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_in(const struct nlm_host * host)102 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
103 {
104 	return (struct sockaddr_in *)&host->h_addr;
105 }
106 
nlm_addr(const struct nlm_host * host)107 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
108 {
109 	return (struct sockaddr *)&host->h_addr;
110 }
111 
nlm_srcaddr_in(const struct nlm_host * host)112 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
113 {
114 	return (struct sockaddr_in *)&host->h_srcaddr;
115 }
116 
nlm_srcaddr(const struct nlm_host * host)117 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
118 {
119 	return (struct sockaddr *)&host->h_srcaddr;
120 }
121 
122 /*
123  * Map an fl_owner_t into a unique 32-bit "pid"
124  */
125 struct nlm_lockowner {
126 	struct list_head list;
127 	refcount_t count;
128 
129 	struct nlm_host *host;
130 	fl_owner_t owner;
131 	uint32_t pid;
132 };
133 
134 struct nlm_wait;
135 
136 /*
137  * Memory chunk for NLM client RPC request.
138  */
139 #define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
140 struct nlm_rqst {
141 	refcount_t		a_count;
142 	unsigned int		a_flags;	/* initial RPC task flags */
143 	struct nlm_host *	a_host;		/* host handle */
144 	struct nlm_args		a_args;		/* arguments */
145 	struct nlm_res		a_res;		/* result */
146 	struct nlm_block *	a_block;
147 	unsigned int		a_retries;	/* Retry count */
148 	u8			a_owner[NLMCLNT_OHSIZE];
149 	void *	a_callback_data; /* sent to nlmclnt_operations callbacks */
150 };
151 
152 /*
153  * This struct describes a file held open by lockd on behalf of
154  * an NFS client.
155  */
156 struct nlm_file {
157 	struct hlist_node	f_list;		/* linked list */
158 	struct nfs_fh		f_handle;	/* NFS file handle */
159 	struct file *		f_file[2];	/* VFS file pointers,
160 						   indexed by O_ flags */
161 	struct nlm_share *	f_shares;	/* DOS shares */
162 	struct list_head	f_blocks;	/* blocked locks */
163 	unsigned int		f_locks;	/* guesstimate # of locks */
164 	unsigned int		f_count;	/* reference count */
165 	struct mutex		f_mutex;	/* avoid concurrent access */
166 };
167 
168 /*
169  * This is a server block (i.e. a lock requested by some client which
170  * couldn't be granted because of a conflicting lock).
171  */
172 #define NLM_NEVER		(~(unsigned long) 0)
173 /* timeout on non-blocking call: */
174 #define NLM_TIMEOUT		(7 * HZ)
175 
176 struct nlm_block {
177 	struct kref		b_count;	/* Reference count */
178 	struct list_head	b_list;		/* linked list of all blocks */
179 	struct list_head	b_flist;	/* linked list (per file) */
180 	struct nlm_rqst	*	b_call;		/* RPC args & callback info */
181 	struct svc_serv *	b_daemon;	/* NLM service */
182 	struct nlm_host *	b_host;		/* host handle for RPC clnt */
183 	unsigned long		b_when;		/* next re-xmit */
184 	unsigned int		b_id;		/* block id */
185 	unsigned char		b_granted;	/* VFS granted lock */
186 	struct nlm_file *	b_file;		/* file in question */
187 	struct cache_req *	b_cache_req;	/* deferred request handling */
188 	struct cache_deferred_req * b_deferred_req;
189 	unsigned int		b_flags;	/* block flags */
190 #define B_QUEUED		1	/* lock queued */
191 #define B_GOT_CALLBACK		2	/* got lock or conflicting lock */
192 #define B_TIMED_OUT		4	/* filesystem too slow to respond */
193 };
194 
195 /*
196  * Global variables
197  */
198 extern const struct rpc_program	nlm_program;
199 extern const struct svc_procedure nlmsvc_procedures[];
200 #ifdef CONFIG_LOCKD_V4
201 extern const struct svc_procedure nlmsvc_procedures4[];
202 #endif
203 extern int			nlmsvc_grace_period;
204 extern unsigned long		nlmsvc_timeout;
205 extern bool			nsm_use_hostnames;
206 extern u32			nsm_local_state;
207 
208 /*
209  * Lockd client functions
210  */
211 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
212 int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
213 int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
214 void		  nlmclnt_release_call(struct nlm_rqst *);
215 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
216 void		  nlmclnt_finish_block(struct nlm_wait *block);
217 int		  nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
218 __be32		  nlmclnt_grant(const struct sockaddr *addr,
219 				const struct nlm_lock *lock);
220 void		  nlmclnt_recovery(struct nlm_host *);
221 int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
222 				  struct nlm_rqst *);
223 void		  nlmclnt_next_cookie(struct nlm_cookie *);
224 
225 /*
226  * Host cache
227  */
228 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
229 					const size_t salen,
230 					const unsigned short protocol,
231 					const u32 version,
232 					const char *hostname,
233 					int noresvport,
234 					struct net *net,
235 					const struct cred *cred);
236 void		  nlmclnt_release_host(struct nlm_host *);
237 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
238 					const char *hostname,
239 					const size_t hostname_len);
240 void		  nlmsvc_release_host(struct nlm_host *);
241 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
242 void		  nlm_rebind_host(struct nlm_host *);
243 struct nlm_host * nlm_get_host(struct nlm_host *);
244 void		  nlm_shutdown_hosts(void);
245 void		  nlm_shutdown_hosts_net(struct net *net);
246 void		  nlm_host_rebooted(const struct net *net,
247 					const struct nlm_reboot *);
248 
249 /*
250  * Host monitoring
251  */
252 int		  nsm_monitor(const struct nlm_host *host);
253 void		  nsm_unmonitor(const struct nlm_host *host);
254 
255 struct nsm_handle *nsm_get_handle(const struct net *net,
256 					const struct sockaddr *sap,
257 					const size_t salen,
258 					const char *hostname,
259 					const size_t hostname_len);
260 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
261 					const struct nlm_reboot *info);
262 void		  nsm_release(struct nsm_handle *nsm);
263 
264 /*
265  * This is used in garbage collection and resource reclaim
266  * A return value != 0 means destroy the lock/block/share
267  */
268 typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
269 
270 /*
271  * Server-side lock handling
272  */
273 int		  lock_to_openmode(struct file_lock *);
274 __be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
275 			      struct nlm_host *, struct nlm_lock *, int,
276 			      struct nlm_cookie *, int);
277 __be32		  nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
278 __be32		  nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
279 			struct nlm_host *, struct nlm_lock *,
280 			struct nlm_lock *, struct nlm_cookie *);
281 __be32		  nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
282 unsigned long	  nlmsvc_retry_blocked(void);
283 void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
284 					nlm_host_match_fn_t match);
285 void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
286 void		  nlmsvc_release_call(struct nlm_rqst *);
287 void		  nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
288 
289 /*
290  * File handling for the server personality
291  */
292 __be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
293 					struct nlm_lock *);
294 void		  nlm_release_file(struct nlm_file *);
295 void		  nlmsvc_release_lockowner(struct nlm_lock *);
296 void		  nlmsvc_mark_resources(struct net *);
297 void		  nlmsvc_free_host_resources(struct nlm_host *);
298 void		  nlmsvc_invalidate_all(void);
299 
300 /*
301  * Cluster failover support
302  */
303 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
304 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
305 
nlmsvc_file_file(struct nlm_file * file)306 static inline struct file *nlmsvc_file_file(struct nlm_file *file)
307 {
308 	return file->f_file[O_RDONLY] ?
309 	       file->f_file[O_RDONLY] : file->f_file[O_WRONLY];
310 }
311 
nlmsvc_file_inode(struct nlm_file * file)312 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
313 {
314 	return locks_inode(nlmsvc_file_file(file));
315 }
316 
__nlm_privileged_request4(const struct sockaddr * sap)317 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
318 {
319 	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
320 
321 	if (ntohs(sin->sin_port) > 1023)
322 		return 0;
323 
324 	return ipv4_is_loopback(sin->sin_addr.s_addr);
325 }
326 
327 #if IS_ENABLED(CONFIG_IPV6)
__nlm_privileged_request6(const struct sockaddr * sap)328 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
329 {
330 	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
331 
332 	if (ntohs(sin6->sin6_port) > 1023)
333 		return 0;
334 
335 	if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
336 		return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
337 
338 	return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
339 }
340 #else	/* IS_ENABLED(CONFIG_IPV6) */
__nlm_privileged_request6(const struct sockaddr * sap)341 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
342 {
343 	return 0;
344 }
345 #endif	/* IS_ENABLED(CONFIG_IPV6) */
346 
347 /*
348  * Ensure incoming requests are from local privileged callers.
349  *
350  * Return TRUE if sender is local and is connecting via a privileged port;
351  * otherwise return FALSE.
352  */
nlm_privileged_requester(const struct svc_rqst * rqstp)353 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
354 {
355 	const struct sockaddr *sap = svc_addr(rqstp);
356 
357 	switch (sap->sa_family) {
358 	case AF_INET:
359 		return __nlm_privileged_request4(sap);
360 	case AF_INET6:
361 		return __nlm_privileged_request6(sap);
362 	default:
363 		return 0;
364 	}
365 }
366 
367 /*
368  * Compare two NLM locks.
369  * When the second lock is of type F_UNLCK, this acts like a wildcard.
370  */
nlm_compare_locks(const struct file_lock * fl1,const struct file_lock * fl2)371 static inline int nlm_compare_locks(const struct file_lock *fl1,
372 				    const struct file_lock *fl2)
373 {
374 	return locks_inode(fl1->fl_file) == locks_inode(fl2->fl_file)
375 	     && fl1->fl_pid   == fl2->fl_pid
376 	     && fl1->fl_owner == fl2->fl_owner
377 	     && fl1->fl_start == fl2->fl_start
378 	     && fl1->fl_end   == fl2->fl_end
379 	     &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
380 }
381 
382 extern const struct lock_manager_operations nlmsvc_lock_operations;
383 
384 #endif /* LINUX_LOCKD_LOCKD_H */
385