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/*
* (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software has been sponsored by Sophos Astaro <http://www.sophos.com>
*/
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <netinet/in.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <libmnl/libmnl.h>
#include <libnftnl/rule.h>
static int table_cb(const struct nlmsghdr *nlh, void *data)
{
struct nftnl_rule *t;
char buf[4096];
uint32_t *type = data;
t = nftnl_rule_alloc();
if (t == NULL) {
perror("OOM");
goto err;
}
if (nftnl_rule_nlmsg_parse(nlh, t) < 0) {
perror("nftnl_rule_nlmsg_parse");
goto err_free;
}
nftnl_rule_snprintf(buf, sizeof(buf), t, *type, 0);
printf("%s\n", buf);
err_free:
nftnl_rule_free(t);
err:
return MNL_CB_OK;
}
static struct nftnl_rule *setup_rule(uint8_t family, const char *table,
const char *chain, const char *handle)
{
struct nftnl_rule *r;
uint64_t handle_num;
r = nftnl_rule_alloc();
if (r == NULL)
return NULL;
if (table != NULL)
nftnl_rule_set_str(r, NFTNL_RULE_TABLE, table);
if (chain != NULL)
nftnl_rule_set_str(r, NFTNL_RULE_CHAIN, chain);
nftnl_rule_set_u32(r, NFTNL_RULE_FAMILY, family);
if (handle != NULL) {
handle_num = atoll(handle);
nftnl_rule_set_u64(r, NFTNL_RULE_POSITION, handle_num);
}
return r;
}
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
uint32_t portid, seq, type = NFTNL_OUTPUT_DEFAULT;
const char *table = NULL, *chain = NULL;
struct nftnl_rule *r;
int ret, family;
if (argc < 2 || argc > 5) {
fprintf(stderr, "Usage: %s <family> [<table> <chain>]\n",
argv[0]);
exit(EXIT_FAILURE);
}
if (strcmp(argv[1], "ip") == 0)
family = NFPROTO_IPV4;
else if (strcmp(argv[1], "ip6") == 0)
family = NFPROTO_IPV6;
else if (strcmp(argv[1], "inet") == 0)
family = NFPROTO_INET;
else if (strcmp(argv[1], "bridge") == 0)
family = NFPROTO_BRIDGE;
else if (strcmp(argv[1], "arp") == 0)
family = NFPROTO_ARP;
else if (strcmp(argv[1], "unspec") == 0)
family = NFPROTO_UNSPEC;
else {
fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp, unspec\n");
exit(EXIT_FAILURE);
}
/* at least [<table> <chain>] specified */
if (argc >= 4) {
table = argv[2];
chain = argv[3];
}
seq = time(NULL);
nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, family,
NLM_F_DUMP, seq);
r = setup_rule(family, table, chain, NULL);
if (!r) {
perror("setup_rule");
exit(EXIT_FAILURE);
}
nftnl_rule_nlmsg_build_payload(nlh, r);
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
perror("mnl_socket_open");
exit(EXIT_FAILURE);
}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
perror("mnl_socket_bind");
exit(EXIT_FAILURE);
}
portid = mnl_socket_get_portid(nl);
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_send");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, table_cb, &type);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (ret == -1) {
perror("error");
exit(EXIT_FAILURE);
}
mnl_socket_close(nl);
return EXIT_SUCCESS;
}
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