1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <unistd.h>
4 #include <time.h>
5 #include <arpa/inet.h>
6
7 #include <libmnl/libmnl.h>
8 #include <libnetfilter_conntrack/libnetfilter_conntrack.h>
9
data_cb(const struct nlmsghdr * nlh,void * data)10 static int data_cb(const struct nlmsghdr *nlh, void *data)
11 {
12 struct nf_conntrack *ct;
13 char buf[4096];
14
15 ct = nfct_new();
16 if (ct == NULL)
17 return MNL_CB_OK;
18
19 nfct_nlmsg_parse(nlh, ct);
20
21 nfct_snprintf(buf, sizeof(buf), ct, NFCT_T_UNKNOWN, NFCT_O_DEFAULT, 0);
22 printf("%s\n", buf);
23
24 nfct_destroy(ct);
25
26 return MNL_CB_OK;
27 }
28
main(void)29 int main(void)
30 {
31 struct mnl_socket *nl;
32 struct nlmsghdr *nlh;
33 struct nfgenmsg *nfh;
34 char buf[MNL_SOCKET_BUFFER_SIZE];
35 unsigned int seq, portid;
36 int ret;
37
38 nl = mnl_socket_open(NETLINK_NETFILTER);
39 if (nl == NULL) {
40 perror("mnl_socket_open");
41 exit(EXIT_FAILURE);
42 }
43
44 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
45 perror("mnl_socket_bind");
46 exit(EXIT_FAILURE);
47 }
48 portid = mnl_socket_get_portid(nl);
49
50 nlh = mnl_nlmsg_put_header(buf);
51 nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
52 nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP;
53 nlh->nlmsg_seq = seq = time(NULL);
54
55 nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
56 nfh->nfgen_family = AF_INET;
57 nfh->version = NFNETLINK_V0;
58 nfh->res_id = 0;
59
60 ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
61 if (ret == -1) {
62 perror("mnl_socket_recvfrom");
63 exit(EXIT_FAILURE);
64 }
65
66 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
67 while (ret > 0) {
68 ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
69 if (ret <= MNL_CB_STOP)
70 break;
71 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
72 }
73 if (ret == -1) {
74 perror("mnl_socket_recvfrom");
75 exit(EXIT_FAILURE);
76 }
77
78 mnl_socket_close(nl);
79
80 return 0;
81 }
82