| /* |
| * CIPSO - Commercial IP Security Option |
| * |
| * This is an implementation of the CIPSO 2.2 protocol as specified in |
| * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in |
| * FIPS-188. While CIPSO never became a full IETF RFC standard many vendors |
| * have chosen to adopt the protocol and over the years it has become a |
| * de-facto standard for labeled networking. |
| * |
| * The CIPSO draft specification can be found in the kernel's Documentation |
| * directory as well as the following URL: |
| * http://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt |
| * The FIPS-188 specification can be found at the following URL: |
| * http://www.itl.nist.gov/fipspubs/fip188.htm |
| * |
| * Author: Paul Moore <paul.moore@hp.com> |
| * |
| */ |
| |
| /* |
| * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| * the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #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/cipso_ipv4.h> |
| #include <linux/atomic.h> |
| #include <linux/bug.h> |
| #include <asm/unaligned.h> |
| |
| /* List of available DOI definitions */ |
| /* XXX - This currently assumes a minimal number of different DOIs in use, |
| * if in practice there are a lot of different DOIs this list should |
| * probably be turned into a hash table or something similar so we |
| * can do quick lookups. */ |
| static DEFINE_SPINLOCK(cipso_v4_doi_list_lock); |
| static LIST_HEAD(cipso_v4_doi_list); |
| |
| /* Label mapping cache */ |
| int cipso_v4_cache_enabled = 1; |
| int cipso_v4_cache_bucketsize = 10; |
| #define CIPSO_V4_CACHE_BUCKETBITS 7 |
| #define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS) |
| #define CIPSO_V4_CACHE_REORDERLIMIT 10 |
| struct cipso_v4_map_cache_bkt { |
| spinlock_t lock; |
| u32 size; |
| struct list_head list; |
| }; |
| |
| struct cipso_v4_map_cache_entry { |
| u32 hash; |
| unsigned char *key; |
| size_t key_len; |
| |
| struct netlbl_lsm_cache *lsm_data; |
| |
| u32 activity; |
| struct list_head list; |
| }; |
| |
| static struct cipso_v4_map_cache_bkt *cipso_v4_cache; |
| |
| /* Restricted bitmap (tag #1) flags */ |
| int cipso_v4_rbm_optfmt = 0; |
| int cipso_v4_rbm_strictvalid = 1; |
| |
| /* |
| * Protocol Constants |
| */ |
| |
| /* Maximum size of the CIPSO IP option, derived from the fact that the maximum |
| * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */ |
| #define CIPSO_V4_OPT_LEN_MAX 40 |
| |
| /* Length of the base CIPSO option, this includes the option type (1 byte), the |
| * option length (1 byte), and the DOI (4 bytes). */ |
| #define CIPSO_V4_HDR_LEN 6 |
| |
| /* Base length of the restrictive category bitmap tag (tag #1). */ |
| #define CIPSO_V4_TAG_RBM_BLEN 4 |
| |
| /* Base length of the enumerated category tag (tag #2). */ |
| #define CIPSO_V4_TAG_ENUM_BLEN 4 |
| |
| /* Base length of the ranged categories bitmap tag (tag #5). */ |
| #define CIPSO_V4_TAG_RNG_BLEN 4 |
| /* The maximum number of category ranges permitted in the ranged category tag |
| * (tag #5). You may note that the IETF draft states that the maximum number |
| * of category ranges is 7, but if the low end of the last category range is |
| * zero then it is possible to fit 8 category ranges because the zero should |
| * be omitted. */ |
| #define CIPSO_V4_TAG_RNG_CAT_MAX 8 |
| |
| /* Base length of the local tag (non-standard tag). |
| * Tag definition (may change between kernel versions) |
| * |
| * 0 8 16 24 32 |
| * +----------+----------+----------+----------+ |
| * | 10000000 | 00000110 | 32-bit secid value | |
| * +----------+----------+----------+----------+ |
| * | in (host byte order)| |
| * +----------+----------+ |
| * |
| */ |
| #define CIPSO_V4_TAG_LOC_BLEN 6 |
| |
| /* |
| * Helper Functions |
| */ |
| |
| /** |
| * cipso_v4_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 cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) |
| { |
| if (entry->lsm_data) |
| netlbl_secattr_cache_free(entry->lsm_data); |
| kfree(entry->key); |
| kfree(entry); |
| } |
| |
| /** |
| * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache |
| * @key: the hash key |
| * @key_len: the length of the key in bytes |
| * |
| * Description: |
| * The CIPSO tag hashing function. Returns a 32-bit hash value. |
| * |
| */ |
| static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len) |
| { |
| return jhash(key, key_len, 0); |
| } |
| |
| /* |
| * Label Mapping Cache Functions |
| */ |
| |
| /** |
| * cipso_v4_cache_init - Initialize the CIPSO cache |
| * |
| * Description: |
| * Initializes the CIPSO 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 cipso_v4_cache_init(void) |
| { |
| u32 iter; |
| |
| cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS, |
| sizeof(struct cipso_v4_map_cache_bkt), |
| GFP_KERNEL); |
| if (!cipso_v4_cache) |
| return -ENOMEM; |
| |
| for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
| spin_lock_init(&cipso_v4_cache[iter].lock); |
| cipso_v4_cache[iter].size = 0; |
| INIT_LIST_HEAD(&cipso_v4_cache[iter].list); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache |
| * |
| * Description: |
| * Invalidates and frees any entries in the CIPSO cache. Returns zero on |
| * success and negative values on failure. |
| * |
| */ |
| void cipso_v4_cache_invalidate(void) |
| { |
| struct cipso_v4_map_cache_entry *entry, *tmp_entry; |
| u32 iter; |
| |
| for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
| spin_lock_bh(&cipso_v4_cache[iter].lock); |
| list_for_each_entry_safe(entry, |
| tmp_entry, |
| &cipso_v4_cache[iter].list, list) { |
| list_del(&entry->list); |
| cipso_v4_cache_entry_free(entry); |
| } |
| cipso_v4_cache[iter].size = 0; |
| spin_unlock_bh(&cipso_v4_cache[iter].lock); |
| } |
| } |
| |
| /** |
| * cipso_v4_cache_check - Check the CIPSO 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 |
| * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped |
| * |
| * Returns zero on success, -ENOENT for a cache miss, and other negative values |
| * on error. |
| * |
| */ |
| static int cipso_v4_cache_check(const unsigned char *key, |
| u32 key_len, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| u32 bkt; |
| struct cipso_v4_map_cache_entry *entry; |
| struct cipso_v4_map_cache_entry *prev_entry = NULL; |
| u32 hash; |
| |
| if (!cipso_v4_cache_enabled) |
| return -ENOENT; |
| |
| hash = cipso_v4_map_cache_hash(key, key_len); |
| bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
| spin_lock_bh(&cipso_v4_cache[bkt].lock); |
| list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) { |
| if (entry->hash == hash && |
| entry->key_len == key_len && |
| memcmp(entry->key, key, key_len) == 0) { |
| entry->activity += 1; |
| atomic_inc(&entry->lsm_data->refcount); |
| secattr->cache = entry->lsm_data; |
| secattr->flags |= NETLBL_SECATTR_CACHE; |
| secattr->type = NETLBL_NLTYPE_CIPSOV4; |
| if (!prev_entry) { |
| spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
| return 0; |
| } |
| |
| if (prev_entry->activity > 0) |
| prev_entry->activity -= 1; |
| if (entry->activity > prev_entry->activity && |
| entry->activity - prev_entry->activity > |
| CIPSO_V4_CACHE_REORDERLIMIT) { |
| __list_del(entry->list.prev, entry->list.next); |
| __list_add(&entry->list, |
| prev_entry->list.prev, |
| &prev_entry->list); |
| } |
| |
| spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
| return 0; |
| } |
| prev_entry = entry; |
| } |
| spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
| |
| return -ENOENT; |
| } |
| |
| /** |
| * cipso_v4_cache_add - Add an entry to the CIPSO cache |
| * @skb: the packet |
| * @secattr: the packet's security attributes |
| * |
| * Description: |
| * Add a new entry into the CIPSO 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. |
| * |
| */ |
| int cipso_v4_cache_add(const unsigned char *cipso_ptr, |
| const struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val = -EPERM; |
| u32 bkt; |
| struct cipso_v4_map_cache_entry *entry = NULL; |
| struct cipso_v4_map_cache_entry *old_entry = NULL; |
| u32 cipso_ptr_len; |
| |
| if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) |
| return 0; |
| |
| cipso_ptr_len = cipso_ptr[1]; |
| |
| entry = kzalloc(sizeof(*entry), GFP_ATOMIC); |
| if (!entry) |
| return -ENOMEM; |
| entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC); |
| if (!entry->key) { |
| ret_val = -ENOMEM; |
| goto cache_add_failure; |
| } |
| entry->key_len = cipso_ptr_len; |
| entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); |
| atomic_inc(&secattr->cache->refcount); |
| entry->lsm_data = secattr->cache; |
| |
| bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
| spin_lock_bh(&cipso_v4_cache[bkt].lock); |
| if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) { |
| list_add(&entry->list, &cipso_v4_cache[bkt].list); |
| cipso_v4_cache[bkt].size += 1; |
| } else { |
| old_entry = list_entry(cipso_v4_cache[bkt].list.prev, |
| struct cipso_v4_map_cache_entry, list); |
| list_del(&old_entry->list); |
| list_add(&entry->list, &cipso_v4_cache[bkt].list); |
| cipso_v4_cache_entry_free(old_entry); |
| } |
| spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
| |
| return 0; |
| |
| cache_add_failure: |
| if (entry) |
| cipso_v4_cache_entry_free(entry); |
| return ret_val; |
| } |
| |
| /* |
| * DOI List Functions |
| */ |
| |
| /** |
| * cipso_v4_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 cipso_v4_doi *cipso_v4_doi_search(u32 doi) |
| { |
| struct cipso_v4_doi *iter; |
| |
| list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) |
| if (iter->doi == doi && atomic_read(&iter->refcount)) |
| return iter; |
| return NULL; |
| } |
| |
| /** |
| * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine |
| * @doi_def: the DOI structure |
| * @audit_info: NetLabel audit information |
| * |
| * Description: |
| * The caller defines a new DOI for use by the CIPSO 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 cipso_ipv4.h for details). Returns |
| * zero on success and non-zero on failure. |
| * |
| */ |
| int cipso_v4_doi_add(struct cipso_v4_doi *doi_def, |
| struct netlbl_audit *audit_info) |
| { |
| int ret_val = -EINVAL; |
| u32 iter; |
| u32 doi; |
| u32 doi_type; |
| struct audit_buffer *audit_buf; |
| |
| doi = doi_def->doi; |
| doi_type = doi_def->type; |
| |
| if (doi_def->doi == CIPSO_V4_DOI_UNKNOWN) |
| goto doi_add_return; |
| for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) { |
| switch (doi_def->tags[iter]) { |
| case CIPSO_V4_TAG_RBITMAP: |
| break; |
| case CIPSO_V4_TAG_RANGE: |
| case CIPSO_V4_TAG_ENUM: |
| if (doi_def->type != CIPSO_V4_MAP_PASS) |
| goto doi_add_return; |
| break; |
| case CIPSO_V4_TAG_LOCAL: |
| if (doi_def->type != CIPSO_V4_MAP_LOCAL) |
| goto doi_add_return; |
| break; |
| case CIPSO_V4_TAG_INVALID: |
| if (iter == 0) |
| goto doi_add_return; |
| break; |
| default: |
| goto doi_add_return; |
| } |
| } |
| |
| atomic_set(&doi_def->refcount, 1); |
| |
| spin_lock(&cipso_v4_doi_list_lock); |
| if (cipso_v4_doi_search(doi_def->doi)) { |
| spin_unlock(&cipso_v4_doi_list_lock); |
| ret_val = -EEXIST; |
| goto doi_add_return; |
| } |
| list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); |
| spin_unlock(&cipso_v4_doi_list_lock); |
| ret_val = 0; |
| |
| doi_add_return: |
| audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_ADD, audit_info); |
| if (audit_buf) { |
| const char *type_str; |
| switch (doi_type) { |
| case CIPSO_V4_MAP_TRANS: |
| type_str = "trans"; |
| break; |
| case CIPSO_V4_MAP_PASS: |
| type_str = "pass"; |
| break; |
| case CIPSO_V4_MAP_LOCAL: |
| type_str = "local"; |
| break; |
| default: |
| type_str = "(unknown)"; |
| } |
| audit_log_format(audit_buf, |
| " cipso_doi=%u cipso_type=%s res=%u", |
| doi, type_str, ret_val == 0 ? 1 : 0); |
| audit_log_end(audit_buf); |
| } |
| |
| return ret_val; |
| } |
| |
| /** |
| * cipso_v4_doi_free - Frees a DOI definition |
| * @doi_def: the DOI definition |
| * |
| * Description: |
| * This function frees all of the memory associated with a DOI definition. |
| * |
| */ |
| void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) |
| { |
| if (!doi_def) |
| return; |
| |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_TRANS: |
| kfree(doi_def->map.std->lvl.cipso); |
| kfree(doi_def->map.std->lvl.local); |
| kfree(doi_def->map.std->cat.cipso); |
| kfree(doi_def->map.std->cat.local); |
| break; |
| } |
| kfree(doi_def); |
| } |
| |
| /** |
| * cipso_v4_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 cipso_v4_doi_free_rcu(struct rcu_head *entry) |
| { |
| struct cipso_v4_doi *doi_def; |
| |
| doi_def = container_of(entry, struct cipso_v4_doi, rcu); |
| cipso_v4_doi_free(doi_def); |
| } |
| |
| /** |
| * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine |
| * @doi: the DOI value |
| * @audit_secid: the LSM secid to use in the audit message |
| * |
| * Description: |
| * Removes a DOI definition from the CIPSO 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. |
| * |
| */ |
| int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) |
| { |
| int ret_val; |
| struct cipso_v4_doi *doi_def; |
| struct audit_buffer *audit_buf; |
| |
| spin_lock(&cipso_v4_doi_list_lock); |
| doi_def = cipso_v4_doi_search(doi); |
| if (!doi_def) { |
| spin_unlock(&cipso_v4_doi_list_lock); |
| ret_val = -ENOENT; |
| goto doi_remove_return; |
| } |
| if (!atomic_dec_and_test(&doi_def->refcount)) { |
| spin_unlock(&cipso_v4_doi_list_lock); |
| ret_val = -EBUSY; |
| goto doi_remove_return; |
| } |
| list_del_rcu(&doi_def->list); |
| spin_unlock(&cipso_v4_doi_list_lock); |
| |
| cipso_v4_cache_invalidate(); |
| call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); |
| ret_val = 0; |
| |
| doi_remove_return: |
| audit_buf = netlbl_audit_start(AUDIT_MAC_CIPSOV4_DEL, audit_info); |
| if (audit_buf) { |
| audit_log_format(audit_buf, |
| " cipso_doi=%u res=%u", |
| doi, ret_val == 0 ? 1 : 0); |
| audit_log_end(audit_buf); |
| } |
| |
| return ret_val; |
| } |
| |
| /** |
| * cipso_v4_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 |
| * rcu_read_lock() is held while accessing the returned definition and the DOI |
| * definition reference count is decremented when the caller is done. |
| * |
| */ |
| struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) |
| { |
| struct cipso_v4_doi *doi_def; |
| |
| rcu_read_lock(); |
| doi_def = cipso_v4_doi_search(doi); |
| if (!doi_def) |
| goto doi_getdef_return; |
| if (!atomic_inc_not_zero(&doi_def->refcount)) |
| doi_def = NULL; |
| |
| doi_getdef_return: |
| rcu_read_unlock(); |
| return doi_def; |
| } |
| |
| /** |
| * cipso_v4_doi_putdef - Releases a reference for the given DOI definition |
| * @doi_def: the DOI definition |
| * |
| * Description: |
| * Releases a DOI definition reference obtained from cipso_v4_doi_getdef(). |
| * |
| */ |
| void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) |
| { |
| if (!doi_def) |
| return; |
| |
| if (!atomic_dec_and_test(&doi_def->refcount)) |
| return; |
| spin_lock(&cipso_v4_doi_list_lock); |
| list_del_rcu(&doi_def->list); |
| spin_unlock(&cipso_v4_doi_list_lock); |
| |
| cipso_v4_cache_invalidate(); |
| call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); |
| } |
| |
| /** |
| * cipso_v4_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. |
| * |
| */ |
| int cipso_v4_doi_walk(u32 *skip_cnt, |
| int (*callback) (struct cipso_v4_doi *doi_def, void *arg), |
| void *cb_arg) |
| { |
| int ret_val = -ENOENT; |
| u32 doi_cnt = 0; |
| struct cipso_v4_doi *iter_doi; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list) |
| if (atomic_read(&iter_doi->refcount) > 0) { |
| if (doi_cnt++ < *skip_cnt) |
| continue; |
| ret_val = callback(iter_doi, cb_arg); |
| if (ret_val < 0) { |
| doi_cnt--; |
| goto doi_walk_return; |
| } |
| } |
| |
| doi_walk_return: |
| rcu_read_unlock(); |
| *skip_cnt = doi_cnt; |
| return ret_val; |
| } |
| |
| /* |
| * Label Mapping Functions |
| */ |
| |
| /** |
| * cipso_v4_map_lvl_valid - Checks to see if the given level is understood |
| * @doi_def: the DOI definition |
| * @level: the level to check |
| * |
| * Description: |
| * Checks the given level against the given DOI definition and returns a |
| * negative value if the level does not have a valid mapping and a zero value |
| * if the level is defined by the DOI. |
| * |
| */ |
| static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level) |
| { |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| return 0; |
| case CIPSO_V4_MAP_TRANS: |
| if ((level < doi_def->map.std->lvl.cipso_size) && |
| (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)) |
| return 0; |
| break; |
| } |
| |
| return -EFAULT; |
| } |
| |
| /** |
| * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network |
| * @doi_def: the DOI definition |
| * @host_lvl: the host MLS level |
| * @net_lvl: the network/CIPSO MLS level |
| * |
| * Description: |
| * Perform a label mapping to translate a local MLS level to the correct |
| * CIPSO level using the given DOI definition. Returns zero on success, |
| * negative values otherwise. |
| * |
| */ |
| static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def, |
| u32 host_lvl, |
| u32 *net_lvl) |
| { |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| *net_lvl = host_lvl; |
| return 0; |
| case CIPSO_V4_MAP_TRANS: |
| if (host_lvl < doi_def->map.std->lvl.local_size && |
| doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) { |
| *net_lvl = doi_def->map.std->lvl.local[host_lvl]; |
| return 0; |
| } |
| return -EPERM; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host |
| * @doi_def: the DOI definition |
| * @net_lvl: the network/CIPSO MLS level |
| * @host_lvl: the host MLS level |
| * |
| * Description: |
| * Perform a label mapping to translate a CIPSO level to the correct local MLS |
| * level using the given DOI definition. Returns zero on success, negative |
| * values otherwise. |
| * |
| */ |
| static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def, |
| u32 net_lvl, |
| u32 *host_lvl) |
| { |
| struct cipso_v4_std_map_tbl *map_tbl; |
| |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| *host_lvl = net_lvl; |
| return 0; |
| case CIPSO_V4_MAP_TRANS: |
| map_tbl = doi_def->map.std; |
| if (net_lvl < map_tbl->lvl.cipso_size && |
| map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) { |
| *host_lvl = doi_def->map.std->lvl.cipso[net_lvl]; |
| return 0; |
| } |
| return -EPERM; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid |
| * @doi_def: the DOI definition |
| * @bitmap: category bitmap |
| * @bitmap_len: bitmap length in bytes |
| * |
| * Description: |
| * Checks the given category bitmap against the given DOI definition and |
| * returns a negative value if any of the categories in the bitmap do not have |
| * a valid mapping and a zero value if all of the categories are valid. |
| * |
| */ |
| static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def, |
| const unsigned char *bitmap, |
| u32 bitmap_len) |
| { |
| int cat = -1; |
| u32 bitmap_len_bits = bitmap_len * 8; |
| u32 cipso_cat_size; |
| u32 *cipso_array; |
| |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| return 0; |
| case CIPSO_V4_MAP_TRANS: |
| cipso_cat_size = doi_def->map.std->cat.cipso_size; |
| cipso_array = doi_def->map.std->cat.cipso; |
| for (;;) { |
| cat = netlbl_bitmap_walk(bitmap, |
| bitmap_len_bits, |
| cat + 1, |
| 1); |
| if (cat < 0) |
| break; |
| if (cat >= cipso_cat_size || |
| cipso_array[cat] >= CIPSO_V4_INV_CAT) |
| return -EFAULT; |
| } |
| |
| if (cat == -1) |
| return 0; |
| break; |
| } |
| |
| return -EFAULT; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rbm_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/CIPSO format |
| * @net_cat_len: the length of the CIPSO bitmap in bytes |
| * |
| * Description: |
| * Perform a label mapping to translate a local MLS category bitmap to the |
| * correct CIPSO bitmap using the given DOI definition. Returns the minimum |
| * size in bytes of the network bitmap on success, negative values otherwise. |
| * |
| */ |
| static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *net_cat, |
| u32 net_cat_len) |
| { |
| int host_spot = -1; |
| u32 net_spot = CIPSO_V4_INV_CAT; |
| u32 net_spot_max = 0; |
| u32 net_clen_bits = net_cat_len * 8; |
| u32 host_cat_size = 0; |
| u32 *host_cat_array = NULL; |
| |
| if (doi_def->type == CIPSO_V4_MAP_TRANS) { |
| host_cat_size = doi_def->map.std->cat.local_size; |
| host_cat_array = doi_def->map.std->cat.local; |
| } |
| |
| for (;;) { |
| host_spot = netlbl_catmap_walk(secattr->attr.mls.cat, |
| host_spot + 1); |
| if (host_spot < 0) |
| break; |
| |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| net_spot = host_spot; |
| break; |
| case CIPSO_V4_MAP_TRANS: |
| if (host_spot >= host_cat_size) |
| return -EPERM; |
| net_spot = host_cat_array[host_spot]; |
| if (net_spot >= CIPSO_V4_INV_CAT) |
| return -EPERM; |
| break; |
| } |
| if (net_spot >= net_clen_bits) |
| return -ENOSPC; |
| netlbl_bitmap_setbit(net_cat, net_spot, 1); |
| |
| if (net_spot > net_spot_max) |
| net_spot_max = net_spot; |
| } |
| |
| if (++net_spot_max % 8) |
| return net_spot_max / 8 + 1; |
| return net_spot_max / 8; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host |
| * @doi_def: the DOI definition |
| * @net_cat: the category bitmap in network/CIPSO format |
| * @net_cat_len: the length of the CIPSO bitmap in bytes |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Perform a label mapping to translate a CIPSO bitmap to the correct local |
| * MLS category bitmap using the given DOI definition. Returns zero on |
| * success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, |
| const unsigned char *net_cat, |
| u32 net_cat_len, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| int net_spot = -1; |
| u32 host_spot = CIPSO_V4_INV_CAT; |
| u32 net_clen_bits = net_cat_len * 8; |
| u32 net_cat_size = 0; |
| u32 *net_cat_array = NULL; |
| |
| if (doi_def->type == CIPSO_V4_MAP_TRANS) { |
| net_cat_size = doi_def->map.std->cat.cipso_size; |
| net_cat_array = doi_def->map.std->cat.cipso; |
| } |
| |
| for (;;) { |
| net_spot = netlbl_bitmap_walk(net_cat, |
| net_clen_bits, |
| net_spot + 1, |
| 1); |
| if (net_spot < 0) { |
| if (net_spot == -2) |
| return -EFAULT; |
| return 0; |
| } |
| |
| switch (doi_def->type) { |
| case CIPSO_V4_MAP_PASS: |
| host_spot = net_spot; |
| break; |
| case CIPSO_V4_MAP_TRANS: |
| if (net_spot >= net_cat_size) |
| return -EPERM; |
| host_spot = net_cat_array[net_spot]; |
| if (host_spot >= CIPSO_V4_INV_CAT) |
| return -EPERM; |
| break; |
| } |
| ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, |
| host_spot, |
| GFP_ATOMIC); |
| if (ret_val != 0) |
| return ret_val; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid |
| * @doi_def: the DOI definition |
| * @enumcat: category list |
| * @enumcat_len: length of the category list in bytes |
| * |
| * Description: |
| * Checks the given categories against the given DOI definition and returns a |
| * negative value if any of the categories do not have a valid mapping and a |
| * zero value if all of the categories are valid. |
| * |
| */ |
| static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def, |
| const unsigned char *enumcat, |
| u32 enumcat_len) |
| { |
| u16 cat; |
| int cat_prev = -1; |
| u32 iter; |
| |
| if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01) |
| return -EFAULT; |
| |
| for (iter = 0; iter < enumcat_len; iter += 2) { |
| cat = get_unaligned_be16(&enumcat[iter]); |
| if (cat <= cat_prev) |
| return -EFAULT; |
| cat_prev = cat; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_map_cat_enum_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 list in network/CIPSO format |
| * @net_cat_len: the length of the CIPSO category list in bytes |
| * |
| * Description: |
| * Perform a label mapping to translate a local MLS category bitmap to the |
| * correct CIPSO category list using the given DOI definition. Returns the |
| * size in bytes of the network category bitmap on success, negative values |
| * otherwise. |
| * |
| */ |
| static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *net_cat, |
| u32 net_cat_len) |
| { |
| int cat = -1; |
| u32 cat_iter = 0; |
| |
| for (;;) { |
| cat = netlbl_catmap_walk(secattr->attr.mls.cat, cat + 1); |
| if (cat < 0) |
| break; |
| if ((cat_iter + 2) > net_cat_len) |
| return -ENOSPC; |
| |
| *((__be16 *)&net_cat[cat_iter]) = htons(cat); |
| cat_iter += 2; |
| } |
| |
| return cat_iter; |
| } |
| |
| /** |
| * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host |
| * @doi_def: the DOI definition |
| * @net_cat: the category list in network/CIPSO format |
| * @net_cat_len: the length of the CIPSO bitmap in bytes |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Perform a label mapping to translate a CIPSO category list to the correct |
| * local MLS category bitmap using the given DOI definition. Returns zero on |
| * success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def, |
| const unsigned char *net_cat, |
| u32 net_cat_len, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u32 iter; |
| |
| for (iter = 0; iter < net_cat_len; iter += 2) { |
| ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat, |
| get_unaligned_be16(&net_cat[iter]), |
| GFP_ATOMIC); |
| if (ret_val != 0) |
| return ret_val; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid |
| * @doi_def: the DOI definition |
| * @rngcat: category list |
| * @rngcat_len: length of the category list in bytes |
| * |
| * Description: |
| * Checks the given categories against the given DOI definition and returns a |
| * negative value if any of the categories do not have a valid mapping and a |
| * zero value if all of the categories are valid. |
| * |
| */ |
| static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def, |
| const unsigned char *rngcat, |
| u32 rngcat_len) |
| { |
| u16 cat_high; |
| u16 cat_low; |
| u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1; |
| u32 iter; |
| |
| if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01) |
| return -EFAULT; |
| |
| for (iter = 0; iter < rngcat_len; iter += 4) { |
| cat_high = get_unaligned_be16(&rngcat[iter]); |
| if ((iter + 4) <= rngcat_len) |
| cat_low = get_unaligned_be16(&rngcat[iter + 2]); |
| else |
| cat_low = 0; |
| |
| if (cat_high > cat_prev) |
| return -EFAULT; |
| |
| cat_prev = cat_low; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rng_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 list in network/CIPSO format |
| * @net_cat_len: the length of the CIPSO category list in bytes |
| * |
| * Description: |
| * Perform a label mapping to translate a local MLS category bitmap to the |
| * correct CIPSO category list using the given DOI definition. Returns the |
| * size in bytes of the network category bitmap on success, negative values |
| * otherwise. |
| * |
| */ |
| static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *net_cat, |
| u32 net_cat_len) |
| { |
| int iter = -1; |
| u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2]; |
| u32 array_cnt = 0; |
| u32 cat_size = 0; |
| |
| /* make sure we don't overflow the 'array[]' variable */ |
| if (net_cat_len > |
| (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN)) |
| return -ENOSPC; |
| |
| for (;;) { |
| iter = netlbl_catmap_walk(secattr->attr.mls.cat, iter + 1); |
| if (iter < 0) |
| break; |
| cat_size += (iter == 0 ? 0 : sizeof(u16)); |
| if (cat_size > net_cat_len) |
| return -ENOSPC; |
| array[array_cnt++] = iter; |
| |
| iter = netlbl_catmap_walkrng(secattr->attr.mls.cat, iter); |
| if (iter < 0) |
| return -EFAULT; |
| cat_size += sizeof(u16); |
| if (cat_size > net_cat_len) |
| return -ENOSPC; |
| array[array_cnt++] = iter; |
| } |
| |
| for (iter = 0; array_cnt > 0;) { |
| *((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]); |
| iter += 2; |
| array_cnt--; |
| if (array[array_cnt] != 0) { |
| *((__be16 *)&net_cat[iter]) = htons(array[array_cnt]); |
| iter += 2; |
| } |
| } |
| |
| return cat_size; |
| } |
| |
| /** |
| * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host |
| * @doi_def: the DOI definition |
| * @net_cat: the category list in network/CIPSO format |
| * @net_cat_len: the length of the CIPSO bitmap in bytes |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Perform a label mapping to translate a CIPSO category list to the correct |
| * local MLS category bitmap using the given DOI definition. Returns zero on |
| * success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def, |
| const unsigned char *net_cat, |
| u32 net_cat_len, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u32 net_iter; |
| u16 cat_low; |
| u16 cat_high; |
| |
| for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) { |
| cat_high = get_unaligned_be16(&net_cat[net_iter]); |
| if ((net_iter + 4) <= net_cat_len) |
| cat_low = get_unaligned_be16(&net_cat[net_iter + 2]); |
| else |
| cat_low = 0; |
| |
| ret_val = netlbl_catmap_setrng(&secattr->attr.mls.cat, |
| cat_low, |
| cat_high, |
| GFP_ATOMIC); |
| if (ret_val != 0) |
| return ret_val; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Protocol Handling Functions |
| */ |
| |
| /** |
| * cipso_v4_gentag_hdr - Generate a CIPSO option header |
| * @doi_def: the DOI definition |
| * @len: the total tag length in bytes, not including this header |
| * @buf: the CIPSO option buffer |
| * |
| * Description: |
| * Write a CIPSO header into the beginning of @buffer. |
| * |
| */ |
| static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def, |
| unsigned char *buf, |
| u32 len) |
| { |
| buf[0] = IPOPT_CIPSO; |
| buf[1] = CIPSO_V4_HDR_LEN + len; |
| *(__be32 *)&buf[2] = htonl(doi_def->doi); |
| } |
| |
| /** |
| * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1) |
| * @doi_def: the DOI definition |
| * @secattr: the security attributes |
| * @buffer: the option buffer |
| * @buffer_len: length of buffer in bytes |
| * |
| * Description: |
| * Generate a CIPSO option using the restricted bitmap tag, tag type #1. The |
| * actual buffer length may be larger than the indicated size due to |
| * translation between host and network category bitmaps. Returns the size of |
| * the tag on success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *buffer, |
| u32 buffer_len) |
| { |
| int ret_val; |
| u32 tag_len; |
| u32 level; |
| |
| if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0) |
| return -EPERM; |
| |
| ret_val = cipso_v4_map_lvl_hton(doi_def, |
| secattr->attr.mls.lvl, |
| &level); |
| if (ret_val != 0) |
| return ret_val; |
| |
| if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
| ret_val = cipso_v4_map_cat_rbm_hton(doi_def, |
| secattr, |
| &buffer[4], |
| buffer_len - 4); |
| if (ret_val < 0) |
| return ret_val; |
| |
| /* This will send packets using the "optimized" format when |
| * possible as specified in section 3.4.2.6 of the |
| * CIPSO draft. */ |
| if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10) |
| tag_len = 14; |
| else |
| tag_len = 4 + ret_val; |
| } else |
| tag_len = 4; |
| |
| buffer[0] = CIPSO_V4_TAG_RBITMAP; |
| buffer[1] = tag_len; |
| buffer[3] = level; |
| |
| return tag_len; |
| } |
| |
| /** |
| * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag |
| * @doi_def: the DOI definition |
| * @tag: the CIPSO tag |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security |
| * attributes in @secattr. Return zero on success, negatives values on |
| * failure. |
| * |
| */ |
| static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, |
| const unsigned char *tag, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u8 tag_len = tag[1]; |
| u32 level; |
| |
| ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
| if (ret_val != 0) |
| return ret_val; |
| secattr->attr.mls.lvl = level; |
| secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
| |
| if (tag_len > 4) { |
| ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def, |
| &tag[4], |
| tag_len - 4, |
| secattr); |
| if (ret_val != 0) { |
| netlbl_catmap_free(secattr->attr.mls.cat); |
| return ret_val; |
| } |
| |
| secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2) |
| * @doi_def: the DOI definition |
| * @secattr: the security attributes |
| * @buffer: the option buffer |
| * @buffer_len: length of buffer in bytes |
| * |
| * Description: |
| * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the |
| * size of the tag on success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *buffer, |
| u32 buffer_len) |
| { |
| int ret_val; |
| u32 tag_len; |
| u32 level; |
| |
| if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) |
| return -EPERM; |
| |
| ret_val = cipso_v4_map_lvl_hton(doi_def, |
| secattr->attr.mls.lvl, |
| &level); |
| if (ret_val != 0) |
| return ret_val; |
| |
| if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
| ret_val = cipso_v4_map_cat_enum_hton(doi_def, |
| secattr, |
| &buffer[4], |
| buffer_len - 4); |
| if (ret_val < 0) |
| return ret_val; |
| |
| tag_len = 4 + ret_val; |
| } else |
| tag_len = 4; |
| |
| buffer[0] = CIPSO_V4_TAG_ENUM; |
| buffer[1] = tag_len; |
| buffer[3] = level; |
| |
| return tag_len; |
| } |
| |
| /** |
| * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag |
| * @doi_def: the DOI definition |
| * @tag: the CIPSO tag |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Parse a CIPSO enumerated tag (tag type #2) and return the security |
| * attributes in @secattr. Return zero on success, negatives values on |
| * failure. |
| * |
| */ |
| static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, |
| const unsigned char *tag, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u8 tag_len = tag[1]; |
| u32 level; |
| |
| ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
| if (ret_val != 0) |
| return ret_val; |
| secattr->attr.mls.lvl = level; |
| secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
| |
| if (tag_len > 4) { |
| ret_val = cipso_v4_map_cat_enum_ntoh(doi_def, |
| &tag[4], |
| tag_len - 4, |
| secattr); |
| if (ret_val != 0) { |
| netlbl_catmap_free(secattr->attr.mls.cat); |
| return ret_val; |
| } |
| |
| secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5) |
| * @doi_def: the DOI definition |
| * @secattr: the security attributes |
| * @buffer: the option buffer |
| * @buffer_len: length of buffer in bytes |
| * |
| * Description: |
| * Generate a CIPSO option using the ranged tag, tag type #5. Returns the |
| * size of the tag on success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *buffer, |
| u32 buffer_len) |
| { |
| int ret_val; |
| u32 tag_len; |
| u32 level; |
| |
| if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) |
| return -EPERM; |
| |
| ret_val = cipso_v4_map_lvl_hton(doi_def, |
| secattr->attr.mls.lvl, |
| &level); |
| if (ret_val != 0) |
| return ret_val; |
| |
| if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { |
| ret_val = cipso_v4_map_cat_rng_hton(doi_def, |
| secattr, |
| &buffer[4], |
| buffer_len - 4); |
| if (ret_val < 0) |
| return ret_val; |
| |
| tag_len = 4 + ret_val; |
| } else |
| tag_len = 4; |
| |
| buffer[0] = CIPSO_V4_TAG_RANGE; |
| buffer[1] = tag_len; |
| buffer[3] = level; |
| |
| return tag_len; |
| } |
| |
| /** |
| * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag |
| * @doi_def: the DOI definition |
| * @tag: the CIPSO tag |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Parse a CIPSO ranged tag (tag type #5) and return the security attributes |
| * in @secattr. Return zero on success, negatives values on failure. |
| * |
| */ |
| static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def, |
| const unsigned char *tag, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u8 tag_len = tag[1]; |
| u32 level; |
| |
| ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); |
| if (ret_val != 0) |
| return ret_val; |
| secattr->attr.mls.lvl = level; |
| secattr->flags |= NETLBL_SECATTR_MLS_LVL; |
| |
| if (tag_len > 4) { |
| ret_val = cipso_v4_map_cat_rng_ntoh(doi_def, |
| &tag[4], |
| tag_len - 4, |
| secattr); |
| if (ret_val != 0) { |
| netlbl_catmap_free(secattr->attr.mls.cat); |
| return ret_val; |
| } |
| |
| secattr->flags |= NETLBL_SECATTR_MLS_CAT; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard) |
| * @doi_def: the DOI definition |
| * @secattr: the security attributes |
| * @buffer: the option buffer |
| * @buffer_len: length of buffer in bytes |
| * |
| * Description: |
| * Generate a CIPSO option using the local tag. Returns the size of the tag |
| * on success, negative values on failure. |
| * |
| */ |
| static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr, |
| unsigned char *buffer, |
| u32 buffer_len) |
| { |
| if (!(secattr->flags & NETLBL_SECATTR_SECID)) |
| return -EPERM; |
| |
| buffer[0] = CIPSO_V4_TAG_LOCAL; |
| buffer[1] = CIPSO_V4_TAG_LOC_BLEN; |
| *(u32 *)&buffer[2] = secattr->attr.secid; |
| |
| return CIPSO_V4_TAG_LOC_BLEN; |
| } |
| |
| /** |
| * cipso_v4_parsetag_loc - Parse a CIPSO local tag |
| * @doi_def: the DOI definition |
| * @tag: the CIPSO tag |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Parse a CIPSO local tag and return the security attributes in @secattr. |
| * Return zero on success, negatives values on failure. |
| * |
| */ |
| static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def, |
| const unsigned char *tag, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| secattr->attr.secid = *(u32 *)&tag[2]; |
| secattr->flags |= NETLBL_SECATTR_SECID; |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_optptr - Find the CIPSO option in the packet |
| * @skb: the packet |
| * |
| * Description: |
| * Parse the packet's IP header looking for a CIPSO option. Returns a pointer |
| * to the start of the CIPSO option on success, NULL if one is not found. |
| * |
| */ |
| unsigned char *cipso_v4_optptr(const struct sk_buff *skb) |
| { |
| const struct iphdr *iph = ip_hdr(skb); |
| unsigned char *optptr = (unsigned char *)&(ip_hdr(skb)[1]); |
| int optlen; |
| int taglen; |
| |
| for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) { |
| switch (optptr[0]) { |
| case IPOPT_END: |
| return NULL; |
| case IPOPT_NOOP: |
| taglen = 1; |
| break; |
| default: |
| taglen = optptr[1]; |
| } |
| if (!taglen || taglen > optlen) |
| return NULL; |
| if (optptr[0] == IPOPT_CIPSO) |
| return optptr; |
| |
| optlen -= taglen; |
| optptr += taglen; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * cipso_v4_validate - Validate a CIPSO option |
| * @option: the start of the option, on error it is set to point to the error |
| * |
| * Description: |
| * This routine is called to validate a CIPSO option, it checks all of the |
| * fields to ensure that they are at least valid, see the draft snippet below |
| * for details. If the option is valid then a zero value is returned and |
| * the value of @option is unchanged. If the option is invalid then a |
| * non-zero value is returned and @option is adjusted to point to the |
| * offending portion of the option. From the IETF draft ... |
| * |
| * "If any field within the CIPSO options, such as the DOI identifier, is not |
| * recognized the IP datagram is discarded and an ICMP 'parameter problem' |
| * (type 12) is generated and returned. The ICMP code field is set to 'bad |
| * parameter' (code 0) and the pointer is set to the start of the CIPSO field |
| * that is unrecognized." |
| * |
| */ |
| int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) |
| { |
| unsigned char *opt = *option; |
| unsigned char *tag; |
| unsigned char opt_iter; |
| unsigned char err_offset = 0; |
| u8 opt_len; |
| u8 tag_len; |
| struct cipso_v4_doi *doi_def = NULL; |
| u32 tag_iter; |
| |
| /* caller already checks for length values that are too large */ |
| opt_len = opt[1]; |
| if (opt_len < 8) { |
| err_offset = 1; |
| goto validate_return; |
| } |
| |
| rcu_read_lock(); |
| doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2])); |
| if (!doi_def) { |
| err_offset = 2; |
| goto validate_return_locked; |
| } |
| |
| opt_iter = CIPSO_V4_HDR_LEN; |
| tag = opt + opt_iter; |
| while (opt_iter < opt_len) { |
| for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];) |
| if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID || |
| ++tag_iter == CIPSO_V4_TAG_MAXCNT) { |
| err_offset = opt_iter; |
| goto validate_return_locked; |
| } |
| |
| if (opt_iter + 1 == opt_len) { |
| err_offset = opt_iter; |
| goto validate_return_locked; |
| } |
| tag_len = tag[1]; |
| if (tag_len > (opt_len - opt_iter)) { |
| err_offset = opt_iter + 1; |
| goto validate_return_locked; |
| } |
| |
| switch (tag[0]) { |
| case CIPSO_V4_TAG_RBITMAP: |
| if (tag_len < CIPSO_V4_TAG_RBM_BLEN) { |
| err_offset = opt_iter + 1; |
| goto validate_return_locked; |
| } |
| |
| /* We are already going to do all the verification |
| * necessary at the socket layer so from our point of |
| * view it is safe to turn these checks off (and less |
| * work), however, the CIPSO draft says we should do |
| * all the CIPSO validations here but it doesn't |
| * really specify _exactly_ what we need to validate |
| * ... so, just make it a sysctl tunable. */ |
| if (cipso_v4_rbm_strictvalid) { |
| if (cipso_v4_map_lvl_valid(doi_def, |
| tag[3]) < 0) { |
| err_offset = opt_iter + 3; |
| goto validate_return_locked; |
| } |
| if (tag_len > CIPSO_V4_TAG_RBM_BLEN && |
| cipso_v4_map_cat_rbm_valid(doi_def, |
| &tag[4], |
| tag_len - 4) < 0) { |
| err_offset = opt_iter + 4; |
| goto validate_return_locked; |
| } |
| } |
| break; |
| case CIPSO_V4_TAG_ENUM: |
| if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) { |
| err_offset = opt_iter + 1; |
| goto validate_return_locked; |
| } |
| |
| if (cipso_v4_map_lvl_valid(doi_def, |
| tag[3]) < 0) { |
| err_offset = opt_iter + 3; |
| goto validate_return_locked; |
| } |
| if (tag_len > CIPSO_V4_TAG_ENUM_BLEN && |
| cipso_v4_map_cat_enum_valid(doi_def, |
| &tag[4], |
| tag_len - 4) < 0) { |
| err_offset = opt_iter + 4; |
| goto validate_return_locked; |
| } |
| break; |
| case CIPSO_V4_TAG_RANGE: |
| if (tag_len < CIPSO_V4_TAG_RNG_BLEN) { |
| err_offset = opt_iter + 1; |
| goto validate_return_locked; |
| } |
| |
| if (cipso_v4_map_lvl_valid(doi_def, |
| tag[3]) < 0) { |
| err_offset = opt_iter + 3; |
| goto validate_return_locked; |
| } |
| if (tag_len > CIPSO_V4_TAG_RNG_BLEN && |
| cipso_v4_map_cat_rng_valid(doi_def, |
| &tag[4], |
| tag_len - 4) < 0) { |
| err_offset = opt_iter + 4; |
| goto validate_return_locked; |
| } |
| break; |
| case CIPSO_V4_TAG_LOCAL: |
| /* This is a non-standard tag that we only allow for |
| * local connections, so if the incoming interface is |
| * not the loopback device drop the packet. Further, |
| * there is no legitimate reason for setting this from |
| * userspace so reject it if skb is NULL. */ |
| if (!skb || !(skb->dev->flags & IFF_LOOPBACK)) { |
| err_offset = opt_iter; |
| goto validate_return_locked; |
| } |
| if (tag_len != CIPSO_V4_TAG_LOC_BLEN) { |
| err_offset = opt_iter + 1; |
| goto validate_return_locked; |
| } |
| break; |
| default: |
| err_offset = opt_iter; |
| goto validate_return_locked; |
| } |
| |
| tag += tag_len; |
| opt_iter += tag_len; |
| } |
| |
| validate_return_locked: |
| rcu_read_unlock(); |
| validate_return: |
| *option = opt + err_offset; |
| return err_offset; |
| } |
| |
| /** |
| * cipso_v4_error - Send the correct response for a bad packet |
| * @skb: the packet |
| * @error: the error code |
| * @gateway: CIPSO gateway flag |
| * |
| * Description: |
| * Based on the error code given in @error, send an ICMP error message back to |
| * the originating host. From the IETF draft ... |
| * |
| * "If the contents of the CIPSO [option] are valid but the security label is |
| * outside of the configured host or port label range, the datagram is |
| * discarded and an ICMP 'destination unreachable' (type 3) is generated and |
| * returned. The code field of the ICMP is set to 'communication with |
| * destination network administratively prohibited' (code 9) or to |
| * 'communication with destination host administratively prohibited' |
| * (code 10). The value of the code is dependent on whether the originator |
| * of the ICMP message is acting as a CIPSO host or a CIPSO gateway. The |
| * recipient of the ICMP message MUST be able to handle either value. The |
| * same procedure is performed if a CIPSO [option] can not be added to an |
| * IP packet because it is too large to fit in the IP options area." |
| * |
| * "If the error is triggered by receipt of an ICMP message, the message is |
| * discarded and no response is permitted (consistent with general ICMP |
| * processing rules)." |
| * |
| */ |
| void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway) |
| { |
| unsigned char optbuf[sizeof(struct ip_options) + 40]; |
| struct ip_options *opt = (struct ip_options *)optbuf; |
| int res; |
| |
| if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES) |
| return; |
| |
| /* |
| * We might be called above the IP layer, |
| * so we can not use icmp_send and IPCB here. |
| */ |
| |
| memset(opt, 0, sizeof(struct ip_options)); |
| opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr); |
| rcu_read_lock(); |
| res = __ip_options_compile(dev_net(skb->dev), opt, skb, NULL); |
| rcu_read_unlock(); |
| |
| if (res) |
| return; |
| |
| if (gateway) |
| __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt); |
| else |
| __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt); |
| } |
| |
| /** |
| * cipso_v4_genopt - Generate a CIPSO option |
| * @buf: the option buffer |
| * @buf_len: the size of opt_buf |
| * @doi_def: the CIPSO DOI to use |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Generate a CIPSO option using the DOI definition and security attributes |
| * passed to the function. Returns the length of the option on success and |
| * negative values on failure. |
| * |
| */ |
| static int cipso_v4_genopt(unsigned char *buf, u32 buf_len, |
| const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| u32 iter; |
| |
| if (buf_len <= CIPSO_V4_HDR_LEN) |
| return -ENOSPC; |
| |
| /* XXX - This code assumes only one tag per CIPSO option which isn't |
| * really a good assumption to make but since we only support the MAC |
| * tags right now it is a safe assumption. */ |
| iter = 0; |
| do { |
| memset(buf, 0, buf_len); |
| switch (doi_def->tags[iter]) { |
| case CIPSO_V4_TAG_RBITMAP: |
| ret_val = cipso_v4_gentag_rbm(doi_def, |
| secattr, |
| &buf[CIPSO_V4_HDR_LEN], |
| buf_len - CIPSO_V4_HDR_LEN); |
| break; |
| case CIPSO_V4_TAG_ENUM: |
| ret_val = cipso_v4_gentag_enum(doi_def, |
| secattr, |
| &buf[CIPSO_V4_HDR_LEN], |
| buf_len - CIPSO_V4_HDR_LEN); |
| break; |
| case CIPSO_V4_TAG_RANGE: |
| ret_val = cipso_v4_gentag_rng(doi_def, |
| secattr, |
| &buf[CIPSO_V4_HDR_LEN], |
| buf_len - CIPSO_V4_HDR_LEN); |
| break; |
| case CIPSO_V4_TAG_LOCAL: |
| ret_val = cipso_v4_gentag_loc(doi_def, |
| secattr, |
| &buf[CIPSO_V4_HDR_LEN], |
| buf_len - CIPSO_V4_HDR_LEN); |
| break; |
| default: |
| return -EPERM; |
| } |
| |
| iter++; |
| } while (ret_val < 0 && |
| iter < CIPSO_V4_TAG_MAXCNT && |
| doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); |
| if (ret_val < 0) |
| return ret_val; |
| cipso_v4_gentag_hdr(doi_def, buf, ret_val); |
| return CIPSO_V4_HDR_LEN + ret_val; |
| } |
| |
| /** |
| * cipso_v4_sock_setattr - Add a CIPSO option to a socket |
| * @sk: the socket |
| * @doi_def: the CIPSO DOI to use |
| * @secattr: the specific security attributes of the socket |
| * |
| * Description: |
| * Set the CIPSO 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. |
| * |
| */ |
| int cipso_v4_sock_setattr(struct sock *sk, |
| const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val = -EPERM; |
| unsigned char *buf = NULL; |
| u32 buf_len; |
| u32 opt_len; |
| struct ip_options_rcu *old, *opt = NULL; |
| struct inet_sock *sk_inet; |
| struct inet_connection_sock *sk_conn; |
| |
| /* In the case of sock_create_lite(), the sock->sk field is not |
| * defined yet but it is not a problem as the only users of these |
| * "lite" PF_INET sockets are functions which do an accept() call |
| * afterwards so we will label the socket as part of the accept(). */ |
| if (!sk) |
| return 0; |
| |
| /* We allocate the maximum CIPSO option size here so we are probably |
| * being a little wasteful, but it makes our life _much_ easier later |
| * on and after all we are only talking about 40 bytes. */ |
| buf_len = CIPSO_V4_OPT_LEN_MAX; |
| buf = kmalloc(buf_len, GFP_ATOMIC); |
| if (!buf) { |
| ret_val = -ENOMEM; |
| goto socket_setattr_failure; |
| } |
| |
| ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
| if (ret_val < 0) |
| goto socket_setattr_failure; |
| buf_len = ret_val; |
| |
| /* We can't use ip_options_get() directly because it makes a call to |
| * ip_options_get_alloc() which allocates memory with GFP_KERNEL and |
| * we won't always have CAP_NET_RAW even though we _always_ want to |
| * set the IPOPT_CIPSO option. */ |
| opt_len = (buf_len + 3) & ~3; |
| opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); |
| if (!opt) { |
| ret_val = -ENOMEM; |
| goto socket_setattr_failure; |
| } |
| memcpy(opt->opt.__data, buf, buf_len); |
| opt->opt.optlen = opt_len; |
| opt->opt.cipso = sizeof(struct iphdr); |
| kfree(buf); |
| buf = NULL; |
| |
| sk_inet = inet_sk(sk); |
| |
| old = rcu_dereference_protected(sk_inet->inet_opt, |
| lockdep_sock_is_held(sk)); |
| if (sk_inet->is_icsk) { |
| sk_conn = inet_csk(sk); |
| if (old) |
| sk_conn->icsk_ext_hdr_len -= old->opt.optlen; |
| sk_conn->icsk_ext_hdr_len += opt->opt.optlen; |
| sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); |
| } |
| rcu_assign_pointer(sk_inet->inet_opt, opt); |
| if (old) |
| kfree_rcu(old, rcu); |
| |
| return 0; |
| |
| socket_setattr_failure: |
| kfree(buf); |
| kfree(opt); |
| return ret_val; |
| } |
| |
| /** |
| * cipso_v4_req_setattr - Add a CIPSO option to a connection request socket |
| * @req: the connection request socket |
| * @doi_def: the CIPSO DOI to use |
| * @secattr: the specific security attributes of the socket |
| * |
| * Description: |
| * Set the CIPSO 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. |
| * |
| */ |
| int cipso_v4_req_setattr(struct request_sock *req, |
| const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val = -EPERM; |
| unsigned char *buf = NULL; |
| u32 buf_len; |
| u32 opt_len; |
| struct ip_options_rcu *opt = NULL; |
| struct inet_request_sock *req_inet; |
| |
| /* We allocate the maximum CIPSO option size here so we are probably |
| * being a little wasteful, but it makes our life _much_ easier later |
| * on and after all we are only talking about 40 bytes. */ |
| buf_len = CIPSO_V4_OPT_LEN_MAX; |
| buf = kmalloc(buf_len, GFP_ATOMIC); |
| if (!buf) { |
| ret_val = -ENOMEM; |
| goto req_setattr_failure; |
| } |
| |
| ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
| if (ret_val < 0) |
| goto req_setattr_failure; |
| buf_len = ret_val; |
| |
| /* We can't use ip_options_get() directly because it makes a call to |
| * ip_options_get_alloc() which allocates memory with GFP_KERNEL and |
| * we won't always have CAP_NET_RAW even though we _always_ want to |
| * set the IPOPT_CIPSO option. */ |
| opt_len = (buf_len + 3) & ~3; |
| opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); |
| if (!opt) { |
| ret_val = -ENOMEM; |
| goto req_setattr_failure; |
| } |
| memcpy(opt->opt.__data, buf, buf_len); |
| opt->opt.optlen = opt_len; |
| opt->opt.cipso = sizeof(struct iphdr); |
| kfree(buf); |
| buf = NULL; |
| |
| req_inet = inet_rsk(req); |
| opt = xchg((__force struct ip_options_rcu **)&req_inet->ireq_opt, opt); |
| if (opt) |
| kfree_rcu(opt, rcu); |
| |
| return 0; |
| |
| req_setattr_failure: |
| kfree(buf); |
| kfree(opt); |
| return ret_val; |
| } |
| |
| /** |
| * cipso_v4_delopt - Delete the CIPSO option from a set of IP options |
| * @opt_ptr: IP option pointer |
| * |
| * Description: |
| * Deletes the CIPSO IP option from a set of IP options and makes the necessary |
| * adjustments to the IP option structure. Returns zero on success, negative |
| * values on failure. |
| * |
| */ |
| static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr) |
| { |
| struct ip_options_rcu *opt = rcu_dereference_protected(*opt_ptr, 1); |
| int hdr_delta = 0; |
| |
| if (!opt || opt->opt.cipso == 0) |
| return 0; |
| if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) { |
| u8 cipso_len; |
| u8 cipso_off; |
| unsigned char *cipso_ptr; |
| int iter; |
| int optlen_new; |
| |
| cipso_off = opt->opt.cipso - sizeof(struct iphdr); |
| cipso_ptr = &opt->opt.__data[cipso_off]; |
| cipso_len = cipso_ptr[1]; |
| |
| if (opt->opt.srr > opt->opt.cipso) |
| opt->opt.srr -= cipso_len; |
| if (opt->opt.rr > opt->opt.cipso) |
| opt->opt.rr -= cipso_len; |
| if (opt->opt.ts > opt->opt.cipso) |
| opt->opt.ts -= cipso_len; |
| if (opt->opt.router_alert > opt->opt.cipso) |
| opt->opt.router_alert -= cipso_len; |
| opt->opt.cipso = 0; |
| |
| memmove(cipso_ptr, cipso_ptr + cipso_len, |
| opt->opt.optlen - cipso_off - cipso_len); |
| |
| /* determining the new total option length is tricky because of |
| * the padding necessary, the only thing i can think to do at |
| * this point is walk the options one-by-one, skipping the |
| * padding at the end to determine the actual option size and |
| * from there we can determine the new total option length */ |
| iter = 0; |
| optlen_new = 0; |
| while (iter < opt->opt.optlen) |
| if (opt->opt.__data[iter] != IPOPT_NOP) { |
| iter += opt->opt.__data[iter + 1]; |
| optlen_new = iter; |
| } else |
| iter++; |
| hdr_delta = opt->opt.optlen; |
| opt->opt.optlen = (optlen_new + 3) & ~3; |
| hdr_delta -= opt->opt.optlen; |
| } else { |
| /* only the cipso option was present on the socket so we can |
| * remove the entire option struct */ |
| *opt_ptr = NULL; |
| hdr_delta = opt->opt.optlen; |
| kfree_rcu(opt, rcu); |
| } |
| |
| return hdr_delta; |
| } |
| |
| /** |
| * cipso_v4_sock_delattr - Delete the CIPSO option from a socket |
| * @sk: the socket |
| * |
| * Description: |
| * Removes the CIPSO option from a socket, if present. |
| * |
| */ |
| void cipso_v4_sock_delattr(struct sock *sk) |
| { |
| struct inet_sock *sk_inet; |
| int hdr_delta; |
| |
| sk_inet = inet_sk(sk); |
| |
| hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt); |
| if (sk_inet->is_icsk && hdr_delta > 0) { |
| struct inet_connection_sock *sk_conn = inet_csk(sk); |
| sk_conn->icsk_ext_hdr_len -= hdr_delta; |
| sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); |
| } |
| } |
| |
| /** |
| * cipso_v4_req_delattr - Delete the CIPSO option from a request socket |
| * @reg: the request socket |
| * |
| * Description: |
| * Removes the CIPSO option from a request socket, if present. |
| * |
| */ |
| void cipso_v4_req_delattr(struct request_sock *req) |
| { |
| cipso_v4_delopt(&inet_rsk(req)->ireq_opt); |
| } |
| |
| /** |
| * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions |
| * @cipso: the CIPSO v4 option |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Inspect @cipso and return the security attributes in @secattr. Returns zero |
| * on success and negative values on failure. |
| * |
| */ |
| int cipso_v4_getattr(const unsigned char *cipso, |
| struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val = -ENOMSG; |
| u32 doi; |
| struct cipso_v4_doi *doi_def; |
| |
| if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0) |
| return 0; |
| |
| doi = get_unaligned_be32(&cipso[2]); |
| rcu_read_lock(); |
| doi_def = cipso_v4_doi_search(doi); |
| if (!doi_def) |
| goto getattr_return; |
| /* XXX - This code assumes only one tag per CIPSO option which isn't |
| * really a good assumption to make but since we only support the MAC |
| * tags right now it is a safe assumption. */ |
| switch (cipso[6]) { |
| case CIPSO_V4_TAG_RBITMAP: |
| ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr); |
| break; |
| case CIPSO_V4_TAG_ENUM: |
| ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr); |
| break; |
| case CIPSO_V4_TAG_RANGE: |
| ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr); |
| break; |
| case CIPSO_V4_TAG_LOCAL: |
| ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr); |
| break; |
| } |
| if (ret_val == 0) |
| secattr->type = NETLBL_NLTYPE_CIPSOV4; |
| |
| getattr_return: |
| rcu_read_unlock(); |
| return ret_val; |
| } |
| |
| /** |
| * cipso_v4_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 CIPSO option attached to the sock and if |
| * there is return the CIPSO 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. |
| * |
| */ |
| int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) |
| { |
| struct ip_options_rcu *opt; |
| int res = -ENOMSG; |
| |
| rcu_read_lock(); |
| opt = rcu_dereference(inet_sk(sk)->inet_opt); |
| if (opt && opt->opt.cipso) |
| res = cipso_v4_getattr(opt->opt.__data + |
| opt->opt.cipso - |
| sizeof(struct iphdr), |
| secattr); |
| rcu_read_unlock(); |
| return res; |
| } |
| |
| /** |
| * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet |
| * @skb: the packet |
| * @secattr: the security attributes |
| * |
| * Description: |
| * Set the CIPSO option on the given packet based on the security attributes. |
| * Returns a pointer to the IP header on success and NULL on failure. |
| * |
| */ |
| int cipso_v4_skbuff_setattr(struct sk_buff *skb, |
| const struct cipso_v4_doi *doi_def, |
| const struct netlbl_lsm_secattr *secattr) |
| { |
| int ret_val; |
| struct iphdr *iph; |
| struct ip_options *opt = &IPCB(skb)->opt; |
| unsigned char buf[CIPSO_V4_OPT_LEN_MAX]; |
| u32 buf_len = CIPSO_V4_OPT_LEN_MAX; |
| u32 opt_len; |
| int len_delta; |
| |
| ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr); |
| if (ret_val < 0) |
| return ret_val; |
| buf_len = ret_val; |
| opt_len = (buf_len + 3) & ~3; |
| |
| /* we overwrite any existing options to ensure that we have enough |
| * room for the CIPSO option, the reason is that we _need_ to guarantee |
| * that the security label is applied to the packet - we do the same |
| * thing when using the socket options and it hasn't caused a problem, |
| * if we need to we can always revisit this choice later */ |
| |
| len_delta = opt_len - opt->optlen; |
| /* if we don't ensure enough headroom we could panic on the skb_push() |
| * call below so make sure we have enough, we are also "mangling" the |
| * packet so we should probably do a copy-on-write call anyway */ |
| ret_val = skb_cow(skb, skb_headroom(skb) + len_delta); |
| if (ret_val < 0) |
| return ret_val; |
| |
| if (len_delta > 0) { |
| /* we assume that the header + opt->optlen have already been |
| * "pushed" in ip_options_build() or similar */ |
| iph = ip_hdr(skb); |
| skb_push(skb, len_delta); |
| memmove((char *)iph - len_delta, iph, iph->ihl << 2); |
| skb_reset_network_header(skb); |
| iph = ip_hdr(skb); |
| } else if (len_delta < 0) { |
| iph = ip_hdr(skb); |
| memset(iph + 1, IPOPT_NOP, opt->optlen); |
| } else |
| iph = ip_hdr(skb); |
| |
| if (opt->optlen > 0) |
| memset(opt, 0, sizeof(*opt)); |
| opt->optlen = opt_len; |
| opt->cipso = sizeof(struct iphdr); |
| opt->is_changed = 1; |
| |
| /* we have to do the following because we are being called from a |
| * netfilter hook which means the packet already has had the header |
| * fields populated and the checksum calculated - yes this means we |
| * are doing more work than needed but we do it to keep the core |
| * stack clean and tidy */ |
| memcpy(iph + 1, buf, buf_len); |
| if (opt_len > buf_len) |
| memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len); |
| if (len_delta != 0) { |
| iph->ihl = 5 + (opt_len >> 2); |
| iph->tot_len = htons(skb->len); |
| } |
| ip_send_check(iph); |
| |
| return 0; |
| } |
| |
| /** |
| * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet |
| * @skb: the packet |
| * |
| * Description: |
| * Removes any and all CIPSO options from the given packet. Returns zero on |
| * success, negative values on failure. |
| * |
| */ |
| int cipso_v4_skbuff_delattr(struct sk_buff *skb) |
| { |
| int ret_val; |
| struct iphdr *iph; |
| struct ip_options *opt = &IPCB(skb)->opt; |
| unsigned char *cipso_ptr; |
| |
| if (opt->cipso == 0) |
| return 0; |
| |
| /* since we are changing the packet we should make a copy */ |
| ret_val = skb_cow(skb, skb_headroom(skb)); |
| if (ret_val < 0) |
| return ret_val; |
| |
| /* the easiest thing to do is just replace the cipso option with noop |
| * options since we don't change the size of the packet, although we |
| * still need to recalculate the checksum */ |
| |
| iph = ip_hdr(skb); |
| cipso_ptr = (unsigned char *)iph + opt->cipso; |
| memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]); |
| opt->cipso = 0; |
| opt->is_changed = 1; |
| |
| ip_send_check(iph); |
| |
| return 0; |
| } |
| |
| /* |
| * Setup Functions |
| */ |
| |
| /** |
| * cipso_v4_init - Initialize the CIPSO module |
| * |
| * Description: |
| * Initialize the CIPSO module and prepare it for use. Returns zero on success |
| * and negative values on failure. |
| * |
| */ |
| static int __init cipso_v4_init(void) |
| { |
| int ret_val; |
| |
| ret_val = cipso_v4_cache_init(); |
| if (ret_val != 0) |
| panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n", |
| ret_val); |
| |
| return 0; |
| } |
| |
| subsys_initcall(cipso_v4_init); |