138451Smsmith/* $NetBSD: rarp.c,v 1.16 1997/07/07 15:52:52 drochner Exp $ */ 238451Smsmith 338451Smsmith/* 438451Smsmith * Copyright (c) 1992 Regents of the University of California. 538451Smsmith * All rights reserved. 638451Smsmith * 738451Smsmith * This software was developed by the Computer Systems Engineering group 838451Smsmith * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 938451Smsmith * contributed to Berkeley. 1038451Smsmith * 1138451Smsmith * Redistribution and use in source and binary forms, with or without 1238451Smsmith * modification, are permitted provided that the following conditions 1338451Smsmith * are met: 1438451Smsmith * 1. Redistributions of source code must retain the above copyright 1538451Smsmith * notice, this list of conditions and the following disclaimer. 1638451Smsmith * 2. Redistributions in binary form must reproduce the above copyright 1738451Smsmith * notice, this list of conditions and the following disclaimer in the 1838451Smsmith * documentation and/or other materials provided with the distribution. 1938451Smsmith * 4. Neither the name of the University nor the names of its contributors 2038451Smsmith * may be used to endorse or promote products derived from this software 2138451Smsmith * without specific prior written permission. 2238451Smsmith * 2338451Smsmith * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2438451Smsmith * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2538451Smsmith * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2638451Smsmith * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2738451Smsmith * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2838451Smsmith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2938451Smsmith * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3038451Smsmith * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3138451Smsmith * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3238451Smsmith * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3338451Smsmith * SUCH DAMAGE. 3438451Smsmith * 3538451Smsmith * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL) 3638451Smsmith */ 3784221Sdillon 3884221Sdillon#include <sys/cdefs.h> 3984221Sdillon__FBSDID("$FreeBSD$"); 4084221Sdillon 4138451Smsmith#include <sys/param.h> 4238451Smsmith#include <sys/socket.h> 4338451Smsmith#include <net/if.h> 4438451Smsmith#include <netinet/in.h> 4538451Smsmith#include <netinet/if_ether.h> 4638451Smsmith 4738451Smsmith#include <netinet/in_systm.h> 4838451Smsmith 4938451Smsmith#include <string.h> 5038451Smsmith 5138451Smsmith#include "stand.h" 5238451Smsmith#include "net.h" 5338451Smsmith#include "netif.h" 5438451Smsmith 5538451Smsmith 5638451Smsmithstatic ssize_t rarpsend(struct iodesc *, void *, size_t); 5738451Smsmithstatic ssize_t rarprecv(struct iodesc *, void *, size_t, time_t); 5838451Smsmith 5938451Smsmith/* 6038451Smsmith * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826). 6138451Smsmith */ 6238451Smsmithint 6338451Smsmithrarp_getipaddress(sock) 6438451Smsmith int sock; 6538451Smsmith{ 6638451Smsmith struct iodesc *d; 6792913Sobrien struct ether_arp *ap; 6838451Smsmith struct { 6938451Smsmith u_char header[ETHER_SIZE]; 7038451Smsmith struct { 7138451Smsmith struct ether_arp arp; 7238451Smsmith u_char pad[18]; /* 60 - sizeof(arp) */ 7338451Smsmith } data; 7438451Smsmith } wbuf; 7538451Smsmith struct { 7638451Smsmith u_char header[ETHER_SIZE]; 7738451Smsmith struct { 7838451Smsmith struct ether_arp arp; 7938451Smsmith u_char pad[24]; /* extra space */ 8038451Smsmith } data; 8138451Smsmith } rbuf; 8238451Smsmith 8338451Smsmith#ifdef RARP_DEBUG 8438451Smsmith if (debug) 8538451Smsmith printf("rarp: socket=%d\n", sock); 8638451Smsmith#endif 8738451Smsmith if (!(d = socktodesc(sock))) { 8838451Smsmith printf("rarp: bad socket. %d\n", sock); 8938451Smsmith return (-1); 9038451Smsmith } 9138451Smsmith#ifdef RARP_DEBUG 9238451Smsmith if (debug) 9338451Smsmith printf("rarp: d=%x\n", (u_int)d); 9438451Smsmith#endif 9538451Smsmith 9638451Smsmith bzero((char*)&wbuf.data, sizeof(wbuf.data)); 9738451Smsmith ap = &wbuf.data.arp; 9838451Smsmith ap->arp_hrd = htons(ARPHRD_ETHER); 9938451Smsmith ap->arp_pro = htons(ETHERTYPE_IP); 10038451Smsmith ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */ 10138451Smsmith ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */ 10238451Smsmith ap->arp_op = htons(ARPOP_REVREQUEST); 10338451Smsmith bcopy(d->myea, ap->arp_sha, 6); 10438451Smsmith bcopy(d->myea, ap->arp_tha, 6); 10538451Smsmith 10638451Smsmith if (sendrecv(d, 10738451Smsmith rarpsend, &wbuf.data, sizeof(wbuf.data), 10838451Smsmith rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0) 10938451Smsmith { 11038451Smsmith printf("No response for RARP request\n"); 11138451Smsmith return (-1); 11238451Smsmith } 11338451Smsmith 11438451Smsmith ap = &rbuf.data.arp; 11538451Smsmith bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip)); 11638451Smsmith#if 0 11738451Smsmith /* XXX - Can NOT assume this is our root server! */ 11838451Smsmith bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip)); 11938451Smsmith#endif 12038451Smsmith 12138451Smsmith /* Compute our "natural" netmask. */ 12238451Smsmith if (IN_CLASSA(myip.s_addr)) 12338451Smsmith netmask = IN_CLASSA_NET; 12438451Smsmith else if (IN_CLASSB(myip.s_addr)) 12538451Smsmith netmask = IN_CLASSB_NET; 12638451Smsmith else 12738451Smsmith netmask = IN_CLASSC_NET; 12838451Smsmith 12938451Smsmith d->myip = myip; 13038451Smsmith return (0); 13138451Smsmith} 13238451Smsmith 13338451Smsmith/* 13438451Smsmith * Broadcast a RARP request (i.e. who knows who I am) 13538451Smsmith */ 13638451Smsmithstatic ssize_t 13738451Smsmithrarpsend(d, pkt, len) 13892913Sobrien struct iodesc *d; 13992913Sobrien void *pkt; 14092913Sobrien size_t len; 14138451Smsmith{ 14238451Smsmith 14338451Smsmith#ifdef RARP_DEBUG 14438451Smsmith if (debug) 14538451Smsmith printf("rarpsend: called\n"); 14638451Smsmith#endif 14738451Smsmith 14838451Smsmith return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP)); 14938451Smsmith} 15038451Smsmith 15138451Smsmith/* 15238451Smsmith * Returns 0 if this is the packet we're waiting for 15338451Smsmith * else -1 (and errno == 0) 15438451Smsmith */ 15538451Smsmithstatic ssize_t 15638451Smsmithrarprecv(d, pkt, len, tleft) 15792913Sobrien struct iodesc *d; 15892913Sobrien void *pkt; 15992913Sobrien size_t len; 16038451Smsmith time_t tleft; 16138451Smsmith{ 16292913Sobrien ssize_t n; 16392913Sobrien struct ether_arp *ap; 16438451Smsmith u_int16_t etype; /* host order */ 16538451Smsmith 16638451Smsmith#ifdef RARP_DEBUG 16738451Smsmith if (debug) 16838451Smsmith printf("rarprecv: "); 16938451Smsmith#endif 17038451Smsmith 17138451Smsmith n = readether(d, pkt, len, tleft, &etype); 17238451Smsmith errno = 0; /* XXX */ 17338451Smsmith if (n == -1 || n < sizeof(struct ether_arp)) { 17438451Smsmith#ifdef RARP_DEBUG 17538451Smsmith if (debug) 17638451Smsmith printf("bad len=%d\n", n); 17738451Smsmith#endif 17838451Smsmith return (-1); 17938451Smsmith } 18038451Smsmith 18138451Smsmith if (etype != ETHERTYPE_REVARP) { 18238451Smsmith#ifdef RARP_DEBUG 18338451Smsmith if (debug) 18438451Smsmith printf("bad type=0x%x\n", etype); 18538451Smsmith#endif 18638451Smsmith return (-1); 18738451Smsmith } 18838451Smsmith 18938451Smsmith ap = (struct ether_arp *)pkt; 19038451Smsmith if (ap->arp_hrd != htons(ARPHRD_ETHER) || 19138451Smsmith ap->arp_pro != htons(ETHERTYPE_IP) || 19238451Smsmith ap->arp_hln != sizeof(ap->arp_sha) || 19338451Smsmith ap->arp_pln != sizeof(ap->arp_spa) ) 19438451Smsmith { 19538451Smsmith#ifdef RARP_DEBUG 19638451Smsmith if (debug) 19738451Smsmith printf("bad hrd/pro/hln/pln\n"); 19838451Smsmith#endif 19938451Smsmith return (-1); 20038451Smsmith } 20138451Smsmith 20238451Smsmith if (ap->arp_op != htons(ARPOP_REVREPLY)) { 20338451Smsmith#ifdef RARP_DEBUG 20438451Smsmith if (debug) 20538451Smsmith printf("bad op=0x%x\n", ntohs(ap->arp_op)); 20638451Smsmith#endif 20738451Smsmith return (-1); 20838451Smsmith } 20938451Smsmith 21038451Smsmith /* Is the reply for our Ethernet address? */ 21138451Smsmith if (bcmp(ap->arp_tha, d->myea, 6)) { 21238451Smsmith#ifdef RARP_DEBUG 21338451Smsmith if (debug) 21438451Smsmith printf("unwanted address\n"); 21538451Smsmith#endif 21638451Smsmith return (-1); 21738451Smsmith } 21838451Smsmith 21938451Smsmith /* We have our answer. */ 22038451Smsmith#ifdef RARP_DEBUG 22138451Smsmith if (debug) 22238451Smsmith printf("got it\n"); 22338451Smsmith#endif 22438451Smsmith return (n); 22538451Smsmith} 226