linux/security/tomoyo/number_group.c
Tetsuo Handa 4c3e9e2ded TOMOYO: Add numeric values grouping support.
This patch adds numeric values grouping support, which is useful for grouping
numeric values such as file's UID, DAC's mode, ioctl()'s cmd number.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:33:35 +10:00

176 lines
4.7 KiB
C

/*
* security/tomoyo/number_group.c
*
* Copyright (C) 2005-2009 NTT DATA CORPORATION
*/
#include <linux/slab.h>
#include "common.h"
/* The list for "struct tomoyo_number_group". */
LIST_HEAD(tomoyo_number_group_list);
/**
* tomoyo_get_number_group - Allocate memory for "struct tomoyo_number_group".
*
* @group_name: The name of number group.
*
* Returns pointer to "struct tomoyo_number_group" on success,
* NULL otherwise.
*/
struct tomoyo_number_group *tomoyo_get_number_group(const char *group_name)
{
struct tomoyo_number_group *entry = NULL;
struct tomoyo_number_group *group = NULL;
const struct tomoyo_path_info *saved_group_name;
int error = -ENOMEM;
if (!tomoyo_is_correct_path(group_name, 0, 0, 0) ||
!group_name[0])
return NULL;
saved_group_name = tomoyo_get_name(group_name);
if (!saved_group_name)
return NULL;
entry = kzalloc(sizeof(*entry), GFP_NOFS);
if (mutex_lock_interruptible(&tomoyo_policy_lock))
goto out;
list_for_each_entry_rcu(group, &tomoyo_number_group_list, list) {
if (saved_group_name != group->group_name)
continue;
atomic_inc(&group->users);
error = 0;
break;
}
if (error && tomoyo_memory_ok(entry)) {
INIT_LIST_HEAD(&entry->member_list);
entry->group_name = saved_group_name;
saved_group_name = NULL;
atomic_set(&entry->users, 1);
list_add_tail_rcu(&entry->list, &tomoyo_number_group_list);
group = entry;
entry = NULL;
error = 0;
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_name(saved_group_name);
kfree(entry);
return !error ? group : NULL;
}
/**
* tomoyo_write_number_group_policy - Write "struct tomoyo_number_group" list.
*
* @data: String to parse.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, nagative value otherwise.
*/
int tomoyo_write_number_group_policy(char *data, const bool is_delete)
{
struct tomoyo_number_group *group;
struct tomoyo_number_group_member e = { };
struct tomoyo_number_group_member *member;
int error = is_delete ? -ENOENT : -ENOMEM;
char *w[2];
if (!tomoyo_tokenize(data, w, sizeof(w)))
return -EINVAL;
if (!tomoyo_parse_number_union(w[1], &e.number))
return -EINVAL;
if (e.number.is_group || e.number.values[0] > e.number.values[1]) {
tomoyo_put_number_union(&e.number);
return -EINVAL;
}
group = tomoyo_get_number_group(w[0]);
if (!group)
return -ENOMEM;
if (mutex_lock_interruptible(&tomoyo_policy_lock))
goto out;
list_for_each_entry_rcu(member, &group->member_list, list) {
if (memcmp(&member->number, &e.number, sizeof(e.number)))
continue;
member->is_deleted = is_delete;
error = 0;
break;
}
if (!is_delete && error) {
struct tomoyo_number_group_member *entry =
tomoyo_commit_ok(&e, sizeof(e));
if (entry) {
list_add_tail_rcu(&entry->list, &group->member_list);
error = 0;
}
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_number_group(group);
return error;
}
/**
* tomoyo_read_number_group_policy - Read "struct tomoyo_number_group" list.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_number_group_policy(struct tomoyo_io_buffer *head)
{
struct list_head *gpos;
struct list_head *mpos;
list_for_each_cookie(gpos, head->read_var1, &tomoyo_number_group_list) {
struct tomoyo_number_group *group;
const char *name;
group = list_entry(gpos, struct tomoyo_number_group, list);
name = group->group_name->name;
list_for_each_cookie(mpos, head->read_var2,
&group->member_list) {
int pos;
const struct tomoyo_number_group_member *member
= list_entry(mpos,
struct tomoyo_number_group_member,
list);
if (member->is_deleted)
continue;
pos = head->read_avail;
if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_NUMBER_GROUP
"%s", name) ||
!tomoyo_print_number_union(head, &member->number) ||
!tomoyo_io_printf(head, "\n")) {
head->read_avail = pos;
return false;
}
}
}
return true;
}
/**
* tomoyo_number_matches_group - Check whether the given number matches members of the given number group.
*
* @min: Min number.
* @max: Max number.
* @group: Pointer to "struct tomoyo_number_group".
*
* Returns true if @min and @max partially overlaps @group, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_number_matches_group(const unsigned long min,
const unsigned long max,
const struct tomoyo_number_group *group)
{
struct tomoyo_number_group_member *member;
bool matched = false;
list_for_each_entry_rcu(member, &group->member_list, list) {
if (member->is_deleted)
continue;
if (min > member->number.values[1] ||
max < member->number.values[0])
continue;
matched = true;
break;
}
return matched;
}