Current Path : /sys/netinet/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/netinet/in_rmx.c |
/*- * 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 in_rtqtimo() below for the exact mechanism. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/netinet/in_rmx.c 215701 2010-11-22 19:32:54Z dim $"); #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 <sys/callout.h> #include <net/if.h> #include <net/route.h> #include <net/vnet.h> #include <netinet/in.h> #include <netinet/in_var.h> #include <netinet/ip_var.h> extern int in_inithead(void **head, int off); #ifdef VIMAGE extern int in_detachhead(void **head, int off); #endif #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ /* * 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); RADIX_NODE_HEAD_WLOCK_ASSERT(head); /* * 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). */ if (rt->rt_flags & RTF_HOST) { if (in_broadcast(sin->sin_addr, rt->rt_ifp)) { rt->rt_flags |= RTF_BROADCAST; } else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr == sin->sin_addr.s_addr) { rt->rt_flags |= RTF_LOCAL; } } if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) rt->rt_flags |= RTF_MULTICAST; if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp) rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; return (rn_addroute(v_arg, n_arg, head, treenodes)); } /* * 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_LOCK(rt); if (rt->rt_flags & RTPRF_OURS) { rt->rt_flags &= ~RTPRF_OURS; rt->rt_rmx.rmx_expire = 0; } RT_UNLOCK(rt); } return rn; } static VNET_DEFINE(int, rtq_reallyold) = 60*60; /* one hour is "really old" */ #define V_rtq_reallyold VNET(rtq_reallyold) SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire, CTLFLAG_RW, &VNET_NAME(rtq_reallyold), 0, "Default expiration time on dynamically learned routes"); /* never automatically crank down to less */ static VNET_DEFINE(int, rtq_minreallyold) = 10; #define V_rtq_minreallyold VNET(rtq_minreallyold) SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW, &VNET_NAME(rtq_minreallyold), 0, "Minimum time to attempt to hold onto dynamically learned routes"); /* 128 cached routes is "too many" */ static VNET_DEFINE(int, rtq_toomany) = 128; #define V_rtq_toomany VNET(rtq_toomany) SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW, &VNET_NAME(rtq_toomany), 0, "Upper limit on dynamically learned routes"); /* * 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; RT_LOCK_ASSERT(rt); if (!(rt->rt_flags & RTF_UP)) return; /* prophylactic measures */ if (rt->rt_flags & RTPRF_OURS) return; if (!(rt->rt_flags & RTF_DYNAMIC)) return; /* * If rtq_reallyold is 0, just delete the route without * waiting for a timeout cycle to kill it. */ if (V_rtq_reallyold != 0) { rt->rt_flags |= RTPRF_OURS; rt->rt_rmx.rmx_expire = time_uptime + V_rtq_reallyold; } else { rtexpunge(rt); } } 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; RADIX_NODE_HEAD_WLOCK_ASSERT(ap->rnh); if (rt->rt_flags & RTPRF_OURS) { ap->found++; if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) { if (rt->rt_refcnt > 0) panic("rtqkill route really not free"); err = in_rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags | RTF_RNH_LOCKED, 0, rt->rt_fibnum); if (err) { log(LOG_WARNING, "in_rtqkill: error %d\n", err); } else { ap->killed++; } } else { if (ap->updating && (rt->rt_rmx.rmx_expire - time_uptime > V_rtq_reallyold)) { rt->rt_rmx.rmx_expire = time_uptime + V_rtq_reallyold; } ap->nextstop = lmin(ap->nextstop, rt->rt_rmx.rmx_expire); } } return 0; } #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ static VNET_DEFINE(int, rtq_timeout) = RTQ_TIMEOUT; static VNET_DEFINE(struct callout, rtq_timer); #define V_rtq_timeout VNET(rtq_timeout) #define V_rtq_timer VNET(rtq_timer) static void in_rtqtimo_one(void *rock); static void in_rtqtimo(void *rock) { CURVNET_SET((struct vnet *) rock); int fibnum; void *newrock; struct timeval atv; for (fibnum = 0; fibnum < rt_numfibs; fibnum++) { newrock = rt_tables_get_rnh(fibnum, AF_INET); if (newrock != NULL) in_rtqtimo_one(newrock); } atv.tv_usec = 0; atv.tv_sec = V_rtq_timeout; callout_reset(&V_rtq_timer, tvtohz(&atv), in_rtqtimo, rock); CURVNET_RESTORE(); } static void in_rtqtimo_one(void *rock) { struct radix_node_head *rnh = rock; struct rtqk_arg arg; static time_t last_adjusted_timeout = 0; arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = time_uptime + V_rtq_timeout; arg.draining = arg.updating = 0; RADIX_NODE_HEAD_LOCK(rnh); rnh->rnh_walktree(rnh, in_rtqkill, &arg); RADIX_NODE_HEAD_UNLOCK(rnh); /* * 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 > V_rtq_toomany) && (time_uptime - last_adjusted_timeout >= V_rtq_timeout) && V_rtq_reallyold > V_rtq_minreallyold) { V_rtq_reallyold = 2 * V_rtq_reallyold / 3; if (V_rtq_reallyold < V_rtq_minreallyold) { V_rtq_reallyold = V_rtq_minreallyold; } last_adjusted_timeout = time_uptime; #ifdef DIAGNOSTIC log(LOG_DEBUG, "in_rtqtimo: adjusted rtq_reallyold to %d\n", V_rtq_reallyold); #endif arg.found = arg.killed = 0; arg.updating = 1; RADIX_NODE_HEAD_LOCK(rnh); rnh->rnh_walktree(rnh, in_rtqkill, &arg); RADIX_NODE_HEAD_UNLOCK(rnh); } } void in_rtqdrain(void) { VNET_ITERATOR_DECL(vnet_iter); struct radix_node_head *rnh; struct rtqk_arg arg; int fibnum; VNET_LIST_RLOCK_NOSLEEP(); VNET_FOREACH(vnet_iter) { CURVNET_SET(vnet_iter); for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { rnh = rt_tables_get_rnh(fibnum, AF_INET); arg.found = arg.killed = 0; arg.rnh = rnh; arg.nextstop = 0; arg.draining = 1; arg.updating = 0; RADIX_NODE_HEAD_LOCK(rnh); rnh->rnh_walktree(rnh, in_rtqkill, &arg); RADIX_NODE_HEAD_UNLOCK(rnh); } CURVNET_RESTORE(); } VNET_LIST_RUNLOCK_NOSLEEP(); } static int _in_rt_was_here; /* * Initialize our routing tree. */ int in_inithead(void **head, int off) { struct radix_node_head *rnh; /* XXX MRT * This can be called from vfs_export.c too in which case 'off' * will be 0. We know the correct value so just use that and * return directly if it was 0. * This is a hack that replaces an even worse hack on a bad hack * on a bad design. After RELENG_7 this should be fixed but that * will change the ABI, so for now do it this way. */ if (!rn_inithead(head, 32)) return 0; if (off == 0) /* XXX MRT see above */ return 1; /* only do the rest for a real routing table */ rnh = *head; rnh->rnh_addaddr = in_addroute; rnh->rnh_matchaddr = in_matroute; rnh->rnh_close = in_clsroute; if (_in_rt_was_here == 0 ) { callout_init(&V_rtq_timer, CALLOUT_MPSAFE); callout_reset(&V_rtq_timer, 1, in_rtqtimo, curvnet); _in_rt_was_here = 1; } return 1; } #ifdef VIMAGE int in_detachhead(void **head, int off) { callout_drain(&V_rtq_timer); return (1); } #endif /* * 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 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; RT_LOCK(rt); if (rt->rt_ifa == ap->ifa && (ap->del || !(rt->rt_flags & RTF_STATIC))) { /* * Aquire a reference so that it can later be freed * as the refcount would be 0 here in case of at least * ap->del. */ RT_ADDREF(rt); /* * Disconnect it from the tree and permit protocols * to cleanup. */ rtexpunge(rt); /* * At this point it is an rttrash node, and in case * the above is the only reference we must free it. * If we do not noone will have a pointer and the * rtentry will be leaked forever. * In case someone else holds a reference, we are * fine as we only decrement the refcount. In that * case if the other entity calls RT_REMREF, we * will still be leaking but at least we tried. */ RTFREE_LOCKED(rt); return (0); } RT_UNLOCK(rt); return 0; } int in_ifadown(struct ifaddr *ifa, int delete) { struct in_ifadown_arg arg; struct radix_node_head *rnh; int fibnum; if (ifa->ifa_addr->sa_family != AF_INET) return 1; for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) { rnh = rt_tables_get_rnh(fibnum, AF_INET); arg.ifa = ifa; arg.del = delete; RADIX_NODE_HEAD_LOCK(rnh); rnh->rnh_walktree(rnh, in_ifadownkill, &arg); RADIX_NODE_HEAD_UNLOCK(rnh); ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ } return 0; } /* * inet versions of rt functions. These have fib extensions and * for now will just reference the _fib variants. * eventually this order will be reversed, */ void in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum) { rtalloc_ign_fib(ro, ignflags, fibnum); } int in_rtrequest( int req, struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct rtentry **ret_nrt, u_int fibnum) { return (rtrequest_fib(req, dst, gateway, netmask, flags, ret_nrt, fibnum)); } struct rtentry * in_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum) { return (rtalloc1_fib(dst, report, ignflags, fibnum)); } void in_rtredirect(struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct sockaddr *src, u_int fibnum) { rtredirect_fib(dst, gateway, netmask, flags, src, fibnum); } void in_rtalloc(struct route *ro, u_int fibnum) { rtalloc_ign_fib(ro, 0UL, fibnum); } #if 0 int in_rt_getifa(struct rt_addrinfo *, u_int fibnum); int in_rtioctl(u_long, caddr_t, u_int); int in_rtrequest1(int, struct rt_addrinfo *, struct rtentry **, u_int); #endif