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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 1996 Olaf Kirch <[email protected]>
4 */
5
6#ifndef _LOCKD_LOCKD_H
7#define _LOCKD_LOCKD_H
8
9#include <linux/exportfs.h>
10#include <linux/in.h>
11#include <linux/in6.h>
12#include <net/ipv6.h>
13#include <linux/fs.h>
14#include <linux/kref.h>
15#include <linux/refcount.h>
16#include <linux/utsname.h>
17#include "nlm.h"
18#include <linux/lockd/bind.h>
19#include "xdr.h"
20#include <linux/sunrpc/debug.h>
21#include <linux/sunrpc/svc.h>
22
23/*
24 * Enable lockd debugging.
25 * Requires CONFIG_SUNRPC_DEBUG.
26 */
27#undef ifdebug
28#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
29# define ifdebug(flag) if (unlikely(nlm_debug & NLMDBG_##flag))
30#else
31# define ifdebug(flag) if (0)
32#endif
33
34#define NLMDBG_SVC 0x0001
35#define NLMDBG_CLIENT 0x0002
36#define NLMDBG_CLNTLOCK 0x0004
37#define NLMDBG_SVCLOCK 0x0008
38#define NLMDBG_MONITOR 0x0010
39#define NLMDBG_CLNTSUBS 0x0020
40#define NLMDBG_SVCSUBS 0x0040
41#define NLMDBG_HOSTCACHE 0x0080
42#define NLMDBG_XDR 0x0100
43#define NLMDBG_ALL 0x7fff
44
45/*
46 * Version string
47 */
48#define LOCKD_VERSION "0.5"
49
50/*
51 * Default timeout for RPC calls (seconds)
52 */
53#define LOCKD_DFLT_TIMEO 10
54
55/*
56 * Number of leading bytes of nfs_fh.data that file_hash()
57 * digests when bucketing nlm_files[]. Sized for historical
58 * NFSv2 handles; nfs_fh.data must be initialized at least
59 * this far before lookup, regardless of fh.size.
60 */
61#define LOCKD_FH_HASH_SIZE 32
62
63/* error codes new to NLMv4 */
64#define nlm4_deadlock cpu_to_be32(NLM_DEADLCK)
65#define nlm4_rofs cpu_to_be32(NLM_ROFS)
66#define nlm4_stale_fh cpu_to_be32(NLM_STALE_FH)
67#define nlm4_fbig cpu_to_be32(NLM_FBIG)
68#define nlm4_failed cpu_to_be32(NLM_FAILED)
69
70/*
71 * Internal-use status codes, not to be placed on the wire.
72 * Version handlers translate these to appropriate wire values.
73 */
74#define nlm__int__drop_reply cpu_to_be32(30000)
75#define nlm__int__deadlock cpu_to_be32(30001)
76#define nlm__int__stale_fh cpu_to_be32(30002)
77#define nlm__int__failed cpu_to_be32(30003)
78
79/*
80 * Lockd host handle (used both by the client and server personality).
81 */
82struct nlm_host {
83 struct hlist_node h_hash; /* doubly linked list */
84 struct sockaddr_storage h_addr; /* peer address */
85 size_t h_addrlen;
86 struct sockaddr_storage h_srcaddr; /* our address (optional) */
87 size_t h_srcaddrlen;
88 struct rpc_clnt *h_rpcclnt; /* RPC client to talk to peer */
89 char *h_name; /* remote hostname */
90 u32 h_version; /* interface version */
91 unsigned short h_proto; /* transport proto */
92 unsigned short h_reclaiming : 1,
93 h_server : 1, /* server side, not client side */
94 h_noresvport : 1,
95 h_inuse : 1;
96 wait_queue_head_t h_gracewait; /* wait while reclaiming */
97 struct rw_semaphore h_rwsem; /* Reboot recovery lock */
98 u32 h_state; /* pseudo-state counter */
99 u32 h_nsmstate; /* true remote NSM state */
100 u32 h_pidcount; /* Pseudopids */
101 refcount_t h_count; /* reference count */
102 struct mutex h_mutex; /* mutex for pmap binding */
103 unsigned long h_nextrebind; /* next portmap call */
104 unsigned long h_expires; /* eligible for GC */
105 struct list_head h_lockowners; /* Lockowners for the client */
106 spinlock_t h_lock;
107 struct list_head h_granted; /* Locks in GRANTED state */
108 struct list_head h_reclaim; /* Locks in RECLAIM state */
109 struct nsm_handle *h_nsmhandle; /* NSM status handle */
110 char *h_addrbuf; /* address eyecatcher */
111 struct net *net; /* host net */
112 const struct cred *h_cred;
113 char nodename[UNX_MAXNODENAME + 1];
114 const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
115};
116
117/*
118 * The largest string sm_addrbuf should hold is a full-size IPv6 address
119 * (no "::" anywhere) with a scope ID. The buffer size is computed to
120 * hold eight groups of colon-separated four-hex-digit numbers, a
121 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
122 */
123#define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1)
124
125struct nsm_handle {
126 struct list_head sm_link;
127 refcount_t sm_count;
128 char *sm_mon_name;
129 char *sm_name;
130 struct sockaddr_storage sm_addr;
131 size_t sm_addrlen;
132 unsigned int sm_monitored : 1,
133 sm_sticky : 1; /* don't unmonitor */
134 struct nsm_private sm_priv;
135 char sm_addrbuf[NSM_ADDRBUF];
136};
137
138/*
139 * Rigorous type checking on sockaddr type conversions
140 */
141static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
142{
143 return (struct sockaddr *)&host->h_addr;
144}
145
146static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
147{
148 return (struct sockaddr *)&host->h_srcaddr;
149}
150
151/*
152 * Map an fl_owner_t into a unique 32-bit "pid"
153 */
154struct nlm_lockowner {
155 struct list_head list;
156 refcount_t count;
157
158 struct nlm_host *host;
159 fl_owner_t owner;
160 uint32_t pid;
161};
162
163/*
164 * This is the representation of a blocked client lock.
165 */
166struct nlm_wait {
167 struct list_head b_list; /* linked list */
168 wait_queue_head_t b_wait; /* where to wait on */
169 struct nlm_host *b_host;
170 struct file_lock *b_lock; /* local file lock */
171 __be32 b_status; /* grant callback status */
172};
173
174/*
175 * Memory chunk for NLM client RPC request.
176 */
177#define NLMCLNT_OHSIZE ((__NEW_UTS_LEN) + 10u)
178struct nlm_rqst {
179 refcount_t a_count;
180 unsigned int a_flags; /* initial RPC task flags */
181 struct nlm_host * a_host; /* host handle */
182 struct lockd_args a_args; /* arguments */
183 struct lockd_res a_res; /* result */
184 struct nlm_block * a_block;
185 unsigned int a_retries; /* Retry count */
186 u8 a_owner[NLMCLNT_OHSIZE];
187 void * a_callback_data; /* sent to nlmclnt_operations callbacks */
188};
189
190struct lockd_share;
191
192/*
193 * This struct describes a file held open by lockd on behalf of
194 * an NFS client.
195 */
196struct nlm_file {
197 struct hlist_node f_list; /* linked list */
198 struct nfs_fh f_handle; /* NFS file handle */
199 struct file * f_file[2]; /* VFS file pointers,
200 indexed by O_ flags */
201 struct lockd_share * f_shares; /* DOS shares */
202 struct list_head f_blocks; /* blocked locks */
203 unsigned int f_locks; /* guesstimate # of locks */
204 unsigned int f_count; /* reference count */
205 struct mutex f_mutex; /* avoid concurrent access */
206};
207
208/*
209 * This is a server block (i.e. a lock requested by some client which
210 * couldn't be granted because of a conflicting lock).
211 */
212#define NLM_NEVER (~(unsigned long) 0)
213/* timeout on non-blocking call: */
214#define NLM_TIMEOUT (7 * HZ)
215
216struct nlm_block {
217 struct kref b_count; /* Reference count */
218 struct list_head b_list; /* linked list of all blocks */
219 struct list_head b_flist; /* linked list (per file) */
220 struct nlm_rqst * b_call; /* RPC args & callback info */
221 struct svc_serv * b_daemon; /* NLM service */
222 struct nlm_host * b_host; /* host handle for RPC clnt */
223 unsigned long b_when; /* next re-xmit */
224 unsigned int b_id; /* block id */
225 unsigned char b_granted; /* VFS granted lock */
226 struct nlm_file * b_file; /* file in question */
227 struct cache_req * b_cache_req; /* deferred request handling */
228 struct cache_deferred_req * b_deferred_req;
229 unsigned int b_flags; /* block flags */
230#define B_QUEUED 1 /* lock queued */
231#define B_GOT_CALLBACK 2 /* got lock or conflicting lock */
232#define B_TIMED_OUT 4 /* filesystem too slow to respond */
233};
234
235/*
236 * Global variables
237 */
238extern const struct rpc_program nlm_program;
239extern const struct svc_version nlmsvc_version1;
240extern const struct svc_version nlmsvc_version3;
241#ifdef CONFIG_LOCKD_V4
242extern const struct svc_version nlmsvc_version4;
243#endif
244extern int nlmsvc_grace_period;
245extern unsigned long nlm_timeout;
246extern bool nsm_use_hostnames;
247extern u32 nsm_local_state;
248
249extern struct timer_list nlmsvc_retry;
250
251/*
252 * Lockd client functions
253 */
254struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
255int nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
256int nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
257void nlmclnt_release_call(struct nlm_rqst *);
258void nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host,
259 struct file_lock *fl);
260void nlmclnt_queue_block(struct nlm_wait *block);
261__be32 nlmclnt_dequeue_block(struct nlm_wait *block);
262int nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
263__be32 nlmclnt_grant(const struct sockaddr *addr,
264 const struct lockd_lock *lock);
265void nlmclnt_recovery(struct nlm_host *);
266int nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
267 struct nlm_rqst *);
268void nlmclnt_next_cookie(struct lockd_cookie *);
269
270#ifdef CONFIG_LOCKD_V4
271extern const struct rpc_version nlm_version4;
272#endif
273
274/*
275 * Host cache
276 */
277struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
278 const size_t salen,
279 const unsigned short protocol,
280 const u32 version,
281 const char *hostname,
282 int noresvport,
283 struct net *net,
284 const struct cred *cred);
285void nlmclnt_release_host(struct nlm_host *);
286struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
287 const char *hostname,
288 const size_t hostname_len);
289void nlmsvc_release_host(struct nlm_host *);
290struct rpc_clnt * nlm_bind_host(struct nlm_host *);
291void nlm_rebind_host(struct nlm_host *);
292struct nlm_host * nlm_get_host(struct nlm_host *);
293void nlm_shutdown_hosts(void);
294void nlm_shutdown_hosts_net(struct net *net);
295void nlm_host_rebooted(const struct net *net,
296 const struct lockd_reboot *);
297
298/*
299 * Host monitoring
300 */
301int nsm_monitor(const struct nlm_host *host);
302void nsm_unmonitor(const struct nlm_host *host);
303
304struct nsm_handle *nsm_get_handle(const struct net *net,
305 const struct sockaddr *sap,
306 const size_t salen,
307 const char *hostname,
308 const size_t hostname_len);
309struct nsm_handle *nsm_reboot_lookup(const struct net *net,
310 const struct lockd_reboot *info);
311void nsm_release(struct nsm_handle *nsm);
312
313/*
314 * This is used in garbage collection and resource reclaim
315 * A return value != 0 means destroy the lock/block/share
316 */
317typedef int (*nlm_host_match_fn_t)(void *owner, struct nlm_host *ref);
318
319/*
320 * Server-side lock handling
321 */
322int lock_to_openmode(struct file_lock *);
323__be32 nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
324 struct nlm_host *, struct lockd_lock *, int,
325 struct lockd_cookie *, int);
326__be32 nlmsvc_unlock(struct net *net, struct nlm_file *, struct lockd_lock *);
327__be32 nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
328 struct nlm_host *host, struct lockd_lock *lock,
329 struct lockd_lock *conflock);
330__be32 nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct lockd_lock *);
331void nlmsvc_retry_blocked(struct svc_rqst *rqstp);
332void nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
333 nlm_host_match_fn_t match);
334void nlmsvc_grant_reply(struct lockd_cookie *, __be32);
335void nlmsvc_release_call(struct nlm_rqst *);
336void nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
337int nlmsvc_dispatch(struct svc_rqst *rqstp);
338
339/*
340 * File handling for the server personality
341 */
342__be32 nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
343 struct lockd_lock *, int);
344void nlm_release_file(struct nlm_file *);
345void nlmsvc_put_lockowner(struct nlm_lockowner *);
346void nlmsvc_release_lockowner(struct lockd_lock *);
347void nlmsvc_mark_resources(struct net *);
348void nlmsvc_free_host_resources(struct nlm_host *);
349void nlmsvc_invalidate_all(void);
350
351static inline struct file *nlmsvc_file_file(const struct nlm_file *file)
352{
353 return file->f_file[O_RDONLY] ?
354 file->f_file[O_RDONLY] : file->f_file[O_WRONLY];
355}
356
357static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
358{
359 return file_inode(nlmsvc_file_file(file));
360}
361
362static inline bool
363nlmsvc_file_cannot_lock(const struct nlm_file *file)
364{
365 return exportfs_cannot_lock(nlmsvc_file_file(file)->f_path.dentry->d_sb->s_export_op);
366}
367
368static inline int __nlm_privileged_request4(const struct sockaddr *sap)
369{
370 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
371
372 if (ntohs(sin->sin_port) > 1023)
373 return 0;
374
375 return ipv4_is_loopback(sin->sin_addr.s_addr);
376}
377
378#if IS_ENABLED(CONFIG_IPV6)
379static inline int __nlm_privileged_request6(const struct sockaddr *sap)
380{
381 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
382
383 if (ntohs(sin6->sin6_port) > 1023)
384 return 0;
385
386 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
387 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
388
389 return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
390}
391#else /* IS_ENABLED(CONFIG_IPV6) */
392static inline int __nlm_privileged_request6(const struct sockaddr *sap)
393{
394 return 0;
395}
396#endif /* IS_ENABLED(CONFIG_IPV6) */
397
398/*
399 * Ensure incoming requests are from local privileged callers.
400 *
401 * Return TRUE if sender is local and is connecting via a privileged port;
402 * otherwise return FALSE.
403 */
404static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
405{
406 const struct sockaddr *sap = svc_addr(rqstp);
407
408 switch (sap->sa_family) {
409 case AF_INET:
410 return __nlm_privileged_request4(sap);
411 case AF_INET6:
412 return __nlm_privileged_request6(sap);
413 default:
414 return 0;
415 }
416}
417
418/*
419 * Compare two NLM locks.
420 * When the second lock is of type F_UNLCK, this acts like a wildcard.
421 */
422static inline int nlm_compare_locks(const struct file_lock *fl1,
423 const struct file_lock *fl2)
424{
425 return file_inode(fl1->c.flc_file) == file_inode(fl2->c.flc_file)
426 && fl1->c.flc_pid == fl2->c.flc_pid
427 && fl1->c.flc_owner == fl2->c.flc_owner
428 && fl1->fl_start == fl2->fl_start
429 && fl1->fl_end == fl2->fl_end
430 &&(fl1->c.flc_type == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK);
431}
432
433/**
434 * lockd_set_file_lock_range3 - set the byte range of a file_lock
435 * @fl: file_lock whose length fields are to be initialized
436 * @off: starting offset of the lock, in bytes
437 * @len: length of the byte range, in bytes, or zero
438 *
439 * NLMv3 uses a (start, length) representation for lock byte ranges,
440 * while the kernel's file_lock uses (start, end). Treat a length of
441 * zero or arithmetic overflow (end wrapping negative when the sum
442 * exceeds S32_MAX) as "lock to end of file."
443 */
444static inline void
445lockd_set_file_lock_range3(struct file_lock *fl, u32 off, u32 len)
446{
447 s32 end = off + len - 1;
448
449 fl->fl_start = off;
450 if (len == 0 || end < 0)
451 fl->fl_end = OFFSET_MAX;
452 else
453 fl->fl_end = end;
454}
455
456/**
457 * lockd_set_file_lock_range4 - set the byte range of a file_lock
458 * @fl: file_lock whose length fields are to be initialized
459 * @off: starting offset of the lock, in bytes
460 * @len: length of the byte range, in bytes, or zero
461 *
462 * The NLMv4 protocol represents lock byte ranges as (start, length),
463 * where length zero means "lock to end of file." The kernel's file_lock
464 * structure uses (start, end) representation. Convert from NLMv4 format
465 * to file_lock format, clamping the starting offset and treating
466 * arithmetic overflow as "lock to EOF."
467 */
468static inline void
469lockd_set_file_lock_range4(struct file_lock *fl, u64 off, u64 len)
470{
471 u64 clamped_off = (off > OFFSET_MAX) ? OFFSET_MAX : off;
472 s64 end = clamped_off + len - 1;
473
474 fl->fl_start = clamped_off;
475 if (len == 0 || end < 0)
476 fl->fl_end = OFFSET_MAX;
477 else
478 fl->fl_end = end;
479}
480
481extern const struct lock_manager_operations nlmsvc_lock_operations;
482
483#endif /* _LOCKD_LOCKD_H */