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/* This structure is a private property of HDLC protocols. 30 Hardware drivers have no interest here */ 31 32struct hdlc_proto { 33 int (*open)(struct net_device *dev); 34 void (*close)(struct net_device *dev); 35 void (*start)(struct net_device *dev); /* if open & DCD */ 36 void (*stop)(struct net_device *dev); /* if open & !DCD */ 37 void (*detach)(struct net_device *dev); 38 int (*ioctl)(struct net_device *dev, struct ifreq *ifr); 39 __be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev); 40 int (*netif_rx)(struct sk_buff *skb); 41 netdev_tx_t (*xmit)(struct sk_buff *skb, struct net_device *dev); 42 struct module *module; 43 struct hdlc_proto *next; /* next protocol in the list */ 44}; 45 46 47/* Pointed to by netdev_priv(dev) */ 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 netdev_tx_t (*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 82static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev) 83{ 84 return netdev_priv(dev); 85} 86 87static __inline__ void debug_frame(const struct sk_buff *skb) 88{ 89 int i; 90 91 for (i=0; i < skb->len; i++) { 92 if (i == 100) { 93 printk("...\n"); 94 return; 95 } 96 printk(" %02X", skb->data[i]); 97 } 98 printk("\n"); 99} 100 101 102/* Must be called by hardware driver when HDLC device is being opened */ 103int hdlc_open(struct net_device *dev); 104/* Must be called by hardware driver when HDLC device is being closed */ 105void hdlc_close(struct net_device *dev); 106/* May be used by hardware driver */ 107int hdlc_change_mtu(struct net_device *dev, int new_mtu); 108/* Must be pointed to by hw driver's dev->netdev_ops->ndo_start_xmit */ 109netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev); 110 111int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, 112 size_t size); 113/* May be used by hardware driver to gain control over HDLC device */ 114void detach_hdlc_protocol(struct net_device *dev); 115 116static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb, 117 struct net_device *dev) 118{ 119 hdlc_device *hdlc = dev_to_hdlc(dev); 120 121 skb->dev = dev; 122 skb_reset_mac_header(skb); 123 124 if (hdlc->proto->type_trans) 125 return hdlc->proto->type_trans(skb, dev); 126 else 127 return htons(ETH_P_HDLC); 128} 129 130#endif /* __KERNEL */ 131#endif /* __HDLC_H */ 132