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/*
 * (C) 2012 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.
 *
 * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
 */

#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <netinet/in.h>

#include <linux/netfilter/nf_tables.h>

#include <libmnl/libmnl.h>
#include <libnftables/table.h>

static int table_cb(const struct nlmsghdr *nlh, void *data)
{
	struct nft_table *t;
	char buf[4096];
	uint32_t *type = data;

	t = nft_table_alloc();
	if (t == NULL) {
		perror("OOM");
		goto err;
	}

	if (nft_table_nlmsg_parse(nlh, t) < 0) {
		perror("nft_table_nlmsg_parse");
		goto err_free;
	}

	nft_table_snprintf(buf, sizeof(buf), t, *type, 0);
	printf("%s\n", buf);

err_free:
	nft_table_free(t);
err:
	return MNL_CB_OK;
}

int main(int argc, char *argv[])
{
	struct mnl_socket *nl;
	char buf[MNL_SOCKET_BUFFER_SIZE];
	struct nlmsghdr *nlh;
	uint32_t portid, seq;
	struct nft_table *t = NULL;
	int ret;
	uint32_t type = NFT_TABLE_O_DEFAULT;

	if (strcmp(argv[argc-1], "xml") == 0) {
		type = NFT_TABLE_O_XML;
		argv[argc-1] = NULL;
		argc--;
	}else if (strcmp(argv[argc-1], "json") == 0) {
		type = NFT_TABLE_O_JSON;
		argv[argc-1] = NULL;
		argc--;
	} else if (strcmp(argv[argc - 1], "default") == 0) {
		argc--;
	}

	if (argc == 2) {
		t = nft_table_alloc();
		if (t == NULL) {
			perror("OOM");
			exit(EXIT_FAILURE);
		}
	}

	seq = time(NULL);
	if (t == NULL) {
		nlh = nft_table_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, AF_INET,
						NLM_F_DUMP, seq);
	} else {
		nlh = nft_table_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, AF_INET,
						NLM_F_ACK, seq);
		nft_table_attr_set(t, NFT_TABLE_ATTR_NAME, argv[1]);
		nft_table_nlmsg_build_payload(nlh, t);
		nft_table_free(t);
	}

	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, nlh, nlh->nlmsg_len) < 0) {
		perror("mnl_socket_send");
		exit(EXIT_FAILURE);
	}

	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
	while (ret > 0) {
		ret = mnl_cb_run(buf, ret, seq, portid, table_cb, &type);
		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;
}