libnftnl 1.2.9
nft-ct-helper-add.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2012-2016 by Pablo Neira Ayuso <pablo@netfilter.org>
4 */
5
6#include <stdlib.h>
7#include <string.h>
8#include <time.h>
9#include <netinet/in.h>
10
11#include <linux/netfilter.h>
12#include <linux/netfilter/nf_tables.h>
13
14#include <libmnl/libmnl.h>
15#include <libnftnl/object.h>
16
17static uint16_t parse_family(char *str, const char *option)
18{
19 if (strcmp(str, "ip") == 0)
20 return NFPROTO_IPV4;
21 else if (strcmp(str, "ip6") == 0)
22 return NFPROTO_IPV6;
23 else if (strcmp(str, "inet") == 0)
24 return NFPROTO_INET;
25 else {
26 fprintf(stderr, "Unknown %s: ip, ip6, inet\n", option);
27 exit(EXIT_FAILURE);
28 }
29}
30
31static uint8_t parse_l4proto(char *str)
32{
33 if (strcmp(str, "udp") == 0)
34 return IPPROTO_UDP;
35 else if (strcmp(str, "tcp") == 0)
36 return IPPROTO_TCP;
37 else {
38 fprintf(stderr, "Unknown l4proto: tcp, udp\n");
39 exit(EXIT_FAILURE);
40 }
41 return IPPROTO_TCP;
42}
43
44static struct nftnl_obj *ct_helper_add_parse(int argc, char *argv[])
45{
46 struct nftnl_obj *t;
47 uint16_t family, l3proto;
48 uint8_t l4proto;
49
50 t = nftnl_obj_alloc();
51 if (t == NULL) {
52 perror("OOM");
53 return NULL;
54 }
55
56 family = parse_family(argv[1], "family");
57 nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family);
58 nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_HELPER);
59 nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
60 nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
61
62 nftnl_obj_set_str(t, NFTNL_OBJ_CT_HELPER_NAME, argv[4]);
63 l4proto = parse_l4proto(argv[5]);
64 nftnl_obj_set_u8(t, NFTNL_OBJ_CT_HELPER_L4PROTO, l4proto);
65 if (argc == 7) {
66 l3proto = parse_family(argv[6], "l3proto");
67 nftnl_obj_set_u16(t, NFTNL_OBJ_CT_HELPER_L3PROTO, l3proto);
68 }
69
70 return t;
71}
72
73int main(int argc, char *argv[])
74{
75 struct nftnl_obj *t;
76 uint32_t seq, obj_seq, family, portid;
77 struct mnl_nlmsg_batch *batch;
78 char buf[MNL_SOCKET_BUFFER_SIZE];
79 struct nlmsghdr *nlh;
80 struct mnl_socket *nl;
81 int ret;
82
83 if (argc < 6) {
84 fprintf(stderr, "%s <family> <table> <name> <type> <l4proto> [l3proto]\n", argv[0]);
85 exit(EXIT_FAILURE);
86 }
87
88 t = ct_helper_add_parse(argc, argv);
89 if (t == NULL)
90 exit(EXIT_FAILURE);
91
92 seq = time(NULL);
93 batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
94
95 nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
96 mnl_nlmsg_batch_next(batch);
97
98 obj_seq = seq;
99 family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY);
100 nlh = nftnl_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
101 NFT_MSG_NEWOBJ, family, NLM_F_CREATE | NLM_F_ACK, seq++);
102
103 nftnl_obj_nlmsg_build_payload(nlh, t);
104 nftnl_obj_free(t);
105 mnl_nlmsg_batch_next(batch);
106
107 nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
108 mnl_nlmsg_batch_next(batch);
109
110 nl = mnl_socket_open(NETLINK_NETFILTER);
111 if (nl == NULL) {
112 perror("mnl_socket_open");
113 exit(EXIT_FAILURE);
114 }
115
116 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
117 perror("mnl_socket_bind");
118 exit(EXIT_FAILURE);
119 }
120 portid = mnl_socket_get_portid(nl);
121
122 if (mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
123 mnl_nlmsg_batch_size(batch)) < 0) {
124 perror("mnl_socket_send");
125 exit(EXIT_FAILURE);
126 }
127
128 mnl_nlmsg_batch_stop(batch);
129
130 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
131 while (ret > 0) {
132 ret = mnl_cb_run(buf, ret, obj_seq, portid, NULL, NULL);
133 if (ret <= 0) {
134 break;
135 }
136 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
137 }
138 if (ret == -1) {
139 perror("error");
140 exit(EXIT_FAILURE);
141 }
142 mnl_socket_close(nl);
143
144 return EXIT_SUCCESS;
145}