release/src-rt-6.x.4708/linux/linux-2.6.36/include/linux/hdlc.h

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