1 /* 2 * Copyright (c) 2005 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Jeffrey Hsu. 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 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * 35 * Copyright (c) 1982, 1986, 1989, 1991, 1993 36 * The Regents of the University of California. All rights reserved. 37 * (c) UNIX System Laboratories, Inc. 38 * All or some portions of this file are derived from material licensed 39 * to the University of California by American Telephone and Telegraph 40 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 41 * the permission of UNIX System Laboratories, Inc. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 72 * $FreeBSD: src/sys/kern/kern_descrip.c,v 1.81.2.19 2004/02/28 00:43:31 tegge Exp $ 73 * $DragonFly: src/sys/kern/kern_descrip.c,v 1.79 2008/08/31 13:18:28 aggelos Exp $ 74 */ 75 76 #include "opt_compat.h" 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/malloc.h> 80 #include <sys/sysproto.h> 81 #include <sys/conf.h> 82 #include <sys/device.h> 83 #include <sys/file.h> 84 #include <sys/filedesc.h> 85 #include <sys/kernel.h> 86 #include <sys/sysctl.h> 87 #include <sys/vnode.h> 88 #include <sys/proc.h> 89 #include <sys/nlookup.h> 90 #include <sys/file.h> 91 #include <sys/stat.h> 92 #include <sys/filio.h> 93 #include <sys/fcntl.h> 94 #include <sys/unistd.h> 95 #include <sys/resourcevar.h> 96 #include <sys/event.h> 97 #include <sys/kern_syscall.h> 98 #include <sys/kcore.h> 99 #include <sys/kinfo.h> 100 #include <sys/un.h> 101 102 #include <vm/vm.h> 103 #include <vm/vm_extern.h> 104 105 #include <sys/thread2.h> 106 #include <sys/file2.h> 107 #include <sys/spinlock2.h> 108 #include <sys/mplock2.h> 109 110 static void fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd); 111 static void fdreserve_locked (struct filedesc *fdp, int fd0, int incr); 112 static struct file *funsetfd_locked (struct filedesc *fdp, int fd); 113 static void ffree(struct file *fp); 114 115 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table"); 116 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader", 117 "file desc to leader structures"); 118 MALLOC_DEFINE(M_FILE, "file", "Open file structure"); 119 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 120 121 static struct krate krate_uidinfo = { .freq = 1 }; 122 123 static d_open_t fdopen; 124 #define NUMFDESC 64 125 126 #define CDEV_MAJOR 22 127 static struct dev_ops fildesc_ops = { 128 { "FD", CDEV_MAJOR, 0 }, 129 .d_open = fdopen, 130 }; 131 132 /* 133 * Descriptor management. 134 */ 135 static struct filelist filehead = LIST_HEAD_INITIALIZER(&filehead); 136 static struct spinlock filehead_spin = SPINLOCK_INITIALIZER(&filehead_spin); 137 static int nfiles; /* actual number of open files */ 138 extern int cmask; 139 140 /* 141 * Fixup fd_freefile and fd_lastfile after a descriptor has been cleared. 142 * 143 * MPSAFE - must be called with fdp->fd_spin exclusively held 144 */ 145 static __inline 146 void 147 fdfixup_locked(struct filedesc *fdp, int fd) 148 { 149 if (fd < fdp->fd_freefile) { 150 fdp->fd_freefile = fd; 151 } 152 while (fdp->fd_lastfile >= 0 && 153 fdp->fd_files[fdp->fd_lastfile].fp == NULL && 154 fdp->fd_files[fdp->fd_lastfile].reserved == 0 155 ) { 156 --fdp->fd_lastfile; 157 } 158 } 159 160 /* 161 * System calls on descriptors. 162 * 163 * MPSAFE 164 */ 165 int 166 sys_getdtablesize(struct getdtablesize_args *uap) 167 { 168 struct proc *p = curproc; 169 struct plimit *limit = p->p_limit; 170 int dtsize; 171 172 spin_lock(&limit->p_spin); 173 if (limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 174 dtsize = INT_MAX; 175 else 176 dtsize = (int)limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur; 177 spin_unlock(&limit->p_spin); 178 179 if (dtsize > maxfilesperproc) 180 dtsize = maxfilesperproc; 181 if (dtsize < minfilesperproc) 182 dtsize = minfilesperproc; 183 if (p->p_ucred->cr_uid && dtsize > maxfilesperuser) 184 dtsize = maxfilesperuser; 185 uap->sysmsg_result = dtsize; 186 return (0); 187 } 188 189 /* 190 * Duplicate a file descriptor to a particular value. 191 * 192 * note: keep in mind that a potential race condition exists when closing 193 * descriptors from a shared descriptor table (via rfork). 194 * 195 * MPSAFE 196 */ 197 int 198 sys_dup2(struct dup2_args *uap) 199 { 200 int error; 201 int fd = 0; 202 203 error = kern_dup(DUP_FIXED, uap->from, uap->to, &fd); 204 uap->sysmsg_fds[0] = fd; 205 206 return (error); 207 } 208 209 /* 210 * Duplicate a file descriptor. 211 * 212 * MPSAFE 213 */ 214 int 215 sys_dup(struct dup_args *uap) 216 { 217 int error; 218 int fd = 0; 219 220 error = kern_dup(DUP_VARIABLE, uap->fd, 0, &fd); 221 uap->sysmsg_fds[0] = fd; 222 223 return (error); 224 } 225 226 /* 227 * MPALMOSTSAFE - acquires mplock for fp operations 228 */ 229 int 230 kern_fcntl(int fd, int cmd, union fcntl_dat *dat, struct ucred *cred) 231 { 232 struct thread *td = curthread; 233 struct proc *p = td->td_proc; 234 struct file *fp; 235 struct vnode *vp; 236 u_int newmin; 237 u_int oflags; 238 u_int nflags; 239 int tmp, error, flg = F_POSIX; 240 241 KKASSERT(p); 242 243 /* 244 * Operations on file descriptors that do not require a file pointer. 245 */ 246 switch (cmd) { 247 case F_GETFD: 248 error = fgetfdflags(p->p_fd, fd, &tmp); 249 if (error == 0) 250 dat->fc_cloexec = (tmp & UF_EXCLOSE) ? FD_CLOEXEC : 0; 251 return (error); 252 253 case F_SETFD: 254 if (dat->fc_cloexec & FD_CLOEXEC) 255 error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE); 256 else 257 error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE); 258 return (error); 259 case F_DUPFD: 260 newmin = dat->fc_fd; 261 error = kern_dup(DUP_VARIABLE, fd, newmin, &dat->fc_fd); 262 return (error); 263 default: 264 break; 265 } 266 267 /* 268 * Operations on file pointers 269 */ 270 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 271 return (EBADF); 272 273 get_mplock(); 274 switch (cmd) { 275 case F_GETFL: 276 dat->fc_flags = OFLAGS(fp->f_flag); 277 error = 0; 278 break; 279 280 case F_SETFL: 281 oflags = fp->f_flag; 282 nflags = FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS; 283 nflags |= oflags & ~FCNTLFLAGS; 284 285 error = 0; 286 if (((nflags ^ oflags) & O_APPEND) && (oflags & FAPPENDONLY)) 287 error = EINVAL; 288 if (error == 0 && ((nflags ^ oflags) & FASYNC)) { 289 tmp = nflags & FASYNC; 290 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, 291 cred, NULL); 292 } 293 if (error == 0) 294 fp->f_flag = nflags; 295 break; 296 297 case F_GETOWN: 298 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner, 299 cred, NULL); 300 break; 301 302 case F_SETOWN: 303 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner, 304 cred, NULL); 305 break; 306 307 case F_SETLKW: 308 flg |= F_WAIT; 309 /* Fall into F_SETLK */ 310 311 case F_SETLK: 312 if (fp->f_type != DTYPE_VNODE) { 313 error = EBADF; 314 break; 315 } 316 vp = (struct vnode *)fp->f_data; 317 318 /* 319 * copyin/lockop may block 320 */ 321 if (dat->fc_flock.l_whence == SEEK_CUR) 322 dat->fc_flock.l_start += fp->f_offset; 323 324 switch (dat->fc_flock.l_type) { 325 case F_RDLCK: 326 if ((fp->f_flag & FREAD) == 0) { 327 error = EBADF; 328 break; 329 } 330 p->p_leader->p_flag |= P_ADVLOCK; 331 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 332 &dat->fc_flock, flg); 333 break; 334 case F_WRLCK: 335 if ((fp->f_flag & FWRITE) == 0) { 336 error = EBADF; 337 break; 338 } 339 p->p_leader->p_flag |= P_ADVLOCK; 340 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 341 &dat->fc_flock, flg); 342 break; 343 case F_UNLCK: 344 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 345 &dat->fc_flock, F_POSIX); 346 break; 347 default: 348 error = EINVAL; 349 break; 350 } 351 352 /* 353 * It is possible to race a close() on the descriptor while 354 * we were blocked getting the lock. If this occurs the 355 * close might not have caught the lock. 356 */ 357 if (checkfdclosed(p->p_fd, fd, fp)) { 358 dat->fc_flock.l_whence = SEEK_SET; 359 dat->fc_flock.l_start = 0; 360 dat->fc_flock.l_len = 0; 361 dat->fc_flock.l_type = F_UNLCK; 362 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 363 F_UNLCK, &dat->fc_flock, F_POSIX); 364 } 365 break; 366 367 case F_GETLK: 368 if (fp->f_type != DTYPE_VNODE) { 369 error = EBADF; 370 break; 371 } 372 vp = (struct vnode *)fp->f_data; 373 /* 374 * copyin/lockop may block 375 */ 376 if (dat->fc_flock.l_type != F_RDLCK && 377 dat->fc_flock.l_type != F_WRLCK && 378 dat->fc_flock.l_type != F_UNLCK) { 379 error = EINVAL; 380 break; 381 } 382 if (dat->fc_flock.l_whence == SEEK_CUR) 383 dat->fc_flock.l_start += fp->f_offset; 384 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, 385 &dat->fc_flock, F_POSIX); 386 break; 387 default: 388 error = EINVAL; 389 break; 390 } 391 rel_mplock(); 392 393 fdrop(fp); 394 return (error); 395 } 396 397 /* 398 * The file control system call. 399 * 400 * MPSAFE 401 */ 402 int 403 sys_fcntl(struct fcntl_args *uap) 404 { 405 union fcntl_dat dat; 406 int error; 407 408 switch (uap->cmd) { 409 case F_DUPFD: 410 dat.fc_fd = uap->arg; 411 break; 412 case F_SETFD: 413 dat.fc_cloexec = uap->arg; 414 break; 415 case F_SETFL: 416 dat.fc_flags = uap->arg; 417 break; 418 case F_SETOWN: 419 dat.fc_owner = uap->arg; 420 break; 421 case F_SETLKW: 422 case F_SETLK: 423 case F_GETLK: 424 error = copyin((caddr_t)uap->arg, &dat.fc_flock, 425 sizeof(struct flock)); 426 if (error) 427 return (error); 428 break; 429 } 430 431 error = kern_fcntl(uap->fd, uap->cmd, &dat, curthread->td_ucred); 432 433 if (error == 0) { 434 switch (uap->cmd) { 435 case F_DUPFD: 436 uap->sysmsg_result = dat.fc_fd; 437 break; 438 case F_GETFD: 439 uap->sysmsg_result = dat.fc_cloexec; 440 break; 441 case F_GETFL: 442 uap->sysmsg_result = dat.fc_flags; 443 break; 444 case F_GETOWN: 445 uap->sysmsg_result = dat.fc_owner; 446 case F_GETLK: 447 error = copyout(&dat.fc_flock, (caddr_t)uap->arg, 448 sizeof(struct flock)); 449 break; 450 } 451 } 452 453 return (error); 454 } 455 456 /* 457 * Common code for dup, dup2, and fcntl(F_DUPFD). 458 * 459 * The type flag can be either DUP_FIXED or DUP_VARIABLE. DUP_FIXED tells 460 * kern_dup() to destructively dup over an existing file descriptor if new 461 * is already open. DUP_VARIABLE tells kern_dup() to find the lowest 462 * unused file descriptor that is greater than or equal to new. 463 * 464 * MPSAFE 465 */ 466 int 467 kern_dup(enum dup_type type, int old, int new, int *res) 468 { 469 struct thread *td = curthread; 470 struct proc *p = td->td_proc; 471 struct filedesc *fdp = p->p_fd; 472 struct file *fp; 473 struct file *delfp; 474 int oldflags; 475 int holdleaders; 476 int dtsize; 477 int error, newfd; 478 479 /* 480 * Verify that we have a valid descriptor to dup from and 481 * possibly to dup to. 482 * 483 * NOTE: maxfilesperuser is not applicable to dup() 484 */ 485 retry: 486 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 487 dtsize = INT_MAX; 488 else 489 dtsize = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 490 if (dtsize > maxfilesperproc) 491 dtsize = maxfilesperproc; 492 if (dtsize < minfilesperproc) 493 dtsize = minfilesperproc; 494 495 if (new < 0 || new > dtsize) 496 return (EINVAL); 497 498 spin_lock(&fdp->fd_spin); 499 if ((unsigned)old >= fdp->fd_nfiles || fdp->fd_files[old].fp == NULL) { 500 spin_unlock(&fdp->fd_spin); 501 return (EBADF); 502 } 503 if (type == DUP_FIXED && old == new) { 504 *res = new; 505 spin_unlock(&fdp->fd_spin); 506 return (0); 507 } 508 fp = fdp->fd_files[old].fp; 509 oldflags = fdp->fd_files[old].fileflags; 510 fhold(fp); /* MPSAFE - can be called with a spinlock held */ 511 512 /* 513 * Allocate a new descriptor if DUP_VARIABLE, or expand the table 514 * if the requested descriptor is beyond the current table size. 515 * 516 * This can block. Retry if the source descriptor no longer matches 517 * or if our expectation in the expansion case races. 518 * 519 * If we are not expanding or allocating a new decriptor, then reset 520 * the target descriptor to a reserved state so we have a uniform 521 * setup for the next code block. 522 */ 523 if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) { 524 spin_unlock(&fdp->fd_spin); 525 error = fdalloc(p, new, &newfd); 526 spin_lock(&fdp->fd_spin); 527 if (error) { 528 spin_unlock(&fdp->fd_spin); 529 fdrop(fp); 530 return (error); 531 } 532 /* 533 * Check for ripout 534 */ 535 if (old >= fdp->fd_nfiles || fdp->fd_files[old].fp != fp) { 536 fsetfd_locked(fdp, NULL, newfd); 537 spin_unlock(&fdp->fd_spin); 538 fdrop(fp); 539 goto retry; 540 } 541 /* 542 * Check for expansion race 543 */ 544 if (type != DUP_VARIABLE && new != newfd) { 545 fsetfd_locked(fdp, NULL, newfd); 546 spin_unlock(&fdp->fd_spin); 547 fdrop(fp); 548 goto retry; 549 } 550 /* 551 * Check for ripout, newfd reused old (this case probably 552 * can't occur). 553 */ 554 if (old == newfd) { 555 fsetfd_locked(fdp, NULL, newfd); 556 spin_unlock(&fdp->fd_spin); 557 fdrop(fp); 558 goto retry; 559 } 560 new = newfd; 561 delfp = NULL; 562 } else { 563 if (fdp->fd_files[new].reserved) { 564 spin_unlock(&fdp->fd_spin); 565 fdrop(fp); 566 kprintf("Warning: dup(): target descriptor %d is reserved, waiting for it to be resolved\n", new); 567 tsleep(fdp, 0, "fdres", hz); 568 goto retry; 569 } 570 571 /* 572 * If the target descriptor was never allocated we have 573 * to allocate it. If it was we have to clean out the 574 * old descriptor. delfp inherits the ref from the 575 * descriptor table. 576 */ 577 delfp = fdp->fd_files[new].fp; 578 fdp->fd_files[new].fp = NULL; 579 fdp->fd_files[new].reserved = 1; 580 if (delfp == NULL) { 581 fdreserve_locked(fdp, new, 1); 582 if (new > fdp->fd_lastfile) 583 fdp->fd_lastfile = new; 584 } 585 586 } 587 588 /* 589 * NOTE: still holding an exclusive spinlock 590 */ 591 592 /* 593 * If a descriptor is being overwritten we may hve to tell 594 * fdfree() to sleep to ensure that all relevant process 595 * leaders can be traversed in closef(). 596 */ 597 if (delfp != NULL && p->p_fdtol != NULL) { 598 fdp->fd_holdleaderscount++; 599 holdleaders = 1; 600 } else { 601 holdleaders = 0; 602 } 603 KASSERT(delfp == NULL || type == DUP_FIXED, 604 ("dup() picked an open file")); 605 606 /* 607 * Duplicate the source descriptor, update lastfile. If the new 608 * descriptor was not allocated and we aren't replacing an existing 609 * descriptor we have to mark the descriptor as being in use. 610 * 611 * The fd_files[] array inherits fp's hold reference. 612 */ 613 fsetfd_locked(fdp, fp, new); 614 fdp->fd_files[new].fileflags = oldflags & ~UF_EXCLOSE; 615 spin_unlock(&fdp->fd_spin); 616 fdrop(fp); 617 *res = new; 618 619 /* 620 * If we dup'd over a valid file, we now own the reference to it 621 * and must dispose of it using closef() semantics (as if a 622 * close() were performed on it). 623 */ 624 if (delfp) { 625 if (SLIST_FIRST(&delfp->f_klist)) 626 knote_fdclose(delfp, fdp, new); 627 closef(delfp, p); 628 if (holdleaders) { 629 spin_lock(&fdp->fd_spin); 630 fdp->fd_holdleaderscount--; 631 if (fdp->fd_holdleaderscount == 0 && 632 fdp->fd_holdleaderswakeup != 0) { 633 fdp->fd_holdleaderswakeup = 0; 634 spin_unlock(&fdp->fd_spin); 635 wakeup(&fdp->fd_holdleaderscount); 636 } else { 637 spin_unlock(&fdp->fd_spin); 638 } 639 } 640 } 641 return (0); 642 } 643 644 /* 645 * If sigio is on the list associated with a process or process group, 646 * disable signalling from the device, remove sigio from the list and 647 * free sigio. 648 */ 649 void 650 funsetown(struct sigio *sigio) 651 { 652 if (sigio == NULL) 653 return; 654 crit_enter(); 655 *(sigio->sio_myref) = NULL; 656 crit_exit(); 657 if (sigio->sio_pgid < 0) { 658 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 659 sigio, sio_pgsigio); 660 } else /* if ((*sigiop)->sio_pgid > 0) */ { 661 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 662 sigio, sio_pgsigio); 663 } 664 crfree(sigio->sio_ucred); 665 kfree(sigio, M_SIGIO); 666 } 667 668 /* Free a list of sigio structures. */ 669 void 670 funsetownlst(struct sigiolst *sigiolst) 671 { 672 struct sigio *sigio; 673 674 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) 675 funsetown(sigio); 676 } 677 678 /* 679 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 680 * 681 * After permission checking, add a sigio structure to the sigio list for 682 * the process or process group. 683 */ 684 int 685 fsetown(pid_t pgid, struct sigio **sigiop) 686 { 687 struct proc *proc; 688 struct pgrp *pgrp; 689 struct sigio *sigio; 690 691 if (pgid == 0) { 692 funsetown(*sigiop); 693 return (0); 694 } 695 if (pgid > 0) { 696 proc = pfind(pgid); 697 if (proc == NULL) 698 return (ESRCH); 699 700 /* 701 * Policy - Don't allow a process to FSETOWN a process 702 * in another session. 703 * 704 * Remove this test to allow maximum flexibility or 705 * restrict FSETOWN to the current process or process 706 * group for maximum safety. 707 */ 708 if (proc->p_session != curproc->p_session) 709 return (EPERM); 710 711 pgrp = NULL; 712 } else /* if (pgid < 0) */ { 713 pgrp = pgfind(-pgid); 714 if (pgrp == NULL) 715 return (ESRCH); 716 717 /* 718 * Policy - Don't allow a process to FSETOWN a process 719 * in another session. 720 * 721 * Remove this test to allow maximum flexibility or 722 * restrict FSETOWN to the current process or process 723 * group for maximum safety. 724 */ 725 if (pgrp->pg_session != curproc->p_session) 726 return (EPERM); 727 728 proc = NULL; 729 } 730 funsetown(*sigiop); 731 sigio = kmalloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 732 if (pgid > 0) { 733 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 734 sigio->sio_proc = proc; 735 } else { 736 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 737 sigio->sio_pgrp = pgrp; 738 } 739 sigio->sio_pgid = pgid; 740 sigio->sio_ucred = crhold(curthread->td_ucred); 741 /* It would be convenient if p_ruid was in ucred. */ 742 sigio->sio_ruid = sigio->sio_ucred->cr_ruid; 743 sigio->sio_myref = sigiop; 744 crit_enter(); 745 *sigiop = sigio; 746 crit_exit(); 747 return (0); 748 } 749 750 /* 751 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 752 */ 753 pid_t 754 fgetown(struct sigio *sigio) 755 { 756 return (sigio != NULL ? sigio->sio_pgid : 0); 757 } 758 759 /* 760 * Close many file descriptors. 761 * 762 * MPSAFE 763 */ 764 int 765 sys_closefrom(struct closefrom_args *uap) 766 { 767 return(kern_closefrom(uap->fd)); 768 } 769 770 /* 771 * Close all file descriptors greater then or equal to fd 772 * 773 * MPSAFE 774 */ 775 int 776 kern_closefrom(int fd) 777 { 778 struct thread *td = curthread; 779 struct proc *p = td->td_proc; 780 struct filedesc *fdp; 781 782 KKASSERT(p); 783 fdp = p->p_fd; 784 785 if (fd < 0) 786 return (EINVAL); 787 788 /* 789 * NOTE: This function will skip unassociated descriptors and 790 * reserved descriptors that have not yet been assigned. 791 * fd_lastfile can change as a side effect of kern_close(). 792 */ 793 spin_lock(&fdp->fd_spin); 794 while (fd <= fdp->fd_lastfile) { 795 if (fdp->fd_files[fd].fp != NULL) { 796 spin_unlock(&fdp->fd_spin); 797 /* ok if this races another close */ 798 if (kern_close(fd) == EINTR) 799 return (EINTR); 800 spin_lock(&fdp->fd_spin); 801 } 802 ++fd; 803 } 804 spin_unlock(&fdp->fd_spin); 805 return (0); 806 } 807 808 /* 809 * Close a file descriptor. 810 * 811 * MPSAFE 812 */ 813 int 814 sys_close(struct close_args *uap) 815 { 816 return(kern_close(uap->fd)); 817 } 818 819 /* 820 * MPALMOSTSAFE - acquires mplock around knote_fdclose() calls 821 */ 822 int 823 kern_close(int fd) 824 { 825 struct thread *td = curthread; 826 struct proc *p = td->td_proc; 827 struct filedesc *fdp; 828 struct file *fp; 829 int error; 830 int holdleaders; 831 832 KKASSERT(p); 833 fdp = p->p_fd; 834 835 spin_lock(&fdp->fd_spin); 836 if ((fp = funsetfd_locked(fdp, fd)) == NULL) { 837 spin_unlock(&fdp->fd_spin); 838 return (EBADF); 839 } 840 holdleaders = 0; 841 if (p->p_fdtol != NULL) { 842 /* 843 * Ask fdfree() to sleep to ensure that all relevant 844 * process leaders can be traversed in closef(). 845 */ 846 fdp->fd_holdleaderscount++; 847 holdleaders = 1; 848 } 849 850 /* 851 * we now hold the fp reference that used to be owned by the descriptor 852 * array. 853 */ 854 spin_unlock(&fdp->fd_spin); 855 if (SLIST_FIRST(&fp->f_klist)) 856 knote_fdclose(fp, fdp, fd); 857 error = closef(fp, p); 858 if (holdleaders) { 859 spin_lock(&fdp->fd_spin); 860 fdp->fd_holdleaderscount--; 861 if (fdp->fd_holdleaderscount == 0 && 862 fdp->fd_holdleaderswakeup != 0) { 863 fdp->fd_holdleaderswakeup = 0; 864 spin_unlock(&fdp->fd_spin); 865 wakeup(&fdp->fd_holdleaderscount); 866 } else { 867 spin_unlock(&fdp->fd_spin); 868 } 869 } 870 return (error); 871 } 872 873 /* 874 * shutdown_args(int fd, int how) 875 */ 876 int 877 kern_shutdown(int fd, int how) 878 { 879 struct thread *td = curthread; 880 struct proc *p = td->td_proc; 881 struct file *fp; 882 int error; 883 884 KKASSERT(p); 885 886 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 887 return (EBADF); 888 error = fo_shutdown(fp, how); 889 fdrop(fp); 890 891 return (error); 892 } 893 894 /* 895 * MPALMOSTSAFE 896 */ 897 int 898 sys_shutdown(struct shutdown_args *uap) 899 { 900 int error; 901 902 get_mplock(); 903 error = kern_shutdown(uap->s, uap->how); 904 rel_mplock(); 905 906 return (error); 907 } 908 909 /* 910 * MPSAFE 911 */ 912 int 913 kern_fstat(int fd, struct stat *ub) 914 { 915 struct thread *td = curthread; 916 struct proc *p = td->td_proc; 917 struct file *fp; 918 int error; 919 920 KKASSERT(p); 921 922 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 923 return (EBADF); 924 error = fo_stat(fp, ub, td->td_ucred); 925 fdrop(fp); 926 927 return (error); 928 } 929 930 /* 931 * Return status information about a file descriptor. 932 * 933 * MPSAFE 934 */ 935 int 936 sys_fstat(struct fstat_args *uap) 937 { 938 struct stat st; 939 int error; 940 941 error = kern_fstat(uap->fd, &st); 942 943 if (error == 0) 944 error = copyout(&st, uap->sb, sizeof(st)); 945 return (error); 946 } 947 948 /* 949 * Return pathconf information about a file descriptor. 950 * 951 * MPALMOSTSAFE 952 */ 953 int 954 sys_fpathconf(struct fpathconf_args *uap) 955 { 956 struct thread *td = curthread; 957 struct proc *p = td->td_proc; 958 struct file *fp; 959 struct vnode *vp; 960 int error = 0; 961 962 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL) 963 return (EBADF); 964 965 switch (fp->f_type) { 966 case DTYPE_PIPE: 967 case DTYPE_SOCKET: 968 if (uap->name != _PC_PIPE_BUF) { 969 error = EINVAL; 970 } else { 971 uap->sysmsg_result = PIPE_BUF; 972 error = 0; 973 } 974 break; 975 case DTYPE_FIFO: 976 case DTYPE_VNODE: 977 vp = (struct vnode *)fp->f_data; 978 get_mplock(); 979 error = VOP_PATHCONF(vp, uap->name, &uap->sysmsg_reg); 980 rel_mplock(); 981 break; 982 default: 983 error = EOPNOTSUPP; 984 break; 985 } 986 fdrop(fp); 987 return(error); 988 } 989 990 static int fdexpand; 991 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 992 0, ""); 993 994 /* 995 * Grow the file table so it can hold through descriptor (want). 996 * 997 * The fdp's spinlock must be held exclusively on entry and may be held 998 * exclusively on return. The spinlock may be cycled by the routine. 999 * 1000 * MPSAFE 1001 */ 1002 static void 1003 fdgrow_locked(struct filedesc *fdp, int want) 1004 { 1005 struct fdnode *newfiles; 1006 struct fdnode *oldfiles; 1007 int nf, extra; 1008 1009 nf = fdp->fd_nfiles; 1010 do { 1011 /* nf has to be of the form 2^n - 1 */ 1012 nf = 2 * nf + 1; 1013 } while (nf <= want); 1014 1015 spin_unlock(&fdp->fd_spin); 1016 newfiles = kmalloc(nf * sizeof(struct fdnode), M_FILEDESC, M_WAITOK); 1017 spin_lock(&fdp->fd_spin); 1018 1019 /* 1020 * We could have raced another extend while we were not holding 1021 * the spinlock. 1022 */ 1023 if (fdp->fd_nfiles >= nf) { 1024 spin_unlock(&fdp->fd_spin); 1025 kfree(newfiles, M_FILEDESC); 1026 spin_lock(&fdp->fd_spin); 1027 return; 1028 } 1029 /* 1030 * Copy the existing ofile and ofileflags arrays 1031 * and zero the new portion of each array. 1032 */ 1033 extra = nf - fdp->fd_nfiles; 1034 bcopy(fdp->fd_files, newfiles, fdp->fd_nfiles * sizeof(struct fdnode)); 1035 bzero(&newfiles[fdp->fd_nfiles], extra * sizeof(struct fdnode)); 1036 1037 oldfiles = fdp->fd_files; 1038 fdp->fd_files = newfiles; 1039 fdp->fd_nfiles = nf; 1040 1041 if (oldfiles != fdp->fd_builtin_files) { 1042 spin_unlock(&fdp->fd_spin); 1043 kfree(oldfiles, M_FILEDESC); 1044 spin_lock(&fdp->fd_spin); 1045 } 1046 fdexpand++; 1047 } 1048 1049 /* 1050 * Number of nodes in right subtree, including the root. 1051 */ 1052 static __inline int 1053 right_subtree_size(int n) 1054 { 1055 return (n ^ (n | (n + 1))); 1056 } 1057 1058 /* 1059 * Bigger ancestor. 1060 */ 1061 static __inline int 1062 right_ancestor(int n) 1063 { 1064 return (n | (n + 1)); 1065 } 1066 1067 /* 1068 * Smaller ancestor. 1069 */ 1070 static __inline int 1071 left_ancestor(int n) 1072 { 1073 return ((n & (n + 1)) - 1); 1074 } 1075 1076 /* 1077 * Traverse the in-place binary tree buttom-up adjusting the allocation 1078 * count so scans can determine where free descriptors are located. 1079 * 1080 * MPSAFE - caller must be holding an exclusive spinlock on fdp 1081 */ 1082 static 1083 void 1084 fdreserve_locked(struct filedesc *fdp, int fd, int incr) 1085 { 1086 while (fd >= 0) { 1087 fdp->fd_files[fd].allocated += incr; 1088 KKASSERT(fdp->fd_files[fd].allocated >= 0); 1089 fd = left_ancestor(fd); 1090 } 1091 } 1092 1093 /* 1094 * Reserve a file descriptor for the process. If no error occurs, the 1095 * caller MUST at some point call fsetfd() or assign a file pointer 1096 * or dispose of the reservation. 1097 * 1098 * MPSAFE 1099 */ 1100 int 1101 fdalloc(struct proc *p, int want, int *result) 1102 { 1103 struct filedesc *fdp = p->p_fd; 1104 struct uidinfo *uip; 1105 int fd, rsize, rsum, node, lim; 1106 1107 /* 1108 * Check dtable size limit 1109 */ 1110 spin_lock(&p->p_limit->p_spin); 1111 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 1112 lim = INT_MAX; 1113 else 1114 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 1115 spin_unlock(&p->p_limit->p_spin); 1116 1117 if (lim > maxfilesperproc) 1118 lim = maxfilesperproc; 1119 if (lim < minfilesperproc) 1120 lim = minfilesperproc; 1121 if (want >= lim) 1122 return (EMFILE); 1123 1124 /* 1125 * Check that the user has not run out of descriptors (non-root only). 1126 * As a safety measure the dtable is allowed to have at least 1127 * minfilesperproc open fds regardless of the maxfilesperuser limit. 1128 */ 1129 if (p->p_ucred->cr_uid && fdp->fd_nfiles >= minfilesperproc) { 1130 uip = p->p_ucred->cr_uidinfo; 1131 if (uip->ui_openfiles > maxfilesperuser) { 1132 krateprintf(&krate_uidinfo, 1133 "Warning: user %d pid %d (%s) ran out of " 1134 "file descriptors (%d/%d)\n", 1135 p->p_ucred->cr_uid, (int)p->p_pid, 1136 p->p_comm, 1137 uip->ui_openfiles, maxfilesperuser); 1138 return(ENFILE); 1139 } 1140 } 1141 1142 /* 1143 * Grow the dtable if necessary 1144 */ 1145 spin_lock(&fdp->fd_spin); 1146 if (want >= fdp->fd_nfiles) 1147 fdgrow_locked(fdp, want); 1148 1149 /* 1150 * Search for a free descriptor starting at the higher 1151 * of want or fd_freefile. If that fails, consider 1152 * expanding the ofile array. 1153 * 1154 * NOTE! the 'allocated' field is a cumulative recursive allocation 1155 * count. If we happen to see a value of 0 then we can shortcut 1156 * our search. Otherwise we run through through the tree going 1157 * down branches we know have free descriptor(s) until we hit a 1158 * leaf node. The leaf node will be free but will not necessarily 1159 * have an allocated field of 0. 1160 */ 1161 retry: 1162 /* move up the tree looking for a subtree with a free node */ 1163 for (fd = max(want, fdp->fd_freefile); fd < min(fdp->fd_nfiles, lim); 1164 fd = right_ancestor(fd)) { 1165 if (fdp->fd_files[fd].allocated == 0) 1166 goto found; 1167 1168 rsize = right_subtree_size(fd); 1169 if (fdp->fd_files[fd].allocated == rsize) 1170 continue; /* right subtree full */ 1171 1172 /* 1173 * Free fd is in the right subtree of the tree rooted at fd. 1174 * Call that subtree R. Look for the smallest (leftmost) 1175 * subtree of R with an unallocated fd: continue moving 1176 * down the left branch until encountering a full left 1177 * subtree, then move to the right. 1178 */ 1179 for (rsum = 0, rsize /= 2; rsize > 0; rsize /= 2) { 1180 node = fd + rsize; 1181 rsum += fdp->fd_files[node].allocated; 1182 if (fdp->fd_files[fd].allocated == rsum + rsize) { 1183 fd = node; /* move to the right */ 1184 if (fdp->fd_files[node].allocated == 0) 1185 goto found; 1186 rsum = 0; 1187 } 1188 } 1189 goto found; 1190 } 1191 1192 /* 1193 * No space in current array. Expand? 1194 */ 1195 if (fdp->fd_nfiles >= lim) { 1196 spin_unlock(&fdp->fd_spin); 1197 return (EMFILE); 1198 } 1199 fdgrow_locked(fdp, want); 1200 goto retry; 1201 1202 found: 1203 KKASSERT(fd < fdp->fd_nfiles); 1204 if (fd > fdp->fd_lastfile) 1205 fdp->fd_lastfile = fd; 1206 if (want <= fdp->fd_freefile) 1207 fdp->fd_freefile = fd; 1208 *result = fd; 1209 KKASSERT(fdp->fd_files[fd].fp == NULL); 1210 KKASSERT(fdp->fd_files[fd].reserved == 0); 1211 fdp->fd_files[fd].fileflags = 0; 1212 fdp->fd_files[fd].reserved = 1; 1213 fdreserve_locked(fdp, fd, 1); 1214 spin_unlock(&fdp->fd_spin); 1215 return (0); 1216 } 1217 1218 /* 1219 * Check to see whether n user file descriptors 1220 * are available to the process p. 1221 * 1222 * MPSAFE 1223 */ 1224 int 1225 fdavail(struct proc *p, int n) 1226 { 1227 struct filedesc *fdp = p->p_fd; 1228 struct fdnode *fdnode; 1229 int i, lim, last; 1230 1231 spin_lock(&p->p_limit->p_spin); 1232 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 1233 lim = INT_MAX; 1234 else 1235 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 1236 spin_unlock(&p->p_limit->p_spin); 1237 1238 if (lim > maxfilesperproc) 1239 lim = maxfilesperproc; 1240 if (lim < minfilesperproc) 1241 lim = minfilesperproc; 1242 1243 spin_lock(&fdp->fd_spin); 1244 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) { 1245 spin_unlock(&fdp->fd_spin); 1246 return (1); 1247 } 1248 last = min(fdp->fd_nfiles, lim); 1249 fdnode = &fdp->fd_files[fdp->fd_freefile]; 1250 for (i = last - fdp->fd_freefile; --i >= 0; ++fdnode) { 1251 if (fdnode->fp == NULL && --n <= 0) { 1252 spin_unlock(&fdp->fd_spin); 1253 return (1); 1254 } 1255 } 1256 spin_unlock(&fdp->fd_spin); 1257 return (0); 1258 } 1259 1260 /* 1261 * Revoke open descriptors referencing (f_data, f_type) 1262 * 1263 * Any revoke executed within a prison is only able to 1264 * revoke descriptors for processes within that prison. 1265 * 1266 * Returns 0 on success or an error code. 1267 */ 1268 struct fdrevoke_info { 1269 void *data; 1270 short type; 1271 short unused; 1272 int count; 1273 int intransit; 1274 struct ucred *cred; 1275 struct file *nfp; 1276 }; 1277 1278 static int fdrevoke_check_callback(struct file *fp, void *vinfo); 1279 static int fdrevoke_proc_callback(struct proc *p, void *vinfo); 1280 1281 int 1282 fdrevoke(void *f_data, short f_type, struct ucred *cred) 1283 { 1284 struct fdrevoke_info info; 1285 int error; 1286 1287 bzero(&info, sizeof(info)); 1288 info.data = f_data; 1289 info.type = f_type; 1290 info.cred = cred; 1291 error = falloc(NULL, &info.nfp, NULL); 1292 if (error) 1293 return (error); 1294 1295 /* 1296 * Scan the file pointer table once. dups do not dup file pointers, 1297 * only descriptors, so there is no leak. Set FREVOKED on the fps 1298 * being revoked. 1299 */ 1300 allfiles_scan_exclusive(fdrevoke_check_callback, &info); 1301 1302 /* 1303 * If any fps were marked track down the related descriptors 1304 * and close them. Any dup()s at this point will notice 1305 * the FREVOKED already set in the fp and do the right thing. 1306 * 1307 * Any fps with non-zero msgcounts (aka sent over a unix-domain 1308 * socket) bumped the intransit counter and will require a 1309 * scan. Races against fps leaving the socket are closed by 1310 * the socket code checking for FREVOKED. 1311 */ 1312 if (info.count) 1313 allproc_scan(fdrevoke_proc_callback, &info); 1314 if (info.intransit) 1315 unp_revoke_gc(info.nfp); 1316 fdrop(info.nfp); 1317 return(0); 1318 } 1319 1320 /* 1321 * Locate matching file pointers directly. 1322 */ 1323 static int 1324 fdrevoke_check_callback(struct file *fp, void *vinfo) 1325 { 1326 struct fdrevoke_info *info = vinfo; 1327 1328 /* 1329 * File pointers already flagged for revokation are skipped. 1330 */ 1331 if (fp->f_flag & FREVOKED) 1332 return(0); 1333 1334 /* 1335 * If revoking from a prison file pointers created outside of 1336 * that prison, or file pointers without creds, cannot be revoked. 1337 */ 1338 if (info->cred->cr_prison && 1339 (fp->f_cred == NULL || 1340 info->cred->cr_prison != fp->f_cred->cr_prison)) { 1341 return(0); 1342 } 1343 1344 /* 1345 * If the file pointer matches then mark it for revocation. The 1346 * flag is currently only used by unp_revoke_gc(). 1347 * 1348 * info->count is a heuristic and can race in a SMP environment. 1349 */ 1350 if (info->data == fp->f_data && info->type == fp->f_type) { 1351 atomic_set_int(&fp->f_flag, FREVOKED); 1352 info->count += fp->f_count; 1353 if (fp->f_msgcount) 1354 ++info->intransit; 1355 } 1356 return(0); 1357 } 1358 1359 /* 1360 * Locate matching file pointers via process descriptor tables. 1361 */ 1362 static int 1363 fdrevoke_proc_callback(struct proc *p, void *vinfo) 1364 { 1365 struct fdrevoke_info *info = vinfo; 1366 struct filedesc *fdp; 1367 struct file *fp; 1368 int n; 1369 1370 if (p->p_stat == SIDL || p->p_stat == SZOMB) 1371 return(0); 1372 if (info->cred->cr_prison && 1373 info->cred->cr_prison != p->p_ucred->cr_prison) { 1374 return(0); 1375 } 1376 1377 /* 1378 * If the controlling terminal of the process matches the 1379 * vnode being revoked we clear the controlling terminal. 1380 * 1381 * The normal spec_close() may not catch this because it 1382 * uses curproc instead of p. 1383 */ 1384 if (p->p_session && info->type == DTYPE_VNODE && 1385 info->data == p->p_session->s_ttyvp) { 1386 p->p_session->s_ttyvp = NULL; 1387 vrele(info->data); 1388 } 1389 1390 /* 1391 * Softref the fdp to prevent it from being destroyed 1392 */ 1393 spin_lock(&p->p_spin); 1394 if ((fdp = p->p_fd) == NULL) { 1395 spin_unlock(&p->p_spin); 1396 return(0); 1397 } 1398 atomic_add_int(&fdp->fd_softrefs, 1); 1399 spin_unlock(&p->p_spin); 1400 1401 /* 1402 * Locate and close any matching file descriptors. 1403 */ 1404 spin_lock(&fdp->fd_spin); 1405 for (n = 0; n < fdp->fd_nfiles; ++n) { 1406 if ((fp = fdp->fd_files[n].fp) == NULL) 1407 continue; 1408 if (fp->f_flag & FREVOKED) { 1409 fhold(info->nfp); 1410 fdp->fd_files[n].fp = info->nfp; 1411 spin_unlock(&fdp->fd_spin); 1412 knote_fdclose(fp, fdp, n); /* XXX */ 1413 closef(fp, p); 1414 spin_lock(&fdp->fd_spin); 1415 --info->count; 1416 } 1417 } 1418 spin_unlock(&fdp->fd_spin); 1419 atomic_subtract_int(&fdp->fd_softrefs, 1); 1420 return(0); 1421 } 1422 1423 /* 1424 * falloc: 1425 * Create a new open file structure and reserve a file decriptor 1426 * for the process that refers to it. 1427 * 1428 * Root creds are checked using lp, or assumed if lp is NULL. If 1429 * resultfd is non-NULL then lp must also be non-NULL. No file 1430 * descriptor is reserved (and no process context is needed) if 1431 * resultfd is NULL. 1432 * 1433 * A file pointer with a refcount of 1 is returned. Note that the 1434 * file pointer is NOT associated with the descriptor. If falloc 1435 * returns success, fsetfd() MUST be called to either associate the 1436 * file pointer or clear the reservation. 1437 * 1438 * MPSAFE 1439 */ 1440 int 1441 falloc(struct lwp *lp, struct file **resultfp, int *resultfd) 1442 { 1443 static struct timeval lastfail; 1444 static int curfail; 1445 struct file *fp; 1446 struct ucred *cred = lp ? lp->lwp_thread->td_ucred : proc0.p_ucred; 1447 int error; 1448 1449 fp = NULL; 1450 1451 /* 1452 * Handle filetable full issues and root overfill. 1453 */ 1454 if (nfiles >= maxfiles - maxfilesrootres && 1455 (cred->cr_ruid != 0 || nfiles >= maxfiles)) { 1456 if (ppsratecheck(&lastfail, &curfail, 1)) { 1457 kprintf("kern.maxfiles limit exceeded by uid %d, " 1458 "please see tuning(7).\n", 1459 cred->cr_ruid); 1460 } 1461 error = ENFILE; 1462 goto done; 1463 } 1464 1465 /* 1466 * Allocate a new file descriptor. 1467 */ 1468 fp = kmalloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO); 1469 spin_init(&fp->f_spin); 1470 SLIST_INIT(&fp->f_klist); 1471 fp->f_count = 1; 1472 fp->f_ops = &badfileops; 1473 fp->f_seqcount = 1; 1474 fsetcred(fp, cred); 1475 spin_lock(&filehead_spin); 1476 nfiles++; 1477 LIST_INSERT_HEAD(&filehead, fp, f_list); 1478 spin_unlock(&filehead_spin); 1479 if (resultfd) { 1480 if ((error = fdalloc(lp->lwp_proc, 0, resultfd)) != 0) { 1481 fdrop(fp); 1482 fp = NULL; 1483 } 1484 } else { 1485 error = 0; 1486 } 1487 done: 1488 *resultfp = fp; 1489 return (error); 1490 } 1491 1492 /* 1493 * Check for races against a file descriptor by determining that the 1494 * file pointer is still associated with the specified file descriptor, 1495 * and a close is not currently in progress. 1496 * 1497 * MPSAFE 1498 */ 1499 int 1500 checkfdclosed(struct filedesc *fdp, int fd, struct file *fp) 1501 { 1502 int error; 1503 1504 spin_lock(&fdp->fd_spin); 1505 if ((unsigned)fd >= fdp->fd_nfiles || fp != fdp->fd_files[fd].fp) 1506 error = EBADF; 1507 else 1508 error = 0; 1509 spin_unlock(&fdp->fd_spin); 1510 return (error); 1511 } 1512 1513 /* 1514 * Associate a file pointer with a previously reserved file descriptor. 1515 * This function always succeeds. 1516 * 1517 * If fp is NULL, the file descriptor is returned to the pool. 1518 */ 1519 1520 /* 1521 * MPSAFE (exclusive spinlock must be held on call) 1522 */ 1523 static void 1524 fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd) 1525 { 1526 KKASSERT((unsigned)fd < fdp->fd_nfiles); 1527 KKASSERT(fdp->fd_files[fd].reserved != 0); 1528 if (fp) { 1529 fhold(fp); 1530 fdp->fd_files[fd].fp = fp; 1531 fdp->fd_files[fd].reserved = 0; 1532 } else { 1533 fdp->fd_files[fd].reserved = 0; 1534 fdreserve_locked(fdp, fd, -1); 1535 fdfixup_locked(fdp, fd); 1536 } 1537 } 1538 1539 /* 1540 * MPSAFE 1541 */ 1542 void 1543 fsetfd(struct filedesc *fdp, struct file *fp, int fd) 1544 { 1545 spin_lock(&fdp->fd_spin); 1546 fsetfd_locked(fdp, fp, fd); 1547 spin_unlock(&fdp->fd_spin); 1548 } 1549 1550 /* 1551 * MPSAFE (exclusive spinlock must be held on call) 1552 */ 1553 static 1554 struct file * 1555 funsetfd_locked(struct filedesc *fdp, int fd) 1556 { 1557 struct file *fp; 1558 1559 if ((unsigned)fd >= fdp->fd_nfiles) 1560 return (NULL); 1561 if ((fp = fdp->fd_files[fd].fp) == NULL) 1562 return (NULL); 1563 fdp->fd_files[fd].fp = NULL; 1564 fdp->fd_files[fd].fileflags = 0; 1565 1566 fdreserve_locked(fdp, fd, -1); 1567 fdfixup_locked(fdp, fd); 1568 return(fp); 1569 } 1570 1571 /* 1572 * MPSAFE 1573 */ 1574 int 1575 fgetfdflags(struct filedesc *fdp, int fd, int *flagsp) 1576 { 1577 int error; 1578 1579 spin_lock(&fdp->fd_spin); 1580 if (((u_int)fd) >= fdp->fd_nfiles) { 1581 error = EBADF; 1582 } else if (fdp->fd_files[fd].fp == NULL) { 1583 error = EBADF; 1584 } else { 1585 *flagsp = fdp->fd_files[fd].fileflags; 1586 error = 0; 1587 } 1588 spin_unlock(&fdp->fd_spin); 1589 return (error); 1590 } 1591 1592 /* 1593 * MPSAFE 1594 */ 1595 int 1596 fsetfdflags(struct filedesc *fdp, int fd, int add_flags) 1597 { 1598 int error; 1599 1600 spin_lock(&fdp->fd_spin); 1601 if (((u_int)fd) >= fdp->fd_nfiles) { 1602 error = EBADF; 1603 } else if (fdp->fd_files[fd].fp == NULL) { 1604 error = EBADF; 1605 } else { 1606 fdp->fd_files[fd].fileflags |= add_flags; 1607 error = 0; 1608 } 1609 spin_unlock(&fdp->fd_spin); 1610 return (error); 1611 } 1612 1613 /* 1614 * MPSAFE 1615 */ 1616 int 1617 fclrfdflags(struct filedesc *fdp, int fd, int rem_flags) 1618 { 1619 int error; 1620 1621 spin_lock(&fdp->fd_spin); 1622 if (((u_int)fd) >= fdp->fd_nfiles) { 1623 error = EBADF; 1624 } else if (fdp->fd_files[fd].fp == NULL) { 1625 error = EBADF; 1626 } else { 1627 fdp->fd_files[fd].fileflags &= ~rem_flags; 1628 error = 0; 1629 } 1630 spin_unlock(&fdp->fd_spin); 1631 return (error); 1632 } 1633 1634 /* 1635 * Set/Change/Clear the creds for a fp and synchronize the uidinfo. 1636 */ 1637 void 1638 fsetcred(struct file *fp, struct ucred *ncr) 1639 { 1640 struct ucred *ocr; 1641 struct uidinfo *uip; 1642 1643 ocr = fp->f_cred; 1644 if (ocr == NULL || ncr == NULL || ocr->cr_uidinfo != ncr->cr_uidinfo) { 1645 if (ocr) { 1646 uip = ocr->cr_uidinfo; 1647 atomic_add_int(&uip->ui_openfiles, -1); 1648 } 1649 if (ncr) { 1650 uip = ncr->cr_uidinfo; 1651 atomic_add_int(&uip->ui_openfiles, 1); 1652 } 1653 } 1654 if (ncr) 1655 crhold(ncr); 1656 fp->f_cred = ncr; 1657 if (ocr) 1658 crfree(ocr); 1659 } 1660 1661 /* 1662 * Free a file descriptor. 1663 */ 1664 static 1665 void 1666 ffree(struct file *fp) 1667 { 1668 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!")); 1669 spin_lock(&filehead_spin); 1670 LIST_REMOVE(fp, f_list); 1671 nfiles--; 1672 spin_unlock(&filehead_spin); 1673 fsetcred(fp, NULL); 1674 if (fp->f_nchandle.ncp) 1675 cache_drop(&fp->f_nchandle); 1676 kfree(fp, M_FILE); 1677 } 1678 1679 /* 1680 * called from init_main, initialize filedesc0 for proc0. 1681 */ 1682 void 1683 fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask) 1684 { 1685 p0->p_fd = fdp0; 1686 p0->p_fdtol = NULL; 1687 fdp0->fd_refcnt = 1; 1688 fdp0->fd_cmask = cmask; 1689 fdp0->fd_files = fdp0->fd_builtin_files; 1690 fdp0->fd_nfiles = NDFILE; 1691 fdp0->fd_lastfile = -1; 1692 spin_init(&fdp0->fd_spin); 1693 } 1694 1695 /* 1696 * Build a new filedesc structure. 1697 * 1698 * NOT MPSAFE (vref) 1699 */ 1700 struct filedesc * 1701 fdinit(struct proc *p) 1702 { 1703 struct filedesc *newfdp; 1704 struct filedesc *fdp = p->p_fd; 1705 1706 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK|M_ZERO); 1707 spin_lock(&fdp->fd_spin); 1708 if (fdp->fd_cdir) { 1709 newfdp->fd_cdir = fdp->fd_cdir; 1710 vref(newfdp->fd_cdir); 1711 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir); 1712 } 1713 1714 /* 1715 * rdir may not be set in e.g. proc0 or anything vm_fork'd off of 1716 * proc0, but should unconditionally exist in other processes. 1717 */ 1718 if (fdp->fd_rdir) { 1719 newfdp->fd_rdir = fdp->fd_rdir; 1720 vref(newfdp->fd_rdir); 1721 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir); 1722 } 1723 if (fdp->fd_jdir) { 1724 newfdp->fd_jdir = fdp->fd_jdir; 1725 vref(newfdp->fd_jdir); 1726 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir); 1727 } 1728 spin_unlock(&fdp->fd_spin); 1729 1730 /* Create the file descriptor table. */ 1731 newfdp->fd_refcnt = 1; 1732 newfdp->fd_cmask = cmask; 1733 newfdp->fd_files = newfdp->fd_builtin_files; 1734 newfdp->fd_nfiles = NDFILE; 1735 newfdp->fd_lastfile = -1; 1736 spin_init(&newfdp->fd_spin); 1737 1738 return (newfdp); 1739 } 1740 1741 /* 1742 * Share a filedesc structure. 1743 * 1744 * MPSAFE 1745 */ 1746 struct filedesc * 1747 fdshare(struct proc *p) 1748 { 1749 struct filedesc *fdp; 1750 1751 fdp = p->p_fd; 1752 spin_lock(&fdp->fd_spin); 1753 fdp->fd_refcnt++; 1754 spin_unlock(&fdp->fd_spin); 1755 return (fdp); 1756 } 1757 1758 /* 1759 * Copy a filedesc structure. 1760 * 1761 * MPSAFE 1762 */ 1763 struct filedesc * 1764 fdcopy(struct proc *p) 1765 { 1766 struct filedesc *fdp = p->p_fd; 1767 struct filedesc *newfdp; 1768 struct fdnode *fdnode; 1769 int i; 1770 int ni; 1771 1772 /* 1773 * Certain daemons might not have file descriptors. 1774 */ 1775 if (fdp == NULL) 1776 return (NULL); 1777 1778 /* 1779 * Allocate the new filedesc and fd_files[] array. This can race 1780 * with operations by other threads on the fdp so we have to be 1781 * careful. 1782 */ 1783 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK | M_ZERO); 1784 again: 1785 spin_lock(&fdp->fd_spin); 1786 if (fdp->fd_lastfile < NDFILE) { 1787 newfdp->fd_files = newfdp->fd_builtin_files; 1788 i = NDFILE; 1789 } else { 1790 /* 1791 * We have to allocate (N^2-1) entries for our in-place 1792 * binary tree. Allow the table to shrink. 1793 */ 1794 i = fdp->fd_nfiles; 1795 ni = (i - 1) / 2; 1796 while (ni > fdp->fd_lastfile && ni > NDFILE) { 1797 i = ni; 1798 ni = (i - 1) / 2; 1799 } 1800 spin_unlock(&fdp->fd_spin); 1801 newfdp->fd_files = kmalloc(i * sizeof(struct fdnode), 1802 M_FILEDESC, M_WAITOK | M_ZERO); 1803 1804 /* 1805 * Check for race, retry 1806 */ 1807 spin_lock(&fdp->fd_spin); 1808 if (i <= fdp->fd_lastfile) { 1809 spin_unlock(&fdp->fd_spin); 1810 kfree(newfdp->fd_files, M_FILEDESC); 1811 goto again; 1812 } 1813 } 1814 1815 /* 1816 * Dup the remaining fields. vref() and cache_hold() can be 1817 * safely called while holding the read spinlock on fdp. 1818 * 1819 * The read spinlock on fdp is still being held. 1820 * 1821 * NOTE: vref and cache_hold calls for the case where the vnode 1822 * or cache entry already has at least one ref may be called 1823 * while holding spin locks. 1824 */ 1825 if ((newfdp->fd_cdir = fdp->fd_cdir) != NULL) { 1826 vref(newfdp->fd_cdir); 1827 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir); 1828 } 1829 /* 1830 * We must check for fd_rdir here, at least for now because 1831 * the init process is created before we have access to the 1832 * rootvode to take a reference to it. 1833 */ 1834 if ((newfdp->fd_rdir = fdp->fd_rdir) != NULL) { 1835 vref(newfdp->fd_rdir); 1836 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir); 1837 } 1838 if ((newfdp->fd_jdir = fdp->fd_jdir) != NULL) { 1839 vref(newfdp->fd_jdir); 1840 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir); 1841 } 1842 newfdp->fd_refcnt = 1; 1843 newfdp->fd_nfiles = i; 1844 newfdp->fd_lastfile = fdp->fd_lastfile; 1845 newfdp->fd_freefile = fdp->fd_freefile; 1846 newfdp->fd_cmask = fdp->fd_cmask; 1847 spin_init(&newfdp->fd_spin); 1848 1849 /* 1850 * Copy the descriptor table through (i). This also copies the 1851 * allocation state. Then go through and ref the file pointers 1852 * and clean up any KQ descriptors. 1853 * 1854 * kq descriptors cannot be copied. Since we haven't ref'd the 1855 * copied files yet we can ignore the return value from funsetfd(). 1856 * 1857 * The read spinlock on fdp is still being held. 1858 */ 1859 bcopy(fdp->fd_files, newfdp->fd_files, i * sizeof(struct fdnode)); 1860 for (i = 0 ; i < newfdp->fd_nfiles; ++i) { 1861 fdnode = &newfdp->fd_files[i]; 1862 if (fdnode->reserved) { 1863 fdreserve_locked(newfdp, i, -1); 1864 fdnode->reserved = 0; 1865 fdfixup_locked(newfdp, i); 1866 } else if (fdnode->fp) { 1867 if (fdnode->fp->f_type == DTYPE_KQUEUE) { 1868 (void)funsetfd_locked(newfdp, i); 1869 } else { 1870 fhold(fdnode->fp); 1871 } 1872 } 1873 } 1874 spin_unlock(&fdp->fd_spin); 1875 return (newfdp); 1876 } 1877 1878 /* 1879 * Release a filedesc structure. 1880 * 1881 * NOT MPSAFE (MPSAFE for refs > 1, but the final cleanup code is not MPSAFE) 1882 */ 1883 void 1884 fdfree(struct proc *p, struct filedesc *repl) 1885 { 1886 struct filedesc *fdp; 1887 struct fdnode *fdnode; 1888 int i; 1889 struct filedesc_to_leader *fdtol; 1890 struct file *fp; 1891 struct vnode *vp; 1892 struct flock lf; 1893 1894 /* 1895 * Certain daemons might not have file descriptors. 1896 */ 1897 fdp = p->p_fd; 1898 if (fdp == NULL) { 1899 p->p_fd = repl; 1900 return; 1901 } 1902 1903 /* 1904 * Severe messing around to follow. 1905 */ 1906 spin_lock(&fdp->fd_spin); 1907 1908 /* Check for special need to clear POSIX style locks */ 1909 fdtol = p->p_fdtol; 1910 if (fdtol != NULL) { 1911 KASSERT(fdtol->fdl_refcount > 0, 1912 ("filedesc_to_refcount botch: fdl_refcount=%d", 1913 fdtol->fdl_refcount)); 1914 if (fdtol->fdl_refcount == 1 && 1915 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1916 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1917 fdnode = &fdp->fd_files[i]; 1918 if (fdnode->fp == NULL || 1919 fdnode->fp->f_type != DTYPE_VNODE) { 1920 continue; 1921 } 1922 fp = fdnode->fp; 1923 fhold(fp); 1924 spin_unlock(&fdp->fd_spin); 1925 1926 lf.l_whence = SEEK_SET; 1927 lf.l_start = 0; 1928 lf.l_len = 0; 1929 lf.l_type = F_UNLCK; 1930 vp = (struct vnode *)fp->f_data; 1931 (void) VOP_ADVLOCK(vp, 1932 (caddr_t)p->p_leader, 1933 F_UNLCK, 1934 &lf, 1935 F_POSIX); 1936 fdrop(fp); 1937 spin_lock(&fdp->fd_spin); 1938 } 1939 } 1940 retry: 1941 if (fdtol->fdl_refcount == 1) { 1942 if (fdp->fd_holdleaderscount > 0 && 1943 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1944 /* 1945 * close() or do_dup() has cleared a reference 1946 * in a shared file descriptor table. 1947 */ 1948 fdp->fd_holdleaderswakeup = 1; 1949 ssleep(&fdp->fd_holdleaderscount, 1950 &fdp->fd_spin, 0, "fdlhold", 0); 1951 goto retry; 1952 } 1953 if (fdtol->fdl_holdcount > 0) { 1954 /* 1955 * Ensure that fdtol->fdl_leader 1956 * remains valid in closef(). 1957 */ 1958 fdtol->fdl_wakeup = 1; 1959 ssleep(fdtol, &fdp->fd_spin, 0, "fdlhold", 0); 1960 goto retry; 1961 } 1962 } 1963 fdtol->fdl_refcount--; 1964 if (fdtol->fdl_refcount == 0 && 1965 fdtol->fdl_holdcount == 0) { 1966 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1967 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1968 } else { 1969 fdtol = NULL; 1970 } 1971 p->p_fdtol = NULL; 1972 if (fdtol != NULL) { 1973 spin_unlock(&fdp->fd_spin); 1974 kfree(fdtol, M_FILEDESC_TO_LEADER); 1975 spin_lock(&fdp->fd_spin); 1976 } 1977 } 1978 if (--fdp->fd_refcnt > 0) { 1979 spin_unlock(&fdp->fd_spin); 1980 spin_lock(&p->p_spin); 1981 p->p_fd = repl; 1982 spin_unlock(&p->p_spin); 1983 return; 1984 } 1985 1986 /* 1987 * Even though we are the last reference to the structure allproc 1988 * scans may still reference the structure. Maintain proper 1989 * locks until we can replace p->p_fd. 1990 * 1991 * Also note that kqueue's closef still needs to reference the 1992 * fdp via p->p_fd, so we have to close the descriptors before 1993 * we replace p->p_fd. 1994 */ 1995 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1996 if (fdp->fd_files[i].fp) { 1997 fp = funsetfd_locked(fdp, i); 1998 if (fp) { 1999 spin_unlock(&fdp->fd_spin); 2000 if (SLIST_FIRST(&fp->f_klist)) 2001 knote_fdclose(fp, fdp, i); 2002 closef(fp, p); 2003 spin_lock(&fdp->fd_spin); 2004 } 2005 } 2006 } 2007 spin_unlock(&fdp->fd_spin); 2008 2009 /* 2010 * Interlock against an allproc scan operations (typically frevoke). 2011 */ 2012 spin_lock(&p->p_spin); 2013 p->p_fd = repl; 2014 spin_unlock(&p->p_spin); 2015 2016 /* 2017 * Wait for any softrefs to go away. This race rarely occurs so 2018 * we can use a non-critical-path style poll/sleep loop. The 2019 * race only occurs against allproc scans. 2020 * 2021 * No new softrefs can occur with the fdp disconnected from the 2022 * process. 2023 */ 2024 if (fdp->fd_softrefs) { 2025 kprintf("pid %d: Warning, fdp race avoided\n", p->p_pid); 2026 while (fdp->fd_softrefs) 2027 tsleep(&fdp->fd_softrefs, 0, "fdsoft", 1); 2028 } 2029 2030 if (fdp->fd_files != fdp->fd_builtin_files) 2031 kfree(fdp->fd_files, M_FILEDESC); 2032 if (fdp->fd_cdir) { 2033 cache_drop(&fdp->fd_ncdir); 2034 vrele(fdp->fd_cdir); 2035 } 2036 if (fdp->fd_rdir) { 2037 cache_drop(&fdp->fd_nrdir); 2038 vrele(fdp->fd_rdir); 2039 } 2040 if (fdp->fd_jdir) { 2041 cache_drop(&fdp->fd_njdir); 2042 vrele(fdp->fd_jdir); 2043 } 2044 kfree(fdp, M_FILEDESC); 2045 } 2046 2047 /* 2048 * Retrieve and reference the file pointer associated with a descriptor. 2049 * 2050 * MPSAFE 2051 */ 2052 struct file * 2053 holdfp(struct filedesc *fdp, int fd, int flag) 2054 { 2055 struct file* fp; 2056 2057 spin_lock(&fdp->fd_spin); 2058 if (((u_int)fd) >= fdp->fd_nfiles) { 2059 fp = NULL; 2060 goto done; 2061 } 2062 if ((fp = fdp->fd_files[fd].fp) == NULL) 2063 goto done; 2064 if ((fp->f_flag & flag) == 0 && flag != -1) { 2065 fp = NULL; 2066 goto done; 2067 } 2068 fhold(fp); 2069 done: 2070 spin_unlock(&fdp->fd_spin); 2071 return (fp); 2072 } 2073 2074 /* 2075 * holdsock() - load the struct file pointer associated 2076 * with a socket into *fpp. If an error occurs, non-zero 2077 * will be returned and *fpp will be set to NULL. 2078 * 2079 * MPSAFE 2080 */ 2081 int 2082 holdsock(struct filedesc *fdp, int fd, struct file **fpp) 2083 { 2084 struct file *fp; 2085 int error; 2086 2087 spin_lock(&fdp->fd_spin); 2088 if ((unsigned)fd >= fdp->fd_nfiles) { 2089 error = EBADF; 2090 fp = NULL; 2091 goto done; 2092 } 2093 if ((fp = fdp->fd_files[fd].fp) == NULL) { 2094 error = EBADF; 2095 goto done; 2096 } 2097 if (fp->f_type != DTYPE_SOCKET) { 2098 error = ENOTSOCK; 2099 goto done; 2100 } 2101 fhold(fp); 2102 error = 0; 2103 done: 2104 spin_unlock(&fdp->fd_spin); 2105 *fpp = fp; 2106 return (error); 2107 } 2108 2109 /* 2110 * Convert a user file descriptor to a held file pointer. 2111 * 2112 * MPSAFE 2113 */ 2114 int 2115 holdvnode(struct filedesc *fdp, int fd, struct file **fpp) 2116 { 2117 struct file *fp; 2118 int error; 2119 2120 spin_lock(&fdp->fd_spin); 2121 if ((unsigned)fd >= fdp->fd_nfiles) { 2122 error = EBADF; 2123 fp = NULL; 2124 goto done; 2125 } 2126 if ((fp = fdp->fd_files[fd].fp) == NULL) { 2127 error = EBADF; 2128 goto done; 2129 } 2130 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 2131 fp = NULL; 2132 error = EINVAL; 2133 goto done; 2134 } 2135 fhold(fp); 2136 error = 0; 2137 done: 2138 spin_unlock(&fdp->fd_spin); 2139 *fpp = fp; 2140 return (error); 2141 } 2142 2143 /* 2144 * For setugid programs, we don't want to people to use that setugidness 2145 * to generate error messages which write to a file which otherwise would 2146 * otherwise be off-limits to the process. 2147 * 2148 * This is a gross hack to plug the hole. A better solution would involve 2149 * a special vop or other form of generalized access control mechanism. We 2150 * go ahead and just reject all procfs file systems accesses as dangerous. 2151 * 2152 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 2153 * sufficient. We also don't for check setugidness since we know we are. 2154 */ 2155 static int 2156 is_unsafe(struct file *fp) 2157 { 2158 if (fp->f_type == DTYPE_VNODE && 2159 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS) 2160 return (1); 2161 return (0); 2162 } 2163 2164 /* 2165 * Make this setguid thing safe, if at all possible. 2166 * 2167 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose() 2168 */ 2169 void 2170 setugidsafety(struct proc *p) 2171 { 2172 struct filedesc *fdp = p->p_fd; 2173 int i; 2174 2175 /* Certain daemons might not have file descriptors. */ 2176 if (fdp == NULL) 2177 return; 2178 2179 /* 2180 * note: fdp->fd_files may be reallocated out from under us while 2181 * we are blocked in a close. Be careful! 2182 */ 2183 for (i = 0; i <= fdp->fd_lastfile; i++) { 2184 if (i > 2) 2185 break; 2186 if (fdp->fd_files[i].fp && is_unsafe(fdp->fd_files[i].fp)) { 2187 struct file *fp; 2188 2189 /* 2190 * NULL-out descriptor prior to close to avoid 2191 * a race while close blocks. 2192 */ 2193 if ((fp = funsetfd_locked(fdp, i)) != NULL) { 2194 knote_fdclose(fp, fdp, i); 2195 closef(fp, p); 2196 } 2197 } 2198 } 2199 } 2200 2201 /* 2202 * Close any files on exec? 2203 * 2204 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose() 2205 */ 2206 void 2207 fdcloseexec(struct proc *p) 2208 { 2209 struct filedesc *fdp = p->p_fd; 2210 int i; 2211 2212 /* Certain daemons might not have file descriptors. */ 2213 if (fdp == NULL) 2214 return; 2215 2216 /* 2217 * We cannot cache fd_files since operations may block and rip 2218 * them out from under us. 2219 */ 2220 for (i = 0; i <= fdp->fd_lastfile; i++) { 2221 if (fdp->fd_files[i].fp != NULL && 2222 (fdp->fd_files[i].fileflags & UF_EXCLOSE)) { 2223 struct file *fp; 2224 2225 /* 2226 * NULL-out descriptor prior to close to avoid 2227 * a race while close blocks. 2228 */ 2229 if ((fp = funsetfd_locked(fdp, i)) != NULL) { 2230 knote_fdclose(fp, fdp, i); 2231 closef(fp, p); 2232 } 2233 } 2234 } 2235 } 2236 2237 /* 2238 * It is unsafe for set[ug]id processes to be started with file 2239 * descriptors 0..2 closed, as these descriptors are given implicit 2240 * significance in the Standard C library. fdcheckstd() will create a 2241 * descriptor referencing /dev/null for each of stdin, stdout, and 2242 * stderr that is not already open. 2243 * 2244 * NOT MPSAFE - calls falloc, vn_open, etc 2245 */ 2246 int 2247 fdcheckstd(struct lwp *lp) 2248 { 2249 struct nlookupdata nd; 2250 struct filedesc *fdp; 2251 struct file *fp; 2252 int retval; 2253 int i, error, flags, devnull; 2254 2255 fdp = lp->lwp_proc->p_fd; 2256 if (fdp == NULL) 2257 return (0); 2258 devnull = -1; 2259 error = 0; 2260 for (i = 0; i < 3; i++) { 2261 if (fdp->fd_files[i].fp != NULL) 2262 continue; 2263 if (devnull < 0) { 2264 if ((error = falloc(lp, &fp, &devnull)) != 0) 2265 break; 2266 2267 error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE, 2268 NLC_FOLLOW|NLC_LOCKVP); 2269 flags = FREAD | FWRITE; 2270 if (error == 0) 2271 error = vn_open(&nd, fp, flags, 0); 2272 if (error == 0) 2273 fsetfd(fdp, fp, devnull); 2274 else 2275 fsetfd(fdp, NULL, devnull); 2276 fdrop(fp); 2277 nlookup_done(&nd); 2278 if (error) 2279 break; 2280 KKASSERT(i == devnull); 2281 } else { 2282 error = kern_dup(DUP_FIXED, devnull, i, &retval); 2283 if (error != 0) 2284 break; 2285 } 2286 } 2287 return (error); 2288 } 2289 2290 /* 2291 * Internal form of close. 2292 * Decrement reference count on file structure. 2293 * Note: td and/or p may be NULL when closing a file 2294 * that was being passed in a message. 2295 * 2296 * MPALMOSTSAFE - acquires mplock for VOP operations 2297 */ 2298 int 2299 closef(struct file *fp, struct proc *p) 2300 { 2301 struct vnode *vp; 2302 struct flock lf; 2303 struct filedesc_to_leader *fdtol; 2304 2305 if (fp == NULL) 2306 return (0); 2307 2308 /* 2309 * POSIX record locking dictates that any close releases ALL 2310 * locks owned by this process. This is handled by setting 2311 * a flag in the unlock to free ONLY locks obeying POSIX 2312 * semantics, and not to free BSD-style file locks. 2313 * If the descriptor was in a message, POSIX-style locks 2314 * aren't passed with the descriptor. 2315 */ 2316 if (p != NULL && fp->f_type == DTYPE_VNODE && 2317 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS) 2318 ) { 2319 get_mplock(); 2320 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) { 2321 lf.l_whence = SEEK_SET; 2322 lf.l_start = 0; 2323 lf.l_len = 0; 2324 lf.l_type = F_UNLCK; 2325 vp = (struct vnode *)fp->f_data; 2326 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 2327 &lf, F_POSIX); 2328 } 2329 fdtol = p->p_fdtol; 2330 if (fdtol != NULL) { 2331 /* 2332 * Handle special case where file descriptor table 2333 * is shared between multiple process leaders. 2334 */ 2335 for (fdtol = fdtol->fdl_next; 2336 fdtol != p->p_fdtol; 2337 fdtol = fdtol->fdl_next) { 2338 if ((fdtol->fdl_leader->p_flag & 2339 P_ADVLOCK) == 0) 2340 continue; 2341 fdtol->fdl_holdcount++; 2342 lf.l_whence = SEEK_SET; 2343 lf.l_start = 0; 2344 lf.l_len = 0; 2345 lf.l_type = F_UNLCK; 2346 vp = (struct vnode *)fp->f_data; 2347 (void) VOP_ADVLOCK(vp, 2348 (caddr_t)fdtol->fdl_leader, 2349 F_UNLCK, &lf, F_POSIX); 2350 fdtol->fdl_holdcount--; 2351 if (fdtol->fdl_holdcount == 0 && 2352 fdtol->fdl_wakeup != 0) { 2353 fdtol->fdl_wakeup = 0; 2354 wakeup(fdtol); 2355 } 2356 } 2357 } 2358 rel_mplock(); 2359 } 2360 return (fdrop(fp)); 2361 } 2362 2363 /* 2364 * MPSAFE 2365 * 2366 * fhold() can only be called if f_count is already at least 1 (i.e. the 2367 * caller of fhold() already has a reference to the file pointer in some 2368 * manner or other). 2369 * 2370 * f_count is not spin-locked. Instead, atomic ops are used for 2371 * incrementing, decrementing, and handling the 1->0 transition. 2372 */ 2373 void 2374 fhold(struct file *fp) 2375 { 2376 atomic_add_int(&fp->f_count, 1); 2377 } 2378 2379 /* 2380 * fdrop() - drop a reference to a descriptor 2381 * 2382 * MPALMOSTSAFE - acquires mplock for final close sequence 2383 */ 2384 int 2385 fdrop(struct file *fp) 2386 { 2387 struct flock lf; 2388 struct vnode *vp; 2389 int error; 2390 2391 /* 2392 * A combined fetch and subtract is needed to properly detect 2393 * 1->0 transitions, otherwise two cpus dropping from a ref 2394 * count of 2 might both try to run the 1->0 code. 2395 */ 2396 if (atomic_fetchadd_int(&fp->f_count, -1) > 1) 2397 return (0); 2398 2399 KKASSERT(SLIST_FIRST(&fp->f_klist) == NULL); 2400 get_mplock(); 2401 2402 /* 2403 * The last reference has gone away, we own the fp structure free 2404 * and clear. 2405 */ 2406 if (fp->f_count < 0) 2407 panic("fdrop: count < 0"); 2408 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE && 2409 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS) 2410 ) { 2411 lf.l_whence = SEEK_SET; 2412 lf.l_start = 0; 2413 lf.l_len = 0; 2414 lf.l_type = F_UNLCK; 2415 vp = (struct vnode *)fp->f_data; 2416 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0); 2417 } 2418 if (fp->f_ops != &badfileops) 2419 error = fo_close(fp); 2420 else 2421 error = 0; 2422 ffree(fp); 2423 rel_mplock(); 2424 return (error); 2425 } 2426 2427 /* 2428 * Apply an advisory lock on a file descriptor. 2429 * 2430 * Just attempt to get a record lock of the requested type on 2431 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2432 * 2433 * MPALMOSTSAFE 2434 */ 2435 int 2436 sys_flock(struct flock_args *uap) 2437 { 2438 struct proc *p = curproc; 2439 struct file *fp; 2440 struct vnode *vp; 2441 struct flock lf; 2442 int error; 2443 2444 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL) 2445 return (EBADF); 2446 get_mplock(); 2447 if (fp->f_type != DTYPE_VNODE) { 2448 error = EOPNOTSUPP; 2449 goto done; 2450 } 2451 vp = (struct vnode *)fp->f_data; 2452 lf.l_whence = SEEK_SET; 2453 lf.l_start = 0; 2454 lf.l_len = 0; 2455 if (uap->how & LOCK_UN) { 2456 lf.l_type = F_UNLCK; 2457 fp->f_flag &= ~FHASLOCK; 2458 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0); 2459 goto done; 2460 } 2461 if (uap->how & LOCK_EX) 2462 lf.l_type = F_WRLCK; 2463 else if (uap->how & LOCK_SH) 2464 lf.l_type = F_RDLCK; 2465 else { 2466 error = EBADF; 2467 goto done; 2468 } 2469 fp->f_flag |= FHASLOCK; 2470 if (uap->how & LOCK_NB) 2471 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 0); 2472 else 2473 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_WAIT); 2474 done: 2475 rel_mplock(); 2476 fdrop(fp); 2477 return (error); 2478 } 2479 2480 /* 2481 * File Descriptor pseudo-device driver (/dev/fd/). 2482 * 2483 * Opening minor device N dup()s the file (if any) connected to file 2484 * descriptor N belonging to the calling process. Note that this driver 2485 * consists of only the ``open()'' routine, because all subsequent 2486 * references to this file will be direct to the other driver. 2487 */ 2488 static int 2489 fdopen(struct dev_open_args *ap) 2490 { 2491 thread_t td = curthread; 2492 2493 KKASSERT(td->td_lwp != NULL); 2494 2495 /* 2496 * XXX Kludge: set curlwp->lwp_dupfd to contain the value of the 2497 * the file descriptor being sought for duplication. The error 2498 * return ensures that the vnode for this device will be released 2499 * by vn_open. Open will detect this special error and take the 2500 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 2501 * will simply report the error. 2502 */ 2503 td->td_lwp->lwp_dupfd = minor(ap->a_head.a_dev); 2504 return (ENODEV); 2505 } 2506 2507 /* 2508 * The caller has reserved the file descriptor dfd for us. On success we 2509 * must fsetfd() it. On failure the caller will clean it up. 2510 * 2511 * MPSAFE 2512 */ 2513 int 2514 dupfdopen(struct filedesc *fdp, int dfd, int sfd, int mode, int error) 2515 { 2516 struct file *wfp; 2517 struct file *xfp; 2518 int werror; 2519 2520 if ((wfp = holdfp(fdp, sfd, -1)) == NULL) 2521 return (EBADF); 2522 2523 /* 2524 * Close a revoke/dup race. Duping a descriptor marked as revoked 2525 * will dup a dummy descriptor instead of the real one. 2526 */ 2527 if (wfp->f_flag & FREVOKED) { 2528 kprintf("Warning: attempt to dup() a revoked descriptor\n"); 2529 fdrop(wfp); 2530 wfp = NULL; 2531 werror = falloc(NULL, &wfp, NULL); 2532 if (werror) 2533 return (werror); 2534 } 2535 2536 /* 2537 * There are two cases of interest here. 2538 * 2539 * For ENODEV simply dup sfd to file descriptor dfd and return. 2540 * 2541 * For ENXIO steal away the file structure from sfd and store it 2542 * dfd. sfd is effectively closed by this operation. 2543 * 2544 * Any other error code is just returned. 2545 */ 2546 switch (error) { 2547 case ENODEV: 2548 /* 2549 * Check that the mode the file is being opened for is a 2550 * subset of the mode of the existing descriptor. 2551 */ 2552 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2553 error = EACCES; 2554 break; 2555 } 2556 spin_lock(&fdp->fd_spin); 2557 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags; 2558 fsetfd_locked(fdp, wfp, dfd); 2559 spin_unlock(&fdp->fd_spin); 2560 error = 0; 2561 break; 2562 case ENXIO: 2563 /* 2564 * Steal away the file pointer from dfd, and stuff it into indx. 2565 */ 2566 spin_lock(&fdp->fd_spin); 2567 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags; 2568 fsetfd(fdp, wfp, dfd); 2569 if ((xfp = funsetfd_locked(fdp, sfd)) != NULL) { 2570 spin_unlock(&fdp->fd_spin); 2571 fdrop(xfp); 2572 } else { 2573 spin_unlock(&fdp->fd_spin); 2574 } 2575 error = 0; 2576 break; 2577 default: 2578 break; 2579 } 2580 fdrop(wfp); 2581 return (error); 2582 } 2583 2584 /* 2585 * NOT MPSAFE - I think these refer to a common file descriptor table 2586 * and we need to spinlock that to link fdtol in. 2587 */ 2588 struct filedesc_to_leader * 2589 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 2590 struct proc *leader) 2591 { 2592 struct filedesc_to_leader *fdtol; 2593 2594 fdtol = kmalloc(sizeof(struct filedesc_to_leader), 2595 M_FILEDESC_TO_LEADER, M_WAITOK); 2596 fdtol->fdl_refcount = 1; 2597 fdtol->fdl_holdcount = 0; 2598 fdtol->fdl_wakeup = 0; 2599 fdtol->fdl_leader = leader; 2600 if (old != NULL) { 2601 fdtol->fdl_next = old->fdl_next; 2602 fdtol->fdl_prev = old; 2603 old->fdl_next = fdtol; 2604 fdtol->fdl_next->fdl_prev = fdtol; 2605 } else { 2606 fdtol->fdl_next = fdtol; 2607 fdtol->fdl_prev = fdtol; 2608 } 2609 return fdtol; 2610 } 2611 2612 /* 2613 * Scan all file pointers in the system. The callback is made with 2614 * the master list spinlock held exclusively. 2615 * 2616 * MPSAFE 2617 */ 2618 void 2619 allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data) 2620 { 2621 struct file *fp; 2622 int res; 2623 2624 spin_lock(&filehead_spin); 2625 LIST_FOREACH(fp, &filehead, f_list) { 2626 res = callback(fp, data); 2627 if (res < 0) 2628 break; 2629 } 2630 spin_unlock(&filehead_spin); 2631 } 2632 2633 /* 2634 * Get file structures. 2635 * 2636 * NOT MPSAFE - process list scan, SYSCTL_OUT (probably not mpsafe) 2637 */ 2638 2639 struct sysctl_kern_file_info { 2640 int count; 2641 int error; 2642 struct sysctl_req *req; 2643 }; 2644 2645 static int sysctl_kern_file_callback(struct proc *p, void *data); 2646 2647 static int 2648 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2649 { 2650 struct sysctl_kern_file_info info; 2651 2652 /* 2653 * Note: because the number of file descriptors is calculated 2654 * in different ways for sizing vs returning the data, 2655 * there is information leakage from the first loop. However, 2656 * it is of a similar order of magnitude to the leakage from 2657 * global system statistics such as kern.openfiles. 2658 * 2659 * When just doing a count, note that we cannot just count 2660 * the elements and add f_count via the filehead list because 2661 * threaded processes share their descriptor table and f_count might 2662 * still be '1' in that case. 2663 * 2664 * Since the SYSCTL op can block, we must hold the process to 2665 * prevent it being ripped out from under us either in the 2666 * file descriptor loop or in the greater LIST_FOREACH. The 2667 * process may be in varying states of disrepair. If the process 2668 * is in SZOMB we may have caught it just as it is being removed 2669 * from the allproc list, we must skip it in that case to maintain 2670 * an unbroken chain through the allproc list. 2671 */ 2672 info.count = 0; 2673 info.error = 0; 2674 info.req = req; 2675 allproc_scan(sysctl_kern_file_callback, &info); 2676 2677 /* 2678 * When just calculating the size, overestimate a bit to try to 2679 * prevent system activity from causing the buffer-fill call 2680 * to fail later on. 2681 */ 2682 if (req->oldptr == NULL) { 2683 info.count = (info.count + 16) + (info.count / 10); 2684 info.error = SYSCTL_OUT(req, NULL, 2685 info.count * sizeof(struct kinfo_file)); 2686 } 2687 return (info.error); 2688 } 2689 2690 static int 2691 sysctl_kern_file_callback(struct proc *p, void *data) 2692 { 2693 struct sysctl_kern_file_info *info = data; 2694 struct kinfo_file kf; 2695 struct filedesc *fdp; 2696 struct file *fp; 2697 uid_t uid; 2698 int n; 2699 2700 if (p->p_stat == SIDL || p->p_stat == SZOMB) 2701 return(0); 2702 if (!PRISON_CHECK(info->req->td->td_ucred, p->p_ucred) != 0) 2703 return(0); 2704 2705 /* 2706 * Softref the fdp to prevent it from being destroyed 2707 */ 2708 spin_lock(&p->p_spin); 2709 if ((fdp = p->p_fd) == NULL) { 2710 spin_unlock(&p->p_spin); 2711 return(0); 2712 } 2713 atomic_add_int(&fdp->fd_softrefs, 1); 2714 spin_unlock(&p->p_spin); 2715 2716 /* 2717 * The fdp's own spinlock prevents the contents from being 2718 * modified. 2719 */ 2720 spin_lock(&fdp->fd_spin); 2721 for (n = 0; n < fdp->fd_nfiles; ++n) { 2722 if ((fp = fdp->fd_files[n].fp) == NULL) 2723 continue; 2724 if (info->req->oldptr == NULL) { 2725 ++info->count; 2726 } else { 2727 uid = p->p_ucred ? p->p_ucred->cr_uid : -1; 2728 kcore_make_file(&kf, fp, p->p_pid, uid, n); 2729 spin_unlock(&fdp->fd_spin); 2730 info->error = SYSCTL_OUT(info->req, &kf, sizeof(kf)); 2731 spin_lock(&fdp->fd_spin); 2732 if (info->error) 2733 break; 2734 } 2735 } 2736 spin_unlock(&fdp->fd_spin); 2737 atomic_subtract_int(&fdp->fd_softrefs, 1); 2738 if (info->error) 2739 return(-1); 2740 return(0); 2741 } 2742 2743 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2744 0, 0, sysctl_kern_file, "S,file", "Entire file table"); 2745 2746 SYSCTL_INT(_kern, OID_AUTO, minfilesperproc, CTLFLAG_RW, 2747 &minfilesperproc, 0, "Minimum files allowed open per process"); 2748 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 2749 &maxfilesperproc, 0, "Maximum files allowed open per process"); 2750 SYSCTL_INT(_kern, OID_AUTO, maxfilesperuser, CTLFLAG_RW, 2751 &maxfilesperuser, 0, "Maximum files allowed open per user"); 2752 2753 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 2754 &maxfiles, 0, "Maximum number of files"); 2755 2756 SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW, 2757 &maxfilesrootres, 0, "Descriptors reserved for root use"); 2758 2759 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 2760 &nfiles, 0, "System-wide number of open files"); 2761 2762 static void 2763 fildesc_drvinit(void *unused) 2764 { 2765 int fd; 2766 2767 for (fd = 0; fd < NUMFDESC; fd++) { 2768 make_dev(&fildesc_ops, fd, 2769 UID_BIN, GID_BIN, 0666, "fd/%d", fd); 2770 } 2771 2772 make_dev(&fildesc_ops, 0, UID_ROOT, GID_WHEEL, 0666, "stdin"); 2773 make_dev(&fildesc_ops, 1, UID_ROOT, GID_WHEEL, 0666, "stdout"); 2774 make_dev(&fildesc_ops, 2, UID_ROOT, GID_WHEEL, 0666, "stderr"); 2775 } 2776 2777 /* 2778 * MPSAFE 2779 */ 2780 struct fileops badfileops = { 2781 .fo_read = badfo_readwrite, 2782 .fo_write = badfo_readwrite, 2783 .fo_ioctl = badfo_ioctl, 2784 .fo_poll = badfo_poll, 2785 .fo_kqfilter = badfo_kqfilter, 2786 .fo_stat = badfo_stat, 2787 .fo_close = badfo_close, 2788 .fo_shutdown = badfo_shutdown 2789 }; 2790 2791 int 2792 badfo_readwrite( 2793 struct file *fp, 2794 struct uio *uio, 2795 struct ucred *cred, 2796 int flags 2797 ) { 2798 return (EBADF); 2799 } 2800 2801 int 2802 badfo_ioctl(struct file *fp, u_long com, caddr_t data, 2803 struct ucred *cred, struct sysmsg *msgv) 2804 { 2805 return (EBADF); 2806 } 2807 2808 int 2809 badfo_poll(struct file *fp, int events, struct ucred *cred) 2810 { 2811 return (0); 2812 } 2813 2814 /* 2815 * Must return an error to prevent registration, typically 2816 * due to a revoked descriptor (file_filtops assigned). 2817 */ 2818 int 2819 badfo_kqfilter(struct file *fp, struct knote *kn) 2820 { 2821 return (EOPNOTSUPP); 2822 } 2823 2824 /* 2825 * MPSAFE 2826 */ 2827 int 2828 badfo_stat(struct file *fp, struct stat *sb, struct ucred *cred) 2829 { 2830 return (EBADF); 2831 } 2832 2833 /* 2834 * MPSAFE 2835 */ 2836 int 2837 badfo_close(struct file *fp) 2838 { 2839 return (EBADF); 2840 } 2841 2842 /* 2843 * MPSAFE 2844 */ 2845 int 2846 badfo_shutdown(struct file *fp, int how) 2847 { 2848 return (EBADF); 2849 } 2850 2851 /* 2852 * MPSAFE 2853 */ 2854 int 2855 nofo_shutdown(struct file *fp, int how) 2856 { 2857 return (EOPNOTSUPP); 2858 } 2859 2860 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 2861 fildesc_drvinit,NULL) 2862