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/*
* NET3: Support for 802.2 demultiplexing off Ethernet (Token ring
* is kept separate see p8022tr.c)
* 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 <net/datalink.h>
#include <linux/mm.h>
#include <linux/in.h>
#include <linux/init.h>
#include <net/p8022.h>
static struct datalink_proto *p8022_list = NULL;
/*
* We don't handle the loopback SAP stuff, the extended
* 802.2 command set, multicast SAP identifiers and non UI
* frames. We have the absolute minimum needed for IPX,
* IP and Appletalk phase 2. See the llc_* routines for
* support libraries if your protocol needs these.
*/
static struct datalink_proto *find_8022_client(unsigned char type)
{
struct datalink_proto *proto;
for (proto = p8022_list;
((proto != NULL) && (*(proto->type) != type));
proto = proto->next)
;
return proto;
}
int p8022_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
{
struct datalink_proto *proto;
proto = find_8022_client(*(skb->h.raw));
if (proto != NULL)
{
skb->h.raw += 3;
skb->nh.raw += 3;
skb_pull(skb,3);
return proto->rcvfunc(skb, dev, pt);
}
skb->sk = NULL;
kfree_skb(skb);
return 0;
}
static void p8022_datalink_header(struct datalink_proto *dl,
struct sk_buff *skb, unsigned char *dest_node)
{
struct net_device *dev = skb->dev;
unsigned char *rawp;
rawp = skb_push(skb,3);
*rawp++ = dl->type[0];
*rawp++ = dl->type[0];
*rawp = 0x03; /* UI */
dev->hard_header(skb, dev, ETH_P_802_3, dest_node, NULL, skb->len);
}
static struct packet_type p8022_packet_type =
{
0, /* MUTTER ntohs(ETH_P_8022),*/
NULL, /* All devices */
p8022_rcv,
NULL,
NULL,
};
EXPORT_SYMBOL(register_8022_client);
EXPORT_SYMBOL(unregister_8022_client);
static int __init p8022_init(void)
{
p8022_packet_type.type=htons(ETH_P_802_2);
dev_add_pack(&p8022_packet_type);
return 0;
}
module_init(p8022_init);
struct datalink_proto *register_8022_client(unsigned char type, int (*rcvfunc)(struct sk_buff *, struct net_device *, struct packet_type *))
{
struct datalink_proto *proto;
if (find_8022_client(type) != NULL)
return NULL;
proto = (struct datalink_proto *) kmalloc(sizeof(*proto), GFP_ATOMIC);
if (proto != NULL) {
proto->type[0] = type;
proto->type_len = 1;
proto->rcvfunc = rcvfunc;
proto->header_length = 3;
proto->datalink_header = p8022_datalink_header;
proto->string_name = "802.2";
proto->next = p8022_list;
p8022_list = proto;
}
return proto;
}
void unregister_8022_client(unsigned char type)
{
struct datalink_proto *tmp, **clients = &p8022_list;
unsigned long flags;
save_flags(flags);
cli();
while ((tmp = *clients) != NULL)
{
if (tmp->type[0] == type) {
*clients = tmp->next;
kfree(tmp);
break;
} else {
clients = &tmp->next;
}
}
restore_flags(flags);
}
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