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- /*
- * 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.
- */
-
- #include <stdint.h>
- #include <stdlib.h>
- #include <byteswap.h>
- #include <string.h>
- #include <errno.h>
- #include <gpxe/if_ether.h>
- #include <gpxe/pkbuff.h>
- #include <gpxe/tables.h>
- #include <gpxe/process.h>
- #include <gpxe/init.h>
- #include <gpxe/netdevice.h>
-
- /** @file
- *
- * Network device management
- *
- */
-
- /** Registered network-layer protocols */
- static struct net_protocol net_protocols[0] __table_start ( net_protocols );
- static struct net_protocol net_protocols_end[0] __table_end ( net_protocols );
-
- /** List of network devices */
- static LIST_HEAD ( net_devices );
-
- /**
- * Transmit raw packet via network device
- *
- * @v netdev Network device
- * @v pkb Packet buffer
- * @ret rc Return status code
- *
- * Transmits the packet via the specified network device. This
- * function takes ownership of the packet buffer.
- */
- int netdev_tx ( struct net_device *netdev, struct pk_buff *pkb ) {
- DBG ( "%s transmitting %p+%zx\n", netdev_name ( netdev ),
- pkb->data, pkb_len ( pkb ) );
- return netdev->transmit ( netdev, pkb );
- }
-
- /**
- * Add packet to receive queue
- *
- * @v netdev Network device
- * @v pkb Packet buffer
- *
- * The packet is added to the network device's RX queue. This
- * function takes ownership of the packet buffer.
- */
- void netdev_rx ( struct net_device *netdev, struct pk_buff *pkb ) {
- DBG ( "%s received %p+%zx\n", netdev_name ( netdev ),
- pkb->data, pkb_len ( pkb ) );
- list_add_tail ( &pkb->list, &netdev->rx_queue );
- }
-
- /**
- * Transmit network-layer packet
- *
- * @v pkb Packet buffer
- * @v netdev Network device
- * @v net_protocol Network-layer protocol
- * @v ll_dest Destination link-layer address
- * @ret rc Return status code
- *
- * Prepends link-layer headers to the packet buffer and transmits the
- * packet via the specified network device. This function takes
- * ownership of the packet buffer.
- */
- int net_tx ( struct pk_buff *pkb, struct net_device *netdev,
- struct net_protocol *net_protocol, const void *ll_dest ) {
- return netdev->ll_protocol->tx ( pkb, netdev, net_protocol, ll_dest );
- }
-
- /**
- * Process received network-layer packet
- *
- * @v pkb Packet buffer
- * @v netdev Network device
- * @v net_proto Network-layer protocol, in network-byte order
- * @v ll_source Source link-layer address
- * @ret rc Return status code
- */
- int net_rx ( struct pk_buff *pkb, struct net_device *netdev,
- uint16_t net_proto, const void *ll_source ) {
- struct net_protocol *net_protocol;
-
- /* Hand off to network-layer protocol, if any */
- for ( net_protocol = net_protocols ; net_protocol < net_protocols_end ;
- net_protocol++ ) {
- if ( net_protocol->net_proto == net_proto ) {
- return net_protocol->rx ( pkb, netdev, ll_source );
- }
- }
- free_pkb ( pkb );
- return 0;
- }
-
- /**
- * Poll for packet on network device
- *
- * @v netdev Network device
- * @ret True There are packets present in the receive queue
- * @ret False There are no packets present in the receive queue
- *
- * Polls the network device for received packets. Any received
- * packets will be added to the RX packet queue via netdev_rx().
- */
- int netdev_poll ( struct net_device *netdev ) {
- netdev->poll ( netdev );
- return ( ! list_empty ( &netdev->rx_queue ) );
- }
-
- /**
- * Remove packet from device's receive queue
- *
- * @v netdev Network device
- * @ret pkb Packet buffer, or NULL
- *
- * Removes the first packet from the device's RX queue and returns it.
- * Ownership of the packet is transferred to the caller.
- */
- struct pk_buff * netdev_rx_dequeue ( struct net_device *netdev ) {
- struct pk_buff *pkb;
-
- list_for_each_entry ( pkb, &netdev->rx_queue, list ) {
- list_del ( &pkb->list );
- return pkb;
- }
- return NULL;
- }
-
- /**
- * Allocate network device
- *
- * @v priv_size Size of private data area (net_device::priv)
- * @ret netdev Network device, or NULL
- *
- * Allocates space for a network device and its private data area.
- */
- struct net_device * alloc_netdev ( size_t priv_size ) {
- struct net_device *netdev;
-
- netdev = calloc ( 1, sizeof ( *netdev ) + priv_size );
- if ( netdev ) {
- INIT_LIST_HEAD ( &netdev->rx_queue );
- netdev->priv = ( ( ( void * ) netdev ) + sizeof ( *netdev ) );
- }
- return netdev;
- }
-
- /**
- * Register network device
- *
- * @v netdev Network device
- * @ret rc Return status code
- *
- * Adds the network device to the list of network devices.
- */
- int register_netdev ( struct net_device *netdev ) {
-
- /* Add to device list */
- list_add_tail ( &netdev->list, &net_devices );
- DBG ( "%s registered\n", netdev_name ( netdev ) );
-
- return 0;
- }
-
- /**
- * Unregister network device
- *
- * @v netdev Network device
- *
- * Removes the network device from the list of network devices.
- */
- void unregister_netdev ( struct net_device *netdev ) {
- struct pk_buff *pkb;
-
- /* Discard any packets in the RX queue */
- while ( ( pkb = netdev_rx_dequeue ( netdev ) ) ) {
- DBG ( "%s discarding %p+%zx\n", netdev_name ( netdev ),
- pkb->data, pkb_len ( pkb ) );
- free_pkb ( pkb );
- }
-
- /* Remove from device list */
- list_del ( &netdev->list );
- DBG ( "%s unregistered\n", netdev_name ( netdev ) );
- }
-
- /**
- * Free network device
- *
- * @v netdev Network device
- */
- void free_netdev ( struct net_device *netdev ) {
- free ( netdev );
- }
-
- /**
- * Iterate through network devices
- *
- * @ret netdev Network device, or NULL
- *
- * This returns the registered network devices in the order of
- * registration. If no network devices are registered, it will return
- * NULL.
- */
- struct net_device * next_netdev ( void ) {
- struct net_device *netdev;
-
- list_for_each_entry ( netdev, &net_devices, list ) {
- list_del ( &netdev->list );
- list_add_tail ( &netdev->list, &net_devices );
- return netdev;
- }
- return NULL;
- }
-
- /**
- * Single-step the network stack
- *
- * @v process Network stack process
- *
- * This polls all interfaces for any received packets, and processes
- * at most one packet from the RX queue.
- *
- * We avoid processing all received packets, because processing the
- * received packet can trigger transmission of a new packet (e.g. an
- * ARP response). Since TX completions will be processed as part of
- * the poll operation, it is easy to overflow small TX queues if
- * multiple packets are processed per poll.
- */
- static void net_step ( struct process *process ) {
- struct net_device *netdev;
- struct pk_buff *pkb;
-
- /* Poll and process each network device */
- list_for_each_entry ( netdev, &net_devices, list ) {
-
- /* Poll for new packets */
- netdev_poll ( netdev );
-
- /* Handle at most one received packet per poll */
- if ( ( pkb = netdev_rx_dequeue ( netdev ) ) ) {
- DBG ( "%s processing %p+%zx\n", netdev_name ( netdev ),
- pkb->data, pkb_len ( pkb ) );
- netdev->ll_protocol->rx ( pkb, netdev );
- }
- }
-
- /* Re-schedule ourself */
- schedule ( process );
- }
-
- /** Networking stack process */
- static struct process net_process = {
- .step = net_step,
- };
-
- /** Initialise the networking stack process */
- static void init_net ( void ) {
- schedule ( &net_process );
- }
-
- INIT_FN ( INIT_PROCESS, init_net, NULL, NULL );
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