/* * Copyright (c) 1985, 1993 * The Regents of the University of California. All rights reserved. * * Copyright (c) 1995 John Hay. All rights reserved. * * This file includes significant work done at Cornell University by * Bill Nesheim. That work included by permission. * * 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. * * $FreeBSD: src/usr.sbin/IPXrouted/input.c,v 1.7 1999/08/28 01:15:02 peter Exp $ * $DragonFly: src/usr.sbin/IPXrouted/input.c,v 1.3 2004/03/11 09:38:59 hmp Exp $ * * @(#)input.c 8.1 (Berkeley) 6/5/93 */ /* * IPX Routing Table Management Daemon */ #include "defs.h" struct sockaddr * ipx_nettosa(union ipx_net net) { static struct sockaddr_ipx sxn; bzero(&sxn, sizeof (struct sockaddr_ipx)); sxn.sipx_family = AF_IPX; sxn.sipx_len = sizeof (sxn); sxn.sipx_addr.x_net = net; return( (struct sockaddr *)&sxn); } /* * Process a newly received packet. */ void rip_input(struct sockaddr *from, int size) { int newsize; int rtchanged = 0; struct rt_entry *rt; struct netinfo *n; struct interface *ifp = 0; struct afswitch *afp; struct sockaddr_ipx *ipxp; ifp = if_ifwithnet(from); ipxp = (struct sockaddr_ipx *)from; if (ifp == 0) { if(ftrace) { fprintf(ftrace, "Received bogus packet from %s\n", ipxdp_ntoa(&ipxp->sipx_addr)); } return; } TRACE_INPUT(ifp, from, size); if (from->sa_family >= AF_MAX) return; afp = &afswitch[from->sa_family]; size -= sizeof (u_short) /* command */; n = msg->rip_nets; switch (ntohs(msg->rip_cmd)) { case RIPCMD_REQUEST: if (ipx_hosteq(satoipx_addr(ifp->int_addr), ipxp->sipx_addr)) return; newsize = 0; while (size > 0) { if (size < sizeof (struct netinfo)) break; size -= sizeof (struct netinfo); /* * A single entry with rip_dst == DSTNETS_ALL and * metric ``infinity'' means ``all routes''. * * XXX According to the IPX RIP spec the metric * and tick fields can be anything. So maybe we * should not check the metric??? */ if (ipx_neteqnn(n->rip_dst, ipx_anynet) && ntohs(n->rip_metric) == HOPCNT_INFINITY && size == 0) { supply(from, 0, ifp, 0); return; } /* * request for specific nets */ rt = rtlookup(ipx_nettosa(n->rip_dst)); if (ftrace) { fprintf(ftrace, "specific request for %s", ipxdp_nettoa(n->rip_dst)); fprintf(ftrace, " yields route %x\n", (u_int)rt); } /* * XXX We break out on the first net that isn't * found. The specs is a bit vague here. I'm not * sure what we should do. */ if (rt == 0) return; /* XXX * According to the spec we should not include * information about networks for which the number * of hops is 16. */ if (rt->rt_metric == (HOPCNT_INFINITY-1)) return; n->rip_metric = htons( rt == 0 ? HOPCNT_INFINITY : min(rt->rt_metric+1, HOPCNT_INFINITY)); n->rip_ticks = htons(rt->rt_ticks+1); /* * We use split horizon with a twist. If the requested * net is the directly connected net we supply an * answer. This is so that the host can learn about * the routers on its net. */ { struct rt_entry *trt = rt; while (trt) { if ((trt->rt_ifp == ifp) && !ipx_neteqnn(n->rip_dst, satoipx_addr(ifp->int_addr).x_net)) return; trt = trt->rt_clone; } n++; newsize += sizeof (struct netinfo); } } if (newsize > 0) { msg->rip_cmd = htons(RIPCMD_RESPONSE); newsize += sizeof (u_short); /* should check for if with dstaddr(from) first */ (*afp->af_output)(ripsock, 0, from, newsize); TRACE_OUTPUT(ifp, from, newsize); if (ftrace) { /* XXX This should not happen anymore. */ if(ifp == 0) fprintf(ftrace, "--- ifp = 0\n"); else fprintf(ftrace, "request arrived on interface %s\n", ifp->int_name); } } 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? */ if ((ifp = if_ifwithaddr(from)) != 0) { rt = rtfind(from); if (rt == 0 || (rt->rt_state & RTS_INTERFACE) == 0) { addrouteforif(ifp); rtchanged = 1; } 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)) { if(ftrace) fprintf(ftrace, "Got route\n"); rt->rt_timer = 0; } else if ((ifp = if_ifwithdstaddr(from)) != 0) { if(ftrace) fprintf(ftrace, "Got partner\n"); addrouteforif(ifp); rtchanged = 1; } for (; size > 0; size -= sizeof (struct netinfo), n++) { struct sockaddr *sa; if (size < sizeof (struct netinfo)) break; if ((unsigned) ntohs(n->rip_metric) > HOPCNT_INFINITY) continue; rt = rtfind(sa = ipx_nettosa(n->rip_dst)); if (rt == 0) { if (ntohs(n->rip_metric) == HOPCNT_INFINITY) continue; rtadd(sa, from, ntohs(n->rip_metric), ntohs(n->rip_ticks), 0); rtchanged = 1; continue; } /* * A clone is a different route to the same net * with exactly the same cost (ticks and metric). * They must all be recorded because those interfaces * must be handled in the same way as the first route * to that net. ie When using the split horizon * algorithm we must look at these interfaces also. * * Update if from gateway and different, * from anywhere and less ticks or * if same ticks and shorter, * or getting stale and equivalent. */ if (!equal(from, &rt->rt_router) && ntohs(n->rip_ticks) == rt->rt_ticks && ntohs(n->rip_metric) == rt->rt_metric && ntohs(n->rip_metric) != HOPCNT_INFINITY) { struct rt_entry *trt = rt->rt_clone; while (trt) { if (equal(from, &trt->rt_router)) { trt->rt_timer = 0; break; } trt = trt->rt_clone; } if (trt == NULL) { rtadd_clone(rt, sa, from, ntohs(n->rip_metric), ntohs(n->rip_ticks), 0); } continue; } if ((equal(from, &rt->rt_router) && ((ntohs(n->rip_ticks) != rt->rt_ticks) || (ntohs(n->rip_metric) != rt->rt_metric))) || (ntohs(n->rip_ticks) < rt->rt_ticks) || ((ntohs(n->rip_ticks) == rt->rt_ticks) && (ntohs(n->rip_metric) < rt->rt_metric)) || (rt->rt_timer > (EXPIRE_TIME*2/3) && rt->rt_metric == ntohs(n->rip_metric) && ntohs(n->rip_metric) != HOPCNT_INFINITY)) { rtchange(rt, from, ntohs(n->rip_metric), ntohs(n->rip_ticks)); if (ntohs(n->rip_metric) == HOPCNT_INFINITY) rt->rt_timer = EXPIRE_TIME; else rt->rt_timer = 0; rtchanged = 1; } else if (equal(from, &rt->rt_router) && (ntohs(n->rip_ticks) == rt->rt_ticks) && (ntohs(n->rip_metric) == rt->rt_metric) && (ntohs(n->rip_metric) != HOPCNT_INFINITY)) { rt->rt_timer = 0; } } if (rtchanged) { struct rthash *rh; struct rt_entry *rt; toall(supply, NULL, 1); for (rh = nethash; rh < &nethash[ROUTEHASHSIZ]; rh++) for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) rt->rt_state &= ~RTS_CHANGED; } return; } }