/* $NetBSD: table.c,v 1.21 2004/04/21 19:01:17 christos Exp $ */ /* * Copyright (c) 1983, 1988, 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 acknowledgment: * 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. */ #include "defs.h" #ifdef __NetBSD__ __RCSID("$NetBSD: table.c,v 1.21 2004/04/21 19:01:17 christos Exp $"); #elif defined(__FreeBSD__) __RCSID("$FreeBSD$"); #else __RCSID("Revision: 2.27 "); #ident "Revision: 2.27 " #endif static struct rt_spare *rts_better(struct rt_entry *); static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0}; static void set_need_flash(void); #ifdef _HAVE_SIN_LEN static void masktrim(struct sockaddr_in *ap); #else static void masktrim(struct sockaddr_in_new *ap); #endif struct radix_node_head *rhead; /* root of the radix tree */ int need_flash = 1; /* flash update needed * start =1 to suppress the 1st */ struct timeval age_timer; /* next check of old routes */ struct timeval need_kern = { /* need to update kernel table */ EPOCH+MIN_WAITTIME-1, 0 }; int stopint; int total_routes; /* zap any old routes through this gateway */ naddr age_bad_gate; /* It is desirable to "aggregate" routes, to combine differing routes of * the same metric and next hop into a common route with a smaller netmask * or to suppress redundant routes, routes that add no information to * routes with smaller netmasks. * * A route is redundant if and only if any and all routes with smaller * but matching netmasks and nets are the same. Since routes are * kept sorted in the radix tree, redundant routes always come second. * * There are two kinds of aggregations. First, two routes of the same bit * mask and differing only in the least significant bit of the network * number can be combined into a single route with a coarser mask. * * Second, a route can be suppressed in favor of another route with a more * coarse mask provided no incompatible routes with intermediate masks * are present. The second kind of aggregation involves suppressing routes. * A route must not be suppressed if an incompatible route exists with * an intermediate mask, since the suppressed route would be covered * by the intermediate. * * This code relies on the radix tree walk encountering routes * sorted first by address, with the smallest address first. */ struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest; /* #define DEBUG_AG */ #ifdef DEBUG_AG #define CHECK_AG() {int acnt = 0; struct ag_info *cag; \ for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \ acnt++; \ for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \ acnt++; \ if (acnt != NUM_AG_SLOTS) { \ (void)fflush(stderr); \ abort(); \ } \ } #else #define CHECK_AG() #endif /* Output the contents of an aggregation table slot. * This function must always be immediately followed with the deletion * of the target slot. */ static void ag_out(struct ag_info *ag, void (*out)(struct ag_info *)) { struct ag_info *ag_cors; naddr bit; /* Forget it if this route should not be output for split-horizon. */ if (ag->ag_state & AGS_SPLIT_HZ) return; /* If we output both the even and odd twins, then the immediate parent, * if it is present, is redundant, unless the parent manages to * aggregate into something coarser. * On successive calls, this code detects the even and odd twins, * and marks the parent. * * Note that the order in which the radix tree code emits routes * ensures that the twins are seen before the parent is emitted. */ ag_cors = ag->ag_cors; if (ag_cors != 0 && ag_cors->ag_mask == ag->ag_mask<<1 && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) { ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h) ? AGS_REDUN0 : AGS_REDUN1); } /* Skip it if this route is itself redundant. * * It is ok to change the contents of the slot here, since it is * always deleted next. */ if (ag->ag_state & AGS_REDUN0) { if (ag->ag_state & AGS_REDUN1) return; /* quit if fully redundant */ /* make it finer if it is half-redundant */ bit = (-ag->ag_mask) >> 1; ag->ag_dst_h |= bit; ag->ag_mask |= bit; } else if (ag->ag_state & AGS_REDUN1) { /* make it finer if it is half-redundant */ bit = (-ag->ag_mask) >> 1; ag->ag_mask |= bit; } out(ag); } static void ag_del(struct ag_info *ag) { CHECK_AG(); if (ag->ag_cors == 0) ag_corsest = ag->ag_fine; else ag->ag_cors->ag_fine = ag->ag_fine; if (ag->ag_fine == 0) ag_finest = ag->ag_cors; else ag->ag_fine->ag_cors = ag->ag_cors; ag->ag_fine = ag_avail; ag_avail = ag; CHECK_AG(); } /* Flush routes waiting for aggregation. * This must not suppress a route unless it is known that among all * routes with coarser masks that match it, the one with the longest * mask is appropriate. This is ensured by scanning the routes * in lexical order, and with the most restrictive mask first * among routes to the same destination. */ void ag_flush(naddr lim_dst_h, /* flush routes to here */ naddr lim_mask, /* matching this mask */ void (*out)(struct ag_info *)) { struct ag_info *ag, *ag_cors; naddr dst_h; for (ag = ag_finest; ag != 0 && ag->ag_mask >= lim_mask; ag = ag_cors) { ag_cors = ag->ag_cors; /* work on only the specified routes */ dst_h = ag->ag_dst_h; if ((dst_h & lim_mask) != lim_dst_h) continue; if (!(ag->ag_state & AGS_SUPPRESS)) ag_out(ag, out); else for ( ; ; ag_cors = ag_cors->ag_cors) { /* Look for a route that can suppress the * current route */ if (ag_cors == 0) { /* failed, so output it and look for * another route to work on */ ag_out(ag, out); break; } if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) { /* We found a route with a coarser mask that * aggregates the current target. * * If it has a different next hop, it * cannot replace the target, so output * the target. */ if (ag->ag_gate != ag_cors->ag_gate && !(ag->ag_state & AGS_FINE_GATE) && !(ag_cors->ag_state & AGS_CORS_GATE)) { ag_out(ag, out); break; } /* If the coarse route has a good enough * metric, it suppresses the target. * If the suppressed target was redundant, * then mark the suppressor redundant. */ if (ag_cors->ag_pref <= ag->ag_pref) { if (AG_IS_REDUN(ag->ag_state) && ag_cors->ag_mask==ag->ag_mask<<1) { if (ag_cors->ag_dst_h == dst_h) ag_cors->ag_state |= AGS_REDUN0; else ag_cors->ag_state |= AGS_REDUN1; } if (ag->ag_tag != ag_cors->ag_tag) ag_cors->ag_tag = 0; if (ag->ag_nhop != ag_cors->ag_nhop) ag_cors->ag_nhop = 0; break; } } } /* That route has either been output or suppressed */ ag_cors = ag->ag_cors; ag_del(ag); } CHECK_AG(); } /* Try to aggregate a route with previous routes. */ void ag_check(naddr dst, naddr mask, naddr gate, naddr nhop, char metric, char pref, u_int new_seqno, u_short tag, u_short state, void (*out)(struct ag_info *)) /* output using this */ { struct ag_info *ag, *nag, *ag_cors; naddr xaddr; int x; NTOHL(dst); /* Punt non-contiguous subnet masks. * * (X & -X) contains a single bit if and only if X is a power of 2. * (X + (X & -X)) == 0 if and only if X is a power of 2. */ if ((mask & -mask) + mask != 0) { struct ag_info nc_ag; nc_ag.ag_dst_h = dst; nc_ag.ag_mask = mask; nc_ag.ag_gate = gate; nc_ag.ag_nhop = nhop; nc_ag.ag_metric = metric; nc_ag.ag_pref = pref; nc_ag.ag_tag = tag; nc_ag.ag_state = state; nc_ag.ag_seqno = new_seqno; out(&nc_ag); return; } /* Search for the right slot in the aggregation table. */ ag_cors = 0; ag = ag_corsest; while (ag != 0) { if (ag->ag_mask >= mask) break; /* Suppress old routes (i.e. combine with compatible routes * with coarser masks) as we look for the right slot in the * aggregation table for the new route. * A route to an address less than the current destination * will not be affected by the current route or any route * seen hereafter. That means it is safe to suppress it. * This check keeps poor routes (e.g. with large hop counts) * from preventing suppression of finer routes. */ if (ag_cors != 0 && ag->ag_dst_h < dst && (ag->ag_state & AGS_SUPPRESS) && ag_cors->ag_pref <= ag->ag_pref && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h && (ag_cors->ag_gate == ag->ag_gate || (ag->ag_state & AGS_FINE_GATE) || (ag_cors->ag_state & AGS_CORS_GATE))) { /* If the suppressed target was redundant, * then mark the suppressor redundant. */ if (AG_IS_REDUN(ag->ag_state) && ag_cors->ag_mask == ag->ag_mask<<1) { if (ag_cors->ag_dst_h == dst) ag_cors->ag_state |= AGS_REDUN0; else ag_cors->ag_state |= AGS_REDUN1; } if (ag->ag_tag != ag_cors->ag_tag) ag_cors->ag_tag = 0; if (ag->ag_nhop != ag_cors->ag_nhop) ag_cors->ag_nhop = 0; ag_del(ag); CHECK_AG(); } else { ag_cors = ag; } ag = ag_cors->ag_fine; } /* If we find the even/odd twin of the new route, and if the * masks and so forth are equal, we can aggregate them. * We can probably promote one of the pair. * * Since the routes are encountered in lexical order, * the new route must be odd. However, the second or later * times around this loop, it could be the even twin promoted * from the even/odd pair of twins of the finer route. */ while (ag != 0 && ag->ag_mask == mask && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) { /* Here we know the target route and the route in the current * slot have the same netmasks and differ by at most the * last bit. They are either for the same destination, or * for an even/odd pair of destinations. */ if (ag->ag_dst_h == dst) { /* We have two routes to the same destination. * Routes are encountered in lexical order, so a * route is never promoted until the parent route is * already present. So we know that the new route is * a promoted (or aggregated) pair and the route * already in the slot is the explicit route. * * Prefer the best route if their metrics differ, * or the aggregated one if not, following a sort * of longest-match rule. */ if (pref <= ag->ag_pref) { ag->ag_gate = gate; ag->ag_nhop = nhop; ag->ag_tag = tag; ag->ag_metric = metric; ag->ag_pref = pref; if (ag->ag_seqno < new_seqno) ag->ag_seqno = new_seqno; x = ag->ag_state; ag->ag_state = state; state = x; } /* Some bits are set if they are set on either route, * except when the route is for an interface. */ if (!(ag->ag_state & AGS_IF)) ag->ag_state |= (state & (AGS_AGGREGATE_EITHER | AGS_REDUN0 | AGS_REDUN1)); return; } /* If one of the routes can be promoted and the other can * be suppressed, it may be possible to combine them or * worthwhile to promote one. * * Any route that can be promoted is always * marked to be eligible to be suppressed. */ if (!((state & AGS_AGGREGATE) && (ag->ag_state & AGS_SUPPRESS)) && !((ag->ag_state & AGS_AGGREGATE) && (state & AGS_SUPPRESS))) break; /* A pair of even/odd twin routes can be combined * if either is redundant, or if they are via the * same gateway and have the same metric. */ if (AG_IS_REDUN(ag->ag_state) || AG_IS_REDUN(state) || (ag->ag_gate == gate && ag->ag_pref == pref && (state & ag->ag_state & AGS_AGGREGATE) != 0)) { /* We have both the even and odd pairs. * Since the routes are encountered in order, * the route in the slot must be the even twin. * * Combine and promote (aggregate) the pair of routes. */ if (new_seqno < ag->ag_seqno) new_seqno = ag->ag_seqno; if (!AG_IS_REDUN(state)) state &= ~AGS_REDUN1; if (AG_IS_REDUN(ag->ag_state)) state |= AGS_REDUN0; else state &= ~AGS_REDUN0; state |= (ag->ag_state & AGS_AGGREGATE_EITHER); if (ag->ag_tag != tag) tag = 0; if (ag->ag_nhop != nhop) nhop = 0; /* Get rid of the even twin that was already * in the slot. */ ag_del(ag); } else if (ag->ag_pref >= pref && (ag->ag_state & AGS_AGGREGATE)) { /* If we cannot combine the pair, maybe the route * with the worse metric can be promoted. * * Promote the old, even twin, by giving its slot * in the table to the new, odd twin. */ ag->ag_dst_h = dst; xaddr = ag->ag_gate; ag->ag_gate = gate; gate = xaddr; xaddr = ag->ag_nhop; ag->ag_nhop = nhop; nhop = xaddr; x = ag->ag_tag; ag->ag_tag = tag; tag = x; /* The promoted route is even-redundant only if the * even twin was fully redundant. It is not * odd-redundant because the odd-twin will still be * in the table. */ x = ag->ag_state; if (!AG_IS_REDUN(x)) x &= ~AGS_REDUN0; x &= ~AGS_REDUN1; ag->ag_state = state; state = x; x = ag->ag_metric; ag->ag_metric = metric; metric = x; x = ag->ag_pref; ag->ag_pref = pref; pref = x; /* take the newest sequence number */ if (new_seqno <= ag->ag_seqno) new_seqno = ag->ag_seqno; else ag->ag_seqno = new_seqno; } else { if (!(state & AGS_AGGREGATE)) break; /* cannot promote either twin */ /* Promote the new, odd twin by shaving its * mask and address. * The promoted route is odd-redundant only if the * odd twin was fully redundant. It is not * even-redundant because the even twin is still in * the table. */ if (!AG_IS_REDUN(state)) state &= ~AGS_REDUN1; state &= ~AGS_REDUN0; if (new_seqno < ag->ag_seqno) new_seqno = ag->ag_seqno; else ag->ag_seqno = new_seqno; } mask <<= 1; dst &= mask; if (ag_cors == 0) { ag = ag_corsest; break; } ag = ag_cors; ag_cors = ag->ag_cors; } /* When we can no longer promote and combine routes, * flush the old route in the target slot. Also flush * any finer routes that we know will never be aggregated by * the new route. * * In case we moved toward coarser masks, * get back where we belong */ if (ag != 0 && ag->ag_mask < mask) { ag_cors = ag; ag = ag->ag_fine; } /* Empty the target slot */ if (ag != 0 && ag->ag_mask == mask) { ag_flush(ag->ag_dst_h, ag->ag_mask, out); ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine; } #ifdef DEBUG_AG (void)fflush(stderr); if (ag == 0 && ag_cors != ag_finest) abort(); if (ag_cors == 0 && ag != ag_corsest) abort(); if (ag != 0 && ag->ag_cors != ag_cors) abort(); if (ag_cors != 0 && ag_cors->ag_fine != ag) abort(); CHECK_AG(); #endif /* Save the new route on the end of the table. */ nag = ag_avail; ag_avail = nag->ag_fine; nag->ag_dst_h = dst; nag->ag_mask = mask; nag->ag_gate = gate; nag->ag_nhop = nhop; nag->ag_metric = metric; nag->ag_pref = pref; nag->ag_tag = tag; nag->ag_state = state; nag->ag_seqno = new_seqno; nag->ag_fine = ag; if (ag != 0) ag->ag_cors = nag; else ag_finest = nag; nag->ag_cors = ag_cors; if (ag_cors == 0) ag_corsest = nag; else ag_cors->ag_fine = nag; CHECK_AG(); } static const char * rtm_type_name(u_char type) { static const char *rtm_types[] = { "RTM_ADD", "RTM_DELETE", "RTM_CHANGE", "RTM_GET", "RTM_LOSING", "RTM_REDIRECT", "RTM_MISS", "RTM_LOCK", "RTM_OLDADD", "RTM_OLDDEL", "RTM_RESOLVE", "RTM_NEWADDR", "RTM_DELADDR", #ifdef RTM_OIFINFO "RTM_OIFINFO", #endif "RTM_IFINFO", "RTM_NEWMADDR", "RTM_DELMADDR" }; #define NEW_RTM_PAT "RTM type %#x" static char name0[sizeof(NEW_RTM_PAT)+2]; if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) || type == 0) { snprintf(name0, sizeof(name0), NEW_RTM_PAT, type); return name0; } else { return rtm_types[type-1]; } #undef NEW_RTM_PAT } /* Trim a mask in a sockaddr * Produce a length of 0 for an address of 0. * Otherwise produce the index of the first zero byte. */ void #ifdef _HAVE_SIN_LEN masktrim(struct sockaddr_in *ap) #else masktrim(struct sockaddr_in_new *ap) #endif { char *cp; if (ap->sin_addr.s_addr == 0) { ap->sin_len = 0; return; } cp = (char *)(&ap->sin_addr.s_addr+1); while (*--cp == 0) continue; ap->sin_len = cp - (char*)ap + 1; } /* Tell the kernel to add, delete or change a route */ static void rtioctl(int action, /* RTM_DELETE, etc */ naddr dst, naddr gate, naddr mask, int metric, int flags) { struct { struct rt_msghdr w_rtm; struct sockaddr_in w_dst; struct sockaddr_in w_gate; #ifdef _HAVE_SA_LEN struct sockaddr_in w_mask; #else struct sockaddr_in_new w_mask; #endif } w; long cc; # define PAT " %-10s %s metric=%d flags=%#x" # define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags again: memset(&w, 0, sizeof(w)); w.w_rtm.rtm_msglen = sizeof(w); w.w_rtm.rtm_version = RTM_VERSION; w.w_rtm.rtm_type = action; w.w_rtm.rtm_flags = flags; w.w_rtm.rtm_seq = ++rt_sock_seqno; w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY; if (metric != 0 || action == RTM_CHANGE) { w.w_rtm.rtm_rmx.rmx_hopcount = metric; w.w_rtm.rtm_inits |= RTV_HOPCOUNT; } w.w_dst.sin_family = AF_INET; w.w_dst.sin_addr.s_addr = dst; w.w_gate.sin_family = AF_INET; w.w_gate.sin_addr.s_addr = gate; #ifdef _HAVE_SA_LEN w.w_dst.sin_len = sizeof(w.w_dst); w.w_gate.sin_len = sizeof(w.w_gate); #endif if (mask == HOST_MASK) { w.w_rtm.rtm_flags |= RTF_HOST; w.w_rtm.rtm_msglen -= sizeof(w.w_mask); } else { w.w_rtm.rtm_addrs |= RTA_NETMASK; w.w_mask.sin_addr.s_addr = htonl(mask); #ifdef _HAVE_SA_LEN masktrim(&w.w_mask); if (w.w_mask.sin_len == 0) w.w_mask.sin_len = sizeof(long); w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len); #endif } #ifndef NO_INSTALL cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); if (cc < 0) { if (errno == ESRCH && (action == RTM_CHANGE || action == RTM_DELETE)) { trace_act("route disappeared before" PAT, ARGS); if (action == RTM_CHANGE) { action = RTM_ADD; goto again; } return; } msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno)); return; } else if (cc != w.w_rtm.rtm_msglen) { msglog("write(rt_sock) wrote %ld instead of %d for" PAT, cc, w.w_rtm.rtm_msglen, ARGS); return; } #endif if (TRACEKERNEL) trace_misc("write kernel" PAT, ARGS); #undef PAT #undef ARGS } #define KHASH_SIZE 71 /* should be prime */ #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE] static struct khash { struct khash *k_next; naddr k_dst; naddr k_mask; naddr k_gate; short k_metric; u_short k_state; #define KS_NEW 0x001 #define KS_DELETE 0x002 /* need to delete the route */ #define KS_ADD 0x004 /* add to the kernel */ #define KS_CHANGE 0x008 /* tell kernel to change the route */ #define KS_DEL_ADD 0x010 /* delete & add to change the kernel */ #define KS_STATIC 0x020 /* Static flag in kernel */ #define KS_GATEWAY 0x040 /* G flag in kernel */ #define KS_DYNAMIC 0x080 /* result of redirect */ #define KS_DELETED 0x100 /* already deleted from kernel */ #define KS_CHECK 0x200 time_t k_keep; #define K_KEEP_LIM 30 time_t k_redirect_time; /* when redirected route 1st seen */ } *khash_bins[KHASH_SIZE]; static struct khash* kern_find(naddr dst, naddr mask, struct khash ***ppk) { struct khash *k, **pk; for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) { if (k->k_dst == dst && k->k_mask == mask) break; } if (ppk != 0) *ppk = pk; return k; } static struct khash* kern_add(naddr dst, naddr mask) { struct khash *k, **pk; k = kern_find(dst, mask, &pk); if (k != 0) return k; k = (struct khash *)rtmalloc(sizeof(*k), "kern_add"); memset(k, 0, sizeof(*k)); k->k_dst = dst; k->k_mask = mask; k->k_state = KS_NEW; k->k_keep = now.tv_sec; *pk = k; return k; } /* If a kernel route has a non-zero metric, check that it is still in the * daemon table, and not deleted by interfaces coming and going. */ static void kern_check_static(struct khash *k, struct interface *ifp) { struct rt_entry *rt; struct rt_spare new; if (k->k_metric == 0) return; memset(&new, 0, sizeof(new)); new.rts_ifp = ifp; new.rts_gate = k->k_gate; new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr; new.rts_metric = k->k_metric; new.rts_time = now.tv_sec; rt = rtget(k->k_dst, k->k_mask); if (rt != 0) { if (!(rt->rt_state & RS_STATIC)) rtchange(rt, rt->rt_state | RS_STATIC, &new, 0); } else { rtadd(k->k_dst, k->k_mask, RS_STATIC, &new); } } /* operate on a kernel entry */ static void kern_ioctl(struct khash *k, int action, /* RTM_DELETE, etc */ int flags) { switch (action) { case RTM_DELETE: k->k_state &= ~KS_DYNAMIC; if (k->k_state & KS_DELETED) return; k->k_state |= KS_DELETED; break; case RTM_ADD: k->k_state &= ~KS_DELETED; break; case RTM_CHANGE: if (k->k_state & KS_DELETED) { action = RTM_ADD; k->k_state &= ~KS_DELETED; } break; } rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags); } /* add a route the kernel told us */ static void rtm_add(struct rt_msghdr *rtm, struct rt_addrinfo *info, time_t keep) { struct khash *k; struct interface *ifp; naddr mask; if (rtm->rtm_flags & RTF_HOST) { mask = HOST_MASK; } else if (INFO_MASK(info) != 0) { mask = ntohl(S_ADDR(INFO_MASK(info))); } else { msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type)); return; } k = kern_add(S_ADDR(INFO_DST(info)), mask); if (k->k_state & KS_NEW) k->k_keep = now.tv_sec+keep; if (INFO_GATE(info) == 0) { trace_act("note %s without gateway", rtm_type_name(rtm->rtm_type)); k->k_metric = HOPCNT_INFINITY; } else if (INFO_GATE(info)->sa_family != AF_INET) { trace_act("note %s with gateway AF=%d", rtm_type_name(rtm->rtm_type), INFO_GATE(info)->sa_family); k->k_metric = HOPCNT_INFINITY; } else { k->k_gate = S_ADDR(INFO_GATE(info)); k->k_metric = rtm->rtm_rmx.rmx_hopcount; if (k->k_metric < 0) k->k_metric = 0; else if (k->k_metric > HOPCNT_INFINITY-1) k->k_metric = HOPCNT_INFINITY-1; } k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD | KS_DELETED | KS_GATEWAY | KS_STATIC | KS_NEW | KS_CHECK); if (rtm->rtm_flags & RTF_GATEWAY) k->k_state |= KS_GATEWAY; if (rtm->rtm_flags & RTF_STATIC) k->k_state |= KS_STATIC; if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { if (INFO_AUTHOR(info) != 0 && INFO_AUTHOR(info)->sa_family == AF_INET) ifp = iflookup(S_ADDR(INFO_AUTHOR(info))); else ifp = 0; if (supplier && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) { /* Routers are not supposed to listen to redirects, * so delete it if it came via an unknown interface * or the interface does not have special permission. */ k->k_state &= ~KS_DYNAMIC; k->k_state |= KS_DELETE; LIM_SEC(need_kern, 0); trace_act("mark for deletion redirected %s --> %s" " via %s", addrname(k->k_dst, k->k_mask, 0), naddr_ntoa(k->k_gate), ifp ? ifp->int_name : "unknown interface"); } else { k->k_state |= KS_DYNAMIC; k->k_redirect_time = now.tv_sec; trace_act("accept redirected %s --> %s via %s", addrname(k->k_dst, k->k_mask, 0), naddr_ntoa(k->k_gate), ifp ? ifp->int_name : "unknown interface"); } return; } /* If it is not a static route, quit until the next comparison * between the kernel and daemon tables, when it will be deleted. */ if (!(k->k_state & KS_STATIC)) { k->k_state |= KS_DELETE; LIM_SEC(need_kern, k->k_keep); return; } /* Put static routes with real metrics into the daemon table so * they can be advertised. * * Find the interface toward the gateway. */ ifp = iflookup(k->k_gate); if (ifp == 0) msglog("static route %s --> %s impossibly lacks ifp", addrname(S_ADDR(INFO_DST(info)), mask, 0), naddr_ntoa(k->k_gate)); kern_check_static(k, ifp); } /* deal with packet loss */ static void rtm_lose(struct rt_msghdr *rtm, struct rt_addrinfo *info) { if (INFO_GATE(info) == 0 || INFO_GATE(info)->sa_family != AF_INET) { trace_act("ignore %s without gateway", rtm_type_name(rtm->rtm_type)); return; } if (rdisc_ok) rdisc_age(S_ADDR(INFO_GATE(info))); age(S_ADDR(INFO_GATE(info))); } /* Make the gateway slot of an info structure point to something * useful. If it is not already useful, but it specifies an interface, * then fill in the sockaddr_in provided and point it there. */ static int get_info_gate(const struct sockaddr **sap, struct sockaddr_in *rsin) { const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)*sap; struct interface *ifp; if (sdl == 0) return 0; if ((sdl)->sdl_family == AF_INET) return 1; if ((sdl)->sdl_family != AF_LINK) return 0; ifp = ifwithindex(sdl->sdl_index, 1); if (ifp == 0) return 0; rsin->sin_addr.s_addr = ifp->int_addr; #ifdef _HAVE_SA_LEN rsin->sin_len = sizeof(*rsin); #endif rsin->sin_family = AF_INET; *sap = (const struct sockaddr*)rsin; return 1; } /* Clean the kernel table by copying it to the daemon image. * Eventually the daemon will delete any extra routes. */ void flush_kern(void) { static char *sysctl_buf; static size_t sysctl_buf_size = 0; size_t needed; int mib[6]; char *next, *lim; struct rt_msghdr *rtm; struct sockaddr_in gate_sin; struct rt_addrinfo info; int i; struct khash *k; for (i = 0; i < KHASH_SIZE; i++) { for (k = khash_bins[i]; k != 0; k = k->k_next) { k->k_state |= KS_CHECK; } } mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; /* protocol */ mib[3] = 0; /* wildcard address family */ mib[4] = NET_RT_DUMP; mib[5] = 0; /* no flags */ for (;;) { if ((needed = sysctl_buf_size) != 0) { if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0) break; if (errno != ENOMEM && errno != EFAULT) BADERR(1,"flush_kern: sysctl(RT_DUMP)"); free(sysctl_buf); needed = 0; } if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate"); /* Kludge around the habit of some systems, such as * BSD/OS 3.1, to not admit how many routes are in the * kernel, or at least to be quite wrong. */ needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr)); sysctl_buf = rtmalloc(sysctl_buf_size = needed, "flush_kern sysctl(RT_DUMP)"); } lim = sysctl_buf + needed; for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) { rtm = (struct rt_msghdr *)next; if (rtm->rtm_msglen == 0) { msglog("zero length kernel route at " " %#lx in buffer %#lx before %#lx", (u_long)rtm, (u_long)sysctl_buf, (u_long)lim); break; } rt_xaddrs(&info, (struct sockaddr *)(rtm+1), (struct sockaddr *)(next + rtm->rtm_msglen), rtm->rtm_addrs); if (INFO_DST(&info) == 0 || INFO_DST(&info)->sa_family != AF_INET) continue; /* ignore ARP table entries on systems with a merged route * and ARP table. */ if (rtm->rtm_flags & RTF_LLINFO) continue; #if defined(RTF_CLONED) && defined(__bsdi__) /* ignore cloned routes */ if (rtm->rtm_flags & RTF_CLONED) continue; #endif /* ignore multicast addresses */ if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) continue; if (!get_info_gate(&INFO_GATE(&info), &gate_sin)) continue; /* Note static routes and interface routes, and also * preload the image of the kernel table so that * we can later clean it, as well as avoid making * unneeded changes. Keep the old kernel routes for a * few seconds to allow a RIP or router-discovery * response to be heard. */ rtm_add(rtm,&info,MIN_WAITTIME); } for (i = 0; i < KHASH_SIZE; i++) { for (k = khash_bins[i]; k != 0; k = k->k_next) { if (k->k_state & KS_CHECK) { msglog("%s --> %s disappeared from kernel", addrname(k->k_dst, k->k_mask, 0), naddr_ntoa(k->k_gate)); del_static(k->k_dst, k->k_mask, k->k_gate, 1); } } } } /* Listen to announcements from the kernel */ void read_rt(void) { long cc; struct interface *ifp; struct sockaddr_in gate_sin; naddr mask, gate; union { struct { struct rt_msghdr rtm; struct sockaddr addrs[RTAX_MAX]; } r; struct if_msghdr ifm; } m; char str[100], *strp; struct rt_addrinfo info; for (;;) { cc = read(rt_sock, &m, sizeof(m)); if (cc <= 0) { if (cc < 0 && errno != EWOULDBLOCK) LOGERR("read(rt_sock)"); return; } if (m.r.rtm.rtm_version != RTM_VERSION) { msglog("bogus routing message version %d", m.r.rtm.rtm_version); continue; } /* Ignore our own results. */ if (m.r.rtm.rtm_type <= RTM_CHANGE && m.r.rtm.rtm_pid == mypid) { static int complained = 0; if (!complained) { msglog("receiving our own change messages"); complained = 1; } continue; } if (m.r.rtm.rtm_type == RTM_IFINFO || m.r.rtm.rtm_type == RTM_NEWADDR || m.r.rtm.rtm_type == RTM_DELADDR) { ifp = ifwithindex(m.ifm.ifm_index, m.r.rtm.rtm_type != RTM_DELADDR); if (ifp == 0) trace_act("note %s with flags %#x" " for unknown interface index #%d", rtm_type_name(m.r.rtm.rtm_type), m.ifm.ifm_flags, m.ifm.ifm_index); else trace_act("note %s with flags %#x for %s", rtm_type_name(m.r.rtm.rtm_type), m.ifm.ifm_flags, ifp->int_name); /* After being informed of a change to an interface, * check them all now if the check would otherwise * be a long time from now, if the interface is * not known, or if the interface has been turned * off or on. */ if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL || ifp == 0 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) & IFF_UP) != 0) ifinit_timer.tv_sec = now.tv_sec; continue; } #ifdef RTM_OIFINFO if (m.r.rtm.rtm_type == RTM_OIFINFO) continue; /* ignore compat message */ #endif strlcpy(str, rtm_type_name(m.r.rtm.rtm_type), sizeof(str)); strp = &str[strlen(str)]; if (m.r.rtm.rtm_type <= RTM_CHANGE) { snprintf(strp, str + sizeof(str) - strp, " from pid %d",m.r.rtm.rtm_pid); strp += strlen(strp); } rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], m.r.rtm.rtm_addrs); if (INFO_DST(&info) == 0) { trace_act("ignore %s without dst", str); continue; } if (INFO_DST(&info)->sa_family != AF_INET) { trace_act("ignore %s for AF %d", str, INFO_DST(&info)->sa_family); continue; } mask = ((INFO_MASK(&info) != 0) ? ntohl(S_ADDR(INFO_MASK(&info))) : (m.r.rtm.rtm_flags & RTF_HOST) ? HOST_MASK : std_mask(S_ADDR(INFO_DST(&info)))); snprintf(strp, str + sizeof(str) - strp, ": %s", addrname(S_ADDR(INFO_DST(&info)), mask, 0)); strp += strlen(strp); if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { trace_act("ignore multicast %s", str); continue; } if (m.r.rtm.rtm_flags & RTF_LLINFO) { trace_act("ignore ARP %s", str); continue; } #if defined(RTF_CLONED) && defined(__bsdi__) if (m.r.rtm.rtm_flags & RTF_CLONED) { trace_act("ignore cloned %s", str); continue; } #endif if (get_info_gate(&INFO_GATE(&info), &gate_sin)) { gate = S_ADDR(INFO_GATE(&info)); snprintf(strp, str + sizeof(str) - strp, " --> %s", naddr_ntoa(gate)); strp += strlen(strp); } else { gate = 0; } if (INFO_AUTHOR(&info) != 0) snprintf(strp, str + sizeof(str) - strp, " by authority of %s", saddr_ntoa(INFO_AUTHOR(&info))); strp += strlen(strp); switch (m.r.rtm.rtm_type) { case RTM_ADD: case RTM_CHANGE: case RTM_REDIRECT: if (m.r.rtm.rtm_errno != 0) { trace_act("ignore %s with \"%s\" error", str, strerror(m.r.rtm.rtm_errno)); } else { trace_act("%s", str); rtm_add(&m.r.rtm,&info,0); } break; case RTM_DELETE: if (m.r.rtm.rtm_errno != 0 && m.r.rtm.rtm_errno != ESRCH) { trace_act("ignore %s with \"%s\" error", str, strerror(m.r.rtm.rtm_errno)); } else { trace_act("%s", str); del_static(S_ADDR(INFO_DST(&info)), mask, gate, 1); } break; case RTM_LOSING: trace_act("%s", str); rtm_lose(&m.r.rtm,&info); break; default: trace_act("ignore %s", str); break; } } } /* after aggregating, note routes that belong in the kernel */ static void kern_out(struct ag_info *ag) { struct khash *k; /* Do not install bad routes if they are not already present. * This includes routes that had RS_NET_SYN for interfaces that * recently died. */ if (ag->ag_metric == HOPCNT_INFINITY) { k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); if (k == 0) return; } else { k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); } if (k->k_state & KS_NEW) { /* will need to add new entry to the kernel table */ k->k_state = KS_ADD; if (ag->ag_state & AGS_GATEWAY) k->k_state |= KS_GATEWAY; k->k_gate = ag->ag_gate; k->k_metric = ag->ag_metric; return; } if (k->k_state & KS_STATIC) return; /* modify existing kernel entry if necessary */ if (k->k_gate != ag->ag_gate || k->k_metric != ag->ag_metric) { /* Must delete bad interface routes etc. to change them. */ if (k->k_metric == HOPCNT_INFINITY) k->k_state |= KS_DEL_ADD; k->k_gate = ag->ag_gate; k->k_metric = ag->ag_metric; k->k_state |= KS_CHANGE; } /* If the daemon thinks the route should exist, forget * about any redirections. * If the daemon thinks the route should exist, eventually * override manual intervention by the operator. */ if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) { k->k_state &= ~KS_DYNAMIC; k->k_state |= (KS_ADD | KS_DEL_ADD); } if ((k->k_state & KS_GATEWAY) && !(ag->ag_state & AGS_GATEWAY)) { k->k_state &= ~KS_GATEWAY; k->k_state |= (KS_ADD | KS_DEL_ADD); } else if (!(k->k_state & KS_GATEWAY) && (ag->ag_state & AGS_GATEWAY)) { k->k_state |= KS_GATEWAY; k->k_state |= (KS_ADD | KS_DEL_ADD); } /* Deleting-and-adding is necessary to change aspects of a route. * Just delete instead of deleting and then adding a bad route. * Otherwise, we want to keep the route in the kernel. */ if (k->k_metric == HOPCNT_INFINITY && (k->k_state & KS_DEL_ADD)) k->k_state |= KS_DELETE; else k->k_state &= ~KS_DELETE; #undef RT } /* ARGSUSED */ static int walk_kern(struct radix_node *rn, struct walkarg *argp UNUSED) { #define RT ((struct rt_entry *)rn) char metric, pref; u_int ags = 0; /* Do not install synthetic routes */ if (RT->rt_state & RS_NET_SYN) return 0; if (!(RT->rt_state & RS_IF)) { /* This is an ordinary route, not for an interface. */ /* aggregate, ordinary good routes without regard to * their metric */ pref = 1; ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); /* Do not install host routes directly to hosts, to avoid * interfering with ARP entries in the kernel table. */ if (RT_ISHOST(RT) && ntohl(RT->rt_dst) == RT->rt_gate) return 0; } else { /* This is an interface route. * Do not install routes for "external" remote interfaces. */ if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) return 0; /* Interfaces should override received routes. */ pref = 0; ags |= (AGS_IF | AGS_CORS_GATE); /* If it is not an interface, or an alias for an interface, * it must be a "gateway." * * If it is a "remote" interface, it is also a "gateway" to * the kernel if is not a alias. */ if (RT->rt_ifp == 0 || (RT->rt_ifp->int_state & IS_REMOTE)) ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); } /* If RIP is off and IRDP is on, let the route to the discovered * route suppress any RIP routes. Eventually the RIP routes * will time-out and be deleted. This reaches the steady-state * quicker. */ if ((RT->rt_state & RS_RDISC) && rip_sock < 0) ags |= AGS_CORS_GATE; metric = RT->rt_metric; if (metric == HOPCNT_INFINITY) { /* if the route is dead, so try hard to aggregate. */ pref = HOPCNT_INFINITY; ags |= (AGS_FINE_GATE | AGS_SUPPRESS); ags &= ~(AGS_IF | AGS_CORS_GATE); } ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, metric,pref, 0, 0, ags, kern_out); return 0; #undef RT } /* Update the kernel table to match the daemon table. */ static void fix_kern(void) { int i; struct khash *k, **pk; need_kern = age_timer; /* Walk daemon table, updating the copy of the kernel table. */ (void)rn_walktree(rhead, walk_kern, 0); ag_flush(0,0,kern_out); for (i = 0; i < KHASH_SIZE; i++) { for (pk = &khash_bins[i]; (k = *pk) != 0; ) { /* Do not touch static routes */ if (k->k_state & KS_STATIC) { kern_check_static(k,0); pk = &k->k_next; continue; } /* check hold on routes deleted by the operator */ if (k->k_keep > now.tv_sec) { /* ensure we check when the hold is over */ LIM_SEC(need_kern, k->k_keep); /* mark for the next cycle */ k->k_state |= KS_DELETE; pk = &k->k_next; continue; } if ((k->k_state & KS_DELETE) && !(k->k_state & KS_DYNAMIC)) { kern_ioctl(k, RTM_DELETE, 0); *pk = k->k_next; free(k); continue; } if (k->k_state & KS_DEL_ADD) kern_ioctl(k, RTM_DELETE, 0); if (k->k_state & KS_ADD) { kern_ioctl(k, RTM_ADD, ((0 != (k->k_state & (KS_GATEWAY | KS_DYNAMIC))) ? RTF_GATEWAY : 0)); } else if (k->k_state & KS_CHANGE) { kern_ioctl(k, RTM_CHANGE, ((0 != (k->k_state & (KS_GATEWAY | KS_DYNAMIC))) ? RTF_GATEWAY : 0)); } k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); /* Mark this route to be deleted in the next cycle. * This deletes routes that disappear from the * daemon table, since the normal aging code * will clear the bit for routes that have not * disappeared from the daemon table. */ k->k_state |= KS_DELETE; pk = &k->k_next; } } } /* Delete a static route in the image of the kernel table. */ void del_static(naddr dst, naddr mask, naddr gate, int gone) { struct khash *k; struct rt_entry *rt; /* Just mark it in the table to be deleted next time the kernel * table is updated. * If it has already been deleted, mark it as such, and set its * keep-timer so that it will not be deleted again for a while. * This lets the operator delete a route added by the daemon * and add a replacement. */ k = kern_find(dst, mask, 0); if (k != 0 && (gate == 0 || k->k_gate == gate)) { k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK); k->k_state |= KS_DELETE; if (gone) { k->k_state |= KS_DELETED; k->k_keep = now.tv_sec + K_KEEP_LIM; } } rt = rtget(dst, mask); if (rt != 0 && (rt->rt_state & RS_STATIC)) rtbad(rt); } /* Delete all routes generated from ICMP Redirects that use a given gateway, * as well as old redirected routes. */ void del_redirects(naddr bad_gate, time_t old) { int i; struct khash *k; for (i = 0; i < KHASH_SIZE; i++) { for (k = khash_bins[i]; k != 0; k = k->k_next) { if (!(k->k_state & KS_DYNAMIC) || (k->k_state & KS_STATIC)) continue; if (k->k_gate != bad_gate && k->k_redirect_time > old && !supplier) continue; k->k_state |= KS_DELETE; k->k_state &= ~KS_DYNAMIC; need_kern.tv_sec = now.tv_sec; trace_act("mark redirected %s --> %s for deletion", addrname(k->k_dst, k->k_mask, 0), naddr_ntoa(k->k_gate)); } } } /* Start the daemon tables. */ extern int max_keylen; void rtinit(void) { int i; struct ag_info *ag; /* Initialize the radix trees */ max_keylen = sizeof(struct sockaddr_in); rn_init(); rn_inithead((void*)&rhead, 32); /* mark all of the slots in the table free */ ag_avail = ag_slots; for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { ag->ag_fine = ag+1; ag++; } } #ifdef _HAVE_SIN_LEN static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}}; static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}}; #else static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; #endif static void set_need_flash(void) { if (!need_flash) { need_flash = 1; /* Do not send the flash update immediately. Wait a little * while to hear from other routers. */ no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; } } /* Get a particular routing table entry */ struct rt_entry * rtget(naddr dst, naddr mask) { struct rt_entry *rt; dst_sock.sin_addr.s_addr = dst; mask_sock.sin_addr.s_addr = htonl(mask); masktrim(&mask_sock); rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); if (!rt || rt->rt_dst != dst || rt->rt_mask != mask) return 0; return rt; } /* Find a route to dst as the kernel would. */ struct rt_entry * rtfind(naddr dst) { dst_sock.sin_addr.s_addr = dst; return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); } /* add a route to the table */ void rtadd(naddr dst, naddr mask, u_int state, /* rt_state for the entry */ struct rt_spare *new) { struct rt_entry *rt; naddr smask; int i; struct rt_spare *rts; rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); memset(rt, 0, sizeof(*rt)); for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) rts->rts_metric = HOPCNT_INFINITY; rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; rt->rt_dst = dst; rt->rt_dst_sock.sin_family = AF_INET; #ifdef _HAVE_SIN_LEN rt->rt_dst_sock.sin_len = dst_sock.sin_len; #endif if (mask != HOST_MASK) { smask = std_mask(dst); if ((smask & ~mask) == 0 && mask > smask) state |= RS_SUBNET; } mask_sock.sin_addr.s_addr = htonl(mask); masktrim(&mask_sock); rt->rt_mask = mask; rt->rt_state = state; rt->rt_spares[0] = *new; rt->rt_time = now.tv_sec; rt->rt_poison_metric = HOPCNT_INFINITY; rt->rt_seqno = update_seqno; if (++total_routes == MAX_ROUTES) msglog("have maximum (%d) routes", total_routes); if (TRACEACTIONS) trace_add_del("Add", rt); need_kern.tv_sec = now.tv_sec; set_need_flash(); if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, rhead, rt->rt_nodes)) { msglog("rnh_addaddr() failed for %s mask=%#lx", naddr_ntoa(dst), (u_long)mask); free(rt); } } /* notice a changed route */ void rtchange(struct rt_entry *rt, u_int state, /* new state bits */ struct rt_spare *new, char *label) { if (rt->rt_metric != new->rts_metric) { /* Fix the kernel immediately if it seems the route * has gone bad, since there may be a working route that * aggregates this route. */ if (new->rts_metric == HOPCNT_INFINITY) { need_kern.tv_sec = now.tv_sec; if (new->rts_time >= now.tv_sec - EXPIRE_TIME) new->rts_time = now.tv_sec - EXPIRE_TIME; } rt->rt_seqno = update_seqno; set_need_flash(); } if (rt->rt_gate != new->rts_gate) { need_kern.tv_sec = now.tv_sec; rt->rt_seqno = update_seqno; set_need_flash(); } state |= (rt->rt_state & RS_SUBNET); /* Keep various things from deciding ageless routes are stale. */ if (!AGE_RT(state, new->rts_ifp)) new->rts_time = now.tv_sec; if (TRACEACTIONS) trace_change(rt, state, new, label ? label : "Chg "); rt->rt_state = state; rt->rt_spares[0] = *new; } /* check for a better route among the spares */ static struct rt_spare * rts_better(struct rt_entry *rt) { struct rt_spare *rts, *rts1; int i; /* find the best alternative among the spares */ rts = rt->rt_spares+1; for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { if (BETTER_LINK(rt,rts1,rts)) rts = rts1; } return rts; } /* switch to a backup route */ void rtswitch(struct rt_entry *rt, struct rt_spare *rts) { struct rt_spare swap; char label[20]; /* Do not change permanent routes */ if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC | RS_NET_SYN | RS_IF))) return; /* find the best alternative among the spares */ if (rts == 0) rts = rts_better(rt); /* Do not bother if it is not worthwhile. */ if (!BETTER_LINK(rt, rts, rt->rt_spares)) return; swap = rt->rt_spares[0]; (void)snprintf(label, sizeof(label), "Use #%d", (int)(rts - rt->rt_spares)); rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label); if (swap.rts_metric == HOPCNT_INFINITY) { *rts = rts_empty; } else { *rts = swap; } } void rtdelete(struct rt_entry *rt) { struct khash *k; if (TRACEACTIONS) trace_add_del("Del", rt); k = kern_find(rt->rt_dst, rt->rt_mask, 0); if (k != 0) { k->k_state |= KS_DELETE; need_kern.tv_sec = now.tv_sec; } dst_sock.sin_addr.s_addr = rt->rt_dst; mask_sock.sin_addr.s_addr = htonl(rt->rt_mask); masktrim(&mask_sock); if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, rhead)) { msglog("rnh_deladdr() failed"); } else { free(rt); total_routes--; } } void rts_delete(struct rt_entry *rt, struct rt_spare *rts) { trace_upslot(rt, rts, &rts_empty); *rts = rts_empty; } /* Get rid of a bad route, and try to switch to a replacement. */ void rtbad(struct rt_entry *rt) { struct rt_spare new; /* Poison the route */ new = rt->rt_spares[0]; new.rts_metric = HOPCNT_INFINITY; rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0); rtswitch(rt, 0); } /* Junk a RS_NET_SYN or RS_LOCAL route, * unless it is needed by another interface. */ void rtbad_sub(struct rt_entry *rt) { struct interface *ifp, *ifp1; struct intnet *intnetp; u_int state; ifp1 = 0; state = 0; if (rt->rt_state & RS_LOCAL) { /* Is this the route through loopback for the interface? * If so, see if it is used by any other interfaces, such * as a point-to-point interface with the same local address. */ for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { /* Retain it if another interface needs it. */ if (ifp->int_addr == rt->rt_ifp->int_addr) { state |= RS_LOCAL; ifp1 = ifp; break; } } } if (!(state & RS_LOCAL)) { /* Retain RIPv1 logical network route if there is another * interface that justifies it. */ if (rt->rt_state & RS_NET_SYN) { for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { if ((ifp->int_state & IS_NEED_NET_SYN) && rt->rt_mask == ifp->int_std_mask && rt->rt_dst == ifp->int_std_addr) { state |= RS_NET_SYN; ifp1 = ifp; break; } } } /* or if there is an authority route that needs it. */ for (intnetp = intnets; intnetp != 0; intnetp = intnetp->intnet_next) { if (intnetp->intnet_addr == rt->rt_dst && intnetp->intnet_mask == rt->rt_mask) { state |= (RS_NET_SYN | RS_NET_INT); break; } } } if (ifp1 != 0 || (state & RS_NET_SYN)) { struct rt_spare new = rt->rt_spares[0]; new.rts_ifp = ifp1; rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state), &new, 0); } else { rtbad(rt); } } /* Called while walking the table looking for sick interfaces * or after a time change. */ /* ARGSUSED */ int walk_bad(struct radix_node *rn, struct walkarg *argp UNUSED) { #define RT ((struct rt_entry *)rn) struct rt_spare *rts; int i; /* fix any spare routes through the interface */ rts = RT->rt_spares; for (i = NUM_SPARES; i != 1; i--) { rts++; if (rts->rts_metric < HOPCNT_INFINITY && (rts->rts_ifp == 0 || (rts->rts_ifp->int_state & IS_BROKE))) rts_delete(RT, rts); } /* Deal with the main route */ /* finished if it has been handled before or if its interface is ok */ if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) return 0; /* Bad routes for other than interfaces are easy. */ if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { rtbad(RT); return 0; } rtbad_sub(RT); return 0; #undef RT } /* Check the age of an individual route. */ /* ARGSUSED */ static int walk_age(struct radix_node *rn, struct walkarg *argp UNUSED) { #define RT ((struct rt_entry *)rn) struct interface *ifp; struct rt_spare *rts; int i; /* age all of the spare routes, including the primary route * currently in use */ rts = RT->rt_spares; for (i = NUM_SPARES; i != 0; i--, rts++) { ifp = rts->rts_ifp; if (i == NUM_SPARES) { if (!AGE_RT(RT->rt_state, ifp)) { /* Keep various things from deciding ageless * routes are stale */ rts->rts_time = now.tv_sec; continue; } /* forget RIP routes after RIP has been turned off. */ if (rip_sock < 0) { rtdelete(RT); return 0; } } /* age failing routes */ if (age_bad_gate == rts->rts_gate && rts->rts_time >= now_stale) { rts->rts_time -= SUPPLY_INTERVAL; } /* trash the spare routes when they go bad */ if (rts->rts_metric < HOPCNT_INFINITY && now_garbage > rts->rts_time && i != NUM_SPARES) rts_delete(RT, rts); } /* finished if the active route is still fresh */ if (now_stale <= RT->rt_time) return 0; /* try to switch to an alternative */ rtswitch(RT, 0); /* Delete a dead route after it has been publically mourned. */ if (now_garbage > RT->rt_time) { rtdelete(RT); return 0; } /* Start poisoning a bad route before deleting it. */ if (now.tv_sec - RT->rt_time > EXPIRE_TIME) { struct rt_spare new = RT->rt_spares[0]; new.rts_metric = HOPCNT_INFINITY; rtchange(RT, RT->rt_state, &new, 0); } return 0; } /* Watch for dead routes and interfaces. */ void age(naddr bad_gate) { struct interface *ifp; int need_query = 0; /* If not listening to RIP, there is no need to age the routes in * the table. */ age_timer.tv_sec = (now.tv_sec + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); /* Check for dead IS_REMOTE interfaces by timing their * transmissions. */ for (ifp = ifnet; ifp; ifp = ifp->int_next) { if (!(ifp->int_state & IS_REMOTE)) continue; /* ignore unreachable remote interfaces */ if (!check_remote(ifp)) continue; /* Restore remote interface that has become reachable */ if (ifp->int_state & IS_BROKE) if_ok(ifp, "remote "); if (ifp->int_act_time != NEVER && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { msglog("remote interface %s to %s timed out after" " %ld:%ld", ifp->int_name, naddr_ntoa(ifp->int_dstaddr), (now.tv_sec - ifp->int_act_time)/60, (now.tv_sec - ifp->int_act_time)%60); if_sick(ifp); } /* If we have not heard from the other router * recently, ask it. */ if (now.tv_sec >= ifp->int_query_time) { ifp->int_query_time = NEVER; need_query = 1; } } /* Age routes. */ age_bad_gate = bad_gate; (void)rn_walktree(rhead, walk_age, 0); /* delete old redirected routes to keep the kernel table small * and prevent blackholes */ del_redirects(bad_gate, now.tv_sec-STALE_TIME); /* Update the kernel routing table. */ fix_kern(); /* poke reticent remote gateways */ if (need_query) rip_query(); }