e6ed2afd1e
class B and C networks routed would use the network number as the netmask. This can cause some real interesting behaviour.
244 lines
6.5 KiB
C
244 lines
6.5 KiB
C
/*
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* Copyright (c) 1983, 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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#ifndef lint
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static char sccsid[] = "@(#)inet.c 8.2 (Berkeley) 8/14/93";
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#endif /* not lint */
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/*
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* Temporarily, copy these routines from the kernel,
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* as we need to know about subnets.
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*/
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#include "defs.h"
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extern struct interface *ifnet;
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/*
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* Formulate an Internet address from network + host.
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*/
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struct in_addr
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inet_makeaddr(net, host)
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u_long net, host;
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{
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register struct interface *ifp;
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register u_long mask;
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u_long addr;
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if (IN_CLASSA(net))
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mask = IN_CLASSA_HOST;
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else if (IN_CLASSB(net))
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mask = IN_CLASSB_HOST;
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else
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mask = IN_CLASSC_HOST;
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for (ifp = ifnet; ifp; ifp = ifp->int_next)
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if ((ifp->int_netmask & net) == ifp->int_net) {
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mask = ~ifp->int_subnetmask;
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break;
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}
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addr = net | (host & mask);
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addr = htonl(addr);
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return (*(struct in_addr *)&addr);
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}
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/*
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* Return the network number from an internet address.
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*/
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inet_netof(in)
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struct in_addr in;
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{
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register u_long i = ntohl(in.s_addr);
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register u_long net;
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register struct interface *ifp;
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if (IN_CLASSA(i))
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net = i & IN_CLASSA_NET;
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else if (IN_CLASSB(i))
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net = i & IN_CLASSB_NET;
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else
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net = i & IN_CLASSC_NET;
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/*
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* Check whether network is a subnet;
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* if so, return subnet number.
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*/
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for (ifp = ifnet; ifp; ifp = ifp->int_next)
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if ((ifp->int_netmask & net) == ifp->int_net)
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return (i & ifp->int_subnetmask);
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return (net);
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}
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/*
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* Return the host portion of an internet address.
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*/
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inet_lnaof(in)
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struct in_addr in;
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{
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register u_long i = ntohl(in.s_addr);
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register u_long net, host;
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register struct interface *ifp;
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if (IN_CLASSA(i)) {
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net = i & IN_CLASSA_NET;
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host = i & IN_CLASSA_HOST;
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} else if (IN_CLASSB(i)) {
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net = i & IN_CLASSB_NET;
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host = i & IN_CLASSB_HOST;
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} else {
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net = i & IN_CLASSC_NET;
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host = i & IN_CLASSC_HOST;
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}
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/*
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* Check whether network is a subnet;
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* if so, use the modified interpretation of `host'.
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*/
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for (ifp = ifnet; ifp; ifp = ifp->int_next)
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if ((ifp->int_netmask & net) == ifp->int_net)
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return (host &~ ifp->int_subnetmask);
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return (host);
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}
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/*
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* Return the netmask pertaining to an internet address.
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*/
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inet_maskof(inaddr)
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u_long inaddr;
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{
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register u_long i = ntohl(inaddr);
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register u_long mask;
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register struct interface *ifp;
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if (i == 0) {
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mask = 0;
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} else if (IN_CLASSA(i)) {
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mask = IN_CLASSA_NET;
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} else if (IN_CLASSB(i)) {
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mask = IN_CLASSB_NET;
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} else
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mask = IN_CLASSC_NET;
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/*
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* Check whether network is subnetted;
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* if so, use the subnet's netmask.
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*/
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for (ifp = ifnet; ifp; ifp = ifp->int_next)
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if ((ifp->int_netmask & i) == ifp->int_net)
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mask = ifp->int_subnetmask;
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return (htonl(mask));
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}
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/*
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* Return RTF_HOST if the address is
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* for an Internet host, RTF_SUBNET for a subnet,
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* 0 for a network.
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*/
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inet_rtflags(sin)
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struct sockaddr_in *sin;
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{
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register u_long i = ntohl(sin->sin_addr.s_addr);
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register u_long net, host;
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register struct interface *ifp;
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if (IN_CLASSA(i)) {
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net = i & IN_CLASSA_NET;
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host = i & IN_CLASSA_HOST;
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} else if (IN_CLASSB(i)) {
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net = i & IN_CLASSB_NET;
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host = i & IN_CLASSB_HOST;
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} else {
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net = i & IN_CLASSC_NET;
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host = i & IN_CLASSC_HOST;
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}
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/*
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* Check whether this network is subnetted;
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* if so, check whether this is a subnet or a host.
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*/
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for (ifp = ifnet; ifp; ifp = ifp->int_next)
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if (net == ifp->int_net) {
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if (host &~ ifp->int_subnetmask)
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return (RTF_HOST);
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else if (ifp->int_subnetmask != ifp->int_netmask)
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return (RTF_SUBNET);
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else
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return (0); /* network */
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}
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if (host == 0)
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return (0); /* network */
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else
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return (RTF_HOST);
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}
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/*
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* Return true if a route to subnet/host of route rt should be sent to dst.
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* Send it only if dst is on the same logical network if not "internal",
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* otherwise only if the route is the "internal" route for the logical net.
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*/
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inet_sendroute(rt, dst)
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struct rt_entry *rt;
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struct sockaddr_in *dst;
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{
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register u_long r =
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ntohl(((struct sockaddr_in *)&rt->rt_dst)->sin_addr.s_addr);
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register u_long d = ntohl(dst->sin_addr.s_addr);
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if (IN_CLASSA(r)) {
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if ((r & IN_CLASSA_NET) == (d & IN_CLASSA_NET)) {
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if ((r & IN_CLASSA_HOST) == 0)
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return ((rt->rt_state & RTS_INTERNAL) == 0);
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return (1);
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}
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if (r & IN_CLASSA_HOST)
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return (0);
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return ((rt->rt_state & RTS_INTERNAL) != 0);
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} else if (IN_CLASSB(r)) {
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if ((r & IN_CLASSB_NET) == (d & IN_CLASSB_NET)) {
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if ((r & IN_CLASSB_HOST) == 0)
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return ((rt->rt_state & RTS_INTERNAL) == 0);
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return (1);
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}
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if (r & IN_CLASSB_HOST)
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return (0);
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return ((rt->rt_state & RTS_INTERNAL) != 0);
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} else {
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if ((r & IN_CLASSC_NET) == (d & IN_CLASSC_NET)) {
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if ((r & IN_CLASSC_HOST) == 0)
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return ((rt->rt_state & RTS_INTERNAL) == 0);
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return (1);
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}
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if (r & IN_CLASSC_HOST)
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return (0);
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return ((rt->rt_state & RTS_INTERNAL) != 0);
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}
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}
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