From 0c9a2ac1f8a2e55b3382dfc27256878a58ea49e9 Mon Sep 17 00:00:00 2001
From: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org>
Date: Sun, 7 Mar 2010 00:14:44 +0000
Subject: ipv6: Optmize translation between IPV6_PREFER_SRC_xxx and
 RT6_LOOKUP_F_xxx.

IPV6_PREFER_SRC_xxx definitions:
| #define IPV6_PREFER_SRC_TMP             0x0001
| #define IPV6_PREFER_SRC_PUBLIC          0x0002
| #define IPV6_PREFER_SRC_COA             0x0004

RT6_LOOKUP_F_xxx definitions:
| #define RT6_LOOKUP_F_SRCPREF_TMP        0x00000008
| #define RT6_LOOKUP_F_SRCPREF_PUBLIC     0x00000010
| #define RT6_LOOKUP_F_SRCPREF_COA        0x00000020

So, we can translate between these two groups by shift operation
instead of multiple 'if's.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/ip6_route.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'include')

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 4a808de7c0f6..68f67836e146 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -37,6 +37,24 @@ struct route_info {
 #define RT6_LOOKUP_F_SRCPREF_PUBLIC	0x00000010
 #define RT6_LOOKUP_F_SRCPREF_COA	0x00000020
 
+/*
+ * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
+ * between IPV6_ADDR_PREFERENCES socket option values
+ *	IPV6_PREFER_SRC_TMP    = 0x1
+ *	IPV6_PREFER_SRC_PUBLIC = 0x2
+ *	IPV6_PREFER_SRC_COA    = 0x4
+ * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
+ */
+static inline int rt6_srcprefs2flags(unsigned int srcprefs)
+{
+	/* No need to bitmask because srcprefs have only 3 bits. */
+	return srcprefs << 3;
+}
+
+static inline unsigned int rt6_flags2srcprefs(int flags)
+{
+	return (flags >> 3) & 7;
+}
 
 extern void			ip6_route_input(struct sk_buff *skb);
 
-- 
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