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76181c13 DH |
1 | /* Definitions for key type implementations |
2 | * | |
3 | * Copyright (C) 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 Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #ifndef _LINUX_KEY_TYPE_H | |
13 | #define _LINUX_KEY_TYPE_H | |
14 | ||
15 | #include <linux/key.h> | |
5935e6dc | 16 | #include <linux/errno.h> |
76181c13 DH |
17 | |
18 | #ifdef CONFIG_KEYS | |
19 | ||
20 | /* | |
21 | * key under-construction record | |
22 | * - passed to the request_key actor if supplied | |
23 | */ | |
24 | struct key_construction { | |
25 | struct key *key; /* key being constructed */ | |
26 | struct key *authkey;/* authorisation for key being constructed */ | |
27 | }; | |
28 | ||
cf7f601c DH |
29 | /* |
30 | * Pre-parsed payload, used by key add, update and instantiate. | |
31 | * | |
32 | * This struct will be cleared and data and datalen will be set with the data | |
33 | * and length parameters from the caller and quotalen will be set from | |
34 | * def_datalen from the key type. Then if the preparse() op is provided by the | |
35 | * key type, that will be called. Then the struct will be passed to the | |
36 | * instantiate() or the update() op. | |
37 | * | |
38 | * If the preparse() op is given, the free_preparse() op will be called to | |
39 | * clear the contents. | |
40 | */ | |
41 | struct key_preparsed_payload { | |
42 | char *description; /* Proposed key description (or NULL) */ | |
43 | void *type_data[2]; /* Private key-type data */ | |
44 | void *payload; /* Proposed payload */ | |
45 | const void *data; /* Raw data */ | |
46 | size_t datalen; /* Raw datalen */ | |
47 | size_t quotalen; /* Quota length for proposed payload */ | |
48 | }; | |
49 | ||
76181c13 DH |
50 | typedef int (*request_key_actor_t)(struct key_construction *key, |
51 | const char *op, void *aux); | |
52 | ||
53 | /* | |
54 | * kernel managed key type definition | |
55 | */ | |
56 | struct key_type { | |
57 | /* name of the type */ | |
58 | const char *name; | |
59 | ||
60 | /* default payload length for quota precalculation (optional) | |
61 | * - this can be used instead of calling key_payload_reserve(), that | |
62 | * function only needs to be called if the real datalen is different | |
63 | */ | |
64 | size_t def_datalen; | |
65 | ||
b9fffa38 DH |
66 | /* vet a description */ |
67 | int (*vet_description)(const char *description); | |
68 | ||
cf7f601c DH |
69 | /* Preparse the data blob from userspace that is to be the payload, |
70 | * generating a proposed description and payload that will be handed to | |
71 | * the instantiate() and update() ops. | |
72 | */ | |
73 | int (*preparse)(struct key_preparsed_payload *prep); | |
74 | ||
75 | /* Free a preparse data structure. | |
76 | */ | |
77 | void (*free_preparse)(struct key_preparsed_payload *prep); | |
78 | ||
76181c13 DH |
79 | /* instantiate a key of this type |
80 | * - this method should call key_payload_reserve() to determine if the | |
81 | * user's quota will hold the payload | |
82 | */ | |
cf7f601c | 83 | int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); |
76181c13 DH |
84 | |
85 | /* update a key of this type (optional) | |
86 | * - this method should call key_payload_reserve() to recalculate the | |
87 | * quota consumption | |
88 | * - the key must be locked against read when modifying | |
89 | */ | |
cf7f601c | 90 | int (*update)(struct key *key, struct key_preparsed_payload *prep); |
76181c13 DH |
91 | |
92 | /* match a key against a description */ | |
93 | int (*match)(const struct key *key, const void *desc); | |
94 | ||
95 | /* clear some of the data from a key on revokation (optional) | |
96 | * - the key's semaphore will be write-locked by the caller | |
97 | */ | |
98 | void (*revoke)(struct key *key); | |
99 | ||
100 | /* clear the data from a key (optional) */ | |
101 | void (*destroy)(struct key *key); | |
102 | ||
103 | /* describe a key */ | |
104 | void (*describe)(const struct key *key, struct seq_file *p); | |
105 | ||
106 | /* read a key's data (optional) | |
107 | * - permission checks will be done by the caller | |
108 | * - the key's semaphore will be readlocked by the caller | |
109 | * - should return the amount of data that could be read, no matter how | |
110 | * much is copied into the buffer | |
111 | * - shouldn't do the copy if the buffer is NULL | |
112 | */ | |
113 | long (*read)(const struct key *key, char __user *buffer, size_t buflen); | |
114 | ||
115 | /* handle request_key() for this type instead of invoking | |
116 | * /sbin/request-key (optional) | |
117 | * - key is the key to instantiate | |
118 | * - authkey is the authority to assume when instantiating this key | |
119 | * - op is the operation to be done, usually "create" | |
120 | * - the call must not return until the instantiation process has run | |
121 | * its course | |
122 | */ | |
123 | request_key_actor_t request_key; | |
124 | ||
125 | /* internal fields */ | |
126 | struct list_head link; /* link in types list */ | |
7845bc39 | 127 | struct lock_class_key lock_class; /* key->sem lock class */ |
76181c13 DH |
128 | }; |
129 | ||
130 | extern struct key_type key_type_keyring; | |
131 | ||
132 | extern int register_key_type(struct key_type *ktype); | |
133 | extern void unregister_key_type(struct key_type *ktype); | |
134 | ||
135 | extern int key_payload_reserve(struct key *key, size_t datalen); | |
136 | extern int key_instantiate_and_link(struct key *key, | |
137 | const void *data, | |
138 | size_t datalen, | |
139 | struct key *keyring, | |
140 | struct key *instkey); | |
fdd1b945 | 141 | extern int key_reject_and_link(struct key *key, |
76181c13 | 142 | unsigned timeout, |
fdd1b945 | 143 | unsigned error, |
76181c13 DH |
144 | struct key *keyring, |
145 | struct key *instkey); | |
146 | extern void complete_request_key(struct key_construction *cons, int error); | |
147 | ||
fdd1b945 DH |
148 | static inline int key_negate_and_link(struct key *key, |
149 | unsigned timeout, | |
150 | struct key *keyring, | |
151 | struct key *instkey) | |
152 | { | |
153 | return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); | |
154 | } | |
155 | ||
76181c13 DH |
156 | #endif /* CONFIG_KEYS */ |
157 | #endif /* _LINUX_KEY_TYPE_H */ |