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_inode(struct nlm_file * file)306 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
307 {
308 return locks_inode(file->f_file[O_RDONLY] ?
309 file->f_file[O_RDONLY] : file->f_file[O_WRONLY]);
310 }
311
__nlm_privileged_request4(const struct sockaddr * sap)312 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
313 {
314 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
315
316 if (ntohs(sin->sin_port) > 1023)
317 return 0;
318
319 return ipv4_is_loopback(sin->sin_addr.s_addr);
320 }
321
322 #if IS_ENABLED(CONFIG_IPV6)
__nlm_privileged_request6(const struct sockaddr * sap)323 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
324 {
325 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
326
327 if (ntohs(sin6->sin6_port) > 1023)
328 return 0;
329
330 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
331 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
332
333 return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
334 }
335 #else /* IS_ENABLED(CONFIG_IPV6) */
__nlm_privileged_request6(const struct sockaddr * sap)336 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
337 {
338 return 0;
339 }
340 #endif /* IS_ENABLED(CONFIG_IPV6) */
341
342 /*
343 * Ensure incoming requests are from local privileged callers.
344 *
345 * Return TRUE if sender is local and is connecting via a privileged port;
346 * otherwise return FALSE.
347 */
nlm_privileged_requester(const struct svc_rqst * rqstp)348 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
349 {
350 const struct sockaddr *sap = svc_addr(rqstp);
351
352 switch (sap->sa_family) {
353 case AF_INET:
354 return __nlm_privileged_request4(sap);
355 case AF_INET6:
356 return __nlm_privileged_request6(sap);
357 default:
358 return 0;
359 }
360 }
361
362 /*
363 * Compare two NLM locks.
364 * When the second lock is of type F_UNLCK, this acts like a wildcard.
365 */
nlm_compare_locks(const struct file_lock * fl1,const struct file_lock * fl2)366 static inline int nlm_compare_locks(const struct file_lock *fl1,
367 const struct file_lock *fl2)
368 {
369 return locks_inode(fl1->fl_file) == locks_inode(fl2->fl_file)
370 && fl1->fl_pid == fl2->fl_pid
371 && fl1->fl_owner == fl2->fl_owner
372 && fl1->fl_start == fl2->fl_start
373 && fl1->fl_end == fl2->fl_end
374 &&(fl1->fl_type == fl2->fl_type || fl2->fl_type == F_UNLCK);
375 }
376
377 extern const struct lock_manager_operations nlmsvc_lock_operations;
378
379 #endif /* LINUX_LOCKD_LOCKD_H */
380
