// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* NetLabel Network Address Lists
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*
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* This file contains network address list functions used to manage ordered
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* lists of network addresses for use by the NetLabel subsystem. The NetLabel
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* system manages static and dynamic label mappings for network protocols such
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* as CIPSO and RIPSO.
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*
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* Author: Paul Moore <paul@paul-moore.com>
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*/
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/*
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* (c) Copyright Hewlett-Packard Development Company, L.P., 2008
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*/
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#include <linux/types.h>
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#include <linux/rcupdate.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <linux/audit.h>
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#include "netlabel_addrlist.h"
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/*
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* Address List Functions
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*/
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/**
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* netlbl_af4list_search - Search for a matching IPv4 address entry
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* @addr: IPv4 address
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* @head: the list head
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*
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* Description:
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* Searches the IPv4 address list given by @head. If a matching address entry
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* is found it is returned, otherwise NULL is returned. The caller is
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* responsible for calling the rcu_read_[un]lock() functions.
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*
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*/
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struct netlbl_af4list *netlbl_af4list_search(__be32 addr,
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struct list_head *head)
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{
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struct netlbl_af4list *iter;
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid && (addr & iter->mask) == iter->addr)
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return iter;
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return NULL;
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}
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/**
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* netlbl_af4list_search_exact - Search for an exact IPv4 address entry
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* @addr: IPv4 address
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* @mask: IPv4 address mask
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* @head: the list head
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*
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* Description:
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* Searches the IPv4 address list given by @head. If an exact match if found
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* it is returned, otherwise NULL is returned. The caller is responsible for
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* calling the rcu_read_[un]lock() functions.
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*
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*/
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struct netlbl_af4list *netlbl_af4list_search_exact(__be32 addr,
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__be32 mask,
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struct list_head *head)
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{
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struct netlbl_af4list *iter;
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid && iter->addr == addr && iter->mask == mask)
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return iter;
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return NULL;
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}
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#if IS_ENABLED(CONFIG_IPV6)
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/**
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* netlbl_af6list_search - Search for a matching IPv6 address entry
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* @addr: IPv6 address
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* @head: the list head
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*
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* Description:
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* Searches the IPv6 address list given by @head. If a matching address entry
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* is found it is returned, otherwise NULL is returned. The caller is
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* responsible for calling the rcu_read_[un]lock() functions.
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*
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*/
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struct netlbl_af6list *netlbl_af6list_search(const struct in6_addr *addr,
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struct list_head *head)
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{
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struct netlbl_af6list *iter;
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid &&
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ipv6_masked_addr_cmp(&iter->addr, &iter->mask, addr) == 0)
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return iter;
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return NULL;
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}
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/**
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* netlbl_af6list_search_exact - Search for an exact IPv6 address entry
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* @addr: IPv6 address
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* @mask: IPv6 address mask
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* @head: the list head
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*
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* Description:
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* Searches the IPv6 address list given by @head. If an exact match if found
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* it is returned, otherwise NULL is returned. The caller is responsible for
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* calling the rcu_read_[un]lock() functions.
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*
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*/
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struct netlbl_af6list *netlbl_af6list_search_exact(const struct in6_addr *addr,
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const struct in6_addr *mask,
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struct list_head *head)
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{
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struct netlbl_af6list *iter;
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid &&
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ipv6_addr_equal(&iter->addr, addr) &&
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ipv6_addr_equal(&iter->mask, mask))
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return iter;
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return NULL;
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}
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#endif /* IPv6 */
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/**
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* netlbl_af4list_add - Add a new IPv4 address entry to a list
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* @entry: address entry
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* @head: the list head
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*
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* Description:
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* Add a new address entry to the list pointed to by @head. On success zero is
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* returned, otherwise a negative value is returned. The caller is responsible
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* for calling the necessary locking functions.
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*
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*/
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int netlbl_af4list_add(struct netlbl_af4list *entry, struct list_head *head)
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{
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struct netlbl_af4list *iter;
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iter = netlbl_af4list_search(entry->addr, head);
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if (iter != NULL &&
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iter->addr == entry->addr && iter->mask == entry->mask)
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return -EEXIST;
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/* in order to speed up address searches through the list (the common
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* case) we need to keep the list in order based on the size of the
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* address mask such that the entry with the widest mask (smallest
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* numerical value) appears first in the list */
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid &&
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ntohl(entry->mask) > ntohl(iter->mask)) {
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__list_add_rcu(&entry->list,
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iter->list.prev,
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&iter->list);
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return 0;
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}
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list_add_tail_rcu(&entry->list, head);
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return 0;
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}
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#if IS_ENABLED(CONFIG_IPV6)
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/**
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* netlbl_af6list_add - Add a new IPv6 address entry to a list
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* @entry: address entry
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* @head: the list head
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*
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* Description:
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* Add a new address entry to the list pointed to by @head. On success zero is
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* returned, otherwise a negative value is returned. The caller is responsible
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* for calling the necessary locking functions.
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*
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*/
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int netlbl_af6list_add(struct netlbl_af6list *entry, struct list_head *head)
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{
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struct netlbl_af6list *iter;
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iter = netlbl_af6list_search(&entry->addr, head);
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if (iter != NULL &&
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ipv6_addr_equal(&iter->addr, &entry->addr) &&
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ipv6_addr_equal(&iter->mask, &entry->mask))
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return -EEXIST;
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/* in order to speed up address searches through the list (the common
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* case) we need to keep the list in order based on the size of the
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* address mask such that the entry with the widest mask (smallest
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* numerical value) appears first in the list */
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list_for_each_entry_rcu(iter, head, list)
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if (iter->valid &&
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ipv6_addr_cmp(&entry->mask, &iter->mask) > 0) {
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__list_add_rcu(&entry->list,
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iter->list.prev,
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&iter->list);
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return 0;
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}
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list_add_tail_rcu(&entry->list, head);
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return 0;
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}
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#endif /* IPv6 */
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/**
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* netlbl_af4list_remove_entry - Remove an IPv4 address entry
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* @entry: address entry
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*
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* Description:
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* Remove the specified IP address entry. The caller is responsible for
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* calling the necessary locking functions.
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*
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*/
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void netlbl_af4list_remove_entry(struct netlbl_af4list *entry)
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{
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entry->valid = 0;
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list_del_rcu(&entry->list);
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}
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/**
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* netlbl_af4list_remove - Remove an IPv4 address entry
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* @addr: IP address
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* @mask: IP address mask
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* @head: the list head
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*
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* Description:
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* Remove an IP address entry from the list pointed to by @head. Returns the
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* entry on success, NULL on failure. The caller is responsible for calling
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* the necessary locking functions.
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*
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*/
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struct netlbl_af4list *netlbl_af4list_remove(__be32 addr, __be32 mask,
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struct list_head *head)
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{
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struct netlbl_af4list *entry;
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entry = netlbl_af4list_search_exact(addr, mask, head);
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if (entry == NULL)
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return NULL;
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netlbl_af4list_remove_entry(entry);
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return entry;
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}
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#if IS_ENABLED(CONFIG_IPV6)
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/**
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* netlbl_af6list_remove_entry - Remove an IPv6 address entry
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* @entry: address entry
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*
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* Description:
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* Remove the specified IP address entry. The caller is responsible for
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* calling the necessary locking functions.
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*
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*/
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void netlbl_af6list_remove_entry(struct netlbl_af6list *entry)
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{
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entry->valid = 0;
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list_del_rcu(&entry->list);
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}
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/**
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* netlbl_af6list_remove - Remove an IPv6 address entry
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* @addr: IP address
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* @mask: IP address mask
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* @head: the list head
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*
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* Description:
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* Remove an IP address entry from the list pointed to by @head. Returns the
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* entry on success, NULL on failure. The caller is responsible for calling
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* the necessary locking functions.
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*
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*/
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struct netlbl_af6list *netlbl_af6list_remove(const struct in6_addr *addr,
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const struct in6_addr *mask,
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struct list_head *head)
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{
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struct netlbl_af6list *entry;
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entry = netlbl_af6list_search_exact(addr, mask, head);
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if (entry == NULL)
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return NULL;
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netlbl_af6list_remove_entry(entry);
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return entry;
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}
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#endif /* IPv6 */
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/*
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* Audit Helper Functions
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*/
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#ifdef CONFIG_AUDIT
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/**
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* netlbl_af4list_audit_addr - Audit an IPv4 address
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* @audit_buf: audit buffer
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* @src: true if source address, false if destination
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* @dev: network interface
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* @addr: IP address
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* @mask: IP address mask
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*
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* Description:
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* Write the IPv4 address and address mask, if necessary, to @audit_buf.
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*
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*/
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void netlbl_af4list_audit_addr(struct audit_buffer *audit_buf,
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int src, const char *dev,
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__be32 addr, __be32 mask)
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{
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u32 mask_val = ntohl(mask);
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char *dir = (src ? "src" : "dst");
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if (dev != NULL)
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audit_log_format(audit_buf, " netif=%s", dev);
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audit_log_format(audit_buf, " %s=%pI4", dir, &addr);
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if (mask_val != 0xffffffff) {
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u32 mask_len = 0;
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while (mask_val > 0) {
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mask_val <<= 1;
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mask_len++;
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}
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audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
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}
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}
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#if IS_ENABLED(CONFIG_IPV6)
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/**
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* netlbl_af6list_audit_addr - Audit an IPv6 address
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* @audit_buf: audit buffer
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* @src: true if source address, false if destination
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* @dev: network interface
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* @addr: IP address
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* @mask: IP address mask
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*
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* Description:
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* Write the IPv6 address and address mask, if necessary, to @audit_buf.
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*
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*/
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void netlbl_af6list_audit_addr(struct audit_buffer *audit_buf,
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int src,
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const char *dev,
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const struct in6_addr *addr,
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const struct in6_addr *mask)
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{
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char *dir = (src ? "src" : "dst");
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if (dev != NULL)
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audit_log_format(audit_buf, " netif=%s", dev);
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audit_log_format(audit_buf, " %s=%pI6", dir, addr);
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if (ntohl(mask->s6_addr32[3]) != 0xffffffff) {
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u32 mask_len = 0;
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u32 mask_val;
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int iter = -1;
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while (ntohl(mask->s6_addr32[++iter]) == 0xffffffff)
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mask_len += 32;
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mask_val = ntohl(mask->s6_addr32[iter]);
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while (mask_val > 0) {
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mask_val <<= 1;
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mask_len++;
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}
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audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
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}
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}
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#endif /* IPv6 */
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#endif /* CONFIG_AUDIT */
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