diff options
| -rw-r--r-- | src/net/arp.c | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/src/net/arp.c b/src/net/arp.c index 4283b669..d6b4e731 100644 --- a/src/net/arp.c +++ b/src/net/arp.c @@ -31,6 +31,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include <ipxe/retry.h> #include <ipxe/timer.h> #include <ipxe/malloc.h> +#include <ipxe/refcnt.h> #include <ipxe/arp.h> /** @file @@ -51,6 +52,8 @@ FILE_LICENCE ( GPL2_OR_LATER ); /** An ARP cache entry */ struct arp_entry { + /** Reference count */ + struct refcnt refcnt; /** List of ARP cache entries */ struct list_head list; /** Network device */ @@ -77,6 +80,25 @@ 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 @@ -91,27 +113,28 @@ static struct arp_entry * arp_create ( struct net_device *netdev, const void *net_source ) { struct arp_entry *arp; - /* Allocate entry and add to cache */ + /* Allocate and initialise entry */ arp = zalloc ( sizeof ( *arp ) ); if ( ! arp ) return NULL; - - /* Initialise entry and add to cache */ + 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, NULL ); + 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 ); - list_add ( &arp->list, &arp_entries ); /* 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; @@ -174,10 +197,9 @@ static void arp_destroy ( struct arp_entry *arp, int rc ) { net_protocol->name, net_protocol->ntoa ( arp->net_dest ), strerror ( rc ) ); - /* Drop reference to network device, remove from cache and free */ - netdev_put ( arp->netdev ); + /* Remove from cache and drop reference */ list_del ( &arp->list ); - free ( arp ); + ref_put ( &arp->refcnt ); } /** @@ -241,7 +263,6 @@ static void arp_update ( struct arp_entry *arp, const void *ll_dest ) { struct ll_protocol *ll_protocol = netdev->ll_protocol; struct net_protocol *net_protocol = arp->net_protocol; struct io_buffer *iobuf; - struct io_buffer *tmp; int rc; DBGC ( arp, "ARP %p %s %s %s updated => %s\n", arp, netdev->name, @@ -254,8 +275,13 @@ static void arp_update ( struct arp_entry *arp, const void *ll_dest ) { /* Stop retransmission timer */ stop_timer ( &arp->timer ); - /* Transmit any packets in queue */ - list_for_each_entry_safe ( iobuf, tmp, &arp->tx_queue, list ) { + /* 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 ) ); @@ -267,6 +293,7 @@ static void arp_update ( struct arp_entry *arp, const void *ll_dest ) { /* Ignore error and continue */ } } + ref_put ( &arp->refcnt ); } /** |