src: add flowtable support

This patch allows you to add, delete and list flowtable through the
existing netlink interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/examples/nft-flowtable-add.c b/examples/nft-flowtable-add.c
new file mode 100644
index 0000000..bd6cd0f
--- /dev/null
+++ b/examples/nft-flowtable-add.c
@@ -0,0 +1,136 @@
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <netinet/in.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include <libmnl/libmnl.h>
+#include <libnftnl/flowtable.h>
+
+static struct nftnl_flowtable *flowtable_add_parse(int argc, char *argv[])
+{
+	const char *dev_array[] = { "eth0", "tap0", NULL };
+	struct nftnl_flowtable *t;
+	int hooknum = 0;
+
+	if (strcmp(argv[4], "ingress") == 0)
+		hooknum = NF_NETDEV_INGRESS;
+	else {
+		fprintf(stderr, "Unknown hook: %s\n", argv[4]);
+		return NULL;
+	}
+
+	t = nftnl_flowtable_alloc();
+	if (t == NULL) {
+		perror("OOM");
+		return NULL;
+	}
+	nftnl_flowtable_set(t, NFTNL_FLOWTABLE_TABLE, argv[2]);
+	nftnl_flowtable_set(t, NFTNL_FLOWTABLE_NAME, argv[3]);
+	if (argc == 6) {
+		nftnl_flowtable_set_u32(t, NFTNL_FLOWTABLE_HOOKNUM, hooknum);
+		nftnl_flowtable_set_u32(t, NFTNL_FLOWTABLE_PRIO, atoi(argv[5]));
+	}
+	nftnl_flowtable_set_array(t, NFTNL_FLOWTABLE_DEVICES, dev_array);
+
+	return t;
+}
+
+int main(int argc, char *argv[])
+{
+	struct mnl_socket *nl;
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	uint32_t portid, seq, flowtable_seq;
+	int ret, family;
+	struct nftnl_flowtable *t;
+	struct mnl_nlmsg_batch *batch;
+	int batching;
+
+	if (argc != 6) {
+		fprintf(stderr, "Usage: %s <family> <table> <name> <hook> <prio>\n",
+			argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	if (strcmp(argv[1], "ip") == 0)
+		family = NFPROTO_IPV4;
+	else if (strcmp(argv[1], "ip6") == 0)
+		family = NFPROTO_IPV6;
+	else if (strcmp(argv[1], "bridge") == 0)
+		family = NFPROTO_BRIDGE;
+	else if (strcmp(argv[1], "arp") == 0)
+		family = NFPROTO_ARP;
+	else {
+		fprintf(stderr, "Unknown family: ip, ip6, bridge, arp\n");
+		exit(EXIT_FAILURE);
+	}
+
+	t = flowtable_add_parse(argc, argv);
+	if (t == NULL)
+		exit(EXIT_FAILURE);
+
+	batching = nftnl_batch_is_supported();
+	if (batching < 0) {
+		perror("cannot talk to nfnetlink");
+		exit(EXIT_FAILURE);
+	}
+
+	seq = time(NULL);
+	batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
+
+	if (batching) {
+		nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
+		mnl_nlmsg_batch_next(batch);
+	}
+
+	flowtable_seq = seq;
+	nlh = nftnl_flowtable_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
+					NFT_MSG_NEWFLOWTABLE, family,
+					NLM_F_CREATE|NLM_F_ACK, seq++);
+	nftnl_flowtable_nlmsg_build_payload(nlh, t);
+	nftnl_flowtable_free(t);
+	mnl_nlmsg_batch_next(batch);
+
+	if (batching) {
+		nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
+		mnl_nlmsg_batch_next(batch);
+	}
+
+	nl = mnl_socket_open(NETLINK_NETFILTER);
+	if (nl == NULL) {
+		perror("mnl_socket_open");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		perror("mnl_socket_bind");
+		exit(EXIT_FAILURE);
+	}
+	portid = mnl_socket_get_portid(nl);
+
+	if (mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
+			      mnl_nlmsg_batch_size(batch)) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	mnl_nlmsg_batch_stop(batch);
+
+	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	while (ret > 0) {
+		ret = mnl_cb_run(buf, ret, flowtable_seq, portid, NULL, NULL);
+		if (ret <= 0)
+			break;
+		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	}
+	if (ret == -1) {
+		perror("error");
+		exit(EXIT_FAILURE);
+	}
+	mnl_socket_close(nl);
+
+	return EXIT_SUCCESS;
+}