root/security/keys/internal.h

INCLUDED FROM

DEFINITIONS

1. no_printk
2. key_check

/* internal.h: authentication token and access key management internal defs
 *
 * Copyright (C) 2003-5, 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 License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#ifndef _INTERNAL_H
#define _INTERNAL_H

#include <linux/key-type.h>
#include <linux/key-ui.h>

static inline __attribute__((format(printf, 1, 2)))
void no_printk(const char *fmt, ...)
{
}

#ifdef __KDEBUG
#define kenter(FMT, ...) \
        printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) \
        printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
        printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
#else
#define kenter(FMT, ...) \
        no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) \
        no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
        no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
#endif

extern struct key_type key_type_user;

/*****************************************************************************/
/*
 * keep track of keys for a user
 * - this needs to be separate to user_struct to avoid a refcount-loop
 *   (user_struct pins some keyrings which pin this struct)
 * - this also keeps track of keys under request from userspace for this UID
 */
struct key_user {
        struct rb_node          node;
        struct mutex            cons_lock;      /* construction initiation lock */
        spinlock_t              lock;
        atomic_t                usage;          /* for accessing qnkeys & qnbytes */
        atomic_t                nkeys;          /* number of keys */
        atomic_t                nikeys;         /* number of instantiated keys */
        uid_t                   uid;
        int                     qnkeys;         /* number of keys allocated to this user */
        int                     qnbytes;        /* number of bytes allocated to this user */
};

extern struct rb_root   key_user_tree;
extern spinlock_t       key_user_lock;
extern struct key_user  root_key_user;

extern struct key_user *key_user_lookup(uid_t uid);
extern void key_user_put(struct key_user *user);

/*
 * key quota limits
 * - root has its own separate limits to everyone else
 */
extern unsigned key_quota_root_maxkeys;
extern unsigned key_quota_root_maxbytes;
extern unsigned key_quota_maxkeys;
extern unsigned key_quota_maxbytes;

#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */


extern struct rb_root key_serial_tree;
extern spinlock_t key_serial_lock;
extern struct mutex key_construction_mutex;
extern wait_queue_head_t request_key_conswq;


extern int __key_link(struct key *keyring, struct key *key);

extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
                                      const struct key_type *type,
                                      const char *description,
                                      key_perm_t perm);

extern struct key *keyring_search_instkey(struct key *keyring,
                                          key_serial_t target_id);

typedef int (*key_match_func_t)(const struct key *, const void *);

extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
                                    struct task_struct *tsk,
                                    struct key_type *type,
                                    const void *description,
                                    key_match_func_t match);

extern key_ref_t search_process_keyrings(struct key_type *type,
                                         const void *description,
                                         key_match_func_t match,
                                         struct task_struct *tsk);

extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);

extern int install_thread_keyring(struct task_struct *tsk);
extern int install_process_keyring(struct task_struct *tsk);

extern struct key *request_key_and_link(struct key_type *type,
                                        const char *description,
                                        const void *callout_info,
                                        size_t callout_len,
                                        void *aux,
                                        struct key *dest_keyring,
                                        unsigned long flags);

/*
 * request_key authorisation
 */
struct request_key_auth {
        struct key              *target_key;
        struct task_struct      *context;
        void                    *callout_info;
        size_t                  callout_len;
        pid_t                   pid;
};

extern struct key_type key_type_request_key_auth;
extern struct key *request_key_auth_new(struct key *target,
                                        const void *callout_info,
                                        size_t callout_len);

extern struct key *key_get_instantiation_authkey(key_serial_t target_id);

/*
 * keyctl functions
 */
extern long keyctl_get_keyring_ID(key_serial_t, int);
extern long keyctl_join_session_keyring(const char __user *);
extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
extern long keyctl_revoke_key(key_serial_t);
extern long keyctl_keyring_clear(key_serial_t);
extern long keyctl_keyring_link(key_serial_t, key_serial_t);
extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
extern long keyctl_keyring_search(key_serial_t, const char __user *,
                                  const char __user *, key_serial_t);
extern long keyctl_read_key(key_serial_t, char __user *, size_t);
extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
extern long keyctl_setperm_key(key_serial_t, key_perm_t);
extern long keyctl_instantiate_key(key_serial_t, const void __user *,
                                   size_t, key_serial_t);
extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
extern long keyctl_set_reqkey_keyring(int);
extern long keyctl_set_timeout(key_serial_t, unsigned);
extern long keyctl_assume_authority(key_serial_t);
extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
                                size_t buflen);

/*
 * debugging key validation
 */
#ifdef KEY_DEBUGGING
extern void __key_check(const struct key *);

static inline void key_check(const struct key *key)
{
        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
                __key_check(key);
}

#else

#define key_check(key) do {} while(0)

#endif

#endif /* _INTERNAL_H */