/* 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/sched.h>
  #include <linux/key-type.h>
  #include <linux/task_work.h>
  
  struct iovec;
  
  #ifdef __KDEBUG
  #define kenter(FMT, ...) \
  	printk(KERN_DEBUG "==> %s("FMT")
  ", __func__, ##__VA_ARGS__)
  #define kleave(FMT, ...) \
  	printk(KERN_DEBUG "<== %s()"FMT"
  ", __func__, ##__VA_ARGS__)
  #define kdebug(FMT, ...) \
  	printk(KERN_DEBUG "   "FMT"
  ", ##__VA_ARGS__)
  #else
  #define kenter(FMT, ...) \
  	no_printk(KERN_DEBUG "==> %s("FMT")
  ", __func__, ##__VA_ARGS__)
  #define kleave(FMT, ...) \
  	no_printk(KERN_DEBUG "<== %s()"FMT"
  ", __func__, ##__VA_ARGS__)
  #define kdebug(FMT, ...) \
  	no_printk(KERN_DEBUG FMT"
  ", ##__VA_ARGS__)
  #endif
  
  extern struct key_type key_type_dead;
  extern struct key_type key_type_user;
  extern struct key_type key_type_logon;
  
  /*****************************************************************************/
  /*
   * 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).
   *
   * We also keep track of keys under request from userspace for this UID here.
   */
  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 */
  	kuid_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(kuid_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 kmem_cache *key_jar;
  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 struct key_type *key_type_lookup(const char *type);
  extern void key_type_put(struct key_type *ktype);
  
  extern int __key_link_begin(struct key *keyring,
  			    const struct keyring_index_key *index_key,
  			    struct assoc_array_edit **_edit);
  extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
  extern void __key_link_end(struct key *keyring,
  			   const struct keyring_index_key *index_key,
  			   struct assoc_array_edit *edit);
  
  extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
  				    const struct keyring_index_key *index_key);
  
  extern struct key *keyring_search_instkey(struct key *keyring,
  					  key_serial_t target_id);
  
  extern int iterate_over_keyring(const struct key *keyring,
  				int (*func)(const struct key *key, void *data),
  				void *data);
  
  typedef int (*key_match_func_t)(const struct key *, const void *);
  
  struct keyring_search_context {
  	struct keyring_index_key index_key;
  	const struct cred	*cred;
  	key_match_func_t	match;
  	const void		*match_data;
  	unsigned		flags;
  #define KEYRING_SEARCH_LOOKUP_TYPE	0x0001	/* [as type->def_lookup_type] */
  #define KEYRING_SEARCH_NO_STATE_CHECK	0x0002	/* Skip state checks */
  #define KEYRING_SEARCH_DO_STATE_CHECK	0x0004	/* Override NO_STATE_CHECK */
  #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0008	/* Don't update times */
  #define KEYRING_SEARCH_NO_CHECK_PERM	0x0010	/* Don't check permissions */
  #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0020	/* Give an error on excessive depth */
  
  	int (*iterator)(const void *object, void *iterator_data);
  
  	/* Internal stuff */
  	int			skipped_ret;
  	bool			possessed;
  	key_ref_t		result;
  	struct timespec		now;
  };
  
  extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
  				    struct keyring_search_context *ctx);
  
  extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
  extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
  
  extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
  
  extern int install_user_keyrings(void);
  extern int install_thread_keyring_to_cred(struct cred *);
  extern int install_process_keyring_to_cred(struct cred *);
  extern int install_session_keyring_to_cred(struct cred *, struct key *);
  
  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);
  
  extern int lookup_user_key_possessed(const struct key *key, const void *target);
  extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
  				 key_perm_t perm);
  #define KEY_LOOKUP_CREATE	0x01
  #define KEY_LOOKUP_PARTIAL	0x02
  #define KEY_LOOKUP_FOR_UNLINK	0x04
  
  extern long join_session_keyring(const char *name);
  extern void key_change_session_keyring(struct callback_head *twork);
  
  extern struct work_struct key_gc_work;
  extern unsigned key_gc_delay;
  extern void keyring_gc(struct key *keyring, time_t limit);
  extern void key_schedule_gc(time_t gc_at);
  extern void key_schedule_gc_links(void);
  extern void key_gc_keytype(struct key_type *ktype);
  
  extern int key_task_permission(const key_ref_t key_ref,
  			       const struct cred *cred,
  			       key_perm_t perm);
  
  /*
   * Check to see whether permission is granted to use a key in the desired way.
   */
  static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
  {
  	return key_task_permission(key_ref, current_cred(), perm);
  }
  
  /* required permissions */
  #define	KEY_VIEW	0x01	/* require permission to view attributes */
  #define	KEY_READ	0x02	/* require permission to read content */
  #define	KEY_WRITE	0x04	/* require permission to update / modify */
  #define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
  #define	KEY_LINK	0x10	/* require permission to link */
  #define	KEY_SETATTR	0x20	/* require permission to change attributes */
  #define	KEY_ALL		0x3f	/* all the above permissions */
  
  /*
   * Authorisation record for request_key().
   */
  struct request_key_auth {
  	struct key		*target_key;
  	struct key		*dest_keyring;
  	const struct cred	*cred;
  	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,
  					struct key *dest_keyring);
  
  extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
  
  /*
   * Determine whether a key is dead.
   */
  static inline bool key_is_dead(const struct key *key, time_t limit)
  {
  	return
  		key->flags & ((1 << KEY_FLAG_DEAD) |
  			      (1 << KEY_FLAG_INVALIDATED)) ||
  		(key->expiry > 0 && key->expiry <= limit);
  }
  
  /*
   * 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);
  extern long keyctl_session_to_parent(void);
  extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
  extern long keyctl_instantiate_key_iov(key_serial_t,
  				       const struct iovec __user *,
  				       unsigned, key_serial_t);
  extern long keyctl_invalidate_key(key_serial_t);
  
  extern long keyctl_instantiate_key_common(key_serial_t,
  					  const struct iovec *,
  					  unsigned, size_t, key_serial_t);
  #ifdef CONFIG_PERSISTENT_KEYRINGS
  extern long keyctl_get_persistent(uid_t, key_serial_t);
  extern unsigned persistent_keyring_expiry;
  #else
  static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
  {
  	return -EOPNOTSUPP;
  }
  #endif
  
  /*
   * 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 */