nl-monitor.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/link.h>
#include <netlink/cli/mdb.h>
 
#include <linux/rtnetlink.h>
 
static const struct {
        enum rtnetlink_groups gr_id;
        const char* gr_name;
} known_groups[] = {
        { RTNLGRP_LINK, "link" },
        { RTNLGRP_NOTIFY, "notify" },
        { RTNLGRP_NEIGH, "neigh" },
        { RTNLGRP_TC, "tc" },
        { RTNLGRP_IPV4_IFADDR, "ipv4-ifaddr" },
        { RTNLGRP_IPV4_MROUTE, "ipv4-mroute" },
        { RTNLGRP_IPV4_ROUTE, "ipv4-route" },
        { RTNLGRP_IPV6_IFADDR, "ipv6-ifaddr" },
        { RTNLGRP_IPV6_MROUTE, "ipv6-mroute" },
        { RTNLGRP_IPV6_ROUTE, "ipv6-route" },
        { RTNLGRP_IPV6_IFINFO, "ipv6-ifinfo" },
        { RTNLGRP_DECnet_IFADDR, "decnet-ifaddr" },
        { RTNLGRP_DECnet_ROUTE, "decnet-route" },
        { RTNLGRP_IPV6_PREFIX, "ipv6-prefix" },
        { RTNLGRP_IPV4_NETCONF, "ipv4-netconf" },
        { RTNLGRP_IPV6_NETCONF, "ipv6-netconf" },
        { RTNLGRP_MPLS_NETCONF, "mpls-netconf" },
        { RTNLGRP_MDB, "mdb" },
        { RTNLGRP_NONE, NULL }
};
 
static void obj_input(struct nl_object *obj, void *arg)
{
        nl_object_dump(obj, arg);
}
 
static int event_input(struct nl_msg *msg, void *arg)
{
        if (nl_msg_parse(msg, &obj_input, arg) < 0)
                fprintf(stderr, "<<EVENT>> Unknown message type\n");
 
        /* Exit nl_recvmsgs_def() and return to the main select() */
        return NL_STOP;
}
 
static void print_usage(void)
{
        int i;
 
        printf(
        "Usage: nl-monitor [OPTION] [<groups>]\n"
        "\n"
        "Options\n"
        " -d, --debug=LEVEL     Set libnl debug level { 0 - 7 }\n"
        " -f, --format=TYPE     Output format { brief | details | stats }\n"
        " -h, --help            Show this help.\n"
        "\n"
        );
        printf("Known groups:");
        for (i = 0; known_groups[i].gr_id != RTNLGRP_NONE; i++)
                printf(" %s", known_groups[i].gr_name);
        printf("\n");
        exit(0);
}
 
int main(int argc, char *argv[])
{
        struct nl_dump_params dp = {
                .dp_type = NL_DUMP_STATS,
                .dp_fd = stdout,
                .dp_dump_msgtype = 1,
        };
 
        struct nl_sock *sock;
        int err = 1;
        int i, idx;
 
        sock = nl_cli_alloc_socket();
        nl_socket_disable_seq_check(sock);
        nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, &dp);
 
        for (;;) {
                int c, optidx = 0;
                static struct option long_opts[] = {
                        { "debug",  1, 0, 'd' },
                        { "format", 1, 0, 'f' },
                        { "help",   0, 0, 'h' },
                        { 0, 0, 0, 0 }
                };
 
                c = getopt_long(argc, argv, "d:f:h", long_opts, &optidx);
                if (c == -1)
                        break;
 
                switch (c) {
                case 'd':
                        nl_debug = atoi(optarg);
                        break;
                case 'f':
                        dp.dp_type = nl_cli_parse_dumptype(optarg);
                        break;
                default:
                        print_usage();
                        break;
                }
        }
 
        nl_cli_connect(sock, NETLINK_ROUTE);
 
        for (idx = optind; argc > idx; idx++) {
                for (i = 0; known_groups[i].gr_id != RTNLGRP_NONE; i++) {
                        if (!strcmp(argv[idx], known_groups[i].gr_name)) {
 
                                if ((err = nl_socket_add_membership(sock, known_groups[i].gr_id)) < 0) {
                                        nl_cli_fatal(err, "%s: %s\n", argv[idx],
                                                     nl_geterror(err));
                                }
 
                                break;
                        }
                }
                if (known_groups[i].gr_id == RTNLGRP_NONE)
                        fprintf(stderr, "Warning: Unknown group: %s\n", argv[idx]);
        }
 
        nl_cli_link_alloc_cache(sock);
 
        while (1) {
                fd_set rfds;
                int fd, retval;
 
                fd = nl_socket_get_fd(sock);
 
                FD_ZERO(&rfds);
                FD_SET(fd, &rfds);
                /* wait for an incoming message on the netlink socket */
                retval = select(fd+1, &rfds, NULL, NULL, NULL);
 
                if (retval) {
                        /* FD_ISSET(fd, &rfds) will be true */
                        nl_recvmsgs_default(sock);
                }
        }
 
        return 0;
}