internal.h revision f70e2e06196ad4c1c762037da2f75354f6c16b81
1/* internal.h: 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
18static inline __attribute__((format(printf, 1, 2)))
19void no_printk(const char *fmt, ...)
20{
21}
22
23#ifdef __KDEBUG
24#define kenter(FMT, ...) \
25	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
26#define kleave(FMT, ...) \
27	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
28#define kdebug(FMT, ...) \
29	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
30#else
31#define kenter(FMT, ...) \
32	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
33#define kleave(FMT, ...) \
34	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
35#define kdebug(FMT, ...) \
36	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
37#endif
38
39extern struct key_type key_type_user;
40
41/*****************************************************************************/
42/*
43 * keep track of keys for a user
44 * - this needs to be separate to user_struct to avoid a refcount-loop
45 *   (user_struct pins some keyrings which pin this struct)
46 * - this also keeps track of keys under request from userspace for this UID
47 */
48struct key_user {
49	struct rb_node		node;
50	struct mutex		cons_lock;	/* construction initiation lock */
51	spinlock_t		lock;
52	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
53	atomic_t		nkeys;		/* number of keys */
54	atomic_t		nikeys;		/* number of instantiated keys */
55	uid_t			uid;
56	struct user_namespace	*user_ns;
57	int			qnkeys;		/* number of keys allocated to this user */
58	int			qnbytes;	/* number of bytes allocated to this user */
59};
60
61extern struct rb_root	key_user_tree;
62extern spinlock_t	key_user_lock;
63extern struct key_user	root_key_user;
64
65extern struct key_user *key_user_lookup(uid_t uid,
66					struct user_namespace *user_ns);
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 rb_root key_serial_tree;
82extern spinlock_t key_serial_lock;
83extern struct mutex key_construction_mutex;
84extern wait_queue_head_t request_key_conswq;
85
86
87extern struct key_type *key_type_lookup(const char *type);
88extern void key_type_put(struct key_type *ktype);
89
90extern int __key_link_begin(struct key *keyring,
91			    const struct key_type *type,
92			    const char *description,
93			    struct keyring_list **_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		       struct keyring_list **_prealloc);
97extern void __key_link_end(struct key *keyring,
98			   struct key_type *type,
99			   struct keyring_list *prealloc);
100
101extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
102				      const struct key_type *type,
103				      const char *description,
104				      key_perm_t perm);
105
106extern struct key *keyring_search_instkey(struct key *keyring,
107					  key_serial_t target_id);
108
109typedef int (*key_match_func_t)(const struct key *, const void *);
110
111extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
112				    const struct cred *cred,
113				    struct key_type *type,
114				    const void *description,
115				    key_match_func_t match);
116
117extern key_ref_t search_process_keyrings(struct key_type *type,
118					 const void *description,
119					 key_match_func_t match,
120					 const struct cred *cred);
121
122extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
123
124extern int install_user_keyrings(void);
125extern int install_thread_keyring_to_cred(struct cred *);
126extern int install_process_keyring_to_cred(struct cred *);
127
128extern struct key *request_key_and_link(struct key_type *type,
129					const char *description,
130					const void *callout_info,
131					size_t callout_len,
132					void *aux,
133					struct key *dest_keyring,
134					unsigned long flags);
135
136extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
137				 key_perm_t perm);
138#define KEY_LOOKUP_CREATE	0x01
139#define KEY_LOOKUP_PARTIAL	0x02
140#define KEY_LOOKUP_FOR_UNLINK	0x04
141
142extern long join_session_keyring(const char *name);
143
144extern unsigned key_gc_delay;
145extern void keyring_gc(struct key *keyring, time_t limit);
146extern void key_schedule_gc(time_t expiry_at);
147
148/*
149 * check to see whether permission is granted to use a key in the desired way
150 */
151extern int key_task_permission(const key_ref_t key_ref,
152			       const struct cred *cred,
153			       key_perm_t perm);
154
155static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
156{
157	return key_task_permission(key_ref, current_cred(), perm);
158}
159
160/* required permissions */
161#define	KEY_VIEW	0x01	/* require permission to view attributes */
162#define	KEY_READ	0x02	/* require permission to read content */
163#define	KEY_WRITE	0x04	/* require permission to update / modify */
164#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
165#define	KEY_LINK	0x10	/* require permission to link */
166#define	KEY_SETATTR	0x20	/* require permission to change attributes */
167#define	KEY_ALL		0x3f	/* all the above permissions */
168
169/*
170 * request_key authorisation
171 */
172struct request_key_auth {
173	struct key		*target_key;
174	struct key		*dest_keyring;
175	const struct cred	*cred;
176	void			*callout_info;
177	size_t			callout_len;
178	pid_t			pid;
179};
180
181extern struct key_type key_type_request_key_auth;
182extern struct key *request_key_auth_new(struct key *target,
183					const void *callout_info,
184					size_t callout_len,
185					struct key *dest_keyring);
186
187extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
188
189/*
190 * keyctl functions
191 */
192extern long keyctl_get_keyring_ID(key_serial_t, int);
193extern long keyctl_join_session_keyring(const char __user *);
194extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
195extern long keyctl_revoke_key(key_serial_t);
196extern long keyctl_keyring_clear(key_serial_t);
197extern long keyctl_keyring_link(key_serial_t, key_serial_t);
198extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
199extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
200extern long keyctl_keyring_search(key_serial_t, const char __user *,
201				  const char __user *, key_serial_t);
202extern long keyctl_read_key(key_serial_t, char __user *, size_t);
203extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
204extern long keyctl_setperm_key(key_serial_t, key_perm_t);
205extern long keyctl_instantiate_key(key_serial_t, const void __user *,
206				   size_t, key_serial_t);
207extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
208extern long keyctl_set_reqkey_keyring(int);
209extern long keyctl_set_timeout(key_serial_t, unsigned);
210extern long keyctl_assume_authority(key_serial_t);
211extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
212				size_t buflen);
213extern long keyctl_session_to_parent(void);
214
215/*
216 * debugging key validation
217 */
218#ifdef KEY_DEBUGGING
219extern void __key_check(const struct key *);
220
221static inline void key_check(const struct key *key)
222{
223	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
224		__key_check(key);
225}
226
227#else
228
229#define key_check(key) do {} while(0)
230
231#endif
232
233#endif /* _INTERNAL_H */
234