Source to bsd/netinet/in.c
/*
* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* The contents of this file constitute Original Code as defined in and
* are subject to the Apple Public Source License Version 1.1 (the
* "License"). You may not use this file except in compliance with the
* License. Please obtain a copy of the License at
* http://www.apple.com/publicsource and read it before using this file.
*
* This Original Code and all software distributed under the License are
* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
* 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
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/socketvar.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_pcb.h>
#include <netinet/igmp_var.h>
#include <net/dlil.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <sys/file.h>
/*
static MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");
*/
static void in_socktrim __P((struct sockaddr_in *));
static int in_ifinit __P((struct ifnet *,
struct in_ifaddr *, struct sockaddr_in *, int));
static int subnetsarelocal = 0;
SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
&subnetsarelocal, 0, "");
struct in_multihead in_multihead; /* XXX BSS initialization */
extern void arp_rtrequest();
/*
* 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_ifaddrhead.tqh_first; ia;
ia = ia->ia_link.tqe_next)
if ((i & ia->ia_netmask) == ia->ia_net)
return (1);
} else {
for (ia = in_ifaddrhead.tqh_first; ia;
ia = ia->ia_link.tqe_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, p)
struct socket *so;
u_long cmd;
caddr_t data;
register struct ifnet *ifp;
struct proc *p;
{
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, dl_tag;
/*
* 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_ifaddrhead.tqh_first; iap;
iap = iap->ia_link.tqe_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 (ifp == 0)
return (EADDRNOTAVAIL);
if (ifra->ifra_addr.sin_family == AF_INET) {
for (oia = ia; ia; ia = ia->ia_link.tqe_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 ISFB31
if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
return error;
#else
if ((so->so_state & SS_PRIV) == 0)
return (EPERM);
#endif
if (ifp == 0)
return (EADDRNOTAVAIL);
if (ia == (struct in_ifaddr *)0) {
ia = (struct in_ifaddr *)
_MALLOC(sizeof *ia, M_IFADDR, M_WAITOK);
if (ia == (struct in_ifaddr *)NULL)
return (ENOBUFS);
bzero((caddr_t)ia, sizeof *ia);
/*
* Protect from ipintr() traversing address list
* while we're modifying it.
*/
s = splnet();
TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
ifa = &ia->ia_ifa;
TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
/*
* Temorary code for protocol attachment XXX
*/
if (strcmp(ifp->if_name, "en") == 0)
dl_tag = ether_attach_inet(ifp);
if (strcmp(ifp->if_name, "lo") == 0)
dl_tag = lo_attach_inet(ifp);
/* End of temp code */
ifa->ifa_dlt = dl_tag;
ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
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 ISFB31
if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
return error;
#else
if ((so->so_state & SS_PRIV) == 0)
return (EPERM);
#endif
/* 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 = dlil_ioctl(0, 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);
/*
* Protect from ipintr() traversing address list
* while we're modifying it.
*/
s = splnet();
ifa = &ia->ia_ifa;
TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
oia = ia;
TAILQ_REMOVE(&in_ifaddrhead, oia, ia_link);
IFAFREE(&oia->ia_ifa);
splx(s);
break;
case SIOCSETOT: {
/*
* Inspiration from tcp_ctloutput() and ip_ctloutput()
*/
struct inpcb *inp, *cloned_inp;
int error = 0;
int cloned_fd = *(int *)data;
s = splnet(); /* XXX */
inp = sotoinpcb(so);
if (inp == NULL) {
splx(s);
break;
}
/* let's make sure it's either -1 or a valid file descriptor */
if (cloned_fd != -1) {
struct socket *cloned_so;
struct file *cloned_fp;
error = getsock(p->p_fd, cloned_fd, &cloned_fp);
if (error){
splx(s);
break;
}
cloned_so = (struct socket *)cloned_fp->f_data;
cloned_inp = sotoinpcb(cloned_so);
} else {
cloned_inp = NULL;
}
if (cloned_inp == NULL) {
/* OT always uses IP_PORTRANGE_HIGH */
inp->inp_flags &= ~(INP_LOWPORT);
inp->inp_flags |= INP_HIGHPORT;
} else {
inp->inp_ip_tos = cloned_inp->inp_ip_tos;
inp->inp_ip_ttl = cloned_inp->inp_ip_ttl;
inp->inp_flags = cloned_inp->inp_flags;
/* Multicast options */
if (cloned_inp->inp_moptions != NULL) {
int i;
struct ip_moptions *cloned_imo = cloned_inp->inp_moptions;
struct ip_moptions *imo = inp->inp_moptions;
if (imo == NULL) {
/*
* No multicast option buffer attached to the pcb;
* allocate one.
*/
splx();
imo = (struct ip_moptions*)
_MALLOC(sizeof(*imo), M_IPMOPTS, M_WAITOK);
if (imo == NULL) {
error = ENOBUFS;
break;
}
s = splnet(); /* XXX */
inp->inp_moptions = imo;
}
imo->imo_multicast_ifp = cloned_imo->imo_multicast_ifp;
imo->imo_multicast_vif = cloned_imo->imo_multicast_vif;
imo->imo_multicast_ttl = cloned_imo->imo_multicast_ttl;
imo->imo_multicast_loop = cloned_imo->imo_multicast_loop;
imo->imo_num_memberships = cloned_imo->imo_num_memberships;
for (i = 0; i < cloned_imo->imo_num_memberships; i++) {
imo->imo_membership[i] =
in_addmulti(&cloned_imo->imo_membership[i]->inm_addr,
cloned_imo->imo_membership[i]->inm_ifp);
}
}
}
splx(s);
break;
}
default:
if (ifp == 0 || ifp->if_ioctl == 0)
return (EOPNOTSUPP);
return dlil_ioctl(0, ifp, cmd, (caddr_t) data);
}
return (0);
}
/*
* Delete any existing route for an interface.
*/
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;
u_long dl_tag;
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 = dlil_ioctl(0, ifp, SIOCSIFADDR, (caddr_t)ia))) {
splx(s);
ia->ia_addr = oldaddr;
return (error);
}
dlil_ioctl(ia->ia_ifa.ifa_dlt, 0, SIOCSIFADDR, (caddr_t) ia);
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;
/*
* 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 = 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_addrhead.tqh_first; ifa;
ifa = ifa->ifa_link.tqe_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;
int error;
struct sockaddr_in sin;
struct ifmultiaddr *ifma;
int s = splnet();
/*
* Call generic routine to add membership or increment
* refcount. It wants addresses in the form of a sockaddr,
* so we build one here (being careful to zero the unused bytes).
*/
bzero(&sin, sizeof sin);
sin.sin_family = AF_INET;
sin.sin_len = sizeof sin;
sin.sin_addr = *ap;
error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
if (error) {
splx(s);
return 0;
}
/*
* If ifma->ifma_protospec is null, then if_addmulti() created
* a new record. Otherwise, we are done.
*/
if (ifma->ifma_protospec != 0)
return ifma->ifma_protospec;
/* XXX - if_addmulti uses M_WAITOK. Can this really be called
at interrupt time? If so, need to fix if_addmulti. XXX */
inm = (struct in_multi *) _MALLOC(sizeof(*inm), M_IPMADDR, M_NOWAIT);
if (inm == NULL) {
splx(s);
return (NULL);
}
bzero(inm, sizeof *inm);
inm->inm_addr = *ap;
inm->inm_ifp = ifp;
inm->inm_ifma = ifma;
ifma->ifma_protospec = inm;
LIST_INSERT_HEAD(&in_multihead, inm, inm_link);
/*
* 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 ifmultiaddr *ifma = inm->inm_ifma;
int s = splnet();
if (ifma->ifma_refcount == 1) {
/*
* No remaining claims to this record; let IGMP know that
* we are leaving the multicast group.
*/
igmp_leavegroup(inm);
ifma->ifma_protospec = 0;
LIST_REMOVE(inm, inm_link);
FREE(inm, M_IPMADDR);
}
/* XXX - should be separate API for when we have an ifma? */
if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
splx(s);
}