1 files changed, 289 insertions, 0 deletions
diff --git a/debian/grub-extras/disabled/gpxe/src/net/arp.c b/debian/grub-extras/disabled/gpxe/src/net/arp.c
new file mode 100644
index 0000000..124a856
--- /dev/null
+++ b/debian/grub-extras/disabled/gpxe/src/net/arp.c
@@ -0,0 +1,289 @@
+/*
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <string.h>
+#include <byteswap.h>
+#include <errno.h>
+#include <gpxe/if_ether.h>
+#include <gpxe/if_arp.h>
+#include <gpxe/iobuf.h>
+#include <gpxe/netdevice.h>
+#include <gpxe/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.
+ *
+ */
+
+/** An ARP cache entry */
+struct arp_entry {
+	/** Network-layer protocol */
+	struct net_protocol *net_protocol;
+	/** Link-layer protocol */
+	struct ll_protocol *ll_protocol;
+	/** Network-layer address */
+	uint8_t net_addr[MAX_NET_ADDR_LEN];
+	/** Link-layer address */
+	uint8_t ll_addr[MAX_LL_ADDR_LEN];
+};
+
+/** Number of entries in the ARP cache
+ *
+ * This is a global cache, covering all network interfaces,
+ * network-layer protocols and link-layer protocols.
+ */
+#define NUM_ARP_ENTRIES 4
+
+/** The ARP cache */
+static struct arp_entry arp_table[NUM_ARP_ENTRIES];
+#define arp_table_end &arp_table[NUM_ARP_ENTRIES]
+
+static unsigned int next_new_arp_entry = 0;
+
+struct net_protocol arp_protocol;
+
+/**
+ * Find entry in the ARP cache
+ *
+ * @v ll_protocol	Link-layer protocol
+ * @v net_protocol	Network-layer protocol
+ * @v net_addr		Network-layer address
+ * @ret arp		ARP cache entry, or NULL if not found
+ *
+ */
+static struct arp_entry *
+arp_find_entry ( struct ll_protocol *ll_protocol,
+		 struct net_protocol *net_protocol,
+		 const void *net_addr ) {
+	struct arp_entry *arp;
+
+	for ( arp = arp_table ; arp < arp_table_end ; arp++ ) {
+		if ( ( arp->ll_protocol == ll_protocol ) &&
+		     ( arp->net_protocol == net_protocol ) &&
+		     ( memcmp ( arp->net_addr, net_addr,
+				net_protocol->net_addr_len ) == 0 ) )
+			return arp;
+	}
+	return NULL;
+}
+
+/**
+ * Look up media-specific link-layer address in the ARP cache
+ *
+ * @v netdev		Network device
+ * @v net_protocol	Network-layer protocol
+ * @v dest_net_addr	Destination network-layer address
+ * @v source_net_addr	Source network-layer address
+ * @ret dest_ll_addr	Destination link layer address
+ * @ret rc		Return status code
+ *
+ * This function will use the ARP cache to look up the link-layer
+ * address for the link-layer protocol associated with the network
+ * device and the given network-layer protocol and addresses.  If
+ * found, the destination link-layer address will be filled in in @c
+ * dest_ll_addr.
+ *
+ * If no address is found in the ARP cache, an ARP request will be
+ * transmitted on the specified network device and -ENOENT will be
+ * returned.
+ */
+int arp_resolve ( struct net_device *netdev, struct net_protocol *net_protocol,
+		  const void *dest_net_addr, const void *source_net_addr,
+		  void *dest_ll_addr ) {
+	struct ll_protocol *ll_protocol = netdev->ll_protocol;
+	const struct arp_entry *arp;
+	struct io_buffer *iobuf;
+	struct arphdr *arphdr;
+	int rc;
+
+	/* Look for existing entry in ARP table */
+	arp = arp_find_entry ( ll_protocol, net_protocol, dest_net_addr );
+	if ( arp ) {
+		DBG ( "ARP cache hit: %s %s => %s %s\n",
+		      net_protocol->name, net_protocol->ntoa ( arp->net_addr ),
+		      ll_protocol->name, ll_protocol->ntoa ( arp->ll_addr ) );
+		memcpy ( dest_ll_addr, arp->ll_addr, ll_protocol->ll_addr_len);
+		return 0;
+	}
+	DBG ( "ARP cache miss: %s %s\n", net_protocol->name,
+	      net_protocol->ntoa ( dest_net_addr ) );
+
+	/* 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 ),
+		 source_net_addr, 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 ),
+		 dest_net_addr, net_protocol->net_addr_len );
+
+	/* Transmit ARP request */
+	if ( ( rc = net_tx ( iobuf, netdev, &arp_protocol, 
+			     netdev->ll_broadcast ) ) != 0 )
+		return rc;
+
+	return -ENOENT;
+}
+
+/**
+ * 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
+ * @ret rc		Return status code
+ *
+ * This handles ARP requests and responses as detailed in RFC826.  The
+ * method detailed within the RFC is pretty optimised, handling
+ * requests and responses with basically a single code path and
+ * avoiding the need for extraneous ARP requests; read the RFC for
+ * details.
+ */
+static int arp_rx ( struct io_buffer *iobuf, struct net_device *netdev,
+		    const void *ll_source __unused ) {
+	struct arphdr *arphdr = iobuf->data;
+	struct arp_net_protocol *arp_net_protocol;
+	struct net_protocol *net_protocol;
+	struct ll_protocol *ll_protocol;
+	struct arp_entry *arp;
+	int merge = 0;
+
+	/* Identify network-layer and link-layer protocols */
+	arp_net_protocol = arp_find_protocol ( arphdr->ar_pro );
+	if ( ! arp_net_protocol )
+		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 ) )
+		goto done;
+
+	/* See if we have an entry for this sender, and update it if so */
+	arp = arp_find_entry ( ll_protocol, net_protocol,
+			       arp_sender_pa ( arphdr ) );
+	if ( arp ) {
+		memcpy ( arp->ll_addr, arp_sender_ha ( arphdr ),
+			 arphdr->ar_hln );
+		merge = 1;
+		DBG ( "ARP cache update: %s %s => %s %s\n",
+		      net_protocol->name, net_protocol->ntoa ( arp->net_addr ),
+		      ll_protocol->name, ll_protocol->ntoa ( arp->ll_addr ) );
+	}
+
+	/* See if we own the target protocol address */
+	if ( arp_net_protocol->check ( netdev, arp_target_pa ( arphdr ) ) != 0)
+		goto done;
+	
+	/* Create new ARP table entry if necessary */
+	if ( ! merge ) {
+		arp = &arp_table[next_new_arp_entry++ % NUM_ARP_ENTRIES];
+		arp->ll_protocol = ll_protocol;
+		arp->net_protocol = net_protocol;
+		memcpy ( arp->ll_addr, arp_sender_ha ( arphdr ),
+			 arphdr->ar_hln );
+		memcpy ( arp->net_addr, arp_sender_pa ( arphdr ),
+			 arphdr->ar_pln);
+		DBG ( "ARP cache add: %s %s => %s %s\n",
+		      net_protocol->name, net_protocol->ntoa ( arp->net_addr ),
+		      ll_protocol->name, ll_protocol->ntoa ( arp->ll_addr ) );
+	}
+
+	/* If it's not a request, there's nothing more to do */
+	if ( arphdr->ar_op != htons ( ARPOP_REQUEST ) )
+		goto done;
+
+	/* Change request to a reply */
+	DBG ( "ARP reply: %s %s => %s %s\n", 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 */
+	net_tx ( iob_disown ( iobuf ), netdev, &arp_protocol,
+		 arp_target_ha ( arphdr ) );
+
+ done:
+	free_iob ( iobuf );
+	return 0;
+}
+
+/**
+ * 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 protocol */
+struct net_protocol arp_protocol __net_protocol = {
+	.name = "ARP",
+	.net_proto = htons ( ETH_P_ARP ),
+	.rx = arp_rx,
+	.ntoa = arp_ntoa,
+};