File introduce-once-2.patch of Package haveged.37149

Index: haveged-1.9.14/src/haveged.c
===================================================================
--- haveged-1.9.14.orig/src/haveged.c
+++ haveged-1.9.14/src/haveged.c
@@ -635,6 +635,33 @@ static void run_daemon(    /* RETURN: no
       if (params->exit_code > 128)
          error_exit("Stopping due to signal %d\n", params->exit_code - 128);
 
+      if (params->once == 1) {
+        if (ioctl(random_fd, RNDGETENTCNT, &current) == -1) {
+          error_exit("Couldn't query entropy-level from kernel");
+        }
+
+        /* get number of bytes needed to fill pool */
+        nbytes = (poolSize - current) / 8;
+        if (nbytes < 1) {
+            params->exit_code = 0;
+            error_exit("Entropy could not be refilled, couldn't discover number of bytes needed to fill the pool.\n");
+        }
+
+        /* get that many random bytes */
+        r = (nbytes + sizeof(H_UINT) - 1) / sizeof(H_UINT);
+        if (havege_rng(h, (H_UINT *)output->buf, r) < 1)
+          error_exit("RNG failed! %d", h->error);
+        output->buf_size = nbytes;
+        /* entropy is 8 bits per byte */
+        output->entropy_count = nbytes * 8;
+        if (ioctl(random_fd, RNDADDENTROPY, output) == -1) {
+          error_exit("RNDADDENTROPY failed!");
+        }
+
+        params->exit_code = 0;
+        error_exit("Entropy refilled once (%d bytes), exiting.\n", nbytes);
+      }
+
       FD_ZERO(&write_fd);
 #ifndef NO_COMMAND_MODE
       if (socket_fd >= 0) {