// SPDX-License-Identifier: GPL-2.0-or-later /* * CALIPSO - Common Architecture Label IPv6 Security Option * * This is an implementation of the CALIPSO protocol as specified in * RFC 5570. * * Authors: Paul Moore <[email protected]> * Huw Davies <[email protected]> */ /* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 * (c) Copyright Huw Davies <[email protected]>, 2015 */ #include <linux/init.h> #include <linux/types.h> #include <linux/rcupdate.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/jhash.h> #include <linux/audit.h> #include <linux/slab.h> #include <net/ip.h> #include <net/icmp.h> #include <net/tcp.h> #include <net/netlabel.h> #include <net/calipso.h> #include <linux/atomic.h> #include <linux/bug.h> #include <asm/unaligned.h> #include <linux/crc-ccitt.h> /* Maximium size of the calipso option including * the two-byte TLV header. */ #define CALIPSO_OPT_LEN_MAX … /* Size of the minimum calipso option including * the two-byte TLV header. */ #define CALIPSO_HDR_LEN … /* Maximium size of the calipso option including * the two-byte TLV header and upto 3 bytes of * leading pad and 7 bytes of trailing pad. */ #define CALIPSO_OPT_LEN_MAX_WITH_PAD … /* Maximium size of u32 aligned buffer required to hold calipso * option. Max of 3 initial pad bytes starting from buffer + 3. * i.e. the worst case is when the previous tlv finishes on 4n + 3. */ #define CALIPSO_MAX_BUFFER … /* List of available DOI definitions */ static DEFINE_SPINLOCK(calipso_doi_list_lock); static LIST_HEAD(calipso_doi_list); /* Label mapping cache */ int calipso_cache_enabled = …; int calipso_cache_bucketsize = …; #define CALIPSO_CACHE_BUCKETBITS … #define CALIPSO_CACHE_BUCKETS … #define CALIPSO_CACHE_REORDERLIMIT … struct calipso_map_cache_bkt { … }; struct calipso_map_cache_entry { … }; static struct calipso_map_cache_bkt *calipso_cache; static void calipso_cache_invalidate(void); static void calipso_doi_putdef(struct calipso_doi *doi_def); /* Label Mapping Cache Functions */ /** * calipso_cache_entry_free - Frees a cache entry * @entry: the entry to free * * Description: * This function frees the memory associated with a cache entry including the * LSM cache data if there are no longer any users, i.e. reference count == 0. * */ static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry) { … } /** * calipso_map_cache_hash - Hashing function for the CALIPSO cache * @key: the hash key * @key_len: the length of the key in bytes * * Description: * The CALIPSO tag hashing function. Returns a 32-bit hash value. * */ static u32 calipso_map_cache_hash(const unsigned char *key, u32 key_len) { … } /** * calipso_cache_init - Initialize the CALIPSO cache * * Description: * Initializes the CALIPSO label mapping cache, this function should be called * before any of the other functions defined in this file. Returns zero on * success, negative values on error. * */ static int __init calipso_cache_init(void) { … } /** * calipso_cache_invalidate - Invalidates the current CALIPSO cache * * Description: * Invalidates and frees any entries in the CALIPSO cache. Returns zero on * success and negative values on failure. * */ static void calipso_cache_invalidate(void) { … } /** * calipso_cache_check - Check the CALIPSO cache for a label mapping * @key: the buffer to check * @key_len: buffer length in bytes * @secattr: the security attribute struct to use * * Description: * This function checks the cache to see if a label mapping already exists for * the given key. If there is a match then the cache is adjusted and the * @secattr struct is populated with the correct LSM security attributes. The * cache is adjusted in the following manner if the entry is not already the * first in the cache bucket: * * 1. The cache entry's activity counter is incremented * 2. The previous (higher ranking) entry's activity counter is decremented * 3. If the difference between the two activity counters is geater than * CALIPSO_CACHE_REORDERLIMIT the two entries are swapped * * Returns zero on success, -ENOENT for a cache miss, and other negative values * on error. * */ static int calipso_cache_check(const unsigned char *key, u32 key_len, struct netlbl_lsm_secattr *secattr) { … } /** * calipso_cache_add - Add an entry to the CALIPSO cache * @calipso_ptr: the CALIPSO option * @secattr: the packet's security attributes * * Description: * Add a new entry into the CALIPSO label mapping cache. Add the new entry to * head of the cache bucket's list, if the cache bucket is out of room remove * the last entry in the list first. It is important to note that there is * currently no checking for duplicate keys. Returns zero on success, * negative values on failure. The key stored starts at calipso_ptr + 2, * i.e. the type and length bytes are not stored, this corresponds to * calipso_ptr[1] bytes of data. * */ static int calipso_cache_add(const unsigned char *calipso_ptr, const struct netlbl_lsm_secattr *secattr) { … } /* DOI List Functions */ /** * calipso_doi_search - Searches for a DOI definition * @doi: the DOI to search for * * Description: * Search the DOI definition list for a DOI definition with a DOI value that * matches @doi. The caller is responsible for calling rcu_read_[un]lock(). * Returns a pointer to the DOI definition on success and NULL on failure. */ static struct calipso_doi *calipso_doi_search(u32 doi) { … } /** * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine * @doi_def: the DOI structure * @audit_info: NetLabel audit information * * Description: * The caller defines a new DOI for use by the CALIPSO engine and calls this * function to add it to the list of acceptable domains. The caller must * ensure that the mapping table specified in @doi_def->map meets all of the * requirements of the mapping type (see calipso.h for details). Returns * zero on success and non-zero on failure. * */ static int calipso_doi_add(struct calipso_doi *doi_def, struct netlbl_audit *audit_info) { … } /** * calipso_doi_free - Frees a DOI definition * @doi_def: the DOI definition * * Description: * This function frees all of the memory associated with a DOI definition. * */ static void calipso_doi_free(struct calipso_doi *doi_def) { … } /** * calipso_doi_free_rcu - Frees a DOI definition via the RCU pointer * @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 the DOI definition can be released * safely. * */ static void calipso_doi_free_rcu(struct rcu_head *entry) { … } /** * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine * @doi: the DOI value * @audit_info: NetLabel audit information * * Description: * Removes a DOI definition from the CALIPSO engine. The NetLabel routines will * be called to release their own LSM domain mappings as well as our own * domain list. Returns zero on success and negative values on failure. * */ static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info) { … } /** * calipso_doi_getdef - Returns a reference to a valid DOI definition * @doi: the DOI value * * Description: * Searches for a valid DOI definition and if one is found it is returned to * the caller. Otherwise NULL is returned. The caller must ensure that * calipso_doi_putdef() is called when the caller is done. * */ static struct calipso_doi *calipso_doi_getdef(u32 doi) { … } /** * calipso_doi_putdef - Releases a reference for the given DOI definition * @doi_def: the DOI definition * * Description: * Releases a DOI definition reference obtained from calipso_doi_getdef(). * */ static void calipso_doi_putdef(struct calipso_doi *doi_def) { … } /** * calipso_doi_walk - Iterate through the DOI definitions * @skip_cnt: skip past this number of DOI definitions, updated * @callback: callback for each DOI definition * @cb_arg: argument for the callback function * * Description: * Iterate over the DOI definition list, skipping the first @skip_cnt entries. * For each entry call @callback, if @callback returns a negative value stop * 'walking' through the list and return. Updates the value in @skip_cnt upon * return. Returns zero on success, negative values on failure. * */ static int calipso_doi_walk(u32 *skip_cnt, int (*callback)(struct calipso_doi *doi_def, void *arg), void *cb_arg) { … } /** * calipso_validate - Validate a CALIPSO option * @skb: the packet * @option: the start of the option * * Description: * This routine is called to validate a CALIPSO option. * If the option is valid then %true is returned, otherwise * %false is returned. * * The caller should have already checked that the length of the * option (including the TLV header) is >= 10 and that the catmap * length is consistent with the option length. * * We leave checks on the level and categories to the socket layer. */ bool calipso_validate(const struct sk_buff *skb, const unsigned char *option) { … } /** * calipso_map_cat_hton - Perform a category mapping from host to network * @doi_def: the DOI definition * @secattr: the security attributes * @net_cat: the zero'd out category bitmap in network/CALIPSO format * @net_cat_len: the length of the CALIPSO bitmap in bytes * * Description: * Perform a label mapping to translate a local MLS category bitmap to the * correct CALIPSO bitmap using the given DOI definition. Returns the minimum * size in bytes of the network bitmap on success, negative values otherwise. * */ static int calipso_map_cat_hton(const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr, unsigned char *net_cat, u32 net_cat_len) { … } /** * calipso_map_cat_ntoh - Perform a category mapping from network to host * @doi_def: the DOI definition * @net_cat: the category bitmap in network/CALIPSO format * @net_cat_len: the length of the CALIPSO bitmap in bytes * @secattr: the security attributes * * Description: * Perform a label mapping to translate a CALIPSO bitmap to the correct local * MLS category bitmap using the given DOI definition. Returns zero on * success, negative values on failure. * */ static int calipso_map_cat_ntoh(const struct calipso_doi *doi_def, const unsigned char *net_cat, u32 net_cat_len, struct netlbl_lsm_secattr *secattr) { … } /** * calipso_pad_write - Writes pad bytes in TLV format * @buf: the buffer * @offset: offset from start of buffer to write padding * @count: number of pad bytes to write * * Description: * Write @count bytes of TLV padding into @buffer starting at offset @offset. * @count should be less than 8 - see RFC 4942. * */ static int calipso_pad_write(unsigned char *buf, unsigned int offset, unsigned int count) { … } /** * calipso_genopt - Generate a CALIPSO option * @buf: the option buffer * @start: offset from which to write * @buf_len: the size of opt_buf * @doi_def: the CALIPSO DOI to use * @secattr: the security attributes * * Description: * Generate a CALIPSO option using the DOI definition and security attributes * passed to the function. This also generates upto three bytes of leading * padding that ensures that the option is 4n + 2 aligned. It returns the * number of bytes written (including any initial padding). */ static int calipso_genopt(unsigned char *buf, u32 start, u32 buf_len, const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr) { … } /* Hop-by-hop hdr helper functions */ /** * calipso_opt_update - Replaces socket's hop options with a new set * @sk: the socket * @hop: new hop options * * Description: * Replaces @sk's hop options with @hop. @hop may be NULL to leave * the socket with no hop options. * */ static int calipso_opt_update(struct sock *sk, struct ipv6_opt_hdr *hop) { … } /** * calipso_tlv_len - Returns the length of the TLV * @opt: the option header * @offset: offset of the TLV within the header * * Description: * Returns the length of the TLV option at offset @offset within * the option header @opt. Checks that the entire TLV fits inside * the option header, returns a negative value if this is not the case. */ static int calipso_tlv_len(struct ipv6_opt_hdr *opt, unsigned int offset) { … } /** * calipso_opt_find - Finds the CALIPSO option in an IPv6 hop options header * @hop: the hop options header * @start: on return holds the offset of any leading padding * @end: on return holds the offset of the first non-pad TLV after CALIPSO * * Description: * Finds the space occupied by a CALIPSO option (including any leading and * trailing padding). * * If a CALIPSO option exists set @start and @end to the * offsets within @hop of the start of padding before the first * CALIPSO option and the end of padding after the first CALIPSO * option. In this case the function returns 0. * * In the absence of a CALIPSO option, @start and @end will be * set to the start and end of any trailing padding in the header. * This is useful when appending a new option, as the caller may want * to overwrite some of this padding. In this case the function will * return -ENOENT. */ static int calipso_opt_find(struct ipv6_opt_hdr *hop, unsigned int *start, unsigned int *end) { … } /** * calipso_opt_insert - Inserts a CALIPSO option into an IPv6 hop opt hdr * @hop: the original hop options header * @doi_def: the CALIPSO DOI to use * @secattr: the specific security attributes of the socket * * Description: * Creates a new hop options header based on @hop with a * CALIPSO option added to it. If @hop already contains a CALIPSO * option this is overwritten, otherwise the new option is appended * after any existing options. If @hop is NULL then the new header * will contain just the CALIPSO option and any needed padding. * */ static struct ipv6_opt_hdr * calipso_opt_insert(struct ipv6_opt_hdr *hop, const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr) { … } /** * calipso_opt_del - Removes the CALIPSO option from an option header * @hop: the original header * @new: the new header * * Description: * Creates a new header based on @hop without any CALIPSO option. If @hop * doesn't contain a CALIPSO option it returns -ENOENT. If @hop contains * no other non-padding options, it returns zero with @new set to NULL. * Otherwise it returns zero, creates a new header without the CALIPSO * option (and removing as much padding as possible) and returns with * @new set to that header. * */ static int calipso_opt_del(struct ipv6_opt_hdr *hop, struct ipv6_opt_hdr **new) { … } /** * calipso_opt_getattr - Get the security attributes from a memory block * @calipso: the CALIPSO option * @secattr: the security attributes * * Description: * Inspect @calipso and return the security attributes in @secattr. * Returns zero on success and negative values on failure. * */ static int calipso_opt_getattr(const unsigned char *calipso, struct netlbl_lsm_secattr *secattr) { … } /* sock functions. */ /** * calipso_sock_getattr - Get the security attributes from a sock * @sk: the sock * @secattr: the security attributes * * Description: * Query @sk to see if there is a CALIPSO option attached to the sock and if * there is return the CALIPSO security attributes in @secattr. This function * requires that @sk be locked, or privately held, but it does not do any * locking itself. Returns zero on success and negative values on failure. * */ static int calipso_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { … } /** * calipso_sock_setattr - Add a CALIPSO option to a socket * @sk: the socket * @doi_def: the CALIPSO DOI to use * @secattr: the specific security attributes of the socket * * Description: * Set the CALIPSO option on the given socket using the DOI definition and * security attributes passed to the function. This function requires * exclusive access to @sk, which means it either needs to be in the * process of being created or locked. Returns zero on success and negative * values on failure. * */ static int calipso_sock_setattr(struct sock *sk, const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr) { … } /** * calipso_sock_delattr - Delete the CALIPSO option from a socket * @sk: the socket * * Description: * Removes the CALIPSO option from a socket, if present. * */ static void calipso_sock_delattr(struct sock *sk) { … } /* request sock functions. */ /** * calipso_req_setattr - Add a CALIPSO option to a connection request socket * @req: the connection request socket * @doi_def: the CALIPSO DOI to use * @secattr: the specific security attributes of the socket * * Description: * Set the CALIPSO option on the given socket using the DOI definition and * security attributes passed to the function. Returns zero on success and * negative values on failure. * */ static int calipso_req_setattr(struct request_sock *req, const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr) { … } /** * calipso_req_delattr - Delete the CALIPSO option from a request socket * @req: the request socket * * Description: * Removes the CALIPSO option from a request socket, if present. * */ static void calipso_req_delattr(struct request_sock *req) { … } /* skbuff functions. */ /** * calipso_skbuff_optptr - Find the CALIPSO option in the packet * @skb: the packet * * Description: * Parse the packet's IP header looking for a CALIPSO option. Returns a pointer * to the start of the CALIPSO option on success, NULL if one if not found. * */ static unsigned char *calipso_skbuff_optptr(const struct sk_buff *skb) { … } /** * calipso_skbuff_setattr - Set the CALIPSO option on a packet * @skb: the packet * @doi_def: the CALIPSO DOI to use * @secattr: the security attributes * * Description: * Set the CALIPSO option on the given packet based on the security attributes. * Returns a pointer to the IP header on success and NULL on failure. * */ static int calipso_skbuff_setattr(struct sk_buff *skb, const struct calipso_doi *doi_def, const struct netlbl_lsm_secattr *secattr) { … } /** * calipso_skbuff_delattr - Delete any CALIPSO options from a packet * @skb: the packet * * Description: * Removes any and all CALIPSO options from the given packet. Returns zero on * success, negative values on failure. * */ static int calipso_skbuff_delattr(struct sk_buff *skb) { … } static const struct netlbl_calipso_ops ops = …; /** * calipso_init - Initialize the CALIPSO module * * Description: * Initialize the CALIPSO module and prepare it for use. Returns zero on * success and negative values on failure. * */ int __init calipso_init(void) { … } void calipso_exit(void) { … }
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