From 5ad8429e52c73cfc64a037d4edd40d167e9724be Mon Sep 17 00:00:00 2001 From: wollman Date: Mon, 16 Sep 1996 16:51:32 +0000 Subject: Virgin import of new BSD/SGI routed. This update contains a number of important bug fixes. Obtained from: Vernon J. Schryver --- sbin/routed/table.c | 1970 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1970 insertions(+) create mode 100644 sbin/routed/table.c (limited to 'sbin/routed/table.c') diff --git a/sbin/routed/table.c b/sbin/routed/table.c new file mode 100644 index 0000000..6ad97f0 --- /dev/null +++ b/sbin/routed/table.c @@ -0,0 +1,1970 @@ +/* + * 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 acknowledgement: + * 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. + */ + +#if !defined(lint) && !defined(sgi) && !defined(__NetBSD__) +static char sccsid[] = "@(#)tables.c 8.1 (Berkeley) 6/5/93"; +#elif defined(__NetBSD__) +static char rcsid[] = "$NetBSD$"; +#endif +#ident "$Revision: 1.25 $" + +#include "defs.h" + +static struct rt_spare *rts_better(struct rt_entry *); + +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 +}; + +int stopint; + +int total_routes; + +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; + + + /* 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; + bit = (-ag->ag_mask) >> 1; + ag->ag_dst_h |= bit; + ag->ag_mask |= bit; + + } else if (ag->ag_state & AGS_REDUN1) { + 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 aggretation. + * 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 restritive 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 (ag_cors->ag_pref <= ag->ag_pref) { + if (ag_cors->ag_seqno > ag->ag_seqno) + ag_cors->ag_seqno = ag->ag_seqno; + 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 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 = 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 (eg. with large hop counts) + * from preventing suppresion 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 (ag_cors->ag_seqno > ag->ag_seqno) + ag_cors->ag_seqno = ag->ag_seqno; + 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 pair and the route already in the slot + * is the explicit route. + * + * Prefer the best route if their metrics differ, + * or the promoted 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; + x = ag->ag_state; + ag->ag_state = state; + state = x; + } + + /* The sequence number controls flash updating, + * and should be the smaller of the two. + */ + if (ag->ag_seqno > seqno) + ag->ag_seqno = seqno; + + /* some bits are set if they are set on either route */ + ag->ag_state |= (state & (AGS_PROMOTE_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. + * + * Note that any route that can be promoted is always + * marked to be eligible to be suppressed. + */ + if (!((state & AGS_PROMOTE) + && (ag->ag_state & AGS_SUPPRESS)) + && !((ag->ag_state & AGS_PROMOTE) + && (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_PROMOTE) != 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 the pair of routes. + */ + if (seqno > ag->ag_seqno) + 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_PROMOTE_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_PROMOTE)) { + /* 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; + + x = ag->ag_state; + ag->ag_state = state; + state = x; + if (!AG_IS_REDUN(state)) + state &= ~AGS_REDUN0; + + x = ag->ag_metric; + ag->ag_metric = metric; + metric = x; + + x = ag->ag_pref; + ag->ag_pref = pref; + pref = x; + + if (seqno >= ag->ag_seqno) + seqno = ag->ag_seqno; + else + ag->ag_seqno = seqno; + + } else { + if (!(state & AGS_PROMOTE)) + break; /* cannot promote either twin */ + + /* promote the new, odd twin by shaving its + * mask and address. + */ + if (seqno > ag->ag_seqno) + seqno = ag->ag_seqno; + else + ag->ag_seqno = seqno; + if (!AG_IS_REDUN(state)) + state &= ~AGS_REDUN1; + } + + 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 = 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 char * +rtm_type_name(u_char type) +{ + static 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", + "RTM_IFINFO" + }; + static char name0[10]; + + + if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) + || type == 0) { + sprintf(name0, "RTM type %#x", type); + return name0; + } else { + return rtm_types[type-1]; + } +} + + +/* 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 +{ + register 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; + +again: + bzero(&w, 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) { + 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 + } + + if (TRACEKERNEL) + trace_kernel("write kernel %s %s->%s metric=%d flags=%#x\n", + rtm_type_name(action), + addrname(dst, mask, 0), naddr_ntoa(gate), + metric, flags); + +#ifndef NO_INSTALL + cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); + if (cc == w.w_rtm.rtm_msglen) + return; + if (cc < 0) { + if (errno == ESRCH + && (action == RTM_CHANGE || action == RTM_DELETE)) { + trace_act("route to %s disappeared before %s\n", + addrname(dst, mask, 0), + rtm_type_name(action)); + if (action == RTM_CHANGE) { + action = RTM_ADD; + goto again; + } + return; + } + msglog("write(rt_sock) %s %s --> %s: %s", + rtm_type_name(action), + addrname(dst, mask, 0), naddr_ntoa(gate), + strerror(errno)); + } else { + msglog("write(rt_sock) wrote %d instead of %d", + cc, w.w_rtm.rtm_msglen); + } +#endif +} + + +#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 +#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 */ + time_t k_keep; +#define K_KEEP_LIM 30 + time_t k_redirect_time; +} *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 *)malloc(sizeof(*k)); + + bzero(k, 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; + naddr int_addr; + + if (k->k_metric == 0) + return; + + int_addr = (ifp != 0) ? ifp->int_addr : loopaddr; + + rt = rtget(k->k_dst, k->k_mask); + if (rt != 0) { + if (!(rt->rt_state & RS_STATIC)) + rtchange(rt, rt->rt_state | RS_STATIC, + k->k_gate, int_addr, + k->k_metric, 0, ifp, now.tv_sec, 0); + } else { + rtadd(k->k_dst, k->k_mask, k->k_gate, int_addr, + k->k_metric, 0, RS_STATIC, ifp); + } +} + + +/* 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("punt %s without mask", + rtm_type_name(rtm->rtm_type)); + return; + } + + if (INFO_GATE(info) == 0 + || INFO_GATE(info)->sa_family != AF_INET) { + msglog("punt %s without gateway", + 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; + 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) + k->k_metric = HOPCNT_INFINITY; + k->k_state &= ~(KS_DELETED | KS_GATEWAY | KS_STATIC | KS_NEW); + 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 (supplier) { + /* Routers are not supposed to listen to redirects, + * so delete it. + */ + k->k_state &= ~KS_DYNAMIC; + k->k_state |= KS_DELETE; + LIM_SEC(need_kern, 0); + trace_act("mark redirected %s --> %s for deletion" + " since this is a router\n", + addrname(k->k_dst, k->k_mask, 0), + naddr_ntoa(k->k_gate)); + } else { + k->k_state |= KS_DYNAMIC; + k->k_redirect_time = now.tv_sec; + } + 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 concerned + */ + ifp = iflookup(k->k_gate); + if (ifp == 0) { + /* if there is no known interface, + * maybe there is a new interface + */ + ifinit(); + 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) { + msglog("punt %s without gateway", + rtm_type_name(rtm->rtm_type)); + return; + } + + if (!supplier) + rdisc_age(S_ADDR(INFO_GATE(info))); + + age(S_ADDR(INFO_GATE(info))); +} + + +/* Clean the kernel table by copying it to the daemon image. + * Eventually the daemon will delete any extra routes. + */ +void +flush_kern(void) +{ + size_t needed; + int mib[6]; + char *buf, *next, *lim; + struct rt_msghdr *rtm; + struct interface *ifp; + static struct sockaddr_in gate_sa; + struct rt_addrinfo info; + + + 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 */ + if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) { + DBGERR(1,"RT_DUMP-sysctl-estimate"); + return; + } + buf = malloc(needed); + if (sysctl(mib, 6, buf, &needed, 0, 0) < 0) + BADERR(1,"RT_DUMP"); + lim = buf + needed; + for (next = buf; next < lim; next += rtm->rtm_msglen) { + rtm = (struct rt_msghdr *)next; + + 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 (INFO_GATE(&info) == 0) + continue; + if (INFO_GATE(&info)->sa_family != AF_INET) { + if (INFO_GATE(&info)->sa_family != AF_LINK) + continue; + ifp = ifwithindex(((struct sockaddr_dl *) + INFO_GATE(&info))->sdl_index); + if (ifp == 0) + continue; + if ((ifp->int_if_flags & IFF_POINTOPOINT) + || S_ADDR(INFO_DST(&info)) == ifp->int_addr) + gate_sa.sin_addr.s_addr = ifp->int_addr; + else + gate_sa.sin_addr.s_addr = htonl(ifp->int_net); +#ifdef _HAVE_SA_LEN + gate_sa.sin_len = sizeof(gate_sa); +#endif + gate_sa.sin_family = AF_INET; + INFO_GATE(&info) = (struct sockaddr *)&gate_sa; + } + + /* ignore multicast addresses + */ + if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) + 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); + } + free(buf); +} + + +/* Listen to announcements from the kernel + */ +void +read_rt(void) +{ + long cc; + struct interface *ifp; + naddr mask; + 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); + if (ifp == 0) + trace_act("note %s with flags %#x" + " for index #%d\n", + 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\n", + 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_RUNNING) != 0) + ifinit_timer.tv_sec = now.tv_sec; + continue; + } + + strcpy(str, rtm_type_name(m.r.rtm.rtm_type)); + strp = &str[strlen(str)]; + if (m.r.rtm.rtm_type <= RTM_CHANGE) + strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid); + + 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\n", str); + continue; + } + + if (INFO_DST(&info)->sa_family != AF_INET) { + trace_act("ignore %s for AF %d\n", 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)))); + + strp += sprintf(strp, ": %s", + addrname(S_ADDR(INFO_DST(&info)), mask, 0)); + + if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { + trace_act("ignore multicast %s\n", str); + continue; + } + + if (INFO_GATE(&info) != 0 + && INFO_GATE(&info)->sa_family == AF_INET) + strp += sprintf(strp, " --> %s", + saddr_ntoa(INFO_GATE(&info))); + + if (INFO_AUTHOR(&info) != 0) + strp += sprintf(strp, " by authority of %s", + saddr_ntoa(INFO_AUTHOR(&info))); + + 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\n", + str, strerror(m.r.rtm.rtm_errno)); + } else { + trace_act("%s\n", str); + rtm_add(&m.r.rtm,&info,0); + } + break; + + case RTM_DELETE: + if (m.r.rtm.rtm_errno != 0) { + trace_act("ignore %s with \"%s\" error\n", + str, strerror(m.r.rtm.rtm_errno)); + } else { + trace_act("%s\n", str); + del_static(S_ADDR(INFO_DST(&info)), mask, 1); + } + break; + + case RTM_LOSING: + trace_act("%s\n", str); + rtm_lose(&m.r.rtm,&info); + break; + + default: + trace_act("ignore %s\n", 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) { + k->k_gate = ag->ag_gate; + k->k_metric = ag->ag_metric; + k->k_state |= KS_CHANGE; + } + + if (k->k_state & KS_DYNAMIC) { + 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 *w) +{ +#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)) { + ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); + + } else { + /* Do not install routes for "external" remote interfaces. + */ + if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) + return 0; + + ags |= AGS_IF; + + /* 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) + && RT->rt_ifp->int_metric == 0)) + ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); + } + + if (RT->rt_state & RS_RDISC) + ags |= AGS_CORS_GATE; + + /* aggregate good routes without regard to their metric */ + pref = 1; + 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); + } + + 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, flags; + 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) { + LIM_SEC(need_kern, k->k_keep); + k->k_state |= KS_DELETE; + pk = &k->k_next; + continue; + } + + if ((k->k_state & (KS_DELETE | KS_DYNAMIC)) + == KS_DELETE) { + if (!(k->k_state & KS_DELETED)) + rtioctl(RTM_DELETE, + k->k_dst, k->k_gate, k->k_mask, + 0, 0); + *pk = k->k_next; + free(k); + continue; + } + + if (0 != (k->k_state&(KS_ADD|KS_CHANGE|KS_DEL_ADD))) { + if (k->k_state & KS_DEL_ADD) { + rtioctl(RTM_DELETE, + k->k_dst,k->k_gate,k->k_mask, + 0, 0); + k->k_state &= ~KS_DYNAMIC; + } + + flags = 0; + if (0 != (k->k_state&(KS_GATEWAY|KS_DYNAMIC))) + flags |= RTF_GATEWAY; + + if (k->k_state & KS_ADD) { + rtioctl(RTM_ADD, + k->k_dst, k->k_gate, k->k_mask, + k->k_metric, flags); + } else if (k->k_state & KS_CHANGE) { + rtioctl(RTM_CHANGE, + k->k_dst,k->k_gate,k->k_mask, + k->k_metric, flags); + } + 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, + 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) { + k->k_state &= ~(KS_STATIC | KS_DYNAMIC); + 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\n", + addrname(k->k_dst, k->k_mask, 0), + naddr_ntoa(k->k_gate)); + } + } +} + + +/* Start the daemon tables. + */ +void +rtinit(void) +{ + extern int max_keylen; + 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}; +static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET}; +#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 + + +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 = 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, + naddr gate, /* forward packets here */ + naddr router, /* on the authority of this router */ + int metric, + u_short tag, + u_int state, /* rs_state for the entry */ + struct interface *ifp) +{ + struct rt_entry *rt; + naddr smask; + int i; + struct rt_spare *rts; + + rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); + bzero(rt, 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 = mask; + masktrim(&mask_sock); + rt->rt_mask = mask; + rt->rt_state = state; + rt->rt_gate = gate; + rt->rt_router = router; + rt->rt_time = now.tv_sec; + rt->rt_metric = metric; + rt->rt_poison_metric = HOPCNT_INFINITY; + rt->rt_tag = tag; + rt->rt_ifp = ifp; + 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=%#x", + naddr_ntoa(dst), mask); + } +} + + +/* notice a changed route + */ +void +rtchange(struct rt_entry *rt, + u_int state, /* new state bits */ + naddr gate, /* now forward packets here */ + naddr router, /* on the authority of this router */ + int metric, /* new metric */ + u_short tag, + struct interface *ifp, + time_t new_time, + char *label) +{ + if (rt->rt_metric != 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 (metric == HOPCNT_INFINITY) { + need_kern.tv_sec = now.tv_sec; + if (new_time >= now.tv_sec - EXPIRE_TIME) + new_time = now.tv_sec - EXPIRE_TIME; + } + rt->rt_seqno = update_seqno; + set_need_flash(); + } + + if (rt->rt_gate != 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, ifp)) + new_time = now.tv_sec; + + if (TRACEACTIONS) + trace_change(rt, state, gate, router, metric, tag, ifp, + new_time, + label ? label : "Chg "); + + rt->rt_state = state; + rt->rt_gate = gate; + rt->rt_router = router; + rt->rt_metric = metric; + rt->rt_tag = tag; + rt->rt_ifp = ifp; + rt->rt_time = new_time; +} + + +/* 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[10]; + + + /* 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)sprintf(label, "Use #%d", rts - rt->rt_spares); + rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), + rts->rts_gate, rts->rts_router, rts->rts_metric, + rts->rts_tag, rts->rts_ifp, rts->rts_time, label); + *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 = 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--; + } +} + + +/* Get rid of a bad route, and try to switch to a replacement. + */ +void +rtbad(struct rt_entry *rt) +{ + /* Poison the route */ + rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), + rt->rt_gate, rt->rt_router, HOPCNT_INFINITY, rt->rt_tag, + 0, rt->rt_time, 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)) { + rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN | RS_LOCAL)) + | state), + rt->rt_gate, rt->rt_router, rt->rt_metric, + rt->rt_tag, ifp1, rt->rt_time, 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 *w) +{ +#define RT ((struct rt_entry *)rn) + struct rt_spare *rts; + int i; + time_t new_time; + + + /* fix any spare routes through the interface + */ + rts = RT->rt_spares; + for (i = NUM_SPARES; i != 1; i--) { + rts++; + + if (rts->rts_ifp != 0 + && (rts->rts_ifp->int_state & IS_BROKE)) { + /* mark the spare route to be deleted immediately */ + new_time = rts->rts_time; + if (new_time >= now_garbage) + new_time = now_garbage-1; + trace_upslot(RT, rts, rts->rts_gate, + rts->rts_router, 0, + HOPCNT_INFINITY, rts->rts_tag, + new_time); + rts->rts_ifp = 0; + rts->rts_metric = HOPCNT_INFINITY; + rts->rts_time = new_time; + } + } + + /* 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 *w) +{ +#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) { + trace_upslot(RT, rts, rts->rts_gate, + rts->rts_router, rts->rts_ifp, + HOPCNT_INFINITY, rts->rts_tag, + rts->rts_time); + rts->rts_metric = HOPCNT_INFINITY; + } + } + + + /* 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) + rtchange(RT, RT->rt_state, RT->rt_gate, RT->rt_router, + HOPCNT_INFINITY, RT->rt_tag, RT->rt_ifp, + RT->rt_time, 0); + return 0; +} + + +/* Watch for dead routes and interfaces. + */ +void +age(naddr bad_gate) +{ + struct interface *ifp; + + + age_timer.tv_sec = now.tv_sec + (rip_sock < 0 + ? NEVER + : SUPPLY_INTERVAL); + + for (ifp = ifnet; ifp; ifp = ifp->int_next) { + /* Check for dead IS_REMOTE interfaces by timing their + * transmissions. + */ + if ((ifp->int_state & IS_REMOTE) + && !(ifp->int_state & IS_PASSIVE) + && (ifp->int_state & IS_ACTIVE)) { + LIM_SEC(age_timer, now.tv_sec+SUPPLY_INTERVAL); + + if (now.tv_sec - ifp->int_act_time > EXPIRE_TIME + && !(ifp->int_state & IS_BROKE)) { + msglog("remote interface %s to %s timed out" + "--turned off", + ifp->int_name, + naddr_ntoa(ifp->int_addr)); + if_bad(ifp); + } + } + } + + /* Age routes. */ + age_bad_gate = bad_gate; + (void)rn_walktree(rhead, walk_age, 0); + + /* Update the kernel routing table. */ + fix_kern(); +} -- cgit v1.1