From: Andreas Schneider <asn@samba.org>
Date: Thu, 14 Jul 2022 05:56:39 +0000 (+0200)
Subject: lib:util: Add generate_random_u64_range()
X-Git-Tag: samba-4.17.0rc1~201
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cc1cac9423384bad26e3d17f9409a41321fd2714;p=thirdparty%2Fsamba.git

lib:util: Add generate_random_u64_range()

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
---

diff --git a/lib/util/genrand_util.c b/lib/util/genrand_util.c
index fdc2654a204..82103f59bd7 100644
--- a/lib/util/genrand_util.c
+++ b/lib/util/genrand_util.c
@@ -50,6 +50,20 @@ _PUBLIC_ uint64_t generate_random_u64(void)
 	return BVAL(v, 0);
 }
 
+/**
+ * @brief Generate a random number in the given range.
+ *
+ * @param lower    The lower value of the range
+
+ * @param upper    The upper value of the range
+ *
+ * @return A random number bigger than than lower and smaller than upper.
+ */
+_PUBLIC_ uint64_t generate_random_u64_range(uint64_t lower, uint64_t upper)
+{
+	return generate_random_u64() % (upper - lower) + lower;
+}
+
 _PUBLIC_ uint64_t generate_unique_u64(uint64_t veto_value)
 {
 	static struct generate_unique_u64_state {
diff --git a/lib/util/samba_util.h b/lib/util/samba_util.h
index b30435b4362..4762a7c523f 100644
--- a/lib/util/samba_util.h
+++ b/lib/util/samba_util.h
@@ -99,6 +99,8 @@ _PUBLIC_ uint32_t generate_random(void);
 **/
 _PUBLIC_ uint64_t generate_random_u64(void);
 
+_PUBLIC_ uint64_t generate_random_u64_range(uint64_t lower, uint64_t upper);
+
 /**
  * @brief Generate random nonces usable for re-use detection.
  *