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
llc_sk_dev_hash(struct llc_sap * sap,int ifindex)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
llc_sk_laddr_hashfn(struct llc_sap * sap,const struct llc_addr * laddr)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
llc_sk_laddr_hash(struct llc_sap * sap,const struct llc_addr * laddr)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));
llc_sap_hold(struct llc_sap * sap)115 static inline void llc_sap_hold(struct llc_sap *sap)
116 {
117 refcount_inc(&sap->refcnt);
118 }
119
llc_sap_hold_safe(struct llc_sap * sap)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
llc_sap_put(struct llc_sap * sap)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 */
164