fifo_vnops.c revision 1.12
1 /* $NetBSD: fifo_vnops.c,v 1.12 1994/11/14 06:05:45 christos 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 8.2 (Berkeley) 1/4/94 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_ioctl_desc, fifo_ioctl }, /* ioctl */ 78 { &vop_select_desc, fifo_select }, /* select */ 79 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 80 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 81 { &vop_seek_desc, fifo_seek }, /* seek */ 82 { &vop_remove_desc, fifo_remove }, /* remove */ 83 { &vop_link_desc, fifo_link }, /* link */ 84 { &vop_rename_desc, fifo_rename }, /* rename */ 85 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 86 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 87 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 88 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 89 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 90 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 91 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 92 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 93 { &vop_lock_desc, fifo_lock }, /* lock */ 94 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 95 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 96 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 97 { &vop_print_desc, fifo_print }, /* print */ 98 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 99 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 100 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 101 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 102 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 103 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 104 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 105 { &vop_update_desc, fifo_update }, /* update */ 106 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 107 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 108 }; 109 struct vnodeopv_desc fifo_vnodeop_opv_desc = 110 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 111 112 /* 113 * Trivial lookup routine that always fails. 114 */ 115 /* ARGSUSED */ 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 fifo_open(ap) 134 struct vop_open_args /* { 135 struct vnode *a_vp; 136 int a_mode; 137 struct ucred *a_cred; 138 struct proc *a_p; 139 struct file *a_fp; 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_LOCAL, &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_LOCAL, &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 fifo_read(ap) 225 struct vop_read_args /* { 226 struct vnode *a_vp; 227 struct uio *a_uio; 228 int a_ioflag; 229 struct ucred *a_cred; 230 } */ *ap; 231 { 232 register struct uio *uio = ap->a_uio; 233 register struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 234 int error, startresid; 235 236 #ifdef DIAGNOSTIC 237 if (uio->uio_rw != UIO_READ) 238 panic("fifo_read mode"); 239 #endif 240 if (uio->uio_resid == 0) 241 return (0); 242 if (ap->a_ioflag & IO_NDELAY) 243 rso->so_state |= SS_NBIO; 244 startresid = uio->uio_resid; 245 VOP_UNLOCK(ap->a_vp); 246 error = soreceive(rso, (struct mbuf **)0, uio, 247 (struct mbuf **)0, (struct mbuf **)0, (int *)0); 248 VOP_LOCK(ap->a_vp); 249 /* 250 * Clear EOF indication after first such return. 251 */ 252 if (uio->uio_resid == startresid) 253 rso->so_state &= ~SS_CANTRCVMORE; 254 if (ap->a_ioflag & IO_NDELAY) 255 rso->so_state &= ~SS_NBIO; 256 return (error); 257 } 258 259 /* 260 * Vnode op for write 261 */ 262 /* ARGSUSED */ 263 fifo_write(ap) 264 struct vop_write_args /* { 265 struct vnode *a_vp; 266 struct uio *a_uio; 267 int a_ioflag; 268 struct ucred *a_cred; 269 } */ *ap; 270 { 271 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 272 int error; 273 274 #ifdef DIAGNOSTIC 275 if (ap->a_uio->uio_rw != UIO_WRITE) 276 panic("fifo_write mode"); 277 #endif 278 if (ap->a_ioflag & IO_NDELAY) 279 wso->so_state |= SS_NBIO; 280 VOP_UNLOCK(ap->a_vp); 281 error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0); 282 VOP_LOCK(ap->a_vp); 283 if (ap->a_ioflag & IO_NDELAY) 284 wso->so_state &= ~SS_NBIO; 285 return (error); 286 } 287 288 /* 289 * Device ioctl operation. 290 */ 291 /* ARGSUSED */ 292 fifo_ioctl(ap) 293 struct vop_ioctl_args /* { 294 struct vnode *a_vp; 295 u_long a_command; 296 caddr_t a_data; 297 int a_fflag; 298 struct ucred *a_cred; 299 struct proc *a_p; 300 } */ *ap; 301 { 302 struct file filetmp; 303 304 if (ap->a_command == FIONBIO) 305 return (0); 306 if (ap->a_fflag & FREAD) 307 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 308 else 309 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 310 return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p)); 311 } 312 313 /* ARGSUSED */ 314 fifo_select(ap) 315 struct vop_select_args /* { 316 struct vnode *a_vp; 317 int a_which; 318 int a_fflags; 319 struct ucred *a_cred; 320 struct proc *a_p; 321 } */ *ap; 322 { 323 struct file filetmp; 324 325 if (ap->a_fflags & FREAD) 326 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 327 else 328 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 329 return (soo_select(&filetmp, ap->a_which, ap->a_p)); 330 } 331 332 /* 333 * This is a noop, simply returning what one has been given. 334 */ 335 fifo_bmap(ap) 336 struct vop_bmap_args /* { 337 struct vnode *a_vp; 338 daddr_t a_bn; 339 struct vnode **a_vpp; 340 daddr_t *a_bnp; 341 } */ *ap; 342 { 343 344 if (ap->a_vpp != NULL) 345 *ap->a_vpp = ap->a_vp; 346 if (ap->a_bnp != NULL) 347 *ap->a_bnp = ap->a_bn; 348 return (0); 349 } 350 351 /* 352 * At the moment we do not do any locking. 353 */ 354 /* ARGSUSED */ 355 fifo_lock(ap) 356 struct vop_lock_args /* { 357 struct vnode *a_vp; 358 } */ *ap; 359 { 360 361 return (0); 362 } 363 364 /* ARGSUSED */ 365 fifo_unlock(ap) 366 struct vop_unlock_args /* { 367 struct vnode *a_vp; 368 } */ *ap; 369 { 370 371 return (0); 372 } 373 374 /* 375 * Device close routine 376 */ 377 /* ARGSUSED */ 378 fifo_close(ap) 379 struct vop_close_args /* { 380 struct vnode *a_vp; 381 int a_fflag; 382 struct ucred *a_cred; 383 struct proc *a_p; 384 } */ *ap; 385 { 386 register struct vnode *vp = ap->a_vp; 387 register struct fifoinfo *fip = vp->v_fifoinfo; 388 int error1, error2; 389 390 if (ap->a_fflag & FWRITE) { 391 fip->fi_writers--; 392 if (fip->fi_writers == 0) 393 socantrcvmore(fip->fi_readsock); 394 } else { 395 fip->fi_readers--; 396 if (fip->fi_readers == 0) 397 socantsendmore(fip->fi_writesock); 398 } 399 if (vp->v_usecount > 1) 400 return (0); 401 error1 = soclose(fip->fi_readsock); 402 error2 = soclose(fip->fi_writesock); 403 FREE(fip, M_VNODE); 404 vp->v_fifoinfo = NULL; 405 if (error1) 406 return (error1); 407 return (error2); 408 } 409 410 /* 411 * Print out the contents of a fifo vnode. 412 */ 413 fifo_print(ap) 414 struct vop_print_args /* { 415 struct vnode *a_vp; 416 } */ *ap; 417 { 418 419 printf("tag VT_NON"); 420 fifo_printinfo(ap->a_vp); 421 printf("\n"); 422 } 423 424 /* 425 * Print out internal contents of a fifo vnode. 426 */ 427 fifo_printinfo(vp) 428 struct vnode *vp; 429 { 430 register struct fifoinfo *fip = vp->v_fifoinfo; 431 432 printf(", fifo with %d readers and %d writers", 433 fip->fi_readers, fip->fi_writers); 434 } 435 436 /* 437 * Return POSIX pathconf information applicable to fifo's. 438 */ 439 fifo_pathconf(ap) 440 struct vop_pathconf_args /* { 441 struct vnode *a_vp; 442 int a_name; 443 register_t *a_retval; 444 } */ *ap; 445 { 446 447 switch (ap->a_name) { 448 case _PC_LINK_MAX: 449 *ap->a_retval = LINK_MAX; 450 return (0); 451 case _PC_PIPE_BUF: 452 *ap->a_retval = PIPE_BUF; 453 return (0); 454 case _PC_CHOWN_RESTRICTED: 455 *ap->a_retval = 1; 456 return (0); 457 default: 458 return (EINVAL); 459 } 460 /* NOTREACHED */ 461 } 462 463 /* 464 * Fifo failed operation 465 */ 466 fifo_ebadf() 467 { 468 469 return (EBADF); 470 } 471 472 /* 473 * Fifo advisory byte-level locks. 474 */ 475 /* ARGSUSED */ 476 fifo_advlock(ap) 477 struct vop_advlock_args /* { 478 struct vnode *a_vp; 479 caddr_t a_id; 480 int a_op; 481 struct flock *a_fl; 482 int a_flags; 483 } */ *ap; 484 { 485 486 return (EOPNOTSUPP); 487 } 488 489 /* 490 * Fifo bad operation 491 */ 492 fifo_badop() 493 { 494 495 panic("fifo_badop called"); 496 /* NOTREACHED */ 497 } 498
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