1 /* 2 * Generic HDLC support routines for Linux 3 * 4 * Copyright (C) 1999-2005 Krzysztof Halasa <[email protected]> 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 32 struct 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 struct module *module; 42 struct hdlc_proto *next; /* next protocol in the list */ 43 }; 44 45 46 /* Pointed to by dev->priv */ 47 typedef struct hdlc_device { 48 /* used by HDLC layer to take control over HDLC device from hw driver*/ 49 int (*attach)(struct net_device *dev, 50 unsigned short encoding, unsigned short parity); 51 52 /* hardware driver must handle this instead of dev->hard_start_xmit */ 53 int (*xmit)(struct sk_buff *skb, struct net_device *dev); 54 55 /* Things below are for HDLC layer internal use only */ 56 const struct hdlc_proto *proto; 57 int carrier; 58 int open; 59 spinlock_t state_lock; 60 void *state; 61 void *priv; 62 }hdlc_device; 63 64 65 66 /* Exported from hdlc module */ 67 68 /* Called by hardware driver when a user requests HDLC service */ 69 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 70 71 /* Must be used by hardware driver on module startup/exit */ 72 #define register_hdlc_device(dev) register_netdev(dev) 73 void unregister_hdlc_device(struct net_device *dev); 74 75 76 void register_hdlc_protocol(struct hdlc_proto *proto); 77 void unregister_hdlc_protocol(struct hdlc_proto *proto); 78 79 struct net_device *alloc_hdlcdev(void *priv); 80 81 static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev) 82 { 83 return netdev_priv(dev); 84 } 85 86 static __inline__ void debug_frame(const struct sk_buff *skb) 87 { 88 int i; 89 90 for (i=0; i < skb->len; i++) { 91 if (i == 100) { 92 printk("...\n"); 93 return; 94 } 95 printk(" %02X", skb->data[i]); 96 } 97 printk("\n"); 98 } 99 100 101 /* Must be called by hardware driver when HDLC device is being opened */ 102 int hdlc_open(struct net_device *dev); 103 /* Must be called by hardware driver when HDLC device is being closed */ 104 void hdlc_close(struct net_device *dev); 105 106 int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, 107 size_t size); 108 /* May be used by hardware driver to gain control over HDLC device */ 109 void detach_hdlc_protocol(struct net_device *dev); 110 111 static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb, 112 struct net_device *dev) 113 { 114 hdlc_device *hdlc = dev_to_hdlc(dev); 115 116 skb->dev = dev; 117 skb_reset_mac_header(skb); 118 119 if (hdlc->proto->type_trans) 120 return hdlc->proto->type_trans(skb, dev); 121 else 122 return htons(ETH_P_HDLC); 123 } 124 125 #endif /* __KERNEL */ 126 #endif /* __HDLC_H */ 127