Feature: Consider machine-id, and boot-id for PRNG

configure.ac

@@ -102,6 +102,27 @@ CFLAGS="${CFLAGS} ${PTHREAD_CFLAGS}"
 CPPFLAGS="${CPPFLAGS} ${PTHREAD_CPPFLAGS}"
 LIBS="${LIBS} ${PTHREAD_LIBS}"
 
+
+AC_DEFUN([IC_CHECK_PATH], [
+	  AC_ARG_WITH([$1],
+		      AS_HELP_STRING([--with-$1=PATH], [Sets the path to the $1 file]),
+		      [],
+		      [AS_IF([test "$build" = "$host"],
+			     [AC_CHECK_FILE([$4],
+					    [with_$2="$4"],
+					    [])],
+					    [])])
+	  AS_IF([test "$with_$2" != "no"],
+		[
+		 AS_IF([test "$with_$2" = "yes"], [AC_MSG_ERROR([You need to supply a path as value for --with-$1])])
+		 AC_DEFINE_UNQUOTED([PATH_$3], ["$with_$2"], [Define to $1 path])
+		 ])
+])
+
+IC_CHECK_PATH([machine-id], [machine_id], [MACHINE_ID], [/etc/machine-id])
+IC_CHECK_PATH([boot-id], [boot_id], [BOOT_ID], [/proc/sys/kernel/random/boot_id])
+
+
 AC_DEFINE(igloo_INTERNAL,1,[Set to signal that we are building libigloo in contrast to linking against libigloo.])
 
 AC_REQUIRE_AUX_FILE([tap-driver.sh])

src/prng.c

@@ -195,6 +195,18 @@ static igloo_error_t get_inited_state(igloo_prng_state_t **state, size_t *instan
         self->bits = 5;
 
         self->state |= STATE_INITED;
+
+#if defined(PATH_BOOT_ID) || defined(PATH_MACHINE_ID)
+        // this is safe as we are inited now. In worst case we read initial seeds twice.
+        pthread_mutex_unlock(&(self->lock));
+#ifdef PATH_BOOT_ID
+        igloo_prng_read_file(instance, PATH_BOOT_ID, -1, -1, igloo_PRNG_FLAG_NONE);
+#endif
+#ifdef PATH_MACHINE_ID
+        igloo_prng_read_file(instance, PATH_MACHINE_ID, -1, 0, igloo_PRNG_FLAG_NONE);
+#endif
+        pthread_mutex_lock(&(self->lock));
+#endif
     }
 
     return igloo_ERROR_NONE;