From 16efd45435fa695b501b7f73c3259bd7c77cc12c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 29 Jan 2008 08:37:59 -0500 Subject: NetLabel: Add secid token support to the NetLabel secattr struct This patch adds support to the NetLabel LSM secattr struct for a secid token and a type field, paving the way for full LSM/SELinux context support and "static" or "fallback" labels. In addition, this patch adds a fair amount of documentation to the core NetLabel structures used as part of the NetLabel kernel API. Signed-off-by: Paul Moore Signed-off-by: James Morris --- include/net/netlabel.h | 91 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 73 insertions(+), 18 deletions(-) (limited to 'include/net') diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 2e5b2f6..18b73cf 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -105,17 +105,49 @@ struct netlbl_dom_map; /* Domain mapping operations */ int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info); -/* LSM security attributes */ +/* + * LSM security attributes + */ + +/** + * struct netlbl_lsm_cache - NetLabel LSM security attribute cache + * @refcount: atomic reference counter + * @free: LSM supplied function to free the cache data + * @data: LSM supplied cache data + * + * Description: + * This structure is provided for LSMs which wish to make use of the NetLabel + * caching mechanism to store LSM specific data/attributes in the NetLabel + * cache. If the LSM has to perform a lot of translation from the NetLabel + * security attributes into it's own internal representation then the cache + * mechanism can provide a way to eliminate some or all of that translation + * overhead on a cache hit. + * + */ struct netlbl_lsm_cache { atomic_t refcount; void (*free) (const void *data); void *data; }; -/* The catmap bitmap field MUST be a power of two in length and large + +/** + * struct netlbl_lsm_secattr_catmap - NetLabel LSM secattr category bitmap + * @startbit: the value of the lowest order bit in the bitmap + * @bitmap: the category bitmap + * @next: pointer to the next bitmap "node" or NULL + * + * Description: + * This structure is used to represent category bitmaps. Due to the large + * number of categories supported by most labeling protocols it is not + * practical to transfer a full bitmap internally so NetLabel adopts a sparse + * bitmap structure modeled after SELinux's ebitmap structure. + * The catmap bitmap field MUST be a power of two in length and large * enough to hold at least 240 bits. Special care (i.e. check the code!) * should be used when changing these values as the LSM implementation * probably has functions which rely on the sizes of these types to speed - * processing. */ + * processing. + * + */ #define NETLBL_CATMAP_MAPTYPE u64 #define NETLBL_CATMAP_MAPCNT 4 #define NETLBL_CATMAP_MAPSIZE (sizeof(NETLBL_CATMAP_MAPTYPE) * 8) @@ -127,22 +159,48 @@ struct netlbl_lsm_secattr_catmap { NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT]; struct netlbl_lsm_secattr_catmap *next; }; + +/** + * struct netlbl_lsm_secattr - NetLabel LSM security attributes + * @flags: indicate which attributes are contained in this structure + * @type: indicate the NLTYPE of the attributes + * @domain: the NetLabel LSM domain + * @cache: NetLabel LSM specific cache + * @attr.mls: MLS sensitivity label + * @attr.mls.cat: MLS category bitmap + * @attr.mls.lvl: MLS sensitivity level + * @attr.secid: LSM specific secid token + * + * Description: + * This structure is used to pass security attributes between NetLabel and the + * LSM modules. The flags field is used to specify which fields within the + * struct are valid and valid values can be created by bitwise OR'ing the + * NETLBL_SECATTR_* defines. The domain field is typically set by the LSM to + * specify domain specific configuration settings and is not usually used by + * NetLabel itself when returning security attributes to the LSM. + * + */ #define NETLBL_SECATTR_NONE 0x00000000 #define NETLBL_SECATTR_DOMAIN 0x00000001 #define NETLBL_SECATTR_CACHE 0x00000002 #define NETLBL_SECATTR_MLS_LVL 0x00000004 #define NETLBL_SECATTR_MLS_CAT 0x00000008 +#define NETLBL_SECATTR_SECID 0x00000010 #define NETLBL_SECATTR_CACHEABLE (NETLBL_SECATTR_MLS_LVL | \ - NETLBL_SECATTR_MLS_CAT) + NETLBL_SECATTR_MLS_CAT | \ + NETLBL_SECATTR_SECID) struct netlbl_lsm_secattr { u32 flags; - + u32 type; char *domain; - - u32 mls_lvl; - struct netlbl_lsm_secattr_catmap *mls_cat; - struct netlbl_lsm_cache *cache; + union { + struct { + struct netlbl_lsm_secattr_catmap *cat; + u32 lvl; + } mls; + u32 secid; + } attr; }; /* @@ -231,10 +289,7 @@ static inline void netlbl_secattr_catmap_free( */ static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr) { - secattr->flags = 0; - secattr->domain = NULL; - secattr->mls_cat = NULL; - secattr->cache = NULL; + memset(secattr, 0, sizeof(*secattr)); } /** @@ -248,11 +303,11 @@ static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr) */ static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr) { - if (secattr->cache) - netlbl_secattr_cache_free(secattr->cache); kfree(secattr->domain); - if (secattr->mls_cat) - netlbl_secattr_catmap_free(secattr->mls_cat); + if (secattr->flags & NETLBL_SECATTR_CACHE) + netlbl_secattr_cache_free(secattr->cache); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) + netlbl_secattr_catmap_free(secattr->attr.mls.cat); } /** @@ -300,7 +355,7 @@ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap, gfp_t flags); /* - * LSM protocol operations + * LSM protocol operations (NetLabel LSM/kernel API) */ int netlbl_enabled(void); int netlbl_sock_setattr(struct sock *sk, -- cgit v1.1