diff options
Diffstat (limited to 'net/ipv4/cipso_ipv4.c')
| -rw-r--r-- | net/ipv4/cipso_ipv4.c | 1607 |
1 files changed, 1607 insertions, 0 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c new file mode 100644 index 000000000000..b82a101c95c5 --- /dev/null +++ b/net/ipv4/cipso_ipv4.c @@ -0,0 +1,1607 @@ +/* + * 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, copies of both documents can be found in the Documentation + * directory. 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. + * + * Author: Paul Moore <paul.moore@hp.com> + * + */ + +/* + * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#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 <net/ip.h> +#include <net/icmp.h> +#include <net/tcp.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> +#include <asm/bug.h> + +struct cipso_v4_domhsh_entry { + char *domain; + u32 valid; + struct list_head list; + struct rcu_head rcu; +}; + +/* List of available DOI definitions */ +/* XXX - Updates should be minimal so having a single lock for the + * cipso_v4_doi_list and the cipso_v4_doi_list->dom_list should be + * okay. */ +/* 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. */ +DEFINE_SPINLOCK(cipso_v4_doi_list_lock); +static struct list_head cipso_v4_doi_list = LIST_HEAD_INIT(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 = NULL; + +/* Restricted bitmap (tag #1) flags */ +int cipso_v4_rbm_optfmt = 0; +int cipso_v4_rbm_strictvalid = 1; + +/* + * Helper Functions + */ + +/** + * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit + * @bitmap: the bitmap + * @bitmap_len: length in bits + * @offset: starting offset + * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit + * + * Description: + * Starting at @offset, walk the bitmap from left to right until either the + * desired bit is found or we reach the end. Return the bit offset, -1 if + * not found, or -2 if error. + */ +static int cipso_v4_bitmap_walk(const unsigned char *bitmap, + u32 bitmap_len, + u32 offset, + u8 state) +{ + u32 bit_spot; + u32 byte_offset; + unsigned char bitmask; + unsigned char byte; + + /* gcc always rounds to zero when doing integer division */ + byte_offset = offset / 8; + byte = bitmap[byte_offset]; + bit_spot = offset; + bitmask = 0x80 >> (offset % 8); + + while (bit_spot < bitmap_len) { + if ((state && (byte & bitmask) == bitmask) || + (state == 0 && (byte & bitmask) == 0)) + return bit_spot; + + bit_spot++; + bitmask >>= 1; + if (bitmask == 0) { + byte = bitmap[++byte_offset]; + bitmask = 0x80; + } + } + + return -1; +} + +/** + * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap + * @bitmap: the bitmap + * @bit: the bit + * @state: if non-zero, set the bit (1) else clear the bit (0) + * + * Description: + * Set a single bit in the bitmask. Returns zero on success, negative values + * on error. + */ +static void cipso_v4_bitmap_setbit(unsigned char *bitmap, + u32 bit, + u8 state) +{ + u32 byte_spot; + u8 bitmask; + + /* gcc always rounds to zero when doing integer division */ + byte_spot = bit / 8; + bitmask = 0x80 >> (bit % 8); + if (state) + bitmap[byte_spot] |= bitmask; + else + bitmap[byte_spot] &= ~bitmask; +} + +/** + * cipso_v4_doi_domhsh_free - Frees a domain list 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 domain list entry can be released + * safely. + * + */ +static void cipso_v4_doi_domhsh_free(struct rcu_head *entry) +{ + struct cipso_v4_domhsh_entry *ptr; + + ptr = container_of(entry, struct cipso_v4_domhsh_entry, rcu); + kfree(ptr->domain); + kfree(ptr); +} + +/** + * 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. + * + */ +static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) +{ + if (entry->lsm_data.free) + entry->lsm_data.free(entry->lsm_data.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 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 == NULL) + 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(&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(&cipso_v4_cache[iter].lock); + } + + return; +} + +/** + * 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_BUCKETBITS - 1); + spin_lock(&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; + secattr->cache.free = entry->lsm_data.free; + secattr->cache.data = entry->lsm_data.data; + if (prev_entry == NULL) { + spin_unlock(&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(&cipso_v4_cache[bkt].lock); + return 0; + } + prev_entry = entry; + } + spin_unlock(&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 struct sk_buff *skb, + 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; + unsigned char *cipso_ptr; + u32 cipso_ptr_len; + + if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) + return 0; + + cipso_ptr = CIPSO_V4_OPTPTR(skb); + cipso_ptr_len = cipso_ptr[1]; + + entry = kzalloc(sizeof(*entry), GFP_ATOMIC); + if (entry == NULL) + return -ENOMEM; + entry->key = kmalloc(cipso_ptr_len, GFP_ATOMIC); + if (entry->key == NULL) { + ret_val = -ENOMEM; + goto cache_add_failure; + } + memcpy(entry->key, cipso_ptr, cipso_ptr_len); + entry->key_len = cipso_ptr_len; + entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); + entry->lsm_data.free = secattr->cache.free; + entry->lsm_data.data = secattr->cache.data; + + bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETBITS - 1); + spin_lock(&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(&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 responsibile 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 && iter->valid) + return iter; + return NULL; +} + +/** + * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine + * @doi_def: the DOI structure + * + * 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) +{ + if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN) + return -EINVAL; + + doi_def->valid = 1; + INIT_RCU_HEAD(&doi_def->rcu); + INIT_LIST_HEAD(&doi_def->dom_list); + + rcu_read_lock(); + if (cipso_v4_doi_search(doi_def->doi) != NULL) + goto doi_add_failure_rlock; + spin_lock(&cipso_v4_doi_list_lock); + if (cipso_v4_doi_search(doi_def->doi) != NULL) + goto doi_add_failure_slock; + list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list); + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + + return 0; + +doi_add_failure_slock: + spin_unlock(&cipso_v4_doi_list_lock); +doi_add_failure_rlock: + rcu_read_unlock(); + return -EEXIST; +} + +/** + * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine + * @doi: the DOI value + * @callback: the DOI cleanup/free callback + * + * Description: + * Removes a DOI definition from the CIPSO engine, @callback is called to + * free any memory. 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, void (*callback) (struct rcu_head * head)) +{ + struct cipso_v4_doi *doi_def; + struct cipso_v4_domhsh_entry *dom_iter; + + rcu_read_lock(); + if (cipso_v4_doi_search(doi) != NULL) { + spin_lock(&cipso_v4_doi_list_lock); + doi_def = cipso_v4_doi_search(doi); + if (doi_def == NULL) { + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + return -ENOENT; + } + doi_def->valid = 0; + list_del_rcu(&doi_def->list); + spin_unlock(&cipso_v4_doi_list_lock); + list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list) + if (dom_iter->valid) + netlbl_domhsh_remove(dom_iter->domain); + cipso_v4_cache_invalidate(); + rcu_read_unlock(); + + call_rcu(&doi_def->rcu, callback); + return 0; + } + rcu_read_unlock(); + + return -ENOENT; +} + +/** + * cipso_v4_doi_getdef - Returns a pointer 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. + * + */ +struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi) +{ + return cipso_v4_doi_search(doi); +} + +/** + * cipso_v4_doi_dump_all - Dump all the CIPSO DOI definitions into a sk_buff + * @headroom: the amount of headroom to allocate for the sk_buff + * + * Description: + * Dump a list of all the configured DOI values into a sk_buff. The returned + * sk_buff has room at the front of the sk_buff for @headroom bytes. See + * net/netlabel/netlabel_cipso_v4.h for the LISTALL message format. This + * function may fail if another process is changing the DOI list at the same + * time. Returns a pointer to a sk_buff on success, NULL on error. + * + */ +struct sk_buff *cipso_v4_doi_dump_all(size_t headroom) +{ + struct sk_buff *skb = NULL; + struct cipso_v4_doi *iter; + u32 doi_cnt = 0; + ssize_t buf_len; + + buf_len = NETLBL_LEN_U32; + rcu_read_lock(); + list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) + if (iter->valid) { + doi_cnt += 1; + buf_len += 2 * NETLBL_LEN_U32; + } + + skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC); + if (skb == NULL) + goto doi_dump_all_failure; + + if (nla_put_u32(skb, NLA_U32, doi_cnt) != 0) + goto doi_dump_all_failure; + buf_len -= NETLBL_LEN_U32; + list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list) + if (iter->valid) { + if (buf_len < 2 * NETLBL_LEN_U32) + goto doi_dump_all_failure; + if (nla_put_u32(skb, NLA_U32, iter->doi) != 0) + goto doi_dump_all_failure; + if (nla_put_u32(skb, NLA_U32, iter->type) != 0) + goto doi_dump_all_failure; + buf_len -= 2 * NETLBL_LEN_U32; + } + rcu_read_unlock(); + + return skb; + +doi_dump_all_failure: + rcu_read_unlock(); + kfree(skb); + return NULL; +} + +/** + * cipso_v4_doi_dump - Dump a CIPSO DOI definition into a sk_buff + * @doi: the DOI value + * @headroom: the amount of headroom to allocate for the sk_buff + * + * Description: + * Lookup the DOI definition matching @doi and dump it's contents into a + * sk_buff. The returned sk_buff has room at the front of the sk_buff for + * @headroom bytes. See net/netlabel/netlabel_cipso_v4.h for the LIST message + * format. This function may fail if another process is changing the DOI list + * at the same time. Returns a pointer to a sk_buff on success, NULL on error. + * + */ +struct sk_buff *cipso_v4_doi_dump(u32 doi, size_t headroom) +{ + struct sk_buff *skb = NULL; + struct cipso_v4_doi *iter; + u32 tag_cnt = 0; + u32 lvl_cnt = 0; + u32 cat_cnt = 0; + ssize_t buf_len; + ssize_t tmp; + + rcu_read_lock(); + iter = cipso_v4_doi_getdef(doi); + if (iter == NULL) + goto doi_dump_failure; + buf_len = NETLBL_LEN_U32; + switch (iter->type) { + case CIPSO_V4_MAP_PASS: + buf_len += NETLBL_LEN_U32; + while(tag_cnt < CIPSO_V4_TAG_MAXCNT && + iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) { + tag_cnt += 1; + buf_len += NETLBL_LEN_U8; + } + break; + case CIPSO_V4_MAP_STD: + buf_len += 3 * NETLBL_LEN_U32; + while (tag_cnt < CIPSO_V4_TAG_MAXCNT && + iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) { + tag_cnt += 1; + buf_len += NETLBL_LEN_U8; + } + for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++) + if (iter->map.std->lvl.local[tmp] != + CIPSO_V4_INV_LVL) { + lvl_cnt += 1; + buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U8; + } + for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++) + if (iter->map.std->cat.local[tmp] != + CIPSO_V4_INV_CAT) { + cat_cnt += 1; + buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U16; + } + break; + } + + skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC); + if (skb == NULL) + goto doi_dump_failure; + + if (nla_put_u32(skb, NLA_U32, iter->type) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U32; + if (iter != cipso_v4_doi_getdef(doi)) + goto doi_dump_failure; + switch (iter->type) { + case CIPSO_V4_MAP_PASS: + if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U32; + for (tmp = 0; + tmp < CIPSO_V4_TAG_MAXCNT && + iter->tags[tmp] != CIPSO_V4_TAG_INVALID; + tmp++) { + if (buf_len < NETLBL_LEN_U8) + goto doi_dump_failure; + if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U8; + } + break; + case CIPSO_V4_MAP_STD: + if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0) + goto doi_dump_failure; + if (nla_put_u32(skb, NLA_U32, lvl_cnt) != 0) + goto doi_dump_failure; + if (nla_put_u32(skb, NLA_U32, cat_cnt) != 0) + goto doi_dump_failure; + buf_len -= 3 * NETLBL_LEN_U32; + for (tmp = 0; + tmp < CIPSO_V4_TAG_MAXCNT && + iter->tags[tmp] != CIPSO_V4_TAG_INVALID; + tmp++) { + if (buf_len < NETLBL_LEN_U8) + goto doi_dump_failure; + if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U8; + } + for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++) + if (iter->map.std->lvl.local[tmp] != + CIPSO_V4_INV_LVL) { + if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U8) + goto doi_dump_failure; + if (nla_put_u32(skb, NLA_U32, tmp) != 0) + goto doi_dump_failure; + if (nla_put_u8(skb, + NLA_U8, + iter->map.std->lvl.local[tmp]) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U8; + } + for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++) + if (iter->map.std->cat.local[tmp] != + CIPSO_V4_INV_CAT) { + if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U16) + goto doi_dump_failure; + if (nla_put_u32(skb, NLA_U32, tmp) != 0) + goto doi_dump_failure; + if (nla_put_u16(skb, + NLA_U16, + iter->map.std->cat.local[tmp]) != 0) + goto doi_dump_failure; + buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U16; + } + break; + } + rcu_read_unlock(); + + return skb; + +doi_dump_failure: + rcu_read_unlock(); + kfree(skb); + return NULL; +} + +/** + * cipso_v4_doi_domhsh_add - Adds a domain entry to a DOI definition + * @doi_def: the DOI definition + * @domain: the domain to add + * + * Description: + * Adds the @domain to the the DOI specified by @doi_def, this function + * should only be called by external functions (i.e. NetLabel). This function + * does allocate memory. Returns zero on success, negative values on failure. + * + */ +int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def, const char *domain) +{ + struct cipso_v4_domhsh_entry *iter; + struct cipso_v4_domhsh_entry *new_dom; + + new_dom = kzalloc(sizeof(*new_dom), GFP_KERNEL); + if (new_dom == NULL) + return -ENOMEM; + if (domain) { + new_dom->domain = kstrdup(domain, GFP_KERNEL); + if (new_dom->domain == NULL) { + kfree(new_dom); + return -ENOMEM; + } + } + new_dom->valid = 1; + INIT_RCU_HEAD(&new_dom->rcu); + + rcu_read_lock(); + spin_lock(&cipso_v4_doi_list_lock); + list_for_each_entry_rcu(iter, &doi_def->dom_list, list) + if (iter->valid && + ((domain != NULL && iter->domain != NULL && + strcmp(iter->domain, domain) == 0) || + (domain == NULL && iter->domain == NULL))) { + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + kfree(new_dom->domain); + kfree(new_dom); + return -EEXIST; + } + list_add_tail_rcu(&new_dom->list, &doi_def->dom_list); + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + + return 0; +} + +/** + * cipso_v4_doi_domhsh_remove - Removes a domain entry from a DOI definition + * @doi_def: the DOI definition + * @domain: the domain to remove + * + * Description: + * Removes the @domain from the DOI specified by @doi_def, this function + * should only be called by external functions (i.e. NetLabel). Returns zero + * on success and negative values on error. + * + */ +int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def, + const char *domain) +{ + struct cipso_v4_domhsh_entry *iter; + + rcu_read_lock(); + spin_lock(&cipso_v4_doi_list_lock); + list_for_each_entry_rcu(iter, &doi_def->dom_list, list) + if (iter->valid && + ((domain != NULL && iter->domain != NULL && + strcmp(iter->domain, domain) == 0) || + (domain == NULL && iter->domain == NULL))) { + iter->valid = 0; + list_del_rcu(&iter->list); + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free); + + return 0; + } + spin_unlock(&cipso_v4_doi_list_lock); + rcu_read_unlock(); + + return -ENOENT; +} + +/* + * 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_STD: + if (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_STD: + if (host_lvl < doi_def->map.std->lvl.local_size) { + *net_lvl = doi_def->map.std->lvl.local[host_lvl]; + return 0; + } + break; + } + + 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_STD: + 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; + } + break; + } + + 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 = doi_def->map.std->cat.cipso_size; + u32 *cipso_array = doi_def->map.std->cat.cipso; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + return 0; + case CIPSO_V4_MAP_STD: + for (;;) { + cat = cipso_v4_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 + * @host_cat: the category bitmap in host format + * @host_cat_len: the length of the host's category bitmap in bytes + * @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 unsigned char *host_cat, + u32 host_cat_len, + unsigned char *net_cat, + u32 net_cat_len) +{ + int host_spot = -1; + u32 net_spot; + u32 net_spot_max = 0; + u32 host_clen_bits = host_cat_len * 8; + u32 net_clen_bits = net_cat_len * 8; + u32 host_cat_size = doi_def->map.std->cat.local_size; + u32 *host_cat_array = doi_def->map.std->cat.local; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + net_spot_max = host_cat_len - 1; + while (net_spot_max > 0 && host_cat[net_spot_max] == 0) + net_spot_max--; + if (net_spot_max > net_cat_len) + return -EINVAL; + memcpy(net_cat, host_cat, net_spot_max); + return net_spot_max; + case CIPSO_V4_MAP_STD: + for (;;) { + host_spot = cipso_v4_bitmap_walk(host_cat, + host_clen_bits, + host_spot + 1, + 1); + if (host_spot < 0) + break; + if (host_spot >= host_cat_size) + return -EPERM; + + net_spot = host_cat_array[host_spot]; + if (net_spot >= net_clen_bits) + return -ENOSPC; + cipso_v4_bitmap_setbit(net_cat, net_spot, 1); + + if (net_spot > net_spot_max) + net_spot_max = net_spot; + } + + if (host_spot == -2) + return -EFAULT; + + if (++net_spot_max % 8) + return net_spot_max / 8 + 1; + return net_spot_max / 8; + } + + return -EINVAL; +} + +/** + * 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 + * @host_cat: the zero'd out category bitmap in host format + * @host_cat_len: the length of the host's category bitmap in bytes + * + * Description: + * Perform a label mapping to translate a CIPSO bitmap to the correct local + * MLS category bitmap using the given DOI definition. Returns the minimum + * size in bytes of the host bitmap on success, negative values otherwise. + * + */ +static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, + const unsigned char *net_cat, + u32 net_cat_len, + unsigned char *host_cat, + u32 host_cat_len) +{ + u32 host_spot; + u32 host_spot_max = 0; + int net_spot = -1; + u32 net_clen_bits = net_cat_len * 8; + u32 host_clen_bits = host_cat_len * 8; + u32 net_cat_size = doi_def->map.std->cat.cipso_size; + u32 *net_cat_array = doi_def->map.std->cat.cipso; + + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + if (net_cat_len > host_cat_len) + return -EINVAL; + memcpy(host_cat, net_cat, net_cat_len); + return net_cat_len; + case CIPSO_V4_MAP_STD: + for (;;) { + net_spot = cipso_v4_bitmap_walk(net_cat, + net_clen_bits, + net_spot + 1, + 1); + if (net_spot < 0) + break; + if (net_spot >= net_cat_size || + net_cat_array[net_spot] >= CIPSO_V4_INV_CAT) + return -EPERM; + + host_spot = net_cat_array[net_spot]; + if (host_spot >= host_clen_bits) + return -ENOSPC; + cipso_v4_bitmap_setbit(host_cat, host_spot, 1); + + if (host_spot > host_spot_max) + host_spot_max = host_spot; + } + + if (net_spot == -2) + return -EFAULT; + + if (++host_spot_max % 8) + return host_spot_max / 8 + 1; + return host_spot_max / 8; + } + + return -EINVAL; +} + +/* + * Protocol Handling Functions + */ + +#define CIPSO_V4_HDR_LEN 6 + +/** + * cipso_v4_gentag_hdr - Generate a CIPSO option header + * @doi_def: the DOI definition + * @len: the total tag length in bytes + * @buf: the CIPSO option buffer + * + * Description: + * Write a CIPSO header into the beginning of @buffer. Return zero on success, + * negative values on failure. + * + */ +static int cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def, + u32 len, + unsigned char *buf) +{ + if (CIPSO_V4_HDR_LEN + len > 40) + return -ENOSPC; + + buf[0] = IPOPT_CIPSO; + buf[1] = CIPSO_V4_HDR_LEN + len; + *(u32 *)&buf[2] = htonl(doi_def->doi); + + return 0; +} + +#define CIPSO_V4_TAG1_CAT_LEN 30 + +/** + * 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 zero 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 = -EPERM; + unsigned char *buf = NULL; + u32 buf_len; + u32 level; + + if (secattr->mls_cat) { + buf = kzalloc(CIPSO_V4_HDR_LEN + 4 + CIPSO_V4_TAG1_CAT_LEN, + GFP_ATOMIC); + if (buf == NULL) + return -ENOMEM; + + ret_val = cipso_v4_map_cat_rbm_hton(doi_def, + secattr->mls_cat, + secattr->mls_cat_len, + &buf[CIPSO_V4_HDR_LEN + 4], + CIPSO_V4_TAG1_CAT_LEN); + if (ret_val < 0) + goto gentag_failure; + + /* This will send packets using the "optimized" format when + * possibile as specified in section 3.4.2.6 of the + * CIPSO draft. */ + if (cipso_v4_rbm_optfmt && (ret_val > 0 && ret_val < 10)) + ret_val = 10; + + buf_len = 4 + ret_val; + } else { + buf = kzalloc(CIPSO_V4_HDR_LEN + 4, GFP_ATOMIC); + if (buf == NULL) + return -ENOMEM; + buf_len = 4; + } + + ret_val = cipso_v4_map_lvl_hton(doi_def, secattr->mls_lvl, &level); + if (ret_val != 0) + goto gentag_failure; + + ret_val = cipso_v4_gentag_hdr(doi_def, buf_len, buf); + if (ret_val != 0) + goto gentag_failure; + + buf[CIPSO_V4_HDR_LEN] = 0x01; + buf[CIPSO_V4_HDR_LEN + 1] = buf_len; + buf[CIPSO_V4_HDR_LEN + 3] = level; + + *buffer = buf; + *buffer_len = CIPSO_V4_HDR_LEN + buf_len; + + return 0; + +gentag_failure: + kfree(buf); + return ret_val; +} + +/** + * 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->mls_lvl = level; + secattr->mls_lvl_vld = 1; + + if (tag_len > 4) { + switch (doi_def->type) { + case CIPSO_V4_MAP_PASS: + secattr->mls_cat_len = tag_len - 4; + break; + case CIPSO_V4_MAP_STD: + secattr->mls_cat_len = + doi_def->map.std->cat.local_size; + break; + } + secattr->mls_cat = kzalloc(secattr->mls_cat_len, GFP_ATOMIC); + if (secattr->mls_cat == NULL) + return -ENOMEM; + + ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def, + &tag[4], + tag_len - 4, + secattr->mls_cat, + secattr->mls_cat_len); + if (ret_val < 0) { + kfree(secattr->mls_cat); + return ret_val; + } + secattr->mls_cat_len = ret_val; + } + + return 0; +} + +/** + * 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(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_getdef(ntohl(*((u32 *)&opt[2]))); + if (doi_def == NULL) { + err_offset = 2; + goto validate_return_locked; + } + + opt_iter = 6; + 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; + } + + 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 < 4) { + 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 > 4 && + cipso_v4_map_cat_rbm_valid(doi_def, + &tag[4], + tag_len - 4) < 0) { + err_offset = opt_iter + 4; + 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 reponse 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) +{ + if (skb->nh.iph->protocol == IPPROTO_ICMP || error != -EACCES) + return; + + if (gateway) + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0); + else + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0); +} + +/** + * cipso_v4_socket_setattr - Add a CIPSO option to a socket + * @sock: 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 @sock->sk, which means it either needs to be in the + * process of being created or locked via lock_sock(sock->sk). Returns zero on + * success and negative values on failure. + * + */ +int cipso_v4_socket_setattr(const struct socket *sock, + const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -EPERM; + u32 iter; + unsigned char *buf = NULL; + u32 buf_len = 0; + u32 opt_len; + struct ip_options *opt = NULL; + struct sock *sk; + 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(). */ + sk = sock->sk; + if (sk == NULL) + return 0; + + /* 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 { + switch (doi_def->tags[iter]) { + case CIPSO_V4_TAG_RBITMAP: + ret_val = cipso_v4_gentag_rbm(doi_def, + secattr, + &buf, + &buf_len); + break; + default: + ret_val = -EPERM; + goto socket_setattr_failure; + } + + iter++; + } while (ret_val != 0 && + iter < CIPSO_V4_TAG_MAXCNT && + doi_def->tags[iter] != CIPSO_V4_TAG_INVALID); + if (ret_val != 0) + goto socket_setattr_failure; + + /* 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 can't block here. */ + opt_len = (buf_len + 3) & ~3; + opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC); + if (opt == NULL) { + ret_val = -ENOMEM; + goto socket_setattr_failure; + } + memcpy(opt->__data, buf, buf_len); + opt->optlen = opt_len; + opt->is_data = 1; + kfree(buf); + buf = NULL; + ret_val = ip_options_compile(opt, NULL); + if (ret_val != 0) + goto socket_setattr_failure; + + sk_inet = inet_sk(sk); + if (sk_inet->is_icsk) { + sk_conn = inet_csk(sk); + if (sk_inet->opt) + sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen; + sk_conn->icsk_ext_hdr_len += opt->optlen; + sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie); + } + opt = xchg(&sk_inet->opt, opt); + kfree(opt); + + return 0; + +socket_setattr_failure: + kfree(buf); + kfree(opt); + return ret_val; +} + +/** + * cipso_v4_socket_getattr - Get the security attributes from a socket + * @sock: the socket + * @secattr: the security attributes + * + * Description: + * Query @sock to see if there is a CIPSO option attached to the socket and if + * there is return the CIPSO security attributes in @secattr. Returns zero on + * success and negative values on failure. + * + */ +int cipso_v4_socket_getattr(const struct socket *sock, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -ENOMSG; + struct sock *sk; + struct inet_sock *sk_inet; + unsigned char *cipso_ptr; + u32 doi; + struct cipso_v4_doi *doi_def; + + sk = sock->sk; + lock_sock(sk); + sk_inet = inet_sk(sk); + if (sk_inet->opt == NULL || sk_inet->opt->cipso == 0) + goto socket_getattr_return; + cipso_ptr = sk_inet->opt->__data + sk_inet->opt->cipso - + sizeof(struct iphdr); + ret_val = cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr); + if (ret_val == 0) + goto socket_getattr_return; + + doi = ntohl(*(u32 *)&cipso_ptr[2]); + rcu_read_lock(); + doi_def = cipso_v4_doi_getdef(doi); + if (doi_def == NULL) { + rcu_read_unlock(); + goto socket_getattr_return; + } + switch (cipso_ptr[6]) { + case CIPSO_V4_TAG_RBITMAP: + ret_val = cipso_v4_parsetag_rbm(doi_def, + &cipso_ptr[6], + secattr); + break; + } + rcu_read_unlock(); + +socket_getattr_return: + release_sock(sk); + return ret_val; +} + +/** + * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option + * @skb: the packet + * @secattr: the security attributes + * + * Description: + * Parse the given packet's CIPSO option and return the security attributes. + * Returns zero on success and negative values on failure. + * + */ +int cipso_v4_skbuff_getattr(const struct sk_buff *skb, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val = -ENOMSG; + unsigned char *cipso_ptr; + u32 doi; + struct cipso_v4_doi *doi_def; + + if (!CIPSO_V4_OPTEXIST(skb)) + return -ENOMSG; + cipso_ptr = CIPSO_V4_OPTPTR(skb); + if (cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr) == 0) + return 0; + + doi = ntohl(*(u32 *)&cipso_ptr[2]); + rcu_read_lock(); + doi_def = cipso_v4_doi_getdef(doi); + if (doi_def == NULL) + goto skbuff_getattr_return; + switch (cipso_ptr[6]) { + case CIPSO_V4_TAG_RBITMAP: + ret_val = cipso_v4_parsetag_rbm(doi_def, + &cipso_ptr[6], + secattr); + break; + } + +skbuff_getattr_return: + rcu_read_unlock(); + return ret_val; +} + +/* + * 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); |