/*
   *  ipc/compat_mq.c
   *    32 bit emulation for POSIX message queue system calls
   *
   *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
   *    Author: Arnd Bergmann <arnd@arndb.de>
   */
  
  #include <linux/compat.h>
  #include <linux/fs.h>
  #include <linux/kernel.h>
  #include <linux/mqueue.h>
  #include <linux/syscalls.h>

  #include <linux/uaccess.h>

  
  struct compat_mq_attr {
  	compat_long_t mq_flags;      /* message queue flags		     */
  	compat_long_t mq_maxmsg;     /* maximum number of messages	     */
  	compat_long_t mq_msgsize;    /* maximum message size		     */
  	compat_long_t mq_curmsgs;    /* number of messages currently queued  */
  	compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
  };
  
  static inline int get_compat_mq_attr(struct mq_attr *attr,
  			const struct compat_mq_attr __user *uattr)
  {
  	if (!access_ok(VERIFY_READ, uattr, sizeof *uattr))
  		return -EFAULT;
  
  	return __get_user(attr->mq_flags, &uattr->mq_flags)
  		| __get_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  		| __get_user(attr->mq_msgsize, &uattr->mq_msgsize)
  		| __get_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  }
  
  static inline int put_compat_mq_attr(const struct mq_attr *attr,
  			struct compat_mq_attr __user *uattr)
  {
  	if (clear_user(uattr, sizeof *uattr))
  		return -EFAULT;
  
  	return __put_user(attr->mq_flags, &uattr->mq_flags)
  		| __put_user(attr->mq_maxmsg, &uattr->mq_maxmsg)
  		| __put_user(attr->mq_msgsize, &uattr->mq_msgsize)
  		| __put_user(attr->mq_curmsgs, &uattr->mq_curmsgs);
  }

  COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
  		       int, oflag, compat_mode_t, mode,
  		       struct compat_mq_attr __user *, u_attr)

  {
  	void __user *p = NULL;
  	if (u_attr && oflag & O_CREAT) {
  		struct mq_attr attr;

  
  		memset(&attr, 0, sizeof(attr));

  		p = compat_alloc_user_space(sizeof(attr));
  		if (get_compat_mq_attr(&attr, u_attr) ||
  		    copy_to_user(p, &attr, sizeof(attr)))
  			return -EFAULT;
  	}
  	return sys_mq_open(u_name, oflag, mode, p);
  }

  COMPAT_SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes,
  		       const char __user *, u_msg_ptr,
  		       compat_size_t, msg_len, unsigned int, msg_prio,
  		       const struct compat_timespec __user *, u_abs_timeout)

  {
  	struct timespec __user *u_ts;

  	if (compat_convert_timespec(&u_ts, u_abs_timeout))

  		return -EFAULT;
  
  	return sys_mq_timedsend(mqdes, u_msg_ptr, msg_len,
  			msg_prio, u_ts);
  }

  COMPAT_SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes,
  		       char __user *, u_msg_ptr,
  		       compat_size_t, msg_len, unsigned int __user *, u_msg_prio,
  		       const struct compat_timespec __user *, u_abs_timeout)

  {
  	struct timespec __user *u_ts;

  
  	if (compat_convert_timespec(&u_ts, u_abs_timeout))

  		return -EFAULT;
  
  	return sys_mq_timedreceive(mqdes, u_msg_ptr, msg_len,
  			u_msg_prio, u_ts);
  }

  COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
  		       const struct compat_sigevent __user *, u_notification)

  {
  	struct sigevent __user *p = NULL;
  	if (u_notification) {
  		struct sigevent n;
  		p = compat_alloc_user_space(sizeof(*p));
  		if (get_compat_sigevent(&n, u_notification))
  			return -EFAULT;
  		if (n.sigev_notify == SIGEV_THREAD)
  			n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
  		if (copy_to_user(p, &n, sizeof(*p)))
  			return -EFAULT;
  	}
  	return sys_mq_notify(mqdes, p);
  }

  COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
  		       const struct compat_mq_attr __user *, u_mqstat,
  		       struct compat_mq_attr __user *, u_omqstat)

  {
  	struct mq_attr mqstat;
  	struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
  	long ret;

  	memset(&mqstat, 0, sizeof(mqstat));

  	if (u_mqstat) {
  		if (get_compat_mq_attr(&mqstat, u_mqstat) ||
  		    copy_to_user(p, &mqstat, sizeof(mqstat)))
  			return -EFAULT;
  	}
  	ret = sys_mq_getsetattr(mqdes,
  				u_mqstat ? p : NULL,
  				u_omqstat ? p + 1 : NULL);
  	if (ret)
  		return ret;
  	if (u_omqstat) {
  		if (copy_from_user(&mqstat, p + 1, sizeof(mqstat)) ||
  		    put_compat_mq_attr(&mqstat, u_omqstat))
  			return -EFAULT;
  	}
  	return 0;
  }