diff options
Diffstat (limited to 'net/netlabel')
| -rw-r--r-- | net/netlabel/netlabel_kapi.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c index b35ebf9..e03a328 100644 --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -40,6 +40,207 @@ #include "netlabel_user.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 */ |