diff options
Diffstat (limited to 'net/netlabel/netlabel_kapi.c')
| -rw-r--r-- | net/netlabel/netlabel_kapi.c | 739 |
1 files changed, 739 insertions, 0 deletions
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c new file mode 100644 index 0000000..b32eceb --- /dev/null +++ b/net/netlabel/netlabel_kapi.c @@ -0,0 +1,739 @@ +/* + * 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 <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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/init.h> +#include <linux/types.h> +#include <linux/audit.h> +#include <net/ip.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> +#include <asm/bug.h> +#include <asm/atomic.h> + +#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); |
