/* * 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, 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, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include #include #include #include #include #include #include #include #include "netlabel_domainhash.h" #include "netlabel_unlabeled.h" #include "netlabel_cipso_v4.h" #include "netlabel_user.h" #include "netlabel_mgmt.h" /* * Configuration Functions */ /** * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping * @domain: the domain mapping to remove * @audit_info: NetLabel audit information * * Description: * Removes a NetLabel/LSM domain mapping. A @domain value of NULL causes the * default domain mapping to be removed. Returns zero on success, negative * values on failure. * */ int netlbl_cfg_map_del(const char *domain, struct netlbl_audit *audit_info) { return netlbl_domhsh_remove(domain, audit_info); } /** * netlbl_cfg_unlbl_add_map - Add an unlabeled NetLabel/LSM domain mapping * @domain: the domain mapping to add * @audit_info: NetLabel audit information * * Description: * Adds a new unlabeled NetLabel/LSM domain mapping. A @domain value of NULL * causes a new default domain mapping to be added. Returns zero on success, * negative values on failure. * */ int netlbl_cfg_unlbl_add_map(const char *domain, struct netlbl_audit *audit_info) { int ret_val = -ENOMEM; struct netlbl_dom_map *entry; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (entry == NULL) return -ENOMEM; if (domain != NULL) { entry->domain = kstrdup(domain, GFP_ATOMIC); if (entry->domain == NULL) goto cfg_unlbl_add_map_failure; } entry->type = NETLBL_NLTYPE_UNLABELED; ret_val = netlbl_domhsh_add(entry, audit_info); if (ret_val != 0) goto cfg_unlbl_add_map_failure; return 0; cfg_unlbl_add_map_failure: if (entry != NULL) kfree(entry->domain); kfree(entry); return ret_val; } /** * netlbl_cfg_cipsov4_add_map - Add a new CIPSOv4 DOI definition and mapping * @doi_def: the DOI definition * @domain: the domain mapping to add * @audit_info: NetLabel audit information * * Description: * Add a new CIPSOv4 DOI definition and NetLabel/LSM domain mapping for this * new DOI definition to the NetLabel subsystem. A @domain value of NULL adds * a new default domain mapping. Returns zero on success, negative values on * failure. * */ int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def, const char *domain, struct netlbl_audit *audit_info) { int ret_val = -ENOMEM; u32 doi; u32 doi_type; struct netlbl_dom_map *entry; const char *type_str; struct audit_buffer *audit_buf; doi = doi_def->doi; doi_type = doi_def->type; entry = kzalloc(sizeof(*entry), GFP_ATOMIC); if (entry == NULL) return -ENOMEM; if (domain != NULL) { entry->domain = kstrdup(domain, GFP_ATOMIC); if (entry->domain == NULL) goto cfg_cipsov4_add_map_failure; } ret_val = cipso_v4_doi_add(doi_def); if (ret_val != 0) goto cfg_cipsov4_add_map_failure_remove_doi; entry->type = NETLBL_NLTYPE_CIPSOV4; entry->type_def.cipsov4 = cipso_v4_doi_getdef(doi); if (entry->type_def.cipsov4 == NULL) { ret_val = -ENOENT; goto cfg_cipsov4_add_map_failure_remove_doi; } ret_val = netlbl_domhsh_add(entry, audit_info); if (ret_val != 0) goto cfg_cipsov4_add_map_failure_release_doi; cfg_cipsov4_add_map_return: audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD, audit_info); if (audit_buf != NULL) { 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; cfg_cipsov4_add_map_failure_release_doi: cipso_v4_doi_putdef(doi_def); cfg_cipsov4_add_map_failure_remove_doi: cipso_v4_doi_remove(doi, audit_info); cfg_cipsov4_add_map_failure: if (entry != NULL) kfree(entry->domain); kfree(entry); goto cfg_cipsov4_add_map_return; } /* * 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 (atomic_read(&netlabel_mgmt_protocount) > 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, -EDESTADDRREQ if the domain is configured to use * network address selectors (can't blindly label the socket), and negative * values on all other failures. * */ 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_ADDRSELECT: ret_val = -EDESTADDRREQ; break; 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_delattr - Delete all the NetLabel labels on a socket * @sk: the socket * * Description: * Remove all the NetLabel labeling from @sk. The caller is responsible for * ensuring that @sk is locked. * */ void netlbl_sock_delattr(struct sock *sk) { cipso_v4_sock_delattr(sk); } /** * netlbl_sock_getattr - Determine the security attributes of a sock * @sk: the sock * @secattr: the security attributes * * Description: * Examines the given sock to see if 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) { return cipso_v4_sock_getattr(sk, secattr); } /** * netlbl_conn_setattr - Label a connected socket using the correct protocol * @sk: the socket to label * @addr: the destination address * @secattr: the security attributes * * Description: * Attach the correct label to the given connected socket using the security * attributes specified in @secattr. The caller is responsible for ensuring * that @sk is locked. Returns zero on success, negative values on failure. * */ int netlbl_conn_setattr(struct sock *sk, struct sockaddr *addr, const struct netlbl_lsm_secattr *secattr) { int ret_val; struct sockaddr_in *addr4; struct netlbl_domaddr4_map *af4_entry; rcu_read_lock(); switch (addr->sa_family) { case AF_INET: addr4 = (struct sockaddr_in *)addr; af4_entry = netlbl_domhsh_getentry_af4(secattr->domain, addr4->sin_addr.s_addr); if (af4_entry == NULL) { ret_val = -ENOENT; goto conn_setattr_return; } switch (af4_entry->type) { case NETLBL_NLTYPE_CIPSOV4: ret_val = cipso_v4_sock_setattr(sk, af4_entry->type_def.cipsov4, secattr); break; case NETLBL_NLTYPE_UNLABELED: /* just delete the protocols we support for right now * but we could remove other protocols if needed */ cipso_v4_sock_delattr(sk); ret_val = 0; break; default: ret_val = -ENOENT; } break; #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) case AF_INET6: /* since we don't support any IPv6 labeling protocols right * now we can optimize everything away until we do */ ret_val = 0; break; #endif /* IPv6 */ default: ret_val = 0; } conn_setattr_return: rcu_read_unlock(); return ret_val; } /** * netlbl_skbuff_setattr - Label a packet using the correct protocol * @skb: the packet * @family: protocol family * @secattr: the security attributes * * Description: * Attach the correct label to the given packet using the security attributes * specified in @secattr. Returns zero on success, negative values on failure. * */ int netlbl_skbuff_setattr(struct sk_buff *skb, u16 family, const struct netlbl_lsm_secattr *secattr) { int ret_val; struct iphdr *hdr4; struct netlbl_domaddr4_map *af4_entry; rcu_read_lock(); switch (family) { case AF_INET: hdr4 = ip_hdr(skb); af4_entry = netlbl_domhsh_getentry_af4(secattr->domain, hdr4->daddr); if (af4_entry == NULL) { ret_val = -ENOENT; goto skbuff_setattr_return; } switch (af4_entry->type) { case NETLBL_NLTYPE_CIPSOV4: ret_val = cipso_v4_skbuff_setattr(skb, af4_entry->type_def.cipsov4, secattr); break; case NETLBL_NLTYPE_UNLABELED: /* just delete the protocols we support for right now * but we could remove other protocols if needed */ ret_val = cipso_v4_skbuff_delattr(skb); break; default: ret_val = -ENOENT; } break; #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) case AF_INET6: /* since we don't support any IPv6 labeling protocols right * now we can optimize everything away until we do */ ret_val = 0; break; #endif /* IPv6 */ default: ret_val = 0; } skbuff_setattr_return: rcu_read_unlock(); return ret_val; } /** * netlbl_skbuff_getattr - Determine the security attributes of a packet * @skb: the packet * @family: protocol family * @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, u16 family, struct netlbl_lsm_secattr *secattr) { if (CIPSO_V4_OPTEXIST(skb) && cipso_v4_skbuff_getattr(skb, secattr) == 0) return 0; return netlbl_unlabel_getattr(skb, family, secattr); } /** * netlbl_skbuff_err - Handle a LSM error on a sk_buff * @skb: the packet * @error: the error code * @gateway: true if host is acting as a gateway, false otherwise * * 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, int gateway) { if (CIPSO_V4_OPTEXIST(skb)) cipso_v4_error(skb, error, gateway); } /** * 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_unlabel_init(NETLBL_UNLHSH_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);