// 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 <paul@paul-moore.com> */ /* * (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 */
