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authorJoe Hershberger <joe.hershberger@ni.com>2012-05-23 07:57:58 +0000
committerJoe Hershberger <joe.hershberger@ni.com>2012-05-23 14:19:22 -0500
commiteafc8db0e35275330f43a4cf7b7ae8aba71c9728 (patch)
tree0f76700afacfdeab0feafbd787e32d347083a0fd /net/net_rand.c
parent806150063a6b98d7e757bd9f640af1755bb387fd (diff)
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net: Move MAC-seeded rand out of bootp.c
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>
Diffstat (limited to 'net/net_rand.c')
-rw-r--r--net/net_rand.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/net/net_rand.c b/net/net_rand.c
new file mode 100644
index 0000000..5387aba
--- /dev/null
+++ b/net/net_rand.c
@@ -0,0 +1,68 @@
+/*
+ * Based on LiMon - BOOTP.
+ *
+ * Copyright 1994, 1995, 2000 Neil Russell.
+ * (See License)
+ * Copyright 2000 Roland Borde
+ * Copyright 2000 Paolo Scaffardi
+ * Copyright 2000-2004 Wolfgang Denk, wd@denx.de
+ */
+
+#include <common.h>
+#include <net.h>
+#include "net_rand.h"
+
+static ulong seed1, seed2;
+
+void srand_mac(void)
+{
+ ulong tst1, tst2, m_mask;
+ ulong m_value = 0;
+ int reg;
+ unsigned char bi_enetaddr[6];
+
+ /* get our mac */
+ eth_getenv_enetaddr("ethaddr", bi_enetaddr);
+
+ debug("BootpRequest => Our Mac: ");
+ for (reg = 0; reg < 6; reg++)
+ debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':');
+
+ /* Mac-Manipulation 2 get seed1 */
+ tst1 = 0;
+ tst2 = 0;
+ for (reg = 2; reg < 6; reg++) {
+ tst1 = tst1 << 8;
+ tst1 = tst1 | bi_enetaddr[reg];
+ }
+ for (reg = 0; reg < 2; reg++) {
+ tst2 = tst2 | bi_enetaddr[reg];
+ tst2 = tst2 << 8;
+ }
+
+ seed1 = tst1^tst2;
+
+ /* Mirror seed1*/
+ m_mask = 0x1;
+ for (reg = 1; reg <= 32; reg++) {
+ m_value |= (m_mask & seed1);
+ seed1 = seed1 >> 1;
+ m_value = m_value << 1;
+ }
+ seed1 = m_value;
+ seed2 = 0xb78d0945;
+}
+
+unsigned long rand(void)
+{
+ ulong sum;
+
+ /* Random Number Generator */
+ sum = seed1 + seed2;
+ if (sum < seed1 || sum < seed2)
+ sum++;
+ seed2 = seed1;
+ seed1 = sum;
+
+ return sum;
+}