| Benny Prijono | 8a0ab28 | 2008-01-23 20:17:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * replay-database.h |
| 3 | * |
| 4 | * interface for a replay database for packet security |
| 5 | * |
| 6 | * David A. McGrew |
| 7 | * Cisco Systems, Inc. |
| 8 | */ |
| 9 | |
| 10 | |
| 11 | #ifndef REPLAY_DB_H |
| 12 | #define REPLAY_DB_H |
| 13 | |
| 14 | #include "integers.h" /* for uint32_t */ |
| 15 | #include "datatypes.h" /* for v128_t */ |
| 16 | #include "err.h" /* for err_status_t */ |
| 17 | |
| 18 | /* |
| 19 | * if the ith least significant bit is one, then the packet index |
| 20 | * window_end-i is in the database |
| 21 | */ |
| 22 | |
| 23 | typedef struct { |
| 24 | uint32_t window_start; /* packet index of the first bit in bitmask */ |
| 25 | v128_t bitmask; |
| 26 | } rdb_t; |
| 27 | |
| 28 | #define rdb_bits_in_bitmask (8*sizeof(v128_t)) |
| 29 | |
| 30 | /* |
| 31 | * rdb init |
| 32 | * |
| 33 | * initalizes rdb |
| 34 | * |
| 35 | * returns err_status_ok on success, err_status_t_fail otherwise |
| 36 | */ |
| 37 | |
| 38 | err_status_t |
| 39 | rdb_init(rdb_t *rdb); |
| 40 | |
| 41 | |
| 42 | /* |
| 43 | * rdb_check |
| 44 | * |
| 45 | * checks to see if index appears in rdb |
| 46 | * |
| 47 | * returns err_status_fail if the index already appears in rdb, |
| 48 | * returns err_status_ok otherwise |
| 49 | */ |
| 50 | |
| 51 | err_status_t |
| 52 | rdb_check(const rdb_t *rdb, uint32_t index); |
| 53 | |
| 54 | /* |
| 55 | * rdb_add_index |
| 56 | * |
| 57 | * adds index to rdb_t (and does *not* check if index appears in db) |
| 58 | * |
| 59 | * returns err_status_ok on success, err_status_fail otherwise |
| 60 | * |
| 61 | */ |
| 62 | |
| 63 | err_status_t |
| 64 | rdb_add_index(rdb_t *rdb, uint32_t index); |
| 65 | |
| 66 | /* |
| 67 | * the functions rdb_increment() and rdb_get_value() are for use by |
| 68 | * senders, not receivers - DO NOT use these functions on the same |
| 69 | * rdb_t upon which rdb_add_index is used! |
| 70 | */ |
| 71 | |
| 72 | |
| 73 | /* |
| 74 | * rdb_increment(db) increments the sequence number in db, if it is |
| 75 | * not too high |
| 76 | * |
| 77 | * return values: |
| 78 | * |
| 79 | * err_status_ok no problem |
| 80 | * err_status_key_expired sequence number too high |
| 81 | * |
| 82 | */ |
| 83 | err_status_t |
| 84 | rdb_increment(rdb_t *rdb); |
| 85 | |
| 86 | /* |
| 87 | * rdb_get_value(db) returns the current sequence number of db |
| 88 | */ |
| 89 | |
| 90 | uint32_t |
| 91 | rdb_get_value(const rdb_t *rdb); |
| 92 | |
| 93 | |
| 94 | #endif /* REPLAY_DB_H */ |