diff options
Diffstat (limited to 'net/llc/llc_core.c')
| -rw-r--r-- | net/llc/llc_core.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c new file mode 100644 index 00000000..2bb0ddff --- /dev/null +++ b/net/llc/llc_core.c @@ -0,0 +1,169 @@ +/* + * 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); +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_list_lock); +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"); |