From 74f1926a81b80ce8719c92b688737c51ece2cb4b Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Tue, 18 Oct 2016 10:50:42 -0400

Subject: [PATCH] If device is not found, exit immediately

This avoids stupid warnings in the logs:

rng[961]: read error

rng[961]: read error

...

https://bugzilla.redhat.com/show_bug.cgi?id=892178

---

 rngd.c           |  4 +---

 rngd_entsource.c | 38 +++++++++++++++++++++++++++-----------

 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/rngd.c b/rngd.c

index cd5bc8a40b..7755651f1c 100644

--- a/rngd.c

+++ b/rngd.c

@@ -315,9 +315,7 @@ int main(int argc, char **argv)

 	if (rc_rng && rc_drng && rc_tpm) {

 		if (!arguments->quiet) {

 			message(LOG_DAEMON|LOG_ERR,

-				"can't open any entropy source");

-			message(LOG_DAEMON|LOG_ERR,

-				"Maybe RNG device modules are not loaded\n");

+				"No entropy sources found, exiting");

 		}

 		return 66;

 	}

diff --git a/rngd_entsource.c b/rngd_entsource.c

index f0e219d7af..468ad1cfc6 100644

--- a/rngd_entsource.c

+++ b/rngd_entsource.c

@@ -63,8 +63,13 @@ int xread(void *buf, size_t size, struct rng *ent_src)

 		size -= r;

 	}

+	if (errno == ENODEV) {

+		message(LOG_DAEMON|LOG_ERR, "%s: %m", ent_src->rng_name);

+		return -ENODEV;

+	}

+

 	if (size) {

-		message(LOG_DAEMON|LOG_ERR, "read error\n");

+		message(LOG_DAEMON|LOG_ERR, "%s: %m", ent_src->rng_name);

 		return -1;

 	}

 	return 0;

@@ -89,14 +94,14 @@ int xread_tpm(void *buf, size_t size, struct rng *ent_src)

 	ent_src->rng_fd = open(ent_src->rng_name, O_RDWR);

 	if (ent_src->rng_fd == -1) {

-		message(LOG_ERR|LOG_INFO,"Unable to open file: %s",ent_src->rng_name);

+		message(LOG_ERR|LOG_INFO,"%s: %m",ent_src->rng_name);

 		return -1;

 	}

 	temp_buf = (unsigned char *) malloc(size + TPM_GET_RNG_OVERHEAD);

 	memset(temp_buf, 0, (size+TPM_GET_RNG_OVERHEAD));

 	if (temp_buf == NULL) {

-		message(LOG_ERR|LOG_INFO,"No memory");

+		message(LOG_ERR|LOG_INFO,"%m");

 		close(ent_src->rng_fd);

 		return -1;

 	}

@@ -114,7 +119,7 @@ int xread_tpm(void *buf, size_t size, struct rng *ent_src)

 				       sizeof(rng_cmd) - r);

 			if (retval < 0) {

 				message(LOG_ERR|LOG_INFO,

-					"Error writing %s\n",

+					"Error writing %s",

 					ent_src->rng_name);

 				retval = -1;

 				goto error_out;

@@ -123,7 +128,7 @@ int xread_tpm(void *buf, size_t size, struct rng *ent_src)

 		}

 		if (r < sizeof(rng_cmd)) {

 			message(LOG_ERR|LOG_INFO,

-				"Error writing %s\n", ent_src->rng_name);

+				"Error writing %s", ent_src->rng_name);

 			retval = -1;

 			goto error_out;

 		}

@@ -152,22 +157,27 @@ error_out:

 }

 /* Initialize entropy source */

-static int discard_initial_data(struct rng *ent_src)

+static int discard_initial_data(struct rng *ent_src, int *data)

 {

 	/* Trash 32 bits of what is probably stale (non-random)

-	 * initial state from the RNG.  For Intel's, 8 bits would

+	 * initial state from the RNG.	For Intel's, 8 bits would

 	 * be enough, but since AMD's generates 32 bits at a time...

 	 *

 	 * The kernel drivers should be doing this at device powerup,

 	 * but at least up to 2.4.24, it doesn't. */

 	unsigned char tempbuf[4];

-	xread(tempbuf, sizeof(tempbuf), ent_src);

+	int r;

+

+	r = xread(tempbuf, sizeof(tempbuf), ent_src);

+	if (r < 0)

+		return r;

 	/* Return 32 bits of bootstrap data */

 	xread(tempbuf, sizeof(tempbuf), ent_src);

-	return tempbuf[0] | (tempbuf[1] << 8) |

+	*data = tempbuf[0] | (tempbuf[1] << 8) |

 		(tempbuf[2] << 16) | (tempbuf[3] << 24);

+	return 0;

 }

 /*

@@ -175,14 +185,20 @@ static int discard_initial_data(struct rng *ent_src)

  */

 int init_entropy_source(struct rng *ent_src)

 {

+	int data;

+

 	ent_src->rng_fd = open(ent_src->rng_name, O_RDONLY);

 	if (ent_src->rng_fd == -1) {

 		return 1;

 	}

+	if (discard_initial_data(ent_src, &data)) {

+		return 1;

+	}

+

 	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));

+	fips_init(ent_src->fipsctx, data);

 	return 0;

 }

@@ -193,7 +209,7 @@ int init_tpm_entropy_source(struct rng *ent_src)

 {

 	ent_src->rng_fd = open(ent_src->rng_name, O_RDWR);

 	if (ent_src->rng_fd == -1) {

-		message(LOG_ERR|LOG_INFO,"Unable to open file: %s",ent_src->rng_name);

+		message(LOG_ERR|LOG_INFO,"%s: %m",ent_src->rng_name);

 		return 1;

 	}

 	src_list_add(ent_src);

-- 

2.9.0