615 lines
14 KiB
C
615 lines
14 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California.
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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. 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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* from: @(#)ip_output.c 7.23 (Berkeley) 11/12/90
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* $Id: ip_output.c,v 1.4 1993/11/05 23:06:26 cgd Exp $
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*/
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#include "param.h"
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#include "malloc.h"
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#include "mbuf.h"
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#include "errno.h"
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#include "protosw.h"
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#include "socket.h"
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#include "socketvar.h"
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#include "../net/if.h"
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#include "../net/route.h"
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#include "in.h"
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#include "in_systm.h"
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#include "ip.h"
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#include "in_pcb.h"
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#include "in_var.h"
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#include "ip_var.h"
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#ifdef vax
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#include "machine/mtpr.h"
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#endif
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struct mbuf *ip_insertoptions();
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/*
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* IP output. The packet in mbuf chain m contains a skeletal IP
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* header (with len, off, ttl, proto, tos, src, dst).
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* The mbuf chain containing the packet will be freed.
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* The mbuf opt, if present, will not be freed.
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*/
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ip_output(m0, opt, ro, flags)
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struct mbuf *m0;
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struct mbuf *opt;
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struct route *ro;
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int flags;
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{
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register struct ip *ip, *mhip;
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register struct ifnet *ifp;
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register struct mbuf *m = m0;
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register int hlen = sizeof (struct ip);
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int len, off, error = 0;
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struct route iproute;
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struct sockaddr_in *dst;
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struct in_ifaddr *ia;
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#ifdef DIAGNOSTIC
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if ((m->m_flags & M_PKTHDR) == 0)
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panic("ip_output no HDR");
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#endif
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if (opt) {
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m = ip_insertoptions(m, opt, &len);
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hlen = len;
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}
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ip = mtod(m, struct ip *);
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/*
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* Fill in IP header.
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*/
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if ((flags & IP_FORWARDING) == 0) {
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ip->ip_v = IPVERSION;
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ip->ip_off &= IP_DF;
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ip->ip_id = htons(ip_id++);
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ip->ip_hl = hlen >> 2;
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} else {
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hlen = ip->ip_hl << 2;
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ipstat.ips_localout++;
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}
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/*
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* Route packet.
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*/
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if (ro == 0) {
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ro = &iproute;
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bzero((caddr_t)ro, sizeof (*ro));
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}
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dst = (struct sockaddr_in *)&ro->ro_dst;
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/*
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* If there is a cached route,
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* check that it is to the same destination
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* and is still up. If not, free it and try again.
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*/
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if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
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dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
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RTFREE(ro->ro_rt);
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ro->ro_rt = (struct rtentry *)0;
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}
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if (ro->ro_rt == 0) {
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dst->sin_family = AF_INET;
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dst->sin_len = sizeof(*dst);
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dst->sin_addr = ip->ip_dst;
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}
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/*
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* If routing to interface only,
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* short circuit routing lookup.
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*/
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if (flags & IP_ROUTETOIF) {
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ia = (struct in_ifaddr *)ifa_ifwithdstaddr((struct sockaddr *)dst);
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if (ia == 0)
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ia = in_iaonnetof(in_netof(ip->ip_dst));
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if (ia == 0) {
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error = ENETUNREACH;
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goto bad;
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}
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ifp = ia->ia_ifp;
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} else {
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if (ro->ro_rt == 0)
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rtalloc(ro);
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if (ro->ro_rt == 0) {
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error = EHOSTUNREACH;
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goto bad;
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}
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ia = (struct in_ifaddr *)ro->ro_rt->rt_ifa;
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ifp = ro->ro_rt->rt_ifp;
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ro->ro_rt->rt_use++;
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if (ro->ro_rt->rt_flags & RTF_GATEWAY)
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dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
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}
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#ifndef notdef
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/*
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* If source address not specified yet, use address
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* of outgoing interface.
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*/
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if (ip->ip_src.s_addr == INADDR_ANY)
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ip->ip_src = IA_SIN(ia)->sin_addr;
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#endif
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/*
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* Verify that we have any chance at all of being able to queue
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* the packet or packet fragments
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*/
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if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
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ifp->if_snd.ifq_maxlen) {
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error = ENOBUFS;
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goto bad;
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}
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/*
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* Look for broadcast address and
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* and verify user is allowed to send
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* such a packet.
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*/
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if (in_broadcast(dst->sin_addr)) {
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if ((ifp->if_flags & IFF_BROADCAST) == 0) {
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error = EADDRNOTAVAIL;
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goto bad;
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}
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if ((flags & IP_ALLOWBROADCAST) == 0) {
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error = EACCES;
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goto bad;
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}
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/* don't allow broadcast messages to be fragmented */
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if ((u_short)ip->ip_len > ifp->if_mtu) {
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error = EMSGSIZE;
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goto bad;
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}
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m->m_flags |= M_BCAST;
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}
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/*
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* If small enough for interface, can just send directly.
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*/
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if ((u_short)ip->ip_len <= ifp->if_mtu) {
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ip->ip_len = htons((u_short)ip->ip_len);
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ip->ip_off = htons((u_short)ip->ip_off);
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ip->ip_sum = 0;
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ip->ip_sum = in_cksum(m, hlen);
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error = (*ifp->if_output)(ifp, m,
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(struct sockaddr *)dst, ro->ro_rt);
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goto done;
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}
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ipstat.ips_fragmented++;
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/*
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* Too large for interface; fragment if possible.
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* Must be able to put at least 8 bytes per fragment.
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*/
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if (ip->ip_off & IP_DF) {
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error = EMSGSIZE;
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goto bad;
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}
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len = (ifp->if_mtu - hlen) &~ 7;
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if (len < 8) {
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error = EMSGSIZE;
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goto bad;
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}
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{
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int mhlen, firstlen = len;
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struct mbuf **mnext = &m->m_nextpkt;
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/*
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* Loop through length of segment after first fragment,
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* make new header and copy data of each part and link onto chain.
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*/
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m0 = m;
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mhlen = sizeof (struct ip);
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for (off = hlen + len; off < (u_short)ip->ip_len; off += len) {
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MGETHDR(m, M_DONTWAIT, MT_HEADER);
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if (m == 0) {
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error = ENOBUFS;
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goto sendorfree;
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}
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m->m_data += max_linkhdr;
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mhip = mtod(m, struct ip *);
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*mhip = *ip;
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if (hlen > sizeof (struct ip)) {
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mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
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mhip->ip_hl = mhlen >> 2;
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}
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m->m_len = mhlen;
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mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF);
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if (ip->ip_off & IP_MF)
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mhip->ip_off |= IP_MF;
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if (off + len >= (u_short)ip->ip_len)
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len = (u_short)ip->ip_len - off;
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else
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mhip->ip_off |= IP_MF;
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mhip->ip_len = htons((u_short)(len + mhlen));
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m->m_next = m_copy(m0, off, len);
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if (m->m_next == 0) {
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error = ENOBUFS; /* ??? */
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goto sendorfree;
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}
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m->m_pkthdr.len = mhlen + len;
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m->m_pkthdr.rcvif = (struct ifnet *)0;
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mhip->ip_off = htons((u_short)mhip->ip_off);
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mhip->ip_sum = 0;
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mhip->ip_sum = in_cksum(m, mhlen);
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*mnext = m;
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mnext = &m->m_nextpkt;
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ipstat.ips_ofragments++;
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}
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/*
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* Update first fragment by trimming what's been copied out
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* and updating header, then send each fragment (in order).
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*/
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m = m0;
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m_adj(m, hlen + firstlen - (u_short)ip->ip_len);
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m->m_pkthdr.len = hlen + firstlen;
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ip->ip_len = htons((u_short)m->m_pkthdr.len);
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ip->ip_off = htons((u_short)(ip->ip_off | IP_MF));
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ip->ip_sum = 0;
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ip->ip_sum = in_cksum(m, hlen);
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sendorfree:
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for (m = m0; m; m = m0) {
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m0 = m->m_nextpkt;
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m->m_nextpkt = 0;
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if (error == 0)
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error = (*ifp->if_output)(ifp, m,
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(struct sockaddr *)dst, ro->ro_rt);
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else
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m_freem(m);
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}
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}
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done:
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if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt)
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RTFREE(ro->ro_rt);
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return (error);
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bad:
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m_freem(m0);
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goto done;
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}
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/*
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* Insert IP options into preformed packet.
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* Adjust IP destination as required for IP source routing,
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* as indicated by a non-zero in_addr at the start of the options.
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*/
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struct mbuf *
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ip_insertoptions(m, opt, phlen)
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register struct mbuf *m;
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struct mbuf *opt;
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int *phlen;
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{
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register struct ipoption *p = mtod(opt, struct ipoption *);
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struct mbuf *n;
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register struct ip *ip = mtod(m, struct ip *);
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unsigned optlen;
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optlen = opt->m_len - sizeof(p->ipopt_dst);
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if (optlen + (u_short)ip->ip_len > IP_MAXPACKET)
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return (m); /* XXX should fail */
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if (p->ipopt_dst.s_addr)
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ip->ip_dst = p->ipopt_dst;
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if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
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MGETHDR(n, M_DONTWAIT, MT_HEADER);
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if (n == 0)
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return (m);
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n->m_pkthdr.len = m->m_pkthdr.len + optlen;
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m->m_len -= sizeof(struct ip);
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m->m_data += sizeof(struct ip);
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n->m_next = m;
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m = n;
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m->m_len = optlen + sizeof(struct ip);
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m->m_data += max_linkhdr;
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bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
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} else {
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m->m_data -= optlen;
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m->m_len += optlen;
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m->m_pkthdr.len += optlen;
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ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
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}
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ip = mtod(m, struct ip *);
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bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen);
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*phlen = sizeof(struct ip) + optlen;
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ip->ip_len += optlen;
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return (m);
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}
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/*
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* Copy options from ip to jp,
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* omitting those not copied during fragmentation.
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*/
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ip_optcopy(ip, jp)
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struct ip *ip, *jp;
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{
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register u_char *cp, *dp;
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int opt, optlen, cnt;
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cp = (u_char *)(ip + 1);
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dp = (u_char *)(jp + 1);
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cnt = (ip->ip_hl << 2) - sizeof (struct ip);
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for (; cnt > 0; cnt -= optlen, cp += optlen) {
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opt = cp[0];
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if (opt == IPOPT_EOL)
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break;
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if (opt == IPOPT_NOP)
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optlen = 1;
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else
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optlen = cp[IPOPT_OLEN];
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/* bogus lengths should have been caught by ip_dooptions */
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if (optlen > cnt)
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optlen = cnt;
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if (IPOPT_COPIED(opt)) {
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bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen);
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dp += optlen;
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}
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}
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for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
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*dp++ = IPOPT_EOL;
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return (optlen);
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}
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/*
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* IP socket option processing.
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*/
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ip_ctloutput(op, so, level, optname, mp)
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int op;
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struct socket *so;
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int level, optname;
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struct mbuf **mp;
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{
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register struct inpcb *inp = sotoinpcb(so);
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register struct mbuf *m = *mp;
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register int optval;
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int error = 0;
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if (level != IPPROTO_IP)
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error = EINVAL;
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else switch (op) {
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case PRCO_SETOPT:
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switch (optname) {
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case IP_OPTIONS:
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#ifdef notyet
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case IP_RETOPTS:
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return (ip_pcbopts(optname, &inp->inp_options, m));
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#else
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return (ip_pcbopts(&inp->inp_options, m));
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#endif
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case IP_TOS:
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case IP_TTL:
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case IP_RECVOPTS:
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case IP_RECVRETOPTS:
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case IP_RECVDSTADDR:
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if (m->m_len != sizeof(int))
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error = EINVAL;
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else {
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optval = *mtod(m, int *);
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switch (optname) {
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case IP_TOS:
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inp->inp_ip.ip_tos = optval;
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break;
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case IP_TTL:
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inp->inp_ip.ip_ttl = optval;
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break;
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#define OPTSET(bit) \
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if (optval) \
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inp->inp_flags |= bit; \
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else \
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inp->inp_flags &= ~bit;
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case IP_RECVOPTS:
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OPTSET(INP_RECVOPTS);
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break;
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case IP_RECVRETOPTS:
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OPTSET(INP_RECVRETOPTS);
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break;
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case IP_RECVDSTADDR:
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OPTSET(INP_RECVDSTADDR);
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break;
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}
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}
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break;
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#undef OPTSET
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default:
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error = EINVAL;
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break;
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}
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if (m)
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(void)m_free(m);
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break;
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case PRCO_GETOPT:
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switch (optname) {
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case IP_OPTIONS:
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case IP_RETOPTS:
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*mp = m = m_get(M_WAIT, MT_SOOPTS);
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if (inp->inp_options) {
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m->m_len = inp->inp_options->m_len;
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bcopy(mtod(inp->inp_options, caddr_t),
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mtod(m, caddr_t), (unsigned)m->m_len);
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} else
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m->m_len = 0;
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break;
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case IP_TOS:
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case IP_TTL:
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case IP_RECVOPTS:
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case IP_RECVRETOPTS:
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case IP_RECVDSTADDR:
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*mp = m = m_get(M_WAIT, MT_SOOPTS);
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m->m_len = sizeof(int);
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switch (optname) {
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case IP_TOS:
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optval = inp->inp_ip.ip_tos;
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break;
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case IP_TTL:
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optval = inp->inp_ip.ip_ttl;
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break;
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#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
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case IP_RECVOPTS:
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optval = OPTBIT(INP_RECVOPTS);
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break;
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case IP_RECVRETOPTS:
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optval = OPTBIT(INP_RECVRETOPTS);
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break;
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case IP_RECVDSTADDR:
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optval = OPTBIT(INP_RECVDSTADDR);
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break;
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}
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*mtod(m, int *) = optval;
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break;
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default:
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error = EINVAL;
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break;
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}
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break;
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}
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return (error);
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}
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/*
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|
* Set up IP options in pcb for insertion in output packets.
|
|
* Store in mbuf with pointer in pcbopt, adding pseudo-option
|
|
* with destination address if source routed.
|
|
*/
|
|
#ifdef notyet
|
|
ip_pcbopts(optname, pcbopt, m)
|
|
int optname;
|
|
#else
|
|
ip_pcbopts(pcbopt, m)
|
|
#endif
|
|
struct mbuf **pcbopt;
|
|
register struct mbuf *m;
|
|
{
|
|
register cnt, optlen;
|
|
register u_char *cp;
|
|
u_char opt;
|
|
|
|
/* turn off any old options */
|
|
if (*pcbopt)
|
|
(void)m_free(*pcbopt);
|
|
*pcbopt = 0;
|
|
if (m == (struct mbuf *)0 || m->m_len == 0) {
|
|
/*
|
|
* Only turning off any previous options.
|
|
*/
|
|
if (m)
|
|
(void)m_free(m);
|
|
return (0);
|
|
}
|
|
|
|
#ifndef vax
|
|
if (m->m_len % sizeof(long))
|
|
goto bad;
|
|
#endif
|
|
/*
|
|
* IP first-hop destination address will be stored before
|
|
* actual options; move other options back
|
|
* and clear it when none present.
|
|
*/
|
|
if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
|
|
goto bad;
|
|
cnt = m->m_len;
|
|
m->m_len += sizeof(struct in_addr);
|
|
cp = mtod(m, u_char *) + sizeof(struct in_addr);
|
|
ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
|
|
bzero(mtod(m, caddr_t), sizeof(struct in_addr));
|
|
|
|
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 <= IPOPT_OLEN || optlen > cnt)
|
|
goto bad;
|
|
}
|
|
switch (opt) {
|
|
|
|
default:
|
|
break;
|
|
|
|
case IPOPT_LSRR:
|
|
case IPOPT_SSRR:
|
|
/*
|
|
* user process specifies route as:
|
|
* ->A->B->C->D
|
|
* D must be our final destination (but we can't
|
|
* check that since we may not have connected yet).
|
|
* A is first hop destination, which doesn't appear in
|
|
* actual IP option, but is stored before the options.
|
|
*/
|
|
if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
|
|
goto bad;
|
|
m->m_len -= sizeof(struct in_addr);
|
|
cnt -= sizeof(struct in_addr);
|
|
optlen -= sizeof(struct in_addr);
|
|
cp[IPOPT_OLEN] = optlen;
|
|
/*
|
|
* Move first hop before start of options.
|
|
*/
|
|
bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
|
|
sizeof(struct in_addr));
|
|
/*
|
|
* Then copy rest of options back
|
|
* to close up the deleted entry.
|
|
*/
|
|
ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
|
|
sizeof(struct in_addr)),
|
|
(caddr_t)&cp[IPOPT_OFFSET+1],
|
|
(unsigned)cnt + sizeof(struct in_addr));
|
|
break;
|
|
}
|
|
}
|
|
if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
|
|
goto bad;
|
|
*pcbopt = m;
|
|
return (0);
|
|
|
|
bad:
|
|
(void)m_free(m);
|
|
return (EINVAL);
|
|
}
|