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 #include <linux/in.h>
14 #include <linux/in6.h>
15 #include <net/ipv6.h>
16 #include <linux/fs.h>
17 #include <linux/kref.h>
18 #include <linux/refcount.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 refcount_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 const struct cred *h_cred;
72 char nodename[UNX_MAXNODENAME + 1];
73 const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
74 };
75
76 /*
77 * The largest string sm_addrbuf should hold is a full-size IPv6 address
78 * (no "::" anywhere) with a scope ID. The buffer size is computed to
79 * hold eight groups of colon-separated four-hex-digit numbers, a
80 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
81 */
82 #define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1)
83
84 struct nsm_handle {
85 struct list_head sm_link;
86 refcount_t sm_count;
87 char *sm_mon_name;
88 char *sm_name;
89 struct sockaddr_storage sm_addr;
90 size_t sm_addrlen;
91 unsigned int sm_monitored : 1,
92 sm_sticky : 1; /* don't unmonitor */
93 struct nsm_private sm_priv;
94 char sm_addrbuf[NSM_ADDRBUF];
95 };
96
97 /*
98 * Rigorous type checking on sockaddr type conversions
99 */
nlm_addr_in(const struct nlm_host * host)100 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
101 {
102 return (struct sockaddr_in *)&host->h_addr;
103 }
104
nlm_addr(const struct nlm_host * host)105 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
106 {
107 return (struct sockaddr *)&host->h_addr;
108 }
109
nlm_srcaddr_in(const struct nlm_host * host)110 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
111 {
112 return (struct sockaddr_in *)&host->h_srcaddr;
113 }
114
nlm_srcaddr(const struct nlm_host * host)115 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
116 {
117 return (struct sockaddr *)&host->h_srcaddr;
118 }
119
120 /*
121 * Map an fl_owner_t into a unique 32-bit "pid"
122 */
123 struct nlm_lockowner {
124 struct list_head list;
125 refcount_t count;
126
127 struct nlm_host *host;
128 fl_owner_t owner;
129 uint32_t pid;
130 };
131
132 struct nlm_wait;
133
134 /*
135 * Memory chunk for NLM client RPC request.
136 */
137 #define NLMCLNT_OHSIZE ((__NEW_UTS_LEN) + 10u)
138 struct nlm_rqst {
139 refcount_t a_count;
140 unsigned int a_flags; /* initial RPC task flags */
141 struct nlm_host * a_host; /* host handle */
142 struct nlm_args a_args; /* arguments */
143 struct nlm_res a_res; /* result */
144 struct nlm_block * a_block;
145 unsigned int a_retries; /* Retry count */
146 u8 a_owner[NLMCLNT_OHSIZE];
147 void * a_callback_data; /* sent to nlmclnt_operations callbacks */
148 };
149
150 /*
151 * This struct describes a file held open by lockd on behalf of
152 * an NFS client.
153 */
154 struct nlm_file {
155 struct hlist_node f_list; /* linked list */
156 struct nfs_fh f_handle; /* NFS file handle */
157 struct file * f_file; /* VFS file pointer */
158 struct nlm_share * f_shares; /* DOS shares */
159 struct list_head f_blocks; /* blocked locks */
160 unsigned int f_locks; /* guesstimate # of locks */
161 unsigned int f_count; /* reference count */
162 struct mutex f_mutex; /* avoid concurrent access */
163 };
164
165 /*
166 * This is a server block (i.e. a lock requested by some client which
167 * couldn't be granted because of a conflicting lock).
168 */
169 #define NLM_NEVER (~(unsigned long) 0)
170 /* timeout on non-blocking call: */
171 #define NLM_TIMEOUT (7 * HZ)
172
173 struct nlm_block {
174 struct kref b_count; /* Reference count */
175 struct list_head b_list; /* linked list of all blocks */
176 struct list_head b_flist; /* linked list (per file) */
177 struct nlm_rqst * b_call; /* RPC args & callback info */
178 struct svc_serv * b_daemon; /* NLM service */
179 struct nlm_host * b_host; /* host handle for RPC clnt */
180 unsigned long b_when; /* next re-xmit */
181 unsigned int b_id; /* block id */
182 unsigned char b_granted; /* VFS granted lock */
183 struct nlm_file * b_file; /* file in question */
184 struct cache_req * b_cache_req; /* deferred request handling */
185 struct cache_deferred_req * b_deferred_req;
186 unsigned int b_flags; /* block flags */
187 #define B_QUEUED 1 /* lock queued */
188 #define B_GOT_CALLBACK 2 /* got lock or conflicting lock */
189 #define B_TIMED_OUT 4 /* filesystem too slow to respond */
190 };
191
192 /*
193 * Global variables
194 */
195 extern const struct rpc_program nlm_program;
196 extern const struct svc_procedure nlmsvc_procedures[];
197 #ifdef CONFIG_LOCKD_V4
198 extern const struct svc_procedure nlmsvc_procedures4[];
199 #endif
200 extern int nlmsvc_grace_period;
201 extern unsigned long nlmsvc_timeout;
202 extern bool nsm_use_hostnames;
203 extern u32 nsm_local_state;
204
205 /*
206 * Lockd client functions
207 */
208 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
209 int nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
210 int nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
211 void nlmclnt_release_call(struct nlm_rqst *);
212 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
213 void nlmclnt_finish_block(struct nlm_wait *block);
214 int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
215 __be32 nlmclnt_grant(const struct sockaddr *addr,
216 const struct nlm_lock *lock);
217 void nlmclnt_recovery(struct nlm_host *);
218 int nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
219 struct nlm_rqst *);
220 void nlmclnt_next_cookie(struct nlm_cookie *);
221
222 /*
223 * Host cache
224 */
225 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
226 const size_t salen,
227 const unsigned short protocol,
228 const u32 version,
229 const char *hostname,
230 int noresvport,
231 struct net *net,
232 const struct cred *cred);
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 void nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
284
285 /*
286 * File handling for the server personality
287 */
288 __be32 nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
289 struct nfs_fh *);
290 void nlm_release_file(struct nlm_file *);
291 void nlmsvc_release_lockowner(struct nlm_lock *);
292 void nlmsvc_mark_resources(struct net *);
293 void nlmsvc_free_host_resources(struct nlm_host *);
294 void nlmsvc_invalidate_all(void);
295
296 /*
297 * Cluster failover support
298 */
299 int nlmsvc_unlock_all_by_sb(struct super_block *sb);
300 int nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
301
nlmsvc_file_inode(struct nlm_file * file)302 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
303 {
304 return locks_inode(file->f_file);
305 }
306
__nlm_privileged_request4(const struct sockaddr * sap)307 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
308 {
309 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
310
311 if (ntohs(sin->sin_port) > 1023)
312 return 0;
313
314 return ipv4_is_loopback(sin->sin_addr.s_addr);
315 }
316
317 #if IS_ENABLED(CONFIG_IPV6)
__nlm_privileged_request6(const struct sockaddr * sap)318 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
319 {
320 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
321
322 if (ntohs(sin6->sin6_port) > 1023)
323 return 0;
324
325 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
326 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
327
328 return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
329 }
330 #else /* IS_ENABLED(CONFIG_IPV6) */
__nlm_privileged_request6(const struct sockaddr * sap)331 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
332 {
333 return 0;
334 }
335 #endif /* IS_ENABLED(CONFIG_IPV6) */
336
337 /*
338 * Ensure incoming requests are from local privileged callers.
339 *
340 * Return TRUE if sender is local and is connecting via a privileged port;
341 * otherwise return FALSE.
342 */
nlm_privileged_requester(const struct svc_rqst * rqstp)343 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
344 {
345 const struct sockaddr *sap = svc_addr(rqstp);
346
347 switch (sap->sa_family) {
348 case AF_INET:
349 return __nlm_privileged_request4(sap);
350 case AF_INET6:
351 return __nlm_privileged_request6(sap);
352 default:
353 return 0;
354 }
355 }
356
357 /*
358 * Compare two NLM locks.
359 * When the second lock is of type F_UNLCK, this acts like a wildcard.
360 */
nlm_compare_locks(const struct file_lock * fl1,const struct file_lock * fl2)361 static inline int nlm_compare_locks(const struct file_lock *fl1,
362 const struct file_lock *fl2)
363 {
364 return locks_inode(fl1->fl_file) == locks_inode(fl2->fl_file)
365 && fl1->fl_pid == fl2->fl_pid
366 && fl1->fl_owner == fl2->fl_owner
367 && fl1->fl_start == fl2->fl_start
368 && fl1->fl_end == fl2->fl_end
369 &&(fl1->fl_type == fl2->fl_type || fl2->fl_type == F_UNLCK);
370 }
371
372 extern const struct lock_manager_operations nlmsvc_lock_operations;
373
374 #endif /* LINUX_LOCKD_LOCKD_H */
375