internal.h revision 4bdf0bc300314141e5475e145acb8b5ad846f00d 
1/* Authentication token and access key management internal defs
2 *
3 * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#ifndef _INTERNAL_H
13#define _INTERNAL_H
14
15#include <linux/sched.h>
16#include <linux/key-type.h>
17#include <linux/task_work.h>
18
19struct iovec;
20
21#ifdef __KDEBUG
22#define kenter(FMT, ...) \
23	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
24#define kleave(FMT, ...) \
25	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
26#define kdebug(FMT, ...) \
27	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
28#else
29#define kenter(FMT, ...) \
30	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
31#define kleave(FMT, ...) \
32	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
33#define kdebug(FMT, ...) \
34	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
35#endif
36
37extern struct key_type key_type_dead;
38extern struct key_type key_type_user;
39extern struct key_type key_type_logon;
40
41/*****************************************************************************/
42/*
43 * Keep track of keys for a user.
44 *
45 * This needs to be separate to user_struct to avoid a refcount-loop
46 * (user_struct pins some keyrings which pin this struct).
47 *
48 * We also keep track of keys under request from userspace for this UID here.
49 */
50struct key_user {
51	struct rb_node		node;
52	struct mutex		cons_lock;	/* construction initiation lock */
53	spinlock_t		lock;
54	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
55	atomic_t		nkeys;		/* number of keys */
56	atomic_t		nikeys;		/* number of instantiated keys */
57	kuid_t			uid;
58	int			qnkeys;		/* number of keys allocated to this user */
59	int			qnbytes;	/* number of bytes allocated to this user */
60};
61
62extern struct rb_root	key_user_tree;
63extern spinlock_t	key_user_lock;
64extern struct key_user	root_key_user;
65
66extern struct key_user *key_user_lookup(kuid_t uid);
67extern void key_user_put(struct key_user *user);
68
69/*
70 * Key quota limits.
71 * - root has its own separate limits to everyone else
72 */
73extern unsigned key_quota_root_maxkeys;
74extern unsigned key_quota_root_maxbytes;
75extern unsigned key_quota_maxkeys;
76extern unsigned key_quota_maxbytes;
77
78#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
79
80
81extern struct kmem_cache *key_jar;
82extern struct rb_root key_serial_tree;
83extern spinlock_t key_serial_lock;
84extern struct mutex key_construction_mutex;
85extern wait_queue_head_t request_key_conswq;
86
87
88extern struct key_type *key_type_lookup(const char *type);
89extern void key_type_put(struct key_type *ktype);
90
91extern int __key_link_begin(struct key *keyring,
92			    const struct keyring_index_key *index_key,
93			    unsigned long *_prealloc);
94extern int __key_link_check_live_key(struct key *keyring, struct key *key);
95extern void __key_link(struct key *keyring, struct key *key,
96		       unsigned long *_prealloc);
97extern void __key_link_end(struct key *keyring,
98			   const struct keyring_index_key *index_key,
99			   unsigned long prealloc);
100
101extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
102				      const struct keyring_index_key *index_key,
103				      key_perm_t perm);
104
105extern struct key *keyring_search_instkey(struct key *keyring,
106					  key_serial_t target_id);
107
108typedef int (*key_match_func_t)(const struct key *, const void *);
109
110struct keyring_search_context {
111	struct keyring_index_key index_key;
112	const struct cred	*cred;
113	key_match_func_t	match;
114	const void		*match_data;
115	unsigned		flags;
116#define KEYRING_SEARCH_LOOKUP_TYPE	0x0001	/* [as type->def_lookup_type] */
117#define KEYRING_SEARCH_NO_STATE_CHECK	0x0002	/* Skip state checks */
118#define KEYRING_SEARCH_DO_STATE_CHECK	0x0004	/* Override NO_STATE_CHECK */
119#define KEYRING_SEARCH_NO_UPDATE_TIME	0x0008	/* Don't update times */
120#define KEYRING_SEARCH_NO_CHECK_PERM	0x0010	/* Don't check permissions */
121#define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0020	/* Give an error on excessive depth */
122
123	/* Internal stuff */
124	int			skipped_ret;
125	bool			possessed;
126	key_ref_t		result;
127	struct timespec		now;
128};
129
130extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
131				    struct keyring_search_context *ctx);
132
133extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
134extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
135
136extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
137
138extern int install_user_keyrings(void);
139extern int install_thread_keyring_to_cred(struct cred *);
140extern int install_process_keyring_to_cred(struct cred *);
141extern int install_session_keyring_to_cred(struct cred *, struct key *);
142
143extern struct key *request_key_and_link(struct key_type *type,
144					const char *description,
145					const void *callout_info,
146					size_t callout_len,
147					void *aux,
148					struct key *dest_keyring,
149					unsigned long flags);
150
151extern int lookup_user_key_possessed(const struct key *key, const void *target);
152extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
153				 key_perm_t perm);
154#define KEY_LOOKUP_CREATE	0x01
155#define KEY_LOOKUP_PARTIAL	0x02
156#define KEY_LOOKUP_FOR_UNLINK	0x04
157
158extern long join_session_keyring(const char *name);
159extern void key_change_session_keyring(struct callback_head *twork);
160
161extern struct work_struct key_gc_work;
162extern unsigned key_gc_delay;
163extern void keyring_gc(struct key *keyring, time_t limit);
164extern void key_schedule_gc(time_t gc_at);
165extern void key_schedule_gc_links(void);
166extern void key_gc_keytype(struct key_type *ktype);
167
168extern int key_task_permission(const key_ref_t key_ref,
169			       const struct cred *cred,
170			       key_perm_t perm);
171
172/*
173 * Check to see whether permission is granted to use a key in the desired way.
174 */
175static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
176{
177	return key_task_permission(key_ref, current_cred(), perm);
178}
179
180/* required permissions */
181#define	KEY_VIEW	0x01	/* require permission to view attributes */
182#define	KEY_READ	0x02	/* require permission to read content */
183#define	KEY_WRITE	0x04	/* require permission to update / modify */
184#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
185#define	KEY_LINK	0x10	/* require permission to link */
186#define	KEY_SETATTR	0x20	/* require permission to change attributes */
187#define	KEY_ALL		0x3f	/* all the above permissions */
188
189/*
190 * Authorisation record for request_key().
191 */
192struct request_key_auth {
193	struct key		*target_key;
194	struct key		*dest_keyring;
195	const struct cred	*cred;
196	void			*callout_info;
197	size_t			callout_len;
198	pid_t			pid;
199};
200
201extern struct key_type key_type_request_key_auth;
202extern struct key *request_key_auth_new(struct key *target,
203					const void *callout_info,
204					size_t callout_len,
205					struct key *dest_keyring);
206
207extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
208
209/*
210 * Determine whether a key is dead.
211 */
212static inline bool key_is_dead(const struct key *key, time_t limit)
213{
214	return
215		key->flags & ((1 << KEY_FLAG_DEAD) |
216			      (1 << KEY_FLAG_INVALIDATED)) ||
217		(key->expiry > 0 && key->expiry <= limit);
218}
219
220/*
221 * keyctl() functions
222 */
223extern long keyctl_get_keyring_ID(key_serial_t, int);
224extern long keyctl_join_session_keyring(const char __user *);
225extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
226extern long keyctl_revoke_key(key_serial_t);
227extern long keyctl_keyring_clear(key_serial_t);
228extern long keyctl_keyring_link(key_serial_t, key_serial_t);
229extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
230extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
231extern long keyctl_keyring_search(key_serial_t, const char __user *,
232				  const char __user *, key_serial_t);
233extern long keyctl_read_key(key_serial_t, char __user *, size_t);
234extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
235extern long keyctl_setperm_key(key_serial_t, key_perm_t);
236extern long keyctl_instantiate_key(key_serial_t, const void __user *,
237				   size_t, key_serial_t);
238extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
239extern long keyctl_set_reqkey_keyring(int);
240extern long keyctl_set_timeout(key_serial_t, unsigned);
241extern long keyctl_assume_authority(key_serial_t);
242extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
243				size_t buflen);
244extern long keyctl_session_to_parent(void);
245extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
246extern long keyctl_instantiate_key_iov(key_serial_t,
247				       const struct iovec __user *,
248				       unsigned, key_serial_t);
249extern long keyctl_invalidate_key(key_serial_t);
250
251extern long keyctl_instantiate_key_common(key_serial_t,
252					  const struct iovec *,
253					  unsigned, size_t, key_serial_t);
254
255/*
256 * Debugging key validation
257 */
258#ifdef KEY_DEBUGGING
259extern void __key_check(const struct key *);
260
261static inline void key_check(const struct key *key)
262{
263	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
264		__key_check(key);
265}
266
267#else
268
269#define key_check(key) do {} while(0)
270
271#endif
272
273#endif /* _INTERNAL_H */
274