rarp.c revision 84221
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 * 3. All advertising materials mentioning features or use of this software 2038451Smsmith * must display the following acknowledgement: 2138451Smsmith * This product includes software developed by the University of 2238451Smsmith * California, Lawrence Berkeley Laboratory and its contributors. 2338451Smsmith * 4. Neither the name of the University nor the names of its contributors 2438451Smsmith * may be used to endorse or promote products derived from this software 2538451Smsmith * without specific prior written permission. 2638451Smsmith * 2738451Smsmith * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2838451Smsmith * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2938451Smsmith * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 3038451Smsmith * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 3138451Smsmith * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 3238451Smsmith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3338451Smsmith * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3438451Smsmith * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3538451Smsmith * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3638451Smsmith * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3738451Smsmith * SUCH DAMAGE. 3838451Smsmith * 3938451Smsmith * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL) 4038451Smsmith */ 4184221Sdillon 4284221Sdillon#include <sys/cdefs.h> 4384221Sdillon__FBSDID("$FreeBSD: head/lib/libstand/rarp.c 84221 2001-09-30 22:28:01Z dillon $"); 4484221Sdillon 4538451Smsmith#include <sys/param.h> 4638451Smsmith#include <sys/socket.h> 4738451Smsmith#include <net/if.h> 4838451Smsmith#include <netinet/in.h> 4938451Smsmith#include <netinet/if_ether.h> 5038451Smsmith 5138451Smsmith#include <netinet/in_systm.h> 5238451Smsmith 5338451Smsmith#include <string.h> 5438451Smsmith 5538451Smsmith#include "stand.h" 5638451Smsmith#include "net.h" 5738451Smsmith#include "netif.h" 5838451Smsmith 5938451Smsmith 6038451Smsmithstatic ssize_t rarpsend(struct iodesc *, void *, size_t); 6138451Smsmithstatic ssize_t rarprecv(struct iodesc *, void *, size_t, time_t); 6238451Smsmith 6338451Smsmith/* 6438451Smsmith * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826). 6538451Smsmith */ 6638451Smsmithint 6738451Smsmithrarp_getipaddress(sock) 6838451Smsmith int sock; 6938451Smsmith{ 7038451Smsmith struct iodesc *d; 7138451Smsmith register struct ether_arp *ap; 7238451Smsmith struct { 7338451Smsmith u_char header[ETHER_SIZE]; 7438451Smsmith struct { 7538451Smsmith struct ether_arp arp; 7638451Smsmith u_char pad[18]; /* 60 - sizeof(arp) */ 7738451Smsmith } data; 7838451Smsmith } wbuf; 7938451Smsmith struct { 8038451Smsmith u_char header[ETHER_SIZE]; 8138451Smsmith struct { 8238451Smsmith struct ether_arp arp; 8338451Smsmith u_char pad[24]; /* extra space */ 8438451Smsmith } data; 8538451Smsmith } rbuf; 8638451Smsmith 8738451Smsmith#ifdef RARP_DEBUG 8838451Smsmith if (debug) 8938451Smsmith printf("rarp: socket=%d\n", sock); 9038451Smsmith#endif 9138451Smsmith if (!(d = socktodesc(sock))) { 9238451Smsmith printf("rarp: bad socket. %d\n", sock); 9338451Smsmith return (-1); 9438451Smsmith } 9538451Smsmith#ifdef RARP_DEBUG 9638451Smsmith if (debug) 9738451Smsmith printf("rarp: d=%x\n", (u_int)d); 9838451Smsmith#endif 9938451Smsmith 10038451Smsmith bzero((char*)&wbuf.data, sizeof(wbuf.data)); 10138451Smsmith ap = &wbuf.data.arp; 10238451Smsmith ap->arp_hrd = htons(ARPHRD_ETHER); 10338451Smsmith ap->arp_pro = htons(ETHERTYPE_IP); 10438451Smsmith ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */ 10538451Smsmith ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */ 10638451Smsmith ap->arp_op = htons(ARPOP_REVREQUEST); 10738451Smsmith bcopy(d->myea, ap->arp_sha, 6); 10838451Smsmith bcopy(d->myea, ap->arp_tha, 6); 10938451Smsmith 11038451Smsmith if (sendrecv(d, 11138451Smsmith rarpsend, &wbuf.data, sizeof(wbuf.data), 11238451Smsmith rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0) 11338451Smsmith { 11438451Smsmith printf("No response for RARP request\n"); 11538451Smsmith return (-1); 11638451Smsmith } 11738451Smsmith 11838451Smsmith ap = &rbuf.data.arp; 11938451Smsmith bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip)); 12038451Smsmith#if 0 12138451Smsmith /* XXX - Can NOT assume this is our root server! */ 12238451Smsmith bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip)); 12338451Smsmith#endif 12438451Smsmith 12538451Smsmith /* Compute our "natural" netmask. */ 12638451Smsmith if (IN_CLASSA(myip.s_addr)) 12738451Smsmith netmask = IN_CLASSA_NET; 12838451Smsmith else if (IN_CLASSB(myip.s_addr)) 12938451Smsmith netmask = IN_CLASSB_NET; 13038451Smsmith else 13138451Smsmith netmask = IN_CLASSC_NET; 13238451Smsmith 13338451Smsmith d->myip = myip; 13438451Smsmith return (0); 13538451Smsmith} 13638451Smsmith 13738451Smsmith/* 13838451Smsmith * Broadcast a RARP request (i.e. who knows who I am) 13938451Smsmith */ 14038451Smsmithstatic ssize_t 14138451Smsmithrarpsend(d, pkt, len) 14238451Smsmith register struct iodesc *d; 14338451Smsmith register void *pkt; 14438451Smsmith register size_t len; 14538451Smsmith{ 14638451Smsmith 14738451Smsmith#ifdef RARP_DEBUG 14838451Smsmith if (debug) 14938451Smsmith printf("rarpsend: called\n"); 15038451Smsmith#endif 15138451Smsmith 15238451Smsmith return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP)); 15338451Smsmith} 15438451Smsmith 15538451Smsmith/* 15638451Smsmith * Returns 0 if this is the packet we're waiting for 15738451Smsmith * else -1 (and errno == 0) 15838451Smsmith */ 15938451Smsmithstatic ssize_t 16038451Smsmithrarprecv(d, pkt, len, tleft) 16138451Smsmith register struct iodesc *d; 16238451Smsmith register void *pkt; 16338451Smsmith register size_t len; 16438451Smsmith time_t tleft; 16538451Smsmith{ 16638451Smsmith register ssize_t n; 16738451Smsmith register struct ether_arp *ap; 16838451Smsmith u_int16_t etype; /* host order */ 16938451Smsmith 17038451Smsmith#ifdef RARP_DEBUG 17138451Smsmith if (debug) 17238451Smsmith printf("rarprecv: "); 17338451Smsmith#endif 17438451Smsmith 17538451Smsmith n = readether(d, pkt, len, tleft, &etype); 17638451Smsmith errno = 0; /* XXX */ 17738451Smsmith if (n == -1 || n < sizeof(struct ether_arp)) { 17838451Smsmith#ifdef RARP_DEBUG 17938451Smsmith if (debug) 18038451Smsmith printf("bad len=%d\n", n); 18138451Smsmith#endif 18238451Smsmith return (-1); 18338451Smsmith } 18438451Smsmith 18538451Smsmith if (etype != ETHERTYPE_REVARP) { 18638451Smsmith#ifdef RARP_DEBUG 18738451Smsmith if (debug) 18838451Smsmith printf("bad type=0x%x\n", etype); 18938451Smsmith#endif 19038451Smsmith return (-1); 19138451Smsmith } 19238451Smsmith 19338451Smsmith ap = (struct ether_arp *)pkt; 19438451Smsmith if (ap->arp_hrd != htons(ARPHRD_ETHER) || 19538451Smsmith ap->arp_pro != htons(ETHERTYPE_IP) || 19638451Smsmith ap->arp_hln != sizeof(ap->arp_sha) || 19738451Smsmith ap->arp_pln != sizeof(ap->arp_spa) ) 19838451Smsmith { 19938451Smsmith#ifdef RARP_DEBUG 20038451Smsmith if (debug) 20138451Smsmith printf("bad hrd/pro/hln/pln\n"); 20238451Smsmith#endif 20338451Smsmith return (-1); 20438451Smsmith } 20538451Smsmith 20638451Smsmith if (ap->arp_op != htons(ARPOP_REVREPLY)) { 20738451Smsmith#ifdef RARP_DEBUG 20838451Smsmith if (debug) 20938451Smsmith printf("bad op=0x%x\n", ntohs(ap->arp_op)); 21038451Smsmith#endif 21138451Smsmith return (-1); 21238451Smsmith } 21338451Smsmith 21438451Smsmith /* Is the reply for our Ethernet address? */ 21538451Smsmith if (bcmp(ap->arp_tha, d->myea, 6)) { 21638451Smsmith#ifdef RARP_DEBUG 21738451Smsmith if (debug) 21838451Smsmith printf("unwanted address\n"); 21938451Smsmith#endif 22038451Smsmith return (-1); 22138451Smsmith } 22238451Smsmith 22338451Smsmith /* We have our answer. */ 22438451Smsmith#ifdef RARP_DEBUG 22538451Smsmith if (debug) 22638451Smsmith printf("got it\n"); 22738451Smsmith#endif 22838451Smsmith return (n); 22938451Smsmith} 230