// SPDX-License-Identifier: GPL-2.0-or-later /* * NetLabel Unlabeled Support * * This file defines functions for dealing with unlabeled packets for the * NetLabel system. 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., 2006 - 2008 */ #include <linux/types.h> #include <linux/rcupdate.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/socket.h> #include <linux/string.h> #include <linux/skbuff.h> #include <linux/audit.h> #include <linux/in.h> #include <linux/in6.h> #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/notifier.h> #include <linux/netdevice.h> #include <linux/security.h> #include <linux/slab.h> #include <net/sock.h> #include <net/netlink.h> #include <net/genetlink.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/net_namespace.h> #include <net/netlabel.h> #include <asm/bug.h> #include <linux/atomic.h> #include "netlabel_user.h" #include "netlabel_addrlist.h" #include "netlabel_domainhash.h" #include "netlabel_unlabeled.h" #include "netlabel_mgmt.h" /* NOTE: at present we always use init's network namespace since we don't * presently support different namespaces even though the majority of * the functions in this file are "namespace safe" */ /* The unlabeled connection hash table which we use to map network interfaces * and addresses of unlabeled packets to a user specified secid value for the * LSM. The hash table is used to lookup the network interface entry * (struct netlbl_unlhsh_iface) and then the interface entry is used to * lookup an IP address match from an ordered list. If a network interface * match can not be found in the hash table then the default entry * (netlbl_unlhsh_def) is used. The IP address entry list * (struct netlbl_unlhsh_addr) is ordered such that the entries with a * larger netmask come first. */ struct netlbl_unlhsh_tbl { … }; #define netlbl_unlhsh_addr4_entry(iter) … struct netlbl_unlhsh_addr4 { … }; #define netlbl_unlhsh_addr6_entry(iter) … struct netlbl_unlhsh_addr6 { … }; struct netlbl_unlhsh_iface { … }; /* Argument struct for netlbl_unlhsh_walk() */ struct netlbl_unlhsh_walk_arg { … }; /* Unlabeled connection hash table */ /* updates should be so rare that having one spinlock for the entire * hash table should be okay */ static DEFINE_SPINLOCK(netlbl_unlhsh_lock); #define netlbl_unlhsh_rcu_deref(p) … static struct netlbl_unlhsh_tbl __rcu *netlbl_unlhsh; static struct netlbl_unlhsh_iface __rcu *netlbl_unlhsh_def; /* Accept unlabeled packets flag */ static u8 netlabel_unlabel_acceptflg; /* NetLabel Generic NETLINK unlabeled family */ static struct genl_family netlbl_unlabel_gnl_family; /* NetLabel Netlink attribute policy */ static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = …; /* * Unlabeled Connection Hash Table Functions */ /** * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table * @entry: the entry's RCU field * * Description: * This function is designed to be used as a callback to the call_rcu() * function so that memory allocated to a hash table interface entry can be * released safely. It is important to note that this function does not free * the IPv4 and IPv6 address lists contained as part of an interface entry. It * is up to the rest of the code to make sure an interface entry is only freed * once it's address lists are empty. * */ static void netlbl_unlhsh_free_iface(struct rcu_head *entry) { … } /** * netlbl_unlhsh_hash - Hashing function for the hash table * @ifindex: the network interface/device to hash * * Description: * This is the hashing function for the unlabeled hash table, it returns the * bucket number for the given device/interface. The caller is responsible for * ensuring that the hash table is protected with either a RCU read lock or * the hash table lock. * */ static u32 netlbl_unlhsh_hash(int ifindex) { … } /** * netlbl_unlhsh_search_iface - Search for a matching interface entry * @ifindex: the network interface * * Description: * Searches the unlabeled connection hash table and returns a pointer to the * interface entry which matches @ifindex, otherwise NULL is returned. The * caller is responsible for ensuring that the hash table is protected with * either a RCU read lock or the hash table lock. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex) { … } /** * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table * @iface: the associated interface entry * @addr: IPv4 address in network byte order * @mask: IPv4 address mask in network byte order * @secid: LSM secid value for entry * * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise * a negative value is returned. * */ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface, const struct in_addr *addr, const struct in_addr *mask, u32 secid) { … } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table * @iface: the associated interface entry * @addr: IPv6 address in network byte order * @mask: IPv6 address mask in network byte order * @secid: LSM secid value for entry * * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise * a negative value is returned. * */ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface, const struct in6_addr *addr, const struct in6_addr *mask, u32 secid) { … } #endif /* IPv6 */ /** * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table * @ifindex: network interface * * Description: * Add a new, empty, interface entry into the unlabeled connection hash table. * On success a pointer to the new interface entry is returned, on failure NULL * is returned. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex) { … } /** * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table * @net: network namespace * @dev_name: interface name * @addr: IP address in network byte order * @mask: address mask in network byte order * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6) * @secid: LSM secid value for the entry * @audit_info: NetLabel audit information * * Description: * Adds a new entry to the unlabeled connection hash table. Returns zero on * success, negative values on failure. * */ int netlbl_unlhsh_add(struct net *net, const char *dev_name, const void *addr, const void *mask, u32 addr_len, u32 secid, struct netlbl_audit *audit_info) { … } /** * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry * @net: network namespace * @iface: interface entry * @addr: IP address * @mask: IP address mask * @audit_info: NetLabel audit information * * Description: * Remove an IP address entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr4(struct net *net, struct netlbl_unlhsh_iface *iface, const struct in_addr *addr, const struct in_addr *mask, struct netlbl_audit *audit_info) { … } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry * @net: network namespace * @iface: interface entry * @addr: IP address * @mask: IP address mask * @audit_info: NetLabel audit information * * Description: * Remove an IP address entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr6(struct net *net, struct netlbl_unlhsh_iface *iface, const struct in6_addr *addr, const struct in6_addr *mask, struct netlbl_audit *audit_info) { … } #endif /* IPv6 */ /** * netlbl_unlhsh_condremove_iface - Remove an interface entry * @iface: the interface entry * * Description: * Remove an interface entry from the unlabeled connection hash table if it is * empty. An interface entry is considered to be empty if there are no * address entries assigned to it. * */ static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface) { … } /** * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table * @net: network namespace * @dev_name: interface name * @addr: IP address in network byte order * @mask: address mask in network byte order * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6) * @audit_info: NetLabel audit information * * Description: * Removes and existing entry from the unlabeled connection hash table. * Returns zero on success, negative values on failure. * */ int netlbl_unlhsh_remove(struct net *net, const char *dev_name, const void *addr, const void *mask, u32 addr_len, struct netlbl_audit *audit_info) { … } /* * General Helper Functions */ /** * netlbl_unlhsh_netdev_handler - Network device notification handler * @this: notifier block * @event: the event * @ptr: the netdevice notifier info (cast to void) * * Description: * Handle network device events, although at present all we care about is a * network device going away. In the case of a device going away we clear any * related entries from the unlabeled connection hash table. * */ static int netlbl_unlhsh_netdev_handler(struct notifier_block *this, unsigned long event, void *ptr) { … } /** * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag * @value: desired value * @audit_info: NetLabel audit information * * Description: * Set the value of the unlabeled accept flag to @value. * */ static void netlbl_unlabel_acceptflg_set(u8 value, struct netlbl_audit *audit_info) { … } /** * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information * @info: the Generic NETLINK info block * @addr: the IP address * @mask: the IP address mask * @len: the address length * * Description: * Examine the Generic NETLINK message and extract the IP address information. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_addrinfo_get(struct genl_info *info, void **addr, void **mask, u32 *len) { … } /* * NetLabel Command Handlers */ /** * netlbl_unlabel_accept - Handle an ACCEPT message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated ACCEPT message and set the accept flag accordingly. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_list - Handle a LIST message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated LIST message and respond with the current status. * Returns zero on success, negative values on failure. * */ static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_staticadd - Handle a STATICADD message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICADD message and add a new unlabeled * connection entry to the hash table. Returns zero on success, negative * values on failure. * */ static int netlbl_unlabel_staticadd(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICADDDEF message and add a new default * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticadddef(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_staticremove - Handle a STATICREMOVE message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICREMOVE message and remove the specified * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticremove(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message * @skb: the NETLINK buffer * @info: the Generic NETLINK info block * * Description: * Process a user generated STATICREMOVEDEF message and remove the default * unlabeled connection entry. Returns zero on success, negative values on * failure. * */ static int netlbl_unlabel_staticremovedef(struct sk_buff *skb, struct genl_info *info) { … } /** * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF] * @cmd: command/message * @iface: the interface entry * @addr4: the IPv4 address entry * @addr6: the IPv6 address entry * @arg: the netlbl_unlhsh_walk_arg structure * * Description: * This function is designed to be used to generate a response for a * STATICLIST or STATICLISTDEF message. When called either @addr4 or @addr6 * can be specified, not both, the other unspecified entry should be set to * NULL by the caller. Returns the size of the message on success, negative * values on failure. * */ static int netlbl_unlabel_staticlist_gen(u32 cmd, const struct netlbl_unlhsh_iface *iface, const struct netlbl_unlhsh_addr4 *addr4, const struct netlbl_unlhsh_addr6 *addr6, void *arg) { … } /** * netlbl_unlabel_staticlist - Handle a STATICLIST message * @skb: the NETLINK buffer * @cb: the NETLINK callback * * Description: * Process a user generated STATICLIST message and dump the unlabeled * connection hash table in a form suitable for use in a kernel generated * STATICLIST message. Returns the length of @skb. * */ static int netlbl_unlabel_staticlist(struct sk_buff *skb, struct netlink_callback *cb) { … } /** * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message * @skb: the NETLINK buffer * @cb: the NETLINK callback * * Description: * Process a user generated STATICLISTDEF message and dump the default * unlabeled connection entry in a form suitable for use in a kernel generated * STATICLISTDEF message. Returns the length of @skb. * */ static int netlbl_unlabel_staticlistdef(struct sk_buff *skb, struct netlink_callback *cb) { … } /* * NetLabel Generic NETLINK Command Definitions */ static const struct genl_small_ops netlbl_unlabel_genl_ops[] = …; static struct genl_family netlbl_unlabel_gnl_family __ro_after_init = …; /* * NetLabel Generic NETLINK Protocol Functions */ /** * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component * * Description: * Register the unlabeled packet NetLabel component with the Generic NETLINK * mechanism. Returns zero on success, negative values on failure. * */ int __init netlbl_unlabel_genl_init(void) { … } /* * NetLabel KAPI Hooks */ static struct notifier_block netlbl_unlhsh_netdev_notifier = …; /** * netlbl_unlabel_init - Initialize the unlabeled connection hash table * @size: the number of bits to use for the hash buckets * * Description: * Initializes the unlabeled connection hash table and registers a network * device notification handler. This function should only be called by the * NetLabel subsystem itself during initialization. Returns zero on success, * non-zero values on error. * */ int __init netlbl_unlabel_init(u32 size) { … } /** * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet * @skb: the packet * @family: protocol family * @secattr: the security attributes * * Description: * Determine the security attributes, if any, for an unlabled packet and return * them in @secattr. Returns zero on success and negative values on failure. * */ int netlbl_unlabel_getattr(const struct sk_buff *skb, u16 family, struct netlbl_lsm_secattr *secattr) { … } /** * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets * * Description: * Set the default NetLabel configuration to allow incoming unlabeled packets * and to send unlabeled network traffic by default. * */ int __init netlbl_unlabel_defconf(void) { … }
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