--- /dev/null
+/*
+ * 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,
+};
Code Review / kvmfornfv.git / blobdiff