libnftnl  1.2.0
nft-ct-helper-get.c
1 /*
2  * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
10  */
11 
12 
13 #include <stdlib.h>
14 #include <time.h>
15 #include <string.h>
16 #include <netinet/in.h>
17 
18 #include <linux/netfilter.h>
19 #include <linux/netfilter/nf_tables.h>
20 
21 #include <libmnl/libmnl.h>
22 #include <libnftnl/object.h>
23 
24 static int obj_cb(const struct nlmsghdr *nlh, void *data)
25 {
26  struct nftnl_obj *t;
27  char buf[4096];
28  uint32_t *type = data;
29 
30  t = nftnl_obj_alloc();
31  if (t == NULL) {
32  perror("OOM");
33  goto err;
34  }
35 
36  if (nftnl_obj_nlmsg_parse(nlh, t) < 0) {
37  perror("nftnl_obj_nlmsg_parse");
38  goto err_free;
39  }
40 
41  nftnl_obj_snprintf(buf, sizeof(buf), t, *type, 0);
42  printf("%s\n", buf);
43 
44 err_free:
45  nftnl_obj_free(t);
46 err:
47  return MNL_CB_OK;
48 }
49 
50 int main(int argc, char *argv[])
51 {
52  struct mnl_socket *nl;
53  char buf[MNL_SOCKET_BUFFER_SIZE];
54  struct nlmsghdr *nlh;
55  uint32_t portid, seq, family;
56  struct nftnl_obj *t = NULL;
57  int ret;
58  uint32_t type = NFTNL_OUTPUT_DEFAULT;
59 
60  if (argc < 3 || argc > 5) {
61  fprintf(stderr, "%s <family> <table> [<obj>]\n",
62  argv[0]);
63  return EXIT_FAILURE;
64  }
65 
66  if (strcmp(argv[1], "ip") == 0)
67  family = NFPROTO_IPV4;
68  else if (strcmp(argv[1], "ip6") == 0)
69  family = NFPROTO_IPV6;
70  else if (strcmp(argv[1], "inet") == 0)
71  family = NFPROTO_INET;
72  else if (strcmp(argv[1], "unspec") == 0)
73  family = NFPROTO_UNSPEC;
74  else {
75  fprintf(stderr, "Unknown family: ip, ip6, inet, unspec");
76  exit(EXIT_FAILURE);
77  }
78 
79  if (argc == 3 || argc == 4) {
80  t = nftnl_obj_alloc();
81  if (t == NULL) {
82  perror("OOM");
83  exit(EXIT_FAILURE);
84  }
85  }
86 
87  seq = time(NULL);
88  nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_HELPER);
89  if (argc < 4) {
90  nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family,
91  NLM_F_DUMP, seq);
92  if (argc == 3) {
93  nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
94  nftnl_obj_nlmsg_build_payload(nlh, t);
95  nftnl_obj_free(t);
96  }
97  } else {
98  nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
99  nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
100 
101  nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family,
102  NLM_F_ACK, seq);
103  nftnl_obj_nlmsg_build_payload(nlh, t);
104  nftnl_obj_free(t);
105  }
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  portid = mnl_socket_get_portid(nl);
118 
119  if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
120  perror("mnl_socket_send");
121  exit(EXIT_FAILURE);
122  }
123 
124  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
125  while (ret > 0) {
126  ret = mnl_cb_run(buf, ret, seq, portid, obj_cb, &type);
127  if (ret <= 0)
128  break;
129  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
130  }
131  if (ret == -1) {
132  perror("error");
133  exit(EXIT_FAILURE);
134  }
135  mnl_socket_close(nl);
136 
137  return EXIT_SUCCESS;
138 }