/*      $NetBSD: vfs_syscalls_12.c,v 1.38 2021/09/07 11:43:02 riastradh Exp $   */

/*
* Copyright (c) 1989, 1993
*      The Regents of the University of California.  All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*      From: @(#)vfs_syscalls.c        8.28 (Berkeley) 12/10/94
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls_12.c,v 1.38 2021/09/07 11:43:02 riastradh Exp $");

#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/socketvar.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/dirent.h>
#include <sys/vfs_syscalls.h>

#include <sys/syscall.h>
#include <sys/syscallvar.h>
#include <sys/syscallargs.h>

#include <compat/sys/stat.h>
#include <compat/sys/dirent.h>

#include <compat/common/compat_mod.h>

static const struct syscall_package vfs_syscalls_12_syscalls[] = {
       { SYS_compat_12_fstat12, 0, (sy_call_t *)compat_12_sys_fstat },
       { SYS_compat_12_getdirentries, 0,
           (sy_call_t *)compat_12_sys_getdirentries },
       { SYS_compat_12_lstat12, 0, (sy_call_t *)compat_12_sys_lstat },
       { SYS_compat_12_stat12, 0, (sy_call_t *)compat_12_sys_stat },
       { 0, 0, NULL }
};

/*
* Convert from a new to an old stat structure.
*/
void
compat_12_stat_conv(const struct stat *st, struct stat12 *ost)
{

       memset(ost, 0, sizeof(*ost));
       ost->st_dev = st->st_dev;
       ost->st_ino = st->st_ino;
       ost->st_mode = st->st_mode & 0xffff;
       if (st->st_nlink >= (1 << 15))
               ost->st_nlink = (1 << 15) - 1;
       else
               ost->st_nlink = st->st_nlink;
       ost->st_uid = st->st_uid;
       ost->st_gid = st->st_gid;
       ost->st_rdev = st->st_rdev;
       timespec_to_timespec50(&st->st_atimespec, &ost->st_atimespec);
       timespec_to_timespec50(&st->st_mtimespec, &ost->st_mtimespec);
       timespec_to_timespec50(&st->st_ctimespec, &ost->st_ctimespec);
       ost->st_size = st->st_size;
       ost->st_blocks = st->st_blocks;
       ost->st_blksize = st->st_blksize;
       ost->st_flags = st->st_flags;
       ost->st_gen = st->st_gen;
}

/*
* Read a block of directory entries in a file system independent format.
*/
int
compat_12_sys_getdirentries(struct lwp *l,
   const struct compat_12_sys_getdirentries_args *uap, register_t *retval)
{
       /* {
               syscallarg(int) fd;
               syscallarg(char *) buf;
               syscallarg(u_int) count;
               syscallarg(long *) basep;
       } */
       struct dirent *bdp;
       struct vnode *vp;
       char *inp, *tbuf;               /* Current-format */
       int len, reclen;                /* Current-format */
       char *outp;                     /* Dirent12-format */
       int resid, old_reclen = 0;      /* Dirent12-format */
       struct file *fp;
       struct uio auio;
       struct iovec aiov;
       struct dirent12 idb;
       off_t off;              /* true file offset */
       int buflen, error, eofflag, nbytes;
       struct vattr va;
       off_t *cookiebuf = NULL, *cookie;
       int ncookies;
       long loff;

       /* fd_getvnode() will use the descriptor for us */
       if ((error = fd_getvnode(SCARG(uap, fd), &fp)) != 0)
               return (error);

       if ((fp->f_flag & FREAD) == 0) {
               error = EBADF;
               goto out1;
       }

       vp = (struct vnode *)fp->f_vnode;
       if (vp->v_type != VDIR) {
               error = ENOTDIR;
               goto out1;
       }

       vn_lock(vp, LK_SHARED | LK_RETRY);
       error = VOP_GETATTR(vp, &va, l->l_cred);
       VOP_UNLOCK(vp);
       if (error)
               goto out1;

       loff = fp->f_offset;
       nbytes = SCARG(uap, count);
       buflen = uimin(MAXBSIZE, nbytes);
       if (buflen < va.va_blocksize)
               buflen = va.va_blocksize;
       tbuf = malloc(buflen, M_TEMP, M_WAITOK);

       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
       off = fp->f_offset;
again:
       aiov.iov_base = tbuf;
       aiov.iov_len = buflen;
       auio.uio_iov = &aiov;
       auio.uio_iovcnt = 1;
       auio.uio_rw = UIO_READ;
       auio.uio_resid = buflen;
       auio.uio_offset = off;
       UIO_SETUP_SYSSPACE(&auio);
       /*
        * First we read into the malloc'ed buffer, then
        * we massage it into user space, one record at a time.
        */
       error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
           &ncookies);
       if (error)
               goto out;

       inp = tbuf;
       outp = SCARG(uap, buf);
       resid = nbytes;
       if ((len = buflen - auio.uio_resid) == 0)
               goto eof;

       for (cookie = cookiebuf; len > 0; len -= reclen) {
               bdp = (struct dirent *)inp;
               reclen = bdp->d_reclen;
               if (reclen & 3) {
                       error = EIO;
                       goto out;
               }
               if (bdp->d_fileno == 0) {
                       inp += reclen;  /* it is a hole; squish it out */
                       if (cookie)
                               off = *cookie++;
                       else
                               off += reclen;
                       continue;
               }
               memset(&idb, 0, sizeof(idb));
               if (bdp->d_namlen >= sizeof(idb.d_name))
                       idb.d_namlen = sizeof(idb.d_name) - 1;
               else
                       idb.d_namlen = bdp->d_namlen;
               old_reclen = _DIRENT_RECLEN(&idb, bdp->d_namlen);
               if (reclen > len || resid < old_reclen) {
                       /* entry too big for buffer, so just stop */
                       outp++;
                       break;
               }
               /*
                * Massage in place to make a Dirent12-shaped dirent (otherwise
                * we have to worry about touching user memory outside of
                * the copyout() call).
                */
               idb.d_fileno = (uint32_t)bdp->d_fileno;
               idb.d_reclen = (uint16_t)old_reclen;
               idb.d_type = (uint8_t)bdp->d_type;
               (void)memcpy(idb.d_name, bdp->d_name, idb.d_namlen);
               memset(idb.d_name + idb.d_namlen, 0,
                   idb.d_reclen - _DIRENT_NAMEOFF(&idb) - idb.d_namlen);
               if ((error = copyout(&idb, outp, old_reclen)))
                       goto out;
               /* advance past this real entry */
               inp += reclen;
               if (cookie)
                       off = *cookie++; /* each entry points to itself */
               else
                       off += reclen;
               /* advance output past Dirent12-shaped entry */
               outp += old_reclen;
               resid -= old_reclen;
       }

       /* if we squished out the whole block, try again */
       if (outp == SCARG(uap, buf)) {
               if (cookiebuf)
                       free(cookiebuf, M_TEMP);
               cookiebuf = NULL;
               goto again;
       }
       fp->f_offset = off;     /* update the vnode offset */

eof:
       *retval = nbytes - resid;
out:
       VOP_UNLOCK(vp);
       if (cookiebuf)
               free(cookiebuf, M_TEMP);
       free(tbuf, M_TEMP);
out1:
       fd_putfile(SCARG(uap, fd));
       if (error)
               return error;
       return copyout(&loff, SCARG(uap, basep), sizeof(long));
}

/*
* Get file status; this version follows links.
*/
/* ARGSUSED */
int
compat_12_sys_stat(struct lwp *l, const struct compat_12_sys_stat_args *uap,
   register_t *retval)
{
       /* {
               syscallarg(const char *) path;
               syscallarg(struct stat12 *) ub;
       } */
       struct stat sb;
       struct stat12 osb;
       int error;

       error = do_sys_stat(SCARG(uap, path), FOLLOW, &sb);
       if (error)
               return (error);
       compat_12_stat_conv(&sb, &osb);
       error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
       return (error);
}


/*
* Get file status; this version does not follow links.
*/
/* ARGSUSED */
int
compat_12_sys_lstat(struct lwp *l, const struct compat_12_sys_lstat_args *uap,
   register_t *retval)
{
       /* {
               syscallarg(const char *) path;
               syscallarg(struct stat12 *) ub;
       } */
       struct stat sb;
       struct stat12 osb;
       int error;

       error = do_sys_stat(SCARG(uap, path), NOFOLLOW, &sb);
       if (error)
               return (error);
       compat_12_stat_conv(&sb, &osb);
       error = copyout(&osb, SCARG(uap, ub), sizeof (osb));
       return (error);
}

/*
* Return status information about a file descriptor.
*/
/* ARGSUSED */
int
compat_12_sys_fstat(struct lwp *l, const struct compat_12_sys_fstat_args *uap,
   register_t *retval)
{
       /* {
               syscallarg(int) fd;
               syscallarg(struct stat12 *) sb;
       } */
       struct stat ub;
       struct stat12 oub;
       int error;

       error = do_sys_fstat(SCARG(uap, fd), &ub);
       if (error == 0) {
               compat_12_stat_conv(&ub, &oub);
               error = copyout(&oub, SCARG(uap, sb), sizeof (oub));
       }
       return (error);
}

int
vfs_syscalls_12_init(void)
{

       return syscall_establish(NULL, vfs_syscalls_12_syscalls);
}

int
vfs_syscalls_12_fini(void)
{

       return syscall_disestablish(NULL, vfs_syscalls_12_syscalls);
}

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