/* 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>

  #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;
  
  /*****************************************************************************/
  /*

   * 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 */
  	uid_t			uid;

  	struct user_namespace	*user_ns;

  	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,
  					struct user_namespace *user_ns);

  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 key_type *type,
  			    const char *description,

  			    unsigned long *_prealloc);

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

  		       unsigned long *_prealloc);

  extern void __key_link_end(struct key *keyring,
  			   struct key_type *type,

  			   unsigned long prealloc);

  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,

  				    const struct cred *cred,

  				    struct key_type *type,
  				    const void *description,

  				    key_match_func_t match,
  				    bool no_state_check);

  extern key_ref_t search_my_process_keyrings(struct key_type *type,
  					    const void *description,
  					    key_match_func_t match,

  					    bool no_state_check,

  					    const struct cred *cred);

  extern key_ref_t search_process_keyrings(struct key_type *type,
  					 const void *description,
  					 key_match_func_t match,

  					 const struct cred *cred);

  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 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 expiry_at);

  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);

  
  /*

   * 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_instantiate_key_common(key_serial_t,
  					  const struct iovec __user *,
  					  unsigned, size_t, key_serial_t);

  
  /*

   * 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 */