kernel-hacking-2024-linux-s.../include/net/llc.h
Octavian Purdila 52d58aef5e llc: replace the socket list with a local address based hash
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>
2009-12-26 20:45:32 -08:00

159 lines
4.5 KiB
C

#ifndef LLC_H
#define LLC_H
/*
* 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/if.h>
#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rculist_nulls.h>
#include <linux/hash.h>
#include <linux/jhash.h>
#include <asm/atomic.h>
struct net_device;
struct packet_type;
struct sk_buff;
struct llc_addr {
unsigned char lsap;
unsigned char mac[IFHWADDRLEN];
};
#define LLC_SAP_STATE_INACTIVE 1
#define LLC_SAP_STATE_ACTIVE 2
#define LLC_SK_DEV_HASH_BITS 6
#define LLC_SK_DEV_HASH_ENTRIES (1<<LLC_SK_DEV_HASH_BITS)
#define LLC_SK_LADDR_HASH_BITS 6
#define LLC_SK_LADDR_HASH_ENTRIES (1<<LLC_SK_LADDR_HASH_BITS)
/**
* struct llc_sap - Defines the SAP component
*
* @station - station this sap belongs to
* @state - sap state
* @p_bit - only lowest-order bit used
* @f_bit - only lowest-order bit used
* @laddr - SAP value in this 'lsap'
* @node - entry in station sap_list
* @sk_list - LLC sockets this one manages
*/
struct llc_sap {
unsigned char state;
unsigned char p_bit;
unsigned char f_bit;
atomic_t refcnt;
int (*rcv_func)(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *pt,
struct net_device *orig_dev);
struct llc_addr laddr;
struct list_head node;
spinlock_t sk_lock;
int sk_count;
struct hlist_nulls_head sk_laddr_hash[LLC_SK_LADDR_HASH_ENTRIES];
struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES];
};
static inline
struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
{
return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES];
}
static inline
u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
{
return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
LLC_SK_LADDR_HASH_BITS);
}
static inline
struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
const struct llc_addr *laddr)
{
return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
}
#define LLC_DEST_INVALID 0 /* Invalid LLC PDU type */
#define LLC_DEST_SAP 1 /* Type 1 goes here */
#define LLC_DEST_CONN 2 /* Type 2 goes here */
extern struct list_head llc_sap_list;
extern rwlock_t llc_sap_list_lock;
extern int llc_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev);
extern int llc_mac_hdr_init(struct sk_buff *skb,
const unsigned char *sa, const unsigned char *da);
extern void llc_add_pack(int type, void (*handler)(struct llc_sap *sap,
struct sk_buff *skb));
extern void llc_remove_pack(int type);
extern void llc_set_station_handler(void (*handler)(struct sk_buff *skb));
extern struct llc_sap *llc_sap_open(unsigned char lsap,
int (*rcv)(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *pt,
struct net_device *orig_dev));
static inline void llc_sap_hold(struct llc_sap *sap)
{
atomic_inc(&sap->refcnt);
}
extern void llc_sap_close(struct llc_sap *sap);
static inline void llc_sap_put(struct llc_sap *sap)
{
if (atomic_dec_and_test(&sap->refcnt))
llc_sap_close(sap);
}
extern struct llc_sap *llc_sap_find(unsigned char sap_value);
extern int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
unsigned char *dmac, unsigned char dsap);
extern void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
extern void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
extern int llc_station_init(void);
extern void llc_station_exit(void);
#ifdef CONFIG_PROC_FS
extern int llc_proc_init(void);
extern void llc_proc_exit(void);
#else
#define llc_proc_init() (0)
#define llc_proc_exit() do { } while(0)
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SYSCTL
extern int llc_sysctl_init(void);
extern void llc_sysctl_exit(void);
extern int sysctl_llc2_ack_timeout;
extern int sysctl_llc2_busy_timeout;
extern int sysctl_llc2_p_timeout;
extern int sysctl_llc2_rej_timeout;
extern int sysctl_llc_station_ack_timeout;
#else
#define llc_sysctl_init() (0)
#define llc_sysctl_exit() do { } while(0)
#endif /* CONFIG_SYSCTL */
#endif /* LLC_H */