aac74aeac7
The module is designed for modification of a packets of any protocols. For now it implements only TCP MSS modification. It adds the external action handler for "tcp-setmss" action. A rule with tcp-setmss action does additional check for protocol and TCP flags. If SYN flag is present, it parses TCP options and modifies MSS option if its value is greater than configured value in the rule. Then it adjustes TCP checksum if needed. After handling the search continues with the next rule. Obtained from: Yandex LLC MFC after: 2 weeks Relnotes: yes Sponsored by: Yandex LLC No objection from: #network Differential Revision: https://reviews.freebsd.org/D10150
102 lines
3.0 KiB
C
102 lines
3.0 KiB
C
/*-
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* Copyright (c) 2017 Yandex LLC
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* Copyright (c) 2017 Andrey V. Elsukov <ae@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/rwlock.h>
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#include <sys/socket.h>
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#include <net/if.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_fw.h>
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#include <netpfil/ipfw/ip_fw_private.h>
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#include <netpfil/ipfw/pmod/pmod.h>
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static int
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vnet_ipfw_pmod_init(const void *arg __unused)
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{
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int error;
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error = tcpmod_init(&V_layer3_chain, IS_DEFAULT_VNET(curvnet));
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return (error);
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}
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static int
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vnet_ipfw_pmod_uninit(const void *arg __unused)
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{
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tcpmod_uninit(&V_layer3_chain, IS_DEFAULT_VNET(curvnet));
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return (0);
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}
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static int
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ipfw_pmod_modevent(module_t mod, int type, void *unused)
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{
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switch (type) {
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case MOD_LOAD:
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case MOD_UNLOAD:
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break;
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default:
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return (EOPNOTSUPP);
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}
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return (0);
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}
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static moduledata_t ipfw_pmod_mod = {
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"ipfw_pmod",
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ipfw_pmod_modevent,
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0
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};
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/* Define startup order. */
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#define IPFW_PMOD_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
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#define IPFW_PMOD_MODEVENT_ORDER (SI_ORDER_ANY - 128) /* after ipfw */
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#define IPFW_PMOD_MODULE_ORDER (IPFW_PMOD_MODEVENT_ORDER + 1)
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#define IPFW_PMOD_VNET_ORDER (IPFW_PMOD_MODEVENT_ORDER + 2)
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DECLARE_MODULE(ipfw_pmod, ipfw_pmod_mod, IPFW_PMOD_SI_SUB_FIREWALL,
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IPFW_PMOD_MODULE_ORDER);
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MODULE_DEPEND(ipfw_pmod, ipfw, 3, 3, 3);
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MODULE_VERSION(ipfw_pmod, 1);
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VNET_SYSINIT(vnet_ipfw_pmod_init, IPFW_PMOD_SI_SUB_FIREWALL,
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IPFW_PMOD_VNET_ORDER, vnet_ipfw_pmod_init, NULL);
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VNET_SYSUNINIT(vnet_ipfw_pmod_uninit, IPFW_PMOD_SI_SUB_FIREWALL,
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IPFW_PMOD_VNET_ORDER, vnet_ipfw_pmod_uninit, NULL);
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