[src/trunk]: src/sys/net/npf npf_addr_mix: use xor rather than sum.

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/65d430a13988
branches:  trunk
changeset: 791517:65d430a13988
user:      rmind <rmind%NetBSD.org@localhost>
date:      Fri Nov 22 01:24:21 2013 +0000

description:
npf_addr_mix: use xor rather than sum.

diffstat:

 sys/net/npf/npf_impl.h    |   4 ++--
 sys/net/npf/npf_inet.c    |  15 +++++++--------
 sys/net/npf/npf_session.c |   6 +++---
 3 files changed, 12 insertions(+), 13 deletions(-)

diffs (89 lines):

diff -r 2a93c168f1d6 -r 65d430a13988 sys/net/npf/npf_impl.h
--- a/sys/net/npf/npf_impl.h    Fri Nov 22 01:09:11 2013 +0000
+++ b/sys/net/npf/npf_impl.h    Fri Nov 22 01:24:21 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: npf_impl.h,v 1.41 2013/11/22 00:25:51 rmind Exp $      */
+/*     $NetBSD: npf_impl.h,v 1.42 2013/11/22 01:24:21 rmind Exp $      */
 
 /*-
  * Copyright (c) 2009-2013 The NetBSD Foundation, Inc.
@@ -193,7 +193,7 @@
 uint16_t       npf_fixup32_cksum(uint16_t, uint32_t, uint32_t);
 uint16_t       npf_addr_cksum(uint16_t, int, const npf_addr_t *,
                    const npf_addr_t *);
-uint32_t       npf_addr_sum(const int, const npf_addr_t *, const npf_addr_t *);
+uint32_t       npf_addr_mix(const int, const npf_addr_t *, const npf_addr_t *);
 int            npf_addr_cmp(const npf_addr_t *, const npf_netmask_t,
                    const npf_addr_t *, const npf_netmask_t, const int);
 void           npf_addr_mask(const npf_addr_t *, const npf_netmask_t,
diff -r 2a93c168f1d6 -r 65d430a13988 sys/net/npf/npf_inet.c
--- a/sys/net/npf/npf_inet.c    Fri Nov 22 01:09:11 2013 +0000
+++ b/sys/net/npf/npf_inet.c    Fri Nov 22 01:24:21 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: npf_inet.c,v 1.25 2013/10/30 08:41:38 mrg Exp $        */
+/*     $NetBSD: npf_inet.c,v 1.26 2013/11/22 01:24:21 rmind Exp $      */
 
 /*-
  * Copyright (c) 2009-2012 The NetBSD Foundation, Inc.
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: npf_inet.c,v 1.25 2013/10/30 08:41:38 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: npf_inet.c,v 1.26 2013/11/22 01:24:21 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -109,20 +109,19 @@
 }
 
 /*
- * npf_addr_sum: provide IP address as a summed (if needed) 32-bit integer.
+ * npf_addr_sum: provide IP addresses as a XORed 32-bit integer.
  * Note: used for hash function.
  */
 uint32_t
-npf_addr_sum(const int sz, const npf_addr_t *a1, const npf_addr_t *a2)
+npf_addr_mix(const int sz, const npf_addr_t *a1, const npf_addr_t *a2)
 {
        uint32_t mix = 0;
-       int i;
 
        KASSERT(sz > 0 && a1 != NULL && a2 != NULL);
 
-       for (i = 0; i < (sz >> 2); i++) {
-               mix += a1->s6_addr32[i];
-               mix += a2->s6_addr32[i];
+       for (int i = 0; i < (sz >> 2); i++) {
+               mix ^= a1->s6_addr32[i];
+               mix ^= a2->s6_addr32[i];
        }
        return mix;
 }
diff -r 2a93c168f1d6 -r 65d430a13988 sys/net/npf/npf_session.c
--- a/sys/net/npf/npf_session.c Fri Nov 22 01:09:11 2013 +0000
+++ b/sys/net/npf/npf_session.c Fri Nov 22 01:24:21 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: npf_session.c,v 1.27 2013/11/08 00:38:26 rmind Exp $   */
+/*     $NetBSD: npf_session.c,v 1.28 2013/11/22 01:24:21 rmind Exp $   */
 
 /*-
  * Copyright (c) 2010-2013 The NetBSD Foundation, Inc.
@@ -92,7 +92,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: npf_session.c,v 1.27 2013/11/08 00:38:26 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: npf_session.c,v 1.28 2013/11/22 01:24:21 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -314,7 +314,7 @@
 
        mix[0] = (scid->proto ^ scid->ifid) << 16;
        mix[0] |= sen->se_src_id ^ sen->se_dst_id;
-       mix[1] = npf_addr_sum(sz, &sen->se_src_addr, &sen->se_dst_addr);
+       mix[1] = npf_addr_mix(sz, &sen->se_src_addr, &sen->se_dst_addr);
        hash = murmurhash2(mix, sizeof(mix), sess_hash_seed);
 
        return &stbl[hash & SESS_HASH_MASK];