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 #ifdef __KERNEL__
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 char nodename[UNX_MAXNODENAME + 1];
74 const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
75 };
76
77 /*
78 * The largest string sm_addrbuf should hold is a full-size IPv6 address
79 * (no "::" anywhere) with a scope ID. The buffer size is computed to
80 * hold eight groups of colon-separated four-hex-digit numbers, a
81 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
82 */
83 #define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1)
84
85 struct nsm_handle {
86 struct list_head sm_link;
87 refcount_t sm_count;
88 char *sm_mon_name;
89 char *sm_name;
90 struct sockaddr_storage sm_addr;
91 size_t sm_addrlen;
92 unsigned int sm_monitored : 1,
93 sm_sticky : 1; /* don't unmonitor */
94 struct nsm_private sm_priv;
95 char sm_addrbuf[NSM_ADDRBUF];
96 };
97
98 /*
99 * Rigorous type checking on sockaddr type conversions
100 */
nlm_addr_in(const struct nlm_host * host)101 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
102 {
103 return (struct sockaddr_in *)&host->h_addr;
104 }
105
nlm_addr(const struct nlm_host * host)106 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
107 {
108 return (struct sockaddr *)&host->h_addr;
109 }
110
nlm_srcaddr_in(const struct nlm_host * host)111 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
112 {
113 return (struct sockaddr_in *)&host->h_srcaddr;
114 }
115
nlm_srcaddr(const struct nlm_host * host)116 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
117 {
118 return (struct sockaddr *)&host->h_srcaddr;
119 }
120
121 /*
122 * Map an fl_owner_t into a unique 32-bit "pid"
123 */
124 struct nlm_lockowner {
125 struct list_head list;
126 refcount_t count;
127
128 struct nlm_host *host;
129 fl_owner_t owner;
130 uint32_t pid;
131 };
132
133 struct nlm_wait;
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; /* VFS file pointer */
159 struct nlm_share * f_shares; /* DOS shares */
160 struct list_head f_blocks; /* blocked locks */
161 unsigned int f_locks; /* guesstimate # of locks */
162 unsigned int f_count; /* reference count */
163 struct mutex f_mutex; /* avoid concurrent access */
164 };
165
166 /*
167 * This is a server block (i.e. a lock requested by some client which
168 * couldn't be granted because of a conflicting lock).
169 */
170 #define NLM_NEVER (~(unsigned long) 0)
171 /* timeout on non-blocking call: */
172 #define NLM_TIMEOUT (7 * HZ)
173
174 struct nlm_block {
175 struct kref b_count; /* Reference count */
176 struct list_head b_list; /* linked list of all blocks */
177 struct list_head b_flist; /* linked list (per file) */
178 struct nlm_rqst * b_call; /* RPC args & callback info */
179 struct svc_serv * b_daemon; /* NLM service */
180 struct nlm_host * b_host; /* host handle for RPC clnt */
181 unsigned long b_when; /* next re-xmit */
182 unsigned int b_id; /* block id */
183 unsigned char b_granted; /* VFS granted lock */
184 struct nlm_file * b_file; /* file in question */
185 struct cache_req * b_cache_req; /* deferred request handling */
186 struct cache_deferred_req * b_deferred_req;
187 unsigned int b_flags; /* block flags */
188 #define B_QUEUED 1 /* lock queued */
189 #define B_GOT_CALLBACK 2 /* got lock or conflicting lock */
190 #define B_TIMED_OUT 4 /* filesystem too slow to respond */
191 };
192
193 /*
194 * Global variables
195 */
196 extern const struct rpc_program nlm_program;
197 extern const struct svc_procedure nlmsvc_procedures[];
198 #ifdef CONFIG_LOCKD_V4
199 extern const struct svc_procedure nlmsvc_procedures4[];
200 #endif
201 extern int nlmsvc_grace_period;
202 extern unsigned long nlmsvc_timeout;
203 extern bool nsm_use_hostnames;
204 extern u32 nsm_local_state;
205
206 /*
207 * Lockd client functions
208 */
209 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
210 int nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
211 int nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
212 void nlmclnt_release_call(struct nlm_rqst *);
213 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
214 void nlmclnt_finish_block(struct nlm_wait *block);
215 int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
216 __be32 nlmclnt_grant(const struct sockaddr *addr,
217 const struct nlm_lock *lock);
218 void nlmclnt_recovery(struct nlm_host *);
219 int nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
220 struct nlm_rqst *);
221 void nlmclnt_next_cookie(struct nlm_cookie *);
222
223 /*
224 * Host cache
225 */
226 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
227 const size_t salen,
228 const unsigned short protocol,
229 const u32 version,
230 const char *hostname,
231 int noresvport,
232 struct net *net);
233 void nlmclnt_release_host(struct nlm_host *);
234 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
235 const char *hostname,
236 const size_t hostname_len);
237 void nlmsvc_release_host(struct nlm_host *);
238 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
239 void nlm_rebind_host(struct nlm_host *);
240 struct nlm_host * nlm_get_host(struct nlm_host *);
241 void nlm_shutdown_hosts(void);
242 void nlm_shutdown_hosts_net(struct net *net);
243 void nlm_host_rebooted(const struct net *net,
244 const struct nlm_reboot *);
245
246 /*
247 * Host monitoring
248 */
249 int nsm_monitor(const struct nlm_host *host);
250 void nsm_unmonitor(const struct nlm_host *host);
251
252 struct nsm_handle *nsm_get_handle(const struct net *net,
253 const struct sockaddr *sap,
254 const size_t salen,
255 const char *hostname,
256 const size_t hostname_len);
257 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
258 const struct nlm_reboot *info);
259 void nsm_release(struct nsm_handle *nsm);
260
261 /*
262 * This is used in garbage collection and resource reclaim
263 * A return value != 0 means destroy the lock/block/share
264 */
265 typedef int (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
266
267 /*
268 * Server-side lock handling
269 */
270 __be32 nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
271 struct nlm_host *, struct nlm_lock *, int,
272 struct nlm_cookie *, int);
273 __be32 nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
274 __be32 nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
275 struct nlm_host *, struct nlm_lock *,
276 struct nlm_lock *, struct nlm_cookie *);
277 __be32 nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
278 unsigned long nlmsvc_retry_blocked(void);
279 void nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
280 nlm_host_match_fn_t match);
281 void nlmsvc_grant_reply(struct nlm_cookie *, __be32);
282 void nlmsvc_release_call(struct nlm_rqst *);
283
284 /*
285 * File handling for the server personality
286 */
287 __be32 nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
288 struct nfs_fh *);
289 void nlm_release_file(struct nlm_file *);
290 void nlmsvc_mark_resources(struct net *);
291 void nlmsvc_free_host_resources(struct nlm_host *);
292 void nlmsvc_invalidate_all(void);
293
294 /*
295 * Cluster failover support
296 */
297 int nlmsvc_unlock_all_by_sb(struct super_block *sb);
298 int nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
299
nlmsvc_file_inode(struct nlm_file * file)300 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
301 {
302 return locks_inode(file->f_file);
303 }
304
__nlm_privileged_request4(const struct sockaddr * sap)305 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
306 {
307 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
308
309 if (ntohs(sin->sin_port) > 1023)
310 return 0;
311
312 return ipv4_is_loopback(sin->sin_addr.s_addr);
313 }
314
315 #if IS_ENABLED(CONFIG_IPV6)
__nlm_privileged_request6(const struct sockaddr * sap)316 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
317 {
318 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
319
320 if (ntohs(sin6->sin6_port) > 1023)
321 return 0;
322
323 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
324 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
325
326 return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
327 }
328 #else /* IS_ENABLED(CONFIG_IPV6) */
__nlm_privileged_request6(const struct sockaddr * sap)329 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
330 {
331 return 0;
332 }
333 #endif /* IS_ENABLED(CONFIG_IPV6) */
334
335 /*
336 * Ensure incoming requests are from local privileged callers.
337 *
338 * Return TRUE if sender is local and is connecting via a privileged port;
339 * otherwise return FALSE.
340 */
nlm_privileged_requester(const struct svc_rqst * rqstp)341 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
342 {
343 const struct sockaddr *sap = svc_addr(rqstp);
344
345 switch (sap->sa_family) {
346 case AF_INET:
347 return __nlm_privileged_request4(sap);
348 case AF_INET6:
349 return __nlm_privileged_request6(sap);
350 default:
351 return 0;
352 }
353 }
354
355 /*
356 * Compare two NLM locks.
357 * When the second lock is of type F_UNLCK, this acts like a wildcard.
358 */
nlm_compare_locks(const struct file_lock * fl1,const struct file_lock * fl2)359 static inline int nlm_compare_locks(const struct file_lock *fl1,
360 const struct file_lock *fl2)
361 {
362 return locks_inode(fl1->fl_file) == locks_inode(fl2->fl_file)
363 && fl1->fl_pid == fl2->fl_pid
364 && fl1->fl_owner == fl2->fl_owner
365 && fl1->fl_start == fl2->fl_start
366 && fl1->fl_end == fl2->fl_end
367 &&(fl1->fl_type == fl2->fl_type || fl2->fl_type == F_UNLCK);
368 }
369
370 extern const struct lock_manager_operations nlmsvc_lock_operations;
371
372 #endif /* __KERNEL__ */
373
374 #endif /* LINUX_LOCKD_LOCKD_H */
375