Linux-2.6.12-rc2
[linux-2.6/kvm.git] / net / llc / llc_core.c
blob5ff02c080a0bfdbfee1bbacda96843c51843fc89
1 /*
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/llc.h>
24 LIST_HEAD(llc_sap_list);
25 DEFINE_RWLOCK(llc_sap_list_lock);
27 unsigned char llc_station_mac_sa[ETH_ALEN];
29 /**
30 * llc_sap_alloc - allocates and initializes sap.
32 * Allocates and initializes sap.
34 static struct llc_sap *llc_sap_alloc(void)
36 struct llc_sap *sap = kmalloc(sizeof(*sap), GFP_ATOMIC);
38 if (sap) {
39 memset(sap, 0, sizeof(*sap));
40 sap->state = LLC_SAP_STATE_ACTIVE;
41 memcpy(sap->laddr.mac, llc_station_mac_sa, ETH_ALEN);
42 rwlock_init(&sap->sk_list.lock);
44 return sap;
47 /**
48 * llc_add_sap - add sap to station list
49 * @sap: Address of the sap
51 * Adds a sap to the LLC's station sap list.
53 static void llc_add_sap(struct llc_sap *sap)
55 write_lock_bh(&llc_sap_list_lock);
56 list_add_tail(&sap->node, &llc_sap_list);
57 write_unlock_bh(&llc_sap_list_lock);
60 /**
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);
69 list_del(&sap->node);
70 write_unlock_bh(&llc_sap_list_lock);
73 /**
74 * llc_sap_find - searchs a SAP in station
75 * @sap_value: sap to be found
77 * Searchs for a sap in the sap list of the LLC's station upon the sap ID.
78 * Returns the sap or %NULL if not found.
80 struct llc_sap *llc_sap_find(unsigned char sap_value)
82 struct llc_sap* sap;
84 read_lock_bh(&llc_sap_list_lock);
85 list_for_each_entry(sap, &llc_sap_list, node)
86 if (sap->laddr.lsap == sap_value)
87 goto out;
88 sap = NULL;
89 out:
90 read_unlock_bh(&llc_sap_list_lock);
91 return sap;
94 /**
95 * llc_sap_open - open interface to the upper layers.
96 * @lsap: SAP number.
97 * @func: rcv func for datalink protos
99 * Interface function to upper layer. Each one who wants to get a SAP
100 * (for example NetBEUI) should call this function. Returns the opened
101 * SAP for success, NULL for failure.
103 struct llc_sap *llc_sap_open(unsigned char lsap,
104 int (*func)(struct sk_buff *skb,
105 struct net_device *dev,
106 struct packet_type *pt))
108 struct llc_sap *sap = llc_sap_find(lsap);
110 if (sap) { /* SAP already exists */
111 sap = NULL;
112 goto out;
114 sap = llc_sap_alloc();
115 if (!sap)
116 goto out;
117 sap->laddr.lsap = lsap;
118 sap->rcv_func = func;
119 llc_add_sap(sap);
120 out:
121 return sap;
125 * llc_sap_close - close interface for upper layers.
126 * @sap: SAP to be closed.
128 * Close interface function to upper layer. Each one who wants to
129 * close an open SAP (for example NetBEUI) should call this function.
130 * Removes this sap from the list of saps in the station and then
131 * frees the memory for this sap.
133 void llc_sap_close(struct llc_sap *sap)
135 WARN_ON(!hlist_empty(&sap->sk_list.list));
136 llc_del_sap(sap);
137 kfree(sap);
140 static struct packet_type llc_packet_type = {
141 .type = __constant_htons(ETH_P_802_2),
142 .func = llc_rcv,
145 static struct packet_type llc_tr_packet_type = {
146 .type = __constant_htons(ETH_P_TR_802_2),
147 .func = llc_rcv,
150 static int __init llc_init(void)
152 if (dev_base->next)
153 memcpy(llc_station_mac_sa, dev_base->next->dev_addr, ETH_ALEN);
154 else
155 memset(llc_station_mac_sa, 0, ETH_ALEN);
156 dev_add_pack(&llc_packet_type);
157 dev_add_pack(&llc_tr_packet_type);
158 return 0;
161 static void __exit llc_exit(void)
163 dev_remove_pack(&llc_packet_type);
164 dev_remove_pack(&llc_tr_packet_type);
167 module_init(llc_init);
168 module_exit(llc_exit);
170 EXPORT_SYMBOL(llc_station_mac_sa);
171 EXPORT_SYMBOL(llc_sap_list);
172 EXPORT_SYMBOL(llc_sap_list_lock);
173 EXPORT_SYMBOL(llc_sap_find);
174 EXPORT_SYMBOL(llc_sap_open);
175 EXPORT_SYMBOL(llc_sap_close);
177 MODULE_LICENSE("GPL");
178 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
179 MODULE_DESCRIPTION("LLC IEEE 802.2 core support");