libnftnl 1.2.6
nft-ct-expectation-get.c
1/*
2 * (C) 2019 by Stéphane Veyret <sveyret@gmail.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published
6 * by 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 <time.h>
12#include <string.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
21static 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 if (strcmp(str, "arp") == 0)
30 return NFPROTO_INET;
31 fprintf(stderr, "Unknown %s: ip, ip6, inet, arp\n", option);
32 exit(EXIT_FAILURE);
33}
34
35static struct nftnl_obj *obj_parse(int argc, char *argv[])
36{
37 struct nftnl_obj *t;
38 uint16_t family;
39
40 t = nftnl_obj_alloc();
41 if (t == NULL) {
42 perror("OOM");
43 return NULL;
44 }
45
46 family = parse_family(argv[1], "family");
47 nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family);
48 nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_EXPECT);
49 nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]);
50
51 if (argc > 3)
52 nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]);
53
54 return t;
55}
56
57static int obj_cb(const struct nlmsghdr *nlh, void *data)
58{
59 uint32_t *type = data;
60 struct nftnl_obj *t;
61 char buf[4096];
62
63 t = nftnl_obj_alloc();
64 if (t == NULL) {
65 perror("OOM");
66 goto err;
67 }
68
69 if (nftnl_obj_nlmsg_parse(nlh, t) < 0) {
70 perror("nftnl_obj_nlmsg_parse");
71 goto err_free;
72 }
73
74 nftnl_obj_snprintf(buf, sizeof(buf), t, *type, 0);
75 printf("%s\n", buf);
76
77err_free:
78 nftnl_obj_free(t);
79err:
80 return MNL_CB_OK;
81}
82
83int main(int argc, char *argv[])
84{
85 struct mnl_socket *nl;
86 char buf[MNL_SOCKET_BUFFER_SIZE];
87 struct nlmsghdr *nlh;
88 uint32_t portid, seq, family;
89 struct nftnl_obj *t;
90 int ret;
91 uint32_t type = NFTNL_OUTPUT_DEFAULT;
92 uint16_t flags = NLM_F_ACK;
93
94 if (argc < 3 || argc > 4) {
95 fprintf(stderr, "%s <family> <table> [<name>]\n", argv[0]);
96 return EXIT_FAILURE;
97 }
98
99 t = obj_parse(argc, argv);
100 if (t == NULL)
101 exit(EXIT_FAILURE);
102 family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY);
103
104 seq = time(NULL);
105 if (argc < 4)
106 flags = NLM_F_DUMP;
107 nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family, flags, seq);
108 nftnl_obj_nlmsg_build_payload(nlh, t);
109 nftnl_obj_free(t);
110
111 nl = mnl_socket_open(NETLINK_NETFILTER);
112 if (nl == NULL) {
113 perror("mnl_socket_open");
114 exit(EXIT_FAILURE);
115 }
116
117 if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
118 perror("mnl_socket_bind");
119 exit(EXIT_FAILURE);
120 }
121 portid = mnl_socket_get_portid(nl);
122
123 if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
124 perror("mnl_socket_send");
125 exit(EXIT_FAILURE);
126 }
127
128 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
129 while (ret > 0) {
130 ret = mnl_cb_run(buf, ret, seq, portid, obj_cb, &type);
131 if (ret <= 0)
132 break;
133 ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
134 }
135 if (ret == -1) {
136 perror("error");
137 exit(EXIT_FAILURE);
138 }
139 mnl_socket_close(nl);
140
141 return EXIT_SUCCESS;
142}