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);
38 /* sap->laddr.mac - leave as a null, it's filled by bind */
39 sap->state = LLC_SAP_STATE_ACTIVE;
40 rwlock_init(&sap->sk_list.lock);
41 atomic_set(&sap->refcnt, 1);
47 * llc_add_sap - add sap to station list
48 * @sap: Address of the sap
50 * Adds a sap to the LLC's station sap list.
52 static void llc_add_sap(struct llc_sap *sap)
54 list_add_tail(&sap->node, &llc_sap_list);
58 * llc_del_sap - del sap from station list
59 * @sap: Address of the sap
61 * Removes a sap to the LLC's station sap list.
63 static void llc_del_sap(struct llc_sap *sap)
65 write_lock_bh(&llc_sap_list_lock);
67 write_unlock_bh(&llc_sap_list_lock);
70 static struct llc_sap *__llc_sap_find(unsigned char sap_value)
74 list_for_each_entry(sap, &llc_sap_list, node)
75 if (sap->laddr.lsap == sap_value)
83 * llc_sap_find - searchs a SAP in station
84 * @sap_value: sap to be found
86 * Searchs for a sap in the sap list of the LLC's station upon the sap ID.
87 * If the sap is found it will be refcounted and the user will have to do
88 * a llc_sap_put after use.
89 * Returns the sap or %NULL if not found.
91 struct llc_sap *llc_sap_find(unsigned char sap_value)
95 read_lock_bh(&llc_sap_list_lock);
96 sap = __llc_sap_find(sap_value);
99 read_unlock_bh(&llc_sap_list_lock);
104 * llc_sap_open - open interface to the upper layers.
106 * @func: rcv func for datalink protos
108 * Interface function to upper layer. Each one who wants to get a SAP
109 * (for example NetBEUI) should call this function. Returns the opened
110 * SAP for success, NULL for failure.
112 struct llc_sap *llc_sap_open(unsigned char lsap,
113 int (*func)(struct sk_buff *skb,
114 struct net_device *dev,
115 struct packet_type *pt,
116 struct net_device *orig_dev))
118 struct llc_sap *sap = NULL;
120 write_lock_bh(&llc_sap_list_lock);
121 if (__llc_sap_find(lsap)) /* SAP already exists */
123 sap = llc_sap_alloc();
126 sap->laddr.lsap = lsap;
127 sap->rcv_func = func;
130 write_unlock_bh(&llc_sap_list_lock);
135 * llc_sap_close - close interface for upper layers.
136 * @sap: SAP to be closed.
138 * Close interface function to upper layer. Each one who wants to
139 * close an open SAP (for example NetBEUI) should call this function.
140 * Removes this sap from the list of saps in the station and then
141 * frees the memory for this sap.
143 void llc_sap_close(struct llc_sap *sap)
145 WARN_ON(!hlist_empty(&sap->sk_list.list));
150 static struct packet_type llc_packet_type = {
151 .type = __constant_htons(ETH_P_802_2),
155 static struct packet_type llc_tr_packet_type = {
156 .type = __constant_htons(ETH_P_TR_802_2),
160 static int __init llc_init(void)
162 struct net_device *dev;
164 dev = first_net_device(&init_net);
166 dev = next_net_device(dev);
168 dev_add_pack(&llc_packet_type);
169 dev_add_pack(&llc_tr_packet_type);
173 static void __exit llc_exit(void)
175 dev_remove_pack(&llc_packet_type);
176 dev_remove_pack(&llc_tr_packet_type);
179 module_init(llc_init);
180 module_exit(llc_exit);
182 EXPORT_SYMBOL(llc_sap_list);
183 EXPORT_SYMBOL(llc_sap_list_lock);
184 EXPORT_SYMBOL(llc_sap_find);
185 EXPORT_SYMBOL(llc_sap_open);
186 EXPORT_SYMBOL(llc_sap_close);
188 MODULE_LICENSE("GPL");
189 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
190 MODULE_DESCRIPTION("LLC IEEE 802.2 core support");