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