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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* 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.
* 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 Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/proc.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/exec.h>
#include <sys/systm.h>
#include <string.h>
/*
* Check if a user address is valid.
*
* @uaddr: User address to check.
*
* Returns true if valid, otherwise false.
*/
static bool
check_uaddr(const void *uaddr)
{
vaddr_t stack_start, stack_end;
struct exec_prog exec;
struct proc *td;
uintptr_t addr;
td = this_td();
exec = td->exec;
addr = (uintptr_t)uaddr;
stack_start = td->stack_base;
stack_end = td->stack_base + PROC_STACK_SIZE;
if (addr >= exec.start && addr <= exec.end)
return true;
if (addr >= stack_start && addr <= stack_end)
return true;
return false;
}
/*
* Copy from userspace to the kernel.
*
* @uaddr: Userspace address.
* @kaddr: Kernelspace address.
* @len: Length of data.
*/
int
copyin(const void *uaddr, void *kaddr, size_t len)
{
char *tmp = (char *)uaddr;
if (!check_uaddr(tmp) || !check_uaddr(tmp + len)) {
return -EFAULT;
}
memcpy(kaddr, uaddr, len);
return 0;
}
/*
* Copy from the kernel to userspace.
*
* @kaddr: Kernelspace address.
* @uaddr: Userspace address.
* @len: Length of data.
*/
int
copyout(const void *kaddr, void *uaddr, size_t len)
{
char *tmp = uaddr;
if (!check_uaddr(tmp) || !check_uaddr(tmp + len)) {
return -EFAULT;
}
memcpy(uaddr, kaddr, len);
return 0;
}
/*
* Copy in a string from userspace
*
* Unlike the typical copyin(), this routine will
* copy until we've hit NUL ('\0')
*
* @uaddr: Userspace address.
* @kaddr: Kernelspace address.
* @len: Length of string.
*
* XXX: Please note that if `len' is less than the actual
* string length, the returned value will not be
* NUL terminated.
*/
int
copyinstr(const void *uaddr, char *kaddr, size_t len)
{
char *dest = (char *)kaddr;
const char *src = (char *)uaddr;
if (!check_uaddr(src)) {
return -EFAULT;
}
for (size_t i = 0; i < len; ++i) {
if (!check_uaddr(src + i)) {
return -EFAULT;
}
dest[i] = src[i];
if (src[i] == '\0') {
break;
}
}
return 0;
}
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