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 static inline __attribute__((format(printf, 1, 2)))
no_printk(const char * fmt,...)19 void 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
39 extern 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 */
48 struct 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 int qnkeys; /* number of keys allocated to this user */
57 int qnbytes; /* number of bytes allocated to this user */
58 };
59
60 extern struct rb_root key_user_tree;
61 extern spinlock_t key_user_lock;
62 extern struct key_user root_key_user;
63
64 extern struct key_user *key_user_lookup(uid_t uid);
65 extern void key_user_put(struct key_user *user);
66
67 /*
68 * key quota limits
69 * - root has its own separate limits to everyone else
70 */
71 extern unsigned key_quota_root_maxkeys;
72 extern unsigned key_quota_root_maxbytes;
73 extern unsigned key_quota_maxkeys;
74 extern unsigned key_quota_maxbytes;
75
76 #define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */
77
78
79 extern struct rb_root key_serial_tree;
80 extern spinlock_t key_serial_lock;
81 extern struct mutex key_construction_mutex;
82 extern wait_queue_head_t request_key_conswq;
83
84
85 extern struct key_type *key_type_lookup(const char *type);
86 extern void key_type_put(struct key_type *ktype);
87
88 extern int __key_link(struct key *keyring, struct key *key);
89
90 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
91 const struct key_type *type,
92 const char *description,
93 key_perm_t perm);
94
95 extern struct key *keyring_search_instkey(struct key *keyring,
96 key_serial_t target_id);
97
98 typedef int (*key_match_func_t)(const struct key *, const void *);
99
100 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
101 const struct cred *cred,
102 struct key_type *type,
103 const void *description,
104 key_match_func_t match);
105
106 extern key_ref_t search_process_keyrings(struct key_type *type,
107 const void *description,
108 key_match_func_t match,
109 const struct cred *cred);
110
111 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
112
113 extern int install_user_keyrings(void);
114 extern int install_thread_keyring_to_cred(struct cred *);
115 extern int install_process_keyring_to_cred(struct cred *);
116
117 extern struct key *request_key_and_link(struct key_type *type,
118 const char *description,
119 const void *callout_info,
120 size_t callout_len,
121 void *aux,
122 struct key *dest_keyring,
123 unsigned long flags);
124
125 extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
126 key_perm_t perm);
127
128 extern long join_session_keyring(const char *name);
129
130 /*
131 * check to see whether permission is granted to use a key in the desired way
132 */
133 extern int key_task_permission(const key_ref_t key_ref,
134 const struct cred *cred,
135 key_perm_t perm);
136
key_permission(const key_ref_t key_ref,key_perm_t perm)137 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
138 {
139 return key_task_permission(key_ref, current_cred(), perm);
140 }
141
142 /* required permissions */
143 #define KEY_VIEW 0x01 /* require permission to view attributes */
144 #define KEY_READ 0x02 /* require permission to read content */
145 #define KEY_WRITE 0x04 /* require permission to update / modify */
146 #define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */
147 #define KEY_LINK 0x10 /* require permission to link */
148 #define KEY_SETATTR 0x20 /* require permission to change attributes */
149 #define KEY_ALL 0x3f /* all the above permissions */
150
151 /*
152 * request_key authorisation
153 */
154 struct request_key_auth {
155 struct key *target_key;
156 struct key *dest_keyring;
157 const struct cred *cred;
158 void *callout_info;
159 size_t callout_len;
160 pid_t pid;
161 };
162
163 extern struct key_type key_type_request_key_auth;
164 extern struct key *request_key_auth_new(struct key *target,
165 const void *callout_info,
166 size_t callout_len,
167 struct key *dest_keyring);
168
169 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
170
171 /*
172 * keyctl functions
173 */
174 extern long keyctl_get_keyring_ID(key_serial_t, int);
175 extern long keyctl_join_session_keyring(const char __user *);
176 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
177 extern long keyctl_revoke_key(key_serial_t);
178 extern long keyctl_keyring_clear(key_serial_t);
179 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
180 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
181 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
182 extern long keyctl_keyring_search(key_serial_t, const char __user *,
183 const char __user *, key_serial_t);
184 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
185 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
186 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
187 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
188 size_t, key_serial_t);
189 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
190 extern long keyctl_set_reqkey_keyring(int);
191 extern long keyctl_set_timeout(key_serial_t, unsigned);
192 extern long keyctl_assume_authority(key_serial_t);
193 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
194 size_t buflen);
195
196 /*
197 * debugging key validation
198 */
199 #ifdef KEY_DEBUGGING
200 extern void __key_check(const struct key *);
201
key_check(const struct key * key)202 static inline void key_check(const struct key *key)
203 {
204 if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
205 __key_check(key);
206 }
207
208 #else
209
210 #define key_check(key) do {} while(0)
211
212 #endif
213
214 #endif /* _INTERNAL_H */
215