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NetBSD/sys/netinet6/in6_src.c
dyoung c2e43be1c5 Reduces the resources demanded by TCP sessions in TIME_WAIT-state using 
methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime
Truncation (MSLT).

MSLT and VTW were contributed by Coyote Point Systems, Inc.

Even after a TCP session enters the TIME_WAIT state, its corresponding
socket and protocol control blocks (PCBs) stick around until the TCP
Maximum Segment Lifetime (MSL) expires.  On a host whose workload
necessarily creates and closes down many TCP sockets, the sockets & PCBs
for TCP sessions in TIME_WAIT state amount to many megabytes of dead
weight in RAM.

Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to
a class based on the nearness of the peer.  Corresponding to each class
is an MSL, and a session uses the MSL of its class.  The classes are
loopback (local host equals remote host), local (local host and remote
host are on the same link/subnet), and remote (local host and remote
host communicate via one or more gateways).  Classes corresponding to
nearer peers have lower MSLs by default: 2 seconds for loopback, 10
seconds for local, 60 seconds for remote.  Loopback and local sessions
expire more quickly when MSLT is used.

Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket
dead weight with a compact representation of the session, called a
"vestigial PCB".  VTW data structures are designed to be very fast and
memory-efficient: for fast insertion and lookup of vestigial PCBs,
the PCBs are stored in a hash table that is designed to minimize the
number of cacheline visits per lookup/insertion.  The memory both
for vestigial PCBs and for elements of the PCB hashtable come from
fixed-size pools, and linked data structures exploit this to conserve
memory by representing references with a narrow index/offset from the
start of a pool instead of a pointer.  When space for new vestigial PCBs
runs out, VTW makes room by discarding old vestigial PCBs, oldest first.
VTW cooperates with MSLT.

It may help to think of VTW as a "FIN cache" by analogy to the SYN
cache.

A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT
sessions as fast as it can is approximately 17% idle when VTW is active
versus 0% idle when VTW is inactive.  It has 103 megabytes more free RAM
when VTW is active (approximately 64k vestigial PCBs are created) than
when it is inactive.
2011-05-03 18:28:44 +00:00

1146 lines
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/* $KAME: in6_src.c,v 1.159 2005/10/19 01:40:32 t-momose Exp $ */
/*
* 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.50 2011/05/03 18:28:45 dyoung Exp $");
#include "opt_inet.h"
#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/ioctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/route.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/ip6_private.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>
#include <net/net_osdep.h>
#ifdef MIP6
#include <netinet6/mip6.h>
#include <netinet6/mip6_var.h>
#include "mip.h"
#if NMIP > 0
#include <net/if_mip.h>
#endif /* NMIP > 0 */
#endif /* MIP6 */
#include <netinet/tcp_vtw.h>
#define ADDR_LABEL_NOTAPP (-1)
struct in6_addrpolicy defaultaddrpolicy;
#ifdef notyet /* until introducing ND extensions and address selection */
int ip6_prefer_tempaddr = 0;
#endif
static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route *, struct ifnet **,
struct rtentry **, int, int);
static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route *, 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(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.
*/
#if 0 /* diabled ad-hoc */
#define REPLACE(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto replace; \
} while(0)
#define NEXT(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto next; /* XXX: we can't use 'continue' here */ \
} while(0)
#define BREAK(r) do { \
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
#else
#define REPLACE(r) goto replace
#define NEXT(r) goto next
#define BREAK(r) goto out
#endif
struct in6_addr *
in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route *ro, struct in6_addr *laddr,
struct ifnet **ifpp, int *errorp)
{
struct in6_addr dst;
struct ifnet *ifp = NULL;
struct in6_ifaddr *ia = NULL, *ia_best = NULL;
struct in6_pktinfo *pi = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
u_int32_t odstzone;
int error;
#ifdef notyet /* until introducing ND extensions and address selection */
int prefer_tempaddr;
#endif
#if defined(MIP6) && NMIP > 0
u_int8_t ip6po_usecoa = 0;
#endif /* MIP6 && NMIP > 0 */
dst = dstsock->sin6_addr; /* make a copy for local operation */
*errorp = 0;
if (ifpp)
*ifpp = NULL;
/*
* Try to determine the outgoing interface for the given destination.
* We do this regardless of whether the socket is bound, since the
* caller may need this information as a side effect of the call
* to this function (e.g., for identifying the appropriate scope zone
* ID).
*/
error = in6_selectif(dstsock, opts, mopts, ro, &ifp);
if (ifpp)
*ifpp = ifp;
/*
* 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;
/*
* 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.
*/
memset(&srcsock, 0, sizeof(srcsock));
srcsock.sin6_family = AF_INET6;
srcsock.sin6_len = sizeof(srcsock);
srcsock.sin6_addr = pi->ipi6_addr;
if (ifp) {
*errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
if (*errorp != 0)
return (NULL);
}
ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock));
if (ia6 == NULL ||
(ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
*errorp = EADDRNOTAVAIL;
return (NULL);
}
pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
return (&ia6->ia_addr.sin6_addr);
}
/*
* If the socket has already bound the source, just use it. We don't
* care at the moment whether in6_selectif() succeeded above, even
* though it would eventually cause an error.
*/
if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
return (laddr);
/*
* The outgoing interface is crucial in the general selection procedure
* below. If it is not known at this point, we fail.
*/
if (ifp == NULL) {
*errorp = error;
return (NULL);
}
/*
* If the address is not yet determined, choose the best one based on
* the outgoing interface and the destination address.
*/
#if defined(MIP6) && NMIP > 0
/*
* a caller can specify IP6PO_USECOA to not to use a home
* address. for example, the case that the neighbour
* unreachability detection to the global address.
*/
if (opts != NULL &&
(opts->ip6po_flags & IP6PO_USECOA) != 0) {
ip6po_usecoa = 1;
}
#endif /* MIP6 && NMIP > 0 */
#ifdef DIAGNOSTIC
if (ifp == NULL) /* this should not happen */
panic("in6_selectsrc: NULL ifp");
#endif
*errorp = in6_setscope(&dst, ifp, &odstzone);
if (*errorp != 0)
return (NULL);
for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
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 (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
continue;
#if defined(MIP6) && NMIP > 0
/* avoid unusable home addresses. */
if ((ia->ia6_flags & IN6_IFF_HOME) &&
!mip6_ifa6_is_addr_valid_hoa(ia))
continue;
#endif /* MIP6 && NMIP > 0 */
/* 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 */
#if defined(MIP6) && NMIP > 0
if (!MIP6_IS_MN)
goto skip_rule4;
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
/* both address are not home addresses. */
goto skip_rule4;
}
/*
* If SA is simultaneously a home address and care-of
* address and SB is not, then prefer SA. Similarly,
* if SB is simultaneously a home address and care-of
* address and SA is not, then prefer SB.
*/
if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
ia_best->ia_ifp->if_type != IFT_MIP)
&&
((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
ia->ia_ifp->if_type == IFT_MIP))
NEXT(4);
if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
ia_best->ia_ifp->if_type == IFT_MIP)
&&
((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
ia->ia_ifp->if_type != IFT_MIP))
REPLACE(4);
if (ip6po_usecoa == 0) {
/*
* If SA is just a home address and SB is just
* a care-of address, then prefer
* SA. Similarly, if SB is just a home address
* and SA is just a care-of address, then
* prefer SB.
*/
if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
NEXT(4);
}
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) != 0) {
REPLACE(4);
}
} else {
/*
* a sender don't want to use a home address
* because:
*
* 1) we cannot use. (ex. NS or NA to global
* addresses.)
*
* 2) a user specified not to use.
* (ex. mip6control -u)
*/
if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
(ia->ia6_flags & IN6_IFF_HOME) != 0) {
/* XXX breaks stat */
NEXT(0);
}
if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
(ia->ia6_flags & IN6_IFF_HOME) == 0) {
/* XXX breaks stat */
REPLACE(0);
}
}
skip_rule4:
#endif /* MIP6 && NMIP > 0 */
/* 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.
*/
#ifdef notyet /* until introducing ND extensions and address selection */
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 (!(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);
}
#endif
/*
* 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 addresses on "preferred" interfaces.
* This is a KAME specific rule.
*/
#ifdef notyet /* until introducing address selection */
#define NDI_BEST ND_IFINFO(ia_best->ia_ifp)
#define NDI_NEW ND_IFINFO(ia->ia_ifp)
if ((NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
!(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
NEXT(9);
if (!(NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
REPLACE(9);
#undef NDI_BEST
#undef NDI_NEW
#endif
/*
* 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) {
*errorp = EADDRNOTAVAIL;
return (NULL);
}
return (&ia->ia_addr.sin6_addr);
}
#undef REPLACE
#undef BREAK
#undef NEXT
static int
selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
struct rtentry **retrt, int clone, 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;
dst = &dstsock->sin6_addr;
#if 0
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(&dstsock->sin6_addr));
} else {
printf("in6_selectroute: destination = %s%%%d\n",
ip6_sprintf(&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 = ifindex2ifnet[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 *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 ((rt = rtcache_lookup(ron, sin6tosa(sin6_next))) == NULL ||
(rt->rt_flags & RTF_GATEWAY) != 0 ||
!nd6_is_addr_neighbor(sin6_next, rt->rt_ifp)) {
rtcache_free(ron);
error = EHOSTUNREACH;
goto done;
}
ifp = 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)
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 != NULL) {
union {
struct sockaddr dst;
struct sockaddr_in6 dst6;
} u;
/* No route yet, so try to acquire one */
u.dst6 = *dstsock;
u.dst6.sin6_scope_id = 0;
rt = rtcache_lookup1(ro, &u.dst, clone);
/*
* do not care about the result if we have the nexthop
* explicitly specified.
*/
if (opts && opts->ip6po_nexthop)
goto done;
if (rt == NULL)
error = EHOSTUNREACH;
else
ifp = rt->rt_ifp;
/*
* 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 (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)
IP6_STATINC(IP6_STAT_NOROUTE);
if (retifp != NULL)
*retifp = ifp;
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 *ro, struct ifnet **retifp)
{
int error, clone;
struct rtentry *rt = NULL;
clone = IN6_IS_ADDR_MULTICAST(&dstsock->sin6_addr) ? 0 : 1;
if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
&rt, clone, 1)) != 0) {
return (error);
}
/*
* do not use a rejected or black hole route.
* XXX: this check should be done in the L2 output routine.
* However, if we skipped this check here, we'd see the following
* scenario:
* - install a rejected route for a scoped address prefix
* (like fe80::/10)
* - send a packet to a destination that matches the scoped prefix,
* with ambiguity about the scope zone.
* - pick the outgoing interface from the route, and disambiguate the
* scope zone with the interface.
* - ip6_output() would try to get another route with the "new"
* destination, which may be valid.
* - we'd see no error on output.
* Although this may not be very harmful, it should still be confusing.
* We thus reject the case here.
*/
if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE)))
return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
/*
* 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 && rt->rt_ifa && rt->rt_ifa->ifa_ifp)
*retifp = rt->rt_ifa->ifa_ifp;
return (0);
}
/*
* close - meaningful only for bsdi and freebsd.
*/
int
in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
struct rtentry **retrt, int clone)
{
return selectroute(dstsock, opts, mopts, ro, retifp,
retrt, clone, 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 in6pcb *in6p, struct ifnet *ifp)
{
if (in6p && in6p->in6p_hops >= 0)
return (in6p->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else
return (ip6_defhlim);
}
/*
* Find an empty port and set it to the specified PCB.
*/
int
in6_pcbsetport(struct sockaddr_in6 *sin6, struct in6pcb *in6p, struct lwp *l)
{
struct socket *so = in6p->in6p_socket;
struct inpcbtable *table = in6p->in6p_table;
int cnt;
u_int16_t minport, maxport;
u_int16_t lport, *lastport;
int wild = 0;
void *t;
int error;
enum kauth_network_req req;
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
(so->so_options & SO_ACCEPTCONN) == 0))
wild = 1;
if (in6p->in6p_flags & IN6P_LOWPORT) {
#ifndef IPNOPRIVPORTS
req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
#else
req = KAUTH_REQ_NETWORK_BIND_PORT;
#endif
minport = ip6_lowportmin;
maxport = ip6_lowportmax;
lastport = &table->inpt_lastlow;
} else {
req = KAUTH_REQ_NETWORK_BIND_PORT;
minport = ip6_anonportmin;
maxport = ip6_anonportmax;
lastport = &table->inpt_lastport;
}
/* XXX-kauth: KAUTH_REQ_NETWORK_BIND_AUTOASSIGN_{,PRIV}PORT */
error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND, req, so,
sin6, NULL);
if (error)
return (EACCES);
if (minport > maxport) { /* sanity check */
u_int16_t swp;
swp = minport;
minport = maxport;
maxport = swp;
}
lport = *lastport - 1;
for (cnt = maxport - minport + 1; cnt; cnt--, lport--) {
vestigial_inpcb_t vestige;
if (lport < minport || lport > maxport)
lport = maxport;
#ifdef INET
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
t = in_pcblookup_port(table,
*(struct in_addr *)&sin6->sin6_addr.s6_addr32[3],
htons(lport), wild, &vestige);
if (!t && vestige.valid)
continue;
} else
#endif
{
t = in6_pcblookup_port(table, &sin6->sin6_addr,
htons(lport), wild, &vestige);
if (!t && vestige.valid)
continue;
}
if (t == 0) {
/* We have a free port. Check with the secmodel. */
sin6->sin6_port = lport;
error = kauth_authorize_network(l->l_cred,
KAUTH_NETWORK_BIND, req, so, sin6, NULL);
if (error) {
/* Secmodel says no. Keep looking. */
continue;
}
goto found;
}
}
return (EAGAIN);
found:
in6p->in6p_flags |= IN6P_ANONPORT;
*lastport = lport;
in6p->in6p_lport = htons(lport);
in6_pcbstate(in6p, IN6P_BOUND);
return (0); /* success */
}
void
addrsel_policy_init(void)
{
init_policy_queue();
/* initialize the "last resort" policy */
memset(&defaultaddrpolicy, 0, sizeof(defaultaddrpolicy));
defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
}
static struct in6_addrpolicy *
lookup_addrsel_policy(struct sockaddr_in6 *key)
{
struct in6_addrpolicy *match = NULL;
match = match_addrsel_policy(key);
if (match == NULL)
match = &defaultaddrpolicy;
else
match->use++;
return (match);
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct sel_walkarg {
size_t w_total;
size_t w_given;
void * w_where;
void *w_limit;
};
int
in6_src_sysctl(void *oldp, size_t *oldlenp, void *newp, size_t newlen)
{
int error = 0;
int s;
s = splsoftnet();
if (newp) {
error = EPERM;
goto end;
}
if (oldp && oldlenp == NULL) {
error = EINVAL;
goto end;
}
if (oldp || oldlenp) {
struct sel_walkarg w;
size_t oldlen = *oldlenp;
memset(&w, 0, sizeof(w));
w.w_given = oldlen;
w.w_where = oldp;
if (oldp)
w.w_limit = (char *)oldp + oldlen;
error = walk_addrsel_policy(dump_addrsel_policyent, &w);
*oldlenp = w.w_total;
if (oldp && w.w_total > oldlen && error == 0)
error = ENOMEM;
}
end:
splx(s);
return (error);
}
int
in6_src_ioctl(u_long cmd, void *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);
struct addrsel_policyhead addrsel_policytab;
static void
init_policy_queue(void)
{
TAILQ_INIT(&addrsel_policytab);
}
static int
add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
{
struct addrsel_policyent *new, *pol;
/* duplication check */
for (pol = TAILQ_FIRST(&addrsel_policytab); pol;
pol = TAILQ_NEXT(pol, 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)) {
return (EEXIST); /* or override it? */
}
}
new = malloc(sizeof(*new), M_IFADDR, M_WAITOK|M_ZERO);
/* XXX: should validate entry */
new->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
return (0);
}
static int
delete_addrsel_policyent(struct in6_addrpolicy *key)
{
struct addrsel_policyent *pol;
/* search for the entry in the table */
for (pol = TAILQ_FIRST(&addrsel_policytab); pol;
pol = TAILQ_NEXT(pol, 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) {
return (ESRCH);
}
TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
return (0);
}
static int
walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
{
struct addrsel_policyent *pol;
int error = 0;
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0)
return error;
}
return error;
}
static int
dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
{
int error = 0;
struct sel_walkarg *w = arg;
if (w->w_where && (char *)w->w_where + sizeof(*pol) <= (char *)w->w_limit) {
if ((error = copyout(pol, w->w_where, sizeof(*pol))) != 0)
return error;
w->w_where = (char *)w->w_where + sizeof(*pol);
}
w->w_total += 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;
for (pent = TAILQ_FIRST(&addrsel_policytab); pent;
pent = TAILQ_NEXT(pent, 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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