nft-chain-add.c
/*
* (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/chain.h>
static struct nftnl_chain *chain_add_parse(int argc, char *argv[])
{
struct nftnl_chain *t;
int hooknum = 0;
if (argc == 6) {
/* This is a base chain, set the hook number */
if (strcmp(argv[4], "NF_INET_LOCAL_IN") == 0)
hooknum = NF_INET_LOCAL_IN;
else if (strcmp(argv[4], "NF_INET_LOCAL_OUT") == 0)
hooknum = NF_INET_LOCAL_OUT;
else if (strcmp(argv[4], "NF_INET_PRE_ROUTING") == 0)
hooknum = NF_INET_PRE_ROUTING;
else if (strcmp(argv[4], "NF_INET_POST_ROUTING") == 0)
hooknum = NF_INET_POST_ROUTING;
else if (strcmp(argv[4], "NF_INET_FORWARD") == 0)
hooknum = NF_INET_FORWARD;
else {
fprintf(stderr, "Unknown hook: %s\n", argv[4]);
return NULL;
}
}
t = nftnl_chain_alloc();
if (t == NULL) {
perror("OOM");
return NULL;
}
nftnl_chain_set_str(t, NFTNL_CHAIN_TABLE, argv[2]);
nftnl_chain_set_str(t, NFTNL_CHAIN_NAME, argv[3]);
if (argc == 6) {
nftnl_chain_set_u32(t, NFTNL_CHAIN_HOOKNUM, hooknum);
nftnl_chain_set_u32(t, NFTNL_CHAIN_PRIO, atoi(argv[5]));
}
return t;
}
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
uint32_t portid, seq, chain_seq;
int ret, family;
struct nftnl_chain *t;
struct mnl_nlmsg_batch *batch;
if (argc != 4 && argc != 6) {
fprintf(stderr, "Usage: %s <family> <table> <chain> "
"[<hooknum> <prio>]\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 {
fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp\n");
exit(EXIT_FAILURE);
}
t = chain_add_parse(argc, argv);
if (t == NULL)
exit(EXIT_FAILURE);
seq = time(NULL);
batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++);
mnl_nlmsg_batch_next(batch);
chain_seq = seq;
nlh = nftnl_chain_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
NFT_MSG_NEWCHAIN, family,
NLM_F_CREATE|NLM_F_ACK, seq++);
nftnl_chain_nlmsg_build_payload(nlh, t);
nftnl_chain_free(t);
mnl_nlmsg_batch_next(batch);
nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++);
mnl_nlmsg_batch_next(batch);
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, mnl_nlmsg_batch_head(batch),
mnl_nlmsg_batch_size(batch)) < 0) {
perror("mnl_socket_send");
exit(EXIT_FAILURE);
}
mnl_nlmsg_batch_stop(batch);
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, chain_seq, portid, NULL, NULL);
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;
}
nftnl_chain
Definition: chain.c:32