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/* libnfqnetlink.c: generic library for access to nf_queue
*
* (C) 2005 by Harald Welte <laforge@gnumonks.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_queue.h>
#include <libnfnetlink/libnfnetlink.h>
#include <libnfnetlink_queue/libnfnetlink_queue.h>
/***********************************************************************
* low level stuff
***********************************************************************/
int nfqnl_open(struct nfqnl_handle *h)
{
int err;
memset(h, 0, sizeof(*h));
err = nfnl_open(&h->nfnlh, NFNL_SUBSYS_QUEUE, 0);
if (err < 0)
return err;
return 0;
}
int nfqnl_close(struct nfqnl_handle *h)
{
return nfnl_close(&h->nfnlh);
}
/* build a NFQNL_MSG_CONFIG message */
static int
__build_send_cfg_msg(struct nfqnl_handle *h, u_int8_t command,
u_int16_t queuenum, u_int16_t pf)
{
char buf[NLMSG_LENGTH(sizeof(struct nlmsghdr))
+NLMSG_LENGTH(sizeof(struct nfgenmsg))
+NFA_LENGTH(sizeof(struct nfqnl_msg_config_cmd))];
struct nfqnl_msg_config_cmd cmd;
struct nlmsghdr *nmh = (struct nlmsghdr *) buf;
nfnl_fill_hdr(&h->nfnlh, nmh, 0, AF_UNSPEC, queuenum,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
cmd.command = command;
cmd.pf = htons(pf);
nfnl_addattr_l(nmh, sizeof(buf), NFQA_CFG_CMD, &cmd, sizeof(cmd));
return nfnl_send(&h->nfnlh, nmh);
}
/* bind nf_queue from a specific protocol family */
int nfqnl_bind_pf(struct nfqnl_handle *h, u_int16_t pf)
{
return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_BIND, 0, pf);
}
/* unbind nf_queue from a specific protocol family */
int nfqnl_unbind_pf(struct nfqnl_handle *h, u_int16_t pf)
{
return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_UNBIND, 0, pf);
}
/* bind this socket to a specific queue number */
int nfqnl_create_queue(struct nfqnl_handle *h,
struct nfqnl_q_handle *qh, u_int16_t num)
{
qh->h = h;
qh->id = num;
return __build_send_cfg_msg(h, NFQNL_CFG_CMD_BIND, num, 0);
}
/* unbind this socket from a specific queue number */
int nfqnl_destroy_queue(struct nfqnl_q_handle *qh)
{
int ret = __build_send_cfg_msg(qh->h, NFQNL_CFG_CMD_UNBIND, qh->id, 0);
if (ret == 0)
qh->h = NULL;
return ret;
}
int nfqnl_set_mode(struct nfqnl_q_handle *qh,
u_int8_t mode, u_int32_t range)
{
char buf[NLMSG_LENGTH(sizeof(struct nlmsghdr))
+NLMSG_LENGTH(sizeof(struct nfgenmsg))
+NFA_LENGTH(sizeof(struct nfqnl_msg_config_params))];
struct nfqnl_msg_config_params params;
struct nlmsghdr *nmh = (struct nlmsghdr *) buf;
nfnl_fill_hdr(&qh->h->nfnlh, nmh, 0, AF_UNSPEC, qh->id,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
params.copy_range = htonl(range);
params.copy_mode = mode;
nfnl_addattr_l(nmh, sizeof(buf), NFQA_CFG_PARAMS, ¶ms,
sizeof(params));
return nfnl_send(&qh->h->nfnlh, nmh);
}
static int __set_verdict(struct nfqnl_q_handle *qh, u_int32_t id,
u_int32_t verdict, u_int32_t mark, int set_mark,
u_int32_t data_len, unsigned char *data)
{
struct nfqnl_msg_verdict_hdr vh;
char buf[NLMSG_LENGTH(sizeof(struct nlmsghdr))
+NLMSG_LENGTH(sizeof(struct nfgenmsg))
+NFA_LENGTH(sizeof(mark))
+NFA_LENGTH(sizeof(vh))];
struct nlmsghdr *nmh = (struct nlmsghdr *) buf;
struct iovec iov[3];
int nvecs;
vh.verdict = htonl(verdict);
vh.id = htonl(id);
nfnl_fill_hdr(&qh->h->nfnlh, nmh, 0, AF_UNSPEC, qh->id,
NFQNL_MSG_VERDICT, NLM_F_REQUEST);
/* add verdict header */
nfnl_addattr_l(nmh, sizeof(buf), NFQA_VERDICT_HDR, &vh, sizeof(vh));
if (set_mark)
nfnl_addattr32(nmh, sizeof(buf), NFQA_MARK, mark);
iov[0].iov_base = nmh;
iov[0].iov_len = NLMSG_TAIL(nmh) - (void *)nmh;
nvecs = 1;
if (data_len) {
struct nfattr data_attr;
nfnl_build_nfa_iovec(&iov[1], &data_attr, NFQA_PAYLOAD,
data_len, data);
nvecs += 2;
}
return nfnl_sendiov(&qh->h->nfnlh, iov, nvecs, 0);
}
int nfqnl_set_verdict(struct nfqnl_q_handle *qh, u_int32_t id,
u_int32_t verdict, u_int32_t data_len,
unsigned char *buf)
{
return __set_verdict(qh, id, verdict, 0, 0, data_len, buf);
}
int nfqnl_set_verdict_mark(struct nfqnl_q_handle *qh, u_int32_t id,
u_int32_t verdict, u_int32_t mark,
u_int32_t datalen, unsigned char *buf)
{
return __set_verdict(qh, id, verdict, mark, 1, datalen, buf);
}
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