1#include <stdio.h>
2#include <stdlib.h>
3#include <string.h>
4#include <time.h>
5
6#include <libmnl/libmnl.h>
7#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
8
9struct callback_args {
10	struct mnl_socket *nl;
11	unsigned int seq;
12	int bit;
13};
14
15static void set_label(struct nf_conntrack *ct, struct callback_args *cbargs)
16{
17	struct nfct_bitmask *b = (void *) nfct_get_attr(ct, ATTR_CONNLABELS);
18	int bit = cbargs->bit;
19	char buf[MNL_SOCKET_BUFFER_SIZE];
20	struct nlmsghdr *nlh;
21	struct nfgenmsg *nfh;
22
23	if (b) {
24		if (bit < 0)
25			b = nfct_bitmask_new(0);
26		else if (nfct_bitmask_test_bit(b, bit))
27			return;
28	} else {
29		b = nfct_bitmask_new(0);
30	}
31
32	if (!b)
33		return;
34	if (bit >= 0)
35		nfct_bitmask_set_bit(b, bit);
36	nfct_set_attr(ct, ATTR_CONNLABELS, b);
37
38	if (bit >= 0) {
39		b = nfct_bitmask_new(bit);
40		if (b) {
41			nfct_bitmask_set_bit(b, bit);
42			nfct_set_attr(ct, ATTR_CONNLABELS_MASK, b);
43		}
44	}
45
46	cbargs->seq++;
47
48	nlh = mnl_nlmsg_put_header(buf);
49	nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_NEW;
50	nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE;
51	nlh->nlmsg_seq = cbargs->seq;
52
53	nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
54	nfh->nfgen_family = nfct_get_attr_u8(ct, ATTR_L3PROTO);
55	nfh->version = NFNETLINK_V0;
56	nfh->res_id = 0;
57
58	nfct_nlmsg_build(nlh, ct);
59
60	if (mnl_socket_sendto(cbargs->nl, nlh, nlh->nlmsg_len) < 0)
61		perror("mnl_socket_sendto");
62}
63
64static int data_cb(const struct nlmsghdr *nlh, void *data)
65{
66	struct nf_conntrack *ct;
67	char buf[4096];
68
69	ct = nfct_new();
70	if (ct == NULL)
71		return MNL_CB_OK;
72
73	nfct_nlmsg_parse(nlh, ct);
74
75	nfct_snprintf(buf, sizeof(buf), ct, NFCT_T_UNKNOWN, NFCT_O_DEFAULT, 0);
76	printf("%s\n", buf);
77
78	set_label(ct, data);
79
80	nfct_destroy(ct);
81
82	return MNL_CB_OK;
83}
84
85static void show_labels(struct nfct_labelmap *l)
86{
87	unsigned int i = 0;
88	const char *name;
89
90	if (l) {
91		fputs("usage: program label, configured labels are:\n", stderr);
92		while ((name = nfct_labelmap_get_name(l, i))) {
93			if (*name)
94				fprintf(stderr, "%s -> bit %d\n", name, i);
95			i++;
96		}
97	} else {
98		fputs("no labels configured, usage: program bit\n", stderr);
99	}
100	exit(1);
101}
102
103static struct mnl_socket *sock_nl_create(void)
104{
105	struct mnl_socket *nl;
106
107	nl = mnl_socket_open(NETLINK_NETFILTER);
108	if (nl == NULL) {
109		perror("mnl_socket_open");
110		exit(EXIT_FAILURE);
111	}
112
113	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
114		perror("mnl_socket_bind");
115		exit(EXIT_FAILURE);
116	}
117
118	return nl;
119}
120
121int main(int argc, char *argv[])
122{
123	struct mnl_socket *nl;
124	struct nlmsghdr *nlh;
125	struct nfgenmsg *nfh;
126	char buf[MNL_SOCKET_BUFFER_SIZE];
127	unsigned int seq, portid;
128	struct callback_args cbargs;
129	int ret;
130	struct nfct_labelmap *l = nfct_labelmap_new(NULL);
131
132	if (argc < 2)
133		show_labels(l);
134
135	cbargs.bit = l ? nfct_labelmap_get_bit(l, argv[1]) : -1;
136
137	if (cbargs.bit < 0) {
138		cbargs.bit = atoi(argv[1]);
139		if (cbargs.bit == 0 && argv[1][0] != '0')
140			show_labels(l);
141	}
142
143	if (cbargs.bit < 0)
144		puts("will clear all labels");
145	else
146		printf("will set label bit %d\n", cbargs.bit);
147
148	nl = sock_nl_create();
149	portid = mnl_socket_get_portid(nl);
150
151	nlh = mnl_nlmsg_put_header(buf);
152	nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
153	nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
154	nlh->nlmsg_seq = seq = time(NULL);
155
156	nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
157	nfh->nfgen_family = AF_UNSPEC;
158	nfh->version = NFNETLINK_V0;
159	nfh->res_id = 0;
160
161
162	ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
163	if (ret == -1) {
164		perror("mnl_socket_sendto");
165		exit(EXIT_FAILURE);
166	}
167
168	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
169
170
171	cbargs.nl = sock_nl_create();
172	cbargs.seq = seq;
173
174	while (ret > 0) {
175		ret = mnl_cb_run(buf, ret, seq, portid, data_cb, &cbargs);
176		if (ret <= MNL_CB_STOP)
177			break;
178		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
179	}
180	if (ret == -1) {
181		perror("mnl_socket_recvfrom");
182		exit(EXIT_FAILURE);
183	}
184
185	if (l)
186		nfct_labelmap_destroy(l);
187	mnl_socket_close(nl);
188
189	return 0;
190}
191