libnftnl  1.2.2
nft-rule-del.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 <stddef.h> /* for offsetof */
16 #include <netinet/in.h>
17 
18 #include <linux/netfilter.h>
19 #include <linux/netfilter/nf_tables.h>
20 #include <linux/netfilter/nfnetlink.h>
21 
22 #include <libmnl/libmnl.h>
23 #include <libnftnl/rule.h>
24 
25 int main(int argc, char *argv[])
26 {
27  struct mnl_socket *nl;
28  char buf[MNL_SOCKET_BUFFER_SIZE];
29  struct nlmsghdr *nlh;
30  struct mnl_nlmsg_batch *batch;
31  uint32_t portid, seq;
32  struct nftnl_rule *r = NULL;
33  int ret, family;
34 
35  if (argc < 4 || argc > 5) {
36  fprintf(stderr, "Usage: %s <family> <table> <chain> [<handle>]\n",
37  argv[0]);
38  exit(EXIT_FAILURE);
39  }
40 
41  r = nftnl_rule_alloc();
42  if (r == NULL) {
43  perror("OOM");
44  exit(EXIT_FAILURE);
45  }
46 
47  if (strcmp(argv[1], "ip") == 0)
48  family = NFPROTO_IPV4;
49  else if (strcmp(argv[1], "ip6") == 0)
50  family = NFPROTO_IPV6;
51  else if (strcmp(argv[1], "inet") == 0)
52  family = NFPROTO_INET;
53  else if (strcmp(argv[1], "bridge") == 0)
54  family = NFPROTO_BRIDGE;
55  else if (strcmp(argv[1], "arp") == 0)
56  family = NFPROTO_ARP;
57  else {
58  fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp\n");
59  exit(EXIT_FAILURE);
60  }
61 
62  seq = time(NULL);
63  nftnl_rule_set_str(r, NFTNL_RULE_TABLE, argv[2]);
64  nftnl_rule_set_str(r, NFTNL_RULE_CHAIN, argv[3]);
65 
66  /* If no handle is specified, delete all rules in the chain */
67  if (argc == 5)
68  nftnl_rule_set_u64(r, NFTNL_RULE_HANDLE, atoi(argv[4]));
69 
70  batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
71 
72  nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
73  mnl_nlmsg_batch_next(batch);
74 
75  nlh = nftnl_rule_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
76  NFT_MSG_DELRULE,
77  family,
78  NLM_F_ACK, seq++);
79 
80  nftnl_rule_nlmsg_build_payload(nlh, r);
81  nftnl_rule_free(r);
82  mnl_nlmsg_batch_next(batch);
83 
84  nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
85  mnl_nlmsg_batch_next(batch);
86 
87  nl = mnl_socket_open(NETLINK_NETFILTER);
88  if (nl == NULL) {
89  perror("mnl_socket_open");
90  exit(EXIT_FAILURE);
91  }
92 
93  if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
94  perror("mnl_socket_bind");
95  exit(EXIT_FAILURE);
96  }
97  portid = mnl_socket_get_portid(nl);
98 
99  if (mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
100  mnl_nlmsg_batch_size(batch)) < 0) {
101  perror("mnl_socket_send");
102  exit(EXIT_FAILURE);
103  }
104 
105  mnl_nlmsg_batch_stop(batch);
106 
107  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
108  while (ret > 0) {
109  ret = mnl_cb_run(buf, ret, 0, portid, NULL, NULL);
110  if (ret <= 0)
111  break;
112  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
113  }
114  if (ret == -1) {
115  perror("error");
116  exit(EXIT_FAILURE);
117  }
118  mnl_socket_close(nl);
119 
120  return EXIT_SUCCESS;
121 }