1 /* 2 * Copyright (c) 1990, 1993, 1995 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 /* 34 * Filesystem FIFO type ops. All entry points are MPSAFE. We primarily 35 * use v_token to interlock operations. 36 */ 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/unistd.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/thread2.h> 44 #include <sys/vnode.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/filio.h> 48 #include <sys/fcntl.h> 49 #include <sys/file.h> 50 #include <sys/event.h> 51 #include <sys/un.h> 52 53 #include <sys/thread2.h> 54 #include <sys/socketvar2.h> 55 56 #include "fifo.h" 57 58 /* 59 * This structure is associated with the FIFO vnode and stores 60 * the state associated with the FIFO. 61 */ 62 struct fifoinfo { 63 struct socket *fi_readsock; 64 struct socket *fi_writesock; 65 long fi_readers; 66 long fi_writers; 67 }; 68 69 static int fifo_badop (void); 70 static int fifo_print (struct vop_print_args *); 71 static int fifo_lookup (struct vop_old_lookup_args *); 72 static int fifo_open (struct vop_open_args *); 73 static int fifo_close (struct vop_close_args *); 74 static int fifo_read (struct vop_read_args *); 75 static int fifo_write (struct vop_write_args *); 76 static int fifo_ioctl (struct vop_ioctl_args *); 77 static int fifo_kqfilter (struct vop_kqfilter_args *); 78 static int fifo_inactive (struct vop_inactive_args *); 79 static int fifo_bmap (struct vop_bmap_args *); 80 static int fifo_pathconf (struct vop_pathconf_args *); 81 static int fifo_advlock (struct vop_advlock_args *); 82 83 static void filt_fifordetach(struct knote *kn); 84 static int filt_fiforead(struct knote *kn, long hint); 85 static void filt_fifowdetach(struct knote *kn); 86 static int filt_fifowrite(struct knote *kn, long hint); 87 88 static struct filterops fiforead_filtops = 89 { FILTEROP_ISFD, NULL, filt_fifordetach, filt_fiforead }; 90 static struct filterops fifowrite_filtops = 91 { FILTEROP_ISFD, NULL, filt_fifowdetach, filt_fifowrite }; 92 93 struct vop_ops fifo_vnode_vops = { 94 .vop_default = vop_defaultop, 95 .vop_access = (void *)vop_ebadf, 96 .vop_advlock = fifo_advlock, 97 .vop_bmap = fifo_bmap, 98 .vop_close = fifo_close, 99 .vop_old_create = (void *)fifo_badop, 100 .vop_getattr = (void *)vop_ebadf, 101 .vop_inactive = fifo_inactive, 102 .vop_ioctl = fifo_ioctl, 103 .vop_kqfilter = fifo_kqfilter, 104 .vop_old_link = (void *)fifo_badop, 105 .vop_old_lookup = fifo_lookup, 106 .vop_old_mkdir = (void *)fifo_badop, 107 .vop_old_mknod = (void *)fifo_badop, 108 .vop_open = fifo_open, 109 .vop_pathconf = fifo_pathconf, 110 .vop_print = fifo_print, 111 .vop_read = fifo_read, 112 .vop_readdir = (void *)fifo_badop, 113 .vop_readlink = (void *)fifo_badop, 114 .vop_reallocblks = (void *)fifo_badop, 115 .vop_reclaim = (void *)vop_null, 116 .vop_old_remove = (void *)fifo_badop, 117 .vop_old_rename = (void *)fifo_badop, 118 .vop_old_rmdir = (void *)fifo_badop, 119 .vop_setattr = (void *)vop_ebadf, 120 .vop_old_symlink = (void *)fifo_badop, 121 .vop_write = fifo_write 122 }; 123 124 VNODEOP_SET(fifo_vnode_vops); 125 126 static MALLOC_DEFINE(M_FIFOINFO, "Fifo info", "Fifo info entries"); 127 128 /* 129 * fifo_vnoperate() 130 */ 131 int 132 fifo_vnoperate(struct vop_generic_args *ap) 133 { 134 return (VOCALL(&fifo_vnode_vops, ap)); 135 } 136 137 /* 138 * Trivial lookup routine that always fails. 139 * 140 * fifo_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 141 * struct componentname *a_cnp) 142 */ 143 /* ARGSUSED */ 144 static int 145 fifo_lookup(struct vop_old_lookup_args *ap) 146 { 147 *ap->a_vpp = NULL; 148 return (ENOTDIR); 149 } 150 151 /* 152 * Open called to set up a new instance of a fifo or 153 * to find an active instance of a fifo. 154 * 155 * fifo_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 156 * struct file *a_fp) 157 */ 158 /* ARGSUSED */ 159 static int 160 fifo_open(struct vop_open_args *ap) 161 { 162 struct thread *td = curthread; 163 struct vnode *vp = ap->a_vp; 164 struct fifoinfo *fip; 165 struct socket *rso, *wso; 166 int error; 167 168 lwkt_gettoken(&vp->v_token); 169 if ((fip = vp->v_fifoinfo) == NULL) { 170 fip = kmalloc(sizeof(*fip), M_FIFOINFO, M_WAITOK); 171 vp->v_fifoinfo = fip; 172 error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0, td); 173 if (error) { 174 kfree(fip, M_FIFOINFO); 175 vp->v_fifoinfo = NULL; 176 goto done; 177 } 178 fip->fi_readsock = rso; 179 error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0, td); 180 if (error) { 181 soclose(rso, FNONBLOCK); 182 kfree(fip, M_FIFOINFO); 183 vp->v_fifoinfo = NULL; 184 goto done; 185 } 186 fip->fi_writesock = wso; 187 error = unp_connect2(wso, rso); 188 if (error) { 189 soclose(wso, FNONBLOCK); 190 soclose(rso, FNONBLOCK); 191 kfree(fip, M_FIFOINFO); 192 vp->v_fifoinfo = NULL; 193 goto done; 194 } 195 fip->fi_readers = fip->fi_writers = 0; 196 wso->so_snd.ssb_lowat = PIPE_BUF; 197 sosetstate(rso, SS_CANTRCVMORE); 198 } 199 if (ap->a_mode & FREAD) { 200 fip->fi_readers++; 201 if (fip->fi_readers == 1) { 202 soisreconnected(fip->fi_writesock); 203 if (fip->fi_writers > 0) { 204 wakeup((caddr_t)&fip->fi_writers); 205 sowwakeup(fip->fi_writesock); 206 } 207 } 208 } 209 if (ap->a_mode & FWRITE) { 210 fip->fi_writers++; 211 if (fip->fi_writers == 1) { 212 soisreconnected(fip->fi_readsock); 213 if (fip->fi_readers > 0) { 214 wakeup((caddr_t)&fip->fi_readers); 215 sorwakeup(fip->fi_writesock); 216 } 217 } 218 } 219 if ((ap->a_mode & FREAD) && (ap->a_mode & O_NONBLOCK) == 0) { 220 if (fip->fi_writers == 0) { 221 vn_unlock(vp); 222 error = tsleep((caddr_t)&fip->fi_readers, 223 PCATCH, "fifoor", 0); 224 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 225 if (error) 226 goto bad; 227 /* 228 * We must have got woken up because we had a writer. 229 * That (and not still having one) is the condition 230 * that we must wait for. 231 */ 232 } 233 } 234 if (ap->a_mode & FWRITE) { 235 if (ap->a_mode & O_NONBLOCK) { 236 if (fip->fi_readers == 0) { 237 error = ENXIO; 238 goto bad; 239 } 240 } else { 241 if (fip->fi_readers == 0) { 242 vn_unlock(vp); 243 error = tsleep((caddr_t)&fip->fi_writers, 244 PCATCH, "fifoow", 0); 245 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 246 if (error) 247 goto bad; 248 /* 249 * We must have got woken up because we had 250 * a reader. That (and not still having one) 251 * is the condition that we must wait for. 252 */ 253 } 254 } 255 } 256 vsetflags(vp, VNOTSEEKABLE); 257 error = vop_stdopen(ap); 258 lwkt_reltoken(&vp->v_token); 259 return (error); 260 bad: 261 vop_stdopen(ap); /* bump opencount/writecount as appropriate */ 262 VOP_CLOSE(vp, ap->a_mode); 263 done: 264 lwkt_reltoken(&vp->v_token); 265 return (error); 266 } 267 268 /* 269 * Vnode op for read 270 * 271 * fifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 272 * struct ucred *a_cred) 273 */ 274 /* ARGSUSED */ 275 static int 276 fifo_read(struct vop_read_args *ap) 277 { 278 struct uio *uio = ap->a_uio; 279 struct vnode *vp = ap->a_vp; 280 struct socket *rso = vp->v_fifoinfo->fi_readsock; 281 int error; 282 int flags; 283 284 #ifdef DIAGNOSTIC 285 if (uio->uio_rw != UIO_READ) 286 panic("fifo_read mode"); 287 #endif 288 if (uio->uio_resid == 0) 289 return (0); 290 if (ap->a_ioflag & IO_NDELAY) 291 flags = MSG_FNONBLOCKING; 292 else 293 flags = 0; 294 vn_unlock(vp); 295 lwkt_gettoken(&vp->v_token); 296 error = soreceive(rso, NULL, uio, NULL, NULL, &flags); 297 lwkt_reltoken(&vp->v_token); 298 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 299 return (error); 300 } 301 302 /* 303 * Vnode op for write 304 * 305 * fifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 306 * struct ucred *a_cred) 307 */ 308 /* ARGSUSED */ 309 static int 310 fifo_write(struct vop_write_args *ap) 311 { 312 struct thread *td = ap->a_uio->uio_td; 313 struct vnode *vp = ap->a_vp; 314 struct socket *wso = vp->v_fifoinfo->fi_writesock; 315 int error; 316 int flags; 317 318 #ifdef DIAGNOSTIC 319 if (ap->a_uio->uio_rw != UIO_WRITE) 320 panic("fifo_write mode"); 321 #endif 322 if (ap->a_ioflag & IO_NDELAY) 323 flags = MSG_FNONBLOCKING; 324 else 325 flags = 0; 326 vn_unlock(vp); 327 lwkt_gettoken(&vp->v_token); 328 error = sosend(wso, NULL, ap->a_uio, 0, NULL, flags, td); 329 lwkt_reltoken(&vp->v_token); 330 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 331 return (error); 332 } 333 334 /* 335 * Device ioctl operation. 336 * 337 * fifo_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 338 * struct ucred *a_cred, struct sysmsg *a_sysmsg) 339 */ 340 /* ARGSUSED */ 341 static int 342 fifo_ioctl(struct vop_ioctl_args *ap) 343 { 344 struct file filetmp; /* Local */ 345 struct vnode *vp = ap->a_vp; 346 int error; 347 348 if (ap->a_fflag & FREAD) { 349 filetmp.f_data = vp->v_fifoinfo->fi_readsock; 350 lwkt_gettoken(&vp->v_token); 351 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 352 ap->a_cred, ap->a_sysmsg); 353 lwkt_reltoken(&vp->v_token); 354 if (error) 355 return (error); 356 } 357 if (ap->a_fflag & FWRITE) { 358 filetmp.f_data = vp->v_fifoinfo->fi_writesock; 359 lwkt_gettoken(&vp->v_token); 360 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 361 ap->a_cred, ap->a_sysmsg); 362 lwkt_reltoken(&vp->v_token); 363 if (error) 364 return (error); 365 } 366 return (0); 367 } 368 369 /* 370 * fifo_kqfilter(struct vnode *a_vp, struct knote *a_kn) 371 */ 372 /* ARGSUSED */ 373 static int 374 fifo_kqfilter(struct vop_kqfilter_args *ap) 375 { 376 struct vnode *vp = ap->a_vp; 377 struct fifoinfo *fi = vp->v_fifoinfo; 378 struct socket *so; 379 struct signalsockbuf *ssb; 380 381 lwkt_gettoken(&vp->v_token); 382 383 switch (ap->a_kn->kn_filter) { 384 case EVFILT_READ: 385 ap->a_kn->kn_fop = &fiforead_filtops; 386 so = fi->fi_readsock; 387 ssb = &so->so_rcv; 388 break; 389 case EVFILT_WRITE: 390 ap->a_kn->kn_fop = &fifowrite_filtops; 391 so = fi->fi_writesock; 392 ssb = &so->so_snd; 393 break; 394 default: 395 lwkt_reltoken(&vp->v_token); 396 return (EOPNOTSUPP); 397 } 398 399 ap->a_kn->kn_hook = (caddr_t)vp; 400 ssb_insert_knote(ssb, ap->a_kn); 401 402 lwkt_reltoken(&vp->v_token); 403 return (0); 404 } 405 406 static void 407 filt_fifordetach(struct knote *kn) 408 { 409 struct vnode *vp = (void *)kn->kn_hook; 410 struct socket *so = vp->v_fifoinfo->fi_readsock; 411 412 lwkt_gettoken(&vp->v_token); 413 ssb_remove_knote(&so->so_rcv, kn); 414 lwkt_reltoken(&vp->v_token); 415 } 416 417 static int 418 filt_fiforead(struct knote *kn, long hint) 419 { 420 struct vnode *vp = (void *)kn->kn_hook; 421 struct socket *so = vp->v_fifoinfo->fi_readsock; 422 423 lwkt_gettoken(&vp->v_token); 424 kn->kn_data = so->so_rcv.ssb_cc; 425 if ((kn->kn_sfflags & NOTE_OLDAPI) == 0 && 426 so->so_state & SS_ISDISCONNECTED) { 427 if (kn->kn_data == 0) 428 kn->kn_flags |= EV_NODATA; 429 kn->kn_flags |= EV_EOF; 430 lwkt_reltoken(&vp->v_token); 431 return (1); 432 } 433 kn->kn_flags &= ~(EV_EOF | EV_NODATA); 434 lwkt_reltoken(&vp->v_token); 435 return (kn->kn_data > 0); 436 } 437 438 static void 439 filt_fifowdetach(struct knote *kn) 440 { 441 struct vnode *vp = (void *)kn->kn_hook; 442 struct socket *so = vp->v_fifoinfo->fi_writesock; 443 444 lwkt_gettoken(&vp->v_token); 445 ssb_remove_knote(&so->so_snd, kn); 446 lwkt_reltoken(&vp->v_token); 447 } 448 449 static int 450 filt_fifowrite(struct knote *kn, long hint) 451 { 452 struct vnode *vp = (void *)kn->kn_hook; 453 struct socket *so = vp->v_fifoinfo->fi_writesock; 454 455 lwkt_gettoken(&vp->v_token); 456 kn->kn_data = ssb_space(&so->so_snd); 457 if (so->so_state & SS_ISDISCONNECTED) { 458 kn->kn_flags |= (EV_EOF | EV_NODATA); 459 lwkt_reltoken(&vp->v_token); 460 return (1); 461 } 462 kn->kn_flags &= ~(EV_EOF | EV_NODATA); 463 lwkt_reltoken(&vp->v_token); 464 return (kn->kn_data >= so->so_snd.ssb_lowat); 465 } 466 467 /* 468 * fifo_inactive(struct vnode *a_vp) 469 */ 470 static int 471 fifo_inactive(struct vop_inactive_args *ap) 472 { 473 return (0); 474 } 475 476 /* 477 * This is a noop, simply returning what one has been given. 478 * 479 * fifo_bmap(struct vnode *a_vp, off_t a_loffset, 480 * off_t *a_doffsetp, int *a_runp, int *a_runb) 481 */ 482 static int 483 fifo_bmap(struct vop_bmap_args *ap) 484 { 485 if (ap->a_doffsetp != NULL) 486 *ap->a_doffsetp = ap->a_loffset; 487 if (ap->a_runp != NULL) 488 *ap->a_runp = 0; 489 if (ap->a_runb != NULL) 490 *ap->a_runb = 0; 491 return (0); 492 } 493 494 /* 495 * Device close routine 496 * 497 * fifo_close(struct vnode *a_vp, int a_fflag) 498 */ 499 /* ARGSUSED */ 500 static int 501 fifo_close(struct vop_close_args *ap) 502 { 503 struct vnode *vp = ap->a_vp; 504 struct fifoinfo *fip; 505 int error1, error2; 506 507 lwkt_gettoken(&vp->v_token); 508 fip = vp->v_fifoinfo; 509 if (ap->a_fflag & FREAD) { 510 fip->fi_readers--; 511 if (fip->fi_readers == 0) 512 soisdisconnected(fip->fi_writesock); 513 } 514 if (ap->a_fflag & FWRITE) { 515 fip->fi_writers--; 516 if (fip->fi_writers == 0) 517 soisdisconnected(fip->fi_readsock); 518 } 519 if (vp->v_sysref.refcnt > 1) { 520 vop_stdclose(ap); 521 lwkt_reltoken(&vp->v_token); 522 return (0); 523 } 524 error1 = soclose(fip->fi_readsock, FNONBLOCK); 525 error2 = soclose(fip->fi_writesock, FNONBLOCK); 526 kfree(fip, M_FIFOINFO); 527 vp->v_fifoinfo = NULL; 528 if (error1) { 529 error2 = error1; 530 } else { 531 vop_stdclose(ap); 532 } 533 lwkt_reltoken(&vp->v_token); 534 return (error2); 535 } 536 537 538 /* 539 * Print out internal contents of a fifo vnode. 540 */ 541 int 542 fifo_printinfo(struct vnode *vp) 543 { 544 struct fifoinfo *fip = vp->v_fifoinfo; 545 546 kprintf(", fifo with %ld readers and %ld writers", 547 fip->fi_readers, fip->fi_writers); 548 return (0); 549 } 550 551 /* 552 * Print out the contents of a fifo vnode. 553 * 554 * fifo_print(struct vnode *a_vp) 555 */ 556 static int 557 fifo_print(struct vop_print_args *ap) 558 { 559 kprintf("tag VT_NON"); 560 fifo_printinfo(ap->a_vp); 561 kprintf("\n"); 562 return (0); 563 } 564 565 /* 566 * Return POSIX pathconf information applicable to fifo's. 567 * 568 * fifo_pathconf(struct vnode *a_vp, int a_name, int *a_retval) 569 */ 570 int 571 fifo_pathconf(struct vop_pathconf_args *ap) 572 { 573 switch (ap->a_name) { 574 case _PC_LINK_MAX: 575 *ap->a_retval = LINK_MAX; 576 return (0); 577 case _PC_PIPE_BUF: 578 *ap->a_retval = PIPE_BUF; 579 return (0); 580 case _PC_CHOWN_RESTRICTED: 581 *ap->a_retval = 1; 582 return (0); 583 default: 584 return (EINVAL); 585 } 586 /* NOTREACHED */ 587 } 588 589 /* 590 * Fifo advisory byte-level locks. 591 * 592 * fifo_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl, 593 * int a_flags) 594 */ 595 /* ARGSUSED */ 596 static int 597 fifo_advlock(struct vop_advlock_args *ap) 598 { 599 return ((ap->a_flags & F_POSIX) ? EINVAL : EOPNOTSUPP); 600 } 601 602 /* 603 * Fifo bad operation 604 */ 605 static int 606 fifo_badop(void) 607 { 608 panic("fifo_badop called"); 609 /* NOTREACHED */ 610 } 611