xref: /openbmc/linux/include/linux/lockd/lockd.h (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
1  /* SPDX-License-Identifier: GPL-2.0 */
2  /*
3   * linux/include/linux/lockd/lockd.h
4   *
5   * General-purpose lockd include file.
6   *
7   * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
8   */
9  
10  #ifndef LINUX_LOCKD_LOCKD_H
11  #define LINUX_LOCKD_LOCKD_H
12  
13  /* XXX: a lot of this should really be under fs/lockd. */
14  
15  #include <linux/in.h>
16  #include <linux/in6.h>
17  #include <net/ipv6.h>
18  #include <linux/fs.h>
19  #include <linux/kref.h>
20  #include <linux/refcount.h>
21  #include <linux/utsname.h>
22  #include <linux/lockd/bind.h>
23  #include <linux/lockd/xdr.h>
24  #ifdef CONFIG_LOCKD_V4
25  #include <linux/lockd/xdr4.h>
26  #endif
27  #include <linux/lockd/debug.h>
28  #include <linux/sunrpc/svc.h>
29  
30  /*
31   * Version string
32   */
33  #define LOCKD_VERSION		"0.5"
34  
35  /*
36   * Default timeout for RPC calls (seconds)
37   */
38  #define LOCKD_DFLT_TIMEO	10
39  
40  /*
41   * Lockd host handle (used both by the client and server personality).
42   */
43  struct nlm_host {
44  	struct hlist_node	h_hash;		/* doubly linked list */
45  	struct sockaddr_storage	h_addr;		/* peer address */
46  	size_t			h_addrlen;
47  	struct sockaddr_storage	h_srcaddr;	/* our address (optional) */
48  	size_t			h_srcaddrlen;
49  	struct rpc_clnt		*h_rpcclnt;	/* RPC client to talk to peer */
50  	char			*h_name;		/* remote hostname */
51  	u32			h_version;	/* interface version */
52  	unsigned short		h_proto;	/* transport proto */
53  	unsigned short		h_reclaiming : 1,
54  				h_server     : 1, /* server side, not client side */
55  				h_noresvport : 1,
56  				h_inuse      : 1;
57  	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
58  	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
59  	u32			h_state;	/* pseudo-state counter */
60  	u32			h_nsmstate;	/* true remote NSM state */
61  	u32			h_pidcount;	/* Pseudopids */
62  	refcount_t		h_count;	/* reference count */
63  	struct mutex		h_mutex;	/* mutex for pmap binding */
64  	unsigned long		h_nextrebind;	/* next portmap call */
65  	unsigned long		h_expires;	/* eligible for GC */
66  	struct list_head	h_lockowners;	/* Lockowners for the client */
67  	spinlock_t		h_lock;
68  	struct list_head	h_granted;	/* Locks in GRANTED state */
69  	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
70  	struct nsm_handle	*h_nsmhandle;	/* NSM status handle */
71  	char			*h_addrbuf;	/* address eyecatcher */
72  	struct net		*net;		/* host net */
73  	const struct cred	*h_cred;
74  	char			nodename[UNX_MAXNODENAME + 1];
75  	const struct nlmclnt_operations	*h_nlmclnt_ops;	/* Callback ops for NLM users */
76  };
77  
78  /*
79   * The largest string sm_addrbuf should hold is a full-size IPv6 address
80   * (no "::" anywhere) with a scope ID.  The buffer size is computed to
81   * hold eight groups of colon-separated four-hex-digit numbers, a
82   * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
83   */
84  #define NSM_ADDRBUF		((8 * 4 + 7) + (1 + 10) + 1)
85  
86  struct nsm_handle {
87  	struct list_head	sm_link;
88  	refcount_t		sm_count;
89  	char			*sm_mon_name;
90  	char			*sm_name;
91  	struct sockaddr_storage	sm_addr;
92  	size_t			sm_addrlen;
93  	unsigned int		sm_monitored : 1,
94  				sm_sticky : 1;	/* don't unmonitor */
95  	struct nsm_private	sm_priv;
96  	char			sm_addrbuf[NSM_ADDRBUF];
97  };
98  
99  /*
100   * Rigorous type checking on sockaddr type conversions
101   */
nlm_addr(const struct nlm_host * host)102  static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
103  {
104  	return (struct sockaddr *)&host->h_addr;
105  }
106  
nlm_srcaddr(const struct nlm_host * host)107  static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
108  {
109  	return (struct sockaddr *)&host->h_srcaddr;
110  }
111  
112  /*
113   * Map an fl_owner_t into a unique 32-bit "pid"
114   */
115  struct nlm_lockowner {
116  	struct list_head list;
117  	refcount_t count;
118  
119  	struct nlm_host *host;
120  	fl_owner_t owner;
121  	uint32_t pid;
122  };
123  
124  /*
125   * This is the representation of a blocked client lock.
126   */
127  struct nlm_wait {
128  	struct list_head	b_list;		/* linked list */
129  	wait_queue_head_t	b_wait;		/* where to wait on */
130  	struct nlm_host		*b_host;
131  	struct file_lock	*b_lock;	/* local file lock */
132  	__be32			b_status;	/* grant callback status */
133  };
134  
135  /*
136   * Memory chunk for NLM client RPC request.
137   */
138  #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
139  struct nlm_rqst {
140  	refcount_t		a_count;
141  	unsigned int		a_flags;	/* initial RPC task flags */
142  	struct nlm_host *	a_host;		/* host handle */
143  	struct nlm_args		a_args;		/* arguments */
144  	struct nlm_res		a_res;		/* result */
145  	struct nlm_block *	a_block;
146  	unsigned int		a_retries;	/* Retry count */
147  	u8			a_owner[NLMCLNT_OHSIZE];
148  	void *	a_callback_data; /* sent to nlmclnt_operations callbacks */
149  };
150  
151  /*
152   * This struct describes a file held open by lockd on behalf of
153   * an NFS client.
154   */
155  struct nlm_file {
156  	struct hlist_node	f_list;		/* linked list */
157  	struct nfs_fh		f_handle;	/* NFS file handle */
158  	struct file *		f_file[2];	/* VFS file pointers,
159  						   indexed by O_ flags */
160  	struct nlm_share *	f_shares;	/* DOS shares */
161  	struct list_head	f_blocks;	/* blocked locks */
162  	unsigned int		f_locks;	/* guesstimate # of locks */
163  	unsigned int		f_count;	/* reference count */
164  	struct mutex		f_mutex;	/* avoid concurrent access */
165  };
166  
167  /*
168   * This is a server block (i.e. a lock requested by some client which
169   * couldn't be granted because of a conflicting lock).
170   */
171  #define NLM_NEVER		(~(unsigned long) 0)
172  /* timeout on non-blocking call: */
173  #define NLM_TIMEOUT		(7 * HZ)
174  
175  struct nlm_block {
176  	struct kref		b_count;	/* Reference count */
177  	struct list_head	b_list;		/* linked list of all blocks */
178  	struct list_head	b_flist;	/* linked list (per file) */
179  	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
180  	struct svc_serv *	b_daemon;	/* NLM service */
181  	struct nlm_host *	b_host;		/* host handle for RPC clnt */
182  	unsigned long		b_when;		/* next re-xmit */
183  	unsigned int		b_id;		/* block id */
184  	unsigned char		b_granted;	/* VFS granted lock */
185  	struct nlm_file *	b_file;		/* file in question */
186  	struct cache_req *	b_cache_req;	/* deferred request handling */
187  	struct cache_deferred_req * b_deferred_req;
188  	unsigned int		b_flags;	/* block flags */
189  #define B_QUEUED		1	/* lock queued */
190  #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
191  #define B_TIMED_OUT		4	/* filesystem too slow to respond */
192  };
193  
194  /*
195   * Global variables
196   */
197  extern const struct rpc_program	nlm_program;
198  extern const struct svc_procedure nlmsvc_procedures[24];
199  #ifdef CONFIG_LOCKD_V4
200  extern const struct svc_procedure nlmsvc_procedures4[24];
201  #endif
202  extern int			nlmsvc_grace_period;
203  extern unsigned long		nlmsvc_timeout;
204  extern bool			nsm_use_hostnames;
205  extern u32			nsm_local_state;
206  
207  extern struct timer_list	nlmsvc_retry;
208  
209  /*
210   * Lockd client functions
211   */
212  struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
213  int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
214  int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
215  void		  nlmclnt_release_call(struct nlm_rqst *);
216  void		  nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host,
217  					struct file_lock *fl);
218  void		  nlmclnt_queue_block(struct nlm_wait *block);
219  __be32		  nlmclnt_dequeue_block(struct nlm_wait *block);
220  int		  nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
221  __be32		  nlmclnt_grant(const struct sockaddr *addr,
222  				const struct nlm_lock *lock);
223  void		  nlmclnt_recovery(struct nlm_host *);
224  int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
225  				  struct nlm_rqst *);
226  void		  nlmclnt_next_cookie(struct nlm_cookie *);
227  
228  /*
229   * Host cache
230   */
231  struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
232  					const size_t salen,
233  					const unsigned short protocol,
234  					const u32 version,
235  					const char *hostname,
236  					int noresvport,
237  					struct net *net,
238  					const struct cred *cred);
239  void		  nlmclnt_release_host(struct nlm_host *);
240  struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
241  					const char *hostname,
242  					const size_t hostname_len);
243  void		  nlmsvc_release_host(struct nlm_host *);
244  struct rpc_clnt * nlm_bind_host(struct nlm_host *);
245  void		  nlm_rebind_host(struct nlm_host *);
246  struct nlm_host * nlm_get_host(struct nlm_host *);
247  void		  nlm_shutdown_hosts(void);
248  void		  nlm_shutdown_hosts_net(struct net *net);
249  void		  nlm_host_rebooted(const struct net *net,
250  					const struct nlm_reboot *);
251  
252  /*
253   * Host monitoring
254   */
255  int		  nsm_monitor(const struct nlm_host *host);
256  void		  nsm_unmonitor(const struct nlm_host *host);
257  
258  struct nsm_handle *nsm_get_handle(const struct net *net,
259  					const struct sockaddr *sap,
260  					const size_t salen,
261  					const char *hostname,
262  					const size_t hostname_len);
263  struct nsm_handle *nsm_reboot_lookup(const struct net *net,
264  					const struct nlm_reboot *info);
265  void		  nsm_release(struct nsm_handle *nsm);
266  
267  /*
268   * This is used in garbage collection and resource reclaim
269   * A return value != 0 means destroy the lock/block/share
270   */
271  typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
272  
273  /*
274   * Server-side lock handling
275   */
276  int		  lock_to_openmode(struct file_lock *);
277  __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
278  			      struct nlm_host *, struct nlm_lock *, int,
279  			      struct nlm_cookie *, int);
280  __be32		  nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
281  __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
282  			struct nlm_host *, struct nlm_lock *,
283  			struct nlm_lock *, struct nlm_cookie *);
284  __be32		  nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
285  void		  nlmsvc_retry_blocked(void);
286  void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
287  					nlm_host_match_fn_t match);
288  void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
289  void		  nlmsvc_release_call(struct nlm_rqst *);
290  void		  nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
291  
292  /*
293   * File handling for the server personality
294   */
295  __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
296  					struct nlm_lock *);
297  void		  nlm_release_file(struct nlm_file *);
298  void		  nlmsvc_put_lockowner(struct nlm_lockowner *);
299  void		  nlmsvc_release_lockowner(struct nlm_lock *);
300  void		  nlmsvc_mark_resources(struct net *);
301  void		  nlmsvc_free_host_resources(struct nlm_host *);
302  void		  nlmsvc_invalidate_all(void);
303  
304  /*
305   * Cluster failover support
306   */
307  int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
308  int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
309  
nlmsvc_file_file(struct nlm_file * file)310  static inline struct file *nlmsvc_file_file(struct nlm_file *file)
311  {
312  	return file->f_file[O_RDONLY] ?
313  	       file->f_file[O_RDONLY] : file->f_file[O_WRONLY];
314  }
315  
nlmsvc_file_inode(struct nlm_file * file)316  static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
317  {
318  	return file_inode(nlmsvc_file_file(file));
319  }
320  
__nlm_privileged_request4(const struct sockaddr * sap)321  static inline int __nlm_privileged_request4(const struct sockaddr *sap)
322  {
323  	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
324  
325  	if (ntohs(sin->sin_port) > 1023)
326  		return 0;
327  
328  	return ipv4_is_loopback(sin->sin_addr.s_addr);
329  }
330  
331  #if IS_ENABLED(CONFIG_IPV6)
__nlm_privileged_request6(const struct sockaddr * sap)332  static inline int __nlm_privileged_request6(const struct sockaddr *sap)
333  {
334  	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
335  
336  	if (ntohs(sin6->sin6_port) > 1023)
337  		return 0;
338  
339  	if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
340  		return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
341  
342  	return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
343  }
344  #else	/* IS_ENABLED(CONFIG_IPV6) */
__nlm_privileged_request6(const struct sockaddr * sap)345  static inline int __nlm_privileged_request6(const struct sockaddr *sap)
346  {
347  	return 0;
348  }
349  #endif	/* IS_ENABLED(CONFIG_IPV6) */
350  
351  /*
352   * Ensure incoming requests are from local privileged callers.
353   *
354   * Return TRUE if sender is local and is connecting via a privileged port;
355   * otherwise return FALSE.
356   */
nlm_privileged_requester(const struct svc_rqst * rqstp)357  static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
358  {
359  	const struct sockaddr *sap = svc_addr(rqstp);
360  
361  	switch (sap->sa_family) {
362  	case AF_INET:
363  		return __nlm_privileged_request4(sap);
364  	case AF_INET6:
365  		return __nlm_privileged_request6(sap);
366  	default:
367  		return 0;
368  	}
369  }
370  
371  /*
372   * Compare two NLM locks.
373   * When the second lock is of type F_UNLCK, this acts like a wildcard.
374   */
nlm_compare_locks(const struct file_lock * fl1,const struct file_lock * fl2)375  static inline int nlm_compare_locks(const struct file_lock *fl1,
376  				    const struct file_lock *fl2)
377  {
378  	return file_inode(fl1->fl_file) == file_inode(fl2->fl_file)
379  	     && fl1->fl_pid   == fl2->fl_pid
380  	     && fl1->fl_owner == fl2->fl_owner
381  	     && fl1->fl_start == fl2->fl_start
382  	     && fl1->fl_end   == fl2->fl_end
383  	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
384  }
385  
386  extern const struct lock_manager_operations nlmsvc_lock_operations;
387  
388  #endif /* LINUX_LOCKD_LOCKD_H */
389