libnftnl  1.0.8
nft-set-elem-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 #include <stdlib.h>
13 #include <time.h>
14 #include <string.h>
15 #include <netinet/in.h>
16 
17 #include <linux/netfilter.h>
18 #include <linux/netfilter/nf_tables.h>
19 
20 #include <libmnl/libmnl.h>
21 #include <libnftnl/set.h>
22 
23 static int set_cb(const struct nlmsghdr *nlh, void *data)
24 {
25  struct nftnl_set *t;
26  char buf[4096];
27  uint32_t *type = data;
28 
29  t = nftnl_set_alloc();
30  if (t == NULL) {
31  perror("OOM");
32  goto err;
33  }
34 
35  if (nftnl_set_elems_nlmsg_parse(nlh, t) < 0) {
36  perror("nftnl_set_nlmsg_parse");
37  goto err_free;
38  }
39 
40  nftnl_set_snprintf(buf, sizeof(buf), t, *type, 0);
41  printf("%s\n", buf);
42 
43 err_free:
44  nftnl_set_free(t);
45 err:
46  return MNL_CB_OK;
47 }
48 
49 int main(int argc, char *argv[])
50 {
51  struct mnl_socket *nl;
52  char buf[MNL_SOCKET_BUFFER_SIZE];
53  struct nlmsghdr *nlh;
54  uint32_t portid, seq, family;
55  uint32_t type = NFTNL_OUTPUT_DEFAULT;
56  struct nftnl_set *t = NULL;
57  struct nftnl_set_elem *e;
58  uint16_t data;
59  int ret;
60 
61  if (argc < 4 || argc > 5) {
62  fprintf(stderr, "%s <family> <table> <set> [<json>]\n",
63  argv[0]);
64  return EXIT_FAILURE;
65  }
66  t = nftnl_set_alloc();
67  if (t == NULL) {
68  perror("OOM");
69  exit(EXIT_FAILURE);
70  }
71  seq = time(NULL);
72  if (strcmp(argv[1], "ip") == 0)
73  family = NFPROTO_IPV4;
74  else if (strcmp(argv[1], "ip6") == 0)
75  family = NFPROTO_IPV6;
76  else if (strcmp(argv[1], "bridge") == 0)
77  family = NFPROTO_BRIDGE;
78  else if (strcmp(argv[1], "arp") == 0)
79  family = NFPROTO_ARP;
80  else {
81  fprintf(stderr, "Unknown family: ip, ip6, bridge, arp\n");
82  exit(EXIT_FAILURE);
83  }
84 
85  if (argc == 5 && strcmp(argv[4], "json") == 0 )
86  type = NFTNL_OUTPUT_JSON;
87 
88  nlh = nftnl_set_nlmsg_build_hdr(buf, NFT_MSG_GETSETELEM, family,
89  NLM_F_ACK, seq);
90  nftnl_set_set(t, NFTNL_SET_NAME, argv[3]);
91  nftnl_set_set(t, NFTNL_SET_TABLE, argv[2]);
92 
93  /* Add to dummy elements to set */
94  e = nftnl_set_elem_alloc();
95  if (e == NULL) {
96  perror("OOM");
97  exit(EXIT_FAILURE);
98  }
99 
100  data = htons(1);
101  nftnl_set_elem_set(e, NFTNL_SET_ELEM_KEY, &data, sizeof(data));
102  nftnl_set_elem_add(t, e);
103 
104  nftnl_set_elems_nlmsg_build_payload(nlh, t);
105  nftnl_set_free(t);
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, set_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 }