NetBSD/sys/netinet/in.c

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/* $NetBSD: in.c,v 1.34 1997/03/15 18:12:36 is Exp $ */
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/*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
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*
* 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 8.2 (Berkeley) 11/15/93
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*/
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#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/malloc.h>
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#include <sys/socket.h>
#include <sys/socketvar.h>
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#include <sys/systm.h>
#include <sys/proc.h>
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#include <net/if.h>
#include <net/route.h>
#include <net/if_ether.h>
#include <netinet/in_systm.h>
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#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_inarp.h>
#include <netinet/ip_mroute.h>
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#include <netinet/igmp_var.h>
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#include "ether.h"
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#ifdef INET
#ifndef SUBNETSARELOCAL
#define SUBNETSARELOCAL 1
#endif
int subnetsarelocal = SUBNETSARELOCAL;
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/*
* 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.
*/
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int
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in_localaddr(in)
struct in_addr in;
{
register struct in_ifaddr *ia;
if (subnetsarelocal) {
for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
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return (1);
} else {
for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
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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.
*/
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int
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in_canforward(in)
struct in_addr in;
{
register u_int32_t net;
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if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
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return (0);
if (IN_CLASSA(in.s_addr)) {
net = in.s_addr & IN_CLASSA_NET;
if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
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return (0);
}
return (1);
}
/*
* Trim a mask in a sockaddr
*/
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;
}
}
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int in_interfaces; /* number of external internet interfaces */
/*
* Generic internet control operations (ioctl's).
* Ifp is 0 if not an interface-specific ioctl.
*/
/* ARGSUSED */
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int
in_control(so, cmd, data, ifp, p)
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struct socket *so;
u_long cmd;
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caddr_t data;
register struct ifnet *ifp;
struct proc *p;
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{
register struct ifreq *ifr = (struct ifreq *)data;
register struct in_ifaddr *ia = 0;
struct in_aliasreq *ifra = (struct in_aliasreq *)data;
struct sockaddr_in oldaddr;
int error, hostIsNew, maskIsNew;
/*
* Find address for this interface, if it exists.
*/
if (ifp)
for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
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if (ia->ia_ifp == ifp)
break;
switch (cmd) {
case SIOCAIFADDR:
case SIOCDIFADDR:
if (ifra->ifra_addr.sin_family == AF_INET)
for (; ia != 0; ia = ia->ia_list.tqe_next) {
if (ia->ia_ifp == ifp &&
in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
break;
}
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if (cmd == SIOCDIFADDR && ia == 0)
return (EADDRNOTAVAIL);
/* FALLTHROUGH */
case SIOCSIFADDR:
case SIOCSIFNETMASK:
case SIOCSIFDSTADDR:
if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
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return (EPERM);
if (ifp == 0)
panic("in_control");
if (ia == 0) {
MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
M_IFADDR, M_WAITOK);
if (ia == 0)
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return (ENOBUFS);
bzero((caddr_t)ia, sizeof *ia);
TAILQ_INSERT_TAIL(&in_ifaddr, ia, ia_list);
TAILQ_INSERT_TAIL(&ifp->if_addrlist, (struct ifaddr *)ia,
ifa_list);
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ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
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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;
LIST_INIT(&ia->ia_multiaddrs);
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
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in_interfaces++;
}
break;
case SIOCSIFBRDADDR:
if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
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return (EPERM);
/* FALLTHROUGH */
case SIOCGIFADDR:
case SIOCGIFNETMASK:
case SIOCGIFDSTADDR:
case SIOCGIFBRDADDR:
if (ia == 0)
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return (EADDRNOTAVAIL);
break;
}
switch (cmd) {
case SIOCGIFADDR:
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*satosin(&ifr->ifr_addr) = ia->ia_addr;
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break;
case SIOCGIFBRDADDR:
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return (EINVAL);
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*satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr;
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break;
case SIOCGIFDSTADDR:
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
return (EINVAL);
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*satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr;
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break;
case SIOCGIFNETMASK:
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*satosin(&ifr->ifr_addr) = ia->ia_sockmask;
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break;
case SIOCSIFDSTADDR:
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
return (EINVAL);
oldaddr = ia->ia_dstaddr;
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ia->ia_dstaddr = *satosin(&ifr->ifr_dstaddr);
if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
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ia->ia_dstaddr = oldaddr;
return (error);
}
if (ia->ia_flags & IFA_ROUTE) {
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ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
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rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
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ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
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rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
}
break;
case SIOCSIFBRDADDR:
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return (EINVAL);
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ia->ia_broadaddr = *satosin(&ifr->ifr_broadaddr);
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break;
case SIOCSIFADDR:
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return (in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1));
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case SIOCSIFNETMASK:
ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr =
ifra->ifra_addr.sin_addr.s_addr;
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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 (in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
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hostIsNew = 0;
}
if (ifra->ifra_mask.sin_len) {
in_ifscrub(ifp, ia);
ia->ia_sockmask = ifra->ifra_mask;
ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
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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);
TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
TAILQ_REMOVE(&in_ifaddr, ia, ia_list);
IFAFREE((&ia->ia_ifa));
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break;
#ifdef MROUTING
case SIOCGETVIFCNT:
case SIOCGETSGCNT:
return (mrt_ioctl(so, cmd, data));
#endif /* MROUTING */
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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.
*/
void
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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
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in_ifinit(ifp, ia, sin, scrub)
register struct ifnet *ifp;
register struct in_ifaddr *ia;
struct sockaddr_in *sin;
int scrub;
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{
register u_int32_t i = sin->sin_addr.s_addr;
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struct sockaddr_in oldaddr;
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int s = splimp(), flags = RTF_UP, error;
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/*
* Set up new addresses.
*/
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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)))
goto bad;
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splx(s);
if (scrub) {
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ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
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in_ifscrub(ifp, ia);
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ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
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}
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.
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*/
if (ia->ia_subnetmask == 0) {
ia->ia_subnetmask = ia->ia_netmask;
ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
} else
ia->ia_netmask &= ia->ia_subnetmask;
ia->ia_net = i & ia->ia_netmask;
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ia->ia_subnet = i & ia->ia_subnetmask;
in_socktrim(&ia->ia_sockmask);
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/*
* Add route for the network.
*/
ia->ia_ifa.ifa_metric = ifp->if_metric;
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if (ifp->if_flags & IFF_BROADCAST) {
ia->ia_broadaddr.sin_addr.s_addr =
ia->ia_subnet | ~ia->ia_subnetmask;
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ia->ia_netbroadcast.s_addr =
ia->ia_net | ~ia->ia_netmask;
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} 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;
}
error = rtinit(&ia->ia_ifa, (int)RTM_ADD, flags);
if (!error)
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ia->ia_flags |= IFA_ROUTE;
/*
* If the interface supports multicast, join the "all hosts"
* multicast group on that interface.
*/
if (ifp->if_flags & IFF_MULTICAST) {
struct in_addr addr;
addr.s_addr = INADDR_ALLHOSTS_GROUP;
in_addmulti(&addr, ifp);
}
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return (error);
bad:
splx(s);
ia->ia_addr = oldaddr;
return (error);
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}
/*
* Return 1 if the address might be a local broadcast address.
*/
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int
in_broadcast(in, ifp)
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struct in_addr in;
struct ifnet *ifp;
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{
register struct ifaddr *ifa;
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if (in.s_addr == INADDR_BROADCAST ||
in_nullhost(in))
return 1;
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return 0;
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/*
* Look through the list of addresses for a match
* with a broadcast address.
*/
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#define ia (ifatoia(ifa))
for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
if (ifa->ifa_addr->sa_family == AF_INET &&
(in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
in_hosteq(in, ia->ia_netbroadcast) ||
/*
* Check for old-style (host 0) broadcast.
*/
in.s_addr == ia->ia_subnet ||
in.s_addr == ia->ia_net))
return 1;
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return (0);
#undef ia
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}
/*
* 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;
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int s = splsoftnet();
/*
* 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;
LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_list);
/*
* Ask the network driver to update its multicast reception
* filter appropriately for the new address.
*/
satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in);
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satosin(&ifr.ifr_addr)->sin_family = AF_INET;
satosin(&ifr.ifr_addr)->sin_addr = *ap;
if ((ifp->if_ioctl == NULL) ||
(*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
LIST_REMOVE(inm, inm_list);
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.
*/
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void
in_delmulti(inm)
register struct in_multi *inm;
{
struct ifreq ifr;
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int s = splsoftnet();
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_list);
/*
* Notify the network driver to update its multicast reception
* filter.
*/
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satosin(&ifr.ifr_addr)->sin_family = AF_INET;
satosin(&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);
}
#endif