cregit-Linux how code gets into the kernel

Release 4.8 net/ipv6/calipso.c

Directory: net/ipv6
/*
 * CALIPSO - Common Architecture Label IPv6 Security Option
 *
 * This is an implementation of the CALIPSO protocol as specified in
 * RFC 5570.
 *
 * Authors: Paul Moore <paul.moore@hp.com>
 *          Huw Davies <huw@codeweavers.com>
 *
 */

/* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
 * (c) Copyright Huw Davies <huw@codeweavers.com>, 2015
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/jhash.h>
#include <linux/audit.h>
#include <linux/slab.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/tcp.h>
#include <net/netlabel.h>
#include <net/calipso.h>
#include <linux/atomic.h>
#include <linux/bug.h>
#include <asm/unaligned.h>
#include <linux/crc-ccitt.h>

/* Maximium size of the calipso option including
 * the two-byte TLV header.
 */

#define CALIPSO_OPT_LEN_MAX (2 + 252)

/* Size of the minimum calipso option including
 * the two-byte TLV header.
 */

#define CALIPSO_HDR_LEN (2 + 8)

/* Maximium size of the calipso option including
 * the two-byte TLV header and upto 3 bytes of
 * leading pad and 7 bytes of trailing pad.
 */

#define CALIPSO_OPT_LEN_MAX_WITH_PAD (3 + CALIPSO_OPT_LEN_MAX + 7)

 /* Maximium size of u32 aligned buffer required to hold calipso
  * option.  Max of 3 initial pad bytes starting from buffer + 3.
  * i.e. the worst case is when the previous tlv finishes on 4n + 3.
  */

#define CALIPSO_MAX_BUFFER (6 + CALIPSO_OPT_LEN_MAX)

/* List of available DOI definitions */
static DEFINE_SPINLOCK(calipso_doi_list_lock);
static LIST_HEAD(calipso_doi_list);

/* Label mapping cache */

int calipso_cache_enabled = 1;

int calipso_cache_bucketsize = 10;

#define CALIPSO_CACHE_BUCKETBITS     7

#define CALIPSO_CACHE_BUCKETS        BIT(CALIPSO_CACHE_BUCKETBITS)

#define CALIPSO_CACHE_REORDERLIMIT   10

struct calipso_map_cache_bkt {
	
spinlock_t lock;
	
u32 size;
	
struct list_head list;
};


struct calipso_map_cache_entry {
	
u32 hash;
	
unsigned char *key;
	
size_t key_len;

	
struct netlbl_lsm_cache *lsm_data;

	
u32 activity;
	
struct list_head list;
};


static struct calipso_map_cache_bkt *calipso_cache;

/* Label Mapping Cache Functions
 */

/**
 * calipso_cache_entry_free - Frees a cache entry
 * @entry: the entry to free
 *
 * Description:
 * This function frees the memory associated with a cache entry including the
 * LSM cache data if there are no longer any users, i.e. reference count == 0.
 *
 */

static void calipso_cache_entry_free(struct calipso_map_cache_entry *entry) { if (entry->lsm_data) netlbl_secattr_cache_free(entry->lsm_data); kfree(entry->key); kfree(entry); }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies36100.00%1100.00%
Total36100.00%1100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies25100.00%1100.00%
Total25100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies85100.00%1100.00%
Total85100.00%1100.00%

/** * 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); } }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies90100.00%1100.00%
Total90100.00%1100.00%

/** * calipso_cache_check - Check the CALIPSO cache for a label mapping * @key: the buffer to check * @key_len: buffer length in bytes * @secattr: the security attribute struct to use * * Description: * This function checks the cache to see if a label mapping already exists for * the given key. If there is a match then the cache is adjusted and the * @secattr struct is populated with the correct LSM security attributes. The * cache is adjusted in the following manner if the entry is not already the * first in the cache bucket: * * 1. The cache entry's activity counter is incremented * 2. The previous (higher ranking) entry's activity counter is decremented * 3. If the difference between the two activity counters is geater than * CALIPSO_CACHE_REORDERLIMIT the two entries are swapped * * Returns zero on success, -ENOENT for a cache miss, and other negative values * on error. * */
static int calipso_cache_check(const unsigned char *key, u32 key_len, struct netlbl_lsm_secattr *secattr) { u32 bkt; struct calipso_map_cache_entry *entry; struct calipso_map_cache_entry *prev_entry = NULL; u32 hash; if (!calipso_cache_enabled) return -ENOENT; hash = calipso_map_cache_hash(key, key_len); bkt = hash & (CALIPSO_CACHE_BUCKETS - 1); spin_lock_bh(&calipso_cache[bkt].lock); list_for_each_entry(entry, &calipso_cache[bkt].list, list) { if (entry->hash == hash && entry->key_len == key_len && memcmp(entry->key, key, key_len) == 0) { entry->activity += 1; atomic_inc(&entry->lsm_data->refcount); secattr->cache = entry->lsm_data; secattr->flags |= NETLBL_SECATTR_CACHE; secattr->type = NETLBL_NLTYPE_CALIPSO; if (!prev_entry) { spin_unlock_bh(&calipso_cache[bkt].lock); return 0; } if (prev_entry->activity > 0) prev_entry->activity -= 1; if (entry->activity > prev_entry->activity && entry->activity - prev_entry->activity > CALIPSO_CACHE_REORDERLIMIT) { __list_del(entry->list.prev, entry->list.next); __list_add(&entry->list, prev_entry->list.prev, &prev_entry->list); } spin_unlock_bh(&calipso_cache[bkt].lock); return 0; } prev_entry = entry; } spin_unlock_bh(&calipso_cache[bkt].lock); return -ENOENT; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies276100.00%1100.00%
Total276100.00%1100.00%

/** * calipso_cache_add - Add an entry to the CALIPSO cache * @calipso_ptr: the CALIPSO option * @secattr: the packet's security attributes * * Description: * Add a new entry into the CALIPSO label mapping cache. Add the new entry to * head of the cache bucket's list, if the cache bucket is out of room remove * the last entry in the list first. It is important to note that there is * currently no checking for duplicate keys. Returns zero on success, * negative values on failure. The key stored starts at calipso_ptr + 2, * i.e. the type and length bytes are not stored, this corresponds to * calipso_ptr[1] bytes of data. * */
static int calipso_cache_add(const unsigned char *calipso_ptr, const struct netlbl_lsm_secattr *secattr) { int ret_val = -EPERM; u32 bkt; struct calipso_map_cache_entry *entry = NULL; struct calipso_map_cache_entry *old_entry = NULL; u32 calipso_ptr_len; if (!calipso_cache_enabled || calipso_cache_bucketsize <= 0) return 0; calipso_ptr_len = calipso_ptr[1]; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (!entry) return -ENOMEM; entry->key = kmemdup(calipso_ptr + 2, calipso_ptr_len, GFP_ATOMIC); if (!entry->key) { ret_val = -ENOMEM; goto cache_add_failure; } entry->key_len = calipso_ptr_len; entry->hash = calipso_map_cache_hash(calipso_ptr, calipso_ptr_len); atomic_inc(&secattr->cache->refcount); entry->lsm_data = secattr->cache; bkt = entry->hash & (CALIPSO_CACHE_BUCKETS - 1); spin_lock_bh(&calipso_cache[bkt].lock); if (calipso_cache[bkt].size < calipso_cache_bucketsize) { list_add(&entry->list, &calipso_cache[bkt].list); calipso_cache[bkt].size += 1; } else { old_entry = list_entry(calipso_cache[bkt].list.prev, struct calipso_map_cache_entry, list); list_del(&old_entry->list); list_add(&entry->list, &calipso_cache[bkt].list); calipso_cache_entry_free(old_entry); } spin_unlock_bh(&calipso_cache[bkt].lock); return 0; cache_add_failure: if (entry) calipso_cache_entry_free(entry); return ret_val; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies292100.00%1100.00%
Total292100.00%1100.00%

/* DOI List Functions */ /** * calipso_doi_search - Searches for a DOI definition * @doi: the DOI to search for * * Description: * Search the DOI definition list for a DOI definition with a DOI value that * matches @doi. The caller is responsible for calling rcu_read_[un]lock(). * Returns a pointer to the DOI definition on success and NULL on failure. */
static struct calipso_doi *calipso_doi_search(u32 doi) { struct calipso_doi *iter; list_for_each_entry_rcu(iter, &calipso_doi_list, list) if (iter->doi == doi && atomic_read(&iter->refcount)) return iter; return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies46100.00%1100.00%
Total46100.00%1100.00%

/** * calipso_doi_add - Add a new DOI to the CALIPSO protocol engine * @doi_def: the DOI structure * @audit_info: NetLabel audit information * * Description: * The caller defines a new DOI for use by the CALIPSO engine and calls this * function to add it to the list of acceptable domains. The caller must * ensure that the mapping table specified in @doi_def->map meets all of the * requirements of the mapping type (see calipso.h for details). Returns * zero on success and non-zero on failure. * */
static int calipso_doi_add(struct calipso_doi *doi_def, struct netlbl_audit *audit_info) { int ret_val = -EINVAL; u32 doi; u32 doi_type; struct audit_buffer *audit_buf; doi = doi_def->doi; doi_type = doi_def->type; if (doi_def->doi == CALIPSO_DOI_UNKNOWN) goto doi_add_return; atomic_set(&doi_def->refcount, 1); spin_lock(&calipso_doi_list_lock); if (calipso_doi_search(doi_def->doi)) { spin_unlock(&calipso_doi_list_lock); ret_val = -EEXIST; goto doi_add_return; } list_add_tail_rcu(&doi_def->list, &calipso_doi_list); spin_unlock(&calipso_doi_list_lock); ret_val = 0; doi_add_return: audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_ADD, audit_info); if (audit_buf) { const char *type_str; switch (doi_type) { case CALIPSO_MAP_PASS: type_str = "pass"; break; default: type_str = "(unknown)"; } audit_log_format(audit_buf, " calipso_doi=%u calipso_type=%s res=%u", doi, type_str, ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); } return ret_val; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies186100.00%1100.00%
Total186100.00%1100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies16100.00%1100.00%
Total16100.00%1100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies33100.00%1100.00%
Total33100.00%1100.00%

/** * calipso_doi_remove - Remove an existing DOI from the CALIPSO protocol engine * @doi: the DOI value * @audit_secid: the LSM secid to use in the audit message * * Description: * Removes a DOI definition from the CALIPSO engine. The NetLabel routines will * be called to release their own LSM domain mappings as well as our own * domain list. Returns zero on success and negative values on failure. * */
static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info) { int ret_val; struct calipso_doi *doi_def; struct audit_buffer *audit_buf; spin_lock(&calipso_doi_list_lock); doi_def = calipso_doi_search(doi); if (!doi_def) { spin_unlock(&calipso_doi_list_lock); ret_val = -ENOENT; goto doi_remove_return; } if (!atomic_dec_and_test(&doi_def->refcount)) { spin_unlock(&calipso_doi_list_lock); ret_val = -EBUSY; goto doi_remove_return; } list_del_rcu(&doi_def->list); spin_unlock(&calipso_doi_list_lock); call_rcu(&doi_def->rcu, calipso_doi_free_rcu); ret_val = 0; doi_remove_return: audit_buf = netlbl_audit_start(AUDIT_MAC_CALIPSO_DEL, audit_info); if (audit_buf) { audit_log_format(audit_buf, " calipso_doi=%u res=%u", doi, ret_val == 0 ? 1 : 0); audit_log_end(audit_buf); } return ret_val; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies158100.00%1100.00%
Total158100.00%1100.00%

/** * calipso_doi_getdef - Returns a reference to a valid DOI definition * @doi: the DOI value * * Description: * Searches for a valid DOI definition and if one is found it is returned to * the caller. Otherwise NULL is returned. The caller must ensure that * calipso_doi_putdef() is called when the caller is done. * */
static struct calipso_doi *calipso_doi_getdef(u32 doi) { struct calipso_doi *doi_def; rcu_read_lock(); doi_def = calipso_doi_search(doi); if (!doi_def) goto doi_getdef_return; if (!atomic_inc_not_zero(&doi_def->refcount)) doi_def = NULL; doi_getdef_return: rcu_read_unlock(); return doi_def; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies57100.00%1100.00%
Total57100.00%1100.00%

/** * calipso_doi_putdef - Releases a reference for the given DOI definition * @doi_def: the DOI definition * * Description: * Releases a DOI definition reference obtained from calipso_doi_getdef(). * */
static void calipso_doi_putdef(struct calipso_doi *doi_def) { if (!doi_def) return; if (!atomic_dec_and_test(&doi_def->refcount)) return; spin_lock(&calipso_doi_list_lock); list_del_rcu(&doi_def->list); spin_unlock(&calipso_doi_list_lock); call_rcu(&doi_def->rcu, calipso_doi_free_rcu); }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies59100.00%1100.00%
Total59100.00%1100.00%

/** * calipso_doi_walk - Iterate through the DOI definitions * @skip_cnt: skip past this number of DOI definitions, updated * @callback: callback for each DOI definition * @cb_arg: argument for the callback function * * Description: * Iterate over the DOI definition list, skipping the first @skip_cnt entries. * For each entry call @callback, if @callback returns a negative value stop * 'walking' through the list and return. Updates the value in @skip_cnt upon * return. Returns zero on success, negative values on failure. * */
static int calipso_doi_walk(u32 *skip_cnt, int (*callback)(struct calipso_doi *doi_def, void *arg), void *cb_arg) { int ret_val = -ENOENT; u32 doi_cnt = 0; struct calipso_doi *iter_doi; rcu_read_lock(); list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list) if (atomic_read(&iter_doi->refcount) > 0) { if (doi_cnt++ < *skip_cnt) continue; ret_val = callback(iter_doi, cb_arg); if (ret_val < 0) { doi_cnt--; goto doi_walk_return; } } doi_walk_return: rcu_read_unlock(); *skip_cnt = doi_cnt; return ret_val; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies116100.00%1100.00%
Total116100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies155100.00%1100.00%
Total155100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies115100.00%4100.00%
Total115100.00%4100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies117100.00%3100.00%
Total117100.00%3100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies97100.00%2100.00%
Total97100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies272100.00%1100.00%
Total272100.00%1100.00%

/* Hop-by-hop hdr helper functions */ /** * calipso_opt_update - Replaces socket's hop options with a new set * @sk: the socket * @hop: new hop options * * Description: * Replaces @sk's hop options with @hop. @hop may be NULL to leave * the socket with no hop options. * */
static int calipso_opt_update(struct sock *sk, struct ipv6_opt_hdr *hop) { struct ipv6_txoptions *old = txopt_get(inet6_sk(sk)), *txopts; txopts = ipv6_renew_options_kern(sk, old, IPV6_HOPOPTS, hop, hop ? ipv6_optlen(hop) : 0); txopt_put(old); if (IS_ERR(txopts)) return PTR_ERR(txopts); txopts = ipv6_update_options(sk, txopts); if (txopts) { atomic_sub(txopts->tot_len, &sk->sk_omem_alloc); txopt_put(txopts); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies107100.00%1100.00%
Total107100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies106100.00%1100.00%
Total106100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
huw davieshuw davies204100.00%1100.00%
Total204100.00%1100.00%

/** * 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