#include <ipxe/tables.h>
#include <ipxe/netdevice.h>
+#include <ipxe/neighbour.h>
/** A network-layer protocol that relies upon ARP */
struct arp_net_protocol {
#define __arp_net_protocol __table_entry ( ARP_NET_PROTOCOLS, 01 )
extern struct net_protocol arp_protocol __net_protocol;
+extern struct neighbour_discovery arp_discovery;
-extern int arp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
- struct net_protocol *net_protocol, const void *net_dest,
- const void *net_source, const void *ll_source );
+/**
+ * Transmit packet, determining link-layer address via ARP
+ *
+ * @v iobuf I/O buffer
+ * @v netdev Network device
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @v net_source Source network-layer address
+ * @v ll_source Source link-layer address
+ * @ret rc Return status code
+ */
+static inline int arp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *net_source,
+ const void *ll_source ) {
+
+ return neighbour_tx ( iobuf, netdev, net_protocol, net_dest,
+ &arp_discovery, net_source, ll_source );
+}
#endif /* _IPXE_ARP_H */
#define ERRFILE_nfs_open ( ERRFILE_NET | 0x00340000 )
#define ERRFILE_mount ( ERRFILE_NET | 0x00350000 )
#define ERRFILE_oncrpc_iob ( ERRFILE_NET | 0x00360000 )
+#define ERRFILE_neighbour ( ERRFILE_NET | 0x00370000 )
#define ERRFILE_image ( ERRFILE_IMAGE | 0x00000000 )
#define ERRFILE_elf ( ERRFILE_IMAGE | 0x00010000 )
--- /dev/null
+#ifndef _IPXE_NEIGHBOUR_H
+#define _IPXE_NEIGHBOUR_H
+
+/** @file
+ *
+ * Neighbour discovery
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <ipxe/netdevice.h>
+
+/** A neighbour discovery protocol */
+struct neighbour_discovery {
+ /** Name */
+ const char *name;
+ /**
+ * Transmit neighbour discovery 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
+ */
+ int ( * tx_request ) ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *net_source );
+};
+
+extern int neighbour_tx ( struct io_buffer *iobuf, struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest,
+ struct neighbour_discovery *discovery,
+ const void *net_source, const void *ll_source );
+extern int neighbour_update ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *ll_dest );
+extern int neighbour_define ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *ll_dest );
+
+#endif /* _IPXE_NEIGHBOUR_H */
#include <ipxe/if_arp.h>
#include <ipxe/iobuf.h>
#include <ipxe/netdevice.h>
-#include <ipxe/list.h>
-#include <ipxe/retry.h>
-#include <ipxe/timer.h>
-#include <ipxe/malloc.h>
-#include <ipxe/refcnt.h>
+#include <ipxe/neighbour.h>
#include <ipxe/arp.h>
/** @file
*
*/
-/** ARP minimum timeout */
-#define ARP_MIN_TIMEOUT ( TICKS_PER_SEC / 8 )
-
-/** ARP maximum timeout */
-#define ARP_MAX_TIMEOUT ( TICKS_PER_SEC * 3 )
-
-/** An ARP cache entry */
-struct arp_entry {
- /** Reference count */
- struct refcnt refcnt;
- /** List of ARP cache entries */
- struct list_head list;
- /** Network device */
- struct net_device *netdev;
- /** Network-layer protocol */
- struct net_protocol *net_protocol;
- /** Network-layer destination address */
- uint8_t net_dest[MAX_NET_ADDR_LEN];
- /** Network-layer source address */
- uint8_t net_source[MAX_NET_ADDR_LEN];
- /** Link-layer destination address */
- uint8_t ll_dest[MAX_LL_ADDR_LEN];
- /** Retransmission timer */
- struct retry_timer timer;
- /** Pending I/O buffers */
- struct list_head tx_queue;
-};
-
-/** The ARP cache */
-static LIST_HEAD ( arp_entries );
-
struct net_protocol arp_protocol __net_protocol;
-static void arp_expired ( struct retry_timer *timer, int over );
-
-/**
- * Free ARP cache entry
- *
- * @v refcnt Reference count
- */
-static void arp_free ( struct refcnt *refcnt ) {
- struct arp_entry *arp =
- container_of ( refcnt, struct arp_entry, refcnt );
-
- /* Sanity check */
- assert ( list_empty ( &arp->tx_queue ) );
-
- /* Drop reference to network device */
- netdev_put ( arp->netdev );
-
- /* Free entry */
- free ( arp );
-}
-
-/**
- * Create ARP cache entry
- *
- * @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 arp ARP cache entry, or NULL if allocation failed
- */
-static struct arp_entry * arp_create ( struct net_device *netdev,
- struct net_protocol *net_protocol,
- const void *net_dest,
- const void *net_source ) {
- struct arp_entry *arp;
-
- /* Allocate and initialise entry */
- arp = zalloc ( sizeof ( *arp ) );
- if ( ! arp )
- return NULL;
- ref_init ( &arp->refcnt, arp_free );
- arp->netdev = netdev_get ( netdev );
- arp->net_protocol = net_protocol;
- memcpy ( arp->net_dest, net_dest,
- net_protocol->net_addr_len );
- memcpy ( arp->net_source, net_source,
- net_protocol->net_addr_len );
- timer_init ( &arp->timer, arp_expired, &arp->refcnt );
- arp->timer.min_timeout = ARP_MIN_TIMEOUT;
- arp->timer.max_timeout = ARP_MAX_TIMEOUT;
- INIT_LIST_HEAD ( &arp->tx_queue );
-
- /* Start timer running to trigger initial transmission */
- start_timer_nodelay ( &arp->timer );
-
- /* Transfer ownership to cache */
- list_add ( &arp->list, &arp_entries );
-
- DBGC ( arp, "ARP %p %s %s %s created\n", arp, netdev->name,
- net_protocol->name, net_protocol->ntoa ( net_dest ) );
- return arp;
-}
-
-/**
- * Find entry in the ARP cache
- *
- * @v netdev Network device
- * @v net_protocol Network-layer protocol
- * @v net_dest Destination network-layer address
- * @ret arp ARP cache entry, or NULL if not found
- */
-static struct arp_entry * arp_find ( struct net_device *netdev,
- struct net_protocol *net_protocol,
- const void *net_dest ) {
- struct arp_entry *arp;
-
- list_for_each_entry ( arp, &arp_entries, list ) {
- if ( ( arp->netdev == netdev ) &&
- ( arp->net_protocol == net_protocol ) &&
- ( memcmp ( arp->net_dest, net_dest,
- net_protocol->net_addr_len ) == 0 ) ) {
-
- /* Move to start of cache */
- list_del ( &arp->list );
- list_add ( &arp->list, &arp_entries );
-
- return arp;
- }
- }
- return NULL;
-}
-
-/**
- * Destroy ARP cache entry
- *
- * @v arp ARP cache entry
- * @v rc Reason for destruction
- */
-static void arp_destroy ( struct arp_entry *arp, int rc ) {
- struct net_device *netdev = arp->netdev;
- struct net_protocol *net_protocol = arp->net_protocol;
- struct io_buffer *iobuf;
-
- /* Take ownership from cache */
- list_del ( &arp->list );
-
- /* Stop timer */
- stop_timer ( &arp->timer );
-
- /* Discard any outstanding I/O buffers */
- while ( ( iobuf = list_first_entry ( &arp->tx_queue, struct io_buffer,
- list ) ) != NULL ) {
- DBGC2 ( arp, "ARP %p %s %s %s discarding deferred packet: "
- "%s\n", arp, netdev->name, net_protocol->name,
- net_protocol->ntoa ( arp->net_dest ), strerror ( rc ) );
- list_del ( &iobuf->list );
- netdev_tx_err ( arp->netdev, iobuf, rc );
- }
-
- DBGC ( arp, "ARP %p %s %s %s destroyed: %s\n", arp, netdev->name,
- net_protocol->name, net_protocol->ntoa ( arp->net_dest ),
- strerror ( rc ) );
-
- /* Drop remaining reference */
- ref_put ( &arp->refcnt );
-}
-
/**
- * Test if ARP cache entry has a valid link-layer address
+ * Transmit ARP request
*
- * @v arp ARP cache entry
- * @ret resolved ARP cache entry is resolved
- */
-static inline int arp_resolved ( struct arp_entry *arp ) {
- return ( ! timer_running ( &arp->timer ) );
-}
-
-/**
- * Transmit packet, determining link-layer address via ARP
- *
- * @v iobuf I/O buffer
* @v netdev Network device
* @v net_protocol Network-layer protocol
* @v net_dest Destination network-layer address
* @v net_source Source network-layer address
- * @v ll_source Source link-layer address
* @ret rc Return status code
*/
-int arp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
- struct net_protocol *net_protocol, const void *net_dest,
- const void *net_source, const void *ll_source ) {
- struct arp_entry *arp;
-
- /* Find or create ARP cache entry */
- arp = arp_find ( netdev, net_protocol, net_dest );
- if ( ! arp ) {
- arp = arp_create ( netdev, net_protocol, net_dest,
- net_source );
- if ( ! arp )
- return -ENOMEM;
- }
-
- /* If a link-layer address is available then transmit
- * immediately, otherwise queue for later transmission.
- */
- if ( arp_resolved ( arp ) ) {
- return net_tx ( iobuf, netdev, net_protocol, arp->ll_dest,
- ll_source );
- } else {
- DBGC2 ( arp, "ARP %p %s %s %s deferring packet\n",
- arp, netdev->name, net_protocol->name,
- net_protocol->ntoa ( net_dest ) );
- list_add_tail ( &iobuf->list, &arp->tx_queue );
- return -EAGAIN;
- }
-}
-
-/**
- * Update ARP cache entry
- *
- * @v arp ARP cache entry
- * @v ll_dest Destination link-layer address
- */
-static void arp_update ( struct arp_entry *arp, const void *ll_dest ) {
- struct net_device *netdev = arp->netdev;
- struct ll_protocol *ll_protocol = netdev->ll_protocol;
- struct net_protocol *net_protocol = arp->net_protocol;
- struct io_buffer *iobuf;
- int rc;
-
- DBGC ( arp, "ARP %p %s %s %s updated => %s\n", arp, netdev->name,
- net_protocol->name, net_protocol->ntoa ( arp->net_dest ),
- ll_protocol->ntoa ( ll_dest ) );
-
- /* Fill in link-layer address */
- memcpy ( arp->ll_dest, ll_dest, ll_protocol->ll_addr_len );
-
- /* Stop retransmission timer */
- stop_timer ( &arp->timer );
-
- /* Transmit any packets in queue. Take out a temporary
- * reference on the entry to prevent it from going out of
- * scope during the call to net_tx().
- */
- ref_get ( &arp->refcnt );
- while ( ( iobuf = list_first_entry ( &arp->tx_queue, struct io_buffer,
- list ) ) != NULL ) {
- DBGC2 ( arp, "ARP %p %s %s %s transmitting deferred packet\n",
- arp, netdev->name, net_protocol->name,
- net_protocol->ntoa ( arp->net_dest ) );
- list_del ( &iobuf->list );
- if ( ( rc = net_tx ( iobuf, netdev, net_protocol, ll_dest,
- netdev->ll_addr ) ) != 0 ) {
- DBGC ( arp, "ARP %p could not transmit deferred "
- "packet: %s\n", arp, strerror ( rc ) );
- /* Ignore error and continue */
- }
- }
- ref_put ( &arp->refcnt );
-}
-
-/**
- * Handle ARP timer expiry
- *
- * @v timer Retry timer
- * @v fail Failure indicator
- */
-static void arp_expired ( struct retry_timer *timer, int fail ) {
- struct arp_entry *arp = container_of ( timer, struct arp_entry, timer );
- struct net_device *netdev = arp->netdev;
+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 net_protocol *net_protocol = arp->net_protocol;
struct io_buffer *iobuf;
struct arphdr *arphdr;
int rc;
- /* If we have failed, destroy the cache entry */
- if ( fail ) {
- arp_destroy ( arp, -ETIMEDOUT );
- return;
- }
-
- /* Restart the timer */
- start_timer ( &arp->timer );
-
/* Allocate ARP packet */
iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *arphdr ) +
( 2 * ( MAX_LL_ADDR_LEN + MAX_NET_ADDR_LEN ) ) );
- if ( ! iobuf ) {
- /* Leave timer running and try again later */
- return;
- }
+ if ( ! iobuf )
+ return -ENOMEM;
iob_reserve ( iobuf, MAX_LL_HEADER_LEN );
/* Build up ARP 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 ),
- arp->net_source, 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 ),
- arp->net_dest, 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 ( arp, "ARP %p could not transmit request: %s\n",
- arp, strerror ( rc ) );
- return;
+ 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
*
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 ) {
+ if ( arp_net_protocol->net_protocol->net_proto == net_proto )
return arp_net_protocol;
- }
}
return NULL;
}
struct arp_net_protocol *arp_net_protocol;
struct net_protocol *net_protocol;
struct ll_protocol *ll_protocol;
- struct arp_entry *arp;
int rc;
/* Identify network-layer and link-layer protocols */
goto done;
}
- /* See if we have an entry for this sender, and update it if so */
- arp = arp_find ( netdev, net_protocol, arp_sender_pa ( arphdr ) );
- if ( arp ) {
- arp_update ( arp, arp_sender_ha ( arphdr ) );
- }
+ /* 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 ) ) {
}
/* Change request to a reply */
- DBGC ( netdev, "ARP reply %s %s %s => %s %s\n",
- netdev->name, net_protocol->name,
- net_protocol->ntoa ( arp_target_pa ( arphdr ) ),
- ll_protocol->name, ll_protocol->ntoa ( netdev->ll_addr ) );
+ 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 );
if ( ( rc = net_tx ( iob_disown ( iobuf ), netdev, &arp_protocol,
arp_target_ha ( arphdr ),
netdev->ll_addr ) ) != 0 ) {
- DBGC ( netdev, "ARP could not transmit reply via %s: %s\n",
- netdev->name, strerror ( rc ) );
+ 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;
}
return "<ARP>";
}
-/** ARP protocol */
+/** ARP network protocol */
struct net_protocol arp_protocol __net_protocol = {
.name = "ARP",
.net_proto = htons ( ETH_P_ARP ),
.rx = arp_rx,
.ntoa = arp_ntoa,
};
-
-/**
- * Update ARP cache on network device creation
- *
- * @v netdev Network device
- */
-static int arp_probe ( struct net_device *netdev __unused ) {
- /* Nothing to do */
- return 0;
-}
-
-/**
- * Update ARP cache on network device state change or removal
- *
- * @v netdev Network device
- */
-static void arp_flush ( struct net_device *netdev ) {
- struct arp_entry *arp;
- struct arp_entry *tmp;
-
- /* Remove all ARP cache entries when a network device is closed */
- if ( ! netdev_is_open ( netdev ) ) {
- list_for_each_entry_safe ( arp, tmp, &arp_entries, list )
- arp_destroy ( arp, -ENODEV );
- }
-}
-
-/** ARP driver (for net device notifications) */
-struct net_driver arp_net_driver __net_driver = {
- .name = "ARP",
- .probe = arp_probe,
- .notify = arp_flush,
- .remove = arp_flush,
-};
-
-/**
- * Discard some cached ARP entries
- *
- * @ret discarded Number of cached items discarded
- */
-static unsigned int arp_discard ( void ) {
- struct arp_entry *arp;
-
- /* Drop oldest cache entry, if any */
- arp = list_last_entry ( &arp_entries, struct arp_entry, list );
- if ( arp ) {
- arp_destroy ( arp, -ENOBUFS );
- return 1;
- } else {
- return 0;
- }
-}
-
-/** ARP cache discarder
- *
- * ARP cache entries are deemed to have a high replacement cost, since
- * flushing an active ARP cache entry midway through a TCP transfer
- * will cause substantial disruption.
- */
-struct cache_discarder arp_discarder __cache_discarder ( CACHE_EXPENSIVE ) = {
- .discard = arp_discard,
-};
--- /dev/null
+/*
+ * Copyright (C) 2013 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 <errno.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/list.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/retry.h>
+#include <ipxe/timer.h>
+#include <ipxe/malloc.h>
+#include <ipxe/neighbour.h>
+
+/** @file
+ *
+ * Neighbour discovery
+ *
+ * This file implements the abstract functions of neighbour discovery,
+ * independent of the underlying network protocol (e.g. ARP or NDP).
+ *
+ */
+
+/** A neighbour cache entry */
+struct neighbour {
+ /** Reference count */
+ struct refcnt refcnt;
+ /** List of neighbour cache entries */
+ struct list_head list;
+
+ /** Network device */
+ struct net_device *netdev;
+ /** Network-layer protocol */
+ struct net_protocol *net_protocol;
+ /** Network-layer destination address */
+ uint8_t net_dest[MAX_NET_ADDR_LEN];
+ /** Link-layer destination address */
+ uint8_t ll_dest[MAX_LL_ADDR_LEN];
+
+ /** Neighbour discovery protocol (if any) */
+ struct neighbour_discovery *discovery;
+ /** Network-layer source address (if any) */
+ uint8_t net_source[MAX_NET_ADDR_LEN];
+ /** Retransmission timer */
+ struct retry_timer timer;
+
+ /** Pending I/O buffers */
+ struct list_head tx_queue;
+};
+
+/** Neighbour discovery minimum timeout */
+#define NEIGHBOUR_MIN_TIMEOUT ( TICKS_PER_SEC / 8 )
+
+/** Neighbour discovery maximum timeout */
+#define NEIGHBOUR_MAX_TIMEOUT ( TICKS_PER_SEC * 3 )
+
+/** The neighbour cache */
+static LIST_HEAD ( neighbours );
+
+static void neighbour_expired ( struct retry_timer *timer, int over );
+
+/**
+ * Free neighbour cache entry
+ *
+ * @v refcnt Reference count
+ */
+static void neighbour_free ( struct refcnt *refcnt ) {
+ struct neighbour *neighbour =
+ container_of ( refcnt, struct neighbour, refcnt );
+
+ /* Sanity check */
+ assert ( list_empty ( &neighbour->tx_queue ) );
+
+ /* Drop reference to network device */
+ netdev_put ( neighbour->netdev );
+
+ /* Free neighbour */
+ free ( neighbour );
+}
+
+/**
+ * Test if neighbour cache entry has a valid link-layer address
+ *
+ * @v neighbour Neighbour cache entry
+ * @ret has_ll_dest Neighbour cache entry has a valid link-layer address
+ */
+static inline __attribute__ (( always_inline )) int
+neighbour_has_ll_dest ( struct neighbour *neighbour ) {
+ return ( ! timer_running ( &neighbour->timer ) );
+}
+
+/**
+ * Create neighbour cache entry
+ *
+ * @v netdev Network device
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @ret neighbour Neighbour cache entry, or NULL if allocation failed
+ */
+static struct neighbour * neighbour_create ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest ) {
+ struct neighbour *neighbour;
+
+ /* Allocate and initialise entry */
+ neighbour = zalloc ( sizeof ( *neighbour ) );
+ if ( ! neighbour )
+ return NULL;
+ ref_init ( &neighbour->refcnt, neighbour_free );
+ neighbour->netdev = netdev_get ( netdev );
+ neighbour->net_protocol = net_protocol;
+ memcpy ( neighbour->net_dest, net_dest,
+ net_protocol->net_addr_len );
+ timer_init ( &neighbour->timer, neighbour_expired, &neighbour->refcnt );
+ neighbour->timer.min_timeout = NEIGHBOUR_MIN_TIMEOUT;
+ neighbour->timer.max_timeout = NEIGHBOUR_MAX_TIMEOUT;
+ INIT_LIST_HEAD ( &neighbour->tx_queue );
+
+ /* Transfer ownership to cache */
+ list_add ( &neighbour->list, &neighbours );
+
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s created\n", netdev->name,
+ net_protocol->name, net_protocol->ntoa ( net_dest ) );
+ return neighbour;
+}
+
+/**
+ * Find neighbour cache entry
+ *
+ * @v netdev Network device
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @ret neighbour Neighbour cache entry, or NULL if not found
+ */
+static struct neighbour * neighbour_find ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest ) {
+ struct neighbour *neighbour;
+
+ list_for_each_entry ( neighbour, &neighbours, list ) {
+ if ( ( neighbour->netdev == netdev ) &&
+ ( neighbour->net_protocol == net_protocol ) &&
+ ( memcmp ( neighbour->net_dest, net_dest,
+ net_protocol->net_addr_len ) == 0 ) ) {
+
+ /* Move to start of cache */
+ list_del ( &neighbour->list );
+ list_add ( &neighbour->list, &neighbours );
+
+ return neighbour;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * Start neighbour discovery
+ *
+ * @v neighbour Neighbour cache entry
+ * @v discovery Neighbour discovery protocol
+ * @v net_source Source network-layer address
+ */
+static void neighbour_discover ( struct neighbour *neighbour,
+ struct neighbour_discovery *discovery,
+ const void *net_source ) {
+ struct net_device *netdev = neighbour->netdev;
+ struct net_protocol *net_protocol = neighbour->net_protocol;
+
+ /* Record discovery protocol and source network-layer address */
+ neighbour->discovery = discovery;
+ memcpy ( neighbour->net_source, net_source,
+ net_protocol->net_addr_len );
+
+ /* Start timer to trigger neighbour discovery */
+ start_timer_nodelay ( &neighbour->timer );
+
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s discovering via %s\n",
+ netdev->name, net_protocol->name,
+ net_protocol->ntoa ( neighbour->net_dest ),
+ neighbour->discovery->name );
+}
+
+/**
+ * Complete neighbour discovery
+ *
+ * @v neighbour Neighbour cache entry
+ * @v ll_dest Destination link-layer address
+ */
+static void neighbour_discovered ( struct neighbour *neighbour,
+ const void *ll_dest ) {
+ struct net_device *netdev = neighbour->netdev;
+ struct ll_protocol *ll_protocol = netdev->ll_protocol;
+ struct net_protocol *net_protocol = neighbour->net_protocol;
+ struct io_buffer *iobuf;
+ int rc;
+
+ /* Fill in link-layer address */
+ memcpy ( neighbour->ll_dest, ll_dest, ll_protocol->ll_addr_len );
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s is %s %s\n", netdev->name,
+ net_protocol->name, net_protocol->ntoa ( neighbour->net_dest ),
+ ll_protocol->name, ll_protocol->ntoa ( neighbour->ll_dest ) );
+
+ /* Stop retransmission timer */
+ stop_timer ( &neighbour->timer );
+
+ /* Transmit any packets in queue. Take out a temporary
+ * reference on the entry to prevent it from going out of
+ * scope during the call to net_tx().
+ */
+ ref_get ( &neighbour->refcnt );
+ while ( ( iobuf = list_first_entry ( &neighbour->tx_queue,
+ struct io_buffer, list )) != NULL){
+ DBGC2 ( neighbour, "NEIGHBOUR %s %s %s transmitting deferred "
+ "packet\n", netdev->name, net_protocol->name,
+ net_protocol->ntoa ( neighbour->net_dest ) );
+ list_del ( &iobuf->list );
+ if ( ( rc = net_tx ( iobuf, netdev, net_protocol, ll_dest,
+ netdev->ll_addr ) ) != 0 ) {
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s could not "
+ "transmit deferred packet: %s\n",
+ netdev->name, net_protocol->name,
+ net_protocol->ntoa ( neighbour->net_dest ),
+ strerror ( rc ) );
+ /* Ignore error and continue */
+ }
+ }
+ ref_put ( &neighbour->refcnt );
+}
+
+/**
+ * Destroy neighbour cache entry
+ *
+ * @v neighbour Neighbour cache entry
+ * @v rc Reason for destruction
+ */
+static void neighbour_destroy ( struct neighbour *neighbour, int rc ) {
+ struct net_device *netdev = neighbour->netdev;
+ struct net_protocol *net_protocol = neighbour->net_protocol;
+ struct io_buffer *iobuf;
+
+ /* Take ownership from cache */
+ list_del ( &neighbour->list );
+
+ /* Stop timer */
+ stop_timer ( &neighbour->timer );
+
+ /* Discard any outstanding I/O buffers */
+ while ( ( iobuf = list_first_entry ( &neighbour->tx_queue,
+ struct io_buffer, list )) != NULL){
+ DBGC2 ( neighbour, "NEIGHBOUR %s %s %s discarding deferred "
+ "packet: %s\n", netdev->name, net_protocol->name,
+ net_protocol->ntoa ( neighbour->net_dest ),
+ strerror ( rc ) );
+ list_del ( &iobuf->list );
+ netdev_tx_err ( neighbour->netdev, iobuf, rc );
+ }
+
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s destroyed: %s\n", netdev->name,
+ net_protocol->name, net_protocol->ntoa ( neighbour->net_dest ),
+ strerror ( rc ) );
+
+ /* Drop remaining reference */
+ ref_put ( &neighbour->refcnt );
+}
+
+/**
+ * Handle neighbour timer expiry
+ *
+ * @v timer Retry timer
+ * @v fail Failure indicator
+ */
+static void neighbour_expired ( struct retry_timer *timer, int fail ) {
+ struct neighbour *neighbour =
+ container_of ( timer, struct neighbour, timer );
+ struct net_device *netdev = neighbour->netdev;
+ struct net_protocol *net_protocol = neighbour->net_protocol;
+ struct neighbour_discovery *discovery =
+ neighbour->discovery;
+ const void *net_dest = neighbour->net_dest;
+ const void *net_source = neighbour->net_source;
+ int rc;
+
+ /* If we have failed, destroy the cache entry */
+ if ( fail ) {
+ neighbour_destroy ( neighbour, -ETIMEDOUT );
+ return;
+ }
+
+ /* Restart the timer */
+ start_timer ( &neighbour->timer );
+
+ /* Transmit neighbour request */
+ if ( ( rc = discovery->tx_request ( netdev, net_protocol, net_dest,
+ net_source ) ) != 0 ) {
+ DBGC ( neighbour, "NEIGHBOUR %s %s %s could not transmit %s "
+ "request: %s\n", netdev->name, net_protocol->name,
+ net_protocol->ntoa ( neighbour->net_dest ),
+ neighbour->discovery->name, strerror ( rc ) );
+ /* Retransmit when timer expires */
+ return;
+ }
+}
+
+/**
+ * Transmit packet, determining link-layer address via neighbour discovery
+ *
+ * @v iobuf I/O buffer
+ * @v netdev Network device
+ * @v discovery Neighbour discovery protocol
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @v net_source Source network-layer address
+ * @v ll_source Source link-layer address
+ * @ret rc Return status code
+ */
+int neighbour_tx ( struct io_buffer *iobuf, struct net_device *netdev,
+ struct net_protocol *net_protocol, const void *net_dest,
+ struct neighbour_discovery *discovery,
+ const void *net_source, const void *ll_source ) {
+ struct neighbour *neighbour;
+
+ /* Find or create neighbour cache entry */
+ neighbour = neighbour_find ( netdev, net_protocol, net_dest );
+ if ( ! neighbour ) {
+ neighbour = neighbour_create ( netdev, net_protocol, net_dest );
+ if ( ! neighbour )
+ return -ENOMEM;
+ neighbour_discover ( neighbour, discovery, net_source );
+ }
+
+ /* If a link-layer address is available then transmit
+ * immediately, otherwise queue for later transmission.
+ */
+ if ( neighbour_has_ll_dest ( neighbour ) ) {
+ return net_tx ( iobuf, netdev, net_protocol, neighbour->ll_dest,
+ ll_source );
+ } else {
+ DBGC2 ( neighbour, "NEIGHBOUR %s %s %s deferring packet\n",
+ netdev->name, net_protocol->name,
+ net_protocol->ntoa ( net_dest ) );
+ list_add_tail ( &iobuf->list, &neighbour->tx_queue );
+ return -EAGAIN;
+ }
+}
+
+/**
+ * Update existing neighbour cache entry
+ *
+ * @v netdev Network device
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @v ll_dest Destination link-layer address
+ * @ret rc Return status code
+ */
+int neighbour_update ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *ll_dest ) {
+ struct neighbour *neighbour;
+
+ /* Find neighbour cache entry */
+ neighbour = neighbour_find ( netdev, net_protocol, net_dest );
+ if ( ! neighbour )
+ return -ENOENT;
+
+ /* Set destination address */
+ neighbour_discovered ( neighbour, ll_dest );
+
+ return 0;
+}
+
+/**
+ * Define neighbour cache entry
+ *
+ * @v netdev Network device
+ * @v net_protocol Network-layer protocol
+ * @v net_dest Destination network-layer address
+ * @v ll_dest Destination link-layer address, if known
+ * @ret rc Return status code
+ */
+int neighbour_define ( struct net_device *netdev,
+ struct net_protocol *net_protocol,
+ const void *net_dest, const void *ll_dest ) {
+ struct neighbour *neighbour;
+
+ /* Find or create neighbour cache entry */
+ neighbour = neighbour_find ( netdev, net_protocol, net_dest );
+ if ( ! neighbour ) {
+ neighbour = neighbour_create ( netdev, net_protocol, net_dest );
+ if ( ! neighbour )
+ return -ENOMEM;
+ }
+
+ /* Set destination address */
+ neighbour_discovered ( neighbour, ll_dest );
+
+ return 0;
+}
+
+/**
+ * Update neighbour cache on network device creation
+ *
+ * @v netdev Network device
+ */
+static int neighbour_probe ( struct net_device *netdev __unused ) {
+ /* Nothing to do */
+ return 0;
+}
+
+/**
+ * Update neighbour cache on network device state change or removal
+ *
+ * @v netdev Network device
+ */
+static void neighbour_flush ( struct net_device *netdev ) {
+ struct neighbour *neighbour;
+ struct neighbour *tmp;
+
+ /* Remove all neighbour cache entries when a network device is closed */
+ if ( ! netdev_is_open ( netdev ) ) {
+ list_for_each_entry_safe ( neighbour, tmp, &neighbours, list )
+ neighbour_destroy ( neighbour, -ENODEV );
+ }
+}
+
+/** Neighbour driver (for net device notifications) */
+struct net_driver neighbour_net_driver __net_driver = {
+ .name = "Neighbour",
+ .probe = neighbour_probe,
+ .notify = neighbour_flush,
+ .remove = neighbour_flush,
+};
+
+/**
+ * Discard some cached neighbour entries
+ *
+ * @ret discarded Number of cached items discarded
+ */
+static unsigned int neighbour_discard ( void ) {
+ struct neighbour *neighbour;
+
+ /* Drop oldest cache entry, if any */
+ neighbour = list_last_entry ( &neighbours, struct neighbour, list );
+ if ( neighbour ) {
+ neighbour_destroy ( neighbour, -ENOBUFS );
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/**
+ * Neighbour cache discarder
+ *
+ * Neighbour cache entries are deemed to have a high replacement cost,
+ * since flushing an active neighbour cache entry midway through a TCP
+ * transfer will cause substantial disruption.
+ */
+struct cache_discarder neighbour_discarder __cache_discarder (CACHE_EXPENSIVE)={
+ .discard = neighbour_discard,
+};
projects / thirdparty / ipxe.git / commitdiff
