nl-route-get.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2009 Thomas Graf <tgraf@suug.ch>
 */
 
#include <netlink/cli/utils.h>
#include <netlink/cli/route.h>
#include <netlink/cli/link.h>
 
#include <linux/rtnetlink.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;
}