--- /dev/null
+/*
+ * CIPSO - Commercial IP Security Option
+ *
+ * This is an implementation of the CIPSO 2.2 protocol as specified in
+ * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
+ * FIPS-188. While CIPSO never became a full IETF RFC standard many vendors
+ * have chosen to adopt the protocol and over the years it has become a
+ * de-facto standard for labeled networking.
+ *
+ * The CIPSO draft specification can be found in the kernel's Documentation
+ * directory as well as the following URL:
+ * http://tools.ietf.org/id/draft-ietf-cipso-ipsecurity-01.txt
+ * The FIPS-188 specification can be found at the following URL:
+ * http://www.itl.nist.gov/fipspubs/fip188.htm
+ *
+ * Author: Paul Moore <paul.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
+ *
+ * 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/cipso_ipv4.h>
+#include <linux/atomic.h>
+#include <linux/bug.h>
+#include <asm/unaligned.h>
+
+/* List of available DOI definitions */
+/* XXX - This currently assumes a minimal number of different DOIs in use,
+ * if in practice there are a lot of different DOIs this list should
+ * probably be turned into a hash table or something similar so we
+ * can do quick lookups. */
+static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
+static LIST_HEAD(cipso_v4_doi_list);
+
+/* Label mapping cache */
+int cipso_v4_cache_enabled = 1;
+int cipso_v4_cache_bucketsize = 10;
+#define CIPSO_V4_CACHE_BUCKETBITS 7
+#define CIPSO_V4_CACHE_BUCKETS (1 << CIPSO_V4_CACHE_BUCKETBITS)
+#define CIPSO_V4_CACHE_REORDERLIMIT 10
+struct cipso_v4_map_cache_bkt {
+ spinlock_t lock;
+ u32 size;
+ struct list_head list;
+};
+
+struct cipso_v4_map_cache_entry {
+ u32 hash;
+ unsigned char *key;
+ size_t key_len;
+
+ struct netlbl_lsm_cache *lsm_data;
+
+ u32 activity;
+ struct list_head list;
+};
+
+static struct cipso_v4_map_cache_bkt *cipso_v4_cache;
+
+/* Restricted bitmap (tag #1) flags */
+int cipso_v4_rbm_optfmt = 0;
+int cipso_v4_rbm_strictvalid = 1;
+
+/*
+ * Protocol Constants
+ */
+
+/* Maximum size of the CIPSO IP option, derived from the fact that the maximum
+ * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
+#define CIPSO_V4_OPT_LEN_MAX 40
+
+/* Length of the base CIPSO option, this includes the option type (1 byte), the
+ * option length (1 byte), and the DOI (4 bytes). */
+#define CIPSO_V4_HDR_LEN 6
+
+/* Base length of the restrictive category bitmap tag (tag #1). */
+#define CIPSO_V4_TAG_RBM_BLEN 4
+
+/* Base length of the enumerated category tag (tag #2). */
+#define CIPSO_V4_TAG_ENUM_BLEN 4
+
+/* Base length of the ranged categories bitmap tag (tag #5). */
+#define CIPSO_V4_TAG_RNG_BLEN 4
+/* The maximum number of category ranges permitted in the ranged category tag
+ * (tag #5). You may note that the IETF draft states that the maximum number
+ * 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. */
+#define CIPSO_V4_TAG_RNG_CAT_MAX 8
+
+/* Base length of the local tag (non-standard tag).
+ * Tag definition (may change between kernel versions)
+ *
+ * 0 8 16 24 32
+ * +----------+----------+----------+----------+
+ * | 10000000 | 00000110 | 32-bit secid value |
+ * +----------+----------+----------+----------+
+ * | in (host byte order)|
+ * +----------+----------+
+ *
+ */
+#define CIPSO_V4_TAG_LOC_BLEN 6
+
+/*
+ * Helper Functions
+ */
+
+/**
+ * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
+ * @bitmap: the bitmap
+ * @bitmap_len: length in bits
+ * @offset: starting offset
+ * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
+ *
+ * Description:
+ * Starting at @offset, walk the bitmap from left to right until either the
+ * desired bit is found or we reach the end. Return the bit offset, -1 if
+ * not found, or -2 if error.
+ */
+static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
+ u32 bitmap_len,
+ u32 offset,
+ u8 state)
+{
+ u32 bit_spot;
+ u32 byte_offset;
+ unsigned char bitmask;
+ unsigned char byte;
+
+ /* gcc always rounds to zero when doing integer division */
+ byte_offset = offset / 8;
+ byte = bitmap[byte_offset];
+ bit_spot = offset;
+ bitmask = 0x80 >> (offset % 8);
+
+ while (bit_spot < bitmap_len) {
+ if ((state && (byte & bitmask) == bitmask) ||
+ (state == 0 && (byte & bitmask) == 0))
+ return bit_spot;
+
+ bit_spot++;
+ bitmask >>= 1;
+ if (bitmask == 0) {
+ byte = bitmap[++byte_offset];
+ bitmask = 0x80;
+ }
+ }
+
+ return -1;
+}
+
+/**
+ * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
+ * @bitmap: the bitmap
+ * @bit: the bit
+ * @state: if non-zero, set the bit (1) else clear the bit (0)
+ *
+ * Description:
+ * Set a single bit in the bitmask. Returns zero on success, negative values
+ * on error.
+ */
+static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
+ u32 bit,
+ u8 state)
+{
+ u32 byte_spot;
+ u8 bitmask;
+
+ /* gcc always rounds to zero when doing integer division */
+ byte_spot = bit / 8;
+ bitmask = 0x80 >> (bit % 8);
+ if (state)
+ bitmap[byte_spot] |= bitmask;
+ else
+ bitmap[byte_spot] &= ~bitmask;
+}
+
+/**
+ * cipso_v4_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 cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
+{
+ if (entry->lsm_data)
+ netlbl_secattr_cache_free(entry->lsm_data);
+ kfree(entry->key);
+ kfree(entry);
+}
+
+/**
+ * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
+ * @key: the hash key
+ * @key_len: the length of the key in bytes
+ *
+ * Description:
+ * The CIPSO tag hashing function. Returns a 32-bit hash value.
+ *
+ */
+static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
+{
+ return jhash(key, key_len, 0);
+}
+
+/*
+ * Label Mapping Cache Functions
+ */
+
+/**
+ * cipso_v4_cache_init - Initialize the CIPSO cache
+ *
+ * Description:
+ * Initializes the CIPSO label mapping cache, this function should be called
+ * before any of the other functions defined in this file. Returns zero on
+ * success, negative values on error.
+ *
+ */
+static int __init cipso_v4_cache_init(void)
+{
+ u32 iter;
+
+ cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
+ sizeof(struct cipso_v4_map_cache_bkt),
+ GFP_KERNEL);
+ if (!cipso_v4_cache)
+ return -ENOMEM;
+
+ for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
+ spin_lock_init(&cipso_v4_cache[iter].lock);
+ cipso_v4_cache[iter].size = 0;
+ INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
+ }
+
+ return 0;
+}
+
+/**
+ * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
+ *
+ * Description:
+ * Invalidates and frees any entries in the CIPSO cache. Returns zero on
+ * success and negative values on failure.
+ *
+ */
+void cipso_v4_cache_invalidate(void)
+{
+ struct cipso_v4_map_cache_entry *entry, *tmp_entry;
+ u32 iter;
+
+ for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
+ spin_lock_bh(&cipso_v4_cache[iter].lock);
+ list_for_each_entry_safe(entry,
+ tmp_entry,
+ &cipso_v4_cache[iter].list, list) {
+ list_del(&entry->list);
+ cipso_v4_cache_entry_free(entry);
+ }
+ cipso_v4_cache[iter].size = 0;
+ spin_unlock_bh(&cipso_v4_cache[iter].lock);
+ }
+}
+
+/**
+ * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
+ * @key: the buffer to check
+ * @key_len: buffer length in bytes
+ * @secattr: the security attribute struct to use
+ *
+ * Description:
+ * This function checks the cache to see if a label mapping already exists for
+ * the given key. If there is a match then the cache is adjusted and the
+ * @secattr struct is populated with the correct LSM security attributes. The
+ * cache is adjusted in the following manner if the entry is not already the
+ * first in the cache bucket:
+ *
+ * 1. The cache entry's activity counter is incremented
+ * 2. The previous (higher ranking) entry's activity counter is decremented
+ * 3. If the difference between the two activity counters is geater than
+ * CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
+ *
+ * Returns zero on success, -ENOENT for a cache miss, and other negative values
+ * on error.
+ *
+ */
+static int cipso_v4_cache_check(const unsigned char *key,
+ u32 key_len,
+ struct netlbl_lsm_secattr *secattr)
+{
+ u32 bkt;
+ struct cipso_v4_map_cache_entry *entry;
+ struct cipso_v4_map_cache_entry *prev_entry = NULL;
+ u32 hash;
+
+ if (!cipso_v4_cache_enabled)
+ return -ENOENT;
+
+ hash = cipso_v4_map_cache_hash(key, key_len);
+ bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
+ spin_lock_bh(&cipso_v4_cache[bkt].lock);
+ list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
+ if (entry->hash == hash &&
+ entry->key_len == key_len &&
+ memcmp(entry->key, key, key_len) == 0) {
+ entry->activity += 1;
+ atomic_inc(&entry->lsm_data->refcount);
+ secattr->cache = entry->lsm_data;
+ secattr->flags |= NETLBL_SECATTR_CACHE;
+ secattr->type = NETLBL_NLTYPE_CIPSOV4;
+ if (!prev_entry) {
+ spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+ return 0;
+ }
+
+ if (prev_entry->activity > 0)
+ prev_entry->activity -= 1;
+ if (entry->activity > prev_entry->activity &&
+ entry->activity - prev_entry->activity >
+ CIPSO_V4_CACHE_REORDERLIMIT) {
+ __list_del(entry->list.prev, entry->list.next);
+ __list_add(&entry->list,
+ prev_entry->list.prev,
+ &prev_entry->list);
+ }
+
+ spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+ return 0;
+ }
+ prev_entry = entry;
+ }
+ spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+
+ return -ENOENT;
+}
+
+/**
+ * cipso_v4_cache_add - Add an entry to the CIPSO cache
+ * @skb: the packet
+ * @secattr: the packet's security attributes
+ *
+ * Description:
+ * Add a new entry into the CIPSO label mapping cache. Add the new entry to
+ * head of the cache bucket's list, if the cache bucket is out of room remove
+ * the last entry in the list first. It is important to note that there is
+ * currently no checking for duplicate keys. Returns zero on success,
+ * negative values on failure.
+ *
+ */
+int cipso_v4_cache_add(const unsigned char *cipso_ptr,
+ const struct netlbl_lsm_secattr *secattr)
+{
+ int ret_val = -EPERM;
+ u32 bkt;
+ struct cipso_v4_map_cache_entry *entry = NULL;
+ struct cipso_v4_map_cache_entry *old_entry = NULL;
+ u32 cipso_ptr_len;
+
+ if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
+ return 0;
+
+ cipso_ptr_len = cipso_ptr[1];
+
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+ if (!entry)
+ return -ENOMEM;
+ entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
+ if (!entry->key) {
+ ret_val = -ENOMEM;
+ goto cache_add_failure;
+ }
+ entry->key_len = cipso_ptr_len;
+ entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
+ atomic_inc(&secattr->cache->refcount);
+ entry->lsm_data = secattr->cache;
+
+ bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
+ spin_lock_bh(&cipso_v4_cache[bkt].lock);
+ if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
+ list_add(&entry->list, &cipso_v4_cache[bkt].list);
+ cipso_v4_cache[bkt].size += 1;
+ } else {
+ old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
+ struct cipso_v4_map_cache_entry, list);
+ list_del(&old_entry->list);
+ list_add(&entry->list, &cipso_v4_cache[bkt].list);
+ cipso_v4_cache_entry_free(old_entry);
+ }
+ spin_unlock_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 && atomic_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;
+ }
+ }
+
+ atomic_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);
+ 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_secid: the LSM secid to use in the audit message
+ *
+ * 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;
+ }
+ if (!atomic_dec_and_test(&doi_def->refcount)) {
+ spin_unlock(&cipso_v4_doi_list_lock);
+ ret_val = -EBUSY;
+ goto doi_remove_return;
+ }
+ list_del_rcu(&doi_def->list);
+ spin_unlock(&cipso_v4_doi_list_lock);
+
+ cipso_v4_cache_invalidate();
+ call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
+ 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 (!atomic_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 (!atomic_dec_and_test(&doi_def->refcount))
+ return;
+ spin_lock(&cipso_v4_doi_list_lock);
+ list_del_rcu(&doi_def->list);
+ spin_unlock(&cipso_v4_doi_list_lock);
+
+ 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 (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;
+}
+
+/*
+ * 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 (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 = cipso_v4_bitmap_walk(bitmap,
+ bitmap_len_bits,
+ cat + 1,
+ 1);
+ if (cat < 0)
+ break;
+ if (cat >= cipso_cat_size ||
+ cipso_array[cat] >= CIPSO_V4_INV_CAT)
+ return -EFAULT;
+ }
+
+ if (cat == -1)
+ return 0;
+ break;
+ }
+
+ return -EFAULT;
+}
+
+/**
+ * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
+ * @doi_def: the DOI definition
+ * @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;
+ cipso_v4_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 = cipso_v4_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;
+ *(__be32 *)&buf[2] = htonl(doi_def->doi);
+}
+
+/**
+ * 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;
+ }
+
+ 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;
+ }
+
+ 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 if 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 > 0; ) {
+ if (optptr[0] == IPOPT_CIPSO)
+ return optptr;
+ taglen = optptr[1];
+ optlen -= taglen;
+ optptr += taglen;
+ }
+
+ return NULL;
+}
+
+/**
+ * cipso_v4_validate - Validate a CIPSO option
+ * @option: the start of the option, on error it is set to point to the error
+ *
+ * Description:
+ * This routine is called to validate a CIPSO option, it checks all of the
+ * fields to ensure that they are at least valid, see the draft snippet below
+ * for details. If the option is valid then a zero value is returned and
+ * the value of @option is unchanged. If the option is invalid then a
+ * non-zero value is returned and @option is adjusted to point to the
+ * offending portion of the option. From the IETF draft ...
+ *
+ * "If any field within the CIPSO options, such as the DOI identifier, is not
+ * recognized the IP datagram is discarded and an ICMP 'parameter problem'
+ * (type 12) is generated and returned. The ICMP code field is set to 'bad
+ * parameter' (code 0) and the pointer is set to the start of the CIPSO field
+ * that is unrecognized."
+ *
+ */
+int cipso_v4_validate(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;
+ }
+
+ 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)
+{
+ if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
+ return;
+
+ if (gateway)
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
+ else
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
+}
+
+/**
+ * cipso_v4_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, sock_owned_by_user(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(&req_inet->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 **opt_ptr)
+{
+ int hdr_delta = 0;
+ struct ip_options_rcu *opt = *opt_ptr;
+
+ 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)
+{
+ int hdr_delta;
+ struct ip_options_rcu *opt;
+ struct inet_sock *sk_inet;
+
+ sk_inet = inet_sk(sk);
+ opt = rcu_dereference_protected(sk_inet->inet_opt, 1);
+ if (!opt || opt->opt.cipso == 0)
+ return;
+
+ 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
+ * @reg: the request socket
+ *
+ * Description:
+ * Removes the CIPSO option from a request socket, if present.
+ *
+ */
+void cipso_v4_req_delattr(struct request_sock *req)
+{
+ struct ip_options_rcu *opt;
+ struct inet_request_sock *req_inet;
+
+ req_inet = inet_rsk(req);
+ opt = req_inet->opt;
+ if (!opt || opt->opt.cipso == 0)
+ return;
+
+ cipso_v4_delopt(&req_inet->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
+ * @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);
Code Review / kvmfornfv.git / blobdiff