libnftnl 1.2.9
nft-ct-helper-get.c
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
4 *
5 * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
6 */
7
8
9#include <stdlib.h>
10#include <time.h>
11#include <string.h>
12#include <netinet/in.h>
13
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16
17#include <libmnl/libmnl.h>
18#include <libnftnl/object.h>
19
20static int obj_cb(const struct nlmsghdr *nlh, void *data)
21{
22 struct nftnl_obj *t;
23 char buf[4096];
24 uint32_t *type = data;
25
26 t = nftnl_obj_alloc();
27 if (t == NULL) {
28 perror("OOM");
29 goto err;
30 }
31
32 if (nftnl_obj_nlmsg_parse(nlh, t) < 0) {
33 perror("nftnl_obj_nlmsg_parse");
34 goto err_free;
35 }
36
37 nftnl_obj_snprintf(buf, sizeof(buf), t, *type, 0);
38 printf("%s\n", buf);
39
40err_free:
41 nftnl_obj_free(t);
42err:
43 return MNL_CB_OK;
44}
45
46int main(int argc, char *argv[])
47{
48 struct mnl_socket *nl;
49 char buf[MNL_SOCKET_BUFFER_SIZE];
50 struct nlmsghdr *nlh;
51 uint32_t portid, seq, family;
52 struct nftnl_obj *t = NULL;
53 int ret;
54 uint32_t type = NFTNL_OUTPUT_DEFAULT;
55
56 if (argc < 3 || argc > 5) {
57 fprintf(stderr, "%s <family> <table> [<obj>]\n",
58 argv[0]);
59 return EXIT_FAILURE;
60 }
61
62 if (strcmp(argv[1], "ip") == 0)
63 family = NFPROTO_IPV4;
64 else if (strcmp(argv[1], "ip6") == 0)
65 family = NFPROTO_IPV6;
66 else if (strcmp(argv[1], "inet") == 0)
67 family = NFPROTO_INET;
68 else if (strcmp(argv[1], "unspec") == 0)
69 family = NFPROTO_UNSPEC;
70 else {
71 fprintf(stderr, "Unknown family: ip, ip6, inet, unspec");
72 exit(EXIT_FAILURE);
73 }
74
75 if (argc == 3 || argc == 4) {
76 t = nftnl_obj_alloc();
77 if (t == NULL) {
78 perror("OOM");
79 exit(EXIT_FAILURE);
80 }
81 }
82
83 seq = time(NULL);
84 nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_HELPER);
85 if (argc < 4) {
86 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family,
87 NLM_F_DUMP, seq);
88 if (argc == 3) {
89 nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
90 nftnl_obj_nlmsg_build_payload(nlh, t);
91 nftnl_obj_free(t);
92 }
93 } else {
94 nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
95 nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
96
97 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family,
98 NLM_F_ACK, seq);
99 nftnl_obj_nlmsg_build_payload(nlh, t);
100 nftnl_obj_free(t);
101 }
102
103 nl = mnl_socket_open(NETLINK_NETFILTER);
104 if (nl == NULL) {
105 perror("mnl_socket_open");
106 exit(EXIT_FAILURE);
107 }
108
109 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
110 perror("mnl_socket_bind");
111 exit(EXIT_FAILURE);
112 }
113 portid = mnl_socket_get_portid(nl);
114
115 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
116 perror("mnl_socket_send");
117 exit(EXIT_FAILURE);
118 }
119
120 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
121 while (ret > 0) {
122 ret = mnl_cb_run(buf, ret, seq, portid, obj_cb, &type);
123 if (ret <= 0)
124 break;
125 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
126 }
127 if (ret == -1) {
128 perror("error");
129 exit(EXIT_FAILURE);
130 }
131 mnl_socket_close(nl);
132
133 return EXIT_SUCCESS;
134}