_args /* { 368 struct vnode *a_vp; 369 } */ *ap; 370 { 371 372 return (0); 373 } 374 375 /* 376 * Device close routine 377 */ 378 /* ARGSUSED */ 379 fifo_close(ap) 380 struct vop_close_args /* { 381 struct vnode *a_vp; 382 int a_fflag; 383 struct ucred *a_cred; 384 struct proc *a_p; 385 } */ *ap; 386 { 387 register struct vnode *vp = ap->a_vp; 388 register struct fifoinfo *fip = vp->v_fifoinfo; 389 int error1, error2; 390 391 if (ap->a_fflag & FWRITE) { 392 fip->fi_writers--; 393 if (fip->fi_writers == 0) 394 socantrcvmore(fip->fi_readsock); 395 } else { 396 fip->fi_readers--; 397 if (fip->fi_readers == 0) 398 socantsendmore(fip->fi_writesock); 399 } 400 if (vp->v_usecount > 1) 401 return (0); 402 error1 = soclose(fip->fi_readsock); 403 error2 = soclose(fip->fi_writesock); 404 FREE(fip, M_VNODE); 405 vp->v_fifoinfo = NULL; 406 if (error1) 407 return (error1); 408 return (error2); 409 } 410 411 /* 412 * Print out the contents of a fifo vnode. 413 */ 414 fifo_print(ap) 415 struct vop_print_args /* { 416 struct vnode *a_vp; 417 } */ *ap; 418 { 419 420 printf("tag VT_NON"); 421 fifo_printinfo(ap->a_vp); 422 printf("\n"); 423 } 424 425 /* 426 * Print out internal contents of a fifo vnode. 427 */ 428 fifo_printinfo(vp) 429 struct vnode *vp; 430 { 431 register struct fifoinfo *fip = vp->v_fifoinfo; 432 433 printf(", fifo with %d readers and %d writers", 434 fip->fi_readers, fip->fi_writers); 435 } 436 437 /* 438 * Return POSIX pathconf information applicable to fifo's. 439 */ 440 fifo_pathconf(ap) 441 struct vop_pathconf_args /* { 442 struct vnode *a_vp; 443 int a_name; 444 register_t *a_retval; 445 } */ *ap; 446 { 447 448 switch (ap->a_name) { 449 case _PC_LINK_MAX: 450 *ap->a_retval = LINK_MAX; 451 return (0); 452 case _PC_PIPE_BUF: 453 *ap->a_retval = PIPE_BUF; 454 return (0); 455 case _PC_CHOWN_RESTRICTED: 456 *ap->a_retval = 1; 457 return (0); 458 default: 459 return (EINVAL); 460 } 461 /* NOTREACHED */ 462 } 463 464 /* 465 * Fifo failed operation 466 */ 467 fifo_ebadf() 468 { 469 470 return (EBADF); 471 } 472 473 /* 474 * Fifo advisory byte-level locks. 475 */ 476 /* ARGSUSED */ 477 fifo_advlock(ap) 478 struct vop_advlock_args /* { 479 struct vnode *a_vp; 480 caddr_t a_id; 481 int a_op; 482 struct flock *a_fl; 483 int a_flags; 484 } */ *ap; 485 { 486 487 return (EOPNOTSUPP); 488 } 489 490 /* 491 * Fifo bad operation 492 */ 493 fifo_badop() 494 { 495 496 panic("fifo_badop called"); 497 /* NOTREACHED */ 498 } 499
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