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authorFlorian Westphal <fw@strlen.de>2012-11-13 12:21:08 +0100
committerFlorian Westphal <fw@strlen.de>2013-05-06 20:57:52 +0200
commit013a5284c901a6ce80320f499685b89d15eeed9e (patch)
tree003a0a7606823ecd6f2a97d782aca5263a2005a1 /src
parent706064d8b9423df0d22e9ebba092ec2fb14b38aa (diff)
api: add nfct_bitmask object
In order to use generic getter/setter API with upcoming conntrack label extension, add helper functions to set/test/unset bits in a vector of arbitrary size. Conntrack labels will then be encoded via nfct_bitmask object. Original idea from Pablo Neira Ayuso. Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'src')
-rw-r--r--src/conntrack/api.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/src/conntrack/api.c b/src/conntrack/api.c
index 0bc2091..7b79e05 100644
--- a/src/conntrack/api.c
+++ b/src/conntrack/api.c
@@ -1483,3 +1483,122 @@ void nfct_filter_dump_set_attr_u8(struct nfct_filter_dump *filter_dump,
/**
* @}
*/
+
+/**
+ * \defgroup bitmask bitmask object
+ *
+ * @{
+ */
+
+/**
+ * nfct_bitmask_new - allocate a new bitmask
+ *
+ * \param max highest valid bit that can be set/unset.
+ *
+ * In case of success, this function returns a valid pointer to a memory blob,
+ * otherwise NULL is returned and errno is set appropiately.
+ */
+struct nfct_bitmask *nfct_bitmask_new(unsigned int max)
+{
+ struct nfct_bitmask *b;
+ unsigned int bytes, words;
+
+ if (max > 0xffff)
+ return NULL;
+
+ words = DIV_ROUND_UP(max+1, 32);
+ bytes = words * sizeof(b->bits[0]);
+
+ b = malloc(sizeof(*b) + bytes);
+ if (b) {
+ memset(b->bits, 0, bytes);
+ b->words = words;
+ }
+ return b;
+}
+
+/*
+ * nfct_bitmask_clone - duplicate a bitmask object
+ *
+ * \param b pointer to the bitmask object to duplicate
+ *
+ * returns an identical copy of the bitmask.
+ */
+struct nfct_bitmask *nfct_bitmask_clone(const struct nfct_bitmask *b)
+{
+ unsigned int bytes = b->words * sizeof(b->bits[0]);
+ struct nfct_bitmask *copy;
+
+ bytes += sizeof(*b);
+
+ copy = malloc(bytes);
+ if (copy)
+ memcpy(copy, b, bytes);
+ return copy;
+}
+
+/*
+ * nfct_bitmask_set_bit - set bit in the bitmask
+ *
+ * \param b pointer to the bitmask object
+ * \param bit the bit to set
+ */
+void nfct_bitmask_set_bit(struct nfct_bitmask *b, unsigned int bit)
+{
+ unsigned int bits = b->words * 32;
+ if (bit < bits)
+ set_bit(bit, b->bits);
+}
+
+/*
+ * nfct_bitmask_test_bit - test if a bit in the bitmask is set
+ *
+ * \param b pointer to the bitmask object
+ * \param bit the bit to test
+ *
+ * returns 0 if the bit is not set.
+ */
+int nfct_bitmask_test_bit(const struct nfct_bitmask *b, unsigned int bit)
+{
+ unsigned int bits = b->words * 32;
+ return bit < bits && test_bit(bit, b->bits);
+}
+
+/*
+ * nfct_bitmask_unset_bit - unset bit in the bitmask
+ *
+ * \param b pointer to the bitmask object
+ * \param bit the bit to clear
+ */
+void nfct_bitmask_unset_bit(struct nfct_bitmask *b, unsigned int bit)
+{
+ unsigned int bits = b->words * 32;
+ if (bit < bits)
+ unset_bit(bit, b->bits);
+}
+
+/*
+ * nfct_bitmask_maxbit - return highest bit that may be set/unset
+ *
+ * \param b pointer to the bitmask object
+ */
+unsigned int nfct_bitmask_maxbit(const struct nfct_bitmask *b)
+{
+ return (b->words * 32) - 1;
+}
+
+/*
+ * nfct_bitmask_destroy - destroy bitmask object
+ *
+ * \param b pointer to the bitmask object
+ *
+ * This function releases the memory that is used by the bitmask object.
+ */
+void nfct_bitmask_destroy(struct nfct_bitmask *b)
+{
+ free(b);
+}
+
+/**
+ * @}
+ */