p8022.c

Go to the documentation of this file.

/*
 *  NET3:   Support for 802.2 demultiplexing off Ethernet
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *      Demultiplex 802.2 encoded protocols. We match the entry by the
 *      SSAP/DSAP pair and then deliver to the registered datalink that
 *      matches. The control byte is ignored and handling of such items
 *      is up to the routine passed the frame.
 *
 *      Unlike the 802.3 datalink we have a list of 802.2 entries as
 *      there are multiple protocols to demux. The list is currently
 *      short (3 or 4 entries at most). The current demux assumes this.
 */
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/datalink.h>
#include <linux/mm.h>
#include <linux/in.h>
#include <linux/init.h>
#include <net/llc.h>
#include <net/p8022.h>

static int p8022_request(struct datalink_proto *dl, struct sk_buff *skb,
             unsigned char *dest)
{
    llc_build_and_send_ui_pkt(dl->sap, skb, dest, dl->sap->laddr.lsap);
    return 0;
}

struct datalink_proto *register_8022_client(unsigned char type,
                        int (*func)(struct sk_buff *skb,
                            struct net_device *dev,
                            struct packet_type *pt,
                            struct net_device *orig_dev))
{
    struct datalink_proto *proto;

    proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
    if (proto) {
        proto->type[0]      = type;
        proto->header_length    = 3;
        proto->request      = p8022_request;
        proto->sap = llc_sap_open(type, func);
        if (!proto->sap) {
            kfree(proto);
            proto = NULL;
        }
    }
    return proto;
}

void unregister_8022_client(struct datalink_proto *proto)
{
    llc_sap_put(proto->sap);
    kfree(proto);
}

EXPORT_SYMBOL(register_8022_client);
EXPORT_SYMBOL(unregister_8022_client);

MODULE_LICENSE("GPL");