Mikio Hara
108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
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* Junior University
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*
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* We are making the OpenFlow specification and associated documentation
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* (Software) available for public use and benefit with the expectation
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* that others will use, modify and enhance the Software and contribute
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* those enhancements back to the community. However, since we would
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* like to make the Software available for broadest use, with as few
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* restrictions as possible permission is hereby granted, free of
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* charge, to any person obtaining a copy of this Software to deal in
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* the Software under the copyrights without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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* The name and trademarks of copyright holder(s) may NOT be used in
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* advertising or publicity pertaining to the Software or any
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* derivatives without specific, written prior permission.
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*/
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#include <config.h>
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#include "random.h"
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#include <errno.h>
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#include <stdlib.h>
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#include <sys/time.h>
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#include "util.h"
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void
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random_init(void)
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{
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static bool inited = false;
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if (!inited) {
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struct timeval tv;
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inited = true;
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if (gettimeofday(&tv, NULL) < 0) {
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ofp_fatal(errno, "gettimeofday");
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}
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srand(tv.tv_sec ^ tv.tv_usec);
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}
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}
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void
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random_bytes(void *p_, size_t n)
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{
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uint8_t *p = p_;
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random_init();
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while (n--) {
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*p++ = rand();
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}
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}
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uint8_t
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random_uint8(void)
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{
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random_init();
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return rand();
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}
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uint16_t
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random_uint16(void)
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{
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if (RAND_MAX >= UINT16_MAX) {
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random_init();
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return rand();
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} else {
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uint16_t x;
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random_bytes(&x, sizeof x);
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return x;
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}
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}
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uint32_t
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random_uint32(void)
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{
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if (RAND_MAX >= UINT32_MAX) {
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random_init();
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return rand();
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} else if (RAND_MAX == INT32_MAX) {
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random_init();
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return rand() | ((rand() & 1u) << 31);
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} else {
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uint32_t x;
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random_bytes(&x, sizeof x);
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return x;
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}
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}
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int
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random_range(int max)
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{
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return random_uint32() % max;
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}
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