1652 lines
41 KiB
C
1652 lines
41 KiB
C
/* $NetBSD: ip_input.c,v 1.92 1999/07/23 15:21:17 itojun Exp $ */
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/*
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* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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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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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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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/*-
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* Copyright (c) 1998 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Public Access Networks Corporation ("Panix"). It was developed under
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* contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
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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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
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*/
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#include "opt_gateway.h"
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#include "opt_pfil_hooks.h"
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#include "opt_ipsec.h"
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#include "opt_mrouting.h"
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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/domain.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/pool.h>
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#include <vm/vm.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/route.h>
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#include <net/pfil.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/in_pcb.h>
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#include <netinet/in_var.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_icmp.h>
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/* just for gif_ttl */
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#include <netinet/in_gif.h>
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#include "gif.h"
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#ifdef IPSEC
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#include <netinet6/ipsec.h>
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#include <netkey/key.h>
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#include <netkey/key_debug.h>
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#endif
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#ifndef IPFORWARDING
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#ifdef GATEWAY
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#define IPFORWARDING 1 /* forward IP packets not for us */
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#else /* GATEWAY */
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#define IPFORWARDING 0 /* don't forward IP packets not for us */
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#endif /* GATEWAY */
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#endif /* IPFORWARDING */
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#ifndef IPSENDREDIRECTS
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#define IPSENDREDIRECTS 1
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#endif
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#ifndef IPFORWSRCRT
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#define IPFORWSRCRT 1 /* forward source-routed packets */
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#endif
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#ifndef IPALLOWSRCRT
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#define IPALLOWSRCRT 1 /* allow source-routed packets */
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#endif
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#ifndef IPMTUDISC
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#define IPMTUDISC 0
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#endif
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#ifndef IPMTUDISCTIMEOUT
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#define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
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#endif
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/*
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* Note: DIRECTED_BROADCAST is handled this way so that previous
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* configuration using this option will Just Work.
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*/
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#ifndef IPDIRECTEDBCAST
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#ifdef DIRECTED_BROADCAST
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#define IPDIRECTEDBCAST 1
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#else
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#define IPDIRECTEDBCAST 0
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#endif /* DIRECTED_BROADCAST */
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#endif /* IPDIRECTEDBCAST */
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int ipforwarding = IPFORWARDING;
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int ipsendredirects = IPSENDREDIRECTS;
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int ip_defttl = IPDEFTTL;
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int ip_forwsrcrt = IPFORWSRCRT;
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int ip_directedbcast = IPDIRECTEDBCAST;
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int ip_allowsrcrt = IPALLOWSRCRT;
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int ip_mtudisc = IPMTUDISC;
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u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
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#ifdef DIAGNOSTIC
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int ipprintfs = 0;
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#endif
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struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
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extern struct domain inetdomain;
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extern struct protosw inetsw[];
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u_char ip_protox[IPPROTO_MAX];
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int ipqmaxlen = IFQ_MAXLEN;
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struct in_ifaddrhead in_ifaddr;
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struct in_ifaddrhashhead *in_ifaddrhashtbl;
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struct ifqueue ipintrq;
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struct ipstat ipstat;
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u_int16_t ip_id;
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int ip_defttl;
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struct ipqhead ipq;
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int ipq_locked;
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static __inline int ipq_lock_try __P((void));
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static __inline void ipq_unlock __P((void));
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static __inline int
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ipq_lock_try()
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{
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int s;
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s = splimp();
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if (ipq_locked) {
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splx(s);
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return (0);
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}
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ipq_locked = 1;
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splx(s);
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return (1);
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}
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static __inline void
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ipq_unlock()
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{
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int s;
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s = splimp();
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ipq_locked = 0;
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splx(s);
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}
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#ifdef DIAGNOSTIC
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#define IPQ_LOCK() \
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do { \
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if (ipq_lock_try() == 0) { \
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printf("%s:%d: ipq already locked\n", __FILE__, __LINE__); \
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panic("ipq_lock"); \
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} \
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} while (0)
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#define IPQ_LOCK_CHECK() \
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do { \
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if (ipq_locked == 0) { \
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printf("%s:%d: ipq lock not held\n", __FILE__, __LINE__); \
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panic("ipq lock check"); \
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} \
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} while (0)
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#else
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#define IPQ_LOCK() (void) ipq_lock_try()
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#define IPQ_LOCK_CHECK() /* nothing */
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#endif
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#define IPQ_UNLOCK() ipq_unlock()
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struct pool ipqent_pool;
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/*
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* We need to save the IP options in case a protocol wants to respond
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* to an incoming packet over the same route if the packet got here
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* using IP source routing. This allows connection establishment and
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* maintenance when the remote end is on a network that is not known
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* to us.
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*/
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int ip_nhops = 0;
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static struct ip_srcrt {
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struct in_addr dst; /* final destination */
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char nop; /* one NOP to align */
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char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
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struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
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} ip_srcrt;
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static void save_rte __P((u_char *, struct in_addr));
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/*
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* IP initialization: fill in IP protocol switch table.
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* All protocols not implemented in kernel go to raw IP protocol handler.
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*/
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void
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ip_init()
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{
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register struct protosw *pr;
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register int i;
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pool_init(&ipqent_pool, sizeof(struct ipqent), 0, 0, 0, "ipqepl",
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0, NULL, NULL, M_IPQ);
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pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
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if (pr == 0)
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panic("ip_init");
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for (i = 0; i < IPPROTO_MAX; i++)
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ip_protox[i] = pr - inetsw;
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for (pr = inetdomain.dom_protosw;
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pr < inetdomain.dom_protoswNPROTOSW; pr++)
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if (pr->pr_domain->dom_family == PF_INET &&
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pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
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ip_protox[pr->pr_protocol] = pr - inetsw;
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LIST_INIT(&ipq);
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ip_id = time.tv_sec & 0xffff;
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ipintrq.ifq_maxlen = ipqmaxlen;
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TAILQ_INIT(&in_ifaddr);
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in_ifaddrhashtbl =
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hashinit(IN_IFADDR_HASH_SIZE, M_IFADDR, M_WAITOK, &in_ifaddrhash);
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if (ip_mtudisc != 0)
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ip_mtudisc_timeout_q =
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rt_timer_queue_create(ip_mtudisc_timeout);
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#ifdef GATEWAY
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ipflow_init();
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#endif
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}
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struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
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struct route ipforward_rt;
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/*
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* IP software interrupt routine
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*/
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void
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ipintr()
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{
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int s;
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struct mbuf *m;
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while (1) {
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s = splimp();
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IF_DEQUEUE(&ipintrq, m);
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splx(s);
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if (m == 0)
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return;
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ip_input(m);
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}
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}
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/*
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* Ip input routine. Checksum and byte swap header. If fragmented
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* try to reassemble. Process options. Pass to next level.
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*/
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void
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ip_input(struct mbuf *m)
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{
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register struct ip *ip = NULL;
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register struct ipq *fp;
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register struct in_ifaddr *ia;
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register struct ifaddr *ifa;
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struct ipqent *ipqe;
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int hlen = 0, mff, len;
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#ifdef PFIL_HOOKS
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struct packet_filter_hook *pfh;
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struct mbuf *m0;
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int rv;
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#endif /* PFIL_HOOKS */
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#ifdef DIAGNOSTIC
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if ((m->m_flags & M_PKTHDR) == 0)
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panic("ipintr no HDR");
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#endif
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#ifdef IPSEC
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/*
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* should the inner packet be considered authentic?
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* see comment in ah4_input().
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*/
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if (m) {
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m->m_flags &= ~M_AUTHIPHDR;
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m->m_flags &= ~M_AUTHIPDGM;
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}
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#endif
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/*
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* If no IP addresses have been set yet but the interfaces
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* are receiving, can't do anything with incoming packets yet.
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*/
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if (in_ifaddr.tqh_first == 0)
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goto bad;
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ipstat.ips_total++;
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if (m->m_len < sizeof (struct ip) &&
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(m = m_pullup(m, sizeof (struct ip))) == 0) {
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ipstat.ips_toosmall++;
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return;
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}
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ip = mtod(m, struct ip *);
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if (ip->ip_v != IPVERSION) {
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ipstat.ips_badvers++;
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goto bad;
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}
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hlen = ip->ip_hl << 2;
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if (hlen < sizeof(struct ip)) { /* minimum header length */
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ipstat.ips_badhlen++;
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goto bad;
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}
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if (hlen > m->m_len) {
|
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if ((m = m_pullup(m, hlen)) == 0) {
|
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ipstat.ips_badhlen++;
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return;
|
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}
|
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ip = mtod(m, struct ip *);
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}
|
|
/*
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* we drop packets that have a multicast address as source
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* as wanted by rfc 1112
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*/
|
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if (IN_MULTICAST(ip->ip_src.s_addr)) {
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goto bad;
|
|
}
|
|
|
|
if (in_cksum(m, hlen) != 0) {
|
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ipstat.ips_badsum++;
|
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goto bad;
|
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}
|
|
|
|
/*
|
|
* Convert fields to host representation.
|
|
*/
|
|
NTOHS(ip->ip_len);
|
|
NTOHS(ip->ip_off);
|
|
len = ip->ip_len;
|
|
|
|
/*
|
|
* Check for additional length bogosity
|
|
*/
|
|
if (len < hlen) {
|
|
ipstat.ips_badlen++;
|
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goto bad;
|
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}
|
|
|
|
/*
|
|
* Check that the amount of data in the buffers
|
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* is as at least much as the IP header would have us expect.
|
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* Trim mbufs if longer than we expect.
|
|
* Drop packet if shorter than we expect.
|
|
*/
|
|
if (m->m_pkthdr.len < len) {
|
|
ipstat.ips_tooshort++;
|
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goto bad;
|
|
}
|
|
if (m->m_pkthdr.len > len) {
|
|
if (m->m_len == m->m_pkthdr.len) {
|
|
m->m_len = len;
|
|
m->m_pkthdr.len = len;
|
|
} else
|
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m_adj(m, len - m->m_pkthdr.len);
|
|
}
|
|
|
|
/*
|
|
* Assume that we can create a fast-forward IP flow entry
|
|
* based on this packet.
|
|
*/
|
|
m->m_flags |= M_CANFASTFWD;
|
|
|
|
#ifdef PFIL_HOOKS
|
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/*
|
|
* Run through list of hooks for input packets. If there are any
|
|
* filters which require that additional packets in the flow are
|
|
* not fast-forwarded, they must clear the M_CANFASTFWD flag.
|
|
* Note that filters must _never_ set this flag, as another filter
|
|
* in the list may have previously cleared it.
|
|
*/
|
|
m0 = m;
|
|
for (pfh = pfil_hook_get(PFIL_IN); pfh; pfh = pfh->pfil_link.tqe_next)
|
|
if (pfh->pfil_func) {
|
|
rv = pfh->pfil_func(ip, hlen, m->m_pkthdr.rcvif, 0, &m0);
|
|
if (rv)
|
|
return;
|
|
m = m0;
|
|
if (m == NULL)
|
|
return;
|
|
ip = mtod(m, struct ip *);
|
|
}
|
|
#endif /* PFIL_HOOKS */
|
|
|
|
/*
|
|
* Process options and, if not destined for us,
|
|
* ship it on. ip_dooptions returns 1 when an
|
|
* error was detected (causing an icmp message
|
|
* to be sent and the original packet to be freed).
|
|
*/
|
|
ip_nhops = 0; /* for source routed packets */
|
|
if (hlen > sizeof (struct ip) && ip_dooptions(m))
|
|
return;
|
|
|
|
/*
|
|
* Check our list of addresses, to see if the packet is for us.
|
|
*/
|
|
INADDR_TO_IA(ip->ip_dst, ia);
|
|
if (ia != NULL)
|
|
goto ours;
|
|
if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
|
|
for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
|
|
ifa != NULL; ifa = ifa->ifa_list.tqe_next) {
|
|
if (ifa->ifa_addr->sa_family != AF_INET) continue;
|
|
ia = ifatoia(ifa);
|
|
if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
|
|
in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
|
|
/*
|
|
* Look for all-0's host part (old broadcast addr),
|
|
* either for subnet or net.
|
|
*/
|
|
ip->ip_dst.s_addr == ia->ia_subnet ||
|
|
ip->ip_dst.s_addr == ia->ia_net)
|
|
goto ours;
|
|
/*
|
|
* An interface with IP address zero accepts
|
|
* all packets that arrive on that interface.
|
|
*/
|
|
if (in_nullhost(ia->ia_addr.sin_addr))
|
|
goto ours;
|
|
}
|
|
}
|
|
if (IN_MULTICAST(ip->ip_dst.s_addr)) {
|
|
struct in_multi *inm;
|
|
#ifdef MROUTING
|
|
extern struct socket *ip_mrouter;
|
|
|
|
if (m->m_flags & M_EXT) {
|
|
if ((m = m_pullup(m, hlen)) == 0) {
|
|
ipstat.ips_toosmall++;
|
|
return;
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
}
|
|
|
|
if (ip_mrouter) {
|
|
/*
|
|
* If we are acting as a multicast router, all
|
|
* incoming multicast packets are passed to the
|
|
* kernel-level multicast forwarding function.
|
|
* The packet is returned (relatively) intact; if
|
|
* ip_mforward() returns a non-zero value, the packet
|
|
* must be discarded, else it may be accepted below.
|
|
*
|
|
* (The IP ident field is put in the same byte order
|
|
* as expected when ip_mforward() is called from
|
|
* ip_output().)
|
|
*/
|
|
if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The process-level routing demon needs to receive
|
|
* all multicast IGMP packets, whether or not this
|
|
* host belongs to their destination groups.
|
|
*/
|
|
if (ip->ip_p == IPPROTO_IGMP)
|
|
goto ours;
|
|
ipstat.ips_forward++;
|
|
}
|
|
#endif
|
|
/*
|
|
* See if we belong to the destination multicast group on the
|
|
* arrival interface.
|
|
*/
|
|
IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
|
|
if (inm == NULL) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
goto ours;
|
|
}
|
|
if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
|
|
in_nullhost(ip->ip_dst))
|
|
goto ours;
|
|
|
|
/*
|
|
* Not for us; forward if possible and desirable.
|
|
*/
|
|
if (ipforwarding == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
} else
|
|
ip_forward(m, 0);
|
|
return;
|
|
|
|
ours:
|
|
/*
|
|
* If offset or IP_MF are set, must reassemble.
|
|
* Otherwise, nothing need be done.
|
|
* (We could look in the reassembly queue to see
|
|
* if the packet was previously fragmented,
|
|
* but it's not worth the time; just let them time out.)
|
|
*/
|
|
if (ip->ip_off & ~(IP_DF|IP_RF)) {
|
|
/*
|
|
* Look for queue of fragments
|
|
* of this datagram.
|
|
*/
|
|
IPQ_LOCK();
|
|
for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
|
|
if (ip->ip_id == fp->ipq_id &&
|
|
in_hosteq(ip->ip_src, fp->ipq_src) &&
|
|
in_hosteq(ip->ip_dst, fp->ipq_dst) &&
|
|
ip->ip_p == fp->ipq_p)
|
|
goto found;
|
|
fp = 0;
|
|
found:
|
|
|
|
/*
|
|
* Adjust ip_len to not reflect header,
|
|
* set ipqe_mff if more fragments are expected,
|
|
* convert offset of this to bytes.
|
|
*/
|
|
ip->ip_len -= hlen;
|
|
mff = (ip->ip_off & IP_MF) != 0;
|
|
if (mff) {
|
|
/*
|
|
* Make sure that fragments have a data length
|
|
* that's a non-zero multiple of 8 bytes.
|
|
*/
|
|
if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
|
|
ipstat.ips_badfrags++;
|
|
IPQ_UNLOCK();
|
|
goto bad;
|
|
}
|
|
}
|
|
ip->ip_off <<= 3;
|
|
|
|
/*
|
|
* If datagram marked as having more fragments
|
|
* or if this is not the first fragment,
|
|
* attempt reassembly; if it succeeds, proceed.
|
|
*/
|
|
if (mff || ip->ip_off) {
|
|
ipstat.ips_fragments++;
|
|
ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
|
|
if (ipqe == NULL) {
|
|
ipstat.ips_rcvmemdrop++;
|
|
IPQ_UNLOCK();
|
|
goto bad;
|
|
}
|
|
ipqe->ipqe_mff = mff;
|
|
ipqe->ipqe_m = m;
|
|
ipqe->ipqe_ip = ip;
|
|
m = ip_reass(ipqe, fp);
|
|
if (m == 0) {
|
|
IPQ_UNLOCK();
|
|
return;
|
|
}
|
|
ipstat.ips_reassembled++;
|
|
ip = mtod(m, struct ip *);
|
|
hlen = ip->ip_hl << 2;
|
|
ip->ip_len += hlen;
|
|
} else
|
|
if (fp)
|
|
ip_freef(fp);
|
|
IPQ_UNLOCK();
|
|
}
|
|
|
|
/*
|
|
* Switch out to protocol's input routine.
|
|
*/
|
|
#if IFA_STATS
|
|
ia->ia_ifa.ifa_data.ifad_inbytes += ip->ip_len;
|
|
#endif
|
|
ipstat.ips_delivered++;
|
|
{
|
|
int off = hlen, nh = ip->ip_p;
|
|
|
|
(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
|
|
return;
|
|
}
|
|
bad:
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* Take incoming datagram fragment and try to
|
|
* reassemble it into whole datagram. If a chain for
|
|
* reassembly of this datagram already exists, then it
|
|
* is given as fp; otherwise have to make a chain.
|
|
*/
|
|
struct mbuf *
|
|
ip_reass(ipqe, fp)
|
|
register struct ipqent *ipqe;
|
|
register struct ipq *fp;
|
|
{
|
|
register struct mbuf *m = ipqe->ipqe_m;
|
|
register struct ipqent *nq, *p, *q;
|
|
struct ip *ip;
|
|
struct mbuf *t;
|
|
int hlen = ipqe->ipqe_ip->ip_hl << 2;
|
|
int i, next;
|
|
|
|
IPQ_LOCK_CHECK();
|
|
|
|
/*
|
|
* Presence of header sizes in mbufs
|
|
* would confuse code below.
|
|
*/
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
|
|
/*
|
|
* If first fragment to arrive, create a reassembly queue.
|
|
*/
|
|
if (fp == 0) {
|
|
MALLOC(fp, struct ipq *, sizeof (struct ipq),
|
|
M_FTABLE, M_NOWAIT);
|
|
if (fp == NULL)
|
|
goto dropfrag;
|
|
LIST_INSERT_HEAD(&ipq, fp, ipq_q);
|
|
fp->ipq_ttl = IPFRAGTTL;
|
|
fp->ipq_p = ipqe->ipqe_ip->ip_p;
|
|
fp->ipq_id = ipqe->ipqe_ip->ip_id;
|
|
LIST_INIT(&fp->ipq_fragq);
|
|
fp->ipq_src = ipqe->ipqe_ip->ip_src;
|
|
fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
|
|
p = NULL;
|
|
goto insert;
|
|
}
|
|
|
|
/*
|
|
* Find a segment which begins after this one does.
|
|
*/
|
|
for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
|
|
p = q, q = q->ipqe_q.le_next)
|
|
if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
|
|
break;
|
|
|
|
/*
|
|
* If there is a preceding segment, it may provide some of
|
|
* our data already. If so, drop the data from the incoming
|
|
* segment. If it provides all of our data, drop us.
|
|
*/
|
|
if (p != NULL) {
|
|
i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
|
|
ipqe->ipqe_ip->ip_off;
|
|
if (i > 0) {
|
|
if (i >= ipqe->ipqe_ip->ip_len)
|
|
goto dropfrag;
|
|
m_adj(ipqe->ipqe_m, i);
|
|
ipqe->ipqe_ip->ip_off += i;
|
|
ipqe->ipqe_ip->ip_len -= i;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* While we overlap succeeding segments trim them or,
|
|
* if they are completely covered, dequeue them.
|
|
*/
|
|
for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
|
|
q->ipqe_ip->ip_off; q = nq) {
|
|
i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
|
|
q->ipqe_ip->ip_off;
|
|
if (i < q->ipqe_ip->ip_len) {
|
|
q->ipqe_ip->ip_len -= i;
|
|
q->ipqe_ip->ip_off += i;
|
|
m_adj(q->ipqe_m, i);
|
|
break;
|
|
}
|
|
nq = q->ipqe_q.le_next;
|
|
m_freem(q->ipqe_m);
|
|
LIST_REMOVE(q, ipqe_q);
|
|
pool_put(&ipqent_pool, q);
|
|
}
|
|
|
|
insert:
|
|
/*
|
|
* Stick new segment in its place;
|
|
* check for complete reassembly.
|
|
*/
|
|
if (p == NULL) {
|
|
LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
|
|
} else {
|
|
LIST_INSERT_AFTER(p, ipqe, ipqe_q);
|
|
}
|
|
next = 0;
|
|
for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
|
|
p = q, q = q->ipqe_q.le_next) {
|
|
if (q->ipqe_ip->ip_off != next)
|
|
return (0);
|
|
next += q->ipqe_ip->ip_len;
|
|
}
|
|
if (p->ipqe_mff)
|
|
return (0);
|
|
|
|
/*
|
|
* Reassembly is complete. Check for a bogus message size and
|
|
* concatenate fragments.
|
|
*/
|
|
q = fp->ipq_fragq.lh_first;
|
|
ip = q->ipqe_ip;
|
|
if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
|
|
ipstat.ips_toolong++;
|
|
ip_freef(fp);
|
|
return (0);
|
|
}
|
|
m = q->ipqe_m;
|
|
t = m->m_next;
|
|
m->m_next = 0;
|
|
m_cat(m, t);
|
|
nq = q->ipqe_q.le_next;
|
|
pool_put(&ipqent_pool, q);
|
|
for (q = nq; q != NULL; q = nq) {
|
|
t = q->ipqe_m;
|
|
nq = q->ipqe_q.le_next;
|
|
pool_put(&ipqent_pool, q);
|
|
m_cat(m, t);
|
|
}
|
|
|
|
/*
|
|
* Create header for new ip packet by
|
|
* modifying header of first packet;
|
|
* dequeue and discard fragment reassembly header.
|
|
* Make header visible.
|
|
*/
|
|
ip->ip_len = next;
|
|
ip->ip_ttl = 0; /* xxx */
|
|
ip->ip_sum = 0;
|
|
ip->ip_src = fp->ipq_src;
|
|
ip->ip_dst = fp->ipq_dst;
|
|
LIST_REMOVE(fp, ipq_q);
|
|
FREE(fp, M_FTABLE);
|
|
m->m_len += (ip->ip_hl << 2);
|
|
m->m_data -= (ip->ip_hl << 2);
|
|
/* some debugging cruft by sklower, below, will go away soon */
|
|
if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
|
|
register int plen = 0;
|
|
for (t = m; t; t = t->m_next)
|
|
plen += t->m_len;
|
|
m->m_pkthdr.len = plen;
|
|
}
|
|
return (m);
|
|
|
|
dropfrag:
|
|
ipstat.ips_fragdropped++;
|
|
m_freem(m);
|
|
pool_put(&ipqent_pool, ipqe);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Free a fragment reassembly header and all
|
|
* associated datagrams.
|
|
*/
|
|
void
|
|
ip_freef(fp)
|
|
struct ipq *fp;
|
|
{
|
|
register struct ipqent *q, *p;
|
|
|
|
IPQ_LOCK_CHECK();
|
|
|
|
for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
|
|
p = q->ipqe_q.le_next;
|
|
m_freem(q->ipqe_m);
|
|
LIST_REMOVE(q, ipqe_q);
|
|
pool_put(&ipqent_pool, q);
|
|
}
|
|
LIST_REMOVE(fp, ipq_q);
|
|
FREE(fp, M_FTABLE);
|
|
}
|
|
|
|
/*
|
|
* IP timer processing;
|
|
* if a timer expires on a reassembly
|
|
* queue, discard it.
|
|
*/
|
|
void
|
|
ip_slowtimo()
|
|
{
|
|
register struct ipq *fp, *nfp;
|
|
int s = splsoftnet();
|
|
|
|
IPQ_LOCK();
|
|
for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
|
|
nfp = fp->ipq_q.le_next;
|
|
if (--fp->ipq_ttl == 0) {
|
|
ipstat.ips_fragtimeout++;
|
|
ip_freef(fp);
|
|
}
|
|
}
|
|
IPQ_UNLOCK();
|
|
#ifdef GATEWAY
|
|
ipflow_slowtimo();
|
|
#endif
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Drain off all datagram fragments.
|
|
*/
|
|
void
|
|
ip_drain()
|
|
{
|
|
|
|
/*
|
|
* We may be called from a device's interrupt context. If
|
|
* the ipq is already busy, just bail out now.
|
|
*/
|
|
if (ipq_lock_try() == 0)
|
|
return;
|
|
|
|
while (ipq.lh_first != NULL) {
|
|
ipstat.ips_fragdropped++;
|
|
ip_freef(ipq.lh_first);
|
|
}
|
|
|
|
IPQ_UNLOCK();
|
|
}
|
|
|
|
/*
|
|
* Do option processing on a datagram,
|
|
* possibly discarding it if bad options are encountered,
|
|
* or forwarding it if source-routed.
|
|
* Returns 1 if packet has been forwarded/freed,
|
|
* 0 if the packet should be processed further.
|
|
*/
|
|
int
|
|
ip_dooptions(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register u_char *cp;
|
|
register struct ip_timestamp *ipt;
|
|
register struct in_ifaddr *ia;
|
|
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
|
|
struct in_addr *sin, dst;
|
|
n_time ntime;
|
|
|
|
dst = ip->ip_dst;
|
|
cp = (u_char *)(ip + 1);
|
|
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
|
|
for (; cnt > 0; cnt -= optlen, cp += optlen) {
|
|
opt = cp[IPOPT_OPTVAL];
|
|
if (opt == IPOPT_EOL)
|
|
break;
|
|
if (opt == IPOPT_NOP)
|
|
optlen = 1;
|
|
else {
|
|
optlen = cp[IPOPT_OLEN];
|
|
if (optlen <= 0 || optlen > cnt) {
|
|
code = &cp[IPOPT_OLEN] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
}
|
|
switch (opt) {
|
|
|
|
default:
|
|
break;
|
|
|
|
/*
|
|
* Source routing with record.
|
|
* Find interface with current destination address.
|
|
* If none on this machine then drop if strictly routed,
|
|
* or do nothing if loosely routed.
|
|
* Record interface address and bring up next address
|
|
* component. If strictly routed make sure next
|
|
* address is on directly accessible net.
|
|
*/
|
|
case IPOPT_LSRR:
|
|
case IPOPT_SSRR:
|
|
if (ip_allowsrcrt == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_NET_PROHIB;
|
|
goto bad;
|
|
}
|
|
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
ipaddr.sin_addr = ip->ip_dst;
|
|
ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
|
|
if (ia == 0) {
|
|
if (opt == IPOPT_SSRR) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
}
|
|
/*
|
|
* Loose routing, and not at next destination
|
|
* yet; nothing to do except forward.
|
|
*/
|
|
break;
|
|
}
|
|
off--; /* 0 origin */
|
|
if (off > optlen - sizeof(struct in_addr)) {
|
|
/*
|
|
* End of source route. Should be for us.
|
|
*/
|
|
save_rte(cp, ip->ip_src);
|
|
break;
|
|
}
|
|
/*
|
|
* locate outgoing interface
|
|
*/
|
|
bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
|
|
sizeof(ipaddr.sin_addr));
|
|
if (opt == IPOPT_SSRR) {
|
|
#define INA struct in_ifaddr *
|
|
#define SA struct sockaddr *
|
|
ia = (INA)ifa_ifwithladdr((SA)&ipaddr);
|
|
} else
|
|
ia = ip_rtaddr(ipaddr.sin_addr);
|
|
if (ia == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
}
|
|
ip->ip_dst = ipaddr.sin_addr;
|
|
bcopy((caddr_t)&ia->ia_addr.sin_addr,
|
|
(caddr_t)(cp + off), sizeof(struct in_addr));
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
/*
|
|
* Let ip_intr's mcast routing check handle mcast pkts
|
|
*/
|
|
forward = !IN_MULTICAST(ip->ip_dst.s_addr);
|
|
break;
|
|
|
|
case IPOPT_RR:
|
|
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
|
|
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
|
|
goto bad;
|
|
}
|
|
/*
|
|
* If no space remains, ignore.
|
|
*/
|
|
off--; /* 0 origin */
|
|
if (off > optlen - sizeof(struct in_addr))
|
|
break;
|
|
bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
|
|
sizeof(ipaddr.sin_addr));
|
|
/*
|
|
* locate outgoing interface; if we're the destination,
|
|
* use the incoming interface (should be same).
|
|
*/
|
|
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
|
|
(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_HOST;
|
|
goto bad;
|
|
}
|
|
bcopy((caddr_t)&ia->ia_addr.sin_addr,
|
|
(caddr_t)(cp + off), sizeof(struct in_addr));
|
|
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
|
|
break;
|
|
|
|
case IPOPT_TS:
|
|
code = cp - (u_char *)ip;
|
|
ipt = (struct ip_timestamp *)cp;
|
|
if (ipt->ipt_len < 5)
|
|
goto bad;
|
|
if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
|
|
if (++ipt->ipt_oflw == 0)
|
|
goto bad;
|
|
break;
|
|
}
|
|
sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
|
|
switch (ipt->ipt_flg) {
|
|
|
|
case IPOPT_TS_TSONLY:
|
|
break;
|
|
|
|
case IPOPT_TS_TSANDADDR:
|
|
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
|
|
sizeof(struct in_addr) > ipt->ipt_len)
|
|
goto bad;
|
|
ipaddr.sin_addr = dst;
|
|
ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
|
|
m->m_pkthdr.rcvif);
|
|
if (ia == 0)
|
|
continue;
|
|
bcopy((caddr_t)&ia->ia_addr.sin_addr,
|
|
(caddr_t)sin, sizeof(struct in_addr));
|
|
ipt->ipt_ptr += sizeof(struct in_addr);
|
|
break;
|
|
|
|
case IPOPT_TS_PRESPEC:
|
|
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
|
|
sizeof(struct in_addr) > ipt->ipt_len)
|
|
goto bad;
|
|
bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
|
|
sizeof(struct in_addr));
|
|
if (ifa_ifwithaddr((SA)&ipaddr) == 0)
|
|
continue;
|
|
ipt->ipt_ptr += sizeof(struct in_addr);
|
|
break;
|
|
|
|
default:
|
|
goto bad;
|
|
}
|
|
ntime = iptime();
|
|
bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
|
|
sizeof(n_time));
|
|
ipt->ipt_ptr += sizeof(n_time);
|
|
}
|
|
}
|
|
if (forward) {
|
|
if (ip_forwsrcrt == 0) {
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_SRCFAIL;
|
|
goto bad;
|
|
}
|
|
ip_forward(m, 1);
|
|
return (1);
|
|
}
|
|
return (0);
|
|
bad:
|
|
icmp_error(m, type, code, 0, 0);
|
|
ipstat.ips_badoptions++;
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* Given address of next destination (final or next hop),
|
|
* return internet address info of interface to be used to get there.
|
|
*/
|
|
struct in_ifaddr *
|
|
ip_rtaddr(dst)
|
|
struct in_addr dst;
|
|
{
|
|
register struct sockaddr_in *sin;
|
|
|
|
sin = satosin(&ipforward_rt.ro_dst);
|
|
|
|
if (ipforward_rt.ro_rt == 0 || !in_hosteq(dst, sin->sin_addr)) {
|
|
if (ipforward_rt.ro_rt) {
|
|
RTFREE(ipforward_rt.ro_rt);
|
|
ipforward_rt.ro_rt = 0;
|
|
}
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_len = sizeof(*sin);
|
|
sin->sin_addr = dst;
|
|
|
|
rtalloc(&ipforward_rt);
|
|
}
|
|
if (ipforward_rt.ro_rt == 0)
|
|
return ((struct in_ifaddr *)0);
|
|
return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
|
|
}
|
|
|
|
/*
|
|
* Save incoming source route for use in replies,
|
|
* to be picked up later by ip_srcroute if the receiver is interested.
|
|
*/
|
|
void
|
|
save_rte(option, dst)
|
|
u_char *option;
|
|
struct in_addr dst;
|
|
{
|
|
unsigned olen;
|
|
|
|
olen = option[IPOPT_OLEN];
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("save_rte: olen %d\n", olen);
|
|
#endif /* 0 */
|
|
if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
|
|
return;
|
|
bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
|
|
ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
|
|
ip_srcrt.dst = dst;
|
|
}
|
|
|
|
/*
|
|
* Retrieve incoming source route for use in replies,
|
|
* in the same form used by setsockopt.
|
|
* The first hop is placed before the options, will be removed later.
|
|
*/
|
|
struct mbuf *
|
|
ip_srcroute()
|
|
{
|
|
register struct in_addr *p, *q;
|
|
register struct mbuf *m;
|
|
|
|
if (ip_nhops == 0)
|
|
return ((struct mbuf *)0);
|
|
m = m_get(M_DONTWAIT, MT_SOOPTS);
|
|
if (m == 0)
|
|
return ((struct mbuf *)0);
|
|
|
|
#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
|
|
|
|
/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
|
|
m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
|
|
OPTSIZ;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
|
|
#endif
|
|
|
|
/*
|
|
* First save first hop for return route
|
|
*/
|
|
p = &ip_srcrt.route[ip_nhops - 1];
|
|
*(mtod(m, struct in_addr *)) = *p--;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
|
|
#endif
|
|
|
|
/*
|
|
* Copy option fields and padding (nop) to mbuf.
|
|
*/
|
|
ip_srcrt.nop = IPOPT_NOP;
|
|
ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
|
|
bcopy((caddr_t)&ip_srcrt.nop,
|
|
mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
|
|
q = (struct in_addr *)(mtod(m, caddr_t) +
|
|
sizeof(struct in_addr) + OPTSIZ);
|
|
#undef OPTSIZ
|
|
/*
|
|
* Record return path as an IP source route,
|
|
* reversing the path (pointers are now aligned).
|
|
*/
|
|
while (p >= ip_srcrt.route) {
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" %x", ntohl(q->s_addr));
|
|
#endif
|
|
*q++ = *p--;
|
|
}
|
|
/*
|
|
* Last hop goes to final destination.
|
|
*/
|
|
*q = ip_srcrt.dst;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf(" %x\n", ntohl(q->s_addr));
|
|
#endif
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Strip out IP options, at higher
|
|
* level protocol in the kernel.
|
|
* Second argument is buffer to which options
|
|
* will be moved, and return value is their length.
|
|
* XXX should be deleted; last arg currently ignored.
|
|
*/
|
|
void
|
|
ip_stripoptions(m, mopt)
|
|
register struct mbuf *m;
|
|
struct mbuf *mopt;
|
|
{
|
|
register int i;
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
register caddr_t opts;
|
|
int olen;
|
|
|
|
olen = (ip->ip_hl << 2) - sizeof (struct ip);
|
|
opts = (caddr_t)(ip + 1);
|
|
i = m->m_len - (sizeof (struct ip) + olen);
|
|
bcopy(opts + olen, opts, (unsigned)i);
|
|
m->m_len -= olen;
|
|
if (m->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len -= olen;
|
|
ip->ip_len -= olen;
|
|
ip->ip_hl = sizeof (struct ip) >> 2;
|
|
}
|
|
|
|
int inetctlerrmap[PRC_NCMDS] = {
|
|
0, 0, 0, 0,
|
|
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
|
|
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
|
|
EMSGSIZE, EHOSTUNREACH, 0, 0,
|
|
0, 0, 0, 0,
|
|
ENOPROTOOPT
|
|
};
|
|
|
|
/*
|
|
* Forward a packet. If some error occurs return the sender
|
|
* an icmp packet. Note we can't always generate a meaningful
|
|
* icmp message because icmp doesn't have a large enough repertoire
|
|
* of codes and types.
|
|
*
|
|
* If not forwarding, just drop the packet. This could be confusing
|
|
* if ipforwarding was zero but some routing protocol was advancing
|
|
* us as a gateway to somewhere. However, we must let the routing
|
|
* protocol deal with that.
|
|
*
|
|
* The srcrt parameter indicates whether the packet is being forwarded
|
|
* via a source route.
|
|
*/
|
|
void
|
|
ip_forward(m, srcrt)
|
|
struct mbuf *m;
|
|
int srcrt;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register struct sockaddr_in *sin;
|
|
register struct rtentry *rt;
|
|
int error, type = 0, code = 0;
|
|
struct mbuf *mcopy;
|
|
n_long dest;
|
|
struct ifnet *destifp;
|
|
#ifdef IPSEC
|
|
struct ifnet dummyifp;
|
|
#endif
|
|
|
|
dest = 0;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("forward: src %2.2x dst %2.2x ttl %x\n",
|
|
ntohl(ip->ip_src.s_addr),
|
|
ntohl(ip->ip_dst.s_addr), ip->ip_ttl);
|
|
#endif
|
|
if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
|
|
ipstat.ips_cantforward++;
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (ip->ip_ttl <= IPTTLDEC) {
|
|
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
|
|
return;
|
|
}
|
|
ip->ip_ttl -= IPTTLDEC;
|
|
|
|
sin = satosin(&ipforward_rt.ro_dst);
|
|
if ((rt = ipforward_rt.ro_rt) == 0 ||
|
|
!in_hosteq(ip->ip_dst, sin->sin_addr)) {
|
|
if (ipforward_rt.ro_rt) {
|
|
RTFREE(ipforward_rt.ro_rt);
|
|
ipforward_rt.ro_rt = 0;
|
|
}
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_len = sizeof(struct sockaddr_in);
|
|
sin->sin_addr = ip->ip_dst;
|
|
|
|
rtalloc(&ipforward_rt);
|
|
if (ipforward_rt.ro_rt == 0) {
|
|
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
|
|
return;
|
|
}
|
|
rt = ipforward_rt.ro_rt;
|
|
}
|
|
|
|
/*
|
|
* Save at most 68 bytes of the packet in case
|
|
* we need to generate an ICMP message to the src.
|
|
*/
|
|
mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
|
|
|
|
/*
|
|
* If forwarding packet using same interface that it came in on,
|
|
* perhaps should send a redirect to sender to shortcut a hop.
|
|
* Only send redirect if source is sending directly to us,
|
|
* and if packet was not source routed (or has any options).
|
|
* Also, don't send redirect if forwarding using a default route
|
|
* or a route modified by a redirect.
|
|
*/
|
|
if (rt->rt_ifp == m->m_pkthdr.rcvif &&
|
|
(rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
|
|
!in_nullhost(satosin(rt_key(rt))->sin_addr) &&
|
|
ipsendredirects && !srcrt) {
|
|
if (rt->rt_ifa &&
|
|
(ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
|
|
ifatoia(rt->rt_ifa)->ia_subnet) {
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
|
dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
|
|
else
|
|
dest = ip->ip_dst.s_addr;
|
|
/*
|
|
* Router requirements says to only send host
|
|
* redirects.
|
|
*/
|
|
type = ICMP_REDIRECT;
|
|
code = ICMP_REDIRECT_HOST;
|
|
#ifdef DIAGNOSTIC
|
|
if (ipprintfs)
|
|
printf("redirect (%d) to %x\n", code,
|
|
(u_int32_t)dest);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
#ifdef IPSEC
|
|
m->m_pkthdr.rcvif = NULL;
|
|
#endif /*IPSEC*/
|
|
error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
|
|
(IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 0);
|
|
if (error)
|
|
ipstat.ips_cantforward++;
|
|
else {
|
|
ipstat.ips_forward++;
|
|
if (type)
|
|
ipstat.ips_redirectsent++;
|
|
else {
|
|
if (mcopy) {
|
|
#ifdef GATEWAY
|
|
if (mcopy->m_flags & M_CANFASTFWD)
|
|
ipflow_create(&ipforward_rt, mcopy);
|
|
#endif
|
|
m_freem(mcopy);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
if (mcopy == NULL)
|
|
return;
|
|
destifp = NULL;
|
|
|
|
switch (error) {
|
|
|
|
case 0: /* forwarded, but need redirect */
|
|
/* type, code set above */
|
|
break;
|
|
|
|
case ENETUNREACH: /* shouldn't happen, checked above */
|
|
case EHOSTUNREACH:
|
|
case ENETDOWN:
|
|
case EHOSTDOWN:
|
|
default:
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_HOST;
|
|
break;
|
|
|
|
case EMSGSIZE:
|
|
type = ICMP_UNREACH;
|
|
code = ICMP_UNREACH_NEEDFRAG;
|
|
#ifndef IPSEC
|
|
if (ipforward_rt.ro_rt)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
#else
|
|
/*
|
|
* If the packet is routed over IPsec tunnel, tell the
|
|
* originator the tunnel MTU.
|
|
* tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
|
|
* XXX quickhack!!!
|
|
*/
|
|
if (ipforward_rt.ro_rt) {
|
|
struct secpolicy *sp;
|
|
int ipsecerror;
|
|
int ipsechdr;
|
|
struct route *ro;
|
|
|
|
sp = ipsec4_getpolicybyaddr(mcopy,
|
|
IP_FORWARDING,
|
|
&ipsecerror);
|
|
|
|
if (sp == NULL)
|
|
destifp = ipforward_rt.ro_rt->rt_ifp;
|
|
else {
|
|
/* count IPsec header size */
|
|
ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
|
|
|
|
/*
|
|
* find the correct route for outer IPv4
|
|
* header, compute tunnel MTU.
|
|
*
|
|
* XXX BUG ALERT
|
|
* The "dummyifp" code relies upon the fact
|
|
* that icmp_error() touches only ifp->if_mtu.
|
|
*/
|
|
/*XXX*/
|
|
destifp = NULL;
|
|
if (sp->req != NULL
|
|
&& sp->req->sa != NULL) {
|
|
ro = &sp->req->sa->saidx->sa_route;
|
|
if (ro->ro_rt && ro->ro_rt->rt_ifp) {
|
|
dummyifp.if_mtu =
|
|
ro->ro_rt->rt_ifp->if_mtu;
|
|
dummyifp.if_mtu -= ipsechdr;
|
|
destifp = &dummyifp;
|
|
}
|
|
}
|
|
|
|
key_freesp(sp);
|
|
}
|
|
}
|
|
#endif /*IPSEC*/
|
|
ipstat.ips_cantfrag++;
|
|
break;
|
|
|
|
case ENOBUFS:
|
|
type = ICMP_SOURCEQUENCH;
|
|
code = 0;
|
|
break;
|
|
}
|
|
icmp_error(mcopy, type, code, dest, destifp);
|
|
}
|
|
|
|
void
|
|
ip_savecontrol(inp, mp, ip, m)
|
|
register struct inpcb *inp;
|
|
register struct mbuf **mp;
|
|
register struct ip *ip;
|
|
register struct mbuf *m;
|
|
{
|
|
|
|
if (inp->inp_socket->so_options & SO_TIMESTAMP) {
|
|
struct timeval tv;
|
|
|
|
microtime(&tv);
|
|
*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
|
|
SCM_TIMESTAMP, SOL_SOCKET);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
if (inp->inp_flags & INP_RECVDSTADDR) {
|
|
*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
|
|
sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
#ifdef notyet
|
|
/*
|
|
* XXX
|
|
* Moving these out of udp_input() made them even more broken
|
|
* than they already were.
|
|
* - fenner@parc.xerox.com
|
|
*/
|
|
/* options were tossed already */
|
|
if (inp->inp_flags & INP_RECVOPTS) {
|
|
*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
|
|
sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
/* ip_srcroute doesn't do what we want here, need to fix */
|
|
if (inp->inp_flags & INP_RECVRETOPTS) {
|
|
*mp = sbcreatecontrol((caddr_t) ip_srcroute(),
|
|
sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
#endif
|
|
if (inp->inp_flags & INP_RECVIF) {
|
|
struct sockaddr_dl sdl;
|
|
|
|
sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
|
|
sdl.sdl_family = AF_LINK;
|
|
sdl.sdl_index = m->m_pkthdr.rcvif ?
|
|
m->m_pkthdr.rcvif->if_index : 0;
|
|
sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
|
|
*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
|
|
IP_RECVIF, IPPROTO_IP);
|
|
if (*mp)
|
|
mp = &(*mp)->m_next;
|
|
}
|
|
}
|
|
|
|
int
|
|
ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
|
|
int *name;
|
|
u_int namelen;
|
|
void *oldp;
|
|
size_t *oldlenp;
|
|
void *newp;
|
|
size_t newlen;
|
|
{
|
|
extern int subnetsarelocal, hostzeroisbroadcast;
|
|
|
|
int error, old;
|
|
|
|
/* All sysctl names at this level are terminal. */
|
|
if (namelen != 1)
|
|
return (ENOTDIR);
|
|
|
|
switch (name[0]) {
|
|
case IPCTL_FORWARDING:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
|
|
case IPCTL_SENDREDIRECTS:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ipsendredirects));
|
|
case IPCTL_DEFTTL:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
|
|
#ifdef notyet
|
|
case IPCTL_DEFMTU:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
|
|
#endif
|
|
case IPCTL_FORWSRCRT:
|
|
/* Don't allow this to change in a secure environment. */
|
|
if (securelevel > 0)
|
|
return (sysctl_rdint(oldp, oldlenp, newp,
|
|
ip_forwsrcrt));
|
|
else
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_forwsrcrt));
|
|
case IPCTL_DIRECTEDBCAST:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_directedbcast));
|
|
case IPCTL_ALLOWSRCRT:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_allowsrcrt));
|
|
case IPCTL_SUBNETSARELOCAL:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&subnetsarelocal));
|
|
case IPCTL_MTUDISC:
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_mtudisc);
|
|
if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
|
|
ip_mtudisc_timeout_q =
|
|
rt_timer_queue_create(ip_mtudisc_timeout);
|
|
} else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
|
|
rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
|
|
ip_mtudisc_timeout_q = NULL;
|
|
}
|
|
return error;
|
|
case IPCTL_ANONPORTMIN:
|
|
old = anonportmin;
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmin);
|
|
if (anonportmin >= anonportmax || anonportmin > 65535
|
|
#ifndef IPNOPRIVPORTS
|
|
|| anonportmin < IPPORT_RESERVED
|
|
#endif
|
|
) {
|
|
anonportmin = old;
|
|
return (EINVAL);
|
|
}
|
|
return (error);
|
|
case IPCTL_ANONPORTMAX:
|
|
old = anonportmax;
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &anonportmax);
|
|
if (anonportmin >= anonportmax || anonportmax > 65535
|
|
#ifndef IPNOPRIVPORTS
|
|
|| anonportmax < IPPORT_RESERVED
|
|
#endif
|
|
) {
|
|
anonportmax = old;
|
|
return (EINVAL);
|
|
}
|
|
return (error);
|
|
case IPCTL_MTUDISCTIMEOUT:
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_mtudisc_timeout);
|
|
if (ip_mtudisc_timeout_q != NULL)
|
|
rt_timer_queue_change(ip_mtudisc_timeout_q,
|
|
ip_mtudisc_timeout);
|
|
return (error);
|
|
#ifdef GATEWAY
|
|
case IPCTL_MAXFLOWS:
|
|
{
|
|
int s;
|
|
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_maxflows);
|
|
s = splsoftnet();
|
|
ipflow_reap(0);
|
|
splx(s);
|
|
return (error);
|
|
}
|
|
#endif
|
|
case IPCTL_HOSTZEROBROADCAST:
|
|
return (sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&hostzeroisbroadcast));
|
|
#if NGIF > 0
|
|
case IPCTL_GIF_TTL:
|
|
return(sysctl_int(oldp, oldlenp, newp, newlen,
|
|
&ip_gif_ttl));
|
|
#endif
|
|
|
|
default:
|
|
return (EOPNOTSUPP);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|