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 #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 72 static inline struct hdlc_device* dev_to_hdlc(struct net_device *dev) 73 { 74 return netdev_priv(dev); 75 } 76 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); 103 104 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