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 u32 bucket = hash_32(ifindex, LLC_SK_DEV_HASH_BITS);
76
77 return &sap->sk_dev_hash[bucket];
78 }
79
80 static inline
llc_sk_laddr_hashfn(struct llc_sap * sap,const struct llc_addr * laddr)81 u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
82 {
83 return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
84 LLC_SK_LADDR_HASH_BITS);
85 }
86
87 static inline
llc_sk_laddr_hash(struct llc_sap * sap,const struct llc_addr * laddr)88 struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
89 const struct llc_addr *laddr)
90 {
91 return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
92 }
93
94 #define LLC_DEST_INVALID 0 /* Invalid LLC PDU type */
95 #define LLC_DEST_SAP 1 /* Type 1 goes here */
96 #define LLC_DEST_CONN 2 /* Type 2 goes here */
97
98 extern struct list_head llc_sap_list;
99
100 int llc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
101 struct net_device *orig_dev);
102
103 int llc_mac_hdr_init(struct sk_buff *skb, const unsigned char *sa,
104 const unsigned char *da);
105
106 void llc_add_pack(int type,
107 void (*handler)(struct llc_sap *sap, struct sk_buff *skb));
108 void llc_remove_pack(int type);
109
110 void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
111
112 struct llc_sap *llc_sap_open(unsigned char lsap,
113 int (*rcv)(struct sk_buff *skb,
114 struct net_device *dev,
115 struct packet_type *pt,
116 struct net_device *orig_dev));
llc_sap_hold(struct llc_sap * sap)117 static inline void llc_sap_hold(struct llc_sap *sap)
118 {
119 refcount_inc(&sap->refcnt);
120 }
121
llc_sap_hold_safe(struct llc_sap * sap)122 static inline bool llc_sap_hold_safe(struct llc_sap *sap)
123 {
124 return refcount_inc_not_zero(&sap->refcnt);
125 }
126
127 void llc_sap_close(struct llc_sap *sap);
128
llc_sap_put(struct llc_sap * sap)129 static inline void llc_sap_put(struct llc_sap *sap)
130 {
131 if (refcount_dec_and_test(&sap->refcnt))
132 llc_sap_close(sap);
133 }
134
135 struct llc_sap *llc_sap_find(unsigned char sap_value);
136
137 int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
138 const unsigned char *dmac, unsigned char dsap);
139
140 void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
141 void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
142
143 void llc_station_init(void);
144 void llc_station_exit(void);
145
146 #ifdef CONFIG_PROC_FS
147 int llc_proc_init(void);
148 void llc_proc_exit(void);
149 #else
150 #define llc_proc_init() (0)
151 #define llc_proc_exit() do { } while(0)
152 #endif /* CONFIG_PROC_FS */
153 #ifdef CONFIG_SYSCTL
154 int llc_sysctl_init(void);
155 void llc_sysctl_exit(void);
156
157 extern int sysctl_llc2_ack_timeout;
158 extern int sysctl_llc2_busy_timeout;
159 extern int sysctl_llc2_p_timeout;
160 extern int sysctl_llc2_rej_timeout;
161 #else
162 #define llc_sysctl_init() (0)
163 #define llc_sysctl_exit() do { } while(0)
164 #endif /* CONFIG_SYSCTL */
165 #endif /* LLC_H */
166