libnetfilter_conntrack  1.0.6
nfct-mnl-dump.c
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 
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 
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 }
void nfct_destroy(struct nf_conntrack *ct)
Definition: conntrack/api.c:92
int nfct_snprintf(char *buf, unsigned int size, const struct nf_conntrack *ct, const unsigned int msg_type, const unsigned int out_type, const unsigned int out_flags)
struct nf_conntrack * nfct_new(void)
Definition: conntrack/api.c:75