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 struct net_device *orig_dev)) 108 { 109 struct llc_sap *sap = llc_sap_find(lsap); 110 111 if (sap) { /* SAP already exists */ 112 sap = NULL; 113 goto out; 114 } 115 sap = llc_sap_alloc(); 116 if (!sap) 117 goto out; 118 sap->laddr.lsap = lsap; 119 sap->rcv_func = func; 120 llc_add_sap(sap); 121 out: 122 return sap; 123 } 124 125 /** 126 * llc_sap_close - close interface for upper layers. 127 * @sap: SAP to be closed. 128 * 129 * Close interface function to upper layer. Each one who wants to 130 * close an open SAP (for example NetBEUI) should call this function. 131 * Removes this sap from the list of saps in the station and then 132 * frees the memory for this sap. 133 */ 134 void llc_sap_close(struct llc_sap *sap) 135 { 136 WARN_ON(!hlist_empty(&sap->sk_list.list)); 137 llc_del_sap(sap); 138 kfree(sap); 139 } 140 141 static struct packet_type llc_packet_type = { 142 .type = __constant_htons(ETH_P_802_2), 143 .func = llc_rcv, 144 }; 145 146 static struct packet_type llc_tr_packet_type = { 147 .type = __constant_htons(ETH_P_TR_802_2), 148 .func = llc_rcv, 149 }; 150 151 static int __init llc_init(void) 152 { 153 if (dev_base->next) 154 memcpy(llc_station_mac_sa, dev_base->next->dev_addr, ETH_ALEN); 155 else 156 memset(llc_station_mac_sa, 0, ETH_ALEN); 157 dev_add_pack(&llc_packet_type); 158 dev_add_pack(&llc_tr_packet_type); 159 return 0; 160 } 161 162 static void __exit llc_exit(void) 163 { 164 dev_remove_pack(&llc_packet_type); 165 dev_remove_pack(&llc_tr_packet_type); 166 } 167 168 module_init(llc_init); 169 module_exit(llc_exit); 170 171 EXPORT_SYMBOL(llc_station_mac_sa); 172 EXPORT_SYMBOL(llc_sap_list); 173 EXPORT_SYMBOL(llc_sap_list_lock); 174 EXPORT_SYMBOL(llc_sap_find); 175 EXPORT_SYMBOL(llc_sap_open); 176 EXPORT_SYMBOL(llc_sap_close); 177 178 MODULE_LICENSE("GPL"); 179 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); 180 MODULE_DESCRIPTION("LLC IEEE 802.2 core support"); 181