// SPDX-License-Identifier: GPL-2.0-or-later /* * NetLabel Domain Hash Table * * This file manages the domain hash table that NetLabel uses to determine * which network labeling protocol to use for a given domain. 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/rculist.h> #include <linux/skbuff.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/audit.h> #include <linux/slab.h> #include <net/netlabel.h> #include <net/cipso_ipv4.h> #include <net/calipso.h> #include <asm/bug.h> #include "netlabel_mgmt.h" #include "netlabel_addrlist.h" #include "netlabel_calipso.h" #include "netlabel_domainhash.h" #include "netlabel_user.h" struct netlbl_domhsh_tbl { … }; /* Domain hash table */ /* updates should be so rare that having one spinlock for the entire hash table * should be okay */ static DEFINE_SPINLOCK(netlbl_domhsh_lock); #define netlbl_domhsh_rcu_deref(p) … static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh; static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv4; static struct netlbl_dom_map __rcu *netlbl_domhsh_def_ipv6; /* * Domain Hash Table Helper Functions */ /** * netlbl_domhsh_free_entry - Frees a domain hash table entry * @entry: the entry's RCU field * * Description: * This function is designed to be used as a callback to the call_rcu() * function so that the memory allocated to a hash table entry can be released * safely. * */ static void netlbl_domhsh_free_entry(struct rcu_head *entry) { … } /** * netlbl_domhsh_hash - Hashing function for the domain hash table * @key: the domain name to hash * * Description: * This is the hashing function for the domain hash table, it returns the * correct bucket number for the domain. 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_domhsh_hash(const char *key) { … } static bool netlbl_family_match(u16 f1, u16 f2) { … } /** * netlbl_domhsh_search - Search for a domain entry * @domain: the domain * @family: the address family * * Description: * Searches the domain hash table and returns a pointer to the hash table * entry if found, otherwise NULL is returned. @family may be %AF_UNSPEC * which matches any address family entries. 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_dom_map *netlbl_domhsh_search(const char *domain, u16 family) { … } /** * netlbl_domhsh_search_def - Search for a domain entry * @domain: the domain * @family: the address family * * Description: * Searches the domain hash table and returns a pointer to the hash table * entry if an exact match is found, if an exact match is not present in the * hash table then the default entry is returned if valid otherwise NULL is * returned. @family may be %AF_UNSPEC which matches any address family * entries. The caller is responsible ensuring that the hash table is * protected with either a RCU read lock or the hash table lock. * */ static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain, u16 family) { … } /** * netlbl_domhsh_audit_add - Generate an audit entry for an add event * @entry: the entry being added * @addr4: the IPv4 address information * @addr6: the IPv6 address information * @result: the result code * @audit_info: NetLabel audit information * * Description: * Generate an audit record for adding a new NetLabel/LSM mapping entry with * the given information. Caller is responsible for holding the necessary * locks. * */ static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry, struct netlbl_af4list *addr4, struct netlbl_af6list *addr6, int result, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_validate - Validate a new domain mapping entry * @entry: the entry to validate * * This function validates the new domain mapping entry to ensure that it is * a valid entry. Returns zero on success, negative values on failure. * */ static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry) { … } /* * Domain Hash Table Functions */ /** * netlbl_domhsh_init - Init for the domain hash * @size: the number of bits to use for the hash buckets * * Description: * Initializes the domain hash table, should be called only by * netlbl_user_init() during initialization. Returns zero on success, non-zero * values on error. * */ int __init netlbl_domhsh_init(u32 size) { … } /** * netlbl_domhsh_add - Adds a entry to the domain hash table * @entry: the entry to add * @audit_info: NetLabel audit information * * Description: * Adds a new entry to the domain hash table and handles any updates to the * lower level protocol handler (i.e. CIPSO). @entry->family may be set to * %AF_UNSPEC which will add an entry that matches all address families. This * is only useful for the unlabelled type and will only succeed if there is no * existing entry for any address family with the same domain. Returns zero * on success, negative on failure. * */ int netlbl_domhsh_add(struct netlbl_dom_map *entry, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_add_default - Adds the default entry to the domain hash table * @entry: the entry to add * @audit_info: NetLabel audit information * * Description: * Adds a new default entry to the domain hash table and handles any updates * to the lower level protocol handler (i.e. CIPSO). Returns zero on success, * negative on failure. * */ int netlbl_domhsh_add_default(struct netlbl_dom_map *entry, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_remove_entry - Removes a given entry from the domain table * @entry: the entry to remove * @audit_info: NetLabel audit information * * Description: * Removes an entry from the domain hash table and handles any updates to the * lower level protocol handler (i.e. CIPSO). Caller is responsible for * ensuring that the RCU read lock is held. Returns zero on success, negative * on failure. * */ int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_remove_af4 - Removes an address selector entry * @domain: the domain * @addr: IPv4 address * @mask: IPv4 address mask * @audit_info: NetLabel audit information * * Description: * Removes an individual address selector from a domain mapping and potentially * the entire mapping if it is empty. Returns zero on success, negative values * on failure. * */ int netlbl_domhsh_remove_af4(const char *domain, const struct in_addr *addr, const struct in_addr *mask, struct netlbl_audit *audit_info) { … } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_domhsh_remove_af6 - Removes an address selector entry * @domain: the domain * @addr: IPv6 address * @mask: IPv6 address mask * @audit_info: NetLabel audit information * * Description: * Removes an individual address selector from a domain mapping and potentially * the entire mapping if it is empty. Returns zero on success, negative values * on failure. * */ int netlbl_domhsh_remove_af6(const char *domain, const struct in6_addr *addr, const struct in6_addr *mask, struct netlbl_audit *audit_info) { … } #endif /* IPv6 */ /** * netlbl_domhsh_remove - Removes an entry from the domain hash table * @domain: the domain to remove * @family: address family * @audit_info: NetLabel audit information * * Description: * Removes an entry from the domain hash table and handles any updates to the * lower level protocol handler (i.e. CIPSO). @family may be %AF_UNSPEC which * removes all address family entries. Returns zero on success, negative on * failure. * */ int netlbl_domhsh_remove(const char *domain, u16 family, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_remove_default - Removes the default entry from the table * @family: address family * @audit_info: NetLabel audit information * * Description: * Removes/resets the default entry corresponding to @family from the domain * hash table and handles any updates to the lower level protocol handler * (i.e. CIPSO). @family may be %AF_UNSPEC which removes all address family * entries. Returns zero on success, negative on failure. * */ int netlbl_domhsh_remove_default(u16 family, struct netlbl_audit *audit_info) { … } /** * netlbl_domhsh_getentry - Get an entry from the domain hash table * @domain: the domain name to search for * @family: address family * * Description: * Look through the domain hash table searching for an entry to match @domain, * with address family @family, return a pointer to a copy of the entry or * NULL. The caller is responsible for ensuring that rcu_read_[un]lock() is * called. * */ struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain, u16 family) { … } /** * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table * @domain: the domain name to search for * @addr: the IP address to search for * * Description: * Look through the domain hash table searching for an entry to match @domain * and @addr, return a pointer to a copy of the entry or NULL. The caller is * responsible for ensuring that rcu_read_[un]lock() is called. * */ struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain, __be32 addr) { … } #if IS_ENABLED(CONFIG_IPV6) /** * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table * @domain: the domain name to search for * @addr: the IP address to search for * * Description: * Look through the domain hash table searching for an entry to match @domain * and @addr, return a pointer to a copy of the entry or NULL. The caller is * responsible for ensuring that rcu_read_[un]lock() is called. * */ struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain, const struct in6_addr *addr) { … } #endif /* IPv6 */ /** * netlbl_domhsh_walk - Iterate through the domain mapping hash table * @skip_bkt: the number of buckets to skip at the start * @skip_chain: the number of entries to skip in the first iterated bucket * @callback: callback for each entry * @cb_arg: argument for the callback function * * Description: * Iterate over the domain mapping hash table, skipping the first @skip_bkt * buckets and @skip_chain entries. For each entry in the table call * @callback, if @callback returns a negative value stop 'walking' through the * table and return. Updates the values in @skip_bkt and @skip_chain on * return. Returns zero on success, negative values on failure. * */ int netlbl_domhsh_walk(u32 *skip_bkt, u32 *skip_chain, int (*callback) (struct netlbl_dom_map *entry, void *arg), void *cb_arg) { … }
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