/* $NetBSD: linux_file.c,v 1.133 2024/10/01 17:46:51 riastradh Exp $ */

/* $NetBSD: linux_file.c,v 1.133 2024/10/01 17:46:51 riastradh Exp $ */

/*-
* Copyright (c) 1995, 1998, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Frank van der Linden and Eric Haszlakiewicz.
*
* 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.
*/

/*
* Functions in multiarch:
* linux_sys_llseek : linux_llseek.c
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_file.c,v 1.133 2024/10/01 17:46:51 riastradh Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/vfs_syscalls.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/tty.h>
#include <sys/socketvar.h>
#include <sys/conf.h>
#include <sys/pipe.h>
#include <sys/fstrans.h>
#include <sys/syscallargs.h>
#include <sys/vfs_syscalls.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_fcntl.h>
#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>

#include <compat/linux/linux_syscallargs.h>

#ifdef DEBUG_LINUX
#define DPRINTF(a, ...) uprintf(a, __VA_ARGS__)
#else
#define DPRINTF(a, ...)
#endif

#define LINUX_COPY_FILE_RANGE_MAX_CHUNK 8192

static int bsd_to_linux_ioflags(int);
#if !defined(__aarch64__) && !defined(__amd64__)
static void bsd_to_linux_stat(struct stat *, struct linux_stat *);
#endif

conv_linux_flock(linux, flock)

/*
* Some file-related calls are handled here. The usual flag conversion
* an structure conversion is done, and alternate emul path searching.
*/

/*
* The next two functions convert between the Linux and NetBSD values
* of the flags used in open(2) and fcntl(2).
*/
int
linux_to_bsd_ioflags(int lflags)
{
int res = 0;

res |= cvtto_bsd_mask(lflags, LINUX_O_WRONLY, O_WRONLY);
res |= cvtto_bsd_mask(lflags, LINUX_O_RDONLY, O_RDONLY);
res |= cvtto_bsd_mask(lflags, LINUX_O_RDWR, O_RDWR);

res |= cvtto_bsd_mask(lflags, LINUX_O_CREAT, O_CREAT);
res |= cvtto_bsd_mask(lflags, LINUX_O_EXCL, O_EXCL);
res |= cvtto_bsd_mask(lflags, LINUX_O_NOCTTY, O_NOCTTY);
res |= cvtto_bsd_mask(lflags, LINUX_O_TRUNC, O_TRUNC);
res |= cvtto_bsd_mask(lflags, LINUX_O_APPEND, O_APPEND);
res |= cvtto_bsd_mask(lflags, LINUX_O_NONBLOCK, O_NONBLOCK);
res |= cvtto_bsd_mask(lflags, LINUX_O_NDELAY, O_NDELAY);
res |= cvtto_bsd_mask(lflags, LINUX_O_SYNC, O_FSYNC);
res |= cvtto_bsd_mask(lflags, LINUX_FASYNC, O_ASYNC);
res |= cvtto_bsd_mask(lflags, LINUX_O_DIRECT, O_DIRECT);
res |= cvtto_bsd_mask(lflags, LINUX_O_DIRECTORY, O_DIRECTORY);
res |= cvtto_bsd_mask(lflags, LINUX_O_NOFOLLOW, O_NOFOLLOW);
res |= cvtto_bsd_mask(lflags, LINUX_O_CLOEXEC, O_CLOEXEC);

return res;
}

static int
bsd_to_linux_ioflags(int bflags)
{
int res = 0;

res |= cvtto_linux_mask(bflags, O_WRONLY, LINUX_O_WRONLY);
res |= cvtto_linux_mask(bflags, O_RDONLY, LINUX_O_RDONLY);
res |= cvtto_linux_mask(bflags, O_RDWR, LINUX_O_RDWR);

res |= cvtto_linux_mask(bflags, O_CREAT, LINUX_O_CREAT);
res |= cvtto_linux_mask(bflags, O_EXCL, LINUX_O_EXCL);
res |= cvtto_linux_mask(bflags, O_NOCTTY, LINUX_O_NOCTTY);
res |= cvtto_linux_mask(bflags, O_TRUNC, LINUX_O_TRUNC);
res |= cvtto_linux_mask(bflags, O_APPEND, LINUX_O_APPEND);
res |= cvtto_linux_mask(bflags, O_NONBLOCK, LINUX_O_NONBLOCK);
res |= cvtto_linux_mask(bflags, O_NDELAY, LINUX_O_NDELAY);
res |= cvtto_linux_mask(bflags, O_FSYNC, LINUX_O_SYNC);
res |= cvtto_linux_mask(bflags, O_ASYNC, LINUX_FASYNC);
res |= cvtto_linux_mask(bflags, O_DIRECT, LINUX_O_DIRECT);
res |= cvtto_linux_mask(bflags, O_DIRECTORY, LINUX_O_DIRECTORY);
res |= cvtto_linux_mask(bflags, O_NOFOLLOW, LINUX_O_NOFOLLOW);
res |= cvtto_linux_mask(bflags, O_CLOEXEC, LINUX_O_CLOEXEC);

return res;
}

static inline off_t
linux_hilo_to_off_t(unsigned long hi, unsigned long lo)
{
#ifdef _LP64
/*
* Linux discards the "hi" portion on LP64 platforms; even though
* glibc puts of the upper 32-bits of the offset into the "hi"
* argument regardless, the "lo" argument has all the bits in
* this case.
*/
(void) hi;
return (off_t)lo;
#else
return (((off_t)hi) << 32) | lo;
#endif /* _LP64 */
}

#if !defined(__aarch64__)
/*
* creat(2) is an obsolete function, but it's present as a Linux
* system call, so let's deal with it.
*
* Note: On the Alpha this doesn't really exist in Linux, but it's defined
* in syscalls.master anyway so this doesn't have to be special cased.
*
* Just call open(2) with the TRUNC, CREAT and WRONLY flags.
*/
int
linux_sys_creat(struct lwp *l, const struct linux_sys_creat_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
syscallarg(linux_umode_t) mode;
} */
struct sys_open_args oa;

SCARG(&oa, path) = SCARG(uap, path);
SCARG(&oa, flags) = O_CREAT | O_TRUNC | O_WRONLY;
SCARG(&oa, mode) = SCARG(uap, mode);

return sys_open(l, &oa, retval);
}
#endif

static void
linux_open_ctty(struct lwp *l, int flags, int fd)
{
struct proc *p = l->l_proc;

/*
* this bit from sunos_misc.c (and svr4_fcntl.c).
* If we are a session leader, and we don't have a controlling
* terminal yet, and the O_NOCTTY flag is not set, try to make
* this the controlling terminal.
*/
if (!(flags & O_NOCTTY) && SESS_LEADER(p) && !(p->p_lflag & PL_CONTROLT)) {
file_t *fp;

fp = fd_getfile(fd);

/* ignore any error, just give it a try */
if (fp != NULL) {
if (fp->f_type == DTYPE_VNODE) {
(fp->f_ops->fo_ioctl) (fp, TIOCSCTTY, NULL);
}
fd_putfile(fd);
}
}
}

/*
* open(2). Take care of the different flag values, and let the
* NetBSD syscall do the real work. See if this operation
* gives the current process a controlling terminal.
* (XXX is this necessary?)
*/
int
linux_sys_open(struct lwp *l, const struct linux_sys_open_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
syscallarg(int) flags;
syscallarg(linux_umode_t) mode;
} */
int error, fl;
struct sys_open_args boa;

fl = linux_to_bsd_ioflags(SCARG(uap, flags));

SCARG(&boa, path) = SCARG(uap, path);
SCARG(&boa, flags) = fl;
SCARG(&boa, mode) = SCARG(uap, mode);

if ((error = sys_open(l, &boa, retval)))
return (error == EFTYPE) ? ELOOP : error;

linux_open_ctty(l, fl, *retval);
return 0;
}

int
linux_sys_openat(struct lwp *l, const struct linux_sys_openat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(int) flags;
syscallarg(linux_umode_t) mode;
} */
int error, fl;
struct sys_openat_args boa;

fl = linux_to_bsd_ioflags(SCARG(uap, flags));

SCARG(&boa, fd) = SCARG(uap, fd);
SCARG(&boa, path) = SCARG(uap, path);
SCARG(&boa, oflags) = fl;
SCARG(&boa, mode) = SCARG(uap, mode);

if ((error = sys_openat(l, &boa, retval)))
return (error == EFTYPE) ? ELOOP : error;

linux_open_ctty(l, fl, *retval);
return 0;
}

/*
* Most actions in the fcntl() call are straightforward; simply
* pass control to the NetBSD system call. A few commands need
* conversions after the actual system call has done its work,
* because the flag values and lock structure are different.
*/
int
linux_sys_fcntl(struct lwp *l, const struct linux_sys_fcntl_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(int) cmd;
syscallarg(void *) arg;
} */
struct proc *p = l->l_proc;
int fd, cmd, error;
u_long val;
void *arg;
struct sys_fcntl_args fca;
file_t *fp;
struct vnode *vp;
struct vattr va;
long pgid;
struct pgrp *pgrp;
struct tty *tp;

fd = SCARG(uap, fd);
cmd = SCARG(uap, cmd);
arg = SCARG(uap, arg);

switch (cmd) {

case LINUX_F_DUPFD:
cmd = F_DUPFD;
break;

case LINUX_F_GETFD:
cmd = F_GETFD;
break;

case LINUX_F_SETFD:
cmd = F_SETFD;
break;

case LINUX_F_GETFL:
SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = F_GETFL;
SCARG(&fca, arg) = arg;
if ((error = sys_fcntl(l, &fca, retval)))
return error;
retval[0] = bsd_to_linux_ioflags(retval[0]);
return 0;

case LINUX_F_SETFL: {
file_t *fp1 = NULL;

val = linux_to_bsd_ioflags((unsigned long)SCARG(uap, arg));
/*
* Linux seems to have same semantics for sending SIGIO to the
* read side of socket, but slightly different semantics
* for SIGIO to the write side. Rather than sending the SIGIO
* every time it's possible to write (directly) more data, it
* only sends SIGIO if last write(2) failed due to insufficient
* memory to hold the data. This is compatible enough
* with NetBSD semantics to not do anything about the
* difference.
*
* Linux does NOT send SIGIO for pipes. Deal with socketpair
* ones and DTYPE_PIPE ones. For these, we don't set
* the underlying flags (we don't pass O_ASYNC flag down
* to sys_fcntl()), but set the FASYNC flag for file descriptor,
* so that F_GETFL would report the ASYNC i/o is on.
*/
if (val & O_ASYNC) {
if (((fp1 = fd_getfile(fd)) == NULL))
return (EBADF);
if (((fp1->f_type == DTYPE_SOCKET) && fp1->f_data
&& ((struct socket *)fp1->f_data)->so_state & SS_ISAPIPE)
|| (fp1->f_type == DTYPE_PIPE))
val &= ~O_ASYNC;
else {
/* not a pipe, do not modify anything */
fd_putfile(fd);
fp1 = NULL;
}
}

SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = F_SETFL;
SCARG(&fca, arg) = (void *) val;

error = sys_fcntl(l, &fca, retval);

/* Now set the FASYNC flag for pipes */
if (fp1) {
if (!error) {
mutex_enter(&fp1->f_lock);
fp1->f_flag |= FASYNC;
mutex_exit(&fp1->f_lock);
}
fd_putfile(fd);
}

return (error);
}

case LINUX_F_GETLK:
do_linux_getlk(fd, cmd, arg, linux, flock);

case LINUX_F_SETLK:
case LINUX_F_SETLKW:
do_linux_setlk(fd, cmd, arg, linux, flock, LINUX_F_SETLK);

case LINUX_F_SETOWN:
case LINUX_F_GETOWN:
/*
* We need to route fcntl() for tty descriptors around normal
* fcntl(), since NetBSD tty TIOC{G,S}PGRP semantics is too
* restrictive for Linux F_{G,S}ETOWN. For non-tty descriptors,
* this is not a problem.
*/
if ((fp = fd_getfile(fd)) == NULL)
return EBADF;

/* Check it's a character device vnode */
if (fp->f_type != DTYPE_VNODE
|| (vp = (struct vnode *)fp->f_data) == NULL
|| vp->v_type != VCHR) {
fd_putfile(fd);

not_tty:
/* Not a tty, proceed with common fcntl() */
cmd = cmd == LINUX_F_SETOWN ? F_SETOWN : F_GETOWN;
break;
}

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

fd_putfile(fd);

if (error)
return error;

if ((tp = cdev_tty(va.va_rdev)) == NULL)
goto not_tty;

/* set tty pg_id appropriately */
mutex_enter(&proc_lock);
if (cmd == LINUX_F_GETOWN) {
retval[0] = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PGID;
mutex_exit(&proc_lock);
return 0;
}
if ((long)arg <= 0) {
pgid = -(long)arg;
} else {
struct proc *p1 = proc_find((long)arg);
if (p1 == NULL) {
mutex_exit(&proc_lock);
return (ESRCH);
}
pgid = (long)p1->p_pgrp->pg_id;
}
pgrp = pgrp_find(pgid);
if (pgrp == NULL || pgrp->pg_session != p->p_session) {
mutex_exit(&proc_lock);
return EPERM;
}
tp->t_pgrp = pgrp;
mutex_exit(&proc_lock);
return 0;

case LINUX_F_DUPFD_CLOEXEC:
cmd = F_DUPFD_CLOEXEC;
break;

case LINUX_F_ADD_SEALS:
cmd = F_ADD_SEALS;
break;

case LINUX_F_GET_SEALS:
cmd = F_GET_SEALS;
break;

default:
return EOPNOTSUPP;
}

SCARG(&fca, fd) = fd;
SCARG(&fca, cmd) = cmd;
SCARG(&fca, arg) = arg;

return sys_fcntl(l, &fca, retval);
}

#if !defined(__aarch64__) && !defined(__amd64__)
/*
* Convert a NetBSD stat structure to a Linux stat structure.
* Only the order of the fields and the padding in the structure
* is different. linux_fakedev is a machine-dependent function
* which optionally converts device driver major/minor numbers
* (XXX horrible, but what can you do against code that compares
* things against constant major device numbers? sigh)
*/
static void
bsd_to_linux_stat(struct stat *bsp, struct linux_stat *lsp)
{

memset(lsp, 0, sizeof(*lsp));
lsp->lst_dev = linux_fakedev(bsp->st_dev, 0);
lsp->lst_ino = bsp->st_ino;
lsp->lst_mode = (linux_mode_t)bsp->st_mode;
if (bsp->st_nlink >= (1 << 15))
lsp->lst_nlink = (1 << 15) - 1;
else
lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
lsp->lst_uid = bsp->st_uid;
lsp->lst_gid = bsp->st_gid;
lsp->lst_rdev = linux_fakedev(bsp->st_rdev, 1);
lsp->lst_size = bsp->st_size;
lsp->lst_blksize = bsp->st_blksize;
lsp->lst_blocks = bsp->st_blocks;
lsp->lst_atime = bsp->st_atime;
lsp->lst_mtime = bsp->st_mtime;
lsp->lst_ctime = bsp->st_ctime;
#ifdef LINUX_STAT_HAS_NSEC
lsp->lst_atime_nsec = bsp->st_atimensec;
lsp->lst_mtime_nsec = bsp->st_mtimensec;
lsp->lst_ctime_nsec = bsp->st_ctimensec;
#endif
}

/*
* The stat functions below are plain sailing. stat and lstat are handled
* by one function to avoid code duplication.
*/
int
linux_sys_fstat(struct lwp *l, const struct linux_sys_fstat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(linux_stat *) sp;
} */
struct linux_stat tmplst;
struct stat tmpst;
int error;

error = do_sys_fstat(SCARG(uap, fd), &tmpst);
if (error != 0)
return error;
bsd_to_linux_stat(&tmpst, &tmplst);

return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
}

static int
linux_stat1(const struct linux_sys_stat_args *uap, register_t *retval,
int flags)
{
struct linux_stat tmplst;
struct stat tmpst;
int error;

error = do_sys_stat(SCARG(uap, path), flags, &tmpst);
if (error != 0)
return error;

bsd_to_linux_stat(&tmpst, &tmplst);

return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
}

int
linux_sys_stat(struct lwp *l, const struct linux_sys_stat_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
syscallarg(struct linux_stat *) sp;
} */

return linux_stat1(uap, retval, FOLLOW);
}

/* Note: this is "newlstat" in the Linux sources */
/* (we don't bother with the old lstat currently) */
int
linux_sys_lstat(struct lwp *l, const struct linux_sys_lstat_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
syscallarg(struct linux_stat *) sp;
} */

return linux_stat1((const void *)uap, retval, NOFOLLOW);
}
#endif /* !__aarch64__ && !__amd64__ */

/*
* The following syscalls are mostly here because of the alternate path check.
*/

int
linux_sys_linkat(struct lwp *l, const struct linux_sys_linkat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd1;
syscallarg(const char *) name1;
syscallarg(int) fd2;
syscallarg(const char *) name2;
syscallarg(int) flags;
} */
int fd1 = SCARG(uap, fd1);
const char *name1 = SCARG(uap, name1);
int fd2 = SCARG(uap, fd2);
const char *name2 = SCARG(uap, name2);
int follow;

follow = SCARG(uap, flags) & LINUX_AT_SYMLINK_FOLLOW;

return do_sys_linkat(l, fd1, name1, fd2, name2, follow, retval);
}

static int
linux_unlink_dircheck(const char *path)
{
struct nameidata nd;
struct pathbuf *pb;
int error;

/*
* Linux returns EISDIR if unlink(2) is called on a directory.
* We return EPERM in such cases. To emulate correct behaviour,
* check if the path points to directory and return EISDIR if this
* is the case.
*
* XXX this should really not copy in the path buffer twice...
*/
error = pathbuf_copyin(path, &pb);
if (error) {
return error;
}
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
if (namei(&nd) == 0) {
struct stat sb;

if (vn_stat(nd.ni_vp, &sb) == 0
&& S_ISDIR(sb.st_mode))
error = EISDIR;

vput(nd.ni_vp);
}
pathbuf_destroy(pb);
return error ? error : EPERM;
}

int
linux_sys_unlink(struct lwp *l, const struct linux_sys_unlink_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
} */
int error;

error = sys_unlink(l, (const void *)uap, retval);
if (error == EPERM)
error = linux_unlink_dircheck(SCARG(uap, path));

return error;
}

int
linux_sys_unlinkat(struct lwp *l, const struct linux_sys_unlinkat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(int) flag;
} */
struct sys_unlinkat_args ua;
int error;

SCARG(&ua, fd) = SCARG(uap, fd);
SCARG(&ua, path) = SCARG(uap, path);
SCARG(&ua, flag) = linux_to_bsd_atflags(SCARG(uap, flag));

error = sys_unlinkat(l, &ua, retval);
if (error == EPERM)
error = linux_unlink_dircheck(SCARG(uap, path));

return error;
}

int
linux_sys_mknod(struct lwp *l, const struct linux_sys_mknod_args *uap,
register_t *retval)
{
/* {
syscallarg(const char *) path;
syscallarg(linux_umode_t) mode;
syscallarg(unsigned) dev;
} */
struct linux_sys_mknodat_args ua;

SCARG(&ua, fd) = LINUX_AT_FDCWD;
SCARG(&ua, path) = SCARG(uap, path);
SCARG(&ua, mode) = SCARG(uap, mode);
SCARG(&ua, dev) = SCARG(uap, dev);

return linux_sys_mknodat(l, &ua, retval);
}

int
linux_sys_mknodat(struct lwp *l, const struct linux_sys_mknodat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(linux_umode_t) mode;
syscallarg(unsigned) dev;
} */

/*
* BSD handles FIFOs separately
*/
if (S_ISFIFO(SCARG(uap, mode))) {
struct sys_mkfifoat_args bma;

SCARG(&bma, fd) = SCARG(uap, fd);
SCARG(&bma, path) = SCARG(uap, path);
SCARG(&bma, mode) = SCARG(uap, mode);
return sys_mkfifoat(l, &bma, retval);
} else {

/*
* Linux device numbers uses 8 bits for minor and 8 bits
* for major. Due to how we map our major and minor,
* this just fits into our dev_t. Just mask off the
* upper 16bit to remove any random junk.
*/

return do_sys_mknodat(l, SCARG(uap, fd), SCARG(uap, path),
SCARG(uap, mode), SCARG(uap, dev) & 0xffff, UIO_USERSPACE);
}
}

int
linux_sys_fchmodat(struct lwp *l, const struct linux_sys_fchmodat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(linux_umode_t) mode;
} */

return do_sys_chmodat(l, SCARG(uap, fd), SCARG(uap, path),
SCARG(uap, mode), AT_SYMLINK_FOLLOW);
}

int
linux_sys_fchownat(struct lwp *l, const struct linux_sys_fchownat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(uid_t) owner;
syscallarg(gid_t) group;
syscallarg(int) flag;
} */
int flag;

flag = linux_to_bsd_atflags(SCARG(uap, flag));
return do_sys_chownat(l, SCARG(uap, fd), SCARG(uap, path),
SCARG(uap, owner), SCARG(uap, group), flag);
}

int
linux_sys_faccessat(struct lwp *l, const struct linux_sys_faccessat_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(int) amode;
} */

return do_sys_accessat(l, SCARG(uap, fd), SCARG(uap, path),
SCARG(uap, amode), AT_SYMLINK_FOLLOW);
}

/*
* This is just fsync() for now (just as it is in the Linux kernel)
* Note: this is not implemented under Linux on Alpha and Arm
* but should still be defined in our syscalls.master.
* (syscall #148 on the arm)
*/
int
linux_sys_fdatasync(struct lwp *l, const struct linux_sys_fdatasync_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
} */

return sys_fsync(l, (const void *)uap, retval);
}

/*
* pread(2).
*/
int
linux_sys_pread(struct lwp *l, const struct linux_sys_pread_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(void *) buf;
syscallarg(size_t) nbyte;
syscallarg(off_t) offset;
} */
struct sys_pread_args pra;

SCARG(&pra, fd) = SCARG(uap, fd);
SCARG(&pra, buf) = SCARG(uap, buf);
SCARG(&pra, nbyte) = SCARG(uap, nbyte);
SCARG(&pra, PAD) = 0;
SCARG(&pra, offset) = SCARG(uap, offset);

return sys_pread(l, &pra, retval);
}

/*
* pwrite(2).
*/
int
linux_sys_pwrite(struct lwp *l, const struct linux_sys_pwrite_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(void *) buf;
syscallarg(size_t) nbyte;
syscallarg(off_t) offset;
} */
struct sys_pwrite_args pra;

SCARG(&pra, fd) = SCARG(uap, fd);
SCARG(&pra, buf) = SCARG(uap, buf);
SCARG(&pra, nbyte) = SCARG(uap, nbyte);
SCARG(&pra, PAD) = 0;
SCARG(&pra, offset) = SCARG(uap, offset);

return sys_pwrite(l, &pra, retval);
}

/*
* preadv(2)
*/
int
linux_sys_preadv(struct lwp *l, const struct linux_sys_preadv_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
syscallarg(unsigned long) off_lo;
syscallarg(unsigned long) off_hi;
} */
struct sys_preadv_args ua;

SCARG(&ua, fd) = SCARG(uap, fd);
SCARG(&ua, iovp) = SCARG(uap, iovp);
SCARG(&ua, iovcnt) = SCARG(uap, iovcnt);
SCARG(&ua, PAD) = 0;
SCARG(&ua, offset) = linux_hilo_to_off_t(SCARG(uap, off_hi),
SCARG(uap, off_lo));
return sys_preadv(l, &ua, retval);
}

/*
* pwritev(2)
*/
int
linux_sys_pwritev(struct lwp *l, const struct linux_sys_pwritev_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
syscallarg(unsigned long) off_lo;
syscallarg(unsigned long) off_hi;
} */
struct sys_pwritev_args ua;

SCARG(&ua, fd) = SCARG(uap, fd);
SCARG(&ua, iovp) = (const void *)SCARG(uap, iovp);
SCARG(&ua, iovcnt) = SCARG(uap, iovcnt);
SCARG(&ua, PAD) = 0;
SCARG(&ua, offset) = linux_hilo_to_off_t(SCARG(uap, off_hi),
SCARG(uap, off_lo));
return sys_pwritev(l, &ua, retval);
}

int
linux_sys_dup3(struct lwp *l, const struct linux_sys_dup3_args *uap,
register_t *retval)
{
/* {
syscallarg(int) from;
syscallarg(int) to;
syscallarg(int) flags;
} */
int flags;

flags = linux_to_bsd_ioflags(SCARG(uap, flags));
if ((flags & ~O_CLOEXEC) != 0)
return EINVAL;

if (SCARG(uap, from) == SCARG(uap, to))
return EINVAL;

return dodup(l, SCARG(uap, from), SCARG(uap, to), flags, retval);
}

int
linux_to_bsd_atflags(int lflags)
{
int bflags = 0;

if (lflags & LINUX_AT_SYMLINK_NOFOLLOW)
bflags |= AT_SYMLINK_NOFOLLOW;
if (lflags & LINUX_AT_REMOVEDIR)
bflags |= AT_REMOVEDIR;
if (lflags & LINUX_AT_SYMLINK_FOLLOW)
bflags |= AT_SYMLINK_FOLLOW;

return bflags;
}

int
linux_sys_faccessat2(lwp_t *l, const struct linux_sys_faccessat2_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(const char *) path;
syscallarg(int) amode;
syscallarg(int) flags;
} */
int flag = linux_to_bsd_atflags(SCARG(uap, flags));
int mode = SCARG(uap, amode);
int fd = SCARG(uap, fd);
const char *path = SCARG(uap, path);

return do_sys_accessat(l, fd, path, mode, flag);
}

int
linux_sys_sync_file_range(lwp_t *l,
const struct linux_sys_sync_file_range_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd;
syscallarg(off_t) offset;
syscallarg(off_t) nbytes;
syscallarg(unsigned int) flags;
} */

struct sys_fsync_range_args ua;

if (SCARG(uap, offset) < 0 || SCARG(uap, nbytes) < 0 ||
((SCARG(uap, flags) & ~LINUX_SYNC_FILE_RANGE_ALL) != 0))
return EINVAL;

/* Fill ua with uap */
SCARG(&ua, fd) = SCARG(uap, fd);
SCARG(&ua, flags) = SCARG(uap, flags);

/* Round down offset to page boundary */
SCARG(&ua, start) = rounddown(SCARG(uap, offset), PAGE_SIZE);
SCARG(&ua, length) = SCARG(uap, nbytes);
if (SCARG(&ua, length) != 0) {
/* Round up length to nbytes+offset to page boundary */
SCARG(&ua, length) = roundup(SCARG(uap, nbytes)
+ SCARG(uap, offset) - SCARG(&ua, start), PAGE_SIZE);
}

return sys_fsync_range(l, &ua, retval);
}

int
linux_sys_syncfs(lwp_t *l, const struct linux_sys_syncfs_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fd;
} */

struct mount *mp;
struct vnode *vp;
file_t *fp;
int error, fd;
fd = SCARG(uap, fd);

/* Get file pointer */
if ((error = fd_getvnode(fd, &fp)) != 0)
return error;

/* Get vnode and mount point */
vp = fp->f_vnode;
mp = vp->v_mount;

mutex_enter(mp->mnt_updating);
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
int asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
VFS_SYNC(mp, MNT_NOWAIT, l->l_cred);
if (asyncflag)
mp->mnt_flag |= MNT_ASYNC;
}
mutex_exit(mp->mnt_updating);

/* Cleanup vnode and file pointer */
vrele(vp);
fd_putfile(fd);
return 0;

}

int
linux_sys_renameat2(struct lwp *l, const struct linux_sys_renameat2_args *uap,
register_t *retval)
{
/* {
syscallarg(int) fromfd;
syscallarg(const char *) from;
syscallarg(int) tofd;
syscallarg(const char *) to;
syscallarg(unsigned int) flags;
} */

struct sys_renameat_args ua;
SCARG(&ua, fromfd) = SCARG(uap, fromfd);
SCARG(&ua, from) = SCARG(uap, from);
SCARG(&ua, tofd) = SCARG(uap, tofd);
SCARG(&ua, to) = SCARG(uap, to);

unsigned int flags = SCARG(uap, flags);
int error;

if (flags != 0) {
if (flags & ~LINUX_RENAME_ALL)
return EINVAL;
if ((flags & LINUX_RENAME_EXCHANGE) != 0 &&
(flags & (LINUX_RENAME_NOREPLACE | LINUX_RENAME_WHITEOUT))
!= 0)
return EINVAL;
/*
* Suppoting renameat2 flags without support from file systems
* becomes a messy affair cause of locks and how VOP_RENAME
* protocol is implemented. So, return EOPNOTSUPP for now.
*/
return EOPNOTSUPP;
}

error = sys_renameat(l, &ua, retval);
return error;
}

int
linux_sys_copy_file_range(lwp_t *l,
const struct linux_sys_copy_file_range_args *uap, register_t *retval)
{
/* {
syscallarg(int) fd_in;
syscallarg(unsigned long) off_in;
syscallarg(int) fd_out;
syscallarg(unsigned long) off_out;
syscallarg(size_t) len;
syscallarg(unsigned int) flags;
} */
const off_t OFF_MAX = __type_max(off_t);
int fd_in, fd_out;
file_t *fp_in, *fp_out;
struct vnode *invp, *outvp;
off_t off_in = 0, off_out = 0;
struct vattr vattr_in, vattr_out;
ssize_t total_copied = 0;
size_t bytes_left, to_copy;
bool have_off_in = false, have_off_out = false;
int error = 0;
size_t len = SCARG(uap, len);
unsigned int flags = SCARG(uap, flags);
/* Structures for actual copy */
char *buffer = NULL;
struct uio auio;
struct iovec aiov;

if (len > SSIZE_MAX) {
DPRINTF("%s: len is greater than SSIZE_MAX\n",
__func__);
return EOVERFLOW;
}

if (flags != 0) {
DPRINTF("%s: unsupported flags %#x\n", __func__, flags);
return EINVAL;
}

fd_in = SCARG(uap, fd_in);
fd_out = SCARG(uap, fd_out);
error = fd_getvnode(fd_in, &fp_in);
if (error) {
return error;
}

error = fd_getvnode(fd_out, &fp_out);
if (error) {
fd_putfile(fd_in);
return error;
}

invp = fp_in->f_vnode;
outvp = fp_out->f_vnode;

/* Get attributes of input and output files */
VOP_GETATTR(invp, &vattr_in, l->l_cred);
VOP_GETATTR(outvp, &vattr_out, l->l_cred);

/* Check if input and output files are regular files */
if (vattr_in.va_type == VDIR || vattr_out.va_type == VDIR) {
error = EISDIR;
DPRINTF("%s: Input or output is a directory\n", __func__);
goto out;
}
if ((SCARG(uap, off_in) != NULL && *SCARG(uap, off_in) < 0) ||
(SCARG(uap, off_out) != NULL && *SCARG(uap, off_out) < 0) ||
vattr_in.va_type != VREG || vattr_out.va_type != VREG) {
error = EINVAL;
DPRINTF("%s: Invalid offset or file type\n", __func__);
goto out;
}

if ((fp_in->f_flag & FREAD) == 0 ||
(fp_out->f_flag & FWRITE) == 0 ||
(fp_out->f_flag & FAPPEND) != 0) {
DPRINTF("%s: input file can't be read or output file "
"can't be written\n", __func__);
error = EBADF;
goto out;
}
/* Retrieve and validate offsets if provided */
if (SCARG(uap, off_in) != NULL) {
error = copyin(SCARG(uap, off_in), &off_in, sizeof(off_in));
if (error) {
goto out;
}
have_off_in = true;
}

if (SCARG(uap, off_out) != NULL) {
error = copyin(SCARG(uap, off_out), &off_out, sizeof(off_out));
if (error) {
goto out;
}
have_off_out = true;
}

if (off_out < 0 || len > OFF_MAX - off_out ||
off_in < 0 || len > OFF_MAX - off_in) {
DPRINTF("%s: New size is greater than OFF_MAX\n", __func__);
error = EFBIG;
goto out;
}

/* Identify overlapping ranges */
if ((invp == outvp) &&
((off_in <= off_out && off_in + (off_t)len > off_out) ||
(off_in > off_out && off_out + (off_t)len > off_in))) {
DPRINTF("%s: Ranges overlap\n", __func__);
error = EINVAL;
goto out;
}

buffer = kmem_alloc(LINUX_COPY_FILE_RANGE_MAX_CHUNK, KM_SLEEP);

bytes_left = len;

while (bytes_left > 0) {
to_copy = MIN(bytes_left, LINUX_COPY_FILE_RANGE_MAX_CHUNK);

/* Lock the input vnode for reading */
vn_lock(fp_in->f_vnode, LK_SHARED | LK_RETRY);
/* Set up iovec and uio for reading */
aiov.iov_base = buffer;
aiov.iov_len = to_copy;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = have_off_in ? off_in : fp_in->f_offset;
auio.uio_resid = to_copy;
auio.uio_rw = UIO_READ;
auio.uio_vmspace = l->l_proc->p_vmspace;
UIO_SETUP_SYSSPACE(&auio);

/* Perform read using vn_read */
error = VOP_READ(fp_in->f_vnode, &auio, 0, l->l_cred);
VOP_UNLOCK(fp_in->f_vnode);
if (error) {
DPRINTF("%s: Read error %d\n", __func__, error);
break;
}

size_t read_bytes = to_copy - auio.uio_resid;
if (read_bytes == 0) {
/* EOF reached */
break;
}

/* Lock the output vnode for writing */
vn_lock(fp_out->f_vnode, LK_EXCLUSIVE | LK_RETRY);
/* Set up iovec and uio for writing */
aiov.iov_base = buffer;
aiov.iov_len = read_bytes;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = have_off_out ? off_out : fp_out->f_offset;
auio.uio_resid = read_bytes;
auio.uio_rw = UIO_WRITE;
auio.uio_vmspace = l->l_proc->p_vmspace;
UIO_SETUP_SYSSPACE(&auio);

/* Perform the write */
error = VOP_WRITE(fp_out->f_vnode, &auio, 0, l->l_cred);
VOP_UNLOCK(fp_out->f_vnode);
if (error) {
DPRINTF("%s: Write error %d\n", __func__, error);
break;
}
size_t written_bytes = read_bytes - auio.uio_resid;
total_copied += written_bytes;
bytes_left -= written_bytes;

/* Update offsets if provided */
if (have_off_in) {
off_in += written_bytes;
} else {
fp_in->f_offset += written_bytes;
}
if (have_off_out) {
off_out += written_bytes;
} else {
fp_out->f_offset += written_bytes;
}
}

if (have_off_in) {
/* Adjust user space offset */
error = copyout(&off_in, SCARG(uap, off_in), sizeof(off_t));
if (error) {
DPRINTF("%s: Error adjusting user space offset\n",
__func__);
}
goto out;
}

if (have_off_out) {
/* Adjust user space offset */
error = copyout(&off_out, SCARG(uap, off_out), sizeof(off_t));
if (error) {
DPRINTF("%s: Error adjusting user space offset\n",
__func__);
}
}

*retval = total_copied;
out:
if (buffer) {
kmem_free(buffer, LINUX_COPY_FILE_RANGE_MAX_CHUNK);
}
if (fp_out) {
fd_putfile(fd_out);
}
if (fp_in) {
fd_putfile(fd_in);
}
return error;
}

#define LINUX_NOT_SUPPORTED(fun) \
int \
fun(struct lwp *l, const struct fun##_args *uap, register_t *retval) \
{ \
return EOPNOTSUPP; \
}

LINUX_NOT_SUPPORTED(linux_sys_setxattr)
LINUX_NOT_SUPPORTED(linux_sys_lsetxattr)
LINUX_NOT_SUPPORTED(linux_sys_fsetxattr)

LINUX_NOT_SUPPORTED(linux_sys_getxattr)
LINUX_NOT_SUPPORTED(linux_sys_lgetxattr)
LINUX_NOT_SUPPORTED(linux_sys_fgetxattr)

LINUX_NOT_SUPPORTED(linux_sys_listxattr)
LINUX_NOT_SUPPORTED(linux_sys_llistxattr)
LINUX_NOT_SUPPORTED(linux_sys_flistxattr)

LINUX_NOT_SUPPORTED(linux_sys_removexattr)
LINUX_NOT_SUPPORTED(linux_sys_lremovexattr)
LINUX_NOT_SUPPORTED(linux_sys_fremovexattr)

/*
* For now just return EOPNOTSUPP, this makes glibc posix_fallocate()
* to fallback to emulation.
* XXX Right now no filesystem actually implements fallocate support,
* so no need for mapping.
*/
LINUX_NOT_SUPPORTED(linux_sys_fallocate)