1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <time.h>
4 
5 #include <libmnl/libmnl.h>
6 #include <libnetfilter_conntrack/libnetfilter_conntrack.h>
7 
print_label(struct nf_conntrack * ct,struct nfct_labelmap * map)8 static void print_label(struct nf_conntrack *ct, struct nfct_labelmap *map)
9 {
10 	unsigned int i, max;
11 	const struct nfct_bitmask *b = nfct_get_attr(ct, ATTR_CONNLABELS);
12 	if (!b)
13 		return;
14 
15 	puts("labels:");
16 	max = nfct_bitmask_maxbit(b);
17 	for (i = 0; i <= max; i++) {
18 		if (nfct_bitmask_test_bit(b, i))
19 			printf("\t'%s' (%d)\n", map ? nfct_labelmap_get_name(map, i) : "", i);
20 	}
21 }
22 
data_cb(const struct nlmsghdr * nlh,void * data)23 static int data_cb(const struct nlmsghdr *nlh, void *data)
24 {
25 	struct nf_conntrack *ct;
26 	char buf[4096];
27 
28 	ct = nfct_new();
29 	if (ct == NULL)
30 		return MNL_CB_OK;
31 
32 	nfct_nlmsg_parse(nlh, ct);
33 
34 	nfct_snprintf(buf, sizeof(buf), ct, NFCT_T_UNKNOWN, NFCT_O_DEFAULT, 0);
35 	printf("%s\n", buf);
36 
37 	print_label(ct, data);
38 
39 	nfct_destroy(ct);
40 
41 	return MNL_CB_OK;
42 }
43 
main(void)44 int main(void)
45 {
46 	struct mnl_socket *nl;
47 	struct nlmsghdr *nlh;
48 	struct nfgenmsg *nfh;
49 	char buf[MNL_SOCKET_BUFFER_SIZE];
50 	unsigned int seq, portid;
51 	int ret;
52 	struct nfct_labelmap *l = nfct_labelmap_new(NULL);
53 
54 	nl = mnl_socket_open(NETLINK_NETFILTER);
55 	if (nl == NULL) {
56 		perror("mnl_socket_open");
57 		exit(EXIT_FAILURE);
58 	}
59 
60 	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
61 		perror("mnl_socket_bind");
62 		exit(EXIT_FAILURE);
63 	}
64 	portid = mnl_socket_get_portid(nl);
65 
66 	nlh = mnl_nlmsg_put_header(buf);
67 	nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
68 	nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
69 	nlh->nlmsg_seq = seq = time(NULL);
70 
71 	nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
72 	nfh->nfgen_family = AF_UNSPEC;
73 	nfh->version = NFNETLINK_V0;
74 	nfh->res_id = 0;
75 
76 
77 	ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
78 	if (ret == -1) {
79 		perror("mnl_socket_sendto");
80 		exit(EXIT_FAILURE);
81 	}
82 
83 	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
84 
85 
86 	while (ret > 0) {
87 		ret = mnl_cb_run(buf, ret, seq, portid, data_cb, l);
88 		if (ret <= MNL_CB_STOP)
89 			break;
90 		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
91 	}
92 	if (ret == -1) {
93 		perror("mnl_socket_recvfrom");
94 		exit(EXIT_FAILURE);
95 	}
96 
97 	if (l)
98 		nfct_labelmap_destroy(l);
99 
100 	mnl_socket_close(nl);
101 
102 	return 0;
103 }
104