mmap_cache.h revision 9028706a00da1bc48547e74aa872c825ac15adb2
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard Mmap Cache Common header
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard Copyright (C) Simo Sorce <ssorce@redhat.com> 2011
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard This program is free software; you can redistribute it and/or modify
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard it under the terms of the GNU General Public License as published by
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard the Free Software Foundation; either version 3 of the License, or
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard (at your option) any later version.
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard This program is distributed in the hope that it will be useful,
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard but WITHOUT ANY WARRANTY; without even the implied warranty of
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard GNU General Public License for more details.
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard You should have received a copy of the GNU General Public License
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard along with this program. If not, see <http://www.gnu.org/licenses/>.
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard/* NOTE: all the code here assumes that writing a uint32_t nto mmapped
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * memory is an atomic operation and can't be split in multiple
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * non-atomic operations */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard/* align macros */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_ALIGN32(size) ( ((size) + MC_32 -1) & (~(MC_32 -1)) )
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_ALIGN64(size) ( ((size) + MC_64 -1) & (~(MC_64 -1)) )
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_HEADER_SIZE MC_ALIGN64(sizeof(struct sss_mc_header))
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_DT_SIZE(elems, payload) ( (elems) * (payload) )
f84cab2da5f8958575b1ce99ca2bf4fda34cecb6mturk/* ^^ 8 bits per byte so we need just elems/8 bytes to represent all blocks */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_PTR_ADD(ptr, bytes) (void *)((uint8_t *)(ptr) + (bytes))
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_PTR_DIFF(ptr, base) ((uint8_t *)(ptr) - (uint8_t *)(base))
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * 32 seem a good compromise for slot size
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * 4 blocks are enough for the average passwd entry of 42 bytes
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * passwd records have 84 bytes of overhead, 128 - 82 = 46 bytes
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * 3 blocks can contain a very minimal entry, 96 - 82 = 14 bytes
4e06302d1825b2a21dfe3ac998ff14e9a40927d7wrowe * 3 blocks are enough for groups w/o users (private user groups)
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard * group records have 68 bytes of overhead, 96 - 66 = 30 bytes
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_SIZE_TO_SLOTS(len) (((len) + (MC_SLOT_SIZE - 1)) / MC_SLOT_SIZE)
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_PTR_TO_SLOT(base, ptr) (MC_PTR_DIFF(ptr, base) / MC_SLOT_SIZE)
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define MC_VALID_BARRIER(val) (((val) & 0xff000000) == 0xf0000000)
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard ((rec)->len >= MC_HEADER_SIZE && (rec)->len != MC_INVALID_VAL32 \
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define SSS_MC_HEADER_UNINIT 0 /* after ftruncate or before reset */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define SSS_MC_HEADER_ALIVE 1 /* current and in use */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard#define SSS_MC_HEADER_RECYCLED 2 /* file was recycled, reopen asap */
43681d859fe7d4cd90a33d6be2232192c108de75wrowe uint32_t seed; /* random seed used to avoid collision attacks */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard rel_ptr_t data_table; /* data table pointer relative to mmap base */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard rel_ptr_t free_table; /* free table pointer relative to mmap base */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard rel_ptr_t hash_table; /* hash table pointer relative to mmap base */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard rel_ptr_t reserved; /* reserved for future changes */
43681d859fe7d4cd90a33d6be2232192c108de75wrowe uint32_t len; /* total record length including record data */
43681d859fe7d4cd90a33d6be2232192c108de75wrowe uint64_t expire; /* record expiration time (cast to time_t) */
43681d859fe7d4cd90a33d6be2232192c108de75wrowe rel_ptr_t next; /* ptr of next record rel to data_table */
43681d859fe7d4cd90a33d6be2232192c108de75wrowe uint32_t hash1; /* val of first hash (usually name of record) */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard uint32_t hash2; /* val of second hash (usually id of record) */
8e117661fd51fd19d6430fca8d7ae87c67d6de20stoddard uint32_t b2; /* barrier 2 - 32 bytes mark, fits a slot */
char data[0];
struct sss_mc_pwd_data {
struct sss_mc_grp_data {
#pragma pack()