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
22 struct 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) */
38 typedef 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 */
60 int 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)
64 void unregister_hdlc_device(struct net_device *dev);
65
66
67 void register_hdlc_protocol(struct hdlc_proto *proto);
68 void unregister_hdlc_protocol(struct hdlc_proto *proto);
69
70 struct net_device *alloc_hdlcdev(void *priv);
71
dev_to_hdlc(struct net_device * dev)72 static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev)
73 {
74 return netdev_priv(dev);
75 }
76
debug_frame(const struct sk_buff * skb)77 static __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 */
93 int hdlc_open(struct net_device *dev);
94 /* Must be called by hardware driver when HDLC device is being closed */
95 void hdlc_close(struct net_device *dev);
96 /* Must be pointed to by hw driver's dev->netdev_ops->ndo_start_xmit */
97 netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev);
98
99 int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
100 size_t size);
101 /* May be used by hardware driver to gain control over HDLC device */
102 int detach_hdlc_protocol(struct net_device *dev);
103
hdlc_type_trans(struct sk_buff * skb,struct net_device * dev)104 static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
105 struct net_device *dev)
106 {
107 hdlc_device *hdlc = dev_to_hdlc(dev);
108
109 skb->dev = dev;
110 skb_reset_mac_header(skb);
111
112 if (hdlc->proto->type_trans)
113 return hdlc->proto->type_trans(skb, dev);
114 else
115 return htons(ETH_P_HDLC);
116 }
117
118 #endif /* __HDLC_H */
119