Annotation of sys/lib/libsa/rarp.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: rarp.c,v 1.10 2003/08/11 06:23:09 deraadt Exp $ */
! 2: /* $NetBSD: rarp.c,v 1.13 1996/10/13 02:29:05 christos Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1992 Regents of the University of California.
! 6: * All rights reserved.
! 7: *
! 8: * This software was developed by the Computer Systems Engineering group
! 9: * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
! 10: * contributed to Berkeley.
! 11: *
! 12: * Redistribution and use in source and binary forms, with or without
! 13: * modification, are permitted provided that the following conditions
! 14: * are met:
! 15: * 1. Redistributions of source code must retain the above copyright
! 16: * notice, this list of conditions and the following disclaimer.
! 17: * 2. Redistributions in binary form must reproduce the above copyright
! 18: * notice, this list of conditions and the following disclaimer in the
! 19: * documentation and/or other materials provided with the distribution.
! 20: * 3. All advertising materials mentioning features or use of this software
! 21: * must display the following acknowledgement:
! 22: * This product includes software developed by the University of
! 23: * California, Lawrence Berkeley Laboratory and its contributors.
! 24: * 4. Neither the name of the University nor the names of its contributors
! 25: * may be used to endorse or promote products derived from this software
! 26: * without specific prior written permission.
! 27: *
! 28: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 29: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 30: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 31: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 32: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 33: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 34: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 35: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 36: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 37: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 38: * SUCH DAMAGE.
! 39: *
! 40: * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
! 41: */
! 42: #include <sys/param.h>
! 43: #include <sys/socket.h>
! 44: #include <net/if.h>
! 45: #include <netinet/in.h>
! 46:
! 47: #include <netinet/if_ether.h>
! 48: #include <netinet/in_systm.h>
! 49:
! 50: #include "stand.h"
! 51: #include "net.h"
! 52: #include "netif.h"
! 53:
! 54: static ssize_t rarpsend(struct iodesc *, void *, size_t);
! 55: static ssize_t rarprecv(struct iodesc *, void *, size_t, time_t);
! 56:
! 57: /*
! 58: * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
! 59: */
! 60: int
! 61: rarp_getipaddress(int sock)
! 62: {
! 63: struct iodesc *d;
! 64: struct ether_arp *ap;
! 65: struct {
! 66: u_char header[ETHER_SIZE];
! 67: struct {
! 68: struct ether_arp arp;
! 69: u_char pad[18]; /* 60 - sizeof(arp) */
! 70: } data;
! 71: } wbuf;
! 72: struct {
! 73: u_char header[ETHER_SIZE];
! 74: struct {
! 75: struct ether_arp arp;
! 76: u_char pad[24]; /* extra space */
! 77: } data;
! 78: } rbuf;
! 79:
! 80: #ifdef RARP_DEBUG
! 81: if (debug)
! 82: printf("rarp: socket=%d\n", sock);
! 83: #endif
! 84: if (!(d = socktodesc(sock))) {
! 85: printf("rarp: bad socket. %d\n", sock);
! 86: return (-1);
! 87: }
! 88: #ifdef RARP_DEBUG
! 89: if (debug)
! 90: printf("rarp: d=%x\n", (u_int)d);
! 91: #endif
! 92:
! 93: bzero((char *)&wbuf.data, sizeof(wbuf.data));
! 94: ap = &wbuf.data.arp;
! 95: ap->arp_hrd = htons(ARPHRD_ETHER);
! 96: ap->arp_pro = htons(ETHERTYPE_IP);
! 97: ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
! 98: ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
! 99: ap->arp_op = htons(ARPOP_REVREQUEST);
! 100: bcopy(d->myea, ap->arp_sha, 6);
! 101: bcopy(d->myea, ap->arp_tha, 6);
! 102:
! 103: if (sendrecv(d,
! 104: rarpsend, &wbuf.data, sizeof(wbuf.data),
! 105: rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0)
! 106: {
! 107: printf("No response for RARP request\n");
! 108: return (-1);
! 109: }
! 110:
! 111: ap = &rbuf.data.arp;
! 112: bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
! 113: #if 0
! 114: /* XXX - Can NOT assume this is our root server! */
! 115: bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
! 116: #endif
! 117:
! 118: /* Compute our "natural" netmask. */
! 119: if (IN_CLASSA(myip.s_addr))
! 120: netmask = IN_CLASSA_NET;
! 121: else if (IN_CLASSB(myip.s_addr))
! 122: netmask = IN_CLASSB_NET;
! 123: else
! 124: netmask = IN_CLASSC_NET;
! 125:
! 126: d->myip = myip;
! 127: return (0);
! 128: }
! 129:
! 130: /*
! 131: * Broadcast a RARP request (i.e. who knows who I am)
! 132: */
! 133: static ssize_t
! 134: rarpsend(struct iodesc *d, void *pkt, size_t len)
! 135: {
! 136:
! 137: #ifdef RARP_DEBUG
! 138: if (debug)
! 139: printf("rarpsend: called\n");
! 140: #endif
! 141:
! 142: return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
! 143: }
! 144:
! 145: /*
! 146: * Returns 0 if this is the packet we're waiting for
! 147: * else -1 (and errno == 0)
! 148: */
! 149: static ssize_t
! 150: rarprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
! 151: {
! 152: ssize_t n;
! 153: struct ether_arp *ap;
! 154: u_int16_t etype; /* host order */
! 155:
! 156: #ifdef RARP_DEBUG
! 157: if (debug)
! 158: printf("rarprecv: ");
! 159: #endif
! 160:
! 161: n = readether(d, pkt, len, tleft, &etype);
! 162: errno = 0; /* XXX */
! 163: if (n < 0 || (size_t)n < sizeof(struct ether_arp)) {
! 164: #ifdef RARP_DEBUG
! 165: if (debug)
! 166: printf("bad len=%d\n", n);
! 167: #endif
! 168: return (-1);
! 169: }
! 170:
! 171: if (etype != ETHERTYPE_REVARP) {
! 172: #ifdef RARP_DEBUG
! 173: if (debug)
! 174: printf("bad type=0x%x\n", etype);
! 175: #endif
! 176: return (-1);
! 177: }
! 178:
! 179: ap = (struct ether_arp *)pkt;
! 180: if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
! 181: ap->arp_pro != htons(ETHERTYPE_IP) ||
! 182: ap->arp_hln != sizeof(ap->arp_sha) ||
! 183: ap->arp_pln != sizeof(ap->arp_spa) )
! 184: {
! 185: #ifdef RARP_DEBUG
! 186: if (debug)
! 187: printf("bad hrd/pro/hln/pln\n");
! 188: #endif
! 189: return (-1);
! 190: }
! 191:
! 192: if (ap->arp_op != htons(ARPOP_REVREPLY)) {
! 193: #ifdef RARP_DEBUG
! 194: if (debug)
! 195: printf("bad op=0x%x\n", ntohs(ap->arp_op));
! 196: #endif
! 197: return (-1);
! 198: }
! 199:
! 200: /* Is the reply for our Ethernet address? */
! 201: if (bcmp(ap->arp_tha, d->myea, 6)) {
! 202: #ifdef RARP_DEBUG
! 203: if (debug)
! 204: printf("unwanted address\n");
! 205: #endif
! 206: return (-1);
! 207: }
! 208:
! 209: /* We have our answer. */
! 210: #ifdef RARP_DEBUG
! 211: if (debug)
! 212: printf("got it\n");
! 213: #endif
! 214: return (n);
! 215: }
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