fifo_vnops.c revision 1.15
1 /* $NetBSD: fifo_vnops.c,v 1.15 1995/04/02 19:27:48 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 } */ *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 #ifdef COMPAT_IBCS2 150 if (ap->a_p->p_emul == EMUL_IBCS2_COFF || 151 ap->a_p->p_emul == EMUL_IBCS2_XOUT) 152 ap->a_mode = (ap->a_mode & ~FWRITE) | O_NONBLOCK; 153 else 154 #endif 155 return (EINVAL); 156 } 157 if ((fip = vp->v_fifoinfo) == NULL) { 158 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 159 vp->v_fifoinfo = fip; 160 if (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) { 161 free(fip, M_VNODE); 162 vp->v_fifoinfo = NULL; 163 return (error); 164 } 165 fip->fi_readsock = rso; 166 if (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) { 167 (void)soclose(rso); 168 free(fip, M_VNODE); 169 vp->v_fifoinfo = NULL; 170 return (error); 171 } 172 fip->fi_writesock = wso; 173 if (error = unp_connect2(wso, rso)) { 174 (void)soclose(wso); 175 (void)soclose(rso); 176 free(fip, M_VNODE); 177 vp->v_fifoinfo = NULL; 178 return (error); 179 } 180 fip->fi_readers = fip->fi_writers = 0; 181 wso->so_state |= SS_CANTRCVMORE; 182 rso->so_state |= SS_CANTSENDMORE; 183 } 184 error = 0; 185 if (ap->a_mode & FREAD) { 186 fip->fi_readers++; 187 if (fip->fi_readers == 1) { 188 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 189 if (fip->fi_writers > 0) 190 wakeup((caddr_t)&fip->fi_writers); 191 } 192 if (ap->a_mode & O_NONBLOCK) 193 return (0); 194 while (fip->fi_writers == 0) { 195 VOP_UNLOCK(vp); 196 error = tsleep((caddr_t)&fip->fi_readers, 197 PCATCH | PSOCK, openstr, 0); 198 VOP_LOCK(vp); 199 if (error) 200 break; 201 } 202 } else { 203 fip->fi_writers++; 204 if (fip->fi_readers == 0 && (ap->a_mode & O_NONBLOCK)) { 205 error = ENXIO; 206 } else { 207 if (fip->fi_writers == 1) { 208 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 209 if (fip->fi_readers > 0) 210 wakeup((caddr_t)&fip->fi_readers); 211 } 212 while (fip->fi_readers == 0) { 213 VOP_UNLOCK(vp); 214 error = tsleep((caddr_t)&fip->fi_writers, 215 PCATCH | PSOCK, openstr, 0); 216 VOP_LOCK(vp); 217 if (error) 218 break; 219 } 220 } 221 } 222 if (error) 223 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, ap->a_p); 224 return (error); 225 } 226 227 /* 228 * Vnode op for read 229 */ 230 /* ARGSUSED */ 231 fifo_read(ap) 232 struct vop_read_args /* { 233 struct vnode *a_vp; 234 struct uio *a_uio; 235 int a_ioflag; 236 struct ucred *a_cred; 237 } */ *ap; 238 { 239 register struct uio *uio = ap->a_uio; 240 register struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 241 int error, startresid; 242 243 #ifdef DIAGNOSTIC 244 if (uio->uio_rw != UIO_READ) 245 panic("fifo_read mode"); 246 #endif 247 if (uio->uio_resid == 0) 248 return (0); 249 if (ap->a_ioflag & IO_NDELAY) 250 rso->so_state |= SS_NBIO; 251 startresid = uio->uio_resid; 252 VOP_UNLOCK(ap->a_vp); 253 error = soreceive(rso, (struct mbuf **)0, uio, (struct mbuf **)0, 254 (struct mbuf **)0, (int *)0); 255 VOP_LOCK(ap->a_vp); 256 /* 257 * Clear EOF indication after first such return. 258 */ 259 if (uio->uio_resid == startresid) 260 rso->so_state &= ~SS_CANTRCVMORE; 261 if (ap->a_ioflag & IO_NDELAY) 262 rso->so_state &= ~SS_NBIO; 263 return (error); 264 } 265 266 /* 267 * Vnode op for write 268 */ 269 /* ARGSUSED */ 270 fifo_write(ap) 271 struct vop_write_args /* { 272 struct vnode *a_vp; 273 struct uio *a_uio; 274 int a_ioflag; 275 struct ucred *a_cred; 276 } */ *ap; 277 { 278 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 279 int error; 280 281 #ifdef DIAGNOSTIC 282 if (ap->a_uio->uio_rw != UIO_WRITE) 283 panic("fifo_write mode"); 284 #endif 285 if (ap->a_ioflag & IO_NDELAY) 286 wso->so_state |= SS_NBIO; 287 VOP_UNLOCK(ap->a_vp); 288 error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0); 289 VOP_LOCK(ap->a_vp); 290 if (ap->a_ioflag & IO_NDELAY) 291 wso->so_state &= ~SS_NBIO; 292 return (error); 293 } 294 295 /* 296 * Device ioctl operation. 297 */ 298 /* ARGSUSED */ 299 fifo_ioctl(ap) 300 struct vop_ioctl_args /* { 301 struct vnode *a_vp; 302 u_long a_command; 303 caddr_t a_data; 304 int a_fflag; 305 struct ucred *a_cred; 306 struct proc *a_p; 307 } */ *ap; 308 { 309 struct file filetmp; 310 311 if (ap->a_command == FIONBIO) 312 return (0); 313 if (ap->a_fflag & FREAD) 314 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 315 else 316 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 317 return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p)); 318 } 319 320 /* ARGSUSED */ 321 fifo_select(ap) 322 struct vop_select_args /* { 323 struct vnode *a_vp; 324 int a_which; 325 int a_fflags; 326 struct ucred *a_cred; 327 struct proc *a_p; 328 } */ *ap; 329 { 330 struct file filetmp; 331 332 if (ap->a_fflags & FREAD) 333 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 334 else 335 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 336 return (soo_select(&filetmp, ap->a_which, ap->a_p)); 337 } 338 339 /* 340 * This is a noop, simply returning what one has been given. 341 */ 342 fifo_bmap(ap) 343 struct vop_bmap_args /* { 344 struct vnode *a_vp; 345 daddr_t a_bn; 346 struct vnode **a_vpp; 347 daddr_t *a_bnp; 348 } */ *ap; 349 { 350 351 if (ap->a_vpp != NULL) 352 *ap->a_vpp = ap->a_vp; 353 if (ap->a_bnp != NULL) 354 *ap->a_bnp = ap->a_bn; 355 return (0); 356 } 357 358 /* 359 * At the moment we do not do any locking. 360 */ 361 /* ARGSUSED */ 362 fifo_lock(ap) 363 struct vop_lock_args /* { 364 struct vnode *a_vp; 365 } */ *ap; 366 { 367 368 return (0); 369 } 370 371 /* ARGSUSED */ 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 fifo_close(ap) 386 struct vop_close_args /* { 387 struct vnode *a_vp; 388 int a_fflag; 389 struct ucred *a_cred; 390 struct proc *a_p; 391 } */ *ap; 392 { 393 register struct vnode *vp = ap->a_vp; 394 register struct fifoinfo *fip = vp->v_fifoinfo; 395 int error1, error2; 396 397 if (ap->a_fflag & FWRITE) { 398 fip->fi_writers--; 399 if (fip->fi_writers == 0) 400 socantrcvmore(fip->fi_readsock); 401 } else { 402 fip->fi_readers--; 403 if (fip->fi_readers == 0) 404 socantsendmore(fip->fi_writesock); 405 } 406 if (vp->v_usecount > 1) 407 return (0); 408 error1 = soclose(fip->fi_readsock); 409 error2 = soclose(fip->fi_writesock); 410 FREE(fip, M_VNODE); 411 vp->v_fifoinfo = NULL; 412 if (error1) 413 return (error1); 414 return (error2); 415 } 416 417 /* 418 * Print out the contents of a fifo vnode. 419 */ 420 fifo_print(ap) 421 struct vop_print_args /* { 422 struct vnode *a_vp; 423 } */ *ap; 424 { 425 426 printf("tag VT_NON"); 427 fifo_printinfo(ap->a_vp); 428 printf("\n"); 429 } 430 431 /* 432 * Print out internal contents of a fifo vnode. 433 */ 434 fifo_printinfo(vp) 435 struct vnode *vp; 436 { 437 register struct fifoinfo *fip = vp->v_fifoinfo; 438 439 printf(", fifo with %d readers and %d writers", 440 fip->fi_readers, fip->fi_writers); 441 } 442 443 /* 444 * Return POSIX pathconf information applicable to fifo's. 445 */ 446 fifo_pathconf(ap) 447 struct vop_pathconf_args /* { 448 struct vnode *a_vp; 449 int a_name; 450 register_t *a_retval; 451 } */ *ap; 452 { 453 454 switch (ap->a_name) { 455 case _PC_LINK_MAX: 456 *ap->a_retval = LINK_MAX; 457 return (0); 458 case _PC_PIPE_BUF: 459 *ap->a_retval = PIPE_BUF; 460 return (0); 461 case _PC_CHOWN_RESTRICTED: 462 *ap->a_retval = 1; 463 return (0); 464 default: 465 return (EINVAL); 466 } 467 /* NOTREACHED */ 468 } 469 470 /* 471 * Fifo failed operation 472 */ 473 fifo_ebadf() 474 { 475 476 return (EBADF); 477 } 478 479 /* 480 * Fifo advisory byte-level locks. 481 */ 482 /* ARGSUSED */ 483 fifo_advlock(ap) 484 struct vop_advlock_args /* { 485 struct vnode *a_vp; 486 caddr_t a_id; 487 int a_op; 488 struct flock *a_fl; 489 int a_flags; 490 } */ *ap; 491 { 492 493 return (EOPNOTSUPP); 494 } 495 496 /* 497 * Fifo bad operation 498 */ 499 fifo_badop() 500 { 501 502 panic("fifo_badop called"); 503 /* NOTREACHED */ 504 } 505
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