internal.h revision 12fdff3fc2483f906ae6404a6e8dcf2550310b6f 
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
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 * - this needs to be separate to user_struct to avoid a refcount-loop
40 *   (user_struct pins some keyrings which pin this struct)
41 * - this also keeps track of keys under request from userspace for this UID
42 */
43struct key_user {
44	struct rb_node		node;
45	struct mutex		cons_lock;	/* construction initiation lock */
46	spinlock_t		lock;
47	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
48	atomic_t		nkeys;		/* number of keys */
49	atomic_t		nikeys;		/* number of instantiated keys */
50	uid_t			uid;
51	struct user_namespace	*user_ns;
52	int			qnkeys;		/* number of keys allocated to this user */
53	int			qnbytes;	/* number of bytes allocated to this user */
54};
55
56extern struct rb_root	key_user_tree;
57extern spinlock_t	key_user_lock;
58extern struct key_user	root_key_user;
59
60extern struct key_user *key_user_lookup(uid_t uid,
61					struct user_namespace *user_ns);
62extern void key_user_put(struct key_user *user);
63
64/*
65 * key quota limits
66 * - root has its own separate limits to everyone else
67 */
68extern unsigned key_quota_root_maxkeys;
69extern unsigned key_quota_root_maxbytes;
70extern unsigned key_quota_maxkeys;
71extern unsigned key_quota_maxbytes;
72
73#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
74
75
76extern struct rb_root key_serial_tree;
77extern spinlock_t key_serial_lock;
78extern struct mutex key_construction_mutex;
79extern wait_queue_head_t request_key_conswq;
80
81
82extern struct key_type *key_type_lookup(const char *type);
83extern void key_type_put(struct key_type *ktype);
84
85extern int __key_link_begin(struct key *keyring,
86			    const struct key_type *type,
87			    const char *description,
88			    struct keyring_list **_prealloc);
89extern int __key_link_check_live_key(struct key *keyring, struct key *key);
90extern void __key_link(struct key *keyring, struct key *key,
91		       struct keyring_list **_prealloc);
92extern void __key_link_end(struct key *keyring,
93			   struct key_type *type,
94			   struct keyring_list *prealloc);
95
96extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
97				      const struct key_type *type,
98				      const char *description,
99				      key_perm_t perm);
100
101extern struct key *keyring_search_instkey(struct key *keyring,
102					  key_serial_t target_id);
103
104typedef int (*key_match_func_t)(const struct key *, const void *);
105
106extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
107				    const struct cred *cred,
108				    struct key_type *type,
109				    const void *description,
110				    key_match_func_t match);
111
112extern key_ref_t search_my_process_keyrings(struct key_type *type,
113					    const void *description,
114					    key_match_func_t match,
115					    const struct cred *cred);
116extern key_ref_t search_process_keyrings(struct key_type *type,
117					 const void *description,
118					 key_match_func_t match,
119					 const struct cred *cred);
120
121extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
122
123extern int install_user_keyrings(void);
124extern int install_thread_keyring_to_cred(struct cred *);
125extern int install_process_keyring_to_cred(struct cred *);
126extern int install_session_keyring_to_cred(struct cred *, struct key *);
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 int lookup_user_key_possessed(const struct key *key, const void *target);
137extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
138				 key_perm_t perm);
139#define KEY_LOOKUP_CREATE	0x01
140#define KEY_LOOKUP_PARTIAL	0x02
141#define KEY_LOOKUP_FOR_UNLINK	0x04
142
143extern long join_session_keyring(const char *name);
144
145extern unsigned key_gc_delay;
146extern void keyring_gc(struct key *keyring, time_t limit);
147extern void key_schedule_gc(time_t expiry_at);
148
149/*
150 * check to see whether permission is granted to use a key in the desired way
151 */
152extern int key_task_permission(const key_ref_t key_ref,
153			       const struct cred *cred,
154			       key_perm_t perm);
155
156static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
157{
158	return key_task_permission(key_ref, current_cred(), perm);
159}
160
161/* required permissions */
162#define	KEY_VIEW	0x01	/* require permission to view attributes */
163#define	KEY_READ	0x02	/* require permission to read content */
164#define	KEY_WRITE	0x04	/* require permission to update / modify */
165#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
166#define	KEY_LINK	0x10	/* require permission to link */
167#define	KEY_SETATTR	0x20	/* require permission to change attributes */
168#define	KEY_ALL		0x3f	/* all the above permissions */
169
170/*
171 * request_key authorisation
172 */
173struct request_key_auth {
174	struct key		*target_key;
175	struct key		*dest_keyring;
176	const struct cred	*cred;
177	void			*callout_info;
178	size_t			callout_len;
179	pid_t			pid;
180};
181
182extern struct key_type key_type_request_key_auth;
183extern struct key *request_key_auth_new(struct key *target,
184					const void *callout_info,
185					size_t callout_len,
186					struct key *dest_keyring);
187
188extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
189
190/*
191 * keyctl functions
192 */
193extern long keyctl_get_keyring_ID(key_serial_t, int);
194extern long keyctl_join_session_keyring(const char __user *);
195extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
196extern long keyctl_revoke_key(key_serial_t);
197extern long keyctl_keyring_clear(key_serial_t);
198extern long keyctl_keyring_link(key_serial_t, key_serial_t);
199extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
200extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
201extern long keyctl_keyring_search(key_serial_t, const char __user *,
202				  const char __user *, key_serial_t);
203extern long keyctl_read_key(key_serial_t, char __user *, size_t);
204extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
205extern long keyctl_setperm_key(key_serial_t, key_perm_t);
206extern long keyctl_instantiate_key(key_serial_t, const void __user *,
207				   size_t, key_serial_t);
208extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
209extern long keyctl_set_reqkey_keyring(int);
210extern long keyctl_set_timeout(key_serial_t, unsigned);
211extern long keyctl_assume_authority(key_serial_t);
212extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
213				size_t buflen);
214extern long keyctl_session_to_parent(void);
215
216/*
217 * debugging key validation
218 */
219#ifdef KEY_DEBUGGING
220extern void __key_check(const struct key *);
221
222static inline void key_check(const struct key *key)
223{
224	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
225		__key_check(key);
226}
227
228#else
229
230#define key_check(key) do {} while(0)
231
232#endif
233
234#endif /* _INTERNAL_H */
235