[src/trunk]: src/sys/dev don't allow /dev/random to be opened (return ENXIO) ...

[explorer <explorer%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/93d056ffe357
branches:  trunk
changeset: 468007:93d056ffe357
user:      explorer <explorer%NetBSD.org@localhost>
date:      Thu Apr 01 19:07:40 1999 +0000

description:
don't allow /dev/random to be opened (return ENXIO) until there is at least
one active entropy source

diffstat:

 sys/dev/rnd.c |  34 ++++++++++++++++++++++++++--------
 1 files changed, 26 insertions(+), 8 deletions(-)

diffs (76 lines):

diff -r 8475e59b956e -r 93d056ffe357 sys/dev/rnd.c
--- a/sys/dev/rnd.c     Thu Apr 01 18:44:37 1999 +0000
+++ b/sys/dev/rnd.c     Thu Apr 01 19:07:40 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rnd.c,v 1.14 1999/02/28 19:01:30 explorer Exp $        */
+/*     $NetBSD: rnd.c,v 1.15 1999/04/01 19:07:40 explorer Exp $        */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -149,6 +149,11 @@
 static inline u_int32_t rnd_timestamp(void);
 static               void      rnd_timeout(void *);
 
+static int             rnd_ready = 0;
+static int             rnd_have_entropy = 0;
+
+LIST_HEAD(, __rndsource_element)       rnd_sources;
+
 /*
  * Generate a 32-bit timestamp.  This should be more machine dependant,
  * using cycle counters and the like when possible.
@@ -184,6 +189,11 @@
                        wakeup(&rnd_selq);
                }
                selwakeup(&rnd_selq);
+
+               /*
+                * Allow open of /dev/random now, too.
+                */
+               rnd_have_entropy = 1;
        }
 }
 
@@ -238,10 +248,6 @@
        return 1;
 }
 
-static int             rnd_ready;
-
-LIST_HEAD(, __rndsource_element)       rnd_sources;
-
 /*
  * attach the random device, and initialize the global random pool
  * for our use.
@@ -286,8 +292,20 @@
        if (rnd_ready == 0)
                return (ENXIO);
 
-       if (minor(dev) == RND_DEV_RANDOM || minor(dev) == RND_DEV_URANDOM)
-               return 0;
+       if (minor(dev) == RND_DEV_URANDOM)
+               return (0);
+
+       /*
+        * If this is the strong random device and we have never collected
+        * entropy (or have not yet) don't allow it to be opened.  This will
+        * prevent waiting forever for something that just will not appear.
+        */
+       if (minor(dev) == RND_DEV_RANDOM) {
+               if (rnd_have_entropy == 0)
+                       return (ENXIO);
+               else
+                       return (0);
+       }
 
        return (ENXIO);
 }
@@ -666,7 +684,7 @@
 }
 
 /*
- * don't want on allocation.  to be used in an interrupt context.
+ * don't wait on allocation.  to be used in an interrupt context.
  */
 static rnd_sample_t *
 rnd_sample_allocate_isr(rndsource_t *source)