libnftnl 1.2.6
nft-table-get.c
1/*
2 * (C) 2012 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 * This software has been sponsored by Sophos Astaro <http://www.sophos.com>
10 */
11
12#include <stdlib.h>
13#include <time.h>
14#include <string.h>
15#include <netinet/in.h>
16
17#include <linux/netfilter.h>
18#include <linux/netfilter/nf_tables.h>
19
20#include <libmnl/libmnl.h>
21#include <libnftnl/table.h>
22
23static int table_cb(const struct nlmsghdr *nlh, void *data)
24{
25 struct nftnl_table *t;
26 char buf[4096];
27 uint32_t *type = data;
28
29 t = nftnl_table_alloc();
30 if (t == NULL) {
31 perror("OOM");
32 goto err;
33 }
34
35 if (nftnl_table_nlmsg_parse(nlh, t) < 0) {
36 perror("nftnl_table_nlmsg_parse");
37 goto err_free;
38 }
39
40 nftnl_table_snprintf(buf, sizeof(buf), t, *type, 0);
41 printf("%s\n", buf);
42
43err_free:
44 nftnl_table_free(t);
45err:
46 return MNL_CB_OK;
47}
48
49int main(int argc, char *argv[])
50{
51 struct mnl_socket *nl;
52 char buf[MNL_SOCKET_BUFFER_SIZE];
53 struct nlmsghdr *nlh;
54 uint32_t portid, seq, family;
55 struct nftnl_table *t = NULL;
56 int ret;
57 uint32_t type = NFTNL_OUTPUT_DEFAULT;
58
59 if (argc < 2 || argc > 4) {
60 fprintf(stderr, "%s <family> [<table>]\n", argv[0]);
61 return EXIT_FAILURE;
62 }
63
64 if (strcmp(argv[1], "ip") == 0)
65 family = NFPROTO_IPV4;
66 else if (strcmp(argv[1], "ip6") == 0)
67 family = NFPROTO_IPV6;
68 else if (strcmp(argv[1], "inet") == 0)
69 family = NFPROTO_INET;
70 else if (strcmp(argv[1], "bridge") == 0)
71 family = NFPROTO_BRIDGE;
72 else if (strcmp(argv[1], "arp") == 0)
73 family = NFPROTO_ARP;
74 else if (strcmp(argv[1], "unspec") == 0)
75 family = NFPROTO_UNSPEC;
76 else {
77 fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp, unspec\n");
78 exit(EXIT_FAILURE);
79 }
80
81 if (argc == 3) {
82 t = nftnl_table_alloc();
83 if (t == NULL) {
84 perror("OOM");
85 exit(EXIT_FAILURE);
86 }
87 }
88
89 seq = time(NULL);
90 if (t == NULL) {
91 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, family,
92 NLM_F_DUMP, seq);
93 } else {
94 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, family,
95 NLM_F_ACK, seq);
96 nftnl_table_set_str(t, NFTNL_TABLE_NAME, argv[2]);
97 nftnl_table_nlmsg_build_payload(nlh, t);
98 nftnl_table_free(t);
99 }
100
101 nl = mnl_socket_open(NETLINK_NETFILTER);
102 if (nl == NULL) {
103 perror("mnl_socket_open");
104 exit(EXIT_FAILURE);
105 }
106
107 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
108 perror("mnl_socket_bind");
109 exit(EXIT_FAILURE);
110 }
111 portid = mnl_socket_get_portid(nl);
112
113 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
114 perror("mnl_socket_send");
115 exit(EXIT_FAILURE);
116 }
117
118 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
119 while (ret > 0) {
120 ret = mnl_cb_run(buf, ret, seq, portid, table_cb, &type);
121 if (ret <= 0)
122 break;
123 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
124 }
125 if (ret == -1) {
126 perror("error");
127 exit(EXIT_FAILURE);
128 }
129 mnl_socket_close(nl);
130
131 return EXIT_SUCCESS;
132}