rng-tools: modify 'read error' message

Make the 'read error' message more descriptive.

Copied from https://bugzilla.redhat.com/attachment.cgi?id=1295857
and modified in one place to apply successfully.  Error message during
bootstrap modified to show device name.

Upstream-Status: pending

Signed-off-by: Joe Slater <joe.slater@windriver.com>


--- a/rngd.c
+++ b/rngd.c
@@ -247,8 +247,11 @@ static void do_loop(int random_step)
 				continue;	/* failed, no work */
 
 			retval = iter->xread(buf, sizeof buf, iter);
-			if (retval)
+			if (retval) {
+				message(LOG_DAEMON|LOG_ERR,
+					"Error reading from entropy source\n");
 				continue;	/* failed, no work */
+			}
 
 			work_done = true;
 
--- a/rngd_entsource.c
+++ b/rngd_entsource.c
@@ -63,10 +63,8 @@ int xread(void *buf, size_t size, struct
 		size -= r;
 	}
 
-	if (size) {
-		message(LOG_DAEMON|LOG_ERR, "read error\n");
+	if (size)
 		return -1;
-	}
 	return 0;
 }
 
@@ -152,7 +150,7 @@ error_out:
 }
 
 /* Initialize entropy source */
-static int discard_initial_data(struct rng *ent_src)
+static int discard_initial_data(struct rng *ent_src, int *buf)
 {
 	/* Trash 32 bits of what is probably stale (non-random)
 	 * initial state from the RNG.  For Intel's, 8 bits would
@@ -164,10 +162,12 @@ static int discard_initial_data(struct r
 	xread(tempbuf, sizeof(tempbuf), ent_src);
 
 	/* Return 32 bits of bootstrap data */
-	xread(tempbuf, sizeof(tempbuf), ent_src);
+	if (xread(tempbuf, sizeof(tempbuf), ent_src) != 0)
+		return -1;
 
-	return tempbuf[0] | (tempbuf[1] << 8) |
+	*buf = tempbuf[0] | (tempbuf[1] << 8) |
 		(tempbuf[2] << 16) | (tempbuf[3] << 24);
+	return 0;
 }
 
 /*
@@ -175,6 +175,8 @@ static int discard_initial_data(struct r
  */
 int init_entropy_source(struct rng *ent_src)
 {
+	int bootstrap;
+
 	ent_src->rng_fd = open(ent_src->rng_name, O_RDONLY);
 	if (ent_src->rng_fd == -1) {
 		return 1;
@@ -182,7 +184,11 @@ int init_entropy_source(struct rng *ent_
 	src_list_add(ent_src);
 	/* Bootstrap FIPS tests */
 	ent_src->fipsctx = malloc(sizeof(fips_ctx_t));
-	fips_init(ent_src->fipsctx, discard_initial_data(ent_src));
+	if (discard_initial_data(ent_src, &bootstrap) != 0) {
+		message(LOG_ERR|LOG_INFO, "Read failure in %s during bootstrap\n",ent_src->rng_name);
+		return 1;
+	}
+	fips_init(ent_src->fipsctx, bootstrap);
 	return 0;
 }
 
--- a/rngtest.c
+++ b/rngtest.c
@@ -335,6 +335,7 @@ static int discard_initial_data(void)
 
 	return tempbuf[0] | (tempbuf[1] << 8) |
 		(tempbuf[2] << 16) | (tempbuf[3] << 24);
+
 }
 
 static void do_rng_fips_test_loop( void )