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freebsd/sys/netinet/in.c
Garrett Wollman a29f300e80 The long-awaited mega-massive-network-code- cleanup. Part I.
This commit includes the following changes:
1) Old-style (pr_usrreq()) protocols are no longer supported, the compatibility
glue for them is deleted, and the kernel will panic on boot if any are compiled
in.

2) Certain protocol entry points are modified to take a process structure,
so they they can easily tell whether or not it is possible to sleep, and
also to access credentials.

3) SS_PRIV is no more, and with it goes the SO_PRIVSTATE setsockopt()
call.  Protocols should use the process pointer they are now passed.

4) The PF_LOCAL and PF_ROUTE families have been updated to use the new
style, as has the `raw' skeleton family.

5) PF_LOCAL sockets now obey the process's umask when creating a socket
in the filesystem.

As a result, LINT is now broken.  I'm hoping that some enterprising hacker
with a bit more time will either make the broken bits work (should be
easy for netipx) or dike them out.
1997-04-27 20:01:29 +00:00

596 lines
16 KiB
C

/*
* 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 1.33 1997/03/24 11:33:25 bde Exp $
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/proc.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>
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 */
/*
* 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;
int 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;
/*
* 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 (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 (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
return error;
if (ifp == 0)
panic("in_control");
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);
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 (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
return error;
/* 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:
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;
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
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;
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;
/*
* 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);
}