linux/include/linux/hdlc.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Generic HDLC support routines for Linux
 *
 * Copyright (C) 1999-2005 Krzysztof Halasa <[email protected]>
 */
#ifndef __HDLC_H
#define __HDLC_H


#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/hdlc/ioctl.h>
#include <uapi/linux/hdlc.h>

/* This structure is a private property of HDLC protocols.
   Hardware drivers have no interest here */

struct hdlc_proto { … };


/* Pointed to by netdev_priv(dev) */
hdlc_device;



/* Exported from hdlc module */

/* Called by hardware driver when a user requests HDLC service */
int hdlc_ioctl(struct net_device *dev, struct if_settings *ifs);

/* Must be used by hardware driver on module startup/exit */
#define register_hdlc_device(dev) …
void unregister_hdlc_device(struct net_device *dev);


void register_hdlc_protocol(struct hdlc_proto *proto);
void unregister_hdlc_protocol(struct hdlc_proto *proto);

struct net_device *alloc_hdlcdev(void *priv);

static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev)
{ … }

static __inline__ void debug_frame(const struct sk_buff *skb)
{ … }


/* Must be called by hardware driver when HDLC device is being opened */
int hdlc_open(struct net_device *dev);
/* Must be called by hardware driver when HDLC device is being closed */
void hdlc_close(struct net_device *dev);
/* Must be pointed to by hw driver's dev->netdev_ops->ndo_start_xmit */
netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev);

int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
			 size_t size);
/* May be used by hardware driver to gain control over HDLC device */
int detach_hdlc_protocol(struct net_device *dev);

static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
					 struct net_device *dev)
{ … }

#endif /* __HDLC_H */