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 */
102 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
103 {
104 return (struct sockaddr *)&host->h_addr;
105 }
106
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(struct svc_rqst *rqstp);
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
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
316 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
317 {
318 return file_inode(nlmsvc_file_file(file));
319 }
320
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)
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) */
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 */
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 */
375 static inline int nlm_compare_locks(const struct file_lock *fl1,
376 const struct file_lock *fl2)
377 {
378 return file_inode(fl1->c.flc_file) == file_inode(fl2->c.flc_file)
379 && fl1->c.flc_pid == fl2->c.flc_pid
380 && fl1->c.flc_owner == fl2->c.flc_owner
381 && fl1->fl_start == fl2->fl_start
382 && fl1->fl_end == fl2->fl_end
383 &&(fl1->c.flc_type == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK);
384 }
385
386 extern const struct lock_manager_operations nlmsvc_lock_operations;
387
388 #endif /* LINUX_LOCKD_LOCKD_H */
389
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