1/*
2 * src/nf-queue.c     Monitor netfilter queue 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) 2007, 2008 Patrick McHardy <kaber@trash.net>
10 * Copyright (c) 2010  Karl Hiramoto <karl@hiramoto.org>
11 */
12
13
14#include <netlink/cli/utils.h>
15#include <netlink/cli/link.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nfnetlink_queue.h>
18#include <netlink/netfilter/nfnl.h>
19#include <netlink/netfilter/queue.h>
20#include <netlink/netfilter/queue_msg.h>
21
22static struct nl_sock *nf_sock;
23
24static struct nfnl_queue *alloc_queue(void)
25{
26	struct nfnl_queue *queue;
27
28	queue = nfnl_queue_alloc();
29	if (!queue)
30		nl_cli_fatal(ENOMEM, "Unable to allocate queue object");
31
32	return queue;
33}
34
35
36static void obj_input(struct nl_object *obj, void *arg)
37{
38	struct nfnl_queue_msg *msg = (struct nfnl_queue_msg *) obj;
39	struct nl_dump_params dp = {
40		.dp_type = NL_DUMP_STATS,
41		.dp_fd = stdout,
42		.dp_dump_msgtype = 1,
43	};
44	uint32_t packet_id = nfnl_queue_msg_get_packetid(msg);
45	static uint32_t next_packet_id = 0;
46	struct nfnl_queue_msg *lost_msg = NULL;
47	uint8_t family;
48	uint16_t group;
49
50	if (packet_id > next_packet_id) {
51		printf("Warning: %d Out of order packets.  Queue or socket overload \n", packet_id - next_packet_id);
52		group = nfnl_queue_msg_get_group(msg);
53		family = nfnl_queue_msg_get_family(msg);
54		lost_msg = nfnl_queue_msg_alloc();
55
56		do {
57			nfnl_queue_msg_set_group(lost_msg, group);
58			nfnl_queue_msg_set_family(lost_msg, family);
59			nfnl_queue_msg_set_packetid(lost_msg, next_packet_id);
60			nfnl_queue_msg_set_verdict(lost_msg, NF_ACCEPT);
61			nfnl_queue_msg_send_verdict(nf_sock, lost_msg);
62			next_packet_id++;
63		} while (packet_id > next_packet_id);
64
65		nfnl_queue_msg_put(lost_msg);
66	}
67
68	next_packet_id = packet_id + 1;
69	nfnl_queue_msg_set_verdict(msg, NF_ACCEPT);
70	nl_object_dump(obj, &dp);
71	nfnl_queue_msg_send_verdict(nf_sock, msg);
72}
73
74static int event_input(struct nl_msg *msg, void *arg)
75{
76	if (nl_msg_parse(msg, &obj_input, NULL) < 0)
77		fprintf(stderr, "<<EVENT>> Unknown message type\n");
78
79	/* Exit nl_recvmsgs_def() and return to the main select() */
80	return NL_STOP;
81}
82
83int main(int argc, char *argv[])
84{
85	struct nl_sock *rt_sock;
86	struct nl_cache *link_cache;
87	struct nfnl_queue *queue;
88	enum nfnl_queue_copy_mode copy_mode;
89	uint32_t copy_range;
90	int err = 1;
91	int family;
92
93	nf_sock = nfnl_queue_socket_alloc();
94	if (nf_sock == NULL)
95		nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");
96
97	nl_socket_disable_seq_check(nf_sock);
98	nl_socket_modify_cb(nf_sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL);
99
100	if ((argc > 1 && !strcasecmp(argv[1], "-h")) || argc < 3) {
101		printf("Usage: nf-queue family group [ copy_mode ] "
102		       "[ copy_range ]\n");
103		printf("family: [ inet | inet6 | ... ] \n");
104		printf("group: the --queue-num arg that you gave to iptables\n");
105		printf("copy_mode: [ none | meta | packet ] \n");
106		return 2;
107	}
108
109	nl_cli_connect(nf_sock, NETLINK_NETFILTER);
110
111	if ((family = nl_str2af(argv[1])) == AF_UNSPEC)
112		nl_cli_fatal(NLE_INVAL, "Unknown family \"%s\"", argv[1]);
113
114	nfnl_queue_pf_unbind(nf_sock, family);
115	if ((err = nfnl_queue_pf_bind(nf_sock, family)) < 0)
116		nl_cli_fatal(err, "Unable to bind logger: %s",
117			     nl_geterror(err));
118
119	queue = alloc_queue();
120	nfnl_queue_set_group(queue, atoi(argv[2]));
121
122	copy_mode = NFNL_QUEUE_COPY_PACKET;
123	if (argc > 3) {
124		copy_mode = nfnl_queue_str2copy_mode(argv[3]);
125		if (copy_mode < 0)
126			nl_cli_fatal(copy_mode,
127				     "Unable to parse copy mode \"%s\": %s",
128				     argv[3], nl_geterror(copy_mode));
129	}
130	nfnl_queue_set_copy_mode(queue, copy_mode);
131
132	copy_range = 0xFFFF;
133	if (argc > 4)
134		copy_range = atoi(argv[4]);
135	nfnl_queue_set_copy_range(queue, copy_range);
136
137	if ((err = nfnl_queue_create(nf_sock, queue)) < 0)
138		nl_cli_fatal(err, "Unable to bind queue: %s", nl_geterror(err));
139
140	rt_sock = nl_cli_alloc_socket();
141	nl_cli_connect(rt_sock, NETLINK_ROUTE);
142	link_cache = nl_cli_link_alloc_cache(rt_sock);
143
144	nl_socket_set_buffer_size(nf_sock, 1024*127, 1024*127);
145
146	while (1) {
147		fd_set rfds;
148		int nffd, rtfd, maxfd, retval;
149
150		FD_ZERO(&rfds);
151
152		maxfd = nffd = nl_socket_get_fd(nf_sock);
153		FD_SET(nffd, &rfds);
154
155		rtfd = nl_socket_get_fd(rt_sock);
156		FD_SET(rtfd, &rfds);
157		if (maxfd < rtfd)
158			maxfd = rtfd;
159
160		/* wait for an incoming message on the netlink socket */
161		retval = select(maxfd+1, &rfds, NULL, NULL, NULL);
162
163		if (retval) {
164			if (FD_ISSET(nffd, &rfds))
165				nl_recvmsgs_default(nf_sock);
166			if (FD_ISSET(rtfd, &rfds))
167				nl_recvmsgs_default(rt_sock);
168		}
169	}
170
171	return 0;
172}
173