/* * Copyright (c) 2003-2009 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@ */ /* $FreeBSD: src/sys/netinet6/in6_rmx.c,v 1.1.2.2 2001/07/03 11:01:52 ume Exp $ */ /* $KAME: in6_rmx.c,v 1.10 2001/05/24 05:44:58 itojun 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 1994, 1995 Massachusetts Institute of Technology * * Permission to use, copy, modify, and distribute this software and * its documentation for any purpose and without fee is hereby * granted, provided that both the above copyright notice and this * permission notice appear in all copies, that both the above * copyright notice and this permission notice appear in all * supporting documentation, and that the name of M.I.T. not be used * in advertising or publicity pertaining to distribution of the * software without specific, written prior permission. M.I.T. makes * no representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied * warranty. * * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT * SHALL M.I.T. 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. * */ /* * This code does two things necessary for the enhanced TCP metrics to * function in a useful manner: * 1) It marks all non-host routes as `cloning', thus ensuring that * every actual reference to such a route actually gets turned * into a reference to a host route to the specific destination * requested. * 2) When such routes lose all their references, it arranges for them * to be deleted in some random collection of circumstances, so that * a large quantity of stale routing data is not kept in kernel memory * indefinitely. See in6_rtqtimo() below for the exact mechanism. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/sysctl.h> #include <kern/queue.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/mbuf.h> #include <sys/syslog.h> #include <kern/lock.h> #include <net/if.h> #include <net/route.h> #include <netinet/in.h> #include <netinet/ip_var.h> #include <netinet/in_var.h> #include <netinet/ip6.h> #include <netinet6/ip6_var.h> #include <netinet/icmp6.h> #include <netinet/tcp.h> #include <netinet/tcp_seq.h> #include <netinet/tcp_timer.h> #include <netinet/tcp_var.h> extern int in6_inithead(void **head, int off); static void in6_rtqtimo(void *rock); static void in6_mtutimo(void *rock); extern int tvtohz(struct timeval *); static struct radix_node *in6_matroute_args(void *, struct radix_node_head *, rn_matchf_t *, void *); #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ /* * Accessed by in6_addroute(), in6_deleteroute() and in6_rtqkill(), during * which the routing lock (rnh_lock) is held and thus protects the variable. */ static int in6dynroutes; /* * Do what we need to do when inserting a route. */ static struct radix_node * in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, struct radix_node *treenodes) { struct rtentry *rt = (struct rtentry *)treenodes; struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt); struct radix_node *ret; lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); RT_LOCK_ASSERT_HELD(rt); /* * If this is a dynamic route (which is created via Redirect) and * we already have the maximum acceptable number of such route entries, * reject creating a new one. We could initiate garbage collection to * make available space right now, but the benefit would probably not * be worth the cleaning overhead; we only have to endure a slightly * suboptimal path even without the redirecbted route. */ if ((rt->rt_flags & RTF_DYNAMIC) != 0 && ip6_maxdynroutes >= 0 && in6dynroutes >= ip6_maxdynroutes) return (NULL); /* * For IPv6, all unicast non-host routes are automatically cloning. */ if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) rt->rt_flags |= RTF_MULTICAST; if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) { rt->rt_flags |= RTF_PRCLONING; } /* * A little bit of help for both IPv6 output and input: * For local addresses, we make sure that RTF_LOCAL is set, * with the thought that this might one day be used to speed up * ip_input(). * * We also mark routes to multicast addresses as such, because * it's easy to do and might be useful (but this is much more * dubious since it's so easy to inspect the address). (This * is done above.) * * XXX * should elaborate the code. */ if (rt->rt_flags & RTF_HOST) { if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr) ->sin6_addr, &sin6->sin6_addr)) { rt->rt_flags |= RTF_LOCAL; } } if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) && rt->rt_ifp) rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; ret = rn_addroute(v_arg, n_arg, head, treenodes); if (ret == NULL && (rt->rt_flags & RTF_HOST)) { struct rtentry *rt2; /* * We are trying to add a host route, but can't. * Find out if it is because of an * ARP entry and delete it if so. */ rt2 = rtalloc1_locked((struct sockaddr *)sin6, 0, RTF_CLONING | RTF_PRCLONING); if (rt2) { RT_LOCK(rt2); if ((rt2->rt_flags & RTF_LLINFO) && (rt2->rt_flags & RTF_HOST) && rt2->rt_gateway != NULL && rt2->rt_gateway->sa_family == AF_LINK) { /* * Safe to drop rt_lock and use rt_key, * rt_gateway, since holding rnh_lock here * prevents another thread from calling * rt_setgate() on this route. */ RT_UNLOCK(rt2); (void) rtrequest_locked(RTM_DELETE, rt_key(rt2), rt2->rt_gateway, rt_mask(rt2), rt2->rt_flags, 0); ret = rn_addroute(v_arg, n_arg, head, treenodes); } else { RT_UNLOCK(rt2); } rtfree_locked(rt2); } } else if (ret == NULL && (rt->rt_flags & RTF_CLONING)) { struct rtentry *rt2; /* * We are trying to add a net route, but can't. * The following case should be allowed, so we'll make a * special check for this: * Two IPv6 addresses with the same prefix is assigned * to a single interrface. * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1) * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2) * In this case, (*1) and (*2) want to add the same * net route entry, 3ffe:0501:: -> if0. * This case should not raise an error. */ rt2 = rtalloc1_locked((struct sockaddr *)sin6, 0, RTF_CLONING | RTF_PRCLONING); if (rt2) { RT_LOCK(rt2); if ((rt2->rt_flags & (RTF_CLONING|RTF_HOST|RTF_GATEWAY)) == RTF_CLONING && rt2->rt_gateway && rt2->rt_gateway->sa_family == AF_LINK && rt2->rt_ifp == rt->rt_ifp) { ret = rt2->rt_nodes; } RT_UNLOCK(rt2); rtfree_locked(rt2); } } if (ret != NULL && (rt->rt_flags & RTF_DYNAMIC) != 0) in6dynroutes++; return ret; } static struct radix_node * in6_deleteroute(void * v_arg, void *netmask_arg, struct radix_node_head *head) { struct radix_node *rn; lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); rn = rn_delete(v_arg, netmask_arg, head); if (rn != NULL) { struct rtentry *rt = (struct rtentry *)rn; RT_LOCK_SPIN(rt); if ((rt->rt_flags & RTF_DYNAMIC) != 0) in6dynroutes--; RT_UNLOCK(rt); } return (rn); } /* * Similar to in6_matroute_args except without the leaf-matching parameters. */ static struct radix_node * in6_matroute(void *v_arg, struct radix_node_head *head) { return (in6_matroute_args(v_arg, head, NULL, NULL)); } /* * This code is the inverse of in6_clsroute: on first reference, if we * were managing the route, stop doing so and set the expiration timer * back off again. */ static struct radix_node * in6_matroute_args(void *v_arg, struct radix_node_head *head, rn_matchf_t *f, void *w) { struct radix_node *rn = rn_match_args(v_arg, head, f, w); struct rtentry *rt = (struct rtentry *)rn; /* This is first reference? */ if (rt != NULL) { RT_LOCK_SPIN(rt); if (rt->rt_refcnt == 0 && (rt->rt_flags & RTPRF_OURS)) { rt->rt_flags &= ~RTPRF_OURS; rt->rt_rmx.rmx_expire = 0; } RT_UNLOCK(rt); } return (rn); } SYSCTL_DECL(_net_inet6_ip6); static int rtq_reallyold = 60*60; /* one hour is ``really old'' */ SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire, CTLFLAG_RW, &rtq_reallyold , 0, ""); static int rtq_minreallyold = 10; /* never automatically crank down to less */ SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW, &rtq_minreallyold , 0, ""); static int rtq_toomany = 128; /* 128 cached routes is ``too many'' */ SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW, &rtq_toomany , 0, ""); /* * On last reference drop, mark the route as belong to us so that it can be * timed out. */ static void in6_clsroute(struct radix_node *rn, __unused struct radix_node_head *head) { struct rtentry *rt = (struct rtentry *)rn; lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); RT_LOCK_ASSERT_HELD(rt); if (!(rt->rt_flags & RTF_UP)) return; /* prophylactic measures */ if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) return; if (rt->rt_flags & RTPRF_OURS) return; if (!(rt->rt_flags & (RTF_WASCLONED | RTF_DYNAMIC))) return; /* * Delete the route immediately if RTF_DELCLONE is set or * if route caching is disabled (rtq_reallyold set to 0). * Otherwise, let it expire and be deleted by in6_rtqkill(). */ if ((rt->rt_flags & RTF_DELCLONE) || rtq_reallyold == 0) { /* * Delete the route from the radix tree but since we are * called when the route's reference count is 0, don't * deallocate it until we return from this routine by * telling rtrequest that we're interested in it. * Safe to drop rt_lock and use rt_key, rt_gateway, * since holding rnh_lock here prevents another thread * from calling rt_setgate() on this route. */ RT_UNLOCK(rt); if (rtrequest_locked(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, &rt) == 0) { /* Now let the caller free it */ RT_LOCK(rt); RT_REMREF_LOCKED(rt); } else { RT_LOCK(rt); } } else { struct timeval timenow; getmicrotime(&timenow); rt->rt_flags |= RTPRF_OURS; rt->rt_rmx.rmx_expire = rt_expiry(rt, timenow.tv_sec, rtq_reallyold); } } struct rtqk_arg { struct radix_node_head *rnh; int mode; int updating; int draining; int killed; int found; time_t nextstop; }; /* * Get rid of old routes. When draining, this deletes everything, even when * the timeout is not expired yet. This also applies if the route is dynamic * and there are sufficiently large number of such routes (more than a half of * maximum). When updating, this makes sure that nothing has a timeout longer * than the current value of rtq_reallyold. */ static int in6_rtqkill(struct radix_node *rn, void *rock) { struct rtqk_arg *ap = rock; struct rtentry *rt = (struct rtentry *)rn; int err; struct timeval timenow; getmicrotime(&timenow); lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); RT_LOCK(rt); if (rt->rt_flags & RTPRF_OURS) { ap->found++; if (ap->draining || rt->rt_rmx.rmx_expire <= timenow.tv_sec || ((rt->rt_flags & RTF_DYNAMIC) != 0 && ip6_maxdynroutes >= 0 && in6dynroutes > ip6_maxdynroutes / 2)) { if (rt->rt_refcnt > 0) panic("rtqkill route really not free"); /* * Delete this route since we're done with it; * the route may be freed afterwards, so we * can no longer refer to 'rt' upon returning * from rtrequest(). Safe to drop rt_lock and * use rt_key, rt_gateway, since holding rnh_lock * here prevents another thread from calling * rt_setgate() on this route. */ RT_UNLOCK(rt); err = rtrequest_locked(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); if (err) { log(LOG_WARNING, "in6_rtqkill: error %d", err); } else { ap->killed++; } } else { if (ap->updating && (unsigned)(rt->rt_rmx.rmx_expire - timenow.tv_sec) > rt_expiry(rt, 0, rtq_reallyold)) { rt->rt_rmx.rmx_expire = rt_expiry(rt, timenow.tv_sec, rtq_reallyold); } ap->nextstop = lmin(ap->nextstop, rt->rt_rmx.rmx_expire); RT_UNLOCK(rt); } } else { RT_UNLOCK(rt); } return 0; } #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ static int rtq_timeout = RTQ_TIMEOUT; static void in6_rtqtimo(void *rock) { struct radix_node_head *rnh = rock; struct rtqk_arg arg; struct timeval atv; static time_t last_adjusted_timeout = 0; struct timeval timenow; lck_mtx_lock(rnh_lock); /* Get the timestamp after we acquire the lock for better accuracy */ getmicrotime(&timenow); arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = timenow.tv_sec + rtq_timeout; arg.draining = arg.updating = 0; rnh->rnh_walktree(rnh, in6_rtqkill, &arg); /* * Attempt to be somewhat dynamic about this: * If there are ``too many'' routes sitting around taking up space, * then crank down the timeout, and see if we can't make some more * go away. However, we make sure that we will never adjust more * than once in rtq_timeout seconds, to keep from cranking down too * hard. */ if ((arg.found - arg.killed > rtq_toomany) && (timenow.tv_sec - last_adjusted_timeout >= rtq_timeout) && rtq_reallyold > rtq_minreallyold) { rtq_reallyold = 2*rtq_reallyold / 3; if (rtq_reallyold < rtq_minreallyold) { rtq_reallyold = rtq_minreallyold; } last_adjusted_timeout = timenow.tv_sec; #if DIAGNOSTIC log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold to %d", rtq_reallyold); #endif arg.found = arg.killed = 0; arg.updating = 1; rnh->rnh_walktree(rnh, in6_rtqkill, &arg); } atv.tv_usec = 0; atv.tv_sec = arg.nextstop - timenow.tv_sec; lck_mtx_unlock(rnh_lock); timeout(in6_rtqtimo, rock, tvtohz(&atv)); } /* * Age old PMTUs. */ struct mtuex_arg { struct radix_node_head *rnh; time_t nextstop; }; static int in6_mtuexpire(struct radix_node *rn, void *rock) { struct rtentry *rt = (struct rtentry *)rn; struct mtuex_arg *ap = rock; struct timeval timenow; getmicrotime(&timenow); /* sanity */ if (!rt) panic("rt == NULL in in6_mtuexpire"); RT_LOCK(rt); if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) { if (rt->rt_rmx.rmx_expire <= timenow.tv_sec) { rt->rt_flags |= RTF_PROBEMTU; } else { ap->nextstop = lmin(ap->nextstop, rt->rt_rmx.rmx_expire); } } RT_UNLOCK(rt); return 0; } #define MTUTIMO_DEFAULT (60*1) static void in6_mtutimo(void *rock) { struct radix_node_head *rnh = rock; struct mtuex_arg arg; struct timeval atv; struct timeval timenow; getmicrotime(&timenow); arg.rnh = rnh; arg.nextstop = timenow.tv_sec + MTUTIMO_DEFAULT; lck_mtx_lock(rnh_lock); rnh->rnh_walktree(rnh, in6_mtuexpire, &arg); atv.tv_usec = 0; atv.tv_sec = arg.nextstop; if (atv.tv_sec < timenow.tv_sec) { #if DIAGNOSTIC log(LOG_DEBUG, "IPv6: invalid mtu expiration time on routing table\n"); #endif arg.nextstop = timenow.tv_sec + 30; /*last resort*/ } atv.tv_sec -= timenow.tv_sec; lck_mtx_unlock(rnh_lock); timeout(in6_mtutimo, rock, tvtohz(&atv)); } void in6_rtqdrain() { struct radix_node_head *rnh = rt_tables[AF_INET6]; struct rtqk_arg arg; arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = 0; arg.draining = 1; arg.updating = 0; lck_mtx_lock(rnh_lock); rnh->rnh_walktree(rnh, in6_rtqkill, &arg); lck_mtx_unlock(rnh_lock); } /* * Initialize our routing tree. */ int in6_inithead(void **head, int off) { struct radix_node_head *rnh; if (!rn_inithead(head, off)) return 0; if (head != (void **)&rt_tables[AF_INET6]) /* BOGUS! */ return 1; /* only do this for the real routing table */ rnh = *head; rnh->rnh_addaddr = in6_addroute; rnh->rnh_deladdr = in6_deleteroute; rnh->rnh_matchaddr = in6_matroute; rnh->rnh_matchaddr_args = in6_matroute_args; rnh->rnh_close = in6_clsroute; in6_rtqtimo(rnh); /* kick off timeout first time */ in6_mtutimo(rnh); /* kick off timeout first time */ return 1; }