1 /*
2 * linux/include/linux/lockd/lockd.h
3 *
4 * General-purpose lockd include file.
5 *
6 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
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 };
72
73 /*
74 * The largest string sm_addrbuf should hold is a full-size IPv6 address
75 * (no "::" anywhere) with a scope ID. The buffer size is computed to
76 * hold eight groups of colon-separated four-hex-digit numbers, a
77 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
78 */
79 #define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1)
80
81 struct nsm_handle {
82 struct list_head sm_link;
83 atomic_t sm_count;
84 char *sm_mon_name;
85 char *sm_name;
86 struct sockaddr_storage sm_addr;
87 size_t sm_addrlen;
88 unsigned int sm_monitored : 1,
89 sm_sticky : 1; /* don't unmonitor */
90 struct nsm_private sm_priv;
91 char sm_addrbuf[NSM_ADDRBUF];
92 };
93
94 /*
95 * Rigorous type checking on sockaddr type conversions
96 */
97 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
98 {
99 return (struct sockaddr_in *)&host->h_addr;
100 }
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_in *nlm_srcaddr_in(const struct nlm_host *host)
108 {
109 return (struct sockaddr_in *)&host->h_srcaddr;
110 }
111
112 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
113 {
114 return (struct sockaddr *)&host->h_srcaddr;
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 cache_deferred_req * b_deferred_req;
182 unsigned int b_flags; /* block flags */
183 #define B_QUEUED 1 /* lock queued */
184 #define B_GOT_CALLBACK 2 /* got lock or conflicting lock */
185 #define B_TIMED_OUT 4 /* filesystem too slow to respond */
186 };
187
188 /*
189 * Global variables
190 */
191 extern const struct rpc_program nlm_program;
192 extern struct svc_procedure nlmsvc_procedures[];
193 #ifdef CONFIG_LOCKD_V4
194 extern struct svc_procedure nlmsvc_procedures4[];
195 #endif
196 extern int nlmsvc_grace_period;
197 extern unsigned long nlmsvc_timeout;
198 extern bool nsm_use_hostnames;
199 extern u32 nsm_local_state;
200
201 /*
202 * Lockd client functions
203 */
204 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
205 int nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
206 int nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
207 void nlmclnt_release_call(struct nlm_rqst *);
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 struct nlm_rqst *);
216 void nlmclnt_next_cookie(struct nlm_cookie *);
217
218 /*
219 * Host cache
220 */
221 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
222 const size_t salen,
223 const unsigned short protocol,
224 const u32 version,
225 const char *hostname,
226 int noresvport,
227 struct net *net);
228 void nlmclnt_release_host(struct nlm_host *);
229 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
230 const char *hostname,
231 const size_t hostname_len);
232 void nlmsvc_release_host(struct nlm_host *);
233 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
234 void nlm_rebind_host(struct nlm_host *);
235 struct nlm_host * nlm_get_host(struct nlm_host *);
236 void nlm_shutdown_hosts(void);
237 void nlm_shutdown_hosts_net(struct net *net);
238 void nlm_host_rebooted(const struct nlm_reboot *);
239
240 /*
241 * Host monitoring
242 */
243 int nsm_monitor(const struct nlm_host *host);
244 void nsm_unmonitor(const struct nlm_host *host);
245
246 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
247 const size_t salen,
248 const char *hostname,
249 const size_t hostname_len);
250 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
251 void nsm_release(struct nsm_handle *nsm);
252
253 /*
254 * This is used in garbage collection and resource reclaim
255 * A return value != 0 means destroy the lock/block/share
256 */
257 typedef int (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
258
259 /*
260 * Server-side lock handling
261 */
262 __be32 nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
263 struct nlm_host *, struct nlm_lock *, int,
264 struct nlm_cookie *, int);
265 __be32 nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
266 __be32 nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
267 struct nlm_host *, struct nlm_lock *,
268 struct nlm_lock *, struct nlm_cookie *);
269 __be32 nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
270 unsigned long nlmsvc_retry_blocked(void);
271 void nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
272 nlm_host_match_fn_t match);
273 void nlmsvc_grant_reply(struct nlm_cookie *, __be32);
274 void nlmsvc_release_call(struct nlm_rqst *);
275
276 /*
277 * File handling for the server personality
278 */
279 __be32 nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
280 struct nfs_fh *);
281 void nlm_release_file(struct nlm_file *);
282 void nlmsvc_mark_resources(struct net *);
283 void nlmsvc_free_host_resources(struct nlm_host *);
284 void nlmsvc_invalidate_all(void);
285
286 /*
287 * Cluster failover support
288 */
289 int nlmsvc_unlock_all_by_sb(struct super_block *sb);
290 int nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
291
292 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
293 {
294 return file_inode(file->f_file);
295 }
296
297 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
298 {
299 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
300
301 if (ntohs(sin->sin_port) > 1023)
302 return 0;
303
304 return ipv4_is_loopback(sin->sin_addr.s_addr);
305 }
306
307 #if IS_ENABLED(CONFIG_IPV6)
308 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
309 {
310 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
311
312 if (ntohs(sin6->sin6_port) > 1023)
313 return 0;
314
315 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
316 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
317
318 return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
319 }
320 #else /* IS_ENABLED(CONFIG_IPV6) */
321 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
322 {
323 return 0;
324 }
325 #endif /* IS_ENABLED(CONFIG_IPV6) */
326
327 /*
328 * Ensure incoming requests are from local privileged callers.
329 *
330 * Return TRUE if sender is local and is connecting via a privileged port;
331 * otherwise return FALSE.
332 */
333 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
334 {
335 const struct sockaddr *sap = svc_addr(rqstp);
336
337 switch (sap->sa_family) {
338 case AF_INET:
339 return __nlm_privileged_request4(sap);
340 case AF_INET6:
341 return __nlm_privileged_request6(sap);
342 default:
343 return 0;
344 }
345 }
346
347 /*
348 * Compare two NLM locks.
349 * When the second lock is of type F_UNLCK, this acts like a wildcard.
350 */
351 static inline int nlm_compare_locks(const struct file_lock *fl1,
352 const struct file_lock *fl2)
353 {
354 return fl1->fl_pid == fl2->fl_pid
355 && fl1->fl_owner == fl2->fl_owner
356 && fl1->fl_start == fl2->fl_start
357 && fl1->fl_end == fl2->fl_end
358 &&(fl1->fl_type == fl2->fl_type || fl2->fl_type == F_UNLCK);
359 }
360
361 extern const struct lock_manager_operations nlmsvc_lock_operations;
362
363 #endif /* __KERNEL__ */
364
365 #endif /* LINUX_LOCKD_LOCKD_H */
366
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