/*
* 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.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <byteswap.h>
#include <string.h>
#include <errno.h>
#include <gpxe/if_ether.h>
#include <gpxe/iobuf.h>
#include <gpxe/tables.h>
#include <gpxe/process.h>
#include <gpxe/init.h>
#include <gpxe/device.h>
#include <gpxe/netdevice.h>
/** @file
*
* Network device management
*
*/
/** List of network devices */
struct list_head net_devices = LIST_HEAD_INIT ( net_devices );
/** List of open network devices, in reverse order of opening */
struct list_head open_net_devices = LIST_HEAD_INIT ( open_net_devices );
/**
* Record network device statistic
*
* @v stats Network device statistics
* @v rc Status code
*/
static void netdev_record_stat ( struct net_device_stats *stats, int rc ) {
struct net_device_error *error;
struct net_device_error *least_common_error;
unsigned int i;
/* If this is not an error, just update the good counter */
if ( rc == 0 ) {
stats->good++;
return;
}
/* Update the bad counter */
stats->bad++;
/* Locate the appropriate error record */
least_common_error = &stats->errors[0];
for ( i = 0 ; i < ( sizeof ( stats->errors ) /
sizeof ( stats->errors[0] ) ) ; i++ ) {
error = &stats->errors[i];
/* Update matching record, if found */
if ( error->rc == rc ) {
error->count++;
return;
}
if ( error->count < least_common_error->count )
least_common_error = error;
}
/* Overwrite the least common error record */
least_common_error->rc = rc;
least_common_error->count = 1;
}
/**
* Transmit raw packet via network device
*
* @v netdev Network device
* @v iobuf I/O buffer
* @ret rc Return status code
*
* Transmits the packet via the specified network device. This
* function takes ownership of the I/O buffer.
*/
int netdev_tx ( struct net_device *netdev, struct io_buffer *iobuf ) {
int rc;
DBGC ( netdev, "NETDEV %p transmitting %p (%p+%zx)\n",
netdev, iobuf, iobuf->data, iob_len ( iobuf ) );
list_add_tail ( &iobuf->list, &netdev->tx_queue );
if ( ! ( netdev->state & NETDEV_OPEN ) ) {
rc = -ENETUNREACH;
goto err;
}
if ( ( rc = netdev->op->transmit ( netdev, iobuf ) ) != 0 )
goto err;
return 0;
err:
netdev_tx_complete_err ( netdev, iobuf, rc );
return rc;
}
/**
* Complete network transmission
*
* @v netdev Network device
* @v iobuf I/O buffer
* @v rc Packet status code
*
* The packet must currently be in the network device's TX queue.
*/
void netdev_tx_complete_err ( struct net_device *netdev,
struct io_buffer *iobuf, int rc ) {
/* Update statistics counter */
netdev_record_stat ( &netdev->tx_stats, rc );
if ( rc == 0 ) {
DBGC ( netdev, "NETDEV %p transmission %p complete\n",
netdev, iobuf );
} else {
DBGC ( netdev, "NETDEV %p transmission %p failed: %s\n",
netdev, iobuf, strerror ( rc ) );
}
/* Catch data corruption as early as possible */
assert ( iobuf->list.next != NULL );
assert ( iobuf->list.prev != NULL );
/* Dequeue and free I/O buffer */
list_del ( &iobuf->list );
free_iob ( iobuf );
}
/**
* Complete network transmission
*
* @v netdev Network device
* @v rc Packet status code
*
* Completes the oldest outstanding packet in the TX queue.
*/
void netdev_tx_complete_next_err ( struct net_device *netdev, int rc ) {
struct io_buffer *iobuf;
list_for_each_entry ( iobuf, &netdev->tx_queue, list ) {
netdev_tx_complete_err ( netdev, iobuf, rc );
return;
}
}
/**
* Flush device's transmit queue
*
* @v netdev Network device
*/
static void netdev_tx_flush ( struct net_device *netdev ) {
/* Discard any packets in the TX queue */
while ( ! list_empty ( &netdev->tx_queue ) ) {
netdev_tx_complete_next_err ( netdev, -ECANCELED );
}
}
/**
* Add packet to receive queue
*
* @v netdev Network device
* @v iobuf I/O buffer, or NULL
*
* The packet is added to the network device's RX queue. This
* function takes ownership of the I/O buffer.
*/
void netdev_rx ( struct net_device *netdev, struct io_buffer *iobuf ) {
DBGC ( netdev, "NETDEV %p received %p (%p+%zx)\n",
netdev, iobuf, iobuf->data, iob_len ( iobuf ) );
/* Enqueue packet */
list_add_tail ( &iobuf->list, &netdev->rx_queue );
/* Update statistics counter */
netdev_record_stat ( &netdev->rx_stats, 0 );
}
/**
* Discard received packet
*
* @v netdev Network device
* @v iobuf I/O buffer, or NULL
* @v rc Packet status code
*
* The packet is discarded and an RX error is recorded. This function
* takes ownership of the I/O buffer. @c iobuf may be NULL if, for
* example, the net device wishes to report an error due to being
* unable to allocate an I/O buffer.
*/
void netdev_rx_err ( struct net_device *netdev,
struct io_buffer *iobuf, int rc ) {
DBGC ( netdev, "NETDEV %p failed to receive %p: %s\n",
netdev, iobuf, strerror ( rc ) );
/* Discard packet */
free_iob ( iobuf );
/* Update statistics counter */
netdev_record_stat ( &netdev->rx_stats, rc );
}
/**
* Poll for completed and received packets on network device
*
* @v netdev Network device
*
* Polls the network device for completed transmissions and received
* packets. Any received packets will be added to the RX packet queue
* via netdev_rx().
*/
void netdev_poll ( struct net_device *netdev ) {
if ( netdev->state & NETDEV_OPEN )
netdev->op->poll ( netdev );
}
/**
* Remove packet from device's receive queue
*
* @v netdev Network device
* @ret iobuf I/O 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 io_buffer * netdev_rx_dequeue ( struct net_device *netdev ) {
struct io_buffer *iobuf;
list_for_each_entry ( iobuf, &netdev->rx_queue, list ) {
list_del ( &iobuf->list );
return iobuf;
}
return NULL;
}
/**
* Flush device's receive queue
*
* @v netdev Network device
*/
static void netdev_rx_flush ( struct net_device *netdev ) {
struct io_buffer *iobuf;
/* Discard any packets in the RX queue */
while ( ( iobuf = netdev_rx_dequeue ( netdev ) ) ) {
netdev_rx_err ( netdev, iobuf, -ECANCELED );
}
}
/**
* Free network device
*
* @v refcnt Network device reference counter
*/
static void free_netdev ( struct refcnt *refcnt ) {
struct net_device *netdev =
container_of ( refcnt, struct net_device, refcnt );
netdev_tx_flush ( netdev );
netdev_rx_flush ( netdev );
clear_settings ( netdev_settings ( netdev ) );
free ( netdev );
}
/**
* 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;
size_t total_len;
total_len = ( sizeof ( *netdev ) + priv_size );
netdev = zalloc ( total_len );
if ( netdev ) {
netdev->refcnt.free = free_netdev;
INIT_LIST_HEAD ( &netdev->tx_queue );
INIT_LIST_HEAD ( &netdev->rx_queue );
netdev_settings_init ( netdev );
netdev->priv = ( ( ( void * ) netdev ) + sizeof ( *netdev ) );
}
return netdev;
}
/**
* Register network device
*
* @v netdev Network device
* @ret rc Return status code
*
* Gives the network device a name and adds it to the list of network
* devices.
*/
int register_netdev ( struct net_device *netdev ) {
static unsigned int ifindex = 0;
int rc;
/* Create device name */
snprintf ( netdev->name, sizeof ( netdev->name ), "net%d",
ifindex++ );
/* Register per-netdev configuration settings */
if ( ( rc = register_settings ( netdev_settings ( netdev ),
NULL ) ) != 0 ) {
DBGC ( netdev, "NETDEV %p could not register settings: %s\n",
netdev, strerror ( rc ) );
return rc;
}
/* Add to device list */
netdev_get ( netdev );
list_add_tail ( &netdev->list, &net_devices );
DBGC ( netdev, "NETDEV %p registered as %s (phys %s hwaddr %s)\n",
netdev, netdev->name, netdev->dev->name,
netdev_hwaddr ( netdev ) );
return 0;
}
/**
* Open network device
*
* @v netdev Network device
* @ret rc Return status code
*/
int netdev_open ( struct net_device *netdev ) {
int rc;
/* Do nothing if device is already open */
if ( netdev->state & NETDEV_OPEN )
return 0;
DBGC ( netdev, "NETDEV %p opening\n", netdev );
/* Open the device */
if ( ( rc = netdev->op->open ( netdev ) ) != 0 )
return rc;
/* Mark as opened */
netdev->state |= NETDEV_OPEN;
/* Add to head of open devices list */
list_add ( &netdev->open_list, &open_net_devices );
return 0;
}
/**
* Close network device
*
* @v netdev Network device
*/
void netdev_close ( struct net_device *netdev ) {
/* Do nothing if device is already closed */
if ( ! ( netdev->state & NETDEV_OPEN ) )
return;
DBGC ( netdev, "NETDEV %p closing\n", netdev );
/* Close the device */
netdev->op->close ( netdev );
/* Flush TX and RX queues */
netdev_tx_flush ( netdev );
netdev_rx_flush ( netdev );
/* Mark as closed */
netdev->state &= ~NETDEV_OPEN;
/* Remove from open devices list */
list_del ( &netdev->open_list );
}
/**
* Unregister network device
*
* @v netdev Network device
*
* Removes the network device from the list of network devices.
*/
void unregister_netdev ( struct net_device *netdev ) {
/* Ensure device is closed */
netdev_close ( netdev );
/* Unregister per-netdev configuration settings */
unregister_settings ( netdev_settings ( netdev ) );
/* Remove from device list */
list_del ( &netdev->list );
netdev_put ( netdev );
DBGC ( netdev, "NETDEV %p unregistered\n", netdev );
}
/** Enable or disable interrupts
*
* @v netdev Network device
* @v enable Interrupts should be enabled
*/
void netdev_irq ( struct net_device *netdev, int enable ) {
netdev->op->irq ( netdev, enable );
}
/**
* Get network device by name
*
* @v name Network device name
* @ret netdev Network device, or NULL
*/
struct net_device * find_netdev ( const char *name ) {
struct net_device *netdev;
list_for_each_entry ( netdev, &net_devices, list ) {
if ( strcmp ( netdev->name, name ) == 0 )
return netdev;
}
return NULL;
}
/**
* Get network device by PCI bus:dev.fn address
*
* @v bus_type Bus type
* @v location Bus location
* @ret netdev Network device, or NULL
*/
struct net_device * find_netdev_by_location ( unsigned int bus_type,
unsigned int location ) {
struct net_device *netdev;
list_for_each_entry ( netdev, &net_devices, list ) {
if ( ( netdev->dev->desc.bus_type == bus_type ) &&
( netdev->dev->desc.location == location ) )
return netdev;
}
return NULL;
}
/**
* Get most recently opened network device
*
* @ret netdev Most recently opened network device, or NULL
*/
struct net_device * last_opened_netdev ( void ) {
struct net_device *netdev;
list_for_each_entry ( netdev, &open_net_devices, open_list ) {
assert ( netdev->state & NETDEV_OPEN );
return netdev;
}
return NULL;
}
/**
* Transmit network-layer packet
*
* @v iobuf I/O 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 I/O buffer and transmits the
* packet via the specified network device. This function takes
* ownership of the I/O buffer.
*/
int net_tx ( struct io_buffer *iobuf, struct net_device *netdev,
struct net_protocol *net_protocol, const void *ll_dest ) {
struct ll_protocol *ll_protocol = netdev->ll_protocol;
int rc;
/* Force a poll on the netdevice to (potentially) clear any
* backed-up TX completions. This is needed on some network
* devices to avoid excessive losses due to small TX ring
* sizes.
*/
netdev_poll ( netdev );
/* Add link-layer header */
if ( ( rc = ll_protocol->push ( iobuf, ll_dest, netdev->ll_addr,
net_protocol->net_proto ) ) != 0 ) {
free_iob ( iobuf );
return rc;
}
/* Transmit packet */
return netdev_tx ( netdev, iobuf );
}
/**
* Process received network-layer packet
*
* @v iobuf I/O 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 io_buffer *iobuf, 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_each_table_entry ( net_protocol, NET_PROTOCOLS ) {
if ( net_protocol->net_proto == net_proto )
return net_protocol->rx ( iobuf, netdev, ll_source );
}
DBGC ( netdev, "NETDEV %p unknown network protocol %04x\n",
netdev, ntohs ( net_proto ) );
free_iob ( iobuf );
return 0;
}
/**
* Single-step the network stack
*
* @v process Network stack process
*
* This polls all interfaces for received packets, and processes
* packets from the RX queue.
*/
static void net_step ( struct process *process __unused ) {
struct net_device *netdev;
struct io_buffer *iobuf;
struct ll_protocol *ll_protocol;
const void *ll_dest;
const void *ll_source;
uint16_t net_proto;
int rc;
/* Poll and process each network device */
list_for_each_entry ( netdev, &net_devices, list ) {
/* Poll for new packets */
netdev_poll ( netdev );
/* Process at most one received packet. Give priority
* to getting packets out of the NIC over processing
* the received packets, because we advertise a window
* that assumes that we can receive packets from the
* NIC faster than they arrive.
*/
if ( ( iobuf = netdev_rx_dequeue ( netdev ) ) ) {
DBGC ( netdev, "NETDEV %p processing %p (%p+%zx)\n",
netdev, iobuf, iobuf->data,
iob_len ( iobuf ) );
/* Remove link-layer header */
ll_protocol = netdev->ll_protocol;
if ( ( rc = ll_protocol->pull ( iobuf, &ll_dest,
&ll_source,
&net_proto ) ) != 0 ) {
free_iob ( iobuf );
continue;
}
net_rx ( iobuf, netdev, net_proto, ll_source );
}
}
}
/** Networking stack process */
struct process net_process __permanent_process = {
.step = net_step,
};
