[libnetfilter_conntrack PATCH] conntrack: introduce clear and equal functions for bitmask object

[Ken-ichirou MATSUZAWA <chamaken@gmail.com>]

 This patch adds two functions, useful for ulogd IPFIX
output module.

---
 .../libnetfilter_conntrack.h                       |  2 ++
 src/conntrack/api.c                                | 31 ++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/libnetfilter_conntrack/libnetfilter_conntrack.h b/include/libnetfilter_conntrack/libnetfilter_conntrack.h
index d4542ba..a5e6a91 100644
--- a/include/libnetfilter_conntrack/libnetfilter_conntrack.h
+++ b/include/libnetfilter_conntrack/libnetfilter_conntrack.h
@@ -286,6 +286,8 @@ void nfct_bitmask_set_bit(struct nfct_bitmask *, unsigned int bit);
 int nfct_bitmask_test_bit(const struct nfct_bitmask *, unsigned int bit);
 void nfct_bitmask_unset_bit(struct nfct_bitmask *, unsigned int bit);
 void nfct_bitmask_destroy(struct nfct_bitmask *);
+void nfct_bitmask_clear(struct nfct_bitmask *);
+int nfct_bitmask_equal(const struct nfct_bitmask *, const struct nfct_bitmask *);
 
 /* connlabel name <-> bit translation mapping */
 struct nfct_labelmap;
diff --git a/src/conntrack/api.c b/src/conntrack/api.c
index 224be86..fc4c58f 100644
--- a/src/conntrack/api.c
+++ b/src/conntrack/api.c
@@ -1704,6 +1704,37 @@ void nfct_bitmask_destroy(struct nfct_bitmask *b)
 	free(b);
 }
 
+/*
+ * nfct_bitmask_clear - clear a bitmask object
+ *
+ * \param b pointer to the bitmask object to clear
+ */
+void nfct_bitmask_clear(struct nfct_bitmask *b)
+{
+	unsigned int bytes = b->words * sizeof(b->bits[0]);
+	memset(b->bits, 0, bytes);
+}
+
+/*
+ * nfct_bitmask_equal - compare two bitmask objects
+ *
+ * \param b1 pointer to a valid bitmask object
+ * \param b2 pointer to a valid bitmask object
+ *
+ * If both bitmask object are equal, this function returns 1, otherwise
+ * -1 or 0 is returned.
+ */
+int nfct_bitmask_equal(const struct nfct_bitmask *b1, const struct nfct_bitmask *b2)
+{
+	if (b1->words != b2->words)
+		return -1;
+
+	if (!memcmp(b1->bits, b2->bits, b1->words * sizeof(b1->bits[0])))
+		return 1;
+	else
+		return 0;
+}
+
 /**
  * @}
  */
-- 
1.8.5.3