3 files changed, 7 insertions, 0 deletions
diff --git a/lib/ip.h b/lib/ip.h
index 87cd3aa..5bf56fc 100644
--- a/lib/ip.h
+++ b/lib/ip.h
@@ -15,6 +15,8 @@
 #include "ipv6.h"
 #endif
 
+#define ipa_in_net(x,n,p) (!ipa_nonzero(ipa_and(ipa_xor((n),(x)),ipa_mkmask(p))))
+
 /*
  *	ip_classify() returns either a negative number for invalid addresses
  *	or scope OR'ed together with address type.
diff --git a/lib/ipv4.h b/lib/ipv4.h
index add406b..af2194c 100644
--- a/lib/ipv4.h
+++ b/lib/ipv4.h
@@ -44,6 +44,7 @@ typedef u32 ip_addr;
 #define ipa_nonzero(x) _I(x)
 #define ipa_and(x,y) _MI(_I(x) & _I(y))
 #define ipa_or(x,y) _MI(_I(x) | _I(y))
+#define ipa_xor(x,y) _MI(_I(x) ^ _I(y))
 #define ipa_not(x) _MI(~_I(x))
 #define ipa_mkmask(x) _MI(u32_mkmask(x))
 #define ipa_mklen(x) u32_masklen(_I(x))
diff --git a/lib/ipv6.h b/lib/ipv6.h
index 08ed5f8..3f775d4 100644
--- a/lib/ipv6.h
+++ b/lib/ipv6.h
@@ -36,6 +36,10 @@ typedef struct ipv4_addr {
 			_I1(a) | _I1(b), \
 			_I2(a) | _I2(b), \
 			_I3(a) | _I3(b))
+#define ipa_xor(a,b) _MI(_I0(a) ^ _I0(b), \
+			 _I1(a) ^ _I1(b), \
+			 _I2(a) ^ _I2(b), \
+			 _I3(a) ^ _I3(b))
 #define ipa_not(a) _MI(~_I0(a),~_I1(a),~_I2(a),~_I3(a))
 #define ipa_mkmask(x) ipv6_mkmask(x)
 #define ipa_mklen(x) ipv6_mklen(&(x))