/***************************************************************************
 *
 * Copyright (C) 2001 International Business Machines
 * All rights reserved.
 *
 * This file is part of the GPFS mmfslinux kernel module.
 *
 * 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. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written
 *     permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 *************************************************************************** */
/* @(#)00       1.19.1.1  src/avs/fs/mmfs/ts/kernext/gpl-linux/acl.c, mmfs, avs_rgpfs24, rgpfs24s012a 4/17/07 15:54:41 */

#if LINUX_KERNEL_VERSION > 2060000
#ifdef CONFIG_FS_POSIX_ACL
#include <Shark-gpl.h>

#include <linux/string.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>

#include <verdep.h>
#include <cxiTSFattr.h>
#include <cxiAclUser.h>

/* Defines from posix_acl.h. We can not include that file because it conflicts
   with GPFS defines in cxiAclUser.h. We can rename all of GPFS defines but it
   will require many changes. */
#define LINUX_ACL_UNDEFINED_ID	(-1)

/* e_tag entry in struct posix_acl_entry */
#define LINUX_ACL_USER_OBJ	(0x01)
#define LINUX_ACL_USER		(0x02)
#define LINUX_ACL_GROUP_OBJ	(0x04)
#define LINUX_ACL_GROUP		(0x08)
#define LINUX_ACL_MASK		(0x10)
#define LINUX_ACL_OTHER		(0x20)

/* permissions in the e_perm field */
#define LINUX_ACL_READ		(0x04)
#define LINUX_ACL_WRITE		(0x02)
#define LINUX_ACL_EXECUTE	(0x01)

struct linux_posix_acl_entry {
	short			e_tag;
	unsigned short		e_perm;
	unsigned int		e_id;
};

struct linux_posix_acl {
	atomic_t			a_refcount;
	unsigned int			a_count;
	struct linux_posix_acl_entry	a_entries[0];
};

struct linux_posix_acl * posix_acl_from_xattr(const void *value, size_t size);
extern int posix_acl_valid(const struct linux_posix_acl *);
int posix_acl_to_xattr(const struct linux_posix_acl *acl, void *buffer, size_t size);

#define PERM_MASK_2_POSIX(perm) perm&(LINUX_ACL_READ|LINUX_ACL_WRITE|LINUX_ACL_EXECUTE)
#define PERM_MASK_2_ACL(perm) perm&(ACL_PERM_EXECUTE|ACL_PERM_WRITE|ACL_PERM_READ)

/* move data from ACL to linux_posix_acl */
int
ACL_2_posix_acl(ACL *tmpaclP, const void *buf, size_t buf_size)
{
  int i, len;
  int rc = 0, count = 0;
  acl_entry_t *aceP;
  struct linux_posix_acl *aclP = (struct linux_posix_acl *)buf;

  ENTER(0);
  memset(aclP, '\0', buf_size);

  TRACE2(TRACE_VNODE, 3, TRCID_LINUXOPS_ACL2POSIX_ENTER,
         "ACL_2_posix_acl: enter size %d buf_size %d\n",
         tmpaclP->aclLength, buf_size);

  /* POSIX ACLs only.  Other types require additional translations.  */
  if (tmpaclP->aclVersion != ACL_FIRST_VERSION)
  {
      rc = -EOPNOTSUPP; 
      goto xerror;
  }

  if (buf_size == 0) {
      rc = tmpaclP->aclLength;
      goto xerror;
  }

  /* Get the address of the first extended acl entry */
  aceP = ACL_ENTRY_START(tmpaclP, tmpaclP->aclVersion);
  len = tmpaclP->aclLength - ACL_HEADER_SIZE_V1;
  buf_size -= sizeof(struct linux_posix_acl);
  i = 0;

  while ((len > 4) && (len >= aceP->aceLength))
  {
    TRACE3(TRACE_VNODE, 3, TRCID_LINUXOPS_ACL2POSIX_2,
         "ACL_2_posix_acl: %d len %d buf_size %d\n",
         i, len, buf_size);

    if (buf_size < sizeof(struct linux_posix_acl_entry)) {
      rc = -ENOSPC;
      goto xerror;
    }
    switch(aceP->aceTagType)
    {
      case ACL_USER:
        aclP->a_entries[i].e_tag = LINUX_ACL_USER;
        aclP->a_entries[i].e_id = aceP->aceQualifier;
        break;
      case ACL_GROUP:
        aclP->a_entries[i].e_tag = LINUX_ACL_GROUP;
        aclP->a_entries[i].e_id = aceP->aceQualifier;
        break;
      case ACL_USER_OBJ:
        aclP->a_entries[i].e_tag = LINUX_ACL_USER_OBJ;
        aclP->a_entries[i].e_id = LINUX_ACL_UNDEFINED_ID;
        break;
      case ACL_GROUP_OBJ:
        aclP->a_entries[i].e_tag = LINUX_ACL_GROUP_OBJ;
        aclP->a_entries[i].e_id = LINUX_ACL_UNDEFINED_ID;
        break;
      case ACL_OTHER:
        aclP->a_entries[i].e_tag = LINUX_ACL_OTHER;
        aclP->a_entries[i].e_id = LINUX_ACL_UNDEFINED_ID;
        break;
      case ACL_MASK:
        aclP->a_entries[i].e_tag = LINUX_ACL_MASK;
        aclP->a_entries[i].e_id = LINUX_ACL_UNDEFINED_ID;
        break;
    }
    aclP->a_entries[i].e_perm = PERM_MASK_2_POSIX(aceP->acePermissions);

    TRACE7(TRACE_VNODE, 3, TRCID_LINUXOPS_ACL2POSIX,
         "ACL_2_posix_acl: %d e_tag 0x%02X aceTagType %d e_id %d aceQualifier %d e_perm 0x%02X acePermissions 0x%01X\n",
         i, aclP->a_entries[i].e_tag, aceP->aceTagType, aclP->a_entries[i].e_id,
         aceP->aceQualifier, aclP->a_entries[i].e_perm, aceP->acePermissions);

    /* move to the next acl entry */
    len -= aceP->aceLength;
    aceP = (acl_entry_t *)((caddr_t)aceP + aceP->aceLength);
    buf_size -= sizeof(struct linux_posix_acl_entry);
    i++;
  }
  aclP->a_count = i;

xerror:
  TRACE1(TRACE_VNODE, 1, TRCID_LINUXOPS_ACL2POSIX_EXIT,
         "ACL_2_posix_acl: exit rc %d\n", rc);

  EXIT(0);
  return rc;
}

/* move data from linux_posix_acl to ACL */
void
posix_acl_2_ACL(ACL *tmpaclP, struct linux_posix_acl *aclP)
{
  int i, count;
  acl_entry_t *aceP;

  count = aclP->a_count;
  /* Get the address of the first extended acl entry */
  aceP = ACL_ENTRY_START(tmpaclP, tmpaclP->aclVersion);

  for (i = 0; i < count; i++)
  {
    if (aclP->a_entries[i].e_tag & LINUX_ACL_USER) {
        aceP->aceTagType = ACL_USER;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    if (aclP->a_entries[i].e_tag & LINUX_ACL_GROUP) {
        aceP->aceTagType = ACL_GROUP;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    if (aclP->a_entries[i].e_tag & LINUX_ACL_USER_OBJ) {
        aceP->aceTagType = ACL_USER_OBJ;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    if (aclP->a_entries[i].e_tag & LINUX_ACL_GROUP_OBJ) {
        aceP->aceTagType = ACL_GROUP_OBJ;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    if (aclP->a_entries[i].e_tag & LINUX_ACL_OTHER) {
        aceP->aceTagType = ACL_OTHER;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    if (aclP->a_entries[i].e_tag & LINUX_ACL_MASK) {
        aceP->aceTagType = ACL_MASK;
        aceP->aceQualifier = aclP->a_entries[i].e_id;
    }
    aceP->acePermissions = PERM_MASK_2_ACL(aclP->a_entries[i].e_perm);
    aceP->aceLength = sizeof(acl_entry_t);

    TRACE6(TRACE_VNODE, 3, TRCID_LINUXOPS_POSIX2ACL,
         "posix_acl_2_ACL: %d e_tag 0x%X aceTagType %d aceQualifier %d e_perm 0x%X acePermissions 0x%X\n",
         i, aclP->a_entries[i].e_tag, aceP->aceTagType, aceP->aceQualifier,
         aclP->a_entries[i].e_perm, aceP->acePermissions);

    /* move to the next acl entry */
    aceP = (acl_entry_t *)((caddr_t)aceP + sizeof(acl_entry_t));
  }
}

int
gpfs_set_posix_acl(struct dentry *dentry, int type, const void *buf, size_t buf_size)
{
  int count, size, rc;
  cxiNode_t *cnP;
  struct gpfsVfsData_t *privVfsP;
  ext_cred_t eCred;
  ACL tmpacl, *tmpaclP = &tmpacl;
  int flags = 0;
  struct inode *iP = dentry->d_inode;
  struct linux_posix_acl *aclP = NULL;
  mm_segment_t oldfs;

  ENTER(0);
  TRACE5(TRACE_VNODE, 1, TRCID_LINUXOPS_SETACLATTR_ENTER,
         "gpfs_i_gpfs_set_posix_acl enter: iP 0x%lX ino %d type 0x%X buf 0x%lX size %d\n",
         iP, iP->i_ino, type, buf, buf_size);

  if (buf) {
    aclP = posix_acl_from_xattr(buf, buf_size);
    if (IS_ERR(aclP)) {
      rc = PTR_ERR(aclP);
      aclP = NULL; /* no aclP to free on exit */
      goto xerror;
    }
  }

  if (aclP == NULL) {
    /* If no buf was given, or no acl was returned, there is nothing else 
     * to do. This is in effect deleting all extended ACLs.
     */
    memset(tmpaclP, '\0', sizeof(ACL));
    tmpaclP->aclLength = ACL_HEADER_SIZE_V1;
    if (type == ACL_TYPE_ACCESS)
      tmpaclP->aclType = ACL_TYPE_ACCESS_DELETE;
    else if (type == ACL_TYPE_DEFAULT)
      tmpaclP->aclType = ACL_TYPE_DEFAULT_DELETE;
    else
    {
      rc = EINVAL;
      goto xerror;
    }
  }
  else {
    rc = posix_acl_valid(aclP);
    if (rc)
      goto xerror;

    count = aclP->a_count;
    size = ACL_HEADER_SIZE_V1 + (sizeof(acl_entry_t) * count);
    if (size > sizeof(ACL)) {
      tmpaclP = cxiMallocUnpinned(size);
      if (tmpaclP == NULL) {
        rc = ENOMEM;
        goto xerror;
      }
    }
    memset(tmpaclP, '\0', size);
    tmpaclP->aclLength = size;
    tmpaclP->aclType = type;
  }

  tmpaclP->aclVersion = ACL_FIRST_VERSION;

  privVfsP = VP_TO_PVP(iP);
  DBGASSERT(privVfsP != NULL);
  cnP = VP_TO_CNP(iP);

  /* Retrieve the ACL data */
  setCred(&eCred);

  oldfs = get_fs();
  set_fs(get_ds());
  if (aclP)
     posix_acl_2_ACL(tmpaclP, aclP);

  rc = gpfs_ops.gpfsPutAcl(privVfsP, cnP, flags, tmpaclP, &eCred);
  set_fs(oldfs);

xerror:
  if (aclP)
    kfree(aclP);

  if (tmpaclP && (tmpaclP != &tmpacl))
    cxiFreeUnpinned(tmpaclP);

  TRACE2(TRACE_VNODE, 1, TRCID_LINUXOPS_SETACLATTR_EXIT,
         "gpfs_i_gpfs_set_posix_acl exit: iP 0x%lX rc %d\n", iP, rc);
  EXIT(0);
  return rc;
}

int
gpfs_get_posix_acl(struct dentry *dentry, int type, const void *buf, size_t buf_size)
{
  int rc = 0;
  int i, size;
  cxiNode_t *cnP;
  struct gpfsVfsData_t *privVfsP;
  ext_cred_t eCred;
  int flags = GETACL_DONOT_BLD_ACL;
  ACL tmpacl, *tmpaclP = &tmpacl;
  struct inode *iP = dentry->d_inode;
  mm_segment_t oldfs;

  ENTER(0);
  TRACE3(TRACE_VNODE, 1, TRCID_LINUXOPS_GETACLATTR_ENTER,
         "gpfs_get_posix_acl enter: iP 0x%lX type %d size %d\n", iP, type, buf_size);

  privVfsP = VP_TO_PVP(iP);
  DBGASSERT(privVfsP != NULL);
  cnP = VP_TO_CNP(iP);

  /* Retrieve the ACL data */
  size = sizeof(ACL);

try_again:

  setCred(&eCred);     // ids may have been remapped before goto try_again

  tmpaclP->aclType = type;
  tmpaclP->aclVersion = ACL_FIRST_VERSION;
  tmpaclP->aclLength = size;

  oldfs = get_fs();
  set_fs(get_ds());
  rc = gpfs_ops.gpfsGetAcl(privVfsP, cnP, flags, tmpaclP, &eCred);
  set_fs(oldfs);
  if (rc)
  {
    if (rc == ENOSPC)
    {
      if (tmpaclP->aclLength >= size)
      {
        size = tmpaclP->aclLength;
        if (tmpaclP != &tmpacl)
          cxiFreeUnpinned(tmpaclP);
        tmpaclP = cxiMallocUnpinned(size);
        if (!tmpaclP)
        {
          rc = -ENOMEM;
          goto xerror;
        }
        goto try_again;
      }
      else
      {
        rc = -EINVAL;  // buffer not even big enough to return length
        goto xerror;
      }
    }
    else {
      if (rc == ENOENT)
        rc = ENODATA;
      rc = -rc;
      goto xerror;
    }
  }

  /* move data from ACL to linux_posix_acl */
  rc = ACL_2_posix_acl(tmpaclP, buf, buf_size);
  if (!rc) {
     if (size < buf_size) {
       if (tmpaclP != &tmpacl)
         cxiFreeUnpinned(tmpaclP);
       tmpaclP = cxiMallocUnpinned(buf_size);
       if (!tmpaclP)
       {
         rc = -ENOMEM;
         goto xerror;
       }
     }
     memcpy(tmpaclP, buf, buf_size);
     rc = posix_acl_to_xattr((struct linux_posix_acl *)tmpaclP, (void *)buf, size);
  }
xerror:

  if (tmpaclP != &tmpacl)
    cxiFreeUnpinned(tmpaclP);

  TRACE2(TRACE_VNODE, 1, TRCID_LINUXOPS_GETACLATTR_EXIT,
         "gpfs_get_posix_acl exit: iP 0x%lX rc %d\n", iP, rc);

  EXIT(0);
  return rc;
}
#endif /* CONFIG_FS_POSIX_ACL */
#endif /* LINUX_KERNEL_VERSION > 2060000 */