![Octavian Purdila](/assets/img/avatar_default.png)
For the cases where a lot of interfaces are used in conjunction with a lot of LLC sockets bound to the same SAP, the iteration of the socket list becomes prohibitively expensive. Replacing the list with a a local address based hash significantly improves the bind and listener lookup operations as well as the datagram delivery. Connected sockets delivery is also improved, but this patch does not address the case where we have lots of sockets with the same local address connected to different remote addresses. In order to keep the socket sanity checks alive and fast a socket counter was added to the SAP structure. Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
194 lines
4.6 KiB
C
194 lines
4.6 KiB
C
/*
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* llc_core.c - Minimum needed routines for sap handling and module init/exit
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*
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* Copyright (c) 1997 by Procom Technology, Inc.
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* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* This program can be redistributed or modified under the terms of the
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* GNU General Public License as published by the Free Software Foundation.
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* This program is distributed without any warranty or implied warranty
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* of merchantability or fitness for a particular purpose.
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*
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* See the GNU General Public License for more details.
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*/
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/if_ether.h>
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#include <linux/netdevice.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <net/net_namespace.h>
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#include <net/llc.h>
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LIST_HEAD(llc_sap_list);
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DEFINE_RWLOCK(llc_sap_list_lock);
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/**
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* llc_sap_alloc - allocates and initializes sap.
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*
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* Allocates and initializes sap.
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*/
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static struct llc_sap *llc_sap_alloc(void)
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{
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struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
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int i;
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if (sap) {
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/* sap->laddr.mac - leave as a null, it's filled by bind */
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sap->state = LLC_SAP_STATE_ACTIVE;
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spin_lock_init(&sap->sk_lock);
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for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
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INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
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atomic_set(&sap->refcnt, 1);
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}
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return sap;
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}
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/**
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* llc_add_sap - add sap to station list
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* @sap: Address of the sap
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*
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* Adds a sap to the LLC's station sap list.
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*/
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static void llc_add_sap(struct llc_sap *sap)
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{
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list_add_tail(&sap->node, &llc_sap_list);
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}
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/**
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* llc_del_sap - del sap from station list
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* @sap: Address of the sap
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*
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* Removes a sap to the LLC's station sap list.
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*/
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static void llc_del_sap(struct llc_sap *sap)
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{
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write_lock_bh(&llc_sap_list_lock);
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list_del(&sap->node);
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write_unlock_bh(&llc_sap_list_lock);
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}
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static struct llc_sap *__llc_sap_find(unsigned char sap_value)
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{
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struct llc_sap* sap;
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list_for_each_entry(sap, &llc_sap_list, node)
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if (sap->laddr.lsap == sap_value)
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goto out;
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sap = NULL;
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out:
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return sap;
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}
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/**
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* llc_sap_find - searchs a SAP in station
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* @sap_value: sap to be found
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*
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* Searchs for a sap in the sap list of the LLC's station upon the sap ID.
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* If the sap is found it will be refcounted and the user will have to do
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* a llc_sap_put after use.
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* Returns the sap or %NULL if not found.
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*/
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struct llc_sap *llc_sap_find(unsigned char sap_value)
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{
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struct llc_sap* sap;
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read_lock_bh(&llc_sap_list_lock);
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sap = __llc_sap_find(sap_value);
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if (sap)
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llc_sap_hold(sap);
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read_unlock_bh(&llc_sap_list_lock);
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return sap;
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}
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/**
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* llc_sap_open - open interface to the upper layers.
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* @lsap: SAP number.
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* @func: rcv func for datalink protos
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*
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* Interface function to upper layer. Each one who wants to get a SAP
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* (for example NetBEUI) should call this function. Returns the opened
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* SAP for success, NULL for failure.
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*/
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struct llc_sap *llc_sap_open(unsigned char lsap,
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int (*func)(struct sk_buff *skb,
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struct net_device *dev,
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struct packet_type *pt,
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struct net_device *orig_dev))
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{
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struct llc_sap *sap = NULL;
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write_lock_bh(&llc_sap_list_lock);
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if (__llc_sap_find(lsap)) /* SAP already exists */
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goto out;
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sap = llc_sap_alloc();
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if (!sap)
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goto out;
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sap->laddr.lsap = lsap;
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sap->rcv_func = func;
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llc_add_sap(sap);
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out:
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write_unlock_bh(&llc_sap_list_lock);
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return sap;
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}
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/**
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* llc_sap_close - close interface for upper layers.
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* @sap: SAP to be closed.
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*
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* Close interface function to upper layer. Each one who wants to
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* close an open SAP (for example NetBEUI) should call this function.
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* Removes this sap from the list of saps in the station and then
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* frees the memory for this sap.
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*/
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void llc_sap_close(struct llc_sap *sap)
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{
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WARN_ON(sap->sk_count);
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llc_del_sap(sap);
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kfree(sap);
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}
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static struct packet_type llc_packet_type __read_mostly = {
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.type = cpu_to_be16(ETH_P_802_2),
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.func = llc_rcv,
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};
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static struct packet_type llc_tr_packet_type __read_mostly = {
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.type = cpu_to_be16(ETH_P_TR_802_2),
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.func = llc_rcv,
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};
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static int __init llc_init(void)
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{
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struct net_device *dev;
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dev = first_net_device(&init_net);
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if (dev != NULL)
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dev = next_net_device(dev);
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dev_add_pack(&llc_packet_type);
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dev_add_pack(&llc_tr_packet_type);
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return 0;
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}
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static void __exit llc_exit(void)
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{
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dev_remove_pack(&llc_packet_type);
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dev_remove_pack(&llc_tr_packet_type);
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}
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module_init(llc_init);
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module_exit(llc_exit);
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EXPORT_SYMBOL(llc_sap_list);
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EXPORT_SYMBOL(llc_sap_list_lock);
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EXPORT_SYMBOL(llc_sap_find);
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EXPORT_SYMBOL(llc_sap_open);
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EXPORT_SYMBOL(llc_sap_close);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
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MODULE_DESCRIPTION("LLC IEEE 802.2 core support");
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