libnftnl  1.1.5
nft-compat-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/nfnetlink.h>
18 #include <linux/netfilter/nf_tables_compat.h>
19 
20 #include <libmnl/libmnl.h>
21 
22 static int data_attr_cb(const struct nlattr *attr, void *data)
23 {
24  const struct nlattr **tb = data;
25  int type = mnl_attr_get_type(attr);
26 
27  if (mnl_attr_type_valid(attr, NFTA_COMPAT_MAX) < 0)
28  return MNL_CB_OK;
29 
30  switch(type) {
31  case NFTA_COMPAT_NAME:
32  if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
33  perror("mnl_attr_validate");
34  return MNL_CB_ERROR;
35  }
36  break;
37  case NFTA_COMPAT_REV:
38  case NFTA_COMPAT_TYPE:
39  if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
40  perror("mnl_attr_validate");
41  return MNL_CB_ERROR;
42  }
43  break;
44  }
45  tb[type] = attr;
46  return MNL_CB_OK;
47 }
48 
49 static int cb(const struct nlmsghdr *nlh, void *data)
50 {
51  struct nlattr *tb[NFTA_COMPAT_MAX+1] = {};
52  struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
53 
54  if (mnl_attr_parse(nlh, sizeof(*nfg), data_attr_cb, tb) < 0)
55  return MNL_CB_ERROR;
56 
57  if (tb[NFTA_COMPAT_NAME])
58  printf("name=%s ", mnl_attr_get_str(tb[NFTA_COMPAT_NAME]));
59  if (tb[NFTA_COMPAT_REV])
60  printf("rev=%d ", ntohl(mnl_attr_get_u32(tb[NFTA_COMPAT_REV])));
61  if (tb[NFTA_COMPAT_TYPE])
62  printf("type=%d ", ntohl(mnl_attr_get_u32(tb[NFTA_COMPAT_REV])));
63 
64  printf("\n");
65 
66  return MNL_CB_OK;
67 }
68 
69 int main(int argc, char *argv[])
70 {
71  struct mnl_socket *nl;
72  char buf[MNL_SOCKET_BUFFER_SIZE];
73  struct nlmsghdr *nlh;
74  uint32_t portid, seq, rev, type;
75  int ret;
76 
77  if (argc != 4) {
78  fprintf(stderr, "Usage: %s <extension_name> <type> <rev>\n",
79  argv[0]);
80  return EXIT_FAILURE;
81  }
82 
83  if (strcmp(argv[2], "target") == 0)
84  type = 1;
85  else if (strcmp(argv[2], "match") == 0)
86  type = 0;
87  else {
88  fprintf(stderr, "type should be `target' or `match'\n");
89  return EXIT_FAILURE;
90  }
91  rev = atoi(argv[3]);
92 
93  nlh = mnl_nlmsg_put_header(buf);
94  nlh->nlmsg_type = (NFNL_SUBSYS_NFT_COMPAT << 8) | NFNL_MSG_COMPAT_GET;
95  nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
96  nlh->nlmsg_seq = seq = time(NULL);
97 
98  struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
99  nfg->nfgen_family = AF_INET;
100  nfg->version = NFNETLINK_V0;
101  nfg->res_id = 0;
102 
103  mnl_attr_put_strz(nlh, NFTA_COMPAT_NAME, argv[1]);
104  mnl_attr_put_u32(nlh, NFTA_COMPAT_REV, htonl(rev));
105  mnl_attr_put_u32(nlh, NFTA_COMPAT_TYPE, htonl(type));
106 
107  printf("requesting `%s' rev=%d type=%d\n", argv[1], rev, type);
108 
109  nl = mnl_socket_open(NETLINK_NETFILTER);
110  if (nl == NULL) {
111  perror("mnl_socket_open");
112  exit(EXIT_FAILURE);
113  }
114 
115  if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
116  perror("mnl_socket_bind");
117  exit(EXIT_FAILURE);
118  }
119  portid = mnl_socket_get_portid(nl);
120 
121  if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
122  perror("mnl_socket_send");
123  exit(EXIT_FAILURE);
124  }
125 
126  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
127  while (ret > 0) {
128  ret = mnl_cb_run(buf, ret, seq, portid, cb, NULL);
129  if (ret <= 0)
130  break;
131  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
132  }
133  if (ret == -1) {
134  perror("error");
135  exit(EXIT_FAILURE);
136  }
137  mnl_socket_close(nl);
138 
139  return EXIT_SUCCESS;
140 }