Hi, On Wed, Aug 10, 2011 at 12:55:08PM +0000, Heiko Hund wrote: > The s6_addr32 member of struct in6_addr is not available when building > for WIN32. To work around this, a local union is defined that allows > accessing 32 bit chunks of the IPv6 address passed to add_in6_addr().
NAK, that's massively ugly.
I've changed the code to do 8-bit rounds. While somewhat slower, the
code is actually more readable that way, and since this is only called
once per connecting client, the few microseconds are well-spent.
My patch attached again. David?
gert
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From 1e3c114d655f65dfc3528b1d8884a026ba8bad6b Mon Sep 17 00:00:00 2001
From: Gert Doering <g...@greenie.muc.de>
List-Post: openvpn-devel@lists.sourceforge.net
Date: Sat, 28 May 2011 22:50:40 +0200
Subject: [PATCH] Replace 32-bit-based add_in6_addr() implementation by an 8-bit
based one
- windows has no 32-bit accessor to the union inside "struct in6_addr",
and the 8-bit accessor is the only common denominator across BSD, Solaris,
Linux and Windows...
Signed-off-by: Gert Doering <g...@greenie.muc.de>
---
socket.c | 34 ++++++++++++++++------------------
1 files changed, 16 insertions(+), 18 deletions(-)
diff --git a/socket.c b/socket.c
index 6b855c0..7903c26 100644
--- a/socket.c
+++ b/socket.c
@@ -2619,32 +2619,30 @@ print_in6_addr (struct in6_addr a6, unsigned int flags,
struct gc_arena *gc)
return BSTR (&out);
}
+#ifndef UINT8_MAX
+# define UINT8_MAX 0xff
+#endif
+
/* add some offset to an ipv6 address
- * (add in steps of 32 bits, taking overflow into next round)
+ * (add in steps of 8 bits, taking overflow into next round)
*/
-#ifndef s6_addr32
-# ifdef TARGET_SOLARIS
-# define s6_addr32 _S6_un._S6_u32
-# else
-# define s6_addr32 __u6_addr.__u6_addr32
-# endif
-#endif
-#ifndef UINT32_MAX
-# define UINT32_MAX (4294967295U)
-#endif
struct in6_addr add_in6_addr( struct in6_addr base, uint32_t add )
{
int i;
- uint32_t h;
- for( i=3; i>=0 && add > 0 ; i-- )
+ for( i=15; i>=0 && add > 0 ; i-- )
{
- h = ntohl( base.s6_addr32[i] );
- base.s6_addr32[i] = htonl( (h+add) & UINT32_MAX );
- /* 32-bit overrun?
- * caveat: can't do "h+add > UINT32_MAX" with 32bit math!
+ register int carry;
+ register uint32_t h;
+
+ h = (unsigned char) base.s6_addr[i];
+ base.s6_addr[i] = (h+add) & UINT8_MAX;
+
+ /* using explicit carry for the 8-bit additions will catch
+ * 8-bit and(!) 32-bit overruns nicely
*/
- add = ( h > UINT32_MAX - add )? 1: 0;
+ carry = ((h & 0xff) + (add & 0xff)) >> 8;
+ add = (add>>8) + carry;
}
return base;
}
--
1.7.3.4
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