sys/lib/libsa/rarp.c
C | 240 lines | 155 code | 25 blank | 60 comment | 28 complexity | 28d5b14b6650ae9527bb0a995627103e MD5 | raw file
Possible License(s): MIT, WTFPL, AGPL-1.0, BSD-3-Clause, GPL-3.0, LGPL-2.0, JSON, 0BSD
- /* $NetBSD: rarp.c,v 1.31 2011/05/11 16:23:40 zoltan Exp $ */
- /*
- * Copyright (c) 1992 Regents of the University of California.
- * All rights reserved.
- *
- * This software was developed by the Computer Systems Engineering group
- * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
- * contributed to Berkeley.
- *
- * 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, Lawrence Berkeley Laboratory 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.
- *
- * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
- */
- #include <sys/param.h>
- #include <sys/socket.h>
- #include <net/if.h>
- #include <net/if_ether.h>
- #include <netinet/in.h>
- #include <netinet/in_systm.h>
- #ifdef _STANDALONE
- #include <lib/libkern/libkern.h>
- #else
- #include <string.h>
- #endif
- #include "stand.h"
- #include "net.h"
- /*
- * Ethernet Address Resolution Protocol.
- *
- * See RFC 826 for protocol description. Structure below is adapted
- * to resolving internet addresses. Field names used correspond to
- * RFC 826.
- */
- struct ether_arp {
- struct arphdr ea_hdr; /* fixed-size header */
- u_int8_t arp_sha[ETHER_ADDR_LEN]; /* sender hardware address */
- u_int8_t arp_spa[4]; /* sender protocol address */
- u_int8_t arp_tha[ETHER_ADDR_LEN]; /* target hardware address */
- u_int8_t arp_tpa[4]; /* target protocol address */
- };
- #define arp_hrd ea_hdr.ar_hrd
- #define arp_pro ea_hdr.ar_pro
- #define arp_hln ea_hdr.ar_hln
- #define arp_pln ea_hdr.ar_pln
- #define arp_op ea_hdr.ar_op
- static ssize_t rarpsend(struct iodesc *, void *, size_t);
- static ssize_t rarprecv(struct iodesc *, void *, size_t, saseconds_t);
- /*
- * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
- */
- int
- rarp_getipaddress(int sock)
- {
- struct iodesc *d;
- struct ether_arp *ap;
- struct {
- u_char header[ETHERNET_HEADER_SIZE];
- struct {
- struct ether_arp arp;
- u_char pad[18]; /* 60 - sizeof(arp) */
- } data;
- } wbuf;
- struct {
- u_char header[ETHERNET_HEADER_SIZE];
- struct {
- struct ether_arp arp;
- u_char pad[24]; /* extra space */
- } data;
- } rbuf;
- #ifdef RARP_DEBUG
- if (debug)
- printf("rarp: socket=%d\n", sock);
- #endif
- if (!(d = socktodesc(sock))) {
- printf("rarp: bad socket. %d\n", sock);
- return -1;
- }
- #ifdef RARP_DEBUG
- if (debug)
- printf("rarp: d=%lx\n", (u_long)d);
- #endif
- (void)memset(&wbuf.data, 0, sizeof(wbuf.data));
- ap = &wbuf.data.arp;
- ap->arp_hrd = htons(ARPHRD_ETHER);
- ap->arp_pro = htons(ETHERTYPE_IP);
- ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
- ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
- ap->arp_op = htons(ARPOP_REVREQUEST);
- (void)memcpy(ap->arp_sha, d->myea, 6);
- (void)memcpy(ap->arp_tha, d->myea, 6);
- if (sendrecv(d,
- rarpsend, &wbuf.data, sizeof(wbuf.data),
- rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0)
- {
- printf("No response for RARP request\n");
- return -1;
- }
- ap = &rbuf.data.arp;
- (void)memcpy(&myip, ap->arp_tpa, sizeof(myip));
- #if 0
- /* XXX - Can NOT assume this is our root server! */
- (void)memcpy(&rootip, ap->arp_spa, sizeof(rootip));
- #endif
- /* Compute our "natural" netmask. */
- if (IN_CLASSA(myip.s_addr))
- netmask = IN_CLASSA_NET;
- else if (IN_CLASSB(myip.s_addr))
- netmask = IN_CLASSB_NET;
- else
- netmask = IN_CLASSC_NET;
- d->myip = myip;
- return 0;
- }
- /*
- * Broadcast a RARP request (i.e. who knows who I am)
- */
- static ssize_t
- rarpsend(struct iodesc *d, void *pkt, size_t len)
- {
- #ifdef RARP_DEBUG
- if (debug)
- printf("rarpsend: called\n");
- #endif
- return sendether(d, pkt, len, bcea, ETHERTYPE_REVARP);
- }
- /*
- * Returns 0 if this is the packet we're waiting for
- * else -1 (and errno == 0)
- */
- static ssize_t
- rarprecv(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
- {
- ssize_t n;
- struct ether_arp *ap;
- u_int16_t etype; /* host order */
- #ifdef RARP_DEBUG
- if (debug)
- printf("rarprecv: ");
- #endif
- n = readether(d, pkt, len, tleft, &etype);
- errno = 0; /* XXX */
- if (n == -1 || (size_t)n < sizeof(struct ether_arp)) {
- #ifdef RARP_DEBUG
- if (debug)
- printf("bad len=%d\n", (int)n);
- #endif
- return -1;
- }
- if (etype != ETHERTYPE_REVARP) {
- #ifdef RARP_DEBUG
- if (debug)
- printf("bad type=0x%x\n", etype);
- #endif
- return -1;
- }
- ap = (struct ether_arp *)pkt;
- if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
- ap->arp_pro != htons(ETHERTYPE_IP) ||
- ap->arp_hln != sizeof(ap->arp_sha) ||
- ap->arp_pln != sizeof(ap->arp_spa) )
- {
- #ifdef RARP_DEBUG
- if (debug)
- printf("bad hrd/pro/hln/pln\n");
- #endif
- return -1;
- }
- if (ap->arp_op != htons(ARPOP_REVREPLY)) {
- #ifdef RARP_DEBUG
- if (debug)
- printf("bad op=0x%x\n", ntohs(ap->arp_op));
- #endif
- return -1;
- }
- /* Is the reply for our Ethernet address? */
- if (memcmp(ap->arp_tha, d->myea, 6)) {
- #ifdef RARP_DEBUG
- if (debug)
- printf("unwanted address\n");
- #endif
- return -1;
- }
- /* We have our answer. */
- #ifdef RARP_DEBUG
- if (debug)
- printf("got it\n");
- #endif
- return n;
- }