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freebsd-dev/sys/netinet6/in6_src.c
Bjoern A. Zeeb 0ecd976e80 IPv6 cleanup: kernel 
Finish what was started a few years ago and harmonize IPv6 and IPv4
kernel names.  We are down to very few places now that it is feasible
to do the change for everything remaining with causing too much disturbance.

Remove "aliases" for IPv6 names which confusingly could indicate
that we are talking about a different data structure or field or
have two fields, one for each address family.
Try to follow common conventions used in FreeBSD.

* Rename sin6p to sin6 as that is how it is spelt in most places.
* Remove "aliases" (#defines) for:
  - in6pcb which really is an inpcb and nothing separate
  - sotoin6pcb which is sotoinpcb (as per above)
  - in6p_sp which is inp_sp
  - in6p_flowinfo which is inp_flow
* Try to use ia6 for in6_addr rather than in6p.
* With all these gone  also rename the in6p variables to inp as
  that is what we call it in most of the network stack including
  parts of netinet6.

The reasons behind this cleanup are that we try to further
unify netinet and netinet6 code where possible and that people
will less ignore one or the other protocol family when doing
code changes as they may not have spotted places due to different
names for the same thing.

No functional changes.

Discussed with:		tuexen (SCTP changes)
MFC after:		3 months
Sponsored by:		Netflix
2019-08-02 07:41:36 +00:00

1248 lines
35 KiB
C
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/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/rmlock.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/if_var.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_fib.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)
VNET_DEFINE_STATIC(struct in6_addrpolicy, defaultaddrpolicy);
#define V_defaultaddrpolicy VNET(defaultaddrpolicy)
VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *, struct ifnet **,
struct rtentry **, int, u_int);
static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct ifnet **,
struct ifnet *, u_int);
static int in6_selectsrc(uint32_t, struct sockaddr_in6 *,
struct ip6_pktopts *, struct inpcb *, struct ucred *,
struct ifnet **, struct in6_addr *);
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.
*/
#define REPLACE(r) do {\
IP6STAT_INC(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 {\
/* { \
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 { \
IP6STAT_INC(ip6s_sources_rule[(r)]); \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
static int
in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock,
struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred,
struct ifnet **ifpp, struct in6_addr *srcp)
{
struct rm_priotracker in6_ifa_tracker;
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)) {
/* get the outgoing interface */
if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
fibnum))
!= 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.
*/
tmp = pi->ipi6_addr;
if (ifp) {
error = in6_setscope(&tmp, ifp, &odstzone);
if (error)
return (error);
}
if (cred != NULL && (error = prison_local_ip6(cred,
&tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0)
return (error);
/*
* If IPV6_BINDANY socket option is set, we allow to specify
* non local addresses as source address in IPV6_PKTINFO
* ancillary data.
*/
if ((inp->inp_flags & INP_BINDANY) == 0) {
ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */);
if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST |
IN6_IFF_NOTREADY))) {
if (ia != NULL)
ifa_free(&ia->ia_ifa);
return (EADDRNOTAVAIL);
}
bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp));
ifa_free(&ia->ia_ifa);
} else
bcopy(&tmp, srcp, sizeof(*srcp));
pi->ipi6_addr = tmp; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
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, &ifp, oifp,
(inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 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(&in6_ifa_tracker);
CK_STAILQ_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 (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) {
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 9: prefer address with better virtual status.
*/
if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa))
REPLACE(9);
if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa))
NEXT(9);
/*
* Rule 10: prefer address with `prefer_source' flag.
*/
if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 &&
(ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0)
REPLACE(10);
if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 &&
(ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0)
NEXT(10);
/*
* 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(&in6_ifa_tracker);
IP6STAT_INC(ip6s_sources_none);
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(&in6_ifa_tracker);
IP6STAT_INC(ip6s_sources_none);
return (EADDRNOTAVAIL);
}
if (ifpp)
*ifpp = ifp;
bcopy(&tmp, srcp, sizeof(*srcp));
if (ia->ia_ifp == ifp)
IP6STAT_INC(ip6s_sources_sameif[best_scope]);
else
IP6STAT_INC(ip6s_sources_otherif[best_scope]);
if (dst_scope == best_scope)
IP6STAT_INC(ip6s_sources_samescope[best_scope]);
else
IP6STAT_INC(ip6s_sources_otherscope[best_scope]);
if (IFA6_IS_DEPRECATED(ia))
IP6STAT_INC(ip6s_sources_deprecated[best_scope]);
IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
return (0);
}
/*
* Select source address based on @inp, @dstsock and @opts.
* Stores selected address to @srcp. If @scope_ambiguous is set,
* embed scope from selected outgoing interface. If @hlim pointer
* is provided, stores calculated hop limit there.
* Returns 0 on success.
*/
int
in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct inpcb *inp, struct ucred *cred, int scope_ambiguous,
struct in6_addr *srcp, int *hlim)
{
struct ifnet *retifp;
uint32_t fibnum;
int error;
fibnum = inp->inp_inc.inc_fibnum;
retifp = NULL;
error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp);
if (error != 0)
return (error);
if (hlim != NULL)
*hlim = in6_selecthlim(inp, retifp);
if (retifp == NULL || scope_ambiguous == 0)
return (0);
/*
* Application should provide a proper zone ID or the use of
* default zone IDs should be enabled. Unfortunately, some
* applications do not behave as it should, so we need a
* workaround. Even if an appropriate ID is not determined
* (when it's required), if we can determine the outgoing
* interface. determine the zone ID based on the interface.
*/
error = in6_setscope(&dstsock->sin6_addr, retifp, NULL);
return (error);
}
/*
* Select source address based on @fibnum, @dst and @scopeid.
* Stores selected address to @srcp.
* Returns 0 on success.
*
* Used by non-socket based consumers (ND code mostly)
*/
int
in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst,
uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp,
int *hlim)
{
struct ifnet *retifp;
struct sockaddr_in6 dst_sa;
int error;
retifp = ifp;
bzero(&dst_sa, sizeof(dst_sa));
dst_sa.sin6_family = AF_INET6;
dst_sa.sin6_len = sizeof(dst_sa);
dst_sa.sin6_addr = *dst;
dst_sa.sin6_scope_id = scopeid;
sa6_embedscope(&dst_sa, 0);
error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp);
if (hlim != NULL)
*hlim = in6_selecthlim(NULL, retifp);
return (error);
}
/*
* 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;
uint32_t zoneid;
#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. */
}
/*
* If destination address is LLA or link- or node-local multicast,
* use it's embedded scope zone id to determine outgoing interface.
*/
if (IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
IN6_IS_ADDR_MC_NODELOCAL(dst)) {
zoneid = ntohs(in6_getscope(dst));
if (zoneid > 0) {
ifp = in6_getlinkifnet(zoneid);
goto done;
}
}
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;
sin6_next = satosin6(opts->ip6po_nexthop);
if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) {
/*
* Next hop is LLA, thus it should be neighbor.
* Determine outgoing interface by zone index.
*/
zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr));
if (zoneid > 0) {
ifp = in6_getlinkifnet(zoneid);
goto done;
}
}
ron = &opts->ip6po_nextroute;
/* Use a cached route if it exists and is valid. */
if (ron->ro_rt != NULL && (
(ron->ro_rt->rt_flags & RTF_UP) == 0 ||
ron->ro_dst.sin6_family != AF_INET6 ||
!IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr,
&sin6_next->sin6_addr)))
RO_RTFREE(ron);
if (ron->ro_rt == NULL) {
ron->ro_dst = *sin6_next;
in6_rtalloc(ron, fibnum); /* multi path case? */
}
/*
* The node identified by that address must be a
* neighbor of the sending host.
*/
if (ron->ro_rt == NULL ||
(ron->ro_rt->rt_flags & RTF_GATEWAY) != 0)
error = EHOSTUNREACH;
else {
rt = ron->ro_rt;
ifp = rt->rt_ifp;
}
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)
IP6STAT_INC(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 ifnet **retifp,
struct ifnet *oifp, u_int fibnum)
{
int error;
struct route_in6 sro;
struct rtentry *rt = NULL;
int rt_flags;
KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__));
bzero(&sro, sizeof(sro));
rt_flags = 0;
error = selectroute(dstsock, opts, mopts, &sro, retifp, &rt, 1, fibnum);
if (rt)
rt_flags = rt->rt_flags;
if (rt && rt == sro.ro_rt)
RTFREE(rt);
if (error != 0) {
/* 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_flags & (RTF_REJECT | RTF_BLACKHOLE)) {
error = (rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
return (error);
}
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 *inp, struct ifnet *ifp)
{
if (inp && inp->in6p_hops >= 0)
return (inp->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else if (inp && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
struct nhop6_basic nh6;
struct in6_addr dst;
uint32_t fibnum, scopeid;
int hlim;
fibnum = inp->inp_inc.inc_fibnum;
in6_splitscope(&inp->in6p_faddr, &dst, &scopeid);
if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6)==0){
hlim = ND_IFINFO(nh6.nh_ifp)->chlim;
return (hlim);
}
}
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|SO_REUSEPORT_LB)) == 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)
{
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. */
IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr);
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);
VNET_DEFINE_STATIC(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();
free(pol, M_IFADDR);
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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