* Copyright (c) 1983 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
static char sccsid
[] = "@(#)inet.c 5.2 (Berkeley) %G%";
* Temporarily, copy these routines from the kernel,
* as we need to know about subnets.
extern struct interface
*ifnet
;
* Formulate an Internet address from network + host.
register struct interface
*ifp
;
for (ifp
= ifnet
; ifp
; ifp
= ifp
->int_next
)
if ((ifp
->int_netmask
& net
) == ifp
->int_net
) {
mask
= ~ifp
->int_subnetmask
;
addr
= net
| (host
& mask
);
return (*(struct in_addr
*)&addr
);
* Return the network number from an internet address.
register u_long i
= ntohl(in
.s_addr
);
register struct interface
*ifp
;
* 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 the host portion of an internet address.
register u_long i
= ntohl(in
.s_addr
);
register u_long net
, host
;
register struct interface
*ifp
;
host
= i
& IN_CLASSA_HOST
;
} else if (IN_CLASSB(i
)) {
host
= i
& IN_CLASSB_HOST
;
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 RTF_HOST if the address is
* for an Internet host, RTF_SUBNET for a subnet,
register u_long i
= ntohl(sin
->sin_addr
.s_addr
);
register u_long net
, host
;
register struct interface
*ifp
;
host
= i
& IN_CLASSA_HOST
;
} else if (IN_CLASSB(i
)) {
host
= i
& IN_CLASSB_HOST
;
host
= i
& IN_CLASSC_HOST
;
return (0); /* network */
* 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
) == 0)
* Return true if a route to subnet rtsin should be sent to dst.
* Send it only if dst is on the same logical network,
* or the route turns out to be for the net (aka subnet 0).
inet_sendsubnet(rtsin
, dst
)
struct sockaddr_in
*rtsin
, *dst
;
register u_long rt
= ntohl(rtsin
->sin_addr
.s_addr
);
register u_long d
= ntohl(dst
->sin_addr
.s_addr
);
if ((rt
& IN_CLASSA_HOST
) == 0)
return ((rt
& IN_CLASSA_NET
) == (d
& IN_CLASSA_NET
));
} else if (IN_CLASSB(rt
)) {
if ((rt
& IN_CLASSB_HOST
) == 0)
return ((rt
& IN_CLASSB_NET
) == (d
& IN_CLASSB_NET
));
if ((rt
& IN_CLASSC_HOST
) == 0)
return ((rt
& IN_CLASSC_NET
) == (d
& IN_CLASSC_NET
));