Loading...
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>
22#include <net/net_namespace.h>
23#include <net/llc.h>
24
25LIST_HEAD(llc_sap_list);
26DEFINE_SPINLOCK(llc_sap_list_lock);
27
28/**
29 * llc_sap_alloc - allocates and initializes sap.
30 *
31 * Allocates and initializes sap.
32 */
33static struct llc_sap *llc_sap_alloc(void)
34{
35 struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
36 int i;
37
38 if (sap) {
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);
45 }
46 return sap;
47}
48
49static struct llc_sap *__llc_sap_find(unsigned char sap_value)
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;
57out:
58 return sap;
59}
60
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.
66 * If the sap is found it will be refcounted and the user will have to do
67 * a llc_sap_put after use.
68 * Returns the sap or %NULL if not found.
69 */
70struct llc_sap *llc_sap_find(unsigned char sap_value)
71{
72 struct llc_sap *sap;
73
74 rcu_read_lock_bh();
75 sap = __llc_sap_find(sap_value);
76 if (sap)
77 llc_sap_hold(sap);
78 rcu_read_unlock_bh();
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 */
91struct llc_sap *llc_sap_open(unsigned char lsap,
92 int (*func)(struct sk_buff *skb,
93 struct net_device *dev,
94 struct packet_type *pt,
95 struct net_device *orig_dev))
96{
97 struct llc_sap *sap = NULL;
98
99 spin_lock_bh(&llc_sap_list_lock);
100 if (__llc_sap_find(lsap)) /* SAP already exists */
101 goto out;
102 sap = llc_sap_alloc();
103 if (!sap)
104 goto out;
105 sap->laddr.lsap = lsap;
106 sap->rcv_func = func;
107 list_add_tail_rcu(&sap->node, &llc_sap_list);
108out:
109 spin_unlock_bh(&llc_sap_list_lock);
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 */
122void llc_sap_close(struct llc_sap *sap)
123{
124 WARN_ON(sap->sk_count);
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
132 kfree(sap);
133}
134
135static struct packet_type llc_packet_type __read_mostly = {
136 .type = cpu_to_be16(ETH_P_802_2),
137 .func = llc_rcv,
138};
139
140static struct packet_type llc_tr_packet_type __read_mostly = {
141 .type = cpu_to_be16(ETH_P_TR_802_2),
142 .func = llc_rcv,
143};
144
145static int __init llc_init(void)
146{
147 dev_add_pack(&llc_packet_type);
148 dev_add_pack(&llc_tr_packet_type);
149 return 0;
150}
151
152static void __exit llc_exit(void)
153{
154 dev_remove_pack(&llc_packet_type);
155 dev_remove_pack(&llc_tr_packet_type);
156}
157
158module_init(llc_init);
159module_exit(llc_exit);
160
161EXPORT_SYMBOL(llc_sap_list);
162EXPORT_SYMBOL(llc_sap_list_lock);
163EXPORT_SYMBOL(llc_sap_find);
164EXPORT_SYMBOL(llc_sap_open);
165EXPORT_SYMBOL(llc_sap_close);
166
167MODULE_LICENSE("GPL");
168MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
169MODULE_DESCRIPTION("LLC IEEE 802.2 core support");
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>
22#include <net/net_namespace.h>
23#include <net/llc.h>
24
25LIST_HEAD(llc_sap_list);
26static DEFINE_SPINLOCK(llc_sap_list_lock);
27
28/**
29 * llc_sap_alloc - allocates and initializes sap.
30 *
31 * Allocates and initializes sap.
32 */
33static struct llc_sap *llc_sap_alloc(void)
34{
35 struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
36 int i;
37
38 if (sap) {
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 refcount_set(&sap->refcnt, 1);
45 }
46 return sap;
47}
48
49static struct llc_sap *__llc_sap_find(unsigned char sap_value)
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;
57out:
58 return sap;
59}
60
61/**
62 * llc_sap_find - searches a SAP in station
63 * @sap_value: sap to be found
64 *
65 * Searches for a sap in the sap list of the LLC's station upon the sap ID.
66 * If the sap is found it will be refcounted and the user will have to do
67 * a llc_sap_put after use.
68 * Returns the sap or %NULL if not found.
69 */
70struct llc_sap *llc_sap_find(unsigned char sap_value)
71{
72 struct llc_sap *sap;
73
74 rcu_read_lock_bh();
75 sap = __llc_sap_find(sap_value);
76 if (!sap || !llc_sap_hold_safe(sap))
77 sap = NULL;
78 rcu_read_unlock_bh();
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 */
91struct llc_sap *llc_sap_open(unsigned char lsap,
92 int (*func)(struct sk_buff *skb,
93 struct net_device *dev,
94 struct packet_type *pt,
95 struct net_device *orig_dev))
96{
97 struct llc_sap *sap = NULL;
98
99 spin_lock_bh(&llc_sap_list_lock);
100 if (__llc_sap_find(lsap)) /* SAP already exists */
101 goto out;
102 sap = llc_sap_alloc();
103 if (!sap)
104 goto out;
105 sap->laddr.lsap = lsap;
106 sap->rcv_func = func;
107 list_add_tail_rcu(&sap->node, &llc_sap_list);
108out:
109 spin_unlock_bh(&llc_sap_list_lock);
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 */
122void llc_sap_close(struct llc_sap *sap)
123{
124 WARN_ON(sap->sk_count);
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 kfree_rcu(sap, rcu);
131}
132
133static struct packet_type llc_packet_type __read_mostly = {
134 .type = cpu_to_be16(ETH_P_802_2),
135 .func = llc_rcv,
136};
137
138static int __init llc_init(void)
139{
140 dev_add_pack(&llc_packet_type);
141 return 0;
142}
143
144static void __exit llc_exit(void)
145{
146 dev_remove_pack(&llc_packet_type);
147}
148
149module_init(llc_init);
150module_exit(llc_exit);
151
152EXPORT_SYMBOL(llc_sap_list);
153EXPORT_SYMBOL(llc_sap_find);
154EXPORT_SYMBOL(llc_sap_open);
155EXPORT_SYMBOL(llc_sap_close);
156
157MODULE_LICENSE("GPL");
158MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
159MODULE_DESCRIPTION("LLC IEEE 802.2 core support");