// SPDX-License-Identifier: GPL-2.0
/*
 * (C) 2001 Clemson University and The University of Chicago
 *
 * See COPYING in top-level directory.
 */

#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
#include <linux/posix_acl_xattr.h>

struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
{
        struct posix_acl *acl;
        int ret;
        char *key = NULL, *value = NULL;

        switch (type) {
        case ACL_TYPE_ACCESS:
                key = XATTR_NAME_POSIX_ACL_ACCESS;
                break;
        case ACL_TYPE_DEFAULT:
                key = XATTR_NAME_POSIX_ACL_DEFAULT;
                break;
        default:
                gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
                return ERR_PTR(-EINVAL);
        }
        /*
         * Rather than incurring a network call just to determine the exact
         * length of the attribute, I just allocate a max length to save on
         * the network call. Conceivably, we could pass NULL to
         * orangefs_inode_getxattr() to probe the length of the value, but
         * I don't do that for now.
         */
        value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
        if (!value)
                return ERR_PTR(-ENOMEM);

        gossip_debug(GOSSIP_ACL_DEBUG,
                     "inode %pU, key %s, type %d\n",
                     get_khandle_from_ino(inode),
                     key,
                     type);
        ret = orangefs_inode_getxattr(inode, key, value,
                                      ORANGEFS_MAX_XATTR_VALUELEN);
        /* if the key exists, convert it to an in-memory rep */
        if (ret > 0) {
                acl = posix_acl_from_xattr(&init_user_ns, value, ret);
        } else if (ret == -ENODATA || ret == -ENOSYS) {
                acl = NULL;
        } else {
                gossip_err("inode %pU retrieving acl's failed with error %d\n",
                           get_khandle_from_ino(inode),
                           ret);
                acl = ERR_PTR(ret);
        }
        /* kfree(NULL) is safe, so don't worry if value ever got used */
        kfree(value);
        return acl;
}

static int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl,
                              int type)
{
        int error = 0;
        void *value = NULL;
        size_t size = 0;
        const char *name = NULL;

        switch (type) {
        case ACL_TYPE_ACCESS:
                name = XATTR_NAME_POSIX_ACL_ACCESS;
                break;
        case ACL_TYPE_DEFAULT:
                name = XATTR_NAME_POSIX_ACL_DEFAULT;
                break;
        default:
                gossip_err("%s: invalid type %d!\n", __func__, type);
                return -EINVAL;
        }

        gossip_debug(GOSSIP_ACL_DEBUG,
                     "%s: inode %pU, key %s type %d\n",
                     __func__, get_khandle_from_ino(inode),
                     name,
                     type);

        if (acl) {
                size = posix_acl_xattr_size(acl->a_count);
                value = kmalloc(size, GFP_KERNEL);
                if (!value)
                        return -ENOMEM;

                error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
                if (error < 0)
                        goto out;
        }

        gossip_debug(GOSSIP_ACL_DEBUG,
                     "%s: name %s, value %p, size %zd, acl %p\n",
                     __func__, name, value, size, acl);
        /*
         * Go ahead and set the extended attribute now. NOTE: Suppose acl
         * was NULL, then value will be NULL and size will be 0 and that
         * will xlate to a removexattr. However, we don't want removexattr
         * complain if attributes does not exist.
         */
        error = orangefs_inode_setxattr(inode, name, value, size, 0);

out:
        kfree(value);
        if (!error)
                set_cached_acl(inode, type, acl);
        return error;
}

int orangefs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
                     struct posix_acl *acl, int type)
{
        int error;
        struct iattr iattr;
        int rc;

        memset(&iattr, 0, sizeof iattr);

        if (type == ACL_TYPE_ACCESS && acl) {
                /*
                 * posix_acl_update_mode checks to see if the permissions
                 * described by the ACL can be encoded into the
                 * object's mode. If so, it sets "acl" to NULL
                 * and "mode" to the new desired value. It is up to
                 * us to propagate the new mode back to the server...
                 */
                error = posix_acl_update_mode(&init_user_ns, inode,
                                              &iattr.ia_mode, &acl);
                if (error) {
                        gossip_err("%s: posix_acl_update_mode err: %d\n",
                                   __func__,
                                   error);
                        return error;
                }

                if (inode->i_mode != iattr.ia_mode)
                        iattr.ia_valid = ATTR_MODE;

        }

        rc = __orangefs_set_acl(inode, acl, type);

        if (!rc && (iattr.ia_valid == ATTR_MODE))
                rc = __orangefs_setattr(inode, &iattr);

        return rc;
}

int orangefs_init_acl(struct inode *inode, struct inode *dir)
{
        struct posix_acl *default_acl, *acl;
        umode_t mode = inode->i_mode;
        struct iattr iattr;
        int error = 0;

        error = posix_acl_create(dir, &mode, &default_acl, &acl);
        if (error)
                return error;

        if (default_acl) {
                error = __orangefs_set_acl(inode, default_acl,
                                           ACL_TYPE_DEFAULT);
                posix_acl_release(default_acl);
        } else {
                inode->i_default_acl = NULL;
        }

        if (acl) {
                if (!error)
                        error = __orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
                posix_acl_release(acl);
        } else {
                inode->i_acl = NULL;
        }

        /* If mode of the inode was changed, then do a forcible ->setattr */
        if (mode != inode->i_mode) {
                memset(&iattr, 0, sizeof iattr);
                inode->i_mode = mode;
                iattr.ia_mode = mode;
                iattr.ia_valid |= ATTR_MODE;
                __orangefs_setattr(inode, &iattr);
        }

        return error;
}