/*      $NetBSD: vfs_syscalls_30.c,v 1.45 2022/03/12 20:46:03 riastradh Exp $   */

/*-
 * Copyright (c) 2005, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls_30.c,v 1.45 2022/03/12 20:46:03 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/mount.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/dirent.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <sys/vfs_syscalls.h>
#include <sys/syscall.h>
#include <sys/syscallvar.h>
#include <sys/syscallargs.h>

#include <compat/common/compat_mod.h>
#include <compat/common/compat_util.h>

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

static const struct syscall_package vfs_syscalls_30_syscalls[] = {
        { SYS_compat_30___fhstat30, 0, (sy_call_t *)compat_30_sys___fhstat30 },
        { SYS_compat_30___fstat13, 0, (sy_call_t *)compat_30_sys___fstat13 },
        { SYS_compat_30___lstat13, 0, (sy_call_t *)compat_30_sys___lstat13 }, 
        { SYS_compat_30___stat13, 0, (sy_call_t *)compat_30_sys___stat13 },  
        { SYS_compat_30_fhopen, 0, (sy_call_t *)compat_30_sys_fhopen },
        { SYS_compat_30_fhstat, 0, (sy_call_t *)compat_30_sys_fhstat },  
        { SYS_compat_30_fhstatvfs1, 0, (sy_call_t *)compat_30_sys_fhstatvfs1 },
        { SYS_compat_30_getdents, 0, (sy_call_t *)compat_30_sys_getdents },
        { SYS_compat_30_getfh, 0, (sy_call_t *)compat_30_sys_getfh },
        { 0,0, NULL }
};

/*
 * Convert from a new to an old stat structure.
 */
static void
cvtstat(struct stat13 *ost, const struct stat *st)
{

        /* Handle any padding. */
        memset(ost, 0, sizeof(*ost));
        ost->st_dev = st->st_dev;
        ost->st_ino = (uint32_t)st->st_ino;
        ost->st_mode = st->st_mode;
        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);
        timespec_to_timespec50(&st->st_birthtimespec, &ost->st_birthtimespec);
        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;
}

/*
 * Get file status; this version follows links.
 */
/* ARGSUSED */
int
compat_30_sys___stat13(struct lwp *l,
    const struct compat_30_sys___stat13_args *uap, register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(struct stat13 *) ub;
        } */
        struct stat sb;
        struct stat13 osb;
        int error;

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


/*
 * Get file status; this version does not follow links.
 */
/* ARGSUSED */
int
compat_30_sys___lstat13(struct lwp *l,
    const struct compat_30_sys___lstat13_args *uap, register_t *retval)
{
        /* {
                syscallarg(const char *) path;
                syscallarg(struct stat13 *) ub;
        } */
        struct stat sb;
        struct stat13 osb;
        int error;

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

/* ARGSUSED */
int
compat_30_sys_fhstat(struct lwp *l,
    const struct compat_30_sys_fhstat_args *uap, register_t *retval)
{
        /* {
                syscallarg(const struct compat_30_fhandle *) fhp;
                syscallarg(struct stat13 *) sb;
        } */
        struct stat sb;
        struct stat13 osb;
        int error;

        error = do_fhstat(l, SCARG(uap, fhp), sizeof(*SCARG(uap, fhp)), &sb);
        if (error)
                return error;
        cvtstat(&osb, &sb);
        return copyout(&osb, SCARG(uap, sb), sizeof(osb));
}

/*
 * Return status information about a file descriptor.
 */
/* ARGSUSED */
int
compat_30_sys___fstat13(struct lwp *l,
    const struct compat_30_sys___fstat13_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(struct stat13 *) sb;
        } */
        struct stat sb;
        struct stat13 osb;
        int error;

        error = do_sys_fstat(SCARG(uap, fd), &sb);
        if (error)
                return error;
        cvtstat(&osb, &sb);
        return copyout(&osb, SCARG(uap, sb), sizeof(osb));
}

/*
 * Read a block of directory entries in a file system independent format.
 */
int
compat_30_sys_getdents(struct lwp *l,
    const struct compat_30_sys_getdents_args *uap, register_t *retval)
{
        /* {
                syscallarg(int) fd;
                syscallarg(char *) buf;
                syscallarg(size_t) count;
        } */
        struct dirent *bdp;
        struct vnode *vp;
        char *inp, *tbuf;       /* BSD-format */
        int len, reclen;        /* BSD-format */
        char *outp;             /* NetBSD-3.0-format */
        int resid;      
        struct file *fp;
        struct uio auio;
        struct iovec aiov;
        struct dirent12 idb;
        off_t off;              /* true file offset */
        int buflen, error, eofflag;
        off_t *cookiebuf = NULL, *cookie;
        int ncookies;
        bool any = false;

        /* 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 = fp->f_vnode;
        if (vp->v_type != VDIR) {
                error = EINVAL;
                goto out1;
        }

        buflen = uimin(MAXBSIZE, SCARG(uap, count));
        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 = SCARG(uap, count);
        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 & _DIRENT_ALIGN(bdp))
                        panic("%s: bad reclen %d", __func__, reclen);
                if (cookie)
                        off = *cookie++; /* each entry points to the next */
                else
                        off += reclen;
                if ((off >> 32) != 0) {
                        compat_offseterr(vp, "netbsd30_getdents");
                        error = EINVAL;
                        goto out;
                }
                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;
                idb.d_reclen = _DIRENT_SIZE(&idb);
                if (reclen > len || resid < idb.d_reclen) {
                        /* entry too big for buffer, so just stop */
                        any = true;
                        break;
                }
                /*
                 * Massage in place to make a NetBSD-3.0-shaped dirent
                 * (otherwise we have to worry about touching user memory
                 * outside of the copyout() call).
                 */
                idb.d_fileno = (u_int32_t)bdp->d_fileno;
                idb.d_type = 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, idb.d_reclen)) != 0)
                        goto out;
                /* advance past this real entry */
                inp += reclen;
                /* advance output past NetBSD-3.0-shaped entry */
                outp += idb.d_reclen;
                resid -= idb.d_reclen;
                any = true;
        }

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

eof:
        *retval = SCARG(uap, count) - resid;
out:
        VOP_UNLOCK(vp);
        if (cookiebuf)
                free(cookiebuf, M_TEMP);
        free(tbuf, M_TEMP);
out1:
        fd_putfile(SCARG(uap, fd));
        return error;
}

/*
 * Get file handle system call
 */
int
compat_30_sys_getfh(struct lwp *l, const struct compat_30_sys_getfh_args *uap,
    register_t *retval)
{
        /* {
                syscallarg(char *) fname;
                syscallarg(struct compat_30_fhandle *) fhp;
        } */
        struct vnode *vp;
        struct compat_30_fhandle fh;
        int error;
        struct pathbuf *pb;
        struct nameidata nd;
        size_t sz;

        /*
         * Must be super user
         */
        error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FILEHANDLE,
            0, NULL, NULL, NULL);
        if (error)
                return (error);

        error = pathbuf_copyin(SCARG(uap, fname), &pb);
        if (error) {
                return error;
        }
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
        error = namei(&nd);
        pathbuf_destroy(pb);
        if (error)
                return error;
        vp = nd.ni_vp;

        sz = sizeof(struct compat_30_fhandle);
        error = vfs_composefh(vp, (void *)&fh, &sz);
        vput(vp);
        CTASSERT(FHANDLE_SIZE_COMPAT == sizeof(struct compat_30_fhandle));
        if (sz != FHANDLE_SIZE_COMPAT) {
                error = EINVAL;
        }
        if (error)
                return error;
        return copyout(&fh, SCARG(uap, fhp), sizeof(fh));
}

/*
 * Open a file given a file handle.
 *
 * Check permissions, allocate an open file structure,
 * and call the device open routine if any.
 */
int
compat_30_sys_fhopen(struct lwp *l,
    const struct compat_30_sys_fhopen_args *uap, register_t *retval)
{
        /* {
                syscallarg(const fhandle_t *) fhp;
                syscallarg(int) flags;
        } */

        return dofhopen(l, SCARG(uap, fhp), FHANDLE_SIZE_COMPAT,
            SCARG(uap, flags), retval);
}

/* ARGSUSED */
int
compat_30_sys___fhstat30(struct lwp *l,
    const struct compat_30_sys___fhstat30_args *uap_30, register_t *retval)
{
        /* {
                syscallarg(const fhandle_t *) fhp;
                syscallarg(struct stat30 *) sb;
        } */
        struct stat sb;
        struct stat13 osb;
        int error;

        error = do_fhstat(l, SCARG(uap_30, fhp), FHANDLE_SIZE_COMPAT, &sb);
        if (error)
                return error;
        cvtstat(&osb, &sb);
        return copyout(&osb, SCARG(uap_30, sb), sizeof(osb));
}

/* ARGSUSED */
int
compat_30_sys_fhstatvfs1(struct lwp *l,
    const struct compat_30_sys_fhstatvfs1_args *uap, register_t *retval)
{
        /* {
                syscallarg(const fhandle_t *) fhp;
                syscallarg(struct statvfs90 *) buf;
                syscallarg(int) flags;
        } */
        struct statvfs *sb = STATVFSBUF_GET();
        int error = do_fhstatvfs(l, SCARG(uap, fhp), FHANDLE_SIZE_COMPAT,
            sb, SCARG(uap, flags));

        if (!error) {
                error = statvfs_to_statvfs90_copy(sb, SCARG(uap, buf),
                    sizeof(struct statvfs90));
        }

        STATVFSBUF_PUT(sb);

        return error;
}

int
vfs_syscalls_30_init(void)
{

        return syscall_establish(NULL, vfs_syscalls_30_syscalls);
}

int
vfs_syscalls_30_fini(void)
{

        return syscall_disestablish(NULL, vfs_syscalls_30_syscalls);
}