1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/netwerk/srtp/src/crypto/include/rdbx.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,221 @@
1.4 +/*
1.5 + * rdbx.h
1.6 + *
1.7 + * replay database with extended packet indices, using a rollover counter
1.8 + *
1.9 + * David A. McGrew
1.10 + * Cisco Systems, Inc.
1.11 + *
1.12 + */
1.13 +/*
1.14 + *
1.15 + * Copyright (c) 2001-2006, Cisco Systems, Inc.
1.16 + * All rights reserved.
1.17 + *
1.18 + * Redistribution and use in source and binary forms, with or without
1.19 + * modification, are permitted provided that the following conditions
1.20 + * are met:
1.21 + *
1.22 + * Redistributions of source code must retain the above copyright
1.23 + * notice, this list of conditions and the following disclaimer.
1.24 + *
1.25 + * Redistributions in binary form must reproduce the above
1.26 + * copyright notice, this list of conditions and the following
1.27 + * disclaimer in the documentation and/or other materials provided
1.28 + * with the distribution.
1.29 + *
1.30 + * Neither the name of the Cisco Systems, Inc. nor the names of its
1.31 + * contributors may be used to endorse or promote products derived
1.32 + * from this software without specific prior written permission.
1.33 + *
1.34 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.35 + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.36 + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
1.37 + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
1.38 + * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
1.39 + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1.40 + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
1.41 + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
1.42 + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
1.43 + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.44 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
1.45 + * OF THE POSSIBILITY OF SUCH DAMAGE.
1.46 + *
1.47 + */
1.48 +
1.49 +#ifndef RDBX_H
1.50 +#define RDBX_H
1.51 +
1.52 +#include "datatypes.h"
1.53 +#include "err.h"
1.54 +
1.55 +/* #define ROC_TEST */
1.56 +
1.57 +#ifndef ROC_TEST
1.58 +
1.59 +typedef uint16_t sequence_number_t; /* 16 bit sequence number */
1.60 +typedef uint32_t rollover_counter_t; /* 32 bit rollover counter */
1.61 +
1.62 +#else /* use small seq_num and roc datatypes for testing purposes */
1.63 +
1.64 +typedef unsigned char sequence_number_t; /* 8 bit sequence number */
1.65 +typedef uint16_t rollover_counter_t; /* 16 bit rollover counter */
1.66 +
1.67 +#endif
1.68 +
1.69 +#define seq_num_median (1 << (8*sizeof(sequence_number_t) - 1))
1.70 +#define seq_num_max (1 << (8*sizeof(sequence_number_t)))
1.71 +
1.72 +/*
1.73 + * An xtd_seq_num_t is a 64-bit unsigned integer used as an 'extended'
1.74 + * sequence number.
1.75 + */
1.76 +
1.77 +typedef uint64_t xtd_seq_num_t;
1.78 +
1.79 +
1.80 +/*
1.81 + * An rdbx_t is a replay database with extended range; it uses an
1.82 + * xtd_seq_num_t and a bitmask of recently received indices.
1.83 + */
1.84 +
1.85 +typedef struct {
1.86 + xtd_seq_num_t index;
1.87 + bitvector_t bitmask;
1.88 +} rdbx_t;
1.89 +
1.90 +
1.91 +/*
1.92 + * rdbx_init(rdbx_ptr, ws)
1.93 + *
1.94 + * initializes the rdbx pointed to by its argument with the window size ws,
1.95 + * setting the rollover counter and sequence number to zero
1.96 + */
1.97 +
1.98 +err_status_t
1.99 +rdbx_init(rdbx_t *rdbx, unsigned long ws);
1.100 +
1.101 +
1.102 +/*
1.103 + * rdbx_dealloc(rdbx_ptr)
1.104 + *
1.105 + * frees memory associated with the rdbx
1.106 + */
1.107 +
1.108 +err_status_t
1.109 +rdbx_dealloc(rdbx_t *rdbx);
1.110 +
1.111 +
1.112 +/*
1.113 + * rdbx_estimate_index(rdbx, guess, s)
1.114 + *
1.115 + * given an rdbx and a sequence number s (from a newly arrived packet),
1.116 + * sets the contents of *guess to contain the best guess of the packet
1.117 + * index to which s corresponds, and returns the difference between
1.118 + * *guess and the locally stored synch info
1.119 + */
1.120 +
1.121 +int
1.122 +rdbx_estimate_index(const rdbx_t *rdbx,
1.123 + xtd_seq_num_t *guess,
1.124 + sequence_number_t s);
1.125 +
1.126 +/*
1.127 + * rdbx_check(rdbx, delta);
1.128 + *
1.129 + * rdbx_check(&r, delta) checks to see if the xtd_seq_num_t
1.130 + * which is at rdbx->window_start + delta is in the rdb
1.131 + *
1.132 + */
1.133 +
1.134 +err_status_t
1.135 +rdbx_check(const rdbx_t *rdbx, int difference);
1.136 +
1.137 +/*
1.138 + * replay_add_index(rdbx, delta)
1.139 + *
1.140 + * adds the xtd_seq_num_t at rdbx->window_start + delta to replay_db
1.141 + * (and does *not* check if that xtd_seq_num_t appears in db)
1.142 + *
1.143 + * this function should be called *only* after replay_check has
1.144 + * indicated that the index does not appear in the rdbx, and a mutex
1.145 + * should protect the rdbx between these calls if necessary.
1.146 + */
1.147 +
1.148 +err_status_t
1.149 +rdbx_add_index(rdbx_t *rdbx, int delta);
1.150 +
1.151 +
1.152 +/*
1.153 + * rdbx_set_roc(rdbx, roc) initalizes the rdbx_t at the location rdbx
1.154 + * to have the rollover counter value roc. If that value is less than
1.155 + * the current rollover counter value, then the function returns
1.156 + * err_status_replay_old; otherwise, err_status_ok is returned.
1.157 + *
1.158 + */
1.159 +
1.160 +err_status_t
1.161 +rdbx_set_roc(rdbx_t *rdbx, uint32_t roc);
1.162 +
1.163 +/*
1.164 + * rdbx_get_roc(rdbx) returns the value of the rollover counter for
1.165 + * the rdbx_t pointed to by rdbx
1.166 + *
1.167 + */
1.168 +
1.169 +xtd_seq_num_t
1.170 +rdbx_get_packet_index(const rdbx_t *rdbx);
1.171 +
1.172 +/*
1.173 + * xtd_seq_num_t functions - these are *internal* functions of rdbx, and
1.174 + * shouldn't be used to manipulate rdbx internal values. use the rdbx
1.175 + * api instead!
1.176 + */
1.177 +
1.178 +/*
1.179 + * rdbx_get_ws(rdbx_ptr)
1.180 + *
1.181 + * gets the window size which was used to initialize the rdbx
1.182 + */
1.183 +
1.184 +unsigned long
1.185 +rdbx_get_window_size(const rdbx_t *rdbx);
1.186 +
1.187 +
1.188 +/* index_init(&pi) initializes a packet index pi (sets it to zero) */
1.189 +
1.190 +void
1.191 +index_init(xtd_seq_num_t *pi);
1.192 +
1.193 +/* index_advance(&pi, s) advances a xtd_seq_num_t forward by s */
1.194 +
1.195 +void
1.196 +index_advance(xtd_seq_num_t *pi, sequence_number_t s);
1.197 +
1.198 +
1.199 +/*
1.200 + * index_guess(local, guess, s)
1.201 + *
1.202 + * given a xtd_seq_num_t local (which represents the highest
1.203 + * known-to-be-good index) and a sequence number s (from a newly
1.204 + * arrived packet), sets the contents of *guess to contain the best
1.205 + * guess of the packet index to which s corresponds, and returns the
1.206 + * difference between *guess and *local
1.207 + */
1.208 +
1.209 +int
1.210 +index_guess(const xtd_seq_num_t *local,
1.211 + xtd_seq_num_t *guess,
1.212 + sequence_number_t s);
1.213 +
1.214 +
1.215 +#endif /* RDBX_H */
1.216 +
1.217 +
1.218 +
1.219 +
1.220 +
1.221 +
1.222 +
1.223 +
1.224 +
