Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
6e1af6b1d7
NetBSD/sys/netinet6/in6_src.c
ozaki-r 4c25fb2f83 Add rtcache_unref to release points of rtentry stemming from rtcache 
In the MP-safe world, a rtentry stemming from a rtcache can be freed at any
points. So we need to protect rtentries somehow say by reference couting or
passive references. Regardless of the method, we need to call some release
function of a rtentry after using it.

The change adds a new function rtcache_unref to release a rtentry. At this
point, this function does nothing because for now we don't add a reference
to a rtentry when we get one from a rtcache. We will add something useful
in a further commit.

This change is a part of changes for MP-safe routing table. It is separated
to avoid one big change that makes difficult to debug by bisecting.
2016-12-08 05:16:33 +00:00

1108 lines
30 KiB
C
Raw Blame History

/* $NetBSD: in6_src.c,v 1.76 2016/12/08 05:16:34 ozaki-r Exp $ */
/* $KAME: in6_src.c,v 1.159 2005/10/19 01:40:32 t-momose 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. 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_pcb.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.76 2016/12/08 05:16:34 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/portalgo.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/ip6_private.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>
#include <net/net_osdep.h>
#ifdef MIP6
#include <netinet6/mip6.h>
#include <netinet6/mip6_var.h>
#include "mip.h"
#if NMIP > 0
#include <net/if_mip.h>
#endif /* NMIP > 0 */
#endif /* MIP6 */
#include <netinet/tcp_vtw.h>
#define ADDR_LABEL_NOTAPP (-1)
struct in6_addrpolicy defaultaddrpolicy;
int ip6_prefer_tempaddr = 0;
static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route *, struct ifnet **, struct psref *);
static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *);
static void init_policy_queue(void);
static int add_addrsel_policyent(struct in6_addrpolicy *);
static int delete_addrsel_policyent(struct in6_addrpolicy *);
static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *),
void *);
static int dump_addrsel_policyent(struct in6_addrpolicy *, void *);
static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
/*
* Return an IPv6 address, which is the most appropriate for a given
* destination and user specified options.
* If necessary, this function lookups the routing table and returns
* an entry to the caller for later use.
*/
#if 0 /* diabled ad-hoc */
#define REPLACE(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto replace; \
} while(0)
#define NEXT(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto next; /* XXX: we can't use 'continue' here */ \
} while(0)
#define BREAK(r) do { \
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
#else
#define REPLACE(r) goto replace
#define NEXT(r) goto next
#define BREAK(r) goto out
#endif
/*
* Called inside pserialize critical section. Don't sleep/block.
*/
static struct in6_ifaddr *
in6_select_best_ia(struct sockaddr_in6 *dstsock, struct in6_addr *dst,
const struct ifnet *ifp, const struct ip6_pktopts *opts,
const u_int32_t odstzone)
{
struct in6_ifaddr *ia, *ia_best = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
IN6_ADDRLIST_READER_FOREACH(ia) {
int new_scope = -1, new_matchlen = -1;
struct in6_addrpolicy *new_policy = NULL;
u_int32_t srczone, osrczone, dstzone;
struct in6_addr src;
struct ifnet *ifp1 = ia->ia_ifp;
int prefer_tempaddr;
/*
* We'll never take an address that breaks the scope zone
* of the destination. We also skip an address if its zone
* does not contain the outgoing interface.
* XXX: we should probably use sin6_scope_id here.
*/
if (in6_setscope(dst, ifp1, &dstzone) ||
odstzone != dstzone) {
continue;
}
src = ia->ia_addr.sin6_addr;
if (in6_setscope(&src, ifp, &osrczone) ||
in6_setscope(&src, ifp1, &srczone) ||
osrczone != srczone) {
continue;
}
/* avoid unusable addresses */
if ((ia->ia6_flags &
(IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
continue;
}
if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
continue;
#if defined(MIP6) && NMIP > 0
/* avoid unusable home addresses. */
if ((ia->ia6_flags & IN6_IFF_HOME) &&
!mip6_ifa6_is_addr_valid_hoa(ia))
continue;
#endif /* MIP6 && NMIP > 0 */
/* Rule 1: Prefer same address */
if (IN6_ARE_ADDR_EQUAL(dst, &ia->ia_addr.sin6_addr)) {
ia_best = ia;
BREAK(1); /* there should be no better candidate */
}
if (ia_best == NULL)
REPLACE(0);
/* Rule 2: Prefer appropriate scope */
if (dst_scope < 0)
dst_scope = in6_addrscope(dst);
new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
REPLACE(2);
NEXT(2);
} else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
NEXT(2);
REPLACE(2);
}
/*
* Rule 3: Avoid deprecated addresses. Note that the case of
* !ip6_use_deprecated is already rejected above.
*/
if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
NEXT(3);
if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
REPLACE(3);
/* Rule 4: Prefer home addresses */
#if defined(MIP6) && NMIP > 0
if (!MIP6_IS_MN)
goto skip_rule4;
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
/* both address are not home addresses. */
goto skip_rule4;
}
/*
* If SA is simultaneously a home address and care-of
* address and SB is not, then prefer SA. Similarly,
* if SB is simultaneously a home address and care-of
* address and SA is not, then prefer SB.
*/
if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
ia_best->ia_ifp->if_type != IFT_MIP)
&&
((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
ia->ia_ifp->if_type == IFT_MIP))
NEXT(4);
if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
ia_best->ia_ifp->if_type == IFT_MIP)
&&
((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
ia->ia_ifp->if_type != IFT_MIP))
REPLACE(4);
if (ip6po_usecoa == 0) {
/*
* If SA is just a home address and SB is just
* a care-of address, then prefer
* SA. Similarly, if SB is just a home address
* and SA is just a care-of address, then
* prefer SB.
*/
if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
NEXT(4);
}
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) != 0) {
REPLACE(4);
}
} else {
/*
* a sender don't want to use a home address
* because:
*
* 1) we cannot use. (ex. NS or NA to global
* addresses.)
*
* 2) a user specified not to use.
* (ex. mip6control -u)
*/
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) != 0) {
/* XXX breaks stat */
NEXT(0);
}
if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
/* XXX breaks stat */
REPLACE(0);
}
}
skip_rule4:
#endif /* MIP6 && NMIP > 0 */
/* Rule 5: Prefer outgoing interface */
if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
NEXT(5);
if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
REPLACE(5);
/*
* Rule 6: Prefer matching label
* Note that best_policy should be non-NULL here.
*/
if (dst_policy == NULL)
dst_policy = lookup_addrsel_policy(dstsock);
if (dst_policy->label != ADDR_LABEL_NOTAPP) {
new_policy = lookup_addrsel_policy(&ia->ia_addr);
if (dst_policy->label == best_policy->label &&
dst_policy->label != new_policy->label)
NEXT(6);
if (dst_policy->label != best_policy->label &&
dst_policy->label == new_policy->label)
REPLACE(6);
}
/*
* Rule 7: Prefer public addresses.
* We allow users to reverse the logic by configuring
* a sysctl variable, so that privacy conscious users can
* always prefer temporary addresses.
*/
if (opts == NULL ||
opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
prefer_tempaddr = ip6_prefer_tempaddr;
} else if (opts->ip6po_prefer_tempaddr ==
IP6PO_TEMPADDR_NOTPREFER) {
prefer_tempaddr = 0;
} else
prefer_tempaddr = 1;
if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
REPLACE(7);
else
NEXT(7);
}
if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
!(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
NEXT(7);
else
REPLACE(7);
}
/*
* Rule 8: prefer addresses on alive interfaces.
* This is a KAME specific rule.
*/
if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
!(ia->ia_ifp->if_flags & IFF_UP))
NEXT(8);
if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
(ia->ia_ifp->if_flags & IFF_UP))
REPLACE(8);
/*
* Rule 9: prefer addresses on "preferred" interfaces.
* This is a KAME specific rule.
*/
#ifdef notyet /* until introducing address selection */
#define NDI_BEST ND_IFINFO(ia_best->ia_ifp)
#define NDI_NEW ND_IFINFO(ia->ia_ifp)
if ((NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
!(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
NEXT(9);
if (!(NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
REPLACE(9);
#undef NDI_BEST
#undef NDI_NEW
#endif
/*
* Rule 14: Use longest matching prefix.
* Note: in the address selection draft, this rule is
* documented as "Rule 8". However, since it is also
* documented that this rule can be overridden, we assign
* a large number so that it is easy to assign smaller numbers
* to more preferred rules.
*/
new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, dst);
if (best_matchlen < new_matchlen)
REPLACE(14);
if (new_matchlen < best_matchlen)
NEXT(14);
/* Rule 15 is reserved. */
/*
* Last resort: just keep the current candidate.
* Or, do we need more rules?
*/
continue;
replace:
ia_best = ia;
best_scope = (new_scope >= 0 ? new_scope :
in6_addrscope(&ia_best->ia_addr.sin6_addr));
best_policy = (new_policy ? new_policy :
lookup_addrsel_policy(&ia_best->ia_addr));
best_matchlen = (new_matchlen >= 0 ? new_matchlen :
in6_matchlen(&ia_best->ia_addr.sin6_addr,
dst));
next:
continue;
out:
break;
}
return ia_best;
}
#undef REPLACE
#undef BREAK
#undef NEXT
int
in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route *ro, struct in6_addr *laddr,
struct ifnet **ifpp, struct psref *psref, struct in6_addr *ret_ia6)
{
struct in6_addr dst;
struct ifnet *ifp = NULL;
struct in6_ifaddr *ia = NULL;
struct in6_pktinfo *pi = NULL;
u_int32_t odstzone;
int error;
#if defined(MIP6) && NMIP > 0
u_int8_t ip6po_usecoa = 0;
#endif /* MIP6 && NMIP > 0 */
struct psref local_psref;
int bound = curlwp_bind();
#define PSREF (psref == NULL) ? &local_psref : psref
int s;
KASSERT((ifpp != NULL && psref != NULL) ||
(ifpp == NULL && psref == NULL));
dst = dstsock->sin6_addr; /* make a copy for local operation */
if (ifpp)
*ifpp = NULL;
/*
* Try to determine the outgoing interface for the given destination.
* We do this regardless of whether the socket is bound, since the
* caller may need this information as a side effect of the call
* to this function (e.g., for identifying the appropriate scope zone
* ID).
*/
error = in6_selectif(dstsock, opts, mopts, ro, &ifp, PSREF);
if (ifpp != NULL)
*ifpp = ifp;
/*
* 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 srcsock;
struct in6_ifaddr *ia6;
int _s;
struct ifaddr *ifa;
/*
* Determine the appropriate zone id of the source based on
* the zone of the destination and the outgoing interface.
* If the specified address is ambiguous wrt the scope zone,
* the interface must be specified; otherwise, ifa_ifwithaddr()
* will fail matching the address.
*/
memset(&srcsock, 0, sizeof(srcsock));
srcsock.sin6_family = AF_INET6;
srcsock.sin6_len = sizeof(srcsock);
srcsock.sin6_addr = pi->ipi6_addr;
if (ifp) {
error = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
if (error != 0)
goto exit;
}
_s = pserialize_read_enter();
ifa = ifa_ifwithaddr(sin6tosa(&srcsock));
if ((ia6 = ifatoia6(ifa)) == NULL ||
ia6->ia6_flags &
(IN6_IFF_ANYCAST | IN6_IFF_NOTREADY)) {
pserialize_read_exit(_s);
error = EADDRNOTAVAIL;
goto exit;
}
pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
*ret_ia6 = ia6->ia_addr.sin6_addr;
pserialize_read_exit(_s);
goto exit;
}
/*
* If the socket has already bound the source, just use it. We don't
* care at the moment whether in6_selectif() succeeded above, even
* though it would eventually cause an error.
*/
if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) {
*ret_ia6 = *laddr;
goto exit;
}
/*
* The outgoing interface is crucial in the general selection procedure
* below. If it is not known at this point, we fail.
*/
if (ifp == NULL)
goto exit;
/*
* If the address is not yet determined, choose the best one based on
* the outgoing interface and the destination address.
*/
#if defined(MIP6) && NMIP > 0
/*
* a caller can specify IP6PO_USECOA to not to use a home
* address. for example, the case that the neighbour
* unreachability detection to the global address.
*/
if (opts != NULL &&
(opts->ip6po_flags & IP6PO_USECOA) != 0) {
ip6po_usecoa = 1;
}
#endif /* MIP6 && NMIP > 0 */
error = in6_setscope(&dst, ifp, &odstzone);
if (error != 0)
goto exit;
s = pserialize_read_enter();
ia = in6_select_best_ia(dstsock, &dst, ifp, opts, odstzone);
if (ia == NULL) {
pserialize_read_exit(s);
error = EADDRNOTAVAIL;
goto exit;
}
*ret_ia6 = ia->ia_addr.sin6_addr;
pserialize_read_exit(s);
exit:
if (ifpp == NULL)
if_put(ifp, PSREF);
curlwp_bindx(bound);
return error;
#undef PSREF
}
int
in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct route **ro, struct rtentry **retrt, bool count_discard)
{
int error = 0;
struct rtentry *rt = NULL;
union {
struct sockaddr dst;
struct sockaddr_in6 dst6;
} u;
KASSERT(ro != NULL);
KASSERT(*ro != NULL);
KASSERT(retrt != NULL);
#if 0
if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
dstsock->sin6_addr.s6_addr32[1] == 0 &&
!IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
printf("in6_selectroute: strange destination %s\n",
ip6_sprintf(&dstsock->sin6_addr));
} else {
printf("in6_selectroute: destination = %s%%%d\n",
ip6_sprintf(&dstsock->sin6_addr),
dstsock->sin6_scope_id); /* for debug */
}
#endif
/*
* If the next hop address for the packet is specified by the caller,
* use it as the gateway.
*/
if (opts && opts->ip6po_nexthop) {
struct route *ron;
struct sockaddr_in6 *sin6_next;
sin6_next = satosin6(opts->ip6po_nexthop);
/* at this moment, we only support AF_INET6 next hops */
if (sin6_next->sin6_family != AF_INET6) {
error = EAFNOSUPPORT; /* or should we proceed? */
goto done;
}
/*
* If the next hop is an IPv6 address, then the node identified
* by that address must be a neighbor of the sending host.
*/
ron = &opts->ip6po_nextroute;
rt = rtcache_lookup(ron, sin6tosa(sin6_next));
if (rt == NULL || (rt->rt_flags & RTF_GATEWAY) != 0 ||
!nd6_is_addr_neighbor(sin6_next, rt->rt_ifp)) {
if (rt != NULL) {
if (count_discard)
in6_ifstat_inc(rt->rt_ifp,
ifs6_out_discard);
rtcache_unref(rt, ron);
rt = NULL;
}
rtcache_free(ron);
error = EHOSTUNREACH;
goto done;
}
*ro = ron;
goto done;
}
/*
* Use a cached route if it exists and is valid, else try to allocate
* a new one. Note that we should check the address family of the
* cached destination, in case of sharing the cache with IPv4.
*/
u.dst6 = *dstsock;
u.dst6.sin6_scope_id = 0;
rt = rtcache_lookup1(*ro, &u.dst, 1);
if (rt == NULL)
error = EHOSTUNREACH;
/*
* 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 && !(rt->rt_ifp->if_flags & IFF_LOOPBACK) &&
rt->rt_ifp->if_index != opts->ip6po_pktinfo->ipi6_ifindex) {
if (count_discard)
in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
error = EHOSTUNREACH;
rt = NULL;
}
}
done:
if (error == EHOSTUNREACH)
IP6_STATINC(IP6_STAT_NOROUTE);
*retrt = rt;
return error;
}
static int
in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
struct psref *psref)
{
int error = 0;
struct rtentry *rt = NULL;
struct in6_addr *dst;
struct in6_pktinfo *pi = NULL;
KASSERT(retifp != NULL);
*retifp = NULL;
dst = &dstsock->sin6_addr;
/* If the caller specify the outgoing interface explicitly, use it. */
if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
/* XXX boundary check is assumed to be already done. */
*retifp = if_get_byindex(pi->ipi6_ifindex, psref);
if (*retifp != NULL)
return 0;
goto getroute;
}
/*
* 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_byindex(mopts->im6o_multicast_if_index, psref);
if (*retifp != NULL)
return 0; /* we do not need a route for multicast. */
}
getroute:
error = in6_selectroute(dstsock, opts, &ro, &rt, false);
if (error != 0)
return error;
*retifp = if_get_byindex(rt->rt_ifp->if_index, psref);
/*
* 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 ((rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
error = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
/* XXX: ifp can be returned with psref even if error */
goto out;
}
/*
* Adjust the "outgoing" interface. If we're going to loop the packet
* back to ourselves, the ifp would be the loopback interface.
* However, we'd rather know the interface associated to the
* destination address (which should probably be one of our own
* addresses.)
*/
if (rt->rt_ifa && rt->rt_ifa->ifa_ifp &&
rt->rt_ifa->ifa_ifp != *retifp &&
!if_is_deactivated(rt->rt_ifa->ifa_ifp)) {
if_put(*retifp, psref);
*retifp = rt->rt_ifa->ifa_ifp;
if_acquire_NOMPSAFE(*retifp, psref);
}
out:
rtcache_unref(rt, ro);
return error;
}
/*
* Default hop limit selection. The precedence is as follows:
* 1. Hoplimit value specified via ioctl.
* 2. (If the outgoing interface is detected) the current
* hop limit of the interface specified by router advertisement.
* 3. The system default hoplimit.
*/
int
in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
{
if (in6p && in6p->in6p_hops >= 0)
return (in6p->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else
return (ip6_defhlim);
}
int
in6_selecthlim_rt(struct in6pcb *in6p)
{
struct rtentry *rt;
if (in6p == NULL)
return in6_selecthlim(in6p, NULL);
rt = rtcache_validate(&in6p->in6p_route);
if (rt != NULL) {
int ret = in6_selecthlim(in6p, rt->rt_ifp);
rtcache_unref(rt, &in6p->in6p_route);
return ret;
} else
return in6_selecthlim(in6p, NULL);
}
/*
* Find an empty port and set it to the specified PCB.
*/
int
in6_pcbsetport(struct sockaddr_in6 *sin6, struct in6pcb *in6p, struct lwp *l)
{
struct socket *so = in6p->in6p_socket;
struct inpcbtable *table = in6p->in6p_table;
u_int16_t lport, *lastport;
enum kauth_network_req req;
int error = 0;
if (in6p->in6p_flags & IN6P_LOWPORT) {
#ifndef IPNOPRIVPORTS
req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
#else
req = KAUTH_REQ_NETWORK_BIND_PORT;
#endif
lastport = &table->inpt_lastlow;
} else {
req = KAUTH_REQ_NETWORK_BIND_PORT;
lastport = &table->inpt_lastport;
}
/* XXX-kauth: KAUTH_REQ_NETWORK_BIND_AUTOASSIGN_{,PRIV}PORT */
error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND, req, so,
sin6, NULL);
if (error)
return (EACCES);
/*
* Use RFC6056 randomized port selection
*/
error = portalgo_randport(&lport, &in6p->in6p_head, l->l_cred);
if (error)
return error;
in6p->in6p_flags |= IN6P_ANONPORT;
*lastport = lport;
in6p->in6p_lport = htons(lport);
in6_pcbstate(in6p, IN6P_BOUND);
return (0); /* success */
}
void
addrsel_policy_init(void)
{
init_policy_queue();
/* initialize the "last resort" policy */
memset(&defaultaddrpolicy, 0, sizeof(defaultaddrpolicy));
defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
}
static struct in6_addrpolicy *
lookup_addrsel_policy(struct sockaddr_in6 *key)
{
struct in6_addrpolicy *match = NULL;
match = match_addrsel_policy(key);
if (match == NULL)
match = &defaultaddrpolicy;
else
match->use++;
return (match);
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct sel_walkarg {
size_t w_total;
size_t w_given;
void * w_where;
void *w_limit;
};
int sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS);
int
sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS)
{
int error = 0;
int s;
s = splsoftnet();
if (newp) {
error = EPERM;
goto end;
}
if (oldp && oldlenp == NULL) {
error = EINVAL;
goto end;
}
if (oldp || oldlenp) {
struct sel_walkarg w;
size_t oldlen = *oldlenp;
memset(&w, 0, sizeof(w));
w.w_given = oldlen;
w.w_where = oldp;
if (oldp)
w.w_limit = (char *)oldp + oldlen;
error = walk_addrsel_policy(dump_addrsel_policyent, &w);
*oldlenp = w.w_total;
if (oldp && w.w_total > oldlen && error == 0)
error = ENOMEM;
}
end:
splx(s);
return (error);
}
int
in6_src_ioctl(u_long cmd, void *data)
{
int i;
struct in6_addrpolicy ent0;
if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
return (EOPNOTSUPP); /* check for safety */
ent0 = *(struct in6_addrpolicy *)data;
if (ent0.label == ADDR_LABEL_NOTAPP)
return (EINVAL);
/* check if the prefix mask is consecutive. */
if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
return (EINVAL);
/* clear trailing garbages (if any) of the prefix address. */
for (i = 0; i < 4; i++) {
ent0.addr.sin6_addr.s6_addr32[i] &=
ent0.addrmask.sin6_addr.s6_addr32[i];
}
ent0.use = 0;
switch (cmd) {
case SIOCAADDRCTL_POLICY:
return (add_addrsel_policyent(&ent0));
case SIOCDADDRCTL_POLICY:
return (delete_addrsel_policyent(&ent0));
}
return (0); /* XXX: compromise compilers */
}
/*
* The followings are implementation of the policy table using a
* simple tail queue.
* XXX such details should be hidden.
* XXX implementation using binary tree should be more efficient.
*/
struct addrsel_policyent {
TAILQ_ENTRY(addrsel_policyent) ape_entry;
struct in6_addrpolicy ape_policy;
};
TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
struct addrsel_policyhead addrsel_policytab;
static void
init_policy_queue(void)
{
TAILQ_INIT(&addrsel_policytab);
}
static int
add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
{
struct addrsel_policyent *newpol, *pol;
/* duplication check */
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
&pol->ape_policy.addr.sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
&pol->ape_policy.addrmask.sin6_addr)) {
return (EEXIST); /* or override it? */
}
}
newpol = malloc(sizeof(*newpol), M_IFADDR, M_WAITOK|M_ZERO);
/* XXX: should validate entry */
newpol->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&addrsel_policytab, newpol, ape_entry);
return (0);
}
static int
delete_addrsel_policyent(struct in6_addrpolicy *key)
{
struct addrsel_policyent *pol;
/* search for the entry in the table */
for (pol = TAILQ_FIRST(&addrsel_policytab); pol;
pol = TAILQ_NEXT(pol, ape_entry)) {
if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
&pol->ape_policy.addr.sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
&pol->ape_policy.addrmask.sin6_addr)) {
break;
}
}
if (pol == NULL) {
return (ESRCH);
}
TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
return (0);
}
static int
walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
{
struct addrsel_policyent *pol;
int error = 0;
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0)
return error;
}
return error;
}
static int
dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
{
int error = 0;
struct sel_walkarg *w = arg;
if (w->w_where && (char *)w->w_where + sizeof(*pol) <= (char *)w->w_limit) {
if ((error = copyout(pol, w->w_where, sizeof(*pol))) != 0)
return error;
w->w_where = (char *)w->w_where + sizeof(*pol);
}
w->w_total += sizeof(*pol);
return error;
}
static struct in6_addrpolicy *
match_addrsel_policy(struct sockaddr_in6 *key)
{
struct addrsel_policyent *pent;
struct in6_addrpolicy *bestpol = NULL, *pol;
int matchlen, bestmatchlen = -1;
u_char *mp, *ep, *k, *p, m;
for (pent = TAILQ_FIRST(&addrsel_policytab); pent;
pent = TAILQ_NEXT(pent, ape_entry)) {
matchlen = 0;
pol = &pent->ape_policy;
mp = (u_char *)&pol->addrmask.sin6_addr;
ep = mp + 16; /* XXX: scope field? */
k = (u_char *)&key->sin6_addr;
p = (u_char *)&pol->addr.sin6_addr;
for (; mp < ep && *mp; mp++, k++, p++) {
m = *mp;
if ((*k & m) != *p)
goto next; /* not match */
if (m == 0xff) /* short cut for a typical case */
matchlen += 8;
else {
while (m >= 0x80) {
matchlen++;
m <<= 1;
}
}
}
/* matched. check if this is better than the current best. */
if (bestpol == NULL ||
matchlen > bestmatchlen) {
bestpol = pol;
bestmatchlen = matchlen;
}
next:
continue;
}
return (bestpol);
}
Reference in New Issue View Git Blame Copy Permalink