LXR linux/include/net/llc.h

   1#ifndef LLC_H
   2#define LLC_H
   3/*
   4 * Copyright (c) 1997 by Procom Technology, Inc.
   5 *               2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6 *
   7 * This program can be redistributed or modified under the terms of the
   8 * GNU General Public License as published by the Free Software Foundation.
   9 * This program is distributed without any warranty or implied warranty
  10 * of merchantability or fitness for a particular purpose.
  11 *
  12 * See the GNU General Public License for more details.
  13 */
  14
  15#include <linux/if.h>
  16#include <linux/if_ether.h>
  17#include <linux/list.h>
  18#include <linux/spinlock.h>
  19#include <linux/rculist_nulls.h>
  20#include <linux/hash.h>
  21#include <linux/jhash.h>
  22
  23#include <linux/atomic.h>
  24
  25struct net_device;
  26struct packet_type;
  27struct sk_buff;
  28
  29struct llc_addr {
  30        unsigned char lsap;
  31        unsigned char mac[IFHWADDRLEN];
  32};
  33
  34#define LLC_SAP_STATE_INACTIVE  1
  35#define LLC_SAP_STATE_ACTIVE    2
  36
  37#define LLC_SK_DEV_HASH_BITS 6
  38#define LLC_SK_DEV_HASH_ENTRIES (1<<LLC_SK_DEV_HASH_BITS)
  39
  40#define LLC_SK_LADDR_HASH_BITS 6
  41#define LLC_SK_LADDR_HASH_ENTRIES (1<<LLC_SK_LADDR_HASH_BITS)
  42
  43/**
  44 * struct llc_sap - Defines the SAP component
  45 *
  46 * @station - station this sap belongs to
  47 * @state - sap state
  48 * @p_bit - only lowest-order bit used
  49 * @f_bit - only lowest-order bit used
  50 * @laddr - SAP value in this 'lsap'
  51 * @node - entry in station sap_list
  52 * @sk_list - LLC sockets this one manages
  53 */
  54struct llc_sap {
  55        unsigned char    state;
  56        unsigned char    p_bit;
  57        unsigned char    f_bit;
  58        refcount_t               refcnt;
  59        int              (*rcv_func)(struct sk_buff *skb,
  60                                     struct net_device *dev,
  61                                     struct packet_type *pt,
  62                                     struct net_device *orig_dev);
  63        struct llc_addr  laddr;
  64        struct list_head node;
  65        spinlock_t sk_lock;
  66        int sk_count;
  67        struct hlist_nulls_head sk_laddr_hash[LLC_SK_LADDR_HASH_ENTRIES];
  68        struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES];
  69        struct rcu_head rcu;
  70};
  71
  72static inline
  73struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
  74{
  75        return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES];
  76}
  77
  78static inline
  79u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
  80{
  81        return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
  82                       LLC_SK_LADDR_HASH_BITS);
  83}
  84
  85static inline
  86struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
  87                                           const struct llc_addr *laddr)
  88{
  89        return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
  90}
  91
  92#define LLC_DEST_INVALID         0      /* Invalid LLC PDU type */
  93#define LLC_DEST_SAP             1      /* Type 1 goes here */
  94#define LLC_DEST_CONN            2      /* Type 2 goes here */
  95
  96extern struct list_head llc_sap_list;
  97
  98int llc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
  99            struct net_device *orig_dev);
 100
 101int llc_mac_hdr_init(struct sk_buff *skb, const unsigned char *sa,
 102                     const unsigned char *da);
 103
 104void llc_add_pack(int type,
 105                  void (*handler)(struct llc_sap *sap, struct sk_buff *skb));
 106void llc_remove_pack(int type);
 107
 108void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
 109
 110struct llc_sap *llc_sap_open(unsigned char lsap,
 111                             int (*rcv)(struct sk_buff *skb,
 112                                        struct net_device *dev,
 113                                        struct packet_type *pt,
 114                                        struct net_device *orig_dev));
 115static inline void llc_sap_hold(struct llc_sap *sap)
 116{
 117        refcount_inc(&sap->refcnt);
 118}
 119
 120static inline bool llc_sap_hold_safe(struct llc_sap *sap)
 121{
 122        return refcount_inc_not_zero(&sap->refcnt);
 123}
 124
 125void llc_sap_close(struct llc_sap *sap);
 126
 127static inline void llc_sap_put(struct llc_sap *sap)
 128{
 129        if (refcount_dec_and_test(&sap->refcnt))
 130                llc_sap_close(sap);
 131}
 132
 133struct llc_sap *llc_sap_find(unsigned char sap_value);
 134
 135int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
 136                              unsigned char *dmac, unsigned char dsap);
 137
 138void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
 139void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
 140
 141void llc_station_init(void);
 142void llc_station_exit(void);
 143
 144#ifdef CONFIG_PROC_FS
 145int llc_proc_init(void);
 146void llc_proc_exit(void);
 147#else
 148#define llc_proc_init() (0)
 149#define llc_proc_exit() do { } while(0)
 150#endif /* CONFIG_PROC_FS */
 151#ifdef CONFIG_SYSCTL
 152int llc_sysctl_init(void);
 153void llc_sysctl_exit(void);
 154
 155extern int sysctl_llc2_ack_timeout;
 156extern int sysctl_llc2_busy_timeout;
 157extern int sysctl_llc2_p_timeout;
 158extern int sysctl_llc2_rej_timeout;
 159#else
 160#define llc_sysctl_init() (0)
 161#define llc_sysctl_exit() do { } while(0)
 162#endif /* CONFIG_SYSCTL */
 163#endif /* LLC_H */
 164