8813217a67
compiled into the kernel. Do not try to build the module in case of no INET support but keep #error calls for now in case we would compile it into the kernel. This should fix an issue where the module would fail to enable IPv6 support from the rc framework, but also other INET and INET6 parts being silently compiled out without giving a warning in the module case. While here garbage collect unneeded opt_*.h includes. opt_ipdn.h is not used anywhere but we need to leave the DUMMYNET entry in options for conditional inclusion in kernel so keep the file with the same name. Reported by: pluknet Reviewed by: plunket, jhb MFC After: 3 days
461 lines
11 KiB
C
461 lines
11 KiB
C
/*-
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* Copyright (c) 2004 Andre Oppermann, Internet Business Solutions AG
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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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* 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 AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* 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 "opt_ipfw.h"
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#include "opt_inet.h"
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#include "opt_inet6.h"
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#ifndef INET
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#error IPFIREWALL requires INET.
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#endif /* INET */
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/module.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/rwlock.h>
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#include <sys/socket.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <net/pfil.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_fw.h>
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#ifdef INET6
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#include <netinet/ip6.h>
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#include <netinet6/ip6_var.h>
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#endif
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#include <netinet/ipfw/ip_fw_private.h>
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#include <netgraph/ng_ipfw.h>
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#include <machine/in_cksum.h>
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static VNET_DEFINE(int, fw_enable) = 1;
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#define V_fw_enable VNET(fw_enable)
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#ifdef INET6
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static VNET_DEFINE(int, fw6_enable) = 1;
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#define V_fw6_enable VNET(fw6_enable)
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#endif
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int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
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/* Forward declarations. */
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static int ipfw_divert(struct mbuf **, int, struct ipfw_rule_ref *, int);
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#ifdef SYSCTL_NODE
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SYSBEGIN(f1)
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SYSCTL_DECL(_net_inet_ip_fw);
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SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, enable,
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CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_enable), 0,
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ipfw_chg_hook, "I", "Enable ipfw");
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#ifdef INET6
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SYSCTL_DECL(_net_inet6_ip6_fw);
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SYSCTL_VNET_PROC(_net_inet6_ip6_fw, OID_AUTO, enable,
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CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw6_enable), 0,
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ipfw_chg_hook, "I", "Enable ipfw+6");
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#endif /* INET6 */
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SYSEND
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#endif /* SYSCTL_NODE */
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/*
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* The pfilter hook to pass packets to ipfw_chk and then to
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* dummynet, divert, netgraph or other modules.
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* The packet may be consumed.
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*/
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int
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ipfw_check_hook(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
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struct inpcb *inp)
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{
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struct ip_fw_args args;
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struct m_tag *tag;
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int ipfw;
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int ret;
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/* all the processing now uses ip_len in net format */
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if (mtod(*m0, struct ip *)->ip_v == 4)
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SET_NET_IPLEN(mtod(*m0, struct ip *));
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/* convert dir to IPFW values */
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dir = (dir == PFIL_IN) ? DIR_IN : DIR_OUT;
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bzero(&args, sizeof(args));
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again:
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/*
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* extract and remove the tag if present. If we are left
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* with onepass, optimize the outgoing path.
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*/
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tag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
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if (tag != NULL) {
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args.rule = *((struct ipfw_rule_ref *)(tag+1));
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m_tag_delete(*m0, tag);
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if (args.rule.info & IPFW_ONEPASS) {
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if (mtod(*m0, struct ip *)->ip_v == 4)
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SET_HOST_IPLEN(mtod(*m0, struct ip *));
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return (0);
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}
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}
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args.m = *m0;
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args.oif = dir == DIR_OUT ? ifp : NULL;
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args.inp = inp;
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ipfw = ipfw_chk(&args);
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*m0 = args.m;
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KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
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__func__));
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/* breaking out of the switch means drop */
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ret = 0; /* default return value for pass */
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switch (ipfw) {
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case IP_FW_PASS:
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/* next_hop may be set by ipfw_chk */
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if (args.next_hop == NULL && args.next_hop6 == NULL)
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break; /* pass */
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#if !defined(IPFIREWALL_FORWARD) || (!defined(INET6) && !defined(INET))
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ret = EACCES;
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#else
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{
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struct m_tag *fwd_tag;
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size_t len;
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KASSERT(args.next_hop == NULL || args.next_hop6 == NULL,
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("%s: both next_hop=%p and next_hop6=%p not NULL", __func__,
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args.next_hop, args.next_hop6));
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#ifdef INET6
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if (args.next_hop6 != NULL)
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len = sizeof(struct sockaddr_in6);
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#endif
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#ifdef INET
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if (args.next_hop != NULL)
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len = sizeof(struct sockaddr_in);
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#endif
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/* Incoming packets should not be tagged so we do not
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* m_tag_find. Outgoing packets may be tagged, so we
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* reuse the tag if present.
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*/
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fwd_tag = (dir == DIR_IN) ? NULL :
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m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
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if (fwd_tag != NULL) {
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m_tag_unlink(*m0, fwd_tag);
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} else {
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fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD, len,
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M_NOWAIT);
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if (fwd_tag == NULL) {
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ret = EACCES;
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break; /* i.e. drop */
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}
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}
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#ifdef INET6
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if (args.next_hop6 != NULL) {
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bcopy(args.next_hop6, (fwd_tag+1), len);
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if (in6_localip(&args.next_hop6->sin6_addr))
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(*m0)->m_flags |= M_FASTFWD_OURS;
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}
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#endif
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#ifdef INET
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if (args.next_hop != NULL) {
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bcopy(args.next_hop, (fwd_tag+1), len);
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if (in_localip(args.next_hop->sin_addr))
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(*m0)->m_flags |= M_FASTFWD_OURS;
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}
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#endif
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m_tag_prepend(*m0, fwd_tag);
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}
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#endif /* IPFIREWALL_FORWARD */
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break;
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case IP_FW_DENY:
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ret = EACCES;
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break; /* i.e. drop */
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case IP_FW_DUMMYNET:
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ret = EACCES;
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if (ip_dn_io_ptr == NULL)
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break; /* i.e. drop */
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if (mtod(*m0, struct ip *)->ip_v == 4)
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ret = ip_dn_io_ptr(m0, dir, &args);
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else if (mtod(*m0, struct ip *)->ip_v == 6)
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ret = ip_dn_io_ptr(m0, dir | PROTO_IPV6, &args);
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else
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break; /* drop it */
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/*
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* XXX should read the return value.
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* dummynet normally eats the packet and sets *m0=NULL
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* unless the packet can be sent immediately. In this
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* case args is updated and we should re-run the
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* check without clearing args.
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*/
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if (*m0 != NULL)
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goto again;
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break;
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case IP_FW_TEE:
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case IP_FW_DIVERT:
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if (ip_divert_ptr == NULL) {
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ret = EACCES;
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break; /* i.e. drop */
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}
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ret = ipfw_divert(m0, dir, &args.rule,
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(ipfw == IP_FW_TEE) ? 1 : 0);
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/* continue processing for the original packet (tee). */
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if (*m0)
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goto again;
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break;
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case IP_FW_NGTEE:
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case IP_FW_NETGRAPH:
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if (ng_ipfw_input_p == NULL) {
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ret = EACCES;
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break; /* i.e. drop */
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}
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ret = ng_ipfw_input_p(m0, dir, &args,
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(ipfw == IP_FW_NGTEE) ? 1 : 0);
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if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
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goto again; /* continue with packet */
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break;
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case IP_FW_NAT:
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/* honor one-pass in case of successful nat */
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if (V_fw_one_pass)
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break; /* ret is already 0 */
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goto again;
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case IP_FW_REASS:
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goto again; /* continue with packet */
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default:
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KASSERT(0, ("%s: unknown retval", __func__));
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}
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if (ret != 0) {
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if (*m0)
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FREE_PKT(*m0);
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*m0 = NULL;
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}
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if (*m0 && mtod(*m0, struct ip *)->ip_v == 4)
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SET_HOST_IPLEN(mtod(*m0, struct ip *));
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return ret;
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}
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/* do the divert, return 1 on error 0 on success */
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static int
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ipfw_divert(struct mbuf **m0, int incoming, struct ipfw_rule_ref *rule,
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int tee)
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{
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/*
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* ipfw_chk() has already tagged the packet with the divert tag.
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* If tee is set, copy packet and return original.
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* If not tee, consume packet and send it to divert socket.
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*/
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struct mbuf *clone;
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struct ip *ip = mtod(*m0, struct ip *);
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struct m_tag *tag;
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/* Cloning needed for tee? */
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if (tee == 0) {
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clone = *m0; /* use the original mbuf */
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*m0 = NULL;
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} else {
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clone = m_dup(*m0, M_DONTWAIT);
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/* If we cannot duplicate the mbuf, we sacrifice the divert
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* chain and continue with the tee-ed packet.
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*/
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if (clone == NULL)
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return 1;
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}
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/*
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* Divert listeners can normally handle non-fragmented packets,
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* but we can only reass in the non-tee case.
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* This means that listeners on a tee rule may get fragments,
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* and have to live with that.
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* Note that we now have the 'reass' ipfw option so if we care
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* we can do it before a 'tee'.
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*/
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if (!tee) switch (ip->ip_v) {
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case IPVERSION:
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if (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
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int hlen;
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struct mbuf *reass;
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SET_HOST_IPLEN(ip); /* ip_reass wants host order */
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reass = ip_reass(clone); /* Reassemble packet. */
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if (reass == NULL)
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return 0; /* not an error */
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/* if reass = NULL then it was consumed by ip_reass */
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/*
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* IP header checksum fixup after reassembly and leave header
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* in network byte order.
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*/
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ip = mtod(reass, struct ip *);
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hlen = ip->ip_hl << 2;
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SET_NET_IPLEN(ip);
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ip->ip_sum = 0;
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if (hlen == sizeof(struct ip))
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ip->ip_sum = in_cksum_hdr(ip);
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else
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ip->ip_sum = in_cksum(reass, hlen);
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clone = reass;
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}
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break;
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#ifdef INET6
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case IPV6_VERSION >> 4:
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{
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struct ip6_hdr *const ip6 = mtod(clone, struct ip6_hdr *);
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if (ip6->ip6_nxt == IPPROTO_FRAGMENT) {
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int nxt, off;
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off = sizeof(struct ip6_hdr);
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nxt = frag6_input(&clone, &off, 0);
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if (nxt == IPPROTO_DONE)
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return (0);
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}
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break;
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}
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#endif
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}
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/* attach a tag to the packet with the reinject info */
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tag = m_tag_alloc(MTAG_IPFW_RULE, 0,
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sizeof(struct ipfw_rule_ref), M_NOWAIT);
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if (tag == NULL) {
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FREE_PKT(clone);
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return 1;
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}
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*((struct ipfw_rule_ref *)(tag+1)) = *rule;
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m_tag_prepend(clone, tag);
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/* Do the dirty job... */
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ip_divert_ptr(clone, incoming);
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return 0;
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}
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/*
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* attach or detach hooks for a given protocol family
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*/
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static int
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ipfw_hook(int onoff, int pf)
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{
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struct pfil_head *pfh;
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pfh = pfil_head_get(PFIL_TYPE_AF, pf);
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if (pfh == NULL)
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return ENOENT;
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(void) (onoff ? pfil_add_hook : pfil_remove_hook)
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(ipfw_check_hook, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh);
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return 0;
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}
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int
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ipfw_attach_hooks(int arg)
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{
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int error = 0;
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if (arg == 0) /* detach */
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ipfw_hook(0, AF_INET);
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else if (V_fw_enable && ipfw_hook(1, AF_INET) != 0) {
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error = ENOENT; /* see ip_fw_pfil.c::ipfw_hook() */
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printf("ipfw_hook() error\n");
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}
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#ifdef INET6
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if (arg == 0) /* detach */
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ipfw_hook(0, AF_INET6);
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else if (V_fw6_enable && ipfw_hook(1, AF_INET6) != 0) {
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error = ENOENT;
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printf("ipfw6_hook() error\n");
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}
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#endif
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return error;
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}
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int
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ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
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{
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int enable;
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int oldenable;
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int error;
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int af;
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if (arg1 == &VNET_NAME(fw_enable)) {
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enable = V_fw_enable;
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af = AF_INET;
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}
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#ifdef INET6
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else if (arg1 == &VNET_NAME(fw6_enable)) {
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enable = V_fw6_enable;
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af = AF_INET6;
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}
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#endif
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else
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return (EINVAL);
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oldenable = enable;
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error = sysctl_handle_int(oidp, &enable, 0, req);
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if (error)
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return (error);
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enable = (enable) ? 1 : 0;
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if (enable == oldenable)
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return (0);
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error = ipfw_hook(enable, af);
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if (error)
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return (error);
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if (af == AF_INET)
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V_fw_enable = enable;
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#ifdef INET6
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else if (af == AF_INET6)
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V_fw6_enable = enable;
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#endif
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return (0);
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}
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/* end of file */
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