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https://github.com/brain-hackers/u-boot-brain
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![Joe Hershberger](/assets/img/avatar_default.png)
Make the MAC-seeded random number generator available to /net in general. MAC-seeded rand will be needed by link-local as well, so give it an interface. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com> Acked-by: Simon Glass <sjg@chromium.org>
69 lines
1.2 KiB
C
69 lines
1.2 KiB
C
/*
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* Based on LiMon - BOOTP.
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*
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* Copyright 1994, 1995, 2000 Neil Russell.
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* (See License)
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* Copyright 2000 Roland Borde
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* Copyright 2000 Paolo Scaffardi
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* Copyright 2000-2004 Wolfgang Denk, wd@denx.de
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*/
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#include <common.h>
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#include <net.h>
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#include "net_rand.h"
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static ulong seed1, seed2;
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void srand_mac(void)
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{
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ulong tst1, tst2, m_mask;
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ulong m_value = 0;
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int reg;
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unsigned char bi_enetaddr[6];
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/* get our mac */
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eth_getenv_enetaddr("ethaddr", bi_enetaddr);
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debug("BootpRequest => Our Mac: ");
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for (reg = 0; reg < 6; reg++)
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debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':');
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/* Mac-Manipulation 2 get seed1 */
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tst1 = 0;
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tst2 = 0;
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for (reg = 2; reg < 6; reg++) {
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tst1 = tst1 << 8;
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tst1 = tst1 | bi_enetaddr[reg];
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}
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for (reg = 0; reg < 2; reg++) {
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tst2 = tst2 | bi_enetaddr[reg];
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tst2 = tst2 << 8;
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}
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seed1 = tst1^tst2;
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/* Mirror seed1*/
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m_mask = 0x1;
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for (reg = 1; reg <= 32; reg++) {
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m_value |= (m_mask & seed1);
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seed1 = seed1 >> 1;
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m_value = m_value << 1;
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}
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seed1 = m_value;
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seed2 = 0xb78d0945;
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}
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unsigned long rand(void)
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{
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ulong sum;
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/* Random Number Generator */
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sum = seed1 + seed2;
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if (sum < seed1 || sum < seed2)
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sum++;
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seed2 = seed1;
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seed1 = sum;
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return sum;
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}
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