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2293 lines
61 KiB
2293 lines
61 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
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* CIPSO - Commercial IP Security Option |
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* |
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* This is an implementation of the CIPSO 2.2 protocol as specified in |
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* draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in |
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* FIPS-188. While CIPSO never became a full IETF RFC standard many vendors |
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* have chosen to adopt the protocol and over the years it has become a |
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* de-facto standard for labeled networking. |
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* |
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* The CIPSO draft specification can be found in the kernel's Documentation |
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* directory as well as the following URL: |
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* https://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt |
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* The FIPS-188 specification can be found at the following URL: |
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* https://www.itl.nist.gov/fipspubs/fip188.htm |
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* |
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* Author: Paul Moore <[email protected]> |
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*/ |
|
|
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/* |
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* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008 |
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*/ |
|
|
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#include <linux/init.h> |
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#include <linux/types.h> |
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#include <linux/rcupdate.h> |
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#include <linux/list.h> |
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#include <linux/spinlock.h> |
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#include <linux/string.h> |
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#include <linux/jhash.h> |
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#include <linux/audit.h> |
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#include <linux/slab.h> |
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#include <net/ip.h> |
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#include <net/icmp.h> |
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#include <net/tcp.h> |
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#include <net/netlabel.h> |
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#include <net/cipso_ipv4.h> |
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#include <linux/atomic.h> |
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#include <linux/bug.h> |
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#include <asm/unaligned.h> |
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|
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/* List of available DOI definitions */ |
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/* XXX - This currently assumes a minimal number of different DOIs in use, |
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* if in practice there are a lot of different DOIs this list should |
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* probably be turned into a hash table or something similar so we |
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* can do quick lookups. */ |
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static DEFINE_SPINLOCK(cipso_v4_doi_list_lock); |
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static LIST_HEAD(cipso_v4_doi_list); |
|
|
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/* Label mapping cache */ |
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int cipso_v4_cache_enabled = 1; |
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int cipso_v4_cache_bucketsize = 10; |
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#define CIPSO_V4_CACHE_BUCKETBITS 7 |
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#define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS) |
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#define CIPSO_V4_CACHE_REORDERLIMIT 10 |
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struct cipso_v4_map_cache_bkt { |
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spinlock_t lock; |
|
u32 size; |
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struct list_head list; |
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}; |
|
|
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struct cipso_v4_map_cache_entry { |
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u32 hash; |
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unsigned char *key; |
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size_t key_len; |
|
|
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struct netlbl_lsm_cache *lsm_data; |
|
|
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u32 activity; |
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struct list_head list; |
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}; |
|
|
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static struct cipso_v4_map_cache_bkt *cipso_v4_cache; |
|
|
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/* Restricted bitmap (tag #1) flags */ |
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int cipso_v4_rbm_optfmt = 0; |
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int cipso_v4_rbm_strictvalid = 1; |
|
|
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/* |
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* Protocol Constants |
|
*/ |
|
|
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/* Maximum size of the CIPSO IP option, derived from the fact that the maximum |
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* IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */ |
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#define CIPSO_V4_OPT_LEN_MAX 40 |
|
|
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/* Length of the base CIPSO option, this includes the option type (1 byte), the |
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* option length (1 byte), and the DOI (4 bytes). */ |
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#define CIPSO_V4_HDR_LEN 6 |
|
|
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/* Base length of the restrictive category bitmap tag (tag #1). */ |
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#define CIPSO_V4_TAG_RBM_BLEN 4 |
|
|
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/* Base length of the enumerated category tag (tag #2). */ |
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#define CIPSO_V4_TAG_ENUM_BLEN 4 |
|
|
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/* Base length of the ranged categories bitmap tag (tag #5). */ |
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#define CIPSO_V4_TAG_RNG_BLEN 4 |
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/* The maximum number of category ranges permitted in the ranged category tag |
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* (tag #5). You may note that the IETF draft states that the maximum number |
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* 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. */ |
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#define CIPSO_V4_TAG_RNG_CAT_MAX 8 |
|
|
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/* Base length of the local tag (non-standard tag). |
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* Tag definition (may change between kernel versions) |
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* |
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* 0 8 16 24 32 |
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* +----------+----------+----------+----------+ |
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* | 10000000 | 00000110 | 32-bit secid value | |
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* +----------+----------+----------+----------+ |
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* | in (host byte order)| |
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* +----------+----------+ |
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* |
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*/ |
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#define CIPSO_V4_TAG_LOC_BLEN 6 |
|
|
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/* |
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* Helper Functions |
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*/ |
|
|
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/** |
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* cipso_v4_cache_entry_free - Frees a cache entry |
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* @entry: the entry to free |
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* |
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* Description: |
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* This function frees the memory associated with a cache entry including the |
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* LSM cache data if there are no longer any users, i.e. reference count == 0. |
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* |
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*/ |
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static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry) |
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{ |
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if (entry->lsm_data) |
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netlbl_secattr_cache_free(entry->lsm_data); |
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kfree(entry->key); |
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kfree(entry); |
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} |
|
|
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/** |
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* cipso_v4_map_cache_hash - Hashing function for the CIPSO cache |
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* @key: the hash key |
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* @key_len: the length of the key in bytes |
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* |
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* Description: |
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* The CIPSO tag hashing function. Returns a 32-bit hash value. |
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* |
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*/ |
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static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len) |
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{ |
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return jhash(key, key_len, 0); |
|
} |
|
|
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/* |
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* Label Mapping Cache Functions |
|
*/ |
|
|
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/** |
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* cipso_v4_cache_init - Initialize the CIPSO cache |
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* |
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* Description: |
|
* Initializes the CIPSO label mapping cache, this function should be called |
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* before any of the other functions defined in this file. Returns zero on |
|
* success, negative values on error. |
|
* |
|
*/ |
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static int __init cipso_v4_cache_init(void) |
|
{ |
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u32 iter; |
|
|
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cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS, |
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sizeof(struct cipso_v4_map_cache_bkt), |
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GFP_KERNEL); |
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if (!cipso_v4_cache) |
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return -ENOMEM; |
|
|
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for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
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spin_lock_init(&cipso_v4_cache[iter].lock); |
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cipso_v4_cache[iter].size = 0; |
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INIT_LIST_HEAD(&cipso_v4_cache[iter].list); |
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} |
|
|
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return 0; |
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} |
|
|
|
/** |
|
* cipso_v4_cache_invalidate - Invalidates the current CIPSO cache |
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* |
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* Description: |
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* Invalidates and frees any entries in the CIPSO cache. |
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* |
|
*/ |
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void cipso_v4_cache_invalidate(void) |
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{ |
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struct cipso_v4_map_cache_entry *entry, *tmp_entry; |
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u32 iter; |
|
|
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for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) { |
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spin_lock_bh(&cipso_v4_cache[iter].lock); |
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list_for_each_entry_safe(entry, |
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tmp_entry, |
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&cipso_v4_cache[iter].list, list) { |
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list_del(&entry->list); |
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cipso_v4_cache_entry_free(entry); |
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} |
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cipso_v4_cache[iter].size = 0; |
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spin_unlock_bh(&cipso_v4_cache[iter].lock); |
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} |
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} |
|
|
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/** |
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* cipso_v4_cache_check - Check the CIPSO cache for a label mapping |
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* @key: the buffer to check |
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* @key_len: buffer length in bytes |
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* @secattr: the security attribute struct to use |
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* |
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* Description: |
|
* This function checks the cache to see if a label mapping already exists for |
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* the given key. If there is a match then the cache is adjusted and the |
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* @secattr struct is populated with the correct LSM security attributes. The |
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* cache is adjusted in the following manner if the entry is not already the |
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* first in the cache bucket: |
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* |
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* 1. The cache entry's activity counter is incremented |
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* 2. The previous (higher ranking) entry's activity counter is decremented |
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* 3. If the difference between the two activity counters is geater than |
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* CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped |
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* |
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* Returns zero on success, -ENOENT for a cache miss, and other negative values |
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* on error. |
|
* |
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*/ |
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static int cipso_v4_cache_check(const unsigned char *key, |
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u32 key_len, |
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struct netlbl_lsm_secattr *secattr) |
|
{ |
|
u32 bkt; |
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struct cipso_v4_map_cache_entry *entry; |
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struct cipso_v4_map_cache_entry *prev_entry = NULL; |
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u32 hash; |
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|
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if (!cipso_v4_cache_enabled) |
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return -ENOENT; |
|
|
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hash = cipso_v4_map_cache_hash(key, key_len); |
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bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
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spin_lock_bh(&cipso_v4_cache[bkt].lock); |
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list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) { |
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if (entry->hash == hash && |
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entry->key_len == key_len && |
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memcmp(entry->key, key, key_len) == 0) { |
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entry->activity += 1; |
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refcount_inc(&entry->lsm_data->refcount); |
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secattr->cache = entry->lsm_data; |
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secattr->flags |= NETLBL_SECATTR_CACHE; |
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secattr->type = NETLBL_NLTYPE_CIPSOV4; |
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if (!prev_entry) { |
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spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
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return 0; |
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} |
|
|
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if (prev_entry->activity > 0) |
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prev_entry->activity -= 1; |
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if (entry->activity > prev_entry->activity && |
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entry->activity - prev_entry->activity > |
|
CIPSO_V4_CACHE_REORDERLIMIT) { |
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__list_del(entry->list.prev, entry->list.next); |
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__list_add(&entry->list, |
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prev_entry->list.prev, |
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&prev_entry->list); |
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} |
|
|
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spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
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return 0; |
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} |
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prev_entry = entry; |
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} |
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spin_unlock_bh(&cipso_v4_cache[bkt].lock); |
|
|
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return -ENOENT; |
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} |
|
|
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/** |
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* cipso_v4_cache_add - Add an entry to the CIPSO cache |
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* @cipso_ptr: pointer to CIPSO IP option |
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* @secattr: the packet's security attributes |
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* |
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* 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, |
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* negative values on failure. |
|
* |
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*/ |
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int cipso_v4_cache_add(const unsigned char *cipso_ptr, |
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const struct netlbl_lsm_secattr *secattr) |
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{ |
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int ret_val = -EPERM; |
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u32 bkt; |
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struct cipso_v4_map_cache_entry *entry = NULL; |
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struct cipso_v4_map_cache_entry *old_entry = NULL; |
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u32 cipso_ptr_len; |
|
|
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if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0) |
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return 0; |
|
|
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cipso_ptr_len = cipso_ptr[1]; |
|
|
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entry = kzalloc(sizeof(*entry), GFP_ATOMIC); |
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if (!entry) |
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return -ENOMEM; |
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entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC); |
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if (!entry->key) { |
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ret_val = -ENOMEM; |
|
goto cache_add_failure; |
|
} |
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entry->key_len = cipso_ptr_len; |
|
entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len); |
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refcount_inc(&secattr->cache->refcount); |
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entry->lsm_data = secattr->cache; |
|
|
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bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1); |
|
spin_lock_bh(&cipso_v4_cache[bkt].lock); |
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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 && refcount_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; |
|
} |
|
} |
|
|
|
refcount_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); |
|
kfree(doi_def->map.std); |
|
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_info: NetLabel audit information |
|
* |
|
* 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; |
|
} |
|
list_del_rcu(&doi_def->list); |
|
spin_unlock(&cipso_v4_doi_list_lock); |
|
|
|
cipso_v4_doi_putdef(doi_def); |
|
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 (!refcount_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 (!refcount_dec_and_test(&doi_def->refcount)) |
|
return; |
|
|
|
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 (refcount_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; |
|
put_unaligned_be32(doi_def->doi, &buf[2]); |
|
} |
|
|
|
/** |
|
* 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; |
|
} |
|
|
|
if (secattr->attr.mls.cat) |
|
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; |
|
} |
|
|
|
if (secattr->attr.mls.cat) |
|
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 |
|
* @skb: the packet |
|
* @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 |
|
* @req: 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 |
|
* @doi_def: the DOI structure |
|
* @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);
|
|
|