/* * NetLabel Kernel API * * This file defines the kernel API for the NetLabel system. The NetLabel * system manages static and dynamic label mappings for network protocols such * as CIPSO and RIPSO. * * Author: Paul Moore * */ /* * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 * * 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, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include #include #include #include #include #include #include "netlabel_domainhash.h" #include "netlabel_unlabeled.h" #include "netlabel_user.h" #include "netlabel_mgmt.h" /* * Security Attribute Functions */ /** * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit * @catmap: the category bitmap * @offset: the offset to start searching at, in bits * * Description: * This function walks a LSM secattr category bitmap starting at @offset and * returns the spot of the first set bit or -ENOENT if no bits are set. * */ int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap, u32 offset) { struct netlbl_lsm_secattr_catmap *iter = catmap; u32 node_idx; u32 node_bit; NETLBL_CATMAP_MAPTYPE bitmap; if (offset > iter->startbit) { while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { iter = iter->next; if (iter == NULL) return -ENOENT; } node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; node_bit = offset - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx); } else { node_idx = 0; node_bit = 0; } bitmap = iter->bitmap[node_idx] >> node_bit; for (;;) { if (bitmap != 0) { while ((bitmap & NETLBL_CATMAP_BIT) == 0) { bitmap >>= 1; node_bit++; } return iter->startbit + (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit; } if (++node_idx >= NETLBL_CATMAP_MAPCNT) { if (iter->next != NULL) { iter = iter->next; node_idx = 0; } else return -ENOENT; } bitmap = iter->bitmap[node_idx]; node_bit = 0; } return -ENOENT; } /** * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits * @catmap: the category bitmap * @offset: the offset to start searching at, in bits * * Description: * This function walks a LSM secattr category bitmap starting at @offset and * returns the spot of the first cleared bit or -ENOENT if the offset is past * the end of the bitmap. * */ int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap, u32 offset) { struct netlbl_lsm_secattr_catmap *iter = catmap; u32 node_idx; u32 node_bit; NETLBL_CATMAP_MAPTYPE bitmask; NETLBL_CATMAP_MAPTYPE bitmap; if (offset > iter->startbit) { while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) { iter = iter->next; if (iter == NULL) return -ENOENT; } node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE; node_bit = offset - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx); } else { node_idx = 0; node_bit = 0; } bitmask = NETLBL_CATMAP_BIT << node_bit; for (;;) { bitmap = iter->bitmap[node_idx]; while (bitmask != 0 && (bitmap & bitmask) != 0) { bitmask <<= 1; node_bit++; } if (bitmask != 0) return iter->startbit + (NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit - 1; else if (++node_idx >= NETLBL_CATMAP_MAPCNT) { if (iter->next == NULL) return iter->startbit + NETLBL_CATMAP_SIZE - 1; iter = iter->next; node_idx = 0; } bitmask = NETLBL_CATMAP_BIT; node_bit = 0; } return -ENOENT; } /** * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap * @catmap: the category bitmap * @bit: the bit to set * @flags: memory allocation flags * * Description: * Set the bit specified by @bit in @catmap. Returns zero on success, * negative values on failure. * */ int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap, u32 bit, gfp_t flags) { struct netlbl_lsm_secattr_catmap *iter = catmap; u32 node_bit; u32 node_idx; while (iter->next != NULL && bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) iter = iter->next; if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) { iter->next = netlbl_secattr_catmap_alloc(flags); if (iter->next == NULL) return -ENOMEM; iter = iter->next; iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1); } /* gcc always rounds to zero when doing integer division */ node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE; node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx); iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit; return 0; } /** * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap * @catmap: the category bitmap * @start: the starting bit * @end: the last bit in the string * @flags: memory allocation flags * * Description: * Set a range of bits, starting at @start and ending with @end. Returns zero * on success, negative values on failure. * */ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap, u32 start, u32 end, gfp_t flags) { int ret_val = 0; struct netlbl_lsm_secattr_catmap *iter = catmap; u32 iter_max_spot; u32 spot; /* XXX - This could probably be made a bit faster by combining writes * to the catmap instead of setting a single bit each time, but for * right now skipping to the start of the range in the catmap should * be a nice improvement over calling the individual setbit function * repeatedly from a loop. */ while (iter->next != NULL && start >= (iter->startbit + NETLBL_CATMAP_SIZE)) iter = iter->next; iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; for (spot = start; spot <= end && ret_val == 0; spot++) { if (spot >= iter_max_spot && iter->next != NULL) { iter = iter->next; iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE; } ret_val = netlbl_secattr_catmap_setbit(iter, spot, GFP_ATOMIC); } return ret_val; } /* * LSM Functions */ /** * netlbl_enabled - Determine if the NetLabel subsystem is enabled * * Description: * The LSM can use this function to determine if it should use NetLabel * security attributes in it's enforcement mechanism. Currently, NetLabel is * considered to be enabled when it's configuration contains a valid setup for * at least one labeled protocol (i.e. NetLabel can understand incoming * labeled packets of at least one type); otherwise NetLabel is considered to * be disabled. * */ int netlbl_enabled(void) { /* At some point we probably want to expose this mechanism to the user * as well so that admins can toggle NetLabel regardless of the * configuration */ return (netlbl_mgmt_protocount_value() > 0 ? 1 : 0); } /** * netlbl_socket_setattr - Label a socket using the correct protocol * @sk: the socket to label * @secattr: the security attributes * * Description: * Attach the correct label to the given socket using the security attributes * specified in @secattr. 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, negative values on failure. * */ int netlbl_sock_setattr(struct sock *sk, const struct netlbl_lsm_secattr *secattr) { int ret_val = -ENOENT; struct netlbl_dom_map *dom_entry; rcu_read_lock(); dom_entry = netlbl_domhsh_getentry(secattr->domain); if (dom_entry == NULL) goto socket_setattr_return; switch (dom_entry->type) { case NETLBL_NLTYPE_CIPSOV4: ret_val = cipso_v4_sock_setattr(sk, dom_entry->type_def.cipsov4, secattr); break; case NETLBL_NLTYPE_UNLABELED: ret_val = 0; break; default: ret_val = -ENOENT; } socket_setattr_return: rcu_read_unlock(); return ret_val; } /** * netlbl_sock_getattr - Determine the security attributes of a sock * @sk: the sock * @secattr: the security attributes * * Description: * Examines the given sock to see any NetLabel style labeling has been * applied to the sock, if so it parses the socket label and returns the * security attributes in @secattr. Returns zero on success, negative values * on failure. * */ int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) { int ret_val; ret_val = cipso_v4_sock_getattr(sk, secattr); if (ret_val == 0) return 0; return netlbl_unlabel_getattr(secattr); } /** * netlbl_skbuff_getattr - Determine the security attributes of a packet * @skb: the packet * @secattr: the security attributes * * Description: * Examines the given packet to see if a recognized form of packet labeling * is present, if so it parses the packet label and returns the security * attributes in @secattr. Returns zero on success, negative values on * failure. * */ int netlbl_skbuff_getattr(const struct sk_buff *skb, struct netlbl_lsm_secattr *secattr) { if (CIPSO_V4_OPTEXIST(skb) && cipso_v4_skbuff_getattr(skb, secattr) == 0) return 0; return netlbl_unlabel_getattr(secattr); } /** * netlbl_skbuff_err - Handle a LSM error on a sk_buff * @skb: the packet * @error: the error code * * Description: * Deal with a LSM problem when handling the packet in @skb, typically this is * a permission denied problem (-EACCES). The correct action is determined * according to the packet's labeling protocol. * */ void netlbl_skbuff_err(struct sk_buff *skb, int error) { if (CIPSO_V4_OPTEXIST(skb)) cipso_v4_error(skb, error, 0); } /** * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches * * Description: * For all of the NetLabel protocols that support some form of label mapping * cache, invalidate the cache. Returns zero on success, negative values on * error. * */ void netlbl_cache_invalidate(void) { cipso_v4_cache_invalidate(); } /** * netlbl_cache_add - Add an entry to a NetLabel protocol cache * @skb: the packet * @secattr: the packet's security attributes * * Description: * Add the LSM security attributes for the given packet to the underlying * NetLabel protocol's label mapping cache. Returns zero on success, negative * values on error. * */ int netlbl_cache_add(const struct sk_buff *skb, const struct netlbl_lsm_secattr *secattr) { if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0) return -ENOMSG; if (CIPSO_V4_OPTEXIST(skb)) return cipso_v4_cache_add(skb, secattr); return -ENOMSG; } /* * Setup Functions */ /** * netlbl_init - Initialize NetLabel * * Description: * Perform the required NetLabel initialization before first use. * */ static int __init netlbl_init(void) { int ret_val; printk(KERN_INFO "NetLabel: Initializing\n"); printk(KERN_INFO "NetLabel: domain hash size = %u\n", (1 << NETLBL_DOMHSH_BITSIZE)); printk(KERN_INFO "NetLabel: protocols =" " UNLABELED" " CIPSOv4" "\n"); ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE); if (ret_val != 0) goto init_failure; ret_val = netlbl_netlink_init(); if (ret_val != 0) goto init_failure; ret_val = netlbl_unlabel_defconf(); if (ret_val != 0) goto init_failure; printk(KERN_INFO "NetLabel: unlabeled traffic allowed by default\n"); return 0; init_failure: panic("NetLabel: failed to initialize properly (%d)\n", ret_val); } subsys_initcall(netlbl_init);