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30 |
unneback |
/*
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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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* $Id: ip_icmp.c,v 1.2 2001-09-27 12:01:55 chris Exp $
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*/
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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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| 40 |
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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/socket.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/route.h>
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#define _IP_VHL
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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/icmp_var.h>
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| 60 |
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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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struct icmpstat icmpstat;
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SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RD,
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&icmpstat, icmpstat, "");
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| 70 |
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static int icmpmaskrepl = 0;
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SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
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&icmpmaskrepl, 0, "");
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static int icmpbmcastecho = 1;
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SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW, &icmpbmcastecho,
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0, "");
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| 78 |
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/* #define ICMPPRINTFS 1 */
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#ifdef ICMPPRINTFS
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int icmpprintfs = 0;
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#endif
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| 83 |
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static void icmp_reflect __P((struct mbuf *));
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static void icmp_send __P((struct mbuf *, struct mbuf *));
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static int ip_next_mtu __P((int, int));
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| 87 |
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extern struct protosw inetsw[];
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| 89 |
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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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register struct ip *oip = mtod(n, struct ip *), *nip;
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register unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
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register struct icmp *icp;
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register struct mbuf *m;
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unsigned icmplen;
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#ifdef ICMPPRINTFS
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if (icmpprintfs)
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printf("icmp_error(%p, %x, %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 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 (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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| 123 |
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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, formulate icmp message
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*/
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m = m_gethdr(M_DONTWAIT, MT_HEADER);
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if (m == NULL)
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goto freeit;
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icmplen = oiplen + min(8, oip->ip_len);
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m->m_len = icmplen + ICMP_MINLEN;
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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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}
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icp->icmp_code = code;
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bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen);
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nip = &icp->icmp_ip;
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nip->ip_len = htons((u_short)(nip->ip_len + oiplen));
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| 164 |
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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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bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
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nip->ip_len = m->m_len;
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nip->ip_vhl = IP_VHL_BORING;
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nip->ip_p = IPPROTO_ICMP;
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nip->ip_tos = 0;
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| 180 |
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icmp_reflect(m);
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| 182 |
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freeit:
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m_freem(n);
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}
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| 186 |
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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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| 188 |
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static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };
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| 189 |
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| 190 |
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/*
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| 191 |
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* Process a received ICMP message.
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| 192 |
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*/
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| 193 |
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void
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| 194 |
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icmp_input(m, hlen)
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| 195 |
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register struct mbuf *m;
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| 196 |
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int hlen;
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| 197 |
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{
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| 198 |
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register struct icmp *icp;
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| 199 |
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register struct ip *ip = mtod(m, struct ip *);
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| 200 |
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int icmplen = ip->ip_len;
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| 201 |
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register int i;
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| 202 |
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struct in_ifaddr *ia;
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| 203 |
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void (*ctlfunc) __P((int, struct sockaddr *, void *));
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| 204 |
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int code;
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| 205 |
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| 206 |
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/*
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| 207 |
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* Locate icmp structure in mbuf, and check
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| 208 |
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* that not corrupted and of at least minimum length.
|
| 209 |
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*/
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| 210 |
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#ifdef ICMPPRINTFS
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| 211 |
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if (icmpprintfs) {
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| 212 |
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char buf[4 * sizeof "123"];
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| 213 |
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strcpy(buf, inet_ntoa(ip->ip_src));
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| 214 |
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printf("icmp_input from %s to %s, len %d\n",
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| 215 |
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buf, inet_ntoa(ip->ip_dst), icmplen);
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| 216 |
|
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}
|
| 217 |
|
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#endif
|
| 218 |
|
|
if (icmplen < ICMP_MINLEN) {
|
| 219 |
|
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icmpstat.icps_tooshort++;
|
| 220 |
|
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goto freeit;
|
| 221 |
|
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}
|
| 222 |
|
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i = hlen + min(icmplen, ICMP_ADVLENMIN);
|
| 223 |
|
|
if (m->m_len < i && (m = m_pullup(m, i)) == 0) {
|
| 224 |
|
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icmpstat.icps_tooshort++;
|
| 225 |
|
|
return;
|
| 226 |
|
|
}
|
| 227 |
|
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ip = mtod(m, struct ip *);
|
| 228 |
|
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m->m_len -= hlen;
|
| 229 |
|
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m->m_data += hlen;
|
| 230 |
|
|
icp = mtod(m, struct icmp *);
|
| 231 |
|
|
if (in_cksum(m, icmplen)) {
|
| 232 |
|
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icmpstat.icps_checksum++;
|
| 233 |
|
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goto freeit;
|
| 234 |
|
|
}
|
| 235 |
|
|
m->m_len += hlen;
|
| 236 |
|
|
m->m_data -= hlen;
|
| 237 |
|
|
|
| 238 |
|
|
#ifdef ICMPPRINTFS
|
| 239 |
|
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if (icmpprintfs)
|
| 240 |
|
|
printf("icmp_input, type %d code %d\n", icp->icmp_type,
|
| 241 |
|
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icp->icmp_code);
|
| 242 |
|
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#endif
|
| 243 |
|
|
|
| 244 |
|
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/*
|
| 245 |
|
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* Message type specific processing.
|
| 246 |
|
|
*/
|
| 247 |
|
|
if (icp->icmp_type > ICMP_MAXTYPE)
|
| 248 |
|
|
goto raw;
|
| 249 |
|
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icmpstat.icps_inhist[icp->icmp_type]++;
|
| 250 |
|
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code = icp->icmp_code;
|
| 251 |
|
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switch (icp->icmp_type) {
|
| 252 |
|
|
|
| 253 |
|
|
case ICMP_UNREACH:
|
| 254 |
|
|
switch (code) {
|
| 255 |
|
|
case ICMP_UNREACH_NET:
|
| 256 |
|
|
case ICMP_UNREACH_HOST:
|
| 257 |
|
|
case ICMP_UNREACH_PROTOCOL:
|
| 258 |
|
|
case ICMP_UNREACH_PORT:
|
| 259 |
|
|
case ICMP_UNREACH_SRCFAIL:
|
| 260 |
|
|
code += PRC_UNREACH_NET;
|
| 261 |
|
|
break;
|
| 262 |
|
|
|
| 263 |
|
|
case ICMP_UNREACH_NEEDFRAG:
|
| 264 |
|
|
code = PRC_MSGSIZE;
|
| 265 |
|
|
break;
|
| 266 |
|
|
|
| 267 |
|
|
case ICMP_UNREACH_NET_UNKNOWN:
|
| 268 |
|
|
case ICMP_UNREACH_NET_PROHIB:
|
| 269 |
|
|
case ICMP_UNREACH_TOSNET:
|
| 270 |
|
|
code = PRC_UNREACH_NET;
|
| 271 |
|
|
break;
|
| 272 |
|
|
|
| 273 |
|
|
case ICMP_UNREACH_HOST_UNKNOWN:
|
| 274 |
|
|
case ICMP_UNREACH_ISOLATED:
|
| 275 |
|
|
case ICMP_UNREACH_HOST_PROHIB:
|
| 276 |
|
|
case ICMP_UNREACH_TOSHOST:
|
| 277 |
|
|
code = PRC_UNREACH_HOST;
|
| 278 |
|
|
break;
|
| 279 |
|
|
|
| 280 |
|
|
case ICMP_UNREACH_FILTER_PROHIB:
|
| 281 |
|
|
case ICMP_UNREACH_HOST_PRECEDENCE:
|
| 282 |
|
|
case ICMP_UNREACH_PRECEDENCE_CUTOFF:
|
| 283 |
|
|
code = PRC_UNREACH_PORT;
|
| 284 |
|
|
break;
|
| 285 |
|
|
|
| 286 |
|
|
default:
|
| 287 |
|
|
goto badcode;
|
| 288 |
|
|
}
|
| 289 |
|
|
goto deliver;
|
| 290 |
|
|
|
| 291 |
|
|
case ICMP_TIMXCEED:
|
| 292 |
|
|
if (code > 1)
|
| 293 |
|
|
goto badcode;
|
| 294 |
|
|
code += PRC_TIMXCEED_INTRANS;
|
| 295 |
|
|
goto deliver;
|
| 296 |
|
|
|
| 297 |
|
|
case ICMP_PARAMPROB:
|
| 298 |
|
|
if (code > 1)
|
| 299 |
|
|
goto badcode;
|
| 300 |
|
|
code = PRC_PARAMPROB;
|
| 301 |
|
|
goto deliver;
|
| 302 |
|
|
|
| 303 |
|
|
case ICMP_SOURCEQUENCH:
|
| 304 |
|
|
if (code)
|
| 305 |
|
|
goto badcode;
|
| 306 |
|
|
code = PRC_QUENCH;
|
| 307 |
|
|
deliver:
|
| 308 |
|
|
/*
|
| 309 |
|
|
* Problem with datagram; advise higher level routines.
|
| 310 |
|
|
*/
|
| 311 |
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
| 312 |
|
|
IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
|
| 313 |
|
|
icmpstat.icps_badlen++;
|
| 314 |
|
|
goto freeit;
|
| 315 |
|
|
}
|
| 316 |
|
|
NTOHS(icp->icmp_ip.ip_len);
|
| 317 |
|
|
/* Discard ICMP's in response to multicast packets */
|
| 318 |
|
|
if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
|
| 319 |
|
|
goto badcode;
|
| 320 |
|
|
#ifdef ICMPPRINTFS
|
| 321 |
|
|
if (icmpprintfs)
|
| 322 |
|
|
printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
|
| 323 |
|
|
#endif
|
| 324 |
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
| 325 |
|
|
#if 1
|
| 326 |
|
|
/*
|
| 327 |
|
|
* MTU discovery:
|
| 328 |
|
|
* If we got a needfrag and there is a host route to the
|
| 329 |
|
|
* original destination, and the MTU is not locked, then
|
| 330 |
|
|
* set the MTU in the route to the suggested new value
|
| 331 |
|
|
* (if given) and then notify as usual. The ULPs will
|
| 332 |
|
|
* notice that the MTU has changed and adapt accordingly.
|
| 333 |
|
|
* If no new MTU was suggested, then we guess a new one
|
| 334 |
|
|
* less than the current value. If the new MTU is
|
| 335 |
|
|
* unreasonably small (arbitrarily set at 296), then
|
| 336 |
|
|
* we reset the MTU to the interface value and enable the
|
| 337 |
|
|
* lock bit, indicating that we are no longer doing MTU
|
| 338 |
|
|
* discovery.
|
| 339 |
|
|
*/
|
| 340 |
|
|
if (code == PRC_MSGSIZE) {
|
| 341 |
|
|
struct rtentry *rt;
|
| 342 |
|
|
int mtu;
|
| 343 |
|
|
|
| 344 |
|
|
rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
|
| 345 |
|
|
RTF_CLONING | RTF_PRCLONING);
|
| 346 |
|
|
if (rt && (rt->rt_flags & RTF_HOST)
|
| 347 |
|
|
&& !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
|
| 348 |
|
|
mtu = ntohs(icp->icmp_nextmtu);
|
| 349 |
|
|
if (!mtu)
|
| 350 |
|
|
mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
|
| 351 |
|
|
1);
|
| 352 |
|
|
#ifdef DEBUG_MTUDISC
|
| 353 |
|
|
printf("MTU for %s reduced to %d\n",
|
| 354 |
|
|
inet_ntoa(icmpsrc.sin_addr), mtu);
|
| 355 |
|
|
#endif
|
| 356 |
|
|
if (mtu < 296) {
|
| 357 |
|
|
/* rt->rt_rmx.rmx_mtu =
|
| 358 |
|
|
rt->rt_ifp->if_mtu; */
|
| 359 |
|
|
rt->rt_rmx.rmx_locks |= RTV_MTU;
|
| 360 |
|
|
} else if (rt->rt_rmx.rmx_mtu > mtu) {
|
| 361 |
|
|
rt->rt_rmx.rmx_mtu = mtu;
|
| 362 |
|
|
}
|
| 363 |
|
|
}
|
| 364 |
|
|
if (rt)
|
| 365 |
|
|
RTFREE(rt);
|
| 366 |
|
|
}
|
| 367 |
|
|
|
| 368 |
|
|
#endif
|
| 369 |
|
|
ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
|
| 370 |
|
|
if (ctlfunc)
|
| 371 |
|
|
(*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
|
| 372 |
|
|
(void *)&icp->icmp_ip);
|
| 373 |
|
|
break;
|
| 374 |
|
|
|
| 375 |
|
|
badcode:
|
| 376 |
|
|
icmpstat.icps_badcode++;
|
| 377 |
|
|
break;
|
| 378 |
|
|
|
| 379 |
|
|
case ICMP_ECHO:
|
| 380 |
|
|
if (!icmpbmcastecho
|
| 381 |
|
|
&& (m->m_flags & (M_MCAST | M_BCAST)) != 0
|
| 382 |
|
|
&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
|
| 383 |
|
|
icmpstat.icps_bmcastecho++;
|
| 384 |
|
|
break;
|
| 385 |
|
|
}
|
| 386 |
|
|
icp->icmp_type = ICMP_ECHOREPLY;
|
| 387 |
|
|
goto reflect;
|
| 388 |
|
|
|
| 389 |
|
|
case ICMP_TSTAMP:
|
| 390 |
|
|
if (!icmpbmcastecho
|
| 391 |
|
|
&& (m->m_flags & (M_MCAST | M_BCAST)) != 0
|
| 392 |
|
|
&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
|
| 393 |
|
|
icmpstat.icps_bmcasttstamp++;
|
| 394 |
|
|
break;
|
| 395 |
|
|
}
|
| 396 |
|
|
if (icmplen < ICMP_TSLEN) {
|
| 397 |
|
|
icmpstat.icps_badlen++;
|
| 398 |
|
|
break;
|
| 399 |
|
|
}
|
| 400 |
|
|
icp->icmp_type = ICMP_TSTAMPREPLY;
|
| 401 |
|
|
icp->icmp_rtime = iptime();
|
| 402 |
|
|
icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
|
| 403 |
|
|
goto reflect;
|
| 404 |
|
|
|
| 405 |
|
|
case ICMP_MASKREQ:
|
| 406 |
|
|
#define satosin(sa) ((struct sockaddr_in *)(sa))
|
| 407 |
|
|
if (icmpmaskrepl == 0)
|
| 408 |
|
|
break;
|
| 409 |
|
|
/*
|
| 410 |
|
|
* We are not able to respond with all ones broadcast
|
| 411 |
|
|
* unless we receive it over a point-to-point interface.
|
| 412 |
|
|
*/
|
| 413 |
|
|
if (icmplen < ICMP_MASKLEN)
|
| 414 |
|
|
break;
|
| 415 |
|
|
switch (ip->ip_dst.s_addr) {
|
| 416 |
|
|
|
| 417 |
|
|
case INADDR_BROADCAST:
|
| 418 |
|
|
case INADDR_ANY:
|
| 419 |
|
|
icmpdst.sin_addr = ip->ip_src;
|
| 420 |
|
|
break;
|
| 421 |
|
|
|
| 422 |
|
|
default:
|
| 423 |
|
|
icmpdst.sin_addr = ip->ip_dst;
|
| 424 |
|
|
}
|
| 425 |
|
|
ia = (struct in_ifaddr *)ifaof_ifpforaddr(
|
| 426 |
|
|
(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
|
| 427 |
|
|
if (ia == 0)
|
| 428 |
|
|
break;
|
| 429 |
|
|
if (ia->ia_ifp == 0)
|
| 430 |
|
|
break;
|
| 431 |
|
|
icp->icmp_type = ICMP_MASKREPLY;
|
| 432 |
|
|
icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
|
| 433 |
|
|
if (ip->ip_src.s_addr == 0) {
|
| 434 |
|
|
if (ia->ia_ifp->if_flags & IFF_BROADCAST)
|
| 435 |
|
|
ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
|
| 436 |
|
|
else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
|
| 437 |
|
|
ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
|
| 438 |
|
|
}
|
| 439 |
|
|
reflect:
|
| 440 |
|
|
ip->ip_len += hlen; /* since ip_input deducts this */
|
| 441 |
|
|
icmpstat.icps_reflect++;
|
| 442 |
|
|
icmpstat.icps_outhist[icp->icmp_type]++;
|
| 443 |
|
|
icmp_reflect(m);
|
| 444 |
|
|
return;
|
| 445 |
|
|
|
| 446 |
|
|
case ICMP_REDIRECT:
|
| 447 |
|
|
if (code > 3)
|
| 448 |
|
|
goto badcode;
|
| 449 |
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
| 450 |
|
|
IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
|
| 451 |
|
|
icmpstat.icps_badlen++;
|
| 452 |
|
|
break;
|
| 453 |
|
|
}
|
| 454 |
|
|
/*
|
| 455 |
|
|
* Short circuit routing redirects to force
|
| 456 |
|
|
* immediate change in the kernel's routing
|
| 457 |
|
|
* tables. The message is also handed to anyone
|
| 458 |
|
|
* listening on a raw socket (e.g. the routing
|
| 459 |
|
|
* daemon for use in updating its tables).
|
| 460 |
|
|
*/
|
| 461 |
|
|
icmpgw.sin_addr = ip->ip_src;
|
| 462 |
|
|
icmpdst.sin_addr = icp->icmp_gwaddr;
|
| 463 |
|
|
#ifdef ICMPPRINTFS
|
| 464 |
|
|
if (icmpprintfs) {
|
| 465 |
|
|
char buf[4 * sizeof "123"];
|
| 466 |
|
|
strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
|
| 467 |
|
|
|
| 468 |
|
|
printf("redirect dst %s to %s\n",
|
| 469 |
|
|
buf, inet_ntoa(icp->icmp_gwaddr));
|
| 470 |
|
|
}
|
| 471 |
|
|
#endif
|
| 472 |
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
| 473 |
|
|
rtredirect((struct sockaddr *)&icmpsrc,
|
| 474 |
|
|
(struct sockaddr *)&icmpdst,
|
| 475 |
|
|
(struct sockaddr *)0, RTF_GATEWAY | RTF_HOST,
|
| 476 |
|
|
(struct sockaddr *)&icmpgw, (struct rtentry **)0);
|
| 477 |
|
|
pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
|
| 478 |
|
|
break;
|
| 479 |
|
|
|
| 480 |
|
|
/*
|
| 481 |
|
|
* No kernel processing for the following;
|
| 482 |
|
|
* just fall through to send to raw listener.
|
| 483 |
|
|
*/
|
| 484 |
|
|
case ICMP_ECHOREPLY:
|
| 485 |
|
|
case ICMP_ROUTERADVERT:
|
| 486 |
|
|
case ICMP_ROUTERSOLICIT:
|
| 487 |
|
|
case ICMP_TSTAMPREPLY:
|
| 488 |
|
|
case ICMP_IREQREPLY:
|
| 489 |
|
|
case ICMP_MASKREPLY:
|
| 490 |
|
|
default:
|
| 491 |
|
|
break;
|
| 492 |
|
|
}
|
| 493 |
|
|
|
| 494 |
|
|
raw:
|
| 495 |
|
|
rip_input(m, hlen);
|
| 496 |
|
|
return;
|
| 497 |
|
|
|
| 498 |
|
|
freeit:
|
| 499 |
|
|
m_freem(m);
|
| 500 |
|
|
}
|
| 501 |
|
|
|
| 502 |
|
|
/*
|
| 503 |
|
|
* Reflect the ip packet back to the source
|
| 504 |
|
|
*/
|
| 505 |
|
|
static void
|
| 506 |
|
|
icmp_reflect(m)
|
| 507 |
|
|
struct mbuf *m;
|
| 508 |
|
|
{
|
| 509 |
|
|
register struct ip *ip = mtod(m, struct ip *);
|
| 510 |
|
|
register struct in_ifaddr *ia;
|
| 511 |
|
|
struct in_addr t;
|
| 512 |
|
|
struct mbuf *opts = 0;
|
| 513 |
|
|
int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
|
| 514 |
|
|
|
| 515 |
|
|
if (!in_canforward(ip->ip_src) &&
|
| 516 |
|
|
((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
|
| 517 |
|
|
(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
|
| 518 |
|
|
m_freem(m); /* Bad return address */
|
| 519 |
|
|
goto done; /* Ip_output() will check for broadcast */
|
| 520 |
|
|
}
|
| 521 |
|
|
t = ip->ip_dst;
|
| 522 |
|
|
ip->ip_dst = ip->ip_src;
|
| 523 |
|
|
/*
|
| 524 |
|
|
* If the incoming packet was addressed directly to us,
|
| 525 |
|
|
* use dst as the src for the reply. Otherwise (broadcast
|
| 526 |
|
|
* or anonymous), use the address which corresponds
|
| 527 |
|
|
* to the incoming interface.
|
| 528 |
|
|
*/
|
| 529 |
|
|
for (ia = in_ifaddr; ia; ia = ia->ia_next) {
|
| 530 |
|
|
if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
|
| 531 |
|
|
break;
|
| 532 |
|
|
if (ia->ia_ifp && (ia->ia_ifp->if_flags & IFF_BROADCAST) &&
|
| 533 |
|
|
t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr)
|
| 534 |
|
|
break;
|
| 535 |
|
|
}
|
| 536 |
|
|
icmpdst.sin_addr = t;
|
| 537 |
|
|
if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif)
|
| 538 |
|
|
ia = (struct in_ifaddr *)ifaof_ifpforaddr(
|
| 539 |
|
|
(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
|
| 540 |
|
|
/*
|
| 541 |
|
|
* The following happens if the packet was not addressed to us,
|
| 542 |
|
|
* and was received on an interface with no IP address.
|
| 543 |
|
|
*/
|
| 544 |
|
|
if (ia == (struct in_ifaddr *)0)
|
| 545 |
|
|
ia = in_ifaddr;
|
| 546 |
|
|
t = IA_SIN(ia)->sin_addr;
|
| 547 |
|
|
ip->ip_src = t;
|
| 548 |
|
|
ip->ip_ttl = MAXTTL;
|
| 549 |
|
|
|
| 550 |
|
|
if (optlen > 0) {
|
| 551 |
|
|
register u_char *cp;
|
| 552 |
|
|
int opt, cnt;
|
| 553 |
|
|
u_int len;
|
| 554 |
|
|
|
| 555 |
|
|
/*
|
| 556 |
|
|
* Retrieve any source routing from the incoming packet;
|
| 557 |
|
|
* add on any record-route or timestamp options.
|
| 558 |
|
|
*/
|
| 559 |
|
|
cp = (u_char *) (ip + 1);
|
| 560 |
|
|
if ((opts = ip_srcroute()) == 0 &&
|
| 561 |
|
|
(opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
|
| 562 |
|
|
opts->m_len = sizeof(struct in_addr);
|
| 563 |
|
|
mtod(opts, struct in_addr *)->s_addr = 0;
|
| 564 |
|
|
}
|
| 565 |
|
|
if (opts) {
|
| 566 |
|
|
#ifdef ICMPPRINTFS
|
| 567 |
|
|
if (icmpprintfs)
|
| 568 |
|
|
printf("icmp_reflect optlen %d rt %d => ",
|
| 569 |
|
|
optlen, opts->m_len);
|
| 570 |
|
|
#endif
|
| 571 |
|
|
for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
|
| 572 |
|
|
opt = cp[IPOPT_OPTVAL];
|
| 573 |
|
|
if (opt == IPOPT_EOL)
|
| 574 |
|
|
break;
|
| 575 |
|
|
if (opt == IPOPT_NOP)
|
| 576 |
|
|
len = 1;
|
| 577 |
|
|
else {
|
| 578 |
|
|
len = cp[IPOPT_OLEN];
|
| 579 |
|
|
if (len <= 0 || len > cnt)
|
| 580 |
|
|
break;
|
| 581 |
|
|
}
|
| 582 |
|
|
/*
|
| 583 |
|
|
* Should check for overflow, but it "can't happen"
|
| 584 |
|
|
*/
|
| 585 |
|
|
if (opt == IPOPT_RR || opt == IPOPT_TS ||
|
| 586 |
|
|
opt == IPOPT_SECURITY) {
|
| 587 |
|
|
bcopy((caddr_t)cp,
|
| 588 |
|
|
mtod(opts, caddr_t) + opts->m_len, len);
|
| 589 |
|
|
opts->m_len += len;
|
| 590 |
|
|
}
|
| 591 |
|
|
}
|
| 592 |
|
|
/* Terminate & pad, if necessary */
|
| 593 |
|
|
cnt = opts->m_len % 4;
|
| 594 |
|
|
if (cnt) {
|
| 595 |
|
|
for (; cnt < 4; cnt++) {
|
| 596 |
|
|
*(mtod(opts, caddr_t) + opts->m_len) =
|
| 597 |
|
|
IPOPT_EOL;
|
| 598 |
|
|
opts->m_len++;
|
| 599 |
|
|
}
|
| 600 |
|
|
}
|
| 601 |
|
|
#ifdef ICMPPRINTFS
|
| 602 |
|
|
if (icmpprintfs)
|
| 603 |
|
|
printf("%d\n", opts->m_len);
|
| 604 |
|
|
#endif
|
| 605 |
|
|
}
|
| 606 |
|
|
/*
|
| 607 |
|
|
* Now strip out original options by copying rest of first
|
| 608 |
|
|
* mbuf's data back, and adjust the IP length.
|
| 609 |
|
|
*/
|
| 610 |
|
|
ip->ip_len -= optlen;
|
| 611 |
|
|
ip->ip_vhl = IP_VHL_BORING;
|
| 612 |
|
|
m->m_len -= optlen;
|
| 613 |
|
|
if (m->m_flags & M_PKTHDR)
|
| 614 |
|
|
m->m_pkthdr.len -= optlen;
|
| 615 |
|
|
optlen += sizeof(struct ip);
|
| 616 |
|
|
bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
|
| 617 |
|
|
(unsigned)(m->m_len - sizeof(struct ip)));
|
| 618 |
|
|
}
|
| 619 |
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
| 620 |
|
|
icmp_send(m, opts);
|
| 621 |
|
|
done:
|
| 622 |
|
|
if (opts)
|
| 623 |
|
|
(void)m_free(opts);
|
| 624 |
|
|
}
|
| 625 |
|
|
|
| 626 |
|
|
/*
|
| 627 |
|
|
* Send an icmp packet back to the ip level,
|
| 628 |
|
|
* after supplying a checksum.
|
| 629 |
|
|
*/
|
| 630 |
|
|
static void
|
| 631 |
|
|
icmp_send(m, opts)
|
| 632 |
|
|
register struct mbuf *m;
|
| 633 |
|
|
struct mbuf *opts;
|
| 634 |
|
|
{
|
| 635 |
|
|
register struct ip *ip = mtod(m, struct ip *);
|
| 636 |
|
|
register int hlen;
|
| 637 |
|
|
register struct icmp *icp;
|
| 638 |
|
|
struct route ro;
|
| 639 |
|
|
|
| 640 |
|
|
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
|
| 641 |
|
|
m->m_data += hlen;
|
| 642 |
|
|
m->m_len -= hlen;
|
| 643 |
|
|
icp = mtod(m, struct icmp *);
|
| 644 |
|
|
icp->icmp_cksum = 0;
|
| 645 |
|
|
icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
|
| 646 |
|
|
m->m_data -= hlen;
|
| 647 |
|
|
m->m_len += hlen;
|
| 648 |
|
|
#ifdef ICMPPRINTFS
|
| 649 |
|
|
if (icmpprintfs) {
|
| 650 |
|
|
char buf[4 * sizeof "123"];
|
| 651 |
|
|
strcpy(buf, inet_ntoa(ip->ip_dst));
|
| 652 |
|
|
printf("icmp_send dst %s src %s\n",
|
| 653 |
|
|
buf, inet_ntoa(ip->ip_src));
|
| 654 |
|
|
}
|
| 655 |
|
|
#endif
|
| 656 |
|
|
bzero(&ro, sizeof ro);
|
| 657 |
|
|
(void) ip_output(m, opts, &ro, 0, NULL);
|
| 658 |
|
|
if (ro.ro_rt)
|
| 659 |
|
|
RTFREE(ro.ro_rt);
|
| 660 |
|
|
}
|
| 661 |
|
|
|
| 662 |
|
|
n_time
|
| 663 |
|
|
iptime()
|
| 664 |
|
|
{
|
| 665 |
|
|
struct timeval atv;
|
| 666 |
|
|
u_long t;
|
| 667 |
|
|
|
| 668 |
|
|
microtime(&atv);
|
| 669 |
|
|
t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
|
| 670 |
|
|
return (htonl(t));
|
| 671 |
|
|
}
|
| 672 |
|
|
|
| 673 |
|
|
#if 1
|
| 674 |
|
|
/*
|
| 675 |
|
|
* Return the next larger or smaller MTU plateau (table from RFC 1191)
|
| 676 |
|
|
* given current value MTU. If DIR is less than zero, a larger plateau
|
| 677 |
|
|
* is returned; otherwise, a smaller value is returned.
|
| 678 |
|
|
*/
|
| 679 |
|
|
static int
|
| 680 |
|
|
ip_next_mtu(mtu, dir)
|
| 681 |
|
|
int mtu;
|
| 682 |
|
|
int dir;
|
| 683 |
|
|
{
|
| 684 |
|
|
static int mtutab[] = {
|
| 685 |
|
|
65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
|
| 686 |
|
|
68, 0
|
| 687 |
|
|
};
|
| 688 |
|
|
int i;
|
| 689 |
|
|
|
| 690 |
|
|
for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
|
| 691 |
|
|
if (mtu >= mtutab[i])
|
| 692 |
|
|
break;
|
| 693 |
|
|
}
|
| 694 |
|
|
|
| 695 |
|
|
if (dir < 0) {
|
| 696 |
|
|
if (i == 0) {
|
| 697 |
|
|
return 0;
|
| 698 |
|
|
} else {
|
| 699 |
|
|
return mtutab[i - 1];
|
| 700 |
|
|
}
|
| 701 |
|
|
} else {
|
| 702 |
|
|
if (mtutab[i] == 0) {
|
| 703 |
|
|
return 0;
|
| 704 |
|
|
} else if(mtu > mtutab[i]) {
|
| 705 |
|
|
return mtutab[i];
|
| 706 |
|
|
} else {
|
| 707 |
|
|
return mtutab[i + 1];
|
| 708 |
|
|
}
|
| 709 |
|
|
}
|
| 710 |
|
|
}
|
| 711 |
|
|
#endif
|
