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 MALLOC(fip, struct fifoinfo *, 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, startresid; 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 startresid = uio->uio_resid; 295 vn_unlock(vp); 296 lwkt_gettoken(&vp->v_token); 297 error = soreceive(rso, NULL, uio, NULL, NULL, &flags); 298 lwkt_reltoken(&vp->v_token); 299 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 300 return (error); 301 } 302 303 /* 304 * Vnode op for write 305 * 306 * fifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 307 * struct ucred *a_cred) 308 */ 309 /* ARGSUSED */ 310 static int 311 fifo_write(struct vop_write_args *ap) 312 { 313 struct thread *td = ap->a_uio->uio_td; 314 struct vnode *vp = ap->a_vp; 315 struct socket *wso = vp->v_fifoinfo->fi_writesock; 316 int error; 317 int flags; 318 319 #ifdef DIAGNOSTIC 320 if (ap->a_uio->uio_rw != UIO_WRITE) 321 panic("fifo_write mode"); 322 #endif 323 if (ap->a_ioflag & IO_NDELAY) 324 flags = MSG_FNONBLOCKING; 325 else 326 flags = 0; 327 vn_unlock(vp); 328 lwkt_gettoken(&vp->v_token); 329 error = sosend(wso, NULL, ap->a_uio, 0, NULL, flags, td); 330 lwkt_reltoken(&vp->v_token); 331 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 332 return (error); 333 } 334 335 /* 336 * Device ioctl operation. 337 * 338 * fifo_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 339 * struct ucred *a_cred, struct sysmsg *a_sysmsg) 340 */ 341 /* ARGSUSED */ 342 static int 343 fifo_ioctl(struct vop_ioctl_args *ap) 344 { 345 struct file filetmp; /* Local */ 346 struct vnode *vp = ap->a_vp; 347 int error; 348 349 if (ap->a_fflag & FREAD) { 350 filetmp.f_data = vp->v_fifoinfo->fi_readsock; 351 lwkt_gettoken(&vp->v_token); 352 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 353 ap->a_cred, ap->a_sysmsg); 354 lwkt_reltoken(&vp->v_token); 355 if (error) 356 return (error); 357 } 358 if (ap->a_fflag & FWRITE) { 359 filetmp.f_data = vp->v_fifoinfo->fi_writesock; 360 lwkt_gettoken(&vp->v_token); 361 error = soo_ioctl(&filetmp, ap->a_command, ap->a_data, 362 ap->a_cred, ap->a_sysmsg); 363 lwkt_reltoken(&vp->v_token); 364 if (error) 365 return (error); 366 } 367 return (0); 368 } 369 370 /* 371 * fifo_kqfilter(struct vnode *a_vp, struct knote *a_kn) 372 */ 373 /* ARGSUSED */ 374 static int 375 fifo_kqfilter(struct vop_kqfilter_args *ap) 376 { 377 struct vnode *vp = ap->a_vp; 378 struct fifoinfo *fi = vp->v_fifoinfo; 379 struct socket *so; 380 struct signalsockbuf *ssb; 381 382 lwkt_gettoken(&vp->v_token); 383 384 switch (ap->a_kn->kn_filter) { 385 case EVFILT_READ: 386 ap->a_kn->kn_fop = &fiforead_filtops; 387 so = fi->fi_readsock; 388 ssb = &so->so_rcv; 389 break; 390 case EVFILT_WRITE: 391 ap->a_kn->kn_fop = &fifowrite_filtops; 392 so = fi->fi_writesock; 393 ssb = &so->so_snd; 394 break; 395 default: 396 lwkt_reltoken(&vp->v_token); 397 return (EOPNOTSUPP); 398 } 399 400 ap->a_kn->kn_hook = (caddr_t)vp; 401 ssb_insert_knote(ssb, ap->a_kn); 402 403 lwkt_reltoken(&vp->v_token); 404 return (0); 405 } 406 407 static void 408 filt_fifordetach(struct knote *kn) 409 { 410 struct vnode *vp = (void *)kn->kn_hook; 411 struct socket *so = vp->v_fifoinfo->fi_readsock; 412 413 lwkt_gettoken(&vp->v_token); 414 ssb_remove_knote(&so->so_rcv, kn); 415 lwkt_reltoken(&vp->v_token); 416 } 417 418 static int 419 filt_fiforead(struct knote *kn, long hint) 420 { 421 struct vnode *vp = (void *)kn->kn_hook; 422 struct socket *so = vp->v_fifoinfo->fi_readsock; 423 424 lwkt_gettoken(&vp->v_token); 425 kn->kn_data = so->so_rcv.ssb_cc; 426 if ((so->so_state & SS_ISDISCONNECTED) && kn->kn_data == 0) { 427 kn->kn_flags |= EV_EOF; 428 lwkt_reltoken(&vp->v_token); 429 return (1); 430 } 431 kn->kn_flags &= ~EV_EOF; 432 lwkt_reltoken(&vp->v_token); 433 return (kn->kn_data > 0); 434 } 435 436 static void 437 filt_fifowdetach(struct knote *kn) 438 { 439 struct vnode *vp = (void *)kn->kn_hook; 440 struct socket *so = vp->v_fifoinfo->fi_writesock; 441 442 lwkt_gettoken(&vp->v_token); 443 ssb_remove_knote(&so->so_snd, kn); 444 lwkt_reltoken(&vp->v_token); 445 } 446 447 static int 448 filt_fifowrite(struct knote *kn, long hint) 449 { 450 struct vnode *vp = (void *)kn->kn_hook; 451 struct socket *so = vp->v_fifoinfo->fi_writesock; 452 453 lwkt_gettoken(&vp->v_token); 454 kn->kn_data = ssb_space(&so->so_snd); 455 if (so->so_state & SS_ISDISCONNECTED) { 456 kn->kn_flags |= EV_EOF; 457 lwkt_reltoken(&vp->v_token); 458 return (1); 459 } 460 kn->kn_flags &= ~EV_EOF; 461 lwkt_reltoken(&vp->v_token); 462 return (kn->kn_data >= so->so_snd.ssb_lowat); 463 } 464 465 /* 466 * fifo_inactive(struct vnode *a_vp) 467 */ 468 static int 469 fifo_inactive(struct vop_inactive_args *ap) 470 { 471 return (0); 472 } 473 474 /* 475 * This is a noop, simply returning what one has been given. 476 * 477 * fifo_bmap(struct vnode *a_vp, off_t a_loffset, 478 * off_t *a_doffsetp, int *a_runp, int *a_runb) 479 */ 480 static int 481 fifo_bmap(struct vop_bmap_args *ap) 482 { 483 if (ap->a_doffsetp != NULL) 484 *ap->a_doffsetp = ap->a_loffset; 485 if (ap->a_runp != NULL) 486 *ap->a_runp = 0; 487 if (ap->a_runb != NULL) 488 *ap->a_runb = 0; 489 return (0); 490 } 491 492 /* 493 * Device close routine 494 * 495 * fifo_close(struct vnode *a_vp, int a_fflag) 496 */ 497 /* ARGSUSED */ 498 static int 499 fifo_close(struct vop_close_args *ap) 500 { 501 struct vnode *vp = ap->a_vp; 502 struct fifoinfo *fip; 503 int error1, error2; 504 505 lwkt_gettoken(&vp->v_token); 506 fip = vp->v_fifoinfo; 507 if (ap->a_fflag & FREAD) { 508 fip->fi_readers--; 509 if (fip->fi_readers == 0) 510 soisdisconnected(fip->fi_writesock); 511 } 512 if (ap->a_fflag & FWRITE) { 513 fip->fi_writers--; 514 if (fip->fi_writers == 0) 515 soisdisconnected(fip->fi_readsock); 516 } 517 if (vp->v_sysref.refcnt > 1) { 518 vop_stdclose(ap); 519 lwkt_reltoken(&vp->v_token); 520 return (0); 521 } 522 error1 = soclose(fip->fi_readsock, FNONBLOCK); 523 error2 = soclose(fip->fi_writesock, FNONBLOCK); 524 FREE(fip, M_FIFOINFO); 525 vp->v_fifoinfo = NULL; 526 if (error1) { 527 error2 = error1; 528 } else { 529 vop_stdclose(ap); 530 } 531 lwkt_reltoken(&vp->v_token); 532 return (error2); 533 } 534 535 536 /* 537 * Print out internal contents of a fifo vnode. 538 */ 539 int 540 fifo_printinfo(struct vnode *vp) 541 { 542 struct fifoinfo *fip = vp->v_fifoinfo; 543 544 kprintf(", fifo with %ld readers and %ld writers", 545 fip->fi_readers, fip->fi_writers); 546 return (0); 547 } 548 549 /* 550 * Print out the contents of a fifo vnode. 551 * 552 * fifo_print(struct vnode *a_vp) 553 */ 554 static int 555 fifo_print(struct vop_print_args *ap) 556 { 557 kprintf("tag VT_NON"); 558 fifo_printinfo(ap->a_vp); 559 kprintf("\n"); 560 return (0); 561 } 562 563 /* 564 * Return POSIX pathconf information applicable to fifo's. 565 * 566 * fifo_pathconf(struct vnode *a_vp, int a_name, int *a_retval) 567 */ 568 int 569 fifo_pathconf(struct vop_pathconf_args *ap) 570 { 571 switch (ap->a_name) { 572 case _PC_LINK_MAX: 573 *ap->a_retval = LINK_MAX; 574 return (0); 575 case _PC_PIPE_BUF: 576 *ap->a_retval = PIPE_BUF; 577 return (0); 578 case _PC_CHOWN_RESTRICTED: 579 *ap->a_retval = 1; 580 return (0); 581 default: 582 return (EINVAL); 583 } 584 /* NOTREACHED */ 585 } 586 587 /* 588 * Fifo advisory byte-level locks. 589 * 590 * fifo_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl, 591 * int a_flags) 592 */ 593 /* ARGSUSED */ 594 static int 595 fifo_advlock(struct vop_advlock_args *ap) 596 { 597 return ((ap->a_flags & F_POSIX) ? EINVAL : EOPNOTSUPP); 598 } 599 600 /* 601 * Fifo bad operation 602 */ 603 static int 604 fifo_badop(void) 605 { 606 panic("fifo_badop called"); 607 /* NOTREACHED */ 608 } 609