Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next

8 files changed, 1587 insertions, 6 deletions

diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index 6d8ea099213e..c174ccb340a1 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -22,6 +22,7 @@ ipv6-$(CONFIG_NETFILTER) += netfilter.o
 ipv6-$(CONFIG_IPV6_MULTIPLE_TABLES) += fib6_rules.o
 ipv6-$(CONFIG_PROC_FS) += proc.o
 ipv6-$(CONFIG_SYN_COOKIES) += syncookies.o
+ipv6-$(CONFIG_NETLABEL) += calipso.o
 
 ipv6-objs += $(ipv6-y)
 
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index bfa86f040c16..b0994a49dfca 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -60,6 +60,7 @@
 #ifdef CONFIG_IPV6_TUNNEL
 #include <net/ip6_tunnel.h>
 #endif
+#include <net/calipso.h>
 
 #include <asm/uaccess.h>
 #include <linux/mroute6.h>
@@ -977,6 +978,10 @@ static int __init inet6_init(void)
 	if (err)
 		goto pingv6_fail;
 
+	err = calipso_init();
+	if (err)
+		goto calipso_fail;
+
 #ifdef CONFIG_SYSCTL
 	err = ipv6_sysctl_register();
 	if (err)
@@ -987,8 +992,10 @@ out:
 
 #ifdef CONFIG_SYSCTL
 sysctl_fail:
-	pingv6_exit();
+	calipso_exit();
 #endif
+calipso_fail:
+	pingv6_exit();
 pingv6_fail:
 	ipv6_packet_cleanup();
 ipv6_packet_fail:
diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
new file mode 100644
index 000000000000..c53b92c617c5
--- /dev/null
+++ b/net/ipv6/calipso.c
@@ -0,0 +1,1473 @@
+/*
+ * CALIPSO - Common Architecture Label IPv6 Security Option
+ *
+ * This is an implementation of the CALIPSO protocol as specified in
+ * RFC 5570.
+ *
+ * Authors: Paul Moore <paul.moore@hp.com>
+ *          Huw Davies <huw@codeweavers.com>
+ *
+ */
+
+/* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
+ * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015
+ *
+ * This program is free software;  you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program;  if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/jhash.h>
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/netlabel.h>
+#include <net/calipso.h>
+#include <linux/atomic.h>
+#include <linux/bug.h>
+#include <asm/unaligned.h>
+#include <linux/crc-ccitt.h>
+
+/* Maximium size of the calipso option including
+ * the two-byte TLV header.
+ */
+#define CALIPSO_OPT_LEN_MAX (2 + 252)
+
+/* Size of the minimum calipso option including
+ * the two-byte TLV header.
+ */
+#define CALIPSO_HDR_LEN (2 + 8)
+
+/* Maximium size of the calipso option including
+ * the two-byte TLV header and upto 3 bytes of
+ * leading pad and 7 bytes of trailing pad.
+ */
+#define CALIPSO_OPT_LEN_MAX_WITH_PAD (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
+ */
+
+/**
+ * calipso_doi_search - Searches for a DOI definition
+ * @doi: the DOI to search for
+ *
+ * Description:
+ * Search the DOI definition list for a DOI definition with a DOI value that
+ * matches @doi.  The caller is responsible for calling rcu_read_[un]lock().
+ * Returns a pointer to the DOI definition on success and NULL on failure.
+ */
+static struct calipso_doi *calipso_doi_search(u32 doi)
+{
+	struct calipso_doi *iter;
+
+	list_for_each_entry_rcu(iter, &calipso_doi_list, list)
+		if (iter->doi == doi && atomic_read(&iter->refcount))
+			return iter;
+	return NULL;
+}
+
+/**
+ * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine
+ * @doi_def: the DOI structure
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * The caller defines a new DOI for use by the CALIPSO engine and calls this
+ * function to add it to the list of acceptable domains.  The caller must
+ * ensure that the mapping table specified in @doi_def->map meets all of the
+ * requirements of the mapping type (see calipso.h for details).  Returns
+ * zero on success and non-zero on failure.
+ *
+ */
+static int calipso_doi_add(struct calipso_doi *doi_def,
+			   struct netlbl_audit *audit_info)
+{
+	int ret_val = -EINVAL;
+	u32 doi;
+	u32 doi_type;
+	struct audit_buffer *audit_buf;
+
+	doi = doi_def->doi;
+	doi_type = doi_def->type;
+
+	if (doi_def->doi == CALIPSO_DOI_UNKNOWN)
+		goto doi_add_return;
+
+	atomic_set(&doi_def->refcount, 1);
+
+	spin_lock(&calipso_doi_list_lock);
+	if (calipso_doi_search(doi_def->doi)) {
+		spin_unlock(&calipso_doi_list_lock);
+		ret_val = -EEXIST;
+		goto doi_add_return;
+	}
+	list_add_tail_rcu(&doi_def->list, &calipso_doi_list);
+	spin_unlock(&calipso_doi_list_lock);
+	ret_val = 0;
+
+doi_add_return:
+	audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_ADD, audit_info);
+	if (audit_buf) {
+		const char *type_str;
+
+		switch (doi_type) {
+		case CALIPSO_MAP_PASS:
+			type_str = "pass";
+			break;
+		default:
+			type_str = "(unknown)";
+		}
+		audit_log_format(audit_buf,
+				 " calipso_doi=%u calipso_type=%s res=%u",
+				 doi, type_str, ret_val == 0 ? 1 : 0);
+		audit_log_end(audit_buf);
+	}
+
+	return ret_val;
+}
+
+/**
+ * calipso_doi_free - Frees a DOI definition
+ * @doi_def: the DOI definition
+ *
+ * Description:
+ * This function frees all of the memory associated with a DOI definition.
+ *
+ */
+static void calipso_doi_free(struct calipso_doi *doi_def)
+{
+	kfree(doi_def);
+}
+
+/**
+ * calipso_doi_free_rcu - Frees a DOI definition via the RCU pointer
+ * @entry: the entry's RCU field
+ *
+ * Description:
+ * This function is designed to be used as a callback to the call_rcu()
+ * function so that the memory allocated to the DOI definition can be released
+ * safely.
+ *
+ */
+static void calipso_doi_free_rcu(struct rcu_head *entry)
+{
+	struct calipso_doi *doi_def;
+
+	doi_def = container_of(entry, struct calipso_doi, rcu);
+	calipso_doi_free(doi_def);
+}
+
+/**
+ * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine
+ * @doi: the DOI value
+ * @audit_secid: the LSM secid to use in the audit message
+ *
+ * Description:
+ * Removes a DOI definition from the CALIPSO engine.  The NetLabel routines will
+ * be called to release their own LSM domain mappings as well as our own
+ * domain list.  Returns zero on success and negative values on failure.
+ *
+ */
+static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info)
+{
+	int ret_val;
+	struct calipso_doi *doi_def;
+	struct audit_buffer *audit_buf;
+
+	spin_lock(&calipso_doi_list_lock);
+	doi_def = calipso_doi_search(doi);
+	if (!doi_def) {
+		spin_unlock(&calipso_doi_list_lock);
+		ret_val = -ENOENT;
+		goto doi_remove_return;
+	}
+	if (!atomic_dec_and_test(&doi_def->refcount)) {
+		spin_unlock(&calipso_doi_list_lock);
+		ret_val = -EBUSY;
+		goto doi_remove_return;
+	}
+	list_del_rcu(&doi_def->list);
+	spin_unlock(&calipso_doi_list_lock);
+
+	call_rcu(&doi_def->rcu, calipso_doi_free_rcu);
+	ret_val = 0;
+
+doi_remove_return:
+	audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_DEL, audit_info);
+	if (audit_buf) {
+		audit_log_format(audit_buf,
+				 " calipso_doi=%u res=%u",
+				 doi, ret_val == 0 ? 1 : 0);
+		audit_log_end(audit_buf);
+	}
+
+	return ret_val;
+}
+
+/**
+ * calipso_doi_getdef - Returns a reference to a valid DOI definition
+ * @doi: the DOI value
+ *
+ * Description:
+ * Searches for a valid DOI definition and if one is found it is returned to
+ * the caller.  Otherwise NULL is returned.  The caller must ensure that
+ * calipso_doi_putdef() is called when the caller is done.
+ *
+ */
+static struct calipso_doi *calipso_doi_getdef(u32 doi)
+{
+	struct calipso_doi *doi_def;
+
+	rcu_read_lock();
+	doi_def = calipso_doi_search(doi);
+	if (!doi_def)
+		goto doi_getdef_return;
+	if (!atomic_inc_not_zero(&doi_def->refcount))
+		doi_def = NULL;
+
+doi_getdef_return:
+	rcu_read_unlock();
+	return doi_def;
+}
+
+/**
+ * calipso_doi_putdef - Releases a reference for the given DOI definition
+ * @doi_def: the DOI definition
+ *
+ * Description:
+ * Releases a DOI definition reference obtained from calipso_doi_getdef().
+ *
+ */
+static void calipso_doi_putdef(struct calipso_doi *doi_def)
+{
+	if (!doi_def)
+		return;
+
+	if (!atomic_dec_and_test(&doi_def->refcount))
+		return;
+	spin_lock(&calipso_doi_list_lock);
+	list_del_rcu(&doi_def->list);
+	spin_unlock(&calipso_doi_list_lock);
+
+	call_rcu(&doi_def->rcu, calipso_doi_free_rcu);
+}
+
+/**
+ * calipso_doi_walk - Iterate through the DOI definitions
+ * @skip_cnt: skip past this number of DOI definitions, updated
+ * @callback: callback for each DOI definition
+ * @cb_arg: argument for the callback function
+ *
+ * Description:
+ * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
+ * For each entry call @callback, if @callback returns a negative value stop
+ * 'walking' through the list and return.  Updates the value in @skip_cnt upon
+ * return.  Returns zero on success, negative values on failure.
+ *
+ */
+static int calipso_doi_walk(u32 *skip_cnt,
+			    int (*callback)(struct calipso_doi *doi_def,
+					    void *arg),
+			    void *cb_arg)
+{
+	int ret_val = -ENOENT;
+	u32 doi_cnt = 0;
+	struct calipso_doi *iter_doi;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list)
+		if (atomic_read(&iter_doi->refcount) > 0) {
+			if (doi_cnt++ < *skip_cnt)
+				continue;
+			ret_val = callback(iter_doi, cb_arg);
+			if (ret_val < 0) {
+				doi_cnt--;
+				goto doi_walk_return;
+			}
+		}
+
+doi_walk_return:
+	rcu_read_unlock();
+	*skip_cnt = doi_cnt;
+	return ret_val;
+}
+
+/**
+ * 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
+ * @secattr: the security attributes
+ * @net_cat: the zero'd out category bitmap in network/CALIPSO format
+ * @net_cat_len: the length of the CALIPSO bitmap in bytes
+ *
+ * Description:
+ * Perform a label mapping to translate a local MLS category bitmap to the
+ * correct CALIPSO bitmap using the given DOI definition.  Returns the minimum
+ * size in bytes of the network bitmap on success, negative values otherwise.
+ *
+ */
+static int calipso_map_cat_hton(const struct calipso_doi *doi_def,
+				const struct netlbl_lsm_secattr *secattr,
+				unsigned char *net_cat,
+				u32 net_cat_len)
+{
+	int spot = -1;
+	u32 net_spot_max = 0;
+	u32 net_clen_bits = net_cat_len * 8;
+
+	for (;;) {
+		spot = netlbl_catmap_walk(secattr->attr.mls.cat,
+					  spot + 1);
+		if (spot < 0)
+			break;
+		if (spot >= net_clen_bits)
+			return -ENOSPC;
+		netlbl_bitmap_setbit(net_cat, spot, 1);
+
+		if (spot > net_spot_max)
+			net_spot_max = spot;
+	}
+
+	return (net_spot_max / 32 + 1) * 4;
+}
+
+/**
+ * calipso_map_cat_ntoh - Perform a category mapping from network to host
+ * @doi_def: the DOI definition
+ * @net_cat: the category bitmap in network/CALIPSO format
+ * @net_cat_len: the length of the CALIPSO bitmap in bytes
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Perform a label mapping to translate a CALIPSO bitmap to the correct local
+ * MLS category bitmap using the given DOI definition.  Returns zero on
+ * success, negative values on failure.
+ *
+ */
+static int calipso_map_cat_ntoh(const struct calipso_doi *doi_def,
+				const unsigned char *net_cat,
+				u32 net_cat_len,
+				struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	int spot = -1;
+	u32 net_clen_bits = net_cat_len * 8;
+
+	for (;;) {
+		spot = netlbl_bitmap_walk(net_cat,
+					  net_clen_bits,
+					  spot + 1,
+					  1);
+		if (spot < 0) {
+			if (spot == -2)
+				return -EFAULT;
+			return 0;
+		}
+
+		ret_val = netlbl_catmap_setbit(&secattr->attr.mls.cat,
+					       spot,
+					       GFP_ATOMIC);
+		if (ret_val != 0)
+			return ret_val;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * calipso_pad_write - Writes pad bytes in TLV format
+ * @buf: the buffer
+ * @offset: offset from start of buffer to write padding
+ * @count: number of pad bytes to write
+ *
+ * Description:
+ * Write @count bytes of TLV padding into @buffer starting at offset @offset.
+ * @count should be less than 8 - see RFC 4942.
+ *
+ */
+static int calipso_pad_write(unsigned char *buf, unsigned int offset,
+			     unsigned int count)
+{
+	if (WARN_ON_ONCE(count >= 8))
+		return -EINVAL;
+
+	switch (count) {
+	case 0:
+		break;
+	case 1:
+		buf[offset] = IPV6_TLV_PAD1;
+		break;
+	default:
+		buf[offset] = IPV6_TLV_PADN;
+		buf[offset + 1] = count - 2;
+		if (count > 2)
+			memset(buf + offset + 2, 0, count - 2);
+		break;
+	}
+	return 0;
+}
+
+/**
+ * calipso_genopt - Generate a CALIPSO option
+ * @buf: the option buffer
+ * @start: offset from which to write
+ * @buf_len: the size of opt_buf
+ * @doi_def: the CALIPSO DOI to use
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Generate a CALIPSO option using the DOI definition and security attributes
+ * passed to the function. This also generates upto three bytes of leading
+ * padding that ensures that the option is 4n + 2 aligned.  It returns the
+ * number of bytes written (including any initial padding).
+ */
+static int calipso_genopt(unsigned char *buf, u32 start, u32 buf_len,
+			  const struct calipso_doi *doi_def,
+			  const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u32 len, pad;
+	u16 crc;
+	static const unsigned char padding[4] = {2, 1, 0, 3};
+	unsigned char *calipso;
+
+	/* CALIPSO has 4n + 2 alignment */
+	pad = padding[start & 3];
+	if (buf_len <= start + pad + CALIPSO_HDR_LEN)
+		return -ENOSPC;
+
+	if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
+		return -EPERM;
+
+	len = CALIPSO_HDR_LEN;
+
+	if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
+		ret_val = calipso_map_cat_hton(doi_def,
+					       secattr,
+					       buf + start + pad + len,
+					       buf_len - start - pad - len);
+		if (ret_val < 0)
+			return ret_val;
+		len += ret_val;
+	}
+
+	calipso_pad_write(buf, start, pad);
+	calipso = buf + start + pad;
+
+	calipso[0] = IPV6_TLV_CALIPSO;
+	calipso[1] = len - 2;
+	*(__be32 *)(calipso + 2) = htonl(doi_def->doi);
+	calipso[6] = (len - CALIPSO_HDR_LEN) / 4;
+	calipso[7] = secattr->attr.mls.lvl,
+	crc = ~crc_ccitt(0xffff, calipso, len);
+	calipso[8] = crc & 0xff;
+	calipso[9] = (crc >> 8) & 0xff;
+	return pad + len;
+}
+
+/* Hop-by-hop hdr helper functions
+ */
+
+/**
+ * calipso_opt_update - Replaces socket's hop options with a new set
+ * @sk: the socket
+ * @hop: new hop options
+ *
+ * Description:
+ * Replaces @sk's hop options with @hop.  @hop may be NULL to leave
+ * the socket with no hop options.
+ *
+ */
+static int calipso_opt_update(struct sock *sk, struct ipv6_opt_hdr *hop)
+{
+	struct ipv6_txoptions *old = txopt_get(inet6_sk(sk)), *txopts;
+
+	txopts = ipv6_renew_options_kern(sk, old, IPV6_HOPOPTS,
+					 hop, hop ? ipv6_optlen(hop) : 0);
+	txopt_put(old);
+	if (IS_ERR(txopts))
+		return PTR_ERR(txopts);
+
+	txopts = ipv6_update_options(sk, txopts);
+	if (txopts) {
+		atomic_sub(txopts->tot_len, &sk->sk_omem_alloc);
+		txopt_put(txopts);
+	}
+
+	return 0;
+}
+
+/**
+ * calipso_tlv_len - Returns the length of the TLV
+ * @opt: the option header
+ * @offset: offset of the TLV within the header
+ *
+ * Description:
+ * Returns the length of the TLV option at offset @offset within
+ * the option header @opt.  Checks that the entire TLV fits inside
+ * the option header, returns a negative value if this is not the case.
+ */
+static int calipso_tlv_len(struct ipv6_opt_hdr *opt, unsigned int offset)
+{
+	unsigned char *tlv = (unsigned char *)opt;
+	unsigned int opt_len = ipv6_optlen(opt), tlv_len;
+
+	if (offset < sizeof(*opt) || offset >= opt_len)
+		return -EINVAL;
+	if (tlv[offset] == IPV6_TLV_PAD1)
+		return 1;
+	if (offset + 1 >= opt_len)
+		return -EINVAL;
+	tlv_len = tlv[offset + 1] + 2;
+	if (offset + tlv_len > opt_len)
+		return -EINVAL;
+	return tlv_len;
+}
+
+/**
+ * calipso_opt_find - Finds the CALIPSO option in an IPv6 hop options header
+ * @hop: the hop options header
+ * @start: on return holds the offset of any leading padding
+ * @end: on return holds the offset of the first non-pad TLV after CALIPSO
+ *
+ * Description:
+ * Finds the space occupied by a CALIPSO option (including any leading and
+ * trailing padding).
+ *
+ * If a CALIPSO option exists set @start and @end to the
+ * offsets within @hop of the start of padding before the first
+ * CALIPSO option and the end of padding after the first CALIPSO
+ * option.  In this case the function returns 0.
+ *
+ * In the absence of a CALIPSO option, @start and @end will be
+ * set to the start and end of any trailing padding in the header.
+ * This is useful when appending a new option, as the caller may want
+ * to overwrite some of this padding.  In this case the function will
+ * return -ENOENT.
+ */
+static int calipso_opt_find(struct ipv6_opt_hdr *hop, unsigned int *start,
+			    unsigned int *end)
+{
+	int ret_val = -ENOENT, tlv_len;
+	unsigned int opt_len, offset, offset_s = 0, offset_e = 0;
+	unsigned char *opt = (unsigned char *)hop;
+
+	opt_len = ipv6_optlen(hop);
+	offset = sizeof(*hop);
+
+	while (offset < opt_len) {
+		tlv_len = calipso_tlv_len(hop, offset);
+		if (tlv_len < 0)
+			return tlv_len;
+
+		switch (opt[offset]) {
+		case IPV6_TLV_PAD1:
+		case IPV6_TLV_PADN:
+			if (offset_e)
+				offset_e = offset;
+			break;
+		case IPV6_TLV_CALIPSO:
+			ret_val = 0;
+			offset_e = offset;
+			break;
+		default:
+			if (offset_e == 0)
+				offset_s = offset;
+			else
+				goto out;
+		}
+		offset += tlv_len;
+	}
+
+out:
+	if (offset_s)
+		*start = offset_s + calipso_tlv_len(hop, offset_s);
+	else
+		*start = sizeof(*hop);
+	if (offset_e)
+		*end = offset_e + calipso_tlv_len(hop, offset_e);
+	else
+		*end = opt_len;
+
+	return ret_val;
+}
+
+/**
+ * calipso_opt_insert - Inserts a CALIPSO option into an IPv6 hop opt hdr
+ * @hop: the original hop options header
+ * @doi_def: the CALIPSO DOI to use
+ * @secattr: the specific security attributes of the socket
+ *
+ * Description:
+ * Creates a new hop options header based on @hop with a
+ * CALIPSO option added to it.  If @hop already contains a CALIPSO
+ * option this is overwritten, otherwise the new option is appended
+ * after any existing options.  If @hop is NULL then the new header
+ * will contain just the CALIPSO option and any needed padding.
+ *
+ */
+static struct ipv6_opt_hdr *
+calipso_opt_insert(struct ipv6_opt_hdr *hop,
+		   const struct calipso_doi *doi_def,
+		   const struct netlbl_lsm_secattr *secattr)
+{
+	unsigned int start, end, buf_len, pad, hop_len;
+	struct ipv6_opt_hdr *new;
+	int ret_val;
+
+	if (hop) {
+		hop_len = ipv6_optlen(hop);
+		ret_val = calipso_opt_find(hop, &start, &end);
+		if (ret_val && ret_val != -ENOENT)
+			return ERR_PTR(ret_val);
+	} else {
+		hop_len = 0;
+		start = sizeof(*hop);
+		end = 0;
+	}
+
+	buf_len = hop_len + start - end + CALIPSO_OPT_LEN_MAX_WITH_PAD;
+	new = kzalloc(buf_len, GFP_ATOMIC);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+
+	if (start > sizeof(*hop))
+		memcpy(new, hop, start);
+	ret_val = calipso_genopt((unsigned char *)new, start, buf_len, doi_def,
+				 secattr);
+	if (ret_val < 0)
+		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 */
+	pad = ((buf_len & 4) + (end & 7)) & 7;
+	calipso_pad_write((unsigned char *)new, buf_len, pad);
+	buf_len += pad;
+
+	if (end != hop_len) {
+		memcpy((char *)new + buf_len, (char *)hop + end, hop_len - end);
+		buf_len += hop_len - end;
+	}
+	new->nexthdr = 0;
+	new->hdrlen = buf_len / 8 - 1;
+
+	return new;
+}
+
+/**
+ * calipso_opt_del - Removes the CALIPSO option from an option header
+ * @hop: the original header
+ * @new: the new header
+ *
+ * Description:
+ * Creates a new header based on @hop without any CALIPSO option.  If @hop
+ * doesn't contain a CALIPSO option it returns -ENOENT.  If @hop contains
+ * no other non-padding options, it returns zero with @new set to NULL.
+ * Otherwise it returns zero, creates a new header without the CALIPSO
+ * option (and removing as much padding as possible) and returns with
+ * @new set to that header.
+ *
+ */
+static int calipso_opt_del(struct ipv6_opt_hdr *hop,
+			   struct ipv6_opt_hdr **new)
+{
+	int ret_val;
+	unsigned int start, end, delta, pad, hop_len;
+
+	ret_val = calipso_opt_find(hop, &start, &end);
+	if (ret_val)
+		return ret_val;
+
+	hop_len = ipv6_optlen(hop);
+	if (start == sizeof(*hop) && end == hop_len) {
+		/* There's no other option in the header so return NULL */
+		*new = NULL;
+		return 0;
+	}
+
+	delta = (end - start) & ~7;
+	*new = kzalloc(hop_len - delta, GFP_ATOMIC);
+	if (!*new)
+		return -ENOMEM;