// SPDX-License-Identifier: GPL-2.0-only

  /*
   *  linux/fs/compat.c
   *
   *  Kernel compatibililty routines for e.g. 32 bit syscall support
   *  on 64 bit kernels.
   *
   *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation
   *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
   *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be)
   *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 

   *  Copyright (C) 2003       Pavel Machek (pavel@ucw.cz)

   */

  #include <linux/compat.h>

  #include <linux/nfs4_mount.h>

  #include <linux/syscalls.h>

  #include <linux/slab.h>

  #include <linux/uaccess.h>

  #include "internal.h"

  struct compat_nfs_string {
  	compat_uint_t len;

  	compat_uptr_t data;

  };
  
  static inline void compat_nfs_string(struct nfs_string *dst,
  				     struct compat_nfs_string *src)
  {
  	dst->data = compat_ptr(src->data);
  	dst->len = src->len;
  }
  
  struct compat_nfs4_mount_data_v1 {
  	compat_int_t version;
  	compat_int_t flags;
  	compat_int_t rsize;
  	compat_int_t wsize;
  	compat_int_t timeo;
  	compat_int_t retrans;
  	compat_int_t acregmin;
  	compat_int_t acregmax;
  	compat_int_t acdirmin;
  	compat_int_t acdirmax;
  	struct compat_nfs_string client_addr;
  	struct compat_nfs_string mnt_path;
  	struct compat_nfs_string hostname;
  	compat_uint_t host_addrlen;

  	compat_uptr_t host_addr;

  	compat_int_t proto;
  	compat_int_t auth_flavourlen;

  	compat_uptr_t auth_flavours;

  };
  
  static int do_nfs4_super_data_conv(void *raw_data)
  {
  	int version = *(compat_uint_t *) raw_data;
  
  	if (version == 1) {
  		struct compat_nfs4_mount_data_v1 *raw = raw_data;
  		struct nfs4_mount_data *real = raw_data;
  
  		/* copy the fields backwards */
  		real->auth_flavours = compat_ptr(raw->auth_flavours);
  		real->auth_flavourlen = raw->auth_flavourlen;
  		real->proto = raw->proto;
  		real->host_addr = compat_ptr(raw->host_addr);
  		real->host_addrlen = raw->host_addrlen;
  		compat_nfs_string(&real->hostname, &raw->hostname);
  		compat_nfs_string(&real->mnt_path, &raw->mnt_path);
  		compat_nfs_string(&real->client_addr, &raw->client_addr);
  		real->acdirmax = raw->acdirmax;
  		real->acdirmin = raw->acdirmin;
  		real->acregmax = raw->acregmax;
  		real->acregmin = raw->acregmin;
  		real->retrans = raw->retrans;
  		real->timeo = raw->timeo;
  		real->wsize = raw->wsize;
  		real->rsize = raw->rsize;
  		real->flags = raw->flags;
  		real->version = raw->version;
  	}

  
  	return 0;
  }

  #define NFS4_NAME	"nfs4"

  COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
  		       const char __user *, dir_name,
  		       const char __user *, type, compat_ulong_t, flags,
  		       const void __user *, data)

  {

  	char *kernel_type;

  	void *options;

  	char *kernel_dev;

  	int retval;

  	kernel_type = copy_mount_string(type);
  	retval = PTR_ERR(kernel_type);
  	if (IS_ERR(kernel_type))

  		goto out;

  	kernel_dev = copy_mount_string(dev_name);
  	retval = PTR_ERR(kernel_dev);
  	if (IS_ERR(kernel_dev))

  		goto out1;

  	options = copy_mount_options(data);
  	retval = PTR_ERR(options);
  	if (IS_ERR(options))

  		goto out2;

  	if (kernel_type && options) {

  		if (!strcmp(kernel_type, NFS4_NAME)) {

  			retval = -EINVAL;
  			if (do_nfs4_super_data_conv(options))

  				goto out3;

  		}
  	}

  	retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);

   out3:

  	kfree(options);

   out2:

  	kfree(kernel_dev);

   out1:

  	kfree(kernel_type);

   out:
  	return retval;
  }