libnftnl  1.2.5
nft-ct-expectation-del.c
1 /*
2  * (C) 2019 by Stéphane Veyret <sveyret@gmail.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published
6  * by the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #include <stdlib.h>
11 #include <time.h>
12 #include <string.h>
13 #include <netinet/in.h>
14 
15 #include <linux/netfilter.h>
16 #include <linux/netfilter/nf_tables.h>
17 
18 #include <libmnl/libmnl.h>
19 #include <libnftnl/object.h>
20 
21 static uint16_t parse_family(char *str, const char *option)
22 {
23  if (strcmp(str, "ip") == 0)
24  return NFPROTO_IPV4;
25  else if (strcmp(str, "ip6") == 0)
26  return NFPROTO_IPV6;
27  else if (strcmp(str, "inet") == 0)
28  return NFPROTO_INET;
29  else if (strcmp(str, "arp") == 0)
30  return NFPROTO_INET;
31  fprintf(stderr, "Unknown %s: ip, ip6, inet, arp\n", option);
32  exit(EXIT_FAILURE);
33 }
34 
35 static struct nftnl_obj *obj_parse(int argc, char *argv[])
36 {
37  struct nftnl_obj *t;
38  uint16_t family;
39 
40  t = nftnl_obj_alloc();
41  if (t == NULL) {
42  perror("OOM");
43  return NULL;
44  }
45 
46  family = parse_family(argv[1], "family");
47  nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family);
48  nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_EXPECT);
49  nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
50  nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
51 
52  return t;
53 }
54 
55 int main(int argc, char *argv[])
56 {
57  struct mnl_socket *nl;
58  char buf[MNL_SOCKET_BUFFER_SIZE];
59  struct nlmsghdr *nlh;
60  uint32_t portid, seq, obj_seq, family;
61  struct nftnl_obj *t;
62  struct mnl_nlmsg_batch *batch;
63  int ret;
64 
65  if (argc != 4) {
66  fprintf(stderr, "%s <family> <table> <name>\n", argv[0]);
67  exit(EXIT_FAILURE);
68  }
69 
70  t = obj_parse(argc, argv);
71  if (t == NULL)
72  exit(EXIT_FAILURE);
73 
74  seq = time(NULL);
75  batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
76 
77  nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
78  mnl_nlmsg_batch_next(batch);
79 
80  obj_seq = seq;
81  family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY);
82  nlh = nftnl_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
83  NFT_MSG_DELOBJ, family, NLM_F_ACK,
84  seq++);
85  nftnl_obj_nlmsg_build_payload(nlh, t);
86  mnl_nlmsg_batch_next(batch);
87  nftnl_obj_free(t);
88 
89  nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
90  mnl_nlmsg_batch_next(batch);
91 
92  nl = mnl_socket_open(NETLINK_NETFILTER);
93  if (nl == NULL) {
94  perror("mnl_socket_open");
95  exit(EXIT_FAILURE);
96  }
97 
98  if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
99  perror("mnl_socket_bind");
100  exit(EXIT_FAILURE);
101  }
102  portid = mnl_socket_get_portid(nl);
103 
104  if (mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
105  mnl_nlmsg_batch_size(batch)) < 0) {
106  perror("mnl_socket_send");
107  exit(EXIT_FAILURE);
108  }
109 
110  mnl_nlmsg_batch_stop(batch);
111 
112  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
113  while (ret > 0) {
114  ret = mnl_cb_run(buf, ret, obj_seq, portid, NULL, NULL);
115  if (ret <= 0)
116  break;
117  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
118  }
119  if (ret == -1) {
120  perror("error");
121  exit(EXIT_FAILURE);
122  }
123  mnl_socket_close(nl);
124 
125  return EXIT_SUCCESS;
126 }