Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
11#ifndef __HDLC_H
12#define __HDLC_H
13
14
15#define HDLC_MAX_MTU 1500 /* Ethernet 1500 bytes */
16#if 0
17#define HDLC_MAX_MRU (HDLC_MAX_MTU + 10 + 14 + 4) /* for ETH+VLAN over FR */
18#else
19#define HDLC_MAX_MRU 1600 /* as required for FR network */
20#endif
21
22
23#ifdef __KERNEL__
24
25#include <linux/skbuff.h>
26#include <linux/netdevice.h>
27#include <linux/hdlc/ioctl.h>
28
29
30/* Used by all network devices here, pointed to by netdev_priv(dev) */
31struct hdlc_device_desc {
32 int (*netif_rx)(struct sk_buff *skb);
33 struct net_device_stats stats;
34};
35
36/* This structure is a private property of HDLC protocols.
37 Hardware drivers have no interest here */
38
39struct hdlc_proto {
40 int (*open)(struct net_device *dev);
41 void (*close)(struct net_device *dev);
42 void (*start)(struct net_device *dev); /* if open & DCD */
43 void (*stop)(struct net_device *dev); /* if open & !DCD */
44 void (*detach)(struct net_device *dev);
45 int (*ioctl)(struct net_device *dev, struct ifreq *ifr);
46 __be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev);
47 struct module *module;
48 struct hdlc_proto *next; /* next protocol in the list */
49};
50
51
52typedef struct hdlc_device {
53 /* used by HDLC layer to take control over HDLC device from hw driver*/
54 int (*attach)(struct net_device *dev,
55 unsigned short encoding, unsigned short parity);
56
57 /* hardware driver must handle this instead of dev->hard_start_xmit */
58 int (*xmit)(struct sk_buff *skb, struct net_device *dev);
59
60 /* Things below are for HDLC layer internal use only */
61 const struct hdlc_proto *proto;
62 int carrier;
63 int open;
64 spinlock_t state_lock;
65 void *state;
66 void *priv;
67}hdlc_device;
68
69
70
71/* Exported from hdlc module */
72
73/* Called by hardware driver when a user requests HDLC service */
74int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
75
76/* Must be used by hardware driver on module startup/exit */
77#define register_hdlc_device(dev) register_netdev(dev)
78void unregister_hdlc_device(struct net_device *dev);
79
80
81void register_hdlc_protocol(struct hdlc_proto *proto);
82void unregister_hdlc_protocol(struct hdlc_proto *proto);
83
84struct net_device *alloc_hdlcdev(void *priv);
85
86
87static __inline__ struct hdlc_device_desc* dev_to_desc(struct net_device *dev)
88{
89 return netdev_priv(dev);
90}
91
92static __inline__ hdlc_device* dev_to_hdlc(struct net_device *dev)
93{
94 return netdev_priv(dev) + sizeof(struct hdlc_device_desc);
95}
96
97
98static __inline__ void debug_frame(const struct sk_buff *skb)
99{
100 int i;
101
102 for (i=0; i < skb->len; i++) {
103 if (i == 100) {
104 printk("...\n");
105 return;
106 }
107 printk(" %02X", skb->data[i]);
108 }
109 printk("\n");
110}
111
112
113/* Must be called by hardware driver when HDLC device is being opened */
114int hdlc_open(struct net_device *dev);
115/* Must be called by hardware driver when HDLC device is being closed */
116void hdlc_close(struct net_device *dev);
117
118int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
119 int (*rx)(struct sk_buff *skb), size_t size);
120/* May be used by hardware driver to gain control over HDLC device */
121void detach_hdlc_protocol(struct net_device *dev);
122
123static __inline__ struct net_device_stats *hdlc_stats(struct net_device *dev)
124{
125 return &dev_to_desc(dev)->stats;
126}
127
128
129static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
130 struct net_device *dev)
131{
132 hdlc_device *hdlc = dev_to_hdlc(dev);
133
134 skb->dev = dev;
135 skb_reset_mac_header(skb);
136
137 if (hdlc->proto->type_trans)
138 return hdlc->proto->type_trans(skb, dev);
139 else
140 return htons(ETH_P_HDLC);
141}
142
143#endif /* __KERNEL */
144#endif /* __HDLC_H */