The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_syscalls.c

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    1 /*-
    2  * Copyright (c) 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)vfs_syscalls.c      8.13 (Berkeley) 4/15/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/11.2/sys/kern/vfs_syscalls.c 338979 2018-09-27 18:32:14Z gordon $");
   39 
   40 #include "opt_capsicum.h"
   41 #include "opt_compat.h"
   42 #include "opt_ktrace.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/bio.h>
   47 #include <sys/buf.h>
   48 #include <sys/capsicum.h>
   49 #include <sys/disk.h>
   50 #include <sys/sysent.h>
   51 #include <sys/malloc.h>
   52 #include <sys/mount.h>
   53 #include <sys/mutex.h>
   54 #include <sys/sysproto.h>
   55 #include <sys/namei.h>
   56 #include <sys/filedesc.h>
   57 #include <sys/kernel.h>
   58 #include <sys/fcntl.h>
   59 #include <sys/file.h>
   60 #include <sys/filio.h>
   61 #include <sys/limits.h>
   62 #include <sys/linker.h>
   63 #include <sys/rwlock.h>
   64 #include <sys/sdt.h>
   65 #include <sys/stat.h>
   66 #include <sys/sx.h>
   67 #include <sys/unistd.h>
   68 #include <sys/vnode.h>
   69 #include <sys/priv.h>
   70 #include <sys/proc.h>
   71 #include <sys/dirent.h>
   72 #include <sys/jail.h>
   73 #include <sys/syscallsubr.h>
   74 #include <sys/sysctl.h>
   75 #ifdef KTRACE
   76 #include <sys/ktrace.h>
   77 #endif
   78 
   79 #include <machine/stdarg.h>
   80 
   81 #include <security/audit/audit.h>
   82 #include <security/mac/mac_framework.h>
   83 
   84 #include <vm/vm.h>
   85 #include <vm/vm_object.h>
   86 #include <vm/vm_page.h>
   87 #include <vm/uma.h>
   88 
   89 #include <ufs/ufs/quota.h>
   90 
   91 MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");
   92 
   93 SDT_PROVIDER_DEFINE(vfs);
   94 SDT_PROBE_DEFINE2(vfs, , stat, mode, "char *", "int");
   95 SDT_PROBE_DEFINE2(vfs, , stat, reg, "char *", "int");
   96 
   97 static int kern_chflagsat(struct thread *td, int fd, const char *path,
   98     enum uio_seg pathseg, u_long flags, int atflag);
   99 static int setfflags(struct thread *td, struct vnode *, u_long);
  100 static int getutimes(const struct timeval *, enum uio_seg, struct timespec *);
  101 static int getutimens(const struct timespec *, enum uio_seg,
  102     struct timespec *, int *);
  103 static int setutimes(struct thread *td, struct vnode *,
  104     const struct timespec *, int, int);
  105 static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
  106     struct thread *td);
  107 
  108 /*
  109  * Sync each mounted filesystem.
  110  */
  111 #ifndef _SYS_SYSPROTO_H_
  112 struct sync_args {
  113         int     dummy;
  114 };
  115 #endif
  116 /* ARGSUSED */
  117 int
  118 sys_sync(struct thread *td, struct sync_args *uap)
  119 {
  120         struct mount *mp, *nmp;
  121         int save;
  122 
  123         mtx_lock(&mountlist_mtx);
  124         for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
  125                 if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
  126                         nmp = TAILQ_NEXT(mp, mnt_list);
  127                         continue;
  128                 }
  129                 if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
  130                     vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
  131                         save = curthread_pflags_set(TDP_SYNCIO);
  132                         vfs_msync(mp, MNT_NOWAIT);
  133                         VFS_SYNC(mp, MNT_NOWAIT);
  134                         curthread_pflags_restore(save);
  135                         vn_finished_write(mp);
  136                 }
  137                 mtx_lock(&mountlist_mtx);
  138                 nmp = TAILQ_NEXT(mp, mnt_list);
  139                 vfs_unbusy(mp);
  140         }
  141         mtx_unlock(&mountlist_mtx);
  142         return (0);
  143 }
  144 
  145 /*
  146  * Change filesystem quotas.
  147  */
  148 #ifndef _SYS_SYSPROTO_H_
  149 struct quotactl_args {
  150         char *path;
  151         int cmd;
  152         int uid;
  153         caddr_t arg;
  154 };
  155 #endif
  156 int
  157 sys_quotactl(struct thread *td, struct quotactl_args *uap)
  158 {
  159         struct mount *mp;
  160         struct nameidata nd;
  161         int error;
  162 
  163         AUDIT_ARG_CMD(uap->cmd);
  164         AUDIT_ARG_UID(uap->uid);
  165         if (!prison_allow(td->td_ucred, PR_ALLOW_QUOTAS))
  166                 return (EPERM);
  167         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
  168             uap->path, td);
  169         if ((error = namei(&nd)) != 0)
  170                 return (error);
  171         NDFREE(&nd, NDF_ONLY_PNBUF);
  172         mp = nd.ni_vp->v_mount;
  173         vfs_ref(mp);
  174         vput(nd.ni_vp);
  175         error = vfs_busy(mp, 0);
  176         vfs_rel(mp);
  177         if (error != 0)
  178                 return (error);
  179         error = VFS_QUOTACTL(mp, uap->cmd, uap->uid, uap->arg);
  180 
  181         /*
  182          * Since quota on operation typically needs to open quota
  183          * file, the Q_QUOTAON handler needs to unbusy the mount point
  184          * before calling into namei.  Otherwise, unmount might be
  185          * started between two vfs_busy() invocations (first is our,
  186          * second is from mount point cross-walk code in lookup()),
  187          * causing deadlock.
  188          *
  189          * Require that Q_QUOTAON handles the vfs_busy() reference on
  190          * its own, always returning with ubusied mount point.
  191          */
  192         if ((uap->cmd >> SUBCMDSHIFT) != Q_QUOTAON)
  193                 vfs_unbusy(mp);
  194         return (error);
  195 }
  196 
  197 /*
  198  * Used by statfs conversion routines to scale the block size up if
  199  * necessary so that all of the block counts are <= 'max_size'.  Note
  200  * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
  201  * value of 'n'.
  202  */
  203 void
  204 statfs_scale_blocks(struct statfs *sf, long max_size)
  205 {
  206         uint64_t count;
  207         int shift;
  208 
  209         KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));
  210 
  211         /*
  212          * Attempt to scale the block counts to give a more accurate
  213          * overview to userland of the ratio of free space to used
  214          * space.  To do this, find the largest block count and compute
  215          * a divisor that lets it fit into a signed integer <= max_size.
  216          */
  217         if (sf->f_bavail < 0)
  218                 count = -sf->f_bavail;
  219         else
  220                 count = sf->f_bavail;
  221         count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
  222         if (count <= max_size)
  223                 return;
  224 
  225         count >>= flsl(max_size);
  226         shift = 0;
  227         while (count > 0) {
  228                 shift++;
  229                 count >>=1;
  230         }
  231 
  232         sf->f_bsize <<= shift;
  233         sf->f_blocks >>= shift;
  234         sf->f_bfree >>= shift;
  235         sf->f_bavail >>= shift;
  236 }
  237 
  238 static int
  239 kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
  240 {
  241         struct statfs *sp;
  242         int error;
  243 
  244         if (mp == NULL)
  245                 return (EBADF);
  246         error = vfs_busy(mp, 0);
  247         vfs_rel(mp);
  248         if (error != 0)
  249                 return (error);
  250 #ifdef MAC
  251         error = mac_mount_check_stat(td->td_ucred, mp);
  252         if (error != 0)
  253                 goto out;
  254 #endif
  255         /*
  256          * Set these in case the underlying filesystem fails to do so.
  257          */
  258         sp = &mp->mnt_stat;
  259         sp->f_version = STATFS_VERSION;
  260         sp->f_namemax = NAME_MAX;
  261         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
  262         error = VFS_STATFS(mp, sp);
  263         if (error != 0)
  264                 goto out;
  265         *buf = *sp;
  266         if (priv_check(td, PRIV_VFS_GENERATION)) {
  267                 buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
  268                 prison_enforce_statfs(td->td_ucred, mp, buf);
  269         }
  270 out:
  271         vfs_unbusy(mp);
  272         return (error);
  273 }
  274 
  275 /*
  276  * Get filesystem statistics.
  277  */
  278 #ifndef _SYS_SYSPROTO_H_
  279 struct statfs_args {
  280         char *path;
  281         struct statfs *buf;
  282 };
  283 #endif
  284 int
  285 sys_statfs(struct thread *td, struct statfs_args *uap)
  286 {
  287         struct statfs *sfp;
  288         int error;
  289 
  290         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  291         error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
  292         if (error == 0)
  293                 error = copyout(sfp, uap->buf, sizeof(struct statfs));
  294         free(sfp, M_STATFS);
  295         return (error);
  296 }
  297 
  298 int
  299 kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
  300     struct statfs *buf)
  301 {
  302         struct mount *mp;
  303         struct nameidata nd;
  304         int error;
  305 
  306         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  307             pathseg, path, td);
  308         error = namei(&nd);
  309         if (error != 0)
  310                 return (error);
  311         mp = nd.ni_vp->v_mount;
  312         vfs_ref(mp);
  313         NDFREE(&nd, NDF_ONLY_PNBUF);
  314         vput(nd.ni_vp);
  315         return (kern_do_statfs(td, mp, buf));
  316 }
  317 
  318 /*
  319  * Get filesystem statistics.
  320  */
  321 #ifndef _SYS_SYSPROTO_H_
  322 struct fstatfs_args {
  323         int fd;
  324         struct statfs *buf;
  325 };
  326 #endif
  327 int
  328 sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
  329 {
  330         struct statfs *sfp;
  331         int error;
  332 
  333         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  334         error = kern_fstatfs(td, uap->fd, sfp);
  335         if (error == 0)
  336                 error = copyout(sfp, uap->buf, sizeof(struct statfs));
  337         free(sfp, M_STATFS);
  338         return (error);
  339 }
  340 
  341 int
  342 kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
  343 {
  344         struct file *fp;
  345         struct mount *mp;
  346         struct vnode *vp;
  347         cap_rights_t rights;
  348         int error;
  349 
  350         AUDIT_ARG_FD(fd);
  351         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSTATFS), &fp);
  352         if (error != 0)
  353                 return (error);
  354         vp = fp->f_vnode;
  355         vn_lock(vp, LK_SHARED | LK_RETRY);
  356 #ifdef AUDIT
  357         AUDIT_ARG_VNODE1(vp);
  358 #endif
  359         mp = vp->v_mount;
  360         if (mp != NULL)
  361                 vfs_ref(mp);
  362         VOP_UNLOCK(vp, 0);
  363         fdrop(fp, td);
  364         return (kern_do_statfs(td, mp, buf));
  365 }
  366 
  367 /*
  368  * Get statistics on all filesystems.
  369  */
  370 #ifndef _SYS_SYSPROTO_H_
  371 struct getfsstat_args {
  372         struct statfs *buf;
  373         long bufsize;
  374         int mode;
  375 };
  376 #endif
  377 int
  378 sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
  379 {
  380         size_t count;
  381         int error;
  382 
  383         if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
  384                 return (EINVAL);
  385         error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
  386             UIO_USERSPACE, uap->mode);
  387         if (error == 0)
  388                 td->td_retval[0] = count;
  389         return (error);
  390 }
  391 
  392 /*
  393  * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
  394  *      The caller is responsible for freeing memory which will be allocated
  395  *      in '*buf'.
  396  */
  397 int
  398 kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
  399     size_t *countp, enum uio_seg bufseg, int mode)
  400 {
  401         struct mount *mp, *nmp;
  402         struct statfs *sfsp, *sp, *sptmp, *tofree;
  403         size_t count, maxcount;
  404         int error;
  405 
  406         switch (mode) {
  407         case MNT_WAIT:
  408         case MNT_NOWAIT:
  409                 break;
  410         default:
  411                 return (EINVAL);
  412         }
  413 restart:
  414         maxcount = bufsize / sizeof(struct statfs);
  415         if (bufsize == 0) {
  416                 sfsp = NULL;
  417                 tofree = NULL;
  418         } else if (bufseg == UIO_USERSPACE) {
  419                 sfsp = *buf;
  420                 tofree = NULL;
  421         } else /* if (bufseg == UIO_SYSSPACE) */ {
  422                 count = 0;
  423                 mtx_lock(&mountlist_mtx);
  424                 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
  425                         count++;
  426                 }
  427                 mtx_unlock(&mountlist_mtx);
  428                 if (maxcount > count)
  429                         maxcount = count;
  430                 tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
  431                     M_STATFS, M_WAITOK);
  432         }
  433         count = 0;
  434         mtx_lock(&mountlist_mtx);
  435         for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
  436                 if (prison_canseemount(td->td_ucred, mp) != 0) {
  437                         nmp = TAILQ_NEXT(mp, mnt_list);
  438                         continue;
  439                 }
  440 #ifdef MAC
  441                 if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
  442                         nmp = TAILQ_NEXT(mp, mnt_list);
  443                         continue;
  444                 }
  445 #endif
  446                 if (mode == MNT_WAIT) {
  447                         if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
  448                                 /*
  449                                  * If vfs_busy() failed, and MBF_NOWAIT
  450                                  * wasn't passed, then the mp is gone.
  451                                  * Furthermore, because of MBF_MNTLSTLOCK,
  452                                  * the mountlist_mtx was dropped.  We have
  453                                  * no other choice than to start over.
  454                                  */
  455                                 mtx_unlock(&mountlist_mtx);
  456                                 free(tofree, M_STATFS);
  457                                 goto restart;
  458                         }
  459                 } else {
  460                         if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
  461                                 nmp = TAILQ_NEXT(mp, mnt_list);
  462                                 continue;
  463                         }
  464                 }
  465                 if (sfsp != NULL && count < maxcount) {
  466                         sp = &mp->mnt_stat;
  467                         /*
  468                          * Set these in case the underlying filesystem
  469                          * fails to do so.
  470                          */
  471                         sp->f_version = STATFS_VERSION;
  472                         sp->f_namemax = NAME_MAX;
  473                         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
  474                         /*
  475                          * If MNT_NOWAIT is specified, do not refresh
  476                          * the fsstat cache.
  477                          */
  478                         if (mode != MNT_NOWAIT) {
  479                                 error = VFS_STATFS(mp, sp);
  480                                 if (error != 0) {
  481                                         mtx_lock(&mountlist_mtx);
  482                                         nmp = TAILQ_NEXT(mp, mnt_list);
  483                                         vfs_unbusy(mp);
  484                                         continue;
  485                                 }
  486                         }
  487                         if (priv_check(td, PRIV_VFS_GENERATION)) {
  488                                 sptmp = malloc(sizeof(struct statfs), M_STATFS,
  489                                     M_WAITOK);
  490                                 *sptmp = *sp;
  491                                 sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
  492                                 prison_enforce_statfs(td->td_ucred, mp, sptmp);
  493                                 sp = sptmp;
  494                         } else
  495                                 sptmp = NULL;
  496                         if (bufseg == UIO_SYSSPACE) {
  497                                 bcopy(sp, sfsp, sizeof(*sp));
  498                                 free(sptmp, M_STATFS);
  499                         } else /* if (bufseg == UIO_USERSPACE) */ {
  500                                 error = copyout(sp, sfsp, sizeof(*sp));
  501                                 free(sptmp, M_STATFS);
  502                                 if (error != 0) {
  503                                         vfs_unbusy(mp);
  504                                         return (error);
  505                                 }
  506                         }
  507                         sfsp++;
  508                 }
  509                 count++;
  510                 mtx_lock(&mountlist_mtx);
  511                 nmp = TAILQ_NEXT(mp, mnt_list);
  512                 vfs_unbusy(mp);
  513         }
  514         mtx_unlock(&mountlist_mtx);
  515         if (sfsp != NULL && count > maxcount)
  516                 *countp = maxcount;
  517         else
  518                 *countp = count;
  519         return (0);
  520 }
  521 
  522 #ifdef COMPAT_FREEBSD4
  523 /*
  524  * Get old format filesystem statistics.
  525  */
  526 static void cvtstatfs(struct statfs *, struct ostatfs *);
  527 
  528 #ifndef _SYS_SYSPROTO_H_
  529 struct freebsd4_statfs_args {
  530         char *path;
  531         struct ostatfs *buf;
  532 };
  533 #endif
  534 int
  535 freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
  536 {
  537         struct ostatfs osb;
  538         struct statfs *sfp;
  539         int error;
  540 
  541         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  542         error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
  543         if (error == 0) {
  544                 cvtstatfs(sfp, &osb);
  545                 error = copyout(&osb, uap->buf, sizeof(osb));
  546         }
  547         free(sfp, M_STATFS);
  548         return (error);
  549 }
  550 
  551 /*
  552  * Get filesystem statistics.
  553  */
  554 #ifndef _SYS_SYSPROTO_H_
  555 struct freebsd4_fstatfs_args {
  556         int fd;
  557         struct ostatfs *buf;
  558 };
  559 #endif
  560 int
  561 freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
  562 {
  563         struct ostatfs osb;
  564         struct statfs *sfp;
  565         int error;
  566 
  567         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  568         error = kern_fstatfs(td, uap->fd, sfp);
  569         if (error == 0) {
  570                 cvtstatfs(sfp, &osb);
  571                 error = copyout(&osb, uap->buf, sizeof(osb));
  572         }
  573         free(sfp, M_STATFS);
  574         return (error);
  575 }
  576 
  577 /*
  578  * Get statistics on all filesystems.
  579  */
  580 #ifndef _SYS_SYSPROTO_H_
  581 struct freebsd4_getfsstat_args {
  582         struct ostatfs *buf;
  583         long bufsize;
  584         int mode;
  585 };
  586 #endif
  587 int
  588 freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
  589 {
  590         struct statfs *buf, *sp;
  591         struct ostatfs osb;
  592         size_t count, size;
  593         int error;
  594 
  595         if (uap->bufsize < 0)
  596                 return (EINVAL);
  597         count = uap->bufsize / sizeof(struct ostatfs);
  598         if (count > SIZE_MAX / sizeof(struct statfs))
  599                 return (EINVAL);
  600         size = count * sizeof(struct statfs);
  601         error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
  602             uap->mode);
  603         if (buf == NULL)
  604                 return (EINVAL);
  605         td->td_retval[0] = count;
  606         if (size != 0) {
  607                 sp = buf;
  608                 while (count != 0 && error == 0) {
  609                         cvtstatfs(sp, &osb);
  610                         error = copyout(&osb, uap->buf, sizeof(osb));
  611                         sp++;
  612                         uap->buf++;
  613                         count--;
  614                 }
  615                 free(buf, M_STATFS);
  616         }
  617         return (error);
  618 }
  619 
  620 /*
  621  * Implement fstatfs() for (NFS) file handles.
  622  */
  623 #ifndef _SYS_SYSPROTO_H_
  624 struct freebsd4_fhstatfs_args {
  625         struct fhandle *u_fhp;
  626         struct ostatfs *buf;
  627 };
  628 #endif
  629 int
  630 freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
  631 {
  632         struct ostatfs osb;
  633         struct statfs *sfp;
  634         fhandle_t fh;
  635         int error;
  636 
  637         error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
  638         if (error != 0)
  639                 return (error);
  640         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  641         error = kern_fhstatfs(td, fh, sfp);
  642         if (error == 0) {
  643                 cvtstatfs(sfp, &osb);
  644                 error = copyout(&osb, uap->buf, sizeof(osb));
  645         }
  646         free(sfp, M_STATFS);
  647         return (error);
  648 }
  649 
  650 /*
  651  * Convert a new format statfs structure to an old format statfs structure.
  652  */
  653 static void
  654 cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
  655 {
  656 
  657         statfs_scale_blocks(nsp, LONG_MAX);
  658         bzero(osp, sizeof(*osp));
  659         osp->f_bsize = nsp->f_bsize;
  660         osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
  661         osp->f_blocks = nsp->f_blocks;
  662         osp->f_bfree = nsp->f_bfree;
  663         osp->f_bavail = nsp->f_bavail;
  664         osp->f_files = MIN(nsp->f_files, LONG_MAX);
  665         osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
  666         osp->f_owner = nsp->f_owner;
  667         osp->f_type = nsp->f_type;
  668         osp->f_flags = nsp->f_flags;
  669         osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
  670         osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
  671         osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
  672         osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
  673         strlcpy(osp->f_fstypename, nsp->f_fstypename,
  674             MIN(MFSNAMELEN, OMFSNAMELEN));
  675         strlcpy(osp->f_mntonname, nsp->f_mntonname,
  676             MIN(MNAMELEN, OMNAMELEN));
  677         strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
  678             MIN(MNAMELEN, OMNAMELEN));
  679         osp->f_fsid = nsp->f_fsid;
  680 }
  681 #endif /* COMPAT_FREEBSD4 */
  682 
  683 /*
  684  * Change current working directory to a given file descriptor.
  685  */
  686 #ifndef _SYS_SYSPROTO_H_
  687 struct fchdir_args {
  688         int     fd;
  689 };
  690 #endif
  691 int
  692 sys_fchdir(struct thread *td, struct fchdir_args *uap)
  693 {
  694         struct vnode *vp, *tdp;
  695         struct mount *mp;
  696         struct file *fp;
  697         cap_rights_t rights;
  698         int error;
  699 
  700         AUDIT_ARG_FD(uap->fd);
  701         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHDIR),
  702             &fp);
  703         if (error != 0)
  704                 return (error);
  705         vp = fp->f_vnode;
  706         vrefact(vp);
  707         fdrop(fp, td);
  708         vn_lock(vp, LK_SHARED | LK_RETRY);
  709         AUDIT_ARG_VNODE1(vp);
  710         error = change_dir(vp, td);
  711         while (!error && (mp = vp->v_mountedhere) != NULL) {
  712                 if (vfs_busy(mp, 0))
  713                         continue;
  714                 error = VFS_ROOT(mp, LK_SHARED, &tdp);
  715                 vfs_unbusy(mp);
  716                 if (error != 0)
  717                         break;
  718                 vput(vp);
  719                 vp = tdp;
  720         }
  721         if (error != 0) {
  722                 vput(vp);
  723                 return (error);
  724         }
  725         VOP_UNLOCK(vp, 0);
  726         pwd_chdir(td, vp);
  727         return (0);
  728 }
  729 
  730 /*
  731  * Change current working directory (``.'').
  732  */
  733 #ifndef _SYS_SYSPROTO_H_
  734 struct chdir_args {
  735         char    *path;
  736 };
  737 #endif
  738 int
  739 sys_chdir(struct thread *td, struct chdir_args *uap)
  740 {
  741 
  742         return (kern_chdir(td, uap->path, UIO_USERSPACE));
  743 }
  744 
  745 int
  746 kern_chdir(struct thread *td, char *path, enum uio_seg pathseg)
  747 {
  748         struct nameidata nd;
  749         int error;
  750 
  751         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  752             pathseg, path, td);
  753         if ((error = namei(&nd)) != 0)
  754                 return (error);
  755         if ((error = change_dir(nd.ni_vp, td)) != 0) {
  756                 vput(nd.ni_vp);
  757                 NDFREE(&nd, NDF_ONLY_PNBUF);
  758                 return (error);
  759         }
  760         VOP_UNLOCK(nd.ni_vp, 0);
  761         NDFREE(&nd, NDF_ONLY_PNBUF);
  762         pwd_chdir(td, nd.ni_vp);
  763         return (0);
  764 }
  765 
  766 /*
  767  * Change notion of root (``/'') directory.
  768  */
  769 #ifndef _SYS_SYSPROTO_H_
  770 struct chroot_args {
  771         char    *path;
  772 };
  773 #endif
  774 int
  775 sys_chroot(struct thread *td, struct chroot_args *uap)
  776 {
  777         struct nameidata nd;
  778         int error;
  779 
  780         error = priv_check(td, PRIV_VFS_CHROOT);
  781         if (error != 0)
  782                 return (error);
  783         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  784             UIO_USERSPACE, uap->path, td);
  785         error = namei(&nd);
  786         if (error != 0)
  787                 goto error;
  788         error = change_dir(nd.ni_vp, td);
  789         if (error != 0)
  790                 goto e_vunlock;
  791 #ifdef MAC
  792         error = mac_vnode_check_chroot(td->td_ucred, nd.ni_vp);
  793         if (error != 0)
  794                 goto e_vunlock;
  795 #endif
  796         VOP_UNLOCK(nd.ni_vp, 0);
  797         error = pwd_chroot(td, nd.ni_vp);
  798         vrele(nd.ni_vp);
  799         NDFREE(&nd, NDF_ONLY_PNBUF);
  800         return (error);
  801 e_vunlock:
  802         vput(nd.ni_vp);
  803 error:
  804         NDFREE(&nd, NDF_ONLY_PNBUF);
  805         return (error);
  806 }
  807 
  808 /*
  809  * Common routine for chroot and chdir.  Callers must provide a locked vnode
  810  * instance.
  811  */
  812 int
  813 change_dir(struct vnode *vp, struct thread *td)
  814 {
  815 #ifdef MAC
  816         int error;
  817 #endif
  818 
  819         ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
  820         if (vp->v_type != VDIR)
  821                 return (ENOTDIR);
  822 #ifdef MAC
  823         error = mac_vnode_check_chdir(td->td_ucred, vp);
  824         if (error != 0)
  825                 return (error);
  826 #endif
  827         return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
  828 }
  829 
  830 static __inline void
  831 flags_to_rights(int flags, cap_rights_t *rightsp)
  832 {
  833 
  834         if (flags & O_EXEC) {
  835                 cap_rights_set(rightsp, CAP_FEXECVE);
  836         } else {
  837                 switch ((flags & O_ACCMODE)) {
  838                 case O_RDONLY:
  839                         cap_rights_set(rightsp, CAP_READ);
  840                         break;
  841                 case O_RDWR:
  842                         cap_rights_set(rightsp, CAP_READ);
  843                         /* FALLTHROUGH */
  844                 case O_WRONLY:
  845                         cap_rights_set(rightsp, CAP_WRITE);
  846                         if (!(flags & (O_APPEND | O_TRUNC)))
  847                                 cap_rights_set(rightsp, CAP_SEEK);
  848                         break;
  849                 }
  850         }
  851 
  852         if (flags & O_CREAT)
  853                 cap_rights_set(rightsp, CAP_CREATE);
  854 
  855         if (flags & O_TRUNC)
  856                 cap_rights_set(rightsp, CAP_FTRUNCATE);
  857 
  858         if (flags & (O_SYNC | O_FSYNC))
  859                 cap_rights_set(rightsp, CAP_FSYNC);
  860 
  861         if (flags & (O_EXLOCK | O_SHLOCK))
  862                 cap_rights_set(rightsp, CAP_FLOCK);
  863 }
  864 
  865 /*
  866  * Check permissions, allocate an open file structure, and call the device
  867  * open routine if any.
  868  */
  869 #ifndef _SYS_SYSPROTO_H_
  870 struct open_args {
  871         char    *path;
  872         int     flags;
  873         int     mode;
  874 };
  875 #endif
  876 int
  877 sys_open(struct thread *td, struct open_args *uap)
  878 {
  879 
  880         return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
  881             uap->flags, uap->mode));
  882 }
  883 
  884 #ifndef _SYS_SYSPROTO_H_
  885 struct openat_args {
  886         int     fd;
  887         char    *path;
  888         int     flag;
  889         int     mode;
  890 };
  891 #endif
  892 int
  893 sys_openat(struct thread *td, struct openat_args *uap)
  894 {
  895 
  896         AUDIT_ARG_FD(uap->fd);
  897         return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
  898             uap->mode));
  899 }
  900 
  901 int
  902 kern_openat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
  903     int flags, int mode)
  904 {
  905         struct proc *p = td->td_proc;
  906         struct filedesc *fdp = p->p_fd;
  907         struct file *fp;
  908         struct vnode *vp;
  909         struct nameidata nd;
  910         cap_rights_t rights;
  911         int cmode, error, indx;
  912 
  913         indx = -1;
  914 
  915         AUDIT_ARG_FFLAGS(flags);
  916         AUDIT_ARG_MODE(mode);
  917         cap_rights_init(&rights, CAP_LOOKUP);
  918         flags_to_rights(flags, &rights);
  919         /*
  920          * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
  921          * may be specified.
  922          */
  923         if (flags & O_EXEC) {
  924                 if (flags & O_ACCMODE)
  925                         return (EINVAL);
  926         } else if ((flags & O_ACCMODE) == O_ACCMODE) {
  927                 return (EINVAL);
  928         } else {
  929                 flags = FFLAGS(flags);
  930         }
  931 
  932         /*
  933          * Allocate a file structure. The descriptor to reference it
  934          * is allocated and set by finstall() below.
  935          */
  936         error = falloc_noinstall(td, &fp);
  937         if (error != 0)
  938                 return (error);
  939         /*
  940          * An extra reference on `fp' has been held for us by
  941          * falloc_noinstall().
  942          */
  943         /* Set the flags early so the finit in devfs can pick them up. */
  944         fp->f_flag = flags & FMASK;
  945         cmode = ((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
  946         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
  947             &rights, td);
  948         td->td_dupfd = -1;              /* XXX check for fdopen */
  949         error = vn_open(&nd, &flags, cmode, fp);
  950         if (error != 0) {
  951                 /*
  952                  * If the vn_open replaced the method vector, something
  953                  * wonderous happened deep below and we just pass it up
  954                  * pretending we know what we do.
  955                  */
  956                 if (error == ENXIO && fp->f_ops != &badfileops)
  957                         goto success;
  958 
  959                 /*
  960                  * Handle special fdopen() case. bleh.
  961                  *
  962                  * Don't do this for relative (capability) lookups; we don't
  963                  * understand exactly what would happen, and we don't think
  964                  * that it ever should.
  965                  */
  966                 if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
  967                     (error == ENODEV || error == ENXIO) &&
  968                     td->td_dupfd >= 0) {
  969                         error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
  970                             &indx);
  971                         if (error == 0)
  972                                 goto success;
  973                 }
  974 
  975                 goto bad;
  976         }
  977         td->td_dupfd = 0;
  978         NDFREE(&nd, NDF_ONLY_PNBUF);
  979         vp = nd.ni_vp;
  980 
  981         /*
  982          * Store the vnode, for any f_type. Typically, the vnode use
  983          * count is decremented by direct call to vn_closefile() for
  984          * files that switched type in the cdevsw fdopen() method.
  985          */
  986         fp->f_vnode = vp;
  987         /*
  988          * If the file wasn't claimed by devfs bind it to the normal
  989          * vnode operations here.
  990          */
  991         if (fp->f_ops == &badfileops) {
  992                 KASSERT(vp->v_type != VFIFO, ("Unexpected fifo."));
  993                 fp->f_seqcount = 1;
  994                 finit(fp, (flags & FMASK) | (fp->f_flag & FHASLOCK),
  995                     DTYPE_VNODE, vp, &vnops);
  996         }
  997 
  998         VOP_UNLOCK(vp, 0);
  999         if (flags & O_TRUNC) {
 1000                 error = fo_truncate(fp, 0, td->td_ucred, td);
 1001                 if (error != 0)
 1002                         goto bad;
 1003         }
 1004 success:
 1005         /*
 1006          * If we haven't already installed the FD (for dupfdopen), do so now.
 1007          */
 1008         if (indx == -1) {
 1009                 struct filecaps *fcaps;
 1010 
 1011 #ifdef CAPABILITIES
 1012                 if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) != 0)
 1013                         fcaps = &nd.ni_filecaps;
 1014                 else
 1015 #endif
 1016                         fcaps = NULL;
 1017                 error = finstall(td, fp, &indx, flags, fcaps);
 1018                 /* On success finstall() consumes fcaps. */
 1019                 if (error != 0) {
 1020                         filecaps_free(&nd.ni_filecaps);
 1021                         goto bad;
 1022                 }
 1023         } else {
 1024                 filecaps_free(&nd.ni_filecaps);
 1025         }
 1026 
 1027         /*
 1028          * Release our private reference, leaving the one associated with
 1029          * the descriptor table intact.
 1030          */
 1031         fdrop(fp, td);
 1032         td->td_retval[0] = indx;
 1033         return (0);
 1034 bad:
 1035         KASSERT(indx == -1, ("indx=%d, should be -1", indx));
 1036         fdrop(fp, td);
 1037         return (error);
 1038 }
 1039 
 1040 #ifdef COMPAT_43
 1041 /*
 1042  * Create a file.
 1043  */
 1044 #ifndef _SYS_SYSPROTO_H_
 1045 struct ocreat_args {
 1046         char    *path;
 1047         int     mode;
 1048 };
 1049 #endif
 1050 int
 1051 ocreat(struct thread *td, struct ocreat_args *uap)
 1052 {
 1053 
 1054         return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1055             O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
 1056 }
 1057 #endif /* COMPAT_43 */
 1058 
 1059 /*
 1060  * Create a special file.
 1061  */
 1062 #ifndef _SYS_SYSPROTO_H_
 1063 struct mknod_args {
 1064         char    *path;
 1065         int     mode;
 1066         int     dev;
 1067 };
 1068 #endif
 1069 int
 1070 sys_mknod(struct thread *td, struct mknod_args *uap)
 1071 {
 1072 
 1073         return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1074             uap->mode, uap->dev));
 1075 }
 1076 
 1077 #ifndef _SYS_SYSPROTO_H_
 1078 struct mknodat_args {
 1079         int     fd;
 1080         char    *path;
 1081         mode_t  mode;
 1082         dev_t   dev;
 1083 };
 1084 #endif
 1085 int
 1086 sys_mknodat(struct thread *td, struct mknodat_args *uap)
 1087 {
 1088 
 1089         return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
 1090             uap->dev));
 1091 }
 1092 
 1093 int
 1094 kern_mknodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1095     int mode, int dev)
 1096 {
 1097         struct vnode *vp;
 1098         struct mount *mp;
 1099         struct vattr vattr;
 1100         struct nameidata nd;
 1101         cap_rights_t rights;
 1102         int error, whiteout = 0;
 1103 
 1104         AUDIT_ARG_MODE(mode);
 1105         AUDIT_ARG_DEV(dev);
 1106         switch (mode & S_IFMT) {
 1107         case S_IFCHR:
 1108         case S_IFBLK:
 1109                 error = priv_check(td, PRIV_VFS_MKNOD_DEV);
 1110                 if (error == 0 && dev == VNOVAL)
 1111                         error = EINVAL;
 1112                 break;
 1113         case S_IFWHT:
 1114                 error = priv_check(td, PRIV_VFS_MKNOD_WHT);
 1115                 break;
 1116         case S_IFIFO:
 1117                 if (dev == 0)
 1118                         return (kern_mkfifoat(td, fd, path, pathseg, mode));
 1119                 /* FALLTHROUGH */
 1120         default:
 1121                 error = EINVAL;
 1122                 break;
 1123         }
 1124         if (error != 0)
 1125                 return (error);
 1126 restart:
 1127         bwillwrite();
 1128         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1129             NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKNODAT),
 1130             td);
 1131         if ((error = namei(&nd)) != 0)
 1132                 return (error);
 1133         vp = nd.ni_vp;
 1134         if (vp != NULL) {
 1135                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1136                 if (vp == nd.ni_dvp)
 1137                         vrele(nd.ni_dvp);
 1138                 else
 1139                         vput(nd.ni_dvp);
 1140                 vrele(vp);
 1141                 return (EEXIST);
 1142         } else {
 1143                 VATTR_NULL(&vattr);
 1144                 vattr.va_mode = (mode & ALLPERMS) &
 1145                     ~td->td_proc->p_fd->fd_cmask;
 1146                 vattr.va_rdev = dev;
 1147                 whiteout = 0;
 1148 
 1149                 switch (mode & S_IFMT) {
 1150                 case S_IFCHR:
 1151                         vattr.va_type = VCHR;
 1152                         break;
 1153                 case S_IFBLK:
 1154                         vattr.va_type = VBLK;
 1155                         break;
 1156                 case S_IFWHT:
 1157                         whiteout = 1;
 1158                         break;
 1159                 default:
 1160                         panic("kern_mknod: invalid mode");
 1161                 }
 1162         }
 1163         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1164                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1165                 vput(nd.ni_dvp);
 1166                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1167                         return (error);
 1168                 goto restart;
 1169         }
 1170 #ifdef MAC
 1171         if (error == 0 && !whiteout)
 1172                 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
 1173                     &nd.ni_cnd, &vattr);
 1174 #endif
 1175         if (error == 0) {
 1176                 if (whiteout)
 1177                         error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
 1178                 else {
 1179                         error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
 1180                                                 &nd.ni_cnd, &vattr);
 1181                         if (error == 0)
 1182                                 vput(nd.ni_vp);
 1183                 }
 1184         }
 1185         NDFREE(&nd, NDF_ONLY_PNBUF);
 1186         vput(nd.ni_dvp);
 1187         vn_finished_write(mp);
 1188         return (error);
 1189 }
 1190 
 1191 /*
 1192  * Create a named pipe.
 1193  */
 1194 #ifndef _SYS_SYSPROTO_H_
 1195 struct mkfifo_args {
 1196         char    *path;
 1197         int     mode;
 1198 };
 1199 #endif
 1200 int
 1201 sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
 1202 {
 1203 
 1204         return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1205             uap->mode));
 1206 }
 1207 
 1208 #ifndef _SYS_SYSPROTO_H_
 1209 struct mkfifoat_args {
 1210         int     fd;
 1211         char    *path;
 1212         mode_t  mode;
 1213 };
 1214 #endif
 1215 int
 1216 sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
 1217 {
 1218 
 1219         return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
 1220             uap->mode));
 1221 }
 1222 
 1223 int
 1224 kern_mkfifoat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1225     int mode)
 1226 {
 1227         struct mount *mp;
 1228         struct vattr vattr;
 1229         struct nameidata nd;
 1230         cap_rights_t rights;
 1231         int error;
 1232 
 1233         AUDIT_ARG_MODE(mode);
 1234 restart:
 1235         bwillwrite();
 1236         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1237             NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKFIFOAT),
 1238             td);
 1239         if ((error = namei(&nd)) != 0)
 1240                 return (error);
 1241         if (nd.ni_vp != NULL) {
 1242                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1243                 if (nd.ni_vp == nd.ni_dvp)
 1244                         vrele(nd.ni_dvp);
 1245                 else
 1246                         vput(nd.ni_dvp);
 1247                 vrele(nd.ni_vp);
 1248                 return (EEXIST);
 1249         }
 1250         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1251                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1252                 vput(nd.ni_dvp);
 1253                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1254                         return (error);
 1255                 goto restart;
 1256         }
 1257         VATTR_NULL(&vattr);
 1258         vattr.va_type = VFIFO;
 1259         vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_fd->fd_cmask;
 1260 #ifdef MAC
 1261         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 1262             &vattr);
 1263         if (error != 0)
 1264                 goto out;
 1265 #endif
 1266         error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 1267         if (error == 0)
 1268                 vput(nd.ni_vp);
 1269 #ifdef MAC
 1270 out:
 1271 #endif
 1272         vput(nd.ni_dvp);
 1273         vn_finished_write(mp);
 1274         NDFREE(&nd, NDF_ONLY_PNBUF);
 1275         return (error);
 1276 }
 1277 
 1278 /*
 1279  * Make a hard file link.
 1280  */
 1281 #ifndef _SYS_SYSPROTO_H_
 1282 struct link_args {
 1283         char    *path;
 1284         char    *link;
 1285 };
 1286 #endif
 1287 int
 1288 sys_link(struct thread *td, struct link_args *uap)
 1289 {
 1290 
 1291         return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
 1292             UIO_USERSPACE, FOLLOW));
 1293 }
 1294 
 1295 #ifndef _SYS_SYSPROTO_H_
 1296 struct linkat_args {
 1297         int     fd1;
 1298         char    *path1;
 1299         int     fd2;
 1300         char    *path2;
 1301         int     flag;
 1302 };
 1303 #endif
 1304 int
 1305 sys_linkat(struct thread *td, struct linkat_args *uap)
 1306 {
 1307         int flag;
 1308 
 1309         flag = uap->flag;
 1310         if (flag & ~AT_SYMLINK_FOLLOW)
 1311                 return (EINVAL);
 1312 
 1313         return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
 1314             UIO_USERSPACE, (flag & AT_SYMLINK_FOLLOW) ? FOLLOW : NOFOLLOW));
 1315 }
 1316 
 1317 int hardlink_check_uid = 0;
 1318 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
 1319     &hardlink_check_uid, 0,
 1320     "Unprivileged processes cannot create hard links to files owned by other "
 1321     "users");
 1322 static int hardlink_check_gid = 0;
 1323 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
 1324     &hardlink_check_gid, 0,
 1325     "Unprivileged processes cannot create hard links to files owned by other "
 1326     "groups");
 1327 
 1328 static int
 1329 can_hardlink(struct vnode *vp, struct ucred *cred)
 1330 {
 1331         struct vattr va;
 1332         int error;
 1333 
 1334         if (!hardlink_check_uid && !hardlink_check_gid)
 1335                 return (0);
 1336 
 1337         error = VOP_GETATTR(vp, &va, cred);
 1338         if (error != 0)
 1339                 return (error);
 1340 
 1341         if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
 1342                 error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
 1343                 if (error != 0)
 1344                         return (error);
 1345         }
 1346 
 1347         if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
 1348                 error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
 1349                 if (error != 0)
 1350                         return (error);
 1351         }
 1352 
 1353         return (0);
 1354 }
 1355 
 1356 int
 1357 kern_linkat(struct thread *td, int fd1, int fd2, char *path1, char *path2,
 1358     enum uio_seg segflg, int follow)
 1359 {
 1360         struct vnode *vp;
 1361         struct mount *mp;
 1362         struct nameidata nd;
 1363         cap_rights_t rights;
 1364         int error;
 1365 
 1366 again:
 1367         bwillwrite();
 1368         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, segflg, path1, fd1,
 1369             cap_rights_init(&rights, CAP_LINKAT_SOURCE), td);
 1370 
 1371         if ((error = namei(&nd)) != 0)
 1372                 return (error);
 1373         NDFREE(&nd, NDF_ONLY_PNBUF);
 1374         vp = nd.ni_vp;
 1375         if (vp->v_type == VDIR) {
 1376                 vrele(vp);
 1377                 return (EPERM);         /* POSIX */
 1378         }
 1379         NDINIT_ATRIGHTS(&nd, CREATE,
 1380             LOCKPARENT | SAVENAME | AUDITVNODE2 | NOCACHE, segflg, path2, fd2,
 1381             cap_rights_init(&rights, CAP_LINKAT_TARGET), td);
 1382         if ((error = namei(&nd)) == 0) {
 1383                 if (nd.ni_vp != NULL) {
 1384                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1385                         if (nd.ni_dvp == nd.ni_vp)
 1386                                 vrele(nd.ni_dvp);
 1387                         else
 1388                                 vput(nd.ni_dvp);
 1389                         vrele(nd.ni_vp);
 1390                         vrele(vp);
 1391                         return (EEXIST);
 1392                 } else if (nd.ni_dvp->v_mount != vp->v_mount) {
 1393                         /*
 1394                          * Cross-device link.  No need to recheck
 1395                          * vp->v_type, since it cannot change, except
 1396                          * to VBAD.
 1397                          */
 1398                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1399                         vput(nd.ni_dvp);
 1400                         vrele(vp);
 1401                         return (EXDEV);
 1402                 } else if ((error = vn_lock(vp, LK_EXCLUSIVE)) == 0) {
 1403                         error = can_hardlink(vp, td->td_ucred);
 1404 #ifdef MAC
 1405                         if (error == 0)
 1406                                 error = mac_vnode_check_link(td->td_ucred,
 1407                                     nd.ni_dvp, vp, &nd.ni_cnd);
 1408 #endif
 1409                         if (error != 0) {
 1410                                 vput(vp);
 1411                                 vput(nd.ni_dvp);
 1412                                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1413                                 return (error);
 1414                         }
 1415                         error = vn_start_write(vp, &mp, V_NOWAIT);
 1416                         if (error != 0) {
 1417                                 vput(vp);
 1418                                 vput(nd.ni_dvp);
 1419                                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1420                                 error = vn_start_write(NULL, &mp,
 1421                                     V_XSLEEP | PCATCH);
 1422                                 if (error != 0)
 1423                                         return (error);
 1424                                 goto again;
 1425                         }
 1426                         error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
 1427                         VOP_UNLOCK(vp, 0);
 1428                         vput(nd.ni_dvp);
 1429                         vn_finished_write(mp);
 1430                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1431                 } else {
 1432                         vput(nd.ni_dvp);
 1433                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1434                         vrele(vp);
 1435                         goto again;
 1436                 }
 1437         }
 1438         vrele(vp);
 1439         return (error);
 1440 }
 1441 
 1442 /*
 1443  * Make a symbolic link.
 1444  */
 1445 #ifndef _SYS_SYSPROTO_H_
 1446 struct symlink_args {
 1447         char    *path;
 1448         char    *link;
 1449 };
 1450 #endif
 1451 int
 1452 sys_symlink(struct thread *td, struct symlink_args *uap)
 1453 {
 1454 
 1455         return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
 1456             UIO_USERSPACE));
 1457 }
 1458 
 1459 #ifndef _SYS_SYSPROTO_H_
 1460 struct symlinkat_args {
 1461         char    *path;
 1462         int     fd;
 1463         char    *path2;
 1464 };
 1465 #endif
 1466 int
 1467 sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
 1468 {
 1469 
 1470         return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
 1471             UIO_USERSPACE));
 1472 }
 1473 
 1474 int
 1475 kern_symlinkat(struct thread *td, char *path1, int fd, char *path2,
 1476     enum uio_seg segflg)
 1477 {
 1478         struct mount *mp;
 1479         struct vattr vattr;
 1480         char *syspath;
 1481         struct nameidata nd;
 1482         int error;
 1483         cap_rights_t rights;
 1484 
 1485         if (segflg == UIO_SYSSPACE) {
 1486                 syspath = path1;
 1487         } else {
 1488                 syspath = uma_zalloc(namei_zone, M_WAITOK);
 1489                 if ((error = copyinstr(path1, syspath, MAXPATHLEN, NULL)) != 0)
 1490                         goto out;
 1491         }
 1492         AUDIT_ARG_TEXT(syspath);
 1493 restart:
 1494         bwillwrite();
 1495         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1496             NOCACHE, segflg, path2, fd, cap_rights_init(&rights, CAP_SYMLINKAT),
 1497             td);
 1498         if ((error = namei(&nd)) != 0)
 1499                 goto out;
 1500         if (nd.ni_vp) {
 1501                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1502                 if (nd.ni_vp == nd.ni_dvp)
 1503                         vrele(nd.ni_dvp);
 1504                 else
 1505                         vput(nd.ni_dvp);
 1506                 vrele(nd.ni_vp);
 1507                 error = EEXIST;
 1508                 goto out;
 1509         }
 1510         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1511                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1512                 vput(nd.ni_dvp);
 1513                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1514                         goto out;
 1515                 goto restart;
 1516         }
 1517         VATTR_NULL(&vattr);
 1518         vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_fd->fd_cmask;
 1519 #ifdef MAC
 1520         vattr.va_type = VLNK;
 1521         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 1522             &vattr);
 1523         if (error != 0)
 1524                 goto out2;
 1525 #endif
 1526         error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
 1527         if (error == 0)
 1528                 vput(nd.ni_vp);
 1529 #ifdef MAC
 1530 out2:
 1531 #endif
 1532         NDFREE(&nd, NDF_ONLY_PNBUF);
 1533         vput(nd.ni_dvp);
 1534         vn_finished_write(mp);
 1535 out:
 1536         if (segflg != UIO_SYSSPACE)
 1537                 uma_zfree(namei_zone, syspath);
 1538         return (error);
 1539 }
 1540 
 1541 /*
 1542  * Delete a whiteout from the filesystem.
 1543  */
 1544 #ifndef _SYS_SYSPROTO_H_
 1545 struct undelete_args {
 1546         char *path;
 1547 };
 1548 #endif
 1549 int
 1550 sys_undelete(struct thread *td, struct undelete_args *uap)
 1551 {
 1552         struct mount *mp;
 1553         struct nameidata nd;
 1554         int error;
 1555 
 1556 restart:
 1557         bwillwrite();
 1558         NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
 1559             UIO_USERSPACE, uap->path, td);
 1560         error = namei(&nd);
 1561         if (error != 0)
 1562                 return (error);
 1563 
 1564         if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
 1565                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1566                 if (nd.ni_vp == nd.ni_dvp)
 1567                         vrele(nd.ni_dvp);
 1568                 else
 1569                         vput(nd.ni_dvp);
 1570                 if (nd.ni_vp)
 1571                         vrele(nd.ni_vp);
 1572                 return (EEXIST);
 1573         }
 1574         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1575                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1576                 vput(nd.ni_dvp);
 1577                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1578                         return (error);
 1579                 goto restart;
 1580         }
 1581         error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
 1582         NDFREE(&nd, NDF_ONLY_PNBUF);
 1583         vput(nd.ni_dvp);
 1584         vn_finished_write(mp);
 1585         return (error);
 1586 }
 1587 
 1588 /*
 1589  * Delete a name from the filesystem.
 1590  */
 1591 #ifndef _SYS_SYSPROTO_H_
 1592 struct unlink_args {
 1593         char    *path;
 1594 };
 1595 #endif
 1596 int
 1597 sys_unlink(struct thread *td, struct unlink_args *uap)
 1598 {
 1599 
 1600         return (kern_unlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE, 0));
 1601 }
 1602 
 1603 #ifndef _SYS_SYSPROTO_H_
 1604 struct unlinkat_args {
 1605         int     fd;
 1606         char    *path;
 1607         int     flag;
 1608 };
 1609 #endif
 1610 int
 1611 sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
 1612 {
 1613         int flag = uap->flag;
 1614         int fd = uap->fd;
 1615         char *path = uap->path;
 1616 
 1617         if (flag & ~AT_REMOVEDIR)
 1618                 return (EINVAL);
 1619 
 1620         if (flag & AT_REMOVEDIR)
 1621                 return (kern_rmdirat(td, fd, path, UIO_USERSPACE));
 1622         else
 1623                 return (kern_unlinkat(td, fd, path, UIO_USERSPACE, 0));
 1624 }
 1625 
 1626 int
 1627 kern_unlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1628     ino_t oldinum)
 1629 {
 1630         struct mount *mp;
 1631         struct vnode *vp;
 1632         struct nameidata nd;
 1633         struct stat sb;
 1634         cap_rights_t rights;
 1635         int error;
 1636 
 1637 restart:
 1638         bwillwrite();
 1639         NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
 1640             pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
 1641         if ((error = namei(&nd)) != 0)
 1642                 return (error == EINVAL ? EPERM : error);
 1643         vp = nd.ni_vp;
 1644         if (vp->v_type == VDIR && oldinum == 0) {
 1645                 error = EPERM;          /* POSIX */
 1646         } else if (oldinum != 0 &&
 1647                   ((error = vn_stat(vp, &sb, td->td_ucred, NOCRED, td)) == 0) &&
 1648                   sb.st_ino != oldinum) {
 1649                         error = EIDRM;  /* Identifier removed */
 1650         } else {
 1651                 /*
 1652                  * The root of a mounted filesystem cannot be deleted.
 1653                  *
 1654                  * XXX: can this only be a VDIR case?
 1655                  */
 1656                 if (vp->v_vflag & VV_ROOT)
 1657                         error = EBUSY;
 1658         }
 1659         if (error == 0) {
 1660                 if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1661                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1662                         vput(nd.ni_dvp);
 1663                         if (vp == nd.ni_dvp)
 1664                                 vrele(vp);
 1665                         else
 1666                                 vput(vp);
 1667                         if ((error = vn_start_write(NULL, &mp,
 1668                             V_XSLEEP | PCATCH)) != 0)
 1669                                 return (error);
 1670                         goto restart;
 1671                 }
 1672 #ifdef MAC
 1673                 error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
 1674                     &nd.ni_cnd);
 1675                 if (error != 0)
 1676                         goto out;
 1677 #endif
 1678                 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
 1679                 error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
 1680 #ifdef MAC
 1681 out:
 1682 #endif
 1683                 vn_finished_write(mp);
 1684         }
 1685         NDFREE(&nd, NDF_ONLY_PNBUF);
 1686         vput(nd.ni_dvp);
 1687         if (vp == nd.ni_dvp)
 1688                 vrele(vp);
 1689         else
 1690                 vput(vp);
 1691         return (error);
 1692 }
 1693 
 1694 /*
 1695  * Reposition read/write file offset.
 1696  */
 1697 #ifndef _SYS_SYSPROTO_H_
 1698 struct lseek_args {
 1699         int     fd;
 1700         int     pad;
 1701         off_t   offset;
 1702         int     whence;
 1703 };
 1704 #endif
 1705 int
 1706 sys_lseek(struct thread *td, struct lseek_args *uap)
 1707 {
 1708 
 1709         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1710 }
 1711 
 1712 int
 1713 kern_lseek(struct thread *td, int fd, off_t offset, int whence)
 1714 {
 1715         struct file *fp;
 1716         cap_rights_t rights;
 1717         int error;
 1718 
 1719         AUDIT_ARG_FD(fd);
 1720         error = fget(td, fd, cap_rights_init(&rights, CAP_SEEK), &fp);
 1721         if (error != 0)
 1722                 return (error);
 1723         error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
 1724             fo_seek(fp, offset, whence, td) : ESPIPE;
 1725         fdrop(fp, td);
 1726         return (error);
 1727 }
 1728 
 1729 #if defined(COMPAT_43)
 1730 /*
 1731  * Reposition read/write file offset.
 1732  */
 1733 #ifndef _SYS_SYSPROTO_H_
 1734 struct olseek_args {
 1735         int     fd;
 1736         long    offset;
 1737         int     whence;
 1738 };
 1739 #endif
 1740 int
 1741 olseek(struct thread *td, struct olseek_args *uap)
 1742 {
 1743 
 1744         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1745 }
 1746 #endif /* COMPAT_43 */
 1747 
 1748 #if defined(COMPAT_FREEBSD6)
 1749 /* Version with the 'pad' argument */
 1750 int
 1751 freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
 1752 {
 1753 
 1754         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1755 }
 1756 #endif
 1757 
 1758 /*
 1759  * Check access permissions using passed credentials.
 1760  */
 1761 static int
 1762 vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
 1763      struct thread *td)
 1764 {
 1765         accmode_t accmode;
 1766         int error;
 1767 
 1768         /* Flags == 0 means only check for existence. */
 1769         if (user_flags == 0)
 1770                 return (0);
 1771 
 1772         accmode = 0;
 1773         if (user_flags & R_OK)
 1774                 accmode |= VREAD;
 1775         if (user_flags & W_OK)
 1776                 accmode |= VWRITE;
 1777         if (user_flags & X_OK)
 1778                 accmode |= VEXEC;
 1779 #ifdef MAC
 1780         error = mac_vnode_check_access(cred, vp, accmode);
 1781         if (error != 0)
 1782                 return (error);
 1783 #endif
 1784         if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
 1785                 error = VOP_ACCESS(vp, accmode, cred, td);
 1786         return (error);
 1787 }
 1788 
 1789 /*
 1790  * Check access permissions using "real" credentials.
 1791  */
 1792 #ifndef _SYS_SYSPROTO_H_
 1793 struct access_args {
 1794         char    *path;
 1795         int     amode;
 1796 };
 1797 #endif
 1798 int
 1799 sys_access(struct thread *td, struct access_args *uap)
 1800 {
 1801 
 1802         return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1803             0, uap->amode));
 1804 }
 1805 
 1806 #ifndef _SYS_SYSPROTO_H_
 1807 struct faccessat_args {
 1808         int     dirfd;
 1809         char    *path;
 1810         int     amode;
 1811         int     flag;
 1812 }
 1813 #endif
 1814 int
 1815 sys_faccessat(struct thread *td, struct faccessat_args *uap)
 1816 {
 1817 
 1818         return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
 1819             uap->amode));
 1820 }
 1821 
 1822 int
 1823 kern_accessat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1824     int flag, int amode)
 1825 {
 1826         struct ucred *cred, *usecred;
 1827         struct vnode *vp;
 1828         struct nameidata nd;
 1829         cap_rights_t rights;
 1830         int error;
 1831 
 1832         if (flag & ~AT_EACCESS)
 1833                 return (EINVAL);
 1834         if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
 1835                 return (EINVAL);
 1836 
 1837         /*
 1838          * Create and modify a temporary credential instead of one that
 1839          * is potentially shared (if we need one).
 1840          */
 1841         cred = td->td_ucred;
 1842         if ((flag & AT_EACCESS) == 0 &&
 1843             ((cred->cr_uid != cred->cr_ruid ||
 1844             cred->cr_rgid != cred->cr_groups[0]))) {
 1845                 usecred = crdup(cred);
 1846                 usecred->cr_uid = cred->cr_ruid;
 1847                 usecred->cr_groups[0] = cred->cr_rgid;
 1848                 td->td_ucred = usecred;
 1849         } else
 1850                 usecred = cred;
 1851         AUDIT_ARG_VALUE(amode);
 1852         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF |
 1853             AUDITVNODE1, pathseg, path, fd, cap_rights_init(&rights, CAP_FSTAT),
 1854             td);
 1855         if ((error = namei(&nd)) != 0)
 1856                 goto out;
 1857         vp = nd.ni_vp;
 1858 
 1859         error = vn_access(vp, amode, usecred, td);
 1860         NDFREE(&nd, NDF_ONLY_PNBUF);
 1861         vput(vp);
 1862 out:
 1863         if (usecred != cred) {
 1864                 td->td_ucred = cred;
 1865                 crfree(usecred);
 1866         }
 1867         return (error);
 1868 }
 1869 
 1870 /*
 1871  * Check access permissions using "effective" credentials.
 1872  */
 1873 #ifndef _SYS_SYSPROTO_H_
 1874 struct eaccess_args {
 1875         char    *path;
 1876         int     amode;
 1877 };
 1878 #endif
 1879 int
 1880 sys_eaccess(struct thread *td, struct eaccess_args *uap)
 1881 {
 1882 
 1883         return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1884             AT_EACCESS, uap->amode));
 1885 }
 1886 
 1887 #if defined(COMPAT_43)
 1888 /*
 1889  * Get file status; this version follows links.
 1890  */
 1891 #ifndef _SYS_SYSPROTO_H_
 1892 struct ostat_args {
 1893         char    *path;
 1894         struct ostat *ub;
 1895 };
 1896 #endif
 1897 int
 1898 ostat(struct thread *td, struct ostat_args *uap)
 1899 {
 1900         struct stat sb;
 1901         struct ostat osb;
 1902         int error;
 1903 
 1904         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 1905             &sb, NULL);
 1906         if (error != 0)
 1907                 return (error);
 1908         cvtstat(&sb, &osb);
 1909         return (copyout(&osb, uap->ub, sizeof (osb)));
 1910 }
 1911 
 1912 /*
 1913  * Get file status; this version does not follow links.
 1914  */
 1915 #ifndef _SYS_SYSPROTO_H_
 1916 struct olstat_args {
 1917         char    *path;
 1918         struct ostat *ub;
 1919 };
 1920 #endif
 1921 int
 1922 olstat(struct thread *td, struct olstat_args *uap)
 1923 {
 1924         struct stat sb;
 1925         struct ostat osb;
 1926         int error;
 1927 
 1928         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 1929             UIO_USERSPACE, &sb, NULL);
 1930         if (error != 0)
 1931                 return (error);
 1932         cvtstat(&sb, &osb);
 1933         return (copyout(&osb, uap->ub, sizeof (osb)));
 1934 }
 1935 
 1936 /*
 1937  * Convert from an old to a new stat structure.
 1938  */
 1939 void
 1940 cvtstat(struct stat *st, struct ostat *ost)
 1941 {
 1942 
 1943         bzero(ost, sizeof(*ost));
 1944         ost->st_dev = st->st_dev;
 1945         ost->st_ino = st->st_ino;
 1946         ost->st_mode = st->st_mode;
 1947         ost->st_nlink = st->st_nlink;
 1948         ost->st_uid = st->st_uid;
 1949         ost->st_gid = st->st_gid;
 1950         ost->st_rdev = st->st_rdev;
 1951         if (st->st_size < (quad_t)1 << 32)
 1952                 ost->st_size = st->st_size;
 1953         else
 1954                 ost->st_size = -2;
 1955         ost->st_atim = st->st_atim;
 1956         ost->st_mtim = st->st_mtim;
 1957         ost->st_ctim = st->st_ctim;
 1958         ost->st_blksize = st->st_blksize;
 1959         ost->st_blocks = st->st_blocks;
 1960         ost->st_flags = st->st_flags;
 1961         ost->st_gen = st->st_gen;
 1962 }
 1963 #endif /* COMPAT_43 */
 1964 
 1965 /*
 1966  * Get file status; this version follows links.
 1967  */
 1968 #ifndef _SYS_SYSPROTO_H_
 1969 struct stat_args {
 1970         char    *path;
 1971         struct stat *ub;
 1972 };
 1973 #endif
 1974 int
 1975 sys_stat(struct thread *td, struct stat_args *uap)
 1976 {
 1977         struct stat sb;
 1978         int error;
 1979 
 1980         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 1981             &sb, NULL);
 1982         if (error == 0)
 1983                 error = copyout(&sb, uap->ub, sizeof (sb));
 1984         return (error);
 1985 }
 1986 
 1987 #ifndef _SYS_SYSPROTO_H_
 1988 struct fstatat_args {
 1989         int     fd;
 1990         char    *path;
 1991         struct stat     *buf;
 1992         int     flag;
 1993 }
 1994 #endif
 1995 int
 1996 sys_fstatat(struct thread *td, struct fstatat_args *uap)
 1997 {
 1998         struct stat sb;
 1999         int error;
 2000 
 2001         error = kern_statat(td, uap->flag, uap->fd, uap->path,
 2002             UIO_USERSPACE, &sb, NULL);
 2003         if (error == 0)
 2004                 error = copyout(&sb, uap->buf, sizeof (sb));
 2005         return (error);
 2006 }
 2007 
 2008 int
 2009 kern_statat(struct thread *td, int flag, int fd, char *path,
 2010     enum uio_seg pathseg, struct stat *sbp,
 2011     void (*hook)(struct vnode *vp, struct stat *sbp))
 2012 {
 2013         struct nameidata nd;
 2014         struct stat sb;
 2015         cap_rights_t rights;
 2016         int error;
 2017 
 2018         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2019                 return (EINVAL);
 2020 
 2021         NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
 2022             FOLLOW) | LOCKSHARED | LOCKLEAF | AUDITVNODE1, pathseg, path, fd,
 2023             cap_rights_init(&rights, CAP_FSTAT), td);
 2024 
 2025         if ((error = namei(&nd)) != 0)
 2026                 return (error);
 2027         error = vn_stat(nd.ni_vp, &sb, td->td_ucred, NOCRED, td);
 2028         if (error == 0) {
 2029                 SDT_PROBE2(vfs, , stat, mode, path, sb.st_mode);
 2030                 if (S_ISREG(sb.st_mode))
 2031                         SDT_PROBE2(vfs, , stat, reg, path, pathseg);
 2032                 if (__predict_false(hook != NULL))
 2033                         hook(nd.ni_vp, &sb);
 2034         }
 2035         NDFREE(&nd, NDF_ONLY_PNBUF);
 2036         vput(nd.ni_vp);
 2037         if (error != 0)
 2038                 return (error);
 2039         *sbp = sb;
 2040 #ifdef KTRACE
 2041         if (KTRPOINT(td, KTR_STRUCT))
 2042                 ktrstat(&sb);
 2043 #endif
 2044         return (0);
 2045 }
 2046 
 2047 /*
 2048  * Get file status; this version does not follow links.
 2049  */
 2050 #ifndef _SYS_SYSPROTO_H_
 2051 struct lstat_args {
 2052         char    *path;
 2053         struct stat *ub;
 2054 };
 2055 #endif
 2056 int
 2057 sys_lstat(struct thread *td, struct lstat_args *uap)
 2058 {
 2059         struct stat sb;
 2060         int error;
 2061 
 2062         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 2063             UIO_USERSPACE, &sb, NULL);
 2064         if (error == 0)
 2065                 error = copyout(&sb, uap->ub, sizeof (sb));
 2066         return (error);
 2067 }
 2068 
 2069 /*
 2070  * Implementation of the NetBSD [l]stat() functions.
 2071  */
 2072 void
 2073 cvtnstat( struct stat *sb, struct nstat *nsb)
 2074 {
 2075 
 2076         bzero(nsb, sizeof *nsb);
 2077         nsb->st_dev = sb->st_dev;
 2078         nsb->st_ino = sb->st_ino;
 2079         nsb->st_mode = sb->st_mode;
 2080         nsb->st_nlink = sb->st_nlink;
 2081         nsb->st_uid = sb->st_uid;
 2082         nsb->st_gid = sb->st_gid;
 2083         nsb->st_rdev = sb->st_rdev;
 2084         nsb->st_atim = sb->st_atim;
 2085         nsb->st_mtim = sb->st_mtim;
 2086         nsb->st_ctim = sb->st_ctim;
 2087         nsb->st_size = sb->st_size;
 2088         nsb->st_blocks = sb->st_blocks;
 2089         nsb->st_blksize = sb->st_blksize;
 2090         nsb->st_flags = sb->st_flags;
 2091         nsb->st_gen = sb->st_gen;
 2092         nsb->st_birthtim = sb->st_birthtim;
 2093 }
 2094 
 2095 #ifndef _SYS_SYSPROTO_H_
 2096 struct nstat_args {
 2097         char    *path;
 2098         struct nstat *ub;
 2099 };
 2100 #endif
 2101 int
 2102 sys_nstat(struct thread *td, struct nstat_args *uap)
 2103 {
 2104         struct stat sb;
 2105         struct nstat nsb;
 2106         int error;
 2107 
 2108         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 2109             &sb, NULL);
 2110         if (error != 0)
 2111                 return (error);
 2112         cvtnstat(&sb, &nsb);
 2113         return (copyout(&nsb, uap->ub, sizeof (nsb)));
 2114 }
 2115 
 2116 /*
 2117  * NetBSD lstat.  Get file status; this version does not follow links.
 2118  */
 2119 #ifndef _SYS_SYSPROTO_H_
 2120 struct lstat_args {
 2121         char    *path;
 2122         struct stat *ub;
 2123 };
 2124 #endif
 2125 int
 2126 sys_nlstat(struct thread *td, struct nlstat_args *uap)
 2127 {
 2128         struct stat sb;
 2129         struct nstat nsb;
 2130         int error;
 2131 
 2132         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 2133             UIO_USERSPACE, &sb, NULL);
 2134         if (error != 0)
 2135                 return (error);
 2136         cvtnstat(&sb, &nsb);
 2137         return (copyout(&nsb, uap->ub, sizeof (nsb)));
 2138 }
 2139 
 2140 /*
 2141  * Get configurable pathname variables.
 2142  */
 2143 #ifndef _SYS_SYSPROTO_H_
 2144 struct pathconf_args {
 2145         char    *path;
 2146         int     name;
 2147 };
 2148 #endif
 2149 int
 2150 sys_pathconf(struct thread *td, struct pathconf_args *uap)
 2151 {
 2152 
 2153         return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW));
 2154 }
 2155 
 2156 #ifndef _SYS_SYSPROTO_H_
 2157 struct lpathconf_args {
 2158         char    *path;
 2159         int     name;
 2160 };
 2161 #endif
 2162 int
 2163 sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
 2164 {
 2165 
 2166         return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
 2167             NOFOLLOW));
 2168 }
 2169 
 2170 int
 2171 kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, int name,
 2172     u_long flags)
 2173 {
 2174         struct nameidata nd;
 2175         int error;
 2176 
 2177         NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
 2178             pathseg, path, td);
 2179         if ((error = namei(&nd)) != 0)
 2180                 return (error);
 2181         NDFREE(&nd, NDF_ONLY_PNBUF);
 2182 
 2183         error = VOP_PATHCONF(nd.ni_vp, name, td->td_retval);
 2184         vput(nd.ni_vp);
 2185         return (error);
 2186 }
 2187 
 2188 /*
 2189  * Return target name of a symbolic link.
 2190  */
 2191 #ifndef _SYS_SYSPROTO_H_
 2192 struct readlink_args {
 2193         char    *path;
 2194         char    *buf;
 2195         size_t  count;
 2196 };
 2197 #endif
 2198 int
 2199 sys_readlink(struct thread *td, struct readlink_args *uap)
 2200 {
 2201 
 2202         return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2203             uap->buf, UIO_USERSPACE, uap->count));
 2204 }
 2205 #ifndef _SYS_SYSPROTO_H_
 2206 struct readlinkat_args {
 2207         int     fd;
 2208         char    *path;
 2209         char    *buf;
 2210         size_t  bufsize;
 2211 };
 2212 #endif
 2213 int
 2214 sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
 2215 {
 2216 
 2217         return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
 2218             uap->buf, UIO_USERSPACE, uap->bufsize));
 2219 }
 2220 
 2221 int
 2222 kern_readlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2223     char *buf, enum uio_seg bufseg, size_t count)
 2224 {
 2225         struct vnode *vp;
 2226         struct iovec aiov;
 2227         struct uio auio;
 2228         struct nameidata nd;
 2229         int error;
 2230 
 2231         if (count > IOSIZE_MAX)
 2232                 return (EINVAL);
 2233 
 2234         NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
 2235             pathseg, path, fd, td);
 2236 
 2237         if ((error = namei(&nd)) != 0)
 2238                 return (error);
 2239         NDFREE(&nd, NDF_ONLY_PNBUF);
 2240         vp = nd.ni_vp;
 2241 #ifdef MAC
 2242         error = mac_vnode_check_readlink(td->td_ucred, vp);
 2243         if (error != 0) {
 2244                 vput(vp);
 2245                 return (error);
 2246         }
 2247 #endif
 2248         if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
 2249                 error = EINVAL;
 2250         else {
 2251                 aiov.iov_base = buf;
 2252                 aiov.iov_len = count;
 2253                 auio.uio_iov = &aiov;
 2254                 auio.uio_iovcnt = 1;
 2255                 auio.uio_offset = 0;
 2256                 auio.uio_rw = UIO_READ;
 2257                 auio.uio_segflg = bufseg;
 2258                 auio.uio_td = td;
 2259                 auio.uio_resid = count;
 2260                 error = VOP_READLINK(vp, &auio, td->td_ucred);
 2261                 td->td_retval[0] = count - auio.uio_resid;
 2262         }
 2263         vput(vp);
 2264         return (error);
 2265 }
 2266 
 2267 /*
 2268  * Common implementation code for chflags() and fchflags().
 2269  */
 2270 static int
 2271 setfflags(struct thread *td, struct vnode *vp, u_long flags)
 2272 {
 2273         struct mount *mp;
 2274         struct vattr vattr;
 2275         int error;
 2276 
 2277         /* We can't support the value matching VNOVAL. */
 2278         if (flags == VNOVAL)
 2279                 return (EOPNOTSUPP);
 2280 
 2281         /*
 2282          * Prevent non-root users from setting flags on devices.  When
 2283          * a device is reused, users can retain ownership of the device
 2284          * if they are allowed to set flags and programs assume that
 2285          * chown can't fail when done as root.
 2286          */
 2287         if (vp->v_type == VCHR || vp->v_type == VBLK) {
 2288                 error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
 2289                 if (error != 0)
 2290                         return (error);
 2291         }
 2292 
 2293         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2294                 return (error);
 2295         VATTR_NULL(&vattr);
 2296         vattr.va_flags = flags;
 2297         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2298 #ifdef MAC
 2299         error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
 2300         if (error == 0)
 2301 #endif
 2302                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 2303         VOP_UNLOCK(vp, 0);
 2304         vn_finished_write(mp);
 2305         return (error);
 2306 }
 2307 
 2308 /*
 2309  * Change flags of a file given a path name.
 2310  */
 2311 #ifndef _SYS_SYSPROTO_H_
 2312 struct chflags_args {
 2313         const char *path;
 2314         u_long  flags;
 2315 };
 2316 #endif
 2317 int
 2318 sys_chflags(struct thread *td, struct chflags_args *uap)
 2319 {
 2320 
 2321         return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2322             uap->flags, 0));
 2323 }
 2324 
 2325 #ifndef _SYS_SYSPROTO_H_
 2326 struct chflagsat_args {
 2327         int     fd;
 2328         const char *path;
 2329         u_long  flags;
 2330         int     atflag;
 2331 }
 2332 #endif
 2333 int
 2334 sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
 2335 {
 2336         int fd = uap->fd;
 2337         const char *path = uap->path;
 2338         u_long flags = uap->flags;
 2339         int atflag = uap->atflag;
 2340 
 2341         if (atflag & ~AT_SYMLINK_NOFOLLOW)
 2342                 return (EINVAL);
 2343 
 2344         return (kern_chflagsat(td, fd, path, UIO_USERSPACE, flags, atflag));
 2345 }
 2346 
 2347 /*
 2348  * Same as chflags() but doesn't follow symlinks.
 2349  */
 2350 #ifndef _SYS_SYSPROTO_H_
 2351 struct lchflags_args {
 2352         const char *path;
 2353         u_long flags;
 2354 };
 2355 #endif
 2356 int
 2357 sys_lchflags(struct thread *td, struct lchflags_args *uap)
 2358 {
 2359 
 2360         return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2361             uap->flags, AT_SYMLINK_NOFOLLOW));
 2362 }
 2363 
 2364 static int
 2365 kern_chflagsat(struct thread *td, int fd, const char *path,
 2366     enum uio_seg pathseg, u_long flags, int atflag)
 2367 {
 2368         struct nameidata nd;
 2369         cap_rights_t rights;
 2370         int error, follow;
 2371 
 2372         AUDIT_ARG_FFLAGS(flags);
 2373         follow = (atflag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2374         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2375             cap_rights_init(&rights, CAP_FCHFLAGS), td);
 2376         if ((error = namei(&nd)) != 0)
 2377                 return (error);
 2378         NDFREE(&nd, NDF_ONLY_PNBUF);
 2379         error = setfflags(td, nd.ni_vp, flags);
 2380         vrele(nd.ni_vp);
 2381         return (error);
 2382 }
 2383 
 2384 /*
 2385  * Change flags of a file given a file descriptor.
 2386  */
 2387 #ifndef _SYS_SYSPROTO_H_
 2388 struct fchflags_args {
 2389         int     fd;
 2390         u_long  flags;
 2391 };
 2392 #endif
 2393 int
 2394 sys_fchflags(struct thread *td, struct fchflags_args *uap)
 2395 {
 2396         struct file *fp;
 2397         cap_rights_t rights;
 2398         int error;
 2399 
 2400         AUDIT_ARG_FD(uap->fd);
 2401         AUDIT_ARG_FFLAGS(uap->flags);
 2402         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHFLAGS),
 2403             &fp);
 2404         if (error != 0)
 2405                 return (error);
 2406 #ifdef AUDIT
 2407         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2408         AUDIT_ARG_VNODE1(fp->f_vnode);
 2409         VOP_UNLOCK(fp->f_vnode, 0);
 2410 #endif
 2411         error = setfflags(td, fp->f_vnode, uap->flags);
 2412         fdrop(fp, td);
 2413         return (error);
 2414 }
 2415 
 2416 /*
 2417  * Common implementation code for chmod(), lchmod() and fchmod().
 2418  */
 2419 int
 2420 setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
 2421 {
 2422         struct mount *mp;
 2423         struct vattr vattr;
 2424         int error;
 2425 
 2426         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2427                 return (error);
 2428         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2429         VATTR_NULL(&vattr);
 2430         vattr.va_mode = mode & ALLPERMS;
 2431 #ifdef MAC
 2432         error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
 2433         if (error == 0)
 2434 #endif
 2435                 error = VOP_SETATTR(vp, &vattr, cred);
 2436         VOP_UNLOCK(vp, 0);
 2437         vn_finished_write(mp);
 2438         return (error);
 2439 }
 2440 
 2441 /*
 2442  * Change mode of a file given path name.
 2443  */
 2444 #ifndef _SYS_SYSPROTO_H_
 2445 struct chmod_args {
 2446         char    *path;
 2447         int     mode;
 2448 };
 2449 #endif
 2450 int
 2451 sys_chmod(struct thread *td, struct chmod_args *uap)
 2452 {
 2453 
 2454         return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2455             uap->mode, 0));
 2456 }
 2457 
 2458 #ifndef _SYS_SYSPROTO_H_
 2459 struct fchmodat_args {
 2460         int     dirfd;
 2461         char    *path;
 2462         mode_t  mode;
 2463         int     flag;
 2464 }
 2465 #endif
 2466 int
 2467 sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
 2468 {
 2469         int flag = uap->flag;
 2470         int fd = uap->fd;
 2471         char *path = uap->path;
 2472         mode_t mode = uap->mode;
 2473 
 2474         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2475                 return (EINVAL);
 2476 
 2477         return (kern_fchmodat(td, fd, path, UIO_USERSPACE, mode, flag));
 2478 }
 2479 
 2480 /*
 2481  * Change mode of a file given path name (don't follow links.)
 2482  */
 2483 #ifndef _SYS_SYSPROTO_H_
 2484 struct lchmod_args {
 2485         char    *path;
 2486         int     mode;
 2487 };
 2488 #endif
 2489 int
 2490 sys_lchmod(struct thread *td, struct lchmod_args *uap)
 2491 {
 2492 
 2493         return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2494             uap->mode, AT_SYMLINK_NOFOLLOW));
 2495 }
 2496 
 2497 int
 2498 kern_fchmodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2499     mode_t mode, int flag)
 2500 {
 2501         struct nameidata nd;
 2502         cap_rights_t rights;
 2503         int error, follow;
 2504 
 2505         AUDIT_ARG_MODE(mode);
 2506         follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2507         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2508             cap_rights_init(&rights, CAP_FCHMOD), td);
 2509         if ((error = namei(&nd)) != 0)
 2510                 return (error);
 2511         NDFREE(&nd, NDF_ONLY_PNBUF);
 2512         error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
 2513         vrele(nd.ni_vp);
 2514         return (error);
 2515 }
 2516 
 2517 /*
 2518  * Change mode of a file given a file descriptor.
 2519  */
 2520 #ifndef _SYS_SYSPROTO_H_
 2521 struct fchmod_args {
 2522         int     fd;
 2523         int     mode;
 2524 };
 2525 #endif
 2526 int
 2527 sys_fchmod(struct thread *td, struct fchmod_args *uap)
 2528 {
 2529         struct file *fp;
 2530         cap_rights_t rights;
 2531         int error;
 2532 
 2533         AUDIT_ARG_FD(uap->fd);
 2534         AUDIT_ARG_MODE(uap->mode);
 2535 
 2536         error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHMOD), &fp);
 2537         if (error != 0)
 2538                 return (error);
 2539         error = fo_chmod(fp, uap->mode, td->td_ucred, td);
 2540         fdrop(fp, td);
 2541         return (error);
 2542 }
 2543 
 2544 /*
 2545  * Common implementation for chown(), lchown(), and fchown()
 2546  */
 2547 int
 2548 setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
 2549     gid_t gid)
 2550 {
 2551         struct mount *mp;
 2552         struct vattr vattr;
 2553         int error;
 2554 
 2555         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2556                 return (error);
 2557         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2558         VATTR_NULL(&vattr);
 2559         vattr.va_uid = uid;
 2560         vattr.va_gid = gid;
 2561 #ifdef MAC
 2562         error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
 2563             vattr.va_gid);
 2564         if (error == 0)
 2565 #endif
 2566                 error = VOP_SETATTR(vp, &vattr, cred);
 2567         VOP_UNLOCK(vp, 0);
 2568         vn_finished_write(mp);
 2569         return (error);
 2570 }
 2571 
 2572 /*
 2573  * Set ownership given a path name.
 2574  */
 2575 #ifndef _SYS_SYSPROTO_H_
 2576 struct chown_args {
 2577         char    *path;
 2578         int     uid;
 2579         int     gid;
 2580 };
 2581 #endif
 2582 int
 2583 sys_chown(struct thread *td, struct chown_args *uap)
 2584 {
 2585 
 2586         return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
 2587             uap->gid, 0));
 2588 }
 2589 
 2590 #ifndef _SYS_SYSPROTO_H_
 2591 struct fchownat_args {
 2592         int fd;
 2593         const char * path;
 2594         uid_t uid;
 2595         gid_t gid;
 2596         int flag;
 2597 };
 2598 #endif
 2599 int
 2600 sys_fchownat(struct thread *td, struct fchownat_args *uap)
 2601 {
 2602         int flag;
 2603 
 2604         flag = uap->flag;
 2605         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2606                 return (EINVAL);
 2607 
 2608         return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
 2609             uap->gid, uap->flag));
 2610 }
 2611 
 2612 int
 2613 kern_fchownat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2614     int uid, int gid, int flag)
 2615 {
 2616         struct nameidata nd;
 2617         cap_rights_t rights;
 2618         int error, follow;
 2619 
 2620         AUDIT_ARG_OWNER(uid, gid);
 2621         follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2622         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2623             cap_rights_init(&rights, CAP_FCHOWN), td);
 2624 
 2625         if ((error = namei(&nd)) != 0)
 2626                 return (error);
 2627         NDFREE(&nd, NDF_ONLY_PNBUF);
 2628         error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
 2629         vrele(nd.ni_vp);
 2630         return (error);
 2631 }
 2632 
 2633 /*
 2634  * Set ownership given a path name, do not cross symlinks.
 2635  */
 2636 #ifndef _SYS_SYSPROTO_H_
 2637 struct lchown_args {
 2638         char    *path;
 2639         int     uid;
 2640         int     gid;
 2641 };
 2642 #endif
 2643 int
 2644 sys_lchown(struct thread *td, struct lchown_args *uap)
 2645 {
 2646 
 2647         return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2648             uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
 2649 }
 2650 
 2651 /*
 2652  * Set ownership given a file descriptor.
 2653  */
 2654 #ifndef _SYS_SYSPROTO_H_
 2655 struct fchown_args {
 2656         int     fd;
 2657         int     uid;
 2658         int     gid;
 2659 };
 2660 #endif
 2661 int
 2662 sys_fchown(struct thread *td, struct fchown_args *uap)
 2663 {
 2664         struct file *fp;
 2665         cap_rights_t rights;
 2666         int error;
 2667 
 2668         AUDIT_ARG_FD(uap->fd);
 2669         AUDIT_ARG_OWNER(uap->uid, uap->gid);
 2670         error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHOWN), &fp);
 2671         if (error != 0)
 2672                 return (error);
 2673         error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
 2674         fdrop(fp, td);
 2675         return (error);
 2676 }
 2677 
 2678 /*
 2679  * Common implementation code for utimes(), lutimes(), and futimes().
 2680  */
 2681 static int
 2682 getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
 2683     struct timespec *tsp)
 2684 {
 2685         struct timeval tv[2];
 2686         const struct timeval *tvp;
 2687         int error;
 2688 
 2689         if (usrtvp == NULL) {
 2690                 vfs_timestamp(&tsp[0]);
 2691                 tsp[1] = tsp[0];
 2692         } else {
 2693                 if (tvpseg == UIO_SYSSPACE) {
 2694                         tvp = usrtvp;
 2695                 } else {
 2696                         if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
 2697                                 return (error);
 2698                         tvp = tv;
 2699                 }
 2700 
 2701                 if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
 2702                     tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
 2703                         return (EINVAL);
 2704                 TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
 2705                 TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
 2706         }
 2707         return (0);
 2708 }
 2709 
 2710 /*
 2711  * Common implementation code for futimens(), utimensat().
 2712  */
 2713 #define UTIMENS_NULL    0x1
 2714 #define UTIMENS_EXIT    0x2
 2715 static int
 2716 getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
 2717     struct timespec *tsp, int *retflags)
 2718 {
 2719         struct timespec tsnow;
 2720         int error;
 2721 
 2722         vfs_timestamp(&tsnow);
 2723         *retflags = 0;
 2724         if (usrtsp == NULL) {
 2725                 tsp[0] = tsnow;
 2726                 tsp[1] = tsnow;
 2727                 *retflags |= UTIMENS_NULL;
 2728                 return (0);
 2729         }
 2730         if (tspseg == UIO_SYSSPACE) {
 2731                 tsp[0] = usrtsp[0];
 2732                 tsp[1] = usrtsp[1];
 2733         } else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
 2734                 return (error);
 2735         if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
 2736                 *retflags |= UTIMENS_EXIT;
 2737         if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
 2738                 *retflags |= UTIMENS_NULL;
 2739         if (tsp[0].tv_nsec == UTIME_OMIT)
 2740                 tsp[0].tv_sec = VNOVAL;
 2741         else if (tsp[0].tv_nsec == UTIME_NOW)
 2742                 tsp[0] = tsnow;
 2743         else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
 2744                 return (EINVAL);
 2745         if (tsp[1].tv_nsec == UTIME_OMIT)
 2746                 tsp[1].tv_sec = VNOVAL;
 2747         else if (tsp[1].tv_nsec == UTIME_NOW)
 2748                 tsp[1] = tsnow;
 2749         else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
 2750                 return (EINVAL);
 2751 
 2752         return (0);
 2753 }
 2754 
 2755 /*
 2756  * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
 2757  * and utimensat().
 2758  */
 2759 static int
 2760 setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
 2761     int numtimes, int nullflag)
 2762 {
 2763         struct mount *mp;
 2764         struct vattr vattr;
 2765         int error, setbirthtime;
 2766 
 2767         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2768                 return (error);
 2769         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2770         setbirthtime = 0;
 2771         if (numtimes < 3 && !VOP_GETATTR(vp, &vattr, td->td_ucred) &&
 2772             timespeccmp(&ts[1], &vattr.va_birthtime, < ))
 2773                 setbirthtime = 1;
 2774         VATTR_NULL(&vattr);
 2775         vattr.va_atime = ts[0];
 2776         vattr.va_mtime = ts[1];
 2777         if (setbirthtime)
 2778                 vattr.va_birthtime = ts[1];
 2779         if (numtimes > 2)
 2780                 vattr.va_birthtime = ts[2];
 2781         if (nullflag)
 2782                 vattr.va_vaflags |= VA_UTIMES_NULL;
 2783 #ifdef MAC
 2784         error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
 2785             vattr.va_mtime);
 2786 #endif
 2787         if (error == 0)
 2788                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 2789         VOP_UNLOCK(vp, 0);
 2790         vn_finished_write(mp);
 2791         return (error);
 2792 }
 2793 
 2794 /*
 2795  * Set the access and modification times of a file.
 2796  */
 2797 #ifndef _SYS_SYSPROTO_H_
 2798 struct utimes_args {
 2799         char    *path;
 2800         struct  timeval *tptr;
 2801 };
 2802 #endif
 2803 int
 2804 sys_utimes(struct thread *td, struct utimes_args *uap)
 2805 {
 2806 
 2807         return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2808             uap->tptr, UIO_USERSPACE));
 2809 }
 2810 
 2811 #ifndef _SYS_SYSPROTO_H_
 2812 struct futimesat_args {
 2813         int fd;
 2814         const char * path;
 2815         const struct timeval * times;
 2816 };
 2817 #endif
 2818 int
 2819 sys_futimesat(struct thread *td, struct futimesat_args *uap)
 2820 {
 2821 
 2822         return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
 2823             uap->times, UIO_USERSPACE));
 2824 }
 2825 
 2826 int
 2827 kern_utimesat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2828     struct timeval *tptr, enum uio_seg tptrseg)
 2829 {
 2830         struct nameidata nd;
 2831         struct timespec ts[2];
 2832         cap_rights_t rights;
 2833         int error;
 2834 
 2835         if ((error = getutimes(tptr, tptrseg, ts)) != 0)
 2836                 return (error);
 2837         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
 2838             cap_rights_init(&rights, CAP_FUTIMES), td);
 2839 
 2840         if ((error = namei(&nd)) != 0)
 2841                 return (error);
 2842         NDFREE(&nd, NDF_ONLY_PNBUF);
 2843         error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
 2844         vrele(nd.ni_vp);
 2845         return (error);
 2846 }
 2847 
 2848 /*
 2849  * Set the access and modification times of a file.
 2850  */
 2851 #ifndef _SYS_SYSPROTO_H_
 2852 struct lutimes_args {
 2853         char    *path;
 2854         struct  timeval *tptr;
 2855 };
 2856 #endif
 2857 int
 2858 sys_lutimes(struct thread *td, struct lutimes_args *uap)
 2859 {
 2860 
 2861         return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
 2862             UIO_USERSPACE));
 2863 }
 2864 
 2865 int
 2866 kern_lutimes(struct thread *td, char *path, enum uio_seg pathseg,
 2867     struct timeval *tptr, enum uio_seg tptrseg)
 2868 {
 2869         struct timespec ts[2];
 2870         struct nameidata nd;
 2871         int error;
 2872 
 2873         if ((error = getutimes(tptr, tptrseg, ts)) != 0)
 2874                 return (error);
 2875         NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td);
 2876         if ((error = namei(&nd)) != 0)
 2877                 return (error);
 2878         NDFREE(&nd, NDF_ONLY_PNBUF);
 2879         error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
 2880         vrele(nd.ni_vp);
 2881         return (error);
 2882 }
 2883 
 2884 /*
 2885  * Set the access and modification times of a file.
 2886  */
 2887 #ifndef _SYS_SYSPROTO_H_
 2888 struct futimes_args {
 2889         int     fd;
 2890         struct  timeval *tptr;
 2891 };
 2892 #endif
 2893 int
 2894 sys_futimes(struct thread *td, struct futimes_args *uap)
 2895 {
 2896 
 2897         return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
 2898 }
 2899 
 2900 int
 2901 kern_futimes(struct thread *td, int fd, struct timeval *tptr,
 2902     enum uio_seg tptrseg)
 2903 {
 2904         struct timespec ts[2];
 2905         struct file *fp;
 2906         cap_rights_t rights;
 2907         int error;
 2908 
 2909         AUDIT_ARG_FD(fd);
 2910         error = getutimes(tptr, tptrseg, ts);
 2911         if (error != 0)
 2912                 return (error);
 2913         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
 2914         if (error != 0)
 2915                 return (error);
 2916 #ifdef AUDIT
 2917         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2918         AUDIT_ARG_VNODE1(fp->f_vnode);
 2919         VOP_UNLOCK(fp->f_vnode, 0);
 2920 #endif
 2921         error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
 2922         fdrop(fp, td);
 2923         return (error);
 2924 }
 2925 
 2926 int
 2927 sys_futimens(struct thread *td, struct futimens_args *uap)
 2928 {
 2929 
 2930         return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
 2931 }
 2932 
 2933 int
 2934 kern_futimens(struct thread *td, int fd, struct timespec *tptr,
 2935     enum uio_seg tptrseg)
 2936 {
 2937         struct timespec ts[2];
 2938         struct file *fp;
 2939         cap_rights_t rights;
 2940         int error, flags;
 2941 
 2942         AUDIT_ARG_FD(fd);
 2943         error = getutimens(tptr, tptrseg, ts, &flags);
 2944         if (error != 0)
 2945                 return (error);
 2946         if (flags & UTIMENS_EXIT)
 2947                 return (0);
 2948         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
 2949         if (error != 0)
 2950                 return (error);
 2951 #ifdef AUDIT
 2952         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2953         AUDIT_ARG_VNODE1(fp->f_vnode);
 2954         VOP_UNLOCK(fp->f_vnode, 0);
 2955 #endif
 2956         error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
 2957         fdrop(fp, td);
 2958         return (error);
 2959 }
 2960 
 2961 int
 2962 sys_utimensat(struct thread *td, struct utimensat_args *uap)
 2963 {
 2964 
 2965         return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
 2966             uap->times, UIO_USERSPACE, uap->flag));
 2967 }
 2968 
 2969 int
 2970 kern_utimensat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2971     struct timespec *tptr, enum uio_seg tptrseg, int flag)
 2972 {
 2973         struct nameidata nd;
 2974         struct timespec ts[2];
 2975         cap_rights_t rights;
 2976         int error, flags;
 2977 
 2978         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2979                 return (EINVAL);
 2980 
 2981         if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
 2982                 return (error);
 2983         NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
 2984             FOLLOW) | AUDITVNODE1, pathseg, path, fd,
 2985             cap_rights_init(&rights, CAP_FUTIMES), td);
 2986         if ((error = namei(&nd)) != 0)
 2987                 return (error);
 2988         /*
 2989          * We are allowed to call namei() regardless of 2xUTIME_OMIT.
 2990          * POSIX states:
 2991          * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
 2992          * "Search permission is denied by a component of the path prefix."
 2993          */
 2994         NDFREE(&nd, NDF_ONLY_PNBUF);
 2995         if ((flags & UTIMENS_EXIT) == 0)
 2996                 error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
 2997         vrele(nd.ni_vp);
 2998         return (error);
 2999 }
 3000 
 3001 /*
 3002  * Truncate a file given its path name.
 3003  */
 3004 #ifndef _SYS_SYSPROTO_H_
 3005 struct truncate_args {
 3006         char    *path;
 3007         int     pad;
 3008         off_t   length;
 3009 };
 3010 #endif
 3011 int
 3012 sys_truncate(struct thread *td, struct truncate_args *uap)
 3013 {
 3014 
 3015         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3016 }
 3017 
 3018 int
 3019 kern_truncate(struct thread *td, char *path, enum uio_seg pathseg, off_t length)
 3020 {
 3021         struct mount *mp;
 3022         struct vnode *vp;
 3023         void *rl_cookie;
 3024         struct vattr vattr;
 3025         struct nameidata nd;
 3026         int error;
 3027 
 3028         if (length < 0)
 3029                 return(EINVAL);
 3030         NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
 3031         if ((error = namei(&nd)) != 0)
 3032                 return (error);
 3033         vp = nd.ni_vp;
 3034         rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
 3035         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) {
 3036                 vn_rangelock_unlock(vp, rl_cookie);
 3037                 vrele(vp);
 3038                 return (error);
 3039         }
 3040         NDFREE(&nd, NDF_ONLY_PNBUF);
 3041         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 3042         if (vp->v_type == VDIR)
 3043                 error = EISDIR;
 3044 #ifdef MAC
 3045         else if ((error = mac_vnode_check_write(td->td_ucred, NOCRED, vp))) {
 3046         }
 3047 #endif
 3048         else if ((error = vn_writechk(vp)) == 0 &&
 3049             (error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td)) == 0) {
 3050                 VATTR_NULL(&vattr);
 3051                 vattr.va_size = length;
 3052                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 3053         }
 3054         VOP_UNLOCK(vp, 0);
 3055         vn_finished_write(mp);
 3056         vn_rangelock_unlock(vp, rl_cookie);
 3057         vrele(vp);
 3058         return (error);
 3059 }
 3060 
 3061 #if defined(COMPAT_43)
 3062 /*
 3063  * Truncate a file given its path name.
 3064  */
 3065 #ifndef _SYS_SYSPROTO_H_
 3066 struct otruncate_args {
 3067         char    *path;
 3068         long    length;
 3069 };
 3070 #endif
 3071 int
 3072 otruncate(struct thread *td, struct otruncate_args *uap)
 3073 {
 3074 
 3075         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3076 }
 3077 #endif /* COMPAT_43 */
 3078 
 3079 #if defined(COMPAT_FREEBSD6)
 3080 /* Versions with the pad argument */
 3081 int
 3082 freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
 3083 {
 3084 
 3085         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3086 }
 3087 
 3088 int
 3089 freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
 3090 {
 3091 
 3092         return (kern_ftruncate(td, uap->fd, uap->length));
 3093 }
 3094 #endif
 3095 
 3096 int
 3097 kern_fsync(struct thread *td, int fd, bool fullsync)
 3098 {
 3099         struct vnode *vp;
 3100         struct mount *mp;
 3101         struct file *fp;
 3102         cap_rights_t rights;
 3103         int error, lock_flags;
 3104 
 3105         AUDIT_ARG_FD(fd);
 3106         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSYNC), &fp);
 3107         if (error != 0)
 3108                 return (error);
 3109         vp = fp->f_vnode;
 3110 #if 0
 3111         if (!fullsync)
 3112                 /* XXXKIB: compete outstanding aio writes */;
 3113 #endif
 3114         error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
 3115         if (error != 0)
 3116                 goto drop;
 3117         if (MNT_SHARED_WRITES(mp) ||
 3118             ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) {
 3119                 lock_flags = LK_SHARED;
 3120         } else {
 3121                 lock_flags = LK_EXCLUSIVE;
 3122         }
 3123         vn_lock(vp, lock_flags | LK_RETRY);
 3124         AUDIT_ARG_VNODE1(vp);
 3125         if (vp->v_object != NULL) {
 3126                 VM_OBJECT_WLOCK(vp->v_object);
 3127                 vm_object_page_clean(vp->v_object, 0, 0, 0);
 3128                 VM_OBJECT_WUNLOCK(vp->v_object);
 3129         }
 3130         error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
 3131         VOP_UNLOCK(vp, 0);
 3132         vn_finished_write(mp);
 3133 drop:
 3134         fdrop(fp, td);
 3135         return (error);
 3136 }
 3137 
 3138 /*
 3139  * Sync an open file.
 3140  */
 3141 #ifndef _SYS_SYSPROTO_H_
 3142 struct fsync_args {
 3143         int     fd;
 3144 };
 3145 #endif
 3146 int
 3147 sys_fsync(struct thread *td, struct fsync_args *uap)
 3148 {
 3149 
 3150         return (kern_fsync(td, uap->fd, true));
 3151 }
 3152 
 3153 int
 3154 sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
 3155 {
 3156 
 3157         return (kern_fsync(td, uap->fd, false));
 3158 }
 3159 
 3160 /*
 3161  * Rename files.  Source and destination must either both be directories, or
 3162  * both not be directories.  If target is a directory, it must be empty.
 3163  */
 3164 #ifndef _SYS_SYSPROTO_H_
 3165 struct rename_args {
 3166         char    *from;
 3167         char    *to;
 3168 };
 3169 #endif
 3170 int
 3171 sys_rename(struct thread *td, struct rename_args *uap)
 3172 {
 3173 
 3174         return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
 3175             uap->to, UIO_USERSPACE));
 3176 }
 3177 
 3178 #ifndef _SYS_SYSPROTO_H_
 3179 struct renameat_args {
 3180         int     oldfd;
 3181         char    *old;
 3182         int     newfd;
 3183         char    *new;
 3184 };
 3185 #endif
 3186 int
 3187 sys_renameat(struct thread *td, struct renameat_args *uap)
 3188 {
 3189 
 3190         return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
 3191             UIO_USERSPACE));
 3192 }
 3193 
 3194 int
 3195 kern_renameat(struct thread *td, int oldfd, char *old, int newfd, char *new,
 3196     enum uio_seg pathseg)
 3197 {
 3198         struct mount *mp = NULL;
 3199         struct vnode *tvp, *fvp, *tdvp;
 3200         struct nameidata fromnd, tond;
 3201         cap_rights_t rights;
 3202         int error;
 3203 
 3204 again:
 3205         bwillwrite();
 3206 #ifdef MAC
 3207         NDINIT_ATRIGHTS(&fromnd, DELETE, LOCKPARENT | LOCKLEAF | SAVESTART |
 3208             AUDITVNODE1, pathseg, old, oldfd,
 3209             cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
 3210 #else
 3211         NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | SAVESTART | AUDITVNODE1,
 3212             pathseg, old, oldfd,
 3213             cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
 3214 #endif
 3215 
 3216         if ((error = namei(&fromnd)) != 0)
 3217                 return (error);
 3218 #ifdef MAC
 3219         error = mac_vnode_check_rename_from(td->td_ucred, fromnd.ni_dvp,
 3220             fromnd.ni_vp, &fromnd.ni_cnd);
 3221         VOP_UNLOCK(fromnd.ni_dvp, 0);
 3222         if (fromnd.ni_dvp != fromnd.ni_vp)
 3223                 VOP_UNLOCK(fromnd.ni_vp, 0);
 3224 #endif
 3225         fvp = fromnd.ni_vp;
 3226         NDINIT_ATRIGHTS(&tond, RENAME, LOCKPARENT | LOCKLEAF | NOCACHE |
 3227             SAVESTART | AUDITVNODE2, pathseg, new, newfd,
 3228             cap_rights_init(&rights, CAP_RENAMEAT_TARGET), td);
 3229         if (fromnd.ni_vp->v_type == VDIR)
 3230                 tond.ni_cnd.cn_flags |= WILLBEDIR;
 3231         if ((error = namei(&tond)) != 0) {
 3232                 /* Translate error code for rename("dir1", "dir2/."). */
 3233                 if (error == EISDIR && fvp->v_type == VDIR)
 3234                         error = EINVAL;
 3235                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3236                 vrele(fromnd.ni_dvp);
 3237                 vrele(fvp);
 3238                 goto out1;
 3239         }
 3240         tdvp = tond.ni_dvp;
 3241         tvp = tond.ni_vp;
 3242         error = vn_start_write(fvp, &mp, V_NOWAIT);
 3243         if (error != 0) {
 3244                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3245                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3246                 if (tvp != NULL)
 3247                         vput(tvp);
 3248                 if (tdvp == tvp)
 3249                         vrele(tdvp);
 3250                 else
 3251                         vput(tdvp);
 3252                 vrele(fromnd.ni_dvp);
 3253                 vrele(fvp);
 3254                 vrele(tond.ni_startdir);
 3255                 if (fromnd.ni_startdir != NULL)
 3256                         vrele(fromnd.ni_startdir);
 3257                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
 3258                 if (error != 0)
 3259                         return (error);
 3260                 goto again;
 3261         }
 3262         if (tvp != NULL) {
 3263                 if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
 3264                         error = ENOTDIR;
 3265                         goto out;
 3266                 } else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
 3267                         error = EISDIR;
 3268                         goto out;
 3269                 }
 3270 #ifdef CAPABILITIES
 3271                 if (newfd != AT_FDCWD) {
 3272                         /*
 3273                          * If the target already exists we require CAP_UNLINKAT
 3274                          * from 'newfd'.
 3275                          */
 3276                         error = cap_check(&tond.ni_filecaps.fc_rights,
 3277                             cap_rights_init(&rights, CAP_UNLINKAT));
 3278                         if (error != 0)
 3279                                 goto out;
 3280                 }
 3281 #endif
 3282         }
 3283         if (fvp == tdvp) {
 3284                 error = EINVAL;
 3285                 goto out;
 3286         }
 3287         /*
 3288          * If the source is the same as the destination (that is, if they
 3289          * are links to the same vnode), then there is nothing to do.
 3290          */
 3291         if (fvp == tvp)
 3292                 error = -1;
 3293 #ifdef MAC
 3294         else
 3295                 error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
 3296                     tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
 3297 #endif
 3298 out:
 3299         if (error == 0) {
 3300                 error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
 3301                     tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
 3302                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3303                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3304         } else {
 3305                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3306                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3307                 if (tvp != NULL)
 3308                         vput(tvp);
 3309                 if (tdvp == tvp)
 3310                         vrele(tdvp);
 3311                 else
 3312                         vput(tdvp);
 3313                 vrele(fromnd.ni_dvp);
 3314                 vrele(fvp);
 3315         }
 3316         vrele(tond.ni_startdir);
 3317         vn_finished_write(mp);
 3318 out1:
 3319         if (fromnd.ni_startdir)
 3320                 vrele(fromnd.ni_startdir);
 3321         if (error == -1)
 3322                 return (0);
 3323         return (error);
 3324 }
 3325 
 3326 /*
 3327  * Make a directory file.
 3328  */
 3329 #ifndef _SYS_SYSPROTO_H_
 3330 struct mkdir_args {
 3331         char    *path;
 3332         int     mode;
 3333 };
 3334 #endif
 3335 int
 3336 sys_mkdir(struct thread *td, struct mkdir_args *uap)
 3337 {
 3338 
 3339         return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 3340             uap->mode));
 3341 }
 3342 
 3343 #ifndef _SYS_SYSPROTO_H_
 3344 struct mkdirat_args {
 3345         int     fd;
 3346         char    *path;
 3347         mode_t  mode;
 3348 };
 3349 #endif
 3350 int
 3351 sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
 3352 {
 3353 
 3354         return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
 3355 }
 3356 
 3357 int
 3358 kern_mkdirat(struct thread *td, int fd, char *path, enum uio_seg segflg,
 3359     int mode)
 3360 {
 3361         struct mount *mp;
 3362         struct vnode *vp;
 3363         struct vattr vattr;
 3364         struct nameidata nd;
 3365         cap_rights_t rights;
 3366         int error;
 3367 
 3368         AUDIT_ARG_MODE(mode);
 3369 restart:
 3370         bwillwrite();
 3371         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 3372             NOCACHE, segflg, path, fd, cap_rights_init(&rights, CAP_MKDIRAT),
 3373             td);
 3374         nd.ni_cnd.cn_flags |= WILLBEDIR;
 3375         if ((error = namei(&nd)) != 0)
 3376                 return (error);
 3377         vp = nd.ni_vp;
 3378         if (vp != NULL) {
 3379                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3380                 /*
 3381                  * XXX namei called with LOCKPARENT but not LOCKLEAF has
 3382                  * the strange behaviour of leaving the vnode unlocked
 3383                  * if the target is the same vnode as the parent.
 3384                  */
 3385                 if (vp == nd.ni_dvp)
 3386                         vrele(nd.ni_dvp);
 3387                 else
 3388                         vput(nd.ni_dvp);
 3389                 vrele(vp);
 3390                 return (EEXIST);
 3391         }
 3392         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 3393                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3394                 vput(nd.ni_dvp);
 3395                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3396                         return (error);
 3397                 goto restart;
 3398         }
 3399         VATTR_NULL(&vattr);
 3400         vattr.va_type = VDIR;
 3401         vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_fd->fd_cmask;
 3402 #ifdef MAC
 3403         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 3404             &vattr);
 3405         if (error != 0)
 3406                 goto out;
 3407 #endif
 3408         error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 3409 #ifdef MAC
 3410 out:
 3411 #endif
 3412         NDFREE(&nd, NDF_ONLY_PNBUF);
 3413         vput(nd.ni_dvp);
 3414         if (error == 0)
 3415                 vput(nd.ni_vp);
 3416         vn_finished_write(mp);
 3417         return (error);
 3418 }
 3419 
 3420 /*
 3421  * Remove a directory file.
 3422  */
 3423 #ifndef _SYS_SYSPROTO_H_
 3424 struct rmdir_args {
 3425         char    *path;
 3426 };
 3427 #endif
 3428 int
 3429 sys_rmdir(struct thread *td, struct rmdir_args *uap)
 3430 {
 3431 
 3432         return (kern_rmdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE));
 3433 }
 3434 
 3435 int
 3436 kern_rmdirat(struct thread *td, int fd, char *path, enum uio_seg pathseg)
 3437 {
 3438         struct mount *mp;
 3439         struct vnode *vp;
 3440         struct nameidata nd;
 3441         cap_rights_t rights;
 3442         int error;
 3443 
 3444 restart:
 3445         bwillwrite();
 3446         NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
 3447             pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
 3448         if ((error = namei(&nd)) != 0)
 3449                 return (error);
 3450         vp = nd.ni_vp;
 3451         if (vp->v_type != VDIR) {
 3452                 error = ENOTDIR;
 3453                 goto out;
 3454         }
 3455         /*
 3456          * No rmdir "." please.
 3457          */
 3458         if (nd.ni_dvp == vp) {
 3459                 error = EINVAL;
 3460                 goto out;
 3461         }
 3462         /*
 3463          * The root of a mounted filesystem cannot be deleted.
 3464          */
 3465         if (vp->v_vflag & VV_ROOT) {
 3466                 error = EBUSY;
 3467                 goto out;
 3468         }
 3469 #ifdef MAC
 3470         error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
 3471             &nd.ni_cnd);
 3472         if (error != 0)
 3473                 goto out;
 3474 #endif
 3475         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 3476                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3477                 vput(vp);
 3478                 if (nd.ni_dvp == vp)
 3479                         vrele(nd.ni_dvp);
 3480                 else
 3481                         vput(nd.ni_dvp);
 3482                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3483                         return (error);
 3484                 goto restart;
 3485         }
 3486         vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
 3487         error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
 3488         vn_finished_write(mp);
 3489 out:
 3490         NDFREE(&nd, NDF_ONLY_PNBUF);
 3491         vput(vp);
 3492         if (nd.ni_dvp == vp)
 3493                 vrele(nd.ni_dvp);
 3494         else
 3495                 vput(nd.ni_dvp);
 3496         return (error);
 3497 }
 3498 
 3499 #ifdef COMPAT_43
 3500 /*
 3501  * Read a block of directory entries in a filesystem independent format.
 3502  */
 3503 #ifndef _SYS_SYSPROTO_H_
 3504 struct ogetdirentries_args {
 3505         int     fd;
 3506         char    *buf;
 3507         u_int   count;
 3508         long    *basep;
 3509 };
 3510 #endif
 3511 int
 3512 ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
 3513 {
 3514         long loff;
 3515         int error;
 3516 
 3517         error = kern_ogetdirentries(td, uap, &loff);
 3518         if (error == 0)
 3519                 error = copyout(&loff, uap->basep, sizeof(long));
 3520         return (error);
 3521 }
 3522 
 3523 int
 3524 kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
 3525     long *ploff)
 3526 {
 3527         struct vnode *vp;
 3528         struct file *fp;
 3529         struct uio auio, kuio;
 3530         struct iovec aiov, kiov;
 3531         struct dirent *dp, *edp;
 3532         cap_rights_t rights;
 3533         caddr_t dirbuf;
 3534         int error, eofflag, readcnt;
 3535         long loff;
 3536         off_t foffset;
 3537 
 3538         /* XXX arbitrary sanity limit on `count'. */
 3539         if (uap->count > 64 * 1024)
 3540                 return (EINVAL);
 3541         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_READ), &fp);
 3542         if (error != 0)
 3543                 return (error);
 3544         if ((fp->f_flag & FREAD) == 0) {
 3545                 fdrop(fp, td);
 3546                 return (EBADF);
 3547         }
 3548         vp = fp->f_vnode;
 3549         foffset = foffset_lock(fp, 0);
 3550 unionread:
 3551         if (vp->v_type != VDIR) {
 3552                 foffset_unlock(fp, foffset, 0);
 3553                 fdrop(fp, td);
 3554                 return (EINVAL);
 3555         }
 3556         aiov.iov_base = uap->buf;
 3557         aiov.iov_len = uap->count;
 3558         auio.uio_iov = &aiov;
 3559         auio.uio_iovcnt = 1;
 3560         auio.uio_rw = UIO_READ;
 3561         auio.uio_segflg = UIO_USERSPACE;
 3562         auio.uio_td = td;
 3563         auio.uio_resid = uap->count;
 3564         vn_lock(vp, LK_SHARED | LK_RETRY);
 3565         loff = auio.uio_offset = foffset;
 3566 #ifdef MAC
 3567         error = mac_vnode_check_readdir(td->td_ucred, vp);
 3568         if (error != 0) {
 3569                 VOP_UNLOCK(vp, 0);
 3570                 foffset_unlock(fp, foffset, FOF_NOUPDATE);
 3571                 fdrop(fp, td);
 3572                 return (error);
 3573         }
 3574 #endif
 3575 #       if (BYTE_ORDER != LITTLE_ENDIAN)
 3576                 if (vp->v_mount->mnt_maxsymlinklen <= 0) {
 3577                         error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag,
 3578                             NULL, NULL);
 3579                         foffset = auio.uio_offset;
 3580                 } else
 3581 #       endif
 3582         {
 3583                 kuio = auio;
 3584                 kuio.uio_iov = &kiov;
 3585                 kuio.uio_segflg = UIO_SYSSPACE;
 3586                 kiov.iov_len = uap->count;
 3587                 dirbuf = malloc(uap->count, M_TEMP, M_WAITOK);
 3588                 kiov.iov_base = dirbuf;
 3589                 error = VOP_READDIR(vp, &kuio, fp->f_cred, &eofflag,
 3590                             NULL, NULL);
 3591                 foffset = kuio.uio_offset;
 3592                 if (error == 0) {
 3593                         readcnt = uap->count - kuio.uio_resid;
 3594                         edp = (struct dirent *)&dirbuf[readcnt];
 3595                         for (dp = (struct dirent *)dirbuf; dp < edp; ) {
 3596 #                               if (BYTE_ORDER == LITTLE_ENDIAN)
 3597                                         /*
 3598                                          * The expected low byte of
 3599                                          * dp->d_namlen is our dp->d_type.
 3600                                          * The high MBZ byte of dp->d_namlen
 3601                                          * is our dp->d_namlen.
 3602                                          */
 3603                                         dp->d_type = dp->d_namlen;
 3604                                         dp->d_namlen = 0;
 3605 #                               else
 3606                                         /*
 3607                                          * The dp->d_type is the high byte
 3608                                          * of the expected dp->d_namlen,
 3609                                          * so must be zero'ed.
 3610                                          */
 3611                                         dp->d_type = 0;
 3612 #                               endif
 3613                                 if (dp->d_reclen > 0) {
 3614                                         dp = (struct dirent *)
 3615                                             ((char *)dp + dp->d_reclen);
 3616                                 } else {
 3617                                         error = EIO;
 3618                                         break;
 3619                                 }
 3620                         }
 3621                         if (dp >= edp)
 3622                                 error = uiomove(dirbuf, readcnt, &auio);
 3623                 }
 3624                 free(dirbuf, M_TEMP);
 3625         }
 3626         if (error != 0) {
 3627                 VOP_UNLOCK(vp, 0);
 3628                 foffset_unlock(fp, foffset, 0);
 3629                 fdrop(fp, td);
 3630                 return (error);
 3631         }
 3632         if (uap->count == auio.uio_resid &&
 3633             (vp->v_vflag & VV_ROOT) &&
 3634             (vp->v_mount->mnt_flag & MNT_UNION)) {
 3635                 struct vnode *tvp = vp;
 3636                 vp = vp->v_mount->mnt_vnodecovered;
 3637                 VREF(vp);
 3638                 fp->f_vnode = vp;
 3639                 fp->f_data = vp;
 3640                 foffset = 0;
 3641                 vput(tvp);
 3642                 goto unionread;
 3643         }
 3644         VOP_UNLOCK(vp, 0);
 3645         foffset_unlock(fp, foffset, 0);
 3646         fdrop(fp, td);
 3647         td->td_retval[0] = uap->count - auio.uio_resid;
 3648         if (error == 0)
 3649                 *ploff = loff;
 3650         return (error);
 3651 }
 3652 #endif /* COMPAT_43 */
 3653 
 3654 /*
 3655  * Read a block of directory entries in a filesystem independent format.
 3656  */
 3657 #ifndef _SYS_SYSPROTO_H_
 3658 struct getdirentries_args {
 3659         int     fd;
 3660         char    *buf;
 3661         u_int   count;
 3662         long    *basep;
 3663 };
 3664 #endif
 3665 int
 3666 sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
 3667 {
 3668         long base;
 3669         int error;
 3670 
 3671         error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
 3672             NULL, UIO_USERSPACE);
 3673         if (error != 0)
 3674                 return (error);
 3675         if (uap->basep != NULL)
 3676                 error = copyout(&base, uap->basep, sizeof(long));
 3677         return (error);
 3678 }
 3679 
 3680 int
 3681 kern_getdirentries(struct thread *td, int fd, char *buf, u_int count,
 3682     long *basep, ssize_t *residp, enum uio_seg bufseg)
 3683 {
 3684         struct vnode *vp;
 3685         struct file *fp;
 3686         struct uio auio;
 3687         struct iovec aiov;
 3688         cap_rights_t rights;
 3689         long loff;
 3690         int error, eofflag;
 3691         off_t foffset;
 3692 
 3693         AUDIT_ARG_FD(fd);
 3694         if (count > IOSIZE_MAX)
 3695                 return (EINVAL);
 3696         auio.uio_resid = count;
 3697         error = getvnode(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
 3698         if (error != 0)
 3699                 return (error);
 3700         if ((fp->f_flag & FREAD) == 0) {
 3701                 fdrop(fp, td);
 3702                 return (EBADF);
 3703         }
 3704         vp = fp->f_vnode;
 3705         foffset = foffset_lock(fp, 0);
 3706 unionread:
 3707         if (vp->v_type != VDIR) {
 3708                 error = EINVAL;
 3709                 goto fail;
 3710         }
 3711         aiov.iov_base = buf;
 3712         aiov.iov_len = count;
 3713         auio.uio_iov = &aiov;
 3714         auio.uio_iovcnt = 1;
 3715         auio.uio_rw = UIO_READ;
 3716         auio.uio_segflg = bufseg;
 3717         auio.uio_td = td;
 3718         vn_lock(vp, LK_SHARED | LK_RETRY);
 3719         AUDIT_ARG_VNODE1(vp);
 3720         loff = auio.uio_offset = foffset;
 3721 #ifdef MAC
 3722         error = mac_vnode_check_readdir(td->td_ucred, vp);
 3723         if (error == 0)
 3724 #endif
 3725                 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
 3726                     NULL);
 3727         foffset = auio.uio_offset;
 3728         if (error != 0) {
 3729                 VOP_UNLOCK(vp, 0);
 3730                 goto fail;
 3731         }
 3732         if (count == auio.uio_resid &&
 3733             (vp->v_vflag & VV_ROOT) &&
 3734             (vp->v_mount->mnt_flag & MNT_UNION)) {
 3735                 struct vnode *tvp = vp;
 3736 
 3737                 vp = vp->v_mount->mnt_vnodecovered;
 3738                 VREF(vp);
 3739                 fp->f_vnode = vp;
 3740                 fp->f_data = vp;
 3741                 foffset = 0;
 3742                 vput(tvp);
 3743                 goto unionread;
 3744         }
 3745         VOP_UNLOCK(vp, 0);
 3746         *basep = loff;
 3747         if (residp != NULL)
 3748                 *residp = auio.uio_resid;
 3749         td->td_retval[0] = count - auio.uio_resid;
 3750 fail:
 3751         foffset_unlock(fp, foffset, 0);
 3752         fdrop(fp, td);
 3753         return (error);
 3754 }
 3755 
 3756 #ifndef _SYS_SYSPROTO_H_
 3757 struct getdents_args {
 3758         int fd;
 3759         char *buf;
 3760         size_t count;
 3761 };
 3762 #endif
 3763 int
 3764 sys_getdents(struct thread *td, struct getdents_args *uap)
 3765 {
 3766         struct getdirentries_args ap;
 3767 
 3768         ap.fd = uap->fd;
 3769         ap.buf = uap->buf;
 3770         ap.count = uap->count;
 3771         ap.basep = NULL;
 3772         return (sys_getdirentries(td, &ap));
 3773 }
 3774 
 3775 /*
 3776  * Set the mode mask for creation of filesystem nodes.
 3777  */
 3778 #ifndef _SYS_SYSPROTO_H_
 3779 struct umask_args {
 3780         int     newmask;
 3781 };
 3782 #endif
 3783 int
 3784 sys_umask(struct thread *td, struct umask_args *uap)
 3785 {
 3786         struct filedesc *fdp;
 3787 
 3788         fdp = td->td_proc->p_fd;
 3789         FILEDESC_XLOCK(fdp);
 3790         td->td_retval[0] = fdp->fd_cmask;
 3791         fdp->fd_cmask = uap->newmask & ALLPERMS;
 3792         FILEDESC_XUNLOCK(fdp);
 3793         return (0);
 3794 }
 3795 
 3796 /*
 3797  * Void all references to file by ripping underlying filesystem away from
 3798  * vnode.
 3799  */
 3800 #ifndef _SYS_SYSPROTO_H_
 3801 struct revoke_args {
 3802         char    *path;
 3803 };
 3804 #endif
 3805 int
 3806 sys_revoke(struct thread *td, struct revoke_args *uap)
 3807 {
 3808         struct vnode *vp;
 3809         struct vattr vattr;
 3810         struct nameidata nd;
 3811         int error;
 3812 
 3813         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3814             uap->path, td);
 3815         if ((error = namei(&nd)) != 0)
 3816                 return (error);
 3817         vp = nd.ni_vp;
 3818         NDFREE(&nd, NDF_ONLY_PNBUF);
 3819         if (vp->v_type != VCHR || vp->v_rdev == NULL) {
 3820                 error = EINVAL;
 3821                 goto out;
 3822         }
 3823 #ifdef MAC
 3824         error = mac_vnode_check_revoke(td->td_ucred, vp);
 3825         if (error != 0)
 3826                 goto out;
 3827 #endif
 3828         error = VOP_GETATTR(vp, &vattr, td->td_ucred);
 3829         if (error != 0)
 3830                 goto out;
 3831         if (td->td_ucred->cr_uid != vattr.va_uid) {
 3832                 error = priv_check(td, PRIV_VFS_ADMIN);
 3833                 if (error != 0)
 3834                         goto out;
 3835         }
 3836         if (vcount(vp) > 1)
 3837                 VOP_REVOKE(vp, REVOKEALL);
 3838 out:
 3839         vput(vp);
 3840         return (error);
 3841 }
 3842 
 3843 /*
 3844  * Convert a user file descriptor to a kernel file entry and check that, if it
 3845  * is a capability, the correct rights are present. A reference on the file
 3846  * entry is held upon returning.
 3847  */
 3848 int
 3849 getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
 3850 {
 3851         struct file *fp;
 3852         int error;
 3853 
 3854         error = fget_unlocked(td->td_proc->p_fd, fd, rightsp, &fp, NULL);
 3855         if (error != 0)
 3856                 return (error);
 3857 
 3858         /*
 3859          * The file could be not of the vnode type, or it may be not
 3860          * yet fully initialized, in which case the f_vnode pointer
 3861          * may be set, but f_ops is still badfileops.  E.g.,
 3862          * devfs_open() transiently create such situation to
 3863          * facilitate csw d_fdopen().
 3864          *
 3865          * Dupfdopen() handling in kern_openat() installs the
 3866          * half-baked file into the process descriptor table, allowing
 3867          * other thread to dereference it. Guard against the race by
 3868          * checking f_ops.
 3869          */
 3870         if (fp->f_vnode == NULL || fp->f_ops == &badfileops) {
 3871                 fdrop(fp, td);
 3872                 return (EINVAL);
 3873         }
 3874         *fpp = fp;
 3875         return (0);
 3876 }
 3877 
 3878 
 3879 /*
 3880  * Get an (NFS) file handle.
 3881  */
 3882 #ifndef _SYS_SYSPROTO_H_
 3883 struct lgetfh_args {
 3884         char    *fname;
 3885         fhandle_t *fhp;
 3886 };
 3887 #endif
 3888 int
 3889 sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
 3890 {
 3891         struct nameidata nd;
 3892         fhandle_t fh;
 3893         struct vnode *vp;
 3894         int error;
 3895 
 3896         error = priv_check(td, PRIV_VFS_GETFH);
 3897         if (error != 0)
 3898                 return (error);
 3899         NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3900             uap->fname, td);
 3901         error = namei(&nd);
 3902         if (error != 0)
 3903                 return (error);
 3904         NDFREE(&nd, NDF_ONLY_PNBUF);
 3905         vp = nd.ni_vp;
 3906         bzero(&fh, sizeof(fh));
 3907         fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 3908         error = VOP_VPTOFH(vp, &fh.fh_fid);
 3909         vput(vp);
 3910         if (error == 0)
 3911                 error = copyout(&fh, uap->fhp, sizeof (fh));
 3912         return (error);
 3913 }
 3914 
 3915 #ifndef _SYS_SYSPROTO_H_
 3916 struct getfh_args {
 3917         char    *fname;
 3918         fhandle_t *fhp;
 3919 };
 3920 #endif
 3921 int
 3922 sys_getfh(struct thread *td, struct getfh_args *uap)
 3923 {
 3924         struct nameidata nd;
 3925         fhandle_t fh;
 3926         struct vnode *vp;
 3927         int error;
 3928 
 3929         error = priv_check(td, PRIV_VFS_GETFH);
 3930         if (error != 0)
 3931                 return (error);
 3932         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3933             uap->fname, td);
 3934         error = namei(&nd);
 3935         if (error != 0)
 3936                 return (error);
 3937         NDFREE(&nd, NDF_ONLY_PNBUF);
 3938         vp = nd.ni_vp;
 3939         bzero(&fh, sizeof(fh));
 3940         fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 3941         error = VOP_VPTOFH(vp, &fh.fh_fid);
 3942         vput(vp);
 3943         if (error == 0)
 3944                 error = copyout(&fh, uap->fhp, sizeof (fh));
 3945         return (error);
 3946 }
 3947 
 3948 /*
 3949  * syscall for the rpc.lockd to use to translate a NFS file handle into an
 3950  * open descriptor.
 3951  *
 3952  * warning: do not remove the priv_check() call or this becomes one giant
 3953  * security hole.
 3954  */
 3955 #ifndef _SYS_SYSPROTO_H_
 3956 struct fhopen_args {
 3957         const struct fhandle *u_fhp;
 3958         int flags;
 3959 };
 3960 #endif
 3961 int
 3962 sys_fhopen(struct thread *td, struct fhopen_args *uap)
 3963 {
 3964         struct mount *mp;
 3965         struct vnode *vp;
 3966         struct fhandle fhp;
 3967         struct file *fp;
 3968         int fmode, error;
 3969         int indx;
 3970 
 3971         error = priv_check(td, PRIV_VFS_FHOPEN);
 3972         if (error != 0)
 3973                 return (error);
 3974         indx = -1;
 3975         fmode = FFLAGS(uap->flags);
 3976         /* why not allow a non-read/write open for our lockd? */
 3977         if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
 3978                 return (EINVAL);
 3979         error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
 3980         if (error != 0)
 3981                 return(error);
 3982         /* find the mount point */
 3983         mp = vfs_busyfs(&fhp.fh_fsid);
 3984         if (mp == NULL)
 3985                 return (ESTALE);
 3986         /* now give me my vnode, it gets returned to me locked */
 3987         error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
 3988         vfs_unbusy(mp);
 3989         if (error != 0)
 3990                 return (error);
 3991 
 3992         error = falloc_noinstall(td, &fp);
 3993         if (error != 0) {
 3994                 vput(vp);
 3995                 return (error);
 3996         }
 3997         /*
 3998          * An extra reference on `fp' has been held for us by
 3999          * falloc_noinstall().
 4000          */
 4001 
 4002 #ifdef INVARIANTS
 4003         td->td_dupfd = -1;
 4004 #endif
 4005         error = vn_open_vnode(vp, fmode, td->td_ucred, td, fp);
 4006         if (error != 0) {
 4007                 KASSERT(fp->f_ops == &badfileops,
 4008                     ("VOP_OPEN in fhopen() set f_ops"));
 4009                 KASSERT(td->td_dupfd < 0,
 4010                     ("fhopen() encountered fdopen()"));
 4011 
 4012                 vput(vp);
 4013                 goto bad;
 4014         }
 4015 #ifdef INVARIANTS
 4016         td->td_dupfd = 0;
 4017 #endif
 4018         fp->f_vnode = vp;
 4019         fp->f_seqcount = 1;
 4020         finit(fp, (fmode & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, vp,
 4021             &vnops);
 4022         VOP_UNLOCK(vp, 0);
 4023         if ((fmode & O_TRUNC) != 0) {
 4024                 error = fo_truncate(fp, 0, td->td_ucred, td);
 4025                 if (error != 0)
 4026                         goto bad;
 4027         }
 4028 
 4029         error = finstall(td, fp, &indx, fmode, NULL);
 4030 bad:
 4031         fdrop(fp, td);
 4032         td->td_retval[0] = indx;
 4033         return (error);
 4034 }
 4035 
 4036 /*
 4037  * Stat an (NFS) file handle.
 4038  */
 4039 #ifndef _SYS_SYSPROTO_H_
 4040 struct fhstat_args {
 4041         struct fhandle *u_fhp;
 4042         struct stat *sb;
 4043 };
 4044 #endif
 4045 int
 4046 sys_fhstat(struct thread *td, struct fhstat_args *uap)
 4047 {
 4048         struct stat sb;
 4049         struct fhandle fh;
 4050         int error;
 4051 
 4052         error = copyin(uap->u_fhp, &fh, sizeof(fh));
 4053         if (error != 0)
 4054                 return (error);
 4055         error = kern_fhstat(td, fh, &sb);
 4056         if (error == 0)
 4057                 error = copyout(&sb, uap->sb, sizeof(sb));
 4058         return (error);
 4059 }
 4060 
 4061 int
 4062 kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
 4063 {
 4064         struct mount *mp;
 4065         struct vnode *vp;
 4066         int error;
 4067 
 4068         error = priv_check(td, PRIV_VFS_FHSTAT);
 4069         if (error != 0)
 4070                 return (error);
 4071         if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
 4072                 return (ESTALE);
 4073         error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
 4074         vfs_unbusy(mp);
 4075         if (error != 0)
 4076                 return (error);
 4077         error = vn_stat(vp, sb, td->td_ucred, NOCRED, td);
 4078         vput(vp);
 4079         return (error);
 4080 }
 4081 
 4082 /*
 4083  * Implement fstatfs() for (NFS) file handles.
 4084  */
 4085 #ifndef _SYS_SYSPROTO_H_
 4086 struct fhstatfs_args {
 4087         struct fhandle *u_fhp;
 4088         struct statfs *buf;
 4089 };
 4090 #endif
 4091 int
 4092 sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
 4093 {
 4094         struct statfs *sfp;
 4095         fhandle_t fh;
 4096         int error;
 4097 
 4098         error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
 4099         if (error != 0)
 4100                 return (error);
 4101         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
 4102         error = kern_fhstatfs(td, fh, sfp);
 4103         if (error == 0)
 4104                 error = copyout(sfp, uap->buf, sizeof(*sfp));
 4105         free(sfp, M_STATFS);
 4106         return (error);
 4107 }
 4108 
 4109 int
 4110 kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
 4111 {
 4112         struct statfs *sp;
 4113         struct mount *mp;
 4114         struct vnode *vp;
 4115         int error;
 4116 
 4117         error = priv_check(td, PRIV_VFS_FHSTATFS);
 4118         if (error != 0)
 4119                 return (error);
 4120         if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
 4121                 return (ESTALE);
 4122         error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
 4123         if (error != 0) {
 4124                 vfs_unbusy(mp);
 4125                 return (error);
 4126         }
 4127         vput(vp);
 4128         error = prison_canseemount(td->td_ucred, mp);
 4129         if (error != 0)
 4130                 goto out;
 4131 #ifdef MAC
 4132         error = mac_mount_check_stat(td->td_ucred, mp);
 4133         if (error != 0)
 4134                 goto out;
 4135 #endif
 4136         /*
 4137          * Set these in case the underlying filesystem fails to do so.
 4138          */
 4139         sp = &mp->mnt_stat;
 4140         sp->f_version = STATFS_VERSION;
 4141         sp->f_namemax = NAME_MAX;
 4142         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
 4143         error = VFS_STATFS(mp, sp);
 4144         if (error == 0)
 4145                 *buf = *sp;
 4146 out:
 4147         vfs_unbusy(mp);
 4148         return (error);
 4149 }
 4150 
 4151 int
 4152 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len)
 4153 {
 4154         struct file *fp;
 4155         struct mount *mp;
 4156         struct vnode *vp;
 4157         cap_rights_t rights;
 4158         off_t olen, ooffset;
 4159         int error;
 4160 
 4161         if (offset < 0 || len <= 0)
 4162                 return (EINVAL);
 4163         /* Check for wrap. */
 4164         if (offset > OFF_MAX - len)
 4165                 return (EFBIG);
 4166         error = fget(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
 4167         if (error != 0)
 4168                 return (error);
 4169         if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
 4170                 error = ESPIPE;
 4171                 goto out;
 4172         }
 4173         if ((fp->f_flag & FWRITE) == 0) {
 4174                 error = EBADF;
 4175                 goto out;
 4176         }
 4177         if (fp->f_type != DTYPE_VNODE) {
 4178                 error = ENODEV;
 4179                 goto out;
 4180         }
 4181         vp = fp->f_vnode;
 4182         if (vp->v_type != VREG) {
 4183                 error = ENODEV;
 4184                 goto out;
 4185         }
 4186 
 4187         /* Allocating blocks may take a long time, so iterate. */
 4188         for (;;) {
 4189                 olen = len;
 4190                 ooffset = offset;
 4191 
 4192                 bwillwrite();
 4193                 mp = NULL;
 4194                 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
 4195                 if (error != 0)
 4196                         break;
 4197                 error = vn_lock(vp, LK_EXCLUSIVE);
 4198                 if (error != 0) {
 4199                         vn_finished_write(mp);
 4200                         break;
 4201                 }
 4202 #ifdef MAC
 4203                 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
 4204                 if (error == 0)
 4205 #endif
 4206                         error = VOP_ALLOCATE(vp, &offset, &len);
 4207                 VOP_UNLOCK(vp, 0);
 4208                 vn_finished_write(mp);
 4209 
 4210                 if (olen + ooffset != offset + len) {
 4211                         panic("offset + len changed from %jx/%jx to %jx/%jx",
 4212                             ooffset, olen, offset, len);
 4213                 }
 4214                 if (error != 0 || len == 0)
 4215                         break;
 4216                 KASSERT(olen > len, ("Iteration did not make progress?"));
 4217                 maybe_yield();
 4218         }
 4219  out:
 4220         fdrop(fp, td);
 4221         return (error);
 4222 }
 4223 
 4224 int
 4225 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
 4226 {
 4227         int error;
 4228 
 4229         error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
 4230         return (kern_posix_error(td, error));
 4231 }
 4232 
 4233 /*
 4234  * Unlike madvise(2), we do not make a best effort to remember every
 4235  * possible caching hint.  Instead, we remember the last setting with
 4236  * the exception that we will allow POSIX_FADV_NORMAL to adjust the
 4237  * region of any current setting.
 4238  */
 4239 int
 4240 kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
 4241     int advice)
 4242 {
 4243         struct fadvise_info *fa, *new;
 4244         struct file *fp;
 4245         struct vnode *vp;
 4246         cap_rights_t rights;
 4247         off_t end;
 4248         int error;
 4249 
 4250         if (offset < 0 || len < 0 || offset > OFF_MAX - len)
 4251                 return (EINVAL);
 4252         switch (advice) {
 4253         case POSIX_FADV_SEQUENTIAL:
 4254         case POSIX_FADV_RANDOM:
 4255         case POSIX_FADV_NOREUSE:
 4256                 new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
 4257                 break;
 4258         case POSIX_FADV_NORMAL:
 4259         case POSIX_FADV_WILLNEED:
 4260         case POSIX_FADV_DONTNEED:
 4261                 new = NULL;
 4262                 break;
 4263         default:
 4264                 return (EINVAL);
 4265         }
 4266         /* XXX: CAP_POSIX_FADVISE? */
 4267         error = fget(td, fd, cap_rights_init(&rights), &fp);
 4268         if (error != 0)
 4269                 goto out;
 4270         if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
 4271                 error = ESPIPE;
 4272                 goto out;
 4273         }
 4274         if (fp->f_type != DTYPE_VNODE) {
 4275                 error = ENODEV;
 4276                 goto out;
 4277         }
 4278         vp = fp->f_vnode;
 4279         if (vp->v_type != VREG) {
 4280                 error = ENODEV;
 4281                 goto out;
 4282         }
 4283         if (len == 0)
 4284                 end = OFF_MAX;
 4285         else
 4286                 end = offset + len - 1;
 4287         switch (advice) {
 4288         case POSIX_FADV_SEQUENTIAL:
 4289         case POSIX_FADV_RANDOM:
 4290         case POSIX_FADV_NOREUSE:
 4291                 /*
 4292                  * Try to merge any existing non-standard region with
 4293                  * this new region if possible, otherwise create a new
 4294                  * non-standard region for this request.
 4295                  */
 4296                 mtx_pool_lock(mtxpool_sleep, fp);
 4297                 fa = fp->f_advice;
 4298                 if (fa != NULL && fa->fa_advice == advice &&
 4299                     ((fa->fa_start <= end && fa->fa_end >= offset) ||
 4300                     (end != OFF_MAX && fa->fa_start == end + 1) ||
 4301                     (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
 4302                         if (offset < fa->fa_start)
 4303                                 fa->fa_start = offset;
 4304                         if (end > fa->fa_end)
 4305                                 fa->fa_end = end;
 4306                 } else {
 4307                         new->fa_advice = advice;
 4308                         new->fa_start = offset;
 4309                         new->fa_end = end;
 4310                         fp->f_advice = new;
 4311                         new = fa;
 4312                 }
 4313                 mtx_pool_unlock(mtxpool_sleep, fp);
 4314                 break;
 4315         case POSIX_FADV_NORMAL:
 4316                 /*
 4317                  * If a the "normal" region overlaps with an existing
 4318                  * non-standard region, trim or remove the
 4319                  * non-standard region.
 4320                  */
 4321                 mtx_pool_lock(mtxpool_sleep, fp);
 4322                 fa = fp->f_advice;
 4323                 if (fa != NULL) {
 4324                         if (offset <= fa->fa_start && end >= fa->fa_end) {
 4325                                 new = fa;
 4326                                 fp->f_advice = NULL;
 4327                         } else if (offset <= fa->fa_start &&
 4328                             end >= fa->fa_start)
 4329                                 fa->fa_start = end + 1;
 4330                         else if (offset <= fa->fa_end && end >= fa->fa_end)
 4331                                 fa->fa_end = offset - 1;
 4332                         else if (offset >= fa->fa_start && end <= fa->fa_end) {
 4333                                 /*
 4334                                  * If the "normal" region is a middle
 4335                                  * portion of the existing
 4336                                  * non-standard region, just remove
 4337                                  * the whole thing rather than picking
 4338                                  * one side or the other to
 4339                                  * preserve.
 4340                                  */
 4341                                 new = fa;
 4342                                 fp->f_advice = NULL;
 4343                         }
 4344                 }
 4345                 mtx_pool_unlock(mtxpool_sleep, fp);
 4346                 break;
 4347         case POSIX_FADV_WILLNEED:
 4348         case POSIX_FADV_DONTNEED:
 4349                 error = VOP_ADVISE(vp, offset, end, advice);
 4350                 break;
 4351         }
 4352 out:
 4353         if (fp != NULL)
 4354                 fdrop(fp, td);
 4355         free(new, M_FADVISE);
 4356         return (error);
 4357 }
 4358 
 4359 int
 4360 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
 4361 {
 4362         int error;
 4363 
 4364         error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
 4365             uap->advice);
 4366         return (kern_posix_error(td, error));
 4367 }

Cache object: 71e6f3c5584eaa55418eaf66a4a9d129


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