/*
 * security/tomoyo/group.c
 *
 * Copyright (C) 2005-2011  NTT DATA CORPORATION
 */

#include <linux/slab.h>
#include "common.h"

/**
 * tomoyo_same_path_group - Check for duplicated "struct tomoyo_path_group" entry.
 *
 * @a: Pointer to "struct tomoyo_acl_head".
 * @b: Pointer to "struct tomoyo_acl_head".
 *
 * Returns true if @a == @b, false otherwise.
 */
static bool tomoyo_same_path_group(const struct tomoyo_acl_head *a,
                                   const struct tomoyo_acl_head *b)
{
        return container_of(a, struct tomoyo_path_group, head)->member_name ==
                container_of(b, struct tomoyo_path_group, head)->member_name;
}

/**
 * tomoyo_same_number_group - Check for duplicated "struct tomoyo_number_group" entry.
 *
 * @a: Pointer to "struct tomoyo_acl_head".
 * @b: Pointer to "struct tomoyo_acl_head".
 *
 * Returns true if @a == @b, false otherwise.
 */
static bool tomoyo_same_number_group(const struct tomoyo_acl_head *a,
                                     const struct tomoyo_acl_head *b)
{
        return !memcmp(&container_of(a, struct tomoyo_number_group, head)
                       ->number,
                       &container_of(b, struct tomoyo_number_group, head)
                       ->number,
                       sizeof(container_of(a, struct tomoyo_number_group, head)
                              ->number));
}

/**
 * tomoyo_same_address_group - Check for duplicated "struct tomoyo_address_group" entry.
 *
 * @a: Pointer to "struct tomoyo_acl_head".
 * @b: Pointer to "struct tomoyo_acl_head".
 *
 * Returns true if @a == @b, false otherwise.
 */
static bool tomoyo_same_address_group(const struct tomoyo_acl_head *a,
                                      const struct tomoyo_acl_head *b)
{
        const struct tomoyo_address_group *p1 = container_of(a, typeof(*p1),
                                                             head);
        const struct tomoyo_address_group *p2 = container_of(b, typeof(*p2),
                                                             head);

        return tomoyo_same_ipaddr_union(&p1->address, &p2->address);
}

/**
 * tomoyo_write_group - Write "struct tomoyo_path_group"/"struct tomoyo_number_group"/"struct tomoyo_address_group" list.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 * @type:  Type of this group.
 *
 * Returns 0 on success, negative value otherwise.
 */
int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type)
{
        struct tomoyo_group *group = tomoyo_get_group(param, type);
        int error = -EINVAL;
        if (!group)
                return -ENOMEM;
        param->list = &group->member_list;
        if (type == TOMOYO_PATH_GROUP) {
                struct tomoyo_path_group e = { };
                e.member_name = tomoyo_get_name(tomoyo_read_token(param));
                if (!e.member_name) {
                        error = -ENOMEM;
                        goto out;
                }
                error = tomoyo_update_policy(&e.head, sizeof(e), param,
                                          tomoyo_same_path_group);
                tomoyo_put_name(e.member_name);
        } else if (type == TOMOYO_NUMBER_GROUP) {
                struct tomoyo_number_group e = { };
                if (param->data[0] == '@' ||
                    !tomoyo_parse_number_union(param, &e.number))
                        goto out;
                error = tomoyo_update_policy(&e.head, sizeof(e), param,
                                          tomoyo_same_number_group);
                /*
                 * tomoyo_put_number_union() is not needed because
                 * param->data[0] != '@'.
                 */
        } else {
                struct tomoyo_address_group e = { };

                if (param->data[0] == '@' ||
                    !tomoyo_parse_ipaddr_union(param, &e.address))
                        goto out;
                error = tomoyo_update_policy(&e.head, sizeof(e), param,
                                             tomoyo_same_address_group);
        }
out:
        tomoyo_put_group(group);
        return error;
}

/**
 * tomoyo_path_matches_group - Check whether the given pathname matches members of the given pathname group.
 *
 * @pathname: The name of pathname.
 * @group:    Pointer to "struct tomoyo_path_group".
 *
 * Returns matched member's pathname if @pathname matches pathnames in @group,
 * NULL otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
const struct tomoyo_path_info *
tomoyo_path_matches_group(const struct tomoyo_path_info *pathname,
                          const struct tomoyo_group *group)
{
        struct tomoyo_path_group *member;
        list_for_each_entry_rcu(member, &group->member_list, head.list) {
                if (member->head.is_deleted)
                        continue;
                if (!tomoyo_path_matches_pattern(pathname, member->member_name))
                        continue;
                return member->member_name;
        }
        return NULL;
}

/**
 * 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_group *group)
{
        struct tomoyo_number_group *member;
        bool matched = false;
        list_for_each_entry_rcu(member, &group->member_list, head.list) {
                if (member->head.is_deleted)
                        continue;
                if (min > member->number.values[1] ||
                    max < member->number.values[0])
                        continue;
                matched = true;
                break;
        }
        return matched;
}

/**
 * tomoyo_address_matches_group - Check whether the given address matches members of the given address group.
 *
 * @is_ipv6: True if @address is an IPv6 address.
 * @address: An IPv4 or IPv6 address.
 * @group:   Pointer to "struct tomoyo_address_group".
 *
 * Returns true if @address matches addresses in @group group, false otherwise.
 *
 * Caller holds tomoyo_read_lock().
 */
bool tomoyo_address_matches_group(const bool is_ipv6, const __be32 *address,
                                  const struct tomoyo_group *group)
{
        struct tomoyo_address_group *member;
        bool matched = false;
        const u8 size = is_ipv6 ? 16 : 4;

        list_for_each_entry_rcu(member, &group->member_list, head.list) {
                if (member->head.is_deleted)
                        continue;
                if (member->address.is_ipv6 != is_ipv6)
                        continue;
                if (memcmp(&member->address.ip[0], address, size) > 0 ||
                    memcmp(address, &member->address.ip[1], size) > 0)
                        continue;
                matched = true;
                break;
        }
        return matched;
}