2 * llc_core.c - Minimum needed routines for sap handling and module init/exit
4 * Copyright (c) 1997 by Procom Technology, Inc.
5 * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
12 * See the GNU General Public License for more details.
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>
22 #include <net/net_namespace.h>
25 LIST_HEAD(llc_sap_list);
26 DEFINE_RWLOCK(llc_sap_list_lock);
29 * llc_sap_alloc - allocates and initializes sap.
31 * Allocates and initializes sap.
33 static struct llc_sap *llc_sap_alloc(void)
35 struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
39 /* sap->laddr.mac - leave as a null, it's filled by bind */
40 sap->state = LLC_SAP_STATE_ACTIVE;
41 spin_lock_init(&sap->sk_lock);
42 for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
43 INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
44 atomic_set(&sap->refcnt, 1);
50 * llc_add_sap - add sap to station list
51 * @sap: Address of the sap
53 * Adds a sap to the LLC's station sap list.
55 static void llc_add_sap(struct llc_sap *sap)
57 list_add_tail(&sap->node, &llc_sap_list);
61 * llc_del_sap - del sap from station list
62 * @sap: Address of the sap
64 * Removes a sap to the LLC's station sap list.
66 static void llc_del_sap(struct llc_sap *sap)
68 write_lock_bh(&llc_sap_list_lock);
70 write_unlock_bh(&llc_sap_list_lock);
73 static struct llc_sap *__llc_sap_find(unsigned char sap_value)
77 list_for_each_entry(sap, &llc_sap_list, node)
78 if (sap->laddr.lsap == sap_value)
86 * llc_sap_find - searchs a SAP in station
87 * @sap_value: sap to be found
89 * Searchs for a sap in the sap list of the LLC's station upon the sap ID.
90 * If the sap is found it will be refcounted and the user will have to do
91 * a llc_sap_put after use.
92 * Returns the sap or %NULL if not found.
94 struct llc_sap *llc_sap_find(unsigned char sap_value)
98 read_lock_bh(&llc_sap_list_lock);
99 sap = __llc_sap_find(sap_value);
102 read_unlock_bh(&llc_sap_list_lock);
107 * llc_sap_open - open interface to the upper layers.
109 * @func: rcv func for datalink protos
111 * Interface function to upper layer. Each one who wants to get a SAP
112 * (for example NetBEUI) should call this function. Returns the opened
113 * SAP for success, NULL for failure.
115 struct llc_sap *llc_sap_open(unsigned char lsap,
116 int (*func)(struct sk_buff *skb,
117 struct net_device *dev,
118 struct packet_type *pt,
119 struct net_device *orig_dev))
121 struct llc_sap *sap = NULL;
123 write_lock_bh(&llc_sap_list_lock);
124 if (__llc_sap_find(lsap)) /* SAP already exists */
126 sap = llc_sap_alloc();
129 sap->laddr.lsap = lsap;
130 sap->rcv_func = func;
133 write_unlock_bh(&llc_sap_list_lock);
138 * llc_sap_close - close interface for upper layers.
139 * @sap: SAP to be closed.
141 * Close interface function to upper layer. Each one who wants to
142 * close an open SAP (for example NetBEUI) should call this function.
143 * Removes this sap from the list of saps in the station and then
144 * frees the memory for this sap.
146 void llc_sap_close(struct llc_sap *sap)
148 WARN_ON(sap->sk_count);
153 static struct packet_type llc_packet_type __read_mostly = {
154 .type = cpu_to_be16(ETH_P_802_2),
158 static struct packet_type llc_tr_packet_type __read_mostly = {
159 .type = cpu_to_be16(ETH_P_TR_802_2),
163 static int __init llc_init(void)
165 struct net_device *dev;
167 dev = first_net_device(&init_net);
169 dev = next_net_device(dev);
171 dev_add_pack(&llc_packet_type);
172 dev_add_pack(&llc_tr_packet_type);
176 static void __exit llc_exit(void)
178 dev_remove_pack(&llc_packet_type);
179 dev_remove_pack(&llc_tr_packet_type);
182 module_init(llc_init);
183 module_exit(llc_exit);
185 EXPORT_SYMBOL(llc_sap_list);
186 EXPORT_SYMBOL(llc_sap_list_lock);
187 EXPORT_SYMBOL(llc_sap_find);
188 EXPORT_SYMBOL(llc_sap_open);
189 EXPORT_SYMBOL(llc_sap_close);
191 MODULE_LICENSE("GPL");
192 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
193 MODULE_DESCRIPTION("LLC IEEE 802.2 core support");