1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Generic HDLC support routines for Linux
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 1999-2005 Krzysztof Halasa <khc@pm.waw.pl>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun #ifndef __HDLC_H
8*4882a593Smuzhiyun #define __HDLC_H
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <linux/skbuff.h>
12*4882a593Smuzhiyun #include <linux/netdevice.h>
13*4882a593Smuzhiyun #include <linux/hdlc/ioctl.h>
14*4882a593Smuzhiyun #include <uapi/linux/hdlc.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /* This structure is a private property of HDLC protocols.
17*4882a593Smuzhiyun Hardware drivers have no interest here */
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun struct hdlc_proto {
20*4882a593Smuzhiyun int (*open)(struct net_device *dev);
21*4882a593Smuzhiyun void (*close)(struct net_device *dev);
22*4882a593Smuzhiyun void (*start)(struct net_device *dev); /* if open & DCD */
23*4882a593Smuzhiyun void (*stop)(struct net_device *dev); /* if open & !DCD */
24*4882a593Smuzhiyun void (*detach)(struct net_device *dev);
25*4882a593Smuzhiyun int (*ioctl)(struct net_device *dev, struct ifreq *ifr);
26*4882a593Smuzhiyun __be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev);
27*4882a593Smuzhiyun int (*netif_rx)(struct sk_buff *skb);
28*4882a593Smuzhiyun netdev_tx_t (*xmit)(struct sk_buff *skb, struct net_device *dev);
29*4882a593Smuzhiyun struct module *module;
30*4882a593Smuzhiyun struct hdlc_proto *next; /* next protocol in the list */
31*4882a593Smuzhiyun };
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun /* Pointed to by netdev_priv(dev) */
35*4882a593Smuzhiyun typedef struct hdlc_device {
36*4882a593Smuzhiyun /* used by HDLC layer to take control over HDLC device from hw driver*/
37*4882a593Smuzhiyun int (*attach)(struct net_device *dev,
38*4882a593Smuzhiyun unsigned short encoding, unsigned short parity);
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun /* hardware driver must handle this instead of dev->hard_start_xmit */
41*4882a593Smuzhiyun netdev_tx_t (*xmit)(struct sk_buff *skb, struct net_device *dev);
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /* Things below are for HDLC layer internal use only */
44*4882a593Smuzhiyun const struct hdlc_proto *proto;
45*4882a593Smuzhiyun int carrier;
46*4882a593Smuzhiyun int open;
47*4882a593Smuzhiyun spinlock_t state_lock;
48*4882a593Smuzhiyun void *state;
49*4882a593Smuzhiyun void *priv;
50*4882a593Smuzhiyun } hdlc_device;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun /* Exported from hdlc module */
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun /* Called by hardware driver when a user requests HDLC service */
57*4882a593Smuzhiyun int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun /* Must be used by hardware driver on module startup/exit */
60*4882a593Smuzhiyun #define register_hdlc_device(dev) register_netdev(dev)
61*4882a593Smuzhiyun void unregister_hdlc_device(struct net_device *dev);
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun void register_hdlc_protocol(struct hdlc_proto *proto);
65*4882a593Smuzhiyun void unregister_hdlc_protocol(struct hdlc_proto *proto);
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun struct net_device *alloc_hdlcdev(void *priv);
68*4882a593Smuzhiyun
dev_to_hdlc(struct net_device * dev)69*4882a593Smuzhiyun static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun return netdev_priv(dev);
72*4882a593Smuzhiyun }
73*4882a593Smuzhiyun
debug_frame(const struct sk_buff * skb)74*4882a593Smuzhiyun static __inline__ void debug_frame(const struct sk_buff *skb)
75*4882a593Smuzhiyun {
76*4882a593Smuzhiyun int i;
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun for (i=0; i < skb->len; i++) {
79*4882a593Smuzhiyun if (i == 100) {
80*4882a593Smuzhiyun printk("...\n");
81*4882a593Smuzhiyun return;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun printk(" %02X", skb->data[i]);
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun printk("\n");
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun /* Must be called by hardware driver when HDLC device is being opened */
90*4882a593Smuzhiyun int hdlc_open(struct net_device *dev);
91*4882a593Smuzhiyun /* Must be called by hardware driver when HDLC device is being closed */
92*4882a593Smuzhiyun void hdlc_close(struct net_device *dev);
93*4882a593Smuzhiyun /* Must be pointed to by hw driver's dev->netdev_ops->ndo_start_xmit */
94*4882a593Smuzhiyun netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev);
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
97*4882a593Smuzhiyun size_t size);
98*4882a593Smuzhiyun /* May be used by hardware driver to gain control over HDLC device */
99*4882a593Smuzhiyun int detach_hdlc_protocol(struct net_device *dev);
100*4882a593Smuzhiyun
hdlc_type_trans(struct sk_buff * skb,struct net_device * dev)101*4882a593Smuzhiyun static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
102*4882a593Smuzhiyun struct net_device *dev)
103*4882a593Smuzhiyun {
104*4882a593Smuzhiyun hdlc_device *hdlc = dev_to_hdlc(dev);
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun skb->dev = dev;
107*4882a593Smuzhiyun skb_reset_mac_header(skb);
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun if (hdlc->proto->type_trans)
110*4882a593Smuzhiyun return hdlc->proto->type_trans(skb, dev);
111*4882a593Smuzhiyun else
112*4882a593Smuzhiyun return htons(ETH_P_HDLC);
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun #endif /* __HDLC_H */
116