From bec199c4a2ca7e9e998438a21ffdd56c59171baa Mon Sep 17 00:00:00 2001
From: Sylvain Rochet <gradator@gradator.net>
Date: Sat, 28 Feb 2015 19:36:03 +0100
Subject: [PATCH] PPP, MAGIC: new function: magic_pow

magic_pow() returns a new random number between 0 and (2^pow)-1 included.
---
 src/include/netif/ppp/magic.h | 5 +++++
 src/netif/ppp/magic.c         | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/src/include/netif/ppp/magic.h b/src/include/netif/ppp/magic.h
index 4661dea5..1c9b96d0 100644
--- a/src/include/netif/ppp/magic.h
+++ b/src/include/netif/ppp/magic.h
@@ -100,6 +100,11 @@ void magic_randomize(void);
  */
 u32_t magic(void);	/* Returns the next magic number */
 
+/*
+ * Return a new random number between 0 and (2^pow)-1 included.
+ */
+u32_t magic_pow(u8_t pow);
+
 #if PPP_MD5_RANDM
 /*
  * Fill buffer with random bytes
diff --git a/src/netif/ppp/magic.c b/src/netif/ppp/magic.c
index a6a55490..de9a700f 100644
--- a/src/netif/ppp/magic.c
+++ b/src/netif/ppp/magic.c
@@ -264,4 +264,11 @@ u32_t magic() {
 
 #endif /* PPP_MD5_RANDM */
 
+/*
+ * Return a new random number between 0 and (2^pow)-1 included.
+ */
+u32_t magic_pow(u8_t pow) {
+  return magic() & ~(~0UL<<pow);
+}
+
 #endif /* PPP_SUPPORT */