[dragonfly.git] / lib / libstand / arp.c

/*	$NetBSD: arp.c,v 1.18 1997/07/07 15:52:49 drochner 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)
 * $DragonFly: src/lib/libstand/arp.c,v 1.4 2005/12/11 02:27:26 swildner Exp $
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <netinet/in_systm.h>

#include <string.h>

#include "stand.h"
#include "net.h"

/* Cache stuff */
#define ARP_NUM 8			/* need at most 3 arp entries */

struct arp_list {
	struct in_addr	addr;
	u_char		ea[6];
} arp_list[ARP_NUM] = {
	/* XXX - net order `INADDR_BROADCAST' must be a constant */
	{ {0xffffffff}, BA }
};
int arp_num = 1;

/* Local forwards */
static	ssize_t arpsend(struct iodesc *, void *, size_t);
static	ssize_t arprecv(struct iodesc *, void *, size_t, time_t);

/* Broadcast an ARP packet, asking who has addr on interface d */
u_char *
arpwhohas(struct iodesc *d, struct in_addr addr)
{
	int i;
	struct ether_arp *ah;
	struct arp_list *al;
	struct {
		struct ether_header eh;
		struct {
			struct ether_arp arp;
			u_char pad[18]; 	/* 60 - sizeof(...) */
		} data;
	} wbuf;
	struct {
		struct ether_header eh;
		struct {
			struct ether_arp arp;
			u_char pad[24]; 	/* extra space */
		} data;
	} rbuf;

	/* Try for cached answer first */
	for (i = 0, al = arp_list; i < arp_num; ++i, ++al)
		if (addr.s_addr == al->addr.s_addr)
			return (al->ea);

	/* Don't overflow cache */
	if (arp_num > ARP_NUM - 1) {
		arp_num = 1;	/* recycle */
		printf("arpwhohas: overflowed arp_list!\n");
	}

#ifdef ARP_DEBUG
 	if (debug)
 	    printf("arpwhohas: send request for %s\n", inet_ntoa(addr));
#endif

	bzero((char*)&wbuf.data, sizeof(wbuf.data));
	ah = &wbuf.data.arp;
	ah->arp_hrd = htons(ARPHRD_ETHER);
	ah->arp_pro = htons(ETHERTYPE_IP);
	ah->arp_hln = sizeof(ah->arp_sha); /* hardware address length */
	ah->arp_pln = sizeof(ah->arp_spa); /* protocol address length */
	ah->arp_op = htons(ARPOP_REQUEST);
	MACPY(d->myea, ah->arp_sha);
	bcopy(&d->myip, ah->arp_spa, sizeof(ah->arp_spa));
	/* Leave zeros in arp_tha */
	bcopy(&addr, ah->arp_tpa, sizeof(ah->arp_tpa));

	/* Store ip address in cache (incomplete entry). */
	al->addr = addr;

	i = sendrecv(d,
	    arpsend, &wbuf.data, sizeof(wbuf.data),
	    arprecv, &rbuf.data, sizeof(rbuf.data));
	if (i == -1) {
		panic("arp: no response for %s\n",
			  inet_ntoa(addr));
	}

	/* Store ethernet address in cache */
	ah = &rbuf.data.arp;
#ifdef ARP_DEBUG
 	if (debug) {
		printf("arp: response from %s\n",
		    ether_sprintf(rbuf.eh.ether_shost));
		printf("arp: cacheing %s --> %s\n",
		    inet_ntoa(addr), ether_sprintf(ah->arp_sha));
	}
#endif
	MACPY(ah->arp_sha, al->ea);
	++arp_num;

	return (al->ea);
}

static ssize_t
arpsend(struct iodesc *d, void *pkt, size_t len)
{

#ifdef ARP_DEBUG
 	if (debug)
		printf("arpsend: called\n");
#endif

	return (sendether(d, pkt, len, bcea, ETHERTYPE_ARP));
}

/*
 * Returns 0 if this is the packet we're waiting for
 * else -1 (and errno == 0)
 */
static ssize_t
arprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
{
	ssize_t n;
	struct ether_arp *ah;
	u_int16_t etype;	/* host order */

#ifdef ARP_DEBUG
 	if (debug)
		printf("arprecv: ");
#endif

	n = readether(d, pkt, len, tleft, &etype);
	errno = 0;	/* XXX */
	if (n == -1 || n < sizeof(struct ether_arp)) {
#ifdef ARP_DEBUG
		if (debug)
			printf("bad len=%d\n", n);
#endif
		return (-1);
	}

	if (etype != ETHERTYPE_ARP) {
#ifdef ARP_DEBUG
		if (debug)
			printf("not arp type=%d\n", etype);
#endif
		return (-1);
	}

	/* Ethernet address now checked in readether() */

	ah = (struct ether_arp *)pkt;
	if (ah->arp_hrd != htons(ARPHRD_ETHER) ||
	    ah->arp_pro != htons(ETHERTYPE_IP) ||
	    ah->arp_hln != sizeof(ah->arp_sha) ||
	    ah->arp_pln != sizeof(ah->arp_spa) )
	{
#ifdef ARP_DEBUG
		if (debug)
			printf("bad hrd/pro/hln/pln\n");
#endif
		return (-1);
	}

	if (ah->arp_op == htons(ARPOP_REQUEST)) {
#ifdef ARP_DEBUG
		if (debug)
			printf("is request\n");
#endif
		arp_reply(d, ah);
		return (-1);
	}

	if (ah->arp_op != htons(ARPOP_REPLY)) {
#ifdef ARP_DEBUG
		if (debug)
			printf("not ARP reply\n");
#endif
		return (-1);
	}

	/* Is the reply from the source we want? */
	if (bcmp(&arp_list[arp_num].addr,
			 ah->arp_spa, sizeof(ah->arp_spa)))
	{
#ifdef ARP_DEBUG
		if (debug)
			printf("unwanted address\n");
#endif
		return (-1);
	}
	/* We don't care who the reply was sent to. */

	/* We have our answer. */
#ifdef ARP_DEBUG
 	if (debug)
		printf("got it\n");
#endif
	return (n);
}

/*
 * Convert an ARP request into a reply and send it.
 * Notes:  Re-uses buffer.  Pad to length = 46.
 *
 * Parameters:
 *	pkt:	the request
 */
void
arp_reply(struct iodesc *d, void *pkt)
{
	struct ether_arp *arp = pkt;

	if (arp->arp_hrd != htons(ARPHRD_ETHER) ||
	    arp->arp_pro != htons(ETHERTYPE_IP) ||
	    arp->arp_hln != sizeof(arp->arp_sha) ||
	    arp->arp_pln != sizeof(arp->arp_spa) )
	{
#ifdef ARP_DEBUG
		if (debug)
			printf("arp_reply: bad hrd/pro/hln/pln\n");
#endif
		return;
	}

	if (arp->arp_op != htons(ARPOP_REQUEST)) {
#ifdef ARP_DEBUG
		if (debug)
			printf("arp_reply: not request!\n");
#endif
		return;
	}

	/* If we are not the target, ignore the request. */
	if (bcmp(arp->arp_tpa, &d->myip, sizeof(arp->arp_tpa)))
		return;

#ifdef ARP_DEBUG
	if (debug) {
		printf("arp_reply: to %s\n", ether_sprintf(arp->arp_sha));
	}
#endif

	arp->arp_op = htons(ARPOP_REPLY);
	/* source becomes target */
	bcopy(arp->arp_sha, arp->arp_tha, sizeof(arp->arp_tha));
	bcopy(arp->arp_spa, arp->arp_tpa, sizeof(arp->arp_tpa));
	/* here becomes source */
	bcopy(d->myea,  arp->arp_sha, sizeof(arp->arp_sha));
	bcopy(&d->myip, arp->arp_spa, sizeof(arp->arp_spa));

	/*
	 * No need to get fancy here.  If the send fails, the
	 * requestor will just ask again.
	 */
	(void) sendether(d, pkt, sizeof(*arp) + 18,
	                 arp->arp_tha, ETHERTYPE_ARP);
}
Commit	Line	Data
984263bc MD	1	/* $NetBSD: arp.c,v 1.18 1997/07/07 15:52:49 drochner Exp $ */
	2
	3	/*
	4	* Copyright (c) 1992 Regents of the University of California.
	5	* All rights reserved.
	6	*
	7	* This software was developed by the Computer Systems Engineering group
	8	* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
	9	* contributed to Berkeley.
	10	*
	11	* Redistribution and use in source and binary forms, with or without
	12	* modification, are permitted provided that the following conditions
	13	* are met:
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions and the following disclaimer.
	16	* 2. Redistributions in binary form must reproduce the above copyright
	17	* notice, this list of conditions and the following disclaimer in the
	18	* documentation and/or other materials provided with the distribution.
	19	* 3. All advertising materials mentioning features or use of this software
	20	* must display the following acknowledgement:
	21	* This product includes software developed by the University of
	22	* California, Lawrence Berkeley Laboratory and its contributors.
	23	* 4. Neither the name of the University nor the names of its contributors
	24	* may be used to endorse or promote products derived from this software
	25	* without specific prior written permission.
	26	*
	27	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	28	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	29	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	30	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	31	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	32	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	33	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	34	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	35	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	36	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	37	* SUCH DAMAGE.
	38	*
	39	* @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
ff2aef30	40	* $DragonFly: src/lib/libstand/arp.c,v 1.4 2005/12/11 02:27:26 swildner Exp $
984263bc MD	41	*/
984263bc MD	42
47883879	43	#include <sys/param.h>
984263bc MD	44	#include <sys/socket.h>
	45	#include <net/if.h>
	46	#include <netinet/in.h>
	47	#include <netinet/if_ether.h>
	48
	49	#include <netinet/in_systm.h>
	50
	51	#include <string.h>
	52
	53	#include "stand.h"
	54	#include "net.h"
	55
	56	/* Cache stuff */
	57	#define ARP_NUM 8 /* need at most 3 arp entries */
	58
	59	struct arp_list {
	60	struct in_addr addr;
	61	u_char ea[6];
	62	} arp_list[ARP_NUM] = {
	63	/* XXX - net order `INADDR_BROADCAST' must be a constant */
	64	{ {0xffffffff}, BA }
	65	};
	66	int arp_num = 1;
	67
	68	/* Local forwards */
	69	static ssize_t arpsend(struct iodesc , void , size_t);
	70	static ssize_t arprecv(struct iodesc , void , size_t, time_t);
	71
	72	/* Broadcast an ARP packet, asking who has addr on interface d */
	73	u_char *
ff2aef30	74	arpwhohas(struct iodesc *d, struct in_addr addr)
984263bc	75	{
660c873b DR	76	int i;
	77	struct ether_arp *ah;
	78	struct arp_list *al;
984263bc MD	79	struct {
	80	struct ether_header eh;
	81	struct {
	82	struct ether_arp arp;
	83	u_char pad[18]; /* 60 - sizeof(...) */
	84	} data;
	85	} wbuf;
	86	struct {
	87	struct ether_header eh;
	88	struct {
	89	struct ether_arp arp;
	90	u_char pad[24]; /* extra space */
	91	} data;
	92	} rbuf;
	93
	94	/* Try for cached answer first */
	95	for (i = 0, al = arp_list; i < arp_num; ++i, ++al)
	96	if (addr.s_addr == al->addr.s_addr)
	97	return (al->ea);
	98
	99	/* Don't overflow cache */
	100	if (arp_num > ARP_NUM - 1) {
	101	arp_num = 1; /* recycle */
	102	printf("arpwhohas: overflowed arp_list!\n");
	103	}
	104
	105	#ifdef ARP_DEBUG
	106	if (debug)
	107	printf("arpwhohas: send request for %s\n", inet_ntoa(addr));
	108	#endif
	109
	110	bzero((char*)&wbuf.data, sizeof(wbuf.data));
	111	ah = &wbuf.data.arp;
	112	ah->arp_hrd = htons(ARPHRD_ETHER);
	113	ah->arp_pro = htons(ETHERTYPE_IP);
	114	ah->arp_hln = sizeof(ah->arp_sha); /* hardware address length */
	115	ah->arp_pln = sizeof(ah->arp_spa); /* protocol address length */
	116	ah->arp_op = htons(ARPOP_REQUEST);
	117	MACPY(d->myea, ah->arp_sha);
	118	bcopy(&d->myip, ah->arp_spa, sizeof(ah->arp_spa));
	119	/* Leave zeros in arp_tha */
	120	bcopy(&addr, ah->arp_tpa, sizeof(ah->arp_tpa));
	121
	122	/* Store ip address in cache (incomplete entry). */
	123	al->addr = addr;
	124
	125	i = sendrecv(d,
	126	arpsend, &wbuf.data, sizeof(wbuf.data),
	127	arprecv, &rbuf.data, sizeof(rbuf.data));
	128	if (i == -1) {
	129	panic("arp: no response for %s\n",
	130	inet_ntoa(addr));
	131	}
	132
	133	/* Store ethernet address in cache */
	134	ah = &rbuf.data.arp;
	135	#ifdef ARP_DEBUG
	136	if (debug) {
	137	printf("arp: response from %s\n",
	138	ether_sprintf(rbuf.eh.ether_shost));
	139	printf("arp: cacheing %s --> %s\n",
	140	inet_ntoa(addr), ether_sprintf(ah->arp_sha));
	141	}
	142	#endif
143	MACPY(ah->arp_sha, al->ea);
144	++arp_num;
145
146	return (al->ea);
147	}
148
149	static ssize_t
ff2aef30	150	arpsend(struct iodesc d, void pkt, size_t len)
984263bc MD	151	{
	152
	153	#ifdef ARP_DEBUG
	154	if (debug)
	155	printf("arpsend: called\n");
	156	#endif
	157
	158	return (sendether(d, pkt, len, bcea, ETHERTYPE_ARP));
	159	}
	160
	161	/*
	162	* Returns 0 if this is the packet we're waiting for
	163	* else -1 (and errno == 0)
	164	*/
	165	static ssize_t
ff2aef30	166	arprecv(struct iodesc d, void pkt, size_t len, time_t tleft)
984263bc	167	{
660c873b DR	168	ssize_t n;
660c873b DR	169	struct ether_arp *ah;
984263bc MD	170	u_int16_t etype; /* host order */
	171
	172	#ifdef ARP_DEBUG
	173	if (debug)
	174	printf("arprecv: ");
	175	#endif
	176
	177	n = readether(d, pkt, len, tleft, &etype);
	178	errno = 0; /* XXX */
	179	if (n == -1 \|\| n < sizeof(struct ether_arp)) {
	180	#ifdef ARP_DEBUG
	181	if (debug)
	182	printf("bad len=%d\n", n);
	183	#endif
	184	return (-1);
	185	}
	186
	187	if (etype != ETHERTYPE_ARP) {
	188	#ifdef ARP_DEBUG
	189	if (debug)
	190	printf("not arp type=%d\n", etype);
	191	#endif
	192	return (-1);
	193	}
	194
	195	/* Ethernet address now checked in readether() */
	196
	197	ah = (struct ether_arp *)pkt;
	198	if (ah->arp_hrd != htons(ARPHRD_ETHER) \|\|
	199	ah->arp_pro != htons(ETHERTYPE_IP) \|\|
	200	ah->arp_hln != sizeof(ah->arp_sha) \|\|
	201	ah->arp_pln != sizeof(ah->arp_spa) )
	202	{
	203	#ifdef ARP_DEBUG
	204	if (debug)
	205	printf("bad hrd/pro/hln/pln\n");
	206	#endif
	207	return (-1);
	208	}
	209
	210	if (ah->arp_op == htons(ARPOP_REQUEST)) {
	211	#ifdef ARP_DEBUG
	212	if (debug)
	213	printf("is request\n");
	214	#endif
	215	arp_reply(d, ah);
	216	return (-1);
	217	}
	218
	219	if (ah->arp_op != htons(ARPOP_REPLY)) {
	220	#ifdef ARP_DEBUG
	221	if (debug)
	222	printf("not ARP reply\n");
	223	#endif
	224	return (-1);
	225	}
	226
	227	/* Is the reply from the source we want? */
	228	if (bcmp(&arp_list[arp_num].addr,
	229	ah->arp_spa, sizeof(ah->arp_spa)))
	230	{
	231	#ifdef ARP_DEBUG
	232	if (debug)
	233	printf("unwanted address\n");
234	#endif
235	return (-1);
236	}
237	/* We don't care who the reply was sent to. */
238
239	/* We have our answer. */
240	#ifdef ARP_DEBUG
241	if (debug)
242	printf("got it\n");
243	#endif
244	return (n);
245	}
246
247	/*
248	* Convert an ARP request into a reply and send it.
249	* Notes: Re-uses buffer. Pad to length = 46.
ff2aef30 SW	250	*
	251	* Parameters:
	252	* pkt: the request
984263bc MD	253	*/
984263bc MD	254	void
ff2aef30	255	arp_reply(struct iodesc d, void pkt)
984263bc MD	256	{
	257	struct ether_arp *arp = pkt;
	258
	259	if (arp->arp_hrd != htons(ARPHRD_ETHER) \|\|
	260	arp->arp_pro != htons(ETHERTYPE_IP) \|\|
	261	arp->arp_hln != sizeof(arp->arp_sha) \|\|
	262	arp->arp_pln != sizeof(arp->arp_spa) )
	263	{
	264	#ifdef ARP_DEBUG
	265	if (debug)
	266	printf("arp_reply: bad hrd/pro/hln/pln\n");
	267	#endif
	268	return;
	269	}
	270
	271	if (arp->arp_op != htons(ARPOP_REQUEST)) {
	272	#ifdef ARP_DEBUG
	273	if (debug)
	274	printf("arp_reply: not request!\n");
	275	#endif
	276	return;
	277	}
	278
	279	/* If we are not the target, ignore the request. */
	280	if (bcmp(arp->arp_tpa, &d->myip, sizeof(arp->arp_tpa)))
	281	return;
	282
	283	#ifdef ARP_DEBUG
	284	if (debug) {
	285	printf("arp_reply: to %s\n", ether_sprintf(arp->arp_sha));
	286	}
	287	#endif
	288
	289	arp->arp_op = htons(ARPOP_REPLY);
	290	/* source becomes target */
	291	bcopy(arp->arp_sha, arp->arp_tha, sizeof(arp->arp_tha));
	292	bcopy(arp->arp_spa, arp->arp_tpa, sizeof(arp->arp_tpa));
	293	/* here becomes source */
	294	bcopy(d->myea, arp->arp_sha, sizeof(arp->arp_sha));
	295	bcopy(&d->myip, arp->arp_spa, sizeof(arp->arp_spa));
	296
	297	/*
	298	* No need to get fancy here. If the send fails, the
	299	* requestor will just ask again.
	300	*/
	301	(void) sendether(d, pkt, sizeof(*arp) + 18,
	302	arp->arp_tha, ETHERTYPE_ARP);
	303	}