internal.h revision 8bbf4976b59fc9fc2861e79cab7beb3f6d647640 
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/key-type.h>
16
17static inline __attribute__((format(printf, 1, 2)))
18void no_printk(const char *fmt, ...)
19{
20}
21
22#ifdef __KDEBUG
23#define kenter(FMT, ...) \
24	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
25#define kleave(FMT, ...) \
26	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
27#define kdebug(FMT, ...) \
28	printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
29#else
30#define kenter(FMT, ...) \
31	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
32#define kleave(FMT, ...) \
33	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
34#define kdebug(FMT, ...) \
35	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
36#endif
37
38extern struct key_type key_type_user;
39
40/*****************************************************************************/
41/*
42 * keep track of keys for a user
43 * - this needs to be separate to user_struct to avoid a refcount-loop
44 *   (user_struct pins some keyrings which pin this struct)
45 * - this also keeps track of keys under request from userspace for this UID
46 */
47struct key_user {
48	struct rb_node		node;
49	struct mutex		cons_lock;	/* construction initiation lock */
50	spinlock_t		lock;
51	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
52	atomic_t		nkeys;		/* number of keys */
53	atomic_t		nikeys;		/* number of instantiated keys */
54	uid_t			uid;
55	int			qnkeys;		/* number of keys allocated to this user */
56	int			qnbytes;	/* number of bytes allocated to this user */
57};
58
59extern struct rb_root	key_user_tree;
60extern spinlock_t	key_user_lock;
61extern struct key_user	root_key_user;
62
63extern struct key_user *key_user_lookup(uid_t uid);
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(struct key *keyring, struct key *key);
88
89extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
90				      const struct key_type *type,
91				      const char *description,
92				      key_perm_t perm);
93
94extern struct key *keyring_search_instkey(struct key *keyring,
95					  key_serial_t target_id);
96
97typedef int (*key_match_func_t)(const struct key *, const void *);
98
99extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
100				    struct task_struct *tsk,
101				    struct key_type *type,
102				    const void *description,
103				    key_match_func_t match);
104
105extern key_ref_t search_process_keyrings(struct key_type *type,
106					 const void *description,
107					 key_match_func_t match,
108					 struct task_struct *tsk);
109
110extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
111
112extern int install_user_keyrings(void);
113extern int install_thread_keyring(void);
114extern int install_process_keyring(void);
115
116extern struct key *request_key_and_link(struct key_type *type,
117					const char *description,
118					const void *callout_info,
119					size_t callout_len,
120					void *aux,
121					struct key *dest_keyring,
122					unsigned long flags);
123
124extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
125				 key_perm_t perm);
126
127extern long join_session_keyring(const char *name);
128
129/*
130 * check to see whether permission is granted to use a key in the desired way
131 */
132extern int key_task_permission(const key_ref_t key_ref,
133			       struct task_struct *context,
134			       key_perm_t perm);
135
136static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
137{
138	return key_task_permission(key_ref, current, perm);
139}
140
141/* required permissions */
142#define	KEY_VIEW	0x01	/* require permission to view attributes */
143#define	KEY_READ	0x02	/* require permission to read content */
144#define	KEY_WRITE	0x04	/* require permission to update / modify */
145#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
146#define	KEY_LINK	0x10	/* require permission to link */
147#define	KEY_SETATTR	0x20	/* require permission to change attributes */
148#define	KEY_ALL		0x3f	/* all the above permissions */
149
150/*
151 * request_key authorisation
152 */
153struct request_key_auth {
154	struct key		*target_key;
155	struct key		*dest_keyring;
156	struct task_struct	*context;
157	void			*callout_info;
158	size_t			callout_len;
159	pid_t			pid;
160};
161
162extern struct key_type key_type_request_key_auth;
163extern struct key *request_key_auth_new(struct key *target,
164					const void *callout_info,
165					size_t callout_len,
166					struct key *dest_keyring);
167
168extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
169
170/*
171 * keyctl functions
172 */
173extern long keyctl_get_keyring_ID(key_serial_t, int);
174extern long keyctl_join_session_keyring(const char __user *);
175extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
176extern long keyctl_revoke_key(key_serial_t);
177extern long keyctl_keyring_clear(key_serial_t);
178extern long keyctl_keyring_link(key_serial_t, key_serial_t);
179extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
180extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
181extern long keyctl_keyring_search(key_serial_t, const char __user *,
182				  const char __user *, key_serial_t);
183extern long keyctl_read_key(key_serial_t, char __user *, size_t);
184extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
185extern long keyctl_setperm_key(key_serial_t, key_perm_t);
186extern long keyctl_instantiate_key(key_serial_t, const void __user *,
187				   size_t, key_serial_t);
188extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
189extern long keyctl_set_reqkey_keyring(int);
190extern long keyctl_set_timeout(key_serial_t, unsigned);
191extern long keyctl_assume_authority(key_serial_t);
192extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
193				size_t buflen);
194
195/*
196 * debugging key validation
197 */
198#ifdef KEY_DEBUGGING
199extern void __key_check(const struct key *);
200
201static inline void key_check(const struct key *key)
202{
203	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
204		__key_check(key);
205}
206
207#else
208
209#define key_check(key) do {} while(0)
210
211#endif
212
213#endif /* _INTERNAL_H */
214