/* * llc_core.c - Minimum needed routines for sap handling and module init/exit * * Copyright (c) 1997 by Procom Technology, Inc. * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> * * This program can be redistributed or modified under the terms of the * GNU General Public License as published by the Free Software Foundation. * This program is distributed without any warranty or implied warranty * of merchantability or fitness for a particular purpose. * * See the GNU General Public License for more details. */ #include <linux/module.h> #include <linux/interrupt.h> #include <linux/if_ether.h> #include <linux/netdevice.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/init.h> #include <net/net_namespace.h> #include <net/llc.h> LIST_HEAD(llc_sap_list); static DEFINE_SPINLOCK(llc_sap_list_lock); /** * llc_sap_alloc - allocates and initializes sap. * * Allocates and initializes sap. */ static struct llc_sap *llc_sap_alloc(void) { struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC); int i; if (sap) { /* sap->laddr.mac - leave as a null, it's filled by bind */ sap->state = LLC_SAP_STATE_ACTIVE; spin_lock_init(&sap->sk_lock); for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i); atomic_set(&sap->refcnt, 1); } return sap; } static struct llc_sap *__llc_sap_find(unsigned char sap_value) { struct llc_sap *sap; list_for_each_entry(sap, &llc_sap_list, node) if (sap->laddr.lsap == sap_value) goto out; sap = NULL; out: return sap; } /** * llc_sap_find - searchs a SAP in station * @sap_value: sap to be found * * Searchs for a sap in the sap list of the LLC's station upon the sap ID. * If the sap is found it will be refcounted and the user will have to do * a llc_sap_put after use. * Returns the sap or %NULL if not found. */ struct llc_sap *llc_sap_find(unsigned char sap_value) { struct llc_sap *sap; rcu_read_lock_bh(); sap = __llc_sap_find(sap_value); if (sap) llc_sap_hold(sap); rcu_read_unlock_bh(); return sap; } /** * llc_sap_open - open interface to the upper layers. * @lsap: SAP number. * @func: rcv func for datalink protos * * Interface function to upper layer. Each one who wants to get a SAP * (for example NetBEUI) should call this function. Returns the opened * SAP for success, NULL for failure. */ struct llc_sap *llc_sap_open(unsigned char lsap, int (*func)(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)) { struct llc_sap *sap = NULL; spin_lock_bh(&llc_sap_list_lock); if (__llc_sap_find(lsap)) /* SAP already exists */ goto out; sap = llc_sap_alloc(); if (!sap) goto out; sap->laddr.lsap = lsap; sap->rcv_func = func; list_add_tail_rcu(&sap->node, &llc_sap_list); out: spin_unlock_bh(&llc_sap_list_lock); return sap; } /** * llc_sap_close - close interface for upper layers. * @sap: SAP to be closed. * * Close interface function to upper layer. Each one who wants to * close an open SAP (for example NetBEUI) should call this function. * Removes this sap from the list of saps in the station and then * frees the memory for this sap. */ void llc_sap_close(struct llc_sap *sap) { WARN_ON(sap->sk_count); spin_lock_bh(&llc_sap_list_lock); list_del_rcu(&sap->node); spin_unlock_bh(&llc_sap_list_lock); synchronize_rcu(); kfree(sap); } static struct packet_type llc_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_802_2), .func = llc_rcv, }; static struct packet_type llc_tr_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_TR_802_2), .func = llc_rcv, }; static int __init llc_init(void) { dev_add_pack(&llc_packet_type); dev_add_pack(&llc_tr_packet_type); return 0; } static void __exit llc_exit(void) { dev_remove_pack(&llc_packet_type); dev_remove_pack(&llc_tr_packet_type); } module_init(llc_init); module_exit(llc_exit); EXPORT_SYMBOL(llc_sap_list); EXPORT_SYMBOL(llc_sap_find); EXPORT_SYMBOL(llc_sap_open); EXPORT_SYMBOL(llc_sap_close); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003"); MODULE_DESCRIPTION("LLC IEEE 802.2 core support");