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
  25 struct net_device;
  26 struct packet_type;
  27 struct sk_buff;
  28
  29 struct 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  */
  54 struct 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
  72 static inline
  73 struct 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
  78 static inline
  79 u32 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
  85 static inline
  86 struct 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
  96 extern struct list_head llc_sap_list;
  97
  98 int llc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
  99             struct net_device *orig_dev);
 100
 101 int llc_mac_hdr_init(struct sk_buff *skb, const unsigned char *sa,
 102                      const unsigned char *da);
 103
 104 void llc_add_pack(int type,
 105                   void (*handler)(struct llc_sap *sap, struct sk_buff *skb));
 106 void llc_remove_pack(int type);
 107
 108 void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
 109
 110 struct 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));
 115 static inline void llc_sap_hold(struct llc_sap *sap)
 116 {
 117         refcount_inc(&sap->refcnt);
 118 }
 119
 120 static inline bool llc_sap_hold_safe(struct llc_sap *sap)
 121 {
 122         return refcount_inc_not_zero(&sap->refcnt);
 123 }
 124
 125 void llc_sap_close(struct llc_sap *sap);
 126
 127 static 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
 133 struct llc_sap *llc_sap_find(unsigned char sap_value);
 134
 135 int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
 136                               unsigned char *dmac, unsigned char dsap);
 137
 138 void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
 139 void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
 140
 141 void llc_station_init(void);
 142 void llc_station_exit(void);
 143
 144 #ifdef CONFIG_PROC_FS
 145 int llc_proc_init(void);
 146 void 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
 152 int llc_sysctl_init(void);
 153 void llc_sysctl_exit(void);
 154
 155 extern int sysctl_llc2_ack_timeout;
 156 extern int sysctl_llc2_busy_timeout;
 157 extern int sysctl_llc2_p_timeout;
 158 extern 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 */