The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: 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("$FreeBSD$");
   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             (uap->cmd >> SUBCMDSHIFT) != Q_QUOTAOFF)
  194                 vfs_unbusy(mp);
  195         return (error);
  196 }
  197 
  198 /*
  199  * Used by statfs conversion routines to scale the block size up if
  200  * necessary so that all of the block counts are <= 'max_size'.  Note
  201  * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
  202  * value of 'n'.
  203  */
  204 void
  205 statfs_scale_blocks(struct statfs *sf, long max_size)
  206 {
  207         uint64_t count;
  208         int shift;
  209 
  210         KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));
  211 
  212         /*
  213          * Attempt to scale the block counts to give a more accurate
  214          * overview to userland of the ratio of free space to used
  215          * space.  To do this, find the largest block count and compute
  216          * a divisor that lets it fit into a signed integer <= max_size.
  217          */
  218         if (sf->f_bavail < 0)
  219                 count = -sf->f_bavail;
  220         else
  221                 count = sf->f_bavail;
  222         count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
  223         if (count <= max_size)
  224                 return;
  225 
  226         count >>= flsl(max_size);
  227         shift = 0;
  228         while (count > 0) {
  229                 shift++;
  230                 count >>=1;
  231         }
  232 
  233         sf->f_bsize <<= shift;
  234         sf->f_blocks >>= shift;
  235         sf->f_bfree >>= shift;
  236         sf->f_bavail >>= shift;
  237 }
  238 
  239 static int
  240 kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
  241 {
  242         struct statfs *sp;
  243         int error;
  244 
  245         if (mp == NULL)
  246                 return (EBADF);
  247         error = vfs_busy(mp, 0);
  248         vfs_rel(mp);
  249         if (error != 0)
  250                 return (error);
  251 #ifdef MAC
  252         error = mac_mount_check_stat(td->td_ucred, mp);
  253         if (error != 0)
  254                 goto out;
  255 #endif
  256         /*
  257          * Set these in case the underlying filesystem fails to do so.
  258          */
  259         sp = &mp->mnt_stat;
  260         sp->f_version = STATFS_VERSION;
  261         sp->f_namemax = NAME_MAX;
  262         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
  263         error = VFS_STATFS(mp, sp);
  264         if (error != 0)
  265                 goto out;
  266         *buf = *sp;
  267         if (priv_check(td, PRIV_VFS_GENERATION)) {
  268                 buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
  269                 prison_enforce_statfs(td->td_ucred, mp, buf);
  270         }
  271 out:
  272         vfs_unbusy(mp);
  273         return (error);
  274 }
  275 
  276 /*
  277  * Get filesystem statistics.
  278  */
  279 #ifndef _SYS_SYSPROTO_H_
  280 struct statfs_args {
  281         char *path;
  282         struct statfs *buf;
  283 };
  284 #endif
  285 int
  286 sys_statfs(struct thread *td, struct statfs_args *uap)
  287 {
  288         struct statfs *sfp;
  289         int error;
  290 
  291         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  292         error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
  293         if (error == 0)
  294                 error = copyout(sfp, uap->buf, sizeof(struct statfs));
  295         free(sfp, M_STATFS);
  296         return (error);
  297 }
  298 
  299 int
  300 kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
  301     struct statfs *buf)
  302 {
  303         struct mount *mp;
  304         struct nameidata nd;
  305         int error;
  306 
  307         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  308             pathseg, path, td);
  309         error = namei(&nd);
  310         if (error != 0)
  311                 return (error);
  312         mp = nd.ni_vp->v_mount;
  313         vfs_ref(mp);
  314         NDFREE(&nd, NDF_ONLY_PNBUF);
  315         vput(nd.ni_vp);
  316         return (kern_do_statfs(td, mp, buf));
  317 }
  318 
  319 /*
  320  * Get filesystem statistics.
  321  */
  322 #ifndef _SYS_SYSPROTO_H_
  323 struct fstatfs_args {
  324         int fd;
  325         struct statfs *buf;
  326 };
  327 #endif
  328 int
  329 sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
  330 {
  331         struct statfs *sfp;
  332         int error;
  333 
  334         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  335         error = kern_fstatfs(td, uap->fd, sfp);
  336         if (error == 0)
  337                 error = copyout(sfp, uap->buf, sizeof(struct statfs));
  338         free(sfp, M_STATFS);
  339         return (error);
  340 }
  341 
  342 int
  343 kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
  344 {
  345         struct file *fp;
  346         struct mount *mp;
  347         struct vnode *vp;
  348         cap_rights_t rights;
  349         int error;
  350 
  351         AUDIT_ARG_FD(fd);
  352         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSTATFS), &fp);
  353         if (error != 0)
  354                 return (error);
  355         vp = fp->f_vnode;
  356         vn_lock(vp, LK_SHARED | LK_RETRY);
  357 #ifdef AUDIT
  358         AUDIT_ARG_VNODE1(vp);
  359 #endif
  360         mp = vp->v_mount;
  361         if (mp != NULL)
  362                 vfs_ref(mp);
  363         VOP_UNLOCK(vp, 0);
  364         fdrop(fp, td);
  365         return (kern_do_statfs(td, mp, buf));
  366 }
  367 
  368 /*
  369  * Get statistics on all filesystems.
  370  */
  371 #ifndef _SYS_SYSPROTO_H_
  372 struct getfsstat_args {
  373         struct statfs *buf;
  374         long bufsize;
  375         int mode;
  376 };
  377 #endif
  378 int
  379 sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
  380 {
  381         size_t count;
  382         int error;
  383 
  384         if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
  385                 return (EINVAL);
  386         error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
  387             UIO_USERSPACE, uap->mode);
  388         if (error == 0)
  389                 td->td_retval[0] = count;
  390         return (error);
  391 }
  392 
  393 /*
  394  * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
  395  *      The caller is responsible for freeing memory which will be allocated
  396  *      in '*buf'.
  397  */
  398 int
  399 kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
  400     size_t *countp, enum uio_seg bufseg, int mode)
  401 {
  402         struct mount *mp, *nmp;
  403         struct statfs *sfsp, *sp, *sptmp, *tofree;
  404         size_t count, maxcount;
  405         int error;
  406 
  407         switch (mode) {
  408         case MNT_WAIT:
  409         case MNT_NOWAIT:
  410                 break;
  411         default:
  412                 if (bufseg == UIO_SYSSPACE)
  413                         *buf = NULL;
  414                 return (EINVAL);
  415         }
  416 restart:
  417         maxcount = bufsize / sizeof(struct statfs);
  418         if (bufsize == 0) {
  419                 sfsp = NULL;
  420                 tofree = NULL;
  421         } else if (bufseg == UIO_USERSPACE) {
  422                 sfsp = *buf;
  423                 tofree = NULL;
  424         } else /* if (bufseg == UIO_SYSSPACE) */ {
  425                 count = 0;
  426                 mtx_lock(&mountlist_mtx);
  427                 TAILQ_FOREACH(mp, &mountlist, mnt_list) {
  428                         count++;
  429                 }
  430                 mtx_unlock(&mountlist_mtx);
  431                 if (maxcount > count)
  432                         maxcount = count;
  433                 tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
  434                     M_STATFS, M_WAITOK);
  435         }
  436         count = 0;
  437         mtx_lock(&mountlist_mtx);
  438         for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
  439                 if (prison_canseemount(td->td_ucred, mp) != 0) {
  440                         nmp = TAILQ_NEXT(mp, mnt_list);
  441                         continue;
  442                 }
  443 #ifdef MAC
  444                 if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
  445                         nmp = TAILQ_NEXT(mp, mnt_list);
  446                         continue;
  447                 }
  448 #endif
  449                 if (mode == MNT_WAIT) {
  450                         if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
  451                                 /*
  452                                  * If vfs_busy() failed, and MBF_NOWAIT
  453                                  * wasn't passed, then the mp is gone.
  454                                  * Furthermore, because of MBF_MNTLSTLOCK,
  455                                  * the mountlist_mtx was dropped.  We have
  456                                  * no other choice than to start over.
  457                                  */
  458                                 mtx_unlock(&mountlist_mtx);
  459                                 free(tofree, M_STATFS);
  460                                 goto restart;
  461                         }
  462                 } else {
  463                         if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
  464                                 nmp = TAILQ_NEXT(mp, mnt_list);
  465                                 continue;
  466                         }
  467                 }
  468                 if (sfsp != NULL && count < maxcount) {
  469                         sp = &mp->mnt_stat;
  470                         /*
  471                          * Set these in case the underlying filesystem
  472                          * fails to do so.
  473                          */
  474                         sp->f_version = STATFS_VERSION;
  475                         sp->f_namemax = NAME_MAX;
  476                         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
  477                         /*
  478                          * If MNT_NOWAIT is specified, do not refresh
  479                          * the fsstat cache.
  480                          */
  481                         if (mode != MNT_NOWAIT) {
  482                                 error = VFS_STATFS(mp, sp);
  483                                 if (error != 0) {
  484                                         mtx_lock(&mountlist_mtx);
  485                                         nmp = TAILQ_NEXT(mp, mnt_list);
  486                                         vfs_unbusy(mp);
  487                                         continue;
  488                                 }
  489                         }
  490                         if (priv_check(td, PRIV_VFS_GENERATION)) {
  491                                 sptmp = malloc(sizeof(struct statfs), M_STATFS,
  492                                     M_WAITOK);
  493                                 *sptmp = *sp;
  494                                 sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
  495                                 prison_enforce_statfs(td->td_ucred, mp, sptmp);
  496                                 sp = sptmp;
  497                         } else
  498                                 sptmp = NULL;
  499                         if (bufseg == UIO_SYSSPACE) {
  500                                 bcopy(sp, sfsp, sizeof(*sp));
  501                                 free(sptmp, M_STATFS);
  502                         } else /* if (bufseg == UIO_USERSPACE) */ {
  503                                 error = copyout(sp, sfsp, sizeof(*sp));
  504                                 free(sptmp, M_STATFS);
  505                                 if (error != 0) {
  506                                         vfs_unbusy(mp);
  507                                         return (error);
  508                                 }
  509                         }
  510                         sfsp++;
  511                 }
  512                 count++;
  513                 mtx_lock(&mountlist_mtx);
  514                 nmp = TAILQ_NEXT(mp, mnt_list);
  515                 vfs_unbusy(mp);
  516         }
  517         mtx_unlock(&mountlist_mtx);
  518         if (sfsp != NULL && count > maxcount)
  519                 *countp = maxcount;
  520         else
  521                 *countp = count;
  522         return (0);
  523 }
  524 
  525 #ifdef COMPAT_FREEBSD4
  526 /*
  527  * Get old format filesystem statistics.
  528  */
  529 static void cvtstatfs(struct statfs *, struct ostatfs *);
  530 
  531 #ifndef _SYS_SYSPROTO_H_
  532 struct freebsd4_statfs_args {
  533         char *path;
  534         struct ostatfs *buf;
  535 };
  536 #endif
  537 int
  538 freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
  539 {
  540         struct ostatfs osb;
  541         struct statfs *sfp;
  542         int error;
  543 
  544         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  545         error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
  546         if (error == 0) {
  547                 cvtstatfs(sfp, &osb);
  548                 error = copyout(&osb, uap->buf, sizeof(osb));
  549         }
  550         free(sfp, M_STATFS);
  551         return (error);
  552 }
  553 
  554 /*
  555  * Get filesystem statistics.
  556  */
  557 #ifndef _SYS_SYSPROTO_H_
  558 struct freebsd4_fstatfs_args {
  559         int fd;
  560         struct ostatfs *buf;
  561 };
  562 #endif
  563 int
  564 freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
  565 {
  566         struct ostatfs osb;
  567         struct statfs *sfp;
  568         int error;
  569 
  570         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  571         error = kern_fstatfs(td, uap->fd, sfp);
  572         if (error == 0) {
  573                 cvtstatfs(sfp, &osb);
  574                 error = copyout(&osb, uap->buf, sizeof(osb));
  575         }
  576         free(sfp, M_STATFS);
  577         return (error);
  578 }
  579 
  580 /*
  581  * Get statistics on all filesystems.
  582  */
  583 #ifndef _SYS_SYSPROTO_H_
  584 struct freebsd4_getfsstat_args {
  585         struct ostatfs *buf;
  586         long bufsize;
  587         int mode;
  588 };
  589 #endif
  590 int
  591 freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
  592 {
  593         struct statfs *buf, *sp;
  594         struct ostatfs osb;
  595         size_t count, size;
  596         int error;
  597 
  598         if (uap->bufsize < 0)
  599                 return (EINVAL);
  600         count = uap->bufsize / sizeof(struct ostatfs);
  601         if (count > SIZE_MAX / sizeof(struct statfs))
  602                 return (EINVAL);
  603         size = count * sizeof(struct statfs);
  604         error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
  605             uap->mode);
  606         if (buf == NULL)
  607                 return (EINVAL);
  608         td->td_retval[0] = count;
  609         if (size != 0) {
  610                 sp = buf;
  611                 while (count != 0 && error == 0) {
  612                         cvtstatfs(sp, &osb);
  613                         error = copyout(&osb, uap->buf, sizeof(osb));
  614                         sp++;
  615                         uap->buf++;
  616                         count--;
  617                 }
  618                 free(buf, M_STATFS);
  619         }
  620         return (error);
  621 }
  622 
  623 /*
  624  * Implement fstatfs() for (NFS) file handles.
  625  */
  626 #ifndef _SYS_SYSPROTO_H_
  627 struct freebsd4_fhstatfs_args {
  628         struct fhandle *u_fhp;
  629         struct ostatfs *buf;
  630 };
  631 #endif
  632 int
  633 freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
  634 {
  635         struct ostatfs osb;
  636         struct statfs *sfp;
  637         fhandle_t fh;
  638         int error;
  639 
  640         error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
  641         if (error != 0)
  642                 return (error);
  643         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
  644         error = kern_fhstatfs(td, fh, sfp);
  645         if (error == 0) {
  646                 cvtstatfs(sfp, &osb);
  647                 error = copyout(&osb, uap->buf, sizeof(osb));
  648         }
  649         free(sfp, M_STATFS);
  650         return (error);
  651 }
  652 
  653 /*
  654  * Convert a new format statfs structure to an old format statfs structure.
  655  */
  656 static void
  657 cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
  658 {
  659 
  660         statfs_scale_blocks(nsp, LONG_MAX);
  661         bzero(osp, sizeof(*osp));
  662         osp->f_bsize = nsp->f_bsize;
  663         osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
  664         osp->f_blocks = nsp->f_blocks;
  665         osp->f_bfree = nsp->f_bfree;
  666         osp->f_bavail = nsp->f_bavail;
  667         osp->f_files = MIN(nsp->f_files, LONG_MAX);
  668         osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
  669         osp->f_owner = nsp->f_owner;
  670         osp->f_type = nsp->f_type;
  671         osp->f_flags = nsp->f_flags;
  672         osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
  673         osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
  674         osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
  675         osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
  676         strlcpy(osp->f_fstypename, nsp->f_fstypename,
  677             MIN(MFSNAMELEN, OMFSNAMELEN));
  678         strlcpy(osp->f_mntonname, nsp->f_mntonname,
  679             MIN(MNAMELEN, OMNAMELEN));
  680         strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
  681             MIN(MNAMELEN, OMNAMELEN));
  682         osp->f_fsid = nsp->f_fsid;
  683 }
  684 #endif /* COMPAT_FREEBSD4 */
  685 
  686 /*
  687  * Change current working directory to a given file descriptor.
  688  */
  689 #ifndef _SYS_SYSPROTO_H_
  690 struct fchdir_args {
  691         int     fd;
  692 };
  693 #endif
  694 int
  695 sys_fchdir(struct thread *td, struct fchdir_args *uap)
  696 {
  697         struct vnode *vp, *tdp;
  698         struct mount *mp;
  699         struct file *fp;
  700         cap_rights_t rights;
  701         int error;
  702 
  703         AUDIT_ARG_FD(uap->fd);
  704         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHDIR),
  705             &fp);
  706         if (error != 0)
  707                 return (error);
  708         vp = fp->f_vnode;
  709         vrefact(vp);
  710         fdrop(fp, td);
  711         vn_lock(vp, LK_SHARED | LK_RETRY);
  712         AUDIT_ARG_VNODE1(vp);
  713         error = change_dir(vp, td);
  714         while (!error && (mp = vp->v_mountedhere) != NULL) {
  715                 if (vfs_busy(mp, 0))
  716                         continue;
  717                 error = VFS_ROOT(mp, LK_SHARED, &tdp);
  718                 vfs_unbusy(mp);
  719                 if (error != 0)
  720                         break;
  721                 vput(vp);
  722                 vp = tdp;
  723         }
  724         if (error != 0) {
  725                 vput(vp);
  726                 return (error);
  727         }
  728         VOP_UNLOCK(vp, 0);
  729         pwd_chdir(td, vp);
  730         return (0);
  731 }
  732 
  733 /*
  734  * Change current working directory (``.'').
  735  */
  736 #ifndef _SYS_SYSPROTO_H_
  737 struct chdir_args {
  738         char    *path;
  739 };
  740 #endif
  741 int
  742 sys_chdir(struct thread *td, struct chdir_args *uap)
  743 {
  744 
  745         return (kern_chdir(td, uap->path, UIO_USERSPACE));
  746 }
  747 
  748 int
  749 kern_chdir(struct thread *td, char *path, enum uio_seg pathseg)
  750 {
  751         struct nameidata nd;
  752         int error;
  753 
  754         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  755             pathseg, path, td);
  756         if ((error = namei(&nd)) != 0)
  757                 return (error);
  758         if ((error = change_dir(nd.ni_vp, td)) != 0) {
  759                 vput(nd.ni_vp);
  760                 NDFREE(&nd, NDF_ONLY_PNBUF);
  761                 return (error);
  762         }
  763         VOP_UNLOCK(nd.ni_vp, 0);
  764         NDFREE(&nd, NDF_ONLY_PNBUF);
  765         pwd_chdir(td, nd.ni_vp);
  766         return (0);
  767 }
  768 
  769 /*
  770  * Change notion of root (``/'') directory.
  771  */
  772 #ifndef _SYS_SYSPROTO_H_
  773 struct chroot_args {
  774         char    *path;
  775 };
  776 #endif
  777 int
  778 sys_chroot(struct thread *td, struct chroot_args *uap)
  779 {
  780         struct nameidata nd;
  781         int error;
  782 
  783         error = priv_check(td, PRIV_VFS_CHROOT);
  784         if (error != 0)
  785                 return (error);
  786         NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
  787             UIO_USERSPACE, uap->path, td);
  788         error = namei(&nd);
  789         if (error != 0)
  790                 goto error;
  791         error = change_dir(nd.ni_vp, td);
  792         if (error != 0)
  793                 goto e_vunlock;
  794 #ifdef MAC
  795         error = mac_vnode_check_chroot(td->td_ucred, nd.ni_vp);
  796         if (error != 0)
  797                 goto e_vunlock;
  798 #endif
  799         VOP_UNLOCK(nd.ni_vp, 0);
  800         error = pwd_chroot(td, nd.ni_vp);
  801         vrele(nd.ni_vp);
  802         NDFREE(&nd, NDF_ONLY_PNBUF);
  803         return (error);
  804 e_vunlock:
  805         vput(nd.ni_vp);
  806 error:
  807         NDFREE(&nd, NDF_ONLY_PNBUF);
  808         return (error);
  809 }
  810 
  811 /*
  812  * Common routine for chroot and chdir.  Callers must provide a locked vnode
  813  * instance.
  814  */
  815 int
  816 change_dir(struct vnode *vp, struct thread *td)
  817 {
  818 #ifdef MAC
  819         int error;
  820 #endif
  821 
  822         ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
  823         if (vp->v_type != VDIR)
  824                 return (ENOTDIR);
  825 #ifdef MAC
  826         error = mac_vnode_check_chdir(td->td_ucred, vp);
  827         if (error != 0)
  828                 return (error);
  829 #endif
  830         return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
  831 }
  832 
  833 static __inline void
  834 flags_to_rights(int flags, cap_rights_t *rightsp)
  835 {
  836 
  837         if (flags & O_EXEC) {
  838                 cap_rights_set(rightsp, CAP_FEXECVE);
  839         } else {
  840                 switch ((flags & O_ACCMODE)) {
  841                 case O_RDONLY:
  842                         cap_rights_set(rightsp, CAP_READ);
  843                         break;
  844                 case O_RDWR:
  845                         cap_rights_set(rightsp, CAP_READ);
  846                         /* FALLTHROUGH */
  847                 case O_WRONLY:
  848                         cap_rights_set(rightsp, CAP_WRITE);
  849                         if (!(flags & (O_APPEND | O_TRUNC)))
  850                                 cap_rights_set(rightsp, CAP_SEEK);
  851                         break;
  852                 }
  853         }
  854 
  855         if (flags & O_CREAT)
  856                 cap_rights_set(rightsp, CAP_CREATE);
  857 
  858         if (flags & O_TRUNC)
  859                 cap_rights_set(rightsp, CAP_FTRUNCATE);
  860 
  861         if (flags & (O_SYNC | O_FSYNC))
  862                 cap_rights_set(rightsp, CAP_FSYNC);
  863 
  864         if (flags & (O_EXLOCK | O_SHLOCK))
  865                 cap_rights_set(rightsp, CAP_FLOCK);
  866 }
  867 
  868 /*
  869  * Check permissions, allocate an open file structure, and call the device
  870  * open routine if any.
  871  */
  872 #ifndef _SYS_SYSPROTO_H_
  873 struct open_args {
  874         char    *path;
  875         int     flags;
  876         int     mode;
  877 };
  878 #endif
  879 int
  880 sys_open(struct thread *td, struct open_args *uap)
  881 {
  882 
  883         return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
  884             uap->flags, uap->mode));
  885 }
  886 
  887 #ifndef _SYS_SYSPROTO_H_
  888 struct openat_args {
  889         int     fd;
  890         char    *path;
  891         int     flag;
  892         int     mode;
  893 };
  894 #endif
  895 int
  896 sys_openat(struct thread *td, struct openat_args *uap)
  897 {
  898 
  899         AUDIT_ARG_FD(uap->fd);
  900         return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
  901             uap->mode));
  902 }
  903 
  904 int
  905 kern_openat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
  906     int flags, int mode)
  907 {
  908         struct proc *p = td->td_proc;
  909         struct filedesc *fdp = p->p_fd;
  910         struct file *fp;
  911         struct vnode *vp;
  912         struct nameidata nd;
  913         cap_rights_t rights;
  914         int cmode, error, indx;
  915 
  916         indx = -1;
  917 
  918         AUDIT_ARG_FFLAGS(flags);
  919         AUDIT_ARG_MODE(mode);
  920         cap_rights_init(&rights, CAP_LOOKUP);
  921         flags_to_rights(flags, &rights);
  922         /*
  923          * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
  924          * may be specified.
  925          */
  926         if (flags & O_EXEC) {
  927                 if (flags & O_ACCMODE)
  928                         return (EINVAL);
  929         } else if ((flags & O_ACCMODE) == O_ACCMODE) {
  930                 return (EINVAL);
  931         } else {
  932                 flags = FFLAGS(flags);
  933         }
  934 
  935         /*
  936          * Allocate a file structure. The descriptor to reference it
  937          * is allocated and set by finstall() below.
  938          */
  939         error = falloc_noinstall(td, &fp);
  940         if (error != 0)
  941                 return (error);
  942         /*
  943          * An extra reference on `fp' has been held for us by
  944          * falloc_noinstall().
  945          */
  946         /* Set the flags early so the finit in devfs can pick them up. */
  947         fp->f_flag = flags & FMASK;
  948         cmode = ((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
  949         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
  950             &rights, td);
  951         td->td_dupfd = -1;              /* XXX check for fdopen */
  952         error = vn_open(&nd, &flags, cmode, fp);
  953         if (error != 0) {
  954                 /*
  955                  * If the vn_open replaced the method vector, something
  956                  * wonderous happened deep below and we just pass it up
  957                  * pretending we know what we do.
  958                  */
  959                 if (error == ENXIO && fp->f_ops != &badfileops)
  960                         goto success;
  961 
  962                 /*
  963                  * Handle special fdopen() case. bleh.
  964                  *
  965                  * Don't do this for relative (capability) lookups; we don't
  966                  * understand exactly what would happen, and we don't think
  967                  * that it ever should.
  968                  */
  969                 if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
  970                     (error == ENODEV || error == ENXIO) &&
  971                     td->td_dupfd >= 0) {
  972                         error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
  973                             &indx);
  974                         if (error == 0)
  975                                 goto success;
  976                 }
  977 
  978                 goto bad;
  979         }
  980         td->td_dupfd = 0;
  981         NDFREE(&nd, NDF_ONLY_PNBUF);
  982         vp = nd.ni_vp;
  983 
  984         /*
  985          * Store the vnode, for any f_type. Typically, the vnode use
  986          * count is decremented by direct call to vn_closefile() for
  987          * files that switched type in the cdevsw fdopen() method.
  988          */
  989         fp->f_vnode = vp;
  990         /*
  991          * If the file wasn't claimed by devfs bind it to the normal
  992          * vnode operations here.
  993          */
  994         if (fp->f_ops == &badfileops) {
  995                 KASSERT(vp->v_type != VFIFO, ("Unexpected fifo."));
  996                 fp->f_seqcount = 1;
  997                 finit(fp, (flags & FMASK) | (fp->f_flag & FHASLOCK),
  998                     DTYPE_VNODE, vp, &vnops);
  999         }
 1000 
 1001         VOP_UNLOCK(vp, 0);
 1002         if (flags & O_TRUNC) {
 1003                 error = fo_truncate(fp, 0, td->td_ucred, td);
 1004                 if (error != 0)
 1005                         goto bad;
 1006         }
 1007 success:
 1008         /*
 1009          * If we haven't already installed the FD (for dupfdopen), do so now.
 1010          */
 1011         if (indx == -1) {
 1012                 struct filecaps *fcaps;
 1013 
 1014 #ifdef CAPABILITIES
 1015                 if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) != 0)
 1016                         fcaps = &nd.ni_filecaps;
 1017                 else
 1018 #endif
 1019                         fcaps = NULL;
 1020                 error = finstall(td, fp, &indx, flags, fcaps);
 1021                 /* On success finstall() consumes fcaps. */
 1022                 if (error != 0) {
 1023                         filecaps_free(&nd.ni_filecaps);
 1024                         goto bad;
 1025                 }
 1026         } else {
 1027                 filecaps_free(&nd.ni_filecaps);
 1028         }
 1029 
 1030         /*
 1031          * Release our private reference, leaving the one associated with
 1032          * the descriptor table intact.
 1033          */
 1034         fdrop(fp, td);
 1035         td->td_retval[0] = indx;
 1036         return (0);
 1037 bad:
 1038         KASSERT(indx == -1, ("indx=%d, should be -1", indx));
 1039         fdrop(fp, td);
 1040         return (error);
 1041 }
 1042 
 1043 #ifdef COMPAT_43
 1044 /*
 1045  * Create a file.
 1046  */
 1047 #ifndef _SYS_SYSPROTO_H_
 1048 struct ocreat_args {
 1049         char    *path;
 1050         int     mode;
 1051 };
 1052 #endif
 1053 int
 1054 ocreat(struct thread *td, struct ocreat_args *uap)
 1055 {
 1056 
 1057         return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1058             O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
 1059 }
 1060 #endif /* COMPAT_43 */
 1061 
 1062 /*
 1063  * Create a special file.
 1064  */
 1065 #ifndef _SYS_SYSPROTO_H_
 1066 struct mknod_args {
 1067         char    *path;
 1068         int     mode;
 1069         int     dev;
 1070 };
 1071 #endif
 1072 int
 1073 sys_mknod(struct thread *td, struct mknod_args *uap)
 1074 {
 1075 
 1076         return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1077             uap->mode, uap->dev));
 1078 }
 1079 
 1080 #ifndef _SYS_SYSPROTO_H_
 1081 struct mknodat_args {
 1082         int     fd;
 1083         char    *path;
 1084         mode_t  mode;
 1085         dev_t   dev;
 1086 };
 1087 #endif
 1088 int
 1089 sys_mknodat(struct thread *td, struct mknodat_args *uap)
 1090 {
 1091 
 1092         return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
 1093             uap->dev));
 1094 }
 1095 
 1096 int
 1097 kern_mknodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1098     int mode, int dev)
 1099 {
 1100         struct vnode *vp;
 1101         struct mount *mp;
 1102         struct vattr vattr;
 1103         struct nameidata nd;
 1104         cap_rights_t rights;
 1105         int error, whiteout = 0;
 1106 
 1107         AUDIT_ARG_MODE(mode);
 1108         AUDIT_ARG_DEV(dev);
 1109         switch (mode & S_IFMT) {
 1110         case S_IFCHR:
 1111         case S_IFBLK:
 1112                 error = priv_check(td, PRIV_VFS_MKNOD_DEV);
 1113                 if (error == 0 && dev == VNOVAL)
 1114                         error = EINVAL;
 1115                 break;
 1116         case S_IFWHT:
 1117                 error = priv_check(td, PRIV_VFS_MKNOD_WHT);
 1118                 break;
 1119         case S_IFIFO:
 1120                 if (dev == 0)
 1121                         return (kern_mkfifoat(td, fd, path, pathseg, mode));
 1122                 /* FALLTHROUGH */
 1123         default:
 1124                 error = EINVAL;
 1125                 break;
 1126         }
 1127         if (error != 0)
 1128                 return (error);
 1129 restart:
 1130         bwillwrite();
 1131         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1132             NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKNODAT),
 1133             td);
 1134         if ((error = namei(&nd)) != 0)
 1135                 return (error);
 1136         vp = nd.ni_vp;
 1137         if (vp != NULL) {
 1138                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1139                 if (vp == nd.ni_dvp)
 1140                         vrele(nd.ni_dvp);
 1141                 else
 1142                         vput(nd.ni_dvp);
 1143                 vrele(vp);
 1144                 return (EEXIST);
 1145         } else {
 1146                 VATTR_NULL(&vattr);
 1147                 vattr.va_mode = (mode & ALLPERMS) &
 1148                     ~td->td_proc->p_fd->fd_cmask;
 1149                 vattr.va_rdev = dev;
 1150                 whiteout = 0;
 1151 
 1152                 switch (mode & S_IFMT) {
 1153                 case S_IFCHR:
 1154                         vattr.va_type = VCHR;
 1155                         break;
 1156                 case S_IFBLK:
 1157                         vattr.va_type = VBLK;
 1158                         break;
 1159                 case S_IFWHT:
 1160                         whiteout = 1;
 1161                         break;
 1162                 default:
 1163                         panic("kern_mknod: invalid mode");
 1164                 }
 1165         }
 1166         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1167                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1168                 vput(nd.ni_dvp);
 1169                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1170                         return (error);
 1171                 goto restart;
 1172         }
 1173 #ifdef MAC
 1174         if (error == 0 && !whiteout)
 1175                 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
 1176                     &nd.ni_cnd, &vattr);
 1177 #endif
 1178         if (error == 0) {
 1179                 if (whiteout)
 1180                         error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
 1181                 else {
 1182                         error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
 1183                                                 &nd.ni_cnd, &vattr);
 1184                         if (error == 0)
 1185                                 vput(nd.ni_vp);
 1186                 }
 1187         }
 1188         NDFREE(&nd, NDF_ONLY_PNBUF);
 1189         vput(nd.ni_dvp);
 1190         vn_finished_write(mp);
 1191         return (error);
 1192 }
 1193 
 1194 /*
 1195  * Create a named pipe.
 1196  */
 1197 #ifndef _SYS_SYSPROTO_H_
 1198 struct mkfifo_args {
 1199         char    *path;
 1200         int     mode;
 1201 };
 1202 #endif
 1203 int
 1204 sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
 1205 {
 1206 
 1207         return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1208             uap->mode));
 1209 }
 1210 
 1211 #ifndef _SYS_SYSPROTO_H_
 1212 struct mkfifoat_args {
 1213         int     fd;
 1214         char    *path;
 1215         mode_t  mode;
 1216 };
 1217 #endif
 1218 int
 1219 sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
 1220 {
 1221 
 1222         return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
 1223             uap->mode));
 1224 }
 1225 
 1226 int
 1227 kern_mkfifoat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1228     int mode)
 1229 {
 1230         struct mount *mp;
 1231         struct vattr vattr;
 1232         struct nameidata nd;
 1233         cap_rights_t rights;
 1234         int error;
 1235 
 1236         AUDIT_ARG_MODE(mode);
 1237 restart:
 1238         bwillwrite();
 1239         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1240             NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKFIFOAT),
 1241             td);
 1242         if ((error = namei(&nd)) != 0)
 1243                 return (error);
 1244         if (nd.ni_vp != NULL) {
 1245                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1246                 if (nd.ni_vp == nd.ni_dvp)
 1247                         vrele(nd.ni_dvp);
 1248                 else
 1249                         vput(nd.ni_dvp);
 1250                 vrele(nd.ni_vp);
 1251                 return (EEXIST);
 1252         }
 1253         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1254                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1255                 vput(nd.ni_dvp);
 1256                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1257                         return (error);
 1258                 goto restart;
 1259         }
 1260         VATTR_NULL(&vattr);
 1261         vattr.va_type = VFIFO;
 1262         vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_fd->fd_cmask;
 1263 #ifdef MAC
 1264         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 1265             &vattr);
 1266         if (error != 0)
 1267                 goto out;
 1268 #endif
 1269         error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 1270         if (error == 0)
 1271                 vput(nd.ni_vp);
 1272 #ifdef MAC
 1273 out:
 1274 #endif
 1275         vput(nd.ni_dvp);
 1276         vn_finished_write(mp);
 1277         NDFREE(&nd, NDF_ONLY_PNBUF);
 1278         return (error);
 1279 }
 1280 
 1281 /*
 1282  * Make a hard file link.
 1283  */
 1284 #ifndef _SYS_SYSPROTO_H_
 1285 struct link_args {
 1286         char    *path;
 1287         char    *link;
 1288 };
 1289 #endif
 1290 int
 1291 sys_link(struct thread *td, struct link_args *uap)
 1292 {
 1293 
 1294         return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
 1295             UIO_USERSPACE, FOLLOW));
 1296 }
 1297 
 1298 #ifndef _SYS_SYSPROTO_H_
 1299 struct linkat_args {
 1300         int     fd1;
 1301         char    *path1;
 1302         int     fd2;
 1303         char    *path2;
 1304         int     flag;
 1305 };
 1306 #endif
 1307 int
 1308 sys_linkat(struct thread *td, struct linkat_args *uap)
 1309 {
 1310         int flag;
 1311 
 1312         flag = uap->flag;
 1313         if (flag & ~AT_SYMLINK_FOLLOW)
 1314                 return (EINVAL);
 1315 
 1316         return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
 1317             UIO_USERSPACE, (flag & AT_SYMLINK_FOLLOW) ? FOLLOW : NOFOLLOW));
 1318 }
 1319 
 1320 int hardlink_check_uid = 0;
 1321 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
 1322     &hardlink_check_uid, 0,
 1323     "Unprivileged processes cannot create hard links to files owned by other "
 1324     "users");
 1325 static int hardlink_check_gid = 0;
 1326 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
 1327     &hardlink_check_gid, 0,
 1328     "Unprivileged processes cannot create hard links to files owned by other "
 1329     "groups");
 1330 
 1331 static int
 1332 can_hardlink(struct vnode *vp, struct ucred *cred)
 1333 {
 1334         struct vattr va;
 1335         int error;
 1336 
 1337         if (!hardlink_check_uid && !hardlink_check_gid)
 1338                 return (0);
 1339 
 1340         error = VOP_GETATTR(vp, &va, cred);
 1341         if (error != 0)
 1342                 return (error);
 1343 
 1344         if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
 1345                 error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
 1346                 if (error != 0)
 1347                         return (error);
 1348         }
 1349 
 1350         if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
 1351                 error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
 1352                 if (error != 0)
 1353                         return (error);
 1354         }
 1355 
 1356         return (0);
 1357 }
 1358 
 1359 int
 1360 kern_linkat(struct thread *td, int fd1, int fd2, char *path1, char *path2,
 1361     enum uio_seg segflg, int follow)
 1362 {
 1363         struct vnode *vp;
 1364         struct mount *mp;
 1365         struct nameidata nd;
 1366         cap_rights_t rights;
 1367         int error;
 1368 
 1369 again:
 1370         bwillwrite();
 1371         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, segflg, path1, fd1,
 1372             cap_rights_init(&rights, CAP_LINKAT_SOURCE), td);
 1373 
 1374         if ((error = namei(&nd)) != 0)
 1375                 return (error);
 1376         NDFREE(&nd, NDF_ONLY_PNBUF);
 1377         vp = nd.ni_vp;
 1378         if (vp->v_type == VDIR) {
 1379                 vrele(vp);
 1380                 return (EPERM);         /* POSIX */
 1381         }
 1382         NDINIT_ATRIGHTS(&nd, CREATE,
 1383             LOCKPARENT | SAVENAME | AUDITVNODE2 | NOCACHE, segflg, path2, fd2,
 1384             cap_rights_init(&rights, CAP_LINKAT_TARGET), td);
 1385         if ((error = namei(&nd)) == 0) {
 1386                 if (nd.ni_vp != NULL) {
 1387                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1388                         if (nd.ni_dvp == nd.ni_vp)
 1389                                 vrele(nd.ni_dvp);
 1390                         else
 1391                                 vput(nd.ni_dvp);
 1392                         vrele(nd.ni_vp);
 1393                         vrele(vp);
 1394                         return (EEXIST);
 1395                 } else if (nd.ni_dvp->v_mount != vp->v_mount) {
 1396                         /*
 1397                          * Cross-device link.  No need to recheck
 1398                          * vp->v_type, since it cannot change, except
 1399                          * to VBAD.
 1400                          */
 1401                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1402                         vput(nd.ni_dvp);
 1403                         vrele(vp);
 1404                         return (EXDEV);
 1405                 } else if ((error = vn_lock(vp, LK_EXCLUSIVE)) == 0) {
 1406                         error = can_hardlink(vp, td->td_ucred);
 1407 #ifdef MAC
 1408                         if (error == 0)
 1409                                 error = mac_vnode_check_link(td->td_ucred,
 1410                                     nd.ni_dvp, vp, &nd.ni_cnd);
 1411 #endif
 1412                         if (error != 0) {
 1413                                 vput(vp);
 1414                                 vput(nd.ni_dvp);
 1415                                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1416                                 return (error);
 1417                         }
 1418                         error = vn_start_write(vp, &mp, V_NOWAIT);
 1419                         if (error != 0) {
 1420                                 vput(vp);
 1421                                 vput(nd.ni_dvp);
 1422                                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1423                                 error = vn_start_write(NULL, &mp,
 1424                                     V_XSLEEP | PCATCH);
 1425                                 if (error != 0)
 1426                                         return (error);
 1427                                 goto again;
 1428                         }
 1429                         error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
 1430                         VOP_UNLOCK(vp, 0);
 1431                         vput(nd.ni_dvp);
 1432                         vn_finished_write(mp);
 1433                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1434                 } else {
 1435                         vput(nd.ni_dvp);
 1436                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1437                         vrele(vp);
 1438                         goto again;
 1439                 }
 1440         }
 1441         vrele(vp);
 1442         return (error);
 1443 }
 1444 
 1445 /*
 1446  * Make a symbolic link.
 1447  */
 1448 #ifndef _SYS_SYSPROTO_H_
 1449 struct symlink_args {
 1450         char    *path;
 1451         char    *link;
 1452 };
 1453 #endif
 1454 int
 1455 sys_symlink(struct thread *td, struct symlink_args *uap)
 1456 {
 1457 
 1458         return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
 1459             UIO_USERSPACE));
 1460 }
 1461 
 1462 #ifndef _SYS_SYSPROTO_H_
 1463 struct symlinkat_args {
 1464         char    *path;
 1465         int     fd;
 1466         char    *path2;
 1467 };
 1468 #endif
 1469 int
 1470 sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
 1471 {
 1472 
 1473         return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
 1474             UIO_USERSPACE));
 1475 }
 1476 
 1477 int
 1478 kern_symlinkat(struct thread *td, char *path1, int fd, char *path2,
 1479     enum uio_seg segflg)
 1480 {
 1481         struct mount *mp;
 1482         struct vattr vattr;
 1483         char *syspath;
 1484         struct nameidata nd;
 1485         int error;
 1486         cap_rights_t rights;
 1487 
 1488         if (segflg == UIO_SYSSPACE) {
 1489                 syspath = path1;
 1490         } else {
 1491                 syspath = uma_zalloc(namei_zone, M_WAITOK);
 1492                 if ((error = copyinstr(path1, syspath, MAXPATHLEN, NULL)) != 0)
 1493                         goto out;
 1494         }
 1495         AUDIT_ARG_TEXT(syspath);
 1496 restart:
 1497         bwillwrite();
 1498         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 1499             NOCACHE, segflg, path2, fd, cap_rights_init(&rights, CAP_SYMLINKAT),
 1500             td);
 1501         if ((error = namei(&nd)) != 0)
 1502                 goto out;
 1503         if (nd.ni_vp) {
 1504                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1505                 if (nd.ni_vp == nd.ni_dvp)
 1506                         vrele(nd.ni_dvp);
 1507                 else
 1508                         vput(nd.ni_dvp);
 1509                 vrele(nd.ni_vp);
 1510                 error = EEXIST;
 1511                 goto out;
 1512         }
 1513         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1514                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1515                 vput(nd.ni_dvp);
 1516                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1517                         goto out;
 1518                 goto restart;
 1519         }
 1520         VATTR_NULL(&vattr);
 1521         vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_fd->fd_cmask;
 1522 #ifdef MAC
 1523         vattr.va_type = VLNK;
 1524         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 1525             &vattr);
 1526         if (error != 0)
 1527                 goto out2;
 1528 #endif
 1529         error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
 1530         if (error == 0)
 1531                 vput(nd.ni_vp);
 1532 #ifdef MAC
 1533 out2:
 1534 #endif
 1535         NDFREE(&nd, NDF_ONLY_PNBUF);
 1536         vput(nd.ni_dvp);
 1537         vn_finished_write(mp);
 1538 out:
 1539         if (segflg != UIO_SYSSPACE)
 1540                 uma_zfree(namei_zone, syspath);
 1541         return (error);
 1542 }
 1543 
 1544 /*
 1545  * Delete a whiteout from the filesystem.
 1546  */
 1547 #ifndef _SYS_SYSPROTO_H_
 1548 struct undelete_args {
 1549         char *path;
 1550 };
 1551 #endif
 1552 int
 1553 sys_undelete(struct thread *td, struct undelete_args *uap)
 1554 {
 1555         struct mount *mp;
 1556         struct nameidata nd;
 1557         int error;
 1558 
 1559 restart:
 1560         bwillwrite();
 1561         NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
 1562             UIO_USERSPACE, uap->path, td);
 1563         error = namei(&nd);
 1564         if (error != 0)
 1565                 return (error);
 1566 
 1567         if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
 1568                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1569                 if (nd.ni_vp == nd.ni_dvp)
 1570                         vrele(nd.ni_dvp);
 1571                 else
 1572                         vput(nd.ni_dvp);
 1573                 if (nd.ni_vp)
 1574                         vrele(nd.ni_vp);
 1575                 return (EEXIST);
 1576         }
 1577         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1578                 NDFREE(&nd, NDF_ONLY_PNBUF);
 1579                 vput(nd.ni_dvp);
 1580                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 1581                         return (error);
 1582                 goto restart;
 1583         }
 1584         error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
 1585         NDFREE(&nd, NDF_ONLY_PNBUF);
 1586         vput(nd.ni_dvp);
 1587         vn_finished_write(mp);
 1588         return (error);
 1589 }
 1590 
 1591 /*
 1592  * Delete a name from the filesystem.
 1593  */
 1594 #ifndef _SYS_SYSPROTO_H_
 1595 struct unlink_args {
 1596         char    *path;
 1597 };
 1598 #endif
 1599 int
 1600 sys_unlink(struct thread *td, struct unlink_args *uap)
 1601 {
 1602 
 1603         return (kern_unlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE, 0));
 1604 }
 1605 
 1606 #ifndef _SYS_SYSPROTO_H_
 1607 struct unlinkat_args {
 1608         int     fd;
 1609         char    *path;
 1610         int     flag;
 1611 };
 1612 #endif
 1613 int
 1614 sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
 1615 {
 1616         int flag = uap->flag;
 1617         int fd = uap->fd;
 1618         char *path = uap->path;
 1619 
 1620         if (flag & ~AT_REMOVEDIR)
 1621                 return (EINVAL);
 1622 
 1623         if (flag & AT_REMOVEDIR)
 1624                 return (kern_rmdirat(td, fd, path, UIO_USERSPACE));
 1625         else
 1626                 return (kern_unlinkat(td, fd, path, UIO_USERSPACE, 0));
 1627 }
 1628 
 1629 int
 1630 kern_unlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1631     ino_t oldinum)
 1632 {
 1633         struct mount *mp;
 1634         struct vnode *vp;
 1635         struct nameidata nd;
 1636         struct stat sb;
 1637         cap_rights_t rights;
 1638         int error;
 1639 
 1640 restart:
 1641         bwillwrite();
 1642         NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
 1643             pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
 1644         if ((error = namei(&nd)) != 0)
 1645                 return (error == EINVAL ? EPERM : error);
 1646         vp = nd.ni_vp;
 1647         if (vp->v_type == VDIR && oldinum == 0) {
 1648                 error = EPERM;          /* POSIX */
 1649         } else if (oldinum != 0 &&
 1650                   ((error = vn_stat(vp, &sb, td->td_ucred, NOCRED, td)) == 0) &&
 1651                   sb.st_ino != oldinum) {
 1652                         error = EIDRM;  /* Identifier removed */
 1653         } else {
 1654                 /*
 1655                  * The root of a mounted filesystem cannot be deleted.
 1656                  *
 1657                  * XXX: can this only be a VDIR case?
 1658                  */
 1659                 if (vp->v_vflag & VV_ROOT)
 1660                         error = EBUSY;
 1661         }
 1662         if (error == 0) {
 1663                 if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 1664                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1665                         vput(nd.ni_dvp);
 1666                         if (vp == nd.ni_dvp)
 1667                                 vrele(vp);
 1668                         else
 1669                                 vput(vp);
 1670                         if ((error = vn_start_write(NULL, &mp,
 1671                             V_XSLEEP | PCATCH)) != 0)
 1672                                 return (error);
 1673                         goto restart;
 1674                 }
 1675 #ifdef MAC
 1676                 error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
 1677                     &nd.ni_cnd);
 1678                 if (error != 0)
 1679                         goto out;
 1680 #endif
 1681                 vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
 1682                 error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
 1683 #ifdef MAC
 1684 out:
 1685 #endif
 1686                 vn_finished_write(mp);
 1687         }
 1688         NDFREE(&nd, NDF_ONLY_PNBUF);
 1689         vput(nd.ni_dvp);
 1690         if (vp == nd.ni_dvp)
 1691                 vrele(vp);
 1692         else
 1693                 vput(vp);
 1694         return (error);
 1695 }
 1696 
 1697 /*
 1698  * Reposition read/write file offset.
 1699  */
 1700 #ifndef _SYS_SYSPROTO_H_
 1701 struct lseek_args {
 1702         int     fd;
 1703         int     pad;
 1704         off_t   offset;
 1705         int     whence;
 1706 };
 1707 #endif
 1708 int
 1709 sys_lseek(struct thread *td, struct lseek_args *uap)
 1710 {
 1711 
 1712         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1713 }
 1714 
 1715 int
 1716 kern_lseek(struct thread *td, int fd, off_t offset, int whence)
 1717 {
 1718         struct file *fp;
 1719         cap_rights_t rights;
 1720         int error;
 1721 
 1722         AUDIT_ARG_FD(fd);
 1723         error = fget(td, fd, cap_rights_init(&rights, CAP_SEEK), &fp);
 1724         if (error != 0)
 1725                 return (error);
 1726         error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
 1727             fo_seek(fp, offset, whence, td) : ESPIPE;
 1728         fdrop(fp, td);
 1729         return (error);
 1730 }
 1731 
 1732 #if defined(COMPAT_43)
 1733 /*
 1734  * Reposition read/write file offset.
 1735  */
 1736 #ifndef _SYS_SYSPROTO_H_
 1737 struct olseek_args {
 1738         int     fd;
 1739         long    offset;
 1740         int     whence;
 1741 };
 1742 #endif
 1743 int
 1744 olseek(struct thread *td, struct olseek_args *uap)
 1745 {
 1746 
 1747         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1748 }
 1749 #endif /* COMPAT_43 */
 1750 
 1751 #if defined(COMPAT_FREEBSD6)
 1752 /* Version with the 'pad' argument */
 1753 int
 1754 freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
 1755 {
 1756 
 1757         return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
 1758 }
 1759 #endif
 1760 
 1761 /*
 1762  * Check access permissions using passed credentials.
 1763  */
 1764 static int
 1765 vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
 1766      struct thread *td)
 1767 {
 1768         accmode_t accmode;
 1769         int error;
 1770 
 1771         /* Flags == 0 means only check for existence. */
 1772         if (user_flags == 0)
 1773                 return (0);
 1774 
 1775         accmode = 0;
 1776         if (user_flags & R_OK)
 1777                 accmode |= VREAD;
 1778         if (user_flags & W_OK)
 1779                 accmode |= VWRITE;
 1780         if (user_flags & X_OK)
 1781                 accmode |= VEXEC;
 1782 #ifdef MAC
 1783         error = mac_vnode_check_access(cred, vp, accmode);
 1784         if (error != 0)
 1785                 return (error);
 1786 #endif
 1787         if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
 1788                 error = VOP_ACCESS(vp, accmode, cred, td);
 1789         return (error);
 1790 }
 1791 
 1792 /*
 1793  * Check access permissions using "real" credentials.
 1794  */
 1795 #ifndef _SYS_SYSPROTO_H_
 1796 struct access_args {
 1797         char    *path;
 1798         int     amode;
 1799 };
 1800 #endif
 1801 int
 1802 sys_access(struct thread *td, struct access_args *uap)
 1803 {
 1804 
 1805         return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1806             0, uap->amode));
 1807 }
 1808 
 1809 #ifndef _SYS_SYSPROTO_H_
 1810 struct faccessat_args {
 1811         int     dirfd;
 1812         char    *path;
 1813         int     amode;
 1814         int     flag;
 1815 }
 1816 #endif
 1817 int
 1818 sys_faccessat(struct thread *td, struct faccessat_args *uap)
 1819 {
 1820 
 1821         return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
 1822             uap->amode));
 1823 }
 1824 
 1825 int
 1826 kern_accessat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 1827     int flag, int amode)
 1828 {
 1829         struct ucred *cred, *usecred;
 1830         struct vnode *vp;
 1831         struct nameidata nd;
 1832         cap_rights_t rights;
 1833         int error;
 1834 
 1835         if (flag & ~AT_EACCESS)
 1836                 return (EINVAL);
 1837         if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
 1838                 return (EINVAL);
 1839 
 1840         /*
 1841          * Create and modify a temporary credential instead of one that
 1842          * is potentially shared (if we need one).
 1843          */
 1844         cred = td->td_ucred;
 1845         if ((flag & AT_EACCESS) == 0 &&
 1846             ((cred->cr_uid != cred->cr_ruid ||
 1847             cred->cr_rgid != cred->cr_groups[0]))) {
 1848                 usecred = crdup(cred);
 1849                 usecred->cr_uid = cred->cr_ruid;
 1850                 usecred->cr_groups[0] = cred->cr_rgid;
 1851                 td->td_ucred = usecred;
 1852         } else
 1853                 usecred = cred;
 1854         AUDIT_ARG_VALUE(amode);
 1855         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF |
 1856             AUDITVNODE1, pathseg, path, fd, cap_rights_init(&rights, CAP_FSTAT),
 1857             td);
 1858         if ((error = namei(&nd)) != 0)
 1859                 goto out;
 1860         vp = nd.ni_vp;
 1861 
 1862         error = vn_access(vp, amode, usecred, td);
 1863         NDFREE(&nd, NDF_ONLY_PNBUF);
 1864         vput(vp);
 1865 out:
 1866         if (usecred != cred) {
 1867                 td->td_ucred = cred;
 1868                 crfree(usecred);
 1869         }
 1870         return (error);
 1871 }
 1872 
 1873 /*
 1874  * Check access permissions using "effective" credentials.
 1875  */
 1876 #ifndef _SYS_SYSPROTO_H_
 1877 struct eaccess_args {
 1878         char    *path;
 1879         int     amode;
 1880 };
 1881 #endif
 1882 int
 1883 sys_eaccess(struct thread *td, struct eaccess_args *uap)
 1884 {
 1885 
 1886         return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 1887             AT_EACCESS, uap->amode));
 1888 }
 1889 
 1890 #if defined(COMPAT_43)
 1891 /*
 1892  * Get file status; this version follows links.
 1893  */
 1894 #ifndef _SYS_SYSPROTO_H_
 1895 struct ostat_args {
 1896         char    *path;
 1897         struct ostat *ub;
 1898 };
 1899 #endif
 1900 int
 1901 ostat(struct thread *td, struct ostat_args *uap)
 1902 {
 1903         struct stat sb;
 1904         struct ostat osb;
 1905         int error;
 1906 
 1907         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 1908             &sb, NULL);
 1909         if (error != 0)
 1910                 return (error);
 1911         cvtstat(&sb, &osb);
 1912         return (copyout(&osb, uap->ub, sizeof (osb)));
 1913 }
 1914 
 1915 /*
 1916  * Get file status; this version does not follow links.
 1917  */
 1918 #ifndef _SYS_SYSPROTO_H_
 1919 struct olstat_args {
 1920         char    *path;
 1921         struct ostat *ub;
 1922 };
 1923 #endif
 1924 int
 1925 olstat(struct thread *td, struct olstat_args *uap)
 1926 {
 1927         struct stat sb;
 1928         struct ostat osb;
 1929         int error;
 1930 
 1931         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 1932             UIO_USERSPACE, &sb, NULL);
 1933         if (error != 0)
 1934                 return (error);
 1935         cvtstat(&sb, &osb);
 1936         return (copyout(&osb, uap->ub, sizeof (osb)));
 1937 }
 1938 
 1939 /*
 1940  * Convert from an old to a new stat structure.
 1941  */
 1942 void
 1943 cvtstat(struct stat *st, struct ostat *ost)
 1944 {
 1945 
 1946         bzero(ost, sizeof(*ost));
 1947         ost->st_dev = st->st_dev;
 1948         ost->st_ino = st->st_ino;
 1949         ost->st_mode = st->st_mode;
 1950         ost->st_nlink = st->st_nlink;
 1951         ost->st_uid = st->st_uid;
 1952         ost->st_gid = st->st_gid;
 1953         ost->st_rdev = st->st_rdev;
 1954         if (st->st_size < (quad_t)1 << 32)
 1955                 ost->st_size = st->st_size;
 1956         else
 1957                 ost->st_size = -2;
 1958         ost->st_atim = st->st_atim;
 1959         ost->st_mtim = st->st_mtim;
 1960         ost->st_ctim = st->st_ctim;
 1961         ost->st_blksize = st->st_blksize;
 1962         ost->st_blocks = st->st_blocks;
 1963         ost->st_flags = st->st_flags;
 1964         ost->st_gen = st->st_gen;
 1965 }
 1966 #endif /* COMPAT_43 */
 1967 
 1968 /*
 1969  * Get file status; this version follows links.
 1970  */
 1971 #ifndef _SYS_SYSPROTO_H_
 1972 struct stat_args {
 1973         char    *path;
 1974         struct stat *ub;
 1975 };
 1976 #endif
 1977 int
 1978 sys_stat(struct thread *td, struct stat_args *uap)
 1979 {
 1980         struct stat sb;
 1981         int error;
 1982 
 1983         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 1984             &sb, NULL);
 1985         if (error == 0)
 1986                 error = copyout(&sb, uap->ub, sizeof (sb));
 1987         return (error);
 1988 }
 1989 
 1990 #ifndef _SYS_SYSPROTO_H_
 1991 struct fstatat_args {
 1992         int     fd;
 1993         char    *path;
 1994         struct stat     *buf;
 1995         int     flag;
 1996 }
 1997 #endif
 1998 int
 1999 sys_fstatat(struct thread *td, struct fstatat_args *uap)
 2000 {
 2001         struct stat sb;
 2002         int error;
 2003 
 2004         error = kern_statat(td, uap->flag, uap->fd, uap->path,
 2005             UIO_USERSPACE, &sb, NULL);
 2006         if (error == 0)
 2007                 error = copyout(&sb, uap->buf, sizeof (sb));
 2008         return (error);
 2009 }
 2010 
 2011 int
 2012 kern_statat(struct thread *td, int flag, int fd, char *path,
 2013     enum uio_seg pathseg, struct stat *sbp,
 2014     void (*hook)(struct vnode *vp, struct stat *sbp))
 2015 {
 2016         struct nameidata nd;
 2017         struct stat sb;
 2018         cap_rights_t rights;
 2019         int error;
 2020 
 2021         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2022                 return (EINVAL);
 2023 
 2024         NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
 2025             FOLLOW) | LOCKSHARED | LOCKLEAF | AUDITVNODE1, pathseg, path, fd,
 2026             cap_rights_init(&rights, CAP_FSTAT), td);
 2027 
 2028         if ((error = namei(&nd)) != 0)
 2029                 return (error);
 2030         error = vn_stat(nd.ni_vp, &sb, td->td_ucred, NOCRED, td);
 2031         if (error == 0) {
 2032                 SDT_PROBE2(vfs, , stat, mode, path, sb.st_mode);
 2033                 if (S_ISREG(sb.st_mode))
 2034                         SDT_PROBE2(vfs, , stat, reg, path, pathseg);
 2035                 if (__predict_false(hook != NULL))
 2036                         hook(nd.ni_vp, &sb);
 2037         }
 2038         NDFREE(&nd, NDF_ONLY_PNBUF);
 2039         vput(nd.ni_vp);
 2040         if (error != 0)
 2041                 return (error);
 2042         *sbp = sb;
 2043 #ifdef KTRACE
 2044         if (KTRPOINT(td, KTR_STRUCT))
 2045                 ktrstat(&sb);
 2046 #endif
 2047         return (0);
 2048 }
 2049 
 2050 /*
 2051  * Get file status; this version does not follow links.
 2052  */
 2053 #ifndef _SYS_SYSPROTO_H_
 2054 struct lstat_args {
 2055         char    *path;
 2056         struct stat *ub;
 2057 };
 2058 #endif
 2059 int
 2060 sys_lstat(struct thread *td, struct lstat_args *uap)
 2061 {
 2062         struct stat sb;
 2063         int error;
 2064 
 2065         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 2066             UIO_USERSPACE, &sb, NULL);
 2067         if (error == 0)
 2068                 error = copyout(&sb, uap->ub, sizeof (sb));
 2069         return (error);
 2070 }
 2071 
 2072 /*
 2073  * Implementation of the NetBSD [l]stat() functions.
 2074  */
 2075 void
 2076 cvtnstat( struct stat *sb, struct nstat *nsb)
 2077 {
 2078 
 2079         bzero(nsb, sizeof *nsb);
 2080         nsb->st_dev = sb->st_dev;
 2081         nsb->st_ino = sb->st_ino;
 2082         nsb->st_mode = sb->st_mode;
 2083         nsb->st_nlink = sb->st_nlink;
 2084         nsb->st_uid = sb->st_uid;
 2085         nsb->st_gid = sb->st_gid;
 2086         nsb->st_rdev = sb->st_rdev;
 2087         nsb->st_atim = sb->st_atim;
 2088         nsb->st_mtim = sb->st_mtim;
 2089         nsb->st_ctim = sb->st_ctim;
 2090         nsb->st_size = sb->st_size;
 2091         nsb->st_blocks = sb->st_blocks;
 2092         nsb->st_blksize = sb->st_blksize;
 2093         nsb->st_flags = sb->st_flags;
 2094         nsb->st_gen = sb->st_gen;
 2095         nsb->st_birthtim = sb->st_birthtim;
 2096 }
 2097 
 2098 #ifndef _SYS_SYSPROTO_H_
 2099 struct nstat_args {
 2100         char    *path;
 2101         struct nstat *ub;
 2102 };
 2103 #endif
 2104 int
 2105 sys_nstat(struct thread *td, struct nstat_args *uap)
 2106 {
 2107         struct stat sb;
 2108         struct nstat nsb;
 2109         int error;
 2110 
 2111         error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
 2112             &sb, NULL);
 2113         if (error != 0)
 2114                 return (error);
 2115         cvtnstat(&sb, &nsb);
 2116         return (copyout(&nsb, uap->ub, sizeof (nsb)));
 2117 }
 2118 
 2119 /*
 2120  * NetBSD lstat.  Get file status; this version does not follow links.
 2121  */
 2122 #ifndef _SYS_SYSPROTO_H_
 2123 struct lstat_args {
 2124         char    *path;
 2125         struct stat *ub;
 2126 };
 2127 #endif
 2128 int
 2129 sys_nlstat(struct thread *td, struct nlstat_args *uap)
 2130 {
 2131         struct stat sb;
 2132         struct nstat nsb;
 2133         int error;
 2134 
 2135         error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
 2136             UIO_USERSPACE, &sb, NULL);
 2137         if (error != 0)
 2138                 return (error);
 2139         cvtnstat(&sb, &nsb);
 2140         return (copyout(&nsb, uap->ub, sizeof (nsb)));
 2141 }
 2142 
 2143 /*
 2144  * Get configurable pathname variables.
 2145  */
 2146 #ifndef _SYS_SYSPROTO_H_
 2147 struct pathconf_args {
 2148         char    *path;
 2149         int     name;
 2150 };
 2151 #endif
 2152 int
 2153 sys_pathconf(struct thread *td, struct pathconf_args *uap)
 2154 {
 2155 
 2156         return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW));
 2157 }
 2158 
 2159 #ifndef _SYS_SYSPROTO_H_
 2160 struct lpathconf_args {
 2161         char    *path;
 2162         int     name;
 2163 };
 2164 #endif
 2165 int
 2166 sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
 2167 {
 2168 
 2169         return (kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
 2170             NOFOLLOW));
 2171 }
 2172 
 2173 int
 2174 kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, int name,
 2175     u_long flags)
 2176 {
 2177         struct nameidata nd;
 2178         int error;
 2179 
 2180         NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
 2181             pathseg, path, td);
 2182         if ((error = namei(&nd)) != 0)
 2183                 return (error);
 2184         NDFREE(&nd, NDF_ONLY_PNBUF);
 2185 
 2186         error = VOP_PATHCONF(nd.ni_vp, name, td->td_retval);
 2187         vput(nd.ni_vp);
 2188         return (error);
 2189 }
 2190 
 2191 /*
 2192  * Return target name of a symbolic link.
 2193  */
 2194 #ifndef _SYS_SYSPROTO_H_
 2195 struct readlink_args {
 2196         char    *path;
 2197         char    *buf;
 2198         size_t  count;
 2199 };
 2200 #endif
 2201 int
 2202 sys_readlink(struct thread *td, struct readlink_args *uap)
 2203 {
 2204 
 2205         return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2206             uap->buf, UIO_USERSPACE, uap->count));
 2207 }
 2208 #ifndef _SYS_SYSPROTO_H_
 2209 struct readlinkat_args {
 2210         int     fd;
 2211         char    *path;
 2212         char    *buf;
 2213         size_t  bufsize;
 2214 };
 2215 #endif
 2216 int
 2217 sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
 2218 {
 2219 
 2220         return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
 2221             uap->buf, UIO_USERSPACE, uap->bufsize));
 2222 }
 2223 
 2224 int
 2225 kern_readlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2226     char *buf, enum uio_seg bufseg, size_t count)
 2227 {
 2228         struct vnode *vp;
 2229         struct iovec aiov;
 2230         struct uio auio;
 2231         struct nameidata nd;
 2232         int error;
 2233 
 2234         if (count > IOSIZE_MAX)
 2235                 return (EINVAL);
 2236 
 2237         NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
 2238             pathseg, path, fd, td);
 2239 
 2240         if ((error = namei(&nd)) != 0)
 2241                 return (error);
 2242         NDFREE(&nd, NDF_ONLY_PNBUF);
 2243         vp = nd.ni_vp;
 2244 #ifdef MAC
 2245         error = mac_vnode_check_readlink(td->td_ucred, vp);
 2246         if (error != 0) {
 2247                 vput(vp);
 2248                 return (error);
 2249         }
 2250 #endif
 2251         if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
 2252                 error = EINVAL;
 2253         else {
 2254                 aiov.iov_base = buf;
 2255                 aiov.iov_len = count;
 2256                 auio.uio_iov = &aiov;
 2257                 auio.uio_iovcnt = 1;
 2258                 auio.uio_offset = 0;
 2259                 auio.uio_rw = UIO_READ;
 2260                 auio.uio_segflg = bufseg;
 2261                 auio.uio_td = td;
 2262                 auio.uio_resid = count;
 2263                 error = VOP_READLINK(vp, &auio, td->td_ucred);
 2264                 td->td_retval[0] = count - auio.uio_resid;
 2265         }
 2266         vput(vp);
 2267         return (error);
 2268 }
 2269 
 2270 /*
 2271  * Common implementation code for chflags() and fchflags().
 2272  */
 2273 static int
 2274 setfflags(struct thread *td, struct vnode *vp, u_long flags)
 2275 {
 2276         struct mount *mp;
 2277         struct vattr vattr;
 2278         int error;
 2279 
 2280         /* We can't support the value matching VNOVAL. */
 2281         if (flags == VNOVAL)
 2282                 return (EOPNOTSUPP);
 2283 
 2284         /*
 2285          * Prevent non-root users from setting flags on devices.  When
 2286          * a device is reused, users can retain ownership of the device
 2287          * if they are allowed to set flags and programs assume that
 2288          * chown can't fail when done as root.
 2289          */
 2290         if (vp->v_type == VCHR || vp->v_type == VBLK) {
 2291                 error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
 2292                 if (error != 0)
 2293                         return (error);
 2294         }
 2295 
 2296         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2297                 return (error);
 2298         VATTR_NULL(&vattr);
 2299         vattr.va_flags = flags;
 2300         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2301 #ifdef MAC
 2302         error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
 2303         if (error == 0)
 2304 #endif
 2305                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 2306         VOP_UNLOCK(vp, 0);
 2307         vn_finished_write(mp);
 2308         return (error);
 2309 }
 2310 
 2311 /*
 2312  * Change flags of a file given a path name.
 2313  */
 2314 #ifndef _SYS_SYSPROTO_H_
 2315 struct chflags_args {
 2316         const char *path;
 2317         u_long  flags;
 2318 };
 2319 #endif
 2320 int
 2321 sys_chflags(struct thread *td, struct chflags_args *uap)
 2322 {
 2323 
 2324         return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2325             uap->flags, 0));
 2326 }
 2327 
 2328 #ifndef _SYS_SYSPROTO_H_
 2329 struct chflagsat_args {
 2330         int     fd;
 2331         const char *path;
 2332         u_long  flags;
 2333         int     atflag;
 2334 }
 2335 #endif
 2336 int
 2337 sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
 2338 {
 2339         int fd = uap->fd;
 2340         const char *path = uap->path;
 2341         u_long flags = uap->flags;
 2342         int atflag = uap->atflag;
 2343 
 2344         if (atflag & ~AT_SYMLINK_NOFOLLOW)
 2345                 return (EINVAL);
 2346 
 2347         return (kern_chflagsat(td, fd, path, UIO_USERSPACE, flags, atflag));
 2348 }
 2349 
 2350 /*
 2351  * Same as chflags() but doesn't follow symlinks.
 2352  */
 2353 #ifndef _SYS_SYSPROTO_H_
 2354 struct lchflags_args {
 2355         const char *path;
 2356         u_long flags;
 2357 };
 2358 #endif
 2359 int
 2360 sys_lchflags(struct thread *td, struct lchflags_args *uap)
 2361 {
 2362 
 2363         return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2364             uap->flags, AT_SYMLINK_NOFOLLOW));
 2365 }
 2366 
 2367 static int
 2368 kern_chflagsat(struct thread *td, int fd, const char *path,
 2369     enum uio_seg pathseg, u_long flags, int atflag)
 2370 {
 2371         struct nameidata nd;
 2372         cap_rights_t rights;
 2373         int error, follow;
 2374 
 2375         AUDIT_ARG_FFLAGS(flags);
 2376         follow = (atflag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2377         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2378             cap_rights_init(&rights, CAP_FCHFLAGS), td);
 2379         if ((error = namei(&nd)) != 0)
 2380                 return (error);
 2381         NDFREE(&nd, NDF_ONLY_PNBUF);
 2382         error = setfflags(td, nd.ni_vp, flags);
 2383         vrele(nd.ni_vp);
 2384         return (error);
 2385 }
 2386 
 2387 /*
 2388  * Change flags of a file given a file descriptor.
 2389  */
 2390 #ifndef _SYS_SYSPROTO_H_
 2391 struct fchflags_args {
 2392         int     fd;
 2393         u_long  flags;
 2394 };
 2395 #endif
 2396 int
 2397 sys_fchflags(struct thread *td, struct fchflags_args *uap)
 2398 {
 2399         struct file *fp;
 2400         cap_rights_t rights;
 2401         int error;
 2402 
 2403         AUDIT_ARG_FD(uap->fd);
 2404         AUDIT_ARG_FFLAGS(uap->flags);
 2405         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHFLAGS),
 2406             &fp);
 2407         if (error != 0)
 2408                 return (error);
 2409 #ifdef AUDIT
 2410         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2411         AUDIT_ARG_VNODE1(fp->f_vnode);
 2412         VOP_UNLOCK(fp->f_vnode, 0);
 2413 #endif
 2414         error = setfflags(td, fp->f_vnode, uap->flags);
 2415         fdrop(fp, td);
 2416         return (error);
 2417 }
 2418 
 2419 /*
 2420  * Common implementation code for chmod(), lchmod() and fchmod().
 2421  */
 2422 int
 2423 setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
 2424 {
 2425         struct mount *mp;
 2426         struct vattr vattr;
 2427         int error;
 2428 
 2429         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2430                 return (error);
 2431         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2432         VATTR_NULL(&vattr);
 2433         vattr.va_mode = mode & ALLPERMS;
 2434 #ifdef MAC
 2435         error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
 2436         if (error == 0)
 2437 #endif
 2438                 error = VOP_SETATTR(vp, &vattr, cred);
 2439         VOP_UNLOCK(vp, 0);
 2440         vn_finished_write(mp);
 2441         return (error);
 2442 }
 2443 
 2444 /*
 2445  * Change mode of a file given path name.
 2446  */
 2447 #ifndef _SYS_SYSPROTO_H_
 2448 struct chmod_args {
 2449         char    *path;
 2450         int     mode;
 2451 };
 2452 #endif
 2453 int
 2454 sys_chmod(struct thread *td, struct chmod_args *uap)
 2455 {
 2456 
 2457         return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2458             uap->mode, 0));
 2459 }
 2460 
 2461 #ifndef _SYS_SYSPROTO_H_
 2462 struct fchmodat_args {
 2463         int     dirfd;
 2464         char    *path;
 2465         mode_t  mode;
 2466         int     flag;
 2467 }
 2468 #endif
 2469 int
 2470 sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
 2471 {
 2472         int flag = uap->flag;
 2473         int fd = uap->fd;
 2474         char *path = uap->path;
 2475         mode_t mode = uap->mode;
 2476 
 2477         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2478                 return (EINVAL);
 2479 
 2480         return (kern_fchmodat(td, fd, path, UIO_USERSPACE, mode, flag));
 2481 }
 2482 
 2483 /*
 2484  * Change mode of a file given path name (don't follow links.)
 2485  */
 2486 #ifndef _SYS_SYSPROTO_H_
 2487 struct lchmod_args {
 2488         char    *path;
 2489         int     mode;
 2490 };
 2491 #endif
 2492 int
 2493 sys_lchmod(struct thread *td, struct lchmod_args *uap)
 2494 {
 2495 
 2496         return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2497             uap->mode, AT_SYMLINK_NOFOLLOW));
 2498 }
 2499 
 2500 int
 2501 kern_fchmodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2502     mode_t mode, int flag)
 2503 {
 2504         struct nameidata nd;
 2505         cap_rights_t rights;
 2506         int error, follow;
 2507 
 2508         AUDIT_ARG_MODE(mode);
 2509         follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2510         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2511             cap_rights_init(&rights, CAP_FCHMOD), td);
 2512         if ((error = namei(&nd)) != 0)
 2513                 return (error);
 2514         NDFREE(&nd, NDF_ONLY_PNBUF);
 2515         error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
 2516         vrele(nd.ni_vp);
 2517         return (error);
 2518 }
 2519 
 2520 /*
 2521  * Change mode of a file given a file descriptor.
 2522  */
 2523 #ifndef _SYS_SYSPROTO_H_
 2524 struct fchmod_args {
 2525         int     fd;
 2526         int     mode;
 2527 };
 2528 #endif
 2529 int
 2530 sys_fchmod(struct thread *td, struct fchmod_args *uap)
 2531 {
 2532         struct file *fp;
 2533         cap_rights_t rights;
 2534         int error;
 2535 
 2536         AUDIT_ARG_FD(uap->fd);
 2537         AUDIT_ARG_MODE(uap->mode);
 2538 
 2539         error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHMOD), &fp);
 2540         if (error != 0)
 2541                 return (error);
 2542         error = fo_chmod(fp, uap->mode, td->td_ucred, td);
 2543         fdrop(fp, td);
 2544         return (error);
 2545 }
 2546 
 2547 /*
 2548  * Common implementation for chown(), lchown(), and fchown()
 2549  */
 2550 int
 2551 setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
 2552     gid_t gid)
 2553 {
 2554         struct mount *mp;
 2555         struct vattr vattr;
 2556         int error;
 2557 
 2558         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2559                 return (error);
 2560         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2561         VATTR_NULL(&vattr);
 2562         vattr.va_uid = uid;
 2563         vattr.va_gid = gid;
 2564 #ifdef MAC
 2565         error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
 2566             vattr.va_gid);
 2567         if (error == 0)
 2568 #endif
 2569                 error = VOP_SETATTR(vp, &vattr, cred);
 2570         VOP_UNLOCK(vp, 0);
 2571         vn_finished_write(mp);
 2572         return (error);
 2573 }
 2574 
 2575 /*
 2576  * Set ownership given a path name.
 2577  */
 2578 #ifndef _SYS_SYSPROTO_H_
 2579 struct chown_args {
 2580         char    *path;
 2581         int     uid;
 2582         int     gid;
 2583 };
 2584 #endif
 2585 int
 2586 sys_chown(struct thread *td, struct chown_args *uap)
 2587 {
 2588 
 2589         return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
 2590             uap->gid, 0));
 2591 }
 2592 
 2593 #ifndef _SYS_SYSPROTO_H_
 2594 struct fchownat_args {
 2595         int fd;
 2596         const char * path;
 2597         uid_t uid;
 2598         gid_t gid;
 2599         int flag;
 2600 };
 2601 #endif
 2602 int
 2603 sys_fchownat(struct thread *td, struct fchownat_args *uap)
 2604 {
 2605         int flag;
 2606 
 2607         flag = uap->flag;
 2608         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2609                 return (EINVAL);
 2610 
 2611         return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
 2612             uap->gid, uap->flag));
 2613 }
 2614 
 2615 int
 2616 kern_fchownat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2617     int uid, int gid, int flag)
 2618 {
 2619         struct nameidata nd;
 2620         cap_rights_t rights;
 2621         int error, follow;
 2622 
 2623         AUDIT_ARG_OWNER(uid, gid);
 2624         follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
 2625         NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
 2626             cap_rights_init(&rights, CAP_FCHOWN), td);
 2627 
 2628         if ((error = namei(&nd)) != 0)
 2629                 return (error);
 2630         NDFREE(&nd, NDF_ONLY_PNBUF);
 2631         error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
 2632         vrele(nd.ni_vp);
 2633         return (error);
 2634 }
 2635 
 2636 /*
 2637  * Set ownership given a path name, do not cross symlinks.
 2638  */
 2639 #ifndef _SYS_SYSPROTO_H_
 2640 struct lchown_args {
 2641         char    *path;
 2642         int     uid;
 2643         int     gid;
 2644 };
 2645 #endif
 2646 int
 2647 sys_lchown(struct thread *td, struct lchown_args *uap)
 2648 {
 2649 
 2650         return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2651             uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
 2652 }
 2653 
 2654 /*
 2655  * Set ownership given a file descriptor.
 2656  */
 2657 #ifndef _SYS_SYSPROTO_H_
 2658 struct fchown_args {
 2659         int     fd;
 2660         int     uid;
 2661         int     gid;
 2662 };
 2663 #endif
 2664 int
 2665 sys_fchown(struct thread *td, struct fchown_args *uap)
 2666 {
 2667         struct file *fp;
 2668         cap_rights_t rights;
 2669         int error;
 2670 
 2671         AUDIT_ARG_FD(uap->fd);
 2672         AUDIT_ARG_OWNER(uap->uid, uap->gid);
 2673         error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHOWN), &fp);
 2674         if (error != 0)
 2675                 return (error);
 2676         error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
 2677         fdrop(fp, td);
 2678         return (error);
 2679 }
 2680 
 2681 /*
 2682  * Common implementation code for utimes(), lutimes(), and futimes().
 2683  */
 2684 static int
 2685 getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
 2686     struct timespec *tsp)
 2687 {
 2688         struct timeval tv[2];
 2689         const struct timeval *tvp;
 2690         int error;
 2691 
 2692         if (usrtvp == NULL) {
 2693                 vfs_timestamp(&tsp[0]);
 2694                 tsp[1] = tsp[0];
 2695         } else {
 2696                 if (tvpseg == UIO_SYSSPACE) {
 2697                         tvp = usrtvp;
 2698                 } else {
 2699                         if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
 2700                                 return (error);
 2701                         tvp = tv;
 2702                 }
 2703 
 2704                 if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
 2705                     tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
 2706                         return (EINVAL);
 2707                 TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
 2708                 TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
 2709         }
 2710         return (0);
 2711 }
 2712 
 2713 /*
 2714  * Common implementation code for futimens(), utimensat().
 2715  */
 2716 #define UTIMENS_NULL    0x1
 2717 #define UTIMENS_EXIT    0x2
 2718 static int
 2719 getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
 2720     struct timespec *tsp, int *retflags)
 2721 {
 2722         struct timespec tsnow;
 2723         int error;
 2724 
 2725         vfs_timestamp(&tsnow);
 2726         *retflags = 0;
 2727         if (usrtsp == NULL) {
 2728                 tsp[0] = tsnow;
 2729                 tsp[1] = tsnow;
 2730                 *retflags |= UTIMENS_NULL;
 2731                 return (0);
 2732         }
 2733         if (tspseg == UIO_SYSSPACE) {
 2734                 tsp[0] = usrtsp[0];
 2735                 tsp[1] = usrtsp[1];
 2736         } else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
 2737                 return (error);
 2738         if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
 2739                 *retflags |= UTIMENS_EXIT;
 2740         if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
 2741                 *retflags |= UTIMENS_NULL;
 2742         if (tsp[0].tv_nsec == UTIME_OMIT)
 2743                 tsp[0].tv_sec = VNOVAL;
 2744         else if (tsp[0].tv_nsec == UTIME_NOW)
 2745                 tsp[0] = tsnow;
 2746         else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
 2747                 return (EINVAL);
 2748         if (tsp[1].tv_nsec == UTIME_OMIT)
 2749                 tsp[1].tv_sec = VNOVAL;
 2750         else if (tsp[1].tv_nsec == UTIME_NOW)
 2751                 tsp[1] = tsnow;
 2752         else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
 2753                 return (EINVAL);
 2754 
 2755         return (0);
 2756 }
 2757 
 2758 /*
 2759  * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
 2760  * and utimensat().
 2761  */
 2762 static int
 2763 setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
 2764     int numtimes, int nullflag)
 2765 {
 2766         struct mount *mp;
 2767         struct vattr vattr;
 2768         int error, setbirthtime;
 2769 
 2770         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
 2771                 return (error);
 2772         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 2773         setbirthtime = 0;
 2774         if (numtimes < 3 && !VOP_GETATTR(vp, &vattr, td->td_ucred) &&
 2775             timespeccmp(&ts[1], &vattr.va_birthtime, < ))
 2776                 setbirthtime = 1;
 2777         VATTR_NULL(&vattr);
 2778         vattr.va_atime = ts[0];
 2779         vattr.va_mtime = ts[1];
 2780         if (setbirthtime)
 2781                 vattr.va_birthtime = ts[1];
 2782         if (numtimes > 2)
 2783                 vattr.va_birthtime = ts[2];
 2784         if (nullflag)
 2785                 vattr.va_vaflags |= VA_UTIMES_NULL;
 2786 #ifdef MAC
 2787         error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
 2788             vattr.va_mtime);
 2789 #endif
 2790         if (error == 0)
 2791                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 2792         VOP_UNLOCK(vp, 0);
 2793         vn_finished_write(mp);
 2794         return (error);
 2795 }
 2796 
 2797 /*
 2798  * Set the access and modification times of a file.
 2799  */
 2800 #ifndef _SYS_SYSPROTO_H_
 2801 struct utimes_args {
 2802         char    *path;
 2803         struct  timeval *tptr;
 2804 };
 2805 #endif
 2806 int
 2807 sys_utimes(struct thread *td, struct utimes_args *uap)
 2808 {
 2809 
 2810         return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 2811             uap->tptr, UIO_USERSPACE));
 2812 }
 2813 
 2814 #ifndef _SYS_SYSPROTO_H_
 2815 struct futimesat_args {
 2816         int fd;
 2817         const char * path;
 2818         const struct timeval * times;
 2819 };
 2820 #endif
 2821 int
 2822 sys_futimesat(struct thread *td, struct futimesat_args *uap)
 2823 {
 2824 
 2825         return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
 2826             uap->times, UIO_USERSPACE));
 2827 }
 2828 
 2829 int
 2830 kern_utimesat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2831     struct timeval *tptr, enum uio_seg tptrseg)
 2832 {
 2833         struct nameidata nd;
 2834         struct timespec ts[2];
 2835         cap_rights_t rights;
 2836         int error;
 2837 
 2838         if ((error = getutimes(tptr, tptrseg, ts)) != 0)
 2839                 return (error);
 2840         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
 2841             cap_rights_init(&rights, CAP_FUTIMES), td);
 2842 
 2843         if ((error = namei(&nd)) != 0)
 2844                 return (error);
 2845         NDFREE(&nd, NDF_ONLY_PNBUF);
 2846         error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
 2847         vrele(nd.ni_vp);
 2848         return (error);
 2849 }
 2850 
 2851 /*
 2852  * Set the access and modification times of a file.
 2853  */
 2854 #ifndef _SYS_SYSPROTO_H_
 2855 struct lutimes_args {
 2856         char    *path;
 2857         struct  timeval *tptr;
 2858 };
 2859 #endif
 2860 int
 2861 sys_lutimes(struct thread *td, struct lutimes_args *uap)
 2862 {
 2863 
 2864         return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
 2865             UIO_USERSPACE));
 2866 }
 2867 
 2868 int
 2869 kern_lutimes(struct thread *td, char *path, enum uio_seg pathseg,
 2870     struct timeval *tptr, enum uio_seg tptrseg)
 2871 {
 2872         struct timespec ts[2];
 2873         struct nameidata nd;
 2874         int error;
 2875 
 2876         if ((error = getutimes(tptr, tptrseg, ts)) != 0)
 2877                 return (error);
 2878         NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td);
 2879         if ((error = namei(&nd)) != 0)
 2880                 return (error);
 2881         NDFREE(&nd, NDF_ONLY_PNBUF);
 2882         error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
 2883         vrele(nd.ni_vp);
 2884         return (error);
 2885 }
 2886 
 2887 /*
 2888  * Set the access and modification times of a file.
 2889  */
 2890 #ifndef _SYS_SYSPROTO_H_
 2891 struct futimes_args {
 2892         int     fd;
 2893         struct  timeval *tptr;
 2894 };
 2895 #endif
 2896 int
 2897 sys_futimes(struct thread *td, struct futimes_args *uap)
 2898 {
 2899 
 2900         return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
 2901 }
 2902 
 2903 int
 2904 kern_futimes(struct thread *td, int fd, struct timeval *tptr,
 2905     enum uio_seg tptrseg)
 2906 {
 2907         struct timespec ts[2];
 2908         struct file *fp;
 2909         cap_rights_t rights;
 2910         int error;
 2911 
 2912         AUDIT_ARG_FD(fd);
 2913         error = getutimes(tptr, tptrseg, ts);
 2914         if (error != 0)
 2915                 return (error);
 2916         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
 2917         if (error != 0)
 2918                 return (error);
 2919 #ifdef AUDIT
 2920         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2921         AUDIT_ARG_VNODE1(fp->f_vnode);
 2922         VOP_UNLOCK(fp->f_vnode, 0);
 2923 #endif
 2924         error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
 2925         fdrop(fp, td);
 2926         return (error);
 2927 }
 2928 
 2929 int
 2930 sys_futimens(struct thread *td, struct futimens_args *uap)
 2931 {
 2932 
 2933         return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
 2934 }
 2935 
 2936 int
 2937 kern_futimens(struct thread *td, int fd, struct timespec *tptr,
 2938     enum uio_seg tptrseg)
 2939 {
 2940         struct timespec ts[2];
 2941         struct file *fp;
 2942         cap_rights_t rights;
 2943         int error, flags;
 2944 
 2945         AUDIT_ARG_FD(fd);
 2946         error = getutimens(tptr, tptrseg, ts, &flags);
 2947         if (error != 0)
 2948                 return (error);
 2949         if (flags & UTIMENS_EXIT)
 2950                 return (0);
 2951         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
 2952         if (error != 0)
 2953                 return (error);
 2954 #ifdef AUDIT
 2955         vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
 2956         AUDIT_ARG_VNODE1(fp->f_vnode);
 2957         VOP_UNLOCK(fp->f_vnode, 0);
 2958 #endif
 2959         error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
 2960         fdrop(fp, td);
 2961         return (error);
 2962 }
 2963 
 2964 int
 2965 sys_utimensat(struct thread *td, struct utimensat_args *uap)
 2966 {
 2967 
 2968         return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
 2969             uap->times, UIO_USERSPACE, uap->flag));
 2970 }
 2971 
 2972 int
 2973 kern_utimensat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
 2974     struct timespec *tptr, enum uio_seg tptrseg, int flag)
 2975 {
 2976         struct nameidata nd;
 2977         struct timespec ts[2];
 2978         cap_rights_t rights;
 2979         int error, flags;
 2980 
 2981         if (flag & ~AT_SYMLINK_NOFOLLOW)
 2982                 return (EINVAL);
 2983 
 2984         if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
 2985                 return (error);
 2986         NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
 2987             FOLLOW) | AUDITVNODE1, pathseg, path, fd,
 2988             cap_rights_init(&rights, CAP_FUTIMES), td);
 2989         if ((error = namei(&nd)) != 0)
 2990                 return (error);
 2991         /*
 2992          * We are allowed to call namei() regardless of 2xUTIME_OMIT.
 2993          * POSIX states:
 2994          * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
 2995          * "Search permission is denied by a component of the path prefix."
 2996          */
 2997         NDFREE(&nd, NDF_ONLY_PNBUF);
 2998         if ((flags & UTIMENS_EXIT) == 0)
 2999                 error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
 3000         vrele(nd.ni_vp);
 3001         return (error);
 3002 }
 3003 
 3004 /*
 3005  * Truncate a file given its path name.
 3006  */
 3007 #ifndef _SYS_SYSPROTO_H_
 3008 struct truncate_args {
 3009         char    *path;
 3010         int     pad;
 3011         off_t   length;
 3012 };
 3013 #endif
 3014 int
 3015 sys_truncate(struct thread *td, struct truncate_args *uap)
 3016 {
 3017 
 3018         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3019 }
 3020 
 3021 int
 3022 kern_truncate(struct thread *td, char *path, enum uio_seg pathseg, off_t length)
 3023 {
 3024         struct mount *mp;
 3025         struct vnode *vp;
 3026         void *rl_cookie;
 3027         struct vattr vattr;
 3028         struct nameidata nd;
 3029         int error;
 3030 
 3031         if (length < 0)
 3032                 return(EINVAL);
 3033         NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
 3034         if ((error = namei(&nd)) != 0)
 3035                 return (error);
 3036         vp = nd.ni_vp;
 3037         rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
 3038         if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) {
 3039                 vn_rangelock_unlock(vp, rl_cookie);
 3040                 vrele(vp);
 3041                 return (error);
 3042         }
 3043         NDFREE(&nd, NDF_ONLY_PNBUF);
 3044         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 3045         if (vp->v_type == VDIR)
 3046                 error = EISDIR;
 3047 #ifdef MAC
 3048         else if ((error = mac_vnode_check_write(td->td_ucred, NOCRED, vp))) {
 3049         }
 3050 #endif
 3051         else if ((error = vn_writechk(vp)) == 0 &&
 3052             (error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td)) == 0) {
 3053                 VATTR_NULL(&vattr);
 3054                 vattr.va_size = length;
 3055                 error = VOP_SETATTR(vp, &vattr, td->td_ucred);
 3056         }
 3057         VOP_UNLOCK(vp, 0);
 3058         vn_finished_write(mp);
 3059         vn_rangelock_unlock(vp, rl_cookie);
 3060         vrele(vp);
 3061         return (error);
 3062 }
 3063 
 3064 #if defined(COMPAT_43)
 3065 /*
 3066  * Truncate a file given its path name.
 3067  */
 3068 #ifndef _SYS_SYSPROTO_H_
 3069 struct otruncate_args {
 3070         char    *path;
 3071         long    length;
 3072 };
 3073 #endif
 3074 int
 3075 otruncate(struct thread *td, struct otruncate_args *uap)
 3076 {
 3077 
 3078         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3079 }
 3080 #endif /* COMPAT_43 */
 3081 
 3082 #if defined(COMPAT_FREEBSD6)
 3083 /* Versions with the pad argument */
 3084 int
 3085 freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
 3086 {
 3087 
 3088         return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
 3089 }
 3090 
 3091 int
 3092 freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
 3093 {
 3094 
 3095         return (kern_ftruncate(td, uap->fd, uap->length));
 3096 }
 3097 #endif
 3098 
 3099 int
 3100 kern_fsync(struct thread *td, int fd, bool fullsync)
 3101 {
 3102         struct vnode *vp;
 3103         struct mount *mp;
 3104         struct file *fp;
 3105         cap_rights_t rights;
 3106         int error, lock_flags;
 3107 
 3108         AUDIT_ARG_FD(fd);
 3109         error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSYNC), &fp);
 3110         if (error != 0)
 3111                 return (error);
 3112         vp = fp->f_vnode;
 3113 #if 0
 3114         if (!fullsync)
 3115                 /* XXXKIB: compete outstanding aio writes */;
 3116 #endif
 3117         error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
 3118         if (error != 0)
 3119                 goto drop;
 3120         if (MNT_SHARED_WRITES(mp) ||
 3121             ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) {
 3122                 lock_flags = LK_SHARED;
 3123         } else {
 3124                 lock_flags = LK_EXCLUSIVE;
 3125         }
 3126         vn_lock(vp, lock_flags | LK_RETRY);
 3127         AUDIT_ARG_VNODE1(vp);
 3128         if (vp->v_object != NULL) {
 3129                 VM_OBJECT_WLOCK(vp->v_object);
 3130                 vm_object_page_clean(vp->v_object, 0, 0, 0);
 3131                 VM_OBJECT_WUNLOCK(vp->v_object);
 3132         }
 3133         error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
 3134         VOP_UNLOCK(vp, 0);
 3135         vn_finished_write(mp);
 3136 drop:
 3137         fdrop(fp, td);
 3138         return (error);
 3139 }
 3140 
 3141 /*
 3142  * Sync an open file.
 3143  */
 3144 #ifndef _SYS_SYSPROTO_H_
 3145 struct fsync_args {
 3146         int     fd;
 3147 };
 3148 #endif
 3149 int
 3150 sys_fsync(struct thread *td, struct fsync_args *uap)
 3151 {
 3152 
 3153         return (kern_fsync(td, uap->fd, true));
 3154 }
 3155 
 3156 int
 3157 sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
 3158 {
 3159 
 3160         return (kern_fsync(td, uap->fd, false));
 3161 }
 3162 
 3163 /*
 3164  * Rename files.  Source and destination must either both be directories, or
 3165  * both not be directories.  If target is a directory, it must be empty.
 3166  */
 3167 #ifndef _SYS_SYSPROTO_H_
 3168 struct rename_args {
 3169         char    *from;
 3170         char    *to;
 3171 };
 3172 #endif
 3173 int
 3174 sys_rename(struct thread *td, struct rename_args *uap)
 3175 {
 3176 
 3177         return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
 3178             uap->to, UIO_USERSPACE));
 3179 }
 3180 
 3181 #ifndef _SYS_SYSPROTO_H_
 3182 struct renameat_args {
 3183         int     oldfd;
 3184         char    *old;
 3185         int     newfd;
 3186         char    *new;
 3187 };
 3188 #endif
 3189 int
 3190 sys_renameat(struct thread *td, struct renameat_args *uap)
 3191 {
 3192 
 3193         return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
 3194             UIO_USERSPACE));
 3195 }
 3196 
 3197 int
 3198 kern_renameat(struct thread *td, int oldfd, char *old, int newfd, char *new,
 3199     enum uio_seg pathseg)
 3200 {
 3201         struct mount *mp = NULL;
 3202         struct vnode *tvp, *fvp, *tdvp;
 3203         struct nameidata fromnd, tond;
 3204         cap_rights_t rights;
 3205         int error;
 3206 
 3207 again:
 3208         bwillwrite();
 3209 #ifdef MAC
 3210         NDINIT_ATRIGHTS(&fromnd, DELETE, LOCKPARENT | LOCKLEAF | SAVESTART |
 3211             AUDITVNODE1, pathseg, old, oldfd,
 3212             cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
 3213 #else
 3214         NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | SAVESTART | AUDITVNODE1,
 3215             pathseg, old, oldfd,
 3216             cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
 3217 #endif
 3218 
 3219         if ((error = namei(&fromnd)) != 0)
 3220                 return (error);
 3221 #ifdef MAC
 3222         error = mac_vnode_check_rename_from(td->td_ucred, fromnd.ni_dvp,
 3223             fromnd.ni_vp, &fromnd.ni_cnd);
 3224         VOP_UNLOCK(fromnd.ni_dvp, 0);
 3225         if (fromnd.ni_dvp != fromnd.ni_vp)
 3226                 VOP_UNLOCK(fromnd.ni_vp, 0);
 3227 #endif
 3228         fvp = fromnd.ni_vp;
 3229         NDINIT_ATRIGHTS(&tond, RENAME, LOCKPARENT | LOCKLEAF | NOCACHE |
 3230             SAVESTART | AUDITVNODE2, pathseg, new, newfd,
 3231             cap_rights_init(&rights, CAP_RENAMEAT_TARGET), td);
 3232         if (fromnd.ni_vp->v_type == VDIR)
 3233                 tond.ni_cnd.cn_flags |= WILLBEDIR;
 3234         if ((error = namei(&tond)) != 0) {
 3235                 /* Translate error code for rename("dir1", "dir2/."). */
 3236                 if (error == EISDIR && fvp->v_type == VDIR)
 3237                         error = EINVAL;
 3238                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3239                 vrele(fromnd.ni_dvp);
 3240                 vrele(fvp);
 3241                 goto out1;
 3242         }
 3243         tdvp = tond.ni_dvp;
 3244         tvp = tond.ni_vp;
 3245         error = vn_start_write(fvp, &mp, V_NOWAIT);
 3246         if (error != 0) {
 3247                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3248                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3249                 if (tvp != NULL)
 3250                         vput(tvp);
 3251                 if (tdvp == tvp)
 3252                         vrele(tdvp);
 3253                 else
 3254                         vput(tdvp);
 3255                 vrele(fromnd.ni_dvp);
 3256                 vrele(fvp);
 3257                 vrele(tond.ni_startdir);
 3258                 if (fromnd.ni_startdir != NULL)
 3259                         vrele(fromnd.ni_startdir);
 3260                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
 3261                 if (error != 0)
 3262                         return (error);
 3263                 goto again;
 3264         }
 3265         if (tvp != NULL) {
 3266                 if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
 3267                         error = ENOTDIR;
 3268                         goto out;
 3269                 } else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
 3270                         error = EISDIR;
 3271                         goto out;
 3272                 }
 3273 #ifdef CAPABILITIES
 3274                 if (newfd != AT_FDCWD) {
 3275                         /*
 3276                          * If the target already exists we require CAP_UNLINKAT
 3277                          * from 'newfd'.
 3278                          */
 3279                         error = cap_check(&tond.ni_filecaps.fc_rights,
 3280                             cap_rights_init(&rights, CAP_UNLINKAT));
 3281                         if (error != 0)
 3282                                 goto out;
 3283                 }
 3284 #endif
 3285         }
 3286         if (fvp == tdvp) {
 3287                 error = EINVAL;
 3288                 goto out;
 3289         }
 3290         /*
 3291          * If the source is the same as the destination (that is, if they
 3292          * are links to the same vnode), then there is nothing to do.
 3293          */
 3294         if (fvp == tvp)
 3295                 error = -1;
 3296 #ifdef MAC
 3297         else
 3298                 error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
 3299                     tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
 3300 #endif
 3301 out:
 3302         if (error == 0) {
 3303                 error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
 3304                     tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
 3305                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3306                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3307         } else {
 3308                 NDFREE(&fromnd, NDF_ONLY_PNBUF);
 3309                 NDFREE(&tond, NDF_ONLY_PNBUF);
 3310                 if (tvp != NULL)
 3311                         vput(tvp);
 3312                 if (tdvp == tvp)
 3313                         vrele(tdvp);
 3314                 else
 3315                         vput(tdvp);
 3316                 vrele(fromnd.ni_dvp);
 3317                 vrele(fvp);
 3318         }
 3319         vrele(tond.ni_startdir);
 3320         vn_finished_write(mp);
 3321 out1:
 3322         if (fromnd.ni_startdir)
 3323                 vrele(fromnd.ni_startdir);
 3324         if (error == -1)
 3325                 return (0);
 3326         return (error);
 3327 }
 3328 
 3329 /*
 3330  * Make a directory file.
 3331  */
 3332 #ifndef _SYS_SYSPROTO_H_
 3333 struct mkdir_args {
 3334         char    *path;
 3335         int     mode;
 3336 };
 3337 #endif
 3338 int
 3339 sys_mkdir(struct thread *td, struct mkdir_args *uap)
 3340 {
 3341 
 3342         return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
 3343             uap->mode));
 3344 }
 3345 
 3346 #ifndef _SYS_SYSPROTO_H_
 3347 struct mkdirat_args {
 3348         int     fd;
 3349         char    *path;
 3350         mode_t  mode;
 3351 };
 3352 #endif
 3353 int
 3354 sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
 3355 {
 3356 
 3357         return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
 3358 }
 3359 
 3360 int
 3361 kern_mkdirat(struct thread *td, int fd, char *path, enum uio_seg segflg,
 3362     int mode)
 3363 {
 3364         struct mount *mp;
 3365         struct vnode *vp;
 3366         struct vattr vattr;
 3367         struct nameidata nd;
 3368         cap_rights_t rights;
 3369         int error;
 3370 
 3371         AUDIT_ARG_MODE(mode);
 3372 restart:
 3373         bwillwrite();
 3374         NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
 3375             NOCACHE, segflg, path, fd, cap_rights_init(&rights, CAP_MKDIRAT),
 3376             td);
 3377         nd.ni_cnd.cn_flags |= WILLBEDIR;
 3378         if ((error = namei(&nd)) != 0)
 3379                 return (error);
 3380         vp = nd.ni_vp;
 3381         if (vp != NULL) {
 3382                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3383                 /*
 3384                  * XXX namei called with LOCKPARENT but not LOCKLEAF has
 3385                  * the strange behaviour of leaving the vnode unlocked
 3386                  * if the target is the same vnode as the parent.
 3387                  */
 3388                 if (vp == nd.ni_dvp)
 3389                         vrele(nd.ni_dvp);
 3390                 else
 3391                         vput(nd.ni_dvp);
 3392                 vrele(vp);
 3393                 return (EEXIST);
 3394         }
 3395         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 3396                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3397                 vput(nd.ni_dvp);
 3398                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3399                         return (error);
 3400                 goto restart;
 3401         }
 3402         VATTR_NULL(&vattr);
 3403         vattr.va_type = VDIR;
 3404         vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_fd->fd_cmask;
 3405 #ifdef MAC
 3406         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 3407             &vattr);
 3408         if (error != 0)
 3409                 goto out;
 3410 #endif
 3411         error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 3412 #ifdef MAC
 3413 out:
 3414 #endif
 3415         NDFREE(&nd, NDF_ONLY_PNBUF);
 3416         vput(nd.ni_dvp);
 3417         if (error == 0)
 3418                 vput(nd.ni_vp);
 3419         vn_finished_write(mp);
 3420         return (error);
 3421 }
 3422 
 3423 /*
 3424  * Remove a directory file.
 3425  */
 3426 #ifndef _SYS_SYSPROTO_H_
 3427 struct rmdir_args {
 3428         char    *path;
 3429 };
 3430 #endif
 3431 int
 3432 sys_rmdir(struct thread *td, struct rmdir_args *uap)
 3433 {
 3434 
 3435         return (kern_rmdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE));
 3436 }
 3437 
 3438 int
 3439 kern_rmdirat(struct thread *td, int fd, char *path, enum uio_seg pathseg)
 3440 {
 3441         struct mount *mp;
 3442         struct vnode *vp;
 3443         struct nameidata nd;
 3444         cap_rights_t rights;
 3445         int error;
 3446 
 3447 restart:
 3448         bwillwrite();
 3449         NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
 3450             pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
 3451         if ((error = namei(&nd)) != 0)
 3452                 return (error);
 3453         vp = nd.ni_vp;
 3454         if (vp->v_type != VDIR) {
 3455                 error = ENOTDIR;
 3456                 goto out;
 3457         }
 3458         /*
 3459          * No rmdir "." please.
 3460          */
 3461         if (nd.ni_dvp == vp) {
 3462                 error = EINVAL;
 3463                 goto out;
 3464         }
 3465         /*
 3466          * The root of a mounted filesystem cannot be deleted.
 3467          */
 3468         if (vp->v_vflag & VV_ROOT) {
 3469                 error = EBUSY;
 3470                 goto out;
 3471         }
 3472 #ifdef MAC
 3473         error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
 3474             &nd.ni_cnd);
 3475         if (error != 0)
 3476                 goto out;
 3477 #endif
 3478         if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 3479                 NDFREE(&nd, NDF_ONLY_PNBUF);
 3480                 vput(vp);
 3481                 if (nd.ni_dvp == vp)
 3482                         vrele(nd.ni_dvp);
 3483                 else
 3484                         vput(nd.ni_dvp);
 3485                 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
 3486                         return (error);
 3487                 goto restart;
 3488         }
 3489         vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
 3490         error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
 3491         vn_finished_write(mp);
 3492 out:
 3493         NDFREE(&nd, NDF_ONLY_PNBUF);
 3494         vput(vp);
 3495         if (nd.ni_dvp == vp)
 3496                 vrele(nd.ni_dvp);
 3497         else
 3498                 vput(nd.ni_dvp);
 3499         return (error);
 3500 }
 3501 
 3502 #ifdef COMPAT_43
 3503 /*
 3504  * Read a block of directory entries in a filesystem independent format.
 3505  */
 3506 #ifndef _SYS_SYSPROTO_H_
 3507 struct ogetdirentries_args {
 3508         int     fd;
 3509         char    *buf;
 3510         u_int   count;
 3511         long    *basep;
 3512 };
 3513 #endif
 3514 int
 3515 ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
 3516 {
 3517         long loff;
 3518         int error;
 3519 
 3520         error = kern_ogetdirentries(td, uap, &loff);
 3521         if (error == 0)
 3522                 error = copyout(&loff, uap->basep, sizeof(long));
 3523         return (error);
 3524 }
 3525 
 3526 int
 3527 kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
 3528     long *ploff)
 3529 {
 3530         struct vnode *vp;
 3531         struct file *fp;
 3532         struct uio auio, kuio;
 3533         struct iovec aiov, kiov;
 3534         struct dirent *dp, *edp;
 3535         cap_rights_t rights;
 3536         caddr_t dirbuf;
 3537         int error, eofflag, readcnt;
 3538         long loff;
 3539         off_t foffset;
 3540 
 3541         /* XXX arbitrary sanity limit on `count'. */
 3542         if (uap->count > 64 * 1024)
 3543                 return (EINVAL);
 3544         error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_READ), &fp);
 3545         if (error != 0)
 3546                 return (error);
 3547         if ((fp->f_flag & FREAD) == 0) {
 3548                 fdrop(fp, td);
 3549                 return (EBADF);
 3550         }
 3551         vp = fp->f_vnode;
 3552         foffset = foffset_lock(fp, 0);
 3553 unionread:
 3554         if (vp->v_type != VDIR) {
 3555                 foffset_unlock(fp, foffset, 0);
 3556                 fdrop(fp, td);
 3557                 return (EINVAL);
 3558         }
 3559         aiov.iov_base = uap->buf;
 3560         aiov.iov_len = uap->count;
 3561         auio.uio_iov = &aiov;
 3562         auio.uio_iovcnt = 1;
 3563         auio.uio_rw = UIO_READ;
 3564         auio.uio_segflg = UIO_USERSPACE;
 3565         auio.uio_td = td;
 3566         auio.uio_resid = uap->count;
 3567         vn_lock(vp, LK_SHARED | LK_RETRY);
 3568         loff = auio.uio_offset = foffset;
 3569 #ifdef MAC
 3570         error = mac_vnode_check_readdir(td->td_ucred, vp);
 3571         if (error != 0) {
 3572                 VOP_UNLOCK(vp, 0);
 3573                 foffset_unlock(fp, foffset, FOF_NOUPDATE);
 3574                 fdrop(fp, td);
 3575                 return (error);
 3576         }
 3577 #endif
 3578 #       if (BYTE_ORDER != LITTLE_ENDIAN)
 3579                 if (vp->v_mount->mnt_maxsymlinklen <= 0) {
 3580                         error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag,
 3581                             NULL, NULL);
 3582                         foffset = auio.uio_offset;
 3583                 } else
 3584 #       endif
 3585         {
 3586                 kuio = auio;
 3587                 kuio.uio_iov = &kiov;
 3588                 kuio.uio_segflg = UIO_SYSSPACE;
 3589                 kiov.iov_len = uap->count;
 3590                 dirbuf = malloc(uap->count, M_TEMP, M_WAITOK);
 3591                 kiov.iov_base = dirbuf;
 3592                 error = VOP_READDIR(vp, &kuio, fp->f_cred, &eofflag,
 3593                             NULL, NULL);
 3594                 foffset = kuio.uio_offset;
 3595                 if (error == 0) {
 3596                         readcnt = uap->count - kuio.uio_resid;
 3597                         edp = (struct dirent *)&dirbuf[readcnt];
 3598                         for (dp = (struct dirent *)dirbuf; dp < edp; ) {
 3599 #                               if (BYTE_ORDER == LITTLE_ENDIAN)
 3600                                         /*
 3601                                          * The expected low byte of
 3602                                          * dp->d_namlen is our dp->d_type.
 3603                                          * The high MBZ byte of dp->d_namlen
 3604                                          * is our dp->d_namlen.
 3605                                          */
 3606                                         dp->d_type = dp->d_namlen;
 3607                                         dp->d_namlen = 0;
 3608 #                               else
 3609                                         /*
 3610                                          * The dp->d_type is the high byte
 3611                                          * of the expected dp->d_namlen,
 3612                                          * so must be zero'ed.
 3613                                          */
 3614                                         dp->d_type = 0;
 3615 #                               endif
 3616                                 if (dp->d_reclen > 0) {
 3617                                         dp = (struct dirent *)
 3618                                             ((char *)dp + dp->d_reclen);
 3619                                 } else {
 3620                                         error = EIO;
 3621                                         break;
 3622                                 }
 3623                         }
 3624                         if (dp >= edp)
 3625                                 error = uiomove(dirbuf, readcnt, &auio);
 3626                 }
 3627                 free(dirbuf, M_TEMP);
 3628         }
 3629         if (error != 0) {
 3630                 VOP_UNLOCK(vp, 0);
 3631                 foffset_unlock(fp, foffset, 0);
 3632                 fdrop(fp, td);
 3633                 return (error);
 3634         }
 3635         if (uap->count == auio.uio_resid &&
 3636             (vp->v_vflag & VV_ROOT) &&
 3637             (vp->v_mount->mnt_flag & MNT_UNION)) {
 3638                 struct vnode *tvp = vp;
 3639                 vp = vp->v_mount->mnt_vnodecovered;
 3640                 VREF(vp);
 3641                 fp->f_vnode = vp;
 3642                 fp->f_data = vp;
 3643                 foffset = 0;
 3644                 vput(tvp);
 3645                 goto unionread;
 3646         }
 3647         VOP_UNLOCK(vp, 0);
 3648         foffset_unlock(fp, foffset, 0);
 3649         fdrop(fp, td);
 3650         td->td_retval[0] = uap->count - auio.uio_resid;
 3651         if (error == 0)
 3652                 *ploff = loff;
 3653         return (error);
 3654 }
 3655 #endif /* COMPAT_43 */
 3656 
 3657 /*
 3658  * Read a block of directory entries in a filesystem independent format.
 3659  */
 3660 #ifndef _SYS_SYSPROTO_H_
 3661 struct getdirentries_args {
 3662         int     fd;
 3663         char    *buf;
 3664         u_int   count;
 3665         long    *basep;
 3666 };
 3667 #endif
 3668 int
 3669 sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
 3670 {
 3671         long base;
 3672         int error;
 3673 
 3674         error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
 3675             NULL, UIO_USERSPACE);
 3676         if (error != 0)
 3677                 return (error);
 3678         if (uap->basep != NULL)
 3679                 error = copyout(&base, uap->basep, sizeof(long));
 3680         return (error);
 3681 }
 3682 
 3683 int
 3684 kern_getdirentries(struct thread *td, int fd, char *buf, u_int count,
 3685     long *basep, ssize_t *residp, enum uio_seg bufseg)
 3686 {
 3687         struct vnode *vp;
 3688         struct file *fp;
 3689         struct uio auio;
 3690         struct iovec aiov;
 3691         cap_rights_t rights;
 3692         long loff;
 3693         int error, eofflag;
 3694         off_t foffset;
 3695 
 3696         AUDIT_ARG_FD(fd);
 3697         if (count > IOSIZE_MAX)
 3698                 return (EINVAL);
 3699         auio.uio_resid = count;
 3700         error = getvnode(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
 3701         if (error != 0)
 3702                 return (error);
 3703         if ((fp->f_flag & FREAD) == 0) {
 3704                 fdrop(fp, td);
 3705                 return (EBADF);
 3706         }
 3707         vp = fp->f_vnode;
 3708         foffset = foffset_lock(fp, 0);
 3709 unionread:
 3710         if (vp->v_type != VDIR) {
 3711                 error = EINVAL;
 3712                 goto fail;
 3713         }
 3714         aiov.iov_base = buf;
 3715         aiov.iov_len = count;
 3716         auio.uio_iov = &aiov;
 3717         auio.uio_iovcnt = 1;
 3718         auio.uio_rw = UIO_READ;
 3719         auio.uio_segflg = bufseg;
 3720         auio.uio_td = td;
 3721         vn_lock(vp, LK_SHARED | LK_RETRY);
 3722         AUDIT_ARG_VNODE1(vp);
 3723         loff = auio.uio_offset = foffset;
 3724 #ifdef MAC
 3725         error = mac_vnode_check_readdir(td->td_ucred, vp);
 3726         if (error == 0)
 3727 #endif
 3728                 error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
 3729                     NULL);
 3730         foffset = auio.uio_offset;
 3731         if (error != 0) {
 3732                 VOP_UNLOCK(vp, 0);
 3733                 goto fail;
 3734         }
 3735         if (count == auio.uio_resid &&
 3736             (vp->v_vflag & VV_ROOT) &&
 3737             (vp->v_mount->mnt_flag & MNT_UNION)) {
 3738                 struct vnode *tvp = vp;
 3739 
 3740                 vp = vp->v_mount->mnt_vnodecovered;
 3741                 VREF(vp);
 3742                 fp->f_vnode = vp;
 3743                 fp->f_data = vp;
 3744                 foffset = 0;
 3745                 vput(tvp);
 3746                 goto unionread;
 3747         }
 3748         VOP_UNLOCK(vp, 0);
 3749         *basep = loff;
 3750         if (residp != NULL)
 3751                 *residp = auio.uio_resid;
 3752         td->td_retval[0] = count - auio.uio_resid;
 3753 fail:
 3754         foffset_unlock(fp, foffset, 0);
 3755         fdrop(fp, td);
 3756         return (error);
 3757 }
 3758 
 3759 #ifndef _SYS_SYSPROTO_H_
 3760 struct getdents_args {
 3761         int fd;
 3762         char *buf;
 3763         size_t count;
 3764 };
 3765 #endif
 3766 int
 3767 sys_getdents(struct thread *td, struct getdents_args *uap)
 3768 {
 3769         struct getdirentries_args ap;
 3770 
 3771         ap.fd = uap->fd;
 3772         ap.buf = uap->buf;
 3773         ap.count = uap->count;
 3774         ap.basep = NULL;
 3775         return (sys_getdirentries(td, &ap));
 3776 }
 3777 
 3778 /*
 3779  * Set the mode mask for creation of filesystem nodes.
 3780  */
 3781 #ifndef _SYS_SYSPROTO_H_
 3782 struct umask_args {
 3783         int     newmask;
 3784 };
 3785 #endif
 3786 int
 3787 sys_umask(struct thread *td, struct umask_args *uap)
 3788 {
 3789         struct filedesc *fdp;
 3790 
 3791         fdp = td->td_proc->p_fd;
 3792         FILEDESC_XLOCK(fdp);
 3793         td->td_retval[0] = fdp->fd_cmask;
 3794         fdp->fd_cmask = uap->newmask & ALLPERMS;
 3795         FILEDESC_XUNLOCK(fdp);
 3796         return (0);
 3797 }
 3798 
 3799 /*
 3800  * Void all references to file by ripping underlying filesystem away from
 3801  * vnode.
 3802  */
 3803 #ifndef _SYS_SYSPROTO_H_
 3804 struct revoke_args {
 3805         char    *path;
 3806 };
 3807 #endif
 3808 int
 3809 sys_revoke(struct thread *td, struct revoke_args *uap)
 3810 {
 3811         struct vnode *vp;
 3812         struct vattr vattr;
 3813         struct nameidata nd;
 3814         int error;
 3815 
 3816         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3817             uap->path, td);
 3818         if ((error = namei(&nd)) != 0)
 3819                 return (error);
 3820         vp = nd.ni_vp;
 3821         NDFREE(&nd, NDF_ONLY_PNBUF);
 3822         if (vp->v_type != VCHR || vp->v_rdev == NULL) {
 3823                 error = EINVAL;
 3824                 goto out;
 3825         }
 3826 #ifdef MAC
 3827         error = mac_vnode_check_revoke(td->td_ucred, vp);
 3828         if (error != 0)
 3829                 goto out;
 3830 #endif
 3831         error = VOP_GETATTR(vp, &vattr, td->td_ucred);
 3832         if (error != 0)
 3833                 goto out;
 3834         if (td->td_ucred->cr_uid != vattr.va_uid) {
 3835                 error = priv_check(td, PRIV_VFS_ADMIN);
 3836                 if (error != 0)
 3837                         goto out;
 3838         }
 3839         if (vcount(vp) > 1)
 3840                 VOP_REVOKE(vp, REVOKEALL);
 3841 out:
 3842         vput(vp);
 3843         return (error);
 3844 }
 3845 
 3846 /*
 3847  * Convert a user file descriptor to a kernel file entry and check that, if it
 3848  * is a capability, the correct rights are present. A reference on the file
 3849  * entry is held upon returning.
 3850  */
 3851 int
 3852 getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
 3853 {
 3854         struct file *fp;
 3855         int error;
 3856 
 3857         error = fget_unlocked(td->td_proc->p_fd, fd, rightsp, &fp, NULL);
 3858         if (error != 0)
 3859                 return (error);
 3860 
 3861         /*
 3862          * The file could be not of the vnode type, or it may be not
 3863          * yet fully initialized, in which case the f_vnode pointer
 3864          * may be set, but f_ops is still badfileops.  E.g.,
 3865          * devfs_open() transiently create such situation to
 3866          * facilitate csw d_fdopen().
 3867          *
 3868          * Dupfdopen() handling in kern_openat() installs the
 3869          * half-baked file into the process descriptor table, allowing
 3870          * other thread to dereference it. Guard against the race by
 3871          * checking f_ops.
 3872          */
 3873         if (fp->f_vnode == NULL || fp->f_ops == &badfileops) {
 3874                 fdrop(fp, td);
 3875                 return (EINVAL);
 3876         }
 3877         *fpp = fp;
 3878         return (0);
 3879 }
 3880 
 3881 
 3882 /*
 3883  * Get an (NFS) file handle.
 3884  */
 3885 #ifndef _SYS_SYSPROTO_H_
 3886 struct lgetfh_args {
 3887         char    *fname;
 3888         fhandle_t *fhp;
 3889 };
 3890 #endif
 3891 int
 3892 sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
 3893 {
 3894         struct nameidata nd;
 3895         fhandle_t fh;
 3896         struct vnode *vp;
 3897         int error;
 3898 
 3899         error = priv_check(td, PRIV_VFS_GETFH);
 3900         if (error != 0)
 3901                 return (error);
 3902         NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3903             uap->fname, td);
 3904         error = namei(&nd);
 3905         if (error != 0)
 3906                 return (error);
 3907         NDFREE(&nd, NDF_ONLY_PNBUF);
 3908         vp = nd.ni_vp;
 3909         bzero(&fh, sizeof(fh));
 3910         fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 3911         error = VOP_VPTOFH(vp, &fh.fh_fid);
 3912         vput(vp);
 3913         if (error == 0)
 3914                 error = copyout(&fh, uap->fhp, sizeof (fh));
 3915         return (error);
 3916 }
 3917 
 3918 #ifndef _SYS_SYSPROTO_H_
 3919 struct getfh_args {
 3920         char    *fname;
 3921         fhandle_t *fhp;
 3922 };
 3923 #endif
 3924 int
 3925 sys_getfh(struct thread *td, struct getfh_args *uap)
 3926 {
 3927         struct nameidata nd;
 3928         fhandle_t fh;
 3929         struct vnode *vp;
 3930         int error;
 3931 
 3932         error = priv_check(td, PRIV_VFS_GETFH);
 3933         if (error != 0)
 3934                 return (error);
 3935         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
 3936             uap->fname, td);
 3937         error = namei(&nd);
 3938         if (error != 0)
 3939                 return (error);
 3940         NDFREE(&nd, NDF_ONLY_PNBUF);
 3941         vp = nd.ni_vp;
 3942         bzero(&fh, sizeof(fh));
 3943         fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 3944         error = VOP_VPTOFH(vp, &fh.fh_fid);
 3945         vput(vp);
 3946         if (error == 0)
 3947                 error = copyout(&fh, uap->fhp, sizeof (fh));
 3948         return (error);
 3949 }
 3950 
 3951 /*
 3952  * syscall for the rpc.lockd to use to translate a NFS file handle into an
 3953  * open descriptor.
 3954  *
 3955  * warning: do not remove the priv_check() call or this becomes one giant
 3956  * security hole.
 3957  */
 3958 #ifndef _SYS_SYSPROTO_H_
 3959 struct fhopen_args {
 3960         const struct fhandle *u_fhp;
 3961         int flags;
 3962 };
 3963 #endif
 3964 int
 3965 sys_fhopen(struct thread *td, struct fhopen_args *uap)
 3966 {
 3967         struct mount *mp;
 3968         struct vnode *vp;
 3969         struct fhandle fhp;
 3970         struct file *fp;
 3971         int fmode, error;
 3972         int indx;
 3973 
 3974         error = priv_check(td, PRIV_VFS_FHOPEN);
 3975         if (error != 0)
 3976                 return (error);
 3977         indx = -1;
 3978         fmode = FFLAGS(uap->flags);
 3979         /* why not allow a non-read/write open for our lockd? */
 3980         if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
 3981                 return (EINVAL);
 3982         error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
 3983         if (error != 0)
 3984                 return(error);
 3985         /* find the mount point */
 3986         mp = vfs_busyfs(&fhp.fh_fsid);
 3987         if (mp == NULL)
 3988                 return (ESTALE);
 3989         /* now give me my vnode, it gets returned to me locked */
 3990         error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
 3991         vfs_unbusy(mp);
 3992         if (error != 0)
 3993                 return (error);
 3994 
 3995         error = falloc_noinstall(td, &fp);
 3996         if (error != 0) {
 3997                 vput(vp);
 3998                 return (error);
 3999         }
 4000         /*
 4001          * An extra reference on `fp' has been held for us by
 4002          * falloc_noinstall().
 4003          */
 4004 
 4005 #ifdef INVARIANTS
 4006         td->td_dupfd = -1;
 4007 #endif
 4008         error = vn_open_vnode(vp, fmode, td->td_ucred, td, fp);
 4009         if (error != 0) {
 4010                 KASSERT(fp->f_ops == &badfileops,
 4011                     ("VOP_OPEN in fhopen() set f_ops"));
 4012                 KASSERT(td->td_dupfd < 0,
 4013                     ("fhopen() encountered fdopen()"));
 4014 
 4015                 vput(vp);
 4016                 goto bad;
 4017         }
 4018 #ifdef INVARIANTS
 4019         td->td_dupfd = 0;
 4020 #endif
 4021         fp->f_vnode = vp;
 4022         fp->f_seqcount = 1;
 4023         finit(fp, (fmode & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, vp,
 4024             &vnops);
 4025         VOP_UNLOCK(vp, 0);
 4026         if ((fmode & O_TRUNC) != 0) {
 4027                 error = fo_truncate(fp, 0, td->td_ucred, td);
 4028                 if (error != 0)
 4029                         goto bad;
 4030         }
 4031 
 4032         error = finstall(td, fp, &indx, fmode, NULL);
 4033 bad:
 4034         fdrop(fp, td);
 4035         td->td_retval[0] = indx;
 4036         return (error);
 4037 }
 4038 
 4039 /*
 4040  * Stat an (NFS) file handle.
 4041  */
 4042 #ifndef _SYS_SYSPROTO_H_
 4043 struct fhstat_args {
 4044         struct fhandle *u_fhp;
 4045         struct stat *sb;
 4046 };
 4047 #endif
 4048 int
 4049 sys_fhstat(struct thread *td, struct fhstat_args *uap)
 4050 {
 4051         struct stat sb;
 4052         struct fhandle fh;
 4053         int error;
 4054 
 4055         error = copyin(uap->u_fhp, &fh, sizeof(fh));
 4056         if (error != 0)
 4057                 return (error);
 4058         error = kern_fhstat(td, fh, &sb);
 4059         if (error == 0)
 4060                 error = copyout(&sb, uap->sb, sizeof(sb));
 4061         return (error);
 4062 }
 4063 
 4064 int
 4065 kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
 4066 {
 4067         struct mount *mp;
 4068         struct vnode *vp;
 4069         int error;
 4070 
 4071         error = priv_check(td, PRIV_VFS_FHSTAT);
 4072         if (error != 0)
 4073                 return (error);
 4074         if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
 4075                 return (ESTALE);
 4076         error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
 4077         vfs_unbusy(mp);
 4078         if (error != 0)
 4079                 return (error);
 4080         error = vn_stat(vp, sb, td->td_ucred, NOCRED, td);
 4081         vput(vp);
 4082         return (error);
 4083 }
 4084 
 4085 /*
 4086  * Implement fstatfs() for (NFS) file handles.
 4087  */
 4088 #ifndef _SYS_SYSPROTO_H_
 4089 struct fhstatfs_args {
 4090         struct fhandle *u_fhp;
 4091         struct statfs *buf;
 4092 };
 4093 #endif
 4094 int
 4095 sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
 4096 {
 4097         struct statfs *sfp;
 4098         fhandle_t fh;
 4099         int error;
 4100 
 4101         error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
 4102         if (error != 0)
 4103                 return (error);
 4104         sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
 4105         error = kern_fhstatfs(td, fh, sfp);
 4106         if (error == 0)
 4107                 error = copyout(sfp, uap->buf, sizeof(*sfp));
 4108         free(sfp, M_STATFS);
 4109         return (error);
 4110 }
 4111 
 4112 int
 4113 kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
 4114 {
 4115         struct statfs *sp;
 4116         struct mount *mp;
 4117         struct vnode *vp;
 4118         int error;
 4119 
 4120         error = priv_check(td, PRIV_VFS_FHSTATFS);
 4121         if (error != 0)
 4122                 return (error);
 4123         if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
 4124                 return (ESTALE);
 4125         error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
 4126         if (error != 0) {
 4127                 vfs_unbusy(mp);
 4128                 return (error);
 4129         }
 4130         vput(vp);
 4131         error = prison_canseemount(td->td_ucred, mp);
 4132         if (error != 0)
 4133                 goto out;
 4134 #ifdef MAC
 4135         error = mac_mount_check_stat(td->td_ucred, mp);
 4136         if (error != 0)
 4137                 goto out;
 4138 #endif
 4139         /*
 4140          * Set these in case the underlying filesystem fails to do so.
 4141          */
 4142         sp = &mp->mnt_stat;
 4143         sp->f_version = STATFS_VERSION;
 4144         sp->f_namemax = NAME_MAX;
 4145         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
 4146         error = VFS_STATFS(mp, sp);
 4147         if (error == 0)
 4148                 *buf = *sp;
 4149 out:
 4150         vfs_unbusy(mp);
 4151         return (error);
 4152 }
 4153 
 4154 int
 4155 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len)
 4156 {
 4157         struct file *fp;
 4158         struct mount *mp;
 4159         struct vnode *vp;
 4160         cap_rights_t rights;
 4161         off_t olen, ooffset;
 4162         int error;
 4163 
 4164         if (offset < 0 || len <= 0)
 4165                 return (EINVAL);
 4166         /* Check for wrap. */
 4167         if (offset > OFF_MAX - len)
 4168                 return (EFBIG);
 4169         error = fget(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
 4170         if (error != 0)
 4171                 return (error);
 4172         if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
 4173                 error = ESPIPE;
 4174                 goto out;
 4175         }
 4176         if ((fp->f_flag & FWRITE) == 0) {
 4177                 error = EBADF;
 4178                 goto out;
 4179         }
 4180         if (fp->f_type != DTYPE_VNODE) {
 4181                 error = ENODEV;
 4182                 goto out;
 4183         }
 4184         vp = fp->f_vnode;
 4185         if (vp->v_type != VREG) {
 4186                 error = ENODEV;
 4187                 goto out;
 4188         }
 4189 
 4190         /* Allocating blocks may take a long time, so iterate. */
 4191         for (;;) {
 4192                 olen = len;
 4193                 ooffset = offset;
 4194 
 4195                 bwillwrite();
 4196                 mp = NULL;
 4197                 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
 4198                 if (error != 0)
 4199                         break;
 4200                 error = vn_lock(vp, LK_EXCLUSIVE);
 4201                 if (error != 0) {
 4202                         vn_finished_write(mp);
 4203                         break;
 4204                 }
 4205 #ifdef MAC
 4206                 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
 4207                 if (error == 0)
 4208 #endif
 4209                         error = VOP_ALLOCATE(vp, &offset, &len);
 4210                 VOP_UNLOCK(vp, 0);
 4211                 vn_finished_write(mp);
 4212 
 4213                 if (olen + ooffset != offset + len) {
 4214                         panic("offset + len changed from %jx/%jx to %jx/%jx",
 4215                             ooffset, olen, offset, len);
 4216                 }
 4217                 if (error != 0 || len == 0)
 4218                         break;
 4219                 KASSERT(olen > len, ("Iteration did not make progress?"));
 4220                 maybe_yield();
 4221         }
 4222  out:
 4223         fdrop(fp, td);
 4224         return (error);
 4225 }
 4226 
 4227 int
 4228 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
 4229 {
 4230         int error;
 4231 
 4232         error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
 4233         return (kern_posix_error(td, error));
 4234 }
 4235 
 4236 /*
 4237  * Unlike madvise(2), we do not make a best effort to remember every
 4238  * possible caching hint.  Instead, we remember the last setting with
 4239  * the exception that we will allow POSIX_FADV_NORMAL to adjust the
 4240  * region of any current setting.
 4241  */
 4242 int
 4243 kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
 4244     int advice)
 4245 {
 4246         struct fadvise_info *fa, *new;
 4247         struct file *fp;
 4248         struct vnode *vp;
 4249         cap_rights_t rights;
 4250         off_t end;
 4251         int error;
 4252 
 4253         if (offset < 0 || len < 0 || offset > OFF_MAX - len)
 4254                 return (EINVAL);
 4255         switch (advice) {
 4256         case POSIX_FADV_SEQUENTIAL:
 4257         case POSIX_FADV_RANDOM:
 4258         case POSIX_FADV_NOREUSE:
 4259                 new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
 4260                 break;
 4261         case POSIX_FADV_NORMAL:
 4262         case POSIX_FADV_WILLNEED:
 4263         case POSIX_FADV_DONTNEED:
 4264                 new = NULL;
 4265                 break;
 4266         default:
 4267                 return (EINVAL);
 4268         }
 4269         /* XXX: CAP_POSIX_FADVISE? */
 4270         error = fget(td, fd, cap_rights_init(&rights), &fp);
 4271         if (error != 0)
 4272                 goto out;
 4273         if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
 4274                 error = ESPIPE;
 4275                 goto out;
 4276         }
 4277         if (fp->f_type != DTYPE_VNODE) {
 4278                 error = ENODEV;
 4279                 goto out;
 4280         }
 4281         vp = fp->f_vnode;
 4282         if (vp->v_type != VREG) {
 4283                 error = ENODEV;
 4284                 goto out;
 4285         }
 4286         if (len == 0)
 4287                 end = OFF_MAX;
 4288         else
 4289                 end = offset + len - 1;
 4290         switch (advice) {
 4291         case POSIX_FADV_SEQUENTIAL:
 4292         case POSIX_FADV_RANDOM:
 4293         case POSIX_FADV_NOREUSE:
 4294                 /*
 4295                  * Try to merge any existing non-standard region with
 4296                  * this new region if possible, otherwise create a new
 4297                  * non-standard region for this request.
 4298                  */
 4299                 mtx_pool_lock(mtxpool_sleep, fp);
 4300                 fa = fp->f_advice;
 4301                 if (fa != NULL && fa->fa_advice == advice &&
 4302                     ((fa->fa_start <= end && fa->fa_end >= offset) ||
 4303                     (end != OFF_MAX && fa->fa_start == end + 1) ||
 4304                     (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
 4305                         if (offset < fa->fa_start)
 4306                                 fa->fa_start = offset;
 4307                         if (end > fa->fa_end)
 4308                                 fa->fa_end = end;
 4309                 } else {
 4310                         new->fa_advice = advice;
 4311                         new->fa_start = offset;
 4312                         new->fa_end = end;
 4313                         fp->f_advice = new;
 4314                         new = fa;
 4315                 }
 4316                 mtx_pool_unlock(mtxpool_sleep, fp);
 4317                 break;
 4318         case POSIX_FADV_NORMAL:
 4319                 /*
 4320                  * If a the "normal" region overlaps with an existing
 4321                  * non-standard region, trim or remove the
 4322                  * non-standard region.
 4323                  */
 4324                 mtx_pool_lock(mtxpool_sleep, fp);
 4325                 fa = fp->f_advice;
 4326                 if (fa != NULL) {
 4327                         if (offset <= fa->fa_start && end >= fa->fa_end) {
 4328                                 new = fa;
 4329                                 fp->f_advice = NULL;
 4330                         } else if (offset <= fa->fa_start &&
 4331                             end >= fa->fa_start)
 4332                                 fa->fa_start = end + 1;
 4333                         else if (offset <= fa->fa_end && end >= fa->fa_end)
 4334                                 fa->fa_end = offset - 1;
 4335                         else if (offset >= fa->fa_start && end <= fa->fa_end) {
 4336                                 /*
 4337                                  * If the "normal" region is a middle
 4338                                  * portion of the existing
 4339                                  * non-standard region, just remove
 4340                                  * the whole thing rather than picking
 4341                                  * one side or the other to
 4342                                  * preserve.
 4343                                  */
 4344                                 new = fa;
 4345                                 fp->f_advice = NULL;
 4346                         }
 4347                 }
 4348                 mtx_pool_unlock(mtxpool_sleep, fp);
 4349                 break;
 4350         case POSIX_FADV_WILLNEED:
 4351         case POSIX_FADV_DONTNEED:
 4352                 error = VOP_ADVISE(vp, offset, end, advice);
 4353                 break;
 4354         }
 4355 out:
 4356         if (fp != NULL)
 4357                 fdrop(fp, td);
 4358         free(new, M_FADVISE);
 4359         return (error);
 4360 }
 4361 
 4362 int
 4363 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
 4364 {
 4365         int error;
 4366 
 4367         error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
 4368             uap->advice);
 4369         return (kern_posix_error(td, error));
 4370 }

Cache object: d2ca41e51f251c87b329dd28f97f5a3b


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