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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Eric W. Biederman881d9662007-09-17 11:56:21 -070022#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <net/llc.h>
24
25LIST_HEAD(llc_sap_list);
26DEFINE_RWLOCK(llc_sap_list_lock);
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028/**
29 * llc_sap_alloc - allocates and initializes sap.
30 *
31 * Allocates and initializes sap.
32 */
33static struct llc_sap *llc_sap_alloc(void)
34{
Panagiotis Issaris0da974f2006-07-21 14:51:30 -070035 struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37 if (sap) {
Joonwoo Parka5a04812008-03-28 16:28:36 -070038 /* sap->laddr.mac - leave as a null, it's filled by bind */
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 sap->state = LLC_SAP_STATE_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 rwlock_init(&sap->sk_list.lock);
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -030041 atomic_set(&sap->refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 }
43 return sap;
44}
45
46/**
47 * llc_add_sap - add sap to station list
48 * @sap: Address of the sap
49 *
50 * Adds a sap to the LLC's station sap list.
51 */
52static void llc_add_sap(struct llc_sap *sap)
53{
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 list_add_tail(&sap->node, &llc_sap_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055}
56
57/**
58 * llc_del_sap - del sap from station list
59 * @sap: Address of the sap
60 *
61 * Removes a sap to the LLC's station sap list.
62 */
63static void llc_del_sap(struct llc_sap *sap)
64{
65 write_lock_bh(&llc_sap_list_lock);
66 list_del(&sap->node);
67 write_unlock_bh(&llc_sap_list_lock);
68}
69
Arnaldo Carvalho de Melo2928c192005-09-22 05:14:33 -030070static struct llc_sap *__llc_sap_find(unsigned char sap_value)
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -030071{
72 struct llc_sap* sap;
73
74 list_for_each_entry(sap, &llc_sap_list, node)
75 if (sap->laddr.lsap == sap_value)
76 goto out;
77 sap = NULL;
78out:
79 return sap;
80}
81
Linus Torvalds1da177e2005-04-16 15:20:36 -070082/**
83 * llc_sap_find - searchs a SAP in station
84 * @sap_value: sap to be found
85 *
86 * Searchs for a sap in the sap list of the LLC's station upon the sap ID.
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -030087 * If the sap is found it will be refcounted and the user will have to do
88 * a llc_sap_put after use.
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 * Returns the sap or %NULL if not found.
90 */
91struct llc_sap *llc_sap_find(unsigned char sap_value)
92{
93 struct llc_sap* sap;
94
95 read_lock_bh(&llc_sap_list_lock);
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -030096 sap = __llc_sap_find(sap_value);
97 if (sap)
98 llc_sap_hold(sap);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 read_unlock_bh(&llc_sap_list_lock);
100 return sap;
101}
102
103/**
104 * llc_sap_open - open interface to the upper layers.
105 * @lsap: SAP number.
106 * @func: rcv func for datalink protos
107 *
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.
111 */
112struct llc_sap *llc_sap_open(unsigned char lsap,
113 int (*func)(struct sk_buff *skb,
114 struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -0700115 struct packet_type *pt,
116 struct net_device *orig_dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -0300118 struct llc_sap *sap = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -0300120 write_lock_bh(&llc_sap_list_lock);
121 if (__llc_sap_find(lsap)) /* SAP already exists */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 sap = llc_sap_alloc();
124 if (!sap)
125 goto out;
126 sap->laddr.lsap = lsap;
127 sap->rcv_func = func;
128 llc_add_sap(sap);
129out:
Arnaldo Carvalho de Melo6e2144b2005-09-22 04:43:05 -0300130 write_unlock_bh(&llc_sap_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 return sap;
132}
133
134/**
135 * llc_sap_close - close interface for upper layers.
136 * @sap: SAP to be closed.
137 *
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.
142 */
143void llc_sap_close(struct llc_sap *sap)
144{
145 WARN_ON(!hlist_empty(&sap->sk_list.list));
146 llc_del_sap(sap);
147 kfree(sap);
148}
149
150static struct packet_type llc_packet_type = {
151 .type = __constant_htons(ETH_P_802_2),
152 .func = llc_rcv,
153};
154
155static struct packet_type llc_tr_packet_type = {
156 .type = __constant_htons(ETH_P_TR_802_2),
157 .func = llc_rcv,
158};
159
160static int __init llc_init(void)
161{
Pavel Emelianov7562f872007-05-03 15:13:45 -0700162 struct net_device *dev;
163
Eric W. Biederman881d9662007-09-17 11:56:21 -0700164 dev = first_net_device(&init_net);
Pavel Emelianov7562f872007-05-03 15:13:45 -0700165 if (dev != NULL)
166 dev = next_net_device(dev);
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 dev_add_pack(&llc_packet_type);
169 dev_add_pack(&llc_tr_packet_type);
170 return 0;
171}
172
173static void __exit llc_exit(void)
174{
175 dev_remove_pack(&llc_packet_type);
176 dev_remove_pack(&llc_tr_packet_type);
177}
178
179module_init(llc_init);
180module_exit(llc_exit);
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182EXPORT_SYMBOL(llc_sap_list);
183EXPORT_SYMBOL(llc_sap_list_lock);
184EXPORT_SYMBOL(llc_sap_find);
185EXPORT_SYMBOL(llc_sap_open);
186EXPORT_SYMBOL(llc_sap_close);
187
188MODULE_LICENSE("GPL");
189MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
190MODULE_DESCRIPTION("LLC IEEE 802.2 core support");