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freebsd-skq/sys/netinet6/in6_src.c
rwatson fdfdadb612 Decompose the current single inpcbinfo lock into two locks: 
- The existing ipi_lock continues to protect the global inpcb list and
  inpcb counter.  This lock is now relegated to a small number of
  allocation and free operations, and occasional operations that walk
  all connections (including, awkwardly, certain UDP multicast receive
  operations -- something to revisit).

- A new ipi_hash_lock protects the two inpcbinfo hash tables for
  looking up connections and bound sockets, manipulated using new
  INP_HASH_*() macros.  This lock, combined with inpcb locks, protects
  the 4-tuple address space.

Unlike the current ipi_lock, ipi_hash_lock follows the individual inpcb
connection locks, so may be acquired while manipulating a connection on
which a lock is already held, avoiding the need to acquire the inpcbinfo
lock preemptively when a binding change might later be required.  As a
result, however, lookup operations necessarily go through a reference
acquire while holding the lookup lock, later acquiring an inpcb lock --
if required.

A new function in_pcblookup() looks up connections, and accepts flags
indicating how to return the inpcb.  Due to lock order changes, callers
no longer need acquire locks before performing a lookup: the lookup
routine will acquire the ipi_hash_lock as needed.  In the future, it will
also be able to use alternative lookup and locking strategies
transparently to callers, such as pcbgroup lookup.  New lookup flags are,
supplementing the existing INPLOOKUP_WILDCARD flag:

  INPLOOKUP_RLOCKPCB - Acquire a read lock on the returned inpcb
  INPLOOKUP_WLOCKPCB - Acquire a write lock on the returned inpcb

Callers must pass exactly one of these flags (for the time being).

Some notes:

- All protocols are updated to work within the new regime; especially,
  TCP, UDPv4, and UDPv6.  pcbinfo ipi_lock acquisitions are largely
  eliminated, and global hash lock hold times are dramatically reduced
  compared to previous locking.
- The TCP syncache still relies on the pcbinfo lock, something that we
  may want to revisit.
- Support for reverting to the FreeBSD 7.x locking strategy in TCP input
  is no longer available -- hash lookup locks are now held only very
  briefly during inpcb lookup, rather than for potentially extended
  periods.  However, the pcbinfo ipi_lock will still be acquired if a
  connection state might change such that a connection is added or
  removed.
- Raw IP sockets continue to use the pcbinfo ipi_lock for protection,
  due to maintaining their own hash tables.
- The interface in6_pcblookup_hash_locked() is maintained, which allows
  callers to acquire hash locks and perform one or more lookups atomically
  with 4-tuple allocation: this is required only for TCPv6, as there is no
  in6_pcbconnect_setup(), which there should be.
- UDPv6 locking remains significantly more conservative than UDPv4
  locking, which relates to source address selection.  This needs
  attention, as it likely significantly reduces parallelism in this code
  for multithreaded socket use (such as in BIND).
- In the UDPv4 and UDPv6 multicast cases, we need to revisit locking
  somewhat, as they relied on ipi_lock to stablise 4-tuple matches, which
  is no longer sufficient.  A second check once the inpcb lock is held
  should do the trick, keeping the general case from requiring the inpcb
  lock for every inpcb visited.
- This work reminds us that we need to revisit locking of the v4/v6 flags,
  which may be accessed lock-free both before and after this change.
- Right now, a single lock name is used for the pcbhash lock -- this is
  undesirable, and probably another argument is required to take care of
  this (or a char array name field in the pcbinfo?).

This is not an MFC candidate for 8.x due to its impact on lookup and
locking semantics.  It's possible some of these issues could be worked
around with compatibility wrappers, if necessary.

Reviewed by:    bz
Sponsored by:   Juniper Networks, Inc.
2011-05-30 09:43:55 +00:00

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/*-
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $
*/
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/if_llatbl.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
static struct mtx addrsel_lock;
#define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
#define ADDRSEL_LOCK() mtx_lock(&addrsel_lock)
#define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock)
#define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED)
static struct sx addrsel_sxlock;
#define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock")
#define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock)
#define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock)
#define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock)
#define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock)
#define ADDR_LABEL_NOTAPP (-1)
static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy);
#define V_defaultaddrpolicy VNET(defaultaddrpolicy)
VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *, struct ifnet **,
struct rtentry **, int));
static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *ro, struct ifnet **));
static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *);
static void init_policy_queue(void);
static int add_addrsel_policyent(struct in6_addrpolicy *);
static int delete_addrsel_policyent(struct in6_addrpolicy *);
static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *),
void *));
static int dump_addrsel_policyent(struct in6_addrpolicy *, void *);
static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
/*
* Return an IPv6 address, which is the most appropriate for a given
* destination and user specified options.
* If necessary, this function lookups the routing table and returns
* an entry to the caller for later use.
*/
#define REPLACE(r) do {\
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
/* { \
char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
} */ \
goto replace; \
} while(0)
#define NEXT(r) do {\
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
/* { \
char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
} */ \
goto next; /* XXX: we can't use 'continue' here */ \
} while(0)
#define BREAK(r) do { \
if ((r) < sizeof(V_ip6stat.ip6s_sources_rule) / \
sizeof(V_ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
V_ip6stat.ip6s_sources_rule[(r)]++; \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
int
in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct inpcb *inp, struct route_in6 *ro, struct ucred *cred,
struct ifnet **ifpp, struct in6_addr *srcp)
{
struct in6_addr dst, tmp;
struct ifnet *ifp = NULL;
struct in6_ifaddr *ia = NULL, *ia_best = NULL;
struct in6_pktinfo *pi = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
u_int32_t odstzone;
int prefer_tempaddr;
int error;
struct ip6_moptions *mopts;
KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__));
dst = dstsock->sin6_addr; /* make a copy for local operation */
if (ifpp)
*ifpp = NULL;
if (inp != NULL) {
INP_LOCK_ASSERT(inp);
mopts = inp->in6p_moptions;
} else {
mopts = NULL;
}
/*
* If the source address is explicitly specified by the caller,
* check if the requested source address is indeed a unicast address
* assigned to the node, and can be used as the packet's source
* address. If everything is okay, use the address as source.
*/
if (opts && (pi = opts->ip6po_pktinfo) &&
!IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
struct sockaddr_in6 srcsock;
struct in6_ifaddr *ia6;
/* get the outgoing interface */
if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0)
return (error);
/*
* determine the appropriate zone id of the source based on
* the zone of the destination and the outgoing interface.
* If the specified address is ambiguous wrt the scope zone,
* the interface must be specified; otherwise, ifa_ifwithaddr()
* will fail matching the address.
*/
bzero(&srcsock, sizeof(srcsock));
srcsock.sin6_family = AF_INET6;
srcsock.sin6_len = sizeof(srcsock);
srcsock.sin6_addr = pi->ipi6_addr;
if (ifp) {
error = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
if (error)
return (error);
}
if (cred != NULL && (error = prison_local_ip6(cred,
&srcsock.sin6_addr, (inp != NULL &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
return (error);
ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(
(struct sockaddr *)&srcsock);
if (ia6 == NULL ||
(ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
if (ia6 != NULL)
ifa_free(&ia6->ia_ifa);
return (EADDRNOTAVAIL);
}
pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
bcopy(&ia6->ia_addr.sin6_addr, srcp, sizeof(*srcp));
ifa_free(&ia6->ia_ifa);
return (0);
}
/*
* Otherwise, if the socket has already bound the source, just use it.
*/
if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
if (cred != NULL &&
(error = prison_local_ip6(cred, &inp->in6p_laddr,
((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
return (error);
bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp));
return (0);
}
/*
* Bypass source address selection and use the primary jail IP
* if requested.
*/
if (cred != NULL && !prison_saddrsel_ip6(cred, srcp))
return (0);
/*
* If the address is not specified, choose the best one based on
* the outgoing interface and the destination address.
*/
/* get the outgoing interface */
if ((error = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0)
return (error);
#ifdef DIAGNOSTIC
if (ifp == NULL) /* this should not happen */
panic("in6_selectsrc: NULL ifp");
#endif
error = in6_setscope(&dst, ifp, &odstzone);
if (error)
return (error);
IN6_IFADDR_RLOCK();
TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
int new_scope = -1, new_matchlen = -1;
struct in6_addrpolicy *new_policy = NULL;
u_int32_t srczone, osrczone, dstzone;
struct in6_addr src;
struct ifnet *ifp1 = ia->ia_ifp;
/*
* We'll never take an address that breaks the scope zone
* of the destination. We also skip an address if its zone
* does not contain the outgoing interface.
* XXX: we should probably use sin6_scope_id here.
*/
if (in6_setscope(&dst, ifp1, &dstzone) ||
odstzone != dstzone) {
continue;
}
src = ia->ia_addr.sin6_addr;
if (in6_setscope(&src, ifp, &osrczone) ||
in6_setscope(&src, ifp1, &srczone) ||
osrczone != srczone) {
continue;
}
/* avoid unusable addresses */
if ((ia->ia6_flags &
(IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
continue;
}
if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
continue;
/* If jailed only take addresses of the jail into account. */
if (cred != NULL &&
prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0)
continue;
/* Rule 1: Prefer same address */
if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
ia_best = ia;
BREAK(1); /* there should be no better candidate */
}
if (ia_best == NULL)
REPLACE(0);
/* Rule 2: Prefer appropriate scope */
if (dst_scope < 0)
dst_scope = in6_addrscope(&dst);
new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
REPLACE(2);
NEXT(2);
} else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
NEXT(2);
REPLACE(2);
}
/*
* Rule 3: Avoid deprecated addresses. Note that the case of
* !ip6_use_deprecated is already rejected above.
*/
if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
NEXT(3);
if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
REPLACE(3);
/* Rule 4: Prefer home addresses */
/*
* XXX: This is a TODO. We should probably merge the MIP6
* case above.
*/
/* Rule 5: Prefer outgoing interface */
if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
NEXT(5);
if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
REPLACE(5);
/*
* Rule 6: Prefer matching label
* Note that best_policy should be non-NULL here.
*/
if (dst_policy == NULL)
dst_policy = lookup_addrsel_policy(dstsock);
if (dst_policy->label != ADDR_LABEL_NOTAPP) {
new_policy = lookup_addrsel_policy(&ia->ia_addr);
if (dst_policy->label == best_policy->label &&
dst_policy->label != new_policy->label)
NEXT(6);
if (dst_policy->label != best_policy->label &&
dst_policy->label == new_policy->label)
REPLACE(6);
}
/*
* Rule 7: Prefer public addresses.
* We allow users to reverse the logic by configuring
* a sysctl variable, so that privacy conscious users can
* always prefer temporary addresses.
*/
if (opts == NULL ||
opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
prefer_tempaddr = V_ip6_prefer_tempaddr;
} else if (opts->ip6po_prefer_tempaddr ==
IP6PO_TEMPADDR_NOTPREFER) {
prefer_tempaddr = 0;
} else
prefer_tempaddr = 1;
if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
REPLACE(7);
else
NEXT(7);
}
if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
!(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
NEXT(7);
else
REPLACE(7);
}
/*
* Rule 8: prefer addresses on alive interfaces.
* This is a KAME specific rule.
*/
if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
!(ia->ia_ifp->if_flags & IFF_UP))
NEXT(8);
if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
(ia->ia_ifp->if_flags & IFF_UP))
REPLACE(8);
/*
* Rule 14: Use longest matching prefix.
* Note: in the address selection draft, this rule is
* documented as "Rule 8". However, since it is also
* documented that this rule can be overridden, we assign
* a large number so that it is easy to assign smaller numbers
* to more preferred rules.
*/
new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
if (best_matchlen < new_matchlen)
REPLACE(14);
if (new_matchlen < best_matchlen)
NEXT(14);
/* Rule 15 is reserved. */
/*
* Last resort: just keep the current candidate.
* Or, do we need more rules?
*/
continue;
replace:
ia_best = ia;
best_scope = (new_scope >= 0 ? new_scope :
in6_addrscope(&ia_best->ia_addr.sin6_addr));
best_policy = (new_policy ? new_policy :
lookup_addrsel_policy(&ia_best->ia_addr));
best_matchlen = (new_matchlen >= 0 ? new_matchlen :
in6_matchlen(&ia_best->ia_addr.sin6_addr,
&dst));
next:
continue;
out:
break;
}
if ((ia = ia_best) == NULL) {
IN6_IFADDR_RUNLOCK();
return (EADDRNOTAVAIL);
}
/*
* At this point at least one of the addresses belonged to the jail
* but it could still be, that we want to further restrict it, e.g.
* theoratically IN6_IS_ADDR_LOOPBACK.
* It must not be IN6_IS_ADDR_UNSPECIFIED anymore.
* prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should
* let all others previously selected pass.
* Use tmp to not change ::1 on lo0 to the primary jail address.
*/
tmp = ia->ia_addr.sin6_addr;
if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) {
IN6_IFADDR_RUNLOCK();
return (EADDRNOTAVAIL);
}
if (ifpp)
*ifpp = ifp;
bcopy(&tmp, srcp, sizeof(*srcp));
IN6_IFADDR_RUNLOCK();
return (0);
}
/*
* clone - meaningful only for bsdi and freebsd
*/
static int
selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt, int norouteok)
{
int error = 0;
struct ifnet *ifp = NULL;
struct rtentry *rt = NULL;
struct sockaddr_in6 *sin6_next;
struct in6_pktinfo *pi = NULL;
struct in6_addr *dst = &dstsock->sin6_addr;
#if 0
char ip6buf[INET6_ADDRSTRLEN];
if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
dstsock->sin6_addr.s6_addr32[1] == 0 &&
!IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
printf("in6_selectroute: strange destination %s\n",
ip6_sprintf(ip6buf, &dstsock->sin6_addr));
} else {
printf("in6_selectroute: destination = %s%%%d\n",
ip6_sprintf(ip6buf, &dstsock->sin6_addr),
dstsock->sin6_scope_id); /* for debug */
}
#endif
/* If the caller specify the outgoing interface explicitly, use it. */
if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
/* XXX boundary check is assumed to be already done. */
ifp = ifnet_byindex(pi->ipi6_ifindex);
if (ifp != NULL &&
(norouteok || retrt == NULL ||
IN6_IS_ADDR_MULTICAST(dst))) {
/*
* we do not have to check or get the route for
* multicast.
*/
goto done;
} else
goto getroute;
}
/*
* If the destination address is a multicast address and the outgoing
* interface for the address is specified by the caller, use it.
*/
if (IN6_IS_ADDR_MULTICAST(dst) &&
mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
goto done; /* we do not need a route for multicast. */
}
getroute:
/*
* If the next hop address for the packet is specified by the caller,
* use it as the gateway.
*/
if (opts && opts->ip6po_nexthop) {
struct route_in6 *ron;
struct llentry *la;
sin6_next = satosin6(opts->ip6po_nexthop);
/* at this moment, we only support AF_INET6 next hops */
if (sin6_next->sin6_family != AF_INET6) {
error = EAFNOSUPPORT; /* or should we proceed? */
goto done;
}
/*
* If the next hop is an IPv6 address, then the node identified
* by that address must be a neighbor of the sending host.
*/
ron = &opts->ip6po_nextroute;
/*
* XXX what do we do here?
* PLZ to be fixing
*/
if (ron->ro_rt == NULL) {
rtalloc((struct route *)ron); /* multi path case? */
if (ron->ro_rt == NULL) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
error = EHOSTUNREACH;
goto done;
}
}
rt = ron->ro_rt;
ifp = rt->rt_ifp;
IF_AFDATA_LOCK(ifp);
la = lla_lookup(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6_next->sin6_addr);
IF_AFDATA_UNLOCK(ifp);
if (la != NULL)
LLE_RUNLOCK(la);
else {
error = EHOSTUNREACH;
goto done;
}
#if 0
if ((ron->ro_rt &&
(ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) !=
(RTF_UP | RTF_LLINFO)) ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ron->ro_dst)->sin6_addr,
&sin6_next->sin6_addr)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
*satosin6(&ron->ro_dst) = *sin6_next;
}
if (ron->ro_rt == NULL) {
rtalloc((struct route *)ron); /* multi path case? */
if (ron->ro_rt == NULL ||
!(ron->ro_rt->rt_flags & RTF_LLINFO)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
error = EHOSTUNREACH;
goto done;
}
}
#endif
/*
* When cloning is required, try to allocate a route to the
* destination so that the caller can store path MTU
* information.
*/
goto done;
}
/*
* Use a cached route if it exists and is valid, else try to allocate
* a new one. Note that we should check the address family of the
* cached destination, in case of sharing the cache with IPv4.
*/
if (ro) {
if (ro->ro_rt &&
(!(ro->ro_rt->rt_flags & RTF_UP) ||
((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
dst))) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)NULL;
}
if (ro->ro_rt == (struct rtentry *)NULL) {
struct sockaddr_in6 *sa6;
/* No route yet, so try to acquire one */
bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
*sa6 = *dstsock;
sa6->sin6_scope_id = 0;
#ifdef RADIX_MPATH
rtalloc_mpath((struct route *)ro,
ntohl(sa6->sin6_addr.s6_addr32[3]));
#else
ro->ro_rt = rtalloc1(&((struct route *)ro)
->ro_dst, 0, 0UL);
if (ro->ro_rt)
RT_UNLOCK(ro->ro_rt);
#endif
}
/*
* do not care about the result if we have the nexthop
* explicitly specified.
*/
if (opts && opts->ip6po_nexthop)
goto done;
if (ro->ro_rt) {
ifp = ro->ro_rt->rt_ifp;
if (ifp == NULL) { /* can this really happen? */
RTFREE(ro->ro_rt);
ro->ro_rt = NULL;
}
}
if (ro->ro_rt == NULL)
error = EHOSTUNREACH;
rt = ro->ro_rt;
/*
* Check if the outgoing interface conflicts with
* the interface specified by ipi6_ifindex (if specified).
* Note that loopback interface is always okay.
* (this may happen when we are sending a packet to one of
* our own addresses.)
*/
if (ifp && opts && opts->ip6po_pktinfo &&
opts->ip6po_pktinfo->ipi6_ifindex) {
if (!(ifp->if_flags & IFF_LOOPBACK) &&
ifp->if_index !=
opts->ip6po_pktinfo->ipi6_ifindex) {
error = EHOSTUNREACH;
goto done;
}
}
}
done:
if (ifp == NULL && rt == NULL) {
/*
* This can happen if the caller did not pass a cached route
* nor any other hints. We treat this case an error.
*/
error = EHOSTUNREACH;
}
if (error == EHOSTUNREACH)
V_ip6stat.ip6s_noroute++;
if (retifp != NULL) {
*retifp = ifp;
/*
* Adjust the "outgoing" interface. If we're going to loop
* the packet back to ourselves, the ifp would be the loopback
* interface. However, we'd rather know the interface associated
* to the destination address (which should probably be one of
* our own addresses.)
*/
if (rt) {
if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) &&
(rt->rt_gateway->sa_family == AF_LINK))
*retifp =
ifnet_byindex(((struct sockaddr_dl *)
rt->rt_gateway)->sdl_index);
}
}
if (retrt != NULL)
*retrt = rt; /* rt may be NULL */
return (error);
}
static int
in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro, struct ifnet **retifp)
{
int error;
struct route_in6 sro;
struct rtentry *rt = NULL;
if (ro == NULL) {
bzero(&sro, sizeof(sro));
ro = &sro;
}
if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
&rt, 1)) != 0) {
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (error);
}
/*
* do not use a rejected or black hole route.
* XXX: this check should be done in the L2 output routine.
* However, if we skipped this check here, we'd see the following
* scenario:
* - install a rejected route for a scoped address prefix
* (like fe80::/10)
* - send a packet to a destination that matches the scoped prefix,
* with ambiguity about the scope zone.
* - pick the outgoing interface from the route, and disambiguate the
* scope zone with the interface.
* - ip6_output() would try to get another route with the "new"
* destination, which may be valid.
* - we'd see no error on output.
* Although this may not be very harmful, it should still be confusing.
* We thus reject the case here.
*/
if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (flags);
}
if (ro == &sro && rt && rt == sro.ro_rt)
RTFREE(rt);
return (0);
}
/*
* clone - meaningful only for bsdi and freebsd
*/
int
in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct rtentry **retrt)
{
return (selectroute(dstsock, opts, mopts, ro, retifp,
retrt, 0));
}
/*
* Default hop limit selection. The precedence is as follows:
* 1. Hoplimit value specified via ioctl.
* 2. (If the outgoing interface is detected) the current
* hop limit of the interface specified by router advertisement.
* 3. The system default hoplimit.
*/
int
in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp)
{
if (in6p && in6p->in6p_hops >= 0)
return (in6p->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
struct route_in6 ro6;
struct ifnet *lifp;
bzero(&ro6, sizeof(ro6));
ro6.ro_dst.sin6_family = AF_INET6;
ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
ro6.ro_dst.sin6_addr = in6p->in6p_faddr;
rtalloc((struct route *)&ro6);
if (ro6.ro_rt) {
lifp = ro6.ro_rt->rt_ifp;
RTFREE(ro6.ro_rt);
if (lifp)
return (ND_IFINFO(lifp)->chlim);
} else
return (V_ip6_defhlim);
}
return (V_ip6_defhlim);
}
/*
* XXX: this is borrowed from in6_pcbbind(). If possible, we should
* share this function by all *bsd*...
*/
int
in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
{
struct socket *so = inp->inp_socket;
u_int16_t lport = 0;
int error, lookupflags = 0;
#ifdef INVARIANTS
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
#endif
INP_WLOCK_ASSERT(inp);
INP_HASH_WLOCK_ASSERT(pcbinfo);
error = prison_local_ip6(cred, laddr,
((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0));
if (error)
return(error);
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
lookupflags = INPLOOKUP_WILDCARD;
inp->inp_flags |= INP_ANONPORT;
error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags);
if (error != 0)
return (error);
inp->inp_lport = lport;
if (in_pcbinshash(inp) != 0) {
inp->in6p_laddr = in6addr_any;
inp->inp_lport = 0;
return (EAGAIN);
}
return (0);
}
void
addrsel_policy_init(void)
{
init_policy_queue();
/* initialize the "last resort" policy */
bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy));
V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
if (!IS_DEFAULT_VNET(curvnet))
return;
ADDRSEL_LOCK_INIT();
ADDRSEL_SXLOCK_INIT();
}
static struct in6_addrpolicy *
lookup_addrsel_policy(struct sockaddr_in6 *key)
{
struct in6_addrpolicy *match = NULL;
ADDRSEL_LOCK();
match = match_addrsel_policy(key);
if (match == NULL)
match = &V_defaultaddrpolicy;
else
match->use++;
ADDRSEL_UNLOCK();
return (match);
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct walkarg {
struct sysctl_req *w_req;
};
static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
CTLFLAG_RD, in6_src_sysctl, "");
static int
in6_src_sysctl(SYSCTL_HANDLER_ARGS)
{
struct walkarg w;
if (req->newptr)
return EPERM;
bzero(&w, sizeof(w));
w.w_req = req;
return (walk_addrsel_policy(dump_addrsel_policyent, &w));
}
int
in6_src_ioctl(u_long cmd, caddr_t data)
{
int i;
struct in6_addrpolicy ent0;
if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
return (EOPNOTSUPP); /* check for safety */
ent0 = *(struct in6_addrpolicy *)data;
if (ent0.label == ADDR_LABEL_NOTAPP)
return (EINVAL);
/* check if the prefix mask is consecutive. */
if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
return (EINVAL);
/* clear trailing garbages (if any) of the prefix address. */
for (i = 0; i < 4; i++) {
ent0.addr.sin6_addr.s6_addr32[i] &=
ent0.addrmask.sin6_addr.s6_addr32[i];
}
ent0.use = 0;
switch (cmd) {
case SIOCAADDRCTL_POLICY:
return (add_addrsel_policyent(&ent0));
case SIOCDADDRCTL_POLICY:
return (delete_addrsel_policyent(&ent0));
}
return (0); /* XXX: compromise compilers */
}
/*
* The followings are implementation of the policy table using a
* simple tail queue.
* XXX such details should be hidden.
* XXX implementation using binary tree should be more efficient.
*/
struct addrsel_policyent {
TAILQ_ENTRY(addrsel_policyent) ape_entry;
struct in6_addrpolicy ape_policy;
};
TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab);
#define V_addrsel_policytab VNET(addrsel_policytab)
static void
init_policy_queue(void)
{
TAILQ_INIT(&V_addrsel_policytab);
}
static int
add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
{
struct addrsel_policyent *new, *pol;
new = malloc(sizeof(*new), M_IFADDR,
M_WAITOK);
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* duplication check */
TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
&pol->ape_policy.addr.sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
&pol->ape_policy.addrmask.sin6_addr)) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
free(new, M_IFADDR);
return (EEXIST); /* or override it? */
}
}
bzero(new, sizeof(*new));
/* XXX: should validate entry */
new->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
delete_addrsel_policyent(struct in6_addrpolicy *key)
{
struct addrsel_policyent *pol;
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* search for the entry in the table */
TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
&pol->ape_policy.addr.sin6_addr) &&
IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
&pol->ape_policy.addrmask.sin6_addr)) {
break;
}
}
if (pol == NULL) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (ESRCH);
}
TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *),
void *w)
{
struct addrsel_policyent *pol;
int error = 0;
ADDRSEL_SLOCK();
TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
ADDRSEL_SUNLOCK();
return (error);
}
}
ADDRSEL_SUNLOCK();
return (error);
}
static int
dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
{
int error = 0;
struct walkarg *w = arg;
error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
return (error);
}
static struct in6_addrpolicy *
match_addrsel_policy(struct sockaddr_in6 *key)
{
struct addrsel_policyent *pent;
struct in6_addrpolicy *bestpol = NULL, *pol;
int matchlen, bestmatchlen = -1;
u_char *mp, *ep, *k, *p, m;
TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) {
matchlen = 0;
pol = &pent->ape_policy;
mp = (u_char *)&pol->addrmask.sin6_addr;
ep = mp + 16; /* XXX: scope field? */
k = (u_char *)&key->sin6_addr;
p = (u_char *)&pol->addr.sin6_addr;
for (; mp < ep && *mp; mp++, k++, p++) {
m = *mp;
if ((*k & m) != *p)
goto next; /* not match */
if (m == 0xff) /* short cut for a typical case */
matchlen += 8;
else {
while (m >= 0x80) {
matchlen++;
m <<= 1;
}
}
}
/* matched. check if this is better than the current best. */
if (bestpol == NULL ||
matchlen > bestmatchlen) {
bestpol = pol;
bestmatchlen = matchlen;
}
next:
continue;
}
return (bestpol);
}
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