NetBSD/share/man/man9/copy.9

.\"	$NetBSD: copy.9,v 1.16 2005/09/10 22:24:42 wiz Exp $
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.\" Copyright (c) 1996, 2002 Jason R. Thorpe.
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.\" This code is derived from software contributed by Kenneth Stailey.
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.Dd August 28, 2005
.Dt COPY 9
.Os
.Sh NAME
.Nm copy ,
.Nm copyin ,
.Nm copyout ,
.Nm copystr ,
.Nm copyinstr ,
.Nm copyoutstr
.Nd kernel space to/from user space copy functions
.Sh SYNOPSIS
.In sys/types.h
.In sys/systm.h
.Ft int
.Fn copyin "const void *uaddr" "void *kaddr" "size_t len"
.Ft int
.Fn copyout "const void *kaddr" "void *uaddr" "size_t len"
.Ft int
.Fn copystr "const void *kfaddr" "void *kdaddr" "size_t len" "size_t *done"
.Ft int
.Fn copyinstr "const void *uaddr" "void *kaddr" "size_t len" "size_t *done"
.Ft int
.Fn copyoutstr "const void *kaddr" "void *uaddr" "size_t len" "size_t *done"
.Ft int
.Fn copyin_proc "struct proc *p" "const void *uaddr" "void *kaddr" "size_t len"
.Ft int
.Fn copyout_proc "struct proc *p" "const void *kaddr" "void *uaddr" "size_t len"
.Ft int
.Fn ioctl_copyin "int ioctlflags" "const void *src" "void *dst" "size_t len"
.Ft int
.Fn ioctl_copyout "int ioctlflags" "const void *src" "void *dst" "size_t len"
.Sh DESCRIPTION
The
.Nm
functions are designed to copy contiguous data from one address
to another.
All but
.Fn copystr
copy data from user-space to kernel-space or vice-versa.
.Pp
The
.Nm
routines provide the following functionality:
.Bl -tag -width "copyout_proc()"
.It Fn copyin
Copies
.Fa len
bytes of data from the user-space address
.Fa uaddr
in the current process to the kernel-space address
.Fa kaddr .
.It Fn copyout
Copies
.Fa len
bytes of data from the kernel-space address
.Fa kaddr
to the user-space address
.Fa uaddr
in the current process.
.It Fn copystr
Copies a NUL-terminated string, at most
.Fa len
bytes long, from kernel-space address
.Fa kfaddr
to kernel-space address
.Fa kdaddr .
If the
.Fa done
argument is non-NULL,
the number of bytes actually copied, including the terminating
NUL, is returned in
.Fa *done .
.It Fn copyinstr
Copies a NUL-terminated string, at most
.Fa len
bytes long, from user-space address
.Fa uaddr
in the current process to kernel-space address
.Fa kaddr .
If the
.Fa done
argument is non-NULL,
the number of bytes actually copied, including the terminating
NUL, is returned in
.Fa *done .
.It Fn copyoutstr
Copies a NUL-terminated string, at most
.Fa len
bytes long, from kernel-space address
.Fa kaddr
to user-space address
.Fa uaddr
in the current process.
If the
.Fa done
argument is non-NULL,
the number of bytes actually copied, including the terminating
NUL, is returned in
.Fa *done .
.It Fn copyin_proc
Like
.Fn copyin ,
except it operates on the address space of the process
.Fa p .
.It Fn copyout_proc
Like
.Fn copyout ,
except it operates on the address space of the process
.Fa p .
.It Fn ioctl_copyin
Like
.Fn copyin ,
except it operates on kernel adresses when the
.Dv FKIOCTL
flag is passed in
.Fa ioctlflags
from the ioctl call.
.It Fn ioctl_copyout
Like
.Fn copyout ,
except it operates on kernel adresses when the
.Dv FKIOCTL
flag is passed in
.Fa ioctlflags
from the ioctl call.
.El
.Sh RETURN VALUES
The
.Nm
functions return 0 on success or
.Er EFAULT
if a bad address is encountered.
In addition, the
.Fn copystr ,
.Fn copyinstr ,
and
.Fn copyoutstr
functions return
.Er ENAMETOOLONG
if the string is longer than
.Fa len
bytes.
.Sh SEE ALSO
.Xr fetch 9 ,
.Xr store 9