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1da177e4 LT |
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/llc.h> | |
23 | ||
24 | LIST_HEAD(llc_sap_list); | |
25 | DEFINE_RWLOCK(llc_sap_list_lock); | |
26 | ||
27 | unsigned char llc_station_mac_sa[ETH_ALEN]; | |
28 | ||
29 | /** | |
30 | * llc_sap_alloc - allocates and initializes sap. | |
31 | * | |
32 | * Allocates and initializes sap. | |
33 | */ | |
34 | static struct llc_sap *llc_sap_alloc(void) | |
35 | { | |
36 | struct llc_sap *sap = kmalloc(sizeof(*sap), GFP_ATOMIC); | |
37 | ||
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); | |
43 | } | |
44 | return sap; | |
45 | } | |
46 | ||
47 | /** | |
48 | * llc_add_sap - add sap to station list | |
49 | * @sap: Address of the sap | |
50 | * | |
51 | * Adds a sap to the LLC's station sap list. | |
52 | */ | |
53 | static void llc_add_sap(struct llc_sap *sap) | |
54 | { | |
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); | |
58 | } | |
59 | ||
60 | /** | |
61 | * llc_del_sap - del sap from station list | |
62 | * @sap: Address of the sap | |
63 | * | |
64 | * Removes a sap to the LLC's station sap list. | |
65 | */ | |
66 | static void llc_del_sap(struct llc_sap *sap) | |
67 | { | |
68 | write_lock_bh(&llc_sap_list_lock); | |
69 | list_del(&sap->node); | |
70 | write_unlock_bh(&llc_sap_list_lock); | |
71 | } | |
72 | ||
73 | /** | |
74 | * llc_sap_find - searchs a SAP in station | |
75 | * @sap_value: sap to be found | |
76 | * | |
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. | |
79 | */ | |
80 | struct llc_sap *llc_sap_find(unsigned char sap_value) | |
81 | { | |
82 | struct llc_sap* sap; | |
83 | ||
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; | |
92 | } | |
93 | ||
94 | /** | |
95 | * llc_sap_open - open interface to the upper layers. | |
96 | * @lsap: SAP number. | |
97 | * @func: rcv func for datalink protos | |
98 | * | |
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. | |
102 | */ | |
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)) | |
107 | { | |
108 | struct llc_sap *sap = llc_sap_find(lsap); | |
109 | ||
110 | if (sap) { /* SAP already exists */ | |
111 | sap = NULL; | |
112 | goto out; | |
113 | } | |
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; | |
122 | } | |
123 | ||
124 | /** | |
125 | * llc_sap_close - close interface for upper layers. | |
126 | * @sap: SAP to be closed. | |
127 | * | |
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. | |
132 | */ | |
133 | void llc_sap_close(struct llc_sap *sap) | |
134 | { | |
135 | WARN_ON(!hlist_empty(&sap->sk_list.list)); | |
136 | llc_del_sap(sap); | |
137 | kfree(sap); | |
138 | } | |
139 | ||
140 | static struct packet_type llc_packet_type = { | |
141 | .type = __constant_htons(ETH_P_802_2), | |
142 | .func = llc_rcv, | |
143 | }; | |
144 | ||
145 | static struct packet_type llc_tr_packet_type = { | |
146 | .type = __constant_htons(ETH_P_TR_802_2), | |
147 | .func = llc_rcv, | |
148 | }; | |
149 | ||
150 | static int __init llc_init(void) | |
151 | { | |
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; | |
159 | } | |
160 | ||
161 | static void __exit llc_exit(void) | |
162 | { | |
163 | dev_remove_pack(&llc_packet_type); | |
164 | dev_remove_pack(&llc_tr_packet_type); | |
165 | } | |
166 | ||
167 | module_init(llc_init); | |
168 | module_exit(llc_exit); | |
169 | ||
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); | |
176 | ||
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"); |