#ifndef _NETDEVICE_H
#define _NETDEVICE_H
/** @file
*
* Network device and network interface
*
*/
#include <stdint.h>
#include <gpxe/list.h>
struct net_device;
struct net_interface;
struct pk_buff;
/** Maximum length of a link-layer address */
#define MAX_LLH_ADDR_LEN 6
/** Maximum length of a network-layer address */
#define MAX_NET_ADDR_LEN 4
/**
* A network device
*
* This structure represents a piece of networking hardware. It has
* properties such as a link-layer address and methods for
* transmitting and receiving raw packets. It does not know anything
* about network-layer protocols (e.g. IP) or their addresses; these
* are handled by struct @c net_interface instead.
*
* Note that this structure must represent a generic network device,
* not just an Ethernet device.
*/
struct net_device {
/** Transmit packet
*
* @v netdev Network device
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method should cause the hardware to initiate
* transmission of the packet buffer. The buffer may be
* reused immediately after the method returns, and so the
* method should either wait for packet transmission to
* complete, or take a copy of the buffer contents.
*/
int ( * transmit ) ( struct net_device *netdev,
struct pk_buff *pkb );
/** Poll for received packet
*
* @v netdev Network device
* @v pkb Packet buffer to contain received packet
* @ret rc Return status code
*
* This method should cause the hardware to check for a
* received packet. If no packet is available, the method
* should return -EAGAIN (i.e. this method is *always*
* considered to be a non-blocking read). If a packet is
* available, the method should fill the packet buffer and
* return zero for success.
*/
int ( * poll ) ( struct net_device *netdev, struct pk_buff *pkb );
/** Build link-layer header
*
* @v netdev Network device
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method should fill in the link-layer header based on
* the metadata contained in @c pkb.
*
* If a link-layer header cannot be constructed (e.g. because
* of a missing ARP cache entry), then this method should
* return an error (after transmitting an ARP request, if
* applicable).
*/
int ( * build_llh ) ( struct net_device *netdev, struct pk_buff *pkb );
/** Parse link-layer header
*
* @v netdev Network device
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method should parse the link-layer header and fill in
* the metadata in @c pkb.
*/
int ( * parse_llh ) ( struct net_device *netdev, struct pk_buff *pkb );
/** Link-layer protocol
*
* This is an ARPHRD_XXX constant, in network byte order.
*/
uint16_t ll_proto;
/** Link-layer header length */
uint8_t ll_hlen;
/** Link-layer address length */
uint8_t ll_addr_len;
/** Link-layer address
*
* For Ethernet, this is the MAC address.
*/
uint8_t ll_addr[MAX_LLH_ADDR_LEN];
/** List of network interfaces */
struct list_head interfaces;
/** Driver private data */
void *priv;
};
/**
* A network interface
*
* This structure represents a particular network layer protocol's
* interface to a piece of network hardware (a struct @c net_device).
*
*/
struct net_interface {
/** Underlying net device */
struct net_device *netdev;
/** Linked list of interfaces for this device */
struct list_head list;
/** Network-layer protocol
*
* This is an ETH_P_XXX constant, in network byte order.
*/
uint16_t net_proto;
/** Network-layer address length */
uint8_t net_addr_len;
/** Network-layer address */
uint8_t net_addr[MAX_NET_ADDR_LEN];
/** Packet processor
*
* @v netif Network interface
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method is called for packets arriving on the
* associated network device that match this interface's
* network-layer protocol.
*
* When this method is called, the link-layer header will
* already have been stripped from the packet.
*/
int ( * process ) ( struct net_interface *netif,
struct pk_buff *pkb );
/** Fill in packet metadata
*
* @v netif Network interface
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method should fill in the @c pkb metadata with enough
* information to enable net_device::build_llh to construct
* the link-layer header.
*/
int ( * add_llh_metadata ) ( struct net_interface *netif,
struct pk_buff *pkb );
};
/**
* Find interface for a specific protocol
*
* @v netdev Network device
* @v net_proto Network-layer protocol, in network byte order
* @ret netif Network interface, or NULL if none found
*
*/
static inline struct net_interface *
netdev_find_netif ( const struct net_device *netdev, uint16_t net_proto ) {
struct net_interface *netif;
list_for_each_entry ( netif, &netdev->interfaces, list ) {
if ( netif->net_proto == net_proto )
return netif;
}
return NULL;
}
extern int netdev_send ( struct net_device *netdev, struct pk_buff *pkb );
extern int netif_send ( struct net_interface *netif, struct pk_buff *pkb );
extern struct net_device static_single_netdev;
/* Must be a macro because priv_data[] is of variable size */
#define alloc_netdevice( priv_size ) ( { \
static char priv_data[priv_size]; \
static_single_netdev.priv = priv_data; \
&static_single_netdev; } )
extern int register_netdevice ( struct net_device *netdev );
extern void unregister_netdevice ( struct net_device *netdev );
static inline void free_netdevice ( struct net_device *netdev __unused ) {
/* Do nothing */
}
#endif /* _NETDEVICE_H */
