63de4c2cb9
need to recompile sbin/sysctl after updating /usr/include. net.inet.tcp.rstratelimit net.inet.icmp.errratelimit net.inet6.icmp6.errratelimit
1036 lines
27 KiB
C
1036 lines
27 KiB
C
/* $NetBSD: ip_icmp.c,v 1.54 2000/07/28 04:06:53 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_icmp.c 8.2 (Berkeley) 1/4/94
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*/
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#include "opt_ipsec.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/protosw.h>
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#include <sys/socket.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 <uvm/uvm_extern.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 <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_var.h>
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#include <netinet/ip.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip_var.h>
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#include <netinet/in_pcb.h>
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#include <netinet/icmp_var.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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#endif
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#include <machine/stdarg.h>
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/*
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* ICMP routines: error generation, receive packet processing, and
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* routines to turnaround packets back to the originator, and
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* host table maintenance routines.
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*/
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int icmpmaskrepl = 0;
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#ifdef ICMPPRINTFS
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int icmpprintfs = 0;
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#endif
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int icmpreturndatabytes = 8;
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#if 0
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static int ip_next_mtu __P((int, int));
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#else
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/*static*/ int ip_next_mtu __P((int, int));
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#endif
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extern int icmperrppslim;
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static int icmperrpps_count = 0;
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static struct timeval icmperrppslim_last;
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static void icmp_mtudisc __P((struct icmp *));
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static void icmp_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
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static int icmp_ratelimit __P((const struct in_addr *, const int, const int));
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/*
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* Generate an error packet of type error
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* in response to bad packet ip.
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*/
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void
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icmp_error(n, type, code, dest, destifp)
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struct mbuf *n;
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int type, code;
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n_long dest;
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struct ifnet *destifp;
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{
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struct ip *oip = mtod(n, struct ip *), *nip;
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unsigned oiplen = oip->ip_hl << 2;
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struct icmp *icp;
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struct mbuf *m;
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unsigned icmplen, mblen;
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#ifdef ICMPPRINTFS
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if (icmpprintfs)
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printf("icmp_error(%x, %d, %d)\n", oip, type, code);
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#endif
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if (type != ICMP_REDIRECT)
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icmpstat.icps_error++;
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/*
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* Don't send error if the original packet was encrypted.
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* Don't send error if not the first fragment of message.
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* Don't error if the old packet protocol was ICMP
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* error message, only known informational types.
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*/
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if (n->m_flags & M_DECRYPTED)
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goto freeit;
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if (oip->ip_off &~ (IP_MF|IP_DF))
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goto freeit;
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if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
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n->m_len >= oiplen + ICMP_MINLEN &&
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!ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
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icmpstat.icps_oldicmp++;
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goto freeit;
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}
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/* Don't send error in response to a multicast or broadcast packet */
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if (n->m_flags & (M_BCAST|M_MCAST))
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goto freeit;
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/*
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* First, do a rate limitation check.
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*/
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if (icmp_ratelimit(&oip->ip_src, type, code)) {
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/* XXX stat */
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goto freeit;
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}
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/*
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* Now, formulate icmp message
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*/
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icmplen = oiplen + min(icmpreturndatabytes, oip->ip_len - oiplen);
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/*
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* Defend against mbuf chains shorter than oip->ip_len:
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*/
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mblen = 0;
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for (m = n; m && (mblen < icmplen); m = m->m_next)
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mblen += m->m_len;
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icmplen = min(mblen, icmplen);
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/*
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* As we are not required to return everything we have,
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* we return whatever we can return at ease.
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*
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* Note that ICMP datagrams longer than 576 octets are out of spec
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* according to RFC1812; the limit on icmpreturndatabytes below in
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* icmp_sysctl will keep things below that limit.
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*/
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KASSERT(ICMP_MINLEN <= MCLBYTES);
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if (icmplen + ICMP_MINLEN > MCLBYTES)
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icmplen = MCLBYTES - ICMP_MINLEN;
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m = m_gethdr(M_DONTWAIT, MT_HEADER);
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if (m && (icmplen + ICMP_MINLEN > MHLEN)) {
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MCLGET(m, M_DONTWAIT);
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if ((m->m_flags & M_EXT) == 0) {
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m_freem(m);
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m = NULL;
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}
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}
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if (m == NULL)
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goto freeit;
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m->m_len = icmplen + ICMP_MINLEN;
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if ((m->m_flags & M_EXT) == 0)
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MH_ALIGN(m, m->m_len);
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icp = mtod(m, struct icmp *);
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if ((u_int)type > ICMP_MAXTYPE)
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panic("icmp_error");
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icmpstat.icps_outhist[type]++;
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icp->icmp_type = type;
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if (type == ICMP_REDIRECT)
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icp->icmp_gwaddr.s_addr = dest;
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else {
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icp->icmp_void = 0;
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/*
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* The following assignments assume an overlay with the
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* zeroed icmp_void field.
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*/
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if (type == ICMP_PARAMPROB) {
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icp->icmp_pptr = code;
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code = 0;
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} else if (type == ICMP_UNREACH &&
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code == ICMP_UNREACH_NEEDFRAG && destifp)
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icp->icmp_nextmtu = htons(destifp->if_mtu);
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}
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HTONS(oip->ip_off);
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HTONS(oip->ip_len);
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icp->icmp_code = code;
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m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
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nip = &icp->icmp_ip;
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/*
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* Now, copy old ip header (without options)
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* in front of icmp message.
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*/
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if (m->m_data - sizeof(struct ip) < m->m_pktdat)
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panic("icmp len");
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m->m_data -= sizeof(struct ip);
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m->m_len += sizeof(struct ip);
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m->m_pkthdr.len = m->m_len;
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m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
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nip = mtod(m, struct ip *);
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/* ip_v set in ip_output */
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nip->ip_hl = sizeof(struct ip) >> 2;
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nip->ip_tos = 0;
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nip->ip_len = m->m_len;
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/* ip_id set in ip_output */
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nip->ip_off = 0;
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/* ip_ttl set in icmp_reflect */
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nip->ip_p = IPPROTO_ICMP;
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nip->ip_src = oip->ip_src;
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nip->ip_dst = oip->ip_dst;
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icmp_reflect(m);
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freeit:
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m_freem(n);
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}
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static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET };
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static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET };
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static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };
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struct sockaddr_in icmpmask = { 8, 0 };
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/*
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* Process a received ICMP message.
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*/
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void
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#if __STDC__
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icmp_input(struct mbuf *m, ...)
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#else
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icmp_input(m, va_alist)
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struct mbuf *m;
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va_dcl
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#endif
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{
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int proto;
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struct icmp *icp;
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struct ip *ip = mtod(m, struct ip *);
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int icmplen;
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int i;
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struct in_ifaddr *ia;
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void *(*ctlfunc) __P((int, struct sockaddr *, void *));
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int code;
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int hlen;
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va_list ap;
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va_start(ap, m);
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hlen = va_arg(ap, int);
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proto = va_arg(ap, int);
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va_end(ap);
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/*
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* Locate icmp structure in mbuf, and check
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* that not corrupted and of at least minimum length.
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*/
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icmplen = ip->ip_len - hlen;
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#ifdef ICMPPRINTFS
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if (icmpprintfs)
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printf("icmp_input from %x to %x, len %d\n",
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ntohl(ip->ip_src.s_addr), ntohl(ip->ip_dst.s_addr),
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icmplen);
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#endif
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if (icmplen < ICMP_MINLEN) {
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icmpstat.icps_tooshort++;
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goto freeit;
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}
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i = hlen + min(icmplen, ICMP_ADVLENMIN);
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if (m->m_len < i && (m = m_pullup(m, i)) == 0) {
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icmpstat.icps_tooshort++;
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return;
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}
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ip = mtod(m, struct ip *);
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m->m_len -= hlen;
|
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m->m_data += hlen;
|
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icp = mtod(m, struct icmp *);
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if (in_cksum(m, icmplen)) {
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icmpstat.icps_checksum++;
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goto freeit;
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}
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m->m_len += hlen;
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m->m_data -= hlen;
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|
|
#ifdef ICMPPRINTFS
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/*
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* Message type specific processing.
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*/
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if (icmpprintfs)
|
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printf("icmp_input, type %d code %d\n", icp->icmp_type,
|
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icp->icmp_code);
|
|
#endif
|
|
#ifdef IPSEC
|
|
/* drop it if it does not match the policy */
|
|
if (ipsec4_in_reject(m, NULL)) {
|
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ipsecstat.in_polvio++;
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goto freeit;
|
|
}
|
|
#endif
|
|
if (icp->icmp_type > ICMP_MAXTYPE)
|
|
goto raw;
|
|
icmpstat.icps_inhist[icp->icmp_type]++;
|
|
code = icp->icmp_code;
|
|
switch (icp->icmp_type) {
|
|
|
|
case ICMP_UNREACH:
|
|
switch (code) {
|
|
case ICMP_UNREACH_NET:
|
|
case ICMP_UNREACH_HOST:
|
|
case ICMP_UNREACH_PROTOCOL:
|
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case ICMP_UNREACH_PORT:
|
|
case ICMP_UNREACH_SRCFAIL:
|
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code += PRC_UNREACH_NET;
|
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break;
|
|
|
|
case ICMP_UNREACH_NEEDFRAG:
|
|
code = PRC_MSGSIZE;
|
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break;
|
|
|
|
case ICMP_UNREACH_NET_UNKNOWN:
|
|
case ICMP_UNREACH_NET_PROHIB:
|
|
case ICMP_UNREACH_TOSNET:
|
|
code = PRC_UNREACH_NET;
|
|
break;
|
|
|
|
case ICMP_UNREACH_HOST_UNKNOWN:
|
|
case ICMP_UNREACH_ISOLATED:
|
|
case ICMP_UNREACH_HOST_PROHIB:
|
|
case ICMP_UNREACH_TOSHOST:
|
|
code = PRC_UNREACH_HOST;
|
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break;
|
|
|
|
default:
|
|
goto badcode;
|
|
}
|
|
goto deliver;
|
|
|
|
case ICMP_TIMXCEED:
|
|
if (code > 1)
|
|
goto badcode;
|
|
code += PRC_TIMXCEED_INTRANS;
|
|
goto deliver;
|
|
|
|
case ICMP_PARAMPROB:
|
|
if (code > 1)
|
|
goto badcode;
|
|
code = PRC_PARAMPROB;
|
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goto deliver;
|
|
|
|
case ICMP_SOURCEQUENCH:
|
|
if (code)
|
|
goto badcode;
|
|
code = PRC_QUENCH;
|
|
goto deliver;
|
|
|
|
deliver:
|
|
/*
|
|
* Problem with datagram; advise higher level routines.
|
|
*/
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
|
icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
|
|
icmpstat.icps_badlen++;
|
|
goto freeit;
|
|
}
|
|
if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr))
|
|
goto badcode;
|
|
NTOHS(icp->icmp_ip.ip_len);
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
|
|
#endif
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
|
if (code == PRC_MSGSIZE && ip_mtudisc)
|
|
icmp_mtudisc(icp);
|
|
/*
|
|
* XXX if the packet contains [IPv4 AH TCP], we can't make a
|
|
* notification to TCP layer.
|
|
*/
|
|
ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
|
|
if (ctlfunc)
|
|
(*ctlfunc)(code, sintosa(&icmpsrc), &icp->icmp_ip);
|
|
break;
|
|
|
|
badcode:
|
|
icmpstat.icps_badcode++;
|
|
break;
|
|
|
|
case ICMP_ECHO:
|
|
icp->icmp_type = ICMP_ECHOREPLY;
|
|
goto reflect;
|
|
|
|
case ICMP_TSTAMP:
|
|
if (icmplen < ICMP_TSLEN) {
|
|
icmpstat.icps_badlen++;
|
|
break;
|
|
}
|
|
icp->icmp_type = ICMP_TSTAMPREPLY;
|
|
icp->icmp_rtime = iptime();
|
|
icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
|
|
goto reflect;
|
|
|
|
case ICMP_MASKREQ:
|
|
if (icmpmaskrepl == 0)
|
|
break;
|
|
/*
|
|
* We are not able to respond with all ones broadcast
|
|
* unless we receive it over a point-to-point interface.
|
|
*/
|
|
if (icmplen < ICMP_MASKLEN) {
|
|
icmpstat.icps_badlen++;
|
|
break;
|
|
}
|
|
if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
|
|
in_nullhost(ip->ip_dst))
|
|
icmpdst.sin_addr = ip->ip_src;
|
|
else
|
|
icmpdst.sin_addr = ip->ip_dst;
|
|
ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst),
|
|
m->m_pkthdr.rcvif));
|
|
if (ia == 0)
|
|
break;
|
|
icp->icmp_type = ICMP_MASKREPLY;
|
|
icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
|
|
if (in_nullhost(ip->ip_src)) {
|
|
if (ia->ia_ifp->if_flags & IFF_BROADCAST)
|
|
ip->ip_src = ia->ia_broadaddr.sin_addr;
|
|
else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
|
|
ip->ip_src = ia->ia_dstaddr.sin_addr;
|
|
}
|
|
reflect:
|
|
icmpstat.icps_reflect++;
|
|
icmpstat.icps_outhist[icp->icmp_type]++;
|
|
icmp_reflect(m);
|
|
return;
|
|
|
|
case ICMP_REDIRECT:
|
|
if (code > 3)
|
|
goto badcode;
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
|
icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
|
|
icmpstat.icps_badlen++;
|
|
break;
|
|
}
|
|
/*
|
|
* Short circuit routing redirects to force
|
|
* immediate change in the kernel's routing
|
|
* tables. The message is also handed to anyone
|
|
* listening on a raw socket (e.g. the routing
|
|
* daemon for use in updating its tables).
|
|
*/
|
|
icmpgw.sin_addr = ip->ip_src;
|
|
icmpdst.sin_addr = icp->icmp_gwaddr;
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("redirect dst %x to %x\n", icp->icmp_ip.ip_dst,
|
|
icp->icmp_gwaddr);
|
|
#endif
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
|
rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst),
|
|
(struct sockaddr *)0, RTF_GATEWAY | RTF_HOST,
|
|
sintosa(&icmpgw), (struct rtentry **)0);
|
|
pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc));
|
|
#ifdef IPSEC
|
|
key_sa_routechange((struct sockaddr *)&icmpsrc);
|
|
#endif
|
|
break;
|
|
|
|
/*
|
|
* No kernel processing for the following;
|
|
* just fall through to send to raw listener.
|
|
*/
|
|
case ICMP_ECHOREPLY:
|
|
case ICMP_ROUTERADVERT:
|
|
case ICMP_ROUTERSOLICIT:
|
|
case ICMP_TSTAMPREPLY:
|
|
case ICMP_IREQREPLY:
|
|
case ICMP_MASKREPLY:
|
|
default:
|
|
break;
|
|
}
|
|
|
|
raw:
|
|
rip_input(m, hlen, proto);
|
|
return;
|
|
|
|
freeit:
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Reflect the ip packet back to the source
|
|
*/
|
|
void
|
|
icmp_reflect(m)
|
|
struct mbuf *m;
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
struct in_ifaddr *ia;
|
|
struct ifaddr *ifa;
|
|
struct sockaddr_in *sin = 0;
|
|
struct in_addr t;
|
|
struct mbuf *opts = 0;
|
|
int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
|
|
|
|
if (!in_canforward(ip->ip_src) &&
|
|
((ip->ip_src.s_addr & IN_CLASSA_NET) !=
|
|
htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
|
|
m_freem(m); /* Bad return address */
|
|
goto done; /* ip_output() will check for broadcast */
|
|
}
|
|
t = ip->ip_dst;
|
|
ip->ip_dst = ip->ip_src;
|
|
/*
|
|
* If the incoming packet was addressed directly to us, use
|
|
* dst as the src for the reply. Otherwise (broadcast or
|
|
* anonymous), use an address which corresponds to the
|
|
* incoming interface, with a preference for the address which
|
|
* corresponds to the route to the destination of the ICMP.
|
|
*/
|
|
|
|
/* Look for packet addressed to us */
|
|
INADDR_TO_IA(t, ia);
|
|
|
|
/* look for packet sent to broadcast address */
|
|
if (ia == NULL && (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;
|
|
if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) {
|
|
ia = ifatoia(ifa);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ia)
|
|
sin = &ia->ia_addr;
|
|
|
|
icmpdst.sin_addr = t;
|
|
|
|
/* if the packet is addressed somewhere else, compute the
|
|
source address for packets routed back to the source, and
|
|
use that, if it's an address on the interface which
|
|
received the packet */
|
|
if (sin == (struct sockaddr_in *)0) {
|
|
struct sockaddr_in sin_dst;
|
|
struct route icmproute;
|
|
int errornum;
|
|
|
|
sin_dst.sin_family = AF_INET;
|
|
sin_dst.sin_len = sizeof(struct sockaddr_in);
|
|
sin_dst.sin_addr = ip->ip_dst;
|
|
bzero(&icmproute, sizeof(icmproute));
|
|
errornum = 0;
|
|
sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum);
|
|
/* errornum is never used */
|
|
if (icmproute.ro_rt)
|
|
RTFREE(icmproute.ro_rt);
|
|
/* check to make sure sin is a source address on rcvif */
|
|
if (sin) {
|
|
t = sin->sin_addr;
|
|
sin = (struct sockaddr_in *)0;
|
|
INADDR_TO_IA(t, ia);
|
|
while (ia) {
|
|
if (ia->ia_ifp == m->m_pkthdr.rcvif) {
|
|
sin = &ia->ia_addr;
|
|
break;
|
|
}
|
|
NEXT_IA_WITH_SAME_ADDR(ia);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* if it was not addressed to us, but the route doesn't go out
|
|
the source interface, pick an address on the source
|
|
interface. This can happen when routing is asymmetric, or
|
|
when the incoming packet was encapsulated */
|
|
if (sin == (struct sockaddr_in *)0) {
|
|
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;
|
|
sin = &(ifatoia(ifa)->ia_addr);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The following happens if the packet was not addressed to us,
|
|
* and was received on an interface with no IP address:
|
|
* We find the first AF_INET address on the first non-loopback
|
|
* interface.
|
|
*/
|
|
if (sin == (struct sockaddr_in *)0)
|
|
for (ia = in_ifaddr.tqh_first; ia != NULL;
|
|
ia = ia->ia_list.tqe_next) {
|
|
if (ia->ia_ifp->if_flags & IFF_LOOPBACK)
|
|
continue;
|
|
sin = &ia->ia_addr;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we still didn't find an address, punt. We could have an
|
|
* interface up (and receiving packets) with no address.
|
|
*/
|
|
if (sin == (struct sockaddr_in *)0) {
|
|
m_freem(m);
|
|
goto done;
|
|
}
|
|
|
|
ip->ip_src = sin->sin_addr;
|
|
ip->ip_ttl = MAXTTL;
|
|
|
|
if (optlen > 0) {
|
|
u_char *cp;
|
|
int opt, cnt;
|
|
u_int len;
|
|
|
|
/*
|
|
* Retrieve any source routing from the incoming packet;
|
|
* add on any record-route or timestamp options.
|
|
*/
|
|
cp = (u_char *) (ip + 1);
|
|
if ((opts = ip_srcroute()) == 0 &&
|
|
(opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
|
|
opts->m_len = sizeof(struct in_addr);
|
|
*mtod(opts, struct in_addr *) = zeroin_addr;
|
|
}
|
|
if (opts) {
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_reflect optlen %d rt %d => ",
|
|
optlen, opts->m_len);
|
|
#endif
|
|
for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
|
|
opt = cp[IPOPT_OPTVAL];
|
|
if (opt == IPOPT_EOL)
|
|
break;
|
|
if (opt == IPOPT_NOP)
|
|
len = 1;
|
|
else {
|
|
if (cnt < IPOPT_OLEN + sizeof(*cp))
|
|
break;
|
|
len = cp[IPOPT_OLEN];
|
|
if (len < IPOPT_OLEN + sizeof(*cp) ||
|
|
len > cnt)
|
|
break;
|
|
}
|
|
/*
|
|
* Should check for overflow, but it "can't happen"
|
|
*/
|
|
if (opt == IPOPT_RR || opt == IPOPT_TS ||
|
|
opt == IPOPT_SECURITY) {
|
|
bcopy((caddr_t)cp,
|
|
mtod(opts, caddr_t) + opts->m_len, len);
|
|
opts->m_len += len;
|
|
}
|
|
}
|
|
/* Terminate & pad, if necessary */
|
|
if ((cnt = opts->m_len % 4) != 0) {
|
|
for (; cnt < 4; cnt++) {
|
|
*(mtod(opts, caddr_t) + opts->m_len) =
|
|
IPOPT_EOL;
|
|
opts->m_len++;
|
|
}
|
|
}
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("%d\n", opts->m_len);
|
|
#endif
|
|
}
|
|
/*
|
|
* Now strip out original options by copying rest of first
|
|
* mbuf's data back, and adjust the IP length.
|
|
*/
|
|
ip->ip_len -= optlen;
|
|
ip->ip_hl = sizeof(struct ip) >> 2;
|
|
m->m_len -= optlen;
|
|
if (m->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len -= optlen;
|
|
optlen += sizeof(struct ip);
|
|
bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
|
|
(unsigned)(m->m_len - sizeof(struct ip)));
|
|
}
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
|
icmp_send(m, opts);
|
|
done:
|
|
if (opts)
|
|
(void)m_free(opts);
|
|
}
|
|
|
|
/*
|
|
* Send an icmp packet back to the ip level,
|
|
* after supplying a checksum.
|
|
*/
|
|
void
|
|
icmp_send(m, opts)
|
|
struct mbuf *m;
|
|
struct mbuf *opts;
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
int hlen;
|
|
struct icmp *icp;
|
|
|
|
hlen = ip->ip_hl << 2;
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
icp = mtod(m, struct icmp *);
|
|
icp->icmp_cksum = 0;
|
|
icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
|
|
m->m_data -= hlen;
|
|
m->m_len += hlen;
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src);
|
|
#endif
|
|
#ifdef IPSEC
|
|
/* Don't lookup socket */
|
|
ipsec_setsocket(m, NULL);
|
|
#endif
|
|
(void) ip_output(m, opts, NULL, 0, NULL);
|
|
}
|
|
|
|
n_time
|
|
iptime()
|
|
{
|
|
struct timeval atv;
|
|
u_long t;
|
|
|
|
microtime(&atv);
|
|
t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
|
|
return (htonl(t));
|
|
}
|
|
|
|
int
|
|
icmp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
|
|
int *name;
|
|
u_int namelen;
|
|
void *oldp;
|
|
size_t *oldlenp;
|
|
void *newp;
|
|
size_t newlen;
|
|
{
|
|
int arg, error;
|
|
|
|
/* All sysctl names at this level are terminal. */
|
|
if (namelen != 1)
|
|
return (ENOTDIR);
|
|
|
|
switch (name[0])
|
|
{
|
|
case ICMPCTL_MASKREPL:
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &icmpmaskrepl);
|
|
break;
|
|
case ICMPCTL_RETURNDATABYTES:
|
|
arg = icmpreturndatabytes;
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &arg);
|
|
if (error)
|
|
break;
|
|
if ((arg >= 8) || (arg <= 512))
|
|
icmpreturndatabytes = arg;
|
|
else
|
|
error = EINVAL;
|
|
break;
|
|
case ICMPCTL_ERRPPSLIMIT:
|
|
error = sysctl_int(oldp, oldlenp, newp, newlen, &icmperrppslim);
|
|
break;
|
|
default:
|
|
error = ENOPROTOOPT;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static void
|
|
icmp_mtudisc(icp)
|
|
struct icmp *icp;
|
|
{
|
|
struct rtentry *rt;
|
|
struct sockaddr *dst = sintosa(&icmpsrc);
|
|
u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */
|
|
int error;
|
|
|
|
/* Table of common MTUs: */
|
|
|
|
static u_long mtu_table[] = {65535, 65280, 32000, 17914, 9180, 8166,
|
|
4352, 2002, 1492, 1006, 508, 296, 68, 0};
|
|
|
|
rt = rtalloc1(dst, 1);
|
|
if (rt == 0)
|
|
return;
|
|
|
|
/* If we didn't get a host route, allocate one */
|
|
|
|
if ((rt->rt_flags & RTF_HOST) == 0) {
|
|
struct rtentry *nrt;
|
|
|
|
error = rtrequest((int) RTM_ADD, dst,
|
|
(struct sockaddr *) rt->rt_gateway,
|
|
(struct sockaddr *) 0,
|
|
RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
|
|
if (error) {
|
|
rtfree(rt);
|
|
rtfree(nrt);
|
|
return;
|
|
}
|
|
nrt->rt_rmx = rt->rt_rmx;
|
|
rtfree(rt);
|
|
rt = nrt;
|
|
}
|
|
error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q);
|
|
if (error) {
|
|
rtfree(rt);
|
|
return;
|
|
}
|
|
|
|
if (mtu == 0) {
|
|
int i = 0;
|
|
|
|
mtu = icp->icmp_ip.ip_len; /* NTOHS happened in deliver: */
|
|
/* Some 4.2BSD-based routers incorrectly adjust the ip_len */
|
|
if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0)
|
|
mtu -= (icp->icmp_ip.ip_hl << 2);
|
|
|
|
/* If we still can't guess a value, try the route */
|
|
|
|
if (mtu == 0) {
|
|
mtu = rt->rt_rmx.rmx_mtu;
|
|
|
|
/* If no route mtu, default to the interface mtu */
|
|
|
|
if (mtu == 0)
|
|
mtu = rt->rt_ifp->if_mtu;
|
|
}
|
|
|
|
for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++)
|
|
if (mtu > mtu_table[i]) {
|
|
mtu = mtu_table[i];
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* XXX: RTV_MTU is overloaded, since the admin can set it
|
|
* to turn off PMTU for a route, and the kernel can
|
|
* set it to indicate a serious problem with PMTU
|
|
* on a route. We should be using a separate flag
|
|
* for the kernel to indicate this.
|
|
*/
|
|
|
|
if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
|
|
if (mtu < 296 || mtu > rt->rt_ifp->if_mtu)
|
|
rt->rt_rmx.rmx_locks |= RTV_MTU;
|
|
else if (rt->rt_rmx.rmx_mtu > mtu ||
|
|
rt->rt_rmx.rmx_mtu == 0)
|
|
rt->rt_rmx.rmx_mtu = mtu;
|
|
}
|
|
|
|
if (rt)
|
|
rtfree(rt);
|
|
}
|
|
|
|
/*
|
|
* Return the next larger or smaller MTU plateau (table from RFC 1191)
|
|
* given current value MTU. If DIR is less than zero, a larger plateau
|
|
* is returned; otherwise, a smaller value is returned.
|
|
*/
|
|
int
|
|
ip_next_mtu(mtu, dir) /* XXX */
|
|
int mtu;
|
|
int dir;
|
|
{
|
|
static int mtutab[] = {
|
|
65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
|
|
68, 0
|
|
};
|
|
int i;
|
|
|
|
for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
|
|
if (mtu >= mtutab[i])
|
|
break;
|
|
}
|
|
|
|
if (dir < 0) {
|
|
if (i == 0) {
|
|
return 0;
|
|
} else {
|
|
return mtutab[i - 1];
|
|
}
|
|
} else {
|
|
if (mtutab[i] == 0) {
|
|
return 0;
|
|
} else if(mtu > mtutab[i]) {
|
|
return mtutab[i];
|
|
} else {
|
|
return mtutab[i + 1];
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
icmp_mtudisc_timeout(rt, r)
|
|
struct rtentry *rt;
|
|
struct rttimer *r;
|
|
{
|
|
if (rt == NULL)
|
|
panic("icmp_mtudisc_timeout: bad route to timeout");
|
|
if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
|
|
(RTF_DYNAMIC | RTF_HOST)) {
|
|
rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
|
|
rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
|
|
} else {
|
|
if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
|
|
rt->rt_rmx.rmx_mtu = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Perform rate limit check.
|
|
* Returns 0 if it is okay to send the icmp packet.
|
|
* Returns 1 if the router SHOULD NOT send this icmp packet due to rate
|
|
* limitation.
|
|
*
|
|
* XXX per-destination/type check necessary?
|
|
*/
|
|
static int
|
|
icmp_ratelimit(dst, type, code)
|
|
const struct in_addr *dst;
|
|
const int type; /* not used at this moment */
|
|
const int code; /* not used at this moment */
|
|
{
|
|
|
|
/* PPS limit */
|
|
if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count,
|
|
icmperrppslim)) {
|
|
/* The packet is subject to rate limit */
|
|
return 1;
|
|
}
|
|
|
|
/*okay to send*/
|
|
return 0;
|
|
}
|