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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
commitd6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch)
treeece253b876159b39c620e62b6c9b1174642e070e /sys/lib/libsa/arp.c
initial import of NetBSD tree
Diffstat (limited to 'sys/lib/libsa/arp.c')
-rw-r--r--sys/lib/libsa/arp.c306
1 files changed, 306 insertions, 0 deletions
diff --git a/sys/lib/libsa/arp.c b/sys/lib/libsa/arp.c
new file mode 100644
index 00000000000..de09484106b
--- /dev/null
+++ b/sys/lib/libsa/arp.c
@@ -0,0 +1,306 @@
+/* $NetBSD: arp.c,v 1.12 1995/09/27 23:14:57 pk 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/types.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 */
+
+static 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 }
+};
+static int arp_num = 1;
+
+/* Local forwards */
+static ssize_t arpsend __P((struct iodesc *, void *, size_t));
+static ssize_t arprecv __P((struct iodesc *, void *, size_t, time_t));
+
+/* Broadcast an ARP packet, asking who has addr on interface d */
+u_char *
+arpwhohas(d, addr)
+ register struct iodesc *d;
+ struct in_addr addr;
+{
+ register int i;
+ register struct ether_arp *ah;
+ register struct arp_list *al;
+ struct {
+ u_char header[ETHER_SIZE];
+ struct {
+ struct ether_arp arp;
+ u_char pad[18]; /* 60 - sizeof(arp) */
+ } data;
+ } wbuf;
+ struct {
+ u_char header[ETHER_SIZE];
+ struct {
+ struct ether_arp arp;
+ u_char pad[24]; /* extra space */
+ } data;
+ } rbuf;
+
+#ifdef ARP_DEBUG
+ if (debug)
+ printf("arpwhohas: called for %s\n", inet_ntoa(addr));
+#endif
+ /* 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)
+ panic("arpwhohas: overflowed arp_list!");
+
+#ifdef ARP_DEBUG
+ if (debug)
+ printf("arpwhohas: not cached\n");
+#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));
+ bcopy(&addr, ah->arp_tpa, sizeof(ah->arp_tpa));
+
+ /* Store ip address in cache */
+ al->addr = addr;
+
+ (void)sendrecv(d,
+ arpsend, &wbuf.data, sizeof(wbuf.data),
+ arprecv, &rbuf.data, sizeof(rbuf.data));
+
+ /* Store ethernet address in cache */
+ ah = &rbuf.data.arp;
+#ifdef ARP_DEBUG
+ if (debug)
+ printf("arp: cacheing %s --> %s\n",
+ intoa(ah->arp_spa),
+ ether_sprintf(ah->arp_sha));
+#endif
+ MACPY(ah->arp_sha, al->ea);
+ ++arp_num;
+
+ return (al->ea);
+}
+
+static ssize_t
+arpsend(d, pkt, len)
+ register struct iodesc *d;
+ register void *pkt;
+ register 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(d, pkt, len, tleft)
+ register struct iodesc *d;
+ register void *pkt;
+ register size_t len;
+ time_t tleft;
+{
+ register ssize_t n;
+ register 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.
+ */
+void
+arp_reply(d, pkt)
+ register struct iodesc *d;
+ register void *pkt; /* the request */
+{
+ 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);
+}