xref: /linux-6.15/include/linux/lockd/lockd.h (revision 652afc27)
1 /*
2  * linux/include/linux/lockd/lockd.h
3  *
4  * General-purpose lockd include file.
5  *
6  * Copyright (C) 1996 Olaf Kirch <[email protected]>
7  */
8 
9 #ifndef LINUX_LOCKD_LOCKD_H
10 #define LINUX_LOCKD_LOCKD_H
11 
12 #ifdef __KERNEL__
13 
14 #include <linux/in.h>
15 #include <linux/in6.h>
16 #include <net/ipv6.h>
17 #include <linux/fs.h>
18 #include <linux/kref.h>
19 #include <linux/utsname.h>
20 #include <linux/nfsd/nfsfh.h>
21 #include <linux/lockd/bind.h>
22 #include <linux/lockd/xdr.h>
23 #ifdef CONFIG_LOCKD_V4
24 #include <linux/lockd/xdr4.h>
25 #endif
26 #include <linux/lockd/debug.h>
27 
28 /*
29  * Version string
30  */
31 #define LOCKD_VERSION		"0.5"
32 
33 /*
34  * Default timeout for RPC calls (seconds)
35  */
36 #define LOCKD_DFLT_TIMEO	10
37 
38 /*
39  * Lockd host handle (used both by the client and server personality).
40  */
41 struct nlm_host {
42 	struct hlist_node	h_hash;		/* doubly linked list */
43 	struct sockaddr_storage	h_addr;		/* peer address */
44 	size_t			h_addrlen;
45 	struct sockaddr_storage	h_srcaddr;	/* our address (optional) */
46 	struct rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
47 	char *			h_name;		/* remote hostname */
48 	u32			h_version;	/* interface version */
49 	unsigned short		h_proto;	/* transport proto */
50 	unsigned short		h_reclaiming : 1,
51 				h_server     : 1, /* server side, not client side */
52 				h_noresvport : 1,
53 				h_inuse      : 1;
54 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
55 	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
56 	u32			h_state;	/* pseudo-state counter */
57 	u32			h_nsmstate;	/* true remote NSM state */
58 	u32			h_pidcount;	/* Pseudopids */
59 	atomic_t		h_count;	/* reference count */
60 	struct mutex		h_mutex;	/* mutex for pmap binding */
61 	unsigned long		h_nextrebind;	/* next portmap call */
62 	unsigned long		h_expires;	/* eligible for GC */
63 	struct list_head	h_lockowners;	/* Lockowners for the client */
64 	spinlock_t		h_lock;
65 	struct list_head	h_granted;	/* Locks in GRANTED state */
66 	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
67 	struct nsm_handle *	h_nsmhandle;	/* NSM status handle */
68 
69 	char			h_addrbuf[48],	/* address eyecatchers */
70 				h_srcaddrbuf[48];
71 };
72 
73 struct nsm_handle {
74 	struct list_head	sm_link;
75 	atomic_t		sm_count;
76 	char *			sm_name;
77 	struct sockaddr_storage	sm_addr;
78 	size_t			sm_addrlen;
79 	unsigned int		sm_monitored : 1,
80 				sm_sticky : 1;	/* don't unmonitor */
81 	char			sm_addrbuf[48];	/* address eyecatcher */
82 };
83 
84 /*
85  * Rigorous type checking on sockaddr type conversions
86  */
87 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
88 {
89 	return (struct sockaddr_in *)&host->h_addr;
90 }
91 
92 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
93 {
94 	return (struct sockaddr *)&host->h_addr;
95 }
96 
97 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
98 {
99 	return (struct sockaddr_in *)&host->h_srcaddr;
100 }
101 
102 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
103 {
104 	return (struct sockaddr *)&host->h_srcaddr;
105 }
106 
107 static inline struct sockaddr_in *nsm_addr_in(const struct nsm_handle *handle)
108 {
109 	return (struct sockaddr_in *)&handle->sm_addr;
110 }
111 
112 static inline struct sockaddr *nsm_addr(const struct nsm_handle *handle)
113 {
114 	return (struct sockaddr *)&handle->sm_addr;
115 }
116 
117 /*
118  * Map an fl_owner_t into a unique 32-bit "pid"
119  */
120 struct nlm_lockowner {
121 	struct list_head list;
122 	atomic_t count;
123 
124 	struct nlm_host *host;
125 	fl_owner_t owner;
126 	uint32_t pid;
127 };
128 
129 struct nlm_wait;
130 
131 /*
132  * Memory chunk for NLM client RPC request.
133  */
134 #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
135 struct nlm_rqst {
136 	atomic_t		a_count;
137 	unsigned int		a_flags;	/* initial RPC task flags */
138 	struct nlm_host *	a_host;		/* host handle */
139 	struct nlm_args		a_args;		/* arguments */
140 	struct nlm_res		a_res;		/* result */
141 	struct nlm_block *	a_block;
142 	unsigned int		a_retries;	/* Retry count */
143 	u8			a_owner[NLMCLNT_OHSIZE];
144 };
145 
146 /*
147  * This struct describes a file held open by lockd on behalf of
148  * an NFS client.
149  */
150 struct nlm_file {
151 	struct hlist_node	f_list;		/* linked list */
152 	struct nfs_fh		f_handle;	/* NFS file handle */
153 	struct file *		f_file;		/* VFS file pointer */
154 	struct nlm_share *	f_shares;	/* DOS shares */
155 	struct list_head	f_blocks;	/* blocked locks */
156 	unsigned int		f_locks;	/* guesstimate # of locks */
157 	unsigned int		f_count;	/* reference count */
158 	struct mutex		f_mutex;	/* avoid concurrent access */
159 };
160 
161 /*
162  * This is a server block (i.e. a lock requested by some client which
163  * couldn't be granted because of a conflicting lock).
164  */
165 #define NLM_NEVER		(~(unsigned long) 0)
166 /* timeout on non-blocking call: */
167 #define NLM_TIMEOUT		(7 * HZ)
168 
169 struct nlm_block {
170 	struct kref		b_count;	/* Reference count */
171 	struct list_head	b_list;		/* linked list of all blocks */
172 	struct list_head	b_flist;	/* linked list (per file) */
173 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
174 	struct svc_serv *	b_daemon;	/* NLM service */
175 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
176 	unsigned long		b_when;		/* next re-xmit */
177 	unsigned int		b_id;		/* block id */
178 	unsigned char		b_granted;	/* VFS granted lock */
179 	struct nlm_file *	b_file;		/* file in question */
180 	struct cache_req *	b_cache_req;	/* deferred request handling */
181 	struct file_lock *	b_fl;		/* set for GETLK */
182 	struct cache_deferred_req * b_deferred_req;
183 	unsigned int		b_flags;	/* block flags */
184 #define B_QUEUED		1	/* lock queued */
185 #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
186 #define B_TIMED_OUT		4	/* filesystem too slow to respond */
187 };
188 
189 /*
190  * Global variables
191  */
192 extern struct rpc_program	nlm_program;
193 extern struct svc_procedure	nlmsvc_procedures[];
194 #ifdef CONFIG_LOCKD_V4
195 extern struct svc_procedure	nlmsvc_procedures4[];
196 #endif
197 extern int			nlmsvc_grace_period;
198 extern unsigned long		nlmsvc_timeout;
199 extern int			nsm_use_hostnames;
200 
201 /*
202  * Lockd client functions
203  */
204 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
205 void		  nlm_release_call(struct nlm_rqst *);
206 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
207 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
208 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
209 void		  nlmclnt_finish_block(struct nlm_wait *block);
210 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
211 __be32		  nlmclnt_grant(const struct sockaddr *addr,
212 				const struct nlm_lock *lock);
213 void		  nlmclnt_recovery(struct nlm_host *);
214 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
215 void		  nlmclnt_next_cookie(struct nlm_cookie *);
216 
217 /*
218  * Host cache
219  */
220 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
221 					const size_t salen,
222 					const unsigned short protocol,
223 					const u32 version,
224 					const char *hostname,
225 					int noresvport);
226 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
227 					const char *hostname,
228 					const size_t hostname_len);
229 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
230 void		  nlm_rebind_host(struct nlm_host *);
231 struct nlm_host * nlm_get_host(struct nlm_host *);
232 void		  nlm_release_host(struct nlm_host *);
233 void		  nlm_shutdown_hosts(void);
234 extern void	  nlm_host_rebooted(const struct sockaddr_in *, const char *,
235 					unsigned int, u32);
236 void		  nsm_release(struct nsm_handle *);
237 
238 
239 /*
240  * This is used in garbage collection and resource reclaim
241  * A return value != 0 means destroy the lock/block/share
242  */
243 typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
244 
245 /*
246  * Server-side lock handling
247  */
248 __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
249 			      struct nlm_host *, struct nlm_lock *, int,
250 			      struct nlm_cookie *, int);
251 __be32		  nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
252 __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
253 			struct nlm_host *, struct nlm_lock *,
254 			struct nlm_lock *, struct nlm_cookie *);
255 __be32		  nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
256 unsigned long	  nlmsvc_retry_blocked(void);
257 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
258 					nlm_host_match_fn_t match);
259 void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
260 
261 /*
262  * File handling for the server personality
263  */
264 __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
265 					struct nfs_fh *);
266 void		  nlm_release_file(struct nlm_file *);
267 void		  nlmsvc_mark_resources(void);
268 void		  nlmsvc_free_host_resources(struct nlm_host *);
269 void		  nlmsvc_invalidate_all(void);
270 
271 /*
272  * Cluster failover support
273  */
274 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
275 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
276 
277 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
278 {
279 	return file->f_file->f_path.dentry->d_inode;
280 }
281 
282 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
283 {
284 	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
285 	return (sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) &&
286 			(ntohs(sin->sin_port) < 1024);
287 }
288 
289 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
290 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
291 {
292 	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
293 	return (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK) &&
294 			(ntohs(sin6->sin6_port) < 1024);
295 }
296 #else	/* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
297 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
298 {
299 	return 0;
300 }
301 #endif	/* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
302 
303 /*
304  * Ensure incoming requests are from local privileged callers.
305  *
306  * Return TRUE if sender is local and is connecting via a privileged port;
307  * otherwise return FALSE.
308  */
309 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
310 {
311 	const struct sockaddr *sap = svc_addr(rqstp);
312 
313 	switch (sap->sa_family) {
314 	case AF_INET:
315 		return __nlm_privileged_request4(sap);
316 	case AF_INET6:
317 		return __nlm_privileged_request6(sap);
318 	default:
319 		return 0;
320 	}
321 }
322 
323 static inline int __nlm_cmp_addr4(const struct sockaddr *sap1,
324 				  const struct sockaddr *sap2)
325 {
326 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sap1;
327 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sap2;
328 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
329 }
330 
331 static inline int __nlm_cmp_addr6(const struct sockaddr *sap1,
332 				  const struct sockaddr *sap2)
333 {
334 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sap1;
335 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sap2;
336 	return ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr);
337 }
338 
339 /*
340  * Compare two host addresses
341  *
342  * Return TRUE if the addresses are the same; otherwise FALSE.
343  */
344 static inline int nlm_cmp_addr(const struct sockaddr *sap1,
345 			       const struct sockaddr *sap2)
346 {
347 	if (sap1->sa_family == sap2->sa_family) {
348 		switch (sap1->sa_family) {
349 		case AF_INET:
350 			return __nlm_cmp_addr4(sap1, sap2);
351 		case AF_INET6:
352 			return __nlm_cmp_addr6(sap1, sap2);
353 		}
354 	}
355 	return 0;
356 }
357 
358 /*
359  * Compare two NLM locks.
360  * When the second lock is of type F_UNLCK, this acts like a wildcard.
361  */
362 static inline int nlm_compare_locks(const struct file_lock *fl1,
363 				    const struct file_lock *fl2)
364 {
365 	return	fl1->fl_pid   == fl2->fl_pid
366 	     && fl1->fl_owner == fl2->fl_owner
367 	     && fl1->fl_start == fl2->fl_start
368 	     && fl1->fl_end   == fl2->fl_end
369 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
370 }
371 
372 extern struct lock_manager_operations nlmsvc_lock_operations;
373 
374 #endif /* __KERNEL__ */
375 
376 #endif /* LINUX_LOCKD_LOCKD_H */
377