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