492 lines
15 KiB
C
492 lines
15 KiB
C
/* $OpenBSD: in6_src.c,v 1.99 2024/04/21 17:32:11 florian Exp $ */
|
|
/* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 itojun 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.
|
|
*/
|
|
|
|
/*
|
|
* 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. 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_pcb.c 8.2 (Berkeley) 1/4/94
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/errno.h>
|
|
#include <sys/time.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_var.h>
|
|
#include <net/route.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/in_pcb.h>
|
|
#include <netinet6/in6_var.h>
|
|
#include <netinet/ip6.h>
|
|
#include <netinet6/ip6_var.h>
|
|
#include <netinet6/nd6.h>
|
|
|
|
int in6_selectif(const struct in6_addr *, struct ip6_pktopts *,
|
|
struct ip6_moptions *, struct route *, struct ifnet **, u_int);
|
|
|
|
/*
|
|
* Return an IPv6 address, which is the most appropriate for a given
|
|
* destination and pcb. We need the additional opt parameter because
|
|
* the values set at pcb level can be overridden via cmsg.
|
|
*/
|
|
int
|
|
in6_pcbselsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
|
|
struct inpcb *inp, struct ip6_pktopts *opts)
|
|
{
|
|
struct ip6_moptions *mopts = inp->inp_moptions6;
|
|
struct rtentry *rt;
|
|
const struct in6_addr *laddr = &inp->inp_laddr6;
|
|
u_int rtableid = inp->inp_rtableid;
|
|
struct ifnet *ifp = NULL;
|
|
struct sockaddr *ip6_source = NULL;
|
|
struct in6_addr *dst;
|
|
struct in6_ifaddr *ia6 = NULL;
|
|
struct in6_pktinfo *pi = NULL;
|
|
int error;
|
|
|
|
dst = &dstsock->sin6_addr;
|
|
|
|
/*
|
|
* If the source address is explicitly specified by the caller,
|
|
* check if the requested source address is indeed a unicast address
|
|
* assigned to the node, and can be used as the packet's source
|
|
* address. If everything is okay, use the address as source.
|
|
*/
|
|
if (opts && (pi = opts->ip6po_pktinfo) &&
|
|
!IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
|
|
struct sockaddr_in6 sa6;
|
|
|
|
/* get the outgoing interface */
|
|
error = in6_selectif(dst, opts, mopts, &inp->inp_route, &ifp,
|
|
rtableid);
|
|
if (error)
|
|
return (error);
|
|
|
|
bzero(&sa6, sizeof(sa6));
|
|
sa6.sin6_family = AF_INET6;
|
|
sa6.sin6_len = sizeof(sa6);
|
|
sa6.sin6_addr = pi->ipi6_addr;
|
|
|
|
if (ifp && IN6_IS_SCOPE_EMBED(&sa6.sin6_addr))
|
|
sa6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
|
|
if_put(ifp); /* put reference from in6_selectif */
|
|
|
|
ia6 = ifatoia6(ifa_ifwithaddr(sin6tosa(&sa6), rtableid));
|
|
if (ia6 == NULL || (ia6->ia6_flags &
|
|
(IN6_IFF_ANYCAST|IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED)))
|
|
return (EADDRNOTAVAIL);
|
|
|
|
pi->ipi6_addr = sa6.sin6_addr; /* XXX: this overrides pi */
|
|
|
|
*in6src = &pi->ipi6_addr;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If the source address is not specified but the socket(if any)
|
|
* is already bound, use the bound address.
|
|
*/
|
|
if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) {
|
|
*in6src = laddr;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If the caller doesn't specify the source address but
|
|
* the outgoing interface, use an address associated with
|
|
* the interface.
|
|
*/
|
|
if (pi && pi->ipi6_ifindex) {
|
|
ifp = if_get(pi->ipi6_ifindex);
|
|
if (ifp == NULL)
|
|
return (ENXIO); /* XXX: better error? */
|
|
|
|
ia6 = in6_ifawithscope(ifp, dst, rtableid, NULL);
|
|
if_put(ifp);
|
|
|
|
if (ia6 == NULL)
|
|
return (EADDRNOTAVAIL);
|
|
|
|
*in6src = &ia6->ia_addr.sin6_addr;
|
|
return (0);
|
|
}
|
|
|
|
error = in6_selectsrc(in6src, dstsock, mopts, rtableid);
|
|
if (error != EADDRNOTAVAIL)
|
|
return (error);
|
|
|
|
/*
|
|
* If route is known or can be allocated now,
|
|
* our src addr is taken from the i/f, else punt.
|
|
*/
|
|
rt = route6_mpath(&inp->inp_route, dst, NULL, rtableid);
|
|
|
|
/*
|
|
* in_pcbconnect() checks out IFF_LOOPBACK to skip using
|
|
* the address. But we don't know why it does so.
|
|
* It is necessary to ensure the scope even for lo0
|
|
* so doesn't check out IFF_LOOPBACK.
|
|
*/
|
|
|
|
if (rt != NULL) {
|
|
ifp = if_get(rt->rt_ifidx);
|
|
if (ifp != NULL) {
|
|
ia6 = in6_ifawithscope(ifp, dst, rtableid, rt);
|
|
if_put(ifp);
|
|
}
|
|
if (ia6 == NULL) /* xxx scope error ?*/
|
|
ia6 = ifatoia6(rt->rt_ifa);
|
|
}
|
|
|
|
/*
|
|
* Use preferred source address if :
|
|
* - destination is not onlink
|
|
* - preferred source address is set
|
|
* - output interface is UP
|
|
*/
|
|
if (rt != NULL && !(rt->rt_flags & RTF_LLINFO) &&
|
|
!(rt->rt_flags & RTF_HOST)) {
|
|
ip6_source = rtable_getsource(rtableid, AF_INET6);
|
|
if (ip6_source != NULL) {
|
|
struct ifaddr *ifa;
|
|
if ((ifa = ifa_ifwithaddr(ip6_source, rtableid)) !=
|
|
NULL && ISSET(ifa->ifa_ifp->if_flags, IFF_UP)) {
|
|
*in6src = &satosin6(ip6_source)->sin6_addr;
|
|
return (0);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ia6 == NULL)
|
|
return (EHOSTUNREACH); /* no route */
|
|
|
|
*in6src = &ia6->ia_addr.sin6_addr;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Return an IPv6 address, which is the most appropriate for a given
|
|
* destination and multicast options.
|
|
* If necessary, this function lookups the routing table and returns
|
|
* an entry to the caller for later use.
|
|
*/
|
|
int
|
|
in6_selectsrc(const struct in6_addr **in6src, struct sockaddr_in6 *dstsock,
|
|
struct ip6_moptions *mopts, unsigned int rtableid)
|
|
{
|
|
struct ifnet *ifp = NULL;
|
|
struct in6_addr *dst;
|
|
struct in6_ifaddr *ia6 = NULL;
|
|
|
|
dst = &dstsock->sin6_addr;
|
|
|
|
/*
|
|
* If the destination address is a link-local unicast address or
|
|
* a link/interface-local multicast address, and if the outgoing
|
|
* interface is specified by the sin6_scope_id filed, use an address
|
|
* associated with the interface.
|
|
* XXX: We're now trying to define more specific semantics of
|
|
* sin6_scope_id field, so this part will be rewritten in
|
|
* the near future.
|
|
*/
|
|
if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
|
|
IN6_IS_ADDR_MC_INTFACELOCAL(dst)) && dstsock->sin6_scope_id) {
|
|
ifp = if_get(dstsock->sin6_scope_id);
|
|
if (ifp == NULL)
|
|
return (ENXIO); /* XXX: better error? */
|
|
|
|
ia6 = in6_ifawithscope(ifp, dst, rtableid, NULL);
|
|
if_put(ifp);
|
|
|
|
if (ia6 == NULL)
|
|
return (EADDRNOTAVAIL);
|
|
|
|
*in6src = &ia6->ia_addr.sin6_addr;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If the destination address is a multicast address and
|
|
* the outgoing interface for the address is specified
|
|
* by the caller, use an address associated with the interface.
|
|
* Even if the outgoing interface is not specified, we also
|
|
* choose a loopback interface as the outgoing interface.
|
|
*/
|
|
if (IN6_IS_ADDR_MULTICAST(dst)) {
|
|
ifp = mopts ? if_get(mopts->im6o_ifidx) : NULL;
|
|
|
|
if (!ifp && dstsock->sin6_scope_id)
|
|
ifp = if_get(htons(dstsock->sin6_scope_id));
|
|
|
|
if (ifp) {
|
|
ia6 = in6_ifawithscope(ifp, dst, rtableid, NULL);
|
|
if_put(ifp);
|
|
|
|
if (ia6 == NULL)
|
|
return (EADDRNOTAVAIL);
|
|
|
|
*in6src = &ia6->ia_addr.sin6_addr;
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
return (EADDRNOTAVAIL);
|
|
}
|
|
|
|
struct rtentry *
|
|
in6_selectroute(const struct in6_addr *dst, struct ip6_pktopts *opts,
|
|
struct route *ro, unsigned int rtableid)
|
|
{
|
|
/*
|
|
* Use a cached route if it exists and is valid, else try to allocate
|
|
* a new one.
|
|
*/
|
|
if (ro) {
|
|
struct rtentry *rt;
|
|
|
|
rt = route6_mpath(ro, dst, NULL, rtableid);
|
|
|
|
/*
|
|
* Check if the outgoing interface conflicts with
|
|
* the interface specified by ipi6_ifindex (if specified).
|
|
* Note that loopback interface is always okay.
|
|
* (this may happen when we are sending a packet to one of
|
|
* our own addresses.)
|
|
*/
|
|
if (opts && opts->ip6po_pktinfo &&
|
|
opts->ip6po_pktinfo->ipi6_ifindex) {
|
|
if (rt != NULL && !ISSET(rt->rt_flags, RTF_LOCAL) &&
|
|
rt->rt_ifidx != opts->ip6po_pktinfo->ipi6_ifindex) {
|
|
return (NULL);
|
|
}
|
|
}
|
|
|
|
return (rt);
|
|
}
|
|
|
|
return (NULL);
|
|
}
|
|
|
|
int
|
|
in6_selectif(const struct in6_addr *dst, struct ip6_pktopts *opts,
|
|
struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
|
|
u_int rtableid)
|
|
{
|
|
struct rtentry *rt;
|
|
struct in6_pktinfo *pi = NULL;
|
|
|
|
/* If the caller specify the outgoing interface explicitly, use it. */
|
|
if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
|
|
*retifp = if_get(pi->ipi6_ifindex);
|
|
if (*retifp != NULL)
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If the destination address is a multicast address and the outgoing
|
|
* interface for the address is specified by the caller, use it.
|
|
*/
|
|
if (IN6_IS_ADDR_MULTICAST(dst) &&
|
|
mopts != NULL && (*retifp = if_get(mopts->im6o_ifidx)) != NULL)
|
|
return (0);
|
|
|
|
rt = in6_selectroute(dst, opts, ro, rtableid);
|
|
if (rt == NULL)
|
|
return (EHOSTUNREACH);
|
|
|
|
/*
|
|
* do not use a rejected or black hole route.
|
|
* XXX: this check should be done in the L2 output routine.
|
|
* However, if we skipped this check here, we'd see the following
|
|
* scenario:
|
|
* - install a rejected route for a scoped address prefix
|
|
* (like fe80::/10)
|
|
* - send a packet to a destination that matches the scoped prefix,
|
|
* with ambiguity about the scope zone.
|
|
* - pick the outgoing interface from the route, and disambiguate the
|
|
* scope zone with the interface.
|
|
* - ip6_output() would try to get another route with the "new"
|
|
* destination, which may be valid.
|
|
* - we'd see no error on output.
|
|
* Although this may not be very harmful, it should still be confusing.
|
|
* We thus reject the case here.
|
|
*/
|
|
if (ISSET(rt->rt_flags, RTF_REJECT | RTF_BLACKHOLE))
|
|
return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
|
|
|
|
*retifp = if_get(rt->rt_ifidx);
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
in6_selecthlim(const struct inpcb *inp)
|
|
{
|
|
if (inp && inp->inp_hops >= 0)
|
|
return (inp->inp_hops);
|
|
|
|
return (ip6_defhlim);
|
|
}
|
|
|
|
/*
|
|
* generate kernel-internal form (scopeid embedded into s6_addr16[1]).
|
|
* If the address scope of is link-local, embed the interface index in the
|
|
* address. The routine determines our precedence
|
|
* between advanced API scope/interface specification and basic API
|
|
* specification.
|
|
*
|
|
* this function should be nuked in the future, when we get rid of
|
|
* embedded scopeid thing.
|
|
*
|
|
* XXX actually, it is over-specification to return ifp against sin6_scope_id.
|
|
* there can be multiple interfaces that belong to a particular scope zone
|
|
* (in specification, we have 1:N mapping between a scope zone and interfaces).
|
|
* we may want to change the function to return something other than ifp.
|
|
*/
|
|
int
|
|
in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6,
|
|
const struct ip6_pktopts *outputopts6, const struct ip6_moptions *moptions6)
|
|
{
|
|
u_int32_t scopeid;
|
|
|
|
*in6 = sin6->sin6_addr;
|
|
|
|
/*
|
|
* don't try to read sin6->sin6_addr beyond here, since the caller may
|
|
* ask us to overwrite existing sockaddr_in6
|
|
*/
|
|
|
|
if (IN6_IS_SCOPE_EMBED(in6)) {
|
|
struct in6_pktinfo *pi;
|
|
|
|
/*
|
|
* KAME assumption: link id == interface id
|
|
*/
|
|
|
|
if (outputopts6 && (pi = outputopts6->ip6po_pktinfo) &&
|
|
pi->ipi6_ifindex)
|
|
scopeid = pi->ipi6_ifindex;
|
|
else if (moptions6 && IN6_IS_ADDR_MULTICAST(in6) &&
|
|
moptions6->im6o_ifidx)
|
|
scopeid = moptions6->im6o_ifidx;
|
|
else
|
|
scopeid = sin6->sin6_scope_id;
|
|
|
|
if (scopeid) {
|
|
struct ifnet *ifp;
|
|
|
|
ifp = if_get(scopeid);
|
|
if (ifp == NULL)
|
|
return ENXIO; /* XXX EINVAL? */
|
|
/*XXX assignment to 16bit from 32bit variable */
|
|
in6->s6_addr16[1] = htons(scopeid & 0xffff);
|
|
if_put(ifp);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* generate standard sockaddr_in6 from embedded form.
|
|
* touches sin6_addr and sin6_scope_id only.
|
|
*
|
|
* this function should be nuked in the future, when we get rid of
|
|
* embedded scopeid thing.
|
|
*/
|
|
void
|
|
in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6)
|
|
{
|
|
u_int32_t scopeid;
|
|
|
|
sin6->sin6_addr = *in6;
|
|
|
|
/*
|
|
* don't try to read *in6 beyond here, since the caller may
|
|
* ask us to overwrite existing sockaddr_in6
|
|
*/
|
|
|
|
sin6->sin6_scope_id = 0;
|
|
if (IN6_IS_SCOPE_EMBED(in6)) {
|
|
/*
|
|
* KAME assumption: link id == interface id
|
|
*/
|
|
scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
|
|
if (scopeid) {
|
|
sin6->sin6_addr.s6_addr16[1] = 0;
|
|
sin6->sin6_scope_id = scopeid;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* just clear the embedded scope identifier.
|
|
*/
|
|
void
|
|
in6_clearscope(struct in6_addr *addr)
|
|
{
|
|
if (IN6_IS_SCOPE_EMBED(addr))
|
|
addr->s6_addr16[1] = 0;
|
|
}
|