Initial commit of djbdns-1.05.tar.gz

Source was http://cr.yp.to/djbdns/djbdns-1.05.tar.gz, SHA1 2efdb3a039d0c548f40936aa9cb30829e0ce8c3d

1 files changed, 63 insertions, 0 deletions

diff --git a/dns_random.c b/dns_random.c
new file mode 100644
index 0000000..2158ed4
--- /dev/null
+++ b/dns_random.c
@@ -0,0 +1,63 @@
+#include <unistd.h>
+#include "dns.h"
+#include "taia.h"
+#include "uint32.h"
+
+static uint32 seed[32];
+static uint32 in[12];
+static uint32 out[8];
+static int outleft = 0;
+
+#define ROTATE(x,b) (((x) << (b)) | ((x) >> (32 - (b))))
+#define MUSH(i,b) x = t[i] += (((x ^ seed[i]) + sum) ^ ROTATE(x,b));
+
+static void surf(void)
+{
+  uint32 t[12]; uint32 x; uint32 sum = 0;
+  int r; int i; int loop;
+
+  for (i = 0;i < 12;++i) t[i] = in[i] ^ seed[12 + i];
+  for (i = 0;i < 8;++i) out[i] = seed[24 + i];
+  x = t[11];
+  for (loop = 0;loop < 2;++loop) {
+    for (r = 0;r < 16;++r) {
+      sum += 0x9e3779b9;
+      MUSH(0,5) MUSH(1,7) MUSH(2,9) MUSH(3,13)
+      MUSH(4,5) MUSH(5,7) MUSH(6,9) MUSH(7,13)
+      MUSH(8,5) MUSH(9,7) MUSH(10,9) MUSH(11,13)
+    }
+    for (i = 0;i < 8;++i) out[i] ^= t[i + 4];
+  }
+}
+
+void dns_random_init(const char data[128])
+{
+  int i;
+  struct taia t;
+  char tpack[16];
+
+  for (i = 0;i < 32;++i)
+    uint32_unpack(data + 4 * i,seed + i);
+
+  taia_now(&t);
+  taia_pack(tpack,&t);
+  for (i = 0;i < 4;++i)
+    uint32_unpack(tpack + 4 * i,in + 4 + i);
+
+  in[8] = getpid();
+  in[9] = getppid();
+  /* more space in 10 and 11, but this is probably enough */
+}
+
+unsigned int dns_random(unsigned int n)
+{
+  if (!n) return 0;
+
+  if (!outleft) {
+    if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3];
+    surf();
+    outleft = 8;
+  }
+
+  return out[--outleft] % n;
+}