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kernel/linux-rt-4.4.41/security/apparmor/include/file.h 6.39 KB
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  /*
   * AppArmor security module
   *
   * This file contains AppArmor file mediation function definitions.
   *
   * Copyright (C) 1998-2008 Novell/SUSE
   * Copyright 2009-2010 Canonical Ltd.
   *
   * 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 of the
   * License.
   */
  
  #ifndef __AA_FILE_H
  #define __AA_FILE_H
  
  #include "domain.h"
  #include "match.h"
  
  struct aa_profile;
  struct path;
  
  /*
   * We use MAY_EXEC, MAY_WRITE, MAY_READ, MAY_APPEND and the following flags
   * for profile permissions
   */
  #define AA_MAY_CREATE                  0x0010
  #define AA_MAY_DELETE                  0x0020
  #define AA_MAY_META_WRITE              0x0040
  #define AA_MAY_META_READ               0x0080
  
  #define AA_MAY_CHMOD                   0x0100
  #define AA_MAY_CHOWN                   0x0200
  #define AA_MAY_LOCK                    0x0400
  #define AA_EXEC_MMAP                   0x0800
  
  #define AA_MAY_LINK			0x1000
  #define AA_LINK_SUBSET			AA_MAY_LOCK	/* overlaid */
  #define AA_MAY_ONEXEC			0x40000000	/* exec allows onexec */
  #define AA_MAY_CHANGE_PROFILE		0x80000000
  #define AA_MAY_CHANGEHAT		0x80000000	/* ctrl auditing only */
  
  #define AA_AUDIT_FILE_MASK	(MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\
  				 AA_MAY_CREATE | AA_MAY_DELETE |	\
  				 AA_MAY_META_READ | AA_MAY_META_WRITE | \
  				 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \
  				 AA_EXEC_MMAP | AA_MAY_LINK)
  
  /*
   * The xindex is broken into 3 parts
   * - index - an index into either the exec name table or the variable table
   * - exec type - which determines how the executable name and index are used
   * - flags - which modify how the destination name is applied
   */
  #define AA_X_INDEX_MASK		0x03ff
  
  #define AA_X_TYPE_MASK		0x0c00
  #define AA_X_TYPE_SHIFT		10
  #define AA_X_NONE		0x0000
  #define AA_X_NAME		0x0400	/* use executable name px */
  #define AA_X_TABLE		0x0800	/* use a specified name ->n# */
  
  #define AA_X_UNSAFE		0x1000
  #define AA_X_CHILD		0x2000	/* make >AA_X_NONE apply to children */
  #define AA_X_INHERIT		0x4000
  #define AA_X_UNCONFINED		0x8000
  
  /* AA_SECURE_X_NEEDED - is passed in the bprm->unsafe field */
  #define AA_SECURE_X_NEEDED	0x8000
  
  /* need to make conditional which ones are being set */
  struct path_cond {
  	kuid_t uid;
  	umode_t mode;
  };
  
  /* struct file_perms - file permission
   * @allow: mask of permissions that are allowed
   * @audit: mask of permissions to force an audit message for
   * @quiet: mask of permissions to quiet audit messages for
   * @kill: mask of permissions that when matched will kill the task
   * @xindex: exec transition index if @allow contains MAY_EXEC
   *
   * The @audit and @queit mask should be mutually exclusive.
   */
  struct file_perms {
  	u32 allow;
  	u32 audit;
  	u32 quiet;
  	u32 kill;
  	u16 xindex;
  };
  
  extern struct file_perms nullperms;
  
  #define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
  
  /* FIXME: split perms from dfa and match this to description
   *        also add delegation info.
   */
  static inline u16 dfa_map_xindex(u16 mask)
  {
  	u16 old_index = (mask >> 10) & 0xf;
  	u16 index = 0;
  
  	if (mask & 0x100)
  		index |= AA_X_UNSAFE;
  	if (mask & 0x200)
  		index |= AA_X_INHERIT;
  	if (mask & 0x80)
  		index |= AA_X_UNCONFINED;
  
  	if (old_index == 1) {
  		index |= AA_X_UNCONFINED;
  	} else if (old_index == 2) {
  		index |= AA_X_NAME;
  	} else if (old_index == 3) {
  		index |= AA_X_NAME | AA_X_CHILD;
  	} else if (old_index) {
  		index |= AA_X_TABLE;
  		index |= old_index - 4;
  	}
  
  	return index;
  }
  
  /*
   * map old dfa inline permissions to new format
   */
  #define dfa_user_allow(dfa, state) (((ACCEPT_TABLE(dfa)[state]) & 0x7f) | \
  				    ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
  #define dfa_user_audit(dfa, state) ((ACCEPT_TABLE2(dfa)[state]) & 0x7f)
  #define dfa_user_quiet(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 7) & 0x7f)
  #define dfa_user_xindex(dfa, state) \
  	(dfa_map_xindex(ACCEPT_TABLE(dfa)[state] & 0x3fff))
  
  #define dfa_other_allow(dfa, state) ((((ACCEPT_TABLE(dfa)[state]) >> 14) & \
  				      0x7f) |				\
  				     ((ACCEPT_TABLE(dfa)[state]) & 0x80000000))
  #define dfa_other_audit(dfa, state) (((ACCEPT_TABLE2(dfa)[state]) >> 14) & 0x7f)
  #define dfa_other_quiet(dfa, state) \
  	((((ACCEPT_TABLE2(dfa)[state]) >> 7) >> 14) & 0x7f)
  #define dfa_other_xindex(dfa, state) \
  	dfa_map_xindex((ACCEPT_TABLE(dfa)[state] >> 14) & 0x3fff)
  
  int aa_audit_file(struct aa_profile *profile, struct file_perms *perms,
  		  gfp_t gfp, int op, u32 request, const char *name,
  		  const char *target, kuid_t ouid, const char *info, int error);
  
  /**
   * struct aa_file_rules - components used for file rule permissions
   * @dfa: dfa to match path names and conditionals against
   * @perms: permission table indexed by the matched state accept entry of @dfa
   * @trans: transition table for indexed by named x transitions
   *
   * File permission are determined by matching a path against @dfa and then
   * then using the value of the accept entry for the matching state as
   * an index into @perms.  If a named exec transition is required it is
   * looked up in the transition table.
   */
  struct aa_file_rules {
  	unsigned int start;
  	struct aa_dfa *dfa;
  	/* struct perms perms; */
  	struct aa_domain trans;
  	/* TODO: add delegate table */
  };
  
  unsigned int aa_str_perms(struct aa_dfa *dfa, unsigned int start,
  			  const char *name, struct path_cond *cond,
  			  struct file_perms *perms);
  
  int aa_path_perm(int op, struct aa_profile *profile, struct path *path,
  		 int flags, u32 request, struct path_cond *cond);
  
  int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
  		 struct path *new_dir, struct dentry *new_dentry);
  
  int aa_file_perm(int op, struct aa_profile *profile, struct file *file,
  		 u32 request);
  
  static inline void aa_free_file_rules(struct aa_file_rules *rules)
  {
  	aa_put_dfa(rules->dfa);
  	aa_free_domain_entries(&rules->trans);
  }
  
  /**
   * aa_map_file_perms - map file flags to AppArmor permissions
   * @file: open file to map flags to AppArmor permissions
   *
   * Returns: apparmor permission set for the file
   */
  static inline u32 aa_map_file_to_perms(struct file *file)
  {
  	int flags = file->f_flags;
  	u32 perms = 0;
  
  	if (file->f_mode & FMODE_WRITE)
  		perms |= MAY_WRITE;
  	if (file->f_mode & FMODE_READ)
  		perms |= MAY_READ;
  
  	if ((flags & O_APPEND) && (perms & MAY_WRITE))
  		perms = (perms & ~MAY_WRITE) | MAY_APPEND;
  	/* trunc implies write permission */
  	if (flags & O_TRUNC)
  		perms |= MAY_WRITE;
  	if (flags & O_CREAT)
  		perms |= AA_MAY_CREATE;
  
  	return perms;
  }
  
  #endif /* __AA_FILE_H */