xref: /linux-6.15/include/linux/lockd/lockd.h (revision bbb03029)
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/lockd/bind.h>
21 #include <linux/lockd/xdr.h>
22 #ifdef CONFIG_LOCKD_V4
23 #include <linux/lockd/xdr4.h>
24 #endif
25 #include <linux/lockd/debug.h>
26 #include <linux/sunrpc/svc.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 	size_t			h_srcaddrlen;
47 	struct rpc_clnt		*h_rpcclnt;	/* RPC client to talk to peer */
48 	char			*h_name;		/* remote hostname */
49 	u32			h_version;	/* interface version */
50 	unsigned short		h_proto;	/* transport proto */
51 	unsigned short		h_reclaiming : 1,
52 				h_server     : 1, /* server side, not client side */
53 				h_noresvport : 1,
54 				h_inuse      : 1;
55 	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
56 	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
57 	u32			h_state;	/* pseudo-state counter */
58 	u32			h_nsmstate;	/* true remote NSM state */
59 	u32			h_pidcount;	/* Pseudopids */
60 	atomic_t		h_count;	/* reference count */
61 	struct mutex		h_mutex;	/* mutex for pmap binding */
62 	unsigned long		h_nextrebind;	/* next portmap call */
63 	unsigned long		h_expires;	/* eligible for GC */
64 	struct list_head	h_lockowners;	/* Lockowners for the client */
65 	spinlock_t		h_lock;
66 	struct list_head	h_granted;	/* Locks in GRANTED state */
67 	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
68 	struct nsm_handle	*h_nsmhandle;	/* NSM status handle */
69 	char			*h_addrbuf;	/* address eyecatcher */
70 	struct net		*net;		/* host net */
71 	char			nodename[UNX_MAXNODENAME + 1];
72 	const struct nlmclnt_operations	*h_nlmclnt_ops;	/* Callback ops for NLM users */
73 };
74 
75 /*
76  * The largest string sm_addrbuf should hold is a full-size IPv6 address
77  * (no "::" anywhere) with a scope ID.  The buffer size is computed to
78  * hold eight groups of colon-separated four-hex-digit numbers, a
79  * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
80  */
81 #define NSM_ADDRBUF		((8 * 4 + 7) + (1 + 10) + 1)
82 
83 struct nsm_handle {
84 	struct list_head	sm_link;
85 	atomic_t		sm_count;
86 	char			*sm_mon_name;
87 	char			*sm_name;
88 	struct sockaddr_storage	sm_addr;
89 	size_t			sm_addrlen;
90 	unsigned int		sm_monitored : 1,
91 				sm_sticky : 1;	/* don't unmonitor */
92 	struct nsm_private	sm_priv;
93 	char			sm_addrbuf[NSM_ADDRBUF];
94 };
95 
96 /*
97  * Rigorous type checking on sockaddr type conversions
98  */
99 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
100 {
101 	return (struct sockaddr_in *)&host->h_addr;
102 }
103 
104 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
105 {
106 	return (struct sockaddr *)&host->h_addr;
107 }
108 
109 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
110 {
111 	return (struct sockaddr_in *)&host->h_srcaddr;
112 }
113 
114 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
115 {
116 	return (struct sockaddr *)&host->h_srcaddr;
117 }
118 
119 /*
120  * Map an fl_owner_t into a unique 32-bit "pid"
121  */
122 struct nlm_lockowner {
123 	struct list_head list;
124 	atomic_t count;
125 
126 	struct nlm_host *host;
127 	fl_owner_t owner;
128 	uint32_t pid;
129 };
130 
131 struct nlm_wait;
132 
133 /*
134  * Memory chunk for NLM client RPC request.
135  */
136 #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
137 struct nlm_rqst {
138 	atomic_t		a_count;
139 	unsigned int		a_flags;	/* initial RPC task flags */
140 	struct nlm_host *	a_host;		/* host handle */
141 	struct nlm_args		a_args;		/* arguments */
142 	struct nlm_res		a_res;		/* result */
143 	struct nlm_block *	a_block;
144 	unsigned int		a_retries;	/* Retry count */
145 	u8			a_owner[NLMCLNT_OHSIZE];
146 	void *	a_callback_data; /* sent to nlmclnt_operations callbacks */
147 };
148 
149 /*
150  * This struct describes a file held open by lockd on behalf of
151  * an NFS client.
152  */
153 struct nlm_file {
154 	struct hlist_node	f_list;		/* linked list */
155 	struct nfs_fh		f_handle;	/* NFS file handle */
156 	struct file *		f_file;		/* VFS file pointer */
157 	struct nlm_share *	f_shares;	/* DOS shares */
158 	struct list_head	f_blocks;	/* blocked locks */
159 	unsigned int		f_locks;	/* guesstimate # of locks */
160 	unsigned int		f_count;	/* reference count */
161 	struct mutex		f_mutex;	/* avoid concurrent access */
162 };
163 
164 /*
165  * This is a server block (i.e. a lock requested by some client which
166  * couldn't be granted because of a conflicting lock).
167  */
168 #define NLM_NEVER		(~(unsigned long) 0)
169 /* timeout on non-blocking call: */
170 #define NLM_TIMEOUT		(7 * HZ)
171 
172 struct nlm_block {
173 	struct kref		b_count;	/* Reference count */
174 	struct list_head	b_list;		/* linked list of all blocks */
175 	struct list_head	b_flist;	/* linked list (per file) */
176 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
177 	struct svc_serv *	b_daemon;	/* NLM service */
178 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
179 	unsigned long		b_when;		/* next re-xmit */
180 	unsigned int		b_id;		/* block id */
181 	unsigned char		b_granted;	/* VFS granted lock */
182 	struct nlm_file *	b_file;		/* file in question */
183 	struct cache_req *	b_cache_req;	/* deferred request handling */
184 	struct cache_deferred_req * b_deferred_req;
185 	unsigned int		b_flags;	/* block flags */
186 #define B_QUEUED		1	/* lock queued */
187 #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
188 #define B_TIMED_OUT		4	/* filesystem too slow to respond */
189 };
190 
191 /*
192  * Global variables
193  */
194 extern const struct rpc_program	nlm_program;
195 extern const struct svc_procedure nlmsvc_procedures[];
196 #ifdef CONFIG_LOCKD_V4
197 extern const struct svc_procedure nlmsvc_procedures4[];
198 #endif
199 extern int			nlmsvc_grace_period;
200 extern unsigned long		nlmsvc_timeout;
201 extern bool			nsm_use_hostnames;
202 extern u32			nsm_local_state;
203 
204 /*
205  * Lockd client functions
206  */
207 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
208 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
209 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
210 void		  nlmclnt_release_call(struct nlm_rqst *);
211 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
212 void		  nlmclnt_finish_block(struct nlm_wait *block);
213 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
214 __be32		  nlmclnt_grant(const struct sockaddr *addr,
215 				const struct nlm_lock *lock);
216 void		  nlmclnt_recovery(struct nlm_host *);
217 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
218 				  struct nlm_rqst *);
219 void		  nlmclnt_next_cookie(struct nlm_cookie *);
220 
221 /*
222  * Host cache
223  */
224 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
225 					const size_t salen,
226 					const unsigned short protocol,
227 					const u32 version,
228 					const char *hostname,
229 					int noresvport,
230 					struct net *net);
231 void		  nlmclnt_release_host(struct nlm_host *);
232 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
233 					const char *hostname,
234 					const size_t hostname_len);
235 void		  nlmsvc_release_host(struct nlm_host *);
236 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
237 void		  nlm_rebind_host(struct nlm_host *);
238 struct nlm_host * nlm_get_host(struct nlm_host *);
239 void		  nlm_shutdown_hosts(void);
240 void		  nlm_shutdown_hosts_net(struct net *net);
241 void		  nlm_host_rebooted(const struct net *net,
242 					const struct nlm_reboot *);
243 
244 /*
245  * Host monitoring
246  */
247 int		  nsm_monitor(const struct nlm_host *host);
248 void		  nsm_unmonitor(const struct nlm_host *host);
249 
250 struct nsm_handle *nsm_get_handle(const struct net *net,
251 					const struct sockaddr *sap,
252 					const size_t salen,
253 					const char *hostname,
254 					const size_t hostname_len);
255 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
256 					const struct nlm_reboot *info);
257 void		  nsm_release(struct nsm_handle *nsm);
258 
259 /*
260  * This is used in garbage collection and resource reclaim
261  * A return value != 0 means destroy the lock/block/share
262  */
263 typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
264 
265 /*
266  * Server-side lock handling
267  */
268 __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
269 			      struct nlm_host *, struct nlm_lock *, int,
270 			      struct nlm_cookie *, int);
271 __be32		  nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
272 __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
273 			struct nlm_host *, struct nlm_lock *,
274 			struct nlm_lock *, struct nlm_cookie *);
275 __be32		  nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
276 unsigned long	  nlmsvc_retry_blocked(void);
277 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
278 					nlm_host_match_fn_t match);
279 void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
280 void		  nlmsvc_release_call(struct nlm_rqst *);
281 
282 /*
283  * File handling for the server personality
284  */
285 __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
286 					struct nfs_fh *);
287 void		  nlm_release_file(struct nlm_file *);
288 void		  nlmsvc_mark_resources(struct net *);
289 void		  nlmsvc_free_host_resources(struct nlm_host *);
290 void		  nlmsvc_invalidate_all(void);
291 
292 /*
293  * Cluster failover support
294  */
295 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
296 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
297 
298 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
299 {
300 	return file_inode(file->f_file);
301 }
302 
303 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
304 {
305 	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
306 
307 	if (ntohs(sin->sin_port) > 1023)
308 		return 0;
309 
310 	return ipv4_is_loopback(sin->sin_addr.s_addr);
311 }
312 
313 #if IS_ENABLED(CONFIG_IPV6)
314 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
315 {
316 	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
317 
318 	if (ntohs(sin6->sin6_port) > 1023)
319 		return 0;
320 
321 	if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
322 		return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
323 
324 	return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
325 }
326 #else	/* IS_ENABLED(CONFIG_IPV6) */
327 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
328 {
329 	return 0;
330 }
331 #endif	/* IS_ENABLED(CONFIG_IPV6) */
332 
333 /*
334  * Ensure incoming requests are from local privileged callers.
335  *
336  * Return TRUE if sender is local and is connecting via a privileged port;
337  * otherwise return FALSE.
338  */
339 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
340 {
341 	const struct sockaddr *sap = svc_addr(rqstp);
342 
343 	switch (sap->sa_family) {
344 	case AF_INET:
345 		return __nlm_privileged_request4(sap);
346 	case AF_INET6:
347 		return __nlm_privileged_request6(sap);
348 	default:
349 		return 0;
350 	}
351 }
352 
353 /*
354  * Compare two NLM locks.
355  * When the second lock is of type F_UNLCK, this acts like a wildcard.
356  */
357 static inline int nlm_compare_locks(const struct file_lock *fl1,
358 				    const struct file_lock *fl2)
359 {
360 	return file_inode(fl1->fl_file) == file_inode(fl2->fl_file)
361 	     && fl1->fl_pid   == fl2->fl_pid
362 	     && fl1->fl_owner == fl2->fl_owner
363 	     && fl1->fl_start == fl2->fl_start
364 	     && fl1->fl_end   == fl2->fl_end
365 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
366 }
367 
368 extern const struct lock_manager_operations nlmsvc_lock_operations;
369 
370 #endif /* __KERNEL__ */
371 
372 #endif /* LINUX_LOCKD_LOCKD_H */
373