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Diffstat (limited to 'kernel/include/linux/key-type.h')
-rw-r--r-- | kernel/include/linux/key-type.h | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/kernel/include/linux/key-type.h b/kernel/include/linux/key-type.h new file mode 100644 index 000000000..ff9f1d394 --- /dev/null +++ b/kernel/include/linux/key-type.h @@ -0,0 +1,186 @@ +/* Definitions for key type implementations + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _LINUX_KEY_TYPE_H +#define _LINUX_KEY_TYPE_H + +#include <linux/key.h> +#include <linux/errno.h> + +#ifdef CONFIG_KEYS + +/* + * key under-construction record + * - passed to the request_key actor if supplied + */ +struct key_construction { + struct key *key; /* key being constructed */ + struct key *authkey;/* authorisation for key being constructed */ +}; + +/* + * Pre-parsed payload, used by key add, update and instantiate. + * + * This struct will be cleared and data and datalen will be set with the data + * and length parameters from the caller and quotalen will be set from + * def_datalen from the key type. Then if the preparse() op is provided by the + * key type, that will be called. Then the struct will be passed to the + * instantiate() or the update() op. + * + * If the preparse() op is given, the free_preparse() op will be called to + * clear the contents. + */ +struct key_preparsed_payload { + char *description; /* Proposed key description (or NULL) */ + void *type_data[2]; /* Private key-type data */ + void *payload[2]; /* Proposed payload */ + const void *data; /* Raw data */ + size_t datalen; /* Raw datalen */ + size_t quotalen; /* Quota length for proposed payload */ + time_t expiry; /* Expiry time of key */ + bool trusted; /* True if key is trusted */ +}; + +typedef int (*request_key_actor_t)(struct key_construction *key, + const char *op, void *aux); + +/* + * Preparsed matching criterion. + */ +struct key_match_data { + /* Comparison function, defaults to exact description match, but can be + * overridden by type->match_preparse(). Should return true if a match + * is found and false if not. + */ + bool (*cmp)(const struct key *key, + const struct key_match_data *match_data); + + const void *raw_data; /* Raw match data */ + void *preparsed; /* For ->match_preparse() to stash stuff */ + unsigned lookup_type; /* Type of lookup for this search. */ +#define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */ +#define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */ +}; + +/* + * kernel managed key type definition + */ +struct key_type { + /* name of the type */ + const char *name; + + /* default payload length for quota precalculation (optional) + * - this can be used instead of calling key_payload_reserve(), that + * function only needs to be called if the real datalen is different + */ + size_t def_datalen; + + /* vet a description */ + int (*vet_description)(const char *description); + + /* Preparse the data blob from userspace that is to be the payload, + * generating a proposed description and payload that will be handed to + * the instantiate() and update() ops. + */ + int (*preparse)(struct key_preparsed_payload *prep); + + /* Free a preparse data structure. + */ + void (*free_preparse)(struct key_preparsed_payload *prep); + + /* instantiate a key of this type + * - this method should call key_payload_reserve() to determine if the + * user's quota will hold the payload + */ + int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); + + /* update a key of this type (optional) + * - this method should call key_payload_reserve() to recalculate the + * quota consumption + * - the key must be locked against read when modifying + */ + int (*update)(struct key *key, struct key_preparsed_payload *prep); + + /* Preparse the data supplied to ->match() (optional). The + * data to be preparsed can be found in match_data->raw_data. + * The lookup type can also be set by this function. + */ + int (*match_preparse)(struct key_match_data *match_data); + + /* Free preparsed match data (optional). This should be supplied it + * ->match_preparse() is supplied. */ + void (*match_free)(struct key_match_data *match_data); + + /* clear some of the data from a key on revokation (optional) + * - the key's semaphore will be write-locked by the caller + */ + void (*revoke)(struct key *key); + + /* clear the data from a key (optional) */ + void (*destroy)(struct key *key); + + /* describe a key */ + void (*describe)(const struct key *key, struct seq_file *p); + + /* read a key's data (optional) + * - permission checks will be done by the caller + * - the key's semaphore will be readlocked by the caller + * - should return the amount of data that could be read, no matter how + * much is copied into the buffer + * - shouldn't do the copy if the buffer is NULL + */ + long (*read)(const struct key *key, char __user *buffer, size_t buflen); + + /* handle request_key() for this type instead of invoking + * /sbin/request-key (optional) + * - key is the key to instantiate + * - authkey is the authority to assume when instantiating this key + * - op is the operation to be done, usually "create" + * - the call must not return until the instantiation process has run + * its course + */ + request_key_actor_t request_key; + + /* internal fields */ + struct list_head link; /* link in types list */ + struct lock_class_key lock_class; /* key->sem lock class */ +}; + +extern struct key_type key_type_keyring; + +extern int register_key_type(struct key_type *ktype); +extern void unregister_key_type(struct key_type *ktype); + +extern int key_payload_reserve(struct key *key, size_t datalen); +extern int key_instantiate_and_link(struct key *key, + const void *data, + size_t datalen, + struct key *keyring, + struct key *instkey); +extern int key_reject_and_link(struct key *key, + unsigned timeout, + unsigned error, + struct key *keyring, + struct key *instkey); +extern void complete_request_key(struct key_construction *cons, int error); + +static inline int key_negate_and_link(struct key *key, + unsigned timeout, + struct key *keyring, + struct key *instkey) +{ + return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); +} + +extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep); + +#endif /* CONFIG_KEYS */ +#endif /* _LINUX_KEY_TYPE_H */ |