xref: /aosp_15_r20/external/libnl/src/nl-route-get.c (revision 4dc78e53d49367fa8e61b07018507c90983a077d)

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2009 Thomas Graf <[email protected]>
 */

#include "nl-default.h"

#include <linux/rtnetlink.h>

#include <netlink/cli/utils.h>
#include <netlink/cli/route.h>
#include <netlink/cli/link.h>

static void print_usage(void)
{
	printf("Usage: nl-route-get <addr>\n");
	exit(1);
}

static void parse_cb(struct nl_object *obj, void *arg)
{
	//struct rtnl_route *route = (struct rtnl_route *) obj;
	struct nl_dump_params params = {
		.dp_fd = stdout,
		.dp_type = NL_DUMP_DETAILS,
	};

	nl_object_dump(obj, &params);
}

static int cb(struct nl_msg *msg, void *arg)
{
	int err;

	if ((err = nl_msg_parse(msg, &parse_cb, NULL)) < 0)
		nl_cli_fatal(err, "Unable to parse object: %s", nl_geterror(err));

	return 0;
}

int main(int argc, char *argv[])
{
	struct nl_sock *sock;
	struct nl_addr *dst;
	int err = 1;

	if (argc < 2 || !strcmp(argv[1], "-h"))
		print_usage();

	sock = nl_cli_alloc_socket();
	nl_cli_connect(sock, NETLINK_ROUTE);
	nl_cli_link_alloc_cache(sock);
	nl_cli_route_alloc_cache(sock, 0);

	dst = nl_cli_addr_parse(argv[1], AF_INET);

	{
		struct nl_msg *m;
		struct rtmsg rmsg = {
			.rtm_family = nl_addr_get_family(dst),
			.rtm_dst_len = nl_addr_get_prefixlen(dst),
		};

		m = nlmsg_alloc_simple(RTM_GETROUTE, 0);
		if (!m)
			nl_cli_fatal(ENOMEM, "out of memory");
		if (nlmsg_append(m, &rmsg, sizeof(rmsg), NLMSG_ALIGNTO) < 0)
			nl_cli_fatal(ENOMEM, "out of memory");
		if (nla_put_addr(m, RTA_DST, dst) < 0)
			nl_cli_fatal(ENOMEM, "out of memory");

		err = nl_send_auto_complete(sock, m);
		nlmsg_free(m);
		if (err < 0)
			nl_cli_fatal(err, "%s", nl_geterror(err));

		nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, cb, NULL);

		if (nl_recvmsgs_default(sock) < 0)
			nl_cli_fatal(err, "%s", nl_geterror(err));
	}

	return 0;
}