mirror of https://github.com/ipxe/ipxe.git
[arp] Maintain an ARP transmission queue
Allow packet transmission to be deferred pending successful ARP resolution. This avoids the time spent waiting for a higher-level protocol (e.g. TCP or TFTP) to attempt retransmission. Signed-off-by: Michael Brown <mcb30@ipxe.org>pull/6/head
Michael Brown
parent
6324bd9389
commit
d620606d3e
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@ -35,10 +35,8 @@ struct arp_net_protocol {
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extern struct net_protocol arp_protocol __net_protocol;
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extern int arp_resolve ( struct net_device *netdev,
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struct net_protocol *net_protocol,
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const void *dest_net_addr,
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const void *source_net_addr,
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void *dest_ll_addr );
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extern int arp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
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struct net_protocol *net_protocol, const void *net_dest,
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const void *net_source, const void *ll_source );
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#endif /* _IPXE_ARP_H */
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428
src/net/arp.c
428
src/net/arp.c
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@ -19,6 +19,7 @@
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FILE_LICENCE ( GPL2_OR_LATER );
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <byteswap.h>
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#include <errno.h>
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@ -26,6 +27,10 @@ FILE_LICENCE ( GPL2_OR_LATER );
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#include <ipxe/if_arp.h>
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#include <ipxe/iobuf.h>
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#include <ipxe/netdevice.h>
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#include <ipxe/list.h>
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#include <ipxe/retry.h>
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#include <ipxe/timer.h>
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#include <ipxe/malloc.h>
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#include <ipxe/arp.h>
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/** @file
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@ -38,104 +43,263 @@ FILE_LICENCE ( GPL2_OR_LATER );
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*
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*/
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/** ARP minimum timeout */
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#define ARP_MIN_TIMEOUT ( TICKS_PER_SEC / 8 )
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/** ARP maximum timeout */
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#define ARP_MAX_TIMEOUT ( TICKS_PER_SEC * 3 )
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/** An ARP cache entry */
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struct arp_entry {
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/** List of ARP cache entries */
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struct list_head list;
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/** Network device */
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struct net_device *netdev;
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/** Network-layer protocol */
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struct net_protocol *net_protocol;
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/** Link-layer protocol */
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struct ll_protocol *ll_protocol;
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/** Network-layer address */
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uint8_t net_addr[MAX_NET_ADDR_LEN];
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/** Link-layer address */
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uint8_t ll_addr[MAX_LL_ADDR_LEN];
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/** Network-layer destination address */
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uint8_t net_dest[MAX_NET_ADDR_LEN];
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/** Network-layer source address */
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uint8_t net_source[MAX_NET_ADDR_LEN];
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/** Link-layer destination address */
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uint8_t ll_dest[MAX_LL_ADDR_LEN];
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/** Retransmission timer */
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struct retry_timer timer;
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/** Pending I/O buffers */
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struct list_head tx_queue;
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};
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/** Number of entries in the ARP cache
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*
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* This is a global cache, covering all network interfaces,
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* network-layer protocols and link-layer protocols.
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*/
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#define NUM_ARP_ENTRIES 4
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/** The ARP cache */
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static struct arp_entry arp_table[NUM_ARP_ENTRIES];
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#define arp_table_end &arp_table[NUM_ARP_ENTRIES]
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static unsigned int next_new_arp_entry = 0;
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static LIST_HEAD ( arp_entries );
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struct net_protocol arp_protocol __net_protocol;
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static void arp_expired ( struct retry_timer *timer, int over );
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/**
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* Create ARP cache entry
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*
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* @v netdev Network device
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* @v net_protocol Network-layer protocol
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* @v net_dest Destination network-layer address
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* @v net_source Source network-layer address
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* @ret arp ARP cache entry, or NULL if allocation failed
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*/
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static struct arp_entry * arp_create ( struct net_device *netdev,
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struct net_protocol *net_protocol,
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const void *net_dest,
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const void *net_source ) {
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struct arp_entry *arp;
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/* Allocate entry and add to cache */
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arp = zalloc ( sizeof ( *arp ) );
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if ( ! arp )
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return NULL;
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/* Initialise entry and add to cache */
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arp->netdev = netdev_get ( netdev );
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arp->net_protocol = net_protocol;
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memcpy ( arp->net_dest, net_dest,
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net_protocol->net_addr_len );
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memcpy ( arp->net_source, net_source,
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net_protocol->net_addr_len );
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timer_init ( &arp->timer, arp_expired, NULL );
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arp->timer.min_timeout = ARP_MIN_TIMEOUT;
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arp->timer.max_timeout = ARP_MAX_TIMEOUT;
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INIT_LIST_HEAD ( &arp->tx_queue );
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list_add ( &arp->list, &arp_entries );
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/* Start timer running to trigger initial transmission */
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start_timer_nodelay ( &arp->timer );
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DBGC ( arp, "ARP %p %s %s %s created\n", arp, netdev->name,
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net_protocol->name, net_protocol->ntoa ( net_dest ) );
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return arp;
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}
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/**
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* Find entry in the ARP cache
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*
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* @v ll_protocol Link-layer protocol
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* @v netdev Network device
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* @v net_protocol Network-layer protocol
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* @v net_addr Network-layer address
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* @v net_dest Destination network-layer address
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* @ret arp ARP cache entry, or NULL if not found
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*
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*/
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static struct arp_entry *
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arp_find_entry ( struct ll_protocol *ll_protocol,
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struct net_protocol *net_protocol,
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const void *net_addr ) {
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static struct arp_entry * arp_find ( struct net_device *netdev,
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struct net_protocol *net_protocol,
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const void *net_dest ) {
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struct arp_entry *arp;
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for ( arp = arp_table ; arp < arp_table_end ; arp++ ) {
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if ( ( arp->ll_protocol == ll_protocol ) &&
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list_for_each_entry ( arp, &arp_entries, list ) {
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if ( ( arp->netdev == netdev ) &&
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( arp->net_protocol == net_protocol ) &&
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( memcmp ( arp->net_addr, net_addr,
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net_protocol->net_addr_len ) == 0 ) )
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( memcmp ( arp->net_dest, net_dest,
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net_protocol->net_addr_len ) == 0 ) ) {
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/* Move to start of cache */
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list_del ( &arp->list );
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list_add ( &arp->list, &arp_entries );
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return arp;
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}
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}
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return NULL;
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}
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/**
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* Look up media-specific link-layer address in the ARP cache
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* Destroy ARP cache entry
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*
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* @v arp ARP cache entry
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* @v rc Reason for destruction
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*/
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static void arp_destroy ( struct arp_entry *arp, int rc ) {
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struct net_device *netdev = arp->netdev;
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struct net_protocol *net_protocol = arp->net_protocol;
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struct io_buffer *iobuf;
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struct io_buffer *tmp;
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/* Stop timer */
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stop_timer ( &arp->timer );
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/* Discard any outstanding I/O buffers */
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list_for_each_entry_safe ( iobuf, tmp, &arp->tx_queue, list ) {
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DBGC2 ( arp, "ARP %p %s %s %s discarding deferred packet: "
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"%s\n", arp, netdev->name, net_protocol->name,
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net_protocol->ntoa ( arp->net_dest ), strerror ( rc ) );
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list_del ( &iobuf->list );
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netdev_tx_err ( arp->netdev, iobuf, rc );
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}
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DBGC ( arp, "ARP %p %s %s %s destroyed: %s\n", arp, netdev->name,
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net_protocol->name, net_protocol->ntoa ( arp->net_dest ),
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strerror ( rc ) );
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/* Drop reference to network device, remove from cache and free */
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netdev_put ( arp->netdev );
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list_del ( &arp->list );
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free ( arp );
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}
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/**
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* Test if ARP cache entry has a valid link-layer address
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*
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* @v arp ARP cache entry
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* @ret resolved ARP cache entry is resolved
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*/
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static inline int arp_resolved ( struct arp_entry *arp ) {
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return ( ! timer_running ( &arp->timer ) );
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}
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/**
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* Transmit packet, determining link-layer address via ARP
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*
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* @v iobuf I/O buffer
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* @v netdev Network device
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* @v net_protocol Network-layer protocol
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* @v dest_net_addr Destination network-layer address
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* @v source_net_addr Source network-layer address
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* @ret dest_ll_addr Destination link layer address
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* @v net_dest Destination network-layer address
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* @v net_source Source network-layer address
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* @v ll_source Source link-layer address
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* @ret rc Return status code
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*
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* This function will use the ARP cache to look up the link-layer
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* address for the link-layer protocol associated with the network
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* device and the given network-layer protocol and addresses. If
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* found, the destination link-layer address will be filled in in @c
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* dest_ll_addr.
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*
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* If no address is found in the ARP cache, an ARP request will be
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* transmitted on the specified network device and -ENOENT will be
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* returned.
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*/
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int arp_resolve ( struct net_device *netdev, struct net_protocol *net_protocol,
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const void *dest_net_addr, const void *source_net_addr,
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void *dest_ll_addr ) {
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int arp_tx ( struct io_buffer *iobuf, struct net_device *netdev,
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struct net_protocol *net_protocol, const void *net_dest,
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const void *net_source, const void *ll_source ) {
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struct arp_entry *arp;
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/* Find or create ARP cache entry */
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arp = arp_find ( netdev, net_protocol, net_dest );
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if ( ! arp ) {
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arp = arp_create ( netdev, net_protocol, net_dest,
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net_source );
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if ( ! arp )
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return -ENOMEM;
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}
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/* If a link-layer address is available then transmit
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* immediately, otherwise queue for later transmission.
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*/
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if ( arp_resolved ( arp ) ) {
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return net_tx ( iobuf, netdev, net_protocol, arp->ll_dest,
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ll_source );
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} else {
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DBGC2 ( arp, "ARP %p %s %s %s deferring packet\n",
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arp, netdev->name, net_protocol->name,
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net_protocol->ntoa ( net_dest ) );
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list_add_tail ( &iobuf->list, &arp->tx_queue );
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return -EAGAIN;
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}
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}
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/**
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* Update ARP cache entry
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*
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* @v arp ARP cache entry
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* @v ll_dest Destination link-layer address
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*/
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static void arp_update ( struct arp_entry *arp, const void *ll_dest ) {
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struct net_device *netdev = arp->netdev;
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struct ll_protocol *ll_protocol = netdev->ll_protocol;
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const struct arp_entry *arp;
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struct net_protocol *net_protocol = arp->net_protocol;
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struct io_buffer *iobuf;
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struct io_buffer *tmp;
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int rc;
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DBGC ( arp, "ARP %p %s %s %s updated => %s\n", arp, netdev->name,
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net_protocol->name, net_protocol->ntoa ( arp->net_dest ),
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ll_protocol->ntoa ( ll_dest ) );
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/* Fill in link-layer address */
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memcpy ( arp->ll_dest, ll_dest, ll_protocol->ll_addr_len );
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/* Stop retransmission timer */
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stop_timer ( &arp->timer );
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/* Transmit any packets in queue */
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list_for_each_entry_safe ( iobuf, tmp, &arp->tx_queue, list ) {
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DBGC2 ( arp, "ARP %p %s %s %s transmitting deferred packet\n",
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arp, netdev->name, net_protocol->name,
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net_protocol->ntoa ( arp->net_dest ) );
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list_del ( &iobuf->list );
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if ( ( rc = net_tx ( iobuf, netdev, net_protocol, ll_dest,
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netdev->ll_addr ) ) != 0 ) {
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DBGC ( arp, "ARP %p could not transmit deferred "
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"packet: %s\n", arp, strerror ( rc ) );
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/* Ignore error and continue */
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}
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}
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}
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/**
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* Handle ARP timer expiry
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*
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* @v timer Retry timer
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* @v fail Failure indicator
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*/
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static void arp_expired ( struct retry_timer *timer, int fail ) {
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struct arp_entry *arp = container_of ( timer, struct arp_entry, timer );
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struct net_device *netdev = arp->netdev;
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struct ll_protocol *ll_protocol = netdev->ll_protocol;
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struct net_protocol *net_protocol = arp->net_protocol;
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struct io_buffer *iobuf;
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struct arphdr *arphdr;
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int rc;
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/* Look for existing entry in ARP table */
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arp = arp_find_entry ( ll_protocol, net_protocol, dest_net_addr );
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if ( arp ) {
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DBG ( "ARP cache hit: %s %s => %s %s\n",
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net_protocol->name, net_protocol->ntoa ( arp->net_addr ),
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ll_protocol->name, ll_protocol->ntoa ( arp->ll_addr ) );
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memcpy ( dest_ll_addr, arp->ll_addr, ll_protocol->ll_addr_len);
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return 0;
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/* If we have failed, destroy the cache entry */
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if ( fail ) {
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arp_destroy ( arp, -ETIMEDOUT );
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return;
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}
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DBG ( "ARP cache miss: %s %s\n", net_protocol->name,
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net_protocol->ntoa ( dest_net_addr ) );
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/* Restart the timer */
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start_timer ( &arp->timer );
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/* Allocate ARP packet */
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iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *arphdr ) +
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2 * ( MAX_LL_ADDR_LEN + MAX_NET_ADDR_LEN ) );
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if ( ! iobuf )
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return -ENOMEM;
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( 2 * ( MAX_LL_ADDR_LEN + MAX_NET_ADDR_LEN ) ) );
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if ( ! iobuf ) {
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/* Leave timer running and try again later */
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return;
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}
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iob_reserve ( iobuf, MAX_LL_HEADER_LEN );
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/* Build up ARP request */
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@ -148,18 +312,19 @@ int arp_resolve ( struct net_device *netdev, struct net_protocol *net_protocol,
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memcpy ( iob_put ( iobuf, ll_protocol->ll_addr_len ),
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netdev->ll_addr, ll_protocol->ll_addr_len );
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memcpy ( iob_put ( iobuf, net_protocol->net_addr_len ),
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source_net_addr, net_protocol->net_addr_len );
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arp->net_source, net_protocol->net_addr_len );
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memset ( iob_put ( iobuf, ll_protocol->ll_addr_len ),
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0, ll_protocol->ll_addr_len );
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memcpy ( iob_put ( iobuf, net_protocol->net_addr_len ),
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dest_net_addr, net_protocol->net_addr_len );
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arp->net_dest, net_protocol->net_addr_len );
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/* Transmit ARP request */
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if ( ( rc = net_tx ( iobuf, netdev, &arp_protocol,
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netdev->ll_broadcast, netdev->ll_addr ) ) != 0 )
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return rc;
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return -ENOENT;
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netdev->ll_broadcast, netdev->ll_addr ) ) != 0 ) {
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DBGC ( arp, "ARP %p could not transmit request: %s\n",
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arp, strerror ( rc ) );
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return;
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}
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}
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/**
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@ -188,12 +353,6 @@ static struct arp_net_protocol * arp_find_protocol ( uint16_t net_proto ) {
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* @v ll_source Link-layer source address
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* @v flags Packet flags
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* @ret rc Return status code
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*
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* This handles ARP requests and responses as detailed in RFC826. The
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* method detailed within the RFC is pretty optimised, handling
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* requests and responses with basically a single code path and
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* avoiding the need for extraneous ARP requests; read the RFC for
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* details.
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*/
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static int arp_rx ( struct io_buffer *iobuf, struct net_device *netdev,
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const void *ll_dest __unused,
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@ -204,71 +363,68 @@ static int arp_rx ( struct io_buffer *iobuf, struct net_device *netdev,
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struct net_protocol *net_protocol;
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struct ll_protocol *ll_protocol;
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struct arp_entry *arp;
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int merge = 0;
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int rc;
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/* Identify network-layer and link-layer protocols */
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arp_net_protocol = arp_find_protocol ( arphdr->ar_pro );
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if ( ! arp_net_protocol )
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if ( ! arp_net_protocol ) {
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rc = -EPROTONOSUPPORT;
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goto done;
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}
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net_protocol = arp_net_protocol->net_protocol;
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ll_protocol = netdev->ll_protocol;
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/* Sanity checks */
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if ( ( arphdr->ar_hrd != ll_protocol->ll_proto ) ||
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( arphdr->ar_hln != ll_protocol->ll_addr_len ) ||
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( arphdr->ar_pln != net_protocol->net_addr_len ) )
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( arphdr->ar_pln != net_protocol->net_addr_len ) ) {
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rc = -EINVAL;
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goto done;
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/* See if we have an entry for this sender, and update it if so */
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arp = arp_find_entry ( ll_protocol, net_protocol,
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arp_sender_pa ( arphdr ) );
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if ( arp ) {
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memcpy ( arp->ll_addr, arp_sender_ha ( arphdr ),
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arphdr->ar_hln );
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merge = 1;
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DBG ( "ARP cache update: %s %s => %s %s\n",
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net_protocol->name, net_protocol->ntoa ( arp->net_addr ),
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ll_protocol->name, ll_protocol->ntoa ( arp->ll_addr ) );
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}
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/* 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 ) );
|
||||
/* 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 ) );
|
||||
}
|
||||
|
||||
/* If it's not a request, there's nothing more to do */
|
||||
if ( arphdr->ar_op != htons ( ARPOP_REQUEST ) )
|
||||
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 */
|
||||
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 ) );
|
||||
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 ) );
|
||||
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 ), netdev->ll_addr );
|
||||
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 ) );
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Success */
|
||||
rc = 0;
|
||||
|
||||
done:
|
||||
free_iob ( iobuf );
|
||||
return 0;
|
||||
return rc;
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
@ -290,3 +446,59 @@ struct net_protocol arp_protocol __net_protocol = {
|
|||
.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 */
|
||||
list_for_each_entry_reverse ( arp, &arp_entries, list ) {
|
||||
arp_destroy ( arp, -ENOBUFS );
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/** ARP cache discarder */
|
||||
struct cache_discarder arp_cache_discarder __cache_discarder = {
|
||||
.discard = arp_discard,
|
||||
};
|
||||
|
|
|
|||
|
|
@ -281,35 +281,6 @@ static uint16_t ipv4_pshdr_chksum ( struct io_buffer *iobuf, uint16_t csum ) {
|
|||
return tcpip_continue_chksum ( csum, &pshdr, sizeof ( pshdr ) );
|
||||
}
|
||||
|
||||
/**
|
||||
* Determine link-layer address
|
||||
*
|
||||
* @v dest IPv4 destination address
|
||||
* @v src IPv4 source address
|
||||
* @v netmask IPv4 subnet mask
|
||||
* @v netdev Network device
|
||||
* @v ll_dest Link-layer destination address buffer
|
||||
* @ret rc Return status code
|
||||
*/
|
||||
static int ipv4_ll_addr ( struct in_addr dest, struct in_addr src,
|
||||
struct in_addr netmask, struct net_device *netdev,
|
||||
uint8_t *ll_dest ) {
|
||||
struct ll_protocol *ll_protocol = netdev->ll_protocol;
|
||||
|
||||
if ( ( ( dest.s_addr ^ INADDR_BROADCAST ) & ~netmask.s_addr ) == 0 ) {
|
||||
/* Broadcast address */
|
||||
memcpy ( ll_dest, netdev->ll_broadcast,
|
||||
ll_protocol->ll_addr_len );
|
||||
return 0;
|
||||
} else if ( IN_MULTICAST ( ntohl ( dest.s_addr ) ) ) {
|
||||
return ll_protocol->mc_hash ( AF_INET, &dest, ll_dest );
|
||||
} else {
|
||||
/* Unicast address: resolve via ARP */
|
||||
return arp_resolve ( netdev, &ipv4_protocol, &dest,
|
||||
&src, ll_dest );
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Transmit IP packet
|
||||
*
|
||||
|
|
@ -335,7 +306,8 @@ static int ipv4_tx ( struct io_buffer *iobuf,
|
|||
struct ipv4_miniroute *miniroute;
|
||||
struct in_addr next_hop;
|
||||
struct in_addr netmask = { .s_addr = 0 };
|
||||
uint8_t ll_dest[MAX_LL_ADDR_LEN];
|
||||
uint8_t ll_dest_buf[MAX_LL_ADDR_LEN];
|
||||
const void *ll_dest;
|
||||
int rc;
|
||||
|
||||
/* Fill up the IP header, except source address */
|
||||
|
|
@ -373,16 +345,6 @@ static int ipv4_tx ( struct io_buffer *iobuf,
|
|||
( ( netdev->rx_stats.bad & 0xf ) << 4 ) |
|
||||
( ( netdev->rx_stats.good & 0xf ) << 0 ) );
|
||||
|
||||
/* Determine link-layer destination address */
|
||||
if ( ( rc = ipv4_ll_addr ( next_hop, iphdr->src, netmask, netdev,
|
||||
ll_dest ) ) != 0 ) {
|
||||
DBGC ( sin_dest->sin_addr, "IPv4 has no link-layer address for "
|
||||
"%s: %s\n", inet_ntoa ( next_hop ), strerror ( rc ) );
|
||||
/* Record error for diagnosis */
|
||||
netdev_tx_err ( netdev, iob_disown ( iobuf ), rc );
|
||||
goto err;
|
||||
}
|
||||
|
||||
/* Fix up checksums */
|
||||
if ( trans_csum )
|
||||
*trans_csum = ipv4_pshdr_chksum ( iobuf, *trans_csum );
|
||||
|
|
@ -395,12 +357,42 @@ static int ipv4_tx ( struct io_buffer *iobuf,
|
|||
iphdr->protocol, ntohs ( iphdr->ident ),
|
||||
ntohs ( iphdr->chksum ) );
|
||||
|
||||
/* Hand off to link layer */
|
||||
if ( ( rc = net_tx ( iobuf, netdev, &ipv4_protocol, ll_dest,
|
||||
netdev->ll_addr ) ) != 0 ) {
|
||||
DBGC ( sin_dest->sin_addr, "IPv4 could not transmit packet "
|
||||
"via %s: %s\n", netdev->name, strerror ( rc ) );
|
||||
return rc;
|
||||
/* Calculate link-layer destination address, if possible */
|
||||
if ( ( ( next_hop.s_addr ^ INADDR_BROADCAST ) & ~netmask.s_addr ) == 0){
|
||||
/* Broadcast address */
|
||||
ll_dest = netdev->ll_broadcast;
|
||||
} else if ( IN_MULTICAST ( ntohl ( next_hop.s_addr ) ) ) {
|
||||
/* Multicast address */
|
||||
if ( ( rc = netdev->ll_protocol->mc_hash ( AF_INET, &next_hop,
|
||||
ll_dest_buf ) ) !=0){
|
||||
DBGC ( sin_dest->sin_addr, "IPv4 could not hash "
|
||||
"multicast %s: %s\n",
|
||||
inet_ntoa ( next_hop ), strerror ( rc ) );
|
||||
return rc;
|
||||
}
|
||||
ll_dest = ll_dest_buf;
|
||||
} else {
|
||||
/* Unicast address */
|
||||
ll_dest = NULL;
|
||||
}
|
||||
|
||||
/* Hand off to link layer (via ARP if applicable) */
|
||||
if ( ll_dest ) {
|
||||
if ( ( rc = net_tx ( iobuf, netdev, &ipv4_protocol, ll_dest,
|
||||
netdev->ll_addr ) ) != 0 ) {
|
||||
DBGC ( sin_dest->sin_addr, "IPv4 could not transmit "
|
||||
"packet via %s: %s\n",
|
||||
netdev->name, strerror ( rc ) );
|
||||
return rc;
|
||||
}
|
||||
} else {
|
||||
if ( ( rc = arp_tx ( iobuf, netdev, &ipv4_protocol, &next_hop,
|
||||
&iphdr->src, netdev->ll_addr ) ) != 0 ) {
|
||||
DBGC ( sin_dest->sin_addr, "IPv4 could not transmit "
|
||||
"packet via %s: %s\n",
|
||||
netdev->name, strerror ( rc ) );
|
||||
return rc;
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
|
|
|||
Loading…
Reference in New Issue