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/*
* Copyright (C) 2010 Martin Willi
* Copyright (C) 2010 revosec AG
*
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
/*
* Copyright (C) 2012 achelos GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "hook.h"
/* this hook is currently only supported on Linux (systems like FreeBSD don't
* actually provide an interface to change the sequence numbers of SAs) */
#ifdef __linux__
#include <linux/xfrm.h>
#include <unistd.h>
#include <errno.h>
#include <processing/jobs/callback_job.h>
#include <plugins/kernel_netlink/kernel_netlink_shared.h>
#define XFRM_RTA(nlh, x) ((struct rtattr*)(NLMSG_DATA(nlh) + NLMSG_ALIGN(sizeof(x))))
typedef struct private_reset_seq_t private_reset_seq_t;
/**
* Private data of an reset_seq_t object.
*/
struct private_reset_seq_t {
/**
* Implements the hook_t interface.
*/
hook_t hook;
/**
* Delay for reset
*/
int delay;
/**
* Sequence number to set for outgoing packages
*/
int oseq;
};
typedef struct reset_cb_data_t reset_cb_data_t;
/**
* Data needed for the callback job
*/
struct reset_cb_data_t {
/**
* The SA to modify
*/
struct xfrm_usersa_id usersa;
/**
* Sequence number to set for outgoing packages
*/
int oseq;
};
/**
* Callback job
*/
static job_requeue_t reset_cb(struct reset_cb_data_t *data)
{
netlink_buf_t request;
struct nlmsghdr *hdr;
struct xfrm_aevent_id *id;
struct rtattr *rthdr;
struct xfrm_replay_state *rpstate;
struct sockaddr_nl addr;
int s, len;
DBG1(DBG_CFG, "setting sequence number of SPI 0x%x to %d",
htonl(data->usersa.spi), data->oseq);
memset(&request, 0, sizeof(request));
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_REPLACE;
hdr->nlmsg_seq = 201;
hdr->nlmsg_pid = getpid();
hdr->nlmsg_type = XFRM_MSG_NEWAE;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_aevent_id));
id = (struct xfrm_aevent_id*)NLMSG_DATA(hdr);
id->sa_id = data->usersa;
rthdr = XFRM_RTA(hdr, struct xfrm_aevent_id);
rthdr->rta_type = XFRMA_REPLAY_VAL;
rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_replay_state));
hdr->nlmsg_len += rthdr->rta_len;
/* xfrm_replay_state is the structure the kernel uses for
* replay detection, and the oseq element contains the
* sequence number for outgoing packets. Currently, this
* function sets the other elements seq (records the number of
* incoming packets) and bitmask to zero, but they could be
* adjusted in the same way as oseq if required. */
rpstate = (struct xfrm_replay_state*)RTA_DATA(rthdr);
rpstate->oseq = data->oseq;
s = socket(AF_NETLINK, SOCK_RAW, NETLINK_XFRM);
if (s == -1)
{
DBG1(DBG_CFG, "opening XFRM socket failed: %s", strerror(errno));
return JOB_REQUEUE_NONE;
}
memset(&addr, 0, sizeof(addr));
addr.nl_family = AF_NETLINK;
len = sendto(s, hdr, hdr->nlmsg_len, 0,
(struct sockaddr*)&addr, sizeof(addr));
if (len != hdr->nlmsg_len)
{
DBG1(DBG_CFG, "sending XFRM aevent failed: %s", strerror(errno));
}
close(s);
return JOB_REQUEUE_NONE;
}
/**
* Schedule sequence number reset job
*/
static void schedule_reset_job(private_reset_seq_t *this, host_t *dst,
u_int32_t spi)
{
struct reset_cb_data_t *data;
chunk_t chunk;
INIT(data,
.usersa = {
.spi = spi,
.family = dst->get_family(dst),
.proto = IPPROTO_ESP,
},
.oseq = this->oseq,
);
chunk = dst->get_address(dst);
memcpy(&data->usersa.daddr, chunk.ptr,
min(chunk.len, sizeof(xfrm_address_t)));
lib->scheduler->schedule_job(lib->scheduler,
(job_t*)callback_job_create(
(void*)reset_cb, data, (void*)free, NULL),
this->delay);
}
METHOD(listener_t, child_updown, bool,
private_reset_seq_t *this, ike_sa_t *ike_sa, child_sa_t *child_sa,
bool up)
{
if (up)
{
schedule_reset_job(this, ike_sa->get_other_host(ike_sa),
child_sa->get_spi(child_sa, FALSE));
}
return TRUE;
}
METHOD(hook_t, destroy, void,
private_reset_seq_t *this)
{
free(this);
}
/**
* Create the IKE_AUTH fill hook
*/
hook_t *reset_seq_hook_create(char *name)
{
private_reset_seq_t *this;
INIT(this,
.hook = {
.listener = {
.child_updown = _child_updown,
},
.destroy = _destroy,
},
.delay = conftest->test->get_int(conftest->test,
"hooks.%s.delay", 10, name),
.oseq = conftest->test->get_int(conftest->test,
"hooks.%s.oseq", 0, name),
);
return &this->hook;
}
#endif /* __linux__ */
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