xref: /openbmc/linux/include/net/llc.h (revision 63705da3)
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 	u32 bucket = hash_32(ifindex, LLC_SK_DEV_HASH_BITS);
76 
77 	return &sap->sk_dev_hash[bucket];
78 }
79 
80 static inline
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
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));
117 static inline void llc_sap_hold(struct llc_sap *sap)
118 {
119 	refcount_inc(&sap->refcnt);
120 }
121 
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 
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