/* * Copyright (c) 2000 Apple Computer, 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 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. * * $FreeBSD: src/sys/netinet/in_rmx.c,v 1.37.2.1 2001/05/14 08:23:49 ru Exp $ */ /* * 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 in_rtqtimo() below for the exact mechanism. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/sysctl.h> #include <sys/socket.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/in_var.h> extern int in_inithead(void **head, int off); #ifdef __APPLE__ static void in_rtqtimo(void *rock); #endif #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ extern lck_mtx_t *rt_mtx; /* * Do what we need to do when inserting a route. */ static struct radix_node * in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, struct radix_node *treenodes) { struct rtentry *rt = (struct rtentry *)treenodes; struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt); struct radix_node *ret; /* * For IP, all unicast non-host routes are automatically cloning. */ if(IN_MULTICAST(ntohl(sin->sin_addr.s_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 IP output and input: * For host routes, we make sure that RTF_BROADCAST * is set for anything that looks like a broadcast address. * This way, we can avoid an expensive call to in_broadcast() * in ip_output() most of the time (because the route passed * to ip_output() is almost always a host route). * * We also do the same for local addresses, 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.) */ if (rt->rt_flags & RTF_HOST) { if (in_broadcast(sin->sin_addr, rt->rt_ifp)) { rt->rt_flags |= RTF_BROADCAST; } else { #define satosin(sa) ((struct sockaddr_in *)sa) if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr == sin->sin_addr.s_addr) rt->rt_flags |= RTF_LOCAL; #undef satosin } } 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 *)sin, 0, RTF_CLONING | RTF_PRCLONING); if (rt2) { if (rt2->rt_flags & RTF_LLINFO && rt2->rt_flags & RTF_HOST && rt2->rt_gateway && rt2->rt_gateway->sa_family == AF_LINK) { rtrequest_locked(RTM_DELETE, (struct sockaddr *)rt_key(rt2), rt2->rt_gateway, rt_mask(rt2), rt2->rt_flags, 0); ret = rn_addroute(v_arg, n_arg, head, treenodes); } rtfree_locked(rt2); } } return ret; } /* * This code is the inverse of in_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 * in_matroute(void *v_arg, struct radix_node_head *head) { struct radix_node *rn = rn_match(v_arg, head); struct rtentry *rt = (struct rtentry *)rn; if(rt && rt->rt_refcnt == 0) { /* this is first reference */ if(rt->rt_flags & RTPRF_OURS) { rt->rt_flags &= ~RTPRF_OURS; rt->rt_rmx.rmx_expire = 0; } } return rn; } static int rtq_reallyold = 60*60; /* one hour is ``really old'' */ SYSCTL_INT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire, CTLFLAG_RW, &rtq_reallyold , 0, "Default expiration time on dynamically learned routes"); static int rtq_minreallyold = 10; /* never automatically crank down to less */ SYSCTL_INT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW, &rtq_minreallyold , 0, "Minimum time to attempt to hold onto dynamically learned routes"); static int rtq_toomany = 128; /* 128 cached routes is ``too many'' */ SYSCTL_INT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW, &rtq_toomany , 0, "Upper limit on dynamically learned routes"); #ifdef __APPLE__ /* XXX LD11JUL02 Special case for AOL 5.1.2 connectivity issue to AirPort BS (Radar 2969954) * AOL is adding a circular route ("10.0.1.1/32 10.0.1.1") when establishing its ppp tunnel * to the AP BaseStation by removing the default gateway and replacing it with their tunnel entry point. * There is no apparent reason to add this route as there is a valid 10.0.1.1/24 route to the BS. * That circular route was ignored on previous version of MacOS X because of a routing bug * corrected with the merge to FreeBSD4.4 (a route generated from an RTF_CLONING route had the RTF_WASCLONED * flag set but did not have a reference to the parent route) and that entry was left in the RT. This workaround is * made in order to provide binary compatibility with AOL. * If we catch a process adding a circular route with a /32 from the routing socket, we error it out instead of * confusing the routing table with a wrong route to the previous default gateway * If for some reason a circular route is needed, turn this sysctl (net.inet.ip.check_route_selfref) to zero. */ int check_routeselfref = 1; SYSCTL_INT(_net_inet_ip, OID_AUTO, check_route_selfref, CTLFLAG_RW, &check_routeselfref , 0, ""); #endif __private_extern__ int use_routegenid = 1; SYSCTL_INT(_net_inet_ip, OID_AUTO, use_route_genid, CTLFLAG_RW, &use_routegenid , 0, ""); /* * On last reference drop, mark the route as belong to us so that it can be * timed out. */ static void in_clsroute(struct radix_node *rn, struct radix_node_head *head) { struct rtentry *rt = (struct rtentry *)rn; struct timeval timenow; if(!(rt->rt_flags & RTF_UP)) return; /* prophylactic measures */ if((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) return; if((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS)) != RTF_WASCLONED) return; /* * As requested by David Greenman: * If rtq_reallyold is 0, just delete the route without * waiting for a timeout cycle to kill it. */ if(rtq_reallyold != 0) { getmicrotime(&timenow); rt->rt_flags |= RTPRF_OURS; rt->rt_rmx.rmx_expire = timenow.tv_sec + rtq_reallyold; } else { rtrequest_locked(RTM_DELETE, (struct sockaddr *)rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); } } struct rtqk_arg { struct radix_node_head *rnh; int draining; int killed; int found; int updating; time_t nextstop; }; /* * Get rid of old routes. When draining, this deletes everything, even when * the timeout is not expired yet. When updating, this makes sure that * nothing has a timeout longer than the current value of rtq_reallyold. */ static int in_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(rt_mtx, LCK_MTX_ASSERT_OWNED); if(rt->rt_flags & RTPRF_OURS) { ap->found++; if(ap->draining || rt->rt_rmx.rmx_expire <= timenow.tv_sec) { if(rt->rt_refcnt > 0) panic("rtqkill route really not free"); err = rtrequest_locked(RTM_DELETE, (struct sockaddr *)rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); if(err) { log(LOG_WARNING, "in_rtqkill: error %d\n", err); } else { ap->killed++; } } else { if(ap->updating && (rt->rt_rmx.rmx_expire - timenow.tv_sec > rtq_reallyold)) { rt->rt_rmx.rmx_expire = timenow.tv_sec + rtq_reallyold; } ap->nextstop = lmin(ap->nextstop, rt->rt_rmx.rmx_expire); } } return 0; } static void in_rtqtimo_funnel(void *rock) { in_rtqtimo(rock); } #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ static int rtq_timeout = RTQ_TIMEOUT; static void in_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; getmicrotime(&timenow); arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = timenow.tv_sec + rtq_timeout; arg.draining = arg.updating = 0; lck_mtx_lock(rt_mtx); rnh->rnh_walktree(rnh, in_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, "in_rtqtimo: adjusted rtq_reallyold to %d\n", rtq_reallyold); #endif arg.found = arg.killed = 0; arg.updating = 1; rnh->rnh_walktree(rnh, in_rtqkill, &arg); } atv.tv_usec = 0; atv.tv_sec = arg.nextstop - timenow.tv_sec; lck_mtx_unlock(rt_mtx); timeout(in_rtqtimo_funnel, rock, tvtohz(&atv)); } void in_rtqdrain(void) { struct radix_node_head *rnh = rt_tables[AF_INET]; struct rtqk_arg arg; arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = 0; arg.draining = 1; arg.updating = 0; lck_mtx_lock(rt_mtx); rnh->rnh_walktree(rnh, in_rtqkill, &arg); lck_mtx_unlock(rt_mtx); } /* * Initialize our routing tree. */ int in_inithead(void **head, int off) { struct radix_node_head *rnh; #ifdef __APPLE__ if (*head) return 1; #endif if(!rn_inithead(head, off)) return 0; if(head != (void **)&rt_tables[AF_INET]) /* BOGUS! */ return 1; /* only do this for the real routing table */ rnh = *head; rnh->rnh_addaddr = in_addroute; rnh->rnh_matchaddr = in_matroute; rnh->rnh_close = in_clsroute; in_rtqtimo(rnh); /* kick off timeout first time */ return 1; } /* * This zaps old routes when the interface goes down or interface * address is deleted. In the latter case, it deletes static routes * that point to this address. If we don't do this, we may end up * using the old address in the future. The ones we always want to * get rid of are things like ARP entries, since the user might down * the interface, walk over to a completely different network, and * plug back in. */ struct in_ifadown_arg { struct radix_node_head *rnh; struct ifaddr *ifa; int del; }; static int in_ifadownkill(struct radix_node *rn, void *xap) { struct in_ifadown_arg *ap = xap; struct rtentry *rt = (struct rtentry *)rn; int err; if (rt->rt_ifa == ap->ifa && (ap->del || !(rt->rt_flags & RTF_STATIC))) { /* * We need to disable the automatic prune that happens * in this case in rtrequest() because it will blow * away the pointers that rn_walktree() needs in order * continue our descent. We will end up deleting all * the routes that rtrequest() would have in any case, * so that behavior is not needed there. */ rt->rt_flags &= ~(RTF_CLONING | RTF_PRCLONING); err = rtrequest_locked(RTM_DELETE, (struct sockaddr *)rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); if (err) { log(LOG_WARNING, "in_ifadownkill: error %d\n", err); } } return 0; } int in_ifadown(struct ifaddr *ifa, int delete) { struct in_ifadown_arg arg; struct radix_node_head *rnh; lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); if (ifa->ifa_addr->sa_family != AF_INET) return 1; arg.rnh = rnh = rt_tables[AF_INET]; arg.ifa = ifa; arg.del = delete; rnh->rnh_walktree(rnh, in_ifadownkill, &arg); ifa->ifa_flags &= ~IFA_ROUTE; return 0; }