api: add connlabel api and attribute

adds new labelmap api to create a name <-> bit mapping
from a text file (default: /etc/xtables/connlabel.conf).

nfct_labelmap_new(filename) is used to create the map,
nfct_labelmap_destroy() releases the resources allocated for the map.

Two functions are added to make map lookups:

nfct_labelmap_get_name(map, bit) returns the name of a bit,
nfct_labelmap_get_bit returns the bit associated with a name.

The connlabel attribute is represented by a nfct_bitmask object, the
nfct_bitmask api can be used to test/set/get individual bits
("labels").

The exisiting nfct_attr_get/set interfaces can be used to read or
replace the existing labels associated with a conntrack with a new set.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 70 insertions, 0 deletions

diff --git a/qa/test_connlabel.c b/qa/test_connlabel.c
new file mode 100644
index 0000000..27cbca2
--- /dev/null
+++ b/qa/test_connlabel.c
@@ -0,0 +1,70 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <libmnl/libmnl.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+
+static void print_label(struct nfct_labelmap *map)
+{
+	int b = nfct_labelmap_get_bit(map, "test label 1");
+	assert(b == 1);
+
+	b = nfct_labelmap_get_bit(map, "zero");
+	assert(b == 0);
+
+	b = nfct_labelmap_get_bit(map, "test label 2");
+	assert(b == 2);
+
+	b = nfct_labelmap_get_bit(map, "duplicate");
+	assert(b < 0);
+
+	b = nfct_labelmap_get_bit(map, "invalid label");
+	assert(b < 0);
+
+	b = nfct_labelmap_get_bit(map, "T");
+	assert(b == 42);
+}
+
+static void print_bits(struct nfct_labelmap *map)
+{
+	unsigned int i = 0;
+
+	for (;;) {
+		const char *name = nfct_labelmap_get_name(map, i);
+		if (!name)
+			break;
+		if (name[0])
+			printf("%s, %d\n", name, i);
+		i++;
+	}
+}
+
+int main(void)
+{
+	struct nfct_labelmap *l;
+
+	l = nfct_labelmap_new("/");
+	assert(l == NULL);
+
+	l = nfct_labelmap_new(NULL);
+	if (l) {
+		print_bits(l);
+		print_label(l);
+		nfct_labelmap_destroy(l);
+	} else {
+		puts("no default config found");
+	}
+
+	l = nfct_labelmap_new("qa-connlabel.conf");
+	if (!l)
+		l = nfct_labelmap_new("qa/qa-connlabel.conf");
+	assert(l);
+	print_bits(l);
+	print_label(l);
+	nfct_labelmap_destroy(l);
+
+
+	return 0;
+}