NetBSD/sys/netinet6/scope6.c

385 lines
9.4 KiB
C

/* $NetBSD: scope6.c,v 1.23 2020/06/16 17:12:18 maxv Exp $ */
/* $KAME$ */
/*
* Copyright (C) 2000 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: scope6.c,v 1.23 2020/06/16 17:12:18 maxv Exp $");
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet6/scope6_var.h>
#ifdef ENABLE_DEFAULT_SCOPE
int ip6_use_defzone = 1;
#else
int ip6_use_defzone = 0;
#endif
static struct scope6_id sid_default;
#define SID(ifp) \
((ifp)->if_afdata[AF_INET6] == NULL ? NULL : \
((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
void
scope6_init(void)
{
memset(&sid_default, 0, sizeof(sid_default));
}
struct scope6_id *
scope6_ifattach(struct ifnet *ifp)
{
struct scope6_id *sid;
sid = malloc(sizeof(*sid), M_IFADDR, M_WAITOK | M_ZERO);
/*
* XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
* Should we rather hardcode here?
*/
sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
#ifdef MULTI_SCOPE
/* by default, we don't care about scope boundary for these scopes. */
sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
#endif
return sid;
}
void
scope6_ifdetach(struct scope6_id *sid)
{
free(sid, M_IFADDR);
}
/*
* Get a scope of the address. Interface-local, link-local, site-local
* or global.
*/
int
in6_addrscope(const struct in6_addr *addr)
{
int scope;
if (addr->s6_addr[0] == 0xfe) {
scope = addr->s6_addr[1] & 0xc0;
switch (scope) {
case 0x80:
return IPV6_ADDR_SCOPE_LINKLOCAL;
case 0xc0:
return IPV6_ADDR_SCOPE_SITELOCAL;
default:
return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
}
}
if (addr->s6_addr[0] == 0xff) {
scope = addr->s6_addr[1] & 0x0f;
/*
* due to other scope such as reserved,
* return scope doesn't work.
*/
switch (scope) {
case IPV6_ADDR_SCOPE_INTFACELOCAL:
return IPV6_ADDR_SCOPE_INTFACELOCAL;
case IPV6_ADDR_SCOPE_LINKLOCAL:
return IPV6_ADDR_SCOPE_LINKLOCAL;
case IPV6_ADDR_SCOPE_SITELOCAL:
return IPV6_ADDR_SCOPE_SITELOCAL;
default:
return IPV6_ADDR_SCOPE_GLOBAL;
}
}
if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
if (addr->s6_addr[15] == 1) /* loopback */
return IPV6_ADDR_SCOPE_LINKLOCAL;
if (addr->s6_addr[15] == 0) {
/*
* Regard the unspecified addresses as global,
* since it has no ambiguity.
* XXX: not sure if it's correct...
*/
return IPV6_ADDR_SCOPE_GLOBAL;
}
}
return IPV6_ADDR_SCOPE_GLOBAL;
}
uint32_t
scope6_addr2default(const struct in6_addr *addr)
{
uint32_t id;
/*
* special case: The loopback address should be considered as
* link-local, but there's no ambiguity in the syntax.
*/
if (IN6_IS_ADDR_LOOPBACK(addr))
return 0;
/*
* XXX: 32-bit read is atomic on all our platforms, is it OK
* not to lock here?
*/
id = sid_default.s6id_list[in6_addrscope(addr)];
return id;
}
/*
* Validate the specified scope zone ID in the sin6_scope_id field. If the ID
* is unspecified (=0), needs to be specified, and the default zone ID can be
* used, the default value will be used.
* This routine then generates the kernel-internal form: if the address scope
* of is interface-local or link-local, embed the interface index in the
* address.
*/
int
sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
{
struct ifnet *ifp;
uint32_t zoneid;
if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
zoneid = scope6_addr2default(&sin6->sin6_addr);
if (zoneid != 0 &&
(IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
int s;
/*
* At this moment, we only check interface-local and
* link-local scope IDs, and use interface indices as the
* zone IDs assuming a one-to-one mapping between interfaces
* and links.
*/
s = pserialize_read_enter();
ifp = if_byindex(zoneid);
if (ifp == NULL) {
pserialize_read_exit(s);
return ENXIO;
}
pserialize_read_exit(s);
/* XXX assignment to 16bit from 32bit variable */
sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
sin6->sin6_scope_id = 0;
}
return 0;
}
struct sockaddr *
sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
const struct sockaddr *src)
{
struct sockaddr_in6 *sin6;
sin6 = satosin6(sockaddr_copy(dst, socklen, src));
if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
return NULL;
return dst;
}
/*
* generate standard sockaddr_in6 from embedded form.
*/
int
sa6_recoverscope(struct sockaddr_in6 *sin6)
{
uint32_t zoneid;
char ip6buf[INET6_ADDRSTRLEN];
if (sin6->sin6_scope_id != 0) {
log(LOG_NOTICE,
"%s: assumption failure (non 0 ID): %s%%%d\n", __func__,
IN6_PRINT(ip6buf, &sin6->sin6_addr), sin6->sin6_scope_id);
/* XXX: proceed anyway... */
}
if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
/*
* KAME assumption: link id == interface id
*/
zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
if (zoneid) {
int s = pserialize_read_enter();
if (!if_byindex(zoneid)) {
pserialize_read_exit(s);
return ENXIO;
}
pserialize_read_exit(s);
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = zoneid;
}
}
return 0;
}
int
in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
{
if (IN6_IS_SCOPE_EMBEDDABLE(in6))
in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
return 0;
}
/*
* Determine the appropriate scope zone ID for in6 and ifp. If ret_id is
* non NULL, it is set to the zone ID. If the zone ID needs to be embedded
* in the in6_addr structure, in6 will be modified.
*/
int
in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
{
int scope;
uint32_t zoneid = 0;
const struct scope6_id *sid = SID(ifp);
if (sid == NULL) {
log(LOG_NOTICE, "%s: no scope id for %s\n", __func__,
if_name(ifp));
return EINVAL;
}
/*
* special case: the loopback address can only belong to a loopback
* interface.
*/
if (IN6_IS_ADDR_LOOPBACK(in6)) {
if (!(ifp->if_flags & IFF_LOOPBACK)) {
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_NOTICE, "%s: can't set scope for not loopback "
"interface %s and loopback address %s\n",
__func__, if_name(ifp), IN6_PRINT(ip6buf, in6));
return EINVAL;
} else {
if (ret_id != NULL)
*ret_id = 0; /* there's no ambiguity */
return 0;
}
}
scope = in6_addrscope(in6);
switch (scope) {
case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
break;
case IPV6_ADDR_SCOPE_LINKLOCAL:
zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
break;
case IPV6_ADDR_SCOPE_SITELOCAL:
zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
break;
case IPV6_ADDR_SCOPE_ORGLOCAL:
zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
break;
default:
zoneid = 0; /* XXX: treat as global. */
break;
}
if (ret_id != NULL)
*ret_id = zoneid;
return in6_setzoneid(in6, zoneid);
}
const char *
in6_getscopename(const struct in6_addr *addr)
{
switch (in6_addrscope(addr)) {
case IPV6_ADDR_SCOPE_INTFACELOCAL:
return "interface";
#if IPV6_ADDR_SCOPE_INTFACELOCAL != IPV6_ADDR_SCOPE_NODELOCAL
case IPV6_ADDR_SCOPE_NODELOCAL:
return "node";
#endif
case IPV6_ADDR_SCOPE_LINKLOCAL:
return "link";
case IPV6_ADDR_SCOPE_SITELOCAL:
return "site";
case IPV6_ADDR_SCOPE_ORGLOCAL:
return "organization";
case IPV6_ADDR_SCOPE_GLOBAL:
return "global";
default:
return "unknown";
}
}
/*
* Just clear the embedded scope identifier. Return 0 if the original address
* is intact; return non 0 if the address is modified.
*/
int
in6_clearscope(struct in6_addr *in6)
{
int modified = 0;
if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
if (in6->s6_addr16[1] != 0)
modified = 1;
in6->s6_addr16[1] = 0;
}
return modified;
}