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