/*- * Copyright (c) 1980, 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. * * @(#)route.c 8.3.1.1 (Berkeley) 2/23/95 * $FreeBSD$ */ /************************************************************************ * Note: In this file a 'fib' is a "forwarding information base" * * Which is the new name for an in kernel routing (next hop) table. * ***********************************************************************/ #include "opt_inet.h" #include "opt_route.h" #include "opt_mrouting.h" #include "opt_mpath.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef RADIX_MPATH #include #endif #include #include #include #include #include u_int rt_numfibs = RT_NUMFIBS; SYSCTL_INT(_net, OID_AUTO, fibs, CTLFLAG_RD, &rt_numfibs, 0, ""); /* * Allow the boot code to allow LESS than RT_MAXFIBS to be used. * We can't do more because storage is statically allocated for now. * (for compatibility reasons.. this will change). */ TUNABLE_INT("net.fibs", &rt_numfibs); /* * By default add routes to all fibs for new interfaces. * Once this is set to 0 then only allocate routes on interface * changes for the FIB of the caller when adding a new set of addresses * to an interface. XXX this is a shotgun aproach to a problem that needs * a more fine grained solution.. that will come. */ u_int rt_add_addr_allfibs = 1; SYSCTL_INT(_net, OID_AUTO, add_addr_allfibs, CTLFLAG_RW, &rt_add_addr_allfibs, 0, ""); TUNABLE_INT("net.add_addr_allfibs", &rt_add_addr_allfibs); #ifdef VIMAGE_GLOBALS static struct rtstat rtstat; /* by default only the first 'row' of tables will be accessed. */ /* * XXXMRT When we fix netstat, and do this differnetly, * we can allocate this dynamically. As long as we are keeping * things backwards compaitble we need to allocate this * statically. */ struct radix_node_head *rt_tables[RT_MAXFIBS][AF_MAX+1]; static int rttrash; /* routes not in table but not freed */ #endif static void rt_maskedcopy(struct sockaddr *, struct sockaddr *, struct sockaddr *); /* compare two sockaddr structures */ #define sa_equal(a1, a2) (bcmp((a1), (a2), (a1)->sa_len) == 0) /* * Convert a 'struct radix_node *' to a 'struct rtentry *'. * The operation can be done safely (in this code) because a * 'struct rtentry' starts with two 'struct radix_node''s, the first * one representing leaf nodes in the routing tree, which is * what the code in radix.c passes us as a 'struct radix_node'. * * But because there are a lot of assumptions in this conversion, * do not cast explicitly, but always use the macro below. */ #define RNTORT(p) ((struct rtentry *)(p)) static uma_zone_t rtzone; /* Routing table UMA zone. */ #if 0 /* default fib for tunnels to use */ u_int tunnel_fib = 0; SYSCTL_INT(_net, OID_AUTO, tunnelfib, CTLFLAG_RD, &tunnel_fib, 0, ""); #endif /* * handler for net.my_fibnum */ static int sysctl_my_fibnum(SYSCTL_HANDLER_ARGS) { int fibnum; int error; fibnum = curthread->td_proc->p_fibnum; error = sysctl_handle_int(oidp, &fibnum, 0, req); return (error); } SYSCTL_PROC(_net, OID_AUTO, my_fibnum, CTLTYPE_INT|CTLFLAG_RD, NULL, 0, &sysctl_my_fibnum, "I", "default FIB of caller"); static void route_init(void) { INIT_VNET_INET(curvnet); int table; struct domain *dom; int fam; /* whack the tunable ints into line. */ if (rt_numfibs > RT_MAXFIBS) rt_numfibs = RT_MAXFIBS; if (rt_numfibs == 0) rt_numfibs = 1; rtzone = uma_zcreate("rtentry", sizeof(struct rtentry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); rn_init(); /* initialize all zeroes, all ones, mask table */ for (dom = domains; dom; dom = dom->dom_next) { if (dom->dom_rtattach) { for (table = 0; table < rt_numfibs; table++) { if ( (fam = dom->dom_family) == AF_INET || table == 0) { /* for now only AF_INET has > 1 table */ /* XXX MRT * rtattach will be also called * from vfs_export.c but the * offset will be 0 * (only for AF_INET and AF_INET6 * which don't need it anyhow) */ dom->dom_rtattach( (void **)&V_rt_tables[table][fam], dom->dom_rtoffset); } else { break; } } } } } #ifndef _SYS_SYSPROTO_H_ struct setfib_args { int fibnum; }; #endif int setfib(struct thread *td, struct setfib_args *uap) { if (uap->fibnum < 0 || uap->fibnum >= rt_numfibs) return EINVAL; td->td_proc->p_fibnum = uap->fibnum; return (0); } /* * Packet routing routines. */ void rtalloc(struct route *ro) { rtalloc_ign_fib(ro, 0UL, 0); } void rtalloc_fib(struct route *ro, u_int fibnum) { rtalloc_ign_fib(ro, 0UL, fibnum); } void rtalloc_ign(struct route *ro, u_long ignore) { struct rtentry *rt; if ((rt = ro->ro_rt) != NULL) { if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP) return; RTFREE(rt); ro->ro_rt = NULL; } ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, 0); if (ro->ro_rt) RT_UNLOCK(ro->ro_rt); } void rtalloc_ign_fib(struct route *ro, u_long ignore, u_int fibnum) { struct rtentry *rt; if ((rt = ro->ro_rt) != NULL) { if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP) return; RTFREE(rt); ro->ro_rt = NULL; } ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, fibnum); if (ro->ro_rt) RT_UNLOCK(ro->ro_rt); } /* * Look up the route that matches the address given * Or, at least try.. Create a cloned route if needed. * * The returned route, if any, is locked. */ struct rtentry * rtalloc1(struct sockaddr *dst, int report, u_long ignflags) { return (rtalloc1_fib(dst, report, ignflags, 0)); } struct rtentry * rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum) { INIT_VNET_NET(curvnet); struct radix_node_head *rnh; struct rtentry *rt; struct radix_node *rn; struct rtentry *newrt; struct rt_addrinfo info; u_long nflags; int needresolve = 0, err = 0, msgtype = RTM_MISS; int needlock; KASSERT((fibnum < rt_numfibs), ("rtalloc1_fib: bad fibnum")); if (dst->sa_family != AF_INET) /* Only INET supports > 1 fib now */ fibnum = 0; rnh = V_rt_tables[fibnum][dst->sa_family]; newrt = NULL; /* * Look up the address in the table for that Address Family */ if (rnh == NULL) { V_rtstat.rts_unreach++; goto miss2; } needlock = !(ignflags & RTF_RNH_LOCKED); retry: if (needlock) RADIX_NODE_HEAD_RLOCK(rnh); #ifdef INVARIANTS else RADIX_NODE_HEAD_LOCK_ASSERT(rnh); #endif rn = rnh->rnh_matchaddr(dst, rnh); if (rn && ((rn->rn_flags & RNF_ROOT) == 0)) { newrt = rt = RNTORT(rn); nflags = rt->rt_flags & ~ignflags; if (report && (nflags & RTF_CLONING)) { if (needlock && !RADIX_NODE_HEAD_LOCK_TRY_UPGRADE(rnh)) { RADIX_NODE_HEAD_RUNLOCK(rnh); RADIX_NODE_HEAD_LOCK(rnh); /* * lookup again to make sure it wasn't changed */ rn = rnh->rnh_matchaddr(dst, rnh); if (!(rn && ((rn->rn_flags & RNF_ROOT) == 0))) { RADIX_NODE_HEAD_UNLOCK(rnh); needresolve = 0; log(LOG_INFO, "retrying route lookup ...\n"); goto retry; } } needresolve = 1; } else { RT_LOCK(newrt); RT_ADDREF(newrt); if (needlock) RADIX_NODE_HEAD_RUNLOCK(rnh); goto done; } } /* * if needresolve is set then we have the exclusive lock * and we need to keep it held for the benefit of rtrequest_fib */ if (!needresolve && needlock) RADIX_NODE_HEAD_RUNLOCK(rnh); if (needresolve) { RADIX_NODE_HEAD_WLOCK_ASSERT(rnh); /* * We are apparently adding (report = 0 in delete). * If it requires that it be cloned, do so. * (This implies it wasn't a HOST route.) */ err = rtrequest_fib(RTM_RESOLVE, dst, NULL, NULL, RTF_RNH_LOCKED, &newrt, fibnum); if (err) { /* * If the cloning didn't succeed, maybe * what we have will do. Return that. */ newrt = rt; /* existing route */ RT_LOCK(newrt); RT_ADDREF(newrt); goto miss; } KASSERT(newrt, ("no route and no error")); RT_LOCK(newrt); if (newrt->rt_flags & RTF_XRESOLVE) { /* * If the new route specifies it be * externally resolved, then go do that. */ msgtype = RTM_RESOLVE; goto miss; } /* Inform listeners of the new route. */ bzero(&info, sizeof(info)); info.rti_info[RTAX_DST] = rt_key(newrt); info.rti_info[RTAX_NETMASK] = rt_mask(newrt); info.rti_info[RTAX_GATEWAY] = newrt->rt_gateway; if (newrt->rt_ifp != NULL) { info.rti_info[RTAX_IFP] = newrt->rt_ifp->if_addr->ifa_addr; info.rti_info[RTAX_IFA] = newrt->rt_ifa->ifa_addr; } rt_missmsg(RTM_ADD, &info, newrt->rt_flags, 0); if (needlock) RADIX_NODE_HEAD_UNLOCK(rnh); } else { /* * Either we hit the root or couldn't find any match, * Which basically means * "caint get there frm here" */ V_rtstat.rts_unreach++; miss: if (needlock && needresolve) RADIX_NODE_HEAD_UNLOCK(rnh); miss2: if (report) { /* * If required, report the failure to the supervising * Authorities. * For a delete, this is not an error. (report == 0) */ bzero(&info, sizeof(info)); info.rti_info[RTAX_DST] = dst; rt_missmsg(msgtype, &info, 0, err); } } done: if (newrt) RT_LOCK_ASSERT(newrt); return (newrt); } /* * Remove a reference count from an rtentry. * If the count gets low enough, take it out of the routing table */ void rtfree(struct rtentry *rt) { INIT_VNET_NET(curvnet); struct radix_node_head *rnh; KASSERT(rt != NULL,("%s: NULL rt", __func__)); rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family]; KASSERT(rnh != NULL,("%s: NULL rnh", __func__)); RT_LOCK_ASSERT(rt); /* * The callers should use RTFREE_LOCKED() or RTFREE(), so * we should come here exactly with the last reference. */ RT_REMREF(rt); if (rt->rt_refcnt > 0) { printf("%s: %p has %lu refs\n", __func__, rt, rt->rt_refcnt); goto done; } /* * On last reference give the "close method" a chance * to cleanup private state. This also permits (for * IPv4 and IPv6) a chance to decide if the routing table * entry should be purged immediately or at a later time. * When an immediate purge is to happen the close routine * typically calls rtexpunge which clears the RTF_UP flag * on the entry so that the code below reclaims the storage. */ if (rt->rt_refcnt == 0 && rnh->rnh_close) rnh->rnh_close((struct radix_node *)rt, rnh); /* * If we are no longer "up" (and ref == 0) * then we can free the resources associated * with the route. */ if ((rt->rt_flags & RTF_UP) == 0) { if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT)) panic("rtfree 2"); /* * the rtentry must have been removed from the routing table * so it is represented in rttrash.. remove that now. */ V_rttrash--; #ifdef DIAGNOSTIC if (rt->rt_refcnt < 0) { printf("rtfree: %p not freed (neg refs)\n", rt); goto done; } #endif /* * release references on items we hold them on.. * e.g other routes and ifaddrs. */ if (rt->rt_ifa) IFAFREE(rt->rt_ifa); rt->rt_parent = NULL; /* NB: no refcnt on parent */ /* * The key is separatly alloc'd so free it (see rt_setgate()). * This also frees the gateway, as they are always malloc'd * together. */ Free(rt_key(rt)); /* * and the rtentry itself of course */ RT_LOCK_DESTROY(rt); uma_zfree(rtzone, rt); return; } done: RT_UNLOCK(rt); } /* * Force a routing table entry to the specified * destination to go through the given gateway. * Normally called as a result of a routing redirect * message from the network layer. */ void rtredirect(struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct sockaddr *src) { rtredirect_fib(dst, gateway, netmask, flags, src, 0); } void rtredirect_fib(struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct sockaddr *src, u_int fibnum) { INIT_VNET_NET(curvnet); struct rtentry *rt, *rt0 = NULL; int error = 0; short *stat = NULL; struct rt_addrinfo info; struct ifaddr *ifa; struct radix_node_head *rnh = V_rt_tables[fibnum][dst->sa_family]; /* verify the gateway is directly reachable */ if ((ifa = ifa_ifwithnet(gateway)) == NULL) { error = ENETUNREACH; goto out; } rt = rtalloc1_fib(dst, 0, 0UL, fibnum); /* NB: rt is locked */ /* * If the redirect isn't from our current router for this dst, * it's either old or wrong. If it redirects us to ourselves, * we have a routing loop, perhaps as a result of an interface * going down recently. */ if (!(flags & RTF_DONE) && rt && (!sa_equal(src, rt->rt_gateway) || rt->rt_ifa != ifa)) error = EINVAL; else if (ifa_ifwithaddr(gateway)) error = EHOSTUNREACH; if (error) goto done; /* * Create a new entry if we just got back a wildcard entry * or the the lookup failed. This is necessary for hosts * which use routing redirects generated by smart gateways * to dynamically build the routing tables. */ if (rt == NULL || (rt_mask(rt) && rt_mask(rt)->sa_len < 2)) goto create; /* * Don't listen to the redirect if it's * for a route to an interface. */ if (rt->rt_flags & RTF_GATEWAY) { if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) { /* * Changing from route to net => route to host. * Create new route, rather than smashing route to net. */ create: rt0 = rt; rt = NULL; flags |= RTF_GATEWAY | RTF_DYNAMIC; bzero((caddr_t)&info, sizeof(info)); info.rti_info[RTAX_DST] = dst; info.rti_info[RTAX_GATEWAY] = gateway; info.rti_info[RTAX_NETMASK] = netmask; info.rti_ifa = ifa; info.rti_flags = flags; if (rt0 != NULL) RT_UNLOCK(rt0); /* drop lock to avoid LOR with RNH */ error = rtrequest1_fib(RTM_ADD, &info, &rt, fibnum); if (rt != NULL) { RT_LOCK(rt); if (rt0 != NULL) EVENTHANDLER_INVOKE(route_redirect_event, rt0, rt, dst); flags = rt->rt_flags; } if (rt0 != NULL) RTFREE(rt0); stat = &V_rtstat.rts_dynamic; } else { struct rtentry *gwrt; /* * Smash the current notion of the gateway to * this destination. Should check about netmask!!! */ rt->rt_flags |= RTF_MODIFIED; flags |= RTF_MODIFIED; stat = &V_rtstat.rts_newgateway; /* * add the key and gateway (in one malloc'd chunk). */ RT_UNLOCK(rt); RADIX_NODE_HEAD_LOCK(rnh); RT_LOCK(rt); rt_setgate(rt, rt_key(rt), gateway); gwrt = rtalloc1(gateway, 1, RTF_RNH_LOCKED); RADIX_NODE_HEAD_UNLOCK(rnh); EVENTHANDLER_INVOKE(route_redirect_event, rt, gwrt, dst); RTFREE_LOCKED(gwrt); } } else error = EHOSTUNREACH; done: if (rt) RTFREE_LOCKED(rt); out: if (error) V_rtstat.rts_badredirect++; else if (stat != NULL) (*stat)++; bzero((caddr_t)&info, sizeof(info)); info.rti_info[RTAX_DST] = dst; info.rti_info[RTAX_GATEWAY] = gateway; info.rti_info[RTAX_NETMASK] = netmask; info.rti_info[RTAX_AUTHOR] = src; rt_missmsg(RTM_REDIRECT, &info, flags, error); } int rtioctl(u_long req, caddr_t data) { return (rtioctl_fib(req, data, 0)); } /* * Routing table ioctl interface. */ int rtioctl_fib(u_long req, caddr_t data, u_int fibnum) { /* * If more ioctl commands are added here, make sure the proper * super-user checks are being performed because it is possible for * prison-root to make it this far if raw sockets have been enabled * in jails. */ #ifdef INET /* Multicast goop, grrr... */ return mrt_ioctl ? mrt_ioctl(req, data, fibnum) : EOPNOTSUPP; #else /* INET */ return ENXIO; #endif /* INET */ } struct ifaddr * ifa_ifwithroute(int flags, struct sockaddr *dst, struct sockaddr *gateway) { return (ifa_ifwithroute_fib(flags, dst, gateway, 0)); } struct ifaddr * ifa_ifwithroute_fib(int flags, struct sockaddr *dst, struct sockaddr *gateway, u_int fibnum) { register struct ifaddr *ifa; int not_found = 0; if ((flags & RTF_GATEWAY) == 0) { /* * If we are adding a route to an interface, * and the interface is a pt to pt link * we should search for the destination * as our clue to the interface. Otherwise * we can use the local address. */ ifa = NULL; if (flags & RTF_HOST) ifa = ifa_ifwithdstaddr(dst); if (ifa == NULL) ifa = ifa_ifwithaddr(gateway); } else { /* * If we are adding a route to a remote net * or host, the gateway may still be on the * other end of a pt to pt link. */ ifa = ifa_ifwithdstaddr(gateway); } if (ifa == NULL) ifa = ifa_ifwithnet(gateway); if (ifa == NULL) { struct rtentry *rt = rtalloc1_fib(gateway, 0, RTF_RNH_LOCKED, fibnum); if (rt == NULL) return (NULL); /* * dismiss a gateway that is reachable only * through the default router */ switch (gateway->sa_family) { case AF_INET: if (satosin(rt_key(rt))->sin_addr.s_addr == INADDR_ANY) not_found = 1; break; case AF_INET6: if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(rt))->sin6_addr)) not_found = 1; break; default: break; } RT_REMREF(rt); RT_UNLOCK(rt); if (not_found) return (NULL); if ((ifa = rt->rt_ifa) == NULL) return (NULL); } if (ifa->ifa_addr->sa_family != dst->sa_family) { struct ifaddr *oifa = ifa; ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp); if (ifa == NULL) ifa = oifa; } return (ifa); } static walktree_f_t rt_fixdelete; static walktree_f_t rt_fixchange; struct rtfc_arg { struct rtentry *rt0; struct radix_node_head *rnh; }; /* * Do appropriate manipulations of a routing tree given * all the bits of info needed */ int rtrequest(int req, struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct rtentry **ret_nrt) { return (rtrequest_fib(req, dst, gateway, netmask, flags, ret_nrt, 0)); } int rtrequest_fib(int req, struct sockaddr *dst, struct sockaddr *gateway, struct sockaddr *netmask, int flags, struct rtentry **ret_nrt, u_int fibnum) { struct rt_addrinfo info; if (dst->sa_len == 0) return(EINVAL); bzero((caddr_t)&info, sizeof(info)); info.rti_flags = flags; info.rti_info[RTAX_DST] = dst; info.rti_info[RTAX_GATEWAY] = gateway; info.rti_info[RTAX_NETMASK] = netmask; return rtrequest1_fib(req, &info, ret_nrt, fibnum); } /* * These (questionable) definitions of apparent local variables apply * to the next two functions. XXXXXX!!! */ #define dst info->rti_info[RTAX_DST] #define gateway info->rti_info[RTAX_GATEWAY] #define netmask info->rti_info[RTAX_NETMASK] #define ifaaddr info->rti_info[RTAX_IFA] #define ifpaddr info->rti_info[RTAX_IFP] #define flags info->rti_flags int rt_getifa(struct rt_addrinfo *info) { return (rt_getifa_fib(info, 0)); } int rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum) { struct ifaddr *ifa; int error = 0; /* * ifp may be specified by sockaddr_dl * when protocol address is ambiguous. */ if (info->rti_ifp == NULL && ifpaddr != NULL && ifpaddr->sa_family == AF_LINK && (ifa = ifa_ifwithnet(ifpaddr)) != NULL) info->rti_ifp = ifa->ifa_ifp; if (info->rti_ifa == NULL && ifaaddr != NULL) info->rti_ifa = ifa_ifwithaddr(ifaaddr); if (info->rti_ifa == NULL) { struct sockaddr *sa; sa = ifaaddr != NULL ? ifaaddr : (gateway != NULL ? gateway : dst); if (sa != NULL && info->rti_ifp != NULL) info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp); else if (dst != NULL && gateway != NULL) info->rti_ifa = ifa_ifwithroute_fib(flags, dst, gateway, fibnum); else if (sa != NULL) info->rti_ifa = ifa_ifwithroute_fib(flags, sa, sa, fibnum); } if ((ifa = info->rti_ifa) != NULL) { if (info->rti_ifp == NULL) info->rti_ifp = ifa->ifa_ifp; } else error = ENETUNREACH; return (error); } /* * Expunges references to a route that's about to be reclaimed. * The route must be locked. */ int rtexpunge(struct rtentry *rt) { INIT_VNET_NET(curvnet); struct radix_node *rn; struct radix_node_head *rnh; struct ifaddr *ifa; int error = 0; rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family]; RT_LOCK_ASSERT(rt); RADIX_NODE_HEAD_LOCK_ASSERT(rnh); #if 0 /* * We cannot assume anything about the reference count * because protocols call us in many situations; often * before unwinding references to the table entry. */ KASSERT(rt->rt_refcnt <= 1, ("bogus refcnt %ld", rt->rt_refcnt)); #endif /* * Find the correct routing tree to use for this Address Family */ rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family]; if (rnh == NULL) return (EAFNOSUPPORT); /* * Remove the item from the tree; it should be there, * but when callers invoke us blindly it may not (sigh). */ rn = rnh->rnh_deladdr(rt_key(rt), rt_mask(rt), rnh); if (rn == NULL) { error = ESRCH; goto bad; } KASSERT((rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) == 0, ("unexpected flags 0x%x", rn->rn_flags)); KASSERT(rt == RNTORT(rn), ("lookup mismatch, rt %p rn %p", rt, rn)); rt->rt_flags &= ~RTF_UP; /* * Now search what's left of the subtree for any cloned * routes which might have been formed from this node. */ if ((rt->rt_flags & RTF_CLONING) && rt_mask(rt)) rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), rt_fixdelete, rt); /* * Remove any external references we may have. * This might result in another rtentry being freed if * we held its last reference. */ if (rt->rt_gwroute) { RTFREE(rt->rt_gwroute); rt->rt_gwroute = NULL; } /* * Give the protocol a chance to keep things in sync. */ if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) { struct rt_addrinfo info; bzero((caddr_t)&info, sizeof(info)); info.rti_flags = rt->rt_flags; info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_NETMASK] = rt_mask(rt); ifa->ifa_rtrequest(RTM_DELETE, rt, &info); } /* * one more rtentry floating around that is not * linked to the routing table. */ V_rttrash++; bad: return (error); } int rtrequest1(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt) { return (rtrequest1_fib(req, info, ret_nrt, 0)); } int rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt, u_int fibnum) { INIT_VNET_NET(curvnet); int error = 0, needlock = 0; register struct rtentry *rt; register struct radix_node *rn; register struct radix_node_head *rnh; struct ifaddr *ifa; struct sockaddr *ndst; #define senderr(x) { error = x ; goto bad; } KASSERT((fibnum < rt_numfibs), ("rtrequest1_fib: bad fibnum")); if (dst->sa_family != AF_INET) /* Only INET supports > 1 fib now */ fibnum = 0; /* * Find the correct routing tree to use for this Address Family */ rnh = V_rt_tables[fibnum][dst->sa_family]; if (rnh == NULL) return (EAFNOSUPPORT); needlock = ((flags & RTF_RNH_LOCKED) == 0); flags &= ~RTF_RNH_LOCKED; if (needlock) RADIX_NODE_HEAD_LOCK(rnh); else RADIX_NODE_HEAD_LOCK_ASSERT(rnh); /* * If we are adding a host route then we don't want to put * a netmask in the tree, nor do we want to clone it. */ if (flags & RTF_HOST) { netmask = NULL; flags &= ~RTF_CLONING; } switch (req) { case RTM_DELETE: #ifdef RADIX_MPATH /* * if we got multipath routes, we require users to specify * a matching RTAX_GATEWAY. */ if (rn_mpath_capable(rnh)) { struct rtentry *rto = NULL; rn = rnh->rnh_matchaddr(dst, rnh); if (rn == NULL) senderr(ESRCH); rto = rt = RNTORT(rn); rt = rt_mpath_matchgate(rt, gateway); if (!rt) senderr(ESRCH); /* * this is the first entry in the chain */ if (rto == rt) { rn = rn_mpath_next((struct radix_node *)rt); /* * there is another entry, now it's active */ if (rn) { rto = RNTORT(rn); RT_LOCK(rto); rto->rt_flags |= RTF_UP; RT_UNLOCK(rto); } else if (rt->rt_flags & RTF_GATEWAY) { /* * For gateway routes, we need to * make sure that we we are deleting * the correct gateway. * rt_mpath_matchgate() does not * check the case when there is only * one route in the chain. */ if (gateway && (rt->rt_gateway->sa_len != gateway->sa_len || memcmp(rt->rt_gateway, gateway, gateway->sa_len))) senderr(ESRCH); } /* * use the normal delete code to remove * the first entry */ goto normal_rtdel; } /* * if the entry is 2nd and on up */ if (!rt_mpath_deldup(rto, rt)) panic ("rtrequest1: rt_mpath_deldup"); RT_LOCK(rt); RT_ADDREF(rt); rt->rt_flags &= ~RTF_UP; goto deldone; /* done with the RTM_DELETE command */ } normal_rtdel: #endif /* * Remove the item from the tree and return it. * Complain if it is not there and do no more processing. */ rn = rnh->rnh_deladdr(dst, netmask, rnh); if (rn == NULL) senderr(ESRCH); if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) panic ("rtrequest delete"); rt = RNTORT(rn); RT_LOCK(rt); RT_ADDREF(rt); rt->rt_flags &= ~RTF_UP; /* * Now search what's left of the subtree for any cloned * routes which might have been formed from this node. */ if ((rt->rt_flags & RTF_CLONING) && rt_mask(rt)) { rnh->rnh_walktree_from(rnh, dst, rt_mask(rt), rt_fixdelete, rt); } /* * Remove any external references we may have. * This might result in another rtentry being freed if * we held its last reference. */ if (rt->rt_gwroute) { RTFREE(rt->rt_gwroute); rt->rt_gwroute = NULL; } /* * give the protocol a chance to keep things in sync. */ if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) ifa->ifa_rtrequest(RTM_DELETE, rt, info); #ifdef RADIX_MPATH deldone: #endif /* * One more rtentry floating around that is not * linked to the routing table. rttrash will be decremented * when RTFREE(rt) is eventually called. */ V_rttrash++; /* * If the caller wants it, then it can have it, * but it's up to it to free the rtentry as we won't be * doing it. */ if (ret_nrt) { *ret_nrt = rt; RT_UNLOCK(rt); } else RTFREE_LOCKED(rt); break; case RTM_RESOLVE: if (ret_nrt == NULL || (rt = *ret_nrt) == NULL) senderr(EINVAL); ifa = rt->rt_ifa; /* XXX locking? */ flags = rt->rt_flags & ~(RTF_CLONING | RTF_STATIC); flags |= RTF_WASCLONED; gateway = rt->rt_gateway; if ((netmask = rt->rt_genmask) == NULL) flags |= RTF_HOST; goto makeroute; case RTM_ADD: if ((flags & RTF_GATEWAY) && !gateway) senderr(EINVAL); if (dst && gateway && (dst->sa_family != gateway->sa_family) && (gateway->sa_family != AF_UNSPEC) && (gateway->sa_family != AF_LINK)) senderr(EINVAL); if (info->rti_ifa == NULL && (error = rt_getifa_fib(info, fibnum))) senderr(error); ifa = info->rti_ifa; makeroute: rt = uma_zalloc(rtzone, M_NOWAIT | M_ZERO); if (rt == NULL) senderr(ENOBUFS); RT_LOCK_INIT(rt); rt->rt_flags = RTF_UP | flags; rt->rt_fibnum = fibnum; /* * Add the gateway. Possibly re-malloc-ing the storage for it * also add the rt_gwroute if possible. */ RT_LOCK(rt); if ((error = rt_setgate(rt, dst, gateway)) != 0) { RT_LOCK_DESTROY(rt); uma_zfree(rtzone, rt); senderr(error); } /* * point to the (possibly newly malloc'd) dest address. */ ndst = (struct sockaddr *)rt_key(rt); /* * make sure it contains the value we want (masked if needed). */ if (netmask) { rt_maskedcopy(dst, ndst, netmask); } else bcopy(dst, ndst, dst->sa_len); /* * Note that we now have a reference to the ifa. * This moved from below so that rnh->rnh_addaddr() can * examine the ifa and ifa->ifa_ifp if it so desires. */ IFAREF(ifa); rt->rt_ifa = ifa; rt->rt_ifp = ifa->ifa_ifp; #ifdef RADIX_MPATH /* do not permit exactly the same dst/mask/gw pair */ if (rn_mpath_capable(rnh) && rt_mpath_conflict(rnh, rt, netmask)) { if (rt->rt_gwroute) RTFREE(rt->rt_gwroute); if (rt->rt_ifa) { IFAFREE(rt->rt_ifa); } Free(rt_key(rt)); RT_LOCK_DESTROY(rt); uma_zfree(rtzone, rt); senderr(EEXIST); } #endif /* XXX mtu manipulation will be done in rnh_addaddr -- itojun */ rn = rnh->rnh_addaddr(ndst, netmask, rnh, rt->rt_nodes); if (rn == NULL) { struct rtentry *rt2; /* * Uh-oh, we already have one of these in the tree. * We do a special hack: if the route that's already * there was generated by the cloning mechanism * then we just blow it away and retry the insertion * of the new one. */ rt2 = rtalloc1_fib(dst, 0, RTF_RNH_LOCKED, fibnum); if (rt2 && rt2->rt_parent) { rtexpunge(rt2); RT_UNLOCK(rt2); rn = rnh->rnh_addaddr(ndst, netmask, rnh, rt->rt_nodes); } else if (rt2) { /* undo the extra ref we got */ RTFREE_LOCKED(rt2); } } /* * If it still failed to go into the tree, * then un-make it (this should be a function) */ if (rn == NULL) { if (rt->rt_gwroute) RTFREE(rt->rt_gwroute); if (rt->rt_ifa) IFAFREE(rt->rt_ifa); Free(rt_key(rt)); RT_LOCK_DESTROY(rt); uma_zfree(rtzone, rt); senderr(EEXIST); } rt->rt_parent = NULL; /* * If we got here from RESOLVE, then we are cloning * so clone the rest, and note that we * are a clone (and increment the parent's references) */ if (req == RTM_RESOLVE) { KASSERT(ret_nrt && *ret_nrt, ("no route to clone from")); rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */ rt->rt_rmx.rmx_pksent = 0; /* reset packet counter */ if ((*ret_nrt)->rt_flags & RTF_CLONING) { /* * NB: We do not bump the refcnt on the parent * entry under the assumption that it will * remain so long as we do. This is * important when deleting the parent route * as this operation requires traversing * the tree to delete all clones and futzing * with refcnts requires us to double-lock * parent through this back reference. */ rt->rt_parent = *ret_nrt; } } /* * If this protocol has something to add to this then * allow it to do that as well. */ if (ifa->ifa_rtrequest) ifa->ifa_rtrequest(req, rt, info); /* * We repeat the same procedure from rt_setgate() here because * it doesn't fire when we call it there because the node * hasn't been added to the tree yet. */ if (req == RTM_ADD && !(rt->rt_flags & RTF_HOST) && rt_mask(rt) != NULL) { struct rtfc_arg arg; arg.rnh = rnh; arg.rt0 = rt; rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), rt_fixchange, &arg); } /* * actually return a resultant rtentry and * give the caller a single reference. */ if (ret_nrt) { *ret_nrt = rt; RT_ADDREF(rt); } RT_UNLOCK(rt); break; default: error = EOPNOTSUPP; } bad: if (needlock) RADIX_NODE_HEAD_UNLOCK(rnh); return (error); #undef senderr } #undef dst #undef gateway #undef netmask #undef ifaaddr #undef ifpaddr #undef flags /* * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family'' * (i.e., the routes related to it by the operation of cloning). This * routine is iterated over all potential former-child-routes by way of * rnh->rnh_walktree_from() above, and those that actually are children of * the late parent (passed in as VP here) are themselves deleted. */ static int rt_fixdelete(struct radix_node *rn, void *vp) { struct rtentry *rt = RNTORT(rn); struct rtentry *rt0 = vp; if (rt->rt_parent == rt0 && !(rt->rt_flags & (RTF_PINNED | RTF_CLONING))) { return rtrequest_fib(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), rt->rt_flags|RTF_RNH_LOCKED, NULL, rt->rt_fibnum); } return 0; } /* * This routine is called from rt_setgate() to do the analogous thing for * adds and changes. There is the added complication in this case of a * middle insert; i.e., insertion of a new network route between an older * network route and (cloned) host routes. For this reason, a simple check * of rt->rt_parent is insufficient; each candidate route must be tested * against the (mask, value) of the new route (passed as before in vp) * to see if the new route matches it. * * XXX - it may be possible to do fixdelete() for changes and reserve this * routine just for adds. I'm not sure why I thought it was necessary to do * changes this way. */ static int rt_fixchange(struct radix_node *rn, void *vp) { struct rtentry *rt = RNTORT(rn); struct rtfc_arg *ap = vp; struct rtentry *rt0 = ap->rt0; struct radix_node_head *rnh = ap->rnh; u_char *xk1, *xm1, *xk2, *xmp; int i, len, mlen; /* make sure we have a parent, and route is not pinned or cloning */ if (!rt->rt_parent || (rt->rt_flags & (RTF_PINNED | RTF_CLONING))) return 0; if (rt->rt_parent == rt0) /* parent match */ goto delete_rt; /* * There probably is a function somewhere which does this... * if not, there should be. */ len = imin(rt_key(rt0)->sa_len, rt_key(rt)->sa_len); xk1 = (u_char *)rt_key(rt0); xm1 = (u_char *)rt_mask(rt0); xk2 = (u_char *)rt_key(rt); /* avoid applying a less specific route */ xmp = (u_char *)rt_mask(rt->rt_parent); mlen = rt_key(rt->rt_parent)->sa_len; if (mlen > rt_key(rt0)->sa_len) /* less specific route */ return 0; for (i = rnh->rnh_treetop->rn_offset; i < mlen; i++) if ((xmp[i] & ~(xmp[i] ^ xm1[i])) != xmp[i]) return 0; /* less specific route */ for (i = rnh->rnh_treetop->rn_offset; i < len; i++) if ((xk2[i] & xm1[i]) != xk1[i]) return 0; /* no match */ /* * OK, this node is a clone, and matches the node currently being * changed/added under the node's mask. So, get rid of it. */ delete_rt: return rtrequest_fib(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), rt->rt_flags, NULL, rt->rt_fibnum); } int rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate) { INIT_VNET_NET(curvnet); /* XXX dst may be overwritten, can we move this to below */ struct radix_node_head *rnh = V_rt_tables[rt->rt_fibnum][dst->sa_family]; int dlen = SA_SIZE(dst), glen = SA_SIZE(gate); again: RT_LOCK_ASSERT(rt); RADIX_NODE_HEAD_LOCK_ASSERT(rnh); /* * A host route with the destination equal to the gateway * will interfere with keeping LLINFO in the routing * table, so disallow it. */ if (((rt->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) == (RTF_HOST|RTF_GATEWAY)) && dst->sa_len == gate->sa_len && bcmp(dst, gate, dst->sa_len) == 0) { /* * The route might already exist if this is an RTM_CHANGE * or a routing redirect, so try to delete it. */ if (rt_key(rt)) rtexpunge(rt); return EADDRNOTAVAIL; } /* * Cloning loop avoidance in case of bad configuration. */ if (rt->rt_flags & RTF_GATEWAY) { struct rtentry *gwrt; RT_UNLOCK(rt); /* XXX workaround LOR */ gwrt = rtalloc1_fib(gate, 1, RTF_RNH_LOCKED, rt->rt_fibnum); if (gwrt == rt) { RT_REMREF(rt); return (EADDRINUSE); /* failure */ } /* * Try to reacquire the lock on rt, and if it fails, * clean state and restart from scratch. */ if (!RT_TRYLOCK(rt)) { RTFREE_LOCKED(gwrt); RT_LOCK(rt); goto again; } /* * If there is already a gwroute, then drop it. If we * are asked to replace route with itself, then do * not leak its refcounter. */ if (rt->rt_gwroute != NULL) { if (rt->rt_gwroute == gwrt) { RT_REMREF(rt->rt_gwroute); } else RTFREE(rt->rt_gwroute); } if ((rt->rt_gwroute = gwrt) != NULL) RT_UNLOCK(rt->rt_gwroute); } /* * Prepare to store the gateway in rt->rt_gateway. * Both dst and gateway are stored one after the other in the same * malloc'd chunk. If we have room, we can reuse the old buffer, * rt_gateway already points to the right place. * Otherwise, malloc a new block and update the 'dst' address. */ if (rt->rt_gateway == NULL || glen > SA_SIZE(rt->rt_gateway)) { caddr_t new; R_Malloc(new, caddr_t, dlen + glen); if (new == NULL) return ENOBUFS; /* * XXX note, we copy from *dst and not *rt_key(rt) because * rt_setgate() can be called to initialize a newly * allocated route entry, in which case rt_key(rt) == NULL * (and also rt->rt_gateway == NULL). * Free()/free() handle a NULL argument just fine. */ bcopy(dst, new, dlen); Free(rt_key(rt)); /* free old block, if any */ rt_key(rt) = (struct sockaddr *)new; rt->rt_gateway = (struct sockaddr *)(new + dlen); } /* * Copy the new gateway value into the memory chunk. */ bcopy(gate, rt->rt_gateway, glen); /* * This isn't going to do anything useful for host routes, so * don't bother. Also make sure we have a reasonable mask * (we don't yet have one during adds). */ if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) { struct rtfc_arg arg; arg.rnh = rnh; arg.rt0 = rt; rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), rt_fixchange, &arg); } return 0; } static void rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netmask) { register u_char *cp1 = (u_char *)src; register u_char *cp2 = (u_char *)dst; register u_char *cp3 = (u_char *)netmask; u_char *cplim = cp2 + *cp3; u_char *cplim2 = cp2 + *cp1; *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */ cp3 += 2; if (cplim > cplim2) cplim = cplim2; while (cp2 < cplim) *cp2++ = *cp1++ & *cp3++; if (cp2 < cplim2) bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2)); } /* * Set up a routing table entry, normally * for an interface. */ #define _SOCKADDR_TMPSIZE 128 /* Not too big.. kernel stack size is limited */ static inline int rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum) { INIT_VNET_NET(curvnet); struct sockaddr *dst; struct sockaddr *netmask; struct rtentry *rt = NULL; struct rt_addrinfo info; int error = 0; int startfib, endfib; char tempbuf[_SOCKADDR_TMPSIZE]; int didwork = 0; int a_failure = 0; if (flags & RTF_HOST) { dst = ifa->ifa_dstaddr; netmask = NULL; } else { dst = ifa->ifa_addr; netmask = ifa->ifa_netmask; } if ( dst->sa_family != AF_INET) fibnum = 0; if (fibnum == -1) { if (rt_add_addr_allfibs == 0 && cmd == (int)RTM_ADD) { startfib = endfib = curthread->td_proc->p_fibnum; } else { startfib = 0; endfib = rt_numfibs - 1; } } else { KASSERT((fibnum < rt_numfibs), ("rtinit1: bad fibnum")); startfib = fibnum; endfib = fibnum; } if (dst->sa_len == 0) return(EINVAL); /* * If it's a delete, check that if it exists, * it's on the correct interface or we might scrub * a route to another ifa which would * be confusing at best and possibly worse. */ if (cmd == RTM_DELETE) { /* * It's a delete, so it should already exist.. * If it's a net, mask off the host bits * (Assuming we have a mask) * XXX this is kinda inet specific.. */ if (netmask != NULL) { rt_maskedcopy(dst, (struct sockaddr *)tempbuf, netmask); dst = (struct sockaddr *)tempbuf; } } /* * Now go through all the requested tables (fibs) and do the * requested action. Realistically, this will either be fib 0 * for protocols that don't do multiple tables or all the * tables for those that do. XXX For this version only AF_INET. * When that changes code should be refactored to protocol * independent parts and protocol dependent parts. */ for ( fibnum = startfib; fibnum <= endfib; fibnum++) { if (cmd == RTM_DELETE) { struct radix_node_head *rnh; struct radix_node *rn; /* * Look up an rtentry that is in the routing tree and * contains the correct info. */ if ((rnh = V_rt_tables[fibnum][dst->sa_family]) == NULL) /* this table doesn't exist but others might */ continue; RADIX_NODE_HEAD_LOCK(rnh); #ifdef RADIX_MPATH if (rn_mpath_capable(rnh)) { rn = rnh->rnh_matchaddr(dst, rnh); if (rn == NULL) error = ESRCH; else { rt = RNTORT(rn); /* * for interface route the * rt->rt_gateway is sockaddr_intf * for cloning ARP entries, so * rt_mpath_matchgate must use the * interface address */ rt = rt_mpath_matchgate(rt, ifa->ifa_addr); if (!rt) error = ESRCH; } } else #endif rn = rnh->rnh_lookup(dst, netmask, rnh); error = (rn == NULL || (rn->rn_flags & RNF_ROOT) || RNTORT(rn)->rt_ifa != ifa || !sa_equal((struct sockaddr *)rn->rn_key, dst)); RADIX_NODE_HEAD_UNLOCK(rnh); if (error) { /* this is only an error if bad on ALL tables */ continue; } } /* * Do the actual request */ bzero((caddr_t)&info, sizeof(info)); info.rti_ifa = ifa; info.rti_flags = flags | ifa->ifa_flags; info.rti_info[RTAX_DST] = dst; info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr; info.rti_info[RTAX_NETMASK] = netmask; error = rtrequest1_fib(cmd, &info, &rt, fibnum); if (error == 0 && rt != NULL) { /* * notify any listening routing agents of the change */ RT_LOCK(rt); #ifdef RADIX_MPATH /* * in case address alias finds the first address * e.g. ifconfig bge0 192.103.54.246/24 * e.g. ifconfig bge0 192.103.54.247/24 * the address set in the route is 192.103.54.246 * so we need to replace it with 192.103.54.247 */ if (memcmp(rt->rt_ifa->ifa_addr, ifa->ifa_addr, ifa->ifa_addr->sa_len)) { IFAFREE(rt->rt_ifa); IFAREF(ifa); rt->rt_ifp = ifa->ifa_ifp; rt->rt_ifa = ifa; } #endif rt_newaddrmsg(cmd, ifa, error, rt); if (cmd == RTM_DELETE) { /* * If we are deleting, and we found an entry, * then it's been removed from the tree.. * now throw it away. */ RTFREE_LOCKED(rt); } else { if (cmd == RTM_ADD) { /* * We just wanted to add it.. * we don't actually need a reference. */ RT_REMREF(rt); } RT_UNLOCK(rt); } didwork = 1; } if (error) a_failure = error; } if (cmd == RTM_DELETE) { if (didwork) { error = 0; } else { /* we only give an error if it wasn't in any table */ error = ((flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH); } } else { if (a_failure) { /* return an error if any of them failed */ error = a_failure; } } return (error); } /* special one for inet internal use. may not use. */ int rtinit_fib(struct ifaddr *ifa, int cmd, int flags) { return (rtinit1(ifa, cmd, flags, -1)); } /* * Set up a routing table entry, normally * for an interface. */ int rtinit(struct ifaddr *ifa, int cmd, int flags) { struct sockaddr *dst; int fib = 0; if (flags & RTF_HOST) { dst = ifa->ifa_dstaddr; } else { dst = ifa->ifa_addr; } if (dst->sa_family == AF_INET) fib = -1; return (rtinit1(ifa, cmd, flags, fib)); } /* * rt_check() is invoked on each layer 2 output path, prior to * encapsulating outbound packets. * * The function is mostly used to find a routing entry for the gateway, * which in some protocol families could also point to the link-level * address for the gateway itself (the side effect of revalidating the * route to the destination is rather pointless at this stage, we did it * already a moment before in the pr_output() routine to locate the ifp * and gateway to use). * * When we remove the layer-3 to layer-2 mapping tables from the * routing table, this function can be removed. * * === On input === * *dst is the address of the NEXT HOP (which coincides with the * final destination if directly reachable); * *lrt0 points to the cached route to the final destination; * *lrt is not meaningful; * (*lrt0 has no ref held on it by us so REMREF is not needed. * Refs only account for major structural references and not usages, * which is actually a bit of a problem.) * * === Operation === * If the route is marked down try to find a new route. If the route * to the gateway is gone, try to setup a new route. Otherwise, * if the route is marked for packets to be rejected, enforce that. * Note that rtalloc returns an rtentry with an extra REF that we may * need to lose. * * === On return === * *dst is unchanged; * *lrt0 points to the (possibly new) route to the final destination * *lrt points to the route to the next hop [LOCKED] * * Their values are meaningful ONLY if no error is returned. * * To follow this you have to remember that: * RT_REMREF reduces the reference count by 1 but doesn't check it for 0 (!) * RTFREE_LOCKED includes an RT_REMREF (or an rtfree if refs == 1) * and an RT_UNLOCK * RTFREE does an RT_LOCK and an RTFREE_LOCKED * The gwroute pointer counts as a reference on the rtentry to which it points. * so when we add it we use the ref that rtalloc gives us and when we lose it * we need to remove the reference. * RT_TEMP_UNLOCK does an RT_ADDREF before freeing the lock, and * RT_RELOCK locks it (it can't have gone away due to the ref) and * drops the ref, possibly freeing it and zeroing the pointer if * the ref goes to 0 (unlocking in the process). */ int rt_check(struct rtentry **lrt, struct rtentry **lrt0, struct sockaddr *dst) { struct rtentry *rt; struct rtentry *rt0; u_int fibnum; KASSERT(*lrt0 != NULL, ("rt_check")); rt0 = *lrt0; rt = NULL; fibnum = rt0->rt_fibnum; /* NB: the locking here is tortuous... */ RT_LOCK(rt0); retry: if (rt0 && (rt0->rt_flags & RTF_UP) == 0) { /* Current rt0 is useless, try get a replacement. */ RT_UNLOCK(rt0); rt0 = NULL; } if (rt0 == NULL) { rt0 = rtalloc1_fib(dst, 1, 0UL, fibnum); if (rt0 == NULL) { return (EHOSTUNREACH); } RT_REMREF(rt0); /* don't need the reference. */ } if (rt0->rt_flags & RTF_GATEWAY) { if ((rt = rt0->rt_gwroute) != NULL) { RT_LOCK(rt); /* NB: gwroute */ if ((rt->rt_flags & RTF_UP) == 0) { /* gw route is dud. ignore/lose it */ RTFREE_LOCKED(rt); /* unref (&unlock) gwroute */ rt = rt0->rt_gwroute = NULL; } } if (rt == NULL) { /* NOT AN ELSE CLAUSE */ RT_TEMP_UNLOCK(rt0); /* MUST return to undo this */ rt = rtalloc1_fib(rt0->rt_gateway, 1, 0UL, fibnum); if ((rt == rt0) || (rt == NULL)) { /* the best we can do is not good enough */ if (rt) { RT_REMREF(rt); /* assumes ref > 0 */ RT_UNLOCK(rt); } RTFREE(rt0); /* lock, unref, (unlock) */ return (ENETUNREACH); } /* * Relock it and lose the added reference. * All sorts of things could have happenned while we * had no lock on it, so check for them. */ RT_RELOCK(rt0); if (rt0 == NULL || ((rt0->rt_flags & RTF_UP) == 0)) /* Ru-roh.. what we had is no longer any good */ goto retry; /* * While we were away, someone replaced the gateway. * Since a reference count is involved we can't just * overwrite it. */ if (rt0->rt_gwroute) { if (rt0->rt_gwroute != rt) { RTFREE_LOCKED(rt); goto retry; } } else { rt0->rt_gwroute = rt; } } RT_LOCK_ASSERT(rt); RT_UNLOCK(rt0); } else { /* think of rt as having the lock from now on.. */ rt = rt0; } /* XXX why are we inspecting rmx_expire? */ if ((rt->rt_flags & RTF_REJECT) && (rt->rt_rmx.rmx_expire == 0 || time_uptime < rt->rt_rmx.rmx_expire)) { RT_UNLOCK(rt); return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); } *lrt = rt; *lrt0 = rt0; return (0); } /* This must be before ip6_init2(), which is now SI_ORDER_MIDDLE */ SYSINIT(route, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);