[unix-history] / sys / netinet / in.c

/*
 * Copyright (c) 1982, 1986, 1991 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.
 *
 *	from: @(#)in.c	7.17 (Berkeley) 4/20/91
 *	$Id: in.c,v 1.7 1993/12/19 00:52:34 wollman Exp $
 */

#include "param.h"
#include "systm.h"
#include "ioctl.h"
#include "mbuf.h"
#include "socket.h"
#include "socketvar.h"
#include "in_systm.h"
#include "net/if.h"
#include "net/route.h"
#include "in.h"
#include "in_var.h"

#ifdef INET

static void in_ifscrub(struct ifnet *, struct in_ifaddr *);

/*
 * Formulate an Internet address from network + host.
 */
struct in_addr
in_makeaddr(net, host)
	u_long net, host;
{
	register struct in_ifaddr *ia;
	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 (ia = in_ifaddr; ia; ia = ia->ia_next)
		if ((ia->ia_netmask & net) == ia->ia_net) {
			mask = ~ia->ia_subnetmask;
			break;
		}
	addr = htonl(net | (host & mask));
	return (*(struct in_addr *)&addr);
}

/*
 * Return the network number from an internet address.
 */
u_long
in_netof(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register u_long net;
	register struct in_ifaddr *ia;

	if (IN_CLASSA(i))
		net = i & IN_CLASSA_NET;
	else if (IN_CLASSB(i))
		net = i & IN_CLASSB_NET;
	else if (IN_CLASSC(i))
		net = i & IN_CLASSC_NET;
	else
		return (0);

	/*
	 * Check whether network is a subnet;
	 * if so, return subnet number.
	 */
	for (ia = in_ifaddr; ia; ia = ia->ia_next)
		if (net == ia->ia_net)
			return (i & ia->ia_subnetmask);
	return (net);
}

/*
 * Compute and save network mask as sockaddr from an internet address.
 */
void
in_sockmaskof(in, sockmask)
	struct in_addr in;
	register struct sockaddr_in *sockmask;
{
	register u_long net;
	register u_long mask;
    {
	register u_long i = ntohl(in.s_addr);

	if (i == 0)
		net = 0, mask = 0;
	else if (IN_CLASSA(i))
		net = i & IN_CLASSA_NET, mask = IN_CLASSA_NET;
	else if (IN_CLASSB(i))
		net = i & IN_CLASSB_NET, mask = IN_CLASSB_NET;
	else if (IN_CLASSC(i))
		net = i & IN_CLASSC_NET, mask = IN_CLASSC_NET;
	else
		net = i, mask = -1;
    }
    {
	register struct in_ifaddr *ia;
	/*
	 * Check whether network is a subnet;
	 * if so, return subnet number.
	 */
	for (ia = in_ifaddr; ia; ia = ia->ia_next)
		if (net == ia->ia_net)
			mask =  ia->ia_subnetmask;
    }
    {
	register char *cpbase = (char *)&(sockmask->sin_addr);
	register char *cp = (char *)(1 + &(sockmask->sin_addr));

	sockmask->sin_addr.s_addr = htonl(mask);
	sockmask->sin_len = 0;
	while (--cp >= cpbase)
		if (*cp) {
			sockmask->sin_len = 1 + cp - (caddr_t)sockmask;
			break;
		}
    }
}

/*
 * Return the host portion of an internet address.
 */
u_long
in_lnaof(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register u_long net, host;
	register struct in_ifaddr *ia;

	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 if (IN_CLASSC(i)) {
		net = i & IN_CLASSC_NET;
		host = i & IN_CLASSC_HOST;
	} else
		return (i);

	/*
	 * Check whether network is a subnet;
	 * if so, use the modified interpretation of `host'.
	 */
	for (ia = in_ifaddr; ia; ia = ia->ia_next)
		if (net == ia->ia_net)
			return (host &~ ia->ia_subnetmask);
	return (host);
}

/*
 * Return 1 if an internet address is for a ``local'' host
 * (one to which we have a connection).  If subnetsarelocal
 * is true, this includes other subnets of the local net.
 * Otherwise, it includes only the directly-connected (sub)nets.
 */
int
in_localaddr(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register struct in_ifaddr *ia;

	if (subnetsarelocal) {
		for (ia = in_ifaddr; ia; ia = ia->ia_next)
			if ((i & ia->ia_netmask) == ia->ia_net)
				return (1);
	} else {
		for (ia = in_ifaddr; ia; ia = ia->ia_next)
			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
				return (1);
	}
	return (0);
}

/*
 * Determine whether an IP address is in a reserved set of addresses
 * that may not be forwarded, or whether datagrams to that destination
 * may be forwarded.
 */
int
in_canforward(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register u_long net;

	if (IN_EXPERIMENTAL(i))
		return (0);
	if (IN_CLASSA(i)) {
		net = i & IN_CLASSA_NET;
		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
			return (0);
	}
	return (1);
}

static int in_interfaces;	/* number of external internet interfaces */

/*
 * Generic internet control operations (ioctl's).
 * Ifp is 0 if not an interface-specific ioctl.
 */
/* ARGSUSED */
int
in_control(so, cmd, data, ifp)
	struct socket *so;
	int cmd;
	caddr_t data;
	register struct ifnet *ifp;
{
	register struct ifreq *ifr = (struct ifreq *)data;
	register struct in_ifaddr *ia = 0;
	register struct ifaddr *ifa;
	struct in_ifaddr *oia;
	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
	struct mbuf *m;
	struct sockaddr_in oldaddr;
	int error, hostIsNew, maskIsNew;
	u_long i;

	/*
	 * Find address for this interface, if it exists.
	 */
	if (ifp)
		for (ia = in_ifaddr; ia; ia = ia->ia_next)
			if (ia->ia_ifp == ifp)
				break;

	switch (cmd) {

	case SIOCAIFADDR:
	case SIOCDIFADDR:
		if (ifra->ifra_addr.sin_family == AF_INET)
		    for (oia = ia; ia; ia = ia->ia_next) {
			if (ia->ia_ifp == ifp  &&
			    ia->ia_addr.sin_addr.s_addr ==
				ifra->ifra_addr.sin_addr.s_addr)
			    break;
		}
		if (cmd == SIOCDIFADDR && ia == 0)
			return (EADDRNOTAVAIL);
		/* FALLTHROUGH */
	case SIOCSIFADDR:
	case SIOCSIFNETMASK:
	case SIOCSIFDSTADDR:
		if ((so->so_state & SS_PRIV) == 0)
			return (EPERM);

		if (ifp == 0)
			panic("in_control");
		if (ia == (struct in_ifaddr *)0) {
			m = m_getclr(M_WAIT, MT_IFADDR);
			if (m == (struct mbuf *)NULL)
				return (ENOBUFS);
			if (ia = in_ifaddr) {
				for ( ; ia->ia_next; ia = ia->ia_next)
					;
				ia->ia_next = mtod(m, struct in_ifaddr *);
			} else
				in_ifaddr = mtod(m, struct in_ifaddr *);
			ia = mtod(m, struct in_ifaddr *);
			if (ifa = ifp->if_addrlist) {
				for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
					;
				ifa->ifa_next = (struct ifaddr *) ia;
			} else
				ifp->if_addrlist = (struct ifaddr *) ia;
			ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
			ia->ia_ifa.ifa_dstaddr
					= (struct sockaddr *)&ia->ia_dstaddr;
			ia->ia_ifa.ifa_netmask
					= (struct sockaddr *)&ia->ia_sockmask;
			ia->ia_sockmask.sin_len = 8;
			if (ifp->if_flags & IFF_BROADCAST) {
				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
				ia->ia_broadaddr.sin_family = AF_INET;
			}
			ia->ia_ifp = ifp;
			if (ifp != &loif)
				in_interfaces++;
		}
		break;

	case SIOCSIFBRDADDR:
		if ((so->so_state & SS_PRIV) == 0)
			return (EPERM);
		/* FALLTHROUGH */

	case SIOCGIFADDR:
	case SIOCGIFNETMASK:
	case SIOCGIFDSTADDR:
	case SIOCGIFBRDADDR:
		if (ia == (struct in_ifaddr *)0)
			return (EADDRNOTAVAIL);
		break;

	default:
		return (EOPNOTSUPP);
		break;
	}
	switch (cmd) {

	case SIOCGIFADDR:
		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
		break;

	case SIOCGIFBRDADDR:
		if ((ifp->if_flags & IFF_BROADCAST) == 0)
			return (EINVAL);
		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
		break;

	case SIOCGIFDSTADDR:
		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
			return (EINVAL);
		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
		break;

	case SIOCGIFNETMASK:
		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
		break;

	case SIOCSIFDSTADDR:
		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
			return (EINVAL);
		oldaddr = ia->ia_dstaddr;
		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
		if (ifp->if_ioctl &&
		    (error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR, 
					      (caddr_t)ia))) {
			ia->ia_dstaddr = oldaddr;
			return (error);
		}
		if (ia->ia_flags & IFA_ROUTE) {
			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
			ia->ia_ifa.ifa_dstaddr =
					(struct sockaddr *)&ia->ia_dstaddr;
			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
		}
		break;

	case SIOCSIFBRDADDR:
		if ((ifp->if_flags & IFF_BROADCAST) == 0)
			return (EINVAL);
		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
		break;

	case SIOCSIFADDR:
		return (in_ifinit(ifp, ia,
		    (struct sockaddr_in *) &ifr->ifr_addr, 1));

	case SIOCSIFNETMASK:
		i = ifra->ifra_addr.sin_addr.s_addr;
		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
		break;

	case SIOCAIFADDR:
		maskIsNew = 0;
		hostIsNew = 1;
		error = 0;
		if (ia->ia_addr.sin_family == AF_INET) {
			if (ifra->ifra_addr.sin_len == 0) {
				ifra->ifra_addr = ia->ia_addr;
				hostIsNew = 0;
			} else if (ifra->ifra_addr.sin_addr.s_addr ==
					       ia->ia_addr.sin_addr.s_addr)
				hostIsNew = 0;
		}
		if (ifra->ifra_mask.sin_len) {
			in_ifscrub(ifp, ia);
			ia->ia_sockmask = ifra->ifra_mask;
			ia->ia_subnetmask =
			     ntohl(ia->ia_sockmask.sin_addr.s_addr);
			maskIsNew = 1;
		}
		if ((ifp->if_flags & IFF_POINTOPOINT) &&
		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
			in_ifscrub(ifp, ia);
			ia->ia_dstaddr = ifra->ifra_dstaddr;
			maskIsNew  = 1; /* We lie; but the effect's the same */
		}
		if (ifra->ifra_addr.sin_family == AF_INET &&
		    (hostIsNew || maskIsNew))
			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
		if ((ifp->if_flags & IFF_BROADCAST) &&
		    (ifra->ifra_broadaddr.sin_family == AF_INET))
			ia->ia_broadaddr = ifra->ifra_broadaddr;
		return (error);

	case SIOCDIFADDR:
		in_ifscrub(ifp, ia);
		if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia)
			ifp->if_addrlist = ifa->ifa_next;
		else {
			while (ifa->ifa_next &&
			       (ifa->ifa_next != (struct ifaddr *)ia))
				    ifa = ifa->ifa_next;
			if (ifa->ifa_next)
				ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next;
			else
				printf("Couldn't unlink inifaddr from ifp\n");
		}
		oia = ia;
		if (oia == (ia = in_ifaddr))
			in_ifaddr = ia->ia_next;
		else {
			while (ia->ia_next && (ia->ia_next != oia))
				ia = ia->ia_next;
			if (ia->ia_next)
				ia->ia_next = oia->ia_next;
			else
				printf("Didn't unlink inifadr from list\n");
		}
		(void) m_free(dtom(oia));
		break;

	default:
		if (ifp == 0 || ifp->if_ioctl == 0)
			return (EOPNOTSUPP);
		return ((*ifp->if_ioctl)(ifp, cmd, data));
	}
	return (0);
}

/*
 * Delete any existing route for an interface.
 */
static void
in_ifscrub(ifp, ia)
	register struct ifnet *ifp;
	register struct in_ifaddr *ia;
{

	if ((ia->ia_flags & IFA_ROUTE) == 0)
		return;
	if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
	else
		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
	ia->ia_flags &= ~IFA_ROUTE;
}

/*
 * Initialize an interface's internet address
 * and routing table entry.
 */
int
in_ifinit(ifp, ia, sin, scrub)
	register struct ifnet *ifp;
	register struct in_ifaddr *ia;
	struct sockaddr_in *sin;
	int scrub;
{
	register u_long i = ntohl(sin->sin_addr.s_addr);
	struct sockaddr_in oldaddr;
	int s = splimp(), error, flags = RTF_UP;

	oldaddr = ia->ia_addr;
	ia->ia_addr = *sin;
	/*
	 * Give the interface a chance to initialize
	 * if this is its first address,
	 * and to validate the address if necessary.
	 */
	if (ifp->if_ioctl && (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, 
						       (caddr_t)ia))) {
		splx(s);
		ia->ia_addr = oldaddr;
		return (error);
	}
	splx(s);
	if (scrub) {
		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
		in_ifscrub(ifp, ia);
		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
	}
	if (IN_CLASSA(i))
		ia->ia_netmask = IN_CLASSA_NET;
	else if (IN_CLASSB(i))
		ia->ia_netmask = IN_CLASSB_NET;
	else
		ia->ia_netmask = IN_CLASSC_NET;
	ia->ia_net = i & ia->ia_netmask;
	/*
	 * The subnet mask includes at least the standard network part,
	 * but may already have been set to a larger value.
	 */
	ia->ia_subnetmask |= ia->ia_netmask;
	ia->ia_subnet = i & ia->ia_subnetmask;
	ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
	{
		register char *cp = (char *) (1 + &(ia->ia_sockmask.sin_addr));
		register char *cpbase = (char *) &(ia->ia_sockmask.sin_addr);
		while (--cp >= cpbase)
			if (*cp) {
				ia->ia_sockmask.sin_len =
					1 + cp - (char *) &(ia->ia_sockmask);
				break;
			}
	}
	/*
	 * Add route for the network.
	 */
	if (ifp->if_flags & IFF_BROADCAST) {
		ia->ia_broadaddr.sin_addr = 
			in_makeaddr(ia->ia_subnet, INADDR_BROADCAST);
		ia->ia_netbroadcast.s_addr =
		    htonl(ia->ia_net | (INADDR_BROADCAST &~ ia->ia_netmask));
	} else if (ifp->if_flags & IFF_LOOPBACK) {
		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
		flags |= RTF_HOST;
	} else if (ifp->if_flags & IFF_POINTOPOINT) {
		if (ia->ia_dstaddr.sin_family != AF_INET)
			return (0);
		flags |= RTF_HOST;
	}
	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
		ia->ia_flags |= IFA_ROUTE;
	return (error);
}

/*
 * Return address info for specified internet network.
 */
struct in_ifaddr *
in_iaonnetof(net)
	u_long net;
{
	register struct in_ifaddr *ia;

	for (ia = in_ifaddr; ia; ia = ia->ia_next)
		if (ia->ia_subnet == net)
			return (ia);
	return ((struct in_ifaddr *)0);
}

/*
 * Return 1 if the address might be a local broadcast address.
 */
int
in_broadcast(in)
	struct in_addr in;
{
	register struct in_ifaddr *ia;
	u_long t;

	/*
	 * Look through the list of addresses for a match
	 * with a broadcast address.
	 */
	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	    if (ia->ia_ifp->if_flags & IFF_BROADCAST) {
		if (ia->ia_broadaddr.sin_addr.s_addr == in.s_addr)
		     return (1);
		/*
		 * Check for old-style (host 0) broadcast.
		 */
		if ((t = ntohl(in.s_addr)) == ia->ia_subnet || t == ia->ia_net)
		    return (1);
	}
	if (in.s_addr == INADDR_BROADCAST || in.s_addr == INADDR_ANY)
		return (1);
	return (0);
}
#endif
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1982, 1986, 1991 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
38e82238	33	* from: @(#)in.c 7.17 (Berkeley) 4/20/91
d4af9a63	34	* $Id: in.c,v 1.7 1993/12/19 00:52:34 wollman Exp $
15637ed4 RG	35	*/
	36
	37	#include "param.h"
2cb63509	38	#include "systm.h"
15637ed4 RG	39	#include "ioctl.h"
	40	#include "mbuf.h"
	41	#include "socket.h"
	42	#include "socketvar.h"
	43	#include "in_systm.h"
	44	#include "net/if.h"
	45	#include "net/route.h"
15637ed4 RG	46	#include "in.h"
	47	#include "in_var.h"
	48
	49	#ifdef INET
8ace4366	50
4c45483e GW	51	static void in_ifscrub(struct ifnet , struct in_ifaddr );
4c45483e GW	52
15637ed4 RG	53	/*
	54	* Formulate an Internet address from network + host.
	55	*/
	56	struct in_addr
	57	in_makeaddr(net, host)
	58	u_long net, host;
	59	{
	60	register struct in_ifaddr *ia;
	61	register u_long mask;
	62	u_long addr;
	63
	64	if (IN_CLASSA(net))
	65	mask = IN_CLASSA_HOST;
	66	else if (IN_CLASSB(net))
	67	mask = IN_CLASSB_HOST;
	68	else
	69	mask = IN_CLASSC_HOST;
	70	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	71	if ((ia->ia_netmask & net) == ia->ia_net) {
	72	mask = ~ia->ia_subnetmask;
	73	break;
	74	}
	75	addr = htonl(net \| (host & mask));
	76	return ((struct in_addr )&addr);
	77	}
	78
	79	/*
	80	* Return the network number from an internet address.
	81	*/
	82	u_long
	83	in_netof(in)
	84	struct in_addr in;
	85	{
	86	register u_long i = ntohl(in.s_addr);
	87	register u_long net;
	88	register struct in_ifaddr *ia;
	89
	90	if (IN_CLASSA(i))
	91	net = i & IN_CLASSA_NET;
	92	else if (IN_CLASSB(i))
	93	net = i & IN_CLASSB_NET;
	94	else if (IN_CLASSC(i))
	95	net = i & IN_CLASSC_NET;
	96	else
	97	return (0);
	98
	99	/*
	100	* Check whether network is a subnet;
	101	* if so, return subnet number.
	102	*/
	103	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	104	if (net == ia->ia_net)
	105	return (i & ia->ia_subnetmask);
	106	return (net);
	107	}
	108
	109	/*
	110	* Compute and save network mask as sockaddr from an internet address.
	111	*/
4c45483e	112	void
15637ed4 RG	113	in_sockmaskof(in, sockmask)
	114	struct in_addr in;
	115	register struct sockaddr_in *sockmask;
	116	{
	117	register u_long net;
	118	register u_long mask;
	119	{
	120	register u_long i = ntohl(in.s_addr);
	121
	122	if (i == 0)
	123	net = 0, mask = 0;
	124	else if (IN_CLASSA(i))
	125	net = i & IN_CLASSA_NET, mask = IN_CLASSA_NET;
	126	else if (IN_CLASSB(i))
	127	net = i & IN_CLASSB_NET, mask = IN_CLASSB_NET;
	128	else if (IN_CLASSC(i))
	129	net = i & IN_CLASSC_NET, mask = IN_CLASSC_NET;
	130	else
	131	net = i, mask = -1;
	132	}
	133	{
	134	register struct in_ifaddr *ia;
	135	/*
	136	* Check whether network is a subnet;
	137	* if so, return subnet number.
	138	*/
	139	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	140	if (net == ia->ia_net)
	141	mask = ia->ia_subnetmask;
	142	}
	143	{
	144	register char cpbase = (char )&(sockmask->sin_addr);
	145	register char cp = (char )(1 + &(sockmask->sin_addr));
	146
	147	sockmask->sin_addr.s_addr = htonl(mask);
	148	sockmask->sin_len = 0;
	149	while (--cp >= cpbase)
	150	if (*cp) {
	151	sockmask->sin_len = 1 + cp - (caddr_t)sockmask;
	152	break;
	153	}
	154	}
	155	}
	156
	157	/*
	158	* Return the host portion of an internet address.
	159	*/
	160	u_long
	161	in_lnaof(in)
	162	struct in_addr in;
	163	{
	164	register u_long i = ntohl(in.s_addr);
	165	register u_long net, host;
	166	register struct in_ifaddr *ia;
	167
	168	if (IN_CLASSA(i)) {
	169	net = i & IN_CLASSA_NET;
	170	host = i & IN_CLASSA_HOST;
	171	} else if (IN_CLASSB(i)) {
	172	net = i & IN_CLASSB_NET;
	173	host = i & IN_CLASSB_HOST;
	174	} else if (IN_CLASSC(i)) {
	175	net = i & IN_CLASSC_NET;
	176	host = i & IN_CLASSC_HOST;
177	} else
178	return (i);
179
180	/*
181	* Check whether network is a subnet;
182	* if so, use the modified interpretation of `host'.
183	*/
184	for (ia = in_ifaddr; ia; ia = ia->ia_next)
185	if (net == ia->ia_net)
186	return (host &~ ia->ia_subnetmask);
187	return (host);
188	}
189
15637ed4 RG	190	/*
	191	* Return 1 if an internet address is for a ``local'' host
	192	* (one to which we have a connection). If subnetsarelocal
	193	* is true, this includes other subnets of the local net.
	194	* Otherwise, it includes only the directly-connected (sub)nets.
	195	*/
4c45483e	196	int
15637ed4 RG	197	in_localaddr(in)
	198	struct in_addr in;
	199	{
	200	register u_long i = ntohl(in.s_addr);
	201	register struct in_ifaddr *ia;
	202
	203	if (subnetsarelocal) {
	204	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	205	if ((i & ia->ia_netmask) == ia->ia_net)
	206	return (1);
	207	} else {
	208	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	209	if ((i & ia->ia_subnetmask) == ia->ia_subnet)
	210	return (1);
	211	}
	212	return (0);
	213	}
	214
	215	/*
	216	* Determine whether an IP address is in a reserved set of addresses
	217	* that may not be forwarded, or whether datagrams to that destination
	218	* may be forwarded.
	219	*/
4c45483e	220	int
15637ed4 RG	221	in_canforward(in)
	222	struct in_addr in;
	223	{
	224	register u_long i = ntohl(in.s_addr);
	225	register u_long net;
	226
	227	if (IN_EXPERIMENTAL(i))
	228	return (0);
	229	if (IN_CLASSA(i)) {
	230	net = i & IN_CLASSA_NET;
d4af9a63	231	if (net == 0 \|\| net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
15637ed4 RG	232	return (0);
	233	}
	234	return (1);
	235	}
	236
fde1aeb2	237	static int in_interfaces; /* number of external internet interfaces */
15637ed4 RG	238
	239	/*
	240	* Generic internet control operations (ioctl's).
	241	* Ifp is 0 if not an interface-specific ioctl.
	242	*/
	243	/* ARGSUSED */
4c45483e	244	int
15637ed4 RG	245	in_control(so, cmd, data, ifp)
	246	struct socket *so;
	247	int cmd;
	248	caddr_t data;
	249	register struct ifnet *ifp;
	250	{
	251	register struct ifreq ifr = (struct ifreq )data;
	252	register struct in_ifaddr *ia = 0;
	253	register struct ifaddr *ifa;
	254	struct in_ifaddr *oia;
	255	struct in_aliasreq ifra = (struct in_aliasreq )data;
	256	struct mbuf *m;
	257	struct sockaddr_in oldaddr;
	258	int error, hostIsNew, maskIsNew;
	259	u_long i;
	260
	261	/*
	262	* Find address for this interface, if it exists.
	263	*/
	264	if (ifp)
	265	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	266	if (ia->ia_ifp == ifp)
	267	break;
	268
	269	switch (cmd) {
	270
	271	case SIOCAIFADDR:
	272	case SIOCDIFADDR:
	273	if (ifra->ifra_addr.sin_family == AF_INET)
	274	for (oia = ia; ia; ia = ia->ia_next) {
	275	if (ia->ia_ifp == ifp &&
	276	ia->ia_addr.sin_addr.s_addr ==
	277	ifra->ifra_addr.sin_addr.s_addr)
	278	break;
	279	}
	280	if (cmd == SIOCDIFADDR && ia == 0)
	281	return (EADDRNOTAVAIL);
	282	/* FALLTHROUGH */
	283	case SIOCSIFADDR:
	284	case SIOCSIFNETMASK:
	285	case SIOCSIFDSTADDR:
	286	if ((so->so_state & SS_PRIV) == 0)
	287	return (EPERM);
	288
	289	if (ifp == 0)
	290	panic("in_control");
	291	if (ia == (struct in_ifaddr *)0) {
	292	m = m_getclr(M_WAIT, MT_IFADDR);
	293	if (m == (struct mbuf *)NULL)
	294	return (ENOBUFS);
	295	if (ia = in_ifaddr) {
	296	for ( ; ia->ia_next; ia = ia->ia_next)
	297	;
	298	ia->ia_next = mtod(m, struct in_ifaddr *);
	299	} else
	300	in_ifaddr = mtod(m, struct in_ifaddr *);
	301	ia = mtod(m, struct in_ifaddr *);
	302	if (ifa = ifp->if_addrlist) {
	303	for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
	304	;
	305	ifa->ifa_next = (struct ifaddr *) ia;
	306	} else
	307	ifp->if_addrlist = (struct ifaddr *) ia;
	308	ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
309	ia->ia_ifa.ifa_dstaddr
310	= (struct sockaddr *)&ia->ia_dstaddr;
311	ia->ia_ifa.ifa_netmask
312	= (struct sockaddr *)&ia->ia_sockmask;
313	ia->ia_sockmask.sin_len = 8;
314	if (ifp->if_flags & IFF_BROADCAST) {
315	ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
316	ia->ia_broadaddr.sin_family = AF_INET;
317	}
318	ia->ia_ifp = ifp;
319	if (ifp != &loif)
320	in_interfaces++;
321	}
322	break;
323
324	case SIOCSIFBRDADDR:
325	if ((so->so_state & SS_PRIV) == 0)
326	return (EPERM);
327	/* FALLTHROUGH */
328
329	case SIOCGIFADDR:
330	case SIOCGIFNETMASK:
331	case SIOCGIFDSTADDR:
332	case SIOCGIFBRDADDR:
333	if (ia == (struct in_ifaddr *)0)
334	return (EADDRNOTAVAIL);
335	break;
336
337	default:
338	return (EOPNOTSUPP);
339	break;
340	}
341	switch (cmd) {
342
343	case SIOCGIFADDR:
344	((struct sockaddr_in )&ifr->ifr_addr) = ia->ia_addr;
345	break;
346
347	case SIOCGIFBRDADDR:
348	if ((ifp->if_flags & IFF_BROADCAST) == 0)
349	return (EINVAL);
350	((struct sockaddr_in )&ifr->ifr_dstaddr) = ia->ia_broadaddr;
351	break;
352
353	case SIOCGIFDSTADDR:
354	if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
355	return (EINVAL);
356	((struct sockaddr_in )&ifr->ifr_dstaddr) = ia->ia_dstaddr;
357	break;
358
359	case SIOCGIFNETMASK:
360	((struct sockaddr_in )&ifr->ifr_addr) = ia->ia_sockmask;
361	break;
362
363	case SIOCSIFDSTADDR:
364	if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
365	return (EINVAL);
366	oldaddr = ia->ia_dstaddr;
367	ia->ia_dstaddr = (struct sockaddr_in )&ifr->ifr_dstaddr;
368	if (ifp->if_ioctl &&
4c45483e GW	369	(error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
4c45483e GW	370	(caddr_t)ia))) {
15637ed4 RG	371	ia->ia_dstaddr = oldaddr;
	372	return (error);
	373	}
	374	if (ia->ia_flags & IFA_ROUTE) {
	375	ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
	376	rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
	377	ia->ia_ifa.ifa_dstaddr =
	378	(struct sockaddr *)&ia->ia_dstaddr;
	379	rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST\|RTF_UP);
	380	}
	381	break;
	382
	383	case SIOCSIFBRDADDR:
	384	if ((ifp->if_flags & IFF_BROADCAST) == 0)
	385	return (EINVAL);
	386	ia->ia_broadaddr = (struct sockaddr_in )&ifr->ifr_broadaddr;
	387	break;
	388
	389	case SIOCSIFADDR:
	390	return (in_ifinit(ifp, ia,
	391	(struct sockaddr_in *) &ifr->ifr_addr, 1));
	392
	393	case SIOCSIFNETMASK:
	394	i = ifra->ifra_addr.sin_addr.s_addr;
	395	ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
	396	break;
	397
	398	case SIOCAIFADDR:
	399	maskIsNew = 0;
	400	hostIsNew = 1;
	401	error = 0;
	402	if (ia->ia_addr.sin_family == AF_INET) {
	403	if (ifra->ifra_addr.sin_len == 0) {
	404	ifra->ifra_addr = ia->ia_addr;
	405	hostIsNew = 0;
	406	} else if (ifra->ifra_addr.sin_addr.s_addr ==
	407	ia->ia_addr.sin_addr.s_addr)
	408	hostIsNew = 0;
	409	}
	410	if (ifra->ifra_mask.sin_len) {
	411	in_ifscrub(ifp, ia);
	412	ia->ia_sockmask = ifra->ifra_mask;
	413	ia->ia_subnetmask =
	414	ntohl(ia->ia_sockmask.sin_addr.s_addr);
	415	maskIsNew = 1;
	416	}
	417	if ((ifp->if_flags & IFF_POINTOPOINT) &&
	418	(ifra->ifra_dstaddr.sin_family == AF_INET)) {
	419	in_ifscrub(ifp, ia);
	420	ia->ia_dstaddr = ifra->ifra_dstaddr;
	421	maskIsNew = 1; /* We lie; but the effect's the same */
	422	}
	423	if (ifra->ifra_addr.sin_family == AF_INET &&
	424	(hostIsNew \|\| maskIsNew))
	425	error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
	426	if ((ifp->if_flags & IFF_BROADCAST) &&
	427	(ifra->ifra_broadaddr.sin_family == AF_INET))
	428	ia->ia_broadaddr = ifra->ifra_broadaddr;
	429	return (error);
	430
	431	case SIOCDIFADDR:
	432	in_ifscrub(ifp, ia);
	433	if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia)
	434	ifp->if_addrlist = ifa->ifa_next;
435	else {
436	while (ifa->ifa_next &&
437	(ifa->ifa_next != (struct ifaddr *)ia))
438	ifa = ifa->ifa_next;
439	if (ifa->ifa_next)
440	ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next;
441	else
442	printf("Couldn't unlink inifaddr from ifp\n");
443	}
444	oia = ia;
445	if (oia == (ia = in_ifaddr))
446	in_ifaddr = ia->ia_next;
447	else {
448	while (ia->ia_next && (ia->ia_next != oia))
449	ia = ia->ia_next;
450	if (ia->ia_next)
451	ia->ia_next = oia->ia_next;
452	else
453	printf("Didn't unlink inifadr from list\n");
454	}
455	(void) m_free(dtom(oia));
456	break;
457
458	default:
459	if (ifp == 0 \|\| ifp->if_ioctl == 0)
460	return (EOPNOTSUPP);
461	return ((*ifp->if_ioctl)(ifp, cmd, data));
462	}
463	return (0);
464	}
465
466	/*
467	* Delete any existing route for an interface.
468	*/
4c45483e	469	static void
15637ed4 RG	470	in_ifscrub(ifp, ia)
	471	register struct ifnet *ifp;
	472	register struct in_ifaddr *ia;
	473	{
	474
	475	if ((ia->ia_flags & IFA_ROUTE) == 0)
	476	return;
	477	if (ifp->if_flags & (IFF_LOOPBACK\|IFF_POINTOPOINT))
	478	rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
	479	else
	480	rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
	481	ia->ia_flags &= ~IFA_ROUTE;
	482	}
	483
	484	/*
	485	* Initialize an interface's internet address
	486	* and routing table entry.
	487	*/
4c45483e	488	int
15637ed4 RG	489	in_ifinit(ifp, ia, sin, scrub)
	490	register struct ifnet *ifp;
	491	register struct in_ifaddr *ia;
	492	struct sockaddr_in *sin;
4c45483e	493	int scrub;
15637ed4 RG	494	{
	495	register u_long i = ntohl(sin->sin_addr.s_addr);
	496	struct sockaddr_in oldaddr;
	497	int s = splimp(), error, flags = RTF_UP;
	498
	499	oldaddr = ia->ia_addr;
	500	ia->ia_addr = *sin;
	501	/*
	502	* Give the interface a chance to initialize
	503	* if this is its first address,
	504	* and to validate the address if necessary.
	505	*/
4c45483e GW	506	if (ifp->if_ioctl && (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR,
4c45483e GW	507	(caddr_t)ia))) {
15637ed4 RG	508	splx(s);
	509	ia->ia_addr = oldaddr;
	510	return (error);
	511	}
	512	splx(s);
	513	if (scrub) {
	514	ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
	515	in_ifscrub(ifp, ia);
	516	ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
	517	}
	518	if (IN_CLASSA(i))
	519	ia->ia_netmask = IN_CLASSA_NET;
	520	else if (IN_CLASSB(i))
	521	ia->ia_netmask = IN_CLASSB_NET;
	522	else
	523	ia->ia_netmask = IN_CLASSC_NET;
	524	ia->ia_net = i & ia->ia_netmask;
	525	/*
	526	* The subnet mask includes at least the standard network part,
	527	* but may already have been set to a larger value.
	528	*/
	529	ia->ia_subnetmask \|= ia->ia_netmask;
	530	ia->ia_subnet = i & ia->ia_subnetmask;
	531	ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
	532	{
	533	register char cp = (char ) (1 + &(ia->ia_sockmask.sin_addr));
	534	register char cpbase = (char ) &(ia->ia_sockmask.sin_addr);
	535	while (--cp >= cpbase)
	536	if (*cp) {
	537	ia->ia_sockmask.sin_len =
	538	1 + cp - (char *) &(ia->ia_sockmask);
	539	break;
	540	}
	541	}
	542	/*
	543	* Add route for the network.
	544	*/
	545	if (ifp->if_flags & IFF_BROADCAST) {
	546	ia->ia_broadaddr.sin_addr =
	547	in_makeaddr(ia->ia_subnet, INADDR_BROADCAST);
	548	ia->ia_netbroadcast.s_addr =
	549	htonl(ia->ia_net \| (INADDR_BROADCAST &~ ia->ia_netmask));
	550	} else if (ifp->if_flags & IFF_LOOPBACK) {
	551	ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
	552	flags \|= RTF_HOST;
	553	} else if (ifp->if_flags & IFF_POINTOPOINT) {
	554	if (ia->ia_dstaddr.sin_family != AF_INET)
	555	return (0);
	556	flags \|= RTF_HOST;
	557	}
	558	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
	559	ia->ia_flags \|= IFA_ROUTE;
	560	return (error);
	561	}
	562
	563	/*
	564	* Return address info for specified internet network.
	565	*/
	566	struct in_ifaddr *
	567	in_iaonnetof(net)
	568	u_long net;
	569	{
	570	register struct in_ifaddr *ia;
	571
572	for (ia = in_ifaddr; ia; ia = ia->ia_next)
573	if (ia->ia_subnet == net)
574	return (ia);
575	return ((struct in_ifaddr *)0);
576	}
577
578	/*
579	* Return 1 if the address might be a local broadcast address.
580	*/
4c45483e	581	int
15637ed4 RG	582	in_broadcast(in)
	583	struct in_addr in;
	584	{
	585	register struct in_ifaddr *ia;
	586	u_long t;
	587
	588	/*
	589	* Look through the list of addresses for a match
	590	* with a broadcast address.
	591	*/
	592	for (ia = in_ifaddr; ia; ia = ia->ia_next)
	593	if (ia->ia_ifp->if_flags & IFF_BROADCAST) {
	594	if (ia->ia_broadaddr.sin_addr.s_addr == in.s_addr)
	595	return (1);
	596	/*
	597	* Check for old-style (host 0) broadcast.
	598	*/
	599	if ((t = ntohl(in.s_addr)) == ia->ia_subnet \|\| t == ia->ia_net)
	600	return (1);
	601	}
	602	if (in.s_addr == INADDR_BROADCAST \|\| in.s_addr == INADDR_ANY)
	603	return (1);
	604	return (0);
	605	}
	606	#endif