Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * llc_core.c - Minimum needed routines for sap handling and module init/exit | |
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/module.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/if_ether.h> | |
18 | #include <linux/netdevice.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/init.h> | |
881d966b | 22 | #include <net/net_namespace.h> |
1da177e4 LT |
23 | #include <net/llc.h> |
24 | ||
25 | LIST_HEAD(llc_sap_list); | |
8beb9ab6 | 26 | DEFINE_SPINLOCK(llc_sap_list_lock); |
1da177e4 | 27 | |
1da177e4 LT |
28 | /** |
29 | * llc_sap_alloc - allocates and initializes sap. | |
30 | * | |
31 | * Allocates and initializes sap. | |
32 | */ | |
33 | static struct llc_sap *llc_sap_alloc(void) | |
34 | { | |
0da974f4 | 35 | struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC); |
52d58aef | 36 | int i; |
1da177e4 LT |
37 | |
38 | if (sap) { | |
a5a04819 | 39 | /* sap->laddr.mac - leave as a null, it's filled by bind */ |
1da177e4 | 40 | sap->state = LLC_SAP_STATE_ACTIVE; |
b76f5a84 | 41 | spin_lock_init(&sap->sk_lock); |
52d58aef OP |
42 | for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) |
43 | INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i); | |
6e2144b7 | 44 | atomic_set(&sap->refcnt, 1); |
1da177e4 LT |
45 | } |
46 | return sap; | |
47 | } | |
48 | ||
2928c19e | 49 | static struct llc_sap *__llc_sap_find(unsigned char sap_value) |
6e2144b7 ACM |
50 | { |
51 | struct llc_sap* sap; | |
52 | ||
53 | list_for_each_entry(sap, &llc_sap_list, node) | |
54 | if (sap->laddr.lsap == sap_value) | |
55 | goto out; | |
56 | sap = NULL; | |
57 | out: | |
58 | return sap; | |
59 | } | |
60 | ||
1da177e4 LT |
61 | /** |
62 | * llc_sap_find - searchs a SAP in station | |
63 | * @sap_value: sap to be found | |
64 | * | |
65 | * Searchs for a sap in the sap list of the LLC's station upon the sap ID. | |
6e2144b7 ACM |
66 | * If the sap is found it will be refcounted and the user will have to do |
67 | * a llc_sap_put after use. | |
1da177e4 LT |
68 | * Returns the sap or %NULL if not found. |
69 | */ | |
70 | struct llc_sap *llc_sap_find(unsigned char sap_value) | |
71 | { | |
8beb9ab6 | 72 | struct llc_sap *sap; |
1da177e4 | 73 | |
8beb9ab6 | 74 | rcu_read_lock_bh(); |
6e2144b7 ACM |
75 | sap = __llc_sap_find(sap_value); |
76 | if (sap) | |
77 | llc_sap_hold(sap); | |
8beb9ab6 | 78 | rcu_read_unlock_bh(); |
1da177e4 LT |
79 | return sap; |
80 | } | |
81 | ||
82 | /** | |
83 | * llc_sap_open - open interface to the upper layers. | |
84 | * @lsap: SAP number. | |
85 | * @func: rcv func for datalink protos | |
86 | * | |
87 | * Interface function to upper layer. Each one who wants to get a SAP | |
88 | * (for example NetBEUI) should call this function. Returns the opened | |
89 | * SAP for success, NULL for failure. | |
90 | */ | |
91 | struct llc_sap *llc_sap_open(unsigned char lsap, | |
92 | int (*func)(struct sk_buff *skb, | |
93 | struct net_device *dev, | |
f2ccd8fa DM |
94 | struct packet_type *pt, |
95 | struct net_device *orig_dev)) | |
1da177e4 | 96 | { |
6e2144b7 | 97 | struct llc_sap *sap = NULL; |
1da177e4 | 98 | |
8beb9ab6 | 99 | spin_lock_bh(&llc_sap_list_lock); |
6e2144b7 | 100 | if (__llc_sap_find(lsap)) /* SAP already exists */ |
1da177e4 | 101 | goto out; |
1da177e4 LT |
102 | sap = llc_sap_alloc(); |
103 | if (!sap) | |
104 | goto out; | |
105 | sap->laddr.lsap = lsap; | |
106 | sap->rcv_func = func; | |
8beb9ab6 | 107 | list_add_tail_rcu(&sap->node, &llc_sap_list); |
1da177e4 | 108 | out: |
8beb9ab6 | 109 | spin_unlock_bh(&llc_sap_list_lock); |
1da177e4 LT |
110 | return sap; |
111 | } | |
112 | ||
113 | /** | |
114 | * llc_sap_close - close interface for upper layers. | |
115 | * @sap: SAP to be closed. | |
116 | * | |
117 | * Close interface function to upper layer. Each one who wants to | |
118 | * close an open SAP (for example NetBEUI) should call this function. | |
119 | * Removes this sap from the list of saps in the station and then | |
120 | * frees the memory for this sap. | |
121 | */ | |
122 | void llc_sap_close(struct llc_sap *sap) | |
123 | { | |
52d58aef | 124 | WARN_ON(sap->sk_count); |
8beb9ab6 OP |
125 | |
126 | spin_lock_bh(&llc_sap_list_lock); | |
127 | list_del_rcu(&sap->node); | |
128 | spin_unlock_bh(&llc_sap_list_lock); | |
129 | ||
130 | synchronize_rcu(); | |
131 | ||
1da177e4 LT |
132 | kfree(sap); |
133 | } | |
134 | ||
7546dd97 | 135 | static struct packet_type llc_packet_type __read_mostly = { |
09640e63 | 136 | .type = cpu_to_be16(ETH_P_802_2), |
1da177e4 LT |
137 | .func = llc_rcv, |
138 | }; | |
139 | ||
7546dd97 | 140 | static struct packet_type llc_tr_packet_type __read_mostly = { |
09640e63 | 141 | .type = cpu_to_be16(ETH_P_TR_802_2), |
1da177e4 LT |
142 | .func = llc_rcv, |
143 | }; | |
144 | ||
145 | static int __init llc_init(void) | |
146 | { | |
7562f876 PE |
147 | struct net_device *dev; |
148 | ||
881d966b | 149 | dev = first_net_device(&init_net); |
7562f876 PE |
150 | if (dev != NULL) |
151 | dev = next_net_device(dev); | |
152 | ||
1da177e4 LT |
153 | dev_add_pack(&llc_packet_type); |
154 | dev_add_pack(&llc_tr_packet_type); | |
155 | return 0; | |
156 | } | |
157 | ||
158 | static void __exit llc_exit(void) | |
159 | { | |
160 | dev_remove_pack(&llc_packet_type); | |
161 | dev_remove_pack(&llc_tr_packet_type); | |
162 | } | |
163 | ||
164 | module_init(llc_init); | |
165 | module_exit(llc_exit); | |
166 | ||
1da177e4 LT |
167 | EXPORT_SYMBOL(llc_sap_list); |
168 | EXPORT_SYMBOL(llc_sap_list_lock); | |
169 | EXPORT_SYMBOL(llc_sap_find); | |
170 | EXPORT_SYMBOL(llc_sap_open); | |
171 | EXPORT_SYMBOL(llc_sap_close); | |
172 | ||
173 | MODULE_LICENSE("GPL"); | |
174 | MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); | |
175 | MODULE_DESCRIPTION("LLC IEEE 802.2 core support"); |