NetBSD/sys/netinet6/in6_ifattach.c

670 lines
18 KiB
C

/* $NetBSD: in6_ifattach.c,v 1.121 2022/12/22 02:52:35 msaitoh Exp $ */
/* $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.121 2022/12/22 02:52:35 msaitoh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kmem.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/md5.h>
#include <sys/socketvar.h>
#include <sys/cprng.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_mroute.h>
#include <netinet6/scope6_var.h>
int ip6_auto_linklocal = 1; /* enable by default */
#if 0
static int get_hostid_ifid(struct ifnet *, struct in6_addr *);
#endif
static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
static int in6_ifattach_loopback(struct ifnet *);
#define EUI64_GBIT 0x01
#define EUI64_UBIT 0x02
#define EUI64_TO_IFID(in6) do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (/*CONSTCOND*/ 0)
#define EUI64_GROUP(in6) ((in6)->s6_addr[8] & EUI64_GBIT)
#define EUI64_INDIVIDUAL(in6) (!EUI64_GROUP(in6))
#define EUI64_LOCAL(in6) ((in6)->s6_addr[8] & EUI64_UBIT)
#define EUI64_UNIVERSAL(in6) (!EUI64_LOCAL(in6))
#define IFID_LOCAL(in6) (!EUI64_LOCAL(in6))
#define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6))
#if 0
/*
* Generate a last-resort interface identifier from hostid.
* works only for certain architectures (like sparc).
* also, using hostid itself may constitute a privacy threat, much worse
* than MAC addresses (hostids are used for software licensing).
* maybe we should use MD5(hostid) instead.
*
* in6 - upper 64bits are preserved
*/
static int
get_hostid_ifid(struct ifnet *ifp, struct in6_addr *in6)
{
int off, len;
static const uint8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static const uint8_t allone[8] =
{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
if (!hostid)
return -1;
/* get up to 8 bytes from the hostid field - should we get */
len = (sizeof(hostid) > 8) ? 8 : sizeof(hostid);
off = sizeof(*in6) - len;
memcpy(&in6->s6_addr[off], &hostid, len);
/* make sure we do not return anything bogus */
if (memcmp(&in6->s6_addr[8], allzero, sizeof(allzero)))
return -1;
if (memcmp(&in6->s6_addr[8], allone, sizeof(allone)))
return -1;
/* make sure to set "u" bit to local, and "g" bit to individual. */
in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */
/* convert EUI64 into IPv6 interface identifier */
EUI64_TO_IFID(in6);
return 0;
}
#endif
/*
* Generate a last-resort interface identifier, when the machine has no
* IEEE802/EUI64 address sources.
* The goal here is to get an interface identifier that is
* (1) random enough and (2) does not change across reboot.
* We currently use MD5(hostname) for it.
*/
static int
get_rand_ifid(struct in6_addr *in6) /* upper 64bits are preserved */
{
MD5_CTX ctxt;
u_int8_t digest[16];
#if 0
/* we need at least several letters as seed for ifid */
if (hostnamelen < 3)
return -1;
#endif
/* generate 8 bytes of pseudo-random value. */
memset(&ctxt, 0, sizeof(ctxt));
MD5Init(&ctxt);
MD5Update(&ctxt, (u_char *)hostname, hostnamelen);
MD5Final(digest, &ctxt);
/* assumes sizeof(digest) > sizeof(ifid) */
memcpy(&in6->s6_addr[8], digest, 8);
/* make sure to set "u" bit to local, and "g" bit to individual. */
in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */
/* convert EUI64 into IPv6 interface identifier */
EUI64_TO_IFID(in6);
return 0;
}
/*
* Get interface identifier for the specified interface.
*
* in6 - upper 64bits are preserved
*/
int
in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
{
struct ifaddr *ifa;
const struct sockaddr_dl *sdl = NULL;
const char *addr = NULL; /* XXX gcc 4.8 -Werror=maybe-uninitialized */
size_t addrlen = 0; /* XXX gcc 4.8 -Werror=maybe-uninitialized */
static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static u_int8_t allone[8] =
{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
int s;
s = pserialize_read_enter();
IFADDR_READER_FOREACH(ifa, ifp) {
const struct sockaddr_dl *tsdl;
if (ifa->ifa_addr->sa_family != AF_LINK)
continue;
tsdl = satocsdl(ifa->ifa_addr);
if (tsdl == NULL || tsdl->sdl_alen == 0)
continue;
if (sdl == NULL || ifa == ifp->if_dl || ifa == ifp->if_hwdl) {
sdl = tsdl;
addr = CLLADDR(sdl);
addrlen = sdl->sdl_alen;
}
if (ifa == ifp->if_hwdl)
break;
}
pserialize_read_exit(s);
if (sdl == NULL)
return -1;
switch (ifp->if_type) {
case IFT_IEEE1394:
case IFT_IEEE80211:
/* IEEE1394 uses 16byte length address starting with EUI64 */
if (addrlen > 8)
addrlen = 8;
break;
default:
break;
}
/* get EUI64 */
switch (ifp->if_type) {
/* IEEE802/EUI64 cases - what others? */
case IFT_ETHER:
case IFT_ATM:
case IFT_IEEE1394:
case IFT_IEEE80211:
/* look at IEEE802/EUI64 only */
if (addrlen != 8 && addrlen != 6)
return -1;
/*
* check for invalid MAC address - on bsdi, we see it a lot
* since wildboar configures all-zero MAC on pccard before
* card insertion.
*/
if (memcmp(addr, allzero, addrlen) == 0)
return -1;
if (memcmp(addr, allone, addrlen) == 0)
return -1;
/* make EUI64 address */
if (addrlen == 8)
memcpy(&in6->s6_addr[8], addr, 8);
else if (addrlen == 6) {
in6->s6_addr[8] = addr[0];
in6->s6_addr[9] = addr[1];
in6->s6_addr[10] = addr[2];
in6->s6_addr[11] = 0xff;
in6->s6_addr[12] = 0xfe;
in6->s6_addr[13] = addr[3];
in6->s6_addr[14] = addr[4];
in6->s6_addr[15] = addr[5];
}
break;
case IFT_ARCNET:
if (addrlen != 1)
return -1;
if (!addr[0])
return -1;
memset(&in6->s6_addr[8], 0, 8);
in6->s6_addr[15] = addr[0];
/*
* due to insufficient bitwidth, we mark it local.
*/
in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */
break;
case IFT_GIF:
#ifdef IFT_STF
case IFT_STF:
#endif
/*
* RFC2893 says: "SHOULD use IPv4 address as ifid source".
* however, IPv4 address is not very suitable as unique
* identifier source (can be renumbered).
* we don't do this.
*/
return -1;
default:
return -1;
}
/* sanity check: g bit must not indicate "group" */
if (EUI64_GROUP(in6))
return -1;
/* convert EUI64 into IPv6 interface identifier */
EUI64_TO_IFID(in6);
/*
* sanity check: ifid must not be all zero, avoid conflict with
* subnet router anycast
*/
if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
memcmp(&in6->s6_addr[9], allzero, 7) == 0) {
return -1;
}
return 0;
}
/*
* Get interface identifier for the specified interface. If it is not
* available on ifp0, borrow interface identifier from other information
* sources.
*
* altifp - secondary EUI64 source
*/
static int
get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
struct in6_addr *in6)
{
struct ifnet *ifp;
int s;
/* first, try to get it from the interface itself */
if (in6_get_hw_ifid(ifp0, in6) == 0) {
nd6log(LOG_DEBUG, "%s: got interface identifier from itself\n",
if_name(ifp0));
goto success;
}
/* try secondary EUI64 source. this basically is for ATM PVC */
if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
nd6log(LOG_DEBUG, "%s: got interface identifier from %s\n",
if_name(ifp0), if_name(altifp));
goto success;
}
/* next, try to get it from some other hardware interface */
s = pserialize_read_enter();
IFNET_READER_FOREACH(ifp) {
if (ifp == ifp0)
continue;
if (in6_get_hw_ifid(ifp, in6) != 0)
continue;
/*
* to borrow ifid from other interface, ifid needs to be
* globally unique
*/
if (IFID_UNIVERSAL(in6)) {
nd6log(LOG_DEBUG,
"%s: borrow interface identifier from %s\n",
if_name(ifp0), if_name(ifp));
pserialize_read_exit(s);
goto success;
}
}
pserialize_read_exit(s);
#if 0
/* get from hostid - only for certain architectures */
if (get_hostid_ifid(ifp, in6) == 0) {
nd6log(LOG_DEBUG,
"%s: interface identifier generated by hostid\n",
if_name(ifp0));
goto success;
}
#endif
/* last resort: get from random number source */
if (get_rand_ifid(in6) == 0) {
nd6log(LOG_DEBUG,
"%s: interface identifier generated by random number\n",
if_name(ifp0));
goto success;
}
printf("%s: failed to get interface identifier\n", if_name(ifp0));
return -1;
success:
nd6log(LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
in6->s6_addr[14], in6->s6_addr[15]);
return 0;
}
/*
* altifp - secondary EUI64 source
*/
static int
in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
{
struct in6_aliasreq ifra;
int error;
/*
* configure link-local address.
*/
memset(&ifra, 0, sizeof(ifra));
/*
* in6_update_ifa() does not use ifra_name, but we accurately set it
* for safety.
*/
strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
ifra.ifra_addr.sin6_family = AF_INET6;
ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
} else {
if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
nd6log(LOG_ERR,
"%s: no ifid available\n", if_name(ifp));
return -1;
}
}
if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
return -1;
sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask64, 0, 0, 0);
/* link-local addresses should NEVER expire. */
ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
/*
* Now call in6_update_ifa() to do a bunch of procedures to configure
* a link-local address. We can set the 3rd argument to NULL, because
* we know there's no other link-local address on the interface
* and therefore we are adding one (instead of updating one).
*/
if ((error = in6_update_ifa(ifp, &ifra, IN6_IFAUPDATE_DADDELAY)) != 0) {
/*
* XXX: When the interface does not support IPv6, this call
* would fail in the SIOCINITIFADDR ioctl. I believe the
* notification is rather confusing in this case, so just
* suppress it. (jinmei@kame.net 20010130)
*/
if (error != EAFNOSUPPORT)
nd6log(LOG_NOTICE,
"failed to configure a link-local address on %s "
"(errno=%d)\n",
if_name(ifp), error);
return -1;
}
return 0;
}
/*
* ifp - must be IFT_LOOP
*/
static int
in6_ifattach_loopback(struct ifnet *ifp)
{
struct in6_aliasreq ifra;
int error;
memset(&ifra, 0, sizeof(ifra));
/*
* in6_update_ifa() does not use ifra_name, but we accurately set it
* for safety.
*/
strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask128, 0, 0, 0);
/*
* Always initialize ia_dstaddr (= broadcast address) to loopback
* address. Follows IPv4 practice - see in_ifinit().
*/
sockaddr_in6_init(&ifra.ifra_dstaddr, &in6addr_loopback, 0, 0, 0);
sockaddr_in6_init(&ifra.ifra_addr, &in6addr_loopback, 0, 0, 0);
/* the loopback address should NEVER expire. */
ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
/* we don't need to perform DAD on loopback interfaces. */
ifra.ifra_flags |= IN6_IFF_NODAD;
/*
* We are sure that this is a newly assigned address, so we can set
* NULL to the 3rd arg.
*/
if ((error = in6_update_ifa(ifp, &ifra, 0)) != 0) {
nd6log(LOG_ERR, "failed to configure "
"the loopback address on %s (errno=%d)\n",
if_name(ifp), error);
return -1;
}
return 0;
}
/*
* compute NI group address, based on the current hostname setting.
* see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
*
* when ifp == NULL, the caller is responsible for filling scopeid.
*/
int
in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
struct sockaddr_in6 *sa6)
{
const char *p;
u_int8_t *q;
MD5_CTX ctxt;
u_int8_t digest[16];
u_int8_t l;
u_int8_t n[64]; /* a single label must not exceed 63 chars */
if (!namelen || !name)
return -1;
p = name;
while (p && *p && *p != '.' && p - name < namelen)
p++;
if (p - name > sizeof(n) - 1)
return -1; /* label too long */
l = p - name;
strncpy((char *)n, name, l);
n[(int)l] = '\0';
for (q = n; *q; q++) {
if ('A' <= *q && *q <= 'Z')
*q = *q - 'A' + 'a';
}
/* generate 8 bytes of pseudo-random value. */
memset(&ctxt, 0, sizeof(ctxt));
MD5Init(&ctxt);
MD5Update(&ctxt, &l, sizeof(l));
MD5Update(&ctxt, n, l);
MD5Final(digest, &ctxt);
memset(sa6, 0, sizeof(*sa6));
sa6->sin6_family = AF_INET6;
sa6->sin6_len = sizeof(*sa6);
sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
sa6->sin6_addr.s6_addr8[11] = 2;
memcpy(&sa6->sin6_addr.s6_addr32[3], digest,
sizeof(sa6->sin6_addr.s6_addr32[3]));
if (in6_setscope(&sa6->sin6_addr, ifp, NULL))
return -1; /* XXX: should not fail */
return 0;
}
/*
* XXX multiple loopback interface needs more care. for instance,
* nodelocal address needs to be configured onto only one of them.
* XXX multiple link-local address case
*
* altifp - secondary EUI64 source
*/
void
in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
{
struct in6_ifaddr *ia;
struct in6_addr in6;
KASSERT(IFNET_LOCKED(ifp));
/* some of the interfaces are inherently not IPv6 capable */
switch (ifp->if_type) {
case IFT_BRIDGE:
case IFT_L2TP:
case IFT_IEEE8023ADLAG:
#ifdef IFT_PFLOG
case IFT_PFLOG:
#endif
#ifdef IFT_PFSYNC
case IFT_PFSYNC:
#endif
ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
return;
}
/*
* if link mtu is too small, don't try to configure IPv6.
* remember there could be some link-layer that has special
* fragmentation logic.
*/
if (ifp->if_mtu < IPV6_MMTU) {
nd6log(LOG_INFO, "%s has too small MTU, IPv6 not enabled\n",
if_name(ifp));
return;
}
/*
* quirks based on interface type
*/
switch (ifp->if_type) {
#ifdef IFT_STF
case IFT_STF:
/*
* 6to4 interface is a very special kind of beast.
* no multicast, no linklocal. RFC2529 specifies how to make
* linklocals for 6to4 interface, but there's no use and
* it is rather harmful to have one.
*/
ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
return;
#endif
case IFT_CARP:
return;
default:
break;
}
/*
* usually, we require multicast capability to the interface
*/
if ((ifp->if_flags & IFF_MULTICAST) == 0) {
nd6log(LOG_INFO,
"%s is not multicast capable, IPv6 not enabled\n",
if_name(ifp));
return;
}
/*
* assign loopback address for loopback interface.
* XXX multiple loopback interface case.
*/
if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
in6 = in6addr_loopback;
/* These are safe and atomic thanks to IFNET_LOCK */
if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
if (in6_ifattach_loopback(ifp) != 0)
return;
}
}
/*
* assign a link-local address, if there's none.
*/
if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
int bound = curlwp_bind();
struct psref psref;
ia = in6ifa_ifpforlinklocal_psref(ifp, 0, &psref);
if (ia == NULL && in6_ifattach_linklocal(ifp, altifp) != 0) {
printf("%s: cannot assign link-local address\n",
ifp->if_xname);
}
ia6_release(ia, &psref);
curlwp_bindx(bound);
}
}
/*
* NOTE: in6_ifdetach() does not support loopback if at this moment.
* We don't need this function in bsdi, because interfaces are never removed
* from the ifnet list in bsdi.
*/
void
in6_ifdetach(struct ifnet *ifp)
{
/* nuke any of IPv6 addresses we have */
if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr);
in6_purge_multi(ifp);
/* remove ip6_mrouter stuff */
ip6_mrouter_detach(ifp);
/* remove neighbor management table */
nd6_purge(ifp, NULL);
}