1/*
2 * Generic HDLC support routines for Linux
3 *
4 * Copyright (C) 1999-2005 Krzysztof Halasa <khc@pm.waw.pl>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2 of the GNU General Public License
8 * as published by the Free Software Foundation.
9 */
10#ifndef __HDLC_H
11#define __HDLC_H
12
13
14#include <linux/skbuff.h>
15#include <linux/netdevice.h>
16#include <linux/hdlc/ioctl.h>
17#include <uapi/linux/hdlc.h>
18
19/* This structure is a private property of HDLC protocols.
20   Hardware drivers have no interest here */
21
22struct hdlc_proto {
23	int (*open)(struct net_device *dev);
24	void (*close)(struct net_device *dev);
25	void (*start)(struct net_device *dev); /* if open & DCD */
26	void (*stop)(struct net_device *dev); /* if open & !DCD */
27	void (*detach)(struct net_device *dev);
28	int (*ioctl)(struct net_device *dev, struct ifreq *ifr);
29	__be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev);
30	int (*netif_rx)(struct sk_buff *skb);
31	netdev_tx_t (*xmit)(struct sk_buff *skb, struct net_device *dev);
32	struct module *module;
33	struct hdlc_proto *next; /* next protocol in the list */
34};
35
36
37/* Pointed to by netdev_priv(dev) */
38typedef struct hdlc_device {
39	/* used by HDLC layer to take control over HDLC device from hw driver*/
40	int (*attach)(struct net_device *dev,
41		      unsigned short encoding, unsigned short parity);
42
43	/* hardware driver must handle this instead of dev->hard_start_xmit */
44	netdev_tx_t (*xmit)(struct sk_buff *skb, struct net_device *dev);
45
46	/* Things below are for HDLC layer internal use only */
47	const struct hdlc_proto *proto;
48	int carrier;
49	int open;
50	spinlock_t state_lock;
51	void *state;
52	void *priv;
53} hdlc_device;
54
55
56
57/* Exported from hdlc module */
58
59/* Called by hardware driver when a user requests HDLC service */
60int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
61
62/* Must be used by hardware driver on module startup/exit */
63#define register_hdlc_device(dev)	register_netdev(dev)
64void unregister_hdlc_device(struct net_device *dev);
65
66
67void register_hdlc_protocol(struct hdlc_proto *proto);
68void unregister_hdlc_protocol(struct hdlc_proto *proto);
69
70struct net_device *alloc_hdlcdev(void *priv);
71
72static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev)
73{
74	return netdev_priv(dev);
75}
76
77static __inline__ void debug_frame(const struct sk_buff *skb)
78{
79	int i;
80
81	for (i=0; i < skb->len; i++) {
82		if (i == 100) {
83			printk("...\n");
84			return;
85		}
86		printk(" %02X", skb->data[i]);
87	}
88	printk("\n");
89}
90
91
92/* Must be called by hardware driver when HDLC device is being opened */
93int hdlc_open(struct net_device *dev);
94/* Must be called by hardware driver when HDLC device is being closed */
95void hdlc_close(struct net_device *dev);
96/* May be used by hardware driver */
97int hdlc_change_mtu(struct net_device *dev, int new_mtu);
98/* Must be pointed to by hw driver's dev->netdev_ops->ndo_start_xmit */
99netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev);
100
101int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
102			 size_t size);
103/* May be used by hardware driver to gain control over HDLC device */
104void detach_hdlc_protocol(struct net_device *dev);
105
106static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
107					 struct net_device *dev)
108{
109	hdlc_device *hdlc = dev_to_hdlc(dev);
110
111	skb->dev = dev;
112	skb_reset_mac_header(skb);
113
114	if (hdlc->proto->type_trans)
115		return hdlc->proto->type_trans(skb, dev);
116	else
117		return htons(ETH_P_HDLC);
118}
119
120#endif /* __HDLC_H */
121