1 files changed, 123 insertions, 0 deletions
diff --git a/misc/unix/randbyte_os2.inc b/misc/unix/randbyte_os2.inc
new file mode 100644
index 0000000..4020e31
--- /dev/null
+++ b/misc/unix/randbyte_os2.inc
@@ -0,0 +1,123 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* The high resolution timer API provides access to the hardware timer 
+ * running at around 1.1MHz. The amount this changes in a time slice is
+ * varies randomly due to system events, hardware interrupts etc
+ */
+static UCHAR randbyte_hrtimer()
+{
+    QWORD t1, t2;
+    UCHAR byte;
+
+    DosTmrQueryTime(&t1);
+    DosSleep(5);
+    DosTmrQueryTime(&t2);
+
+    byte = (t2.ulLo - t1.ulLo) & 0xFF;
+    byte ^= (t2.ulLo - t1.ulLo) >> 8;
+    return byte;
+}
+
+
+
+/* A bunch of system information like memory & process stats.
+ * Not highly random but every bit helps....
+ */
+static UCHAR randbyte_sysinfo()
+{
+    UCHAR byte = 0;
+    UCHAR SysVars[100];
+    int b;
+
+    DosQuerySysInfo(1, QSV_FOREGROUND_PROCESS, SysVars, sizeof(SysVars));
+
+    for (b = 0; b < 100; b++) {
+        byte ^= SysVars[b];
+    }
+
+    return byte;
+}
+
+
+
+/* Similar in concept to randbyte_hrtimer() but accesses the CPU's internal
+ * counters which run at the CPU's MHz speed. We get separate 
+ * idle / busy / interrupt cycle counts which should provide very good 
+ * randomness due to interference of hardware events.
+ * This only works on newer CPUs (at least PPro or K6) and newer OS/2 versions
+ * which is why it's run-time linked.
+ */
+
+static APIRET APIENTRY(*DosPerfSysCall) (ULONG ulCommand, ULONG ulParm1,
+                                         ULONG ulParm2, ULONG ulParm3) = NULL;
+static HMODULE hDoscalls = 0;
+#define   CMD_KI_RDCNT    (0x63)
+
+typedef struct _CPUUTIL {
+    ULONG ulTimeLow;            /* Low 32 bits of time stamp      */
+    ULONG ulTimeHigh;           /* High 32 bits of time stamp     */
+    ULONG ulIdleLow;            /* Low 32 bits of idle time       */
+    ULONG ulIdleHigh;           /* High 32 bits of idle time      */
+    ULONG ulBusyLow;            /* Low 32 bits of busy time       */
+    ULONG ulBusyHigh;           /* High 32 bits of busy time      */
+    ULONG ulIntrLow;            /* Low 32 bits of interrupt time  */
+    ULONG ulIntrHigh;           /* High 32 bits of interrupt time */
+} CPUUTIL;
+
+
+static UCHAR randbyte_perf()
+{
+    UCHAR byte = 0;
+    CPUUTIL util;
+    int c;
+
+    if (hDoscalls == 0) {
+        char failed_module[20];
+        ULONG rc;
+
+        rc = DosLoadModule(failed_module, sizeof(failed_module), "DOSCALLS",
+                           &hDoscalls);
+
+        if (rc == 0) {
+            rc = DosQueryProcAddr(hDoscalls, 976, NULL, (PFN *)&DosPerfSysCall);
+
+            if (rc) {
+                DosPerfSysCall = NULL;
+            }
+        }
+    }
+
+    if (DosPerfSysCall) {
+        if (DosPerfSysCall(CMD_KI_RDCNT, (ULONG)&util, 0, 0) == 0) {
+            for (c = 0; c < sizeof(util); c++) {
+                byte ^= ((UCHAR *)&util)[c];
+            }
+        }
+        else {
+            DosPerfSysCall = NULL;
+        }
+    }
+
+    return byte;
+}
+
+
+
+static UCHAR randbyte()
+{
+    return randbyte_hrtimer() ^ randbyte_sysinfo() ^ randbyte_perf();
+}