/*
   * linux/net/sunrpc/auth_null.c
   *
   * AUTH_NULL authentication. Really :-)
   *
   * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   */
  
  #include <linux/types.h>

  #include <linux/module.h>

  #include <linux/sunrpc/clnt.h>

  #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)

  # define RPCDBG_FACILITY	RPCDBG_AUTH
  #endif
  
  static struct rpc_auth null_auth;
  static struct rpc_cred null_cred;
  
  static struct rpc_auth *

  nul_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)

  {
  	atomic_inc(&null_auth.au_count);
  	return &null_auth;
  }
  
  static void
  nul_destroy(struct rpc_auth *auth)
  {
  }
  
  /*
   * Lookup NULL creds for current process
   */
  static struct rpc_cred *
  nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
  {

  	if (flags & RPCAUTH_LOOKUP_RCU)
  		return &null_cred;

  	return get_rpccred(&null_cred);
  }
  
  /*
   * Destroy cred handle.
   */
  static void
  nul_destroy_cred(struct rpc_cred *cred)
  {
  }
  
  /*
   * Match cred handle against current process
   */
  static int
  nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
  {
  	return 1;
  }
  
  /*
   * Marshal credential.
   */

  static __be32 *
  nul_marshal(struct rpc_task *task, __be32 *p)

  {
  	*p++ = htonl(RPC_AUTH_NULL);
  	*p++ = 0;
  	*p++ = htonl(RPC_AUTH_NULL);
  	*p++ = 0;
  
  	return p;
  }
  
  /*
   * Refresh credential. This is a no-op for AUTH_NULL
   */
  static int
  nul_refresh(struct rpc_task *task)
  {

  	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);

  	return 0;
  }

  static __be32 *
  nul_validate(struct rpc_task *task, __be32 *p)

  {
  	rpc_authflavor_t	flavor;
  	u32			size;
  
  	flavor = ntohl(*p++);
  	if (flavor != RPC_AUTH_NULL) {
  		printk("RPC: bad verf flavor: %u
  ", flavor);

  		return ERR_PTR(-EIO);

  	}
  
  	size = ntohl(*p++);
  	if (size != 0) {
  		printk("RPC: bad verf size: %u
  ", size);

  		return ERR_PTR(-EIO);

  	}
  
  	return p;
  }

  const struct rpc_authops authnull_ops = {

  	.owner		= THIS_MODULE,
  	.au_flavor	= RPC_AUTH_NULL,

  	.au_name	= "NULL",

  	.create		= nul_create,
  	.destroy	= nul_destroy,
  	.lookup_cred	= nul_lookup_cred,
  };
  
  static
  struct rpc_auth null_auth = {
  	.au_cslack	= 4,
  	.au_rslack	= 2,
  	.au_ops		= &authnull_ops,

  	.au_flavor	= RPC_AUTH_NULL,
  	.au_count	= ATOMIC_INIT(0),

  };
  
  static

  const struct rpc_credops null_credops = {

  	.cr_name	= "AUTH_NULL",
  	.crdestroy	= nul_destroy_cred,

  	.crbind		= rpcauth_generic_bind_cred,

  	.crmatch	= nul_match,
  	.crmarshal	= nul_marshal,
  	.crrefresh	= nul_refresh,
  	.crvalidate	= nul_validate,
  };
  
  static
  struct rpc_cred null_cred = {

  	.cr_lru		= LIST_HEAD_INIT(null_cred.cr_lru),

  	.cr_auth	= &null_auth,

  	.cr_ops		= &null_credops,
  	.cr_count	= ATOMIC_INIT(1),

  	.cr_flags	= 1UL << RPCAUTH_CRED_UPTODATE,

  #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)

  	.cr_magic	= RPCAUTH_CRED_MAGIC,
  #endif
  };