*/
#define CALIPSO_OPT_LEN_MAX_WITH_PAD (3 + CALIPSO_OPT_LEN_MAX + 7)
+ /* Maximium size of u32 aligned buffer required to hold calipso
+ * option. Max of 3 initial pad bytes starting from buffer + 3.
+ * i.e. the worst case is when the previous tlv finishes on 4n + 3.
+ */
+#define CALIPSO_MAX_BUFFER (6 + CALIPSO_OPT_LEN_MAX)
/* List of available DOI definitions */
static DEFINE_SPINLOCK(calipso_doi_list_lock);
static LIST_HEAD(calipso_doi_list);
+/* Label mapping cache */
+int calipso_cache_enabled = 1;
+int calipso_cache_bucketsize = 10;
+#define CALIPSO_CACHE_BUCKETBITS 7
+#define CALIPSO_CACHE_BUCKETS BIT(CALIPSO_CACHE_BUCKETBITS)
+#define CALIPSO_CACHE_REORDERLIMIT 10
+struct calipso_map_cache_bkt {
+ spinlock_t lock;
+ u32 size;
+ struct list_head list;
+};
+
+struct calipso_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 calipso_map_cache_bkt *calipso_cache;
+
+/* Label Mapping Cache Functions
+ */
+
+/**
+ * calipso_cache_entry_free - Frees a cache entry
+ * @entry: the entry to free
+ *
+ * Description:
+ * This function frees the memory associated with a cache entry including the
+ * LSM cache data if there are no longer any users, i.e. reference count == 0.
+ *
+ */
+static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry)
+{
+ if (entry->lsm_data)
+ netlbl_secattr_cache_free(entry->lsm_data);
+ kfree(entry->key);
+ kfree(entry);
+}
+
+/**
+ * calipso_map_cache_hash - Hashing function for the CALIPSO cache
+ * @key: the hash key
+ * @key_len: the length of the key in bytes
+ *
+ * Description:
+ * The CALIPSO tag hashing function. Returns a 32-bit hash value.
+ *
+ */
+static u32 calipso_map_cache_hash(const unsigned char *key, u32 key_len)
+{
+ return jhash(key, key_len, 0);
+}
+
+/**
+ * calipso_cache_init - Initialize the CALIPSO cache
+ *
+ * Description:
+ * Initializes the CALIPSO label mapping cache, this function should be called
+ * before any of the other functions defined in this file. Returns zero on
+ * success, negative values on error.
+ *
+ */
+static int __init calipso_cache_init(void)
+{
+ u32 iter;
+
+ calipso_cache = kcalloc(CALIPSO_CACHE_BUCKETS,
+ sizeof(struct calipso_map_cache_bkt),
+ GFP_KERNEL);
+ if (!calipso_cache)
+ return -ENOMEM;
+
+ for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
+ spin_lock_init(&calipso_cache[iter].lock);
+ calipso_cache[iter].size = 0;
+ INIT_LIST_HEAD(&calipso_cache[iter].list);
+ }
+
+ return 0;
+}
+
+/**
+ * calipso_cache_invalidate - Invalidates the current CALIPSO cache
+ *
+ * Description:
+ * Invalidates and frees any entries in the CALIPSO cache. Returns zero on
+ * success and negative values on failure.
+ *
+ */
+static void calipso_cache_invalidate(void)
+{
+ struct calipso_map_cache_entry *entry, *tmp_entry;
+ u32 iter;
+
+ for (iter = 0; iter < CALIPSO_CACHE_BUCKETS; iter++) {
+ spin_lock_bh(&calipso_cache[iter].lock);
+ list_for_each_entry_safe(entry,
+ tmp_entry,
+ &calipso_cache[iter].list, list) {
+ list_del(&entry->list);
+ calipso_cache_entry_free(entry);
+ }
+ calipso_cache[iter].size = 0;
+ spin_unlock_bh(&calipso_cache[iter].lock);
+ }
+}
+
+/**
+ * calipso_cache_check - Check the CALIPSO cache for a label mapping
+ * @key: the buffer to check
+ * @key_len: buffer length in bytes
+ * @secattr: the security attribute struct to use
+ *
+ * Description:
+ * This function checks the cache to see if a label mapping already exists for
+ * the given key. If there is a match then the cache is adjusted and the
+ * @secattr struct is populated with the correct LSM security attributes. The
+ * cache is adjusted in the following manner if the entry is not already the
+ * first in the cache bucket:
+ *
+ * 1. The cache entry's activity counter is incremented
+ * 2. The previous (higher ranking) entry's activity counter is decremented
+ * 3. If the difference between the two activity counters is geater than
+ * CALIPSO_CACHE_REORDERLIMIT the two entries are swapped
+ *
+ * Returns zero on success, -ENOENT for a cache miss, and other negative values
+ * on error.
+ *
+ */
+static int calipso_cache_check(const unsigned char *key,
+ u32 key_len,
+ struct netlbl_lsm_secattr *secattr)
+{
+ u32 bkt;
+ struct calipso_map_cache_entry *entry;
+ struct calipso_map_cache_entry *prev_entry = NULL;
+ u32 hash;
+
+ if (!calipso_cache_enabled)
+ return -ENOENT;
+
+ hash = calipso_map_cache_hash(key, key_len);
+ bkt = hash & (CALIPSO_CACHE_BUCKETS - 1);
+ spin_lock_bh(&calipso_cache[bkt].lock);
+ list_for_each_entry(entry, &calipso_cache[bkt].list, list) {
+ if (entry->hash == hash &&
+ entry->key_len == key_len &&
+ memcmp(entry->key, key, key_len) == 0) {
+ entry->activity += 1;
+ atomic_inc(&entry->lsm_data->refcount);
+ secattr->cache = entry->lsm_data;
+ secattr->flags |= NETLBL_SECATTR_CACHE;
+ secattr->type = NETLBL_NLTYPE_CALIPSO;
+ if (!prev_entry) {
+ spin_unlock_bh(&calipso_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 >
+ CALIPSO_CACHE_REORDERLIMIT) {
+ __list_del(entry->list.prev, entry->list.next);
+ __list_add(&entry->list,
+ prev_entry->list.prev,
+ &prev_entry->list);
+ }
+
+ spin_unlock_bh(&calipso_cache[bkt].lock);
+ return 0;
+ }
+ prev_entry = entry;
+ }
+ spin_unlock_bh(&calipso_cache[bkt].lock);
+
+ return -ENOENT;
+}
+
+/**
+ * calipso_cache_add - Add an entry to the CALIPSO cache
+ * @calipso_ptr: the CALIPSO option
+ * @secattr: the packet's security attributes
+ *
+ * Description:
+ * Add a new entry into the CALIPSO label mapping cache. Add the new entry to
+ * head of the cache bucket's list, if the cache bucket is out of room remove
+ * the last entry in the list first. It is important to note that there is
+ * currently no checking for duplicate keys. Returns zero on success,
+ * negative values on failure. The key stored starts at calipso_ptr + 2,
+ * i.e. the type and length bytes are not stored, this corresponds to
+ * calipso_ptr[1] bytes of data.
+ *
+ */
+static int calipso_cache_add(const unsigned char *calipso_ptr,
+ const struct netlbl_lsm_secattr *secattr)
+{
+ int ret_val = -EPERM;
+ u32 bkt;
+ struct calipso_map_cache_entry *entry = NULL;
+ struct calipso_map_cache_entry *old_entry = NULL;
+ u32 calipso_ptr_len;
+
+ if (!calipso_cache_enabled || calipso_cache_bucketsize <= 0)
+ return 0;
+
+ calipso_ptr_len = calipso_ptr[1];
+
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+ if (!entry)
+ return -ENOMEM;
+ entry->key = kmemdup(calipso_ptr + 2, calipso_ptr_len, GFP_ATOMIC);
+ if (!entry->key) {
+ ret_val = -ENOMEM;
+ goto cache_add_failure;
+ }
+ entry->key_len = calipso_ptr_len;
+ entry->hash = calipso_map_cache_hash(calipso_ptr, calipso_ptr_len);
+ atomic_inc(&secattr->cache->refcount);
+ entry->lsm_data = secattr->cache;
+
+ bkt = entry->hash & (CALIPSO_CACHE_BUCKETS - 1);
+ spin_lock_bh(&calipso_cache[bkt].lock);
+ if (calipso_cache[bkt].size < calipso_cache_bucketsize) {
+ list_add(&entry->list, &calipso_cache[bkt].list);
+ calipso_cache[bkt].size += 1;
+ } else {
+ old_entry = list_entry(calipso_cache[bkt].list.prev,
+ struct calipso_map_cache_entry, list);
+ list_del(&old_entry->list);
+ list_add(&entry->list, &calipso_cache[bkt].list);
+ calipso_cache_entry_free(old_entry);
+ }
+ spin_unlock_bh(&calipso_cache[bkt].lock);
+
+ return 0;
+
+cache_add_failure:
+ if (entry)
+ calipso_cache_entry_free(entry);
+ return ret_val;
+}
+
/* DOI List Functions
*/
return ret_val;
}
+/**
+ * calipso_validate - Validate a CALIPSO option
+ * @skb: the packet
+ * @option: the start of the option
+ *
+ * Description:
+ * This routine is called to validate a CALIPSO option.
+ * If the option is valid then %true is returned, otherwise
+ * %false is returned.
+ *
+ * The caller should have already checked that the length of the
+ * option (including the TLV header) is >= 10 and that the catmap
+ * length is consistent with the option length.
+ *
+ * We leave checks on the level and categories to the socket layer.
+ */
+bool calipso_validate(const struct sk_buff *skb, const unsigned char *option)
+{
+ struct calipso_doi *doi_def;
+ bool ret_val;
+ u16 crc, len = option[1] + 2;
+ static const u8 zero[2];
+
+ /* The original CRC runs over the option including the TLV header
+ * with the CRC-16 field (at offset 8) zeroed out. */
+ crc = crc_ccitt(0xffff, option, 8);
+ crc = crc_ccitt(crc, zero, sizeof(zero));
+ if (len > 10)
+ crc = crc_ccitt(crc, option + 10, len - 10);
+ crc = ~crc;
+ if (option[8] != (crc & 0xff) || option[9] != ((crc >> 8) & 0xff))
+ return false;
+
+ rcu_read_lock();
+ doi_def = calipso_doi_search(get_unaligned_be32(option + 2));
+ ret_val = !!doi_def;
+ rcu_read_unlock();
+
+ return ret_val;
+}
+
/**
* calipso_map_cat_hton - Perform a category mapping from host to network
* @doi_def: the DOI definition
memcpy(new, hop, start);
ret_val = calipso_genopt((unsigned char *)new, start, buf_len, doi_def,
secattr);
- if (ret_val < 0)
+ if (ret_val < 0) {
+ kfree(new);
return ERR_PTR(ret_val);
+ }
buf_len = start + ret_val;
/* At this point buf_len aligns to 4n, so (buf_len & 4) pads to 8n */
if (cat_len + 8 > len)
return -EINVAL;
+ if (calipso_cache_check(calipso + 2, calipso[1], secattr) == 0)
+ return 0;
+
doi = get_unaligned_be32(calipso + 2);
rcu_read_lock();
doi_def = calipso_doi_search(doi);
txopt_put(txopts);
}
+/* request sock functions.
+ */
+
+/**
+ * calipso_req_setattr - Add a CALIPSO option to a connection request socket
+ * @req: the connection request socket
+ * @doi_def: the CALIPSO DOI to use
+ * @secattr: the specific security attributes of the socket
+ *
+ * Description:
+ * Set the CALIPSO option on the given socket using the DOI definition and
+ * security attributes passed to the function. Returns zero on success and
+ * negative values on failure.
+ *
+ */
+static int calipso_req_setattr(struct request_sock *req,
+ const struct calipso_doi *doi_def,
+ const struct netlbl_lsm_secattr *secattr)
+{
+ struct ipv6_txoptions *txopts;
+ struct inet_request_sock *req_inet = inet_rsk(req);
+ struct ipv6_opt_hdr *old, *new;
+ struct sock *sk = sk_to_full_sk(req_to_sk(req));
+
+ if (req_inet->ipv6_opt && req_inet->ipv6_opt->hopopt)
+ old = req_inet->ipv6_opt->hopopt;
+ else
+ old = NULL;
+
+ new = calipso_opt_insert(old, doi_def, secattr);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ txopts = ipv6_renew_options_kern(sk, req_inet->ipv6_opt, IPV6_HOPOPTS,
+ new, new ? ipv6_optlen(new) : 0);
+
+ kfree(new);
+
+ if (IS_ERR(txopts))
+ return PTR_ERR(txopts);
+
+ txopts = xchg(&req_inet->ipv6_opt, txopts);
+ if (txopts) {
+ atomic_sub(txopts->tot_len, &sk->sk_omem_alloc);
+ txopt_put(txopts);
+ }
+
+ return 0;
+}
+
+/**
+ * calipso_req_delattr - Delete the CALIPSO option from a request socket
+ * @reg: the request socket
+ *
+ * Description:
+ * Removes the CALIPSO option from a request socket, if present.
+ *
+ */
+static void calipso_req_delattr(struct request_sock *req)
+{
+ struct inet_request_sock *req_inet = inet_rsk(req);
+ struct ipv6_opt_hdr *new;
+ struct ipv6_txoptions *txopts;
+ struct sock *sk = sk_to_full_sk(req_to_sk(req));
+
+ if (!req_inet->ipv6_opt || !req_inet->ipv6_opt->hopopt)
+ return;
+
+ if (calipso_opt_del(req_inet->ipv6_opt->hopopt, &new))
+ return; /* Nothing to do */
+
+ txopts = ipv6_renew_options_kern(sk, req_inet->ipv6_opt, IPV6_HOPOPTS,
+ new, new ? ipv6_optlen(new) : 0);
+
+ if (!IS_ERR(txopts)) {
+ txopts = xchg(&req_inet->ipv6_opt, txopts);
+ if (txopts) {
+ atomic_sub(txopts->tot_len, &sk->sk_omem_alloc);
+ txopt_put(txopts);
+ }
+ }
+ kfree(new);
+}
+
+/* skbuff functions.
+ */
+
+/**
+ * calipso_skbuff_optptr - Find the CALIPSO option in the packet
+ * @skb: the packet
+ *
+ * Description:
+ * Parse the packet's IP header looking for a CALIPSO option. Returns a pointer
+ * to the start of the CALIPSO option on success, NULL if one if not found.
+ *
+ */
+static unsigned char *calipso_skbuff_optptr(const struct sk_buff *skb)
+{
+ const struct ipv6hdr *ip6_hdr = ipv6_hdr(skb);
+ int offset;
+
+ if (ip6_hdr->nexthdr != NEXTHDR_HOP)
+ return NULL;
+
+ offset = ipv6_find_tlv(skb, sizeof(*ip6_hdr), IPV6_TLV_CALIPSO);
+ if (offset >= 0)
+ return (unsigned char *)ip6_hdr + offset;
+
+ return NULL;
+}
+
+/**
+ * calipso_skbuff_setattr - Set the CALIPSO option on a packet
+ * @skb: the packet
+ * @doi_def: the CALIPSO DOI to use
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Set the CALIPSO option on the given packet based on the security attributes.
+ * Returns a pointer to the IP header on success and NULL on failure.
+ *
+ */
+static int calipso_skbuff_setattr(struct sk_buff *skb,
+ const struct calipso_doi *doi_def,
+ const struct netlbl_lsm_secattr *secattr)
+{
+ int ret_val;
+ struct ipv6hdr *ip6_hdr;
+ struct ipv6_opt_hdr *hop;
+ unsigned char buf[CALIPSO_MAX_BUFFER];
+ int len_delta, new_end, pad;
+ unsigned int start, end;
+
+ ip6_hdr = ipv6_hdr(skb);
+ if (ip6_hdr->nexthdr == NEXTHDR_HOP) {
+ hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
+ ret_val = calipso_opt_find(hop, &start, &end);
+ if (ret_val && ret_val != -ENOENT)
+ return ret_val;
+ } else {
+ start = 0;
+ end = 0;
+ }
+
+ memset(buf, 0, sizeof(buf));
+ ret_val = calipso_genopt(buf, start & 3, sizeof(buf), doi_def, secattr);
+ if (ret_val < 0)
+ return ret_val;
+
+ new_end = start + ret_val;
+ /* At this point new_end aligns to 4n, so (new_end & 4) pads to 8n */
+ pad = ((new_end & 4) + (end & 7)) & 7;
+ len_delta = new_end - (int)end + pad;
+ ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
+ if (ret_val < 0)
+ return ret_val;
+
+ if (len_delta) {
+ if (len_delta > 0)
+ skb_push(skb, len_delta);
+ else
+ skb_pull(skb, -len_delta);
+ memmove((char *)ip6_hdr - len_delta, ip6_hdr,
+ sizeof(*ip6_hdr) + start);
+ skb_reset_network_header(skb);
+ ip6_hdr = ipv6_hdr(skb);
+ }
+
+ hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
+ if (start == 0) {
+ struct ipv6_opt_hdr *new_hop = (struct ipv6_opt_hdr *)buf;
+
+ new_hop->nexthdr = ip6_hdr->nexthdr;
+ new_hop->hdrlen = len_delta / 8 - 1;
+ ip6_hdr->nexthdr = NEXTHDR_HOP;
+ } else {
+ hop->hdrlen += len_delta / 8;
+ }
+ memcpy((char *)hop + start, buf + (start & 3), new_end - start);
+ calipso_pad_write((unsigned char *)hop, new_end, pad);
+
+ return 0;
+}
+
+/**
+ * calipso_skbuff_delattr - Delete any CALIPSO options from a packet
+ * @skb: the packet
+ *
+ * Description:
+ * Removes any and all CALIPSO options from the given packet. Returns zero on
+ * success, negative values on failure.
+ *
+ */
+static int calipso_skbuff_delattr(struct sk_buff *skb)
+{
+ int ret_val;
+ struct ipv6hdr *ip6_hdr;
+ struct ipv6_opt_hdr *old_hop;
+ u32 old_hop_len, start = 0, end = 0, delta, size, pad;
+
+ if (!calipso_skbuff_optptr(skb))
+ 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;
+
+ ip6_hdr = ipv6_hdr(skb);
+ old_hop = (struct ipv6_opt_hdr *)(ip6_hdr + 1);
+ old_hop_len = ipv6_optlen(old_hop);
+
+ ret_val = calipso_opt_find(old_hop, &start, &end);
+ if (ret_val)
+ return ret_val;
+
+ if (start == sizeof(*old_hop) && end == old_hop_len) {
+ /* There's no other option in the header so we delete
+ * the whole thing. */
+ delta = old_hop_len;
+ size = sizeof(*ip6_hdr);
+ ip6_hdr->nexthdr = old_hop->nexthdr;
+ } else {
+ delta = (end - start) & ~7;
+ if (delta)
+ old_hop->hdrlen -= delta / 8;
+ pad = (end - start) & 7;
+ size = sizeof(*ip6_hdr) + start + pad;
+ calipso_pad_write((unsigned char *)old_hop, start, pad);
+ }
+
+ if (delta) {
+ skb_pull(skb, delta);
+ memmove((char *)ip6_hdr + delta, ip6_hdr, size);
+ skb_reset_network_header(skb);
+ }
+
+ return 0;
+}
+
static const struct netlbl_calipso_ops ops = {
.doi_add = calipso_doi_add,
.doi_free = calipso_doi_free,
.sock_getattr = calipso_sock_getattr,
.sock_setattr = calipso_sock_setattr,
.sock_delattr = calipso_sock_delattr,
+ .req_setattr = calipso_req_setattr,
+ .req_delattr = calipso_req_delattr,
+ .opt_getattr = calipso_opt_getattr,
+ .skbuff_optptr = calipso_skbuff_optptr,
+ .skbuff_setattr = calipso_skbuff_setattr,
+ .skbuff_delattr = calipso_skbuff_delattr,
+ .cache_invalidate = calipso_cache_invalidate,
+ .cache_add = calipso_cache_add
};
/**
*/
int __init calipso_init(void)
{
- netlbl_calipso_ops_register(&ops);
- return 0;
+ int ret_val;
+
+ ret_val = calipso_cache_init();
+ if (!ret_val)
+ netlbl_calipso_ops_register(&ops);
+ return ret_val;
}
void calipso_exit(void)
{
netlbl_calipso_ops_register(NULL);
+ calipso_cache_invalidate();
+ kfree(calipso_cache);
}
projects / linux-2.6-block.git / blobdiff