/* Copyright (C) 2005  David Decotigny
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    USA. 
 */
 #ifndef _SOS_UACCESS_H_
 #define _SOS_UACCESS_H_
 
 
 /**
  * @file uaccess.h
  *
  * Routines to access user-space data from inside the kernel space.
  */
 
 #include <sos/types.h>
 #include <sos/errno.h>
 
 
 /**
  * Retrieve a bunch of data from the user space of the
  * current_thread->process
  *
  * @return <0 on error ! Return the number of bytes successfully copied
  * otherwise.
  */
 sos_ret_t sos_memcpy_from_user(sos_vaddr_t kernel_to,
                                sos_uaddr_t user_from,
                                sos_size_t size);
 
 
 /**
  * Retrieve a bunch of data from the user space of the
  * current_thread->process and copy it in a newly allocated kernel
  * area
  *
  * @return NULL on error (including unresolved page fault during
  * transfer)
  */
 sos_ret_t sos_memdup_from_user(sos_vaddr_t * kernel_to, sos_uaddr_t from_user,
                                sos_size_t length,
                                sos_ui32_t kmalloc_flags);
 
 
 /**
  * Transfer a bunch of data to the user space of the
  * current_thread->process
  *
  * @return <0 n error ! Return the number of bytes successfully copied
  * otherwise.
  */
 sos_ret_t sos_memcpy_to_user(sos_uaddr_t user_to,
                              sos_vaddr_t kernel_from,
                              sos_size_t size);
 
 
 /**
  * @return the length of the given user space string user_str
  * (excluding the trailing \0), up to max_len bytes. <0 on error
  * (unresolved page fault, etc.)
  */
 sos_ret_t sos_strnlen_from_user(sos_uaddr_t user_str, sos_size_t max_len);
 
 
 /**
  * Copy the given user space string to kernel space, up to max_len
  * bytes (including trailing \0)
  *
  * @return SOS_OK on success, <0 otherwise (unresolved page fault, etc.)
  */
 sos_ret_t sos_strzcpy_from_user(char *kernel_to, sos_uaddr_t user_from,
                                 sos_size_t max_len);
 
 
 /**
  * Copy the given kernel string to user space, up to max_len bytes
  * (including trailing \0)
  *
  * @return SOS_OK on success, <0 otherwise (unresolved page fault, etc.)
  */
 sos_ret_t sos_strzcpy_to_user(sos_uaddr_t user_to, const char *kernel_from,
                               sos_size_t max_len);
 
 
 /**
  * Copy the given user space string into a new allocated kernel space
  * area of the correct size, up to max_len bytes (including trailing
  * \0)
  *
  * @return SOS_OK on success + *kernel_to is set to the freshly
  * allocated kernel string, <0 otherwise (unresolved page fault, etc.)
  */
 sos_ret_t sos_strndup_from_user(char ** kernel_to, sos_uaddr_t from_user,
                                 sos_size_t max_len,
                                 sos_ui32_t kmalloc_flags);
 
 
 /*
  * Special functions to access both kernel/user space
  */
 /** Generic (Kernel or User) virtual address. We define a structure to
     force the compiler to signal when we call this special function
     with a usual address... */
 typedef struct sos_genaddr { sos_bool_t is_user;
                              sos_ui32_t addr; } sos_genaddr_t;
 #define SOS_GENADDR_DECL(name,_is_user,_addr) \
   sos_genaddr_t name = (struct sos_genaddr) { .is_user=_is_user, .addr=_addr }
 
 sos_ret_t sos_memcpy_generic_to(sos_genaddr_t to_addr,
                                 sos_vaddr_t kernel_from,
                                 sos_size_t size);
 
 sos_ret_t sos_memcpy_generic_from(sos_vaddr_t kernel_from,
                                   sos_genaddr_t from_addr,
                                   sos_size_t size);
 
 #endif /* _SOS_UACCESS_H_ */