linux/net/llc/llc_input.c

/*
 * llc_input.c - Minimal input path for LLC
 *
 * Copyright (c) 1997 by Procom Technology, Inc.
 * 		 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
 *
 * 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/netdevice.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/llc.h>
#include <net/llc_pdu.h>
#include <net/llc_sap.h>

#if 0
#define dprintk …
#else
#define dprintk(args...) …
#endif

/*
 * Packet handler for the station, registerable because in the minimal
 * LLC core that is taking shape only the very minimal subset of LLC that
 * is needed for things like IPX, Appletalk, etc will stay, with all the
 * rest in the llc1 and llc2 modules.
 */
static void (*llc_station_handler)(struct sk_buff *skb);

/*
 * Packet handlers for LLC_DEST_SAP and LLC_DEST_CONN.
 */
static void (*llc_type_handlers[2])(struct llc_sap *sap,
				    struct sk_buff *skb);

void llc_add_pack(int type, void (*handler)(struct llc_sap *sap,
					    struct sk_buff *skb))
{ … }

void llc_remove_pack(int type)
{ … }

void llc_set_station_handler(void (*handler)(struct sk_buff *skb))
{ … }

/**
 *	llc_pdu_type - returns which LLC component must handle for PDU
 *	@skb: input skb
 *
 *	This function returns which LLC component must handle this PDU.
 */
static __inline__ int llc_pdu_type(struct sk_buff *skb)
{ … }

/**
 *	llc_fixup_skb - initializes skb pointers
 *	@skb: This argument points to incoming skb
 *
 *	Initializes internal skb pointer to start of network layer by deriving
 *	length of LLC header; finds length of LLC control field in LLC header
 *	by looking at the two lowest-order bits of the first control field
 *	byte; field is either 3 or 4 bytes long.
 */
static inline int llc_fixup_skb(struct sk_buff *skb)
{ … }

/**
 *	llc_rcv - 802.2 entry point from net lower layers
 *	@skb: received pdu
 *	@dev: device that receive pdu
 *	@pt: packet type
 *	@orig_dev: the original receive net device
 *
 *	When the system receives a 802.2 frame this function is called. It
 *	checks SAP and connection of received pdu and passes frame to
 *	llc_{station,sap,conn}_rcv for sending to proper state machine. If
 *	the frame is related to a busy connection (a connection is sending
 *	data now), it queues this frame in the connection's backlog.
 */
int llc_rcv(struct sk_buff *skb, struct net_device *dev,
	    struct packet_type *pt, struct net_device *orig_dev)
{ … }

EXPORT_SYMBOL(…);
EXPORT_SYMBOL(…);
EXPORT_SYMBOL(…);