2.11BSD/sys/netinet/in.c
/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at Berkeley. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*
* @(#)in.c 7.7.1 (2.11BSD) 1995/10/10
*/
#include "param.h"
#include "ioctl.h"
#include "mbuf.h"
#include "domain.h"
#include "protosw.h"
#include "socket.h"
#include "socketvar.h"
#include "user.h"
#include "in_systm.h"
#include "../net/if.h"
#include "../net/route.h"
#include "../net/af.h"
#include "in.h"
#include "in_var.h"
#ifdef INET
inet_hash(sin, hp)
register struct sockaddr_in *sin;
struct afhash *hp;
{
register u_long n;
n = in_netof(sin->sin_addr);
if (n)
while ((n & 0xffL) == 0L)
n >>= 8;
hp->afh_nethash = n;
hp->afh_hosthash = ntohl(sin->sin_addr.s_addr);
}
inet_netmatch(sin1, sin2)
struct sockaddr_in *sin1, *sin2;
{
return (in_netof(sin1->sin_addr) == in_netof(sin2->sin_addr));
}
/*
* 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);
}
/*
* 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);
}
#ifndef SUBNETSARELOCAL
#define SUBNETSARELOCAL 1
#endif
int subnetsarelocal = SUBNETSARELOCAL;
/*
* 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.
*/
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.
*/
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)
return (0);
}
return (1);
}
extern struct ifnet loif;
/*
* Generic internet control operations (ioctl's).
* Ifp is 0 if not an interface-specific ioctl.
*/
/* ARGSUSED */
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;
struct ifaddr *ifa;
struct mbuf *m;
int error;
/*
* 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 SIOCSIFADDR:
case SIOCSIFNETMASK:
case SIOCSIFDSTADDR:
if (!suser())
return (u.u_error);
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_ifp = ifp;
IA_SIN(ia)->sin_family = AF_INET;
}
break;
case SIOCSIFBRDADDR:
if (!suser())
return (u.u_error);
/* FALLTHROUGH */
default:
if (ia == (struct in_ifaddr *)0)
return (EADDRNOTAVAIL);
break;
}
switch (cmd) {
case SIOCGIFADDR:
ifr->ifr_addr = ia->ia_addr;
break;
case SIOCGIFBRDADDR:
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return (EINVAL);
ifr->ifr_dstaddr = ia->ia_broadaddr;
break;
case SIOCGIFDSTADDR:
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
return (EINVAL);
ifr->ifr_dstaddr = ia->ia_dstaddr;
break;
case SIOCGIFNETMASK:
#define satosin(sa) ((struct sockaddr_in *)(sa))
satosin(&ifr->ifr_addr)->sin_family = AF_INET;
satosin(&ifr->ifr_addr)->sin_addr.s_addr = htonl(ia->ia_subnetmask);
break;
case SIOCSIFDSTADDR:
{
struct sockaddr oldaddr;
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
return (EINVAL);
oldaddr = ia->ia_dstaddr;
ia->ia_dstaddr = ifr->ifr_dstaddr;
if (ifp->if_ioctl &&
(error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR, ia))) {
ia->ia_dstaddr = oldaddr;
return (error);
}
if (ia->ia_flags & IFA_ROUTE) {
rtinit(&oldaddr, &ia->ia_addr, (int)SIOCDELRT,
RTF_HOST);
rtinit(&ia->ia_dstaddr, &ia->ia_addr, (int)SIOCADDRT,
RTF_HOST|RTF_UP);
}
}
break;
case SIOCSIFBRDADDR:
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return (EINVAL);
ia->ia_broadaddr = ifr->ifr_broadaddr;
break;
case SIOCSIFADDR:
return (in_ifinit(ifp, ia, &ifr->ifr_addr));
case SIOCSIFNETMASK:
ia->ia_subnetmask = ntohl(satosin(&ifr->ifr_addr)->sin_addr.s_addr);
break;
default:
if (ifp == 0 || ifp->if_ioctl == 0)
return (EOPNOTSUPP);
return ((*ifp->if_ioctl)(ifp, cmd, data));
}
return (0);
}
/*
* Initialize an interface's internet address
* and routing table entry.
*/
in_ifinit(ifp, ia, sin)
register struct ifnet *ifp;
register struct in_ifaddr *ia;
struct sockaddr_in *sin;
{
register u_long i = ntohl(sin->sin_addr.s_addr);
struct sockaddr oldaddr;
struct sockaddr_in netaddr;
int s = splimp(), error;
oldaddr = ia->ia_addr;
ia->ia_addr = *(struct sockaddr *)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, ia))) {
splx(s);
ia->ia_addr = oldaddr;
return (error);
}
/*
* Delete any previous route for an old address.
*/
bzero((caddr_t)&netaddr, sizeof (netaddr));
netaddr.sin_family = AF_INET;
if (ia->ia_flags & IFA_ROUTE) {
if (ifp->if_flags & IFF_LOOPBACK)
rtinit(&oldaddr, &oldaddr, (int)SIOCDELRT, RTF_HOST);
else if (ifp->if_flags & IFF_POINTOPOINT)
rtinit(&ia->ia_dstaddr, &oldaddr, (int)SIOCDELRT,
RTF_HOST);
else {
netaddr.sin_addr = in_makeaddr(ia->ia_subnet,
INADDR_ANY);
rtinit((struct sockaddr *)&netaddr, &oldaddr,
(int)SIOCDELRT, 0);
}
ia->ia_flags &= ~IFA_ROUTE;
}
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;
if (ifp->if_flags & IFF_BROADCAST) {
ia->ia_broadaddr.sa_family = AF_INET;
((struct sockaddr_in *)(&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));
}
/*
* Add route for the network.
*/
if (ifp->if_flags & IFF_LOOPBACK)
rtinit(&ia->ia_addr, &ia->ia_addr, (int)SIOCADDRT,
RTF_HOST|RTF_UP);
else if (ifp->if_flags & IFF_POINTOPOINT)
rtinit(&ia->ia_dstaddr, &ia->ia_addr, (int)SIOCADDRT,
RTF_HOST|RTF_UP);
else {
netaddr.sin_addr = in_makeaddr(ia->ia_subnet, INADDR_ANY);
rtinit((struct sockaddr *)&netaddr, &ia->ia_addr,
(int)SIOCADDRT, RTF_UP);
}
ia->ia_flags |= IFA_ROUTE;
splx(s);
return (0);
}
/*
* 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.
*/
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 (satosin(&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