mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![stephen hemminger](/assets/img/avatar_default.png)
The llc_sap_list_lock does not need to be global, only acquired in core. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
168 lines
4.1 KiB
C
168 lines
4.1 KiB
C
/*
|
|
* 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");
|