/*
   * linux/include/linux/lockd/lockd.h
   *
   * General-purpose lockd include file.
   *
   * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
   */
  
  #ifndef LINUX_LOCKD_LOCKD_H
  #define LINUX_LOCKD_LOCKD_H
  
  #ifdef __KERNEL__
  
  #include <linux/in.h>
  #include <linux/in6.h>
  #include <net/ipv6.h>
  #include <linux/fs.h>
  #include <linux/kref.h>
  #include <linux/utsname.h>
  #include <linux/nfsd/nfsfh.h>
  #include <linux/lockd/bind.h>
  #include <linux/lockd/xdr.h>
  #ifdef CONFIG_LOCKD_V4
  #include <linux/lockd/xdr4.h>
  #endif
  #include <linux/lockd/debug.h>
  
  /*
   * Version string
   */
  #define LOCKD_VERSION		"0.5"
  
  /*
   * Default timeout for RPC calls (seconds)
   */
  #define LOCKD_DFLT_TIMEO	10
  
  /*
   * Lockd host handle (used both by the client and server personality).
   */
  struct nlm_host {
  	struct hlist_node	h_hash;		/* doubly linked list */
  	struct sockaddr_storage	h_addr;		/* peer address */
  	size_t			h_addrlen;
  	struct sockaddr_storage	h_srcaddr;	/* our address (optional) */
  	size_t			h_srcaddrlen;
  	struct rpc_clnt		*h_rpcclnt;	/* RPC client to talk to peer */
  	char			*h_name;		/* remote hostname */
  	u32			h_version;	/* interface version */
  	unsigned short		h_proto;	/* transport proto */
  	unsigned short		h_reclaiming : 1,
  				h_server     : 1, /* server side, not client side */
  				h_noresvport : 1,
  				h_inuse      : 1;
  	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
  	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
  	u32			h_state;	/* pseudo-state counter */
  	u32			h_nsmstate;	/* true remote NSM state */
  	u32			h_pidcount;	/* Pseudopids */
  	atomic_t		h_count;	/* reference count */
  	struct mutex		h_mutex;	/* mutex for pmap binding */
  	unsigned long		h_nextrebind;	/* next portmap call */
  	unsigned long		h_expires;	/* eligible for GC */
  	struct list_head	h_lockowners;	/* Lockowners for the client */
  	spinlock_t		h_lock;
  	struct list_head	h_granted;	/* Locks in GRANTED state */
  	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
  	struct nsm_handle	*h_nsmhandle;	/* NSM status handle */
  	char			*h_addrbuf;	/* address eyecatcher */
  	struct net		*net;		/* host net */
  };
  
  /*
   * The largest string sm_addrbuf should hold is a full-size IPv6 address
   * (no "::" anywhere) with a scope ID.  The buffer size is computed to
   * hold eight groups of colon-separated four-hex-digit numbers, a
   * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
   */
  #define NSM_ADDRBUF		((8 * 4 + 7) + (1 + 10) + 1)
  
  struct nsm_handle {
  	struct list_head	sm_link;
  	atomic_t		sm_count;
  	char			*sm_mon_name;
  	char			*sm_name;
  	struct sockaddr_storage	sm_addr;
  	size_t			sm_addrlen;
  	unsigned int		sm_monitored : 1,
  				sm_sticky : 1;	/* don't unmonitor */
  	struct nsm_private	sm_priv;
  	char			sm_addrbuf[NSM_ADDRBUF];
  };
  
  /*
   * Rigorous type checking on sockaddr type conversions
   */
  static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
  {
  	return (struct sockaddr_in *)&host->h_addr;
  }
  
  static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
  {
  	return (struct sockaddr *)&host->h_addr;
  }
  
  static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
  {
  	return (struct sockaddr_in *)&host->h_srcaddr;
  }
  
  static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
  {
  	return (struct sockaddr *)&host->h_srcaddr;
  }
  
  /*
   * Map an fl_owner_t into a unique 32-bit "pid"
   */
  struct nlm_lockowner {
  	struct list_head list;
  	atomic_t count;
  
  	struct nlm_host *host;
  	fl_owner_t owner;
  	uint32_t pid;
  };
  
  struct nlm_wait;
  
  /*
   * Memory chunk for NLM client RPC request.
   */
  #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
  struct nlm_rqst {
  	atomic_t		a_count;
  	unsigned int		a_flags;	/* initial RPC task flags */
  	struct nlm_host *	a_host;		/* host handle */
  	struct nlm_args		a_args;		/* arguments */
  	struct nlm_res		a_res;		/* result */
  	struct nlm_block *	a_block;
  	unsigned int		a_retries;	/* Retry count */
  	u8			a_owner[NLMCLNT_OHSIZE];
  };
  
  /*
   * This struct describes a file held open by lockd on behalf of
   * an NFS client.
   */
  struct nlm_file {
  	struct hlist_node	f_list;		/* linked list */
  	struct nfs_fh		f_handle;	/* NFS file handle */
  	struct file *		f_file;		/* VFS file pointer */
  	struct nlm_share *	f_shares;	/* DOS shares */
  	struct list_head	f_blocks;	/* blocked locks */
  	unsigned int		f_locks;	/* guesstimate # of locks */
  	unsigned int		f_count;	/* reference count */
  	struct mutex		f_mutex;	/* avoid concurrent access */
  };
  
  /*
   * This is a server block (i.e. a lock requested by some client which
   * couldn't be granted because of a conflicting lock).
   */
  #define NLM_NEVER		(~(unsigned long) 0)
  /* timeout on non-blocking call: */
  #define NLM_TIMEOUT		(7 * HZ)
  
  struct nlm_block {
  	struct kref		b_count;	/* Reference count */
  	struct list_head	b_list;		/* linked list of all blocks */
  	struct list_head	b_flist;	/* linked list (per file) */
  	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
  	struct svc_serv *	b_daemon;	/* NLM service */
  	struct nlm_host *	b_host;		/* host handle for RPC clnt */
  	unsigned long		b_when;		/* next re-xmit */
  	unsigned int		b_id;		/* block id */
  	unsigned char		b_granted;	/* VFS granted lock */
  	struct nlm_file *	b_file;		/* file in question */
  	struct cache_req *	b_cache_req;	/* deferred request handling */
  	struct file_lock *	b_fl;		/* set for GETLK */
  	struct cache_deferred_req * b_deferred_req;
  	unsigned int		b_flags;	/* block flags */
  #define B_QUEUED		1	/* lock queued */
  #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
  #define B_TIMED_OUT		4	/* filesystem too slow to respond */
  };
  
  /*
   * Global variables
   */
  extern const struct rpc_program	nlm_program;
  extern struct svc_procedure	nlmsvc_procedures[];
  #ifdef CONFIG_LOCKD_V4
  extern struct svc_procedure	nlmsvc_procedures4[];
  #endif
  extern int			nlmsvc_grace_period;
  extern unsigned long		nlmsvc_timeout;
  extern bool			nsm_use_hostnames;
  extern u32			nsm_local_state;
  
  /*
   * Lockd client functions
   */
  struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
  int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
  int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
  void		  nlmclnt_release_call(struct nlm_rqst *);
  struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
  void		  nlmclnt_finish_block(struct nlm_wait *block);
  int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
  __be32		  nlmclnt_grant(const struct sockaddr *addr,
  				const struct nlm_lock *lock);
  void		  nlmclnt_recovery(struct nlm_host *);
  int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
  				  struct nlm_rqst *);
  void		  nlmclnt_next_cookie(struct nlm_cookie *);
  
  /*
   * Host cache
   */
  struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
  					const size_t salen,
  					const unsigned short protocol,
  					const u32 version,
  					const char *hostname,
  					int noresvport,
  					struct net *net);
  void		  nlmclnt_release_host(struct nlm_host *);
  struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
  					const char *hostname,
  					const size_t hostname_len);
  void		  nlmsvc_release_host(struct nlm_host *);
  struct rpc_clnt * nlm_bind_host(struct nlm_host *);
  void		  nlm_rebind_host(struct nlm_host *);
  struct nlm_host * nlm_get_host(struct nlm_host *);
  void		  nlm_shutdown_hosts(void);
  void		  nlm_shutdown_hosts_net(struct net *net);
  void		  nlm_host_rebooted(const struct nlm_reboot *);
  
  /*
   * Host monitoring
   */
  int		  nsm_monitor(const struct nlm_host *host);
  void		  nsm_unmonitor(const struct nlm_host *host);
  
  struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
  					const size_t salen,
  					const char *hostname,
  					const size_t hostname_len);
  struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
  void		  nsm_release(struct nsm_handle *nsm);
  
  /*
   * This is used in garbage collection and resource reclaim
   * A return value != 0 means destroy the lock/block/share
   */
  typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
  
  /*
   * Server-side lock handling
   */
  __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
  			      struct nlm_host *, struct nlm_lock *, int,
  			      struct nlm_cookie *, int);
  __be32		  nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
  __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
  			struct nlm_host *, struct nlm_lock *,
  			struct nlm_lock *, struct nlm_cookie *);
  __be32		  nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
  unsigned long	  nlmsvc_retry_blocked(void);
  void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
  					nlm_host_match_fn_t match);
  void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
  void		  nlmsvc_release_call(struct nlm_rqst *);
  
  /*
   * File handling for the server personality
   */
  __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
  					struct nfs_fh *);
  void		  nlm_release_file(struct nlm_file *);
  void		  nlmsvc_mark_resources(struct net *);
  void		  nlmsvc_free_host_resources(struct nlm_host *);
  void		  nlmsvc_invalidate_all(void);
  
  /*
   * Cluster failover support
   */
  int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
  int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
  
  static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
  {
  	return file_inode(file->f_file);
  }
  
  static inline int __nlm_privileged_request4(const struct sockaddr *sap)
  {
  	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
  
  	if (ntohs(sin->sin_port) > 1023)
  		return 0;
  
  	return ipv4_is_loopback(sin->sin_addr.s_addr);
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static inline int __nlm_privileged_request6(const struct sockaddr *sap)
  {
  	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
  
  	if (ntohs(sin6->sin6_port) > 1023)
  		return 0;
  
  	if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
  		return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
  
  	return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
  }
  #else	/* IS_ENABLED(CONFIG_IPV6) */
  static inline int __nlm_privileged_request6(const struct sockaddr *sap)
  {
  	return 0;
  }
  #endif	/* IS_ENABLED(CONFIG_IPV6) */
  
  /*
   * Ensure incoming requests are from local privileged callers.
   *
   * Return TRUE if sender is local and is connecting via a privileged port;
   * otherwise return FALSE.
   */
  static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
  {
  	const struct sockaddr *sap = svc_addr(rqstp);
  
  	switch (sap->sa_family) {
  	case AF_INET:
  		return __nlm_privileged_request4(sap);
  	case AF_INET6:
  		return __nlm_privileged_request6(sap);
  	default:
  		return 0;
  	}
  }
  
  /*
   * Compare two NLM locks.
   * When the second lock is of type F_UNLCK, this acts like a wildcard.
   */
  static inline int nlm_compare_locks(const struct file_lock *fl1,
  				    const struct file_lock *fl2)
  {
  	return	fl1->fl_pid   == fl2->fl_pid
  	     && fl1->fl_owner == fl2->fl_owner
  	     && fl1->fl_start == fl2->fl_start
  	     && fl1->fl_end   == fl2->fl_end
  	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
  }
  
  extern const struct lock_manager_operations nlmsvc_lock_operations;
  
  #endif /* __KERNEL__ */
  
  #endif /* LINUX_LOCKD_LOCKD_H */