diff options
Diffstat (limited to 'usr.sbin/routed/input.c')
| -rw-r--r-- | usr.sbin/routed/input.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/usr.sbin/routed/input.c b/usr.sbin/routed/input.c new file mode 100644 index 0000000..fb0ee79 --- /dev/null +++ b/usr.sbin/routed/input.c @@ -0,0 +1,362 @@ +/* + * 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. + */ + +#ifndef lint +static char sccsid[] = "@(#)input.c 8.1 (Berkeley) 6/5/93"; +#endif /* not lint */ + +/* + * Routing Table Management Daemon + */ +#include "defs.h" +#include <sys/syslog.h> + +/* + * Process a newly received packet. + */ +rip_input(from, rip, size) + struct sockaddr *from; + register struct rip *rip; + int size; +{ + register struct rt_entry *rt; + register struct netinfo *n; + register struct interface *ifp; + struct interface *if_ifwithdstaddr(); + int count, changes = 0; + register struct afswitch *afp; + static struct sockaddr badfrom, badfrom2; + + ifp = 0; + TRACE_INPUT(ifp, from, (char *)rip, size); + if (from->sa_family >= af_max || + (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) { + syslog(LOG_INFO, + "\"from\" address in unsupported address family (%d), cmd %d\n", + from->sa_family, rip->rip_cmd); + return; + } + if (rip->rip_vers == 0) { + syslog(LOG_ERR, + "RIP version 0 packet received from %s! (cmd %d)", + (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd); + return; + } + switch (rip->rip_cmd) { + + case RIPCMD_REQUEST: + n = rip->rip_nets; + count = size - ((char *)n - (char *)rip); + if (count < sizeof (struct netinfo)) + return; + for (; count > 0; n++) { + if (count < sizeof (struct netinfo)) + break; + count -= sizeof (struct netinfo); + +#if BSD < 198810 + if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ + n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); +#else +#define osa(x) ((struct osockaddr *)(&(x))) + n->rip_dst.sa_family = + ntohs(osa(n->rip_dst)->sa_family); + n->rip_dst.sa_len = sizeof(n->rip_dst); +#endif + n->rip_metric = ntohl(n->rip_metric); + /* + * A single entry with sa_family == AF_UNSPEC and + * metric ``infinity'' means ``all routes''. + * We respond to routers only if we are acting + * as a supplier, or to anyone other than a router + * (eg, query). + */ + if (n->rip_dst.sa_family == AF_UNSPEC && + n->rip_metric == HOPCNT_INFINITY && count == 0) { + if (supplier || (*afp->af_portmatch)(from) == 0) + supply(from, 0, 0, 0); + return; + } + if (n->rip_dst.sa_family < af_max && + afswitch[n->rip_dst.sa_family].af_hash) + rt = rtlookup(&n->rip_dst); + else + rt = 0; +#define min(a, b) (a < b ? a : b) + n->rip_metric = rt == 0 ? HOPCNT_INFINITY : + min(rt->rt_metric + 1, HOPCNT_INFINITY); +#if BSD < 198810 + if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ + n->rip_dst.sa_family = htons(n->rip_dst.sa_family); +#else + osa(n->rip_dst)->sa_family = + htons(n->rip_dst.sa_family); +#endif + n->rip_metric = htonl(n->rip_metric); + } + rip->rip_cmd = RIPCMD_RESPONSE; + bcopy((char *)rip, packet, size); + (*afp->af_output)(s, 0, from, size); + return; + + case RIPCMD_TRACEON: + case RIPCMD_TRACEOFF: + /* verify message came from a privileged port */ + if ((*afp->af_portcheck)(from) == 0) + return; + if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & + (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || + ifp->int_flags & IFF_PASSIVE) { + syslog(LOG_ERR, "trace command from unknown router, %s", + (*afswitch[from->sa_family].af_format)(from)); + return; + } + ((char *)rip)[size] = '\0'; + if (rip->rip_cmd == RIPCMD_TRACEON) + traceon(rip->rip_tracefile); + else + traceoff(); + return; + + case RIPCMD_RESPONSE: + /* verify message came from a router */ + if ((*afp->af_portmatch)(from) == 0) + return; + (*afp->af_canon)(from); + /* are we talking to ourselves? */ + ifp = if_ifwithaddr(from); + if (ifp) { + if (ifp->int_flags & IFF_PASSIVE) { + syslog(LOG_ERR, + "bogus input (from passive interface, %s)", + (*afswitch[from->sa_family].af_format)(from)); + return; + } + rt = rtfind(from); + if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && + rt->rt_metric >= ifp->int_metric) + addrouteforif(ifp); + else + rt->rt_timer = 0; + return; + } + /* + * Update timer for interface on which the packet arrived. + * If from other end of a point-to-point link that isn't + * in the routing tables, (re-)add the route. + */ + if ((rt = rtfind(from)) && + (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) + rt->rt_timer = 0; + else if ((ifp = if_ifwithdstaddr(from)) && + (rt == 0 || rt->rt_metric >= ifp->int_metric)) + addrouteforif(ifp); + /* + * "Authenticate" router from which message originated. + * We accept routing packets from routers directly connected + * via broadcast or point-to-point networks, + * and from those listed in /etc/gateways. + */ + if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & + (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || + ifp->int_flags & IFF_PASSIVE) { + if (bcmp((char *)from, (char *)&badfrom, + sizeof(badfrom)) != 0) { + syslog(LOG_ERR, + "packet from unknown router, %s", + (*afswitch[from->sa_family].af_format)(from)); + badfrom = *from; + } + return; + } + size -= 4 * sizeof (char); + n = rip->rip_nets; + for (; size > 0; size -= sizeof (struct netinfo), n++) { + if (size < sizeof (struct netinfo)) + break; +#if BSD < 198810 + if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ + n->rip_dst.sa_family = + ntohs(n->rip_dst.sa_family); +#else + n->rip_dst.sa_family = + ntohs(osa(n->rip_dst)->sa_family); + n->rip_dst.sa_len = sizeof(n->rip_dst); +#endif + n->rip_metric = ntohl(n->rip_metric); + if (n->rip_dst.sa_family >= af_max || + (afp = &afswitch[n->rip_dst.sa_family])->af_hash == + (int (*)())0) { + syslog(LOG_INFO, + "route in unsupported address family (%d), from %s (af %d)\n", + n->rip_dst.sa_family, + (*afswitch[from->sa_family].af_format)(from), + from->sa_family); + continue; + } + if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { + syslog(LOG_DEBUG, + "bad host in route from %s (af %d)\n", + (*afswitch[from->sa_family].af_format)(from), + from->sa_family); + continue; + } + if (n->rip_metric == 0 || + (unsigned) n->rip_metric > HOPCNT_INFINITY) { + if (bcmp((char *)from, (char *)&badfrom2, + sizeof(badfrom2)) != 0) { + syslog(LOG_ERR, + "bad metric (%d) from %s\n", + n->rip_metric, + (*afswitch[from->sa_family].af_format)(from)); + badfrom2 = *from; + } + continue; + } + /* + * Adjust metric according to incoming interface. + */ + if ((unsigned) n->rip_metric < HOPCNT_INFINITY) + n->rip_metric += ifp->int_metric; + if ((unsigned) n->rip_metric > HOPCNT_INFINITY) + n->rip_metric = HOPCNT_INFINITY; + rt = rtlookup(&n->rip_dst); + if (rt == 0 || + (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == + (RTS_INTERNAL|RTS_INTERFACE)) { + /* + * If we're hearing a logical network route + * back from a peer to which we sent it, + * ignore it. + */ + if (rt && rt->rt_state & RTS_SUBNET && + (*afp->af_sendroute)(rt, from)) + continue; + if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { + /* + * Look for an equivalent route that + * includes this one before adding + * this route. + */ + rt = rtfind(&n->rip_dst); + if (rt && equal(from, &rt->rt_router)) + continue; + rtadd(&n->rip_dst, from, n->rip_metric, 0); + changes++; + } + continue; + } + + /* + * Update if from gateway and different, + * shorter, or equivalent but old route + * is getting stale. + */ + if (equal(from, &rt->rt_router)) { + if (n->rip_metric != rt->rt_metric) { + rtchange(rt, from, n->rip_metric); + changes++; + rt->rt_timer = 0; + if (rt->rt_metric >= HOPCNT_INFINITY) + rt->rt_timer = + GARBAGE_TIME - EXPIRE_TIME; + } else if (rt->rt_metric < HOPCNT_INFINITY) + rt->rt_timer = 0; + } else if ((unsigned) n->rip_metric < rt->rt_metric || + (rt->rt_metric == n->rip_metric && + rt->rt_timer > (EXPIRE_TIME/2) && + (unsigned) n->rip_metric < HOPCNT_INFINITY)) { + rtchange(rt, from, n->rip_metric); + changes++; + rt->rt_timer = 0; + } + } + break; + } + + /* + * If changes have occurred, and if we have not sent a broadcast + * recently, send a dynamic update. This update is sent only + * on interfaces other than the one on which we received notice + * of the change. If we are within MIN_WAITTIME of a full update, + * don't bother sending; if we just sent a dynamic update + * and set a timer (nextbcast), delay until that time. + * If we just sent a full update, delay the dynamic update. + * Set a timer for a randomized value to suppress additional + * dynamic updates until it expires; if we delayed sending + * the current changes, set needupdate. + */ + if (changes && supplier && + now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { + u_long delay; + extern long random(); + + if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && + timercmp(&nextbcast, &now, <)) { + if (traceactions) + fprintf(ftrace, "send dynamic update\n"); + toall(supply, RTS_CHANGED, ifp); + lastbcast = now; + needupdate = 0; + nextbcast.tv_sec = 0; + } else { + needupdate++; + if (traceactions) + fprintf(ftrace, "delay dynamic update\n"); + } +#define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ + (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) + + if (nextbcast.tv_sec == 0) { + delay = RANDOMDELAY(); + if (traceactions) + fprintf(ftrace, + "inhibit dynamic update for %d usec\n", + delay); + nextbcast.tv_sec = delay / 1000000; + nextbcast.tv_usec = delay % 1000000; + timevaladd(&nextbcast, &now); + /* + * If the next possibly dynamic update + * is within MIN_WAITTIME of the next full update, + * force the delay past the full update, + * or we might send a dynamic update just before + * the full update. + */ + if (nextbcast.tv_sec > lastfullupdate.tv_sec + + SUPPLY_INTERVAL - MIN_WAITTIME) + nextbcast.tv_sec = lastfullupdate.tv_sec + + SUPPLY_INTERVAL + 1; + } + } +} |
