1/*
2 * src/nf-monitor.c     Monitor netfilter events
3 *
4 *	This library is free software; you can redistribute it and/or
5 *	modify it under the terms of the GNU Lesser General Public
6 *	License as published by the Free Software Foundation version 2.1
7 *	of the License.
8 *
9 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
10 * Copyright (c) 2007 Philip Craig <philipc@snapgear.com>
11 * Copyright (c) 2007 Secure Computing Corporation
12 */
13
14#include <netlink/cli/utils.h>
15#include <netlink/netfilter/nfnl.h>
16
17static void obj_input(struct nl_object *obj, void *arg)
18{
19	struct nl_dump_params dp = {
20		.dp_type = NL_DUMP_STATS,
21		.dp_fd = stdout,
22		.dp_dump_msgtype = 1,
23	};
24
25	nl_object_dump(obj, &dp);
26}
27
28static int event_input(struct nl_msg *msg, void *arg)
29{
30	if (nl_msg_parse(msg, &obj_input, NULL) < 0)
31		fprintf(stderr, "<<EVENT>> Unknown message type\n");
32
33	/* Exit nl_recvmsgs_def() and return to the main select() */
34	return NL_STOP;
35}
36
37int main(int argc, char *argv[])
38{
39	struct nl_sock *sock;
40	int err;
41	int i, idx;
42
43	static const struct {
44		enum nfnetlink_groups gr_id;
45		const char* gr_name;
46	} groups[] = {
47		{ NFNLGRP_CONNTRACK_NEW, "ct-new" },
48		{ NFNLGRP_CONNTRACK_UPDATE, "ct-update" },
49		{ NFNLGRP_CONNTRACK_DESTROY, "ct-destroy" },
50		{ NFNLGRP_NONE, NULL }
51	};
52
53	sock = nl_cli_alloc_socket();
54	nl_socket_disable_seq_check(sock);
55	nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL);
56
57	if (argc > 1 && !strcasecmp(argv[1], "-h")) {
58		printf("Usage: nf-monitor [<groups>]\n");
59
60		printf("Known groups:");
61		for (i = 0; groups[i].gr_id != NFNLGRP_NONE; i++)
62			printf(" %s", groups[i].gr_name);
63		printf("\n");
64		return 2;
65	}
66
67	nl_cli_connect(sock, NETLINK_NETFILTER);
68
69	for (idx = 1; argc > idx; idx++) {
70		for (i = 0; groups[i].gr_id != NFNLGRP_NONE; i++) {
71			if (strcmp(argv[idx], groups[i].gr_name))
72				continue;
73
74			err = nl_socket_add_membership(sock, groups[i].gr_id);
75			if (err < 0)
76				nl_cli_fatal(err,
77					     "Unable to add membership: %s",
78					     nl_geterror(err));
79			break;
80		}
81
82		if (groups[i].gr_id == NFNLGRP_NONE)
83			nl_cli_fatal(NLE_OBJ_NOTFOUND, "Unknown group: \"%s\"",
84				     argv[idx]);
85	}
86
87	while (1) {
88		fd_set rfds;
89		int fd, retval;
90
91		fd = nl_socket_get_fd(sock);
92
93		FD_ZERO(&rfds);
94		FD_SET(fd, &rfds);
95		/* wait for an incoming message on the netlink socket */
96		retval = select(fd+1, &rfds, NULL, NULL, NULL);
97
98		if (retval) {
99			/* FD_ISSET(fd, &rfds) will be true */
100			nl_recvmsgs_default(sock);
101		}
102	}
103
104	return 0;
105}
106