libnftnl  1.2.6
nft-ct-helper-add.c
1 /*
2  * (C) 2012-2016 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 
10 #include <stdlib.h>
11 #include <string.h>
12 #include <time.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 {
30  fprintf(stderr, "Unknown %s: ip, ip6, inet\n", option);
31  exit(EXIT_FAILURE);
32  }
33 }
34 
35 static uint8_t parse_l4proto(char *str)
36 {
37  if (strcmp(str, "udp") == 0)
38  return IPPROTO_UDP;
39  else if (strcmp(str, "tcp") == 0)
40  return IPPROTO_TCP;
41  else {
42  fprintf(stderr, "Unknown l4proto: tcp, udp\n");
43  exit(EXIT_FAILURE);
44  }
45  return IPPROTO_TCP;
46 }
47 
48 static struct nftnl_obj *ct_helper_add_parse(int argc, char *argv[])
49 {
50  struct nftnl_obj *t;
51  uint16_t family, l3proto;
52  uint8_t l4proto;
53 
54  t = nftnl_obj_alloc();
55  if (t == NULL) {
56  perror("OOM");
57  return NULL;
58  }
59 
60  family = parse_family(argv[1], "family");
61  nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family);
62  nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_HELPER);
63  nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
64  nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
65 
66  nftnl_obj_set_str(t, NFTNL_OBJ_CT_HELPER_NAME, argv[4]);
67  l4proto = parse_l4proto(argv[5]);
68  nftnl_obj_set_u8(t, NFTNL_OBJ_CT_HELPER_L4PROTO, l4proto);
69  if (argc == 7) {
70  l3proto = parse_family(argv[6], "l3proto");
71  nftnl_obj_set_u16(t, NFTNL_OBJ_CT_HELPER_L3PROTO, l3proto);
72  }
73 
74  return t;
75 }
76 
77 int main(int argc, char *argv[])
78 {
79  struct nftnl_obj *t;
80  uint32_t seq, obj_seq, family, portid;
81  struct mnl_nlmsg_batch *batch;
82  char buf[MNL_SOCKET_BUFFER_SIZE];
83  struct nlmsghdr *nlh;
84  struct mnl_socket *nl;
85  int ret;
86 
87  if (argc < 6) {
88  fprintf(stderr, "%s <family> <table> <name> <type> <l4proto> [l3proto]\n", argv[0]);
89  exit(EXIT_FAILURE);
90  }
91 
92  t = ct_helper_add_parse(argc, argv);
93  if (t == NULL)
94  exit(EXIT_FAILURE);
95 
96  seq = time(NULL);
97  batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
98 
99  nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
100  mnl_nlmsg_batch_next(batch);
101 
102  obj_seq = seq;
103  family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY);
104  nlh = nftnl_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
105  NFT_MSG_NEWOBJ, family, NLM_F_CREATE | NLM_F_ACK, seq++);
106 
107  nftnl_obj_nlmsg_build_payload(nlh, t);
108  nftnl_obj_free(t);
109  mnl_nlmsg_batch_next(batch);
110 
111  nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
112  mnl_nlmsg_batch_next(batch);
113 
114  nl = mnl_socket_open(NETLINK_NETFILTER);
115  if (nl == NULL) {
116  perror("mnl_socket_open");
117  exit(EXIT_FAILURE);
118  }
119 
120  if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
121  perror("mnl_socket_bind");
122  exit(EXIT_FAILURE);
123  }
124  portid = mnl_socket_get_portid(nl);
125 
126  if (mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
127  mnl_nlmsg_batch_size(batch)) < 0) {
128  perror("mnl_socket_send");
129  exit(EXIT_FAILURE);
130  }
131 
132  mnl_nlmsg_batch_stop(batch);
133 
134  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
135  while (ret > 0) {
136  ret = mnl_cb_run(buf, ret, obj_seq, portid, NULL, NULL);
137  if (ret <= 0) {
138  break;
139  }
140  ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
141  }
142  if (ret == -1) {
143  perror("error");
144  exit(EXIT_FAILURE);
145  }
146  mnl_socket_close(nl);
147 
148  return EXIT_SUCCESS;
149 }