nft-compat-get.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/nfnetlink.h>
#include <linux/netfilter/nf_tables_compat.h>
#include <libmnl/libmnl.h>
static int data_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, NFTA_COMPAT_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_COMPAT_NAME:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
case NFTA_COMPAT_REV:
case NFTA_COMPAT_TYPE:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
perror("mnl_attr_validate");
return MNL_CB_ERROR;
}
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[NFTA_COMPAT_MAX+1] = {};
struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh);
if (mnl_attr_parse(nlh, sizeof(*nfg), data_attr_cb, tb) < 0)
return MNL_CB_ERROR;
if (tb[NFTA_COMPAT_NAME])
printf("name=%s ", mnl_attr_get_str(tb[NFTA_COMPAT_NAME]));
if (tb[NFTA_COMPAT_REV])
printf("rev=%d ", ntohl(mnl_attr_get_u32(tb[NFTA_COMPAT_REV])));
if (tb[NFTA_COMPAT_TYPE])
printf("type=%d ", ntohl(mnl_attr_get_u32(tb[NFTA_COMPAT_REV])));
printf("\n");
return MNL_CB_OK;
}
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
uint32_t portid, seq, rev, type;
int ret;
if (argc != 4) {
fprintf(stderr, "Usage: %s <extension_name> <type> <rev>\n",
argv[0]);
return EXIT_FAILURE;
}
if (strcmp(argv[2], "target") == 0)
type = 1;
else if (strcmp(argv[2], "match") == 0)
type = 0;
else {
fprintf(stderr, "type should be `target' or `match'\n");
return EXIT_FAILURE;
}
rev = atoi(argv[3]);
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_NFT_COMPAT << 8) | NFNL_MSG_COMPAT_GET;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
nlh->nlmsg_seq = seq = time(NULL);
struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
nfg->nfgen_family = AF_INET;
nfg->version = NFNETLINK_V0;
nfg->res_id = 0;
mnl_attr_put_strz(nlh, NFTA_COMPAT_NAME, argv[1]);
mnl_attr_put_u32(nlh, NFTA_COMPAT_REV, htonl(rev));
mnl_attr_put_u32(nlh, NFTA_COMPAT_TYPE, htonl(type));
printf("requesting `%s' rev=%d type=%d\n", argv[1], rev, type);
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, cb, 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;
}