src: support for stateful objects

This patch allows you to add, to delete and to get stateful objects,
this support two object types: counter and quota.

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

1 files changed, 123 insertions, 0 deletions

diff --git a/examples/nft-obj-add.c b/examples/nft-obj-add.c
new file mode 100644
index 0000000..83941c4
--- /dev/null
+++ b/examples/nft-obj-add.c
@@ -0,0 +1,123 @@
+/*
+ * (C) 2012-2016 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#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/object.h>
+
+static struct nftnl_obj *obj_add_parse(int argc, char *argv[])
+{
+	struct nftnl_obj *t;
+	uint16_t family;
+
+	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");
+		return NULL;
+	}
+
+	t = nftnl_obj_alloc();
+	if (t == NULL) {
+		perror("OOM");
+		return NULL;
+	}
+
+	nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family);
+	nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_COUNTER);
+	nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
+	nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
+
+	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, obj_seq, family;
+	struct nftnl_obj *t;
+	struct mnl_nlmsg_batch *batch;
+	int ret;
+
+	if (argc != 4) {
+		fprintf(stderr, "%s <family> <table> <name>\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	t = obj_add_parse(argc, argv);
+	if (t == NULL)
+		exit(EXIT_FAILURE);
+
+	seq = time(NULL);
+	batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
+
+	nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
+	mnl_nlmsg_batch_next(batch);
+
+	obj_seq = seq;
+	family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY);
+	nlh = nftnl_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
+				    NFT_MSG_NEWOBJ, family, NLM_F_ACK, seq++);
+	nftnl_obj_nlmsg_build_payload(nlh, t);
+	nftnl_obj_free(t);
+	mnl_nlmsg_batch_next(batch);
+
+	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, obj_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;
+}