freebsd-skq/usr.sbin/routed/inet.c
fenner 5f45605dbe Make routed use real netmasks when installing routes; for unknown
class B and C networks routed would use the network number as the
netmask.  This can cause some real interesting behaviour.
1996-02-01 16:25:29 +00:00

244 lines
6.5 KiB
C

/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)inet.c 8.2 (Berkeley) 8/14/93";
#endif /* not lint */
/*
* Temporarily, copy these routines from the kernel,
* as we need to know about subnets.
*/
#include "defs.h"
extern struct interface *ifnet;
/*
* Formulate an Internet address from network + host.
*/
struct in_addr
inet_makeaddr(net, host)
u_long net, host;
{
register struct interface *ifp;
register u_long mask;
u_long addr;
if (IN_CLASSA(net))
mask = IN_CLASSA_HOST;
else if (IN_CLASSB(net))
mask = IN_CLASSB_HOST;
else
mask = IN_CLASSC_HOST;
for (ifp = ifnet; ifp; ifp = ifp->int_next)
if ((ifp->int_netmask & net) == ifp->int_net) {
mask = ~ifp->int_subnetmask;
break;
}
addr = net | (host & mask);
addr = htonl(addr);
return (*(struct in_addr *)&addr);
}
/*
* Return the network number from an internet address.
*/
inet_netof(in)
struct in_addr in;
{
register u_long i = ntohl(in.s_addr);
register u_long net;
register struct interface *ifp;
if (IN_CLASSA(i))
net = i & IN_CLASSA_NET;
else if (IN_CLASSB(i))
net = i & IN_CLASSB_NET;
else
net = i & IN_CLASSC_NET;
/*
* Check whether network is a subnet;
* if so, return subnet number.
*/
for (ifp = ifnet; ifp; ifp = ifp->int_next)
if ((ifp->int_netmask & net) == ifp->int_net)
return (i & ifp->int_subnetmask);
return (net);
}
/*
* Return the host portion of an internet address.
*/
inet_lnaof(in)
struct in_addr in;
{
register u_long i = ntohl(in.s_addr);
register u_long net, host;
register struct interface *ifp;
if (IN_CLASSA(i)) {
net = i & IN_CLASSA_NET;
host = i & IN_CLASSA_HOST;
} else if (IN_CLASSB(i)) {
net = i & IN_CLASSB_NET;
host = i & IN_CLASSB_HOST;
} else {
net = i & IN_CLASSC_NET;
host = i & IN_CLASSC_HOST;
}
/*
* Check whether network is a subnet;
* if so, use the modified interpretation of `host'.
*/
for (ifp = ifnet; ifp; ifp = ifp->int_next)
if ((ifp->int_netmask & net) == ifp->int_net)
return (host &~ ifp->int_subnetmask);
return (host);
}
/*
* Return the netmask pertaining to an internet address.
*/
inet_maskof(inaddr)
u_long inaddr;
{
register u_long i = ntohl(inaddr);
register u_long mask;
register struct interface *ifp;
if (i == 0) {
mask = 0;
} else if (IN_CLASSA(i)) {
mask = IN_CLASSA_NET;
} else if (IN_CLASSB(i)) {
mask = IN_CLASSB_NET;
} else
mask = IN_CLASSC_NET;
/*
* Check whether network is subnetted;
* if so, use the subnet's netmask.
*/
for (ifp = ifnet; ifp; ifp = ifp->int_next)
if ((ifp->int_netmask & i) == ifp->int_net)
mask = ifp->int_subnetmask;
return (htonl(mask));
}
/*
* Return RTF_HOST if the address is
* for an Internet host, RTF_SUBNET for a subnet,
* 0 for a network.
*/
inet_rtflags(sin)
struct sockaddr_in *sin;
{
register u_long i = ntohl(sin->sin_addr.s_addr);
register u_long net, host;
register struct interface *ifp;
if (IN_CLASSA(i)) {
net = i & IN_CLASSA_NET;
host = i & IN_CLASSA_HOST;
} else if (IN_CLASSB(i)) {
net = i & IN_CLASSB_NET;
host = i & IN_CLASSB_HOST;
} else {
net = i & IN_CLASSC_NET;
host = i & IN_CLASSC_HOST;
}
/*
* Check whether this network is subnetted;
* if so, check whether this is a subnet or a host.
*/
for (ifp = ifnet; ifp; ifp = ifp->int_next)
if (net == ifp->int_net) {
if (host &~ ifp->int_subnetmask)
return (RTF_HOST);
else if (ifp->int_subnetmask != ifp->int_netmask)
return (RTF_SUBNET);
else
return (0); /* network */
}
if (host == 0)
return (0); /* network */
else
return (RTF_HOST);
}
/*
* Return true if a route to subnet/host of route rt should be sent to dst.
* Send it only if dst is on the same logical network if not "internal",
* otherwise only if the route is the "internal" route for the logical net.
*/
inet_sendroute(rt, dst)
struct rt_entry *rt;
struct sockaddr_in *dst;
{
register u_long r =
ntohl(((struct sockaddr_in *)&rt->rt_dst)->sin_addr.s_addr);
register u_long d = ntohl(dst->sin_addr.s_addr);
if (IN_CLASSA(r)) {
if ((r & IN_CLASSA_NET) == (d & IN_CLASSA_NET)) {
if ((r & IN_CLASSA_HOST) == 0)
return ((rt->rt_state & RTS_INTERNAL) == 0);
return (1);
}
if (r & IN_CLASSA_HOST)
return (0);
return ((rt->rt_state & RTS_INTERNAL) != 0);
} else if (IN_CLASSB(r)) {
if ((r & IN_CLASSB_NET) == (d & IN_CLASSB_NET)) {
if ((r & IN_CLASSB_HOST) == 0)
return ((rt->rt_state & RTS_INTERNAL) == 0);
return (1);
}
if (r & IN_CLASSB_HOST)
return (0);
return ((rt->rt_state & RTS_INTERNAL) != 0);
} else {
if ((r & IN_CLASSC_NET) == (d & IN_CLASSC_NET)) {
if ((r & IN_CLASSC_HOST) == 0)
return ((rt->rt_state & RTS_INTERNAL) == 0);
return (1);
}
if (r & IN_CLASSC_HOST)
return (0);
return ((rt->rt_state & RTS_INTERNAL) != 0);
}
}