libnftnl 1.2.9
nft-set-elem-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#include <stdlib.h>
9#include <time.h>
10#include <string.h>
11#include <netinet/in.h>
12
13#include <linux/netfilter.h>
14#include <linux/netfilter/nf_tables.h>
15
16#include <libmnl/libmnl.h>
17#include <libnftnl/set.h>
18
19static int set_cb(const struct nlmsghdr *nlh, void *data)
20{
21 struct nftnl_set *t;
22 char buf[4096];
23 uint32_t *type = data;
24
25 t = nftnl_set_alloc();
26 if (t == NULL) {
27 perror("OOM");
28 goto err;
29 }
30
31 if (nftnl_set_elems_nlmsg_parse(nlh, t) < 0) {
32 perror("nftnl_set_nlmsg_parse");
33 goto err_free;
34 }
35
36 nftnl_set_snprintf(buf, sizeof(buf), t, *type, 0);
37 printf("%s\n", buf);
38
39err_free:
40 nftnl_set_free(t);
41err:
42 return MNL_CB_OK;
43}
44
45int main(int argc, char *argv[])
46{
47 struct mnl_socket *nl;
48 char buf[MNL_SOCKET_BUFFER_SIZE];
49 struct nlmsghdr *nlh;
50 uint32_t portid, seq, family;
51 uint32_t type = NFTNL_OUTPUT_DEFAULT;
52 struct nftnl_set *t = NULL;
53 int ret;
54
55 if (argc < 4 || argc > 5) {
56 fprintf(stderr, "%s <family> <table> <set>\n", argv[0]);
57 return EXIT_FAILURE;
58 }
59 t = nftnl_set_alloc();
60 if (t == NULL) {
61 perror("OOM");
62 exit(EXIT_FAILURE);
63 }
64 seq = time(NULL);
65 if (strcmp(argv[1], "ip") == 0)
66 family = NFPROTO_IPV4;
67 else if (strcmp(argv[1], "ip6") == 0)
68 family = NFPROTO_IPV6;
69 else if (strcmp(argv[1], "inet") == 0)
70 family = NFPROTO_INET;
71 else if (strcmp(argv[1], "bridge") == 0)
72 family = NFPROTO_BRIDGE;
73 else if (strcmp(argv[1], "arp") == 0)
74 family = NFPROTO_ARP;
75 else {
76 fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp\n");
77 exit(EXIT_FAILURE);
78 }
79
80 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETSETELEM, family,
81 NLM_F_DUMP | NLM_F_ACK, seq);
82 nftnl_set_set_str(t, NFTNL_SET_NAME, argv[3]);
83 nftnl_set_set_str(t, NFTNL_SET_TABLE, argv[2]);
84 nftnl_set_elems_nlmsg_build_payload(nlh, t);
85 nftnl_set_free(t);
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, nlh, nlh->nlmsg_len) < 0) {
100 perror("mnl_socket_send");
101 exit(EXIT_FAILURE);
102 }
103
104 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
105 while (ret > 0) {
106 ret = mnl_cb_run(buf, ret, seq, portid, set_cb, &type);
107 if (ret <= 0)
108 break;
109 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
110 }
111 if (ret == -1) {
112 perror("error");
113 exit(EXIT_FAILURE);
114 }
115 mnl_socket_close(nl);
116
117 return EXIT_SUCCESS;
118}