net: Use NDRNG device in srand_mac()
When calling srand_mac we use a weak seed dependent on the
mac address. If present, use a RNG device instead to incerase entropy.
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Torsten Duwe <duwe@suse.de>
diff --git a/net/net_rand.h b/net/net_rand.h
index 4bf9bd8..6a52cda 100644
--- a/net/net_rand.h
+++ b/net/net_rand.h
@@ -10,6 +10,8 @@
#define __NET_RAND_H__
#include <common.h>
+#include <dm/uclass.h>
+#include <rng.h>
/*
* Return a seed for the PRNG derived from the eth0 MAC address.
@@ -37,7 +39,22 @@
*/
static inline void srand_mac(void)
{
- srand(seed_mac());
+ int ret;
+ struct udevice *devp;
+ u32 randv = 0;
+
+ if (IS_ENABLED(CONFIG_DM_RNG)) {
+ ret = uclass_get_device(UCLASS_RNG, 0, &devp);
+ if (ret) {
+ ret = dm_rng_read(devp, &randv, sizeof(randv));
+ if (ret < 0)
+ randv = 0;
+ }
+ }
+ if (randv)
+ srand(randv);
+ else
+ srand(seed_mac());
}
#endif /* __NET_RAND_H__ */