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freebsd-dev/sys/netinet6/in6_src.c
Qing Li 9452b0d2de This patch fixes the following issues: 
- Interface link-local address is not reachable within the
  node that owns the interface, this is due to the mismatch
  in address scope as the result of the installed interface
  address loopback route. Therefore for each interface
  address loopback route, the rt_gateway field (of AF_LINK
  type) will be used to track which interface a given
  address belongs to. This will aid the address source to
  use the proper interface for address scope/zone validation.
- The loopback address is not reachable. The root cause is
  the same as the above.
- Empty nd6 entries are created for the IPv6 loopback addresses
  only for validation reason. Doing so will eliminate as much
  of the special case (loopback addresses) handling code
  as possible, however, these empty nd6 entries should not
  be returned to the userland applications such as the
  "ndp" command.
Since both of the above issues contain common files, these
files are committed together.

Reviewed by:	bz
MFC after:	immediately
2009-09-05 16:43:16 +00:00

1184 lines
32 KiB
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/*-
* 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.
*
* $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $
*/
/*-
* 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.
* 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>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/if_llatbl.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#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/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
static struct mtx addrsel_lock;
#define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
#define ADDRSEL_LOCK() mtx_lock(&addrsel_lock)
#define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock)
#define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED)
static struct sx addrsel_sxlock;
#define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock")
#define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock)
#define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock)
#define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock)
#define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock)
#define ADDR_LABEL_NOTAPP (-1)
static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy);
VNET_DEFINE(int, ip6_prefer_tempaddr);
#define V_defaultaddrpolicy VNET(defaultaddrpolicy)
static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *, struct ifnet **,
struct rtentry **, int));
static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *ro, struct ifnet **));
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 __P((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.
*/
#define REPLACE(r) do {\
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
/* { \
char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
} */ \
goto replace; \
} while(0)
#define NEXT(r) do {\
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
/* { \
char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
} */ \
goto next; /* XXX: we can't use 'continue' here */ \
} while(0)
#define BREAK(r) do { \
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
int
in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct inpcb *inp, struct route_in6 *ro, struct ucred *cred,
struct ifnet **ifpp, struct in6_addr *srcp)
{
struct in6_addr dst;
struct ifnet *ifp = NULL;
struct in6_ifaddr *ia = NULL, *ia_best = NULL;
struct in6_pktinfo *pi = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
u_int32_t odstzone;
int prefer_tempaddr;
int error;
struct ip6_moptions *mopts;
KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__));
dst = dstsock->sin6_addr; /* make a copy for local operation */
if (ifpp)
*ifpp = NULL;
if (inp != NULL) {
INP_LOCK_ASSERT(inp);
mopts = inp->in6p_moptions;
} else {
mopts = NULL;
}
/*
* 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;
/* get the outgoing interface */
if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0)
return (error);
/*
* 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.
*/
bzero(&srcsock, 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)
return (error);
}
if (cred != NULL && (error = prison_local_ip6(cred,
&srcsock.sin6_addr, (inp != NULL &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
return (error);
ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(
(struct sockaddr *)&srcsock);
if (ia6 == NULL ||
(ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
if (ia6 != NULL)
ifa_free(&ia6->ia_ifa);
return (EADDRNOTAVAIL);
}
pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
bcopy(&ia6->ia_addr.sin6_addr, srcp, sizeof(*srcp));
ifa_free(&ia6->ia_ifa);
return (0);
}
/*
* Otherwise, if the socket has already bound the source, just use it.
*/
if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
if (cred != NULL &&
(error = prison_local_ip6(cred, &inp->in6p_laddr,
((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
return (error);
bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp));
return (0);
}
/*
* If the address is not specified, choose the best one based on
* the outgoing interface and the destination address.
*/
/* get the outgoing interface */
if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0)
return (error);
#ifdef DIAGNOSTIC
if (ifp == NULL) /* this should not happen */
panic("in6_selectsrc: NULL ifp");
#endif
error = in6_setscope(&dst, ifp, &odstzone);
if (error)
return (error);
IN6_IFADDR_RLOCK();
TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
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;
/*
* 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 (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
continue;
if (cred != NULL &&
prison_local_ip6(cred, &ia->ia_addr.sin6_addr,
(inp != NULL &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0)
continue;
/* 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 */
/*
* XXX: This is a TODO. We should probably merge the MIP6
* case above.
*/
/* 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 = V_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 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;
}
if ((ia = ia_best) == NULL) {
IN6_IFADDR_RUNLOCK();
return (EADDRNOTAVAIL);
}
if (ifpp)
*ifpp = ifp;
bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp));
IN6_IFADDR_RUNLOCK();
return (0);
}
/*
* clone - meaningful only for bsdi and freebsd
*/
static int
selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt, int norouteok)
{
int error = 0;
struct ifnet *ifp = NULL;
struct rtentry *rt = NULL;
struct sockaddr_in6 *sin6_next;
struct in6_pktinfo *pi = NULL;
struct in6_addr *dst = &dstsock->sin6_addr;
#if 0
char ip6buf[INET6_ADDRSTRLEN];
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(ip6buf, &dstsock->sin6_addr));
} else {
printf("in6_selectroute: destination = %s%%%d\n",
ip6_sprintf(ip6buf, &dstsock->sin6_addr),
dstsock->sin6_scope_id); /* for debug */
}
#endif
/* 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. */
ifp = ifnet_byindex(pi->ipi6_ifindex);
if (ifp != NULL &&
(norouteok || retrt == NULL ||
IN6_IS_ADDR_MULTICAST(dst))) {
/*
* we do not have to check or get the route for
* multicast.
*/
goto done;
} else
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 && (ifp = mopts->im6o_multicast_ifp) != NULL) {
goto done; /* we do not need a route for multicast. */
}
getroute:
/*
* 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_in6 *ron;
struct llentry *la;
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;
/*
* XXX what do we do here?
* PLZ to be fixing
*/
if (ron->ro_rt == NULL) {
rtalloc((struct route *)ron); /* multi path case? */
if (ron->ro_rt == NULL) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
error = EHOSTUNREACH;
goto done;
}
}
rt = ron->ro_rt;
ifp = rt->rt_ifp;
IF_AFDATA_LOCK(ifp);
la = lla_lookup(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6_next->sin6_addr);
IF_AFDATA_UNLOCK(ifp);
if (la != NULL)
LLE_RUNLOCK(la);
else {
error = EHOSTUNREACH;
goto done;
}
#if 0
if ((ron->ro_rt &&
(ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) !=
(RTF_UP | RTF_LLINFO)) ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr,
&sin6_next->sin6_addr)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
*satosin6(&ron->ro_dst) = *sin6_next;
}
if (ron->ro_rt == NULL) {
rtalloc((struct route *)ron); /* multi path case? */
if (ron->ro_rt == NULL ||
!(ron->ro_rt->rt_flags & RTF_LLINFO)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
error = EHOSTUNREACH;
goto done;
}
}
#endif
/*
* When cloning is required, try to allocate a route to the
* destination so that the caller can store path MTU
* information.
*/
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.
*/
if (ro) {
if (ro->ro_rt &&
(!(ro->ro_rt->rt_flags & RTF_UP) ||
((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
dst))) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)NULL;
}
if (ro->ro_rt == (struct rtentry *)NULL) {
struct sockaddr_in6 *sa6;
/* No route yet, so try to acquire one */
bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
*sa6 = *dstsock;
sa6->sin6_scope_id = 0;
#ifdef RADIX_MPATH
rtalloc_mpath((struct route *)ro,
ntohl(sa6->sin6_addr.s6_addr32[3]));
#else
ro->ro_rt = rtalloc1(&((struct route *)ro)
->ro_dst, 0, 0UL);
if (ro->ro_rt)
RT_UNLOCK(ro->ro_rt);
#endif
}
/*
* do not care about the result if we have the nexthop
* explicitly specified.
*/
if (opts && opts->ip6po_nexthop)
goto done;
if (ro->ro_rt) {
ifp = ro->ro_rt->rt_ifp;
if (ifp == NULL) { /* can this really happen? */
RTFREE(ro->ro_rt);
ro->ro_rt = NULL;
}
}
if (ro->ro_rt == NULL)
error = EHOSTUNREACH;
rt = ro->ro_rt;
/*
* 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 (ifp && opts && opts->ip6po_pktinfo &&
opts->ip6po_pktinfo->ipi6_ifindex) {
if (!(ifp->if_flags & IFF_LOOPBACK) &&
ifp->if_index !=
opts->ip6po_pktinfo->ipi6_ifindex) {
error = EHOSTUNREACH;
goto done;
}
}
}
done:
if (ifp == NULL && rt == NULL) {
/*
* This can happen if the caller did not pass a cached route
* nor any other hints. We treat this case an error.
*/
error = EHOSTUNREACH;
}
if (error == EHOSTUNREACH)
V_ip6stat.ip6s_noroute++;
if (retifp != NULL) {
*retifp = ifp;
/*
* 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) {
if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) &&
(rt->rt_gateway->sa_family == AF_LINK))
*retifp =
ifnet_byindex(((struct sockaddr_dl *)
rt->rt_gateway)->sdl_index);
}
}
if (retrt != NULL)
*retrt = rt; /* rt may be NULL */
return (error);
}
static int
in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp)
{
int error;
struct route_in6 sro;
struct rtentry *rt = NULL;
if (ro == NULL) {
bzero(&sro, sizeof(sro));
ro = &sro;
}
if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
&rt, 1)) != 0) {
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (error);
}
/*
* 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->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (flags);
}
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (0);
}
/*
* clone - meaningful only for bsdi and freebsd
*/
int
in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt)
{
return (selectroute(dstsock, opts, mopts, ro, retifp,
retrt, 0));
}
/*
* 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 inpcb *in6p, struct ifnet *ifp)
{
if (in6p && in6p->in6p_hops >= 0)
return (in6p->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
struct route_in6 ro6;
struct ifnet *lifp;
bzero(&ro6, sizeof(ro6));
ro6.ro_dst.sin6_family = AF_INET6;
ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
ro6.ro_dst.sin6_addr = in6p->in6p_faddr;
rtalloc((struct route *)&ro6);
if (ro6.ro_rt) {
lifp = ro6.ro_rt->rt_ifp;
RTFREE(ro6.ro_rt);
if (lifp)
return (ND_IFINFO(lifp)->chlim);
} else
return (V_ip6_defhlim);
}
return (V_ip6_defhlim);
}
/*
* XXX: this is borrowed from in6_pcbbind(). If possible, we should
* share this function by all *bsd*...
*/
int
in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
{
struct socket *so = inp->inp_socket;
u_int16_t lport = 0, first, last, *lastport;
int count, error, wild = 0, dorandom;
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
INP_INFO_WLOCK_ASSERT(pcbinfo);
INP_WLOCK_ASSERT(inp);
error = prison_local_ip6(cred, laddr,
((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0));
if (error)
return(error);
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
wild = INPLOOKUP_WILDCARD;
inp->inp_flags |= INP_ANONPORT;
if (inp->inp_flags & INP_HIGHPORT) {
first = V_ipport_hifirstauto; /* sysctl */
last = V_ipport_hilastauto;
lastport = &pcbinfo->ipi_lasthi;
} else if (inp->inp_flags & INP_LOWPORT) {
error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
if (error)
return error;
first = V_ipport_lowfirstauto; /* 1023 */
last = V_ipport_lowlastauto; /* 600 */
lastport = &pcbinfo->ipi_lastlow;
} else {
first = V_ipport_firstauto; /* sysctl */
last = V_ipport_lastauto;
lastport = &pcbinfo->ipi_lastport;
}
/*
* For UDP, use random port allocation as long as the user
* allows it. For TCP (and as of yet unknown) connections,
* use random port allocation only if the user allows it AND
* ipport_tick() allows it.
*/
if (V_ipport_randomized &&
(!V_ipport_stoprandom || pcbinfo == &V_udbinfo))
dorandom = 1;
else
dorandom = 0;
/*
* It makes no sense to do random port allocation if
* we have the only port available.
*/
if (first == last)
dorandom = 0;
/* Make sure to not include UDP packets in the count. */
if (pcbinfo != &V_udbinfo)
V_ipport_tcpallocs++;
/*
* Instead of having two loops further down counting up or down
* make sure that first is always <= last and go with only one
* code path implementing all logic.
*/
if (first > last) {
u_int16_t aux;
aux = first;
first = last;
last = aux;
}
if (dorandom)
*lastport = first + (arc4random() % (last - first));
count = last - first;
do {
if (count-- < 0) { /* completely used? */
/* Undo an address bind that may have occurred. */
inp->in6p_laddr = in6addr_any;
return (EADDRNOTAVAIL);
}
++*lastport;
if (*lastport < first || *lastport > last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild, cred));
inp->inp_lport = lport;
if (in_pcbinshash(inp) != 0) {
inp->in6p_laddr = in6addr_any;
inp->inp_lport = 0;
return (EAGAIN);
}
return (0);
}
void
addrsel_policy_init(void)
{
V_ip6_prefer_tempaddr = 0;
init_policy_queue();
/* initialize the "last resort" policy */
bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy));
V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
if (!IS_DEFAULT_VNET(curvnet))
return;
ADDRSEL_LOCK_INIT();
ADDRSEL_SXLOCK_INIT();
}
static struct in6_addrpolicy *
lookup_addrsel_policy(struct sockaddr_in6 *key)
{
struct in6_addrpolicy *match = NULL;
ADDRSEL_LOCK();
match = match_addrsel_policy(key);
if (match == NULL)
match = &V_defaultaddrpolicy;
else
match->use++;
ADDRSEL_UNLOCK();
return (match);
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct walkarg {
struct sysctl_req *w_req;
};
static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
CTLFLAG_RD, in6_src_sysctl, "");
static int
in6_src_sysctl(SYSCTL_HANDLER_ARGS)
{
struct walkarg w;
if (req->newptr)
return EPERM;
bzero(&w, sizeof(w));
w.w_req = req;
return (walk_addrsel_policy(dump_addrsel_policyent, &w));
}
int
in6_src_ioctl(u_long cmd, caddr_t 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);
static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab);
#define V_addrsel_policytab VNET(addrsel_policytab)
static void
init_policy_queue(void)
{
TAILQ_INIT(&V_addrsel_policytab);
}
static int
add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
{
struct addrsel_policyent *new, *pol;
new = malloc(sizeof(*new), M_IFADDR,
M_WAITOK);
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* duplication check */
TAILQ_FOREACH(pol, &V_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)) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
free(new, M_IFADDR);
return (EEXIST); /* or override it? */
}
}
bzero(new, sizeof(*new));
/* XXX: should validate entry */
new->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
delete_addrsel_policyent(struct in6_addrpolicy *key)
{
struct addrsel_policyent *pol;
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* search for the entry in the table */
TAILQ_FOREACH(pol, &V_addrsel_policytab, 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) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (ESRCH);
}
TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *),
void *w)
{
struct addrsel_policyent *pol;
int error = 0;
ADDRSEL_SLOCK();
TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
ADDRSEL_SUNLOCK();
return (error);
}
}
ADDRSEL_SUNLOCK();
return (error);
}
static int
dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
{
int error = 0;
struct walkarg *w = arg;
error = SYSCTL_OUT(w->w_req, pol, 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;
TAILQ_FOREACH(pent, &V_addrsel_policytab, 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);
}
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