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/* $Id: concap.h,v 2004/01/12 23:08:35 keil Exp $
* Copyright 1997 by Henner Eisen <>
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
#include <linux/skbuff.h>
#include <linux/netdevice.h>
/* Stuff to support encapsulation protocols genericly. The encapsulation
protocol is processed at the uppermost layer of the network interface.
Based on a ideas developed in a 'synchronous device' thread in the
linux-x25 mailing list contributed by Alan Cox, Thomasz Motylewski
and Jonathan Naylor.
For more documetation on this refer to Documentation/isdn/README.concap
struct concap_proto_ops;
struct concap_device_ops;
/* this manages all data needed by the encapsulation protocol
struct concap_proto{
struct net_device *net_dev; /* net device using our service */
struct concap_device_ops *dops; /* callbacks provided by device */
struct concap_proto_ops *pops; /* callbacks provided by us */
spinlock_t lock;
int flags;
void *proto_data; /* protocol specific private data, to
be accessed via *pops methods only*/
/* Operations to be supported by the net device. Called by the encapsulation
* protocol entity. No receive method is offered because the encapsulation
* protocol directly calls netif_rx().
struct concap_device_ops{
/* to request data is submitted by device*/
int (*data_req)(struct concap_proto *, struct sk_buff *);
/* Control methods must be set to NULL by devices which do not
support connection control.*/
/* to request a connection is set up */
int (*connect_req)(struct concap_proto *);
/* to request a connection is released */
int (*disconn_req)(struct concap_proto *);
/* Operations to be supported by the encapsulation protocol. Called by
* device driver.
struct concap_proto_ops{
/* create a new encapsulation protocol instance of same type */
struct concap_proto * (*proto_new) (void);
/* delete encapsulation protocol instance and free all its resources.
cprot may no loger be referenced after calling this */
void (*proto_del)(struct concap_proto *cprot);
/* initialize the protocol's data. To be called at interface startup
or when the device driver resets the interface. All services of the
encapsulation protocol may be used after this*/
int (*restart)(struct concap_proto *cprot,
struct net_device *ndev,
struct concap_device_ops *dops);
/* inactivate an encapsulation protocol instance. The encapsulation
protocol may not call any *dops methods after this. */
int (*close)(struct concap_proto *cprot);
/* process a frame handed down to us by upper layer */
int (*encap_and_xmit)(struct concap_proto *cprot, struct sk_buff *skb);
/* to be called for each data entity received from lower layer*/
int (*data_ind)(struct concap_proto *cprot, struct sk_buff *skb);
/* to be called when a connection was set up/down.
Protocols that don't process these primitives might fill in
dummy methods here */
int (*connect_ind)(struct concap_proto *cprot);
int (*disconn_ind)(struct concap_proto *cprot);
Some network device support functions, like net_header(), rebuild_header(),
and others, that depend solely on the encapsulation protocol, might
be provided here, too. The net device would just fill them in its
corresponding fields when it is opened.
/* dummy restart/close/connect/reset/disconn methods
extern int concap_nop(struct concap_proto *cprot);
/* dummy submit method
extern int concap_drop_skb(struct concap_proto *cprot, struct sk_buff *skb);