From 7335fb0d5c8025c9f46f978085cfdabc7da0da99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Thu, 22 Oct 2020 16:48:05 +0200
Subject: [PATCH] in6.h: declare in6_addr with a union and extra fields

According to https://tools.ietf.org/html/rfc3493:
3.2 IPv6 Address Structure
"The structure in6_addr above is usually implemented with an embedded
union with extra fields that force the desired alignment level in a
manner similar to BSD implementations of "struct in_addr"."

Change-Id: Ibe0ee685366398c143cdf9573dcb77566a12888b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3348
Reviewed-by: Rene Gollent <rene@gollent.com>
---
 headers/posix/netinet6/in6.h | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/headers/posix/netinet6/in6.h b/headers/posix/netinet6/in6.h
index 8f897c8373..e3af7fa3a3 100644
--- a/headers/posix/netinet6/in6.h
+++ b/headers/posix/netinet6/in6.h
@@ -11,8 +11,17 @@
 
 
 struct in6_addr {
-	uint8_t		s6_addr[16];
-};
+	union {
+		uint8_t		u6_addr8[16];
+		uint16_t	u6_addr16[8];
+		uint32_t	u6_addr32[4];
+	} in6_u;
+	#define s6_addr		in6_u.u6_addr8
+	#define s6_addr16	in6_u.u6_addr16
+	#define s6_addr32	in6_u.u6_addr32
+} _PACKED;
+
+
 
 /* IP Version 6 socket address. */
 struct sockaddr_in6 {
@@ -25,21 +34,21 @@ struct sockaddr_in6 {
 };
 
 
-#define IN6ADDR_ANY_INIT {{ \
+#define IN6ADDR_ANY_INIT {{{ \
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }}
-#define IN6ADDR_LOOPBACK_INIT {{ \
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }}}
+#define IN6ADDR_LOOPBACK_INIT {{{ \
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}
-#define IN6ADDR_NODELOCAL_ALLNODES_INIT {{ \
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}}
+#define IN6ADDR_NODELOCAL_ALLNODES_INIT {{{ \
 	0xff, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}
-#define IN6ADDR_LINKLOCAL_ALLNODES_INIT {{ \
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}}
+#define IN6ADDR_LINKLOCAL_ALLNODES_INIT {{{ \
 	0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}
-#define IN6ADDR_LINKLOCAL_ALLROUTERS_INIT {{ \
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 }}}
+#define IN6ADDR_LINKLOCAL_ALLROUTERS_INIT {{{ \
 	0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 }}
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 }}}
 
 extern const struct in6_addr in6addr_any;
 extern const struct in6_addr in6addr_loopback;