sys/kern/kern_descrip.c

   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 1.51 2005/12/01 18:30:08 dillon 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/filedesc.h>
  83 #include <sys/kernel.h>
  84 #include <sys/sysctl.h>
  85 #include <sys/vnode.h>
  86 #include <sys/proc.h>
  87 #include <sys/nlookup.h>
  88 #include <sys/file.h>
  89 #include <sys/stat.h>
  90 #include <sys/filio.h>
  91 #include <sys/fcntl.h>
  92 #include <sys/unistd.h>
  93 #include <sys/resourcevar.h>
  94 #include <sys/event.h>
  95 #include <sys/kern_syscall.h>
  96 #include <sys/kcore.h>
  97 #include <sys/kinfo.h>
  98
  99 #include <vm/vm.h>
 100 #include <vm/vm_extern.h>
 101
 102 #include <sys/thread2.h>
 103 #include <sys/file2.h>
 104
 105 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
 106 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader",
 107                      "file desc to leader structures");
 108 MALLOC_DEFINE(M_FILE, "file", "Open file structure");
 109 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
 110
 111 static   d_open_t  fdopen;
 112 #define NUMFDESC 64
 113
 114 #define CDEV_MAJOR 22
 115 static struct cdevsw fildesc_cdevsw = {
 116         /* name */      "FD",
 117         /* maj */       CDEV_MAJOR,
 118         /* flags */     0,
 119         /* port */      NULL,
 120         /* clone */     NULL,
 121
 122         /* open */      fdopen,
 123         /* close */     noclose,
 124         /* read */      noread,
 125         /* write */     nowrite,
 126         /* ioctl */     noioctl,
 127         /* poll */      nopoll,
 128         /* mmap */      nommap,
 129         /* strategy */  nostrategy,
 130         /* dump */      nodump,
 131         /* psize */     nopsize
 132 };
 133
 134 static int badfo_readwrite (struct file *fp, struct uio *uio,
 135     struct ucred *cred, int flags, struct thread *td);
 136 static int badfo_ioctl (struct file *fp, u_long com, caddr_t data,
 137     struct thread *td);
 138 static int badfo_poll (struct file *fp, int events,
 139     struct ucred *cred, struct thread *td);
 140 static int badfo_kqfilter (struct file *fp, struct knote *kn);
 141 static int badfo_stat (struct file *fp, struct stat *sb, struct thread *td);
 142 static int badfo_close (struct file *fp, struct thread *td);
 143 static int badfo_shutdown (struct file *fp, int how, struct thread *td);
 144
 145 /*
 146  * Descriptor management.
 147  */
 148 struct filelist filehead;       /* head of list of open files */
 149 int nfiles;                     /* actual number of open files */
 150 extern int cmask;
 151
 152 /*
 153  * System calls on descriptors.
 154  */
 155 /* ARGSUSED */
 156 int
 157 getdtablesize(struct getdtablesize_args *uap)
 158 {
 159         struct proc *p = curproc;
 160
 161         uap->sysmsg_result =
 162             min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
 163         return (0);
 164 }
 165
 166 /*
 167  * Duplicate a file descriptor to a particular value.
 168  *
 169  * note: keep in mind that a potential race condition exists when closing
 170  * descriptors from a shared descriptor table (via rfork).
 171  */
 172 /* ARGSUSED */
 173 int
 174 dup2(struct dup2_args *uap)
 175 {
 176         int error;
 177
 178         error = kern_dup(DUP_FIXED, uap->from, uap->to, uap->sysmsg_fds);
 179
 180         return (error);
 181 }
 182
 183 /*
 184  * Duplicate a file descriptor.
 185  */
 186 /* ARGSUSED */
 187 int
 188 dup(struct dup_args *uap)
 189 {
 190         int error;
 191
 192         error = kern_dup(DUP_VARIABLE, uap->fd, 0, uap->sysmsg_fds);
 193
 194         return (error);
 195 }
 196
 197 int
 198 kern_fcntl(int fd, int cmd, union fcntl_dat *dat)
 199 {
 200         struct thread *td = curthread;
 201         struct proc *p = td->td_proc;
 202         struct filedesc *fdp = p->p_fd;
 203         struct file *fp;
 204         char *pop;
 205         struct vnode *vp;
 206         u_int newmin;
 207         int tmp, error, flg = F_POSIX;
 208
 209         KKASSERT(p);
 210
 211         if ((unsigned)fd >= fdp->fd_nfiles ||
 212             (fp = fdp->fd_files[fd].fp) == NULL)
 213                 return (EBADF);
 214         pop = &fdp->fd_files[fd].fileflags;
 215
 216         switch (cmd) {
 217         case F_DUPFD:
 218                 newmin = dat->fc_fd;
 219                 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
 220                     newmin > maxfilesperproc)
 221                         return (EINVAL);
 222                 error = kern_dup(DUP_VARIABLE, fd, newmin, &dat->fc_fd);
 223                 return (error);
 224
 225         case F_GETFD:
 226                 dat->fc_cloexec = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
 227                 return (0);
 228
 229         case F_SETFD:
 230                 *pop = (*pop &~ UF_EXCLOSE) |
 231                     (dat->fc_cloexec & FD_CLOEXEC ? UF_EXCLOSE : 0);
 232                 return (0);
 233
 234         case F_GETFL:
 235                 dat->fc_flags = OFLAGS(fp->f_flag);
 236                 return (0);
 237
 238         case F_SETFL:
 239                 fhold(fp);
 240                 fp->f_flag &= ~FCNTLFLAGS;
 241                 fp->f_flag |= FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS;
 242                 tmp = fp->f_flag & FNONBLOCK;
 243                 error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td);
 244                 if (error) {
 245                         fdrop(fp, td);
 246                         return (error);
 247                 }
 248                 tmp = fp->f_flag & FASYNC;
 249                 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td);
 250                 if (!error) {
 251                         fdrop(fp, td);
 252                         return (0);
 253                 }
 254                 fp->f_flag &= ~FNONBLOCK;
 255                 tmp = 0;
 256                 fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td);
 257                 fdrop(fp, td);
 258                 return (error);
 259
 260         case F_GETOWN:
 261                 fhold(fp);
 262                 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner, td);
 263                 fdrop(fp, td);
 264                 return(error);
 265
 266         case F_SETOWN:
 267                 fhold(fp);
 268                 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner, td);
 269                 fdrop(fp, td);
 270                 return(error);
 271
 272         case F_SETLKW:
 273                 flg |= F_WAIT;
 274                 /* Fall into F_SETLK */
 275
 276         case F_SETLK:
 277                 if (fp->f_type != DTYPE_VNODE)
 278                         return (EBADF);
 279                 vp = (struct vnode *)fp->f_data;
 280
 281                 /*
 282                  * copyin/lockop may block
 283                  */
 284                 fhold(fp);
 285                 if (dat->fc_flock.l_whence == SEEK_CUR)
 286                         dat->fc_flock.l_start += fp->f_offset;
 287
 288                 switch (dat->fc_flock.l_type) {
 289                 case F_RDLCK:
 290                         if ((fp->f_flag & FREAD) == 0) {
 291                                 error = EBADF;
 292                                 break;
 293                         }
 294                         p->p_leader->p_flag |= P_ADVLOCK;
 295                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
 296                             &dat->fc_flock, flg);
 297                         break;
 298                 case F_WRLCK:
 299                         if ((fp->f_flag & FWRITE) == 0) {
 300                                 error = EBADF;
 301                                 break;
 302                         }
 303                         p->p_leader->p_flag |= P_ADVLOCK;
 304                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
 305                             &dat->fc_flock, flg);
 306                         break;
 307                 case F_UNLCK:
 308                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
 309                                 &dat->fc_flock, F_POSIX);
 310                         break;
 311                 default:
 312                         error = EINVAL;
 313                         break;
 314                 }
 315                 /* Check for race with close */
 316                 if ((unsigned) fd >= fdp->fd_nfiles ||
 317                     fp != fdp->fd_files[fd].fp) {
 318                         dat->fc_flock.l_whence = SEEK_SET;
 319                         dat->fc_flock.l_start = 0;
 320                         dat->fc_flock.l_len = 0;
 321                         dat->fc_flock.l_type = F_UNLCK;
 322                         (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
 323                                            F_UNLCK, &dat->fc_flock, F_POSIX);
 324                 }
 325                 fdrop(fp, td);
 326                 return(error);
 327
 328         case F_GETLK:
 329                 if (fp->f_type != DTYPE_VNODE)
 330                         return (EBADF);
 331                 vp = (struct vnode *)fp->f_data;
 332                 /*
 333                  * copyin/lockop may block
 334                  */
 335                 fhold(fp);
 336                 if (dat->fc_flock.l_type != F_RDLCK &&
 337                     dat->fc_flock.l_type != F_WRLCK &&
 338                     dat->fc_flock.l_type != F_UNLCK) {
 339                         fdrop(fp, td);
 340                         return (EINVAL);
 341                 }
 342                 if (dat->fc_flock.l_whence == SEEK_CUR)
 343                         dat->fc_flock.l_start += fp->f_offset;
 344                 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK,
 345                             &dat->fc_flock, F_POSIX);
 346                 fdrop(fp, td);
 347                 return(error);
 348         default:
 349                 return (EINVAL);
 350         }
 351         /* NOTREACHED */
 352 }
 353
 354 /*
 355  * The file control system call.
 356  */
 357 int
 358 fcntl(struct fcntl_args *uap)
 359 {
 360         union fcntl_dat dat;
 361         int error;
 362
 363         switch (uap->cmd) {
 364         case F_DUPFD:
 365                 dat.fc_fd = uap->arg;
 366                 break;
 367         case F_SETFD:
 368                 dat.fc_cloexec = uap->arg;
 369                 break;
 370         case F_SETFL:
 371                 dat.fc_flags = uap->arg;
 372                 break;
 373         case F_SETOWN:
 374                 dat.fc_owner = uap->arg;
 375                 break;
 376         case F_SETLKW:
 377         case F_SETLK:
 378         case F_GETLK:
 379                 error = copyin((caddr_t)uap->arg, &dat.fc_flock,
 380                     sizeof(struct flock));
 381                 if (error)
 382                         return (error);
 383                 break;
 384         }
 385
 386         error = kern_fcntl(uap->fd, uap->cmd, &dat);
 387
 388         if (error == 0) {
 389                 switch (uap->cmd) {
 390                 case F_DUPFD:
 391                         uap->sysmsg_result = dat.fc_fd;
 392                         break;
 393                 case F_GETFD:
 394                         uap->sysmsg_result = dat.fc_cloexec;
 395                         break;
 396                 case F_GETFL:
 397                         uap->sysmsg_result = dat.fc_flags;
 398                         break;
 399                 case F_GETOWN:
 400                         uap->sysmsg_result = dat.fc_owner;
 401                 case F_GETLK:
 402                         error = copyout(&dat.fc_flock, (caddr_t)uap->arg,
 403                             sizeof(struct flock));
 404                         break;
 405                 }
 406         }
 407
 408         return (error);
 409 }
 410
 411 /*
 412  * Common code for dup, dup2, and fcntl(F_DUPFD).
 413  *
 414  * The type flag can be either DUP_FIXED or DUP_VARIABLE.  DUP_FIXED tells
 415  * kern_dup() to destructively dup over an existing file descriptor if new
 416  * is already open.  DUP_VARIABLE tells kern_dup() to find the lowest
 417  * unused file descriptor that is greater than or equal to new.
 418  */
 419 int
 420 kern_dup(enum dup_type type, int old, int new, int *res)
 421 {
 422         struct thread *td = curthread;
 423         struct proc *p = td->td_proc;
 424         struct filedesc *fdp = p->p_fd;
 425         struct file *fp;
 426         struct file *delfp;
 427         int holdleaders;
 428         boolean_t fdalloced = FALSE;
 429         int error, newfd;
 430
 431         /*
 432          * Verify that we have a valid descriptor to dup from and
 433          * possibly to dup to.
 434          */
 435         if (old < 0 || new < 0 || new > p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
 436             new >= maxfilesperproc)
 437                 return (EBADF);
 438         if (old >= fdp->fd_nfiles || fdp->fd_files[old].fp == NULL)
 439                 return (EBADF);
 440         if (type == DUP_FIXED && old == new) {
 441                 *res = new;
 442                 return (0);
 443         }
 444         fp = fdp->fd_files[old].fp;
 445         fhold(fp);
 446
 447         /*
 448          * Expand the table for the new descriptor if needed.  This may
 449          * block and drop and reacquire the fidedesc lock.
 450          */
 451         if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) {
 452                 error = fdalloc(p, new, &newfd);
 453                 if (error) {
 454                         fdrop(fp, td);
 455                         return (error);
 456                 }
 457                 fdalloced = TRUE;
 458         }
 459         if (type == DUP_VARIABLE)
 460                 new = newfd;
 461
 462         /*
 463          * If the old file changed out from under us then treat it as a
 464          * bad file descriptor.  Userland should do its own locking to
 465          * avoid this case.
 466          */
 467         if (fdp->fd_files[old].fp != fp) {
 468                 if (fdp->fd_files[new].fp == NULL) {
 469                         if (fdalloced)
 470                                 fdreserve(fdp, newfd, -1);
 471                         if (new < fdp->fd_freefile)
 472                                 fdp->fd_freefile = new;
 473                         while (fdp->fd_lastfile > 0 &&
 474                             fdp->fd_files[fdp->fd_lastfile].fp == NULL)
 475                                 fdp->fd_lastfile--;
 476                 }
 477                 fdrop(fp, td);
 478                 return (EBADF);
 479         }
 480         KASSERT(old != new, ("new fd is same as old"));
 481
 482         /*
 483          * Save info on the descriptor being overwritten.  We have
 484          * to do the unmap now, but we cannot close it without
 485          * introducing an ownership race for the slot.
 486          */
 487         delfp = fdp->fd_files[new].fp;
 488         if (delfp != NULL && p->p_fdtol != NULL) {
 489                 /*
 490                  * Ask fdfree() to sleep to ensure that all relevant
 491                  * process leaders can be traversed in closef().
 492                  */
 493                 fdp->fd_holdleaderscount++;
 494                 holdleaders = 1;
 495         } else
 496                 holdleaders = 0;
 497         KASSERT(delfp == NULL || type == DUP_FIXED,
 498             ("dup() picked an open file"));
 499 #if 0
 500         if (delfp && (fdp->fd_files[new].fileflags & UF_MAPPED))
 501                 (void) munmapfd(p, new);
 502 #endif
 503
 504         /*
 505          * Duplicate the source descriptor, update lastfile
 506          */
 507         if (new > fdp->fd_lastfile)
 508                 fdp->fd_lastfile = new;
 509         if (!fdalloced && fdp->fd_files[new].fp == NULL)
 510                 fdreserve(fdp, new, 1);
 511         fdp->fd_files[new].fp = fp;
 512         fdp->fd_files[new].fileflags =
 513                         fdp->fd_files[old].fileflags & ~UF_EXCLOSE;
 514         *res = new;
 515
 516         /*
 517          * If we dup'd over a valid file, we now own the reference to it
 518          * and must dispose of it using closef() semantics (as if a
 519          * close() were performed on it).
 520          */
 521         if (delfp) {
 522                 (void) closef(delfp, td);
 523                 if (holdleaders) {
 524                         fdp->fd_holdleaderscount--;
 525                         if (fdp->fd_holdleaderscount == 0 &&
 526                             fdp->fd_holdleaderswakeup != 0) {
 527                                 fdp->fd_holdleaderswakeup = 0;
 528                                 wakeup(&fdp->fd_holdleaderscount);
 529                         }
 530                 }
 531         }
 532         return (0);
 533 }
 534
 535 /*
 536  * If sigio is on the list associated with a process or process group,
 537  * disable signalling from the device, remove sigio from the list and
 538  * free sigio.
 539  */
 540 void
 541 funsetown(struct sigio *sigio)
 542 {
 543         if (sigio == NULL)
 544                 return;
 545         crit_enter();
 546         *(sigio->sio_myref) = NULL;
 547         crit_exit();
 548         if (sigio->sio_pgid < 0) {
 549                 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
 550                              sigio, sio_pgsigio);
 551         } else /* if ((*sigiop)->sio_pgid > 0) */ {
 552                 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
 553                              sigio, sio_pgsigio);
 554         }
 555         crfree(sigio->sio_ucred);
 556         free(sigio, M_SIGIO);
 557 }
 558
 559 /* Free a list of sigio structures. */
 560 void
 561 funsetownlst(struct sigiolst *sigiolst)
 562 {
 563         struct sigio *sigio;
 564
 565         while ((sigio = SLIST_FIRST(sigiolst)) != NULL)
 566                 funsetown(sigio);
 567 }
 568
 569 /*
 570  * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
 571  *
 572  * After permission checking, add a sigio structure to the sigio list for
 573  * the process or process group.
 574  */
 575 int
 576 fsetown(pid_t pgid, struct sigio **sigiop)
 577 {
 578         struct proc *proc;
 579         struct pgrp *pgrp;
 580         struct sigio *sigio;
 581
 582         if (pgid == 0) {
 583                 funsetown(*sigiop);
 584                 return (0);
 585         }
 586         if (pgid > 0) {
 587                 proc = pfind(pgid);
 588                 if (proc == NULL)
 589                         return (ESRCH);
 590
 591                 /*
 592                  * Policy - Don't allow a process to FSETOWN a process
 593                  * in another session.
 594                  *
 595                  * Remove this test to allow maximum flexibility or
 596                  * restrict FSETOWN to the current process or process
 597                  * group for maximum safety.
 598                  */
 599                 if (proc->p_session != curproc->p_session)
 600                         return (EPERM);
 601
 602                 pgrp = NULL;
 603         } else /* if (pgid < 0) */ {
 604                 pgrp = pgfind(-pgid);
 605                 if (pgrp == NULL)
 606                         return (ESRCH);
 607
 608                 /*
 609                  * Policy - Don't allow a process to FSETOWN a process
 610                  * in another session.
 611                  *
 612                  * Remove this test to allow maximum flexibility or
 613                  * restrict FSETOWN to the current process or process
 614                  * group for maximum safety.
 615                  */
 616                 if (pgrp->pg_session != curproc->p_session)
 617                         return (EPERM);
 618
 619                 proc = NULL;
 620         }
 621         funsetown(*sigiop);
 622         sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
 623         if (pgid > 0) {
 624                 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
 625                 sigio->sio_proc = proc;
 626         } else {
 627                 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
 628                 sigio->sio_pgrp = pgrp;
 629         }
 630         sigio->sio_pgid = pgid;
 631         sigio->sio_ucred = crhold(curproc->p_ucred);
 632         /* It would be convenient if p_ruid was in ucred. */
 633         sigio->sio_ruid = curproc->p_ucred->cr_ruid;
 634         sigio->sio_myref = sigiop;
 635         crit_enter();
 636         *sigiop = sigio;
 637         crit_exit();
 638         return (0);
 639 }
 640
 641 /*
 642  * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
 643  */
 644 pid_t
 645 fgetown(struct sigio *sigio)
 646 {
 647         return (sigio != NULL ? sigio->sio_pgid : 0);
 648 }
 649
 650 /*
 651  * Close many file descriptors.
 652  */
 653 /* ARGSUSED */
 654
 655 int
 656 closefrom(struct closefrom_args *uap)
 657 {
 658         return(kern_closefrom(uap->fd));
 659 }
 660
 661 int
 662 kern_closefrom(int fd)
 663 {
 664         struct thread *td = curthread;
 665         struct proc *p = td->td_proc;
 666         struct filedesc *fdp;
 667
 668         KKASSERT(p);
 669         fdp = p->p_fd;
 670
 671         if (fd < 0 || fd > fdp->fd_lastfile)
 672                 return (0);
 673
 674         do {
 675                 if (kern_close(fdp->fd_lastfile) == EINTR)
 676                         return (EINTR);
 677         } while (fdp->fd_lastfile > fd);
 678
 679         return (0);
 680 }
 681
 682 /*
 683  * Close a file descriptor.
 684  */
 685 /* ARGSUSED */
 686
 687 int
 688 close(struct close_args *uap)
 689 {
 690         return(kern_close(uap->fd));
 691 }
 692
 693 int
 694 kern_close(int fd)
 695 {
 696         struct thread *td = curthread;
 697         struct proc *p = td->td_proc;
 698         struct filedesc *fdp;
 699         struct file *fp;
 700         int error;
 701         int holdleaders;
 702
 703         KKASSERT(p);
 704         fdp = p->p_fd;
 705
 706         if ((unsigned)fd >= fdp->fd_nfiles ||
 707             (fp = fdp->fd_files[fd].fp) == NULL)
 708                 return (EBADF);
 709 #if 0
 710         if (fdp->fd_files[fd].fileflags & UF_MAPPED)
 711                 (void) munmapfd(p, fd);
 712 #endif
 713         funsetfd(fdp, fd);
 714         holdleaders = 0;
 715         if (p->p_fdtol != NULL) {
 716                 /*
 717                  * Ask fdfree() to sleep to ensure that all relevant
 718                  * process leaders can be traversed in closef().
 719                  */
 720                 fdp->fd_holdleaderscount++;
 721                 holdleaders = 1;
 722         }
 723
 724         /*
 725          * we now hold the fp reference that used to be owned by the descriptor
 726          * array.
 727          */
 728         while (fdp->fd_lastfile > 0 && fdp->fd_files[fdp->fd_lastfile].fp == NULL)
 729                 fdp->fd_lastfile--;
 730         if (fd < fdp->fd_knlistsize)
 731                 knote_fdclose(p, fd);
 732         error = closef(fp, td);
 733         if (holdleaders) {
 734                 fdp->fd_holdleaderscount--;
 735                 if (fdp->fd_holdleaderscount == 0 &&
 736                     fdp->fd_holdleaderswakeup != 0) {
 737                         fdp->fd_holdleaderswakeup = 0;
 738                         wakeup(&fdp->fd_holdleaderscount);
 739                 }
 740         }
 741         return (error);
 742 }
 743
 744 /*
 745  * shutdown_args(int fd, int how)
 746  */
 747 int
 748 kern_shutdown(int fd, int how)
 749 {
 750         struct thread *td = curthread;
 751         struct proc *p = td->td_proc;
 752         struct filedesc *fdp;
 753         struct file *fp;
 754         int error;
 755
 756         KKASSERT(p);
 757
 758         fdp = p->p_fd;
 759         if ((unsigned)fd >= fdp->fd_nfiles ||
 760             (fp = fdp->fd_files[fd].fp) == NULL)
 761                 return (EBADF);
 762         fhold(fp);
 763         error = fo_shutdown(fp, how, td);
 764         fdrop(fp, td);
 765
 766         return (error);
 767 }
 768
 769 int
 770 shutdown(struct shutdown_args *uap)
 771 {
 772         int error;
 773
 774         error = kern_shutdown(uap->s, uap->how);
 775
 776         return (error);
 777 }
 778
 779 int
 780 kern_fstat(int fd, struct stat *ub)
 781 {
 782         struct thread *td = curthread;
 783         struct proc *p = td->td_proc;
 784         struct filedesc *fdp;
 785         struct file *fp;
 786         int error;
 787
 788         KKASSERT(p);
 789
 790         fdp = p->p_fd;
 791         if ((unsigned)fd >= fdp->fd_nfiles ||
 792             (fp = fdp->fd_files[fd].fp) == NULL)
 793                 return (EBADF);
 794         fhold(fp);
 795         error = fo_stat(fp, ub, td);
 796         fdrop(fp, td);
 797
 798         return (error);
 799 }
 800
 801 /*
 802  * Return status information about a file descriptor.
 803  */
 804 int
 805 fstat(struct fstat_args *uap)
 806 {
 807         struct stat st;
 808         int error;
 809
 810         error = kern_fstat(uap->fd, &st);
 811
 812         if (error == 0)
 813                 error = copyout(&st, uap->sb, sizeof(st));
 814         return (error);
 815 }
 816
 817 /*
 818  * Return pathconf information about a file descriptor.
 819  */
 820 /* ARGSUSED */
 821 int
 822 fpathconf(struct fpathconf_args *uap)
 823 {
 824         struct thread *td = curthread;
 825         struct proc *p = td->td_proc;
 826         struct filedesc *fdp;
 827         struct file *fp;
 828         struct vnode *vp;
 829         int error = 0;
 830
 831         KKASSERT(p);
 832         fdp = p->p_fd;
 833         if ((unsigned)uap->fd >= fdp->fd_nfiles ||
 834             (fp = fdp->fd_files[uap->fd].fp) == NULL)
 835                 return (EBADF);
 836
 837         fhold(fp);
 838
 839         switch (fp->f_type) {
 840         case DTYPE_PIPE:
 841         case DTYPE_SOCKET:
 842                 if (uap->name != _PC_PIPE_BUF) {
 843                         error = EINVAL;
 844                 } else {
 845                         uap->sysmsg_result = PIPE_BUF;
 846                         error = 0;
 847                 }
 848                 break;
 849         case DTYPE_FIFO:
 850         case DTYPE_VNODE:
 851                 vp = (struct vnode *)fp->f_data;
 852                 error = VOP_PATHCONF(vp, uap->name, uap->sysmsg_fds);
 853                 break;
 854         default:
 855                 error = EOPNOTSUPP;
 856                 break;
 857         }
 858         fdrop(fp, td);
 859         return(error);
 860 }
 861
 862 static int fdexpand;
 863 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, "");
 864
 865 static void
 866 fdgrow(struct filedesc *fdp, int want)
 867 {
 868         struct fdnode *newfiles;
 869         struct fdnode *oldfiles;
 870         int nf, extra;
 871
 872         nf = fdp->fd_nfiles;
 873         do {
 874                 /* nf has to be of the form 2^n - 1 */
 875                 nf = 2 * nf + 1;
 876         } while (nf <= want);
 877
 878         newfiles = malloc(nf * sizeof(struct fdnode), M_FILEDESC, M_WAITOK);
 879
 880         /*
 881          * deal with file-table extend race that might have occured
 882          * when malloc was blocked.
 883          */
 884         if (fdp->fd_nfiles >= nf) {
 885                 free(newfiles, M_FILEDESC);
 886                 return;
 887         }
 888         /*
 889          * Copy the existing ofile and ofileflags arrays
 890          * and zero the new portion of each array.
 891          */
 892         extra = nf - fdp->fd_nfiles;
 893         bcopy(fdp->fd_files, newfiles, fdp->fd_nfiles * sizeof(struct fdnode));
 894         bzero(&newfiles[fdp->fd_nfiles], extra * sizeof(struct fdnode));
 895
 896         oldfiles = fdp->fd_files;
 897         fdp->fd_files = newfiles;
 898         fdp->fd_nfiles = nf;
 899
 900         if (oldfiles != fdp->fd_builtin_files)
 901                 free(oldfiles, M_FILEDESC);
 902         fdexpand++;
 903 }
 904
 905 /*
 906  * Number of nodes in right subtree, including the root.
 907  */
 908 static __inline int
 909 right_subtree_size(int n)
 910 {
 911         return (n ^ (n | (n + 1)));
 912 }
 913
 914 /*
 915  * Bigger ancestor.
 916  */
 917 static __inline int
 918 right_ancestor(int n)
 919 {
 920         return (n | (n + 1));
 921 }
 922
 923 /*
 924  * Smaller ancestor.
 925  */
 926 static __inline int
 927 left_ancestor(int n)
 928 {
 929         return ((n & (n + 1)) - 1);
 930 }
 931
 932 void
 933 fdreserve(struct filedesc *fdp, int fd, int incr)
 934 {
 935         while (fd >= 0) {
 936                 fdp->fd_files[fd].allocated += incr;
 937                 KKASSERT(fdp->fd_files[fd].allocated >= 0);
 938                 fd = left_ancestor(fd);
 939         }
 940 }
 941
 942 /*
 943  * Allocate a file descriptor for the process.
 944  */
 945 int
 946 fdalloc(struct proc *p, int want, int *result)
 947 {
 948         struct filedesc *fdp = p->p_fd;
 949         int fd, rsize, rsum, node, lim;
 950
 951         lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
 952         if (want >= lim)
 953                 return (EMFILE);
 954         if (want >= fdp->fd_nfiles)
 955                 fdgrow(fdp, want);
 956
 957         /*
 958          * Search for a free descriptor starting at the higher
 959          * of want or fd_freefile.  If that fails, consider
 960          * expanding the ofile array.
 961          */
 962 retry:
 963         /* move up the tree looking for a subtree with a free node */
 964         for (fd = max(want, fdp->fd_freefile); fd < min(fdp->fd_nfiles, lim);
 965              fd = right_ancestor(fd)) {
 966                 if (fdp->fd_files[fd].allocated == 0)
 967                         goto found;
 968
 969                 rsize = right_subtree_size(fd);
 970                 if (fdp->fd_files[fd].allocated == rsize)
 971                         continue;       /* right subtree full */
 972
 973                 /*
 974                  * Free fd is in the right subtree of the tree rooted at fd.
 975                  * Call that subtree R.  Look for the smallest (leftmost)
 976                  * subtree of R with an unallocated fd: continue moving
 977                  * down the left branch until encountering a full left
 978                  * subtree, then move to the right.
 979                  */
 980                 for (rsum = 0, rsize /= 2; rsize > 0; rsize /= 2) {
 981                         node = fd + rsize;
 982                         rsum += fdp->fd_files[node].allocated;
 983                         if (fdp->fd_files[fd].allocated == rsum + rsize) {
 984                                 fd = node;      /* move to the right */
 985                                 if (fdp->fd_files[node].allocated == 0)
 986                                         goto found;
 987                                 rsum = 0;
 988                         }
 989                 }
 990                 goto found;
 991         }
 992
 993         /*
 994          * No space in current array.  Expand?
 995          */
 996         if (fdp->fd_nfiles >= lim)
 997                 return (EMFILE);
 998         fdgrow(fdp, want);
 999         goto retry;
1000
1001 found:
1002         KKASSERT(fd < fdp->fd_nfiles);
1003         fdp->fd_files[fd].fileflags = 0;
1004         if (fd > fdp->fd_lastfile)
1005                 fdp->fd_lastfile = fd;
1006         if (want <= fdp->fd_freefile)
1007                 fdp->fd_freefile = fd;
1008         *result = fd;
1009         KKASSERT(fdp->fd_files[fd].fp == NULL);
1010         fdreserve(fdp, fd, 1);
1011         return (0);
1012 }
1013
1014 /*
1015  * Check to see whether n user file descriptors
1016  * are available to the process p.
1017  */
1018 int
1019 fdavail(struct proc *p, int n)
1020 {
1021         struct filedesc *fdp = p->p_fd;
1022         struct fdnode *fdnode;
1023         int i, lim, last;
1024
1025         lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
1026         if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
1027                 return (1);
1028
1029         last = min(fdp->fd_nfiles, lim);
1030         fdnode = &fdp->fd_files[fdp->fd_freefile];
1031         for (i = last - fdp->fd_freefile; --i >= 0; ++fdnode) {
1032                 if (fdnode->fp == NULL && --n <= 0)
1033                         return (1);
1034         }
1035         return (0);
1036 }
1037
1038 /*
1039  * falloc:
1040  *      Create a new open file structure and allocate a file decriptor
1041  *      for the process that refers to it.  If p is NULL, no descriptor
1042  *      is allocated and the file pointer is returned unassociated with
1043  *      any process.  resultfd is only used if p is not NULL and may
1044  *      separately be NULL indicating that you don't need the returned fd.
1045  *
1046  *      A held file pointer is returned.  If a descriptor has been allocated
1047  *      an additional hold on the fp will be made due to the fd_files[]
1048  *      reference.
1049  */
1050 int
1051 falloc(struct proc *p, struct file **resultfp, int *resultfd)
1052 {
1053         static struct timeval lastfail;
1054         static int curfail;
1055         struct file *fp;
1056         int error;
1057
1058         fp = NULL;
1059
1060         /*
1061          * Handle filetable full issues and root overfill.
1062          */
1063         if (nfiles >= maxfiles - maxfilesrootres &&
1064             ((p && p->p_ucred->cr_ruid != 0) || nfiles >= maxfiles)) {
1065                 if (ppsratecheck(&lastfail, &curfail, 1)) {
1066                         printf("kern.maxfiles limit exceeded by uid %d, please see tuning(7).\n",
1067                                 (p ? p->p_ucred->cr_ruid : -1));
1068                 }
1069                 error = ENFILE;
1070                 goto done;
1071         }
1072
1073         /*
1074          * Allocate a new file descriptor.
1075          */
1076         nfiles++;
1077         fp = malloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO);
1078         fp->f_count = 1;
1079         fp->f_ops = &badfileops;
1080         fp->f_seqcount = 1;
1081         if (p)
1082                 fp->f_cred = crhold(p->p_ucred);
1083         else
1084                 fp->f_cred = crhold(proc0.p_ucred);
1085         LIST_INSERT_HEAD(&filehead, fp, f_list);
1086         if (resultfd) {
1087                 if ((error = fsetfd(p, fp, resultfd)) != 0) {
1088                         fdrop(fp, p->p_thread);
1089                         fp = NULL;
1090                 }
1091         } else {
1092                 error = 0;
1093         }
1094 done:
1095         *resultfp = fp;
1096         return (error);
1097 }
1098
1099 /*
1100  * Associate a file pointer with a file descriptor.  On success the fp
1101  * will have an additional ref representing the fd_files[] association.
1102  */
1103 int
1104 fsetfd(struct proc *p, struct file *fp, int *resultfd)
1105 {
1106         int fd, error;
1107
1108         fd = -1;
1109         if ((error = fdalloc(p, 0, &fd)) == 0) {
1110                 fhold(fp);
1111                 p->p_fd->fd_files[fd].fp = fp;
1112         }
1113         *resultfd = fd;
1114         return (error);
1115 }
1116
1117 void
1118 funsetfd(struct filedesc *fdp, int fd)
1119 {
1120         fdp->fd_files[fd].fp = NULL;
1121         fdp->fd_files[fd].fileflags = 0;
1122         fdreserve(fdp, fd, -1);
1123         if (fd < fdp->fd_freefile)
1124                 fdp->fd_freefile = fd;
1125 }
1126
1127 void
1128 fsetcred(struct file *fp, struct ucred *cr)
1129 {
1130         crhold(cr);
1131         crfree(fp->f_cred);
1132         fp->f_cred = cr;
1133 }
1134
1135 /*
1136  * Free a file descriptor.
1137  */
1138 void
1139 ffree(struct file *fp)
1140 {
1141         KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!"));
1142         LIST_REMOVE(fp, f_list);
1143         crfree(fp->f_cred);
1144         if (fp->f_ncp) {
1145             cache_drop(fp->f_ncp);
1146             fp->f_ncp = NULL;
1147         }
1148         nfiles--;
1149         free(fp, M_FILE);
1150 }
1151
1152 /*
1153  * Build a new filedesc structure.
1154  */
1155 struct filedesc *
1156 fdinit(struct proc *p)
1157 {
1158         struct filedesc *newfdp;
1159         struct filedesc *fdp = p->p_fd;
1160
1161         newfdp = malloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK|M_ZERO);
1162         if (fdp->fd_cdir) {
1163                 newfdp->fd_cdir = fdp->fd_cdir;
1164                 vref(newfdp->fd_cdir);
1165                 newfdp->fd_ncdir = cache_hold(fdp->fd_ncdir);
1166         }
1167
1168         /*
1169          * rdir may not be set in e.g. proc0 or anything vm_fork'd off of
1170          * proc0, but should unconditionally exist in other processes.
1171          */
1172         if (fdp->fd_rdir) {
1173                 newfdp->fd_rdir = fdp->fd_rdir;
1174                 vref(newfdp->fd_rdir);
1175                 newfdp->fd_nrdir = cache_hold(fdp->fd_nrdir);
1176         }
1177         if (fdp->fd_jdir) {
1178                 newfdp->fd_jdir = fdp->fd_jdir;
1179                 vref(newfdp->fd_jdir);
1180                 newfdp->fd_njdir = cache_hold(fdp->fd_njdir);
1181         }
1182
1183         /* Create the file descriptor table. */
1184         newfdp->fd_refcnt = 1;
1185         newfdp->fd_cmask = cmask;
1186         newfdp->fd_files = newfdp->fd_builtin_files;
1187         newfdp->fd_nfiles = NDFILE;
1188         newfdp->fd_knlistsize = -1;
1189
1190         return (newfdp);
1191 }
1192
1193 /*
1194  * Share a filedesc structure.
1195  */
1196 struct filedesc *
1197 fdshare(struct proc *p)
1198 {
1199         p->p_fd->fd_refcnt++;
1200         return (p->p_fd);
1201 }
1202
1203 /*
1204  * Copy a filedesc structure.
1205  */
1206 struct filedesc *
1207 fdcopy(struct proc *p)
1208 {
1209         struct filedesc *newfdp, *fdp = p->p_fd;
1210         struct fdnode *fdnode;
1211         int i;
1212
1213         /* Certain daemons might not have file descriptors. */
1214         if (fdp == NULL)
1215                 return (NULL);
1216
1217         newfdp = malloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK);
1218         *newfdp = *fdp;
1219         if (newfdp->fd_cdir) {
1220                 vref(newfdp->fd_cdir);
1221                 newfdp->fd_ncdir = cache_hold(newfdp->fd_ncdir);
1222         }
1223         /*
1224          * We must check for fd_rdir here, at least for now because
1225          * the init process is created before we have access to the
1226          * rootvode to take a reference to it.
1227          */
1228         if (newfdp->fd_rdir) {
1229                 vref(newfdp->fd_rdir);
1230                 newfdp->fd_nrdir = cache_hold(newfdp->fd_nrdir);
1231         }
1232         if (newfdp->fd_jdir) {
1233                 vref(newfdp->fd_jdir);
1234                 newfdp->fd_njdir = cache_hold(newfdp->fd_njdir);
1235         }
1236         newfdp->fd_refcnt = 1;
1237
1238         /*
1239          * If the number of open files fits in the internal arrays
1240          * of the open file structure, use them, otherwise allocate
1241          * additional memory for the number of descriptors currently
1242          * in use.
1243          */
1244         if (newfdp->fd_lastfile < NDFILE) {
1245                 newfdp->fd_files = newfdp->fd_builtin_files;
1246                 i = NDFILE;
1247         } else {
1248                 /*
1249                  * Compute the smallest file table size
1250                  * for the file descriptors currently in use,
1251                  * allowing the table to shrink.
1252                  */
1253                 i = newfdp->fd_nfiles;
1254                 while ((i-1)/2 > newfdp->fd_lastfile && (i-1)/2 > NDFILE)
1255                         i = (i-1)/2;
1256                 newfdp->fd_files = malloc(i * sizeof(struct fdnode),
1257                                           M_FILEDESC, M_WAITOK);
1258         }
1259         newfdp->fd_nfiles = i;
1260
1261         if (fdp->fd_files != fdp->fd_builtin_files ||
1262             newfdp->fd_files != newfdp->fd_builtin_files
1263         ) {
1264                 bcopy(fdp->fd_files, newfdp->fd_files,
1265                       i * sizeof(struct fdnode));
1266         }
1267
1268         /*
1269          * kq descriptors cannot be copied.
1270          */
1271         if (newfdp->fd_knlistsize != -1) {
1272                 fdnode = &newfdp->fd_files[newfdp->fd_lastfile];
1273                 for (i = newfdp->fd_lastfile; i >= 0; i--, fdnode--) {
1274                         if (fdnode->fp != NULL && fdnode->fp->f_type == DTYPE_KQUEUE)
1275                                 funsetfd(newfdp, i);    /* nulls out *fpp */
1276                         if (fdnode->fp == NULL && i == newfdp->fd_lastfile && i > 0)
1277                                 newfdp->fd_lastfile--;
1278                 }
1279                 newfdp->fd_knlist = NULL;
1280                 newfdp->fd_knlistsize = -1;
1281                 newfdp->fd_knhash = NULL;
1282                 newfdp->fd_knhashmask = 0;
1283         }
1284
1285         fdnode = newfdp->fd_files;
1286         for (i = newfdp->fd_lastfile; i-- >= 0; fdnode++) {
1287                 if (fdnode->fp != NULL)
1288                         fhold(fdnode->fp);
1289         }
1290         return (newfdp);
1291 }
1292
1293 /*
1294  * Release a filedesc structure.
1295  */
1296 void
1297 fdfree(struct proc *p)
1298 {
1299         struct thread *td = p->p_thread;
1300         struct filedesc *fdp = p->p_fd;
1301         struct fdnode *fdnode;
1302         int i;
1303         struct filedesc_to_leader *fdtol;
1304         struct file *fp;
1305         struct vnode *vp;
1306         struct flock lf;
1307
1308         /* Certain daemons might not have file descriptors. */
1309         if (fdp == NULL)
1310                 return;
1311
1312         /* Check for special need to clear POSIX style locks */
1313         fdtol = p->p_fdtol;
1314         if (fdtol != NULL) {
1315                 KASSERT(fdtol->fdl_refcount > 0,
1316                         ("filedesc_to_refcount botch: fdl_refcount=%d",
1317                          fdtol->fdl_refcount));
1318                 if (fdtol->fdl_refcount == 1 &&
1319                     (p->p_leader->p_flag & P_ADVLOCK) != 0) {
1320                         i = 0;
1321                         fdnode = fdp->fd_files;
1322                         for (i = 0; i <= fdp->fd_lastfile; i++, fdnode++) {
1323                                 if (fdnode->fp == NULL ||
1324                                     fdnode->fp->f_type != DTYPE_VNODE)
1325                                         continue;
1326                                 fp = fdnode->fp;
1327                                 fhold(fp);
1328                                 lf.l_whence = SEEK_SET;
1329                                 lf.l_start = 0;
1330                                 lf.l_len = 0;
1331                                 lf.l_type = F_UNLCK;
1332                                 vp = (struct vnode *)fp->f_data;
1333                                 (void) VOP_ADVLOCK(vp,
1334                                                    (caddr_t)p->p_leader,
1335                                                    F_UNLCK,
1336                                                    &lf,
1337                                                    F_POSIX);
1338                                 fdrop(fp, p->p_thread);
1339                                 /* reload due to possible reallocation */
1340                                 fdnode = &fdp->fd_files[i];
1341                         }
1342                 }
1343         retry:
1344                 if (fdtol->fdl_refcount == 1) {
1345                         if (fdp->fd_holdleaderscount > 0 &&
1346                             (p->p_leader->p_flag & P_ADVLOCK) != 0) {
1347                                 /*
1348                                  * close() or do_dup() has cleared a reference
1349                                  * in a shared file descriptor table.
1350                                  */
1351                                 fdp->fd_holdleaderswakeup = 1;
1352                                 tsleep(&fdp->fd_holdleaderscount,
1353                                        0, "fdlhold", 0);
1354                                 goto retry;
1355                         }
1356                         if (fdtol->fdl_holdcount > 0) {
1357                                 /*
1358                                  * Ensure that fdtol->fdl_leader
1359                                  * remains valid in closef().
1360                                  */
1361                                 fdtol->fdl_wakeup = 1;
1362                                 tsleep(fdtol, 0, "fdlhold", 0);
1363                                 goto retry;
1364                         }
1365                 }
1366                 fdtol->fdl_refcount--;
1367                 if (fdtol->fdl_refcount == 0 &&
1368                     fdtol->fdl_holdcount == 0) {
1369                         fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
1370                         fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
1371                 } else
1372                         fdtol = NULL;
1373                 p->p_fdtol = NULL;
1374                 if (fdtol != NULL)
1375                         free(fdtol, M_FILEDESC_TO_LEADER);
1376         }
1377         if (--fdp->fd_refcnt > 0)
1378                 return;
1379         /*
1380          * we are the last reference to the structure, we can
1381          * safely assume it will not change out from under us.
1382          */
1383         for (i = 0; i <= fdp->fd_lastfile; ++i) {
1384                 if (fdp->fd_files[i].fp)
1385                         closef(fdp->fd_files[i].fp, td);
1386         }
1387         if (fdp->fd_files != fdp->fd_builtin_files)
1388                 free(fdp->fd_files, M_FILEDESC);
1389         if (fdp->fd_cdir) {
1390                 cache_drop(fdp->fd_ncdir);
1391                 vrele(fdp->fd_cdir);
1392         }
1393         if (fdp->fd_rdir) {
1394                 cache_drop(fdp->fd_nrdir);
1395                 vrele(fdp->fd_rdir);
1396         }
1397         if (fdp->fd_jdir) {
1398                 cache_drop(fdp->fd_njdir);
1399                 vrele(fdp->fd_jdir);
1400         }
1401         if (fdp->fd_knlist)
1402                 free(fdp->fd_knlist, M_KQUEUE);
1403         if (fdp->fd_knhash)
1404                 free(fdp->fd_knhash, M_KQUEUE);
1405         free(fdp, M_FILEDESC);
1406 }
1407
1408 /*
1409  * For setugid programs, we don't want to people to use that setugidness
1410  * to generate error messages which write to a file which otherwise would
1411  * otherwise be off-limits to the process.
1412  *
1413  * This is a gross hack to plug the hole.  A better solution would involve
1414  * a special vop or other form of generalized access control mechanism.  We
1415  * go ahead and just reject all procfs file systems accesses as dangerous.
1416  *
1417  * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
1418  * sufficient.  We also don't for check setugidness since we know we are.
1419  */
1420 static int
1421 is_unsafe(struct file *fp)
1422 {
1423         if (fp->f_type == DTYPE_VNODE &&
1424             ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS)
1425                 return (1);
1426         return (0);
1427 }
1428
1429 /*
1430  * Make this setguid thing safe, if at all possible.
1431  */
1432 void
1433 setugidsafety(struct proc *p)
1434 {
1435         struct thread *td = p->p_thread;
1436         struct filedesc *fdp = p->p_fd;
1437         int i;
1438
1439         /* Certain daemons might not have file descriptors. */
1440         if (fdp == NULL)
1441                 return;
1442
1443         /*
1444          * note: fdp->fd_files may be reallocated out from under us while
1445          * we are blocked in a close.  Be careful!
1446          */
1447         for (i = 0; i <= fdp->fd_lastfile; i++) {
1448                 if (i > 2)
1449                         break;
1450                 if (fdp->fd_files[i].fp && is_unsafe(fdp->fd_files[i].fp)) {
1451                         struct file *fp;
1452
1453 #if 0
1454                         if ((fdp->fd_files[i].fileflags & UF_MAPPED) != 0)
1455                                 (void) munmapfd(p, i);
1456 #endif
1457                         if (i < fdp->fd_knlistsize)
1458                                 knote_fdclose(p, i);
1459                         /*
1460                          * NULL-out descriptor prior to close to avoid
1461                          * a race while close blocks.
1462                          */
1463                         fp = fdp->fd_files[i].fp;
1464                         funsetfd(fdp, i);
1465                         closef(fp, td);
1466                 }
1467         }
1468         while (fdp->fd_lastfile > 0 && fdp->fd_files[fdp->fd_lastfile].fp == NULL)
1469                 fdp->fd_lastfile--;
1470 }
1471
1472 /*
1473  * Close any files on exec?
1474  */
1475 void
1476 fdcloseexec(struct proc *p)
1477 {
1478         struct thread *td = p->p_thread;
1479         struct filedesc *fdp = p->p_fd;
1480         int i;
1481
1482         /* Certain daemons might not have file descriptors. */
1483         if (fdp == NULL)
1484                 return;
1485
1486         /*
1487          * We cannot cache fd_files since operations may block and rip
1488          * them out from under us.
1489          */
1490         for (i = 0; i <= fdp->fd_lastfile; i++) {
1491                 if (fdp->fd_files[i].fp != NULL &&
1492                     (fdp->fd_files[i].fileflags & UF_EXCLOSE)) {
1493                         struct file *fp;
1494
1495 #if 0
1496                         if (fdp->fd_files[i].fileflags & UF_MAPPED)
1497                                 (void) munmapfd(p, i);
1498 #endif
1499                         if (i < fdp->fd_knlistsize)
1500                                 knote_fdclose(p, i);
1501                         /*
1502                          * NULL-out descriptor prior to close to avoid
1503                          * a race while close blocks.
1504                          */
1505                         fp = fdp->fd_files[i].fp;
1506                         funsetfd(fdp, i);
1507                         closef(fp, td);
1508                 }
1509         }
1510         while (fdp->fd_lastfile > 0 && fdp->fd_files[fdp->fd_lastfile].fp == NULL)
1511                 fdp->fd_lastfile--;
1512 }
1513
1514 /*
1515  * It is unsafe for set[ug]id processes to be started with file
1516  * descriptors 0..2 closed, as these descriptors are given implicit
1517  * significance in the Standard C library.  fdcheckstd() will create a
1518  * descriptor referencing /dev/null for each of stdin, stdout, and
1519  * stderr that is not already open.
1520  */
1521 int
1522 fdcheckstd(struct proc *p)
1523 {
1524         struct thread *td = p->p_thread;
1525         struct nlookupdata nd;
1526         struct filedesc *fdp;
1527         struct file *fp;
1528         register_t retval;
1529         int fd, i, error, flags, devnull;
1530
1531        fdp = p->p_fd;
1532        if (fdp == NULL)
1533                return (0);
1534        devnull = -1;
1535        error = 0;
1536        for (i = 0; i < 3; i++) {
1537                 if (fdp->fd_files[i].fp != NULL)
1538                         continue;
1539                 if (devnull < 0) {
1540                         if ((error = falloc(p, &fp, NULL)) != 0)
1541                                 break;
1542
1543                         error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE,
1544                                                 NLC_FOLLOW|NLC_LOCKVP);
1545                         flags = FREAD | FWRITE;
1546                         if (error == 0)
1547                                 error = vn_open(&nd, fp, flags, 0);
1548                         if (error == 0)
1549                                 error = fsetfd(p, fp, &fd);
1550                         fdrop(fp, td);
1551                         nlookup_done(&nd);
1552                         if (error)
1553                                 break;
1554                         KKASSERT(i == fd);
1555                         devnull = fd;
1556                 } else {
1557                         error = kern_dup(DUP_FIXED, devnull, i, &retval);
1558                         if (error != 0)
1559                                 break;
1560                 }
1561        }
1562        return (error);
1563 }
1564
1565 /*
1566  * Internal form of close.
1567  * Decrement reference count on file structure.
1568  * Note: td and/or p may be NULL when closing a file
1569  * that was being passed in a message.
1570  */
1571 int
1572 closef(struct file *fp, struct thread *td)
1573 {
1574         struct vnode *vp;
1575         struct flock lf;
1576         struct filedesc_to_leader *fdtol;
1577         struct proc *p;
1578
1579         if (fp == NULL)
1580                 return (0);
1581         if (td == NULL) {
1582                 td = curthread;
1583                 p = NULL;               /* allow no proc association */
1584         } else {
1585                 p = td->td_proc;        /* can also be NULL */
1586         }
1587         /*
1588          * POSIX record locking dictates that any close releases ALL
1589          * locks owned by this process.  This is handled by setting
1590          * a flag in the unlock to free ONLY locks obeying POSIX
1591          * semantics, and not to free BSD-style file locks.
1592          * If the descriptor was in a message, POSIX-style locks
1593          * aren't passed with the descriptor.
1594          */
1595         if (p != NULL &&
1596             fp->f_type == DTYPE_VNODE) {
1597                 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) {
1598                         lf.l_whence = SEEK_SET;
1599                         lf.l_start = 0;
1600                         lf.l_len = 0;
1601                         lf.l_type = F_UNLCK;
1602                         vp = (struct vnode *)fp->f_data;
1603                         (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
1604                                            &lf, F_POSIX);
1605                 }
1606                 fdtol = p->p_fdtol;
1607                 if (fdtol != NULL) {
1608                         /*
1609                          * Handle special case where file descriptor table
1610                          * is shared between multiple process leaders.
1611                          */
1612                         for (fdtol = fdtol->fdl_next;
1613                              fdtol != p->p_fdtol;
1614                              fdtol = fdtol->fdl_next) {
1615                                 if ((fdtol->fdl_leader->p_flag &
1616                                      P_ADVLOCK) == 0)
1617                                         continue;
1618                                 fdtol->fdl_holdcount++;
1619                                 lf.l_whence = SEEK_SET;
1620                                 lf.l_start = 0;
1621                                 lf.l_len = 0;
1622                                 lf.l_type = F_UNLCK;
1623                                 vp = (struct vnode *)fp->f_data;
1624                                 (void) VOP_ADVLOCK(vp,
1625                                                    (caddr_t)p->p_leader,
1626                                                    F_UNLCK, &lf, F_POSIX);
1627                                 fdtol->fdl_holdcount--;
1628                                 if (fdtol->fdl_holdcount == 0 &&
1629                                     fdtol->fdl_wakeup != 0) {
1630                                         fdtol->fdl_wakeup = 0;
1631                                         wakeup(fdtol);
1632                                 }
1633                         }
1634                 }
1635         }
1636         return (fdrop(fp, td));
1637 }
1638
1639 int
1640 fdrop(struct file *fp, struct thread *td)
1641 {
1642         struct flock lf;
1643         struct vnode *vp;
1644         int error;
1645
1646         if (--fp->f_count > 0)
1647                 return (0);
1648         if (fp->f_count < 0)
1649                 panic("fdrop: count < 0");
1650         if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) {
1651                 lf.l_whence = SEEK_SET;
1652                 lf.l_start = 0;
1653                 lf.l_len = 0;
1654                 lf.l_type = F_UNLCK;
1655                 vp = (struct vnode *)fp->f_data;
1656                 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
1657         }
1658         if (fp->f_ops != &badfileops)
1659                 error = fo_close(fp, td);
1660         else
1661                 error = 0;
1662         ffree(fp);
1663         return (error);
1664 }
1665
1666 /*
1667  * Apply an advisory lock on a file descriptor.
1668  *
1669  * Just attempt to get a record lock of the requested type on
1670  * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
1671  */
1672 /* ARGSUSED */
1673 int
1674 flock(struct flock_args *uap)
1675 {
1676         struct proc *p = curproc;
1677         struct filedesc *fdp = p->p_fd;
1678         struct file *fp;
1679         struct vnode *vp;
1680         struct flock lf;
1681
1682         if ((unsigned)uap->fd >= fdp->fd_nfiles ||
1683             (fp = fdp->fd_files[uap->fd].fp) == NULL)
1684                 return (EBADF);
1685         if (fp->f_type != DTYPE_VNODE)
1686                 return (EOPNOTSUPP);
1687         vp = (struct vnode *)fp->f_data;
1688         lf.l_whence = SEEK_SET;
1689         lf.l_start = 0;
1690         lf.l_len = 0;
1691         if (uap->how & LOCK_UN) {
1692                 lf.l_type = F_UNLCK;
1693                 fp->f_flag &= ~FHASLOCK;
1694                 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK));
1695         }
1696         if (uap->how & LOCK_EX)
1697                 lf.l_type = F_WRLCK;
1698         else if (uap->how & LOCK_SH)
1699                 lf.l_type = F_RDLCK;
1700         else
1701                 return (EBADF);
1702         fp->f_flag |= FHASLOCK;
1703         if (uap->how & LOCK_NB)
1704                 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK));
1705         return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT));
1706 }
1707
1708 /*
1709  * File Descriptor pseudo-device driver (/dev/fd/).
1710  *
1711  * Opening minor device N dup()s the file (if any) connected to file
1712  * descriptor N belonging to the calling process.  Note that this driver
1713  * consists of only the ``open()'' routine, because all subsequent
1714  * references to this file will be direct to the other driver.
1715  */
1716 /* ARGSUSED */
1717 static int
1718 fdopen(dev_t dev, int mode, int type, struct thread *td)
1719 {
1720         KKASSERT(td->td_lwp != NULL);
1721
1722         /*
1723          * XXX Kludge: set curlwp->lwp_dupfd to contain the value of the
1724          * the file descriptor being sought for duplication. The error
1725          * return ensures that the vnode for this device will be released
1726          * by vn_open. Open will detect this special error and take the
1727          * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
1728          * will simply report the error.
1729          */
1730         td->td_lwp->lwp_dupfd = minor(dev);
1731         return (ENODEV);
1732 }
1733
1734 /*
1735  * Duplicate the specified descriptor to a free descriptor.
1736  */
1737 int
1738 dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode, int error)
1739 {
1740         struct file *wfp;
1741         struct file *fp;
1742
1743         /*
1744          * If the to-be-dup'd fd number is greater than the allowed number
1745          * of file descriptors, or the fd to be dup'd has already been
1746          * closed, then reject.
1747          */
1748         if ((u_int)dfd >= fdp->fd_nfiles ||
1749             (wfp = fdp->fd_files[dfd].fp) == NULL) {
1750                 return (EBADF);
1751         }
1752
1753         /*
1754          * There are two cases of interest here.
1755          *
1756          * For ENODEV simply dup (dfd) to file descriptor
1757          * (indx) and return.
1758          *
1759          * For ENXIO steal away the file structure from (dfd) and
1760          * store it in (indx).  (dfd) is effectively closed by
1761          * this operation.
1762          *
1763          * Any other error code is just returned.
1764          */
1765         switch (error) {
1766         case ENODEV:
1767                 /*
1768                  * Check that the mode the file is being opened for is a
1769                  * subset of the mode of the existing descriptor.
1770                  */
1771                 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag)
1772                         return (EACCES);
1773                 fp = fdp->fd_files[indx].fp;
1774 #if 0
1775                 if (fp && fdp->fd_files[indx].fileflags & UF_MAPPED)
1776                         (void) munmapfd(p, indx);
1777 #endif
1778                 fdp->fd_files[indx].fp = wfp;
1779                 fdp->fd_files[indx].fileflags = fdp->fd_files[dfd].fileflags;
1780                 fhold(wfp);
1781                 if (indx > fdp->fd_lastfile)
1782                         fdp->fd_lastfile = indx;
1783                 /*
1784                  * we now own the reference to fp that the ofiles[] array
1785                  * used to own.  Release it.
1786                  */
1787                 if (fp)
1788                         fdrop(fp, curthread);
1789                 return (0);
1790
1791         case ENXIO:
1792                 /*
1793                  * Steal away the file pointer from dfd, and stuff it into indx.
1794                  */
1795                 fp = fdp->fd_files[indx].fp;
1796 #if 0
1797                 if (fp && fdp->fd_files[indx].fileflags & UF_MAPPED)
1798                         (void) munmapfd(p, indx);
1799 #endif
1800                 fdp->fd_files[indx].fp = fdp->fd_files[dfd].fp;
1801                 fdp->fd_files[indx].fileflags = fdp->fd_files[dfd].fileflags;
1802                 funsetfd(fdp, dfd);
1803
1804                 /*
1805                  * we now own the reference to fp that the files[] array
1806                  * used to own.  Release it.
1807                  */
1808                 if (fp)
1809                         fdrop(fp, curthread);
1810                 /*
1811                  * Complete the clean up of the filedesc structure by
1812                  * recomputing the various hints.
1813                  */
1814                 if (indx > fdp->fd_lastfile) {
1815                         fdp->fd_lastfile = indx;
1816                 } else {
1817                         while (fdp->fd_lastfile > 0 &&
1818                            fdp->fd_files[fdp->fd_lastfile].fp == NULL) {
1819                                 fdp->fd_lastfile--;
1820                         }
1821                 }
1822                 return (0);
1823
1824         default:
1825                 return (error);
1826         }
1827         /* NOTREACHED */
1828 }
1829
1830
1831 struct filedesc_to_leader *
1832 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
1833                          struct proc *leader)
1834 {
1835         struct filedesc_to_leader *fdtol;
1836
1837         fdtol = malloc(sizeof(struct filedesc_to_leader),
1838                         M_FILEDESC_TO_LEADER, M_WAITOK);
1839         fdtol->fdl_refcount = 1;
1840         fdtol->fdl_holdcount = 0;
1841         fdtol->fdl_wakeup = 0;
1842         fdtol->fdl_leader = leader;
1843         if (old != NULL) {
1844                 fdtol->fdl_next = old->fdl_next;
1845                 fdtol->fdl_prev = old;
1846                 old->fdl_next = fdtol;
1847                 fdtol->fdl_next->fdl_prev = fdtol;
1848         } else {
1849                 fdtol->fdl_next = fdtol;
1850                 fdtol->fdl_prev = fdtol;
1851         }
1852         return fdtol;
1853 }
1854
1855 /*
1856  * Get file structures.
1857  */
1858 static int
1859 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
1860 {
1861         struct kinfo_file kf;
1862         struct filedesc *fdp;
1863         struct file *fp;
1864         struct proc *p;
1865         uid_t uid;
1866         int count;
1867         int error;
1868         int n;
1869
1870         /*
1871          * Note: because the number of file descriptors is calculated
1872          * in different ways for sizing vs returning the data,
1873          * there is information leakage from the first loop.  However,
1874          * it is of a similar order of magnitude to the leakage from
1875          * global system statistics such as kern.openfiles.
1876          *
1877          * When just doing a count, note that we cannot just count
1878          * the elements and add f_count via the filehead list because
1879          * threaded processes share their descriptor table and f_count might
1880          * still be '1' in that case.
1881          *
1882          * Since the SYSCTL op can block, we must hold the process to
1883          * prevent it being ripped out from under us either in the
1884          * file descriptor loop or in the greater LIST_FOREACH.  The
1885          * process may be in varying states of disrepair.  If the process
1886          * is in SZOMB we may have caught it just as it is being removed
1887          * from the allproc list, we must skip it in that case to maintain
1888          * an unbroken chain through the allproc list.
1889          */
1890         count = 0;
1891         error = 0;
1892         LIST_FOREACH(p, &allproc, p_list) {
1893                 if (p->p_stat == SIDL || (p->p_flag & P_ZOMBIE))
1894                         continue;
1895                 if (!PRISON_CHECK(req->td->td_proc->p_ucred, p->p_ucred) != 0)
1896                         continue;
1897                 if ((fdp = p->p_fd) == NULL)
1898                         continue;
1899                 PHOLD(p);
1900                 for (n = 0; n < fdp->fd_nfiles; ++n) {
1901                         if ((fp = fdp->fd_files[n].fp) == NULL)
1902                                 continue;
1903                         if (req->oldptr == NULL) {
1904                                 ++count;
1905                         } else {
1906                                 uid = p->p_ucred ? p->p_ucred->cr_uid : -1;
1907                                 kcore_make_file(&kf, fp, p->p_pid, uid, n);
1908                                 error = SYSCTL_OUT(req, &kf, sizeof(kf));
1909                                 if (error)
1910                                         break;
1911                         }
1912                 }
1913                 PRELE(p);
1914                 if (error)
1915                         break;
1916         }
1917
1918         /*
1919          * When just calculating the size, overestimate a bit to try to
1920          * prevent system activity from causing the buffer-fill call
1921          * to fail later on.
1922          */
1923         if (req->oldptr == NULL) {
1924                 count = (count + 16) + (count / 10);
1925                 error = SYSCTL_OUT(req, NULL, count * sizeof(kf));
1926         }
1927         return (error);
1928 }
1929
1930 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
1931     0, 0, sysctl_kern_file, "S,file", "Entire file table");
1932
1933 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
1934     &maxfilesperproc, 0, "Maximum files allowed open per process");
1935
1936 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
1937     &maxfiles, 0, "Maximum number of files");
1938
1939 SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW,
1940     &maxfilesrootres, 0, "Descriptors reserved for root use");
1941
1942 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
1943         &nfiles, 0, "System-wide number of open files");
1944
1945 static void
1946 fildesc_drvinit(void *unused)
1947 {
1948         int fd;
1949
1950         cdevsw_add(&fildesc_cdevsw, 0, 0);
1951         for (fd = 0; fd < NUMFDESC; fd++) {
1952                 make_dev(&fildesc_cdevsw, fd,
1953                     UID_BIN, GID_BIN, 0666, "fd/%d", fd);
1954         }
1955         make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "stdin");
1956         make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "stdout");
1957         make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "stderr");
1958 }
1959
1960 struct fileops badfileops = {
1961         NULL,   /* port */
1962         NULL,   /* clone */
1963         badfo_readwrite,
1964         badfo_readwrite,
1965         badfo_ioctl,
1966         badfo_poll,
1967         badfo_kqfilter,
1968         badfo_stat,
1969         badfo_close,
1970         badfo_shutdown
1971 };
1972
1973 static int
1974 badfo_readwrite(
1975         struct file *fp,
1976         struct uio *uio,
1977         struct ucred *cred,
1978         int flags,
1979         struct thread *td
1980 ) {
1981         return (EBADF);
1982 }
1983
1984 static int
1985 badfo_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td)
1986 {
1987         return (EBADF);
1988 }
1989
1990 static int
1991 badfo_poll(struct file *fp, int events, struct ucred *cred, struct thread *td)
1992 {
1993         return (0);
1994 }
1995
1996 static int
1997 badfo_kqfilter(struct file *fp, struct knote *kn)
1998 {
1999         return (0);
2000 }
2001
2002 static int
2003 badfo_stat(struct file *fp, struct stat *sb, struct thread *td)
2004 {
2005         return (EBADF);
2006 }
2007
2008 static int
2009 badfo_close(struct file *fp, struct thread *td)
2010 {
2011         return (EBADF);
2012 }
2013
2014 static int
2015 badfo_shutdown(struct file *fp, int how, struct thread *td)
2016 {
2017         return (EBADF);
2018 }
2019
2020 int
2021 nofo_shutdown(struct file *fp, int how, struct thread *td)
2022 {
2023         return (EOPNOTSUPP);
2024 }
2025
2026 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,
2027                                         fildesc_drvinit,NULL)