1 files changed, 220 insertions, 0 deletions
diff --git a/roms/ipxe/src/net/arp.c b/roms/ipxe/src/net/arp.c
new file mode 100644
index 00000000..261e681e
--- /dev/null
+++ b/roms/ipxe/src/net/arp.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <byteswap.h>
+#include <errno.h>
+#include <ipxe/if_ether.h>
+#include <ipxe/if_arp.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/neighbour.h>
+#include <ipxe/arp.h>
+
+/** @file
+ *
+ * Address Resolution Protocol
+ *
+ * This file implements the address resolution protocol as defined in
+ * RFC826.  The implementation is media-independent and
+ * protocol-independent; it is not limited to Ethernet or to IPv4.
+ *
+ */
+
+struct net_protocol arp_protocol __net_protocol;
+
+/**
+ * Transmit ARP request
+ *
+ * @v netdev		Network device
+ * @v net_protocol	Network-layer protocol
+ * @v net_dest		Destination network-layer address
+ * @v net_source	Source network-layer address
+ * @ret rc		Return status code
+ */
+static int arp_tx_request ( struct net_device *netdev,
+			    struct net_protocol *net_protocol,
+			    const void *net_dest, const void *net_source ) {
+	struct ll_protocol *ll_protocol = netdev->ll_protocol;
+	struct io_buffer *iobuf;
+	struct arphdr *arphdr;
+	int rc;
+
+	/* Allocate ARP packet */
+	iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *arphdr ) +
+			    ( 2 * ( MAX_LL_ADDR_LEN + MAX_NET_ADDR_LEN ) ) );
+	if ( ! iobuf )
+		return -ENOMEM;
+	iob_reserve ( iobuf, MAX_LL_HEADER_LEN );
+
+	/* Build up ARP request */
+	arphdr = iob_put ( iobuf, sizeof ( *arphdr ) );
+	arphdr->ar_hrd = ll_protocol->ll_proto;
+	arphdr->ar_hln = ll_protocol->ll_addr_len;
+	arphdr->ar_pro = net_protocol->net_proto;
+	arphdr->ar_pln = net_protocol->net_addr_len;
+	arphdr->ar_op = htons ( ARPOP_REQUEST );
+	memcpy ( iob_put ( iobuf, ll_protocol->ll_addr_len ),
+		 netdev->ll_addr, ll_protocol->ll_addr_len );
+	memcpy ( iob_put ( iobuf, net_protocol->net_addr_len ),
+		 net_source, net_protocol->net_addr_len );
+	memset ( iob_put ( iobuf, ll_protocol->ll_addr_len ),
+		 0, ll_protocol->ll_addr_len );
+	memcpy ( iob_put ( iobuf, net_protocol->net_addr_len ),
+		 net_dest, net_protocol->net_addr_len );
+
+	/* Transmit ARP request */
+	if ( ( rc = net_tx ( iobuf, netdev, &arp_protocol,
+			     netdev->ll_broadcast, netdev->ll_addr ) ) != 0 ) {
+		DBGC ( netdev, "ARP %s %s %s could not transmit request: %s\n",
+		       netdev->name, net_protocol->name,
+		       net_protocol->ntoa ( net_dest ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/** ARP neighbour discovery protocol */
+struct neighbour_discovery arp_discovery = {
+	.name = "ARP",
+	.tx_request = arp_tx_request,
+};
+
+/**
+ * Identify ARP protocol
+ *
+ * @v net_proto			Network-layer protocol, in network-endian order
+ * @ret arp_net_protocol	ARP protocol, or NULL
+ *
+ */
+static struct arp_net_protocol * arp_find_protocol ( uint16_t net_proto ) {
+	struct arp_net_protocol *arp_net_protocol;
+
+	for_each_table_entry ( arp_net_protocol, ARP_NET_PROTOCOLS ) {
+		if ( arp_net_protocol->net_protocol->net_proto == net_proto )
+			return arp_net_protocol;
+	}
+	return NULL;
+}
+
+/**
+ * Process incoming ARP packets
+ *
+ * @v iobuf		I/O buffer
+ * @v netdev		Network device
+ * @v ll_source		Link-layer source address
+ * @v flags		Packet flags
+ * @ret rc		Return status code
+ */
+static int arp_rx ( struct io_buffer *iobuf, struct net_device *netdev,
+		    const void *ll_dest __unused,
+		    const void *ll_source __unused,
+		    unsigned int flags __unused ) {
+	struct arphdr *arphdr = iobuf->data;
+	struct arp_net_protocol *arp_net_protocol;
+	struct net_protocol *net_protocol;
+	struct ll_protocol *ll_protocol;
+	int rc;
+
+	/* Identify network-layer and link-layer protocols */
+	arp_net_protocol = arp_find_protocol ( arphdr->ar_pro );
+	if ( ! arp_net_protocol ) {
+		rc = -EPROTONOSUPPORT;
+		goto done;
+	}
+	net_protocol = arp_net_protocol->net_protocol;
+	ll_protocol = netdev->ll_protocol;
+
+	/* Sanity checks */
+	if ( ( arphdr->ar_hrd != ll_protocol->ll_proto ) ||
+	     ( arphdr->ar_hln != ll_protocol->ll_addr_len ) ||
+	     ( arphdr->ar_pln != net_protocol->net_addr_len ) ) {
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Update neighbour cache entry for this sender, if any */
+	neighbour_update ( netdev, net_protocol, arp_sender_pa ( arphdr ),
+			   arp_sender_ha ( arphdr ) );
+
+	/* If it's not a request, there's nothing more to do */
+	if ( arphdr->ar_op != htons ( ARPOP_REQUEST ) ) {
+		rc = 0;
+		goto done;
+	}
+
+	/* See if we own the target protocol address */
+	if ( arp_net_protocol->check ( netdev, arp_target_pa ( arphdr ) ) != 0){
+		rc = 0;
+		goto done;
+	}
+
+	/* Change request to a reply */
+	DBGC2 ( netdev, "ARP %s %s %s reply => %s %s\n",
+		netdev->name, net_protocol->name,
+		net_protocol->ntoa ( arp_target_pa ( arphdr ) ),
+		ll_protocol->name, ll_protocol->ntoa ( netdev->ll_addr ) );
+	arphdr->ar_op = htons ( ARPOP_REPLY );
+	memswap ( arp_sender_ha ( arphdr ), arp_target_ha ( arphdr ),
+		 arphdr->ar_hln + arphdr->ar_pln );
+	memcpy ( arp_sender_ha ( arphdr ), netdev->ll_addr, arphdr->ar_hln );
+
+	/* Send reply */
+	if ( ( rc = net_tx ( iob_disown ( iobuf ), netdev, &arp_protocol,
+			     arp_target_ha ( arphdr ),
+			     netdev->ll_addr ) ) != 0 ) {
+		DBGC ( netdev, "ARP %s %s %s could not transmit reply: %s\n",
+		       netdev->name, net_protocol->name,
+		       net_protocol->ntoa ( arp_target_pa ( arphdr ) ),
+		       strerror ( rc ) );
+		goto done;
+	}
+
+	/* Success */
+	rc = 0;
+
+ done:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/**
+ * Transcribe ARP address
+ *
+ * @v net_addr	ARP address
+ * @ret string	"<ARP>"
+ *
+ * This operation is meaningless for the ARP protocol.
+ */
+static const char * arp_ntoa ( const void *net_addr __unused ) {
+	return "<ARP>";
+}
+
+/** ARP network protocol */
+struct net_protocol arp_protocol __net_protocol = {
+	.name = "ARP",
+	.net_proto = htons ( ETH_P_ARP ),
+	.rx = arp_rx,
+	.ntoa = arp_ntoa,
+};