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7eee712c27
freebsd/sys/netinet6/in6_src.c
Bjoern A. Zeeb 23bc7025c4 Just add a comment to further investigate when being closer to that code 
again next time.  The condition of the 2nd if() is very unlikely ever met.
2012-06-22 21:26:35 +00:00

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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);
#define V_defaultaddrpolicy VNET(defaultaddrpolicy)
VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *, struct ifnet **,
struct rtentry **, int, u_int));
static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *ro, struct ifnet **,
struct ifnet *, u_int));
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, tmp;
struct ifnet *ifp = NULL, *oifp = 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) {
/*
* Save a possibly passed in ifp for in6_selectsrc. Only
* neighbor discovery code should use this feature, where
* we may know the interface but not the FIB number holding
* the connected subnet in case someone deleted it from the
* default FIB and we need to check the interface.
*/
if (*ifpp != NULL)
oifp = *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, oifp,
(inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB))
!= 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);
}
/*
* Bypass source address selection and use the primary jail IP
* if requested.
*/
if (cred != NULL && !prison_saddrsel_ip6(cred, 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, oifp,
(inp != NULL) ? inp->inp_inc.inc_fibnum : RT_DEFAULT_FIB)) != 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 jailed only take addresses of the jail into account. */
if (cred != NULL &&
prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 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);
}
/*
* At this point at least one of the addresses belonged to the jail
* but it could still be, that we want to further restrict it, e.g.
* theoratically IN6_IS_ADDR_LOOPBACK.
* It must not be IN6_IS_ADDR_UNSPECIFIED anymore.
* prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should
* let all others previously selected pass.
* Use tmp to not change ::1 on lo0 to the primary jail address.
*/
tmp = ia->ia_addr.sin6_addr;
if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) {
IN6_IFADDR_RUNLOCK();
return (EADDRNOTAVAIL);
}
if (ifpp)
*ifpp = ifp;
bcopy(&tmp, 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, u_int fibnum)
{
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) {
in6_rtalloc(ron, fibnum); /* multi path case? */
if (ron->ro_rt == NULL) {
/* XXX-BZ WT.? */
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) {
in6_rtalloc(ron, fibnum); /* 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_fib((struct route *)ro,
ntohl(sa6->sin6_addr.s6_addr32[3]), fibnum);
#else
ro->ro_rt = in6_rtalloc1((struct sockaddr *)
&ro->ro_dst, 0, 0UL, fibnum);
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,
struct ifnet *oifp, u_int fibnum)
{
int error;
struct route_in6 sro;
struct rtentry *rt = NULL;
KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__));
if (ro == NULL) {
bzero(&sro, sizeof(sro));
ro = &sro;
}
if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
&rt, 1, fibnum)) != 0) {
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
/* Help ND. See oifp comment in in6_selectsrc(). */
if (oifp != NULL && fibnum == RT_DEFAULT_FIB) {
*retifp = oifp;
error = 0;
}
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);
}
/*
* Public wrapper function to selectroute().
*
* XXX-BZ in6_selectroute() should and will grow the FIB argument. The
* in6_selectroute_fib() function is only there for backward compat on stable.
*/
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, RT_DEFAULT_FIB));
}
#ifndef BURN_BRIDGES
int
in6_selectroute_fib(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt, u_int fibnum)
{
return (selectroute(dstsock, opts, mopts, ro, retifp,
retrt, 0, fibnum));
}
#endif
/*
* 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;
in6_rtalloc(&ro6, in6p->inp_inc.inc_fibnum);
if (ro6.ro_rt) {
lifp = ro6.ro_rt->rt_ifp;
RTFREE(ro6.ro_rt);
if (lifp)
return (ND_IFINFO(lifp)->chlim);
}
}
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;
int error, lookupflags = 0;
#ifdef INVARIANTS
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
#endif
INP_WLOCK_ASSERT(inp);
INP_HASH_WLOCK_ASSERT(pcbinfo);
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)
lookupflags = INPLOOKUP_WILDCARD;
inp->inp_flags |= INP_ANONPORT;
error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags);
if (error != 0)
return (error);
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)
{
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);
static 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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