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freebsd-skq/sys/netinet/in.c
wollman 140bceea65 Set subnetsarelocal to false. In a classless world, the other case 
is almost never useful.  (This is only a quick hack; someone should
go back and delete the entire subnetsarelocal==1 code path.)
1996-09-09 20:17:24 +00:00

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/*
* Copyright (c) 1982, 1986, 1991, 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.
*
* @(#)in.c 8.4 (Berkeley) 1/9/95
* $Id: in.c,v 1.24 1996/04/07 06:59:52 davidg Exp $
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <netinet/igmp_var.h>
/*
* This structure is used to keep track of in_multi chains which belong to
* deleted interface addresses.
*/
static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */
struct multi_kludge {
LIST_ENTRY(multi_kludge) mk_entry;
struct ifnet *mk_ifp;
struct in_multihead mk_head;
};
static void in_socktrim __P((struct sockaddr_in *));
static int in_ifinit __P((struct ifnet *,
struct in_ifaddr *, struct sockaddr_in *, int));
static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *));
static int subnetsarelocal = 0;
SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
&subnetsarelocal, 0, "");
/*
* 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) || IN_MULTICAST(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);
}
/*
* Trim a mask in a sockaddr
*/
static void
in_socktrim(ap)
struct sockaddr_in *ap;
{
register char *cplim = (char *) &ap->sin_addr;
register char *cp = (char *) (&ap->sin_addr + 1);
ap->sin_len = 0;
while (--cp >= cplim)
if (*cp) {
(ap)->sin_len = cp - (char *) (ap) + 1;
break;
}
}
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;
u_long cmd;
caddr_t data;
register struct ifnet *ifp;
{
register struct ifreq *ifr = (struct ifreq *)data;
register struct in_ifaddr *ia = 0, *iap;
register struct ifaddr *ifa;
struct in_ifaddr *oia;
struct in_aliasreq *ifra = (struct in_aliasreq *)data;
struct sockaddr_in oldaddr;
int error, hostIsNew, maskIsNew, s;
u_long i;
struct multi_kludge *mk;
/*
* Find address for this interface, if it exists.
*
* If an alias address was specified, find that one instead of
* the first one on the interface.
*/
if (ifp)
for (iap = in_ifaddr; iap; iap = iap->ia_next)
if (iap->ia_ifp == ifp) {
if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr ==
iap->ia_addr.sin_addr.s_addr) {
ia = iap;
break;
} else if (ia == NULL) {
ia = iap;
if (ifr->ifr_addr.sa_family != AF_INET)
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 ((ifp->if_flags & IFF_POINTOPOINT)
&& (cmd == SIOCAIFADDR)
&& (ifra->ifra_dstaddr.sin_addr.s_addr
== INADDR_ANY)) {
return EDESTADDRREQ;
}
}
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) {
oia = (struct in_ifaddr *)
malloc(sizeof *oia, M_IFADDR, M_WAITOK);
if (oia == (struct in_ifaddr *)NULL)
return (ENOBUFS);
bzero((caddr_t)oia, sizeof *oia);
ia = in_ifaddr;
/*
* Protect from ipintr() traversing address list
* while we're modifying it.
*/
s = splnet();
if (ia) {
for ( ; ia->ia_next; ia = ia->ia_next)
continue;
ia->ia_next = oia;
} else
in_ifaddr = oia;
ia = oia;
ifa = ifp->if_addrlist;
if (ifa) {
for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
continue;
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->if_flags & IFF_LOOPBACK))
in_interfaces++;
splx(s);
}
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;
}
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:
mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK);
if (!mk)
return ENOBUFS;
in_ifscrub(ifp, ia);
/*
* Protect from ipintr() traversing address list
* while we're modifying it.
*/
s = splnet();
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");
}
if (!oia->ia_multiaddrs.lh_first) {
IFAFREE(&oia->ia_ifa);
FREE(mk, M_IPMADDR);
splx(s);
break;
}
/*
* Multicast address kludge:
* If there were any multicast addresses attached to this
* interface address, either move them to another address
* on this interface, or save them until such time as this
* interface is reconfigured for IP.
*/
IFP_TO_IA(oia->ia_ifp, ia);
if (ia) { /* there is another address */
struct in_multi *inm;
for(inm = oia->ia_multiaddrs.lh_first; inm;
inm = inm->inm_entry.le_next) {
IFAFREE(&inm->inm_ia->ia_ifa);
ia->ia_ifa.ifa_refcnt++;
inm->inm_ia = ia;
LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm,
inm_entry);
}
FREE(mk, M_IPMADDR);
} else { /* last address on this if deleted, save */
struct in_multi *inm;
LIST_INIT(&mk->mk_head);
mk->mk_ifp = ifp;
for(inm = oia->ia_multiaddrs.lh_first; inm;
inm = inm->inm_entry.le_next) {
LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry);
}
if (mk->mk_head.lh_first) {
LIST_INSERT_HEAD(&in_mk, mk, mk_entry);
} else {
FREE(mk, M_IPMADDR);
}
}
IFAFREE((&oia->ia_ifa));
splx(s);
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.
*/
static 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(), flags = RTF_UP, error;
struct multi_kludge *mk;
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;
/*
* The subnet mask usually includes at least the standard network part,
* but may may be smaller in the case of supernetting.
* If it is set, we believe it.
*/
if (ia->ia_subnetmask == 0) {
ia->ia_subnetmask = ia->ia_netmask;
ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
} else
ia->ia_netmask &= ia->ia_subnetmask;
ia->ia_net = i & ia->ia_netmask;
ia->ia_subnet = i & ia->ia_subnetmask;
in_socktrim(&ia->ia_sockmask);
/*
* Add route for the network.
*/
ia->ia_ifa.ifa_metric = ifp->if_metric;
if (ifp->if_flags & IFF_BROADCAST) {
ia->ia_broadaddr.sin_addr.s_addr =
htonl(ia->ia_subnet | ~ia->ia_subnetmask);
ia->ia_netbroadcast.s_addr =
htonl(ia->ia_net | ~ 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;
LIST_INIT(&ia->ia_multiaddrs);
/*
* If the interface supports multicast, join the "all hosts"
* multicast group on that interface.
*/
if (ifp->if_flags & IFF_MULTICAST) {
struct in_addr addr;
/*
* Continuation of multicast address hack:
* If there was a multicast group list previously saved
* for this interface, then we re-attach it to the first
* address configured on the i/f.
*/
for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
if(mk->mk_ifp == ifp) {
struct in_multi *inm;
for(inm = mk->mk_head.lh_first; inm;
inm = inm->inm_entry.le_next) {
IFAFREE(&inm->inm_ia->ia_ifa);
ia->ia_ifa.ifa_refcnt++;
inm->inm_ia = ia;
LIST_INSERT_HEAD(&ia->ia_multiaddrs,
inm, inm_entry);
}
LIST_REMOVE(mk, mk_entry);
free(mk, M_IPMADDR);
break;
}
}
addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
in_addmulti(&addr, ifp);
}
return (error);
}
/*
* Return 1 if the address might be a local broadcast address.
*/
int
in_broadcast(in, ifp)
struct in_addr in;
struct ifnet *ifp;
{
register struct ifaddr *ifa;
u_long t;
if (in.s_addr == INADDR_BROADCAST ||
in.s_addr == INADDR_ANY)
return 1;
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return 0;
t = ntohl(in.s_addr);
/*
* Look through the list of addresses for a match
* with a broadcast address.
*/
#define ia ((struct in_ifaddr *)ifa)
for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
if (ifa->ifa_addr->sa_family == AF_INET &&
(in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
in.s_addr == ia->ia_netbroadcast.s_addr ||
/*
* Check for old-style (host 0) broadcast.
*/
t == ia->ia_subnet || t == ia->ia_net) &&
/*
* Check for an all one subnetmask. These
* only exist when an interface gets a secondary
* address.
*/
ia->ia_subnetmask != (u_long)0xffffffff)
return 1;
return (0);
#undef ia
}
/*
* Add an address to the list of IP multicast addresses for a given interface.
*/
struct in_multi *
in_addmulti(ap, ifp)
register struct in_addr *ap;
register struct ifnet *ifp;
{
register struct in_multi *inm;
struct ifreq ifr;
struct in_ifaddr *ia;
int s = splnet();
/*
* See if address already in list.
*/
IN_LOOKUP_MULTI(*ap, ifp, inm);
if (inm != NULL) {
/*
* Found it; just increment the reference count.
*/
++inm->inm_refcount;
}
else {
/*
* New address; allocate a new multicast record
* and link it into the interface's multicast list.
*/
inm = (struct in_multi *)malloc(sizeof(*inm),
M_IPMADDR, M_NOWAIT);
if (inm == NULL) {
splx(s);
return (NULL);
}
inm->inm_addr = *ap;
inm->inm_ifp = ifp;
inm->inm_refcount = 1;
IFP_TO_IA(ifp, ia);
if (ia == NULL) {
free(inm, M_IPMADDR);
splx(s);
return (NULL);
}
inm->inm_ia = ia;
ia->ia_ifa.ifa_refcnt++; /* gain a reference */
LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry);
/*
* Ask the network driver to update its multicast reception
* filter appropriately for the new address.
*/
((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET;
((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap;
if ((ifp->if_ioctl == NULL) ||
(*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
LIST_REMOVE(inm, inm_entry);
IFAFREE(&ia->ia_ifa); /* release reference */
free(inm, M_IPMADDR);
splx(s);
return (NULL);
}
/*
* Let IGMP know that we have joined a new IP multicast group.
*/
igmp_joingroup(inm);
}
splx(s);
return (inm);
}
/*
* Delete a multicast address record.
*/
void
in_delmulti(inm)
register struct in_multi *inm;
{
struct ifreq ifr;
int s = splnet();
if (--inm->inm_refcount == 0) {
/*
* No remaining claims to this record; let IGMP know that
* we are leaving the multicast group.
*/
igmp_leavegroup(inm);
/*
* Unlink from list.
*/
LIST_REMOVE(inm, inm_entry);
IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */
/*
* Notify the network driver to update its multicast reception
* filter.
*/
((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr =
inm->inm_addr;
(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
(caddr_t)&ifr);
free(inm, M_IPMADDR);
}
splx(s);
}
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