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-rw-r--r--net/llc/llc_core.c179
1 files changed, 179 insertions, 0 deletions
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
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+/*
+ * 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/llc.h>
+
+LIST_HEAD(llc_sap_list);
+DEFINE_RWLOCK(llc_sap_list_lock);
+
+unsigned char llc_station_mac_sa[ETH_ALEN];
+
+/**
+ * llc_sap_alloc - allocates and initializes sap.
+ *
+ * Allocates and initializes sap.
+ */
+static struct llc_sap *llc_sap_alloc(void)
+{
+ struct llc_sap *sap = kmalloc(sizeof(*sap), GFP_ATOMIC);
+
+ if (sap) {
+ memset(sap, 0, sizeof(*sap));
+ sap->state = LLC_SAP_STATE_ACTIVE;
+ memcpy(sap->laddr.mac, llc_station_mac_sa, ETH_ALEN);
+ rwlock_init(&sap->sk_list.lock);
+ }
+ return sap;
+}
+
+/**
+ * llc_add_sap - add sap to station list
+ * @sap: Address of the sap
+ *
+ * Adds a sap to the LLC's station sap list.
+ */
+static void llc_add_sap(struct llc_sap *sap)
+{
+ write_lock_bh(&llc_sap_list_lock);
+ list_add_tail(&sap->node, &llc_sap_list);
+ write_unlock_bh(&llc_sap_list_lock);
+}
+
+/**
+ * llc_del_sap - del sap from station list
+ * @sap: Address of the sap
+ *
+ * Removes a sap to the LLC's station sap list.
+ */
+static void llc_del_sap(struct llc_sap *sap)
+{
+ write_lock_bh(&llc_sap_list_lock);
+ list_del(&sap->node);
+ write_unlock_bh(&llc_sap_list_lock);
+}
+
+/**
+ * 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.
+ * Returns the sap or %NULL if not found.
+ */
+struct llc_sap *llc_sap_find(unsigned char sap_value)
+{
+ struct llc_sap* sap;
+
+ read_lock_bh(&llc_sap_list_lock);
+ list_for_each_entry(sap, &llc_sap_list, node)
+ if (sap->laddr.lsap == sap_value)
+ goto out;
+ sap = NULL;
+out:
+ read_unlock_bh(&llc_sap_list_lock);
+ 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 llc_sap *sap = llc_sap_find(lsap);
+
+ if (sap) { /* SAP already exists */
+ sap = NULL;
+ goto out;
+ }
+ sap = llc_sap_alloc();
+ if (!sap)
+ goto out;
+ sap->laddr.lsap = lsap;
+ sap->rcv_func = func;
+ llc_add_sap(sap);
+out:
+ 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(!hlist_empty(&sap->sk_list.list));
+ llc_del_sap(sap);
+ kfree(sap);
+}
+
+static struct packet_type llc_packet_type = {
+ .type = __constant_htons(ETH_P_802_2),
+ .func = llc_rcv,
+};
+
+static struct packet_type llc_tr_packet_type = {
+ .type = __constant_htons(ETH_P_TR_802_2),
+ .func = llc_rcv,
+};
+
+static int __init llc_init(void)
+{
+ if (dev_base->next)
+ memcpy(llc_station_mac_sa, dev_base->next->dev_addr, ETH_ALEN);
+ else
+ memset(llc_station_mac_sa, 0, ETH_ALEN);
+ 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_station_mac_sa);
+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");