lockd.h

  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/exportfs.h>
 16#include <linux/in.h>
 17#include <linux/in6.h>
 18#include <net/ipv6.h>
 19#include <linux/fs.h>
 20#include <linux/kref.h>
 21#include <linux/refcount.h>
 22#include <linux/utsname.h>
 23#include <linux/lockd/bind.h>
 24#include <linux/lockd/xdr.h>
 25#ifdef CONFIG_LOCKD_V4
 26#include <linux/lockd/xdr4.h>
 27#endif
 28#include <linux/lockd/debug.h>
 29#include <linux/sunrpc/svc.h>
 30
 31/*
 32 * Version string
 33 */
 34#define LOCKD_VERSION		"0.5"
 35
 36/*
 37 * Default timeout for RPC calls (seconds)
 38 */
 39#define LOCKD_DFLT_TIMEO	10
 40
 41/*
 42 * Lockd host handle (used both by the client and server personality).
 43 */
 44struct nlm_host {
 45	struct hlist_node	h_hash;		/* doubly linked list */
 46	struct sockaddr_storage	h_addr;		/* peer address */
 47	size_t			h_addrlen;
 48	struct sockaddr_storage	h_srcaddr;	/* our address (optional) */
 49	size_t			h_srcaddrlen;
 50	struct rpc_clnt		*h_rpcclnt;	/* RPC client to talk to peer */
 51	char			*h_name;		/* remote hostname */
 52	u32			h_version;	/* interface version */
 53	unsigned short		h_proto;	/* transport proto */
 54	unsigned short		h_reclaiming : 1,
 55				h_server     : 1, /* server side, not client side */
 56				h_noresvport : 1,
 57				h_inuse      : 1;
 58	wait_queue_head_t	h_gracewait;	/* wait while reclaiming */
 59	struct rw_semaphore	h_rwsem;	/* Reboot recovery lock */
 60	u32			h_state;	/* pseudo-state counter */
 61	u32			h_nsmstate;	/* true remote NSM state */
 62	u32			h_pidcount;	/* Pseudopids */
 63	refcount_t		h_count;	/* reference count */
 64	struct mutex		h_mutex;	/* mutex for pmap binding */
 65	unsigned long		h_nextrebind;	/* next portmap call */
 66	unsigned long		h_expires;	/* eligible for GC */
 67	struct list_head	h_lockowners;	/* Lockowners for the client */
 68	spinlock_t		h_lock;
 69	struct list_head	h_granted;	/* Locks in GRANTED state */
 70	struct list_head	h_reclaim;	/* Locks in RECLAIM state */
 71	struct nsm_handle	*h_nsmhandle;	/* NSM status handle */
 72	char			*h_addrbuf;	/* address eyecatcher */
 73	struct net		*net;		/* host net */
 74	const struct cred	*h_cred;
 75	char			nodename[UNX_MAXNODENAME + 1];
 76	const struct nlmclnt_operations	*h_nlmclnt_ops;	/* Callback ops for NLM users */
 77};
 78
 79/*
 80 * The largest string sm_addrbuf should hold is a full-size IPv6 address
 81 * (no "::" anywhere) with a scope ID.  The buffer size is computed to
 82 * hold eight groups of colon-separated four-hex-digit numbers, a
 83 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
 84 */
 85#define NSM_ADDRBUF		((8 * 4 + 7) + (1 + 10) + 1)
 86
 87struct nsm_handle {
 88	struct list_head	sm_link;
 89	refcount_t		sm_count;
 90	char			*sm_mon_name;
 91	char			*sm_name;
 92	struct sockaddr_storage	sm_addr;
 93	size_t			sm_addrlen;
 94	unsigned int		sm_monitored : 1,
 95				sm_sticky : 1;	/* don't unmonitor */
 96	struct nsm_private	sm_priv;
 97	char			sm_addrbuf[NSM_ADDRBUF];
 98};
 99
100/*
101 * Rigorous type checking on sockaddr type conversions
102 */
103static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
104{
105	return (struct sockaddr *)&host->h_addr;
106}
107
108static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
109{
110	return (struct sockaddr *)&host->h_srcaddr;
111}
112
113/*
114 * Map an fl_owner_t into a unique 32-bit "pid"
115 */
116struct nlm_lockowner {
117	struct list_head list;
118	refcount_t count;
119
120	struct nlm_host *host;
121	fl_owner_t owner;
122	uint32_t pid;
123};
124
125/*
126 * This is the representation of a blocked client lock.
127 */
128struct nlm_wait {
129	struct list_head	b_list;		/* linked list */
130	wait_queue_head_t	b_wait;		/* where to wait on */
131	struct nlm_host		*b_host;
132	struct file_lock	*b_lock;	/* local file lock */
133	__be32			b_status;	/* grant callback status */
134};
135
136/*
137 * Memory chunk for NLM client RPC request.
138 */
139#define NLMCLNT_OHSIZE		((__NEW_UTS_LEN) + 10u)
140struct 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 */
156struct 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
176struct 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 */
198extern const struct rpc_program	nlm_program;
199extern const struct svc_procedure nlmsvc_procedures[24];
200#ifdef CONFIG_LOCKD_V4
201extern const struct svc_procedure nlmsvc_procedures4[24];
202#endif
203extern int			nlmsvc_grace_period;
204extern unsigned long		nlm_timeout;
205extern bool			nsm_use_hostnames;
206extern u32			nsm_local_state;
207
208extern struct timer_list	nlmsvc_retry;
209
210/*
211 * Lockd client functions
212 */
213struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
214int		  nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
215int		  nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
216void		  nlmclnt_release_call(struct nlm_rqst *);
217void		  nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host,
218					struct file_lock *fl);
219void		  nlmclnt_queue_block(struct nlm_wait *block);
220__be32		  nlmclnt_dequeue_block(struct nlm_wait *block);
221int		  nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
222__be32		  nlmclnt_grant(const struct sockaddr *addr,
223				const struct nlm_lock *lock);
224void		  nlmclnt_recovery(struct nlm_host *);
225int		  nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
226				  struct nlm_rqst *);
227void		  nlmclnt_next_cookie(struct nlm_cookie *);
228
229/*
230 * Host cache
231 */
232struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
233					const size_t salen,
234					const unsigned short protocol,
235					const u32 version,
236					const char *hostname,
237					int noresvport,
238					struct net *net,
239					const struct cred *cred);
240void		  nlmclnt_release_host(struct nlm_host *);
241struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
242					const char *hostname,
243					const size_t hostname_len);
244void		  nlmsvc_release_host(struct nlm_host *);
245struct rpc_clnt * nlm_bind_host(struct nlm_host *);
246void		  nlm_rebind_host(struct nlm_host *);
247struct nlm_host * nlm_get_host(struct nlm_host *);
248void		  nlm_shutdown_hosts(void);
249void		  nlm_shutdown_hosts_net(struct net *net);
250void		  nlm_host_rebooted(const struct net *net,
251					const struct nlm_reboot *);
252
253/*
254 * Host monitoring
255 */
256int		  nsm_monitor(const struct nlm_host *host);
257void		  nsm_unmonitor(const struct nlm_host *host);
258
259struct nsm_handle *nsm_get_handle(const struct net *net,
260					const struct sockaddr *sap,
261					const size_t salen,
262					const char *hostname,
263					const size_t hostname_len);
264struct nsm_handle *nsm_reboot_lookup(const struct net *net,
265					const struct nlm_reboot *info);
266void		  nsm_release(struct nsm_handle *nsm);
267
268/*
269 * This is used in garbage collection and resource reclaim
270 * A return value != 0 means destroy the lock/block/share
271 */
272typedef int	  (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
273
274/*
275 * Server-side lock handling
276 */
277int		  lock_to_openmode(struct file_lock *);
278__be32		  nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
279			      struct nlm_host *, struct nlm_lock *, int,
280			      struct nlm_cookie *, int);
281__be32		  nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
282__be32		  nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
283			struct nlm_host *host, struct nlm_lock *lock,
284			struct nlm_lock *conflock);
285__be32		  nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
286void		  nlmsvc_retry_blocked(struct svc_rqst *rqstp);
287void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
288					nlm_host_match_fn_t match);
289void		  nlmsvc_grant_reply(struct nlm_cookie *, __be32);
290void		  nlmsvc_release_call(struct nlm_rqst *);
291void		  nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
292
293/*
294 * File handling for the server personality
295 */
296__be32		  nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
297					struct nlm_lock *);
298void		  nlm_release_file(struct nlm_file *);
299void		  nlmsvc_put_lockowner(struct nlm_lockowner *);
300void		  nlmsvc_release_lockowner(struct nlm_lock *);
301void		  nlmsvc_mark_resources(struct net *);
302void		  nlmsvc_free_host_resources(struct nlm_host *);
303void		  nlmsvc_invalidate_all(void);
304
305/*
306 * Cluster failover support
307 */
308int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
309int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
310
311static inline struct file *nlmsvc_file_file(const struct nlm_file *file)
312{
313	return file->f_file[O_RDONLY] ?
314	       file->f_file[O_RDONLY] : file->f_file[O_WRONLY];
315}
316
317static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
318{
319	return file_inode(nlmsvc_file_file(file));
320}
321
322static inline bool
323nlmsvc_file_cannot_lock(const struct nlm_file *file)
324{
325	return exportfs_cannot_lock(nlmsvc_file_file(file)->f_path.dentry->d_sb->s_export_op);
326}
327
328static inline int __nlm_privileged_request4(const struct sockaddr *sap)
329{
330	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
331
332	if (ntohs(sin->sin_port) > 1023)
333		return 0;
334
335	return ipv4_is_loopback(sin->sin_addr.s_addr);
336}
337
338#if IS_ENABLED(CONFIG_IPV6)
339static inline int __nlm_privileged_request6(const struct sockaddr *sap)
340{
341	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
342
343	if (ntohs(sin6->sin6_port) > 1023)
344		return 0;
345
346	if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
347		return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
348
349	return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
350}
351#else	/* IS_ENABLED(CONFIG_IPV6) */
352static inline int __nlm_privileged_request6(const struct sockaddr *sap)
353{
354	return 0;
355}
356#endif	/* IS_ENABLED(CONFIG_IPV6) */
357
358/*
359 * Ensure incoming requests are from local privileged callers.
360 *
361 * Return TRUE if sender is local and is connecting via a privileged port;
362 * otherwise return FALSE.
363 */
364static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
365{
366	const struct sockaddr *sap = svc_addr(rqstp);
367
368	switch (sap->sa_family) {
369	case AF_INET:
370		return __nlm_privileged_request4(sap);
371	case AF_INET6:
372		return __nlm_privileged_request6(sap);
373	default:
374		return 0;
375	}
376}
377
378/*
379 * Compare two NLM locks.
380 * When the second lock is of type F_UNLCK, this acts like a wildcard.
381 */
382static inline int nlm_compare_locks(const struct file_lock *fl1,
383				    const struct file_lock *fl2)
384{
385	return file_inode(fl1->c.flc_file) == file_inode(fl2->c.flc_file)
386	     && fl1->c.flc_pid   == fl2->c.flc_pid
387	     && fl1->c.flc_owner == fl2->c.flc_owner
388	     && fl1->fl_start == fl2->fl_start
389	     && fl1->fl_end   == fl2->fl_end
390	     &&(fl1->c.flc_type  == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK);
391}
392
393extern const struct lock_manager_operations nlmsvc_lock_operations;
394
395#endif /* LINUX_LOCKD_LOCKD_H */