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_rd(&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_rd(&limit->p_spin); 178 if (dtsize > maxfilesperproc) 179 dtsize = maxfilesperproc; 180 if (dtsize < minfilesperproc) 181 dtsize = minfilesperproc; 182 if (p->p_ucred->cr_uid && dtsize > maxfilesperuser) 183 dtsize = maxfilesperuser; 184 uap->sysmsg_result = dtsize; 185 return (0); 186 } 187 188 /* 189 * Duplicate a file descriptor to a particular value. 190 * 191 * note: keep in mind that a potential race condition exists when closing 192 * descriptors from a shared descriptor table (via rfork). 193 * 194 * MPSAFE 195 */ 196 int 197 sys_dup2(struct dup2_args *uap) 198 { 199 int error; 200 int fd = 0; 201 202 error = kern_dup(DUP_FIXED, uap->from, uap->to, &fd); 203 uap->sysmsg_fds[0] = fd; 204 205 return (error); 206 } 207 208 /* 209 * Duplicate a file descriptor. 210 * 211 * MPSAFE 212 */ 213 int 214 sys_dup(struct dup_args *uap) 215 { 216 int error; 217 int fd = 0; 218 219 error = kern_dup(DUP_VARIABLE, uap->fd, 0, &fd); 220 uap->sysmsg_fds[0] = fd; 221 222 return (error); 223 } 224 225 /* 226 * MPALMOSTSAFE - acquires mplock for fp operations 227 */ 228 int 229 kern_fcntl(int fd, int cmd, union fcntl_dat *dat, struct ucred *cred) 230 { 231 struct thread *td = curthread; 232 struct proc *p = td->td_proc; 233 struct file *fp; 234 struct vnode *vp; 235 u_int newmin; 236 u_int oflags; 237 u_int nflags; 238 int tmp, error, flg = F_POSIX; 239 240 KKASSERT(p); 241 242 /* 243 * Operations on file descriptors that do not require a file pointer. 244 */ 245 switch (cmd) { 246 case F_GETFD: 247 error = fgetfdflags(p->p_fd, fd, &tmp); 248 if (error == 0) 249 dat->fc_cloexec = (tmp & UF_EXCLOSE) ? FD_CLOEXEC : 0; 250 return (error); 251 252 case F_SETFD: 253 if (dat->fc_cloexec & FD_CLOEXEC) 254 error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE); 255 else 256 error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE); 257 return (error); 258 case F_DUPFD: 259 newmin = dat->fc_fd; 260 error = kern_dup(DUP_VARIABLE, fd, newmin, &dat->fc_fd); 261 return (error); 262 default: 263 break; 264 } 265 266 /* 267 * Operations on file pointers 268 */ 269 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 270 return (EBADF); 271 272 get_mplock(); 273 switch (cmd) { 274 case F_GETFL: 275 dat->fc_flags = OFLAGS(fp->f_flag); 276 error = 0; 277 break; 278 279 case F_SETFL: 280 oflags = fp->f_flag; 281 nflags = FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS; 282 nflags |= oflags & ~FCNTLFLAGS; 283 284 error = 0; 285 if (((nflags ^ oflags) & O_APPEND) && (oflags & FAPPENDONLY)) 286 error = EINVAL; 287 if (error == 0 && ((nflags ^ oflags) & FASYNC)) { 288 tmp = nflags & FASYNC; 289 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, 290 cred, NULL); 291 } 292 if (error == 0) 293 fp->f_flag = nflags; 294 break; 295 296 case F_GETOWN: 297 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner, 298 cred, NULL); 299 break; 300 301 case F_SETOWN: 302 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner, 303 cred, NULL); 304 break; 305 306 case F_SETLKW: 307 flg |= F_WAIT; 308 /* Fall into F_SETLK */ 309 310 case F_SETLK: 311 if (fp->f_type != DTYPE_VNODE) { 312 error = EBADF; 313 break; 314 } 315 vp = (struct vnode *)fp->f_data; 316 317 /* 318 * copyin/lockop may block 319 */ 320 if (dat->fc_flock.l_whence == SEEK_CUR) 321 dat->fc_flock.l_start += fp->f_offset; 322 323 switch (dat->fc_flock.l_type) { 324 case F_RDLCK: 325 if ((fp->f_flag & FREAD) == 0) { 326 error = EBADF; 327 break; 328 } 329 p->p_leader->p_flag |= P_ADVLOCK; 330 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 331 &dat->fc_flock, flg); 332 break; 333 case F_WRLCK: 334 if ((fp->f_flag & FWRITE) == 0) { 335 error = EBADF; 336 break; 337 } 338 p->p_leader->p_flag |= P_ADVLOCK; 339 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 340 &dat->fc_flock, flg); 341 break; 342 case F_UNLCK: 343 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 344 &dat->fc_flock, F_POSIX); 345 break; 346 default: 347 error = EINVAL; 348 break; 349 } 350 351 /* 352 * It is possible to race a close() on the descriptor while 353 * we were blocked getting the lock. If this occurs the 354 * close might not have caught the lock. 355 */ 356 if (checkfdclosed(p->p_fd, fd, fp)) { 357 dat->fc_flock.l_whence = SEEK_SET; 358 dat->fc_flock.l_start = 0; 359 dat->fc_flock.l_len = 0; 360 dat->fc_flock.l_type = F_UNLCK; 361 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 362 F_UNLCK, &dat->fc_flock, F_POSIX); 363 } 364 break; 365 366 case F_GETLK: 367 if (fp->f_type != DTYPE_VNODE) { 368 error = EBADF; 369 break; 370 } 371 vp = (struct vnode *)fp->f_data; 372 /* 373 * copyin/lockop may block 374 */ 375 if (dat->fc_flock.l_type != F_RDLCK && 376 dat->fc_flock.l_type != F_WRLCK && 377 dat->fc_flock.l_type != F_UNLCK) { 378 error = EINVAL; 379 break; 380 } 381 if (dat->fc_flock.l_whence == SEEK_CUR) 382 dat->fc_flock.l_start += fp->f_offset; 383 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, 384 &dat->fc_flock, F_POSIX); 385 break; 386 default: 387 error = EINVAL; 388 break; 389 } 390 rel_mplock(); 391 392 fdrop(fp); 393 return (error); 394 } 395 396 /* 397 * The file control system call. 398 * 399 * MPSAFE 400 */ 401 int 402 sys_fcntl(struct fcntl_args *uap) 403 { 404 union fcntl_dat dat; 405 int error; 406 407 switch (uap->cmd) { 408 case F_DUPFD: 409 dat.fc_fd = uap->arg; 410 break; 411 case F_SETFD: 412 dat.fc_cloexec = uap->arg; 413 break; 414 case F_SETFL: 415 dat.fc_flags = uap->arg; 416 break; 417 case F_SETOWN: 418 dat.fc_owner = uap->arg; 419 break; 420 case F_SETLKW: 421 case F_SETLK: 422 case F_GETLK: 423 error = copyin((caddr_t)uap->arg, &dat.fc_flock, 424 sizeof(struct flock)); 425 if (error) 426 return (error); 427 break; 428 } 429 430 error = kern_fcntl(uap->fd, uap->cmd, &dat, curthread->td_ucred); 431 432 if (error == 0) { 433 switch (uap->cmd) { 434 case F_DUPFD: 435 uap->sysmsg_result = dat.fc_fd; 436 break; 437 case F_GETFD: 438 uap->sysmsg_result = dat.fc_cloexec; 439 break; 440 case F_GETFL: 441 uap->sysmsg_result = dat.fc_flags; 442 break; 443 case F_GETOWN: 444 uap->sysmsg_result = dat.fc_owner; 445 case F_GETLK: 446 error = copyout(&dat.fc_flock, (caddr_t)uap->arg, 447 sizeof(struct flock)); 448 break; 449 } 450 } 451 452 return (error); 453 } 454 455 /* 456 * Common code for dup, dup2, and fcntl(F_DUPFD). 457 * 458 * The type flag can be either DUP_FIXED or DUP_VARIABLE. DUP_FIXED tells 459 * kern_dup() to destructively dup over an existing file descriptor if new 460 * is already open. DUP_VARIABLE tells kern_dup() to find the lowest 461 * unused file descriptor that is greater than or equal to new. 462 * 463 * MPSAFE 464 */ 465 int 466 kern_dup(enum dup_type type, int old, int new, int *res) 467 { 468 struct thread *td = curthread; 469 struct proc *p = td->td_proc; 470 struct filedesc *fdp = p->p_fd; 471 struct file *fp; 472 struct file *delfp; 473 int oldflags; 474 int holdleaders; 475 int dtsize; 476 int error, newfd; 477 478 /* 479 * Verify that we have a valid descriptor to dup from and 480 * possibly to dup to. 481 * 482 * NOTE: maxfilesperuser is not applicable to dup() 483 */ 484 retry: 485 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 486 dtsize = INT_MAX; 487 else 488 dtsize = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 489 if (dtsize > maxfilesperproc) 490 dtsize = maxfilesperproc; 491 if (dtsize < minfilesperproc) 492 dtsize = minfilesperproc; 493 494 if (new < 0 || new > dtsize) 495 return (EINVAL); 496 497 spin_lock_wr(&fdp->fd_spin); 498 if ((unsigned)old >= fdp->fd_nfiles || fdp->fd_files[old].fp == NULL) { 499 spin_unlock_wr(&fdp->fd_spin); 500 return (EBADF); 501 } 502 if (type == DUP_FIXED && old == new) { 503 *res = new; 504 spin_unlock_wr(&fdp->fd_spin); 505 return (0); 506 } 507 fp = fdp->fd_files[old].fp; 508 oldflags = fdp->fd_files[old].fileflags; 509 fhold(fp); /* MPSAFE - can be called with a spinlock held */ 510 511 /* 512 * Allocate a new descriptor if DUP_VARIABLE, or expand the table 513 * if the requested descriptor is beyond the current table size. 514 * 515 * This can block. Retry if the source descriptor no longer matches 516 * or if our expectation in the expansion case races. 517 * 518 * If we are not expanding or allocating a new decriptor, then reset 519 * the target descriptor to a reserved state so we have a uniform 520 * setup for the next code block. 521 */ 522 if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) { 523 spin_unlock_wr(&fdp->fd_spin); 524 error = fdalloc(p, new, &newfd); 525 spin_lock_wr(&fdp->fd_spin); 526 if (error) { 527 spin_unlock_wr(&fdp->fd_spin); 528 fdrop(fp); 529 return (error); 530 } 531 /* 532 * Check for ripout 533 */ 534 if (old >= fdp->fd_nfiles || fdp->fd_files[old].fp != fp) { 535 fsetfd_locked(fdp, NULL, newfd); 536 spin_unlock_wr(&fdp->fd_spin); 537 fdrop(fp); 538 goto retry; 539 } 540 /* 541 * Check for expansion race 542 */ 543 if (type != DUP_VARIABLE && new != newfd) { 544 fsetfd_locked(fdp, NULL, newfd); 545 spin_unlock_wr(&fdp->fd_spin); 546 fdrop(fp); 547 goto retry; 548 } 549 /* 550 * Check for ripout, newfd reused old (this case probably 551 * can't occur). 552 */ 553 if (old == newfd) { 554 fsetfd_locked(fdp, NULL, newfd); 555 spin_unlock_wr(&fdp->fd_spin); 556 fdrop(fp); 557 goto retry; 558 } 559 new = newfd; 560 delfp = NULL; 561 } else { 562 if (fdp->fd_files[new].reserved) { 563 spin_unlock_wr(&fdp->fd_spin); 564 fdrop(fp); 565 kprintf("Warning: dup(): target descriptor %d is reserved, waiting for it to be resolved\n", new); 566 tsleep(fdp, 0, "fdres", hz); 567 goto retry; 568 } 569 570 /* 571 * If the target descriptor was never allocated we have 572 * to allocate it. If it was we have to clean out the 573 * old descriptor. delfp inherits the ref from the 574 * descriptor table. 575 */ 576 delfp = fdp->fd_files[new].fp; 577 fdp->fd_files[new].fp = NULL; 578 fdp->fd_files[new].reserved = 1; 579 if (delfp == NULL) { 580 fdreserve_locked(fdp, new, 1); 581 if (new > fdp->fd_lastfile) 582 fdp->fd_lastfile = new; 583 } 584 585 } 586 587 /* 588 * NOTE: still holding an exclusive spinlock 589 */ 590 591 /* 592 * If a descriptor is being overwritten we may hve to tell 593 * fdfree() to sleep to ensure that all relevant process 594 * leaders can be traversed in closef(). 595 */ 596 if (delfp != NULL && p->p_fdtol != NULL) { 597 fdp->fd_holdleaderscount++; 598 holdleaders = 1; 599 } else { 600 holdleaders = 0; 601 } 602 KASSERT(delfp == NULL || type == DUP_FIXED, 603 ("dup() picked an open file")); 604 605 /* 606 * Duplicate the source descriptor, update lastfile. If the new 607 * descriptor was not allocated and we aren't replacing an existing 608 * descriptor we have to mark the descriptor as being in use. 609 * 610 * The fd_files[] array inherits fp's hold reference. 611 */ 612 fsetfd_locked(fdp, fp, new); 613 fdp->fd_files[new].fileflags = oldflags & ~UF_EXCLOSE; 614 spin_unlock_wr(&fdp->fd_spin); 615 fdrop(fp); 616 *res = new; 617 618 /* 619 * If we dup'd over a valid file, we now own the reference to it 620 * and must dispose of it using closef() semantics (as if a 621 * close() were performed on it). 622 */ 623 if (delfp) { 624 if (SLIST_FIRST(&delfp->f_klist)) { 625 get_mplock(); 626 knote_fdclose(delfp, fdp, new); 627 rel_mplock(); 628 } 629 closef(delfp, p); 630 if (holdleaders) { 631 spin_lock_wr(&fdp->fd_spin); 632 fdp->fd_holdleaderscount--; 633 if (fdp->fd_holdleaderscount == 0 && 634 fdp->fd_holdleaderswakeup != 0) { 635 fdp->fd_holdleaderswakeup = 0; 636 spin_unlock_wr(&fdp->fd_spin); 637 wakeup(&fdp->fd_holdleaderscount); 638 } else { 639 spin_unlock_wr(&fdp->fd_spin); 640 } 641 } 642 } 643 return (0); 644 } 645 646 /* 647 * If sigio is on the list associated with a process or process group, 648 * disable signalling from the device, remove sigio from the list and 649 * free sigio. 650 */ 651 void 652 funsetown(struct sigio *sigio) 653 { 654 if (sigio == NULL) 655 return; 656 crit_enter(); 657 *(sigio->sio_myref) = NULL; 658 crit_exit(); 659 if (sigio->sio_pgid < 0) { 660 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 661 sigio, sio_pgsigio); 662 } else /* if ((*sigiop)->sio_pgid > 0) */ { 663 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 664 sigio, sio_pgsigio); 665 } 666 crfree(sigio->sio_ucred); 667 kfree(sigio, M_SIGIO); 668 } 669 670 /* Free a list of sigio structures. */ 671 void 672 funsetownlst(struct sigiolst *sigiolst) 673 { 674 struct sigio *sigio; 675 676 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) 677 funsetown(sigio); 678 } 679 680 /* 681 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 682 * 683 * After permission checking, add a sigio structure to the sigio list for 684 * the process or process group. 685 */ 686 int 687 fsetown(pid_t pgid, struct sigio **sigiop) 688 { 689 struct proc *proc; 690 struct pgrp *pgrp; 691 struct sigio *sigio; 692 693 if (pgid == 0) { 694 funsetown(*sigiop); 695 return (0); 696 } 697 if (pgid > 0) { 698 proc = pfind(pgid); 699 if (proc == NULL) 700 return (ESRCH); 701 702 /* 703 * Policy - Don't allow a process to FSETOWN a process 704 * in another session. 705 * 706 * Remove this test to allow maximum flexibility or 707 * restrict FSETOWN to the current process or process 708 * group for maximum safety. 709 */ 710 if (proc->p_session != curproc->p_session) 711 return (EPERM); 712 713 pgrp = NULL; 714 } else /* if (pgid < 0) */ { 715 pgrp = pgfind(-pgid); 716 if (pgrp == NULL) 717 return (ESRCH); 718 719 /* 720 * Policy - Don't allow a process to FSETOWN a process 721 * in another session. 722 * 723 * Remove this test to allow maximum flexibility or 724 * restrict FSETOWN to the current process or process 725 * group for maximum safety. 726 */ 727 if (pgrp->pg_session != curproc->p_session) 728 return (EPERM); 729 730 proc = NULL; 731 } 732 funsetown(*sigiop); 733 sigio = kmalloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 734 if (pgid > 0) { 735 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 736 sigio->sio_proc = proc; 737 } else { 738 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 739 sigio->sio_pgrp = pgrp; 740 } 741 sigio->sio_pgid = pgid; 742 sigio->sio_ucred = crhold(curthread->td_ucred); 743 /* It would be convenient if p_ruid was in ucred. */ 744 sigio->sio_ruid = sigio->sio_ucred->cr_ruid; 745 sigio->sio_myref = sigiop; 746 crit_enter(); 747 *sigiop = sigio; 748 crit_exit(); 749 return (0); 750 } 751 752 /* 753 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 754 */ 755 pid_t 756 fgetown(struct sigio *sigio) 757 { 758 return (sigio != NULL ? sigio->sio_pgid : 0); 759 } 760 761 /* 762 * Close many file descriptors. 763 * 764 * MPSAFE 765 */ 766 int 767 sys_closefrom(struct closefrom_args *uap) 768 { 769 return(kern_closefrom(uap->fd)); 770 } 771 772 /* 773 * Close all file descriptors greater then or equal to fd 774 * 775 * MPSAFE 776 */ 777 int 778 kern_closefrom(int fd) 779 { 780 struct thread *td = curthread; 781 struct proc *p = td->td_proc; 782 struct filedesc *fdp; 783 784 KKASSERT(p); 785 fdp = p->p_fd; 786 787 if (fd < 0) 788 return (EINVAL); 789 790 /* 791 * NOTE: This function will skip unassociated descriptors and 792 * reserved descriptors that have not yet been assigned. 793 * fd_lastfile can change as a side effect of kern_close(). 794 */ 795 spin_lock_wr(&fdp->fd_spin); 796 while (fd <= fdp->fd_lastfile) { 797 if (fdp->fd_files[fd].fp != NULL) { 798 spin_unlock_wr(&fdp->fd_spin); 799 /* ok if this races another close */ 800 if (kern_close(fd) == EINTR) 801 return (EINTR); 802 spin_lock_wr(&fdp->fd_spin); 803 } 804 ++fd; 805 } 806 spin_unlock_wr(&fdp->fd_spin); 807 return (0); 808 } 809 810 /* 811 * Close a file descriptor. 812 * 813 * MPSAFE 814 */ 815 int 816 sys_close(struct close_args *uap) 817 { 818 return(kern_close(uap->fd)); 819 } 820 821 /* 822 * MPALMOSTSAFE - acquires mplock around knote_fdclose() calls 823 */ 824 int 825 kern_close(int fd) 826 { 827 struct thread *td = curthread; 828 struct proc *p = td->td_proc; 829 struct filedesc *fdp; 830 struct file *fp; 831 int error; 832 int holdleaders; 833 834 KKASSERT(p); 835 fdp = p->p_fd; 836 837 spin_lock_wr(&fdp->fd_spin); 838 if ((fp = funsetfd_locked(fdp, fd)) == NULL) { 839 spin_unlock_wr(&fdp->fd_spin); 840 return (EBADF); 841 } 842 holdleaders = 0; 843 if (p->p_fdtol != NULL) { 844 /* 845 * Ask fdfree() to sleep to ensure that all relevant 846 * process leaders can be traversed in closef(). 847 */ 848 fdp->fd_holdleaderscount++; 849 holdleaders = 1; 850 } 851 852 /* 853 * we now hold the fp reference that used to be owned by the descriptor 854 * array. 855 */ 856 spin_unlock_wr(&fdp->fd_spin); 857 if (SLIST_FIRST(&fp->f_klist)) { 858 get_mplock(); 859 knote_fdclose(fp, fdp, fd); 860 rel_mplock(); 861 } 862 error = closef(fp, p); 863 if (holdleaders) { 864 spin_lock_wr(&fdp->fd_spin); 865 fdp->fd_holdleaderscount--; 866 if (fdp->fd_holdleaderscount == 0 && 867 fdp->fd_holdleaderswakeup != 0) { 868 fdp->fd_holdleaderswakeup = 0; 869 spin_unlock_wr(&fdp->fd_spin); 870 wakeup(&fdp->fd_holdleaderscount); 871 } else { 872 spin_unlock_wr(&fdp->fd_spin); 873 } 874 } 875 return (error); 876 } 877 878 /* 879 * shutdown_args(int fd, int how) 880 */ 881 int 882 kern_shutdown(int fd, int how) 883 { 884 struct thread *td = curthread; 885 struct proc *p = td->td_proc; 886 struct file *fp; 887 int error; 888 889 KKASSERT(p); 890 891 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 892 return (EBADF); 893 error = fo_shutdown(fp, how); 894 fdrop(fp); 895 896 return (error); 897 } 898 899 /* 900 * MPALMOSTSAFE 901 */ 902 int 903 sys_shutdown(struct shutdown_args *uap) 904 { 905 int error; 906 907 get_mplock(); 908 error = kern_shutdown(uap->s, uap->how); 909 rel_mplock(); 910 911 return (error); 912 } 913 914 /* 915 * MPSAFE 916 */ 917 int 918 kern_fstat(int fd, struct stat *ub) 919 { 920 struct thread *td = curthread; 921 struct proc *p = td->td_proc; 922 struct file *fp; 923 int error; 924 925 KKASSERT(p); 926 927 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL) 928 return (EBADF); 929 error = fo_stat(fp, ub, td->td_ucred); 930 fdrop(fp); 931 932 return (error); 933 } 934 935 /* 936 * Return status information about a file descriptor. 937 * 938 * MPSAFE 939 */ 940 int 941 sys_fstat(struct fstat_args *uap) 942 { 943 struct stat st; 944 int error; 945 946 error = kern_fstat(uap->fd, &st); 947 948 if (error == 0) 949 error = copyout(&st, uap->sb, sizeof(st)); 950 return (error); 951 } 952 953 /* 954 * Return pathconf information about a file descriptor. 955 * 956 * MPALMOSTSAFE 957 */ 958 int 959 sys_fpathconf(struct fpathconf_args *uap) 960 { 961 struct thread *td = curthread; 962 struct proc *p = td->td_proc; 963 struct file *fp; 964 struct vnode *vp; 965 int error = 0; 966 967 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL) 968 return (EBADF); 969 970 switch (fp->f_type) { 971 case DTYPE_PIPE: 972 case DTYPE_SOCKET: 973 if (uap->name != _PC_PIPE_BUF) { 974 error = EINVAL; 975 } else { 976 uap->sysmsg_result = PIPE_BUF; 977 error = 0; 978 } 979 break; 980 case DTYPE_FIFO: 981 case DTYPE_VNODE: 982 vp = (struct vnode *)fp->f_data; 983 get_mplock(); 984 error = VOP_PATHCONF(vp, uap->name, &uap->sysmsg_reg); 985 rel_mplock(); 986 break; 987 default: 988 error = EOPNOTSUPP; 989 break; 990 } 991 fdrop(fp); 992 return(error); 993 } 994 995 static int fdexpand; 996 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 997 0, ""); 998 999 /* 1000 * Grow the file table so it can hold through descriptor (want). 1001 * 1002 * The fdp's spinlock must be held exclusively on entry and may be held 1003 * exclusively on return. The spinlock may be cycled by the routine. 1004 * 1005 * MPSAFE 1006 */ 1007 static void 1008 fdgrow_locked(struct filedesc *fdp, int want) 1009 { 1010 struct fdnode *newfiles; 1011 struct fdnode *oldfiles; 1012 int nf, extra; 1013 1014 nf = fdp->fd_nfiles; 1015 do { 1016 /* nf has to be of the form 2^n - 1 */ 1017 nf = 2 * nf + 1; 1018 } while (nf <= want); 1019 1020 spin_unlock_wr(&fdp->fd_spin); 1021 newfiles = kmalloc(nf * sizeof(struct fdnode), M_FILEDESC, M_WAITOK); 1022 spin_lock_wr(&fdp->fd_spin); 1023 1024 /* 1025 * We could have raced another extend while we were not holding 1026 * the spinlock. 1027 */ 1028 if (fdp->fd_nfiles >= nf) { 1029 spin_unlock_wr(&fdp->fd_spin); 1030 kfree(newfiles, M_FILEDESC); 1031 spin_lock_wr(&fdp->fd_spin); 1032 return; 1033 } 1034 /* 1035 * Copy the existing ofile and ofileflags arrays 1036 * and zero the new portion of each array. 1037 */ 1038 extra = nf - fdp->fd_nfiles; 1039 bcopy(fdp->fd_files, newfiles, fdp->fd_nfiles * sizeof(struct fdnode)); 1040 bzero(&newfiles[fdp->fd_nfiles], extra * sizeof(struct fdnode)); 1041 1042 oldfiles = fdp->fd_files; 1043 fdp->fd_files = newfiles; 1044 fdp->fd_nfiles = nf; 1045 1046 if (oldfiles != fdp->fd_builtin_files) { 1047 spin_unlock_wr(&fdp->fd_spin); 1048 kfree(oldfiles, M_FILEDESC); 1049 spin_lock_wr(&fdp->fd_spin); 1050 } 1051 fdexpand++; 1052 } 1053 1054 /* 1055 * Number of nodes in right subtree, including the root. 1056 */ 1057 static __inline int 1058 right_subtree_size(int n) 1059 { 1060 return (n ^ (n | (n + 1))); 1061 } 1062 1063 /* 1064 * Bigger ancestor. 1065 */ 1066 static __inline int 1067 right_ancestor(int n) 1068 { 1069 return (n | (n + 1)); 1070 } 1071 1072 /* 1073 * Smaller ancestor. 1074 */ 1075 static __inline int 1076 left_ancestor(int n) 1077 { 1078 return ((n & (n + 1)) - 1); 1079 } 1080 1081 /* 1082 * Traverse the in-place binary tree buttom-up adjusting the allocation 1083 * count so scans can determine where free descriptors are located. 1084 * 1085 * MPSAFE - caller must be holding an exclusive spinlock on fdp 1086 */ 1087 static 1088 void 1089 fdreserve_locked(struct filedesc *fdp, int fd, int incr) 1090 { 1091 while (fd >= 0) { 1092 fdp->fd_files[fd].allocated += incr; 1093 KKASSERT(fdp->fd_files[fd].allocated >= 0); 1094 fd = left_ancestor(fd); 1095 } 1096 } 1097 1098 /* 1099 * Reserve a file descriptor for the process. If no error occurs, the 1100 * caller MUST at some point call fsetfd() or assign a file pointer 1101 * or dispose of the reservation. 1102 * 1103 * MPSAFE 1104 */ 1105 int 1106 fdalloc(struct proc *p, int want, int *result) 1107 { 1108 struct filedesc *fdp = p->p_fd; 1109 struct uidinfo *uip; 1110 int fd, rsize, rsum, node, lim; 1111 1112 /* 1113 * Check dtable size limit 1114 */ 1115 spin_lock_rd(&p->p_limit->p_spin); 1116 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 1117 lim = INT_MAX; 1118 else 1119 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 1120 spin_unlock_rd(&p->p_limit->p_spin); 1121 if (lim > maxfilesperproc) 1122 lim = maxfilesperproc; 1123 if (lim < minfilesperproc) 1124 lim = minfilesperproc; 1125 if (want >= lim) 1126 return (EMFILE); 1127 1128 /* 1129 * Check that the user has not run out of descriptors (non-root only). 1130 * As a safety measure the dtable is allowed to have at least 1131 * minfilesperproc open fds regardless of the maxfilesperuser limit. 1132 */ 1133 if (p->p_ucred->cr_uid && fdp->fd_nfiles >= minfilesperproc) { 1134 uip = p->p_ucred->cr_uidinfo; 1135 if (uip->ui_openfiles > maxfilesperuser) { 1136 krateprintf(&krate_uidinfo, 1137 "Warning: user %d pid %d (%s) ran out of " 1138 "file descriptors (%d/%d)\n", 1139 p->p_ucred->cr_uid, (int)p->p_pid, 1140 p->p_comm, 1141 uip->ui_openfiles, maxfilesperuser); 1142 return(ENFILE); 1143 } 1144 } 1145 1146 /* 1147 * Grow the dtable if necessary 1148 */ 1149 spin_lock_wr(&fdp->fd_spin); 1150 if (want >= fdp->fd_nfiles) 1151 fdgrow_locked(fdp, want); 1152 1153 /* 1154 * Search for a free descriptor starting at the higher 1155 * of want or fd_freefile. If that fails, consider 1156 * expanding the ofile array. 1157 * 1158 * NOTE! the 'allocated' field is a cumulative recursive allocation 1159 * count. If we happen to see a value of 0 then we can shortcut 1160 * our search. Otherwise we run through through the tree going 1161 * down branches we know have free descriptor(s) until we hit a 1162 * leaf node. The leaf node will be free but will not necessarily 1163 * have an allocated field of 0. 1164 */ 1165 retry: 1166 /* move up the tree looking for a subtree with a free node */ 1167 for (fd = max(want, fdp->fd_freefile); fd < min(fdp->fd_nfiles, lim); 1168 fd = right_ancestor(fd)) { 1169 if (fdp->fd_files[fd].allocated == 0) 1170 goto found; 1171 1172 rsize = right_subtree_size(fd); 1173 if (fdp->fd_files[fd].allocated == rsize) 1174 continue; /* right subtree full */ 1175 1176 /* 1177 * Free fd is in the right subtree of the tree rooted at fd. 1178 * Call that subtree R. Look for the smallest (leftmost) 1179 * subtree of R with an unallocated fd: continue moving 1180 * down the left branch until encountering a full left 1181 * subtree, then move to the right. 1182 */ 1183 for (rsum = 0, rsize /= 2; rsize > 0; rsize /= 2) { 1184 node = fd + rsize; 1185 rsum += fdp->fd_files[node].allocated; 1186 if (fdp->fd_files[fd].allocated == rsum + rsize) { 1187 fd = node; /* move to the right */ 1188 if (fdp->fd_files[node].allocated == 0) 1189 goto found; 1190 rsum = 0; 1191 } 1192 } 1193 goto found; 1194 } 1195 1196 /* 1197 * No space in current array. Expand? 1198 */ 1199 if (fdp->fd_nfiles >= lim) { 1200 spin_unlock_wr(&fdp->fd_spin); 1201 return (EMFILE); 1202 } 1203 fdgrow_locked(fdp, want); 1204 goto retry; 1205 1206 found: 1207 KKASSERT(fd < fdp->fd_nfiles); 1208 if (fd > fdp->fd_lastfile) 1209 fdp->fd_lastfile = fd; 1210 if (want <= fdp->fd_freefile) 1211 fdp->fd_freefile = fd; 1212 *result = fd; 1213 KKASSERT(fdp->fd_files[fd].fp == NULL); 1214 KKASSERT(fdp->fd_files[fd].reserved == 0); 1215 fdp->fd_files[fd].fileflags = 0; 1216 fdp->fd_files[fd].reserved = 1; 1217 fdreserve_locked(fdp, fd, 1); 1218 spin_unlock_wr(&fdp->fd_spin); 1219 return (0); 1220 } 1221 1222 /* 1223 * Check to see whether n user file descriptors 1224 * are available to the process p. 1225 * 1226 * MPSAFE 1227 */ 1228 int 1229 fdavail(struct proc *p, int n) 1230 { 1231 struct filedesc *fdp = p->p_fd; 1232 struct fdnode *fdnode; 1233 int i, lim, last; 1234 1235 spin_lock_rd(&p->p_limit->p_spin); 1236 if (p->p_rlimit[RLIMIT_NOFILE].rlim_cur > INT_MAX) 1237 lim = INT_MAX; 1238 else 1239 lim = (int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 1240 spin_unlock_rd(&p->p_limit->p_spin); 1241 if (lim > maxfilesperproc) 1242 lim = maxfilesperproc; 1243 if (lim < minfilesperproc) 1244 lim = minfilesperproc; 1245 1246 spin_lock_rd(&fdp->fd_spin); 1247 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) { 1248 spin_unlock_rd(&fdp->fd_spin); 1249 return (1); 1250 } 1251 last = min(fdp->fd_nfiles, lim); 1252 fdnode = &fdp->fd_files[fdp->fd_freefile]; 1253 for (i = last - fdp->fd_freefile; --i >= 0; ++fdnode) { 1254 if (fdnode->fp == NULL && --n <= 0) { 1255 spin_unlock_rd(&fdp->fd_spin); 1256 return (1); 1257 } 1258 } 1259 spin_unlock_rd(&fdp->fd_spin); 1260 return (0); 1261 } 1262 1263 /* 1264 * Revoke open descriptors referencing (f_data, f_type) 1265 * 1266 * Any revoke executed within a prison is only able to 1267 * revoke descriptors for processes within that prison. 1268 * 1269 * Returns 0 on success or an error code. 1270 */ 1271 struct fdrevoke_info { 1272 void *data; 1273 short type; 1274 short unused; 1275 int count; 1276 int intransit; 1277 struct ucred *cred; 1278 struct file *nfp; 1279 }; 1280 1281 static int fdrevoke_check_callback(struct file *fp, void *vinfo); 1282 static int fdrevoke_proc_callback(struct proc *p, void *vinfo); 1283 1284 int 1285 fdrevoke(void *f_data, short f_type, struct ucred *cred) 1286 { 1287 struct fdrevoke_info info; 1288 int error; 1289 1290 bzero(&info, sizeof(info)); 1291 info.data = f_data; 1292 info.type = f_type; 1293 info.cred = cred; 1294 error = falloc(NULL, &info.nfp, NULL); 1295 if (error) 1296 return (error); 1297 1298 /* 1299 * Scan the file pointer table once. dups do not dup file pointers, 1300 * only descriptors, so there is no leak. Set FREVOKED on the fps 1301 * being revoked. 1302 */ 1303 allfiles_scan_exclusive(fdrevoke_check_callback, &info); 1304 1305 /* 1306 * If any fps were marked track down the related descriptors 1307 * and close them. Any dup()s at this point will notice 1308 * the FREVOKED already set in the fp and do the right thing. 1309 * 1310 * Any fps with non-zero msgcounts (aka sent over a unix-domain 1311 * socket) bumped the intransit counter and will require a 1312 * scan. Races against fps leaving the socket are closed by 1313 * the socket code checking for FREVOKED. 1314 */ 1315 if (info.count) 1316 allproc_scan(fdrevoke_proc_callback, &info); 1317 if (info.intransit) 1318 unp_revoke_gc(info.nfp); 1319 fdrop(info.nfp); 1320 return(0); 1321 } 1322 1323 /* 1324 * Locate matching file pointers directly. 1325 */ 1326 static int 1327 fdrevoke_check_callback(struct file *fp, void *vinfo) 1328 { 1329 struct fdrevoke_info *info = vinfo; 1330 1331 /* 1332 * File pointers already flagged for revokation are skipped. 1333 */ 1334 if (fp->f_flag & FREVOKED) 1335 return(0); 1336 1337 /* 1338 * If revoking from a prison file pointers created outside of 1339 * that prison, or file pointers without creds, cannot be revoked. 1340 */ 1341 if (info->cred->cr_prison && 1342 (fp->f_cred == NULL || 1343 info->cred->cr_prison != fp->f_cred->cr_prison)) { 1344 return(0); 1345 } 1346 1347 /* 1348 * If the file pointer matches then mark it for revocation. The 1349 * flag is currently only used by unp_revoke_gc(). 1350 * 1351 * info->count is a heuristic and can race in a SMP environment. 1352 */ 1353 if (info->data == fp->f_data && info->type == fp->f_type) { 1354 atomic_set_int(&fp->f_flag, FREVOKED); 1355 info->count += fp->f_count; 1356 if (fp->f_msgcount) 1357 ++info->intransit; 1358 } 1359 return(0); 1360 } 1361 1362 /* 1363 * Locate matching file pointers via process descriptor tables. 1364 */ 1365 static int 1366 fdrevoke_proc_callback(struct proc *p, void *vinfo) 1367 { 1368 struct fdrevoke_info *info = vinfo; 1369 struct filedesc *fdp; 1370 struct file *fp; 1371 int n; 1372 1373 if (p->p_stat == SIDL || p->p_stat == SZOMB) 1374 return(0); 1375 if (info->cred->cr_prison && 1376 info->cred->cr_prison != p->p_ucred->cr_prison) { 1377 return(0); 1378 } 1379 1380 /* 1381 * If the controlling terminal of the process matches the 1382 * vnode being revoked we clear the controlling terminal. 1383 * 1384 * The normal spec_close() may not catch this because it 1385 * uses curproc instead of p. 1386 */ 1387 if (p->p_session && info->type == DTYPE_VNODE && 1388 info->data == p->p_session->s_ttyvp) { 1389 p->p_session->s_ttyvp = NULL; 1390 vrele(info->data); 1391 } 1392 1393 /* 1394 * Softref the fdp to prevent it from being destroyed 1395 */ 1396 spin_lock_wr(&p->p_spin); 1397 if ((fdp = p->p_fd) == NULL) { 1398 spin_unlock_wr(&p->p_spin); 1399 return(0); 1400 } 1401 atomic_add_int(&fdp->fd_softrefs, 1); 1402 spin_unlock_wr(&p->p_spin); 1403 1404 /* 1405 * Locate and close any matching file descriptors. 1406 */ 1407 spin_lock_wr(&fdp->fd_spin); 1408 for (n = 0; n < fdp->fd_nfiles; ++n) { 1409 if ((fp = fdp->fd_files[n].fp) == NULL) 1410 continue; 1411 if (fp->f_flag & FREVOKED) { 1412 fhold(info->nfp); 1413 fdp->fd_files[n].fp = info->nfp; 1414 spin_unlock_wr(&fdp->fd_spin); 1415 knote_fdclose(fp, fdp, n); /* XXX */ 1416 closef(fp, p); 1417 spin_lock_wr(&fdp->fd_spin); 1418 --info->count; 1419 } 1420 } 1421 spin_unlock_wr(&fdp->fd_spin); 1422 atomic_subtract_int(&fdp->fd_softrefs, 1); 1423 return(0); 1424 } 1425 1426 /* 1427 * falloc: 1428 * Create a new open file structure and reserve a file decriptor 1429 * for the process that refers to it. 1430 * 1431 * Root creds are checked using lp, or assumed if lp is NULL. If 1432 * resultfd is non-NULL then lp must also be non-NULL. No file 1433 * descriptor is reserved (and no process context is needed) if 1434 * resultfd is NULL. 1435 * 1436 * A file pointer with a refcount of 1 is returned. Note that the 1437 * file pointer is NOT associated with the descriptor. If falloc 1438 * returns success, fsetfd() MUST be called to either associate the 1439 * file pointer or clear the reservation. 1440 * 1441 * MPSAFE 1442 */ 1443 int 1444 falloc(struct lwp *lp, struct file **resultfp, int *resultfd) 1445 { 1446 static struct timeval lastfail; 1447 static int curfail; 1448 struct file *fp; 1449 struct ucred *cred = lp ? lp->lwp_thread->td_ucred : proc0.p_ucred; 1450 int error; 1451 1452 fp = NULL; 1453 1454 /* 1455 * Handle filetable full issues and root overfill. 1456 */ 1457 if (nfiles >= maxfiles - maxfilesrootres && 1458 (cred->cr_ruid != 0 || nfiles >= maxfiles)) { 1459 if (ppsratecheck(&lastfail, &curfail, 1)) { 1460 kprintf("kern.maxfiles limit exceeded by uid %d, " 1461 "please see tuning(7).\n", 1462 cred->cr_ruid); 1463 } 1464 error = ENFILE; 1465 goto done; 1466 } 1467 1468 /* 1469 * Allocate a new file descriptor. 1470 */ 1471 fp = kmalloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO); 1472 spin_init(&fp->f_spin); 1473 SLIST_INIT(&fp->f_klist); 1474 fp->f_count = 1; 1475 fp->f_ops = &badfileops; 1476 fp->f_seqcount = 1; 1477 fsetcred(fp, cred); 1478 spin_lock_wr(&filehead_spin); 1479 nfiles++; 1480 LIST_INSERT_HEAD(&filehead, fp, f_list); 1481 spin_unlock_wr(&filehead_spin); 1482 if (resultfd) { 1483 if ((error = fdalloc(lp->lwp_proc, 0, resultfd)) != 0) { 1484 fdrop(fp); 1485 fp = NULL; 1486 } 1487 } else { 1488 error = 0; 1489 } 1490 done: 1491 *resultfp = fp; 1492 return (error); 1493 } 1494 1495 /* 1496 * Check for races against a file descriptor by determining that the 1497 * file pointer is still associated with the specified file descriptor, 1498 * and a close is not currently in progress. 1499 * 1500 * MPSAFE 1501 */ 1502 int 1503 checkfdclosed(struct filedesc *fdp, int fd, struct file *fp) 1504 { 1505 int error; 1506 1507 spin_lock_rd(&fdp->fd_spin); 1508 if ((unsigned)fd >= fdp->fd_nfiles || fp != fdp->fd_files[fd].fp) 1509 error = EBADF; 1510 else 1511 error = 0; 1512 spin_unlock_rd(&fdp->fd_spin); 1513 return (error); 1514 } 1515 1516 /* 1517 * Associate a file pointer with a previously reserved file descriptor. 1518 * This function always succeeds. 1519 * 1520 * If fp is NULL, the file descriptor is returned to the pool. 1521 */ 1522 1523 /* 1524 * MPSAFE (exclusive spinlock must be held on call) 1525 */ 1526 static void 1527 fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd) 1528 { 1529 KKASSERT((unsigned)fd < fdp->fd_nfiles); 1530 KKASSERT(fdp->fd_files[fd].reserved != 0); 1531 if (fp) { 1532 fhold(fp); 1533 fdp->fd_files[fd].fp = fp; 1534 fdp->fd_files[fd].reserved = 0; 1535 } else { 1536 fdp->fd_files[fd].reserved = 0; 1537 fdreserve_locked(fdp, fd, -1); 1538 fdfixup_locked(fdp, fd); 1539 } 1540 } 1541 1542 /* 1543 * MPSAFE 1544 */ 1545 void 1546 fsetfd(struct filedesc *fdp, struct file *fp, int fd) 1547 { 1548 spin_lock_wr(&fdp->fd_spin); 1549 fsetfd_locked(fdp, fp, fd); 1550 spin_unlock_wr(&fdp->fd_spin); 1551 } 1552 1553 /* 1554 * MPSAFE (exclusive spinlock must be held on call) 1555 */ 1556 static 1557 struct file * 1558 funsetfd_locked(struct filedesc *fdp, int fd) 1559 { 1560 struct file *fp; 1561 1562 if ((unsigned)fd >= fdp->fd_nfiles) 1563 return (NULL); 1564 if ((fp = fdp->fd_files[fd].fp) == NULL) 1565 return (NULL); 1566 fdp->fd_files[fd].fp = NULL; 1567 fdp->fd_files[fd].fileflags = 0; 1568 1569 fdreserve_locked(fdp, fd, -1); 1570 fdfixup_locked(fdp, fd); 1571 return(fp); 1572 } 1573 1574 /* 1575 * MPSAFE 1576 */ 1577 int 1578 fgetfdflags(struct filedesc *fdp, int fd, int *flagsp) 1579 { 1580 int error; 1581 1582 spin_lock_rd(&fdp->fd_spin); 1583 if (((u_int)fd) >= fdp->fd_nfiles) { 1584 error = EBADF; 1585 } else if (fdp->fd_files[fd].fp == NULL) { 1586 error = EBADF; 1587 } else { 1588 *flagsp = fdp->fd_files[fd].fileflags; 1589 error = 0; 1590 } 1591 spin_unlock_rd(&fdp->fd_spin); 1592 return (error); 1593 } 1594 1595 /* 1596 * MPSAFE 1597 */ 1598 int 1599 fsetfdflags(struct filedesc *fdp, int fd, int add_flags) 1600 { 1601 int error; 1602 1603 spin_lock_wr(&fdp->fd_spin); 1604 if (((u_int)fd) >= fdp->fd_nfiles) { 1605 error = EBADF; 1606 } else if (fdp->fd_files[fd].fp == NULL) { 1607 error = EBADF; 1608 } else { 1609 fdp->fd_files[fd].fileflags |= add_flags; 1610 error = 0; 1611 } 1612 spin_unlock_wr(&fdp->fd_spin); 1613 return (error); 1614 } 1615 1616 /* 1617 * MPSAFE 1618 */ 1619 int 1620 fclrfdflags(struct filedesc *fdp, int fd, int rem_flags) 1621 { 1622 int error; 1623 1624 spin_lock_wr(&fdp->fd_spin); 1625 if (((u_int)fd) >= fdp->fd_nfiles) { 1626 error = EBADF; 1627 } else if (fdp->fd_files[fd].fp == NULL) { 1628 error = EBADF; 1629 } else { 1630 fdp->fd_files[fd].fileflags &= ~rem_flags; 1631 error = 0; 1632 } 1633 spin_unlock_wr(&fdp->fd_spin); 1634 return (error); 1635 } 1636 1637 /* 1638 * Set/Change/Clear the creds for a fp and synchronize the uidinfo. 1639 */ 1640 void 1641 fsetcred(struct file *fp, struct ucred *ncr) 1642 { 1643 struct ucred *ocr; 1644 struct uidinfo *uip; 1645 1646 ocr = fp->f_cred; 1647 if (ocr == NULL || ncr == NULL || ocr->cr_uidinfo != ncr->cr_uidinfo) { 1648 if (ocr) { 1649 uip = ocr->cr_uidinfo; 1650 atomic_add_int(&uip->ui_openfiles, -1); 1651 } 1652 if (ncr) { 1653 uip = ncr->cr_uidinfo; 1654 atomic_add_int(&uip->ui_openfiles, 1); 1655 } 1656 } 1657 if (ncr) 1658 crhold(ncr); 1659 fp->f_cred = ncr; 1660 if (ocr) 1661 crfree(ocr); 1662 } 1663 1664 /* 1665 * Free a file descriptor. 1666 */ 1667 static 1668 void 1669 ffree(struct file *fp) 1670 { 1671 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!")); 1672 spin_lock_wr(&filehead_spin); 1673 LIST_REMOVE(fp, f_list); 1674 nfiles--; 1675 spin_unlock_wr(&filehead_spin); 1676 fsetcred(fp, NULL); 1677 if (fp->f_nchandle.ncp) 1678 cache_drop(&fp->f_nchandle); 1679 kfree(fp, M_FILE); 1680 } 1681 1682 /* 1683 * called from init_main, initialize filedesc0 for proc0. 1684 */ 1685 void 1686 fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask) 1687 { 1688 p0->p_fd = fdp0; 1689 p0->p_fdtol = NULL; 1690 fdp0->fd_refcnt = 1; 1691 fdp0->fd_cmask = cmask; 1692 fdp0->fd_files = fdp0->fd_builtin_files; 1693 fdp0->fd_nfiles = NDFILE; 1694 fdp0->fd_lastfile = -1; 1695 spin_init(&fdp0->fd_spin); 1696 } 1697 1698 /* 1699 * Build a new filedesc structure. 1700 * 1701 * NOT MPSAFE (vref) 1702 */ 1703 struct filedesc * 1704 fdinit(struct proc *p) 1705 { 1706 struct filedesc *newfdp; 1707 struct filedesc *fdp = p->p_fd; 1708 1709 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK|M_ZERO); 1710 spin_lock_rd(&fdp->fd_spin); 1711 if (fdp->fd_cdir) { 1712 newfdp->fd_cdir = fdp->fd_cdir; 1713 vref(newfdp->fd_cdir); 1714 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir); 1715 } 1716 1717 /* 1718 * rdir may not be set in e.g. proc0 or anything vm_fork'd off of 1719 * proc0, but should unconditionally exist in other processes. 1720 */ 1721 if (fdp->fd_rdir) { 1722 newfdp->fd_rdir = fdp->fd_rdir; 1723 vref(newfdp->fd_rdir); 1724 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir); 1725 } 1726 if (fdp->fd_jdir) { 1727 newfdp->fd_jdir = fdp->fd_jdir; 1728 vref(newfdp->fd_jdir); 1729 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir); 1730 } 1731 spin_unlock_rd(&fdp->fd_spin); 1732 1733 /* Create the file descriptor table. */ 1734 newfdp->fd_refcnt = 1; 1735 newfdp->fd_cmask = cmask; 1736 newfdp->fd_files = newfdp->fd_builtin_files; 1737 newfdp->fd_nfiles = NDFILE; 1738 newfdp->fd_lastfile = -1; 1739 spin_init(&newfdp->fd_spin); 1740 1741 return (newfdp); 1742 } 1743 1744 /* 1745 * Share a filedesc structure. 1746 * 1747 * MPSAFE 1748 */ 1749 struct filedesc * 1750 fdshare(struct proc *p) 1751 { 1752 struct filedesc *fdp; 1753 1754 fdp = p->p_fd; 1755 spin_lock_wr(&fdp->fd_spin); 1756 fdp->fd_refcnt++; 1757 spin_unlock_wr(&fdp->fd_spin); 1758 return (fdp); 1759 } 1760 1761 /* 1762 * Copy a filedesc structure. 1763 * 1764 * MPSAFE 1765 */ 1766 struct filedesc * 1767 fdcopy(struct proc *p) 1768 { 1769 struct filedesc *fdp = p->p_fd; 1770 struct filedesc *newfdp; 1771 struct fdnode *fdnode; 1772 int i; 1773 int ni; 1774 1775 /* 1776 * Certain daemons might not have file descriptors. 1777 */ 1778 if (fdp == NULL) 1779 return (NULL); 1780 1781 /* 1782 * Allocate the new filedesc and fd_files[] array. This can race 1783 * with operations by other threads on the fdp so we have to be 1784 * careful. 1785 */ 1786 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK | M_ZERO); 1787 again: 1788 spin_lock_rd(&fdp->fd_spin); 1789 if (fdp->fd_lastfile < NDFILE) { 1790 newfdp->fd_files = newfdp->fd_builtin_files; 1791 i = NDFILE; 1792 } else { 1793 /* 1794 * We have to allocate (N^2-1) entries for our in-place 1795 * binary tree. Allow the table to shrink. 1796 */ 1797 i = fdp->fd_nfiles; 1798 ni = (i - 1) / 2; 1799 while (ni > fdp->fd_lastfile && ni > NDFILE) { 1800 i = ni; 1801 ni = (i - 1) / 2; 1802 } 1803 spin_unlock_rd(&fdp->fd_spin); 1804 newfdp->fd_files = kmalloc(i * sizeof(struct fdnode), 1805 M_FILEDESC, M_WAITOK | M_ZERO); 1806 1807 /* 1808 * Check for race, retry 1809 */ 1810 spin_lock_rd(&fdp->fd_spin); 1811 if (i <= fdp->fd_lastfile) { 1812 spin_unlock_rd(&fdp->fd_spin); 1813 kfree(newfdp->fd_files, M_FILEDESC); 1814 goto again; 1815 } 1816 } 1817 1818 /* 1819 * Dup the remaining fields. vref() and cache_hold() can be 1820 * safely called while holding the read spinlock on fdp. 1821 * 1822 * The read spinlock on fdp is still being held. 1823 * 1824 * NOTE: vref and cache_hold calls for the case where the vnode 1825 * or cache entry already has at least one ref may be called 1826 * while holding spin locks. 1827 */ 1828 if ((newfdp->fd_cdir = fdp->fd_cdir) != NULL) { 1829 vref(newfdp->fd_cdir); 1830 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir); 1831 } 1832 /* 1833 * We must check for fd_rdir here, at least for now because 1834 * the init process is created before we have access to the 1835 * rootvode to take a reference to it. 1836 */ 1837 if ((newfdp->fd_rdir = fdp->fd_rdir) != NULL) { 1838 vref(newfdp->fd_rdir); 1839 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir); 1840 } 1841 if ((newfdp->fd_jdir = fdp->fd_jdir) != NULL) { 1842 vref(newfdp->fd_jdir); 1843 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir); 1844 } 1845 newfdp->fd_refcnt = 1; 1846 newfdp->fd_nfiles = i; 1847 newfdp->fd_lastfile = fdp->fd_lastfile; 1848 newfdp->fd_freefile = fdp->fd_freefile; 1849 newfdp->fd_cmask = fdp->fd_cmask; 1850 spin_init(&newfdp->fd_spin); 1851 1852 /* 1853 * Copy the descriptor table through (i). This also copies the 1854 * allocation state. Then go through and ref the file pointers 1855 * and clean up any KQ descriptors. 1856 * 1857 * kq descriptors cannot be copied. Since we haven't ref'd the 1858 * copied files yet we can ignore the return value from funsetfd(). 1859 * 1860 * The read spinlock on fdp is still being held. 1861 */ 1862 bcopy(fdp->fd_files, newfdp->fd_files, i * sizeof(struct fdnode)); 1863 for (i = 0 ; i < newfdp->fd_nfiles; ++i) { 1864 fdnode = &newfdp->fd_files[i]; 1865 if (fdnode->reserved) { 1866 fdreserve_locked(newfdp, i, -1); 1867 fdnode->reserved = 0; 1868 fdfixup_locked(newfdp, i); 1869 } else if (fdnode->fp) { 1870 if (fdnode->fp->f_type == DTYPE_KQUEUE) { 1871 (void)funsetfd_locked(newfdp, i); 1872 } else { 1873 fhold(fdnode->fp); 1874 } 1875 } 1876 } 1877 spin_unlock_rd(&fdp->fd_spin); 1878 return (newfdp); 1879 } 1880 1881 /* 1882 * Release a filedesc structure. 1883 * 1884 * NOT MPSAFE (MPSAFE for refs > 1, but the final cleanup code is not MPSAFE) 1885 */ 1886 void 1887 fdfree(struct proc *p, struct filedesc *repl) 1888 { 1889 struct filedesc *fdp; 1890 struct fdnode *fdnode; 1891 int i; 1892 struct filedesc_to_leader *fdtol; 1893 struct file *fp; 1894 struct vnode *vp; 1895 struct flock lf; 1896 1897 /* 1898 * Certain daemons might not have file descriptors. 1899 */ 1900 fdp = p->p_fd; 1901 if (fdp == NULL) { 1902 p->p_fd = repl; 1903 return; 1904 } 1905 1906 /* 1907 * Severe messing around to follow. 1908 */ 1909 spin_lock_wr(&fdp->fd_spin); 1910 1911 /* Check for special need to clear POSIX style locks */ 1912 fdtol = p->p_fdtol; 1913 if (fdtol != NULL) { 1914 KASSERT(fdtol->fdl_refcount > 0, 1915 ("filedesc_to_refcount botch: fdl_refcount=%d", 1916 fdtol->fdl_refcount)); 1917 if (fdtol->fdl_refcount == 1 && 1918 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1919 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1920 fdnode = &fdp->fd_files[i]; 1921 if (fdnode->fp == NULL || 1922 fdnode->fp->f_type != DTYPE_VNODE) { 1923 continue; 1924 } 1925 fp = fdnode->fp; 1926 fhold(fp); 1927 spin_unlock_wr(&fdp->fd_spin); 1928 1929 lf.l_whence = SEEK_SET; 1930 lf.l_start = 0; 1931 lf.l_len = 0; 1932 lf.l_type = F_UNLCK; 1933 vp = (struct vnode *)fp->f_data; 1934 (void) VOP_ADVLOCK(vp, 1935 (caddr_t)p->p_leader, 1936 F_UNLCK, 1937 &lf, 1938 F_POSIX); 1939 fdrop(fp); 1940 spin_lock_wr(&fdp->fd_spin); 1941 } 1942 } 1943 retry: 1944 if (fdtol->fdl_refcount == 1) { 1945 if (fdp->fd_holdleaderscount > 0 && 1946 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1947 /* 1948 * close() or do_dup() has cleared a reference 1949 * in a shared file descriptor table. 1950 */ 1951 fdp->fd_holdleaderswakeup = 1; 1952 ssleep(&fdp->fd_holdleaderscount, 1953 &fdp->fd_spin, 0, "fdlhold", 0); 1954 goto retry; 1955 } 1956 if (fdtol->fdl_holdcount > 0) { 1957 /* 1958 * Ensure that fdtol->fdl_leader 1959 * remains valid in closef(). 1960 */ 1961 fdtol->fdl_wakeup = 1; 1962 ssleep(fdtol, &fdp->fd_spin, 0, "fdlhold", 0); 1963 goto retry; 1964 } 1965 } 1966 fdtol->fdl_refcount--; 1967 if (fdtol->fdl_refcount == 0 && 1968 fdtol->fdl_holdcount == 0) { 1969 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1970 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1971 } else { 1972 fdtol = NULL; 1973 } 1974 p->p_fdtol = NULL; 1975 if (fdtol != NULL) { 1976 spin_unlock_wr(&fdp->fd_spin); 1977 kfree(fdtol, M_FILEDESC_TO_LEADER); 1978 spin_lock_wr(&fdp->fd_spin); 1979 } 1980 } 1981 if (--fdp->fd_refcnt > 0) { 1982 spin_unlock_wr(&fdp->fd_spin); 1983 spin_lock_wr(&p->p_spin); 1984 p->p_fd = repl; 1985 spin_unlock_wr(&p->p_spin); 1986 return; 1987 } 1988 1989 /* 1990 * Even though we are the last reference to the structure allproc 1991 * scans may still reference the structure. Maintain proper 1992 * locks until we can replace p->p_fd. 1993 * 1994 * Also note that kqueue's closef still needs to reference the 1995 * fdp via p->p_fd, so we have to close the descriptors before 1996 * we replace p->p_fd. 1997 */ 1998 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1999 if (fdp->fd_files[i].fp) { 2000 fp = funsetfd_locked(fdp, i); 2001 if (fp) { 2002 spin_unlock_wr(&fdp->fd_spin); 2003 if (SLIST_FIRST(&fp->f_klist)) { 2004 get_mplock(); 2005 knote_fdclose(fp, fdp, i); 2006 rel_mplock(); 2007 } 2008 closef(fp, p); 2009 spin_lock_wr(&fdp->fd_spin); 2010 } 2011 } 2012 } 2013 spin_unlock_wr(&fdp->fd_spin); 2014 2015 /* 2016 * Interlock against an allproc scan operations (typically frevoke). 2017 */ 2018 spin_lock_wr(&p->p_spin); 2019 p->p_fd = repl; 2020 spin_unlock_wr(&p->p_spin); 2021 2022 /* 2023 * Wait for any softrefs to go away. This race rarely occurs so 2024 * we can use a non-critical-path style poll/sleep loop. The 2025 * race only occurs against allproc scans. 2026 * 2027 * No new softrefs can occur with the fdp disconnected from the 2028 * process. 2029 */ 2030 if (fdp->fd_softrefs) { 2031 kprintf("pid %d: Warning, fdp race avoided\n", p->p_pid); 2032 while (fdp->fd_softrefs) 2033 tsleep(&fdp->fd_softrefs, 0, "fdsoft", 1); 2034 } 2035 2036 if (fdp->fd_files != fdp->fd_builtin_files) 2037 kfree(fdp->fd_files, M_FILEDESC); 2038 if (fdp->fd_cdir) { 2039 cache_drop(&fdp->fd_ncdir); 2040 vrele(fdp->fd_cdir); 2041 } 2042 if (fdp->fd_rdir) { 2043 cache_drop(&fdp->fd_nrdir); 2044 vrele(fdp->fd_rdir); 2045 } 2046 if (fdp->fd_jdir) { 2047 cache_drop(&fdp->fd_njdir); 2048 vrele(fdp->fd_jdir); 2049 } 2050 kfree(fdp, M_FILEDESC); 2051 } 2052 2053 /* 2054 * Retrieve and reference the file pointer associated with a descriptor. 2055 * 2056 * MPSAFE 2057 */ 2058 struct file * 2059 holdfp(struct filedesc *fdp, int fd, int flag) 2060 { 2061 struct file* fp; 2062 2063 spin_lock_rd(&fdp->fd_spin); 2064 if (((u_int)fd) >= fdp->fd_nfiles) { 2065 fp = NULL; 2066 goto done; 2067 } 2068 if ((fp = fdp->fd_files[fd].fp) == NULL) 2069 goto done; 2070 if ((fp->f_flag & flag) == 0 && flag != -1) { 2071 fp = NULL; 2072 goto done; 2073 } 2074 fhold(fp); 2075 done: 2076 spin_unlock_rd(&fdp->fd_spin); 2077 return (fp); 2078 } 2079 2080 /* 2081 * holdsock() - load the struct file pointer associated 2082 * with a socket into *fpp. If an error occurs, non-zero 2083 * will be returned and *fpp will be set to NULL. 2084 * 2085 * MPSAFE 2086 */ 2087 int 2088 holdsock(struct filedesc *fdp, int fd, struct file **fpp) 2089 { 2090 struct file *fp; 2091 int error; 2092 2093 spin_lock_rd(&fdp->fd_spin); 2094 if ((unsigned)fd >= fdp->fd_nfiles) { 2095 error = EBADF; 2096 fp = NULL; 2097 goto done; 2098 } 2099 if ((fp = fdp->fd_files[fd].fp) == NULL) { 2100 error = EBADF; 2101 goto done; 2102 } 2103 if (fp->f_type != DTYPE_SOCKET) { 2104 error = ENOTSOCK; 2105 goto done; 2106 } 2107 fhold(fp); 2108 error = 0; 2109 done: 2110 spin_unlock_rd(&fdp->fd_spin); 2111 *fpp = fp; 2112 return (error); 2113 } 2114 2115 /* 2116 * Convert a user file descriptor to a held file pointer. 2117 * 2118 * MPSAFE 2119 */ 2120 int 2121 holdvnode(struct filedesc *fdp, int fd, struct file **fpp) 2122 { 2123 struct file *fp; 2124 int error; 2125 2126 spin_lock_rd(&fdp->fd_spin); 2127 if ((unsigned)fd >= fdp->fd_nfiles) { 2128 error = EBADF; 2129 fp = NULL; 2130 goto done; 2131 } 2132 if ((fp = fdp->fd_files[fd].fp) == NULL) { 2133 error = EBADF; 2134 goto done; 2135 } 2136 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 2137 fp = NULL; 2138 error = EINVAL; 2139 goto done; 2140 } 2141 fhold(fp); 2142 error = 0; 2143 done: 2144 spin_unlock_rd(&fdp->fd_spin); 2145 *fpp = fp; 2146 return (error); 2147 } 2148 2149 /* 2150 * For setugid programs, we don't want to people to use that setugidness 2151 * to generate error messages which write to a file which otherwise would 2152 * otherwise be off-limits to the process. 2153 * 2154 * This is a gross hack to plug the hole. A better solution would involve 2155 * a special vop or other form of generalized access control mechanism. We 2156 * go ahead and just reject all procfs file systems accesses as dangerous. 2157 * 2158 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 2159 * sufficient. We also don't for check setugidness since we know we are. 2160 */ 2161 static int 2162 is_unsafe(struct file *fp) 2163 { 2164 if (fp->f_type == DTYPE_VNODE && 2165 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS) 2166 return (1); 2167 return (0); 2168 } 2169 2170 /* 2171 * Make this setguid thing safe, if at all possible. 2172 * 2173 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose() 2174 */ 2175 void 2176 setugidsafety(struct proc *p) 2177 { 2178 struct filedesc *fdp = p->p_fd; 2179 int i; 2180 2181 /* Certain daemons might not have file descriptors. */ 2182 if (fdp == NULL) 2183 return; 2184 2185 /* 2186 * note: fdp->fd_files may be reallocated out from under us while 2187 * we are blocked in a close. Be careful! 2188 */ 2189 for (i = 0; i <= fdp->fd_lastfile; i++) { 2190 if (i > 2) 2191 break; 2192 if (fdp->fd_files[i].fp && is_unsafe(fdp->fd_files[i].fp)) { 2193 struct file *fp; 2194 2195 /* 2196 * NULL-out descriptor prior to close to avoid 2197 * a race while close blocks. 2198 */ 2199 if ((fp = funsetfd_locked(fdp, i)) != NULL) { 2200 knote_fdclose(fp, fdp, i); 2201 closef(fp, p); 2202 } 2203 } 2204 } 2205 } 2206 2207 /* 2208 * Close any files on exec? 2209 * 2210 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose() 2211 */ 2212 void 2213 fdcloseexec(struct proc *p) 2214 { 2215 struct filedesc *fdp = p->p_fd; 2216 int i; 2217 2218 /* Certain daemons might not have file descriptors. */ 2219 if (fdp == NULL) 2220 return; 2221 2222 /* 2223 * We cannot cache fd_files since operations may block and rip 2224 * them out from under us. 2225 */ 2226 for (i = 0; i <= fdp->fd_lastfile; i++) { 2227 if (fdp->fd_files[i].fp != NULL && 2228 (fdp->fd_files[i].fileflags & UF_EXCLOSE)) { 2229 struct file *fp; 2230 2231 /* 2232 * NULL-out descriptor prior to close to avoid 2233 * a race while close blocks. 2234 */ 2235 if ((fp = funsetfd_locked(fdp, i)) != NULL) { 2236 knote_fdclose(fp, fdp, i); 2237 closef(fp, p); 2238 } 2239 } 2240 } 2241 } 2242 2243 /* 2244 * It is unsafe for set[ug]id processes to be started with file 2245 * descriptors 0..2 closed, as these descriptors are given implicit 2246 * significance in the Standard C library. fdcheckstd() will create a 2247 * descriptor referencing /dev/null for each of stdin, stdout, and 2248 * stderr that is not already open. 2249 * 2250 * NOT MPSAFE - calls falloc, vn_open, etc 2251 */ 2252 int 2253 fdcheckstd(struct lwp *lp) 2254 { 2255 struct nlookupdata nd; 2256 struct filedesc *fdp; 2257 struct file *fp; 2258 int retval; 2259 int i, error, flags, devnull; 2260 2261 fdp = lp->lwp_proc->p_fd; 2262 if (fdp == NULL) 2263 return (0); 2264 devnull = -1; 2265 error = 0; 2266 for (i = 0; i < 3; i++) { 2267 if (fdp->fd_files[i].fp != NULL) 2268 continue; 2269 if (devnull < 0) { 2270 if ((error = falloc(lp, &fp, &devnull)) != 0) 2271 break; 2272 2273 error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE, 2274 NLC_FOLLOW|NLC_LOCKVP); 2275 flags = FREAD | FWRITE; 2276 if (error == 0) 2277 error = vn_open(&nd, fp, flags, 0); 2278 if (error == 0) 2279 fsetfd(fdp, fp, devnull); 2280 else 2281 fsetfd(fdp, NULL, devnull); 2282 fdrop(fp); 2283 nlookup_done(&nd); 2284 if (error) 2285 break; 2286 KKASSERT(i == devnull); 2287 } else { 2288 error = kern_dup(DUP_FIXED, devnull, i, &retval); 2289 if (error != 0) 2290 break; 2291 } 2292 } 2293 return (error); 2294 } 2295 2296 /* 2297 * Internal form of close. 2298 * Decrement reference count on file structure. 2299 * Note: td and/or p may be NULL when closing a file 2300 * that was being passed in a message. 2301 * 2302 * MPALMOSTSAFE - acquires mplock for VOP operations 2303 */ 2304 int 2305 closef(struct file *fp, struct proc *p) 2306 { 2307 struct vnode *vp; 2308 struct flock lf; 2309 struct filedesc_to_leader *fdtol; 2310 2311 if (fp == NULL) 2312 return (0); 2313 2314 /* 2315 * POSIX record locking dictates that any close releases ALL 2316 * locks owned by this process. This is handled by setting 2317 * a flag in the unlock to free ONLY locks obeying POSIX 2318 * semantics, and not to free BSD-style file locks. 2319 * If the descriptor was in a message, POSIX-style locks 2320 * aren't passed with the descriptor. 2321 */ 2322 if (p != NULL && fp->f_type == DTYPE_VNODE && 2323 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS) 2324 ) { 2325 get_mplock(); 2326 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) { 2327 lf.l_whence = SEEK_SET; 2328 lf.l_start = 0; 2329 lf.l_len = 0; 2330 lf.l_type = F_UNLCK; 2331 vp = (struct vnode *)fp->f_data; 2332 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 2333 &lf, F_POSIX); 2334 } 2335 fdtol = p->p_fdtol; 2336 if (fdtol != NULL) { 2337 /* 2338 * Handle special case where file descriptor table 2339 * is shared between multiple process leaders. 2340 */ 2341 for (fdtol = fdtol->fdl_next; 2342 fdtol != p->p_fdtol; 2343 fdtol = fdtol->fdl_next) { 2344 if ((fdtol->fdl_leader->p_flag & 2345 P_ADVLOCK) == 0) 2346 continue; 2347 fdtol->fdl_holdcount++; 2348 lf.l_whence = SEEK_SET; 2349 lf.l_start = 0; 2350 lf.l_len = 0; 2351 lf.l_type = F_UNLCK; 2352 vp = (struct vnode *)fp->f_data; 2353 (void) VOP_ADVLOCK(vp, 2354 (caddr_t)fdtol->fdl_leader, 2355 F_UNLCK, &lf, F_POSIX); 2356 fdtol->fdl_holdcount--; 2357 if (fdtol->fdl_holdcount == 0 && 2358 fdtol->fdl_wakeup != 0) { 2359 fdtol->fdl_wakeup = 0; 2360 wakeup(fdtol); 2361 } 2362 } 2363 } 2364 rel_mplock(); 2365 } 2366 return (fdrop(fp)); 2367 } 2368 2369 /* 2370 * MPSAFE 2371 * 2372 * fhold() can only be called if f_count is already at least 1 (i.e. the 2373 * caller of fhold() already has a reference to the file pointer in some 2374 * manner or other). 2375 * 2376 * f_count is not spin-locked. Instead, atomic ops are used for 2377 * incrementing, decrementing, and handling the 1->0 transition. 2378 */ 2379 void 2380 fhold(struct file *fp) 2381 { 2382 atomic_add_int(&fp->f_count, 1); 2383 } 2384 2385 /* 2386 * fdrop() - drop a reference to a descriptor 2387 * 2388 * MPALMOSTSAFE - acquires mplock for final close sequence 2389 */ 2390 int 2391 fdrop(struct file *fp) 2392 { 2393 struct flock lf; 2394 struct vnode *vp; 2395 int error; 2396 2397 /* 2398 * A combined fetch and subtract is needed to properly detect 2399 * 1->0 transitions, otherwise two cpus dropping from a ref 2400 * count of 2 might both try to run the 1->0 code. 2401 */ 2402 if (atomic_fetchadd_int(&fp->f_count, -1) > 1) 2403 return (0); 2404 2405 KKASSERT(SLIST_FIRST(&fp->f_klist) == NULL); 2406 get_mplock(); 2407 2408 /* 2409 * The last reference has gone away, we own the fp structure free 2410 * and clear. 2411 */ 2412 if (fp->f_count < 0) 2413 panic("fdrop: count < 0"); 2414 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE && 2415 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS) 2416 ) { 2417 lf.l_whence = SEEK_SET; 2418 lf.l_start = 0; 2419 lf.l_len = 0; 2420 lf.l_type = F_UNLCK; 2421 vp = (struct vnode *)fp->f_data; 2422 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0); 2423 } 2424 if (fp->f_ops != &badfileops) 2425 error = fo_close(fp); 2426 else 2427 error = 0; 2428 ffree(fp); 2429 rel_mplock(); 2430 return (error); 2431 } 2432 2433 /* 2434 * Apply an advisory lock on a file descriptor. 2435 * 2436 * Just attempt to get a record lock of the requested type on 2437 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2438 * 2439 * MPALMOSTSAFE 2440 */ 2441 int 2442 sys_flock(struct flock_args *uap) 2443 { 2444 struct proc *p = curproc; 2445 struct file *fp; 2446 struct vnode *vp; 2447 struct flock lf; 2448 int error; 2449 2450 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL) 2451 return (EBADF); 2452 get_mplock(); 2453 if (fp->f_type != DTYPE_VNODE) { 2454 error = EOPNOTSUPP; 2455 goto done; 2456 } 2457 vp = (struct vnode *)fp->f_data; 2458 lf.l_whence = SEEK_SET; 2459 lf.l_start = 0; 2460 lf.l_len = 0; 2461 if (uap->how & LOCK_UN) { 2462 lf.l_type = F_UNLCK; 2463 fp->f_flag &= ~FHASLOCK; 2464 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0); 2465 goto done; 2466 } 2467 if (uap->how & LOCK_EX) 2468 lf.l_type = F_WRLCK; 2469 else if (uap->how & LOCK_SH) 2470 lf.l_type = F_RDLCK; 2471 else { 2472 error = EBADF; 2473 goto done; 2474 } 2475 fp->f_flag |= FHASLOCK; 2476 if (uap->how & LOCK_NB) 2477 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 0); 2478 else 2479 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_WAIT); 2480 done: 2481 rel_mplock(); 2482 fdrop(fp); 2483 return (error); 2484 } 2485 2486 /* 2487 * File Descriptor pseudo-device driver (/dev/fd/). 2488 * 2489 * Opening minor device N dup()s the file (if any) connected to file 2490 * descriptor N belonging to the calling process. Note that this driver 2491 * consists of only the ``open()'' routine, because all subsequent 2492 * references to this file will be direct to the other driver. 2493 */ 2494 static int 2495 fdopen(struct dev_open_args *ap) 2496 { 2497 thread_t td = curthread; 2498 2499 KKASSERT(td->td_lwp != NULL); 2500 2501 /* 2502 * XXX Kludge: set curlwp->lwp_dupfd to contain the value of the 2503 * the file descriptor being sought for duplication. The error 2504 * return ensures that the vnode for this device will be released 2505 * by vn_open. Open will detect this special error and take the 2506 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 2507 * will simply report the error. 2508 */ 2509 td->td_lwp->lwp_dupfd = minor(ap->a_head.a_dev); 2510 return (ENODEV); 2511 } 2512 2513 /* 2514 * The caller has reserved the file descriptor dfd for us. On success we 2515 * must fsetfd() it. On failure the caller will clean it up. 2516 * 2517 * MPSAFE 2518 */ 2519 int 2520 dupfdopen(struct filedesc *fdp, int dfd, int sfd, int mode, int error) 2521 { 2522 struct file *wfp; 2523 struct file *xfp; 2524 int werror; 2525 2526 if ((wfp = holdfp(fdp, sfd, -1)) == NULL) 2527 return (EBADF); 2528 2529 /* 2530 * Close a revoke/dup race. Duping a descriptor marked as revoked 2531 * will dup a dummy descriptor instead of the real one. 2532 */ 2533 if (wfp->f_flag & FREVOKED) { 2534 kprintf("Warning: attempt to dup() a revoked descriptor\n"); 2535 fdrop(wfp); 2536 wfp = NULL; 2537 werror = falloc(NULL, &wfp, NULL); 2538 if (werror) 2539 return (werror); 2540 } 2541 2542 /* 2543 * There are two cases of interest here. 2544 * 2545 * For ENODEV simply dup sfd to file descriptor dfd and return. 2546 * 2547 * For ENXIO steal away the file structure from sfd and store it 2548 * dfd. sfd is effectively closed by this operation. 2549 * 2550 * Any other error code is just returned. 2551 */ 2552 switch (error) { 2553 case ENODEV: 2554 /* 2555 * Check that the mode the file is being opened for is a 2556 * subset of the mode of the existing descriptor. 2557 */ 2558 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2559 error = EACCES; 2560 break; 2561 } 2562 spin_lock_wr(&fdp->fd_spin); 2563 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags; 2564 fsetfd_locked(fdp, wfp, dfd); 2565 spin_unlock_wr(&fdp->fd_spin); 2566 error = 0; 2567 break; 2568 case ENXIO: 2569 /* 2570 * Steal away the file pointer from dfd, and stuff it into indx. 2571 */ 2572 spin_lock_wr(&fdp->fd_spin); 2573 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags; 2574 fsetfd(fdp, wfp, dfd); 2575 if ((xfp = funsetfd_locked(fdp, sfd)) != NULL) { 2576 spin_unlock_wr(&fdp->fd_spin); 2577 fdrop(xfp); 2578 } else { 2579 spin_unlock_wr(&fdp->fd_spin); 2580 } 2581 error = 0; 2582 break; 2583 default: 2584 break; 2585 } 2586 fdrop(wfp); 2587 return (error); 2588 } 2589 2590 /* 2591 * NOT MPSAFE - I think these refer to a common file descriptor table 2592 * and we need to spinlock that to link fdtol in. 2593 */ 2594 struct filedesc_to_leader * 2595 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 2596 struct proc *leader) 2597 { 2598 struct filedesc_to_leader *fdtol; 2599 2600 fdtol = kmalloc(sizeof(struct filedesc_to_leader), 2601 M_FILEDESC_TO_LEADER, M_WAITOK); 2602 fdtol->fdl_refcount = 1; 2603 fdtol->fdl_holdcount = 0; 2604 fdtol->fdl_wakeup = 0; 2605 fdtol->fdl_leader = leader; 2606 if (old != NULL) { 2607 fdtol->fdl_next = old->fdl_next; 2608 fdtol->fdl_prev = old; 2609 old->fdl_next = fdtol; 2610 fdtol->fdl_next->fdl_prev = fdtol; 2611 } else { 2612 fdtol->fdl_next = fdtol; 2613 fdtol->fdl_prev = fdtol; 2614 } 2615 return fdtol; 2616 } 2617 2618 /* 2619 * Scan all file pointers in the system. The callback is made with 2620 * the master list spinlock held exclusively. 2621 * 2622 * MPSAFE 2623 */ 2624 void 2625 allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data) 2626 { 2627 struct file *fp; 2628 int res; 2629 2630 spin_lock_wr(&filehead_spin); 2631 LIST_FOREACH(fp, &filehead, f_list) { 2632 res = callback(fp, data); 2633 if (res < 0) 2634 break; 2635 } 2636 spin_unlock_wr(&filehead_spin); 2637 } 2638 2639 /* 2640 * Get file structures. 2641 * 2642 * NOT MPSAFE - process list scan, SYSCTL_OUT (probably not mpsafe) 2643 */ 2644 2645 struct sysctl_kern_file_info { 2646 int count; 2647 int error; 2648 struct sysctl_req *req; 2649 }; 2650 2651 static int sysctl_kern_file_callback(struct proc *p, void *data); 2652 2653 static int 2654 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2655 { 2656 struct sysctl_kern_file_info info; 2657 2658 /* 2659 * Note: because the number of file descriptors is calculated 2660 * in different ways for sizing vs returning the data, 2661 * there is information leakage from the first loop. However, 2662 * it is of a similar order of magnitude to the leakage from 2663 * global system statistics such as kern.openfiles. 2664 * 2665 * When just doing a count, note that we cannot just count 2666 * the elements and add f_count via the filehead list because 2667 * threaded processes share their descriptor table and f_count might 2668 * still be '1' in that case. 2669 * 2670 * Since the SYSCTL op can block, we must hold the process to 2671 * prevent it being ripped out from under us either in the 2672 * file descriptor loop or in the greater LIST_FOREACH. The 2673 * process may be in varying states of disrepair. If the process 2674 * is in SZOMB we may have caught it just as it is being removed 2675 * from the allproc list, we must skip it in that case to maintain 2676 * an unbroken chain through the allproc list. 2677 */ 2678 info.count = 0; 2679 info.error = 0; 2680 info.req = req; 2681 allproc_scan(sysctl_kern_file_callback, &info); 2682 2683 /* 2684 * When just calculating the size, overestimate a bit to try to 2685 * prevent system activity from causing the buffer-fill call 2686 * to fail later on. 2687 */ 2688 if (req->oldptr == NULL) { 2689 info.count = (info.count + 16) + (info.count / 10); 2690 info.error = SYSCTL_OUT(req, NULL, 2691 info.count * sizeof(struct kinfo_file)); 2692 } 2693 return (info.error); 2694 } 2695 2696 static int 2697 sysctl_kern_file_callback(struct proc *p, void *data) 2698 { 2699 struct sysctl_kern_file_info *info = data; 2700 struct kinfo_file kf; 2701 struct filedesc *fdp; 2702 struct file *fp; 2703 uid_t uid; 2704 int n; 2705 2706 if (p->p_stat == SIDL || p->p_stat == SZOMB) 2707 return(0); 2708 if (!PRISON_CHECK(info->req->td->td_ucred, p->p_ucred) != 0) 2709 return(0); 2710 2711 /* 2712 * Softref the fdp to prevent it from being destroyed 2713 */ 2714 spin_lock_wr(&p->p_spin); 2715 if ((fdp = p->p_fd) == NULL) { 2716 spin_unlock_wr(&p->p_spin); 2717 return(0); 2718 } 2719 atomic_add_int(&fdp->fd_softrefs, 1); 2720 spin_unlock_wr(&p->p_spin); 2721 2722 /* 2723 * The fdp's own spinlock prevents the contents from being 2724 * modified. 2725 */ 2726 spin_lock_rd(&fdp->fd_spin); 2727 for (n = 0; n < fdp->fd_nfiles; ++n) { 2728 if ((fp = fdp->fd_files[n].fp) == NULL) 2729 continue; 2730 if (info->req->oldptr == NULL) { 2731 ++info->count; 2732 } else { 2733 uid = p->p_ucred ? p->p_ucred->cr_uid : -1; 2734 kcore_make_file(&kf, fp, p->p_pid, uid, n); 2735 spin_unlock_rd(&fdp->fd_spin); 2736 info->error = SYSCTL_OUT(info->req, &kf, sizeof(kf)); 2737 spin_lock_rd(&fdp->fd_spin); 2738 if (info->error) 2739 break; 2740 } 2741 } 2742 spin_unlock_rd(&fdp->fd_spin); 2743 atomic_subtract_int(&fdp->fd_softrefs, 1); 2744 if (info->error) 2745 return(-1); 2746 return(0); 2747 } 2748 2749 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2750 0, 0, sysctl_kern_file, "S,file", "Entire file table"); 2751 2752 SYSCTL_INT(_kern, OID_AUTO, minfilesperproc, CTLFLAG_RW, 2753 &minfilesperproc, 0, "Minimum files allowed open per process"); 2754 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 2755 &maxfilesperproc, 0, "Maximum files allowed open per process"); 2756 SYSCTL_INT(_kern, OID_AUTO, maxfilesperuser, CTLFLAG_RW, 2757 &maxfilesperuser, 0, "Maximum files allowed open per user"); 2758 2759 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 2760 &maxfiles, 0, "Maximum number of files"); 2761 2762 SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW, 2763 &maxfilesrootres, 0, "Descriptors reserved for root use"); 2764 2765 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 2766 &nfiles, 0, "System-wide number of open files"); 2767 2768 static void 2769 fildesc_drvinit(void *unused) 2770 { 2771 int fd; 2772 2773 for (fd = 0; fd < NUMFDESC; fd++) { 2774 make_dev(&fildesc_ops, fd, 2775 UID_BIN, GID_BIN, 0666, "fd/%d", fd); 2776 } 2777 2778 make_dev(&fildesc_ops, 0, UID_ROOT, GID_WHEEL, 0666, "stdin"); 2779 make_dev(&fildesc_ops, 1, UID_ROOT, GID_WHEEL, 0666, "stdout"); 2780 make_dev(&fildesc_ops, 2, UID_ROOT, GID_WHEEL, 0666, "stderr"); 2781 } 2782 2783 /* 2784 * MPSAFE 2785 */ 2786 struct fileops badfileops = { 2787 .fo_read = badfo_readwrite, 2788 .fo_write = badfo_readwrite, 2789 .fo_ioctl = badfo_ioctl, 2790 .fo_poll = badfo_poll, 2791 .fo_kqfilter = badfo_kqfilter, 2792 .fo_stat = badfo_stat, 2793 .fo_close = badfo_close, 2794 .fo_shutdown = badfo_shutdown 2795 }; 2796 2797 /* 2798 * MPSAFE 2799 */ 2800 int 2801 badfo_readwrite( 2802 struct file *fp, 2803 struct uio *uio, 2804 struct ucred *cred, 2805 int flags 2806 ) { 2807 return (EBADF); 2808 } 2809 2810 /* 2811 * MPSAFE 2812 */ 2813 int 2814 badfo_ioctl(struct file *fp, u_long com, caddr_t data, 2815 struct ucred *cred, struct sysmsg *msgv) 2816 { 2817 return (EBADF); 2818 } 2819 2820 /* 2821 * MPSAFE 2822 */ 2823 int 2824 badfo_poll(struct file *fp, int events, struct ucred *cred) 2825 { 2826 return (0); 2827 } 2828 2829 /* 2830 * MPSAFE 2831 */ 2832 int 2833 badfo_kqfilter(struct file *fp, struct knote *kn) 2834 { 2835 return (0); 2836 } 2837 2838 int 2839 badfo_stat(struct file *fp, struct stat *sb, struct ucred *cred) 2840 { 2841 return (EBADF); 2842 } 2843 2844 /* 2845 * MPSAFE 2846 */ 2847 int 2848 badfo_close(struct file *fp) 2849 { 2850 return (EBADF); 2851 } 2852 2853 /* 2854 * MPSAFE 2855 */ 2856 int 2857 badfo_shutdown(struct file *fp, int how) 2858 { 2859 return (EBADF); 2860 } 2861 2862 /* 2863 * MPSAFE 2864 */ 2865 int 2866 nofo_shutdown(struct file *fp, int how) 2867 { 2868 return (EOPNOTSUPP); 2869 } 2870 2871 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, 2872 fildesc_drvinit,NULL) 2873