Make the probe for RNG sources at runtime since the configure script isn't

compatible with cross-compiling.


git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@744 fefdeb5f-60dc-0310-8127-8f9354f1896f

configure.ac

@@ -396,26 +396,6 @@ AC_SUBST(LIRC_CFLAGS)
 AC_SUBST(LIRC_LIBS)
 AM_CONDITIONAL([HAVE_LIRC], [test "x$HAVE_LIRC" = x1])
 
-### /dev/random ###
-
-AC_MSG_CHECKING([whether a random device is available])
-
-rnd="no"
-
-if test -e /dev/urandom ; then
-   rnd=/dev/urandom
-else
-   if test -e /dev/random ; then
-      rnd=/dev/random
-   fi
-fi
-
-if test "x$rnd" != "no" ; then
-   AC_DEFINE_UNQUOTED([RANDOM_DEVICE], ["$rnd"], [Random device])
-fi
-
-AC_MSG_RESULT([$rnd])
-
 ###################################
 #            Output               #
 ###################################

src/daemon/main.c

@@ -63,6 +63,7 @@
 #include <polypcore/cli-text.h>
 #include <polypcore/pid.h>
 #include <polypcore/namereg.h>
+#include <polypcore/random.h>
 
 #include "cmdline.h"
 #include "cpulimit.h"
@@ -135,29 +136,6 @@ static void close_pipe(int p[2]) {
     p[0] = p[1] = -1;
 }
 
-static void set_random_seed(void) {
-    unsigned int seed = 0;
-    
-#ifdef RANDOM_DEVICE
-    int fd;
-    
-    if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
-        ssize_t r;
-
-        if ((r = pa_loop_read(fd, &seed, sizeof(seed))) < 0 || (size_t) r != sizeof(seed)) {
-            pa_log_error(__FILE__": failed to read entropy from '"RANDOM_DEVICE"'");
-            seed += (unsigned int) time(NULL);
-        }
-
-        close(fd);
-    }
-#else
-    seed = (unsigned int) time(NULL);
-#endif
-    
-    srand(seed);
-}
-
 int main(int argc, char *argv[]) {
     pa_core *c;
     pa_strbuf *buf = NULL;
@@ -203,7 +181,7 @@ int main(int argc, char *argv[]) {
     }
 #endif
 
-    set_random_seed();
+    pa_random_seed();
     
     pa_log_set_ident("polypaudio");
     

src/polypcore/random.c

@@ -36,31 +36,72 @@
 
 #include "random.h"
 
-void pa_random(void *ret_data, size_t length) {
+static int has_whined = 0;
-    int fd;
+
-    ssize_t r = 0;
+static const char *devices[] = { "/dev/urandom", "/dev/random", NULL };
+
+static int pa_random_proper(void *ret_data, size_t length) {
     assert(ret_data && length);
 
-#ifdef RANDOM_DEVICE
+#ifdef OS_IS_WIN32
-    if ((fd = open(RANDOM_DEVICE, O_RDONLY)) >= 0) {
+
+    return -1;
+
+#else /* OS_IS_WIN32 */
+
+    int fd, ret;
+    ssize_t r = 0;
+    const char **device;
+
+    device = devices;
+
+    while (*device) {
+        ret = 0;
+
+        if ((fd = open(*device, O_RDONLY)) >= 0) {
 
             if ((r = pa_loop_read(fd, ret_data, length)) < 0 || (size_t) r != length)
-            pa_log_error(__FILE__": failed to read entropy from '%s'", RANDOM_DEVICE);
+                ret = -1;
 
             close(fd);
-    }
+        } else
-#endif
+            ret = -1;
 
-    if ((size_t) r != length) {
+        if (ret == 0)
+            break;
+    }
+
+    return ret;
+#endif /* OS_IS_WIN32 */
+}
+
+void pa_random_seed() {
+    unsigned int seed;
+
+    if (pa_random_proper(&seed, sizeof(unsigned int)) < 0) {
+        if (!has_whined)
+            pa_log_warn(__FILE__": failed to get proper entropy. Falling back to seeding with current time.");
+        has_whined = 1;
+
+        seed = (unsigned int) time(NULL);
+    }
+
+    srand(seed);
+}
+
+void pa_random(void *ret_data, size_t length) {
     uint8_t *p;
     size_t l;
 
-#ifdef RANDOM_DEVICE        
+    assert(ret_data && length);
-        pa_log_warn(__FILE__": WARNING: Failed to open entropy device '"RANDOM_DEVICE"': %s"
+
-                    ", falling back to unsecure pseudo RNG.\n", strerror(errno));
+    if (pa_random_proper(ret_data, length) >= 0)
-#endif
+        return;
+
+    if (!has_whined)
+        pa_log_warn(__FILE__": failed to get proper entropy. Falling back to unsecure pseudo RNG.");
+    has_whined = 1;
 
     for (p = ret_data, l = length; l > 0; p++, l--)
         *p = (uint8_t) rand();
-    }
 }

src/polypcore/random.h

@@ -22,6 +22,7 @@
   USA.
 ***/
 
+void pa_random_seed();
 void pa_random(void *ret_data, size_t length);
     
 #endif