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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,
const char *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(const char *op, struct aa_profile *profile,
const struct path *path, int flags, u32 request,
struct path_cond *cond);
int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
const struct path *new_dir, struct dentry *new_dentry);
int aa_file_perm(const char *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 */
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