From b0ad27f3ad975ae35dc2cae76271f62079087c12 Mon Sep 17 00:00:00 2001
From: Justin Pettit <jpettit@ovn.org>
Date: Wed, 22 Jun 2016 18:17:07 -0700
Subject: [PATCH] packets: Introduce xor and is_zero functions on IPv6
 addresses.

These will have callers later.

This also rewrites ipv6_addr_bitand() to use newly defined macros.

Co-authored-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Justin Pettit <jpettit@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>
---
 lib/packets.c | 46 +++++++++++++++++++++++++++++++++-------------
 lib/packets.h |  3 +++
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/lib/packets.c b/lib/packets.c
index a27264c93..b9c179e2e 100644
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -674,23 +674,43 @@ ipv6_string_mapped(char *addr_str, const struct in6_addr *addr)
     }
 }
 
-struct in6_addr ipv6_addr_bitand(const struct in6_addr *a,
-                                 const struct in6_addr *b)
-{
-    int i;
-    struct in6_addr dst;
-
 #ifdef s6_addr32
-    for (i=0; i<4; i++) {
-        dst.s6_addr32[i] = a->s6_addr32[i] & b->s6_addr32[i];
-    }
+#define s6_addrX s6_addr32
+#define IPV6_FOR_EACH(VAR) for (int VAR = 0; VAR < 4; VAR++)
 #else
-    for (i=0; i<16; i++) {
-        dst.s6_addr[i] = a->s6_addr[i] & b->s6_addr[i];
-    }
+#define s6_addrX s6_addr
+#define IPV6_FOR_EACH(VAR) for (int VAR = 0; VAR < 16; VAR++)
 #endif
 
-    return dst;
+struct in6_addr
+ipv6_addr_bitand(const struct in6_addr *a, const struct in6_addr *b)
+{
+   struct in6_addr dst;
+   IPV6_FOR_EACH (i) {
+       dst.s6_addrX[i] = a->s6_addrX[i] & b->s6_addrX[i];
+   }
+   return dst;
+}
+
+struct in6_addr
+ipv6_addr_bitxor(const struct in6_addr *a, const struct in6_addr *b)
+{
+   struct in6_addr dst;
+   IPV6_FOR_EACH (i) {
+       dst.s6_addrX[i] = a->s6_addrX[i] ^ b->s6_addrX[i];
+   }
+   return dst;
+}
+
+bool
+ipv6_is_zero(const struct in6_addr *a)
+{
+   IPV6_FOR_EACH (i) {
+       if (a->s6_addrX[i]) {
+           return false;
+       }
+   }
+   return true;
 }
 
 /* Returns an in6_addr consisting of 'mask' high-order 1-bits and 128-N
diff --git a/lib/packets.h b/lib/packets.h
index 077ccfafa..819366eb4 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -1027,6 +1027,9 @@ void ipv6_format_masked(const struct in6_addr *addr,
 const char * ipv6_string_mapped(char *addr_str, const struct in6_addr *addr);
 struct in6_addr ipv6_addr_bitand(const struct in6_addr *src,
                                  const struct in6_addr *mask);
+struct in6_addr ipv6_addr_bitxor(const struct in6_addr *a,
+                                 const struct in6_addr *b);
+bool ipv6_is_zero(const struct in6_addr *a);
 struct in6_addr ipv6_create_mask(int mask);
 int ipv6_count_cidr_bits(const struct in6_addr *netmask);
 bool ipv6_is_cidr(const struct in6_addr *netmask);
-- 
2.20.1