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darling-xnu/bsd/netinet6/in6_src.c
Thomas A cdbc10b677 Upload xnu-7195.141.2 Source
2023-05-16 21:41:14 -07:00

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/*
* Copyright (c) 2000-2020 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <sys/priv.h>
#include <kern/locks.h>
#include <sys/random.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/restricted_in_port.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <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>
#include <net/net_osdep.h>
#include "loop.h"
SYSCTL_DECL(_net_inet6_ip6);
static int ip6_select_srcif_debug = 0;
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcif_debug,
CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcif_debug, 0,
"log source interface selection debug info");
static int ip6_select_srcaddr_debug = 0;
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcaddr_debug,
CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcaddr_debug, 0,
"log source address selection debug info");
static int ip6_select_src_expensive_secondary_if = 0;
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_expensive_secondary_if,
CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_expensive_secondary_if, 0,
"allow source interface selection to use expensive secondaries");
static int ip6_select_src_strong_end = 1;
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_strong_end,
CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_strong_end, 0,
"limit source address selection to outgoing interface");
#define ADDR_LABEL_NOTAPP (-1)
struct in6_addrpolicy defaultaddrpolicy;
int ip6_prefer_tempaddr = 1;
int ip6_cga_conflict_retries = IPV6_CGA_CONFLICT_RETRIES_DEFAULT;
#ifdef ENABLE_ADDRSEL
extern lck_mtx_t *addrsel_mutex;
#define ADDRSEL_LOCK() lck_mtx_lock(addrsel_mutex)
#define ADDRSEL_UNLOCK() lck_mtx_unlock(addrsel_mutex)
#else
#define ADDRSEL_LOCK()
#define ADDRSEL_UNLOCK()
#endif
extern int udp_use_randomport;
extern int tcp_use_randomport;
static int selectroute(struct sockaddr_in6 *, struct sockaddr_in6 *,
struct ip6_pktopts *, struct ip6_moptions *, struct in6_ifaddr **,
struct route_in6 *, struct ifnet **, struct rtentry **, int, int,
struct ip6_out_args *ip6oa);
static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *ro,
struct ip6_out_args *, struct ifnet **);
static void init_policy_queue(void);
static int add_addrsel_policyent(const struct in6_addrpolicy *);
#ifdef ENABLE_ADDRSEL
static int delete_addrsel_policyent(const struct in6_addrpolicy *);
#endif
static int walk_addrsel_policy(int (*)(const struct in6_addrpolicy *, void *),
void *);
static int dump_addrsel_policyent(const struct in6_addrpolicy *, void *);
static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
void addrsel_policy_init(void);
#define SASEL_DO_DBG(inp) \
(ip6_select_srcaddr_debug && (inp) != NULL && \
(inp)->inp_socket != NULL && \
((inp)->inp_socket->so_options & SO_DEBUG))
#define SASEL_LOG(fmt, ...) \
do { \
if (srcsel_debug) \
printf("%s:%d " fmt "\n",\
__FUNCTION__, __LINE__, ##__VA_ARGS__); \
} while (0); \
/*
* 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 {\
SASEL_LOG("REPLACE r %d ia %s ifp1 %s\n", \
(r), s_src, ifp1->if_xname); \
srcrule = (r); \
goto replace; \
} while (0)
#define NEXTSRC(r) do {\
SASEL_LOG("NEXTSRC r %d ia %s ifp1 %s\n", \
(r), s_src, ifp1->if_xname); \
goto next; /* XXX: we can't use 'continue' here */ \
} while (0)
#define BREAK(r) do { \
SASEL_LOG("BREAK r %d ia %s ifp1 %s\n", \
(r), s_src, ifp1->if_xname); \
srcrule = (r); \
goto out; /* XXX: we can't use 'break' here */ \
} while (0)
struct ifaddr *
in6_selectsrc_core_ifa(struct sockaddr_in6 *addr, struct ifnet *ifp, int srcsel_debug)
{
int err = 0;
struct ifnet *src_ifp = NULL;
struct in6_addr src_storage = {};
struct in6_addr *in6 = NULL;
struct ifaddr *ifa = NULL;
if ((in6 = in6_selectsrc_core(addr,
(ip6_prefer_tempaddr ? IPV6_SRCSEL_HINT_PREFER_TMPADDR : 0),
ifp, 0, &src_storage, &src_ifp, &err, &ifa)) == NULL) {
if (err == 0) {
err = EADDRNOTAVAIL;
}
VERIFY(src_ifp == NULL);
if (ifa != NULL) {
IFA_REMREF(ifa);
ifa = NULL;
}
goto done;
}
if (src_ifp != ifp) {
if (err == 0) {
err = ENETUNREACH;
}
if (ifa != NULL) {
IFA_REMREF(ifa);
ifa = NULL;
}
goto done;
}
VERIFY(ifa != NULL);
ifnet_lock_shared(ifp);
if ((ifa->ifa_debug & IFD_DETACHING) != 0) {
err = EHOSTUNREACH;
ifnet_lock_done(ifp);
IFA_REMREF(ifa);
ifa = NULL;
goto done;
}
ifnet_lock_done(ifp);
done:
SASEL_LOG("Returned with error: %d", err);
if (src_ifp != NULL) {
ifnet_release(src_ifp);
}
return ifa;
}
struct in6_addr *
in6_selectsrc_core(struct sockaddr_in6 *dstsock, uint32_t hint_mask,
struct ifnet *ifp, int srcsel_debug, struct in6_addr *src_storage,
struct ifnet **sifp, int *errorp, struct ifaddr **ifapp)
{
u_int32_t odstzone;
int bestrule = IP6S_SRCRULE_0;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
struct in6_addr dst;
struct in6_ifaddr *ia = NULL, *ia_best = NULL;
char s_src[MAX_IPv6_STR_LEN] = {0};
char s_dst[MAX_IPv6_STR_LEN] = {0};
const struct in6_addr *tmp = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
uint64_t secs = net_uptime();
VERIFY(dstsock != NULL);
VERIFY(src_storage != NULL);
VERIFY(ifp != NULL);
if (sifp != NULL) {
*sifp = NULL;
}
if (ifapp != NULL) {
*ifapp = NULL;
}
dst = dstsock->sin6_addr; /* make a copy for local operation */
if (srcsel_debug) {
(void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
tmp = &in6addr_any;
(void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
printf("%s out src %s dst %s ifp %s\n",
__func__, s_src, s_dst, ifp->if_xname);
}
*errorp = in6_setscope(&dst, ifp, &odstzone);
if (*errorp != 0) {
src_storage = NULL;
goto done;
}
lck_rw_lock_shared(&in6_ifaddr_rwlock);
TAILQ_FOREACH(ia, &in6_ifaddrhead, ia6_link) {
int new_scope = -1, new_matchlen = -1;
struct in6_addrpolicy *new_policy = NULL;
u_int32_t srczone = 0, osrczone, dstzone;
struct in6_addr src;
struct ifnet *ifp1 = ia->ia_ifp;
int srcrule;
if (srcsel_debug) {
(void) inet_ntop(AF_INET6, &ia->ia_addr.sin6_addr,
s_src, sizeof(s_src));
}
IFA_LOCK(&ia->ia_ifa);
/*
* Simply skip addresses reserved for CLAT46
*/
if (ia->ia6_flags & IN6_IFF_CLAT46) {
SASEL_LOG("NEXT ia %s address on ifp1 %s skipped as it is "
"reserved for CLAT46", s_src, ifp1->if_xname);
goto next;
}
/*
* XXX By default we are strong end system and will
* limit candidate set of source address to the ones
* configured on the outgoing interface.
*/
if (ip6_select_src_strong_end &&
ifp1 != ifp) {
SASEL_LOG("NEXT ia %s ifp1 %s address is not on outgoing "
"interface \n", s_src, ifp1->if_xname);
goto next;
}
/*
* 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) {
SASEL_LOG("NEXT ia %s ifp1 %s odstzone %d != dstzone %d\n",
s_src, ifp1->if_xname, odstzone, dstzone);
goto next;
}
src = ia->ia_addr.sin6_addr;
if (in6_setscope(&src, ifp, &osrczone) ||
in6_setscope(&src, ifp1, &srczone) ||
osrczone != srczone) {
SASEL_LOG("NEXT ia %s ifp1 %s osrczone %d != srczone %d\n",
s_src, ifp1->if_xname, osrczone, srczone);
goto next;
}
/* avoid unusable addresses */
if ((ia->ia6_flags &
(IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
SASEL_LOG("NEXT ia %s ifp1 %s ia6_flags 0x%x\n",
s_src, ifp1->if_xname, ia->ia6_flags);
goto next;
}
if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia, secs)) {
SASEL_LOG("NEXT ia %s ifp1 %s IFA6_IS_DEPRECATED\n",
s_src, ifp1->if_xname);
goto next;
}
if (!nd6_optimistic_dad &&
(ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
SASEL_LOG("NEXT ia %s ifp1 %s IN6_IFF_OPTIMISTIC\n",
s_src, ifp1->if_xname);
goto next;
}
/* Rule 1: Prefer same address */
if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
BREAK(IP6S_SRCRULE_1); /* there should be no better candidate */
}
if (ia_best == NULL) {
REPLACE(IP6S_SRCRULE_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(IP6S_SRCRULE_2);
}
NEXTSRC(IP6S_SRCRULE_2);
} else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) {
NEXTSRC(IP6S_SRCRULE_2);
}
REPLACE(IP6S_SRCRULE_2);
}
/*
* Rule 3: Avoid deprecated addresses. Note that the case of
* !ip6_use_deprecated is already rejected above.
*/
if (!IFA6_IS_DEPRECATED(ia_best, secs) &&
IFA6_IS_DEPRECATED(ia, secs)) {
NEXTSRC(IP6S_SRCRULE_3);
}
if (IFA6_IS_DEPRECATED(ia_best, secs) &&
!IFA6_IS_DEPRECATED(ia, secs)) {
REPLACE(IP6S_SRCRULE_3);
}
/*
* RFC 4429 says that optimistic addresses are equivalent to
* deprecated addresses, so avoid them here.
*/
if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) == 0 &&
(ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
NEXTSRC(IP6S_SRCRULE_3);
}
if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) != 0 &&
(ia->ia6_flags & IN6_IFF_OPTIMISTIC) == 0) {
REPLACE(IP6S_SRCRULE_3);
}
/* Rule 4: Prefer home addresses */
/*
* XXX: This is a TODO. We should probably merge the MIP6
* case above.
*/
/* Rule 5: Prefer outgoing interface */
/*
* XXX By default we are strong end with source address
* selection. That means all address selection candidate
* addresses will be the ones hosted on the outgoing interface
* making the following check redundant.
*/
if (ip6_select_src_strong_end == 0) {
if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) {
NEXTSRC(IP6S_SRCRULE_5);
}
if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) {
REPLACE(IP6S_SRCRULE_5);
}
}
/*
* Rule 6: Prefer matching label
* Note that best_policy should be non-NULL here.
*/
if (dst_policy == NULL) {
dst_policy = in6_addrsel_lookup_policy(dstsock);
}
if (dst_policy->label != ADDR_LABEL_NOTAPP) {
new_policy = in6_addrsel_lookup_policy(&ia->ia_addr);
if (dst_policy->label == best_policy->label &&
dst_policy->label != new_policy->label) {
NEXTSRC(IP6S_SRCRULE_6);
}
if (dst_policy->label != best_policy->label &&
dst_policy->label == new_policy->label) {
REPLACE(IP6S_SRCRULE_6);
}
}
/*
* Rule 7: Prefer temporary addresses.
* We allow users to reverse the logic by configuring
* a sysctl variable, so that transparency conscious users can
* always prefer stable addresses.
*/
if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
REPLACE(IP6S_SRCRULE_7);
} else {
NEXTSRC(IP6S_SRCRULE_7);
}
}
if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
!(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
NEXTSRC(IP6S_SRCRULE_7);
} else {
REPLACE(IP6S_SRCRULE_7);
}
}
/*
* Rule 7x: 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)) {
NEXTSRC(IP6S_SRCRULE_7x);
}
if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
(ia->ia_ifp->if_flags & IFF_UP)) {
REPLACE(IP6S_SRCRULE_7x);
}
/*
* Rule 8: Use longest matching prefix.
*/
new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
if (best_matchlen < new_matchlen) {
REPLACE(IP6S_SRCRULE_8);
}
if (new_matchlen < best_matchlen) {
NEXTSRC(IP6S_SRCRULE_8);
}
/*
* Last resort: just keep the current candidate.
* Or, do we need more rules?
*/
if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
ip6_select_src_expensive_secondary_if == 0) {
SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
s_src, ifp1->if_xname);
ip6stat.ip6s_sources_skip_expensive_secondary_if++;
goto next;
}
SASEL_LOG("NEXT ia %s ifp1 %s last resort\n",
s_src, ifp1->if_xname);
IFA_UNLOCK(&ia->ia_ifa);
continue;
replace:
/*
* Ignore addresses on secondary interfaces that are marked
* expensive
*/
if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
ip6_select_src_expensive_secondary_if == 0) {
SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
s_src, ifp1->if_xname);
ip6stat.ip6s_sources_skip_expensive_secondary_if++;
goto next;
}
bestrule = srcrule;
best_scope = (new_scope >= 0 ? new_scope :
in6_addrscope(&ia->ia_addr.sin6_addr));
best_policy = (new_policy ? new_policy :
in6_addrsel_lookup_policy(&ia->ia_addr));
best_matchlen = (new_matchlen >= 0 ? new_matchlen :
in6_matchlen(&ia->ia_addr.sin6_addr, &dst));
SASEL_LOG("NEXT ia %s ifp1 %s best_scope %d new_scope %d dst_scope %d\n",
s_src, ifp1->if_xname, best_scope, new_scope, dst_scope);
IFA_ADDREF_LOCKED(&ia->ia_ifa); /* for ia_best */
IFA_UNLOCK(&ia->ia_ifa);
if (ia_best != NULL) {
IFA_REMREF(&ia_best->ia_ifa);
}
ia_best = ia;
continue;
next:
IFA_UNLOCK(&ia->ia_ifa);
continue;
out:
IFA_ADDREF_LOCKED(&ia->ia_ifa); /* for ia_best */
IFA_UNLOCK(&ia->ia_ifa);
if (ia_best != NULL) {
IFA_REMREF(&ia_best->ia_ifa);
}
ia_best = ia;
break;
}
lck_rw_done(&in6_ifaddr_rwlock);
if ((ia = ia_best) == NULL) {
if (*errorp == 0) {
*errorp = EADDRNOTAVAIL;
}
src_storage = NULL;
goto done;
}
if (sifp != NULL) {
*sifp = ia->ia_ifa.ifa_ifp;
ifnet_reference(*sifp);
}
IFA_LOCK_SPIN(&ia->ia_ifa);
if (bestrule < IP6S_SRCRULE_COUNT) {
ip6stat.ip6s_sources_rule[bestrule]++;
}
*src_storage = satosin6(&ia->ia_addr)->sin6_addr;
IFA_UNLOCK(&ia->ia_ifa);
if (ifapp != NULL) {
*ifapp = &ia->ia_ifa;
} else {
IFA_REMREF(&ia->ia_ifa);
}
done:
if (srcsel_debug) {
(void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
tmp = (src_storage != NULL) ? src_storage : &in6addr_any;
(void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
printf("%s out src %s dst %s dst_scope %d best_scope %d\n",
__func__, s_src, s_dst, dst_scope, best_scope);
}
return src_storage;
}
/*
* Regardless of error, it will return an ifp with a reference held if the
* caller provides a non-NULL ifpp. The caller is responsible for checking
* if the returned ifp is valid and release its reference at all times.
*/
struct in6_addr *
in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct inpcb *inp, struct route_in6 *ro,
struct ifnet **ifpp, struct in6_addr *src_storage, unsigned int ifscope,
int *errorp)
{
struct ifnet *ifp = NULL;
struct in6_pktinfo *pi = NULL;
struct ip6_moptions *mopts;
struct ip6_out_args ip6oa;
boolean_t inp_debug = FALSE;
uint32_t hint_mask = 0;
int prefer_tempaddr = 0;
struct ifnet *sifp = NULL;
bzero(&ip6oa, sizeof(ip6oa));
ip6oa.ip6oa_boundif = ifscope;
ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF;
ip6oa.ip6oa_sotc = SO_TC_UNSPEC;
ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
*errorp = 0;
if (ifpp != NULL) {
*ifpp = NULL;
}
if (inp != NULL) {
inp_debug = SASEL_DO_DBG(inp);
mopts = inp->in6p_moptions;
if (INP_NO_CELLULAR(inp)) {
ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
}
if (INP_NO_EXPENSIVE(inp)) {
ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
}
if (INP_NO_CONSTRAINED(inp)) {
ip6oa.ip6oa_flags |= IP6OAF_NO_CONSTRAINED;
}
if (INP_AWDL_UNRESTRICTED(inp)) {
ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
}
if (INP_INTCOPROC_ALLOWED(inp)) {
ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED;
}
} else {
mopts = NULL;
/* Allow the kernel to retransmit packets. */
ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED |
IP6OAF_AWDL_UNRESTRICTED;
}
if (ip6oa.ip6oa_boundif != IFSCOPE_NONE) {
ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
}
/*
* 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 ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
&ifp)) != 0) {
src_storage = NULL;
goto done;
}
/*
* 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 != NULL) {
*errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
if (*errorp != 0) {
src_storage = NULL;
goto done;
}
}
ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)
(&srcsock));
if (ia6 == NULL) {
*errorp = EADDRNOTAVAIL;
src_storage = NULL;
goto done;
}
IFA_LOCK_SPIN(&ia6->ia_ifa);
if ((ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY | IN6_IFF_CLAT46)) ||
(inp && inp_restricted_send(inp, ia6->ia_ifa.ifa_ifp))) {
IFA_UNLOCK(&ia6->ia_ifa);
IFA_REMREF(&ia6->ia_ifa);
*errorp = EHOSTUNREACH;
src_storage = NULL;
goto done;
}
*src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
IFA_UNLOCK(&ia6->ia_ifa);
IFA_REMREF(&ia6->ia_ifa);
goto done;
}
/*
* Otherwise, if the socket has already bound the source, just use it.
*/
if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
src_storage = &inp->in6p_laddr;
goto done;
}
/*
* If the address is not specified, choose the best one based on
* the outgoing interface and the destination address.
*/
/* get the outgoing interface */
if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
&ifp)) != 0) {
src_storage = NULL;
goto done;
}
VERIFY(ifp != NULL);
if (opts == NULL ||
opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
prefer_tempaddr = ip6_prefer_tempaddr;
} else if (opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_NOTPREFER) {
prefer_tempaddr = 0;
} else {
prefer_tempaddr = 1;
}
if (prefer_tempaddr) {
hint_mask |= IPV6_SRCSEL_HINT_PREFER_TMPADDR;
}
if (in6_selectsrc_core(dstsock, hint_mask, ifp, inp_debug, src_storage,
&sifp, errorp, NULL) == NULL) {
src_storage = NULL;
goto done;
}
VERIFY(sifp != NULL);
if (inp && inp_restricted_send(inp, sifp)) {
src_storage = NULL;
*errorp = EHOSTUNREACH;
ifnet_release(sifp);
goto done;
} else {
ifnet_release(sifp);
}
done:
if (ifpp != NULL) {
/* if ifp is non-NULL, refcnt held in in6_selectif() */
*ifpp = ifp;
} else if (ifp != NULL) {
ifnet_release(ifp);
}
return src_storage;
}
/*
* Given a source IPv6 address (and route, if available), determine the best
* interface to send the packet from. Checking for (and updating) the
* ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done
* without any locks, based on the assumption that in the event this is
* called from ip6_output(), the output operation is single-threaded per-pcb,
* i.e. for any given pcb there can only be one thread performing output at
* the IPv6 layer.
*
* This routine is analogous to in_selectsrcif() for IPv4. Regardless of
* error, it will return an ifp with a reference held if the caller provides
* a non-NULL retifp. The caller is responsible for checking if the
* returned ifp is valid and release its reference at all times.
*
* clone - meaningful only for bsdi and freebsd
*/
static int
selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
struct ip6_pktopts *opts, struct ip6_moptions *mopts,
struct in6_ifaddr **retsrcia, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt, int clone,
int norouteok, struct ip6_out_args *ip6oa)
{
int error = 0;
struct ifnet *ifp = NULL, *ifp0 = NULL;
struct route_in6 *route = NULL;
struct sockaddr_in6 *sin6_next;
struct in6_pktinfo *pi = NULL;
struct in6_addr *dst = &dstsock->sin6_addr;
struct ifaddr *ifa = NULL;
char s_src[MAX_IPv6_STR_LEN], s_dst[MAX_IPv6_STR_LEN];
boolean_t select_srcif, proxied_ifa = FALSE, local_dst = FALSE;
unsigned int ifscope = ((ip6oa != NULL) ?
ip6oa->ip6oa_boundif : IFSCOPE_NONE);
boolean_t is_direct = FALSE;
if (retifp != NULL) {
*retifp = NULL;
}
if (retrt != NULL) {
*retrt = NULL;
}
if (ip6_select_srcif_debug) {
struct in6_addr src;
src = (srcsock != NULL) ? srcsock->sin6_addr : in6addr_any;
(void) inet_ntop(AF_INET6, &src, s_src, sizeof(s_src));
(void) inet_ntop(AF_INET6, dst, s_dst, sizeof(s_dst));
}
/*
* If the destination address is UNSPECIFIED addr, bail out.
*/
if (IN6_IS_ADDR_UNSPECIFIED(dst)) {
error = EHOSTUNREACH;
goto done;
}
/*
* Perform source interface selection if Scoped Routing
* is enabled and a source address that isn't unspecified.
*/
select_srcif = (srcsock != NULL &&
!IN6_IS_ADDR_UNSPECIFIED(&srcsock->sin6_addr));
/*
* For scoped routing, if interface scope is 0 or src/dst addr is linklocal
* or dst addr is multicast, source interface selection should be performed even
* if the destination is directly reachable.
*/
if (ifscope != IFSCOPE_NONE &&
!(srcsock != NULL && IN6_IS_ADDR_LINKLOCAL(&srcsock->sin6_addr)) &&
!IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_LINKLOCAL(dst)) {
struct rtentry *temp_rt = NULL;
lck_mtx_lock(rnh_lock);
temp_rt = rt_lookup(TRUE, (struct sockaddr *)dstsock,
NULL, rt_tables[AF_INET6], ifscope);
lck_mtx_unlock(rnh_lock);
/*
* If the destination is directly reachable, relax
* the behavior around select_srcif, i.e. don't force
* the packet to go out from the interface that is hosting
* the source address.
* It happens when we share v6 with NAT66 and want
* the external interface's v6 address to be reachable
* to the clients we are sharing v6 connectivity with
* using NAT.
*/
if (temp_rt != NULL) {
if ((temp_rt->rt_flags & RTF_GATEWAY) == 0) {
select_srcif = FALSE;
is_direct = TRUE;
}
rtfree(temp_rt);
}
}
if (ip6_select_srcif_debug) {
printf("%s src %s dst %s ifscope %d is_direct %d select_srcif %d\n",
__func__, s_src, s_dst, ifscope, is_direct, select_srcif);
}
/* If the caller specified the outgoing interface explicitly, use it */
if (opts != NULL && (pi = opts->ip6po_pktinfo) != NULL &&
pi->ipi6_ifindex != 0) {
/*
* If IPV6_PKTINFO takes precedence over IPV6_BOUND_IF.
*/
ifscope = pi->ipi6_ifindex;
ifnet_head_lock_shared();
/* ifp may be NULL if detached or out of range */
ifp = ifp0 =
((ifscope <= if_index) ? ifindex2ifnet[ifscope] : NULL);
ifnet_head_done();
if (norouteok || retrt == NULL || IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
/*
* We do not have to check or get the route for
* multicast. If the caller didn't ask/care for
* the route and we have no interface to use,
* it's an error.
*/
if (ifp == NULL) {
error = EHOSTUNREACH;
}
goto done;
} else {
goto getsrcif;
}
}
/*
* 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) {
IM6O_LOCK(mopts);
ifp = ifp0 = mopts->im6o_multicast_ifp;
if (ifp != NULL && IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
IM6O_UNLOCK(mopts);
goto done; /* we don't need a route for link-local multicast */
}
IM6O_UNLOCK(mopts);
}
getsrcif:
/*
* If the outgoing interface was not set via IPV6_BOUND_IF or
* IPV6_PKTINFO, use the scope ID in the destination address.
*/
if (ifscope == IFSCOPE_NONE) {
ifscope = dstsock->sin6_scope_id;
}
/*
* Perform source interface selection; the source IPv6 address
* must belong to one of the addresses of the interface used
* by the route. For performance reasons, do this only if
* there is no route, or if the routing table has changed,
* or if we haven't done source interface selection on this
* route (for this PCB instance) before.
*/
if (!select_srcif) {
goto getroute;
} else if (!ROUTE_UNUSABLE(ro) && ro->ro_srcia != NULL &&
(ro->ro_flags & ROF_SRCIF_SELECTED)) {
if (ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) {
local_dst = TRUE;
}
ifa = ro->ro_srcia;
IFA_ADDREF(ifa); /* for caller */
goto getroute;
}
/*
* Given the source IPv6 address, find a suitable source interface
* to use for transmission; if a scope ID has been specified,
* optimize the search by looking at the addresses only for that
* interface. This is still suboptimal, however, as we need to
* traverse the per-interface list.
*/
if (ifscope != IFSCOPE_NONE || (ro != NULL && ro->ro_rt != NULL)) {
unsigned int scope = ifscope;
struct ifnet *rt_ifp;
rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL;
/*
* If no scope is specified and the route is stale (pointing
* to a defunct interface) use the current primary interface;
* this happens when switching between interfaces configured
* with the same IPv6 address. Otherwise pick up the scope
* information from the route; the ULP may have looked up a
* correct route and we just need to verify it here and mark
* it with the ROF_SRCIF_SELECTED flag below.
*/
if (scope == IFSCOPE_NONE) {
scope = rt_ifp->if_index;
if (scope != get_primary_ifscope(AF_INET6) &&
ROUTE_UNUSABLE(ro)) {
scope = get_primary_ifscope(AF_INET6);
}
}
ifa = (struct ifaddr *)
ifa_foraddr6_scoped(&srcsock->sin6_addr, scope);
/*
* If we are forwarding and proxying prefix(es), see if the
* source address is one of ours and is a proxied address;
* if so, use it.
*/
if (ifa == NULL && ip6_forwarding && nd6_prproxy) {
ifa = (struct ifaddr *)
ifa_foraddr6(&srcsock->sin6_addr);
if (ifa != NULL && !(proxied_ifa =
nd6_prproxy_ifaddr((struct in6_ifaddr *)ifa))) {
IFA_REMREF(ifa);
ifa = NULL;
}
}
if (ip6_select_srcif_debug && ifa != NULL) {
if (ro->ro_rt != NULL) {
printf("%s %s->%s ifscope %d->%d ifa_if %s "
"ro_if %s\n",
__func__,
s_src, s_dst, ifscope,
scope, if_name(ifa->ifa_ifp),
if_name(rt_ifp));
} else {
printf("%s %s->%s ifscope %d->%d ifa_if %s\n",
__func__,
s_src, s_dst, ifscope, scope,
if_name(ifa->ifa_ifp));
}
}
}
/*
* Slow path; search for an interface having the corresponding source
* IPv6 address if the scope was not specified by the caller, and:
*
* 1) There currently isn't any route, or,
* 2) The interface used by the route does not own that source
* IPv6 address; in this case, the route will get blown away
* and we'll do a more specific scoped search using the newly
* found interface.
*/
if (ifa == NULL && ifscope == IFSCOPE_NONE) {
struct ifaddr *ifadst;
/* Check if the destination address is one of ours */
ifadst = (struct ifaddr *)ifa_foraddr6(&dstsock->sin6_addr);
if (ifadst != NULL) {
local_dst = TRUE;
IFA_REMREF(ifadst);
}
ifa = (struct ifaddr *)ifa_foraddr6(&srcsock->sin6_addr);
if (ip6_select_srcif_debug && ifa != NULL) {
printf("%s %s->%s ifscope %d ifa_if %s\n",
__func__,
s_src, s_dst, ifscope, if_name(ifa->ifa_ifp));
} else if (ip6_select_srcif_debug) {
printf("%s %s->%s ifscope %d ifa_if NULL\n",
__func__,
s_src, s_dst, ifscope);
}
}
getroute:
if (ifa != NULL && !proxied_ifa && !local_dst) {
ifscope = ifa->ifa_ifp->if_index;
}
/*
* If the next hop address for the packet is specified by the caller,
* use it as the gateway.
*/
if (opts != NULL && opts->ip6po_nexthop != NULL) {
struct route_in6 *ron;
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;
if (ron->ro_rt != NULL) {
RT_LOCK(ron->ro_rt);
}
if (ROUTE_UNUSABLE(ron) || (ron->ro_rt != NULL &&
(!(ron->ro_rt->rt_flags & RTF_LLINFO) ||
(select_srcif && (ifa == NULL ||
(ifa->ifa_ifp != ron->ro_rt->rt_ifp && !proxied_ifa))))) ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr,
&sin6_next->sin6_addr)) {
if (ron->ro_rt != NULL) {
RT_UNLOCK(ron->ro_rt);
}
ROUTE_RELEASE(ron);
*satosin6(&ron->ro_dst) = *sin6_next;
}
if (ron->ro_rt == NULL) {
rtalloc_scoped((struct route *)ron, ifscope);
if (ron->ro_rt != NULL) {
RT_LOCK(ron->ro_rt);
}
if (ROUTE_UNUSABLE(ron) ||
!(ron->ro_rt->rt_flags & RTF_LLINFO) ||
!IN6_ARE_ADDR_EQUAL(&satosin6(rt_key(ron->ro_rt))->
sin6_addr, &sin6_next->sin6_addr)) {
if (ron->ro_rt != NULL) {
RT_UNLOCK(ron->ro_rt);
}
ROUTE_RELEASE(ron);
error = EHOSTUNREACH;
goto done;
}
}
route = ron;
ifp = ifp0 = ron->ro_rt->rt_ifp;
/*
* When cloning is required, try to allocate a route to the
* destination so that the caller can store path MTU
* information.
*/
if (!clone) {
if (select_srcif) {
/* Keep the route locked */
goto validateroute;
}
RT_UNLOCK(ron->ro_rt);
goto done;
}
RT_UNLOCK(ron->ro_rt);
}
/*
* 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 == NULL) {
goto done;
}
if (ro->ro_rt != NULL) {
RT_LOCK_SPIN(ro->ro_rt);
}
if (ROUTE_UNUSABLE(ro) || (ro->ro_rt != NULL &&
(satosin6(&ro->ro_dst)->sin6_family != AF_INET6 ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst) ||
(select_srcif && (ifa == NULL ||
(ifa->ifa_ifp != ro->ro_rt->rt_ifp && !proxied_ifa)))))) {
if (ro->ro_rt != NULL) {
RT_UNLOCK(ro->ro_rt);
}
ROUTE_RELEASE(ro);
}
if (ro->ro_rt == 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->sin6_family = AF_INET6;
sa6->sin6_len = sizeof(struct sockaddr_in6);
sa6->sin6_addr = *dst;
if (IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
ro->ro_rt = rtalloc1_scoped(
&((struct route *)ro)->ro_dst, 0, 0, ifscope);
} else {
rtalloc_scoped((struct route *)ro, ifscope);
}
if (ro->ro_rt != NULL) {
RT_LOCK_SPIN(ro->ro_rt);
}
}
/*
* Do not care about the result if we have the nexthop
* explicitly specified (in case we're asked to clone.)
*/
if (opts != NULL && opts->ip6po_nexthop != NULL) {
if (ro->ro_rt != NULL) {
RT_UNLOCK(ro->ro_rt);
}
goto done;
}
if (ro->ro_rt != NULL) {
RT_LOCK_ASSERT_HELD(ro->ro_rt);
ifp = ifp0 = ro->ro_rt->rt_ifp;
} else {
error = EHOSTUNREACH;
}
route = ro;
validateroute:
if (select_srcif) {
boolean_t has_route = (route != NULL && route->ro_rt != NULL);
boolean_t srcif_selected = FALSE;
if (has_route) {
RT_LOCK_ASSERT_HELD(route->ro_rt);
}
/*
* If there is a non-loopback route with the wrong interface,
* or if there is no interface configured with such an address,
* blow it away. Except for local/loopback, we look for one
* with a matching interface scope/index.
*/
if (has_route && (ifa == NULL ||
(ifa->ifa_ifp != ifp && ifp != lo_ifp) ||
!(route->ro_rt->rt_flags & RTF_UP))) {
/*
* If the destination address belongs to a proxied
* prefix, relax the requirement and allow the packet
* to come out of the proxy interface with the source
* address of the real interface.
*/
if (ifa != NULL && proxied_ifa &&
(route->ro_rt->rt_flags & (RTF_UP | RTF_PROXY)) ==
(RTF_UP | RTF_PROXY)) {
srcif_selected = TRUE;
} else {
if (ip6_select_srcif_debug) {
if (ifa != NULL) {
printf("%s->%s ifscope %d "
"ro_if %s != ifa_if %s "
"(cached route cleared)\n",
s_src, s_dst,
ifscope, if_name(ifp),
if_name(ifa->ifa_ifp));
} else {
printf("%s->%s ifscope %d "
"ro_if %s (no ifa_if "
"found)\n", s_src, s_dst,
ifscope, if_name(ifp));
}
}
RT_UNLOCK(route->ro_rt);
ROUTE_RELEASE(route);
error = EHOSTUNREACH;
/* Undo the settings done above */
route = NULL;
ifp = NULL; /* ditch ifp; keep ifp0 */
has_route = FALSE;
}
} else if (has_route) {
srcif_selected = TRUE;
}
if (srcif_selected) {
VERIFY(has_route);
if (ifa != route->ro_srcia ||
!(route->ro_flags & ROF_SRCIF_SELECTED)) {
RT_CONVERT_LOCK(route->ro_rt);
if (ifa != NULL) {
IFA_ADDREF(ifa); /* for route_in6 */
}
if (route->ro_srcia != NULL) {
IFA_REMREF(route->ro_srcia);
}
route->ro_srcia = ifa;
route->ro_flags |= ROF_SRCIF_SELECTED;
RT_GENID_SYNC(route->ro_rt);
}
RT_UNLOCK(route->ro_rt);
}
} else {
if (ro->ro_rt != NULL) {
RT_UNLOCK(ro->ro_rt);
}
if (ifp != NULL && opts != NULL &&
opts->ip6po_pktinfo != NULL &&
opts->ip6po_pktinfo->ipi6_ifindex != 0) {
/*
* 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->if_flags & IFF_LOOPBACK) && ifp->if_index !=
opts->ip6po_pktinfo->ipi6_ifindex) {
error = EHOSTUNREACH;
goto done;
}
}
}
done:
/*
* Check for interface restrictions.
*/
#define CHECK_RESTRICTIONS(_ip6oa, _ifp) \
((((_ip6oa)->ip6oa_flags & IP6OAF_NO_CELLULAR) && \
IFNET_IS_CELLULAR(_ifp)) || \
(((_ip6oa)->ip6oa_flags & IP6OAF_NO_EXPENSIVE) && \
IFNET_IS_EXPENSIVE(_ifp)) || \
(((_ip6oa)->ip6oa_flags & IP6OAF_NO_CONSTRAINED) && \
IFNET_IS_CONSTRAINED(_ifp)) || \
(!((_ip6oa)->ip6oa_flags & IP6OAF_INTCOPROC_ALLOWED) && \
IFNET_IS_INTCOPROC(_ifp)) || \
(!((_ip6oa)->ip6oa_flags & IP6OAF_AWDL_UNRESTRICTED) && \
IFNET_IS_AWDL_RESTRICTED(_ifp)))
if (error == 0 && ip6oa != NULL &&
((ifp && CHECK_RESTRICTIONS(ip6oa, ifp)) ||
(route && route->ro_rt &&
CHECK_RESTRICTIONS(ip6oa, route->ro_rt->rt_ifp)))) {
if (route != NULL && route->ro_rt != NULL) {
ROUTE_RELEASE(route);
route = NULL;
}
ifp = NULL; /* ditch ifp; keep ifp0 */
error = EHOSTUNREACH;
ip6oa->ip6oa_retflags |= IP6OARF_IFDENIED;
}
#undef CHECK_RESTRICTIONS
/*
* If the interface is disabled for IPv6, then ENETDOWN error.
*/
if (error == 0 &&
ifp != NULL && (ifp->if_eflags & IFEF_IPV6_DISABLED)) {
error = ENETDOWN;
}
if (ifp == NULL && (route == NULL || route->ro_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 || error == ENETDOWN) {
ip6stat.ip6s_noroute++;
}
/*
* We'll return ifp regardless of error, so pick it up from ifp0
* in case it was nullified above. Caller is responsible for
* releasing the ifp if it is non-NULL.
*/
ifp = ifp0;
if (retifp != NULL) {
if (ifp != NULL) {
ifnet_reference(ifp); /* for caller */
}
*retifp = ifp;
}
if (retsrcia != NULL) {
if (ifa != NULL) {
IFA_ADDREF(ifa); /* for caller */
}
*retsrcia = (struct in6_ifaddr *)ifa;
}
if (error == 0) {
if (retrt != NULL && route != NULL) {
*retrt = route->ro_rt; /* ro_rt may be NULL */
}
}
if (ip6_select_srcif_debug) {
printf("%s %s->%s ifscope %d ifa_if %s ro_if %s (error=%d)\n",
__func__,
s_src, s_dst, ifscope,
(ifa != NULL) ? if_name(ifa->ifa_ifp) : "NONE",
(ifp != NULL) ? if_name(ifp) : "NONE", error);
}
if (ifa != NULL) {
IFA_REMREF(ifa);
}
return error;
}
/*
* Regardless of error, it will return an ifp with a reference held if the
* caller provides a non-NULL retifp. The caller is responsible for checking
* if the returned ifp is valid and release its reference at all times.
*/
int
in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ip6_out_args *ip6oa, struct ifnet **retifp)
{
int err = 0;
struct route_in6 sro;
struct rtentry *rt = NULL;
if (ro == NULL) {
bzero(&sro, sizeof(sro));
ro = &sro;
}
if ((err = selectroute(NULL, dstsock, opts, mopts, NULL, ro, retifp,
&rt, 0, 1, ip6oa)) != 0) {
goto done;
}
/*
* 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))) {
err = ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH);
goto done;
}
/*
* 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 != NULL && rt->rt_ifa != NULL && rt->rt_ifa->ifa_ifp != NULL &&
retifp != NULL) {
ifnet_reference(rt->rt_ifa->ifa_ifp);
if (*retifp != NULL) {
ifnet_release(*retifp);
}
*retifp = rt->rt_ifa->ifa_ifp;
}
done:
if (ro == &sro) {
VERIFY(rt == NULL || rt == ro->ro_rt);
ROUTE_RELEASE(ro);
}
/*
* retifp might point to a valid ifp with a reference held;
* caller is responsible for releasing it if non-NULL.
*/
return err;
}
/*
* Regardless of error, it will return an ifp with a reference held if the
* caller provides a non-NULL retifp. The caller is responsible for checking
* if the returned ifp is valid and release its reference at all times.
*
* clone - meaningful only for bsdi and freebsd
*/
int
in6_selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
struct ip6_pktopts *opts, struct ip6_moptions *mopts,
struct in6_ifaddr **retsrcia, struct route_in6 *ro, struct ifnet **retifp,
struct rtentry **retrt, int clone, struct ip6_out_args *ip6oa)
{
return selectroute(srcsock, dstsock, opts, mopts, retsrcia, ro, retifp,
retrt, clone, 0, ip6oa);
}
/*
* Default hop limit selection. The precedence is as follows:
* 1. Hoplimit value specified via socket option.
* 2. (If the outgoing interface is detected) the current
* hop limit of the interface specified by router advertisement.
* 3. The system default hoplimit.
*/
uint8_t
in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
{
if (in6p && in6p->in6p_hops >= 0) {
return (uint8_t)in6p->in6p_hops;
} else if (NULL != ifp) {
uint8_t chlim;
struct nd_ifinfo *ndi = ND_IFINFO(ifp);
if (ndi && ndi->initialized) {
/* access chlim without lock, for performance */
chlim = ndi->chlim;
} else {
chlim = (uint8_t)ip6_defhlim;
}
return chlim;
}
return (uint8_t)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 proc *p,
int locked)
{
struct socket *so = inp->inp_socket;
uint16_t lport = 0, first, last, *lastport, rand_port;
int count, error = 0, wild = 0;
boolean_t counting_down;
bool found, randomport;
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
kauth_cred_t cred;
#pragma unused(laddr)
if (!locked) { /* Make sure we don't run into a deadlock: 4052373 */
if (!lck_rw_try_lock_exclusive(pcbinfo->ipi_lock)) {
socket_unlock(inp->inp_socket, 0);
lck_rw_lock_exclusive(pcbinfo->ipi_lock);
socket_lock(inp->inp_socket, 0);
}
/*
* Check if a local port was assigned to the inp while
* this thread was waiting for the pcbinfo lock
*/
if (inp->inp_lport != 0) {
VERIFY(inp->inp_flags2 & INP2_INHASHLIST);
lck_rw_done(pcbinfo->ipi_lock);
/*
* It is not an error if another thread allocated
* a port
*/
return 0;
}
}
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR | SO_REUSEPORT)) == 0) {
wild = INPLOOKUP_WILDCARD;
}
randomport = (so->so_flags & SOF_BINDRANDOMPORT) > 0 ||
(so->so_type == SOCK_STREAM ? tcp_use_randomport :
udp_use_randomport) > 0;
if (inp->inp_flags & INP_HIGHPORT) {
first = (uint16_t)ipport_hifirstauto; /* sysctl */
last = (uint16_t)ipport_hilastauto;
lastport = &pcbinfo->ipi_lasthi;
} else if (inp->inp_flags & INP_LOWPORT) {
cred = kauth_cred_proc_ref(p);
error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
kauth_cred_unref(&cred);
if (error != 0) {
if (!locked) {
lck_rw_done(pcbinfo->ipi_lock);
}
return error;
}
first = (uint16_t)ipport_lowfirstauto; /* 1023 */
last = (uint16_t)ipport_lowlastauto; /* 600 */
lastport = &pcbinfo->ipi_lastlow;
} else {
first = (uint16_t)ipport_firstauto; /* sysctl */
last = (uint16_t)ipport_lastauto;
lastport = &pcbinfo->ipi_lastport;
}
if (first == last) {
randomport = false;
}
/*
* Simple check to ensure all ports are not used up causing
* a deadlock here.
*/
found = false;
if (first > last) {
/* counting down */
if (randomport) {
read_frandom(&rand_port, sizeof(rand_port));
*lastport = first - (rand_port % (first - last));
}
count = first - last;
counting_down = TRUE;
} else {
/* counting up */
if (randomport) {
read_frandom(&rand_port, sizeof(rand_port));
*lastport = first + (rand_port % (first - last));
}
count = last - first;
counting_down = FALSE;
}
do {
if (count-- < 0) { /* completely used? */
/*
* Undo any address bind that may have
* occurred above.
*/
inp->in6p_laddr = in6addr_any;
inp->in6p_last_outifp = NULL;
if (!locked) {
lck_rw_done(pcbinfo->ipi_lock);
}
return EAGAIN;
}
if (counting_down) {
--*lastport;
if (*lastport > first || *lastport < last) {
*lastport = first;
}
} else {
++*lastport;
if (*lastport < first || *lastport > last) {
*lastport = first;
}
}
lport = htons(*lastport);
/*
* Skip if this is a restricted port as we do not want to
* restricted ports as ephemeral
*/
if (IS_RESTRICTED_IN_PORT(lport)) {
continue;
}
found = (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild) == NULL);
} while (!found);
inp->inp_lport = lport;
inp->inp_flags |= INP_ANONPORT;
if (in_pcbinshash(inp, 1) != 0) {
inp->in6p_laddr = in6addr_any;
inp->in6p_last_outifp = NULL;
inp->inp_lport = 0;
inp->inp_flags &= ~INP_ANONPORT;
if (!locked) {
lck_rw_done(pcbinfo->ipi_lock);
}
return EAGAIN;
}
if (!locked) {
lck_rw_done(pcbinfo->ipi_lock);
}
return 0;
}
/*
* The followings are implementation of the policy table using a
* simple tail queue.
* XXX such details should be hidden.
* XXX implementation using binary tree should be more efficient.
*/
struct addrsel_policyent {
TAILQ_ENTRY(addrsel_policyent) ape_entry;
struct in6_addrpolicy ape_policy;
};
TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
struct addrsel_policyhead addrsel_policytab;
static void
init_policy_queue(void)
{
TAILQ_INIT(&addrsel_policytab);
}
void
addrsel_policy_init(void)
{
/*
* Default address selection policy based on RFC 6724.
*/
static const struct in6_addrpolicy defaddrsel[] = {
/* Loopback -- prefix=::1/128, precedence=50, label=0 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_LOOPBACK_INIT,
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK128,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 50,
.label = 0
},
/* Unspecified -- prefix=::/0, precedence=40, label=1 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK0,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 40,
.label = 1
},
/* IPv4 Mapped -- prefix=::ffff:0:0/96, precedence=35, label=4 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_V4MAPPED_INIT,
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK96,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 35,
.label = 4
},
/* 6to4 -- prefix=2002::/16, precedence=30, label=2 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = {{{ 0x20, 0x02 }}},
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK16,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 30,
.label = 2
},
/* Teredo -- prefix=2001::/32, precedence=5, label=5 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = {{{ 0x20, 0x01 }}},
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK32,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 5,
.label = 5
},
/* Unique Local (ULA) -- prefix=fc00::/7, precedence=3, label=13 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = {{{ 0xfc }}},
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK7,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 3,
.label = 13
},
/* IPv4 Compatible -- prefix=::/96, precedence=1, label=3 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK96,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 1,
.label = 3
},
/* Site-local (deprecated) -- prefix=fec0::/10, precedence=1, label=11 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = {{{ 0xfe, 0xc0 }}},
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK16,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 1,
.label = 11
},
/* 6bone (deprecated) -- prefix=3ffe::/16, precedence=1, label=12 */
{
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = {{{ 0x3f, 0xfe }}},
.sin6_len = sizeof(struct sockaddr_in6)
},
.addrmask = {
.sin6_family = AF_INET6,
.sin6_addr = IN6MASK16,
.sin6_len = sizeof(struct sockaddr_in6)
},
.preced = 1,
.label = 12
},
};
int i;
init_policy_queue();
/* initialize the "last resort" policy */
bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy));
defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
for (i = 0; i < sizeof(defaddrsel) / sizeof(defaddrsel[0]); i++) {
add_addrsel_policyent(&defaddrsel[i]);
}
}
struct in6_addrpolicy *
in6_addrsel_lookup_policy(struct sockaddr_in6 *key)
{
struct in6_addrpolicy *match = NULL;
ADDRSEL_LOCK();
match = match_addrsel_policy(key);
if (match == NULL) {
match = &defaultaddrpolicy;
} else {
match->use++;
}
ADDRSEL_UNLOCK();
return match;
}
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, &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;
}
static int
add_addrsel_policyent(const struct in6_addrpolicy *newpolicy)
{
struct addrsel_policyent *new, *pol;
MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR,
M_WAITOK);
ADDRSEL_LOCK();
/* duplication check */
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
&pol->ape_policy.addr.sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
&pol->ape_policy.addrmask.sin6_addr)) {
ADDRSEL_UNLOCK();
FREE(new, M_IFADDR);
return EEXIST; /* or override it? */
}
}
bzero(new, sizeof(*new));
/* XXX: should validate entry */
new->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
ADDRSEL_UNLOCK();
return 0;
}
#ifdef ENABLE_ADDRSEL
static int
delete_addrsel_policyent(const struct in6_addrpolicy *key)
{
struct addrsel_policyent *pol;
ADDRSEL_LOCK();
/* search for the entry in the table */
TAILQ_FOREACH(pol, &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();
return ESRCH;
}
TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
FREE(pol, M_IFADDR);
pol = NULL;
ADDRSEL_UNLOCK();
return 0;
}
#endif /* ENABLE_ADDRSEL */
int
walk_addrsel_policy(int (*callback)(const struct in6_addrpolicy *, void *),
void *w)
{
struct addrsel_policyent *pol;
int error = 0;
ADDRSEL_LOCK();
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
ADDRSEL_UNLOCK();
return error;
}
}
ADDRSEL_UNLOCK();
return error;
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct walkarg {
struct sysctl_req *w_req;
};
static int
dump_addrsel_policyent(const 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 int
in6_src_sysctl SYSCTL_HANDLER_ARGS
{
#pragma unused(oidp, arg1, arg2)
struct walkarg w;
if (req->newptr) {
return EPERM;
}
bzero(&w, sizeof(w));
w.w_req = req;
return walk_addrsel_policy(dump_addrsel_policyent, &w);
}
SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
CTLFLAG_RD | CTLFLAG_LOCKED, in6_src_sysctl, "");
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 */
}
bcopy(data, &ent0, sizeof(ent0));
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:
#ifdef ENABLE_ADDRSEL
return add_addrsel_policyent(&ent0);
#else
return ENOTSUP;
#endif
case SIOCDADDRCTL_POLICY:
#ifdef ENABLE_ADDRSEL
return delete_addrsel_policyent(&ent0);
#else
return ENOTSUP;
#endif
}
return 0; /* XXX: compromise compilers */
}
/*
* generate kernel-internal form (scopeid embedded into s6_addr16[1]).
* If the address scope of is link-local, embed the interface index in the
* address. The routine determines our precedence
* between advanced API scope/interface specification and basic API
* specification.
*
* this function should be nuked in the future, when we get rid of
* embedded scopeid thing.
*
* XXX actually, it is over-specification to return ifp against sin6_scope_id.
* there can be multiple interfaces that belong to a particular scope zone
* (in specification, we have 1:N mapping between a scope zone and interfaces).
* we may want to change the function to return something other than ifp.
*/
int
in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6,
struct in6pcb *in6p, struct ifnet **ifpp, struct ip6_pktopts *opt)
{
struct ifnet *ifp = NULL;
u_int32_t scopeid;
struct ip6_pktopts *optp = NULL;
*in6 = sin6->sin6_addr;
scopeid = sin6->sin6_scope_id;
if (ifpp != NULL) {
*ifpp = NULL;
}
/*
* don't try to read sin6->sin6_addr beyond here, since the caller may
* ask us to overwrite existing sockaddr_in6
*/
#ifdef ENABLE_DEFAULT_SCOPE
if (scopeid == 0) {
scopeid = scope6_addr2default(in6);
}
#endif
if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
struct in6_pktinfo *pi;
struct ifnet *im6o_multicast_ifp = NULL;
if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
in6p->in6p_moptions != NULL) {
IM6O_LOCK(in6p->in6p_moptions);
im6o_multicast_ifp =
in6p->in6p_moptions->im6o_multicast_ifp;
IM6O_UNLOCK(in6p->in6p_moptions);
}
if (opt != NULL) {
optp = opt;
} else if (in6p != NULL) {
optp = in6p->in6p_outputopts;
}
/*
* KAME assumption: link id == interface id
*/
if (in6p != NULL && optp != NULL &&
(pi = optp->ip6po_pktinfo) != NULL &&
pi->ipi6_ifindex != 0) {
/* ifp is needed here if only we're returning it */
if (ifpp != NULL) {
ifnet_head_lock_shared();
ifp = ifindex2ifnet[pi->ipi6_ifindex];
ifnet_head_done();
}
in6->s6_addr16[1] = htons((uint16_t)pi->ipi6_ifindex);
} else if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
in6p->in6p_moptions != NULL && im6o_multicast_ifp != NULL) {
ifp = im6o_multicast_ifp;
in6->s6_addr16[1] = htons(ifp->if_index);
} else if (scopeid != 0) {
/*
* Since scopeid is unsigned, we only have to check it
* against if_index (ifnet_head_lock not needed since
* if_index is an ever-increasing integer.)
*/
if (if_index < scopeid) {
return ENXIO; /* XXX EINVAL? */
}
/* ifp is needed here only if we're returning it */
if (ifpp != NULL) {
ifnet_head_lock_shared();
ifp = ifindex2ifnet[scopeid];
ifnet_head_done();
}
/* XXX assignment to 16bit from 32bit variable */
in6->s6_addr16[1] = htons(scopeid & 0xffff);
}
if (ifpp != NULL) {
if (ifp != NULL) {
ifnet_reference(ifp); /* for caller */
}
*ifpp = ifp;
}
}
return 0;
}
/*
* generate standard sockaddr_in6 from embedded form.
* touches sin6_addr and sin6_scope_id only.
*
* this function should be nuked in the future, when we get rid of
* embedded scopeid thing.
*/
int
in6_recoverscope(
struct sockaddr_in6 *sin6,
const struct in6_addr *in6,
struct ifnet *ifp)
{
u_int32_t scopeid;
sin6->sin6_addr = *in6;
/*
* don't try to read *in6 beyond here, since the caller may
* ask us to overwrite existing sockaddr_in6
*/
sin6->sin6_scope_id = 0;
if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
/*
* KAME assumption: link id == interface id
*/
scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
if (scopeid) {
/*
* sanity check
*
* Since scopeid is unsigned, we only have to check it
* against if_index
*/
if (if_index < scopeid) {
return ENXIO;
}
if (ifp && ifp->if_index != scopeid) {
return ENXIO;
}
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = scopeid;
}
}
return 0;
}
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