internal.h revision ceb73c12047b8d543570b23353e7848eb7c540a1 
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
18#ifdef __KDEBUG
19#define kenter(FMT, ...) \
20	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
21#define kleave(FMT, ...) \
22	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
23#define kdebug(FMT, ...) \
24	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
25#else
26#define kenter(FMT, ...) \
27	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
28#define kleave(FMT, ...) \
29	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
30#define kdebug(FMT, ...) \
31	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
32#endif
33
34extern struct key_type key_type_user;
35
36/*****************************************************************************/
37/*
38 * Keep track of keys for a user.
39 *
40 * This needs to be separate to user_struct to avoid a refcount-loop
41 * (user_struct pins some keyrings which pin this struct).
42 *
43 * We also keep track of keys under request from userspace for this UID here.
44 */
45struct key_user {
46	struct rb_node		node;
47	struct mutex		cons_lock;	/* construction initiation lock */
48	spinlock_t		lock;
49	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
50	atomic_t		nkeys;		/* number of keys */
51	atomic_t		nikeys;		/* number of instantiated keys */
52	uid_t			uid;
53	struct user_namespace	*user_ns;
54	int			qnkeys;		/* number of keys allocated to this user */
55	int			qnbytes;	/* number of bytes allocated to this user */
56};
57
58extern struct rb_root	key_user_tree;
59extern spinlock_t	key_user_lock;
60extern struct key_user	root_key_user;
61
62extern struct key_user *key_user_lookup(uid_t uid,
63					struct user_namespace *user_ns);
64extern void key_user_put(struct key_user *user);
65
66/*
67 * Key quota limits.
68 * - root has its own separate limits to everyone else
69 */
70extern unsigned key_quota_root_maxkeys;
71extern unsigned key_quota_root_maxbytes;
72extern unsigned key_quota_maxkeys;
73extern unsigned key_quota_maxbytes;
74
75#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
76
77
78extern struct rb_root key_serial_tree;
79extern spinlock_t key_serial_lock;
80extern struct mutex key_construction_mutex;
81extern wait_queue_head_t request_key_conswq;
82
83
84extern struct key_type *key_type_lookup(const char *type);
85extern void key_type_put(struct key_type *ktype);
86
87extern int __key_link_begin(struct key *keyring,
88			    const struct key_type *type,
89			    const char *description,
90			    unsigned long *_prealloc);
91extern int __key_link_check_live_key(struct key *keyring, struct key *key);
92extern void __key_link(struct key *keyring, struct key *key,
93		       unsigned long *_prealloc);
94extern void __key_link_end(struct key *keyring,
95			   struct key_type *type,
96			   unsigned long prealloc);
97
98extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
99				      const struct key_type *type,
100				      const char *description,
101				      key_perm_t perm);
102
103extern struct key *keyring_search_instkey(struct key *keyring,
104					  key_serial_t target_id);
105
106typedef int (*key_match_func_t)(const struct key *, const void *);
107
108extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
109				    const struct cred *cred,
110				    struct key_type *type,
111				    const void *description,
112				    key_match_func_t match);
113
114extern key_ref_t search_my_process_keyrings(struct key_type *type,
115					    const void *description,
116					    key_match_func_t match,
117					    const struct cred *cred);
118extern key_ref_t search_process_keyrings(struct key_type *type,
119					 const void *description,
120					 key_match_func_t match,
121					 const struct cred *cred);
122
123extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
124
125extern int install_user_keyrings(void);
126extern int install_thread_keyring_to_cred(struct cred *);
127extern int install_process_keyring_to_cred(struct cred *);
128extern int install_session_keyring_to_cred(struct cred *, struct key *);
129
130extern struct key *request_key_and_link(struct key_type *type,
131					const char *description,
132					const void *callout_info,
133					size_t callout_len,
134					void *aux,
135					struct key *dest_keyring,
136					unsigned long flags);
137
138extern int lookup_user_key_possessed(const struct key *key, const void *target);
139extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
140				 key_perm_t perm);
141#define KEY_LOOKUP_CREATE	0x01
142#define KEY_LOOKUP_PARTIAL	0x02
143#define KEY_LOOKUP_FOR_UNLINK	0x04
144
145extern long join_session_keyring(const char *name);
146
147extern unsigned key_gc_delay;
148extern void keyring_gc(struct key *keyring, time_t limit);
149extern void key_schedule_gc(time_t expiry_at);
150
151extern int key_task_permission(const key_ref_t key_ref,
152			       const struct cred *cred,
153			       key_perm_t perm);
154
155/*
156 * Check to see whether permission is granted to use a key in the desired way.
157 */
158static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
159{
160	return key_task_permission(key_ref, current_cred(), perm);
161}
162
163/* required permissions */
164#define	KEY_VIEW	0x01	/* require permission to view attributes */
165#define	KEY_READ	0x02	/* require permission to read content */
166#define	KEY_WRITE	0x04	/* require permission to update / modify */
167#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
168#define	KEY_LINK	0x10	/* require permission to link */
169#define	KEY_SETATTR	0x20	/* require permission to change attributes */
170#define	KEY_ALL		0x3f	/* all the above permissions */
171
172/*
173 * Authorisation record for request_key().
174 */
175struct request_key_auth {
176	struct key		*target_key;
177	struct key		*dest_keyring;
178	const struct cred	*cred;
179	void			*callout_info;
180	size_t			callout_len;
181	pid_t			pid;
182};
183
184extern struct key_type key_type_request_key_auth;
185extern struct key *request_key_auth_new(struct key *target,
186					const void *callout_info,
187					size_t callout_len,
188					struct key *dest_keyring);
189
190extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
191
192/*
193 * keyctl() functions
194 */
195extern long keyctl_get_keyring_ID(key_serial_t, int);
196extern long keyctl_join_session_keyring(const char __user *);
197extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
198extern long keyctl_revoke_key(key_serial_t);
199extern long keyctl_keyring_clear(key_serial_t);
200extern long keyctl_keyring_link(key_serial_t, key_serial_t);
201extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
202extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
203extern long keyctl_keyring_search(key_serial_t, const char __user *,
204				  const char __user *, key_serial_t);
205extern long keyctl_read_key(key_serial_t, char __user *, size_t);
206extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
207extern long keyctl_setperm_key(key_serial_t, key_perm_t);
208extern long keyctl_instantiate_key(key_serial_t, const void __user *,
209				   size_t, key_serial_t);
210extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
211extern long keyctl_set_reqkey_keyring(int);
212extern long keyctl_set_timeout(key_serial_t, unsigned);
213extern long keyctl_assume_authority(key_serial_t);
214extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
215				size_t buflen);
216extern long keyctl_session_to_parent(void);
217
218/*
219 * Debugging key validation
220 */
221#ifdef KEY_DEBUGGING
222extern void __key_check(const struct key *);
223
224static inline void key_check(const struct key *key)
225{
226	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
227		__key_check(key);
228}
229
230#else
231
232#define key_check(key) do {} while(0)
233
234#endif
235
236#endif /* _INTERNAL_H */
237