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input.c revision 1.1
      1  1.1  cgd /*
      2  1.1  cgd  * Copyright (c) 1983, 1988 Regents of the University of California.
      3  1.1  cgd  * All rights reserved.
      4  1.1  cgd  *
      5  1.1  cgd  * Redistribution and use in source and binary forms, with or without
      6  1.1  cgd  * modification, are permitted provided that the following conditions
      7  1.1  cgd  * are met:
      8  1.1  cgd  * 1. Redistributions of source code must retain the above copyright
      9  1.1  cgd  *    notice, this list of conditions and the following disclaimer.
     10  1.1  cgd  * 2. Redistributions in binary form must reproduce the above copyright
     11  1.1  cgd  *    notice, this list of conditions and the following disclaimer in the
     12  1.1  cgd  *    documentation and/or other materials provided with the distribution.
     13  1.1  cgd  * 3. All advertising materials mentioning features or use of this software
     14  1.1  cgd  *    must display the following acknowledgement:
     15  1.1  cgd  *	This product includes software developed by the University of
     16  1.1  cgd  *	California, Berkeley and its contributors.
     17  1.1  cgd  * 4. Neither the name of the University nor the names of its contributors
     18  1.1  cgd  *    may be used to endorse or promote products derived from this software
     19  1.1  cgd  *    without specific prior written permission.
     20  1.1  cgd  *
     21  1.1  cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  1.1  cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  1.1  cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  1.1  cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  1.1  cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  1.1  cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  1.1  cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  1.1  cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  1.1  cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  1.1  cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  1.1  cgd  * SUCH DAMAGE.
     32  1.1  cgd  */
     33  1.1  cgd 
     34  1.1  cgd #ifndef lint
     35  1.1  cgd static char sccsid[] = "@(#)input.c	5.22 (Berkeley) 6/1/90";
     36  1.1  cgd #endif /* not lint */
     37  1.1  cgd 
     38  1.1  cgd /*
     39  1.1  cgd  * Routing Table Management Daemon
     40  1.1  cgd  */
     41  1.1  cgd #include "defs.h"
     42  1.1  cgd #include <sys/syslog.h>
     43  1.1  cgd 
     44  1.1  cgd /*
     45  1.1  cgd  * Process a newly received packet.
     46  1.1  cgd  */
     47  1.1  cgd rip_input(from, rip, size)
     48  1.1  cgd 	struct sockaddr *from;
     49  1.1  cgd 	register struct rip *rip;
     50  1.1  cgd 	int size;
     51  1.1  cgd {
     52  1.1  cgd 	register struct rt_entry *rt;
     53  1.1  cgd 	register struct netinfo *n;
     54  1.1  cgd 	register struct interface *ifp;
     55  1.1  cgd 	struct interface *if_ifwithdstaddr();
     56  1.1  cgd 	int count, changes = 0;
     57  1.1  cgd 	register struct afswitch *afp;
     58  1.1  cgd 	static struct sockaddr badfrom, badfrom2;
     59  1.1  cgd 
     60  1.1  cgd 	ifp = 0;
     61  1.1  cgd 	TRACE_INPUT(ifp, from, (char *)rip, size);
     62  1.1  cgd 	if (from->sa_family >= af_max ||
     63  1.1  cgd 	    (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
     64  1.1  cgd 		syslog(LOG_INFO,
     65  1.1  cgd 	 "\"from\" address in unsupported address family (%d), cmd %d\n",
     66  1.1  cgd 		    from->sa_family, rip->rip_cmd);
     67  1.1  cgd 		return;
     68  1.1  cgd 	}
     69  1.1  cgd 	if (rip->rip_vers == 0) {
     70  1.1  cgd 		syslog(LOG_ERR,
     71  1.1  cgd 		    "RIP version 0 packet received from %s! (cmd %d)",
     72  1.1  cgd 		    (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
     73  1.1  cgd 		return;
     74  1.1  cgd 	}
     75  1.1  cgd 	switch (rip->rip_cmd) {
     76  1.1  cgd 
     77  1.1  cgd 	case RIPCMD_REQUEST:
     78  1.1  cgd 		n = rip->rip_nets;
     79  1.1  cgd 		count = size - ((char *)n - (char *)rip);
     80  1.1  cgd 		if (count < sizeof (struct netinfo))
     81  1.1  cgd 			return;
     82  1.1  cgd 		for (; count > 0; n++) {
     83  1.1  cgd 			if (count < sizeof (struct netinfo))
     84  1.1  cgd 				break;
     85  1.1  cgd 			count -= sizeof (struct netinfo);
     86  1.1  cgd 
     87  1.1  cgd #if BSD < 198810
     88  1.1  cgd 			if (sizeof(n->rip_dst.sa_family) > 1)	/* XXX */
     89  1.1  cgd 			    n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
     90  1.1  cgd #else
     91  1.1  cgd #define osa(x) ((struct osockaddr *)(&(x)))
     92  1.1  cgd 			    n->rip_dst.sa_family =
     93  1.1  cgd 					ntohs(osa(n->rip_dst)->sa_family);
     94  1.1  cgd 			    n->rip_dst.sa_len = sizeof(n->rip_dst);
     95  1.1  cgd #endif
     96  1.1  cgd 			n->rip_metric = ntohl(n->rip_metric);
     97  1.1  cgd 			/*
     98  1.1  cgd 			 * A single entry with sa_family == AF_UNSPEC and
     99  1.1  cgd 			 * metric ``infinity'' means ``all routes''.
    100  1.1  cgd 			 * We respond to routers only if we are acting
    101  1.1  cgd 			 * as a supplier, or to anyone other than a router
    102  1.1  cgd 			 * (eg, query).
    103  1.1  cgd 			 */
    104  1.1  cgd 			if (n->rip_dst.sa_family == AF_UNSPEC &&
    105  1.1  cgd 			    n->rip_metric == HOPCNT_INFINITY && count == 0) {
    106  1.1  cgd 			    	if (supplier || (*afp->af_portmatch)(from) == 0)
    107  1.1  cgd 					supply(from, 0, 0, 0);
    108  1.1  cgd 				return;
    109  1.1  cgd 			}
    110  1.1  cgd 			if (n->rip_dst.sa_family < af_max &&
    111  1.1  cgd 			    afswitch[n->rip_dst.sa_family].af_hash)
    112  1.1  cgd 				rt = rtlookup(&n->rip_dst);
    113  1.1  cgd 			else
    114  1.1  cgd 				rt = 0;
    115  1.1  cgd #define min(a, b) (a < b ? a : b)
    116  1.1  cgd 			n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
    117  1.1  cgd 				min(rt->rt_metric + 1, HOPCNT_INFINITY);
    118  1.1  cgd #if BSD < 198810
    119  1.1  cgd 			if (sizeof(n->rip_dst.sa_family) > 1)	/* XXX */
    120  1.1  cgd 			    n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
    121  1.1  cgd #else
    122  1.1  cgd 			    osa(n->rip_dst)->sa_family =
    123  1.1  cgd 						htons(n->rip_dst.sa_family);
    124  1.1  cgd #endif
    125  1.1  cgd 			n->rip_metric = htonl(n->rip_metric);
    126  1.1  cgd 		}
    127  1.1  cgd 		rip->rip_cmd = RIPCMD_RESPONSE;
    128  1.1  cgd 		bcopy((char *)rip, packet, size);
    129  1.1  cgd 		(*afp->af_output)(s, 0, from, size);
    130  1.1  cgd 		return;
    131  1.1  cgd 
    132  1.1  cgd 	case RIPCMD_TRACEON:
    133  1.1  cgd 	case RIPCMD_TRACEOFF:
    134  1.1  cgd 		/* verify message came from a privileged port */
    135  1.1  cgd 		if ((*afp->af_portcheck)(from) == 0)
    136  1.1  cgd 			return;
    137  1.1  cgd 		if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
    138  1.1  cgd 		    (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
    139  1.1  cgd 		    ifp->int_flags & IFF_PASSIVE) {
    140  1.1  cgd 			syslog(LOG_ERR, "trace command from unknown router, %s",
    141  1.1  cgd 			    (*afswitch[from->sa_family].af_format)(from));
    142  1.1  cgd 			return;
    143  1.1  cgd 		}
    144  1.1  cgd 		((char *)rip)[size] = '\0';
    145  1.1  cgd 		if (rip->rip_cmd == RIPCMD_TRACEON)
    146  1.1  cgd 			traceon(rip->rip_tracefile);
    147  1.1  cgd 		else
    148  1.1  cgd 			traceoff();
    149  1.1  cgd 		return;
    150  1.1  cgd 
    151  1.1  cgd 	case RIPCMD_RESPONSE:
    152  1.1  cgd 		/* verify message came from a router */
    153  1.1  cgd 		if ((*afp->af_portmatch)(from) == 0)
    154  1.1  cgd 			return;
    155  1.1  cgd 		(*afp->af_canon)(from);
    156  1.1  cgd 		/* are we talking to ourselves? */
    157  1.1  cgd 		ifp = if_ifwithaddr(from);
    158  1.1  cgd 		if (ifp) {
    159  1.1  cgd 			if (ifp->int_flags & IFF_PASSIVE) {
    160  1.1  cgd 				syslog(LOG_ERR,
    161  1.1  cgd 				  "bogus input (from passive interface, %s)",
    162  1.1  cgd 				  (*afswitch[from->sa_family].af_format)(from));
    163  1.1  cgd 				return;
    164  1.1  cgd 			}
    165  1.1  cgd 			rt = rtfind(from);
    166  1.1  cgd 			if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) &&
    167  1.1  cgd 			    rt->rt_metric >= ifp->int_metric)
    168  1.1  cgd 				addrouteforif(ifp);
    169  1.1  cgd 			else
    170  1.1  cgd 				rt->rt_timer = 0;
    171  1.1  cgd 			return;
    172  1.1  cgd 		}
    173  1.1  cgd 		/*
    174  1.1  cgd 		 * Update timer for interface on which the packet arrived.
    175  1.1  cgd 		 * If from other end of a point-to-point link that isn't
    176  1.1  cgd 		 * in the routing tables, (re-)add the route.
    177  1.1  cgd 		 */
    178  1.1  cgd 		if ((rt = rtfind(from)) &&
    179  1.1  cgd 		    (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE)))
    180  1.1  cgd 			rt->rt_timer = 0;
    181  1.1  cgd 		else if ((ifp = if_ifwithdstaddr(from)) &&
    182  1.1  cgd 		    (rt == 0 || rt->rt_metric >= ifp->int_metric))
    183  1.1  cgd 			addrouteforif(ifp);
    184  1.1  cgd 		/*
    185  1.1  cgd 		 * "Authenticate" router from which message originated.
    186  1.1  cgd 		 * We accept routing packets from routers directly connected
    187  1.1  cgd 		 * via broadcast or point-to-point networks,
    188  1.1  cgd 		 * and from those listed in /etc/gateways.
    189  1.1  cgd 		 */
    190  1.1  cgd 		if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
    191  1.1  cgd 		    (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
    192  1.1  cgd 		    ifp->int_flags & IFF_PASSIVE) {
    193  1.1  cgd 			if (bcmp((char *)from, (char *)&badfrom,
    194  1.1  cgd 			    sizeof(badfrom)) != 0) {
    195  1.1  cgd 				syslog(LOG_ERR,
    196  1.1  cgd 				  "packet from unknown router, %s",
    197  1.1  cgd 				  (*afswitch[from->sa_family].af_format)(from));
    198  1.1  cgd 				badfrom = *from;
    199  1.1  cgd 			}
    200  1.1  cgd 			return;
    201  1.1  cgd 		}
    202  1.1  cgd 		size -= 4 * sizeof (char);
    203  1.1  cgd 		n = rip->rip_nets;
    204  1.1  cgd 		for (; size > 0; size -= sizeof (struct netinfo), n++) {
    205  1.1  cgd 			if (size < sizeof (struct netinfo))
    206  1.1  cgd 				break;
    207  1.1  cgd #if BSD < 198810
    208  1.1  cgd 			if (sizeof(n->rip_dst.sa_family) > 1)	/* XXX */
    209  1.1  cgd 				n->rip_dst.sa_family =
    210  1.1  cgd 					ntohs(n->rip_dst.sa_family);
    211  1.1  cgd #else
    212  1.1  cgd 			    n->rip_dst.sa_family =
    213  1.1  cgd 					ntohs(osa(n->rip_dst)->sa_family);
    214  1.1  cgd 			    n->rip_dst.sa_len = sizeof(n->rip_dst);
    215  1.1  cgd #endif
    216  1.1  cgd 			n->rip_metric = ntohl(n->rip_metric);
    217  1.1  cgd 			if (n->rip_dst.sa_family >= af_max ||
    218  1.1  cgd 			    (afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
    219  1.1  cgd 			    (int (*)())0) {
    220  1.1  cgd 				syslog(LOG_INFO,
    221  1.1  cgd 		"route in unsupported address family (%d), from %s (af %d)\n",
    222  1.1  cgd 				   n->rip_dst.sa_family,
    223  1.1  cgd 				   (*afswitch[from->sa_family].af_format)(from),
    224  1.1  cgd 				   from->sa_family);
    225  1.1  cgd 				continue;
    226  1.1  cgd 			}
    227  1.1  cgd 			if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
    228  1.1  cgd 				syslog(LOG_DEBUG,
    229  1.1  cgd 				    "bad host in route from %s (af %d)\n",
    230  1.1  cgd 				   (*afswitch[from->sa_family].af_format)(from),
    231  1.1  cgd 				   from->sa_family);
    232  1.1  cgd 				continue;
    233  1.1  cgd 			}
    234  1.1  cgd 			if (n->rip_metric == 0 ||
    235  1.1  cgd 			    (unsigned) n->rip_metric > HOPCNT_INFINITY) {
    236  1.1  cgd 				if (bcmp((char *)from, (char *)&badfrom2,
    237  1.1  cgd 				    sizeof(badfrom2)) != 0) {
    238  1.1  cgd 					syslog(LOG_ERR,
    239  1.1  cgd 					    "bad metric (%d) from %s\n",
    240  1.1  cgd 					    n->rip_metric,
    241  1.1  cgd 				  (*afswitch[from->sa_family].af_format)(from));
    242  1.1  cgd 					badfrom2 = *from;
    243  1.1  cgd 				}
    244  1.1  cgd 				continue;
    245  1.1  cgd 			}
    246  1.1  cgd 			/*
    247  1.1  cgd 			 * Adjust metric according to incoming interface.
    248  1.1  cgd 			 */
    249  1.1  cgd 			if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
    250  1.1  cgd 				n->rip_metric += ifp->int_metric;
    251  1.1  cgd 			if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
    252  1.1  cgd 				n->rip_metric = HOPCNT_INFINITY;
    253  1.1  cgd 			rt = rtlookup(&n->rip_dst);
    254  1.1  cgd 			if (rt == 0 ||
    255  1.1  cgd 			    (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
    256  1.1  cgd 			    (RTS_INTERNAL|RTS_INTERFACE)) {
    257  1.1  cgd 				/*
    258  1.1  cgd 				 * If we're hearing a logical network route
    259  1.1  cgd 				 * back from a peer to which we sent it,
    260  1.1  cgd 				 * ignore it.
    261  1.1  cgd 				 */
    262  1.1  cgd 				if (rt && rt->rt_state & RTS_SUBNET &&
    263  1.1  cgd 				    (*afp->af_sendroute)(rt, from))
    264  1.1  cgd 					continue;
    265  1.1  cgd 				if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
    266  1.1  cgd 				    /*
    267  1.1  cgd 				     * Look for an equivalent route that
    268  1.1  cgd 				     * includes this one before adding
    269  1.1  cgd 				     * this route.
    270  1.1  cgd 				     */
    271  1.1  cgd 				    rt = rtfind(&n->rip_dst);
    272  1.1  cgd 				    if (rt && equal(from, &rt->rt_router))
    273  1.1  cgd 					    continue;
    274  1.1  cgd 				    rtadd(&n->rip_dst, from, n->rip_metric, 0);
    275  1.1  cgd 				    changes++;
    276  1.1  cgd 				}
    277  1.1  cgd 				continue;
    278  1.1  cgd 			}
    279  1.1  cgd 
    280  1.1  cgd 			/*
    281  1.1  cgd 			 * Update if from gateway and different,
    282  1.1  cgd 			 * shorter, or equivalent but old route
    283  1.1  cgd 			 * is getting stale.
    284  1.1  cgd 			 */
    285  1.1  cgd 			if (equal(from, &rt->rt_router)) {
    286  1.1  cgd 				if (n->rip_metric != rt->rt_metric) {
    287  1.1  cgd 					rtchange(rt, from, n->rip_metric);
    288  1.1  cgd 					changes++;
    289  1.1  cgd 					rt->rt_timer = 0;
    290  1.1  cgd 					if (rt->rt_metric >= HOPCNT_INFINITY)
    291  1.1  cgd 						rt->rt_timer =
    292  1.1  cgd 						    GARBAGE_TIME - EXPIRE_TIME;
    293  1.1  cgd 				} else if (rt->rt_metric < HOPCNT_INFINITY)
    294  1.1  cgd 					rt->rt_timer = 0;
    295  1.1  cgd 			} else if ((unsigned) n->rip_metric < rt->rt_metric ||
    296  1.1  cgd 			    (rt->rt_metric == n->rip_metric &&
    297  1.1  cgd 			    rt->rt_timer > (EXPIRE_TIME/2) &&
    298  1.1  cgd 			    (unsigned) n->rip_metric < HOPCNT_INFINITY)) {
    299  1.1  cgd 				rtchange(rt, from, n->rip_metric);
    300  1.1  cgd 				changes++;
    301  1.1  cgd 				rt->rt_timer = 0;
    302  1.1  cgd 			}
    303  1.1  cgd 		}
    304  1.1  cgd 		break;
    305  1.1  cgd 	}
    306  1.1  cgd 
    307  1.1  cgd 	/*
    308  1.1  cgd 	 * If changes have occurred, and if we have not sent a broadcast
    309  1.1  cgd 	 * recently, send a dynamic update.  This update is sent only
    310  1.1  cgd 	 * on interfaces other than the one on which we received notice
    311  1.1  cgd 	 * of the change.  If we are within MIN_WAITTIME of a full update,
    312  1.1  cgd 	 * don't bother sending; if we just sent a dynamic update
    313  1.1  cgd 	 * and set a timer (nextbcast), delay until that time.
    314  1.1  cgd 	 * If we just sent a full update, delay the dynamic update.
    315  1.1  cgd 	 * Set a timer for a randomized value to suppress additional
    316  1.1  cgd 	 * dynamic updates until it expires; if we delayed sending
    317  1.1  cgd 	 * the current changes, set needupdate.
    318  1.1  cgd 	 */
    319  1.1  cgd 	if (changes && supplier &&
    320  1.1  cgd 	   now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
    321  1.1  cgd 		u_long delay;
    322  1.1  cgd 		extern long random();
    323  1.1  cgd 
    324  1.1  cgd 		if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
    325  1.1  cgd 		    timercmp(&nextbcast, &now, <)) {
    326  1.1  cgd 			if (traceactions)
    327  1.1  cgd 				fprintf(ftrace, "send dynamic update\n");
    328  1.1  cgd 			toall(supply, RTS_CHANGED, ifp);
    329  1.1  cgd 			lastbcast = now;
    330  1.1  cgd 			needupdate = 0;
    331  1.1  cgd 			nextbcast.tv_sec = 0;
    332  1.1  cgd 		} else {
    333  1.1  cgd 			needupdate++;
    334  1.1  cgd 			if (traceactions)
    335  1.1  cgd 				fprintf(ftrace, "delay dynamic update\n");
    336  1.1  cgd 		}
    337  1.1  cgd #define RANDOMDELAY()	(MIN_WAITTIME * 1000000 + \
    338  1.1  cgd 		(u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
    339  1.1  cgd 
    340  1.1  cgd 		if (nextbcast.tv_sec == 0) {
    341  1.1  cgd 			delay = RANDOMDELAY();
    342  1.1  cgd 			if (traceactions)
    343  1.1  cgd 				fprintf(ftrace,
    344  1.1  cgd 				    "inhibit dynamic update for %d usec\n",
    345  1.1  cgd 				    delay);
    346  1.1  cgd 			nextbcast.tv_sec = delay / 1000000;
    347  1.1  cgd 			nextbcast.tv_usec = delay % 1000000;
    348  1.1  cgd 			timevaladd(&nextbcast, &now);
    349  1.1  cgd 			/*
    350  1.1  cgd 			 * If the next possibly dynamic update
    351  1.1  cgd 			 * is within MIN_WAITTIME of the next full update,
    352  1.1  cgd 			 * force the delay past the full update,
    353  1.1  cgd 			 * or we might send a dynamic update just before
    354  1.1  cgd 			 * the full update.
    355  1.1  cgd 			 */
    356  1.1  cgd 			if (nextbcast.tv_sec > lastfullupdate.tv_sec +
    357  1.1  cgd 			    SUPPLY_INTERVAL - MIN_WAITTIME)
    358  1.1  cgd 				nextbcast.tv_sec = lastfullupdate.tv_sec +
    359  1.1  cgd 				    SUPPLY_INTERVAL + 1;
    360  1.1  cgd 		}
    361  1.1  cgd 	}
    362  1.1  cgd }
    363