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internal.h
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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 ([email protected])
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 #include <linux/task_work.h>
18 
19 #ifdef __KDEBUG
20 #define kenter(FMT, ...) \
21  printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
22 #define kleave(FMT, ...) \
23  printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
24 #define kdebug(FMT, ...) \
25  printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__)
26 #else
27 #define kenter(FMT, ...) \
28  no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
29 #define kleave(FMT, ...) \
30  no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
31 #define kdebug(FMT, ...) \
32  no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
33 #endif
34 
35 extern struct key_type key_type_dead;
36 extern struct key_type key_type_user;
37 extern struct key_type key_type_logon;
38 
39 /*****************************************************************************/
40 /*
41  * Keep track of keys for a user.
42  *
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  *
46  * We also keep track of keys under request from userspace for this UID here.
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  kuid_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(kuid_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 kmem_cache *key_jar;
80 extern struct rb_root key_serial_tree;
81 extern spinlock_t key_serial_lock;
82 extern struct mutex key_construction_mutex;
83 extern wait_queue_head_t request_key_conswq;
84 
85 
86 extern struct key_type *key_type_lookup(const char *type);
87 extern void key_type_put(struct key_type *ktype);
88 
89 extern int __key_link_begin(struct key *keyring,
90  const struct key_type *type,
91  const char *description,
92  unsigned long *_prealloc);
93 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
94 extern void __key_link(struct key *keyring, struct key *key,
95  unsigned long *_prealloc);
96 extern void __key_link_end(struct key *keyring,
97  struct key_type *type,
98  unsigned long prealloc);
99 
100 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
101  const struct key_type *type,
102  const char *description,
103  key_perm_t perm);
104 
105 extern struct key *keyring_search_instkey(struct key *keyring,
106  key_serial_t target_id);
107 
108 typedef int (*key_match_func_t)(const struct key *, const void *);
109 
110 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
111  const struct cred *cred,
112  struct key_type *type,
113  const void *description,
114  key_match_func_t match,
115  bool no_state_check);
116 
117 extern key_ref_t search_my_process_keyrings(struct key_type *type,
118  const void *description,
119  key_match_func_t match,
120  bool no_state_check,
121  const struct cred *cred);
122 extern key_ref_t search_process_keyrings(struct key_type *type,
123  const void *description,
124  key_match_func_t match,
125  const struct cred *cred);
126 
127 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
128 
129 extern int install_user_keyrings(void);
130 extern int install_thread_keyring_to_cred(struct cred *);
131 extern int install_process_keyring_to_cred(struct cred *);
132 extern int install_session_keyring_to_cred(struct cred *, struct key *);
133 
134 extern struct key *request_key_and_link(struct key_type *type,
135  const char *description,
136  const void *callout_info,
137  size_t callout_len,
138  void *aux,
139  struct key *dest_keyring,
140  unsigned long flags);
141 
142 extern int lookup_user_key_possessed(const struct key *key, const void *target);
143 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
144  key_perm_t perm);
145 #define KEY_LOOKUP_CREATE 0x01
146 #define KEY_LOOKUP_PARTIAL 0x02
147 #define KEY_LOOKUP_FOR_UNLINK 0x04
148 
149 extern long join_session_keyring(const char *name);
150 extern void key_change_session_keyring(struct callback_head *twork);
151 
152 extern struct work_struct key_gc_work;
153 extern unsigned key_gc_delay;
154 extern void keyring_gc(struct key *keyring, time_t limit);
155 extern void key_schedule_gc(time_t gc_at);
156 extern void key_schedule_gc_links(void);
157 extern void key_gc_keytype(struct key_type *ktype);
158 
159 extern int key_task_permission(const key_ref_t key_ref,
160  const struct cred *cred,
161  key_perm_t perm);
162 
163 /*
164  * Check to see whether permission is granted to use a key in the desired way.
165  */
166 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
167 {
168  return key_task_permission(key_ref, current_cred(), perm);
169 }
170 
171 /* required permissions */
172 #define KEY_VIEW 0x01 /* require permission to view attributes */
173 #define KEY_READ 0x02 /* require permission to read content */
174 #define KEY_WRITE 0x04 /* require permission to update / modify */
175 #define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */
176 #define KEY_LINK 0x10 /* require permission to link */
177 #define KEY_SETATTR 0x20 /* require permission to change attributes */
178 #define KEY_ALL 0x3f /* all the above permissions */
179 
180 /*
181  * Authorisation record for request_key().
182  */
183 struct request_key_auth {
184  struct key *target_key;
185  struct key *dest_keyring;
186  const struct cred *cred;
187  void *callout_info;
188  size_t callout_len;
189  pid_t pid;
190 };
191 
192 extern struct key_type key_type_request_key_auth;
193 extern struct key *request_key_auth_new(struct key *target,
194  const void *callout_info,
195  size_t callout_len,
196  struct key *dest_keyring);
197 
198 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
199 
200 /*
201  * Determine whether a key is dead.
202  */
203 static inline bool key_is_dead(struct key *key, time_t limit)
204 {
205  return
206  key->flags & ((1 << KEY_FLAG_DEAD) |
207  (1 << KEY_FLAG_INVALIDATED)) ||
208  (key->expiry > 0 && key->expiry <= limit);
209 }
210 
211 /*
212  * keyctl() functions
213  */
214 extern long keyctl_get_keyring_ID(key_serial_t, int);
215 extern long keyctl_join_session_keyring(const char __user *);
216 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
217 extern long keyctl_revoke_key(key_serial_t);
218 extern long keyctl_keyring_clear(key_serial_t);
219 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
220 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
221 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
222 extern long keyctl_keyring_search(key_serial_t, const char __user *,
223  const char __user *, key_serial_t);
224 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
225 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
226 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
227 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
228  size_t, key_serial_t);
229 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
230 extern long keyctl_set_reqkey_keyring(int);
231 extern long keyctl_set_timeout(key_serial_t, unsigned);
232 extern long keyctl_assume_authority(key_serial_t);
233 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
234  size_t buflen);
235 extern long keyctl_session_to_parent(void);
236 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
237 extern long keyctl_instantiate_key_iov(key_serial_t,
238  const struct iovec __user *,
239  unsigned, key_serial_t);
240 extern long keyctl_invalidate_key(key_serial_t);
241 
242 extern long keyctl_instantiate_key_common(key_serial_t,
243  const struct iovec *,
244  unsigned, size_t, key_serial_t);
245 
246 /*
247  * Debugging key validation
248  */
249 #ifdef KEY_DEBUGGING
250 extern void __key_check(const struct key *);
251 
252 static inline void key_check(const struct key *key)
253 {
254  if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
255  __key_check(key);
256 }
257 
258 #else
259 
260 #define key_check(key) do {} while(0)
261 
262 #endif
263 
264 #endif /* _INTERNAL_H */
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