xref: /openbmc/linux/include/net/llc.h (revision 93f5715e)
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 };
70 
71 static inline
72 struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
73 {
74 	return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES];
75 }
76 
77 static inline
78 u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
79 {
80 	return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
81 		       LLC_SK_LADDR_HASH_BITS);
82 }
83 
84 static inline
85 struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
86 					   const struct llc_addr *laddr)
87 {
88 	return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
89 }
90 
91 #define LLC_DEST_INVALID         0      /* Invalid LLC PDU type */
92 #define LLC_DEST_SAP             1      /* Type 1 goes here */
93 #define LLC_DEST_CONN            2      /* Type 2 goes here */
94 
95 extern struct list_head llc_sap_list;
96 
97 int llc_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
98 	    struct net_device *orig_dev);
99 
100 int llc_mac_hdr_init(struct sk_buff *skb, const unsigned char *sa,
101 		     const unsigned char *da);
102 
103 void llc_add_pack(int type,
104 		  void (*handler)(struct llc_sap *sap, struct sk_buff *skb));
105 void llc_remove_pack(int type);
106 
107 void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
108 
109 struct llc_sap *llc_sap_open(unsigned char lsap,
110 			     int (*rcv)(struct sk_buff *skb,
111 					struct net_device *dev,
112 					struct packet_type *pt,
113 					struct net_device *orig_dev));
114 static inline void llc_sap_hold(struct llc_sap *sap)
115 {
116 	refcount_inc(&sap->refcnt);
117 }
118 
119 static inline bool llc_sap_hold_safe(struct llc_sap *sap)
120 {
121 	return refcount_inc_not_zero(&sap->refcnt);
122 }
123 
124 void llc_sap_close(struct llc_sap *sap);
125 
126 static inline void llc_sap_put(struct llc_sap *sap)
127 {
128 	if (refcount_dec_and_test(&sap->refcnt))
129 		llc_sap_close(sap);
130 }
131 
132 struct llc_sap *llc_sap_find(unsigned char sap_value);
133 
134 int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
135 			      unsigned char *dmac, unsigned char dsap);
136 
137 void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
138 void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
139 
140 void llc_station_init(void);
141 void llc_station_exit(void);
142 
143 #ifdef CONFIG_PROC_FS
144 int llc_proc_init(void);
145 void llc_proc_exit(void);
146 #else
147 #define llc_proc_init()	(0)
148 #define llc_proc_exit()	do { } while(0)
149 #endif /* CONFIG_PROC_FS */
150 #ifdef CONFIG_SYSCTL
151 int llc_sysctl_init(void);
152 void llc_sysctl_exit(void);
153 
154 extern int sysctl_llc2_ack_timeout;
155 extern int sysctl_llc2_busy_timeout;
156 extern int sysctl_llc2_p_timeout;
157 extern int sysctl_llc2_rej_timeout;
158 #else
159 #define llc_sysctl_init() (0)
160 #define llc_sysctl_exit() do { } while(0)
161 #endif /* CONFIG_SYSCTL */
162 #endif /* LLC_H */
163