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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /net/ipv6/calipso.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ipv6/calipso.c')
-rw-r--r--net/ipv6/calipso.c1473
1 files changed, 1473 insertions, 0 deletions
diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
new file mode 100644
index 000000000..afc76062e
--- /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;
+
+static void calipso_cache_invalidate(void);
+static void calipso_doi_putdef(struct calipso_doi *doi_def);
+
+/* 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;
+ refcount_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);
+ refcount_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 && refcount_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;
+
+ refcount_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;
+ }
+ list_del_rcu(&doi_def->list);
+ spin_unlock(&calipso_doi_list_lock);
+
+ calipso_doi_putdef(doi_def);
+ 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 (!refcount_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 (!refcount_dec_and_test(&doi_def->refcount))
+ return;
+
+ calipso_cache_invalidate();
+ 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 (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;
+}
+
+/**
+ * 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(sk, old, IPV6_HOPOPTS, hop);
+ 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) {
+ 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 */
+ 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;
+
+ memcpy(*new, hop, start);
+ (*new)->hdrlen -= delta / 8;
+ pad = (end - start) & 7;
+ calipso_pad_write((unsigned char *)*new, start, pad);
+ if (end != hop_len)
+ memcpy((char *)*new + start + pad, (char *)hop + end,
+ hop_len - end);
+
+ return 0;
+}
+
+/**
+ * calipso_opt_getattr - Get the security attributes from a memory block
+ * @calipso: the CALIPSO option
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Inspect @calipso and return the security attributes in @secattr.
+ * Returns zero on success and negative values on failure.
+ *
+ */
+static int calipso_opt_getattr(const unsigned char *calipso,
+ struct netlbl_lsm_secattr *secattr)
+{
+ int ret_val = -ENOMSG;
+ u32 doi, len = calipso[1], cat_len = calipso[6] * 4;
+ struct calipso_doi *doi_def;
+
+ 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);
+ if (!doi_def)
+ goto getattr_return;
+
+ secattr->attr.mls.lvl = calipso[7];
+ secattr->flags |= NETLBL_SECATTR_MLS_LVL;
+
+ if (cat_len) {
+ ret_val = calipso_map_cat_ntoh(doi_def,
+ calipso + 10,
+ cat_len,
+ secattr);
+ if (ret_val != 0) {
+ netlbl_catmap_free(secattr->attr.mls.cat);
+ goto getattr_return;
+ }
+
+ if (secattr->attr.mls.cat)
+ secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+ }
+
+ secattr->type = NETLBL_NLTYPE_CALIPSO;
+
+getattr_return:
+ rcu_read_unlock();
+ return ret_val;
+}
+
+/* sock functions.
+ */
+
+/**
+ * calipso_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 CALIPSO option attached to the sock and if
+ * there is return the CALIPSO 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.
+ *
+ */
+static int calipso_sock_getattr(struct sock *sk,
+ struct netlbl_lsm_secattr *secattr)
+{
+ struct ipv6_opt_hdr *hop;
+ int opt_len, len, ret_val = -ENOMSG, offset;
+ unsigned char *opt;
+ struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk));
+
+ if (!txopts || !txopts->hopopt)
+ goto done;
+
+ hop = txopts->hopopt;
+ opt = (unsigned char *)hop;
+ opt_len = ipv6_optlen(hop);
+ offset = sizeof(*hop);
+ while (offset < opt_len) {
+ len = calipso_tlv_len(hop, offset);
+ if (len < 0) {
+ ret_val = len;
+ goto done;
+ }
+ switch (opt[offset]) {
+ case IPV6_TLV_CALIPSO:
+ if (len < CALIPSO_HDR_LEN)
+ ret_val = -EINVAL;
+ else
+ ret_val = calipso_opt_getattr(&opt[offset],
+ secattr);
+ goto done;
+ default:
+ offset += len;
+ break;
+ }
+ }
+done:
+ txopt_put(txopts);
+ return ret_val;
+}
+
+/**
+ * calipso_sock_setattr - Add a CALIPSO option to a socket
+ * @sk: the 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. 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.
+ *
+ */
+static int calipso_sock_setattr(struct sock *sk,
+ const struct calipso_doi *doi_def,
+ const struct netlbl_lsm_secattr *secattr)
+{
+ int ret_val;
+ struct ipv6_opt_hdr *old, *new;
+ struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk));
+
+ old = NULL;
+ if (txopts)
+ old = txopts->hopopt;
+
+ new = calipso_opt_insert(old, doi_def, secattr);
+ txopt_put(txopts);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ ret_val = calipso_opt_update(sk, new);
+
+ kfree(new);
+ return ret_val;
+}
+
+/**
+ * calipso_sock_delattr - Delete the CALIPSO option from a socket
+ * @sk: the socket
+ *
+ * Description:
+ * Removes the CALIPSO option from a socket, if present.
+ *
+ */
+static void calipso_sock_delattr(struct sock *sk)
+{
+ struct ipv6_opt_hdr *new_hop;
+ struct ipv6_txoptions *txopts = txopt_get(inet6_sk(sk));
+
+ if (!txopts || !txopts->hopopt)
+ goto done;
+
+ if (calipso_opt_del(txopts->hopopt, &new_hop))
+ goto done;
+
+ calipso_opt_update(sk, new_hop);
+ kfree(new_hop);
+
+done:
+ 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(sk, req_inet->ipv6_opt, IPV6_HOPOPTS, new);
+
+ 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(sk, req_inet->ipv6_opt, IPV6_HOPOPTS, new);
+
+ 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, payload;
+ 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;
+
+ ip6_hdr = ipv6_hdr(skb); /* Reset as skb_cow() may have moved it */
+
+ 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);
+ payload = ntohs(ip6_hdr->payload_len);
+ ip6_hdr->payload_len = htons(payload + len_delta);
+ }
+
+ 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,
+ .doi_remove = calipso_doi_remove,
+ .doi_getdef = calipso_doi_getdef,
+ .doi_putdef = calipso_doi_putdef,
+ .doi_walk = calipso_doi_walk,
+ .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
+};
+
+/**
+ * calipso_init - Initialize the CALIPSO module
+ *
+ * Description:
+ * Initialize the CALIPSO module and prepare it for use. Returns zero on
+ * success and negative values on failure.
+ *
+ */
+int __init calipso_init(void)
+{
+ 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);
+}