/*
   * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.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, version 2.
   *
   * Author:
   *      Casey Schaufler <casey@schaufler-ca.com>
   *
   */
  
  #ifndef _SECURITY_SMACK_H
  #define _SECURITY_SMACK_H
  
  #include <linux/capability.h>
  #include <linux/spinlock.h>

  #include <linux/lsm_hooks.h>

  #include <linux/in.h>

  #if IS_ENABLED(CONFIG_IPV6)
  #include <linux/in6.h>
  #endif /* CONFIG_IPV6 */

  #include <net/netlabel.h>

  #include <linux/list.h>
  #include <linux/rculist.h>

  #include <linux/lsm_audit.h>

  
  /*

   * Use IPv6 port labeling if IPv6 is enabled and secmarks
   * are not being used.
   */
  #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
  #define SMACK_IPV6_PORT_LABELING 1
  #endif
  
  #if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER)
  #define SMACK_IPV6_SECMARK_LABELING 1
  #endif
  
  /*

   * Smack labels were limited to 23 characters for a long time.
   */
  #define SMK_LABELLEN	24
  #define SMK_LONGLABEL	256
  
  /*

   * This is the repository for labels seen so that it is
   * not necessary to keep allocating tiny chuncks of memory
   * and so that they can be shared.
   *
   * Labels are never modified in place. Anytime a label
   * is imported (e.g. xattrset on a file) the list is checked
   * for it and it is added if it doesn't exist. The address
   * is passed out in either case. Entries are added, but
   * never deleted.
   *
   * Since labels are hanging around anyway it doesn't
   * hurt to maintain a secid for those awkward situations
   * where kernel components that ought to use LSM independent
   * interfaces don't. The secid should go away when all of
   * these components have been repaired.
   *
   * The cipso value associated with the label gets stored here, too.
   *
   * Keep the access rules for this subject label here so that
   * the entire set of rules does not need to be examined every
   * time.
   */
  struct smack_known {
  	struct list_head		list;

  	struct hlist_node		smk_hashed;

  	char				*smk_known;
  	u32				smk_secid;
  	struct netlbl_lsm_secattr	smk_netlabel;	/* on wire labels */
  	struct list_head		smk_rules;	/* access rules */
  	struct mutex			smk_rules_lock;	/* lock for rules */
  };
  
  /*

   * Maximum number of bytes for the levels in a CIPSO IP option.

   * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
   * bigger than can be used, and 24 is the next lower multiple
   * of 8, and there are too many issues if there isn't space set
   * aside for the terminating null byte.
   */

  #define SMK_CIPSOLEN	24

  struct superblock_smack {

  	struct smack_known	*smk_root;
  	struct smack_known	*smk_floor;
  	struct smack_known	*smk_hat;
  	struct smack_known	*smk_default;

  	int			smk_flags;

  };

  /*
   * Superblock flags
   */
  #define SMK_SB_INITIALIZED	0x01
  #define SMK_SB_UNTRUSTED	0x02

  struct socket_smack {

  	struct smack_known	*smk_out;	/* outbound label */

  	struct smack_known	*smk_in;	/* inbound label */
  	struct smack_known	*smk_packet;	/* TCP peer label */

  };
  
  /*
   * Inode smack data
   */
  struct inode_smack {

  	struct smack_known	*smk_inode;	/* label of the fso */

  	struct smack_known	*smk_task;	/* label of the task */
  	struct smack_known	*smk_mmap;	/* label of the mmap domain */
  	struct mutex		smk_lock;	/* initialization lock */
  	int			smk_flags;	/* smack inode flags */

  };

  struct task_smack {

  	struct smack_known	*smk_task;	/* label for access control */
  	struct smack_known	*smk_forked;	/* label when forked */

  	struct list_head	smk_rules;	/* per task access rules */
  	struct mutex		smk_rules_lock;	/* lock for the rules */

  	struct list_head	smk_relabel;	/* transit allowed labels */

  };

  #define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */

  #define	SMK_INODE_TRANSMUTE	0x02	/* directory is transmuting */

  #define	SMK_INODE_CHANGED	0x04	/* smack was transmuted */

  #define	SMK_INODE_IMPURE	0x08	/* involved in an impure transaction */

  
  /*
   * A label access rule.
   */
  struct smack_rule {

  	struct list_head	list;

  	struct smack_known	*smk_subject;

  	struct smack_known	*smk_object;

  	int			smk_access;

  };
  
  /*

   * An entry in the table identifying IPv4 hosts.

   */

  struct smk_net4addr {

  	struct list_head	list;

  	struct in_addr		smk_host;	/* network address */

  	struct in_addr		smk_mask;	/* network mask */

  	int			smk_masks;	/* mask size */
  	struct smack_known	*smk_label;	/* label */
  };
  
  #if IS_ENABLED(CONFIG_IPV6)
  /*
   * An entry in the table identifying IPv6 hosts.
   */
  struct smk_net6addr {
  	struct list_head	list;
  	struct in6_addr		smk_host;	/* network address */
  	struct in6_addr		smk_mask;	/* network mask */
  	int			smk_masks;	/* mask size */

  	struct smack_known	*smk_label;	/* label */

  };

  #endif /* CONFIG_IPV6 */

  #ifdef SMACK_IPV6_PORT_LABELING

  /*

   * An entry in the table identifying ports.
   */
  struct smk_port_label {
  	struct list_head	list;
  	struct sock		*smk_sock;	/* socket initialized on */
  	unsigned short		smk_port;	/* the port number */

  	struct smack_known	*smk_in;	/* inbound label */

  	struct smack_known	*smk_out;	/* outgoing label */

  };

  #endif /* SMACK_IPV6_PORT_LABELING */

  struct smack_known_list_elem {

  	struct list_head	list;
  	struct smack_known	*smk_label;
  };

  /* Super block security struct flags for mount options */
  #define FSDEFAULT_MNT	0x01
  #define FSFLOOR_MNT	0x02
  #define FSHAT_MNT	0x04
  #define FSROOT_MNT	0x08
  #define FSTRANS_MNT	0x10
  
  #define NUM_SMK_MNT_OPTS	5
  
  enum {
  	Opt_error = -1,
  	Opt_fsdefault = 1,
  	Opt_fsfloor = 2,
  	Opt_fshat = 3,
  	Opt_fsroot = 4,
  	Opt_fstransmute = 5,
  };

  /*
   * Mount options
   */
  #define SMK_FSDEFAULT	"smackfsdef="
  #define SMK_FSFLOOR	"smackfsfloor="
  #define SMK_FSHAT	"smackfshat="
  #define SMK_FSROOT	"smackfsroot="

  #define SMK_FSTRANS	"smackfstransmute="

  #define SMACK_DELETE_OPTION	"-DELETE"

  #define SMACK_CIPSO_OPTION 	"-CIPSO"

  /*

   * How communications on this socket are treated.
   * Usually it's determined by the underlying netlabel code
   * but there are certain cases, including single label hosts
   * and potentially single label interfaces for which the
   * treatment can not be known in advance.
   *
   * The possibility of additional labeling schemes being
   * introduced in the future exists as well.
   */
  #define SMACK_UNLABELED_SOCKET	0
  #define SMACK_CIPSO_SOCKET	1
  
  /*

   * CIPSO defaults.
   */
  #define SMACK_CIPSO_DOI_DEFAULT		3	/* Historical */

  #define SMACK_CIPSO_DOI_INVALID		-1	/* Not a DOI */

  #define SMACK_CIPSO_DIRECT_DEFAULT	250	/* Arbitrary */

  #define SMACK_CIPSO_MAPPED_DEFAULT	251	/* Also arbitrary */

  #define SMACK_CIPSO_MAXLEVEL            255     /* CIPSO 2.2 standard */

  /*
   * CIPSO 2.2 standard is 239, but Smack wants to use the
   * categories in a structured way that limits the value to
   * the bits in 23 bytes, hence the unusual number.
   */
  #define SMACK_CIPSO_MAXCATNUM           184     /* 23 * 8 */

  
  /*

   * Ptrace rules
   */
  #define SMACK_PTRACE_DEFAULT	0
  #define SMACK_PTRACE_EXACT	1
  #define SMACK_PTRACE_DRACONIAN	2
  #define SMACK_PTRACE_MAX	SMACK_PTRACE_DRACONIAN
  
  /*

   * Flags for untraditional access modes.
   * It shouldn't be necessary to avoid conflicts with definitions
   * in fs.h, but do so anyway.

   */

  #define MAY_TRANSMUTE	0x00001000	/* Controls directory labeling */
  #define MAY_LOCK	0x00002000	/* Locks should be writes, but ... */

  #define MAY_BRINGUP	0x00004000	/* Report use of this rule */

  /*
   * The policy for delivering signals is configurable.
   * It is usually "write", but can be "append".
   */
  #ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS
  #define MAY_DELIVER	MAY_APPEND	/* Signal delivery requires append */
  #else
  #define MAY_DELIVER	MAY_WRITE	/* Signal delivery requires write */
  #endif

  #define SMACK_BRINGUP_ALLOW		1	/* Allow bringup mode */
  #define SMACK_UNCONFINED_SUBJECT	2	/* Allow unconfined label */
  #define SMACK_UNCONFINED_OBJECT		3	/* Allow unconfined label */

  /*

   * Just to make the common cases easier to deal with
   */

  #define MAY_ANYREAD	(MAY_READ | MAY_EXEC)

  #define MAY_READWRITE	(MAY_READ | MAY_WRITE)
  #define MAY_NOT		0
  
  /*

   * Number of access types used by Smack (rwxatlb)

   */

  #define SMK_NUM_ACCESS_TYPE 7

  /* SMACK data */
  struct smack_audit_data {
  	const char *function;
  	char *subject;
  	char *object;
  	char *request;
  	int result;
  };

  /*
   * Smack audit data; is empty if CONFIG_AUDIT not set
   * to save some stack
   */
  struct smk_audit_info {
  #ifdef CONFIG_AUDIT
  	struct common_audit_data a;

  	struct smack_audit_data sad;

  #endif
  };

  
  /*
   * These functions are in smack_access.c
   */

  int smk_access_entry(char *, char *, struct list_head *);

  int smk_access(struct smack_known *, struct smack_known *,
  	       int, struct smk_audit_info *);
  int smk_tskacc(struct task_smack *, struct smack_known *,
  	       u32, struct smk_audit_info *);
  int smk_curacc(struct smack_known *, u32, struct smk_audit_info *);

  struct smack_known *smack_from_secid(const u32);

  char *smk_parse_smack(const char *string, int len);
  int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);

  struct smack_known *smk_import_entry(const char *, int);

  void smk_insert_entry(struct smack_known *skp);

  struct smack_known *smk_find_entry(const char *);

  int smack_privileged(int cap);

  void smk_destroy_label_list(struct list_head *list);

  
  /*
   * Shared data.
   */

  extern int smack_enabled;

  extern int smack_cipso_direct;

  extern int smack_cipso_mapped;

  extern struct smack_known *smack_net_ambient;

  extern struct smack_known *smack_syslog_label;

  #ifdef CONFIG_SECURITY_SMACK_BRINGUP
  extern struct smack_known *smack_unconfined;
  #endif

  extern int smack_ptrace_rule;

  extern struct smack_known smack_known_floor;
  extern struct smack_known smack_known_hat;
  extern struct smack_known smack_known_huh;

  extern struct smack_known smack_known_star;

  extern struct smack_known smack_known_web;

  extern struct mutex	smack_known_lock;

  extern struct list_head smack_known_list;

  extern struct list_head smk_net4addr_list;
  #if IS_ENABLED(CONFIG_IPV6)
  extern struct list_head smk_net6addr_list;
  #endif /* CONFIG_IPV6 */

  extern struct mutex     smack_onlycap_lock;
  extern struct list_head smack_onlycap_list;

  #define SMACK_HASH_SLOTS 16
  extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];

  /*

   * Is the directory transmuting?
   */
  static inline int smk_inode_transmutable(const struct inode *isp)
  {
  	struct inode_smack *sip = isp->i_security;
  	return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
  }
  
  /*

   * Present a pointer to the smack label entry in an inode blob.

   */

  static inline struct smack_known *smk_of_inode(const struct inode *isp)

  {
  	struct inode_smack *sip = isp->i_security;
  	return sip->smk_inode;
  }

  /*

   * Present a pointer to the smack label entry in an task blob.

   */

  static inline struct smack_known *smk_of_task(const struct task_smack *tsp)

  {
  	return tsp->smk_task;
  }

  static inline struct smack_known *smk_of_task_struct(const struct task_struct *t)
  {
  	struct smack_known *skp;
  
  	rcu_read_lock();
  	skp = smk_of_task(__task_cred(t)->security);
  	rcu_read_unlock();
  	return skp;
  }

  /*

   * Present a pointer to the forked smack label entry in an task blob.

   */

  static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)

  {
  	return tsp->smk_forked;
  }
  
  /*

   * Present a pointer to the smack label in the current task blob.

   */

  static inline struct smack_known *smk_of_current(void)

  {
  	return smk_of_task(current_security());
  }
  
  /*

   * logging functions
   */
  #define SMACK_AUDIT_DENIED 0x1
  #define SMACK_AUDIT_ACCEPT 0x2
  extern int log_policy;
  
  void smack_log(char *subject_label, char *object_label,
  		int request,
  		int result, struct smk_audit_info *auditdata);
  
  #ifdef CONFIG_AUDIT
  
  /*
   * some inline functions to set up audit data
   * they do nothing if CONFIG_AUDIT is not set
   *
   */
  static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
  			       char type)
  {

  	memset(&a->sad, 0, sizeof(a->sad));

  	a->a.type = type;

  	a->a.smack_audit_data = &a->sad;
  	a->a.smack_audit_data->function = func;

  }

  static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
  				   char type, struct lsm_network_audit *net)
  {
  	smk_ad_init(a, func, type);
  	memset(net, 0, sizeof(*net));
  	a->a.u.net = net;
  }

  static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
  					 struct task_struct *t)
  {
  	a->a.u.tsk = t;
  }
  static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
  						    struct dentry *d)
  {

  	a->a.u.dentry = d;

  }
  static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
  					      struct inode *i)
  {

  	a->a.u.inode = i;

  }
  static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
  					     struct path p)
  {

  	a->a.u.path = p;

  }
  static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
  					    struct sock *sk)
  {

  	a->a.u.net->sk = sk;

  }
  
  #else /* no AUDIT */
  
  static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
  			       char type)
  {
  }
  static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
  					 struct task_struct *t)
  {
  }
  static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
  						    struct dentry *d)
  {
  }
  static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a,
  						 struct vfsmount *m)
  {
  }
  static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
  					      struct inode *i)
  {
  }
  static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
  					     struct path p)
  {
  }
  static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
  					    struct sock *sk)
  {
  }
  #endif

  #endif  /* _SECURITY_SMACK_H */