xref: /freebsd-11-stable/sys/compat/linux/linux_file.c

/*-
 * Copyright (c) 1994-1995 S�ren Schmidt
 * All rights reserved.
 *
 * 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
 *    in this position and unchanged.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
__FBSDID("$FreeBSD: head/sys/compat/linux/linux_file.c 227693 2011-11-19 07:19:37Z ed $");

#include "opt_compat.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/capability.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/tty.h>
#include <sys/unistd.h>
#include <sys/vnode.h>

#include <security/mac/mac_framework.h>

#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>

#ifdef COMPAT_LINUX32
#include <machine/../linux32/linux.h>
#include <machine/../linux32/linux32_proto.h>
#else
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#endif
#include <compat/linux/linux_util.h>
#include <compat/linux/linux_file.h>

int
linux_creat(struct thread *td, struct linux_creat_args *args)
{
    char *path;
    int error;

    LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(creat))
		printf(ARGS(creat, "%s, %d"), path, args->mode);
#endif
    error = kern_open(td, path, UIO_SYSSPACE, O_WRONLY | O_CREAT | O_TRUNC,
	args->mode);
    LFREEPATH(path);
    return (error);
}


static int
linux_common_open(struct thread *td, int dirfd, char *path, int l_flags, int mode)
{
    struct proc *p = td->td_proc;
    struct file *fp;
    int fd;
    int bsd_flags, error;

    bsd_flags = 0;
    switch (l_flags & LINUX_O_ACCMODE) {
    case LINUX_O_WRONLY:
	bsd_flags |= O_WRONLY;
	break;
    case LINUX_O_RDWR:
	bsd_flags |= O_RDWR;
	break;
    default:
	bsd_flags |= O_RDONLY;
    }
    if (l_flags & LINUX_O_NDELAY)
	bsd_flags |= O_NONBLOCK;
    if (l_flags & LINUX_O_APPEND)
	bsd_flags |= O_APPEND;
    if (l_flags & LINUX_O_SYNC)
	bsd_flags |= O_FSYNC;
    if (l_flags & LINUX_O_NONBLOCK)
	bsd_flags |= O_NONBLOCK;
    if (l_flags & LINUX_FASYNC)
	bsd_flags |= O_ASYNC;
    if (l_flags & LINUX_O_CREAT)
	bsd_flags |= O_CREAT;
    if (l_flags & LINUX_O_TRUNC)
	bsd_flags |= O_TRUNC;
    if (l_flags & LINUX_O_EXCL)
	bsd_flags |= O_EXCL;
    if (l_flags & LINUX_O_NOCTTY)
	bsd_flags |= O_NOCTTY;
    if (l_flags & LINUX_O_DIRECT)
	bsd_flags |= O_DIRECT;
    if (l_flags & LINUX_O_NOFOLLOW)
	bsd_flags |= O_NOFOLLOW;
    if (l_flags & LINUX_O_DIRECTORY)
	bsd_flags |= O_DIRECTORY;
    /* XXX LINUX_O_NOATIME: unable to be easily implemented. */

    error = kern_openat(td, dirfd, path, UIO_SYSSPACE, bsd_flags, mode);

    if (!error) {
	    fd = td->td_retval[0];
	    /*
	     * XXX In between kern_open() and fget(), another process
	     * having the same filedesc could use that fd without
	     * checking below.
	     */
	    error = fget(td, fd, CAP_IOCTL, &fp);
	    if (!error) {
		    sx_slock(&proctree_lock);
		    PROC_LOCK(p);
		    if (!(bsd_flags & O_NOCTTY) &&
			SESS_LEADER(p) && !(p->p_flag & P_CONTROLT)) {
			    PROC_UNLOCK(p);
			    sx_unlock(&proctree_lock);
			    if (fp->f_type == DTYPE_VNODE)
				    (void) fo_ioctl(fp, TIOCSCTTY, (caddr_t) 0,
					     td->td_ucred, td);
		    } else {
			    PROC_UNLOCK(p);
			    sx_sunlock(&proctree_lock);
		    }
		    fdrop(fp, td);
		    /*
		     * XXX as above, fdrop()/kern_close() pair is racy.
		     */
		    if (error)
			    kern_close(td, fd);
	    }
    }

#ifdef DEBUG
    if (ldebug(open))
	    printf(LMSG("open returns error %d"), error);
#endif
    LFREEPATH(path);
    return (error);
}

int
linux_openat(struct thread *td, struct linux_openat_args *args)
{
	char *path;
	int dfd;

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	if (args->flags & LINUX_O_CREAT)
		LCONVPATH_AT(td, args->filename, &path, 1, dfd);
	else
		LCONVPATH_AT(td, args->filename, &path, 0, dfd);
#ifdef DEBUG
	if (ldebug(openat))
		printf(ARGS(openat, "%i, %s, 0x%x, 0x%x"), args->dfd,
		    path, args->flags, args->mode);
#endif
	return (linux_common_open(td, dfd, path, args->flags, args->mode));
}

int
linux_open(struct thread *td, struct linux_open_args *args)
{
    char *path;

    if (args->flags & LINUX_O_CREAT)
	LCONVPATHCREAT(td, args->path, &path);
    else
	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(open))
		printf(ARGS(open, "%s, 0x%x, 0x%x"),
		    path, args->flags, args->mode);
#endif

	return (linux_common_open(td, AT_FDCWD, path, args->flags, args->mode));
}

int
linux_lseek(struct thread *td, struct linux_lseek_args *args)
{

    struct lseek_args /* {
	int fd;
	int pad;
	off_t offset;
	int whence;
    } */ tmp_args;
    int error;

#ifdef DEBUG
	if (ldebug(lseek))
		printf(ARGS(lseek, "%d, %ld, %d"),
		    args->fdes, (long)args->off, args->whence);
#endif
    tmp_args.fd = args->fdes;
    tmp_args.offset = (off_t)args->off;
    tmp_args.whence = args->whence;
    error = sys_lseek(td, &tmp_args);
    return error;
}

int
linux_llseek(struct thread *td, struct linux_llseek_args *args)
{
	struct lseek_args bsd_args;
	int error;
	off_t off;

#ifdef DEBUG
	if (ldebug(llseek))
		printf(ARGS(llseek, "%d, %d:%d, %d"),
		    args->fd, args->ohigh, args->olow, args->whence);
#endif
	off = (args->olow) | (((off_t) args->ohigh) << 32);

	bsd_args.fd = args->fd;
	bsd_args.offset = off;
	bsd_args.whence = args->whence;

	if ((error = sys_lseek(td, &bsd_args)))
		return error;

	if ((error = copyout(td->td_retval, args->res, sizeof (off_t))))
		return error;

	td->td_retval[0] = 0;
	return 0;
}

int
linux_readdir(struct thread *td, struct linux_readdir_args *args)
{
	struct linux_getdents_args lda;

	lda.fd = args->fd;
	lda.dent = args->dent;
	lda.count = 1;
	return linux_getdents(td, &lda);
}

/*
 * Note that linux_getdents(2) and linux_getdents64(2) have the same
 * arguments. They only differ in the definition of struct dirent they
 * operate on. We use this to common the code, with the exception of
 * accessing struct dirent. Note that linux_readdir(2) is implemented
 * by means of linux_getdents(2). In this case we never operate on
 * struct dirent64 and thus don't need to handle it...
 */

struct l_dirent {
	l_ulong		d_ino;
	l_off_t		d_off;
	l_ushort	d_reclen;
	char		d_name[LINUX_NAME_MAX + 1];
};

struct l_dirent64 {
	uint64_t	d_ino;
	int64_t		d_off;
	l_ushort	d_reclen;
	u_char		d_type;
	char		d_name[LINUX_NAME_MAX + 1];
};

/*
 * Linux uses the last byte in the dirent buffer to store d_type,
 * at least glibc-2.7 requires it. That is why l_dirent is padded with 2 bytes.
 */
#define LINUX_RECLEN(namlen)						\
    roundup((offsetof(struct l_dirent, d_name) + (namlen) + 2),		\
    sizeof(l_ulong))

#define LINUX_RECLEN64(namlen)						\
    roundup((offsetof(struct l_dirent64, d_name) + (namlen) + 1),	\
    sizeof(uint64_t))

#define LINUX_MAXRECLEN		max(LINUX_RECLEN(LINUX_NAME_MAX),	\
				    LINUX_RECLEN64(LINUX_NAME_MAX))
#define	LINUX_DIRBLKSIZ		512

static int
getdents_common(struct thread *td, struct linux_getdents64_args *args,
    int is64bit)
{
	struct dirent *bdp;
	struct vnode *vp;
	caddr_t inp, buf;		/* BSD-format */
	int len, reclen;		/* BSD-format */
	caddr_t outp;			/* Linux-format */
	int resid, linuxreclen=0;	/* Linux-format */
	caddr_t lbuf;			/* Linux-format */
	struct file *fp;
	struct uio auio;
	struct iovec aiov;
	off_t off;
	struct l_dirent *linux_dirent;
	struct l_dirent64 *linux_dirent64;
	int buflen, error, eofflag, nbytes, justone;
	u_long *cookies = NULL, *cookiep;
	int ncookies, vfslocked;

	nbytes = args->count;
	if (nbytes == 1) {
		/* readdir(2) case. Always struct dirent. */
		if (is64bit)
			return (EINVAL);
		nbytes = sizeof(*linux_dirent);
		justone = 1;
	} else
		justone = 0;

	if ((error = getvnode(td->td_proc->p_fd, args->fd, CAP_READ, &fp)) != 0)
		return (error);

	if ((fp->f_flag & FREAD) == 0) {
		fdrop(fp, td);
		return (EBADF);
	}

	vp = fp->f_vnode;
	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
	if (vp->v_type != VDIR) {
		VFS_UNLOCK_GIANT(vfslocked);
		fdrop(fp, td);
		return (EINVAL);
	}

	off = fp->f_offset;

	buflen = max(LINUX_DIRBLKSIZ, nbytes);
	buflen = min(buflen, MAXBSIZE);
	buf = malloc(buflen, M_TEMP, M_WAITOK);
	lbuf = malloc(LINUX_MAXRECLEN, M_TEMP, M_WAITOK | M_ZERO);
	vn_lock(vp, LK_SHARED | LK_RETRY);

	aiov.iov_base = buf;
	aiov.iov_len = buflen;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_rw = UIO_READ;
	auio.uio_segflg = UIO_SYSSPACE;
	auio.uio_td = td;
	auio.uio_resid = buflen;
	auio.uio_offset = off;

	if (cookies) {
		free(cookies, M_TEMP);
		cookies = NULL;
	}

#ifdef MAC
	/*
	 * Do directory search MAC check using non-cached credentials.
	 */
	if ((error = mac_vnode_check_readdir(td->td_ucred, vp)))
		goto out;
#endif /* MAC */
	if ((error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &ncookies,
		 &cookies)))
		goto out;

	inp = buf;
	outp = (caddr_t)args->dirent;
	resid = nbytes;
	if ((len = buflen - auio.uio_resid) <= 0)
		goto eof;

	cookiep = cookies;

	if (cookies) {
		/*
		 * When using cookies, the vfs has the option of reading from
		 * a different offset than that supplied (UFS truncates the
		 * offset to a block boundary to make sure that it never reads
		 * partway through a directory entry, even if the directory
		 * has been compacted).
		 */
		while (len > 0 && ncookies > 0 && *cookiep <= off) {
			bdp = (struct dirent *) inp;
			len -= bdp->d_reclen;
			inp += bdp->d_reclen;
			cookiep++;
			ncookies--;
		}
	}

	while (len > 0) {
		if (cookiep && ncookies == 0)
			break;
		bdp = (struct dirent *) inp;
		reclen = bdp->d_reclen;
		if (reclen & 3) {
			error = EFAULT;
			goto out;
		}

		if (bdp->d_fileno == 0) {
			inp += reclen;
			if (cookiep) {
				off = *cookiep++;
				ncookies--;
			} else
				off += reclen;

			len -= reclen;
			continue;
		}

		linuxreclen = (is64bit)
		    ? LINUX_RECLEN64(bdp->d_namlen)
		    : LINUX_RECLEN(bdp->d_namlen);

		if (reclen > len || resid < linuxreclen) {
			outp++;
			break;
		}

		if (justone) {
			/* readdir(2) case. */
			linux_dirent = (struct l_dirent*)lbuf;
			linux_dirent->d_ino = bdp->d_fileno;
			linux_dirent->d_off = (l_off_t)linuxreclen;
			linux_dirent->d_reclen = (l_ushort)bdp->d_namlen;
			strlcpy(linux_dirent->d_name, bdp->d_name,
			    linuxreclen - offsetof(struct l_dirent, d_name));
			error = copyout(linux_dirent, outp, linuxreclen);
		}
		if (is64bit) {
			linux_dirent64 = (struct l_dirent64*)lbuf;
			linux_dirent64->d_ino = bdp->d_fileno;
			linux_dirent64->d_off = (cookiep)
			    ? (l_off_t)*cookiep
			    : (l_off_t)(off + reclen);
			linux_dirent64->d_reclen = (l_ushort)linuxreclen;
			linux_dirent64->d_type = bdp->d_type;
			strlcpy(linux_dirent64->d_name, bdp->d_name,
			    linuxreclen - offsetof(struct l_dirent64, d_name));
			error = copyout(linux_dirent64, outp, linuxreclen);
		} else if (!justone) {
			linux_dirent = (struct l_dirent*)lbuf;
			linux_dirent->d_ino = bdp->d_fileno;
			linux_dirent->d_off = (cookiep)
			    ? (l_off_t)*cookiep
			    : (l_off_t)(off + reclen);
			linux_dirent->d_reclen = (l_ushort)linuxreclen;
			/*
			 * Copy d_type to last byte of l_dirent buffer
			 */
			lbuf[linuxreclen-1] = bdp->d_type;
			strlcpy(linux_dirent->d_name, bdp->d_name,
			    linuxreclen - offsetof(struct l_dirent, d_name)-1);
			error = copyout(linux_dirent, outp, linuxreclen);
		}

		if (error)
			goto out;

		inp += reclen;
		if (cookiep) {
			off = *cookiep++;
			ncookies--;
		} else
			off += reclen;

		outp += linuxreclen;
		resid -= linuxreclen;
		len -= reclen;
		if (justone)
			break;
	}

	if (outp == (caddr_t)args->dirent) {
		nbytes = resid;
		goto eof;
	}

	fp->f_offset = off;
	if (justone)
		nbytes = resid + linuxreclen;

eof:
	td->td_retval[0] = nbytes - resid;

out:
	if (cookies)
		free(cookies, M_TEMP);

	VOP_UNLOCK(vp, 0);
	VFS_UNLOCK_GIANT(vfslocked);
	fdrop(fp, td);
	free(buf, M_TEMP);
	free(lbuf, M_TEMP);
	return (error);
}

int
linux_getdents(struct thread *td, struct linux_getdents_args *args)
{

#ifdef DEBUG
	if (ldebug(getdents))
		printf(ARGS(getdents, "%d, *, %d"), args->fd, args->count);
#endif

	return (getdents_common(td, (struct linux_getdents64_args*)args, 0));
}

int
linux_getdents64(struct thread *td, struct linux_getdents64_args *args)
{

#ifdef DEBUG
	if (ldebug(getdents64))
		printf(ARGS(getdents64, "%d, *, %d"), args->fd, args->count);
#endif

	return (getdents_common(td, args, 1));
}

/*
 * These exist mainly for hooks for doing /compat/linux translation.
 */

int
linux_access(struct thread *td, struct linux_access_args *args)
{
	char *path;
	int error;

	/* linux convention */
	if (args->amode & ~(F_OK | X_OK | W_OK | R_OK))
		return (EINVAL);

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(access))
		printf(ARGS(access, "%s, %d"), path, args->amode);
#endif
	error = kern_access(td, path, UIO_SYSSPACE, args->amode);
	LFREEPATH(path);

	return (error);
}

int
linux_faccessat(struct thread *td, struct linux_faccessat_args *args)
{
	char *path;
	int error, dfd, flag;

	if (args->flag & ~LINUX_AT_EACCESS)
		return (EINVAL);
	/* linux convention */
	if (args->amode & ~(F_OK | X_OK | W_OK | R_OK))
		return (EINVAL);

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	LCONVPATHEXIST_AT(td, args->filename, &path, dfd);

#ifdef DEBUG
	if (ldebug(access))
		printf(ARGS(access, "%s, %d"), path, args->amode);
#endif

	flag = (args->flag & LINUX_AT_EACCESS) == 0 ? 0 : AT_EACCESS;
	error = kern_accessat(td, dfd, path, UIO_SYSSPACE, flag, args->amode);
	LFREEPATH(path);

	return (error);
}

int
linux_unlink(struct thread *td, struct linux_unlink_args *args)
{
	char *path;
	int error;
	struct stat st;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(unlink))
		printf(ARGS(unlink, "%s"), path);
#endif

	error = kern_unlink(td, path, UIO_SYSSPACE);
	if (error == EPERM)
		/* Introduce POSIX noncompliant behaviour of Linux */
		if (kern_stat(td, path, UIO_SYSSPACE, &st) == 0)
			if (S_ISDIR(st.st_mode))
				error = EISDIR;
	LFREEPATH(path);
	return (error);
}

int
linux_unlinkat(struct thread *td, struct linux_unlinkat_args *args)
{
	char *path;
	int error, dfd;
	struct stat st;

	if (args->flag & ~LINUX_AT_REMOVEDIR)
		return (EINVAL);

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	LCONVPATHEXIST_AT(td, args->pathname, &path, dfd);

#ifdef DEBUG
	if (ldebug(unlinkat))
		printf(ARGS(unlinkat, "%s"), path);
#endif

	if (args->flag & LINUX_AT_REMOVEDIR)
		error = kern_rmdirat(td, dfd, path, UIO_SYSSPACE);
	else
		error = kern_unlinkat(td, dfd, path, UIO_SYSSPACE, 0);
	if (error == EPERM && !(args->flag & LINUX_AT_REMOVEDIR)) {
		/* Introduce POSIX noncompliant behaviour of Linux */
		if (kern_statat(td, AT_SYMLINK_NOFOLLOW, dfd, path,
		    UIO_SYSSPACE, &st) == 0 && S_ISDIR(st.st_mode))
			error = EISDIR;
	}
	LFREEPATH(path);
	return (error);
}
int
linux_chdir(struct thread *td, struct linux_chdir_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(chdir))
		printf(ARGS(chdir, "%s"), path);
#endif
	error = kern_chdir(td, path, UIO_SYSSPACE);
	LFREEPATH(path);
	return (error);
}

int
linux_chmod(struct thread *td, struct linux_chmod_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(chmod))
		printf(ARGS(chmod, "%s, %d"), path, args->mode);
#endif
	error = kern_chmod(td, path, UIO_SYSSPACE, args->mode);
	LFREEPATH(path);
	return (error);
}

int
linux_fchmodat(struct thread *td, struct linux_fchmodat_args *args)
{
	char *path;
	int error, dfd;

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	LCONVPATHEXIST_AT(td, args->filename, &path, dfd);

#ifdef DEBUG
	if (ldebug(fchmodat))
		printf(ARGS(fchmodat, "%s, %d"), path, args->mode);
#endif

	error = kern_fchmodat(td, dfd, path, UIO_SYSSPACE, args->mode, 0);
	LFREEPATH(path);
	return (error);
}

int
linux_mkdir(struct thread *td, struct linux_mkdir_args *args)
{
	char *path;
	int error;

	LCONVPATHCREAT(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(mkdir))
		printf(ARGS(mkdir, "%s, %d"), path, args->mode);
#endif
	error = kern_mkdir(td, path, UIO_SYSSPACE, args->mode);
	LFREEPATH(path);
	return (error);
}

int
linux_mkdirat(struct thread *td, struct linux_mkdirat_args *args)
{
	char *path;
	int error, dfd;

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	LCONVPATHCREAT_AT(td, args->pathname, &path, dfd);

#ifdef DEBUG
	if (ldebug(mkdirat))
		printf(ARGS(mkdirat, "%s, %d"), path, args->mode);
#endif
	error = kern_mkdirat(td, dfd, path, UIO_SYSSPACE, args->mode);
	LFREEPATH(path);
	return (error);
}

int
linux_rmdir(struct thread *td, struct linux_rmdir_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(rmdir))
		printf(ARGS(rmdir, "%s"), path);
#endif
	error = kern_rmdir(td, path, UIO_SYSSPACE);
	LFREEPATH(path);
	return (error);
}

int
linux_rename(struct thread *td, struct linux_rename_args *args)
{
	char *from, *to;
	int error;

	LCONVPATHEXIST(td, args->from, &from);
	/* Expand LCONVPATHCREATE so that `from' can be freed on errors */
	error = linux_emul_convpath(td, args->to, UIO_USERSPACE, &to, 1, AT_FDCWD);
	if (to == NULL) {
		LFREEPATH(from);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(rename))
		printf(ARGS(rename, "%s, %s"), from, to);
#endif
	error = kern_rename(td, from, to, UIO_SYSSPACE);
	LFREEPATH(from);
	LFREEPATH(to);
	return (error);
}

int
linux_renameat(struct thread *td, struct linux_renameat_args *args)
{
	char *from, *to;
	int error, olddfd, newdfd;

	olddfd = (args->olddfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->olddfd;
	newdfd = (args->newdfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->newdfd;
	LCONVPATHEXIST_AT(td, args->oldname, &from, olddfd);
	/* Expand LCONVPATHCREATE so that `from' can be freed on errors */
	error = linux_emul_convpath(td, args->newname, UIO_USERSPACE, &to, 1, newdfd);
	if (to == NULL) {
		LFREEPATH(from);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(renameat))
		printf(ARGS(renameat, "%s, %s"), from, to);
#endif
	error = kern_renameat(td, olddfd, from, newdfd, to, UIO_SYSSPACE);
	LFREEPATH(from);
	LFREEPATH(to);
	return (error);
}

int
linux_symlink(struct thread *td, struct linux_symlink_args *args)
{
	char *path, *to;
	int error;

	LCONVPATHEXIST(td, args->path, &path);
	/* Expand LCONVPATHCREATE so that `path' can be freed on errors */
	error = linux_emul_convpath(td, args->to, UIO_USERSPACE, &to, 1, AT_FDCWD);
	if (to == NULL) {
		LFREEPATH(path);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(symlink))
		printf(ARGS(symlink, "%s, %s"), path, to);
#endif
	error = kern_symlink(td, path, to, UIO_SYSSPACE);
	LFREEPATH(path);
	LFREEPATH(to);
	return (error);
}

int
linux_symlinkat(struct thread *td, struct linux_symlinkat_args *args)
{
	char *path, *to;
	int error, dfd;

	dfd = (args->newdfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->newdfd;
	LCONVPATHEXIST_AT(td, args->oldname, &path, dfd);
	/* Expand LCONVPATHCREATE so that `path' can be freed on errors */
	error = linux_emul_convpath(td, args->newname, UIO_USERSPACE, &to, 1, dfd);
	if (to == NULL) {
		LFREEPATH(path);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(symlinkat))
		printf(ARGS(symlinkat, "%s, %s"), path, to);
#endif

	error = kern_symlinkat(td, path, dfd, to, UIO_SYSSPACE);
	LFREEPATH(path);
	LFREEPATH(to);
	return (error);
}

int
linux_readlink(struct thread *td, struct linux_readlink_args *args)
{
	char *name;
	int error;

	LCONVPATHEXIST(td, args->name, &name);

#ifdef DEBUG
	if (ldebug(readlink))
		printf(ARGS(readlink, "%s, %p, %d"), name, (void *)args->buf,
		    args->count);
#endif
	error = kern_readlink(td, name, UIO_SYSSPACE, args->buf, UIO_USERSPACE,
	    args->count);
	LFREEPATH(name);
	return (error);
}

int
linux_readlinkat(struct thread *td, struct linux_readlinkat_args *args)
{
	char *name;
	int error, dfd;

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
	LCONVPATHEXIST_AT(td, args->path, &name, dfd);

#ifdef DEBUG
	if (ldebug(readlinkat))
		printf(ARGS(readlinkat, "%s, %p, %d"), name, (void *)args->buf,
		    args->bufsiz);
#endif

	error = kern_readlinkat(td, dfd, name, UIO_SYSSPACE, args->buf,
	    UIO_USERSPACE, args->bufsiz);
	LFREEPATH(name);
	return (error);
}

int
linux_truncate(struct thread *td, struct linux_truncate_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(truncate))
		printf(ARGS(truncate, "%s, %ld"), path, (long)args->length);
#endif

	error = kern_truncate(td, path, UIO_SYSSPACE, args->length);
	LFREEPATH(path);
	return (error);
}

int
linux_truncate64(struct thread *td, struct linux_truncate64_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(truncate64))
		printf(ARGS(truncate64, "%s, %jd"), path, args->length);
#endif

	error = kern_truncate(td, path, UIO_SYSSPACE, args->length);
	LFREEPATH(path);
	return (error);
}
int
linux_ftruncate(struct thread *td, struct linux_ftruncate_args *args)
{
	struct ftruncate_args /* {
		int fd;
		int pad;
		off_t length;
		} */ nuap;

	nuap.fd = args->fd;
	nuap.length = args->length;
	return (sys_ftruncate(td, &nuap));
}

int
linux_link(struct thread *td, struct linux_link_args *args)
{
	char *path, *to;
	int error;

	LCONVPATHEXIST(td, args->path, &path);
	/* Expand LCONVPATHCREATE so that `path' can be freed on errors */
	error = linux_emul_convpath(td, args->to, UIO_USERSPACE, &to, 1, AT_FDCWD);
	if (to == NULL) {
		LFREEPATH(path);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(link))
		printf(ARGS(link, "%s, %s"), path, to);
#endif
	error = kern_link(td, path, to, UIO_SYSSPACE);
	LFREEPATH(path);
	LFREEPATH(to);
	return (error);
}

int
linux_linkat(struct thread *td, struct linux_linkat_args *args)
{
	char *path, *to;
	int error, olddfd, newdfd, follow;

	if (args->flag & ~LINUX_AT_SYMLINK_FOLLOW)
		return (EINVAL);

	olddfd = (args->olddfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->olddfd;
	newdfd = (args->newdfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->newdfd;
	LCONVPATHEXIST_AT(td, args->oldname, &path, olddfd);
	/* Expand LCONVPATHCREATE so that `path' can be freed on errors */
	error = linux_emul_convpath(td, args->newname, UIO_USERSPACE, &to, 1, newdfd);
	if (to == NULL) {
		LFREEPATH(path);
		return (error);
	}

#ifdef DEBUG
	if (ldebug(linkat))
		printf(ARGS(linkat, "%i, %s, %i, %s, %i"), args->olddfd, path,
			args->newdfd, to, args->flag);
#endif

	follow = (args->flag & LINUX_AT_SYMLINK_FOLLOW) == 0 ? NOFOLLOW :
	    FOLLOW;
	error = kern_linkat(td, olddfd, newdfd, path, to, UIO_SYSSPACE, follow);
	LFREEPATH(path);
	LFREEPATH(to);
	return (error);
}

int
linux_fdatasync(td, uap)
	struct thread *td;
	struct linux_fdatasync_args *uap;
{
	struct fsync_args bsd;

	bsd.fd = uap->fd;
	return sys_fsync(td, &bsd);
}

int
linux_pread(td, uap)
	struct thread *td;
	struct linux_pread_args *uap;
{
	struct pread_args bsd;
	struct vnode *vp;
	int error;

	bsd.fd = uap->fd;
	bsd.buf = uap->buf;
	bsd.nbyte = uap->nbyte;
	bsd.offset = uap->offset;

	error = sys_pread(td, &bsd);

	if (error == 0) {
   	   	/* This seems to violate POSIX but linux does it */
		if ((error = fgetvp(td, uap->fd, CAP_READ, &vp)) != 0)
   		   	return (error);
		if (vp->v_type == VDIR) {
   		   	vrele(vp);
			return (EISDIR);
		}
		vrele(vp);
	}

	return (error);
}

int
linux_pwrite(td, uap)
	struct thread *td;
	struct linux_pwrite_args *uap;
{
	struct pwrite_args bsd;

	bsd.fd = uap->fd;
	bsd.buf = uap->buf;
	bsd.nbyte = uap->nbyte;
	bsd.offset = uap->offset;
	return sys_pwrite(td, &bsd);
}

int
linux_mount(struct thread *td, struct linux_mount_args *args)
{
	struct ufs_args ufs;
	char fstypename[MFSNAMELEN];
	char mntonname[MNAMELEN], mntfromname[MNAMELEN];
	int error;
	int fsflags;
	void *fsdata;

	error = copyinstr(args->filesystemtype, fstypename, MFSNAMELEN - 1,
	    NULL);
	if (error)
		return (error);
	error = copyinstr(args->specialfile, mntfromname, MNAMELEN - 1, NULL);
	if (error)
		return (error);
	error = copyinstr(args->dir, mntonname, MNAMELEN - 1, NULL);
	if (error)
		return (error);

#ifdef DEBUG
	if (ldebug(mount))
		printf(ARGS(mount, "%s, %s, %s"),
		    fstypename, mntfromname, mntonname);
#endif

	if (strcmp(fstypename, "ext2") == 0) {
		strcpy(fstypename, "ext2fs");
		fsdata = &ufs;
		ufs.fspec = mntfromname;
#define DEFAULT_ROOTID		-2
		ufs.export.ex_root = DEFAULT_ROOTID;
		ufs.export.ex_flags =
		    args->rwflag & LINUX_MS_RDONLY ? MNT_EXRDONLY : 0;
	} else if (strcmp(fstypename, "proc") == 0) {
		strcpy(fstypename, "linprocfs");
		fsdata = NULL;
	} else if (strcmp(fstypename, "vfat") == 0) {
		strcpy(fstypename, "msdosfs");
		fsdata = NULL;
	} else {
		return (ENODEV);
	}

	fsflags = 0;

	if ((args->rwflag & 0xffff0000) == 0xc0ed0000) {
		/*
		 * Linux SYNC flag is not included; the closest equivalent
		 * FreeBSD has is !ASYNC, which is our default.
		 */
		if (args->rwflag & LINUX_MS_RDONLY)
			fsflags |= MNT_RDONLY;
		if (args->rwflag & LINUX_MS_NOSUID)
			fsflags |= MNT_NOSUID;
		if (args->rwflag & LINUX_MS_NOEXEC)
			fsflags |= MNT_NOEXEC;
		if (args->rwflag & LINUX_MS_REMOUNT)
			fsflags |= MNT_UPDATE;
	}

	if (strcmp(fstypename, "linprocfs") == 0) {
		error = kernel_vmount(fsflags,
			"fstype", fstypename,
			"fspath", mntonname,
			NULL);
	} else if (strcmp(fstypename, "msdosfs") == 0) {
		error = kernel_vmount(fsflags,
			"fstype", fstypename,
			"fspath", mntonname,
			"from", mntfromname,
			NULL);
	} else
		error = EOPNOTSUPP;
	return (error);
}

int
linux_oldumount(struct thread *td, struct linux_oldumount_args *args)
{
	struct linux_umount_args args2;

	args2.path = args->path;
	args2.flags = 0;
	return (linux_umount(td, &args2));
}

int
linux_umount(struct thread *td, struct linux_umount_args *args)
{
	struct unmount_args bsd;

	bsd.path = args->path;
	bsd.flags = args->flags;	/* XXX correct? */
	return (sys_unmount(td, &bsd));
}

/*
 * fcntl family of syscalls
 */

struct l_flock {
	l_short		l_type;
	l_short		l_whence;
	l_off_t		l_start;
	l_off_t		l_len;
	l_pid_t		l_pid;
}
#if defined(__amd64__) && defined(COMPAT_LINUX32)
__packed
#endif
;

static void
linux_to_bsd_flock(struct l_flock *linux_flock, struct flock *bsd_flock)
{
	switch (linux_flock->l_type) {
	case LINUX_F_RDLCK:
		bsd_flock->l_type = F_RDLCK;
		break;
	case LINUX_F_WRLCK:
		bsd_flock->l_type = F_WRLCK;
		break;
	case LINUX_F_UNLCK:
		bsd_flock->l_type = F_UNLCK;
		break;
	default:
		bsd_flock->l_type = -1;
		break;
	}
	bsd_flock->l_whence = linux_flock->l_whence;
	bsd_flock->l_start = (off_t)linux_flock->l_start;
	bsd_flock->l_len = (off_t)linux_flock->l_len;
	bsd_flock->l_pid = (pid_t)linux_flock->l_pid;
	bsd_flock->l_sysid = 0;
}

static void
bsd_to_linux_flock(struct flock *bsd_flock, struct l_flock *linux_flock)
{
	switch (bsd_flock->l_type) {
	case F_RDLCK:
		linux_flock->l_type = LINUX_F_RDLCK;
		break;
	case F_WRLCK:
		linux_flock->l_type = LINUX_F_WRLCK;
		break;
	case F_UNLCK:
		linux_flock->l_type = LINUX_F_UNLCK;
		break;
	}
	linux_flock->l_whence = bsd_flock->l_whence;
	linux_flock->l_start = (l_off_t)bsd_flock->l_start;
	linux_flock->l_len = (l_off_t)bsd_flock->l_len;
	linux_flock->l_pid = (l_pid_t)bsd_flock->l_pid;
}

#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
struct l_flock64 {
	l_short		l_type;
	l_short		l_whence;
	l_loff_t	l_start;
	l_loff_t	l_len;
	l_pid_t		l_pid;
}
#if defined(__amd64__) && defined(COMPAT_LINUX32)
__packed
#endif
;

static void
linux_to_bsd_flock64(struct l_flock64 *linux_flock, struct flock *bsd_flock)
{
	switch (linux_flock->l_type) {
	case LINUX_F_RDLCK:
		bsd_flock->l_type = F_RDLCK;
		break;
	case LINUX_F_WRLCK:
		bsd_flock->l_type = F_WRLCK;
		break;
	case LINUX_F_UNLCK:
		bsd_flock->l_type = F_UNLCK;
		break;
	default:
		bsd_flock->l_type = -1;
		break;
	}
	bsd_flock->l_whence = linux_flock->l_whence;
	bsd_flock->l_start = (off_t)linux_flock->l_start;
	bsd_flock->l_len = (off_t)linux_flock->l_len;
	bsd_flock->l_pid = (pid_t)linux_flock->l_pid;
	bsd_flock->l_sysid = 0;
}

static void
bsd_to_linux_flock64(struct flock *bsd_flock, struct l_flock64 *linux_flock)
{
	switch (bsd_flock->l_type) {
	case F_RDLCK:
		linux_flock->l_type = LINUX_F_RDLCK;
		break;
	case F_WRLCK:
		linux_flock->l_type = LINUX_F_WRLCK;
		break;
	case F_UNLCK:
		linux_flock->l_type = LINUX_F_UNLCK;
		break;
	}
	linux_flock->l_whence = bsd_flock->l_whence;
	linux_flock->l_start = (l_loff_t)bsd_flock->l_start;
	linux_flock->l_len = (l_loff_t)bsd_flock->l_len;
	linux_flock->l_pid = (l_pid_t)bsd_flock->l_pid;
}
#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */

static int
fcntl_common(struct thread *td, struct linux_fcntl64_args *args)
{
	struct l_flock linux_flock;
	struct flock bsd_flock;
	struct file *fp;
	long arg;
	int error, result;

	switch (args->cmd) {
	case LINUX_F_DUPFD:
		return (kern_fcntl(td, args->fd, F_DUPFD, args->arg));

	case LINUX_F_GETFD:
		return (kern_fcntl(td, args->fd, F_GETFD, 0));

	case LINUX_F_SETFD:
		return (kern_fcntl(td, args->fd, F_SETFD, args->arg));

	case LINUX_F_GETFL:
		error = kern_fcntl(td, args->fd, F_GETFL, 0);
		result = td->td_retval[0];
		td->td_retval[0] = 0;
		if (result & O_RDONLY)
			td->td_retval[0] |= LINUX_O_RDONLY;
		if (result & O_WRONLY)
			td->td_retval[0] |= LINUX_O_WRONLY;
		if (result & O_RDWR)
			td->td_retval[0] |= LINUX_O_RDWR;
		if (result & O_NDELAY)
			td->td_retval[0] |= LINUX_O_NONBLOCK;
		if (result & O_APPEND)
			td->td_retval[0] |= LINUX_O_APPEND;
		if (result & O_FSYNC)
			td->td_retval[0] |= LINUX_O_SYNC;
		if (result & O_ASYNC)
			td->td_retval[0] |= LINUX_FASYNC;
#ifdef LINUX_O_NOFOLLOW
		if (result & O_NOFOLLOW)
			td->td_retval[0] |= LINUX_O_NOFOLLOW;
#endif
#ifdef LINUX_O_DIRECT
		if (result & O_DIRECT)
			td->td_retval[0] |= LINUX_O_DIRECT;
#endif
		return (error);

	case LINUX_F_SETFL:
		arg = 0;
		if (args->arg & LINUX_O_NDELAY)
			arg |= O_NONBLOCK;
		if (args->arg & LINUX_O_APPEND)
			arg |= O_APPEND;
		if (args->arg & LINUX_O_SYNC)
			arg |= O_FSYNC;
		if (args->arg & LINUX_FASYNC)
			arg |= O_ASYNC;
#ifdef LINUX_O_NOFOLLOW
		if (args->arg & LINUX_O_NOFOLLOW)
			arg |= O_NOFOLLOW;
#endif
#ifdef LINUX_O_DIRECT
		if (args->arg & LINUX_O_DIRECT)
			arg |= O_DIRECT;
#endif
		return (kern_fcntl(td, args->fd, F_SETFL, arg));

	case LINUX_F_GETLK:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock(&linux_flock, &bsd_flock);
		error = kern_fcntl(td, args->fd, F_GETLK, (intptr_t)&bsd_flock);
		if (error)
			return (error);
		bsd_to_linux_flock(&bsd_flock, &linux_flock);
		return (copyout(&linux_flock, (void *)args->arg,
		    sizeof(linux_flock)));

	case LINUX_F_SETLK:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock(&linux_flock, &bsd_flock);
		return (kern_fcntl(td, args->fd, F_SETLK,
		    (intptr_t)&bsd_flock));

	case LINUX_F_SETLKW:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock(&linux_flock, &bsd_flock);
		return (kern_fcntl(td, args->fd, F_SETLKW,
		     (intptr_t)&bsd_flock));

	case LINUX_F_GETOWN:
		return (kern_fcntl(td, args->fd, F_GETOWN, 0));

	case LINUX_F_SETOWN:
		/*
		 * XXX some Linux applications depend on F_SETOWN having no
		 * significant effect for pipes (SIGIO is not delivered for
		 * pipes under Linux-2.2.35 at least).
		 */
		error = fget(td, args->fd, CAP_FCNTL, &fp);
		if (error)
			return (error);
		if (fp->f_type == DTYPE_PIPE) {
			fdrop(fp, td);
			return (EINVAL);
		}
		fdrop(fp, td);

		return (kern_fcntl(td, args->fd, F_SETOWN, args->arg));
	}

	return (EINVAL);
}

int
linux_fcntl(struct thread *td, struct linux_fcntl_args *args)
{
	struct linux_fcntl64_args args64;

#ifdef DEBUG
	if (ldebug(fcntl))
		printf(ARGS(fcntl, "%d, %08x, *"), args->fd, args->cmd);
#endif

	args64.fd = args->fd;
	args64.cmd = args->cmd;
	args64.arg = args->arg;
	return (fcntl_common(td, &args64));
}

#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
int
linux_fcntl64(struct thread *td, struct linux_fcntl64_args *args)
{
	struct l_flock64 linux_flock;
	struct flock bsd_flock;
	int error;

#ifdef DEBUG
	if (ldebug(fcntl64))
		printf(ARGS(fcntl64, "%d, %08x, *"), args->fd, args->cmd);
#endif

	switch (args->cmd) {
	case LINUX_F_GETLK64:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock64(&linux_flock, &bsd_flock);
		error = kern_fcntl(td, args->fd, F_GETLK, (intptr_t)&bsd_flock);
		if (error)
			return (error);
		bsd_to_linux_flock64(&bsd_flock, &linux_flock);
		return (copyout(&linux_flock, (void *)args->arg,
			    sizeof(linux_flock)));

	case LINUX_F_SETLK64:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock64(&linux_flock, &bsd_flock);
		return (kern_fcntl(td, args->fd, F_SETLK,
		    (intptr_t)&bsd_flock));

	case LINUX_F_SETLKW64:
		error = copyin((void *)args->arg, &linux_flock,
		    sizeof(linux_flock));
		if (error)
			return (error);
		linux_to_bsd_flock64(&linux_flock, &bsd_flock);
		return (kern_fcntl(td, args->fd, F_SETLKW,
		    (intptr_t)&bsd_flock));
	}

	return (fcntl_common(td, args));
}
#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */

int
linux_chown(struct thread *td, struct linux_chown_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(chown))
		printf(ARGS(chown, "%s, %d, %d"), path, args->uid, args->gid);
#endif
	error = kern_chown(td, path, UIO_SYSSPACE, args->uid, args->gid);
	LFREEPATH(path);
	return (error);
}

int
linux_fchownat(struct thread *td, struct linux_fchownat_args *args)
{
	char *path;
	int error, dfd, flag;

	if (args->flag & ~LINUX_AT_SYMLINK_NOFOLLOW)
		return (EINVAL);

	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD :  args->dfd;
	LCONVPATHEXIST_AT(td, args->filename, &path, dfd);

#ifdef DEBUG
	if (ldebug(fchownat))
		printf(ARGS(fchownat, "%s, %d, %d"), path, args->uid, args->gid);
#endif

	flag = (args->flag & LINUX_AT_SYMLINK_NOFOLLOW) == 0 ? 0 :
	    AT_SYMLINK_NOFOLLOW;
	error = kern_fchownat(td, dfd, path, UIO_SYSSPACE, args->uid, args->gid,
	    flag);
	LFREEPATH(path);
	return (error);
}

int
linux_lchown(struct thread *td, struct linux_lchown_args *args)
{
	char *path;
	int error;

	LCONVPATHEXIST(td, args->path, &path);

#ifdef DEBUG
	if (ldebug(lchown))
		printf(ARGS(lchown, "%s, %d, %d"), path, args->uid, args->gid);
#endif
	error = kern_lchown(td, path, UIO_SYSSPACE, args->uid, args->gid);
	LFREEPATH(path);
	return (error);
}